Low dosage of aripiprazole induced neuroleptic malignant syndrome after interaction with other neuroleptic drugs

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Albino Petrone

2013-09-01

Full Text Available Aripiprazole is a 2nd generation antipsychotic medication, atypical neuroleptic used for treatment of schizophrenia improving symptoms such as hallucinations, delusions, and disorganized thinking. A potentially fatal symptom complex sometimes referred to as neuroleptic malignant syndrome (NMS has been reported in association with administration of antipsychotic drugs, including aripiprazole. Rare cases of NMS occurred during aripiprazole treatment in the worldwide clinical database. The disease is characterized by a distinctive clinical syndrome of mental status change, rigidity, fever, and dysautonomia. We report on a 63-year old woman with depression syndrome who developed neuroleptic malignant syndrome after twelve days of aripripazole 5 mg per day. Our case is added to the small number already described and suggests the need for caution when aripripazole is added to increase the effect of other antipsychotics.

Prevalence of neuroleptic-induced movement disorders in chronic schizophrenia inpatients.

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Janno, Sven; Holi, Matti; Tuisku, Katinka; Wahlbeck, Kristian

2004-01-01

Since most of the world's schizophrenia patients are treated with conventional antipsychotics, the authors evaluated various methods for establishing the prevalence of neuroleptic-induced movement disorders in these patients. DSM-IV criteria and established score thresholds on a movement disorder rating scale were used to identify cases of neuroleptic-induced movement disorder in a representative Estonian patient sample of 99 chronic institutionalized schizophrenia patients, 18-65 years old, treated with conventional neuroleptics (79.8%) or clozapine (20.2%). Neuroleptic-induced movement disorders according to DSM-IV criteria were found in 61.6% of the group: 31.3% had neuroleptic-induced akathisia, 23.2% had neuroleptic-induced parkinsonism, and 32.3% had neuroleptic-induced tardive dyskinesia. Prevalence rates for akathisia and tardive dyskinesia were similar when either DSM-IV criteria or rating scale scores were used, but the prevalence rate for parkinsonism was much lower per DSM-IV criteria than according to rating scale score. Nearly two-thirds of chronic schizophrenia patients suffered from a neuroleptic-induced movement disorder. Globally, extrapyramidal adverse effects still impose a huge burden on the majority of neuroleptic-treated individuals with schizophrenia. The discrepancy between the standard identification methods for neuroleptic-induced movement disorder indicate the need for further research.

Quantitative structure-activity relationships of salicylamide neuroleptic agents.

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Gupta, S P; Saha, R N; Singh, P

1990-05-01

The in vitro antidopamine activity of substituted N-[(1-alkyl-2-pyrrolidinyl)methyl]-6-methoxysalicylamides was found to be well correlated with the hydrophobic and electronic nature of substituents at the 3-position, and with the steric nature of groups replacing the hydrogen atom of the salicyl hydroxy group. In contrast, only the hydrophobic and steric characteristics were found to be important in the in vivo activity of these neuroleptics. This difference suggests that different mechanisms are probably involved in their in vitro and in vivo actions, and that the relevant receptors are slightly different in structure. The in vitro results suggest that electron donation by the 3-substituent strengthens the formation of a hydrogen bond between the carbonyl group of the amide moiety and a hydrogen of the receptor.

Plasma homovanillic acid levels and therapeutic outcome in schizophrenics: comparisons of neuroleptic-naive first-episode patients and patients with disease exacerbation due to neuroleptic discontinuance.

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Akiyama, K; Tsuchida, K; Kanzaki, A; Ujike, H; Hamamura, T; Kondo, K; Mutoh, S; Miyanagi, K; Kuroda, S; Otsuki, S

1995-11-15

Plasma homovanillic acid (pHVA) levels were measured and the Brief Psychiatric Rating Scale (BPRS) scores were evaluated in 26 schizophrenic patients who had either never been medicated (neuroleptic-naive, first-episode subjects) or whose condition had become exacerbated following neuroleptic discontinuance (exacerbated subjects). All the subjects received medication with a fixed dose of a neuroleptic (haloperidol or fluphenazine, both 9 mg/day) for the first week and variable doses for the subsequent 4 weeks. In the neuroleptic-naive subjects, pHVA levels increased significantly 1 week after starting the protocol; this increase correlated significantly with clinical improvement of the BPRS positive symptom scores at week 5. In the neuroleptic-naive subjects, pHVA levels had declined to the baseline level by week 5. In the exacerbated subjects, there were no significant correlations between pHVA level changes at week 1 and later improvements of the BPRS positive symptom scores. These results suggest that the rise in pHVA levels occurring within 1 week after starting a fixed neuroleptic dose may predict a favorable clinical response in neuroleptic-naive schizophrenic patients.

Autoradiographic analysis of regional alterations in brain receptors following chronic administration and withdrawal of typical and atypical neuroleptics in rats

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See, R.E.; Ellison, G.; Toga, A.W.

1990-01-01

Rats were administered haloperidol, clozapine, raclopride, or no drug for 28 days or 8 months. Following a 3 week withdrawal period, in vitro autoradiography was utilized to examine receptor binding for dopamine D2([ 3 H]spiperone and [ 3 H]raclopride), dopamine D1([ 3 H]SCH23390), GABA A ([ 3 H]muscimol), benzodiazepine ([ 3 H]RO15-1788), and muscarinic ACh receptors ([ 3 H]QNB). [ 3 H]spiperone was elevated in striatal subregions only in haloperidol-treated rats, with the largest increases seen in the 8 month duration animals. Striatal [ 3 H]raclopride binding was increased after both short- and long-term treatment in both haloperidol and raclopride, but not clozapine-treated animals. Clozapine-treated rats showed significant increases in [ 3 H]SCH23390 in the nucleus accumbens after 28-day administration; otherwise no changes were seen for this ligand in any other groups. Increases in [ 3 H]muscimol binding in the substantia nigra reticulata were seen in haloperidol-treated rats after 8 month treatment. Binding of [ 3 H]QNB and [ 3 H]RO15-1788 were not significantly different from control for any of the drug-treated groups. These data suggest that persisting alterations in receptor binding are primarily seen in dopamine D2 and GABA receptors after withdrawal from chronic administration of haloperidol but not the atypical neuroleptics, clozapine and raclopride. (Authors)

Increased brain dopamine and dopamine receptors in schizophrenia

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Mackay, A.V.; Iversen, L.L.; Rossor, M.; Spokes, E.; Bird, E.; Arregui, A.; Creese, I.; Synder, S.H.

1982-01-01

In postmortem samples of caudate nucleus and nucleus accumbens from 48 schizophrenic patients, there were significant increases in both the maximum number of binding sites (Bmax) and the apparent dissociation constant (KD) for tritiated spiperone. The increase in apparent KD probably reflects the presence of residual neuroleptic drugs, but changes in Bmax for tritiated spiperone reflect genuine changes in receptor numbers. The increases in receptors were seen only in patients in whom neuroleptic medication had been maintained until the time of death, indicating that they may be entirely iatrogenic. Dopamine measurements for a larger series of schizophrenic and control cases (n greater than 60) show significantly increased concentrations in both the nucleus accumbens and caudate nucleus. The changes in dopamine were not obviously related to neuroleptic medication and, unlike the receptor changes, were most severe in younger patients

Autoradiographic analysis of regional alterations in brain receptors following chronic administration and withdrawal of typical and atypical neuroleptics in rats

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See, R E; Ellison, G; Toga, A W [California Univ., Los Angeles, CA (USA). School of Medicine

1990-01-01

Rats were administered haloperidol, clozapine, raclopride, or no drug for 28 days or 8 months. Following a 3 week withdrawal period, in vitro autoradiography was utilized to examine receptor binding for dopamine D2(({sup 3}H)spiperone and ({sup 3}H)raclopride), dopamine D1(({sup 3}H)SCH23390), GABA{sub A}(({sup 3}H)muscimol), benzodiazepine (({sup 3}H)RO15-1788), and muscarinic ACh receptors (({sup 3}H)QNB). ({sup 3}H)spiperone was elevated in striatal subregions only in haloperidol-treated rats, with the largest increases seen in the 8 month duration animals. Striatal ({sup 3}H)raclopride binding was increased after both short- and long-term treatment in both haloperidol and raclopride, but not clozapine-treated animals. Clozapine-treated rats showed significant increases in ({sup 3}H)SCH23390 in the nucleus accumbens after 28-day administration; otherwise no changes were seen for this ligand in any other groups. Increases in ({sup 3}H)muscimol binding in the substantia nigra reticulata were seen in haloperidol-treated rats after 8 month treatment. Binding of ({sup 3}H)QNB and ({sup 3}H)RO15-1788 were not significantly different from control for any of the drug-treated groups. These data suggest that persisting alterations in receptor binding are primarily seen in dopamine D2 and GABA receptors after withdrawal from chronic administration of haloperidol but not the atypical neuroleptics, clozapine and raclopride. (Authors).

Receptor studies in biological psychiatry

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Fujiwara, Yutaka

1992-01-01

Recent advances in the pharmacological treatment of endogenous psychosis have led to the development of biological studies in psychiatry. Studies on neurotransmitter receptors were reviewed in order to apply positron-emission tomograph (PET) for biological psychiatry. The dopamine (DA) hypothesis for schizophrenia was advanced on the basis of the observed effects of neuroleptics and methamphetamine, and DA(D 2 ) receptor supersensitivity measured by PET and receptor binding in the schizophrenic brain. The clinical potencies of neuroleptics for schizophrenia were correlated with their abilities to inhibit the D 2 receptor, and not other receptors. The σ receptor was expected to be a site of antipsychotic action. However, the potency of drugs action on it was not correlated with clinical efficacy. Haloperidol binds with high affinity to the σ receptor, which may mediate acute dystonia, an extrapyramidal side effect of neuroleptics. Behavioral and neurochemical changes induced by methamphetamine treatment were studied as an animal model of schizophrenia, and both a decrease of D 2 receptor density and an increase of DA release were detected. The monoamine hypothesis for manic-depressive psychosis was advanced on the basis of the effect of reserpine, monoamine oxidase inhibitor and antidepressants. 3 H-clonidine binding sites were increased in platelet membranes of depressive patients, 3 H-imipramine binding sites were decreased. The GABA A receptor is the target site for the action of anxiolytics and antiepileptics such as benzodiazepines and barbiturates. Recent developments in molecular biology techniques have revealed the structure of receptor proteins, which are classified into two receptor families, the G-protein coupled type (D 2 ) and the ion-channel type (GABA A ). (J.P.N.)

Comparison of three /sup 18/F-labeled butyrophenone neuroleptic drugs in the baboon using positron emission tomography

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Arnett, C D; Shiue, C Y; Wolf, A P; Fowler, J S; Logan, J; Watanabe, M

1985-03-01

The butyrophenone neuroleptics spiroperidol, benperidol, and haloperidol were radiolabeled with fluorine-/sup 18/ and studied in baboon brain using positron emission transaxial tomography (PETT). Pretreatment of the baboon with a high pharmacological dose of (+)-butaclamol reduced the specifically bound component of radioactivity distribution in the striatum to approximately the radioactivity distribution found in the cerebellum. Comparative studies of brain distribution kinetics over a 4-h period indicated that either (/sup 18/F)spiroperidol or (/sup 18/F)benperidol may be suitable for specific labeling of neuroleptic receptors. In an 8-h study with (/sup 18/F)spiroperidol, striatal radioactivity did not decline, suggesting that spiroperidol either has a very slow dissociation rate or that it binds irreversibly to these receptors in vivo. (/sup 18/F)Haloperidol may not be suitable for in vivo PETT studies, because of a relatively high component of nonspecific distribution and a faster dissociation from the receptor. Analysis of /sup 18/F in plasma after injection of (/sup 18/F)spiroperidol indicated rapid metabolism to polar and acidic metabolites, with only 40% of the total radioactivity being present as unchanged drug after 30 min. Analysis of the metabolic stability of the radioactively labeled compound in rat striatum indicated that greater than 95% of (/sup 18/F)spiroperidol remains unchanged after 4 h.

Neuroleptic-induced deficit syndrome in bipolar disorder with psychosis

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Ueda S

2016-02-01

Full Text Available Satoshi Ueda,1 Takeshi Sakayori,1 Ataru Omori,2 Hajime Fukuta,3 Takashi Kobayashi,3 Kousuke Ishizaka,1 Tomoyuki Saijo,4 Yoshiro Okubo1 1Department of Neuropsychiatry, Nippon Medical School, Tokyo, Japan; 2Tamachuo Hospital, Tokyo, Japan; 3Kurumegaoka Hospital, Tokyo, Japan; 4Saijo Clinic, Tokyo, Japan Abstract: Neuroleptics can induce not only physical adverse effects but also mental effects that produce deficit status in thought, affect, cognition, and behavior. This condition is known as neuroleptic-induced deficit syndrome (NIDS, which includes apathy, lack of initiative, anhedonia, indifference, blunted affect, and reduced insight into disease. Although this old concept now appears almost forgotten, neuroleptics, whether typical or atypical, can make depression or bipolar disorder resemble other more refractory conditions, readily leading to mistaken diagnosis and inappropriate treatment. The authors describe three cases of NIDS superimposed on depressive phase in bipolar disorder with psychosis, where the attending psychiatrist’s failure to recognize NIDS prevented patients from receiving effective treatment and achieving remission. All cases achieved remission after reduction of neuroleptics and intensive therapy, including electroconvulsive therapy, for bipolar depression. The concept of NIDS was originally introduced for schizophrenia, and it has rarely been highlighted in other diseases. In recent years, however, atypical antipsychotics are being more often administered to patients with bipolar disorder. Psychiatrists, therefore, should also remember and exercise caution regarding NIDS in the pharmacotherapy of bipolar disorder with and without psychosis. The authors believe that the concept of NIDS needs to be reappraised in current psychiatry. Keywords: neuroleptic-induced deficit syndrome (NIDS, bipolar disorder, psychosis, atypical antipsychotics, electroconvulsive therapy

Negative symptoms in nondeficit syndrome respond to neuroleptic treatment with changes in plasma homovanillic acid concentrations.

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Suzuki, E; Kanba, S; Koshikawa, H; Nibuya, M; Yagi, G; Asai, M

1996-05-01

Deficit syndrome (DS) in schizophrenia is characterized by serious, chronic, and primary negative symptoms. We investigated differences in response to neuroleptic treatment between 8 DS patients and 6 nondeficit syndrome (NDS) patients who had the selective dopamine-D2 receptor blocker bromperidol added to their neuroleptic regimens. First, 9 mg/d was administered for 4 weeks, followed by 18 mg/d for another 4 weeks. Plasma homovanillic acid (pHVA) and plasma bromperidol concentrations were measured, and psychiatric symptoms were scored. In the NDS patients, both positive and negative symptoms improved. However, only the positive symptom scores changed in the DS patients. On day 4, pHVA concentrations of the NDS patients alone were significantly elevated. Plasma bromperidol concentrations did not differ between the groups. These results suggest that bromperidol exerts different effects on negative symptoms and pHVA concentrations between NDS and DS patients, effects that are unrelated to plasma bromperidol concentrations.

Side effects in preventive maintenance therapy with neuroleptics with special emphasis on tardive dyskinesia.

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Logothetis, J; Paraschos, A; Frangos, E

1981-01-01

Neuroleptics induce hypersensitivity reactions, and toxic, systemic and extrapyramidal manifestations. The latter mainly include acute dystonic reactions, other early dyskinesias, akathisia, parkinsonism and TD. These drugs have been implicated for DA antagonism exerted by an adenylate cyclase inhibition. Prolonged blockade of DA receptors is considered as the motivation for a counterbalancing mechanism inducing the DA supersensitivity from which TD results. Recent reports suggest cholinergic and GABA ergic insufficiency as secondary participants. The increasing frequency of TD calls for prevention by modifying treatment practices and searching for effective measures to combat the symptoms.

Afebrile Neuroleptic Malignant Syndrome associated with Fluphenazine decanoate: A case report

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Marzieh Assareh

2010-06-01

Full Text Available "nNeuroleptic Malignant Syndrome (NMS is unusual but could be a lethal reaction associated with neuroleptic drugs. It occurs in almost 0.07-2.2% of patients under treatment with neuroleptics. There are some medical treatments that may also be helpful for its treatment, including dopamine agonists, muscle relaxants, and electroconvulsive therapy (ECT. We present this case to alert the clinicians to the potential for inducing afebrile NMS. Our case is a 41-year-old man with a history of schizophrenia showing signs and symptoms in accordance with NMS, 2 weeks after receiving one dose of 12.5 mg fluphenazine decanoate, abruptly following the 3rdsession of ECT. The patient presented with decreased level of consciousness, muscular rigidity, waxy flexibility, mutism ,generalized tremor, sever diaphoresis and tachycardia which progressed during the previous 24 h. Laboratory data indicated primarily leukocytosis, an increasing level of creatinine phosphokinase and hypokalemia during the next 72h. In patients receiving antipsychotics, any feature of NMS should carefully be evaluated whether it is usual or unusual particularly in patients receiving long acting neuroleptics.

Increments in plasma homovanillic acid concentrations after neuroleptic discontinuation are associated with worsening of schizophrenic symptoms.

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Khan, R S; Amin, F; Powchik, P; Knott, P; Goldstein, M; Apter, S; Kerman, B; Jaff, S; Davidson, M

1990-01-01

1. Thirty-two male schizophrenic patients participated in this study. 2. Plasma concentrations of the dopamine metabolite, homovanillic acid (pHVA) were assessed once on neuroleptic medication and twice a week for a maximum of six weeks after its discontinuation. 3. Psychiatric symptomatology was assessed once on neuroleptic medication and once a week for a maximum of six weeks after its discontinuation, using the brief psychiatric rating scale (BPRS). 4. pHVA and total BPRS score increased significantly after discontinuation of neuroleptic as compared to baseline. 5. The magnitude of pHVA and BPRS increments after discontinuation of neuroleptic correlated significantly. 6. Results of this study suggest that worsening of schizophrenic symptoms after discontinuation of neuroleptic treatment is associated with increased pHVA concentrations.

Malignant neuroleptic syndrome following deep brain stimulation surgery: a case report

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Stavrinou Lampis C

2011-06-01

Full Text Available Abstract Background The neuroleptic malignant syndrome is an uncommon but dangerous complication characterized by hyperthermia, autonomic dysfunction, altered mental state, hemodynamic dysregulation, elevated serum creatine kinase, and rigor. It is most often caused by an adverse reaction to anti-psychotic drugs or abrupt discontinuation of neuroleptic or anti-parkinsonian agents. To the best of our knowledge, it has never been reported following the common practice of discontinuation of anti-parkinsonian drugs during the pre-operative preparation for deep brain stimulation surgery for Parkinson's disease. Case presentation We present the first case of neuroleptic malignant syndrome associated with discontinuation of anti-parkinsonian medication prior to deep brain stimulation surgery in a 54-year-old Caucasian man. Conclusion The characteristic neuroleptic malignant syndrome symptoms can be attributed to other, more common causes associated with deep brain stimulation treatment for Parkinson's disease, thus requiring a high index of clinical suspicion to timely establish the correct diagnosis. As more centers become eligible to perform deep brain stimulation, neurologists and neurosurgeons alike should be aware of this potentially fatal complication. Timely activation of the deep brain stimulation system may be important in accelerating the patient's recovery.

Malignant neuroleptic syndrome following deep brain stimulation surgery: a case report.

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Themistocleous, Marios S; Boviatsis, Efstathios J; Stavrinou, Lampis C; Stathis, Pantelis; Sakas, Damianos E

2011-06-29

The neuroleptic malignant syndrome is an uncommon but dangerous complication characterized by hyperthermia, autonomic dysfunction, altered mental state, hemodynamic dysregulation, elevated serum creatine kinase, and rigor. It is most often caused by an adverse reaction to anti-psychotic drugs or abrupt discontinuation of neuroleptic or anti-parkinsonian agents. To the best of our knowledge, it has never been reported following the common practice of discontinuation of anti-parkinsonian drugs during the pre-operative preparation for deep brain stimulation surgery for Parkinson's disease. We present the first case of neuroleptic malignant syndrome associated with discontinuation of anti-parkinsonian medication prior to deep brain stimulation surgery in a 54-year-old Caucasian man. The characteristic neuroleptic malignant syndrome symptoms can be attributed to other, more common causes associated with deep brain stimulation treatment for Parkinson's disease, thus requiring a high index of clinical suspicion to timely establish the correct diagnosis. As more centers become eligible to perform deep brain stimulation, neurologists and neurosurgeons alike should be aware of this potentially fatal complication. Timely activation of the deep brain stimulation system may be important in accelerating the patient's recovery.

Atypical Neuroleptic Malignant Syndrome Associated with Use of Clozapine

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Quevedo-Florez Leonardo

2017-01-01

Full Text Available The Neuroleptic Malignant Syndrome (NMS is a medical emergency of infrequent presentation in the emergency department, which is associated with the use of psychiatric drugs, such as typical and atypical antipsychotics. Our case addresses a 55-year-old patient diagnosed with undifferentiated schizophrenia for 10 years, who had been receiving clozapine and clonazepam as part of their treatment. This patient presents the symptoms of Neuroleptic Malignant Syndrome without fever, which improves with treatment especially with the withdrawal of clozapine. In the absence of fever and clinical improvement, the patient is considered to have an atypical presentation of this disease.

Malignant neuroleptic syndrome following deep brain stimulation surgery: a case report

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Themistocleous, Marios S; Boviatsis, Efstathios J; Stavrinou, Lampis C; Stathis, Pantelis; Sakas, Damianos E

2011-01-01

Abstract Background The neuroleptic malignant syndrome is an uncommon but dangerous complication characterized by hyperthermia, autonomic dysfunction, altered mental state, hemodynamic dysregulation, elevated serum creatine kinase, and rigor. It is most often caused by an adverse reaction to anti-psychotic drugs or abrupt discontinuation of neuroleptic or anti-parkinsonian agents. To the best of our knowledge, it has never been reported following the common practice of discontinuation of anti...

Olanzapine-Induced Neuroleptic Malignant Syndrome

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Seyedhamze Hosseini

2017-05-01

Full Text Available Neuroleptic malignant syndrome (NMS is a rare but life-threatening idiosyncratic side effect resulting from neuroleptic drugs. NMS mainly occurs in patients treated with high-potency typical antipsychotics, but rarely caused by atypical antipsychotics. Although NMS is less common with atypical antipsychotic, but it seems that its incidence is rising due to increased administration of such drugs. We present the case of a 27-year-old man with a history of paranoid schizophrenia that showed signs consistent with NMS that occurred after treatment with olanzapine. The patient was adherent to treatment. He had decreased level of consciousness, muscle rigidity, diaphoresis, fever, drooling, urinary incontinence, and high blood pressure. This patient illustrates that NMS can occur due to treatment with atypical antipsychotic drugs like olanzapine, particularly in the presence of risk factors. This phenomenon is often unrecognized, underdiagnosed, or not treated properly. Physicians should be aware that NMS with extrapyramidal syndrome could occur with olanzapine at steady state doses without recent dosage adjustments or titration. It is essential that adequate and safe dose of medication is chosen and the patient is monitored by the signs and symptoms of this lethal syndrome.

Delirium followed by neuroleptic malignant syndrome in ...

African Journals Online (AJOL)

Delirium and neuroleptic malignant syndrome (NMS) are two uncommon syndromes that are often unrecognized or misdiagnosed by the primary physicians as functional psychiatric disorders. The infrequency and the heterogeneity of clinical manifestation, progression and outcome with which those diagnoses are ...

[Identification and evaluation of the neuroleptic activity of phenotropil].

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Akhapkina, V I; Akhapkin, R V

2013-01-01

The neuroleptic (antipsychotic) activity of phenotropil was studied in an experimental animal model. Phenotropil had a marked neuroleptic activity in models of positive (apomorphine-induced verticalization test) and negative (5-HTP-induced hyperkinesis test) symptoms of psychoses as well as in the m-cholinergic pathway hyperactivation (arecoline-induced tremor test). The compound markedly antagonized haloperidol catalepsy. Used in a single dose or as a course treatment, phenotropil did not provoke aggression nor intensify it. In contrast to typical and atypical antipsychotics, phenotropil had no sedative action and other adverse effects. It exhibited a positive effect on exploratory behavior and motor activity, had anxiolytic and antidepressant action.

GABA receptor imaging

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Lee, Jong Doo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

2007-04-15

GABA is primary an inhibitory neurotransmitter that is localized in inhibitory interneurons. GABA is released from presynaptic terminals and functions by binding to GABA receptors. There are two types of GABA receptors, GABA{sub A}-receptor that allows chloride to pass through a ligand gated ion channel and GABA{sub B}-receptor that uses G-proteins for signaling. The GABA{sub A}-receptor has a GABA binding site as well as a benzodiazepine binding sites, which modulate GABA{sub A}-receptor function. Benzodiazepine GABAA receptor imaging can be accomplished by radiolabeling derivates that activates benzodiazepine binding sites. There has been much research on flumazenil (FMZ) labeled with {sup 11}C-FMZ, a benzodiazepine derivate that is a selective, reversible antagonist to GABAA receptors. Recently, {sup 18}F-fluoroflumazenil (FFMZ) has been developed to overcome {sup 11}C's short half-life. {sup 18}F-FFMZ shows high selective affinity and good pharmacodynamics, and is a promising PET agent with better central benzodiazepine receptor imaging capabilities. In an epileptic focus, because the GABA/benzodiazepine receptor amount is decreased, using '1{sup 1}C-FMZ PET instead of {sup 18}F-FDG, PET, restrict the foci better and may also help find lesions better than high resolution MR. GABA{sub A} receptors are widely distributed in the cerebral cortex, and can be used as an viable neuronal marker. Therefore it can be used as a neuronal cell viability marker in cerebral ischemia. Also, GABA-receptors decrease in areas where neuronal plasticity develops, therefore, GABA imaging can be used to evaluate plasticity. Besides these usages, GABA receptors are related with psychological diseases, especially depression and schizophrenia as well as cerebral palsy, a motor-related disorder, so further in-depth studies are needed for these areas.

GABA receptor imaging

International Nuclear Information System (INIS)

Lee, Jong Doo

2007-01-01

GABA is primary an inhibitory neurotransmitter that is localized in inhibitory interneurons. GABA is released from presynaptic terminals and functions by binding to GABA receptors. There are two types of GABA receptors, GABA A -receptor that allows chloride to pass through a ligand gated ion channel and GABA B -receptor that uses G-proteins for signaling. The GABA A -receptor has a GABA binding site as well as a benzodiazepine binding sites, which modulate GABA A -receptor function. Benzodiazepine GABAA receptor imaging can be accomplished by radiolabeling derivates that activates benzodiazepine binding sites. There has been much research on flumazenil (FMZ) labeled with 11 C-FMZ, a benzodiazepine derivate that is a selective, reversible antagonist to GABAA receptors. Recently, 18 F-fluoroflumazenil (FFMZ) has been developed to overcome 11 C's short half-life. 18 F-FFMZ shows high selective affinity and good pharmacodynamics, and is a promising PET agent with better central benzodiazepine receptor imaging capabilities. In an epileptic focus, because the GABA/benzodiazepine receptor amount is decreased, using '1 1 C-FMZ PET instead of 18 F-FDG, PET, restrict the foci better and may also help find lesions better than high resolution MR. GABA A receptors are widely distributed in the cerebral cortex, and can be used as an viable neuronal marker. Therefore it can be used as a neuronal cell viability marker in cerebral ischemia. Also, GABA-receptors decrease in areas where neuronal plasticity develops, therefore, GABA imaging can be used to evaluate plasticity. Besides these usages, GABA receptors are related with psychological diseases, especially depression and schizophrenia as well as cerebral palsy, a motor-related disorder, so further in-depth studies are needed for these areas

Short-term cognitive improvement in schizophrenics treated with typical and atypical neuroleptics.

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Rollnik, Jens D; Borsutzky, Marthias; Huber, Thomas J; Mogk, Hannu; Seifert, Jürgen; Emrich, Hinderk M; Schneider, Udo

2002-01-01

Atypical neuroleptics seem to be more beneficial than typical ones with respect to long-term neuropsychological functioning. Thus, most studies focus on the long-term effects of neuroleptics. We were interested in whether atypical neuroleptic treatment is also superior to typical drugs over relatively short periods of time. We studied 20 schizophrenic patients [10 males, mean age 35.5 years, mean Brief Psychiatric Rating Scale (BPRS) score at entry 58.9] admitted to our hospital with acute psychotic exacerbation. Nine of them were treated with typical and 11 with atypical neuroleptics. In addition, 14 healthy drug-free subjects (6 males, mean age 31.2 years) were enrolled in the study and compared to the patients. As neuropsychological tools, a divided attention test, the Vienna reaction time test, the Benton visual retention test, digit span and a Multiple Choice Word Fluency Test (MWT-B) were used during the first week after admission, within the third week and before discharge (approximately 3 months). Patients scored significantly worse than healthy controls on nearly all tests (except Vienna reaction time). Clinical ratings [BPRS and Positive and Negative Symptom Scale for Schizophrenia (PANSS)] improved markedly (p divided attention task (r = 0.705, p = 0.034). Neuropsychological functioning (explicit memory, p divided attention, p < 0.05) moderately improved for both groups under treatment but without a significant difference between atypical and typical antipsychotic drugs. Over short periods of time (3 months), neuropsychological disturbances in schizophrenia seem to be moderately responsive to both typical and atypical neuroleptics. Copyright 2002 S. Karger AG, Basel

Cure or curse? Ambivalent attitudes towards neuroleptic medication in schizophrenia and non-schizophrenia patients.

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Moritz, Steffen; Peters, Maarten J V; Karow, Anne; Deljkovic, Azra; Tonn, Peter; Naber, Dieter

2009-10-30

Neuroleptic non-compliance remains a serious challenge for the treatment of psychosis. Non-compliance is predominantly attributed to side effects, lack of illness insight, reduced well-being or poor therapeutic alliance. However, other still neglected factors may also play a role. Further, little is known about whether psychiatric patients without psychosis who are increasingly prescribed neuroleptics differ in terms of medication compliance or about reasons for non-compliance by psychosis patients. As direct questioning is notoriously prone to social desirability biases, we conducted an anonymous survey. After a strict selection process blind to results, 95 psychiatric patients were retained for the final analyses (69 participants with a presumed diagnosis of schizophrenia psychosis, 26 without psychosis). Self-reported neuroleptic non-compliance was more prevalent in psychosis patients than non-psychosis patients. Apart from side effects and illness insight, main reasons for non-compliance in both groups were forgetfulness, distrust in therapist, and no subjective need for treatment. Other notable reasons were stigma and advice of relatives/acquaintances against neuroleptic medication. Gain from illness was a reason for non-compliance in 11-18% of the psychosis patients. Only 9% of all patients reported no side effects and full compliance and at the same time acknowledged that neuroleptics worked well for them. While pills were preferred over depot injections by the majority of patients, depot was judged as an alternative by a substantial subgroup. Although many patients acknowledge the need and benefits of neuroleptic medication, non-compliance was the norm rather than the exception in our samples.

Cure or curse? Ambivalent attitudes towards neuroleptic medication in schizophrenia and non-schizophrenia patients

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Dieter Naber

2009-10-01

Full Text Available Neuroleptic non-compliance remains a serious challenge for the treatment of psychosis. Non-compliance is predominantly attributed to side effects, lack of illness insight, reduced well-being or poor therapeutic alliance. However, other still neglected factors may also play a role. Further, little is known about whether psychiatric patients without psychosis who are increasingly prescribed neuroleptics differ in terms of medication compliance or about reasons for non-compliance by psychosis patients. As direct questioning is notoriously prone to social desirability biases, we conducted an anonymous survey. After a strict selection process blind to results, 95 psychiatric patients were retained for the final analyses (69 participants with a presumed diagnosis of schizophrenia psychosis, 26 without psychosis. Self-reported neuroleptic non-compliance was more prevalent in psychosis patients than non-psychosis patients. Apart from side effects and illness insight, main reasons for non-compliance in both groups were forgetfulness, distrust in therapist, and no subjective need for treatment. Other notable reasons were stigma and advice of relatives/acquaintances against neuroleptic medication. Gain from illness was a reason for non-compliance in 11-18% of the psychosis patients. Only 9% of all patients reported no side effects and full compliance and at the same time acknowledged that neuroleptics worked well for them. While pills were preferred over depot injections by the majority of patients, depot was judged as an alternative by a substantial subgroup. Although many patients acknowledge the need and benefits of neuroleptic medication, non-compliance was the norm rather than the exception in our samples.

Cortical and subcortical 5-HT2A receptor binding in neuroleptic-naive first-episode schizophrenic patients

DEFF Research Database (Denmark)

Erritzoe, David; Rasmussen, Hans; Kristiansen, Klaus Nyegaard

2008-01-01

MRIs and PET images. The cerebellum was used as a reference region. The binding potential of specific tracer binding (BP(p)) was used as the outcome measure. No significant difference was seen in cortical receptor distribution between patients and controls. An increase in 5-HT(2A) receptor binding...

Neuroleptic Malignant Syndrome After the Use of Venlafaxine in a Patient with Generalized Anxiety Disorder

Directory of Open Access Journals (Sweden)

Tsung-Chien Lu

2006-01-01

Full Text Available Neuroleptic malignant syndrome (NMS is a potentially lethal adverse reaction to neuroleptics, which is characterized by hyperthermia, extrapyramidal symptoms, altered consciousness and autonomic dysfunction. Although NMS is most commonly induced by the high-potency neuroleptics, its development has also been associated with the use of non-neuroleptic agents that block central dopamine pathways. A 68-year-old man with generalized anxiety disorder and depressive symptoms presented at the emergency department (ED with high fever, tremor, muscle rigidity, rhabdomyolysis and altered mental status. NMS was considered to have been caused by the recent addition and subsequent dose increase in his treatment regimen of venlafaxine, a serotonin norepinephrine reuptake inhibitor. He was successfully treated with bromocriptine, lorazepam, and fluid hydration in the ED and intensive care unit.

Neuroleptic malignant syndrome (a case report.

Directory of Open Access Journals (Sweden)

Patkar A

1991-07-01

Full Text Available An adult schizophrenic patient developed neuroleptic malignant syndrome following treatment with parenteral haloperidol. An early recognition of the syndrome, immediate discontinuation of the offending agent and prompt treatment with bromocriptine and lorazepam produced a good recovery. The various features of the case are discussed in view of the potential lethality of the syndrome.

A rare case of neuroleptic malignant syndrome presenting with serious hyperthermia treated with a non-invasive cooling device: a case report

Directory of Open Access Journals (Sweden)

Storm Christian

2009-02-01

Full Text Available Abstract Introduction A rare side effect of antipsychotic medication is neuroleptic malignant syndrome, mainly characterized by hyperthermia, altered mental state, haemodynamic dysregulation, elevated serum creatine kinase and rigor. There may be multi-organ dysfunction including renal and hepatic failure as well as serious rhabdomyolysis, acute respiratory distress syndrome and disseminated intravascular coagulation. The prevalence of neuroleptic malignant syndrome is between 0.02% and 2.44% for patients taking neuroleptics and it is not necessary to fulfil all cardinal features characterizing the syndrome to be diagnosed with neuroleptic malignant syndrome. Because of other different life-threatening diseases matching the various clinical findings, the correct diagnosis can sometimes be hard to make. A special problem of intensive care treatment is the management of severe hyperthermia. Lowering of body temperature, however, may be a major clinical problem because hyperthermia in neuroleptic malignant syndrome is typically unresponsive to antipyretic agents while manual cooling proves difficult due to peripheral vasoconstriction. Case presentation A 22-year-old Caucasian man was admitted unconscious with a body temperature of 42°C, elevated serum creatine phosphokinase, tachycardia and hypotonic blood pressure. In addition to intensive care standard therapy for coma and shock, a non-invasive cooling device (Arctic Sun 2000®, Medivance Inc., USA, originally designed to induce mild therapeutic hypothermia in patients after cardiopulmonary resuscitation, was used to lower body temperature. After successful treatment it became possible to obtain information from the patient about his recent ambulant treatment with Olanzapin (Zyprexa® for schizophrenia. Conclusion Numerous case reports have been published about patients who developed neuroleptic malignant syndrome due to Olanzapin (Zyprexa® medication. Frequently hyperthermia has been observed

Measuring neuroleptic-induced akathisia by three-channel actometry.

Science.gov (United States)

Tuisku, K; Lauerma, H; Holi, M; Markkula, J; Rimon, R

1999-11-30

Three-channel actometry was used to study neuroleptic-induced akathisia (NIA), a common and often serious disorder in association of traditional neuroleptic therapy. The aim was to explore the diagnostic possibilities of actometry in NIA and to examine in detail the motor phenomenology of the disorder in detail. The actometers were attached to the ankles and waists of ten patients, suffering from NIA, and to ten matched healthy controls. Five of the patients were changed to olanzapine treatment, and these patients were re-examined during the no-NIA condition. NIA was associated with manyfold movement activity during controlled rest (sitting) but not with increased daily overall motor activity. Movement frequencies in NIA seemed to be pathognomonic. Actometry is promising for investigation and clinical assessment of NIA. Olanzapine proved to be an adequate treatment choice for NIA patients.

Acute cardiac failure in neuroleptic malignant syndrome.

LENUS (Irish Health Repository)

Sparrow, Patrick

2012-02-03

We present a case of rapid onset acute cardiac failure developing as part of neuroleptic malignant syndrome in a 35-year-old woman following treatment with thioridazine and lithium. Post mortem histology of cardiac and skeletal muscle showed similar changes of focal cellular necrosis and vacuolation suggesting a common disease process.

Neuroleptic malignant syndrome following catatonia: Vigilance is the price of antipsychotic prescription

Directory of Open Access Journals (Sweden)

Thomas J Reilly

2017-03-01

Full Text Available Objectives: To describe a case of neuroleptic malignant syndrome following antipsychotic treatment of catatonia, highlighting the potentially serious complications of this rare adverse drug reaction. Methods: We present a case report of a patient who developed this syndrome with various sequelae. Results: The patient developed neuroleptic after being treated with lorazepam and olanzapine for catatonia. He subsequently developed the complications of rhabdomyolysis, acute kidney injury, pulmonary embolism, urinary retention and ileus. He received high-dose lorazepam, anticoagulation and intravenous fluids. Antipsychotic medication in the form of haloperidol was reinstated with no adverse effect, and he went on to make a full recovery. Conclusions: This case illustrates the potential life-threatening complications of neuroleptic malignant syndrome and the need for a low index of clinical suspicion. It also highlights the lack of evidence for treatment of catatonia, including the use of antipsychotics.

Rocuronium-sugammadex for electroconvulsive therapy management in neuroleptic malignant syndrome: A case report.

Science.gov (United States)

Casas Reza, P; Gestal Vázquez, M; Outeiro Rosato, Á; López Álvarez, S; Diéguez García, P

2017-02-01

Neuroleptics are a group of drugs widely used in the treatment of psychotic symptoms. Among their adverse effects is the ability to trigger a neuroleptic malignant syndrome (NMS). The diagnosis of NMS is determined by exclusion, and its initial therapeutic management should be the withdrawal of neuroleptics, the administration of benzodiazepines, and electroconvulsive therapy (ECT). ECT is an effective treatment in these patients, and in those cases with a poor response to treatment with antipsychotic drugs. A review is presented on the treatment options and anaesthetic implications of ECT used to handle a patient diagnosed with paranoid schizophrenia in the context of NMS. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Neuroleptic Malignant Syndrome Caused by a Combination of Carbamazepine and Amitriptyline

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A. Bruce Janati

2012-01-01

Full Text Available A 32-year-old female, with a history of secondarily-generalized convulsive epilepsy, mental retardation, and a psychiatric illness, developed neuroleptic malignant syndrome while receiving carbamazepine and amitriptyline concurrently. We hypothesize that the addition of amitriptyline to carbamazepine caused a decrease in the serum level of carbamazepine, resulting in NMS. We conclude that combination therapy with carbamazepine and amitriptyline should be avoided in patients who are predisposed to NMS. The purpose of this paper is to warn physicians against combination therapy with carbamazepine and tricyclic antidepressants which may be conducive to neuroleptic malignant syndrome in susceptible patients.

[Case of neuroleptic malignant syndrome following open heart surgery for thoracic aortic aneurysm with parkinson's disease].

Science.gov (United States)

Shinoda, Maiko; Sakamoto, Mik; Shindo, Yuki; Ando, Yumi; Tateda, Takeshi

2013-12-01

An 80-year-old woman with Parkinson's disease was scheduled for open heart surgery to repair thoracic aortic aneurysm. Parkinson's symptoms were normally treated using oral levodopa (200 mg), selegiline-hydrochloride (5 mg), bromocriptine-mesilate (2 mg), and amantadine-hydrochloride (200 mg) daily. On the day before surgery, levodopa 50mg was infused intravenously. Another 25 mg of levodopa was infused immediately after surgery. Twenty hours later, the patient developed tremors, heyperventilation, but no obvious muscle rigidity. Two days after surgery, the patient exhibited high fever, hydropoiesis, elevated creatine kinase, and a rise in blood leukocytes. She was diagnosed with neuroleptic malignant syndrome. She was intubated, and received dantrolene sodium. Symptoms of neuroleptic malignant syndrome disappeared on the fourth postoperative day. The stress of open heart surgery, specifically extracorporeal circulation and concomitant dilution of levodopa, triggered neuroleptic malignant syndrome in this patient. Parkinson's patients require higher doses of levodopa prior to surgery to compensate and prevent neuroleptic malignant syndrome after surgery.

Catatonia versus neuroleptic malignant syndrome: the diagnostic dilemma and treatment.

Science.gov (United States)

Sahoo, Manoj Kumar; Agarwal, Sanjay; Biswas, Harshita

2014-01-01

Catatonia is a syndrome, comprised of symptoms such as motor immobility, excessive motor activity, extreme negativism, and stereotyped movements. Neuroleptic is able to induce catatonia like symptoms, that is, the neuroleptic malignant syndrome (NMS). In NMS, patients typically show symptoms such as an altered mental state, muscle rigidity, tremor, tachycardia, hyperpyrexia, leukocytosis, and elevated serum creatine phosphorous kinase. Several researchers have reported studies on catatonia and the association between catatonia and NMS, but none were from this part of the eastern India. In our case, we observed overlapping symptoms of catatonia and NMS; we wish to present a case of this diagnostic dilemma in a patient with catatonia, where a detailed history, investigation, and symptom management added as a great contribution to the patient's rapid improvement.

Cure or curse? Ambivalent attitudes towards neuroleptic medication in schizophrenia and non-schizophrenia patients

OpenAIRE

Dieter Naber; Peter Tonn; Azra Deljkovic; Anne Karow; Maarten J.V. Peters; Steffen Moritz

2009-01-01

Neuroleptic non-compliance remains a serious challenge for the treatment of psychosis. Non-compliance is predominantly attributed to side effects, lack of illness insight, reduced well-being or poor therapeutic alliance. However, other still neglected factors may also play a role. Further, little is known about whether psychiatric patients without psychosis who are increasingly prescribed neuroleptics differ in terms of medication compliance or about reasons for non-compliance by psychosis pa...

Organic anion and cation transport in vitro by dog choroid plexus: Effects of neuroleptics and tricyclic antidepressants

Energy Technology Data Exchange (ETDEWEB)

Barany, E H [Uppsala Univ. (Sweden)

1979-01-01

Dog lateral choroid plexus accumulates the cation /sup 14/C-emepronium and the divalent anion /sup 125/I-iodipamide in vitro. At 10 ..mu..M, high potency neuroleptics with a substituted piperazine side chain and also haloperidol depress only the uptake of the cation and even stimulate the uptake of the anion. In contrast, at 1-10..mu..M, the accumulation of both test substances is inhibited by neuroleptics and tricyclic antidepresssants with an aliphatic side chain. Such unspecific effects on seemingly unrelated transport systems at concentrations reached clinically in the CSF might explain some side actions of low potency neuroleptics and antidepressants.

Catatonia versus neuroleptic malignant syndrome: the diagnostic dilemma and treatment

Directory of Open Access Journals (Sweden)

Manoj Kumar Sahoo

2014-01-01

Full Text Available Catatonia is a syndrome, comprised of symptoms such as motor immobility, excessive motor activity, extreme negativism, and stereotyped movements. Neuroleptic is able to induce catatonia like symptoms, that is, the neuroleptic malignant syndrome (NMS. In NMS, patients typically show symptoms such as an altered mental state, muscle rigidity, tremor, tachycardia, hyperpyrexia, leukocytosis, and elevated serum creatine phosphorous kinase. Several researchers have reported studies on catatonia and the association between catatonia and NMS, but none were from this part of the eastern India. In our case, we observed overlapping symptoms of catatonia and NMS; we wish to present a case of this diagnostic dilemma in a patient with catatonia, where a detailed history, investigation, and symptom management added as a great contribution to the patient′s rapid improvement.

New detection of brain dopamine receptors with [3H]dihydroergocryptine

International Nuclear Information System (INIS)

Tittler, M.; Weinreich, P.; Seeman, P.

1977-01-01

Because dihydroergocryptine (DHE) and closely related ergots are dopamine-mimetic agonists, we tested [ 3 H]DHE as a possible ligand for [ 3 H]dopamine receptors in the calf caudate. In order to avoid [ 3 H]DHE from tagging α-adrenergic receptors, an excess of 500 nM phentolamine was used to block these sites, permitting the dopamine receptors to be measured separately. Specific binding of [ 3 H]DHE was defined as total binding minus that occurring in the presence of 1 μM (+)-butaclamol. Excess phentolamine reduced the specific binding of [ 3 H]DHE from 328 down to 138 fmol/mg, the difference presumably representing α-receptors. The K/sub D/ for [ 3 H]DHE was 0.55 nM (with or without phentolamine), and this high affinity site was blocked (in the presence of phentolamine) by 250 nM apomorphine, 650 nM dopamine, and 1200 nM (-)-norepinephrine, indicating that [ 3 H]DHE was binding to dopamine receptors. All neuroleptics blocked specific [ 3 H]DHE binding in direct relation to the clinical potency of the neuroleptic. The displacement of specific [ 3 H]DHE binding by dopamine or by norepinephrine (in the presence of phentolamine) revealed two subsets of dopamine receptors

A case of neuroleptic malignant syndrome induced by risperidone in a schizophrenic woman.

Science.gov (United States)

Gallelli, Luca; Spagnuolo, Vincenzo; Palleria, Caterina; De Sarro, Giovambattista; Ferraro, Maria

2009-05-01

We report a case of neuroleptic malignant syndrome in a woman who assumed risperidone for schizoaffective disorders. A 45-year-old woman affected by schizoaffective disorders was admitted to Infectious Disease unit of Crotone Hospital because of a diagnosis of a fever of unknown origin. Clinical evaluation documented confusion and dysphoria, whereas chemical blood evaluation revealed acidosis and liver dysfunction. After few days she was transferred to the Operative Unit of Internal Medicine of San Giovanni in Fiore Hospital because of an increase in liver transaminases. Clinical evaluation showed the persistence of fever (38.8 degrees Celsius), with an increase in CPK, and liver enzymes. Pharmacological evaluation indicated a probable relationship between risperidone and NMS and led to a diagnosis of neuroleptic malignant syndrome associated with risperidone in a woman with schizophrenia. About seven days later, we recorded a complete resolution of her psychiatric symptoms. We postulate a possible interaction between risperidone and neuroleptic malignant syndrome and we suggest to use risperidone with caution in both young and middle aged people.

Sex differences in plasma homovanillic acid levels in schizophrenia and normal controls: relation to neuroleptic resistance.

Science.gov (United States)

Sumiyoshi, T; Hasegawa, M; Jayathilake, K; Meltzer, H Y

1997-03-01

Plasma homovanillic acid (pHVA) levels were compared in a large number of neuroleptic-resistant and -responsive schizophrenic patients (male/female = 161/46) and normal controls (67/27), and correlated with various measures of psychopathology. Psychopathology was evaluated with the brief psychiatric rating scale, the Schedule for Affective Disorders and Schizophrenia-Change version (SADS-C) and SADS-C Global Assessment Scale, the Scale for Assessment of Negative Symptoms, the Scale for Assessment of Positive Symptoms (SAPS), and the Quality of Life Scale. No significant differences in pHVA levels between neuroleptic-resistant (n = 104) or -responsive (n = 103) schizophrenic patients, and normal controls, were found; however, there was a main effect for sex, due to higher pHVA levels in women than men. There were no diagnosis x gender or age effects on pHVA levels. No significant correlations were observed between psychopathology ratings and baseline pHVA levels, except with the Hallucinations subscale of SAPS in neuroleptic-responsive patients. Neither duration of neuroleptic washout nor plasma prolactin levels correlated with pHVA levels. Further studies on the origin and significance of the gender difference in pHVA are indicated.

Synthesis of the possible receptor Ligand [125I]-spiperone for D2-dopamine receptor and in-vivo biodistribution

International Nuclear Information System (INIS)

Amin, A.M.; Shoukry, M.; Abd EL-Bary, A.

2009-01-01

The spiperone is a selective D2-dopamine receptor antagonist radioiodination of spiperone is of interest for dopamine (DA) receptor studies both in vivo and in vitro. The labeling of spiperone with iodine-125 was extremely done in a neutral ph 7, using chloramine-T as oxidizing agent via heating the reaction mixture at 70 C (degree) for 10 - 15 minutes producing radiochemical yield of 97 %. In vivo biodistribution studies showed that the initial brain uptake correlated fairly well with the brain uptake index and that the kinetics of the radioactivity specifically bound to the striatum were strongly influenced by the dopamine receptor binding affinity of the compound. The brain uptake of 125 I-Spiperone was high and equal to 3.5, 3.25,2.75 and 1.7 % per gram tissue at 5, 30, 60 and 120 minutes post injection, respectively. 125 I-Spiperone binds with high affinity to dopamine receptors in vivo. Specific binding is about 65% of the total binding as is displaced stereo-specifically by clozapine. 125 I-spiperone may prove to be a useful ligand in studies examining D2-dopamine receptors. Furthermore iodinated spiperone may be useful in radioreceptor assays of neuroleptic drug levels and, in a 123 I-labeled form, for imaging of dopamine receptors, in vivo, using single photon tomography.

Quantitative analysis of receptor imaging

International Nuclear Information System (INIS)

Fu Zhanli; Wang Rongfu

2004-01-01

Model-based methods for quantitative analysis of receptor imaging, including kinetic, graphical and equilibrium methods, are introduced in detail. Some technical problem facing quantitative analysis of receptor imaging, such as the correction for in vivo metabolism of the tracer and the radioactivity contribution from blood volume within ROI, and the estimation of the nondisplaceable ligand concentration, is also reviewed briefly

Neuroleptic malignant syndrome revisited in the perspective of pakistan

International Nuclear Information System (INIS)

Shakoor, A.

2012-01-01

Objective: Neuroleptic malignant syndrome (NMS) is a life threatening adverse reaction of antipsychotic drugs, especially of dopamine receptor antagonists (DRA's). In addition to clinical and pharmacological risk factors, legal and ethical risk factors may be contributory towards the incidence, diagnosis and prognosis of NMS in Pakistan. Study Design: Experimental case study. Place and Duration of Study: The department of psychiatry and behavioral sciences of Bahawal Victoria Hospital affiliated with Quaid-e-Azam Medical College, from July 2011 to October 2012. Subjects and Methods: All the patients with probable NMS, received consecutively at the inpatient department of psychiatry, were included and investigated to rule out any other medical condition mimicking the syndrome. The patients were treated till complete recovery from the syndrome. The psychiatric diagnoses were confirmed, during their hospital stay, according to ICD10 Diagnostic Criteria for Research, the residual symptoms were recorded and tabulated along with other important characteristics of the patients. Results: Reckless use of DRA's in the form of intramuscular depot injections or high initial oral doses, along with certain other previously perceived clinical risk factors, increased the chance of developing NMS. Female gender and younger age along with early detection and prudent management proved to be good pro-gnostic factors for NMS in our study. The diverse categories of the first hand attending health providers e.g. doctors, quacks and faith healers of our psychiatric patients frequently used antipsychotics. This scenario points towards the lapses in determination of pathways to care, legality and ethics governing the mental health care in Pakistan. Conclusion: Standard protocol must be followed to start antipsychotics in psychotic patients, especially while planning to use depot DRA's. The manic patients are even more sensitive to develop extrapyramidal side effects and neuroleptic

On the clinical impact of cerebral dopamine D2 receptor scintigraphy

International Nuclear Information System (INIS)

Larisch, R.; Klimke, A.

1998-01-01

The present review describes findings and clinical indications for the dopamine D 2 receptor scintigraphy. Methods for the examination of D 2 receptors are positron emission tomography (PET) using 11 C- or 18 F-labelled butyrophenones or benzamides or single photon emission tomography (SPECT) using 123 I-iodobenzamide (IBZM) respectively. The most important indication in neurology is the differential diagnosis of Parkinsonism: Patients with early Parkinson's disease show an increased D 2 receptor binding (D 2 -RB) compared to control subjects. However, patients suffering from Steele-Richardson-Olszewski-Syndrome or Multiple System Atrophy show a decreased D 2 -RB and are generally non-responsive to treatment. Postsynaptic blockade of D 2 receptors results in a drug induced Parkinsonian syndrome, which can be diagnosed by D 2 scintigraphy. Further possible indications occur in psychiatry: The assessment of receptor occupancy is useful in schizophrenic patients treated with neuroleptics. Additionally, D 2 receptor scintigraphy might help to clarify the differential diagnosis between neuroleptic malignant syndrome and lethal catatonia. The method might be useful for supervising neurobiochemical changes in drug dependency and during withdrawal. Assessment of dopamine D 2 receptor binding can simplify the choice of therapy in depressive disorder: Patients showing a low D 2 binding are likely to improve following an antidepressive drug treatment whereas sleep deprivation is promising in patients with high D 2 binding. (orig.) [de

Characterization with 3H-haloperidol of the dopamine receptor in the rat kidney particulate preparation

International Nuclear Information System (INIS)

Nakajima, Tohru; Kuruma, Isami

1980-01-01

The dopamine receptor of rat kidney particulate preparation was identified and characterized by the use of 3 H-haloperidol binding. Binding of 3 H-haloperidol to the kidney particulate preparation was slow and saturable. The dissociation constants (K sub(D)) were 0.41 nM and 5.88 nM, respectively, according to the model of two classes of independent binding sites. Maximal binding of high affinity site was obtained with 166 fmole/mg protein which was about 40% of the total receptor density. A wide variety of neuroleptics at specifically low concentrations in nanomolar range inhibited the 3 H-haloperidol binding. There was an excellent correlation between the affinity of numerous neuroleptics for the kidney particulate preparation and that for the brain striatum. (author)

Improved delineation of human dopamine receptors using [18F]-N-methylspiroperidol and PET

International Nuclear Information System (INIS)

Arnett, C.D.; Wolf, A.P.; Shiue, C.Y.; Fowler, J.S.; MacGregor, R.R.; Christman, D.R.; Smith, M.R.

1986-01-01

The brain uptake of [18F]-N-methylspiroperidol, a butyrophenone neuroleptic with high selectivity for the dopamine receptor, has been measured in three normal human volunteers using positron emission tomography for times up to 12 hr postinjection. These studies demonstrated two unique findings concerning the in vivo distribution of this neuroleptic: (a) it is tightly bound to dopamine D-2 receptors in the caudate-putamen brain regions, and (b) these regions are the only large brain structures which exhibit appreciable long-term retention. In addition, radioactivity clears rapidly from plasma, and the percentage of unchanged [18F]-N-methylspiroperidol in plasma declines rapidly. These results suggest that this compound binds irreversibly to dopamine D-2 receptors, and that there are few if any dopamine D-2 receptors in the human frontal cortex. These studies emphasize not only the importance of characterizing neurotransmitter receptors in living human brain using a ligand labeled with a positron emitting nuclide of sufficiently long half-life to allow monitoring of brain radioactivity distribution for several hours after the injection of radioligand, but also of accurately determining the amount of unchanged tracer in plasma for tracer kinetic modeling

Real-Time G-Protein-Coupled Receptor Imaging to Understand and Quantify Receptor Dynamics

Directory of Open Access Journals (Sweden)

María S. Aymerich

2011-01-01

Full Text Available Understanding the trafficking of G-protein-coupled receptors (GPCRs and their regulation by agonists and antagonists is fundamental to develop more effective drugs. Optical methods using fluorescent-tagged receptors and spinning disk confocal microscopy are useful tools to investigate membrane receptor dynamics in living cells. The aim of this study was to develop a method to characterize receptor dynamics using this system which offers the advantage of very fast image acquisition with minimal cell perturbation. However, in short-term assays photobleaching was still a problem. Thus, we developed a procedure to perform a photobleaching-corrected image analysis. A study of short-term dynamics of the long isoform of the dopamine type 2 receptor revealed an agonist-induced increase in the mobile fraction of receptors with a rate of movement of 0.08 μm/s For long-term assays, the ratio between the relative fluorescence intensity at the cell surface versus that in the intracellular compartment indicated that receptor internalization only occurred in cells co-expressing G protein-coupled receptor kinase 2. These results indicate that the lateral movement of receptors and receptor internalization are not directly coupled. Thus, we believe that live imaging of GPCRs using spinning disk confocal image analysis constitutes a powerful tool to study of receptor dynamics.

Characterization with /sup 3/H-haloperidol of the dopamine receptor in the rat kidney particulate preparation

Energy Technology Data Exchange (ETDEWEB)

Nakajima, T; Kuruma, I [Nippon Roche Research Center, Kanagawa (Japan)

1980-12-01

The dopamine receptor of rat kidney particulate preparation was identified and characterized by the use of /sup 3/H-haloperidol binding. Binding of /sup 3/H-haloperidol to the kidney particulate preparation was slow and saturable. The dissociation constants (K sub(D)) were 0.41 nM and 5.88 nM, respectively, according to the model of two classes of independent binding sites. Maximal binding of high affinity site was obtained with 166 fmole/mg protein which was about 40% of the total receptor density. A wide variety of neuroleptics at specifically low concentrations in nanomolar range inhibited the /sup 3/H-haloperidol binding. There was an excellent correlation between the affinity of numerous neuroleptics for the kidney particulate preparation and that for the brain striatum.

Neuroleptic malignant syndrome during zuclopenthixol therapy in X-linked cerebral adrenoleukodystrophy.

NARCIS (Netherlands)

Rubio Gozalbo, M.E.; Waardenburg, D.A. van; Forget, P.P.; Spaapen, L.J.; Verrips, A.; Vroomen, P.C.

2001-01-01

An 8 year-old boy with X-ALD under treatment with simvastatin developed a severe adverse reaction when the dose of his other medication, zuclopenthixol was increased. Both drugs were withdrawn after a diagnosis of neuroleptic malignant syndrome was made.

The effects of psychoactive drugs and neuroleptics on language in normal subjects and schizophrenic patients: a review.

Science.gov (United States)

Salomé, F; Boyer, P; Fayol, M

2000-12-01

The aim of this survey is to present an overview of research into psychopharmacology as regards the effects of different psychoactive drugs and neuroleptics (NL) on language in normal subjects and schizophrenic patients. Eighteen studies that have investigated the effects of different drugs (alcohol, amphetamines, secobarbital, L-dopa, psilocybin, ketamine, fenfluramine) and neuroleptics (conventional and atypical) on language are reviewed. There are no studies concerning the effects of neuroleptics on language in healthy subjects. The results of the effects of other molecules indicate that language production can be increased (alcohol, amphetamine, secobarbital), rendered more complex (d-amphetamine), more focused (L-dopa) or more unfocused (psilocybin) and clearly impaired (ketamine). For schizophrenic patients, most studies show that conventional neuroleptic treatments, at a therapeutic dosage and in acute or chronic mode, reduce language disorders at all levels (clinic, linguistic, psycholinguistic). In conjunction with other molecules, the classical NL, when administered at a moderate dosage and in chronic mode, modify language in schizophrenia, either by improving the verbal flow and reducing pauses and positive thought disorder (NL + amphetamine) or by inducing an impairment in the language measurements (NL + fenfluramine). Clinical, methodological and theoretical considerations of results are debated in the framework of schizophrenic language disorders.

Neuroleptics as therapeutic compounds stabilizing neuromuscular transmission in amyotrophic lateral sclerosis.

Science.gov (United States)

Patten, Shunmoogum A; Aggad, Dina; Martinez, Jose; Tremblay, Elsa; Petrillo, Janet; Armstrong, Gary Ab; La Fontaine, Alexandre; Maios, Claudia; Liao, Meijiang; Ciura, Sorana; Wen, Xiao-Yan; Rafuse, Victor; Ichida, Justin; Zinman, Lorne; Julien, Jean-Pierre; Kabashi, Edor; Robitaille, Richard; Korngut, Lawrence; Parker, J Alexander; Drapeau, Pierre

2017-11-16

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing, fatal disorder with no effective treatment. We used simple genetic models of ALS to screen phenotypically for potential therapeutic compounds. We screened libraries of compounds in C. elegans, validated hits in zebrafish, and tested the most potent molecule in mice and in a small clinical trial. We identified a class of neuroleptics that restored motility in C. elegans and in zebrafish, and the most potent was pimozide, which blocked T-type Ca2+ channels in these simple models and stabilized neuromuscular transmission in zebrafish and enhanced it in mice. Finally, a short randomized controlled trial of sporadic ALS subjects demonstrated stabilization of motility and evidence of target engagement at the neuromuscular junction. Simple genetic models are, thus, useful in identifying promising compounds for the treatment of ALS, such as neuroleptics, which may stabilize neuromuscular transmission and prolong survival in this disease.

Neuroleptic malignant syndrome and subsequent clozapine-withdrawal effects in a patient with refractory schizophrenia

Directory of Open Access Journals (Sweden)

Cheng MF

2016-03-01

Full Text Available Minfeng Cheng,* Huaying Gu,* Liangrong Zheng, Houliang Wang, Zhiyong Zhong, Shenglin Wen Department of Psychiatry, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Here, we report a female patient developing neuroleptic malignant syndrome following the use of a combination of clozapine and haloperidol. Subsequently, the patient presented withdrawal effects after an abrupt discontinuation of clozapine. Psychiatrists not aware of possible clozapine-withdrawal effects may misdiagnose as a part of the primary mental illness or as the initial symptoms worsening, if unrecognized. Keywords: clozapine, neuroleptic malignant syndrome, withdrawal effect, schizophrenia

Neurotransmitter receptor imaging

International Nuclear Information System (INIS)

Cordes, M.; Hierholzer, J.; Nikolai-Beyer, K.

1993-01-01

The importance of neuroreceptor imaging in vivo using single photon emission tomography (SPECT) and positron emission tomography (PET) has increased enormously. The principal neurotransmitters, such as dopamine, GABA/benzodiazepine, acetylcholine, and serotonin, are presented with reference to anatomical, biochemical, and physiological features. The main radioligands for SPECT and PET are introduced, and methodological characteristics of both PET and SPECT presented. Finally, the results of neurotransmitter receptor imaging obtained so far will be discussed. (orig.) [de

Neuroleptic malignant syndrome: a case responding to electroconvulsive therapy plus bupropion

Directory of Open Access Journals (Sweden)

Quintí Foguet-Boreu

2018-01-01

Full Text Available Neuroleptic malignant syndrome (NMS is a severe motor syndrome occurring as a consequence of neuroleptic treatment. We present a case of a 67-year-old Caucasian woman with a history of a major depressive disorder with psychotic features. During her third hospital admission, symptoms of autonomic instability, hyperpyrexia, severe extrapyramidal side effects, and delirium appeared, suggesting NMS due to concomitant treatment with risperidone and quetiapine, among other drugs. Despite several consecutive pharmacological treatments (lorazepam, bromocriptine and amantadine and prompt initiation of electroconvulsive therapy (ECT, clinical improvement was observed only after combining bupropion with ECT. The symptoms that had motivated the admission gradually remitted and the patient was discharged home. Bupropion increases dopaminergic activity in both the nucleus accumbens and the prefrontal cortex. Therefore, from a physiopathological standpoint, bupropion has a potential role in treating NMS. However, there is scarce evidence supporting this approach and therefore future cases should be carefully considered.

Neuroleptics and β-carbolines displace (3H)imipramine from its binding sites in human and rat tissues

International Nuclear Information System (INIS)

Rommelspacher, H.; Strauss, S.

1985-01-01

Most investigations dealing with the pharmacological characterization of ( 3 H)imipramine binding sites focus on tricyclic antidepressants (TCA). This approach seemed to be justified since imipramine belongs to that chemical group. Langer and coworkers, however, introduced a tetrahydro-β-carboline (THβC) as a possible endogenous ligand. Thus, the high affinity of imipramine towards the binding sites might not be due to its special chemical structure but due to its tricyclic nature. In the present paper the structure-activity-relationships of neuroleptics and β-carbolines were investigated and compared with that of tricyclic antidepressants. Among the tricyclic neuroleptics those with an electron attracting substituent (-Cl) exerted highest affinity. The effect was attenuated by a long, cyclic side chain. The affinity of tricyclic neuroleptics was only slightly weaker than that of 6-Meo-THβC the suggested endogenous ligand. The experiments with other THβCs supported the observation that an electron attracting substituent increases the affinity of a compound to the ( 3 H)imipramine binding sites. Comparison of the binding characteristics of ( 3 H)imipramine to membranes of human brain and thrombocytes as well as those of rat brain and thrombocytes revealed no differences among both species. Furthermore, the displacing potencies of neuroleptics were very similar with only slightly more activity in human tissue. As a methodological aspect the applicability of the 'Lowry' method to determine the protein concentration is discussed. (Author)

Plasma homovanillic acid, plasma anti-D1 and -D2 dopamine-receptor activity, and negative symptoms in chronically mediated schizophrenia.

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Suzuki, E; Kanba, S; Nibuya, M; Koshikawa, H; Nakaki, T; Yagi, G

1992-02-15

We have investigated the relationship between the concentration of homovanillic acid in human plasma (pHVA) and plasma anti-D1 and anti-D2 dopamine receptor activity in chronic schizophrenic patients whose neuroleptic dosage was changed. The change in pHVA level correlated with that in anti-D1, not anti-D2 activity, thus suggesting that the neuroleptic-induced changes in pHVA concentration may be associated with the blocking of D1- as well as D2- receptors. The change of scores on the Scale for the Assessment of Negative Symptoms did not significantly correlate with changes in anti-D1 or anti-D2 activity, but did so correlated with the change in pHVA level.

An in vivo study of the dopaminergic receptors in the brain of man using 11C-pimozide and positron emission tomography

International Nuclear Information System (INIS)

Baron, J.C.; Comar, D.; Crouzel, C.; Mestelan, G.; Zarifian, E.; Loo, H.; Agid, Y.

1982-09-01

Positron emission tomography was used to establish the regional cerebral pharmacokinetics of a carbon 11-labelled neuroleptic, pimozide, in an attempt to observe its specific bonding to dopaminergic receptors in vivo. The 11 C-pimozide kinetics were compared in two brain structures at the two ends of the dopaminergic receptor density scale: the striatum and cerebellum, very rich in and devoid of these receptors respectively. In 8 patients a significant radioactivity uptake was observed in the striatum as compared with the cerebellum, in agreement with in vivo studies on animals using tritiated pimozide. In 5 patients pre-treated by a therapeutic dose of a cold neuroleptic (haloperidol) this difference in kinetics no longer existed. Moreover no kinetic difference is observed, either before or after haloperidol administration, between the frontal cortex (relatively low in dopaminergic receptors) and cerebellum. These results strongly suggest that pharmacokinetic phenomena directly related to the specific bonding of 11 C-pimozide on the striatal dopaminergic receptors are observable on man in vivo. This specific bonding however remains quantitatively weak as compared with the strong non-specific bonding

A randomised, blinded, placebo-controlled trial in dementia patients continuing or stopping neuroleptics (the DART-AD trial.

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Clive Ballard

2008-04-01

Full Text Available BACKGROUND: There have been increasing concerns regarding the safety and efficacy of neuroleptics in people with dementia, but there are very few long-term trials to inform clinical practice. The aim of this study was to determine the impact of long-term treatment with neuroleptic agents upon global cognitive decline and neuropsychiatric symptoms in patients with Alzheimer disease. METHODS AND FINDINGS: DESIGN: Randomised, blinded, placebo-controlled parallel two-group treatment discontinuation trial. SETTING: Oxfordshire, Newcastle and Gateshead, London and Edinburgh, United Kingdom. PARTICIPANTS: Patients currently prescribed the neuroleptics thioridazine, chlorpromazine, haloperidol trifluoperazine or risperidone for behavioural or psychiatric disturbance in dementia for at least 3 mo. INTERVENTIONS: Continue neuroleptic treatment for 12 mo or switch to an identical placebo. OUTCOME MEASURES: Primary outcome was total Severe Impairment Battery (SIB score. Neuropsychiatric symptoms were evaluated with the Neuropsychiatric Inventory (NPI. RESULTS: 165 patients were randomised (83 to continue treatment and 82 to placebo, i.e., discontinue treatment, of whom 128 (78% commenced treatment (64 continue/64 placebo. Of those, 26 were lost to follow-up (13 per arm, resulting in 51 patients per arm analysed for the primary outcome. There was no significant difference between the continue treatment and placebo groups in the estimated mean change in SIB scores between baseline and 6 mo; estimated mean difference in deterioration (favouring placebo -0.4 (95% confidence interval [CI] -6.4 to 5.5, adjusted for baseline value (p = 0.9. For neuropsychiatric symptoms, there was no significant difference between the continue treatment and placebo groups (n = 56 and 53, respectively in the estimated mean change in NPI scores between baseline and 6 mo; estimated mean difference in deterioration (favouring continue treatment -2.4 (95% CI -8.2 to 3.5, adjusted for

Immunohistochemical evidence for the involvement of gonadotropin releasing hormone in neuroleptic and cataleptic effects of haloperidol in mice.

Science.gov (United States)

Fegade, Harshal A; Umathe, Sudhir N

2016-04-01

Blockade of dopamine D2 receptor by haloperidol is attributed for neuroleptic and cataleptic effects; and also for the release of gonadotropin releasing hormone (GnRH) from the hypothalamus. GnRH agonist is reported to exhibit similar behavioural effects as that of haloperidol, and pre-treatment with GnRH antagonist is shown to attenuate the effects of haloperidol, suggesting a possibility that GnRH might mediate the effects of haloperidol. To substantiate such possibility, the influence of haloperidol on GnRH immunoreactivity (GnRH-ir) in the brain was studied in vehicle/antide pre-treated mice by peroxidase-antiperoxidase method. Initially, an earlier reported antide-haloperidol interaction in rat was confirmed in mice, wherein haloperidol (250μg/kg, i.p.) exhibited suppression of conditioned avoidance response (CAR) on two-way shuttle box, and induced catalepsy in bar test; and pre-treatment with antide (50μg/kg, s.c., GnRH antagonist) attenuated both effects of haloperidol. Immunohistochemical study was carried out to identify GnRH-ir in the brain, isolated 1h after haloperidol treatment to mice pre-treated with vehicle/antide. The morphometric analysis of microphotographs of brain sections revealed that haloperidol treatment increased integrated density units of GnRH-ir in various regions of the limbic system. Considering basal GnRH-ir in vehicle treated group as 100%, the increase in GnRH-ir after haloperidol treatment was by 100.98% in the medial septum; 54.26% in the bed nucleus of the stria terminalis; 1152.85% in the anteroventral periventricular nucleus; 120.79% in the preoptic area-organum vasculosum of the lamina terminalis and 138.82% in the arcuate nucleus. Antide did not influence basal and haloperidol induced increase in GnRH-ir in any of the regions. As significant increase in GnRH-ir after haloperidol treatment was observed in such regions of the brain which are reported to directly or indirectly communicate with the hippocampus and basal

PET imaging for receptor occupancy: meditations on calculation and simplification.

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Zhang, Yumin; Fox, Gerard B

2012-03-01

This invited mini-review briefly summarizes procedures and challenges of measuring receptor occupancy with positron emission tomography. Instead of describing the detailed analytic procedures of in vivo ligand-receptor imaging, the authors provide a pragmatic approach, along with personal perspectives, for conducting positron emission tomography imaging for receptor occupancy, and systematically elucidate the mathematics of receptor occupancy calculations in practical ways that can be understood with elementary algebra. The authors also share insights regarding positron emission tomography imaging for receptor occupancy to facilitate applications for the development of drugs targeting receptors in the central nervous system.

Functional antagonistic properties of clozapine at the 5-HT3 receptor.

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Hermann, B; Wetzel, C H; Pestel, E; Zieglgänsberger, W; Holsboer, F; Rupprecht, R

1996-08-23

The atypical neuroleptic clozapine is thought to exert its psychopharmacological actions through a variety of neurotransmitter receptors. It binds preferentially to D4 and 5-HT2 receptors; however, little is known on it's interaction with the 5-HT3 receptor. Using a cell line stably expressing the 5-HT3 receptor, whole-cell voltage-clamp analysis revealed functional antagonistic properties of clozapine at low nanomolar concentrations in view of a binding affinity in the upper nanomolar range. Because the concentration of clozapine required for an interaction with the 5-HT3 receptor can be achieved with therapeutical doses, functional antagonistic properties at this ligand-gated ion channel may contribute to its unique psychopharmacological profile.

Neuroleptic-induced movement disorders in a naturalistic schizophrenia population: diagnostic value of actometric movement patterns.

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Janno, Sven; Holi, Matti M; Tuisku, Katinka; Wahlbeck, Kristian

2008-04-18

Neuroleptic-induced movement disorders (NIMDs) have overlapping co-morbidity. Earlier studies have described typical clinical movement patterns for individual NIMDs. This study aimed to identify specific movement patterns for each individual NIMD using actometry. A naturalistic population of 99 schizophrenia inpatients using conventional antipsychotics and clozapine was evaluated. Subjects with NIMDs were categorized using the criteria for NIMD found in the Diagnostic and Statistical Manual for Mental Disorders - Fourth Edition (DSM-IV).Two blinded raters evaluated the actometric-controlled rest activity data for activity periods, rhythmical activity, frequencies, and highest acceleration peaks. A simple subjective question was formulated to test patient-based evaluation of NIMD. The patterns of neuroleptic-induced akathisia (NIA) and pseudoakathisia (PsA) were identifiable in actometry with excellent inter-rater reliability. The answers to the subjective question about troubles with movements distinguished NIA patients from other patients rather well. Also actometry had rather good screening performances in distinguishing akathisia from other NIMD. Actometry was not able to reliably detect patterns of neuroleptic-induced parkinsonism and tardive dyskinesia. The present study showed that pooled NIA and PsA patients had a different pattern in lower limb descriptive actometry than other patients in a non-selected sample. Careful questioning of patients is a useful method of diagnosing NIA in a clinical setting.

Actometry and Barnes Akathisia Rating Scale in neuroleptic-induced akathisia.

Science.gov (United States)

Janno, Sven; Holi, Matti M; Tuisku, Katinka; Wahlbeck, Kristian

2005-01-01

We evaluated Barnes Akathisia Rating Scale (BARS) and standardized lower limb actometry in quantifying neuroleptic-induced akathisia (NIA) in 99 schizophrenia patients. Both instruments discriminated well between NIA and non-NIA patients and they correlated weakly but significantly. BARS was superior to actometry in screening DSM-IV diagnosed NIA patients. The results of this methodological study provide BARS with objective validation through movement measuring, that it has been suggested to need.

[3H]Haloperidol labels brain dopamine receptors after its injection into the internal carotid artery of the rat

International Nuclear Information System (INIS)

D'Ambrosio, A.; Zivkovic, B.; Bartholini, G.

1982-01-01

Pulse injection of [ 3 H]haloperidol (0.1 μCi; 0.003 μg) into the internal carotid artery of the rat specifically labelled dopamine receptors in striatum and olfactory tubercle, as indicated by the kinetics of, and the effects of neuroleptic drugs on, the ligand disposition. The described method may prove useful for labelling brain receptors with ligands which readily cross the blood-brain barrier but which do not selectively mark their receptors if injected systemically. (Auth.)

Neuroleptic-induced movement disorders in a naturalistic schizophrenia population: diagnostic value of actometric movement patterns

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Tuisku Katinka

2008-04-01

Full Text Available Abstract Background Neuroleptic-induced movement disorders (NIMDs have overlapping co-morbidity. Earlier studies have described typical clinical movement patterns for individual NIMDs. This study aimed to identify specific movement patterns for each individual NIMD using actometry. Methods A naturalistic population of 99 schizophrenia inpatients using conventional antipsychotics and clozapine was evaluated. Subjects with NIMDs were categorized using the criteria for NIMD found in the Diagnostic and Statistical Manual for Mental Disorders – Fourth Edition (DSM-IV. Two blinded raters evaluated the actometric-controlled rest activity data for activity periods, rhythmical activity, frequencies, and highest acceleration peaks. A simple subjective question was formulated to test patient-based evaluation of NIMD. Results The patterns of neuroleptic-induced akathisia (NIA and pseudoakathisia (PsA were identifiable in actometry with excellent inter-rater reliability. The answers to the subjective question about troubles with movements distinguished NIA patients from other patients rather well. Also actometry had rather good screening performances in distinguishing akathisia from other NIMD. Actometry was not able to reliably detect patterns of neuroleptic-induced parkinsonism and tardive dyskinesia. Conclusion The present study showed that pooled NIA and PsA patients had a different pattern in lower limb descriptive actometry than other patients in a non-selected sample. Careful questioning of patients is a useful method of diagnosing NIA in a clinical setting.

Granulocytopenia associated with neuroleptic therapy in a patient with benign familial leukopenia.

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Reznik, Ilya; Loewenthal, Ron; Kotler, Moshe; Apter, Inna; Mester, Roberto; Weizman, Abraham

2003-01-01

Benign familial leukopenia (BFL) has been reported in several ethnic groups, including Ethiopians of Jewish origin. To date, there are no reported cases of patients with BFL developing granulocytopenia following administration of neuroleptics. We report a case of a young Ethiopian Jew suffering from schizophrenia, who exhibited premorbid benign reduced white blood cells (WBC) count and developed leukopenia and neutropenia following exposure to typical (zuclopentixol, perphenazine, haloperidol) antipsychotics and the atypical antipsychotic risperidone. The diagnosis of BFL was established and tissue typing of the patient was determined. To the best of our knowledge, this is the first report of leukopenia with neutropenia in an ethnically susceptible (due to BFL) schizophrenia patient following exposure to typical and atypical antipsychotics. HLA typing of this patient was distinct from that reported in patients susceptible to clozapine-induced agranulocytosis. Further extensive investigations including HLA typing in a larger cohort of schizophrenic patients is needed in order to define the association between HLA haplotypes and neuroleptic-induced hematological reactions and to identify the potentially vulnerable individuals.

Progress of study on the dopamine D4 receptor imaging agent

International Nuclear Information System (INIS)

Tian Haibin; Zhang Lan; Zhang Chunfu; Li Junling; Yin Duanzhi

2001-01-01

Dopamine receptors were originally classified into five receptors subtypes, the dopamine D 4 receptor was included. Schizophrenic pathophysiology may be associated with expression and function of the dopamine D 4 receptor; it is of great importance to study the imaging agent of dopamine D 4 receptor. The study on radioactivity distribution and metabolize of radioligand remains hampered by the lack radioligand for the D 4 receptor which can be labeled using suitable nuclei. This paper reviews the progress of study on the dopamine D 4 receptor imaging agent, with particular emphasis vary nuclei, for example 11 C, 18 F, 123 I, labeled D 4 receptor ligands, antagonists and analogs as PET or SPECT imaging agents. Authors estimated affinity and selectivity of radioligands for the dopamine D 4 receptor in laboratory animal tests

(/sup 3/H)Haloperidol labels brain dopamine receptors after its injection into the internal carotid artery of the rat

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D' Ambrosio, A; Zivkovic, B; Bartholini, G [Research Department, Synthelabo-L.E.R.S., Paris (France)

1982-04-29

Pulse injection of (/sup 3/H)haloperidol (0.1 ..mu..Ci; 0.003 ..mu..g) into the internal carotid artery of the rat specifically labelled dopamine receptors in striatum and olfactory tubercle, as indicated by the kinetics of, and the effects of neuroleptic drugs on, the ligand disposition. The described method may prove useful for labelling brain receptors with ligands which readily cross the blood-brain barrier but which do not selectively mark their receptors if injected systemically.

Detection and management of the neuroleptic malignant syndrome.

Science.gov (United States)

Bond, W S

1984-01-01

Two patients who developed the neuroleptic malignant syndrome (NMS) are described, and pertinent literature is reviewed. A 30-year-old man developed NMS, apparently as a result of haloperidol treatment of chronic undifferentiated schizophrenia. Treatment with cooling blankets, acetaminophen, dantrolene sodium, and bromocriptine mesylate decreased abnormal vital signs, but catatonia continued. After 30 treatments with electroconvulsive therapy over a one-month period, the patient's catatonia was resolved, and he was discharged on no medication with the schizophrenia in remission. The second patient was a 22-year-old woman who developed NMS after five weeks of therapy with haloperidol and thiothixene for an acute episode of abnormal behavior. She did not respond to therapy with cooling blankets, acetaminophen, antibiotics, and amobarbital sodium. Dantrolene sodium therapy produced no improvement except for some relief of muscular rigidity. Electroconvulsive therapy (22 treatments over one month) successfully decreased the patient's elevated liver enzymes and leukocyte count, but periodic temperature elevations and catatonia continued. Prompt diagnosis and treatment of NMS are essential, as the mortality rate is 20%. Acute lethal catatonia and malignant hyperthermia are considered in differential diagnosis. Both central and peripheral pathophysiologic mechanisms are probably involved in NMS, and most cases are seen in patients with psychiatric illness. Onset of NMS does not seem related to duration of neuroleptic therapy and, in susceptible persons, additional factors may be required to trigger onset of NMS. Symptoms, including diffuse muscular rigidity, akinesia, and fever, develop within 24-72 hours. Neurologic symptoms may develop or worsen, and leukocytosis and elevated levels of liver enzymes occur. Death can result from respiratory or cardiovascular failure, and rhabdomyolysis can lead to acute renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain dopaminergic systems : imaging with positron tomography

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Baron, J C [University of Caen/INSERM U, Caen (France). CYCERON; Comar, D [E.E.C. Concerted Action on P.E.T. Investigations of Cellular Regeneration and Degeneration, Orsay (France) CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot; Farde, L [Karolinska Sjukhuset, Stockholm (Sweden); Martinot, J L; Mazoyer, B [CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot Paris-

1991-01-01

Imaging of the dopaminergic system in the human brain with the in vivo use of Positron Emission Tomography emerged in the late 1980s as a tool of major importance in clinical neurosciences and pharmacology. The last few years have witnessed rapid development of new radiotracers specific to receptors, reuptake sites and enzymes of the dopamine system; the application of these radiotracers has led to major break-troughs in the pathophysiology and therapy of movement disorders and schizophrenic-like psychoses. This book is the first to collect, in a single volume, state-of-the-art contributions to the various aspects of this research. Its contents address methodological issues related to the design, labelling, quantitative imaging and compartmental modeli-sation of radioligands of the post-synaptic, pre-synaptic and enzyme sites of the dopamine system and to their use in clinical research in the fields of Parkinson's disease as well as other movement disorders, psychoses and neuroleptic receptor occupancy. The chapters were written by leading European scientists in the field of PET, gathered together in Caen (France, November 1990) under the aegis of the EEC Concerted Action on PET Investigations of Cellular Regeneration and Degeneration. This book provides a current and comprehensive overview on PET studies of the brain dopamine system which should aid and interest neurologists , psychiatrists, pharmacologists and medical imaging scientists. (author). refs.; figs.; tabs.

Radiosynthesis and pharmacokinetics of high specific activity /sup 75,77/Br-bromperidol, a potent butyrophenone neuroleptic

International Nuclear Information System (INIS)

Moerlein, S.M.; Stocklin, G.

1984-01-01

Bromperidol, 4-[4-(4-bromophenyl)-4-hydroxypiperidino]-4'- fluorobutyrophenone, is a potent neuroleptic which has found clinical use in the treatment of schizophrenia. Of the major dopaminergic receptor-binding ligands, bromperidol has the greatest specificity for binding to cerebral dopamine receptors (K/sub i/ = 3.7 nM) relative to competitive cerebral serotonin (K/sub i/ = 26 nM), α-adrenergic (K/sub i/ = 100 nM) or histamine (K/sub i/ = 700 nM) receptors. The authors have therefore prepared bromperidol labelled with no-carrier-added (n.c.a.) /sup 75/Br (t/sub 1/2/ = 1.6 hr β/sup +/) or /sup 77/Br (t/sub 1/2/ = 52 hr EC) for evaluation as a radiopharmaceutical for mapping cerebral dopamine receptor areas with PECT technology, as well as for non-invasive pharmacodynamic studies in man with conventional nuclear medicine equipment. 4-[4-(4-trimethylstannylphenyl)-4-hydroxypiperidino]-4'- fluorobutyrophenone, TMSn-P, was synthesized in 40% chemical yield by reaction of trimethylstannyl sodium with bromperidol. TMSn-P was purified by preparative HPLC and characterized by /sup 1/H-NMR and GC-MS. TMSn-P was radiobrominated in methanol using n.c.a. /sup 75/Br/sup -/ or /sup 77/Br/sup -/ and dichloramine-T as oxidizing agent. Product /sup 75,77/Br-bromperidol was separated from impurities, including chlorinated side-product halo-peridol, using HPLC (RP-18; MeOH/H/sub 2/O/Et/sub 3/N = 70/30/0.3). For a reaction time of 5 minutes, and an overall radiopharmaceutical production time of 30 minutes, /sup 75,77/Br-bromperidol was obtained in physiological saline solution with 40% radiochemical yield and a specific activity > 10,000 Ci/mmole. The pharmacokinetics in rodents and PECT studies in primates using /sup 75,77/Br-bromperidol are compared with that of previously-reported /sup 75,77/Br-brombenperidol

Síndrome neuroléptico maligno Neuroleptic malignant syndrome

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Ricardo J. Toro

1989-02-01

Full Text Available

El síndrome neuroléptico maligno (SNM es una complicación rara, idiosincrática y potencialmente fatal, relacionada con el uso de drogas que afectan el sistema dopaminérgico; su cuadro clínico consiste en síntomas extrapiramidales, signos de disfunción autonómica y trastornos en el estado de conciencia, asociados a leucocitosis ya cifras muy elevadas de creatina fosfoquinasa. Reportamos el caso de un hombre de 32 años que presentó un síndrome catatónico severo después del uso intrahospitalario de antipsicóticos potentes a altas dosis para el control de una depresión psicótica. Se discuten las características clínicas del paciente y los hallazgos comunes en el SNM.

The Neuroleptic Malignant Syndrome (NMS Is a rare, idiosyncratic and potentially fatal complication of therapy with many drugs affecting the dopaminergic system; It Includes extrapyramidal symptoms, signs of autonomic dysfunction, disorders of consciousness, leucocytosis and an increase in serum creatine phosphokinase .We report the case of a 32 years old man, who developed a severe catatonic syndrome after receiving high doses of potent neuroleptics to control a psychotic depression. Clinical features of this case and common findings of NMS are discussed.

Non-opiate [beta]-endorphin fragments and dopamine--III [gamma]-type endorphins and various neuroleptics counteract the hypoactivity elicited by injection of apomorphine into the nucleus accumbens

NARCIS (Netherlands)

Ree, J.M. van; Caffe, A.R.; Wolterink, G.

1982-01-01

The hypoactivity in rats induced by small doses of apomorphine, injected bilaterally into the nucleus accumbens area of the brain, could be antagonized by pretreatment with the neuroleptic-like neuropeptide des-enkephalin-γ-endorphin (DEγE, β-endorphin 6–17) as well as with the neuroleptic drugs

Radioiodinated ligands for dopamine receptors

International Nuclear Information System (INIS)

Kung, H.F.

1994-01-01

The dopamine receptor system is important for normal brain function; it is also the apparent action site for various neuroleptic drugs for the treatment of schizophrenia and other metal disorders. In the past few years radioiodinated ligands for single photon emission tomography (SPECT) have been successfully developed and tested in humans: [ 123 I]TISCH for D1 dopamine receptors; [ 123 I]IBZM, epidepride, IBF and FIDA2, four iodobenzamide derivatives, for D2/D3 dopamine receptors. In addition, [ 123 I]β-CIT (RTI-55) and IPT, cocaine derivatives, for the dopamine reuptake site are potentially useful for diagnosis of loss of dopamine neurons. The first iodinated ligand, (R)trans-7-OH-PIPAT, for D3 dopamine receptors, was synthesized and characterized with cloned cell lines (Spodoptera frugiperda, Sf9) expressing the D2 and D3 dopamine receptors and with rat basal forebrain membrane preparations. Most of the known iodobenzamides displayed similar potency in binding to both D2 and D3 dopamine receptors expressed in the cell lines. Initial studies appear to suggest that by fine tuning the structures it may be possible to develop agents specific for D2 and D3 dopamine receptors. It is important to investigate D2/D3 selectivity for this series of potent ligands

A Rare Case of Myxedema Coma with Neuroleptic Malignant Syndrome (NMS)

OpenAIRE

Dixit, Siddharth; Dutta, Manoj Kumar; Namdeo, Mayank

2015-01-01

Myxedema coma or hypothyroid crisis is an endocrine emergency and needs ICU management. Neuroleptic malignant syndrome (NMS) is another medical emergency which needs high degree of clinical suspicion else mortality can be high. There is a paradox in co existence of myxedema coma and NMS. While one is hypometabolic state another is hypermetabolic state and both can be precipitated by antipsychotics use. Hypothermia and flaccidity commonly expected in myxedema coma may mask fever and rigidity o...

Neuroleptic Malignant Syndrome: A Case Aimed at Raising Clinical Awareness

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Jad Al Danaf

2015-01-01

Full Text Available A 60-year-old man with a history of bipolar disorder on risperidone, bupropion, and escitalopram was admitted for community acquired streptococcal pneumonia. Four days later, he developed persistent hyperthermia, dysautonomia, rigidity, hyporeflexia, and marked elevation of serum creatine phosphokinase. He was diagnosed with neuroleptic malignant syndrome (NMS and improved with dantrolene, bromocriptine, and supportive therapy. This case emphasizes the importance of considering a broad differential diagnosis for fever in the ICU, carefully reviewing the medication list for all patients, and considering NMS in patients with fever and rigidity.

PET imaging of human cardiac opioid receptors

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Villemagne, Patricia S.R.; Dannals, Robert F. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Department of Environmental Health Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Ravert, Hayden T. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Frost, James J. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Department of Environmental Health Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

2002-10-01

The presence of opioid peptides and receptors and their role in the regulation of cardiovascular function has been previously demonstrated in the mammalian heart. The aim of this study was to image {mu} and {delta} opioid receptors in the human heart using positron emission tomography (PET). Five subjects (three females, two males, 65{+-}8 years old) underwent PET scanning of the chest with [{sup 11}C]carfentanil ([{sup 11}C]CFN) and [{sup 11}C]-N-methyl-naltrindole ([{sup 11}C]MeNTI) and the images were analyzed for evidence of opioid receptor binding in the heart. Either [{sup 11}C]CFN or [{sup 11}C]MeNTI (20 mCi) was injected i.v. with subsequent dynamic acquisitions over 90 min. For the blocking studies, either 0.2 mg/kg or 1 mg/kg of naloxone was injected i.v. 5 min prior to the injection of [{sup 11}C]CFN and [{sup 11}C]MeNTI, respectively. Regions of interest were placed over the left ventricle, left ventricular chamber, lung and skeletal muscle. Graphical analysis demonstrated average baseline myocardial binding potentials (BP) of 4.37{+-}0.91 with [{sup 11}C]CFN and 3.86{+-}0.60 with [{sup 11}C]MeNTI. Administration of 0.2 mg/kg naloxone prior to [{sup 11}C]CFN produced a 25% reduction in BP in one subject in comparison with baseline values, and a 19% decrease in myocardial distribution volume (DV). Administration of 1 mg/kg of naloxone before [{sup 11}C]MeNTI in another subject produced a 14% decrease in BP and a 21% decrease in the myocardial DV. These results demonstrate the ability to image these receptors in vivo by PET. PET imaging of cardiac opioid receptors may help to better understand their role in cardiovascular pathophysiology and the effect of abuse of opioids and drugs on heart function. (orig.)

Neuroleptic Malignant Syndrome in a Patient with Tongue Cancer: A Report of a Rare Case

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Osamu Baba

2013-01-01

Full Text Available Background. Neuroleptic malignant syndrome (NMS is a rare but life-threatening complication of neuroleptic drugs, which are used widely in head and neck cancer (HANC patients who develop delirium. Methods and Results. Postoperative delirium in a 39-year-old man with tongue cancer was treated with haloperidol and chlorpromazine. Three days after the first administration of antipsychotics, the patient exhibited elevated body temperature, autonomic and extrapyramidal symptoms, and impaired consciousness. A definitive diagnosis was made using the research diagnostic criteria for NMS in the DSM-IV, and the antipsychotics were immediately discontinued. The patient was given dantrolene and bromocriptine to treat the NMS. The patient’s hyperthermia, elevated creatinin kinase (CK, and muscle rigidity improved gradually, with all symptoms of NMS resolving completely by 13 days after the diagnosis. Conclusions. HANC surgeons must be alert for early signs of NMS and use antipsychotics conservatively to avoid NMS and its potentially fatal outcome.

The development of epidermal growth factor receptor molecular imaging in cancer

International Nuclear Information System (INIS)

Zhou Xiaoliang; Wang Hao; Shi Peiji; Liu Jianfeng; Meng Aimin

2013-01-01

In vivo epidermal growth factor receptor (EGFR) targeted therapy has great potential for cancer diagnosis and the evaluation of curative effects. Enhancement of EGFR-targeted therapy needs a reliable quantitative molecular imaging method which could enable monitoring of receptor drug binding and receptor occupancy in vivo, and identification of the mutation in EGFR. PET or SPECT is the most advanced molecular imaging technology of non-invasively selecting responders, predicting therapeutic outcome and monitoring EGFR-targeted treatment. This review analyzed the present situation and research progress of molecular imaging agents. (authors)

[Initial experiences with amisulpride, an in Germany novel, atypical neuroleptic drug in treatment of adolescents with psychiatric disorders].

Science.gov (United States)

Göpel, C; Marcus, A

2001-08-01

In addition to conventional antipsychotic drugs, during the past decade an increasing number of atypical neuroleptics has been introduced in the treatment of juvenile schizophrenic and schizoaffective disorders. In 1999 Germany legalized the benzamide amisulpride for the treatment of acute and chronic schizophrenic symptoms. Preliminary treatment results are reported here. Ten adolescent cases are presented with regard to the efficacy, side effects and dosage of amisulpride. Preliminary results on the use of amisulpride are promising. The rate of side effects is tolerable. Amisulprise seems to constitute a useful alternative in the treatment of juvenile schizophrenia for those who suffer from intolerable side effects of classical or atypical neuroleptics. Controlled studies are warranted to further clarify its efficacy and safety in the treatment of adolescents.

Evaluation of health resources expenditure in two groups of psychotic patients treated with olanzapine and typical neuroleptics in a Italian Mental Health Department in Calabria Region

Directory of Open Access Journals (Sweden)

Anna Caputo

2008-01-01

Full Text Available Numerous Italian and international trials have studied the global costs of treatment with olanzapine and typical neuroleptics. Our analysis confirms those results. In our study, treatment with olanzapine, as compared to typical neuroleptics, was associated with a greater reduction in emergency interventions (hospitalisations, with an increased use of rehabilitation services and with a small increase in the number of working days. The differences between the two groups for this variable were not great, while the differences in the assessment scores appeared important and statistically significant. The results of present study are relative to the practice of one Italian Mental Health Department and, for this reason, cannot be generalized. Anyway, they are another indication of increased efficiency of atypicals treatment over older neuroleptics in schizophrenia.

Correlates of rapid neuroleptic response in male patients with schizophrenia.

Science.gov (United States)

Petrie, E C; Faustman, W O; Moses, J A; Lombrozo, L; Csernansky, J G

1990-08-01

Correlates of neuroleptic response latency were assessed in 16 male schizophrenic inpatients during 4 weeks of fixed dose (20 mg/day) haloperidol treatment. Rapid responders showed a mean 40% reduction in Brief Psychiatric Rating Scale (BPRS) positive symptom scores by day 10 of treatment. Rapid responders had significantly lower plasma homovanillic acid (pHVA) concentrations compared to non-rapid responders during week 4 of haloperidol treatment. However, rapid versus non-rapid responders did not differ with respect to demographics, baseline positive or negative BPRS symptom scores, performance on tests of neuropsychological function, or mean plasma haloperidol concentrations.

Electrochemical behaviour of some neuroleptics: Haloperidol and its derivatives.

Science.gov (United States)

Vire, J C; Fischer, M; Patriarche, G J; Christian, G D

1981-05-01

The electrochemical characteristics of Haloperidol and related compounds, representative neuroleptics of the butyrophenone family, have been investigated as a function of pH and concentration by direct-current, alternating-current and differential-pulse polarography and cyclic voltammetry at a hanging mercury drop electrode. A single cathodic wave representing an irreversible two-electron reduction is obtained, and its half-wave potential differs from that characteristic of aromatic ketone reduction. Adsorption processes disturb the wave behaviour and an adsorption prewave is observed at high concentrations. Quantitative measurements were successful in the concentration range 1 x 10(-4)-1 x 10(-6)M (0.4 mg/l.), the lower concentration representing the detection limit by differential-pulse polarography.

Development of radiodiagnostics for image diagnosis of intracerebral dopamine receptor

Energy Technology Data Exchange (ETDEWEB)

Fujita, Motoi; Kitamura, Hideaki; Nakajima, Takashi [Saigata, National Hospital, Niigata (Japan)

1998-02-01

Single photon emission tomography (SPECT) able to evaluate the local blood flow in the brain is a safety and effective system for clinical diagnosis and pathological evaluation of incurable neulopsychotic diseases. Development of receptor imaging agents for SPECT, which has not been approved are progressing now. Using gerbits as an animal model for cerebrovascular diseases, an investigation was made on {sup 125}I-Iomazenil (Ro16-0154), an antagonist of benzodiazepin receptor in CNS as well as dopamine receptor ligands. {sup 125}I-Iomazenil was found to markedly accumulate in the regions; cerebral cortex (especially, layer VI and V), amygdala, thalamus, hypothalamus, nigra, cerebellar cortex, etc., where benzodiazepin is specifically localized. The accumulation was inhibited by preadministered flumazenil, indicating that {sup 125}I-Iomazenil can bind to the benzodiazepin receptor in CNS. The present study demonstrated that the late images of {sup 123}I-Iomazenil-SPECT are useful for detecting a lesion in the crebral cortex and cerabellar one, but it was unable to image out a lesion in the dentate-red nuclei due to DRPLA or Joseph disease. Therefore, {sup 123}I-Iomazenil was thought to be a valuable radiomedicine for imaging out and pathological evaluation. (M.N.)

Dynamics of Corticosteroid Receptors: Lessons from Live Cell Imaging

International Nuclear Information System (INIS)

Nishi, Mayumi

2011-01-01

Adrenal corticosteroids (cortisol in humans or corticosterone in rodents) exert numerous effects on the central nervous system that regulates the stress response, mood, learning and memory, and various neuroendocrine functions. Corticosterone (CORT) actions in the brain are mediated via two receptor systems: the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). It has been shown that GR and MR are highly colocalized in the hippocampus. These receptors are mainly distributed in the cytoplasm without hormones and translocated into the nucleus after treatment with hormones to act as transcriptional factors. Thus the subcellular dynamics of both receptors are one of the most important issues. Given the differential action of MR and GR in the central nervous system, it is of great consequence to clarify how these receptors are trafficked between cytoplasm and nucleus and their interactions are regulated by hormones and/or other molecules to exert their transcriptional activity. In this review, we focus on the nucleocytoplasmic and subnuclear trafficking of GR and MR in neural cells and non-neural cells analyzed by using molecular imaging techniques with green fluorescent protein (GFP) including fluorescence recovery after photobleaching (FRAP) and fluorescence resonance energy transfer (FRET), and discuss various factors affecting the dynamics of these receptors. Furthermore, we discuss the future directions of in vivo molecular imaging of corticosteroid receptors at the whole brain level

Development of radiodiagnostics for image diagnosis of intracerebral dopamine receptor

International Nuclear Information System (INIS)

Fujita, Motoi; Kitamura, Hideaki; Nakajima, Takashi

1999-01-01

By measuring Vd value as an index to catch a functional change of nonspecific amine receptor at pathological regeneration region, Table Look Up method was thought to be useful for evaluation on functions of cerebellum and brainstem in Machado-Joseph disease. As it could simply calculate r-CBF and Vd values only adding SPWCT image to single time artery blood collection, it was thought to be useful for evaluation of Machado-Joseph disease. In last fiscal years, some animal experiments and clinical SPECT were conducted and evaluated to conduct research and development of a receptor imaging chemicals for clinics using radioactive reagent. In 1997 fiscal year, some examination of quantitative image analysis method on Vd value considering to reflex change of neural degeneration and receptor by using SPECT was conducted. (G.K.)

Optimization studies concerning the direct nucleophilic fluorination of butyrophenone neuroleptics

Energy Technology Data Exchange (ETDEWEB)

Katsifis, A; Hamacher, K; Schnitter, J; Stoecklin, G [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Chemie 1 - Nuklearchemie

1993-07-01

Based on the direct nucleophilic aromatic substitution described previously for [[sup 18]F]N-methylspiperone the butyrophenone neuroleptics benperidol, droperidol, fluanisone and haloperidol were labelled with fluorine-18. The n.c.a. aromatic nucleophilic NO[sub 2] [yields] [sup 18]F substitution takes place in the presence of the moderately basic cryptate system consisting of Kryptofix 2.2.2., potassium oxalate and potassium carbonate. The one step labeling reaction was performed in different solvents and is equally successful in dimethylsulfoxide, dimethylformamide or dimethylacetamide yielding 25-35% (EOS) within a reaction time of 5-30 min in the range of 140-160[sup o]C at analytical activity levels. (author).

Effects of acute and long-term typical or atypical neuroleptics on morphine-induced behavioural effects in mice.

Science.gov (United States)

Hollais, André W; Patti, Camilla L; Zanin, Karina A; Fukushiro, Daniela F; Berro, Laís F; Carvalho, Rita C; Kameda, Sonia R; Frussa-Filho, Roberto

2014-03-01

1. It has been suggested that the high prevalence of drug abuse in schizophrenics is related to chronic treatment with typical neuroleptics and dopaminergic supersensitivity that develops as a consequence. Within this context, atypical neuroleptics do not seem to induce this phenomenon. In the present study, we investigated the effects of acute administration or withdrawal from long-term administration of haloperidol and/or ziprasidone on morphine-induced open-field behaviour in mice. 2. In the first experiment, mice were given a single injection of haloperidol (1 mg/kg, i.p.) or several doses of ziprasidone (2, 4 or 6 mg/kg, i.p.) and motor activity was quantified by the open-field test. The aim of the second experiment was to verify the effects of an acute injection of haloperidol (1 mg/kg) or ziprasidone (6 mg/kg) on 20 mg/kg morphine-induced behaviours in the open-field test. In the third experiment, mice were treated with 1 mg/kg haloperidol and/or 2, 4 or 6 mg/kg ziprasidone for 20 days. Seventy-two hours after the last injection, mice were injected with 20 mg/kg, i.p., morphine and then subjected to the open-field test. Acute haloperidol or ziprasidone decreased spontaneous general activity and abolished morphine-induced locomotor stimulation. 3. Withdrawal from haloperidol or ziprasidone did not modify morphine-elicited behaviours in the open-field test. The results suggest that withdrawal from neuroleptic treatments does not contribute to the acute effect of morphine in schizophrenic patients. © 2014 Wiley Publishing Asia Pty Ltd.

Neuroleptic malignant syndrome and subsequent clozapine-withdrawal effects in a patient with refractory schizophrenia

OpenAIRE

Cheng, Minfeng; Gu, Huaying; Zheng, Liangrong; Wang, Houliang; Zhong, Zhiyong; Wen, Shenglin

2016-01-01

Minfeng Cheng,* Huaying Gu,* Liangrong Zheng, Houliang Wang, Zhiyong Zhong, Shenglin Wen Department of Psychiatry, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Here, we report a female patient developing neuroleptic malignant syndrome following the use of a combination of clozapine and haloperidol. Subsequently, the patient presented withdrawal effects after an abrupt ...

Pavor nocturnus: a complication of single daily tricyclic or neuroleptic dosage.

Science.gov (United States)

Flemenbaum, A

1976-05-01

The author tested the hypothesis that a single bedtime dosage schedule of tricyclic or neuroleptic medication produces increased frequency of night terrors by administering a questionnaire to 30 medical patients who were not receiving such medications and 100 psychiatric patients on either multiple- or single-dosage schedules. Psychiatric patients on multiple-dosage schedules reported no more frightening dreams than the medical patients, whereas almost three-fourths of those receiving single bedtime doses had frightening dreams, a significant difference from the medical sample. This preliminary report is presented to call attention to the possible undesirable effects of a single dose schedule.

Biological reagents and their use

International Nuclear Information System (INIS)

1981-01-01

The patent relates to a technique for enabling rapid determination of the concentration of neuroleptic drugs such as the phenthiazines and butyrophenones in body fluids of patients. The method is based on the discovery that a neuroleptic drug contained in the body fluid of a patient will successfully compete with the binding of radioactive dopamine receptor site binders to dopamine receptor sites of dopamine receptor material in such a manner that an accurate determination of neuroleptic drug concentration can readily be made. The invention relates to method of radioassay, to a composition of matter for enabling such assays, and to a test kit for the performance of such assays. (U.K.)

Dopamine receptors in the Parkinsonian brain

Energy Technology Data Exchange (ETDEWEB)

Rinne, U K; Loennberg, P; Koskinen, V [Turku Univ. (Finland). Dept. of Neurology

1981-01-01

Striatal dopamine receptors were studied in 44 patients with Parkinson disease by the radioligand-binding technique using /sup 3/H-spiroperidol. The specific binding of /sup 3/H-spiroperidol was either significantly increased or reduced in the caudate nucleus and putamen of parkinsonian patients without levodopa therapy. Scatchard analysis showed that there were corresponding changes in the receptor number, but no significant changes in the mean dissociation constant. The increased binding of /sup 3/H-spiroperidol in the basal ganglia was also found in parkinsonian patients suffering from psychotic episodes and treated with neuroleptic drugs. Normal and low binding of /sup 3/H-spiroperidol was found in patients treated with levodopa. Clinically, the patient with low binding were more disabled and had lost the beneficial response to levodopa. Thus in Parkinson disease in some patients a denervation supersensitivity seemed to develop and in some others a loss of postsynaptic dopamine receptor sites in the neostriatium. The latter alteration may contribute to the decreased response of parkinsonian patients to chronic levodopa therapy.

Dopamine receptors in the Parkinsonian brain

International Nuclear Information System (INIS)

Rinne, U.K.; Loennberg, P.; Koskinen, V.

1981-01-01

Striatal dopamine receptors were studied in 44 patients with Parkinson disease by the radioligand-binding technique using 3 H-spiroperidol. The specific binding of 3 H-spiroperidol was either significantly increased or reduced in the caudate nucleus and putamen of parkinsonian patients without levodopa therapy. Scatchard analysis showed that there were corresponding changes in the receptor number, but no significant changes in the mean dissociation constant. The increased binding of 3 H-spiroperidol in the basal ganglia was also found in parkinsonian patients suffering from psychotic episodes and treated with neuroleptic drugs. Normal and low binding of 3 H-spiroperidol was found in patients treated with levodopa. Clinically, the patient with low binding were more disabled and had lost the beneficial response to levodopa. Thus in Parkinson disease in some patients a denervation supersensitivity seemed to develop and in some others a loss of postsynaptic dopamine receptor sites in the neostriatium. The latter alteration may contribute to the decreased response of parkinsonian patients to chronic levodopa therapy. (author)

Evaluation of potential PET imaging probes for the orexin 2 receptors

International Nuclear Information System (INIS)

Wang, Changning; Wilson, Colin M.; Moseley, Christian K.; Carlin, Stephen M.; Hsu, Shirley; Arabasz, Grae; Schroeder, Frederick A.; Sander, Christin Y.; Hooker, Jacob M.

2013-01-01

A wide range of central nervous system (CNS) disorders, particularly those related to sleep, are associated with the abnormal function of orexin (OX) receptors. Several orexin receptor antagonists have been reported in recent years, but currently there are no imaging tools to probe the density and function of orexin receptors in vivo. To date there are no published data on the pharmacokinetics (PK) and accumulation of some lead orexin receptor antagonists. Evaluation of CNS pharmacokinetics in the pursuit of positron emission tomography (PET) radiotracer development could be used to elucidate the association of orexin receptors with diseases and to facilitate the drug discovery and development. To this end, we designed and evaluated carbon-11 labeled compounds based on diazepane orexin receptor antagonists previously described. One of the synthesized compounds, [ 11 C]CW4, showed high brain uptake in rats and further evaluated in non-human primate (NHP) using PET-MR imaging. PET scans performed in a baboon showed appropriate early brain uptake for consideration as a radiotracer. However, [ 11 C]CW4 exhibited fast kinetics and high nonspecific binding, as determined after co-administration of [ 11 C]CW4 and unlabeled CW4. These properties indicate that [ 11 C]CW4 has excellent brain penetrance and could be used as a lead compound for developing new CNS-penetrant PET imaging probes of orexin receptors

Positron emission tomography with (18F)methylspiperone demonstrates D2 dopamine receptor binding differences of clozapine and haloperidol

International Nuclear Information System (INIS)

Karbe, H.; Wienhard, K.; Huber, M.; Herholz, K.; Heiss, W.D.; Hamacher, K.; Coenen, H.H.; Stoecklin, G.; Loevenich, A.

1991-01-01

Four schizophrenic patients were investigated with dynamic positron emission tomography (PET) using ( 18 F)fluorodeoxyglucose (FDG) and ( 18 F)methylspiperone (MSP) as tracers. Two schizophrenics were on haloperidol therapy at the time of MSP PET. The other two schizophrenics were treated with clozapine, in one of them MSP PET was carried out twice with different daily doses (100 mg and 450mg respectively). Neuroleptic serum levels were measured in all patients. Results were compared with MSP PET of two drugfree male control subjects and with a previous fluoroethylspiperone (FESP) study of normals. Three hours after tracer injection specific binding of MSP was observed in the striatum in all cases. The striatum to cerebellum ratio was used to estimate the degree of neuroleptic-caused striatal D 2 dopamine receptor occupancy. In the haloperidol treated patients MSP binding was significantly decreased, whereas in the clozapine treated patients striatum to cerebellum ratio was normal. Even the increase of clozapine dose in the same patient had no influence on this ratio. Despite the smaller number of patients the study shows for the first time in humans that striatal MSP binding reflects the different D 2 dopamine receptor affinities of clozapine and haloperidol. (authors)

[Selective attention and schizophrenia before the administration of neuroleptics].

Science.gov (United States)

Lussier, I; Stip, E

1999-01-01

In recent years, the presence of attention deficits has been recognized as a key feature of schizophrenia. Past studies reveal that selective attention, or the ability to select relevant information while ignoring simultaneously irrelevant information, is disturbed in schizophrenic patients. According to Treisman feature-integration theory of selective attention, visual search for conjunctive targets (e.g., shape and color) requires controlled processes, that necessitate attention and operate in a serial manner. Reaction times (RTs) are therefore function of the number of stimuli in the display. When subjects are asked to detect the presence or absence of a target in an array of a variable number of stimuli, different performance patterns are expected for positive (present target) and negative trials (absent target). For positive trials, a self-terminating search is triggered, that is, the search is ended when the target is encountered. For negative trials, an exhaustive search strategy is displayed, where each stimulus is examined before the search can end; the RT slope pattern is thus double that of the positive trials. To assess the integrity of these processes, thirteen drug naive schizophrenic patients were compared to twenty normal control subjects. Neuroleptic naive patients were chosen as subjects to avoid the potential influence of medication and chronicity-related factors on performance. The subjects had to specify as fast as possible the presence or absence of the target in an array of a variable number of stimuli presented in a circular display, and comprising or not the target. Results showed that the patients can use self-terminating search strategies as well as normal control subjects. However, their ability to trigger exhaustive search strategies is impaired. Not only were patients slower than controls, but their pattern of RT results was different. These results argue in favor of an early impairment in selective attention capacities in

Antagonism of presynaptic dopamine receptors by phenothiazine drug metabolites

International Nuclear Information System (INIS)

Nowak, J.Z.; Arbilla, S.; Langer, S.Z.; Dahl, S.G.

1990-01-01

Electrically evoked release of dopamine from the caudate nucleus is reduced by the dopamine receptor agonists, apomorphine and bromocriptine, and facilitated by neuroleptic drugs, which act as dopamine autoreceptor antagonists. The potencies of chlorpromazine, fluphenazine, levomepromazine and their hydroxy-metabolites in modulating electrically evoked release of dopamine were examined by superfusion of rabbit caudate nucleus slices pre-incubated with 3 H-dopamine. O-Desmethyl levomepromazine, 3-hydroxy- and 7-hydroxy metabolites of chlorpromazine and levomepromazine facilitated electrically evoked release of 3 H-dopamine, having potencies similar to that of the parent compounds. 7-Hydroxy fluphenazine was less active than fluphenazine in this system. These results indicate that phenolic metabolites of chlorpromazine and levomepromazine, but not of fluphenazine, may contribute to effects of the drugs mediated by presynaptic dopamine receptors

Receptor mapping in psychiatric patients with SPECT

International Nuclear Information System (INIS)

Schlegel, S.

1997-01-01

This paper summarizes some data of our studies with the single-photon-emission-computerized tomography (SPECT), focussing on the dopamine-D2- and the benzodiazepine receptor mapping. Benzodiazepine receptors: Central benzodiazepine receptors (BZr) can be visualized with iomazenil which is an analogue of the benzodiazepine antagonist flumazenil, labeled with 123-iodine. Since the involvement of the BZr system is discussed in the pathogenesis of anxiety and depression, patients with these disorders were investigated. A third study investigated the BZr-occupancy during benzodiazepine treatment (lorazepam). Results: (a) Patients with panic disorders had lower iomazenil uptake values compared to epileptic patients. (b) Depressed patients showed a positive correlation between severity of illness and frontal uptake. (c) BZr occupancy during lorazepam treatment was measurable, but not associated with lorazepam plasma levels. Dopamine-D2-receptors: With 123-I-iodobenzamide (IBZM), and iodine-labeled dopamine receptor ligand, the D2 receptor density can be measured by a semiquantitative approach (striatum/frontal cortex=ST/FC). Therefore, we investigated the D2-receptor occupancy during treatment with typical and atypical neuroleptics in relationship to dosages (normalized with different formulas of chlorpromazine equivalents), side effects, and prolactin plasma levels. Results: Dependent on the selected formula for chlorpromazine equivalents, the ST/FC ratio was correlated with dosages. Side effects and prolactin plasma levels showed a negative association with lower ST/FC ratios. (orig.) [de

Predictors of response to neuroleptic treatment in schizophrenia.

Science.gov (United States)

Stern, R G; Kahn, R S; Davidson, M

1993-06-01

Baseline symptom severity, early reduction in symptom severity, initial subjective response to neuroleptic treatment, the degree of brain atrophy, and early changes in pHVA levels appear to predict treatment outcome in schizophrenic patients. Computerized EEG results, neuropsychological and neurophysiologic tests, and baseline pHVA concentrations require further examination. Only a limited proportion of variance in treatment response, however, could be explained by either of the nine predictors alone or combined. Therefore, further research is necessary to discover yet unidentified determinants of treatment response. Future studies should test the validity and reliability of these five promising predictors in large groups of male and female patients, employ high standards for assessment reliability of clinical parameters, and use absolute rating scores on psychopathology as well as functional scales for the definition of good and poor treatment response. Furthermore, the statistical approach for data analysis should take in consideration the need for appropriate corrections when multiple correlations are performed and should test the extent to which these predictors are interdependent.

Anaesthesia For ECT In Neuroleptic Malignant Syndrome - What Is Ideal?

Directory of Open Access Journals (Sweden)

Priyaneka Baskaran

2017-09-01

Full Text Available We report a case involving a 46 year old male with schizophrenia who presented with fever, inability to speak, sialorrhoea, limb stiffness, profuse sweating, tremors and rigidity of bilateral upper and lower limbs following an increase in dosage of his antipsychotics.  A provisional diagnosis of neuroleptic malignant syndrome (NMS was made based on the Levensen criteria. His anti psychotics were promptly discontinued and he was transferred to ICU for critical care support. We utilised lorazepam and prescribed bromocriptine and his NMS symptoms improved. However, in view of residual catatonic symptoms, decision was made to commence ECT. A combination of rocuronium sugammadex was used successfully in all his ECT procedures and found to be an excellent alternative to succinycholine in this patient.

Differential Expression of Chemokine Receptors and their Roles in Cancer Imaging

Energy Technology Data Exchange (ETDEWEB)

Nimmagadda, Sridhar, E-mail: snimmag1@jhmi.edu [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD (United States)

2012-05-30

Chemokine/chemokine receptor interactions play diverse roles in cell migration and homeostasis. Emerging evidence suggests that cancer cells co-opt chemokine networks for survival, proliferation, immune evasion, and metastasis. Most of the chemokine receptors are reported to be involved in tumor progression. Given their extensive implication in cancer progression, several chemokine receptor/ligand axes are considered as potential therapeutic targets. This review provides a survey of chemokine receptor expression in cancer and evaluates the potential of chemokine receptor imaging as a tool for molecular characterization of cancer.

Differential Expression of Chemokine Receptors and their Roles in Cancer Imaging

International Nuclear Information System (INIS)

Nimmagadda, Sridhar

2012-01-01

Chemokine/chemokine receptor interactions play diverse roles in cell migration and homeostasis. Emerging evidence suggests that cancer cells co-opt chemokine networks for survival, proliferation, immune evasion, and metastasis. Most of the chemokine receptors are reported to be involved in tumor progression. Given their extensive implication in cancer progression, several chemokine receptor/ligand axes are considered as potential therapeutic targets. This review provides a survey of chemokine receptor expression in cancer and evaluates the potential of chemokine receptor imaging as a tool for molecular characterization of cancer.

Development of 99mTc agents for imaging central neural system receptors

International Nuclear Information System (INIS)

2004-01-01

Radiopharmaceuticals that bind to central neural system (CNS) receptors in vivo are potentially useful for understanding the pathophysiology of anumber of neurological and psychiatric disorders, their diagnosis and treatment. Carbon-11 labelled compounds and positron emission tomography(PET) imaging have played a vital role in establishing the usefulness of imaging the dopaminergic, cholinergic, serotonergic and benzodiazapine receptors, and relating the receptor density to disease status. Since the use of 11C agents is constrained due to their 20 min half-life, various radiohalogenated analogues based on the structure of 11C compounds have been successfully developed, providing comparable information. Iodine- 123 is the most widely employed of these radioisotopes; it has a longer, 13 h, half-life. Through the use of 123I, there has been a steady growth in CNS receptor imaging studies employing single photon emission computerized tomography (SPECT). SPECT, as compared with PET, has slightly inferior image resolution but has the advantage of being readily available worldwide. However, the 123I radiopharmaceutical is expensive and the distribution system outside of the major markets is not well developed for its supply on a routine basis. The ideal radioisotope for SPECT imaging is 99mTc, due to its low cost per dose, availability through commercially available generator systems and physical decay characteristics. Over 80% of all diagnostic nuclear medicine imaging studies worldwide are conducted using this radioisotope. Development of 99mTc radiopharmaceuticals for imaging CNS receptors is therefore of considerable importance. On the basis of the recommendations of a consultants meeting, the International Atomic Energy Agency (IAEA) initiated in 1996 a Co-ordinated Research Project (CRP) on Development of Agents for Imaging CNS Receptors based on 99mTc. At that time there were no 99mTc CNS receptor imaging radiopharmaceuticals available even though work on

N-acetylaspartate (NAA) levels in selected areas of the brain in patients with chronic schizophrenia treated with typical and atypical neuroleptics: a proton magnetic resonance spectroscopy (1H MRS) study.

Science.gov (United States)

Szulc, Agata; Galińska, Beata; Tarasów, Eugeniusz; Kubas, Bozena; Dzienis, Wojciech; Konarzewska, Beata; Poplawska, Regina; Tomczak, Anna A; Czernikiewicz, Andrzej; Walecki, Jerzy

2007-05-01

NAA, marker of neurons integrity and viability, is one of the most important brain metabolites visible in 1H MRS. In most studies of schizophrenia, the decrease of NAA level was observed in the temporal, frontal lobes and in the thalamus. This finding was observed more often among chronic patients, what suggests the influence of disease duration or the effect of neuroleptic treatment. The aim of the present study was the comparison of NAA levels in brain of schizophrenic patients taking typical and atypical neuroleptics. We analyzed the NAA levels in selected brain areas in 58 schizophrenic patients and 21 healthy controls. 10 patients were treated with typical neuroleptics, 10 patients with clozapine, 17 received olanzapine and 21 - risperidone. 1H MRS was performed on a 1,5 MR scanner with PRESS sequence. Voxels of 2x2x2 cm were localized in the left frontal, left temporal lobe and left thalamus. There were no differences in NAA levels between patients on typical and atypical medications analyzed together and separately (olanzapine, clozapine and risperidone groups). We also did not find any differences between patients taking selected atypical neuroleptics and controls. The NAA level in the thalamus in the group of patients receiving typical antipsychotics was the lowest among all groups and differed significantly from healthy controls. The results of our study suggest that atypical neuroleptics may have favorable effect on NAA concentration in brain of schizophrenic patients. Decrease in NAA level in patients taking typical medication may be caused by the progression of the disease or by the direct action of these drugs.

Effect of antidepressants and neuroleptics on phosphoinositide turnover in human platelets

Energy Technology Data Exchange (ETDEWEB)

Pandey, S.C.; Davis, J.M.; Schwertz, D.; Pandey, G.N. (Illinois State Psychiatric Inst., Chicago (United States))

1990-02-26

The authors previously reported that tricyclic antidepressants and iprindole inhibit thrombin-stimulated formation of inositol-1, 4 bisphosphate (IP2) and inositol-1,4,5 triphosphate (IP3) but do not cause any change in inositol-1 phosphate (IP1). In order to examine if this decrease in IP2 and IP3 formation by antidepressants is related to the inhibition of the enzyme phospholipase C (PLC), the authors determined the effects of antidepressants and neuroleptics on the levels of 3(H) phosphotidylinositol (PI), 3(H) PI-4 phosphate (PIP), 3(H) PI-4, 5 bisphosphate (PIP2) in human platelets. The implications of the findings and their relevance to the mode of action of antidepressants are discussed.

Rocuronium and sugammadex: An alternative to succinylcholine for electro convulsive therapy in patients with suspected neuroleptic malignant syndrome.

LENUS (Irish Health Repository)

Ramamoorthy, Karthik G

2012-01-31

We report a case of presumptive neuroleptic malignant syndrome requiring muscle relaxation for electro-convulsive therapy. short acting muscle relaxation without the use of succinylcholine was achieved using rocvronivm reversed with the novel reversal agent sugammadex. We suggest that this combination is a safe and effective alternative to succinylcholine in such cases.

Imaging GABAc Receptors with Ligand-Conjugated Quantum Dots

Directory of Open Access Journals (Sweden)

Ian D. Tomlinson

2007-01-01

Full Text Available We report a methodology for labeling the GABAc receptor on the surface membrane of intact cells. This work builds upon our earlier work with serotonin-conjugated quantum dots and our studies with PEGylated quantum dots to reduce nonspecific binding. In the current approach, a PEGylated derivative of muscimol was synthesized and attached via an amide linkage to quantum dots coated in an amphiphilic polymer derivative of a modified polyacrylamide. These conjugates were used to image GABAC receptors heterologously expressed in Xenopus laevis oocytes.

Rocuronium and sugammadex: An alternative to succinylcholine for electro convulsive therapy in patients with suspected neuroleptic malignant syndrome

Directory of Open Access Journals (Sweden)

Karthik G Ramamoorthy

2011-01-01

Full Text Available We report a case of presumptive neuroleptic malignant syndrome requiring muscle relaxation for electro-convulsive therapy. short acting muscle relaxation without the use of succinylcholine was achieved using rocvronivm reversed with the novel reversal agent sugammadex. We suggest that this combination is a safe and effective alternative to succinylcholine in such cases.

Synthesis of opioid receptor imaging agent 7α-o-IA-DPN

International Nuclear Information System (INIS)

Wang Rongfu

1997-01-01

A new opioid receptor imaging agent is designed and synthesized. 7α-o-iodoallyl diprenorphine (7α-o-IA-DPN) was obtained in one step by radioiododestannylation, which involved in the selection of DPN as an opioid antagonist, the regioselective protection of the DPN phenol tertiary-OH using acetylation and the introduction of vinylstannane as prosthetic group into the tertiary alcohol group position in the 7α-side chain. The iodinated DPN derivation was possessed of high radiolabeled yield (>90%) with 80 TBq/mmol specific radioactivity and more than 95% radiochemical purity. In vitro opioid receptor binding analysis showed very high affinity (Ki = 0.4 nmol/L). This new radioiodinated opioid ligand is suitable for SPECT study of opioid receptor imaging

Clinical value of somatostatin receptor imaging in patients with suspected head and neck paragangliomas

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Matthias; Dietlein, Markus; Weber, Kerstin; Moka, Detlef; Schicha, Harald [Klinik und Poliklinik fuer Nuklearmedizin, Universitaet zu Koeln, Joseph-Stelzmann-Strasse 9, 50924 Koeln (Germany); Fischer, Eva; Michel, Olaf; Stennert, Eberhard [Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenheilkunde, Universitaet zu Koeln, Koeln (Germany)

2002-12-01

Paragangliomas or glomus tumours of the head and neck region are rare somatostatin receptor-expressing neuroendocrine tumours. Precise preoperative diagnosis is of special importance in order to adequately weigh the potential benefit of the operation against the inherent risks of the procedure. In this study, the clinical value of somatostatin receptor imaging was assessed in 19 patients who underwent somatostatin receptor scintigraphy because of known or suspected paraganglioma of the head and neck region. The results were compared with the results of computed tomography and/or magnetic resonance imaging, histology and clinical follow-up. [{sup 111}In-DTPA-D-Phe{sup 1}]-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 140-220 MBq {sup 111}In-octreotide. Whole-body and planar images as well as single-photon emission tomography images were acquired and lesions were graded according to qualitative tracer uptake. Somatostatin receptor imaging was positive in nine patients, identifying paragangliomas for the first time in three patients and recurrent disease in six patients. In one patient, a second, previously unknown paraganglioma site was identified. Negative results were obtained in ten patients. These patients included one suffering from chronic hyperplastic otitis externa, one with granuloma tissue and an organised haematoma, one with an acoustic neuroma, one with an asymmetric internal carotid artery, two with ectasia of the bulbus venae jugularis and one with a jugular vein thrombosis. In two patients with a strong family history of paraganglioma, individual involvement could be excluded. In only one patient did somatostatin receptor imaging and magnetic resonance imaging yield false negative results in respect of recurrent paraganglioma tissue. It is concluded that somatostatin receptor scintigraphy provides important information in patients with suspected paragangliomas of the head and neck region and has a strong impact on further

Positron emission tomography with ( sup 18 F)methylspiperone demonstrates D sub 2 dopamine receptor binding differences of clozapine and haloperidol

Energy Technology Data Exchange (ETDEWEB)

Karbe, H; Wienhard, K; Huber, M; Herholz, K; Heiss, W D [Klinik fuer Neurologie, Univ. of Koeln, Koeln (Germany); Hamacher, K; Coenen, H H; Stoecklin, G [Inst. fuer Chemie 1, Forschungszentrum Juelich Gmbh (Germany); Loevenich, A [Klinik fuer Psychiatrie, Univ. of Koeln, Koeln (Germany)

1991-01-01

Four schizophrenic patients were investigated with dynamic positron emission tomography (PET) using ({sup 18}F)fluorodeoxyglucose (FDG) and ({sup 18}F)methylspiperone (MSP) as tracers. Two schizophrenics were on haloperidol therapy at the time of MSP PET. The other two schizophrenics were treated with clozapine, in one of them MSP PET was carried out twice with different daily doses (100 mg and 450mg respectively). Neuroleptic serum levels were measured in all patients. Results were compared with MSP PET of two drugfree male control subjects and with a previous fluoroethylspiperone (FESP) study of normals. Three hours after tracer injection specific binding of MSP was observed in the striatum in all cases. The striatum to cerebellum ratio was used to estimate the degree of neuroleptic-caused striatal D{sub 2} dopamine receptor occupancy. In the haloperidol treated patients MSP binding was significantly decreased, whereas in the clozapine treated patients striatum to cerebellum ratio was normal. Even the increase of clozapine dose in the same patient had no influence on this ratio. Despite the smaller number of patients the study shows for the first time in humans that striatal MSP binding reflects the different D{sub 2} dopamine receptor affinities of clozapine and haloperidol. (authors).

Quantitative Impact of Plasma Clearance and Down-regulation on GLP-1 Receptor Molecular Imaging.

Science.gov (United States)

Zhang, Liang; Thurber, Greg M

2016-02-01

Quantitative molecular imaging of beta cell mass (BCM) would enable early detection and treatment monitoring of type 1 diabetes. The glucagon-like peptide-1 (GLP-1) receptor is an attractive target due to its beta cell specificity and cell surface location. We quantitatively investigated the impact of plasma clearance and receptor internalization on targeting efficiency in healthy B6 mice. Four exenatide-based probes were synthesized that varied in molecular weight, binding affinity, and plasma clearance. The GLP-1 receptor internalization rate and in vivo receptor expression were quantified. Receptor internalization (54,000 receptors/cell in vivo) decreased significantly within minutes, reducing the benefit of a slower-clearing agent. The multimers and albumin binding probes had higher kidney and liver uptake, respectively. Slow plasma clearance is beneficial for GLP-1 receptor peptide therapeutics. However, for exendin-based imaging of islets, down-regulation of the GLP-1 receptor and non-specific background uptake result in a higher target-to-background ratio for fast-clearing agents.

Evaluation of radioiodinated vesamicol analogs for sigma receptor imaging in tumor and radionuclide receptor therapy.

Science.gov (United States)

Ogawa, Kazuma; Shiba, Kazuhiro; Akhter, Nasima; Yoshimoto, Mitsuyoshi; Washiyama, Kohshin; Kinuya, Seigo; Kawai, Keiichi; Mori, Hirofumi

2009-11-01

It has been reported that sigma receptors are highly expressed in a variety of human tumors. In this study, we selected (+)-2-[4-(4-iodophenyl)piperidino] cyclohexanol [(+)-pIV] as a sigma receptor ligand and evaluated the potential of radioiodinated (+)-pIV for tumor imaging and therapy. (+)-[(125/131)I]pIV was prepared by an iododestannylation reaction under no-carrier-added conditions with radiochemical purity over 99% after HPLC purification. Biodistribution experiments were performed by the intravenous injection of (+)-[(125)I]pIV into mice bearing human prostate tumors (DU-145). Blocking studies were performed by intravenous injection of (+)-[(125)I]pIV mixed with an excess amount of unlabeled sigma ligand into DU-145 tumor-bearing mice. For therapeutic study, (+)-[(131)I]pIV was injected at a dose of 7.4 MBq followed by measurement of the tumor size. In biodistribution experiments, (+)-[(125)I]pIV showed high uptake and long residence in the tumor. High tumor to blood and muscle ratios were achieved because the radioactivity levels of blood and muscle were low. However, the accumulations of radioactivity in non-target tissues, such as liver and kidney, were high. The radioactivity in the non-target tissues slowly decreased over time. Co-injection of (+)-[(125)I]pIV with an excess amount of unlabeled sigma ligand resulted in a significant decrease in the tumor/blood ratio, indicating sigma receptor-mediated tumor uptake. In therapeutic study, tumor growth in mice treated with (+)-[(131)I]pIV was significantly inhibited compared to that of an untreated group. These results indicate that radioiodinated (+)-pIV has a high potential for sigma receptor imaging in tumor and radionuclide receptor therapy.

PET imaging of adenosine A2A receptors

NARCIS (Netherlands)

Zhou, Xiaoyun

2017-01-01

This thesis describes the development and evaluation of [11C]preladenant as a novel radioligand for in vivo imaging of adenosine A2A receptors in the brain with positron-emission tomography (PET). The 11C-labeled drug [11C]preladenant was produced with high radiochemical yield and specific activity.

Dopamine D/sub 2/ and D/sub 1/ receptors: biochemical characterization

Energy Technology Data Exchange (ETDEWEB)

Niznik, H B

1986-01-01

In order to label dopamine D/sub 2/ receptors reversibly and selectively the potent substituted benzamide neuroleptic, YM-09151-2, was tritium labeled and its binding characteristics to striatal homogenates investigated. (/sup 3/H) YM-09151-2 bound to D/sub 2/ receptors with high affinity in a specific, saturable, reversible and sodium dependent fashion, displaying an appropriate pharmacological D/sub 2/ receptor profile. (/sup 3/H) YM-09151-2 appears to be the ligand of choice for labeling D/sub 2/ receptors since it displays approximately 20-fold lower affinity for serotonergic S/sub 2/ receptors than does (/sup 3/H) spiperone. As an initial step towards the molecular identification of the ligand binding subunit of the striatal D/sub 2/ receptor, photolabile analogues of the substituted benzamide clebopride were synthesized and their reversible and irreversible binding interactions to D/sub 2/ receptors characterized. D/sub 2/ receptor photoinactivation was prevented in a concentration and stereoselective manner by dopaminergic agonists and antagonists. In vivo biodistribution studies with (/sup 125/I) iodoazidoclebopride confirmed the ligand's ability to bind to D/sub 2/ receptor-rich regions and as such, may become a useful tool for the molecular characterization of D/sub 2/ receptor proteins. Digitonin solubilized striatal dopamine D/sub 2/ and D/sub 1/ receptors can be completely separated with full retention of biological activity by steric exclusion High Pressure Liquid Chromatography (HPLC) with corresponding Stokes radii of 7.1 and 5.6 nm.

Imaging dopamine and opiate receptors in the human brain in health and disease

International Nuclear Information System (INIS)

Wagner, H.N. Jr.; Dannals, R.F.; Frost, J.J.

1986-01-01

Chemical activity accompanies mental activity, but only recently has it been possible to begin to examine its nature. In 1983 the first imaging of a neuroreceptor in the human brain was accomplished with carbon-11 methyl spipeone, a ligand that binds preferentially to dopamine-2 receptors, 80% of which are located in the caudate nucleus and putamen. Quantitative imaging of serotonin-2, opiate, benzodiazapine and muscarinic cholinergic receptors has subsequently been accomplished. In studies of normal men and women, it has been found that dopamine and serotonin receptor activity decreases dramatically with age, such a decrease being more pronounced in men than in women and greater in the case of dopamine receptors than serotonin-2 receptors. Preliminary studies in patients with neuropsychiatric disorders suggests that dopamine-2 receptor activity is diminished in the caudate nucleus of patients with Huntington's disease. Positron tomography permits quantitative assay of picomolar quantities of neuroreceptors within the living human brain. Studies of patients with Parkinson's disease, Alzheimer's disease, depression, anxiety, schizophrenia, acute and chronic pain states and drug addiction are now in progress

In vivo assessment of dopamine D-2 and serotonin S-2 receptors measured by C-11 N-methylspiperone (NMSP) in manic-depressive illness

International Nuclear Information System (INIS)

Wong, D.F.; Pearlson, G.; Wagner, H.N. Jr.

1985-01-01

The hypothesis has been suggested that either the dopaminergic or serotonergic neurotransmitter systems may be involved in manic-depressive illness (MD). The authors have studied 16 subjects with C-11 NMSP PET imaging. Two had never received neuroleptics; 4 were drug free for 1 month at the time of scanning; of these 3 were acutely manic; the rest were on stable lithium treatment. The dopamine and serotonin binding was estimated by the 43 min. caudate/cerebellum (Ca/Cb) and frontal/cerebellum (FC/Cb) ratios, respectively. No statistically significant difference was detected when compared to 44 age and sex matched controls. Based upon the variance in the normal data and the average age of the patient group studied, the probability of detecting a difference of >30% between patients and normals is >0.8. Hence, identification of receptor abnormalities if present will be improved with increased sample size of both normals and patients

Nicotinic α4β2 receptor imaging agents

International Nuclear Information System (INIS)

Pichika, Rama; Easwaramoorthy, Balasubramaniam; Collins, Daphne; Christian, Bradley T.; Shi, Bingzhi; Narayanan, Tanjore K.; Potkin, Steven G.; Mukherjee, Jogeshwar

2006-01-01

The α4β2 nicotinic acetylcholine receptor (nAChR) has been implicated in various neurodegenerative diseases. Optimal positron emission tomography (PET) imaging agents are therefore highly desired for this receptor. We report here the development and initial evaluation of 2-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine (nifene). In vitro binding affinity of nifene in rat brain homogenate using 3 H-cytisine exhibited a K i =0.50 nM for the α4β2 sites. The radiosynthesis of 2- 18 F-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine ( 18 F-nifene) was accomplished in 2.5 h with an overall radiochemical yield of 40-50%, decay corrected. The specific activity was estimated to be approx. 37-185 GBq/μmol. In vitro autoradiography in rat brain slices indicated selective binding of 18 F-nifene to anteroventral thalamic (AVT) nucleus, thalamus, subiculum, striata, cortex and other regions consistent with α4β2 receptor distribution. Rat cerebellum showed some binding, whereas regions in the hippocampus had the lowest binding. The highest ratio of >13 between AVT and cerebellum was measured for 18 F-nifene in rat brain slices. The specific binding was reduced (>95%) by 300 μM nicotine in these brain regions. Positron emission tomography imaging study of 18 F-nifene (130 MBq) in anesthetized rhesus monkey was carried out using an ECAT EXACT HR+ scanner. PET study showed selective maximal uptake in the regions of the anterior medial thalamus, ventro-lateral thalamus, lateral geniculate, cingulate gyrus, temporal cortex including the subiculum. The cerebellum in the monkeys showed lower binding than the other regions. Thalamus-to-cerebellum ratio peaked at 30-35 min postinjection to a value of 2.2 and subsequently reduced. The faster binding profile of 18 F-nifene indicates promise as a PET imaging agent and thus needs further evaluation

The rapid synthesis of high purity [{sup 18}F]butyrophenone neuroleptics from nitro precursors for PET study

Energy Technology Data Exchange (ETDEWEB)

Hashizume, Kazunari; Hashimoto, Naoto; Kato, Hiroo; Cork, D G; Miyake, Yoshihiro [National Cardiovascular Center, Suita, Osaka (Japan)

1995-04-01

We have completed rapid syntheses of [{sup 18}F]butyrophenone neuroleptics ([{sup 18}F]haloperidol and [{sup 18}F]spiperone) from their nitro precursors in high radiochemical yields (up to 21%) by combining a one-step nitro-fluoro exchange reaction and a novel high performance liquid chromatography (HPLC) separation method. The synthesis time was ca. 95 min and both the radiochemical and chemical purities of the labeled products were over 99%. (author).

Stimulation of (3H) spiroperidol binding after prolonged neuroleptic therapy by the cholecystokinin octapeptide analog cerulein

International Nuclear Information System (INIS)

Vasar, E.E.; Allikmets, L.K.; Maimets, O.O.; Nurk, A.M.

1985-01-01

Evidence has recently been obtained that cholecystokinin and its analog cerulein have marked antipsychotic action on patients with schizophrenia who are resistant to neuroleptics; this is the basis for interest in this study of the effect of cerulein, a high-affinity analog of the octapeptide cholecystokinin, on binding of tritium-spiroperidol in vivo. Considering the apormorphine-like action of cerulein, this biochemical analysis was undertaken in the form of a comparative study with N-propyl-norapomorphine, a high-affinity analogy of apomorphine

Advances in technetium chemistry towards 99mTc receptor imaging agents

International Nuclear Information System (INIS)

Johannsen, B.; Spies, H.

1997-01-01

The development of the chemistry of technetium and its non-radioactive surrogate rhenium has been prompted by the trends and needs of nuclear medicine, which predominantly uses 99m Tc radiopharmaceuticals for a broad range of diagnostics. Technetium-99m is the ideal radioisotope for tomographic single-photon emission tomography (SPECT) imaging due to its nuclear properties (6.2 h, E γ 140 keV) and ready availability through generator systems. Transition metals offer many opportunities for designing molecules by modifying the environment around the core, allowing certain biological properties to be imposed upon the molecule. Whereas research in the past was mainly concerned with biological properties that allow relatively unspecific functional imaging, as in brain or myocardium perfusion studies, nuclear medicine is now requiring more and more biochemical information on low capacity, high specificity targets. Many research groups have become involved in the search for new technetium-based compounds, called the third generation of 99m Tc radiopharmaceuticals, that employ the principles of modern pharmacology to achieve biochemical specificity. There has been considerable interest in imaging CNS and other receptors with 99m Tc receptor-binding ligands. Such a 99m Tc CNS receptor-imaging agent is currently not yet in use because of the significant hurdles to be overcome in attaining this ambitious goal. However, some Tc and Re complexes of remarkable affinity in vitro, and the first high-affinity 99m Tc probes able to label the dopamine transporter in the brain by SPECT imaging prove the feasibility of this approach. (Author)

Making Sense of the 'Chemical Revolution'. Patients' Voices on the Introduction of Neuroleptics in the 1950s.

Science.gov (United States)

Majerus, Benoît

2016-01-01

The so-called chemical revolution has produced a vast historiographical corpus. Yet the patient's voice remains surprisingly absent from these stories. Based on the archives of the Institut de Psychiatrie (Brussels), this paper traces the introduction of Largactil as recounted in patient letters, physician records and nurse notes. The paper thus contributes to the history of therapies from below, but also participates in the historiographical debate about whether the introduction of neuroleptics can indeed be considered a revolution.

Differences in the time course of haloperidol-induced up-regulation of rat striatal and mesolimbic dopamine receptors

International Nuclear Information System (INIS)

Prosser, E.S.; Csernansky, J.G.; Hollister, L.E.

1988-01-01

Regional differences in the onset and persistence of increased dopamine D2 receptor density in rat brain were studied following daily injections of haloperidol for 3, 7, 14, or 28 days. Striatal [ 3 H]-spiroperidol Bmax values were significantly increased following 3 - 28 days of haloperidol treatment, as compared to saline controls. Olfactory tubercle Bmax values were significantly increased only after 14 or 28 days of haloperidol treatment. Nucleus accumbens Bmax values were significantly increased only in the 14-day drug treatment group, suggesting that dopamine D2 receptor up-regulation in nucleus accumbens may reverse during ongoing neuroleptic treatment. These findings suggest that important differences in adaptive responses to chronic dopamine blockade may exist between dopaminergic synapses located in various rat brain regions

Analysis of PETT images in psychiatric disorders

Energy Technology Data Exchange (ETDEWEB)

Brodie, J.D.; Gomez-Mont, F.; Volkow, N.D.; Corona, J.F.; Wolf, A.P.; Wolkin, A.; Russell, J.A.G.; Christman, D.; Jaeger, J.

1983-01-01

A quantitative method is presented for studying the pattern of metabolic activity in a set of Positron Emission Transaxial Tomography (PETT) images. Using complex Fourier coefficients as a feature vector for each image, cluster, principal components, and discriminant function analyses are used to empirically describe metabolic differences between control subjects and patients with DSM III diagnosis for schizophrenia or endogenous depression. We also present data on the effects of neuroleptic treatment on the local cerebral metabolic rate of glucose utilization (LCMRGI) in a group of chronic schizophrenics using the region of interest approach. 15 references, 4 figures, 3 tables.

Analysis of PETT images in psychiatric disorders

International Nuclear Information System (INIS)

Brodie, J.D.; Gomez-Mont, F.; Volkow, N.D.; Corona, J.F.; Wolf, A.P.; Wolkin, A.; Russell, J.A.G.; Christman, D.; Jaeger, J.

1983-01-01

A quantitative method is presented for studying the pattern of metabolic activity in a set of Positron Emission Transaxial Tomography (PETT) images. Using complex Fourier coefficients as a feature vector for each image, cluster, principal components, and discriminant function analyses are used to empirically describe metabolic differences between control subjects and patients with DSM III diagnosis for schizophrenia or endogenous depression. We also present data on the effects of neuroleptic treatment on the local cerebral metabolic rate of glucose utilization (LCMRGI) in a group of chronic schizophrenics using the region of interest approach. 15 references, 4 figures, 3 tables

Pet imaging of human pituitary 5-HT2 receptors with F-18 setoperone

Energy Technology Data Exchange (ETDEWEB)

Fischman, A.J.; Bonab, A.A.; Babich, J.W. [Massachusetts General Hospital, Boston, MA (United States)] [and others

1995-05-01

Serotonin (5-HT) receptors play an important role in the regulation of pituitary function. In particular, 5HT agonists stimulate ACTH, {beta}-endorphin, prolactin and growth hormone secretion but inhibit TSH release. 5-HT binding sites have been identified by autoradiographic studies of rat and human pituitary. In the present investigation, we used PET with F-18 setoperone to image 5-HT2 receptors in normal humans. Setoperone, a piperidine derivative with potent 5-HT2 receptor blocking properties was labelled with F-18 by nucleophilic substitution on the nitro derivative. After HPLC purification, specific activity was between 10,000 and 15,000 mCi/{mu} mole and radiochemical purity was >98%. Six healthy male volunteers were injected with 5-7 mCi of F-18. Setoperone and serial PET images and arterial blood samples were collected over 2 hrs. Specific binding to 5-HT2 receptors in the frontal cortex (FC), striatum (ST) and pituitary (P) was quantitated using the cerebellum (C) as reference. The tracer showed clear retention in FC, ST and P (known to contain a high density of 5-HT2 receptors) relative to C (known to be devoid of 5-HT2 receptors). In all subjects, FC/C, ST/C and P/C ratios increased during the first hr. and remained stable thereafter. For FC and ST, the ratios reached similar values; 3.92{plus_minus}0.73 and 3.53{plus_minus}0.32. For pituitary, a significantly higher ratio, was measured at all times; 6.53{plus_minus}1.82 (p<0.01). These results indicate that F-18 setoperone is an effective PET radiopharmaceutical for imaging 5-HT2 receptors in the human pituitary. Future applications of this agent could provide important new insights into neuroendocrine function.

Positron emission tomography imaging studies of dopamine receptors in primate models of addiction

OpenAIRE

Nader, Michael A; Czoty, Paul W; Gould, Robert W; Riddick, Natallia V

2008-01-01

Animal models have provided valuable information related to trait and state variables associated with vulnerability to drug addiction. Our brain imaging studies in monkeys have implicated D2 receptors in cocaine addiction. For example, an inverse relationship between D2 receptor availability and rates of cocaine self-administration has been documented. Moreover, environmental variables, such as those associated with formation of the social hierarchy, can impact receptor availability and sensi...

Islet-selectivity of G-protein coupled receptor ligands evaluated for PET imaging of pancreatic {beta}-cell mass

Energy Technology Data Exchange (ETDEWEB)

Cline, Gary W., E-mail: gary.cline@yale.edu [Yale University School of Medicine (United States); Zhao, Xiaojian [Yale University School of Medicine (United States); Jakowski, Amy B.; Soeller, Walter C.; Treadway, Judith L. [Pfizer Global Research and Development, Pfizer Inc., Groton CT (United States)

2011-09-02

Highlights: {yields} We screened G-protein coupled receptors for imaging pancreatic. {yields} Database mining and immunohistochemistry identified GPCRs enriched in {beta}-cells. {yields} In vitro and in vivo assays were used to determine exocrine vs endocrine specificity. {yields} GPCR candidates for imaging of {beta}-cell mass are Prokineticin-1R, mGluR5, and GLP-1R. -- Abstract: A critical unmet need exists for methods to quantitatively measure endogenous pancreatic {beta}-cell mass (BCM) for the clinical evaluation of therapies to prevent or reverse loss of BCM and diabetes progression. Our objective was to identify G-protein coupled receptors (GPCRs) that are expressed with a high degree of specificity to islet {beta}-cells for receptor-targeted imaging of BCM. GPCRs enriched in pancreatic islets relative to pancreas acinar and hepatic tissue were identified using a database screen. Islet-specific expression was confirmed by human pancreas immunohistochemistry (IHC). In vitro selectivity assessment was determined from the binding and uptake of radiolabeled ligands to the rat insulinoma INS-1 832/13 cell line and isolated rat islets relative to the exocrine pancreas cell-type, PANC-1. Tail-vein injections of radioligands into rats were used to determine favorable image criteria of in vivo biodistribution to the pancreas relative to other internal organs (i.e., liver, spleen, stomach, and lungs). Database and IHC screening identified four candidate receptors for further in vitro and in vivo evaluation for PET imaging of BCM: prokineticin-1 receptor (PK-1R), metabotropic glutamate receptor type-5 (mGluR5), neuropeptide Y-2 receptor (NPY-2R), and glucagon-like peptide 1 receptor (GLP-1R). In vitro specificity ratios gave the following receptor rank order: PK-1R > GLP-1R > NPY-2R > mGluR5. The biodistribution rank order of selectivity to the pancreas was found to be PK-1R > VMAT2 {approx} GLP-1R > mGluR5. Favorable islet selectivity and biodistribution

Islet-selectivity of G-protein coupled receptor ligands evaluated for PET imaging of pancreatic β-cell mass

International Nuclear Information System (INIS)

Cline, Gary W.; Zhao, Xiaojian; Jakowski, Amy B.; Soeller, Walter C.; Treadway, Judith L.

2011-01-01

Highlights: → We screened G-protein coupled receptors for imaging pancreatic. → Database mining and immunohistochemistry identified GPCRs enriched in β-cells. → In vitro and in vivo assays were used to determine exocrine vs endocrine specificity. → GPCR candidates for imaging of β-cell mass are Prokineticin-1R, mGluR5, and GLP-1R. -- Abstract: A critical unmet need exists for methods to quantitatively measure endogenous pancreatic β-cell mass (BCM) for the clinical evaluation of therapies to prevent or reverse loss of BCM and diabetes progression. Our objective was to identify G-protein coupled receptors (GPCRs) that are expressed with a high degree of specificity to islet β-cells for receptor-targeted imaging of BCM. GPCRs enriched in pancreatic islets relative to pancreas acinar and hepatic tissue were identified using a database screen. Islet-specific expression was confirmed by human pancreas immunohistochemistry (IHC). In vitro selectivity assessment was determined from the binding and uptake of radiolabeled ligands to the rat insulinoma INS-1 832/13 cell line and isolated rat islets relative to the exocrine pancreas cell-type, PANC-1. Tail-vein injections of radioligands into rats were used to determine favorable image criteria of in vivo biodistribution to the pancreas relative to other internal organs (i.e., liver, spleen, stomach, and lungs). Database and IHC screening identified four candidate receptors for further in vitro and in vivo evaluation for PET imaging of BCM: prokineticin-1 receptor (PK-1R), metabotropic glutamate receptor type-5 (mGluR5), neuropeptide Y-2 receptor (NPY-2R), and glucagon-like peptide 1 receptor (GLP-1R). In vitro specificity ratios gave the following receptor rank order: PK-1R > GLP-1R > NPY-2R > mGluR5. The biodistribution rank order of selectivity to the pancreas was found to be PK-1R > VMAT2 ∼ GLP-1R > mGluR5. Favorable islet selectivity and biodistribution characteristics suggest several GPCRs as potential

Study on folate receptor PET imaging agent 18F-flurophenethyl folate

International Nuclear Information System (INIS)

Guo Congying; Zhu Jianhua; Qian Jun; Yang Yang; Shen Haixing; Zhang Zhengwei

2009-01-01

This work is aimed at synthesizing an 18 F-labelled folate derivative that can be used as folate-receptor induced tumor PET imaging agent. Under the optimal reaction and testing specification formulated during the cold-labeling experiments, 18 F labeling of folic acid was achieved in three steps of 18 F pre-labeling,bromination and esterification. The receptor binding property of the newly-synthesized folate radio-derivative was studied through β-lactoglobulin binding test. Tumor-bearing nude mice injected with the new compound were used to study whether the derivative can accumulate within tumor issue. Preliminary studies in vitro and in vivo showed that this new PET agent still possessed receptor binding qualities of folic acid. 18 F-flurophenethyl folate remained good affinity and specificity with β-lactoglobulin. Accumulation of activities in tumor tissues was found in tumor-bearing nude mice. A new folate receptor ligand: 18 F-flurophenethyl folate was synthesized,with high yield and good stability. Since the pre-labeling method was used, the fluorine labeling was not directly imposed upon folic acid.In this way, the structure destruction, which happens in high temperature reaction of folic acid, can be avoided. The synthesized folate derivative remained the binding structural quality of folic acid and could bind with the folate-binding protein: β-lactoglobulin. Through the folate receptors located on tumor tissues, 18 F-flurophenethyl folate accumulated in the tumor tissue, exhibiting its potential as a tumor PET imaging agent. (authors)

Somatostatin receptor imaging in intracranial tumours

International Nuclear Information System (INIS)

Schmidt, M.; Scheidhauer, K.; Voth, E.; Schicha, H.; Luyken, C.; Hildebrandt, G.; Klug, N.

1998-01-01

The somatostatin analogue [ 111 In-DTPA-d-Phe 1 ]-octreotide ( 111 In-octreotide) allows scintigraphic visualization of somatostatin receptor-expressing tissue. While it is well known that a large variety of tissues express somatostatin receptors and 111 In-octreotide scintigraphy has a clearly defined role in various neuroendocrine diseases, the clinical value of 111 In-octreotide scintigraphy in brain tumours is still under clinical investigation. In 124 patients with 141 brain lesions (63 meningiomas, 24 pituitary adenomas, 10 gliomas WHO class I and II, 12 gliomas WHO class III and IV, 11 neurinomas and 2 neurofibromas, 7 metastases and 12 other varieties: three non-Hodgkin B-cell lymphomas, two epidermoids, one abscess, one angioleiomyoma, one chordoma, one haemangiopericytoma, one osteosarcoma, one plasmacytoma and one pseudocyst), 111 In-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 110-220 MBq 111 In-octreotide. Planar images of the head in four views with a 128 x 128 matrix and single-photon emission tomographic images (64 x 64 matrix) were acquired, and lesions were graded according to qualitative tracer uptake. Fifty-nine of the 63 meningiomas showed moderate to intense tracer uptake. Nine of 24 pituitary adenomas were visible; the remaining 15 did not show any tracer uptake. None of the class I and II gliomas with an intact blood-brain barrier were detected whereas 11/12 class III and IV gliomas showed 111 In-octreotide uptake. None of the neurinomas or neurofibromas were positive. Five of seven metastases were classified as positive, as were the osteosarcoma, two of three non-Hodgkin B-cell lymphomas, one abscess, one angioleiomyoma, one chordoma and one haemangiopericytoma. The other varieties (one non-Hodgkin B-cell lymphoma, two epidermoids, one plasmacytoma and one pseudocyst) did not show 111 In-octreotide uptake. The results demonstrate that a large variety of intracranial lesions express somatostatin receptors and

Somatostatin receptor imaging in intracranial tumours

Energy Technology Data Exchange (ETDEWEB)

Schmidt, M.; Scheidhauer, K.; Voth, E.; Schicha, H. [Department of Nuclear Medicine, University of Koeln (Germany); Luyken, C.; Hildebrandt, G.; Klug, N. [Department of Neurosurgery, University of Kolen (Germany)

1998-07-01

The somatostatin analogue [{sup 111}In-DTPA-d-Phe{sup 1}]-octreotide ({sup 111}In-octreotide) allows scintigraphic visualization of somatostatin receptor-expressing tissue. While it is well known that a large variety of tissues express somatostatin receptors and {sup 111}In-octreotide scintigraphy has a clearly defined role in various neuroendocrine diseases, the clinical value of {sup 111}In-octreotide scintigraphy in brain tumours is still under clinical investigation. In 124 patients with 141 brain lesions (63 meningiomas, 24 pituitary adenomas, 10 gliomas WHO class I and II, 12 gliomas WHO class III and IV, 11 neurinomas and 2 neurofibromas, 7 metastases and 12 other varieties: three non-Hodgkin B-cell lymphomas, two epidermoids, one abscess, one angioleiomyoma, one chordoma, one haemangiopericytoma, one osteosarcoma, one plasmacytoma and one pseudocyst), {sup 111}In-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 110-220 MBq {sup 111}In-octreotide. Planar images of the head in four views with a 128 x 128 matrix and single-photon emission tomographic images (64 x 64 matrix) were acquired, and lesions were graded according to qualitative tracer uptake. Fifty-nine of the 63 meningiomas showed moderate to intense tracer uptake. Nine of 24 pituitary adenomas were visible; the remaining 15 did not show any tracer uptake. None of the class I and II gliomas with an intact blood-brain barrier were detected whereas 11/12 class III and IV gliomas showed {sup 111}In-octreotide uptake. None of the neurinomas or neurofibromas were positive. Five of seven metastases were classified as positive, as were the osteosarcoma, two of three non-Hodgkin B-cell lymphomas, one abscess, one angioleiomyoma, one chordoma and one haemangiopericytoma. The other varieties (one non-Hodgkin B-cell lymphoma, two epidermoids, one plasmacytoma and one pseudocyst) did not show {sup 111}In-octreotide uptake. The results demonstrate that a large variety of intracranial

Nicotinic {alpha}4{beta}2 receptor imaging agents

Energy Technology Data Exchange (ETDEWEB)

Pichika, Rama [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Easwaramoorthy, Balasubramaniam [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Collins, Daphne [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Christian, Bradley T. [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Shi, Bingzhi [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Narayanan, Tanjore K. [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Potkin, Steven G. [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Mukherjee, Jogeshwar [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States)]. E-mail: j.mukherjee@uci.edu

2006-04-15

The {alpha}4{beta}2 nicotinic acetylcholine receptor (nAChR) has been implicated in various neurodegenerative diseases. Optimal positron emission tomography (PET) imaging agents are therefore highly desired for this receptor. We report here the development and initial evaluation of 2-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine (nifene). In vitro binding affinity of nifene in rat brain homogenate using {sup 3}H-cytisine exhibited a K {sub i}=0.50 nM for the {alpha}4{beta}2 sites. The radiosynthesis of 2-{sup 18}F-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine ({sup 18}F-nifene) was accomplished in 2.5 h with an overall radiochemical yield of 40-50%, decay corrected. The specific activity was estimated to be approx. 37-185 GBq/{mu}mol. In vitro autoradiography in rat brain slices indicated selective binding of {sup 18}F-nifene to anteroventral thalamic (AVT) nucleus, thalamus, subiculum, striata, cortex and other regions consistent with {alpha}4{beta}2 receptor distribution. Rat cerebellum showed some binding, whereas regions in the hippocampus had the lowest binding. The highest ratio of >13 between AVT and cerebellum was measured for {sup 18}F-nifene in rat brain slices. The specific binding was reduced (>95%) by 300 {mu}M nicotine in these brain regions. Positron emission tomography imaging study of {sup 18}F-nifene (130 MBq) in anesthetized rhesus monkey was carried out using an ECAT EXACT HR+ scanner. PET study showed selective maximal uptake in the regions of the anterior medial thalamus, ventro-lateral thalamus, lateral geniculate, cingulate gyrus, temporal cortex including the subiculum. The cerebellum in the monkeys showed lower binding than the other regions. Thalamus-to-cerebellum ratio peaked at 30-35 min postinjection to a value of 2.2 and subsequently reduced. The faster binding profile of {sup 18}F-nifene indicates promise as a PET imaging agent and thus needs further evaluation.

Imaging opiate receptors with positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Frost, J.J.; Dannals, R.F.; Ravert, H.T.; Wilson, A.A.; Wong, D.F.; Links, J.M.; Burns, H.D.; Kuhar, M.J.; Snyder, S.H.; Wagner, H.N. Jr.

1984-01-01

Opiate receptors exist in the mammalian brain and are thought to meditate the diverse pharmacological actions of the opiates, such as analgesia, euphoria, and sedation. The 4-carbomethoxyl derivatives of fentanyl, such as lofentanil and R31833 (4-carbomethoxyfentanyl) bind to the opiate receptor with high affinity. C-11 R31833 was synthesized by reacting C-11 methyl iodide with the appropriate carboxylate. Male ICR mice were injected intravenously with C-11 R31833 (5..mu..g/kg), killed 30 minutes later, and the brains rapidly dissected. The thalami, striata, and cerebral cortex are rich in opiate receptors, but the cerebellum contains a very low concentration of opiate receptors. The thalamus/cerebellum and striatum/cerebellum activity ratios, calculated per mg of wet tissue, were 4.1 and 5.2 respectively. Coinjection of 5mg/kg naloxone reduced the ratios to 1.1, which indicates that the preferential localization of C-11 R31833 in the thalami and striata is due to binding to opiate is due to binding to opiate receptors. A 22 kg anesthetized male baboon was imaged using the NeuroECAT after injection of 18.9 mCi of C-11 R13833 (0.50 ..mu..g/kg, specific activity 616 Ci/mmole at time of injection). From 15-70 minutes after injection preferential accumulation of activity could be seen in the thalami, caudate nuclei, and cerebral cortex and, conversely, low activity was demonstrated in the cerebellum. At one hour postinjection the maximum measured caudate/cerebellum activity ratio per pixel was 2.9. For the NeuroECAT the recovery coefficient for the baboon caudate is ca. 0.2-0.3, and therefore the actual caudate/cerebellum ratio is ca. 10-15.

Imaging opiate receptors with positron emission tomography

International Nuclear Information System (INIS)

Frost, J.J.; Dannals, R.F.; Ravert, H.T.

1984-01-01

Opiate receptors exist in the mammalian brain and are thought to meditate the diverse pharmacological actions of the opiates, such as analgesia, euphoria, and sedation. The 4-carbomethoxyl derivatives of fentanyl, such as lofentanil and R31833 (4-carbomethoxyfentanyl) bind to the opiate receptor with high affinity. C-11 R31833 was synthesized by reacting C-11 methyl iodide with the appropriate carboxylate. Male ICR mice were injected intravenously with C-11 R31833 (5μg/kg), killed 30 minutes later, and the brains rapidly dissected. The thalami, striata, and cerebral cortex are rich in opiate receptors, but the cerebellum contains a very low concentration of opiate receptors. The thalamus/cerebellum and striatum/cerebellum activity ratios, calculated per mg of wet tissue, were 4.1 and 5.2 respectively. Coinjection of 5mg/kg naloxone reduced the ratios to 1.1, which indicates that the preferential localization of C-11 R31833 in the thalami and striata is due to binding to opiate is due to binding to opiate receptors. A 22 kg anesthetized male baboon was imaged using the NeuroECAT after injection of 18.9 mCi of C-11 R13833 (0.50 μg/kg, specific activity 616 Ci/mmole at time of injection). From 15-70 minutes after injection preferential accumulation of activity could be seen in the thalami, caudate nuclei, and cerebral cortex and, conversely, low activity was demonstrated in the cerebellum. At one hour postinjection the maximum measured caudate/cerebellum activity ratio per pixel was 2.9. For the NeuroECAT the recovery coefficient for the baboon caudate is ca. 0.2-0.3, and therefore the actual caudate/cerebellum ratio is ca. 10-15

Central D2-dopamine receptor occupancy in schizophrenic patients treated with antipsychotic drugs

International Nuclear Information System (INIS)

Farde, L.; Wiesel, F.A.; Halldin, C.; Sedvall, G.

1988-01-01

Using positron emission tomography and the carbon 11-labeled ligand raclopride, central D2-dopamine receptor occupancy in the putamen was determined in psychiatric patients treated with clinical doses of psychoactive drugs. Receptor occupancy in drug-treated patients was defined as the percent reduction of specific carbon 11-raclopride binding in relation to the expected binding in the absence of drug treatment. Clinical treatment of schizophrenic patients with 11 chemically distinct antipsychotic drugs (including both classic and atypical neuroleptics such as clozapine) resulted in a 65% to 85% occupancy of D2-dopamine receptors. In a depressed patient treated with the tricyclic antidepressant nortriptyline, no occupancy was found. The time course for receptor occupancy and drug levels was followed after withdrawal of sulpiride or haloperidol. D2-dopamine receptor occupancy remained above 65% for many hours despite a substantial reduction of serum drug concentrations. In a sulpiride-treated patient, the dosage was reduced in four steps over a nine-week period and a curvilinear relationship was demonstrated between central D2-dopamine receptor occupancy and serum drug concentrations. The results demonstrate that clinical doses of all the currently used classes of antipsychotic drugs cause a substantial blockade of central D2-dopamine receptors in humans. This effect appears to be selective for the antipsychotics, since it was not induced by the antidepressant nortriptyline

Automated synthesis of the estrogen receptors imaging agent 18F-FES

International Nuclear Information System (INIS)

Guo Shen; Chen Guobao; Dai Hongfeng; Lin Meifu; Chen Wenxin

2011-01-01

Objective: 18 F-16α-17β-fluoroestradiol ( 18 F-FES), an estrogen receptors imaging agent, is synthesized with Tracerlab FX FN system. Methods: 18 F-FES is obtained by two steps reactions, including the nucleophilic displacement reaction of no-carrier-added 18 F-fluoride with 3-O-methoxymethyl-16, 17-O-sulfuryl-16-epiesteriol, then the intermediate is evaporated and hydrolyzed with HCI and finally gives 18 F-FES. Results: The synthesis of 18 F-FES can be completed in about 80 min.The radiochemical yield and radio-chemical purity are about 10% and 95% respectively. Conclusion: The procedure of synthesis is simple and automatical. 18 F-FES has an extremely low toxicity, which suggests that 18 F-FES may be a safe, a nd effective estrogen receptors imaging agent. (authors)

Temporal changes in serum creatine kinase concentration and degree of muscle rigidity in 24 patients with neuroleptic malignant syndrome

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Nisijima K

2013-06-01

Full Text Available Koichi Nisijima, Katutoshi ShiodaDepartment of Psychiatry, Jichi Medical University, Tochigi, JapanAbstract: Neuroleptic malignant syndrome (NMS is a dangerous adverse response to antipsychotic drugs. It is characterized by the four major clinical symptoms of hyperthermia, severe muscle rigidity, autonomic dysfunction, and altered mental state. Serum creatine kinase (CK elevation occurs in over 90% of NMS cases. In the present study, the detailed temporal changes in serum CK and degree of muscle rigidity, and the relationship between CK concentration and degree of muscle rigidity over the time course from fever onset, were evaluated in 24 affected patients. The results showed that serum CK peaked on day 2 after onset of fever and returned to within normal limits at day 12. Mild muscle rigidity was observed before the onset of fever in 17 of 24 cases (71%. Muscle rigidity was gradually exacerbated and worsened until day 4 after onset of fever. These findings confirm physicians' empirical understanding of serum CK concentrations and muscle rigidity in NMS based on data accumulated from numerous patients with the syndrome, and they indicate that serum CK may contribute to the early detection of NMS.Keywords: neuroleptic malignant syndrome, creatine kinase, muscle rigidity

Registration of dynamic dopamine D2receptor images using principal component analysis

International Nuclear Information System (INIS)

Acton, P.D.; Ell, P.J.; Pilowsky, L.S.; Brammer, M.J.; Suckling, J.

1997-01-01

This paper describes a novel technique for registering a dynamic sequence of single-photon emission tomography (SPET) dopamine D 2 receptor images, using principal component analysis (PCA). Conventional methods for registering images, such as count difference and correlation coefficient algorithms, fail to take into account the dynamic nature of the data, resulting in large systematic errors when registering time-varying images. However, by using principal component analysis to extract the temporal structure of the image sequence, misregistration can be quantified by examining the distribution of eigenvalues. The registration procedures were tested using a computer-generated dynamic phantom derived from a high-resolution magnetic resonance image of a realistic brain phantom. Each method was also applied to clinical SPET images of dopamine D 2 receptors, using the ligands iodine-123 iodobenzamide and iodine-123 epidepride, to investigate the influence of misregistration on kinetic modelling parameters and the binding potential. The PCA technique gave highly significant (P 123 I-epidepride scans. The PCA method produced data of much greater quality for subsequent kinetic modelling, with an improvement of nearly 50% in the χ 2 of the fit to the compartmental model, and provided superior quality registration of particularly difficult dynamic sequences. (orig.)

A Rare Case of Myxedema Coma with Neuroleptic Malignant Syndrome (NMS).

Science.gov (United States)

Dixit, Siddharth; Dutta, Manoj Kumar; Namdeo, Mayank

2015-05-01

Myxedema coma or hypothyroid crisis is an endocrine emergency and needs ICU management. Neuroleptic malignant syndrome (NMS) is another medical emergency which needs high degree of clinical suspicion else mortality can be high. There is a paradox in co existence of myxedema coma and NMS. While one is hypometabolic state another is hypermetabolic state and both can be precipitated by antipsychotics use. Hypothermia and flaccidity commonly expected in myxedema coma may mask fever and rigidity of classical NMS contributing to diagnostic problem and treatment delay. Scientific literature on coexistance of myxedema coma and NMS is sparse. We hereby report first case with coexisting myxedema coma and NMS in a patient of schizophrenia treated with antipsychotic, where classical symptoms of NMS were masked by myxedema coma. Prompt diagnosis and effective management by a team resulted in favourable outcome in our patient. This case is reported to alert intensive care physicians to atypical manifestations of NMS in presence of hypothyroidism.

Molecular imaging of neuroendocrine tumors using 68Ga-labeled peptides (Somatostatin receptor PET/CT)

International Nuclear Information System (INIS)

Baum, R.P.; Prasad, V.; Hoersch, D.

2009-01-01

Receptor PET/CT using 68 Ga-labeled somatostatin analogues (DOTA-NOC, DOTA-TOC or DOTA-TATE) enables the highly sensitive molecular imaging of neuroendocrine tumors (NETs) based on the expression of somatostatin receptors and even the detection of receptor subtypes. Our experience after more than 3000 studies shows that receptor PET/CT has a significantly higher tumor detection rate than conventional scintigraphy (even in SPECT/CT technique), and that tumor lesions can be very accurately localized. By calculating standardized uptake values (SUV) - which are reproducible and investigator-independent - patients can be selected for peptide receptor radiotherapy and also the course after therapy can be controlled. Receptor-PET/CT is the most sensitive imaging modality for the detection of unknown primary tumors (CUP syndrome), which is especially true for the detection of neuroendocrine tumors of the pancreas and small bowel; whole-body staging (''one stop shop'') as well as restaging and selection of patients for peptide receptor radiotherapy can be performed using a patient-friendly procedure (examination finished within one hour) exposing the patient to less radiation than whole-body CT scanning. The 68 Ge/ 68 Ga generator has proved very reliable over the years - even in a hospital environment. The effective costs for 68 Ga labeled somatostatin analogues might be less than for scintigraphic agents, provided a certain number of studies per year are performed. The development of new tumor-specific peptides as well as of other DOTA- or NOTA-coupled radiopharmaceuticals opens a new avenue into the future: finally, the 68 Ga generator could play a similar important role for PET/CT as did the 99m Tc-Generator for conventional gamma camera imaging over the last decades. (orig.)

Drug information update. Atypical antipsychotics and neuroleptic malignant syndrome: nuances and pragmatics of the association.

Science.gov (United States)

Sarkar, Siddharth; Gupta, Nitin

2017-08-01

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal adverse event associated with the use of antipsychotics. Although atypical antipsychotics were initially considered to carry no risk of NMS, reports have accumulated over time implicating them in NMS causation. Almost all atypical antipsychotics have been reported to be associated with NMS. The clinical profile of NMS caused by certain atypical antipsychotics such as clozapine has been reported to be considerably different from the NMS produced by typical antipsychotics, with diaphoresis encountered more commonly, and rigidity and tremor encountered less frequently. This article briefly discusses the evidence relating to the occurrence, presentation and management of NMS induced by atypical antipsychotics.

Progressive Encephalomyelitis with Rigidity and Myoclonus in an Intellectually Disabled Patient Mimicking Neuroleptic Malignant Syndrome

Directory of Open Access Journals (Sweden)

Zheyu Xu

2017-05-01

Full Text Available We present a case of 32-year-old male with profound mental retardation and autism spectrum disorder who had presented with seizures, rigidity and elevated creatine kinase and was initially diagnosed as neuroleptic malignant syndrome (NMS. The patient subsequently had a complicated clinical course, developing refractory status epilepticus, which lead to the eventual diagnosis of progressive encephalomyelitis with rigidity and myoclonus (PERM. We discuss the clinical similarities and differences between NMS and PERM, and highlight the need to consider alternative diagnoses when the clinical picture of NMS is atypical, particularly in this patient group where the history and clinical examination may be challenging.

Advances of 11C-flumazenil receptor imaging in ischemic penumbra

International Nuclear Information System (INIS)

Zhang Jun

2004-01-01

The ischemic penumbra is the target of therapy for ischemic stroke patients, so it is extremely important to investigate an imaging technique that may identify accurately the viability of cerebral tissues early. The neuroreceptor imaging with positron emission tomography has achieved some successes in this study field, in particular, the 11 C-flumazenil receptor imaging, which can not only differentiate between the neurons of functional impairment and those of morphological destruction, and then distinguish the ischemic penumbra from the irreversible damage tissues, but predict the malignant course of cerebral infarction. Consequently, these will help to select the patients benefiting from the intervention therapy and plan effectively the therapeutic strategies. (authors)

Virus-resembling nano-structures for near infrared fluorescence imaging of ovarian cancer HER2 receptors

Science.gov (United States)

Guerrero, Yadir A.; Bahmani, Baharak; Singh, Sheela P.; Vullev, Valentine I.; Kundra, Vikas; Anvari, Bahman

2015-10-01

Ovarian cancer remains the dominant cause of death due to malignancies of the female reproductive system. The capability to identify and remove all tumors during intraoperative procedures may ultimately reduce cancer recurrence, and lead to increased patient survival. The objective of this study is to investigate the effectiveness of an optical nano-structured system for targeted near infrared (NIR) imaging of ovarian cancer cells that over-express the human epidermal growth factor receptor 2 (HER2), an important biomarker associated with ovarian cancer. The nano-structured system is comprised of genome-depleted plant-infecting brome mosaic virus doped with NIR chromophore, indocyanine green, and functionalized at the surface by covalent attachment of monoclonal antibodies against the HER2 receptor. We use absorption and fluorescence spectroscopy, and dynamic light scattering to characterize the physical properties of the constructs. Using fluorescence imaging and flow cytometry, we demonstrate the effectiveness of these nano-structures for targeted NIR imaging of HER2 receptors in vitro. These functionalized nano-materials may provide a platform for NIR imaging of ovarian cancer.

Virus-resembling nano-structures for near infrared fluorescence imaging of ovarian cancer HER2 receptors

International Nuclear Information System (INIS)

Guerrero, Yadir A; Bahmani, Baharak; Vullev, Valentine I; Anvari, Bahman; Singh, Sheela P; Kundra, Vikas

2015-01-01

Ovarian cancer remains the dominant cause of death due to malignancies of the female reproductive system. The capability to identify and remove all tumors during intraoperative procedures may ultimately reduce cancer recurrence, and lead to increased patient survival. The objective of this study is to investigate the effectiveness of an optical nano-structured system for targeted near infrared (NIR) imaging of ovarian cancer cells that over-express the human epidermal growth factor receptor 2 (HER2), an important biomarker associated with ovarian cancer. The nano-structured system is comprised of genome-depleted plant-infecting brome mosaic virus doped with NIR chromophore, indocyanine green, and functionalized at the surface by covalent attachment of monoclonal antibodies against the HER2 receptor. We use absorption and fluorescence spectroscopy, and dynamic light scattering to characterize the physical properties of the constructs. Using fluorescence imaging and flow cytometry, we demonstrate the effectiveness of these nano-structures for targeted NIR imaging of HER2 receptors in vitro. These functionalized nano-materials may provide a platform for NIR imaging of ovarian cancer. (paper)

Somatostatin receptor-mediated imaging and therapy: basic science, current knowledge, limitations and future perspectives

Energy Technology Data Exchange (ETDEWEB)

Breeman, W.A.P.; Jong, M. de; Kwekkeboom, D.J.; Valkema, R.; Bakker, W.H.; Kooij, P.P.M. [Dept. of Nuclear Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Visser, T.J. [Dept. of Internal Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Krenning, E.P. [Dept. of Nuclear Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Dept. of Internal Medicine, Erasmus Medical Centre Rotterdam (Netherlands)

2001-09-01

In vivo somatostatin receptor-mediated scintigraphy has proven to be a valuable method for the visualisation of neuroendocrine tumours and their metastases. A new application is the use of radiolabelled analogues for somatostatin receptor-mediated therapy. This paper presents a review on the basic science, historical background and current knowledge of somatostatin receptor subtypes and their expression in neuroendocrine tumours. New somatostatin analogues, new chelators, ''new'' radionuclides and combinations thereof are also discussed. Due attention is given to limitations and future perspectives of somatostatin receptor-mediated imaging and therapy. (orig.)

Somatostatin receptor-mediated imaging and therapy: basic science, current knowledge, limitations and future perspectives

International Nuclear Information System (INIS)

Breeman, W.A.P.; Jong, M. de; Kwekkeboom, D.J.; Valkema, R.; Bakker, W.H.; Kooij, P.P.M.; Visser, T.J.; Krenning, E.P.

2001-01-01

In vivo somatostatin receptor-mediated scintigraphy has proven to be a valuable method for the visualisation of neuroendocrine tumours and their metastases. A new application is the use of radiolabelled analogues for somatostatin receptor-mediated therapy. This paper presents a review on the basic science, historical background and current knowledge of somatostatin receptor subtypes and their expression in neuroendocrine tumours. New somatostatin analogues, new chelators, ''new'' radionuclides and combinations thereof are also discussed. Due attention is given to limitations and future perspectives of somatostatin receptor-mediated imaging and therapy. (orig.)

Imaging of sigma receptors in tumors by PET with [C-11]SA4503

International Nuclear Information System (INIS)

Kawamura, K.; Kobayashi, T.; Oda, K.; Ishiwata, K.; Kubota, K.

2002-01-01

Aim: Sigma receptors are implicated in some diseases in the central nervous system (CNS), such as schizophrenia, depression, dementia and ischemia, and are also expressed in a variety of human tumors, such as melanoma, carcinoma of the breast, lung and prostate, and the brain tumor. Therefore, several radioligands have been proposed for imaging of sigma receptors by positron emission tomography (PET) and by single photon emission computed tomography. Recently, we have applied [C-11]labeled 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine ([C-11]SA4503) to mapping sigma1 receptors in the brain of monkeys and human. In the present study, we evaluated the potential of the [C-11]SA4503 PET for imaging of sigma receptors using the AH109A bearing rats, and the VX-2 carcinoma bearing rabbits. Materials and Methods: [C-11]SA4503 was injected i.v. into AH109A bearing rats, and the tissue distribution was measured by tissue dissection. To determine the receptor-specific uptake, cold SA4503 or haloperidol was co-injected into the other group of rats. The PET scanning were performed in the rats in the baseline condition and after pretreatment with haloperidol. In the VX-2 carcinoma bearing rabbits, PET scanning was also performed in the baseline and blockade conditions. The sigma receptors in the AH109A and VX-2 were measured in vitro by the standard membrane binding assays. Results: The sigma receptors were found in AH109A and VX-2. The density was much higher in VX-2 than in AH109A. In the tissue dissection study, the AH109A uptake of [C-11]SA4503 increased for 60 min after injection. By the co-injection of SA4503 or haloperidol, the AH109A uptake was enhanced. The PET study also confirmed that the radioactivity level in the AH109A was enhanced by the pretreatment with haloperidol. On the other hand, In the VX-2 carcinoma bearing rabbits, the radioactivity level of in VX-2 remained constant after initial uptake in the baseline PET measurement, but the VX-2 uptake was

Benchmarking the performance of fixed-image receptor digital radiographic systems part 1: a novel method for image quality analysis.

Science.gov (United States)

Lee, Kam L; Ireland, Timothy A; Bernardo, Michael

2016-06-01

This is the first part of a two-part study in benchmarking the performance of fixed digital radiographic general X-ray systems. This paper concentrates on reporting findings related to quantitative analysis techniques used to establish comparative image quality metrics. A systematic technical comparison of the evaluated systems is presented in part two of this study. A novel quantitative image quality analysis method is presented with technical considerations addressed for peer review. The novel method was applied to seven general radiographic systems with four different makes of radiographic image receptor (12 image receptors in total). For the System Modulation Transfer Function (sMTF), the use of grid was found to reduce veiling glare and decrease roll-off. The major contributor in sMTF degradation was found to be focal spot blurring. For the System Normalised Noise Power Spectrum (sNNPS), it was found that all systems examined had similar sNNPS responses. A mathematical model is presented to explain how the use of stationary grid may cause a difference between horizontal and vertical sNNPS responses.

An inquiry into the semiquantitative parameters of striatal dopamine receptor imaging

International Nuclear Information System (INIS)

Cao Guoxiang; Tan Tianzhi; Kuang Anren; Liang Zhenglu

1998-01-01

Purpose: To inquire into the optimal striatal reference region for nonspecific IBZM uptake in brain dopamine receptor imaging. Methods: Using in vivo data from rats, the authors compared the results of 125 I-iodobenzamide ( 125 I-IBZM) striatal specific binding that were respectively obtained taking cerebellum and frontal cortex as striatal reference region of nonspecific uptake of ligand. Results: Radioiodination labelled IBZM bound stereoselectively and reversibly to striatal D2 receptors. Frontal cortex and cerebellum showed rapid uptake and rapid washout of ligand. When cerebellar uptake was used as a reference of nonspecific uptake in striatum, IBZM saturation could not be demonstrated. But when the frontal cortex was used as reference region, saturation could be demonstrated with B max = 44 pmol/g striatum tissue. The percentage of haloperidol replacement and the percentage of uptake difference between striatum and other brain regions which were derived from competitive inhibition experiments with a large does of spiperone or haloperidol, suggested that the cerebellar uptake underestimated nonspecific uptake in the striatum while frontal cortex was an appropriate reference region for nonspecific uptake of ligand in striatum. Conclusions: For the calculation of specific IBZM binding and other semiquantitative parameters of striatal dopamine D2 receptor imaging, frontal cortex would be the nonspecific reference region of choice

Synthesis and pharmacological evaluation of several N-(2-nitrophenylpiperazine derivatives

Directory of Open Access Journals (Sweden)

DEANA ANDRIC

2007-05-01

Full Text Available Six newly synthesized heterocyclic (2-nitrophenylpiperazines, with a specific structure of the heteroaryl group, whichmimics the catechol moiety of dopamine (benzimidazoles and substituted benzimidazoles, were evaluated for their binding affinity to rat dopamine (DA, serotonin (5-HT and α1 receptors. All compounds with a benzimidazole group had a 5-HT2A/D2 receptors binding ratio characteristic for atypical neuroleptics (>1, pKi values. Compound 7c, 4-bromo-6-{2-[4-(2-nitrophenylpiperazin-1-yl]ethyl}-1H-benzimidazole, expressed higher affinities for all receptor classes than clozapine. Also, it exhibited the best characteristic for atypical neuroleptics and presents a compound with the best profile for further in vivo investigations.

The development of fluoroandrogens and fluoroprogestins as potential imaging agents for receptor-positive prostate and breast tumors

International Nuclear Information System (INIS)

Brandes, S.J.; Katzenellenbogen, J.A.

1986-01-01

The assay of progesterone receptor (PR) concentration in breast tumors and androgen receptor (AR) concentration in prostate tumors enables hormone responsive neoplasms to be distinguished from those that are non-responsive. In principle, a positron-emitting progestin or androgen with suitably high affinity and selectivity for PR and AR, respectively, and an adequately high specific activity might provide a means for imaging receptor-positive tumors and quantifying their receptor content in vivo. The use of fluorine-18 as a radiolabel, coupled with the use of positron emission transaxial tomography, appears to be a most favorable approach in the development of receptor binding radiopharmaceuticals for in vivo imaging. Therefore, we have begun a systematic investigation of the development of fluorine-substituted androgens and progestins that might be prepared in F-18 labeled form as probes for AR and PR. (author)

GLP-1 receptor antagonist as a potential probe for pancreatic β-cell imaging

International Nuclear Information System (INIS)

Mukai, Eri; Toyoda, Kentaro; Kimura, Hiroyuki; Kawashima, Hidekazu; Fujimoto, Hiroyuki; Ueda, Masashi; Temma, Takashi; Hirao, Konomu; Nagakawa, Kenji; Saji, Hideo; Inagaki, Nobuya

2009-01-01

We examined exendin(9-39), an antagonist of glucagon-like peptide-1 (GLP-1) receptor (GLP-1R), as a potential probe for imaging of pancreatic β-cells. To evaluate in vitro receptor specificity, binding assay was performed using dispersed mouse islet cells. Binding assay showed competitive inhibition of [ 125 I]BH-exendin(9-39) binding by non-radioactive exendin(9-39). To assess in vivo selectivity, the biodistribution was evaluated by intravenous administration of [ 125 I]BH-exendin(9-39) to mice. Radioactivity of harvested pancreas reached highest levels at 60 and 120 min among organs examined except lung. Pre-administration of excess non-radioactive exendin(9-39) remarkably and specifically blocked the radioactivity of pancreas. After [ 125 I]BH-exendin(9-39) injection into transgenic mice with pancreatic β-cells expressing GFP, fluorescent and radioactive signals of sections of pancreas were evaluated with an image analyzer. Imaging analysis showed that the fluorescent GFP signals and the radioactive signals were correspondingly located. Thus, the GLP-1R antagonist exendin(9-39) may serve as a useful probe for pancreatic β-cell imaging.

Intravascular optical imaging of high-risk plaques in vivo by targeting macrophage mannose receptors

Science.gov (United States)

Kim, Ji Bak; Park, Kyeongsoon; Ryu, Jiheun; Lee, Jae Joong; Lee, Min Woo; Cho, Han Saem; Nam, Hyeong Soo; Park, Ok Kyu; Song, Joon Woo; Kim, Tae Shik; Oh, Dong Joo; Gweon, Daegab; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

2016-03-01

Macrophages mediate atheroma expansion and disruption, and denote high-risk arterial plaques. Therefore, they are substantially gaining importance as a diagnostic imaging target for the detection of rupture-prone plaques. Here, we developed an injectable near-infrared fluorescence (NIRF) probe by chemically conjugating thiolated glycol chitosan with cholesteryl chloroformate, NIRF dye (cyanine 5.5 or 7), and maleimide-polyethylene glycol-mannose as mannose receptor binding ligands to specifically target a subset of macrophages abundant in high-risk plaques. This probe showed high affinity to mannose receptors, low toxicity, and allowed the direct visualization of plaque macrophages in murine carotid atheroma. After the scale-up of the MMR-NIRF probe, the administration of the probe facilitated in vivo intravascular imaging of plaque inflammation in coronary-sized vessels of atheromatous rabbits using a custom-built dual-modal optical coherence tomography (OCT)-NIRF catheter-based imaging system. This novel imaging approach represents a potential imaging strategy enabling the identification of high-risk plaques in vivo and holds promise for future clinical implications.

Comparison of benzodiazepine receptor and regional cerebral blood flow imagings of epileptiform foci in hippocampal kindled rabbits

International Nuclear Information System (INIS)

Kurokawa, Kenzo

1993-01-01

To compare the benzodiazepine (Bz) receptor imaging and regional cerebral blood flow (rCBF) imaging in the detection of epileptic foci, the distribution pattern of the Bz receptor and rCBF in hippocampal kindled rabbits was examined by a double tracer autoradiography using ethyl 7-[ 125 I]-5,6-dihydro-5-methyl-6-oxo-4H-imidazo [1, 5-a][1,4] benzodiazepine-3-carboxylate ( 125 I-Ro 16-0154) and 99m Tc-hexamethyl-propyleneamine oxime ( 99m Tc-HMPAO). In visual and quantitative analyses, 125 I-Ro 16-0154 accumulation in brain slices extracted after the completion of the kindling was markedly and extensively decreased in the kindled CA1 region mimicking a primary epileptic focus. 125 I-Ro 16-0154 accumulation was moderately decreased in the ipsilateral temporal lobe, dentate gyrus, CA2, CA4, and bilateral CA3 regions, regarded as the propagated sites of seizure discharges. 99m Tc-HMPAO accumulation was found to be decreased in the ipsilateral CA1, frontal, temporal and dentate gyri. However, the decrease was much more slight and less extensive than that in 125 I-Ro 16-0154 accumulation. These results suggest that Bz receptor imaging is much more sensitive in the detection of epileptic foci than rCBF imaging, and therefore that Bz receptor imaging is useful in clinical epilepsy. (author)

Near infrared spectral polarization imaging of prostate cancer tissues using Cybesin: a receptor-targeted contrast agent

Science.gov (United States)

Pu, Yang; Wang, W. B.; Tang, G. C.; Liang, Kexian; Achilefu, S.; Alfano, R. R.

2013-03-01

Cybesin, a smart contrast agent to target cancer cells, was investigated using a near infrared (NIR) spectral polarization imaging technique for prostate cancer detection. The approach relies on applying a contrast agent that can target cancer cells. Cybesin, as a small ICG-derivative dye-peptide, emit fluorescence between 750 nm and 900 nm, which is in the "tissue optical window". Cybesin was reported targeting the over-expressed bombesin receptors in cancer cells in animal model and the human prostate cancers over-expressing bombesin receptors. The NIR spectral polarization imaging study reported here demonstrated that Cybesin can be used as a smart optical biomarker and as a prostate cancer receptor targeted contrast agent.

Linearized method: A new approach for kinetic analysis of central dopamine D2 receptor specific binding

International Nuclear Information System (INIS)

Watabe, Hiroshi; Hatazawa, Jun; Ishiwata, Kiichi; Ido, Tatsuo; Itoh, Masatoshi; Iwata, Ren; Nakamura, Takashi; Takahashi, Toshihiro; Hatano, Kentaro

1995-01-01

The authors proposed a new method (Linearized method) to analyze neuroleptic ligand-receptor specific binding in a human brain using positron emission tomography (PET). They derived the linear equation to solve four rate constants, k 3 , k 4 , k 5 , k 6 from PET data. This method does not demand radioactivity curve in plasma as an input function to brain, and can do fast calculations in order to determine rate constants. They also tested Nonlinearized method including nonlinear equations which is conventional analysis using plasma radioactivity corrected for ligand metabolites as an input function. The authors applied these methods to evaluate dopamine D 2 receptor specific binding of [ 11 C] YM-09151-2. The value of B max /K d = k 3 k 4 obtained by Linearized method was 5.72 ± 3.1 which was consistent with the value of 5.78 ± 3.4 obtained by Nonlinearized method

Anti-N-methyl-D-aspartate receptor encephalitis with an imaging-invisible ovarian teratoma: a case report.

Science.gov (United States)

Abdul-Rahman, Zainab M; Panegyres, Peter K; Roeck, Margareta; Hawkins, David; Bharath, Jude; Grolman, Paul; Neppe, Cliffe; Palmer, David

2016-10-24

Anti-N-methyl-D-aspartate receptor encephalitis is a recently discovered disease entity of paraneoplastic limbic encephalitis. It largely affects young women and is often associated with an ovarian teratoma. It is a serious yet treatable condition if diagnosed early. Its remedy involves immunotherapy and surgical removal of the teratoma of the ovaries. This case of anti-N-methyl-D-aspartate receptor encephalitis involves an early surgical intervention with bilateral oophorectomy, despite negative imaging evidence of a teratoma. A 25-year-old white woman with anti-N-methyl-D-aspartate receptor encephalitis presented with behavioral changes and seizures that were confirmed to be secondary to anti-N-methyl-D-aspartate receptor encephalitis. She required an admission to our intensive care unit for ventilator support and received a number of immunological therapies. Multiple imaging investigations showed no evidence of an ovarian teratoma; she had a bilateral oophorectomy 29 days after admission. Ovarian histology confirmed the presence of a teratoma with neuronal cells. A few days after the operation she began to show signs of improvement and, apart from mild short-term memory loss, she returned to normal function. Our patient is an example of teratoma-associated anti-N-methyl-D-aspartate receptor encephalitis, in which the teratoma was identified only microscopically. Her case highlights that even with negative imaging evidence of a teratoma, ovarian pathology should still be considered and explored.

Ligand-Induced Dynamics of Neurotrophin Receptors Investigated by Single-Molecule Imaging Approaches

Science.gov (United States)

Marchetti, Laura; Luin, Stefano; Bonsignore, Fulvio; de Nadai, Teresa; Beltram, Fabio; Cattaneo, Antonino

2015-01-01

Neurotrophins are secreted proteins that regulate neuronal development and survival, as well as maintenance and plasticity of the adult nervous system. The biological activity of neurotrophins stems from their binding to two membrane receptor types, the tropomyosin receptor kinase and the p75 neurotrophin receptors (NRs). The intracellular signalling cascades thereby activated have been extensively investigated. Nevertheless, a comprehensive description of the ligand-induced nanoscale details of NRs dynamics and interactions spanning from the initial lateral movements triggered at the plasma membrane to the internalization and transport processes is still missing. Recent advances in high spatio-temporal resolution imaging techniques have yielded new insight on the dynamics of NRs upon ligand binding. Here we discuss requirements, potential and practical implementation of these novel approaches for the study of neurotrophin trafficking and signalling, in the framework of current knowledge available also for other ligand-receptor systems. We shall especially highlight the correlation between the receptor dynamics activated by different neurotrophins and the respective signalling outcome, as recently revealed by single-molecule tracking of NRs in living neuronal cells. PMID:25603178

[Association polymorphic variants of GRIN2B gene with paranoid schizophrenia and response to common neuroleptics in Russians and Tatars from Bashkortostan Republic].

Science.gov (United States)

Gareeva, A E; Zakirov, D F; Khusnutdinova, E K

2013-09-01

An analysis of the association of paranoid schizophrenia seeking with polymorphic variants of GRIN2B gene was performed in order to identify genetic risk factors of disease development and genetic markers of the response to therapy by neuroleptics in Russian and Tatar patients from Bashkortostan Republic (BB). In the course of the analysis, we revealed the following: 1) genetic markers of increased risk of developing paranoid schizophrenia in various ethnic groups, including, in Tatars, the GRIN2B* T/*Tgenotype (p = 0.003; OR = 2.33) and GRIN2B*T allele (p = 0.001; OR = 2.36), rs1805247; in Russians, the GRIN2B*T/*T genotype (p = 0.038; OR = 2.12) and GRIN2B* T allele (p = 0.028; OR = 2.03), rs1805247, genotype GRIN2B*A/*A (p = 0.042; OR = 2.12), rs1805476; 2) genetic markers of the reduced risk of developing paranoid schizophrenia; 3) genetic markers of therapy response and the risk of side effects development during neuroleptics (haloperidol) treatment in Bashkortostan. The significant interethnic diversity of genetic factors related to the risk of this disease development was noted.

Characterization of the Distance Relationship Between Localized Serotonin Receptors and Glia Cells on Fluorescence Microscopy Images of Brain Tissue.

Science.gov (United States)

Jacak, Jaroslaw; Schaller, Susanne; Borgmann, Daniela; Winkler, Stephan M

2015-08-01

We here present two new methods for the characterization of fluorescent localization microscopy images obtained from immunostained brain tissue sections. Direct stochastic optical reconstruction microscopy images of 5-HT1A serotonin receptors and glial fibrillary acidic proteins in healthy cryopreserved brain tissues are analyzed. In detail, we here present two image processing methods for characterizing differences in receptor distribution on glial cells and their distribution on neural cells: One variant relies on skeleton extraction and adaptive thresholding, the other on k-means based discrete layer segmentation. Experimental results show that both methods can be applied for distinguishing classes of images with respect to serotonin receptor distribution. Quantification of nanoscopic changes in relative protein expression on particular cell types can be used to analyze degeneration in tissues caused by diseases or medical treatment.

[11C]-MeJDTic: a novel radioligand for κ-opioid receptor positron emission tomography imaging

International Nuclear Information System (INIS)

Poisnel, Geraldine; Oueslati, Farhana; Dhilly, Martine; Delamare, Jerome; Perrio, Cecile; Debruyne, Daniele; Barre, Louisa

2008-01-01

Introduction: Radiopharmaceuticals that can bind selectively the κ-opioid receptor may present opportunities for staging clinical brain disorders and evaluating the efficiency of new therapies related to stroke, neurodegenerative diseases or opiate addiction. The N-methylated derivative of JDTic (named MeJDTic), which has been recently described as a potent and selective antagonist of κ-opioid receptor in vitro, was labeled with carbon-11 and evaluated for in vivo imaging the κ-opioid receptor in mice. Methods: [ 11 C]-MeJDTic was prepared by methylation of JDTic with [ 11 C]-methyl triflate. The binding of [ 11 C]-MeJDTic to κ-opioid receptor was investigated ex vivo by biodistribution and competition studies using nonfasted male CD1 mice. Results: [ 11 C]-MeJDTic exhibited a high and rapid distribution in peripheral organs. The uptake was maximal in lung where the κ receptor is largely expressed. [ 11 C]-MeJDTic rapidly crossed the blood-brain barrier and accumulated in the brain regions of interest (hypothalamus). The parent ligand remained the major radioactive compound in brain during the experiment. Chase studies with U50,488 (a κ referring agonist), morphine (a μ agonist) and naltrindole (a δ antagonist) demonstrated that this uptake was the result of specific binding to the κ-opioid receptor. Conclusion: These findings suggested that [ 11 C]-MeJDTic appeared to be a promising selective 'lead' radioligand for κ-opioid receptor PET imaging

Neuroleptic malignant syndrome in an elderly with quetiapine: A case report and review of literature

Directory of Open Access Journals (Sweden)

Devakshi Dua

2017-01-01

Full Text Available Over the years, there is an increase in the prescription of antipsychotics among elderly patients, and these are used for various clinical indications such as psychotic disorders, affective disorders, behavioral and psychological symptoms of dementia and delirium. Quetiapine is one of the preferred antipsychotics among elderly because of its safety profile. However, quetiapine has been rarely been associated with the development of neuroleptic malignant syndrome (NMS among elderly. In this report, we discuss a case of NMS in a 70-year-old female, who developed symptoms of NMS at the dose of 200 mg/day, while quetiapine was being used along with lithium. A review of literature suggests that there are 12 cases of NMS reported in subjects older than 55 years of age.

Nociceptive thermal threshold testing in horses – effect of neuroleptic sedation and neuroleptanalgesia at different stimulation sites

Science.gov (United States)

2013-01-01

Background Aim of the study was to compare the effect of neuroleptic sedation with acepromazine and neuroleptanalgesia with acepromazine and buprenorphine on thermal thresholds (TT) obtained at the nostrils and at the withers. The study was carried out as a randomized, blinded, controlled trial with cross-over design. Thermal thresholds were determined by incremental contact heat applied to the skin above the nostril (N) or the withers (W). Eleven horses were treated with saline (S), acepromazine (0.05 mg/kg) (ACE) or acepromazine and buprenorphine (0.0075 mg/kg) (AB) intravenously (IV). Single stimulations were performed 15 minutes prior and 15, 45, 75, 105, 165, 225, 285, 405 and 525 minutes after treatment. Sedation score, gastrointestinal auscultation score and occurrence of skin lesions were recorded. Data were analysed with analysis of variance for repeated measurements. Results There were no significant differences in TT between N and W with all treatments. The TT remained constant after S and there was no difference in TT between S and ACE. After AB there was a significant increase above baseline in TT until 405 minutes after treatment. Restlessness occurred 30–90 minutes after AB in 7 horses. All horses had reduced to absent borborygmi after AB administration for 165 to 495 minutes. Conclusion Thermal stimulation at both described body areas gives comparable results in the assessment of cutaneous anti-nociception in horses. There is no differential influence of neuroleptic sedation or neuroleptanalgesia on TTs obtained at N or W. Buprenorphine combined with acepromazine has a long lasting anti-nociceptive effect associated with the typical opioid induced side effects in horses. PMID:23837730

Labeled receptor ligands for spect

International Nuclear Information System (INIS)

Kung, H.F.

1989-01-01

Receptor specific imaging agents for single photon emission computed tomography (SPECT) can potentially be useful in the understanding of basic biochemistry and pharmacology of receptors. SPECT images may also provide tools for evaluation of density and binding kinetics of a specific receptor, information important for diagnosis and patient management. Basic requirements for receptor imaging agents are: (a) they are labeled with short-lived isotopes, (b) they show high selectivity and specific uptake, (c) they exhibit high target/background ratio, and (d) they can be modeled to obtain quantitative information. Several good examples of CNS receptor specific ligands labeled with I-123 have been developed, including iodoQNB, iodoestrogen iodobenzadiazepine, iodobenazepine, iodobenzamides for muscarinic, estrogen benzadiazepine, D-1 and D-2 dopamine receptors. With the advent of newer and faster SPECT imaging devices, it may be feasible to quantitate the receptor density by in vivo imaging techniques. These new brain imaging agents can provide unique diagnostic information, which may not be available through other imaging modalities, such as CT and MRI

In Vivo Imaging of Retinoic Acid Receptor Activity using a Sodium/Iodide Symporter and Luciferase Dual Imaging Reporter Gene

Directory of Open Access Journals (Sweden)

Min Kyung So

2004-07-01

Full Text Available Retinoic acids are natural derivatives of vitamin A, and play important roles in modulating tumor cell growth by regulating differentiation, thus suggesting the potential use of these derivatives in cancer therapy and prevention. To visualize the intranuclear responses of functional retinoic acid receptors, we have developed a dual-imaging reporter gene system based on the use of sodium/iodide symporter (NIS and luciferase in cancer cell lines. NIS and luciferase genes were linked with an internal ribosome entry site, and placed under the control of an artificial cis-acting retinoic acid responsive element (pRARE/NL. After retinoic acid treatment, I-125 uptake by pRARE/NL transfected cells was found to have increased by up to about five times that of nontreated cells. The bioluminescence intensity of pRARE/NL transfected cells showed dose-dependency. In vivo luciferase images showed higher intensity in retinoic acid treated SK-RARE/NL tumors, and scintigraphic images of SK-RARE/NL tumors showed increased Tc-99m uptake after retinoic acid treatment. The NIS/luciferase imaging reporter system was sufficiently sensitive to allow the visualization of intranuclear retinoic acid receptor activity. This cis-enhancer imaging reporter system may be useful in vitro and in vivo for the evaluation of retinoic acid responses in such areas as cellular differentiation and chemoprevention.

Imaging of Prostate Cancer Using Urokinase-Type Plasminogen Activator Receptor PET

DEFF Research Database (Denmark)

Skovgaard, Dorthe; Persson, Morten; Kjaer, Andreas

2017-01-01

Urokinase-type plasminogen activator receptor (uPAR) overexpression is an important biomarker for aggressiveness in cancer including prostate cancer (PC) and provides independent clinical information in addition to prostate-specific antigen and Gleason score. This article focuses on uPAR PET...... as a new diagnostic and prognostic imaging biomarker in PC. Many preclinical uPAR-targeted PET imaging studies using AE105 in cancer models have been undertaken with promising results. A major breakthrough was obtained with the recent human translation of uPAR PET in using 64Cu- and 68Ga-labelled versions...

Registration of dynamic dopamine D{sub 2}receptor images using principal component analysis

Energy Technology Data Exchange (ETDEWEB)

Acton, P.D.; Ell, P.J. [Institute of Nuclear Medicine, University College London Medical School, London (United Kingdom); Pilowsky, L.S.; Brammer, M.J. [Institute of Psychiatry, De Crespigny Park, London (United Kingdom); Suckling, J. [Clinical Age Research Unit, Kings College School of Medicine and Dentistry, London (United Kingdom)

1997-11-01

This paper describes a novel technique for registering a dynamic sequence of single-photon emission tomography (SPET) dopamine D{sub 2}receptor images, using principal component analysis (PCA). Conventional methods for registering images, such as count difference and correlation coefficient algorithms, fail to take into account the dynamic nature of the data, resulting in large systematic errors when registering time-varying images. However, by using principal component analysis to extract the temporal structure of the image sequence, misregistration can be quantified by examining the distribution of eigenvalues. The registration procedures were tested using a computer-generated dynamic phantom derived from a high-resolution magnetic resonance image of a realistic brain phantom. Each method was also applied to clinical SPET images of dopamine D {sub 2}receptors, using the ligands iodine-123 iodobenzamide and iodine-123 epidepride, to investigate the influence of misregistration on kinetic modelling parameters and the binding potential. The PCA technique gave highly significant (P <0.001) improvements in image registration, leading to alignment errors in x and y of about 25% of the alternative methods, with reductions in autocorrelations over time. It could also be applied to align image sequences which the other methods failed completely to register, particularly {sup 123}I-epidepride scans. The PCA method produced data of much greater quality for subsequent kinetic modelling, with an improvement of nearly 50% in the {chi}{sup 2}of the fit to the compartmental model, and provided superior quality registration of particularly difficult dynamic sequences. (orig.) With 4 figs., 2 tabs., 26 refs.

Multivariate cluster analysis of dynamic iodine-123 iodobenzamide SPET dopamine D2receptor images in schizophrenia

International Nuclear Information System (INIS)

Acton, P.D.; Pilowsky, L.S.; Costa, D.C.; Ell, P.J.

1997-01-01

This paper describes the application of a multivariate statistical technique to investigate striatal dopamine D 2 receptor concentrations measured by iodine-123 iodobenzamide ( 123 I-IBZM) single-photon emission tomography (SPET). This technique enables the automatic segmentation of dynamic nuclear medicine images based on the underlying time-activity curves present in the data. Once the time-activity curves have been extracted, each pixel can be mapped back on to the underlying distribution, considerably reducing image noise. Cluster analysis has been verified using computer simulations and phantom studies. The technique has been applied to SPET images of dopamine D 2 receptors in a total of 20 healthy and 20 schizophrenic volunteers (22 male, 18 female), using the ligand 123 I-IBZM. Following automatic image segmentation, the concentration of striatal dopamine D 2 receptors shows a significant left-sided asymmetry in male schizophrenics compared with male controls. The mean left-minus-right laterality index for controls is -1.52 (95% CI -3.72-0.66) and for patients 4.04 (95% CI 1.07-7.01). Analysis of variance shows a case-by-sex-by-side interaction, with F=10.01, P=0.005. We can now demonstrate that the previously observed male sex-specific D 2 receptor asymmetry in schizophrenia, which had failed to attain statistical significance, is valid. Cluster analysis of dynamic nuclear medicine studies provides a powerful tool for automatic segmentation and noise reduction of the images, removing much of the subjectivity inherent in region-of-interest analysis. The observed striatal D 2 asymmetry could reflect long hypothesized disruptions in dopamine-rich cortico-striatal-limbic circuits in schizophrenic males. (orig.). With 4 figs., 2 tabs

The gastrin/cholecystokinin-B receptor on prostate cells--a novel target for bifunctional prostate cancer imaging.

Science.gov (United States)

Sturzu, Alexander; Klose, Uwe; Sheikh, Sumbla; Echner, Hartmut; Kalbacher, Hubert; Deeg, Martin; Nägele, Thomas; Schwentner, Christian; Ernemann, Ulrike; Heckl, Stefan

2014-02-14

The means of identifying prostate carcinoma and its metastases are limited. The contrast agents used in magnetic resonance imaging clinical diagnostics are not taken up into the tumor cells, but only accumulate in the interstitial space of the highly vasculated tumor. We examined the gastrin/cholecystokinin-B receptor as a possible target for prostate-specific detection using the C-terminal seven amino acid sequence of the gastrin peptide hormone. The correct sequence and a scrambled control sequence were coupled to the fluorescent dye rhodamine and the magnetic resonance imaging contrast agent gadolinium (Gd)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Expression analysis of the gastrin receptor mRNA was performed by reverse transcriptase polymerase chain reaction on PC3 prostate carcinoma cells, U373 glioma, U2OS osteosarcoma and Colo205 colon carcinoma cells. After having confirmed elevated expression of gastrin receptor in PC3 cells and very low expression of the receptor in Colo205 cells, these two cell lines were used to create tumor xenografts on nude mice for in vivo experiments. Confocal lasers scanning microscopy and magnetic resonance imaging showed a high specificity of the correct conjugate for the PC3 xenografts. Staining of the PC3 xenografts was much weaker with the scrambled conjugate while the Colo205 xenografts showed no marked staining with any of the conjugates. In vitro experiments comparing the correct and scrambled conjugates on PC3 cells by magnetic resonance relaxometry and fluorescence-activated cell sorting confirmed markedly higher specificity of the correct conjugate. The investigations show that the gastrin receptor is a promising tumor cell surface target for future prostate-cancer-specific imaging applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Imaging Agonist-Induced D2/D3 Receptor Desensitization and Internalization In Vivo with PET/fMRI.

Science.gov (United States)

Sander, Christin Y; Hooker, Jacob M; Catana, Ciprian; Rosen, Bruce R; Mandeville, Joseph B

2016-04-01

This study investigated the dynamics of dopamine receptor desensitization and internalization, thereby proposing a new technique for non-invasive, in vivo measurements of receptor adaptations. The D2/D3 agonist quinpirole, which induces receptor internalization in vitro, was administered at graded doses in non-human primates while imaging with simultaneous positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). A pronounced temporal divergence between receptor occupancy and fMRI signal was observed: occupancy remained elevated while fMRI responded transiently. Analogous experiments with an antagonist (prochlorperazine) and a lower-affinity agonist (ropinirole) exhibited reduced temporal dissociation between occupancy and function, consistent with a mechanism of desensitization and internalization that depends upon drug efficacy and affinity. We postulated a model that incorporates internalization into a neurovascular-coupling relationship. This model yielded in vivo desensitization/internalization rates (0.2/min for quinpirole) consistent with published in vitro measurements. Overall, these results suggest that simultaneous PET/fMRI enables characterization of dynamic neuroreceptor adaptations in vivo, and may offer a first non-invasive method for assessing receptor desensitization and internalization.

[{sup 11}C]-MeJDTic: a novel radioligand for {kappa}-opioid receptor positron emission tomography imaging

Energy Technology Data Exchange (ETDEWEB)

Poisnel, Geraldine; Oueslati, Farhana; Dhilly, Martine; Delamare, Jerome [Groupe de Developpements Methodologiques en Tomographie par Emission de Positons, DSV/DRM UMR CEA 2E, Universite de Caen-Basse Normandie, Centre Cyceron, 14074 Caen Cedex (France); Perrio, Cecile [Groupe de Developpements Methodologiques en Tomographie par Emission de Positons, DSV/DRM UMR CEA 2E, Universite de Caen-Basse Normandie, Centre Cyceron, 14074 Caen Cedex (France)], E-mail: perrio@cyceron.fr; Debruyne, Daniele [Groupe de Developpements Methodologiques en Tomographie par Emission de Positons, DSV/DRM UMR CEA 2E, Universite de Caen-Basse Normandie, Centre Cyceron, 14074 Caen Cedex (France)], E-mail: debruyne@cyceron.fr; Barre, Louisa [Groupe de Developpements Methodologiques en Tomographie par Emission de Positons, DSV/DRM UMR CEA 2E, Universite de Caen-Basse Normandie, Centre Cyceron, 14074 Caen Cedex (France)

2008-07-15

Introduction: Radiopharmaceuticals that can bind selectively the {kappa}-opioid receptor may present opportunities for staging clinical brain disorders and evaluating the efficiency of new therapies related to stroke, neurodegenerative diseases or opiate addiction. The N-methylated derivative of JDTic (named MeJDTic), which has been recently described as a potent and selective antagonist of {kappa}-opioid receptor in vitro, was labeled with carbon-11 and evaluated for in vivo imaging the {kappa}-opioid receptor in mice. Methods: [{sup 11}C]-MeJDTic was prepared by methylation of JDTic with [{sup 11}C]-methyl triflate. The binding of [{sup 11}C]-MeJDTic to {kappa}-opioid receptor was investigated ex vivo by biodistribution and competition studies using nonfasted male CD1 mice. Results: [{sup 11}C]-MeJDTic exhibited a high and rapid distribution in peripheral organs. The uptake was maximal in lung where the {kappa} receptor is largely expressed. [{sup 11}C]-MeJDTic rapidly crossed the blood-brain barrier and accumulated in the brain regions of interest (hypothalamus). The parent ligand remained the major radioactive compound in brain during the experiment. Chase studies with U50,488 (a {kappa} referring agonist), morphine (a {mu} agonist) and naltrindole (a {delta} antagonist) demonstrated that this uptake was the result of specific binding to the {kappa}-opioid receptor. Conclusion: These findings suggested that [{sup 11}C]-MeJDTic appeared to be a promising selective 'lead' radioligand for {kappa}-opioid receptor PET imaging.

Molecular imaging of neutropilin-1 receptor using photoacoustic spectroscopy in breast tumors

Science.gov (United States)

Stantz, Keith M.; Cao, Minsong; Liu, Bo; Miller, Kathy D.; Guo, Lili

2010-02-01

Purpose: Our purpose is to develop and test a molecular probe that can detect the expression of neutropilin-1 receptor (NPR-1) in vivo using fluorescence imaging and photoacoustic spectroscopy. Introduction: NPR-1 is expressed on endothelial cells and some breast cancer cells, and binds to vascular endothelial growth factor VEGF165, a growth factor associated with pathological tumor angiogenesis. This receptor is coexpressed with VEGFR2 and shown to enhance the binding of VEGF165; therefore, it has the potential to be used as a marker of angiogenic activity and targeted for therapy. Material and Methods: A peptide specific to NPR-1 receptor was synthesized and conjugated to a NIR fluorochrome (IRDye800CW) and was intravenously injected into mice with breast tumors (MCF7VEGF). Probe kinetics was monitored in vivo via near infrared fluorescence (NIRF) within an optical imager for up to 72 hours within the tumor and compared to other organs (liver, muscle) for binding specificity. A multivariate fitting algorithm was used to spectrally deconvolve the IRDye800CW from endogenous hemoglobin signature (hemoglobin concentration and oxygen saturation). Results: Dynamics of the NIR fluorescence signal within the first hour after injection indicates specific binding compared to muscle, with an average tumor-to-muscle ration of 2.00 (+/- 0.27). Spectral analysis clearly indentified the presence of the NPR-1 probe. Based on calibration data, the average tumor concentration from both NIRF and PCT-S was measured to be ~200-300nM. Conclusion: These preliminary results show the capability of PCT to image an exogenous probe in vivo in addition to its hemoglobin state.

Iodine-123 N-methyl-4-iododexetimide: a new radioligand for single-photon emission tomographic imaging of myocardial muscarinic receptors

International Nuclear Information System (INIS)

Hicks, R.J.; Kassiou, M.; Eu, P.; Katsifis, A.G.; Garra, M.; Power, J.; Najdovski, L.; Lambrecht, R.M.

1995-01-01

Cardiac muscarinic receptor ligands suitable for positron emission tomography have previously been characterised. Attempts to develop radioligands of these receptors suitable for single-photon emission tomographic (SPET) imaging have not been successful due to high lung retention and high non-specific binding of previously investigated potential tracers. The purpose of this study was to evaluate the biodistribution and in vivo imaging characteristics of a new radiopharmaceutical, [ 123 I]N-methyl-4-iododexetimide. Biodistribution studies performed in rats showed high cardiac uptake (2.4% ID/g) 10 min after injection with a heart to lung activity ratio of 5:1. Specificity and stereoselectivity of cardiac binding were demonstrated using blocking experiments in rats. Dynamic imaging studies in anaesthetised greyhounds demonstrated rapid and high myocardial uptake and low lung binding with stable heart to lung activity ratios of >2.5:1 between 10 and 30 min, making SPET imaging feasible. Administration of an excess of an unlabelled muscarinic antagonist, methyl-quinuclidinyl benzylate rapidly displaced myocardial activity to background levels and the pharmacologically inactive enantiomer, [ 123 I]N-methyl-4-iodolevetimide, had no detectable cardiac uptake, indicating specific and stereoselective muscarinic receptor binding. SPET revealed higher activity in the inferior than in the anterior wall, this being consistent with previously described regional variation of cardiac parasympathetic innervation. [ 123 I]N-methyl-4-iododexetimide shows promise as an imaging agent for muscarinic receptor distribution in the heart and may be helpful in evaluating diverse cardiac diseases associated with altered muscarinic receptor function, including heart failure and diabetic heart disease. (orig.)

Plasma prolactin and homovanillic acid as markers for psychopathology and abnormal movements after neuroleptic dose decrease.

Science.gov (United States)

Newcomer, J W; Riney, S J; Vinogradov, S; Csernansky, J G

1992-01-01

Plasma prolactin concentration (pPRL), plasma homovanillic acid concentration (pHVA), and symptomatology were measured in 24 male subjects with schizophrenia during maintenance haloperidol treatment. Fourteen subjects subsequently underwent 50 percent dose decreases under placebo-controlled, double-blind conditions. At baseline, a significant inverse correlation was found between pPRL and both tardive dyskinesia (TD) and "thinking disorder"; pPRL was directly correlated with negative symptoms. No such relationship was found with pHVA. In the patients who underwent a dose decrease, no relationship was found between baseline pPRL or pHVA and any clinical variable after the decrease. These data do not support the use of baseline pPRL or pHVA as markers of central dopamine function subsequent to a neuroleptic dose decrease.

Cellular imaging and folate receptor targeting delivery of gum kondagogu capped gold nanoparticles in cancer cells.

Science.gov (United States)

Kumar, Sathish Sundar Dhilip; Mahesh, Ayyavu; Antoniraj, M Gover; Rathore, Hanumant Singh; Houreld, N N; Kandasamy, Ruckmani

2018-04-01

In this study, the green synthesis of gum kondagogu capped gold nanoparticles (GK-GNPs) was prepared using a naturally available polysaccharide. The anionic gum capped GK-GNPs enabled the successful coupling of folic acid (FA) and fluorescein isothiocyanate (FITC) to produce a fluorescently labelled GNP (F2-GNP). F2-GNPs were further characterized using different physicochemical methods Cellular viability, cellular imaging, and targeted delivery of F2-GNPs were further evaluated in both folate receptor positive (MCF-7) and folate receptor negative (A549) cancer cells. Physicochemical characterization revealed a nanoparticle with a small size (37 nm), smooth surface (surface charge of -23.7 mV), crystallinity of gold nanoparticles and existence of gum kondagogu in the F2-GNPs. Cellular uptake of F2-GNPs indicated a greater affinity towards folate receptor positive cells. This study shows that the F2-GNPs is as an effective nanocarrier for targeted drug delivery and cellular imaging via folate receptors. Copyright © 2017. Published by Elsevier B.V.

Live Cell Imaging and 3D Analysis of Angiotensin Receptor Type 1a Trafficking in Transfected Human Embryonic Kidney Cells Using Confocal Microscopy.

Science.gov (United States)

Kadam, Parnika; McAllister, Ryan; Urbach, Jeffrey S; Sandberg, Kathryn; Mueller, Susette C

2017-03-27

Live-cell imaging is used to simultaneously capture time-lapse images of angiotensin type 1a receptors (AT1aR) and intracellular compartments in transfected human embryonic kidney-293 (HEK) cells following stimulation with angiotensin II (Ang II). HEK cells are transiently transfected with plasmid DNA containing AT1aR tagged with enhanced green fluorescent protein (EGFP). Lysosomes are identified with a red fluorescent dye. Live-cell images are captured on a laser scanning confocal microscope after Ang II stimulation and analyzed by software in three dimensions (3D, voxels) over time. Live-cell imaging enables investigations into receptor trafficking and avoids confounds associated with fixation, and in particular, the loss or artefactual displacement of EGFP-tagged membrane receptors. Thus, as individual cells are tracked through time, the subcellular localization of receptors can be imaged and measured. Images must be acquired sufficiently rapidly to capture rapid vesicle movement. Yet, at faster imaging speeds, the number of photons collected is reduced. Compromises must also be made in the selection of imaging parameters like voxel size in order to gain imaging speed. Significant applications of live-cell imaging are to study protein trafficking, migration, proliferation, cell cycle, apoptosis, autophagy and protein-protein interaction and dynamics, to name but a few.

Receptor binding radiotracers for the angiotensin II receptor: radioiodinated [Sar1, Ile8]angiotensin II

International Nuclear Information System (INIS)

Gibson, R.E.; Beauchamp, H.T.; Fioravanti, C.; Brenner, N.; Burns, H.D.

1994-01-01

The potential for imaging the angiotensin II receptor was evaluated using the radioiodinated peptide antagonist [ 125 I][Sar 1 , Ile 8 ]angiotensin II. The radioligand provides a receptor-mediated signal in several tissues in rat (kidneys, adrenal and liver). The receptor-mediated signal of 3% ID/g kidney cortex should be sufficient to permit imaging, at least via SPECT. The radiotracer is sensitive to reductions in receptor concentration and can be used to define in vivo dose-occupancy curves of angiotensin II receptor ligands. Receptor-mediated images of [ 123 I][Sar 1 , Ile 8 ]angiotensin II were obtained in the rat kidney and Rhesus monkey liver. (author)

Imaging of receptors in clinical neurosciences

NARCIS (Netherlands)

Korf, J

This article deals with the question why should one determine receptors in the brain with positron and single photon emission tomography (PET and SPECT, respectively). Radiopharmaceuticals for a wide variety of receptors are available now. Receptors studies with PET and SPECT have thus far focused

Fundamental considerations in the design of fluorine-18 labeled progestins and androgens as imaging agents for receptor-positive tumors of the breast and prostate

International Nuclear Information System (INIS)

Brandes, S.J.; Katzenellenbogen, J.A.

1988-01-01

A review is given of the structural and functional features which are important in the design and development of imaging agents for the progesterone receptor (PR) and the androgen receptor (AR) directed towards imaging receptor-positive tumors in the breast and prostate respectively. In particular the effects of various substituents on the biological activities and homologous receptor binding of progesterone, testosterone, nortestosterone and dihydrotestosterone are discussed. The effect of fluorine substitution on the affinities of progestins and androgens for their respective receptors is described. Other ligand systems that have high affinity for AR and PR and which may provide good bases for the design of fluorine-substituted imaging agents are also discussed. Finally, previous studies with radiolabelled progestins and androgens are described. (U.K.)

Radioiodinated SB 207710 as a radioligand in vivo: imaging of brain 5-HT{sub 4} receptors with SPET

Energy Technology Data Exchange (ETDEWEB)

Pike, Victor W. [MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, W12 0NN, London (United Kingdom); PET Radiopharmaceutical Sciences Section, Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, MD 20892-1003, Bethesda (United States); Halldin, Christer; Nobuhara, Kenji; Swahn, Carl-Gunnar; Karlsson, Per; Olsson, Hans; Larsson, Stig; Schnell, Per-Olof; Farde, Lars [Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institutet, Karolinska Hospital, 17176, Stockholm (Sweden); Hiltunen, Julka [MAP Medical Technologies, Oy, Tikkakoski (Finland); Mulligan, Rachel S. [MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, W12 0NN, London (United Kingdom); Institute of Psychiatry, SE 8AF, De Crespigny Park, Denmark Hill, London (United Kingdom); Centre for PET, Austin and Repatriation Medical Centre, Studley Road, Melbourne VIC 3084 (Australia); Hume, Susan P.; Hirani, Ella [MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, W12 0NN, London (United Kingdom); Imaging Research Solutions Ltd., Cyclotron Building, Hammersmith Hospital, Ducane Road, W12 0NN, London (United Kingdom); Whalley, Jaqueline [MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, W12 0NN, London (United Kingdom); Pilowsky, Lyn S. [Institute of Psychiatry, SE 8AF, De Crespigny Park, Denmark Hill, London (United Kingdom); Institute of Nuclear Medicine, Royal Free and University College, Medical School, Mortimer Street, W1N 8AA, London (United Kingdom); Ell, Peter J. [Institute of Nuclear Medicine, Royal Free and University College, Medical School, Mortimer Street, W1N 8AA, London (United Kingdom)

2003-11-01

Single-photon emission tomography (SPET) and positron emission tomography (PET), when coupled to suitable radioligands, are uniquely powerful for investigating the status of neurotransmitter receptors in vivo. The serotonin subtype-4 (5-HT{sub 4}) receptor has discrete and very similar distributions in rodent and primate brain. This receptor population may play a role in normal cognition and memory and is perhaps perturbed in some neuropsychiatric disorders. SB 207710 [(1-butyl-4-piperidinylmethyl)-8-amino-7-iodo-1,4-benzodioxan-5-carboxylate] is a selective high-affinity antagonist at 5-HT{sub 4} receptors. We explored radioiodinated SB 207710 as a possible radioligand for imaging 5-HT{sub 4} receptors in vivo. Rats were injected intravenously with iodine-125 labelled SB 207710, euthanised at known times and dissected to establish radioactivity content in brain tissues. Radioactivity entered brain but cleared rapidly and to a high extent from blood and plasma. Between 45 and 75 min after injection, the ratios of radioactivity concentration in each of 12 selected brain tissues to that in receptor-poor cerebellum correlated with previous measures of 5-HT{sub 4} receptor density distribution in vitro. The highest ratio was about 3.4 in striatum. SB 207710 was labelled with iodine-123 by an iododestannylation procedure. A cynomolgus monkey was injected intravenously with [{sup 123}I]SB 207710 and examined by SPET. Maximal whole brain uptake of radioactivity was 2.3% of the injected dose at 18 min after radioligand injection. Brain images acquired between 9 and 90 min showed high radioactivity uptake in 5-HT{sub 4} receptor-rich regions, such as striatum, and low uptake in receptor-poor cerebellum. At 169 min the ratio of radioactivity concentration in striatum to that in cerebellum was 4.0. In a second SPET experiment, the cynomolgus monkey was pretreated with a selective 5-HT{sub 4} receptor antagonist, SB 204070, at 20 min before [{sup 123}I]SB 207710 injection

Imaging of D2 dopamine receptors of patients with Parkinson's disease using SPECT and 131I-IBZM

International Nuclear Information System (INIS)

Zhang Wei; Wang Jian; Jiang Yuping; Lu Chuanzhen

2001-01-01

Objective: To evaluate the usefulness of SPECT with 131 I-IBZM in imaging of D 2 Dopamine receptors in patients with Parkinson's disease (PD). Methods: Six patients which early unmedicated PD, six patients with moderate or advanced PD treated with long-term oral L-Dopa and Four control subjects were investigated with SPECT using 131 I-IBZM as dopamine receptor ligand. The ratio of basal ganglia to occipital cortex (BG/OC) and ratio of basal ganglia to frontal cortex (BG/FC) were calculated as semiquantitative parameter of striatal D 2 dopamine receptor's function. Results: The SPECT images revealed high uptake of IBZM in the basal ganglia. In the early unmedicated PD group, the BG/PC and BG/FC rates were significantly higher in the striatum contralateral to the parkinsonism. In the moderate or advanced PD group, no significant differences were observed bilaterally, and the BG/OC and the BG/FC rates in this group was lower than those of the control. Conclusion: 131 I-IBZM with SPECT imaging is useful in evaluating patients with Parkinson's disease

Experimental research for tumor VIP receptor imaging

International Nuclear Information System (INIS)

Li Qianwei; Tan Tianzhi

1998-01-01

To study the possibility of radioactive labelled vasoactive intestinal peptide (VIP) for tumor VIP receptor imaging. 125 I-VIP was prepared by chloramine-T method, and purified by Sephadex G-50 column chromatography. The bioactivity and stability of 125 I-VIP were measured by silica 60 F 254 TLC and competition test to SGC7901 cell in vitro. The biodistribution of 125 I-VIP was studied in the nude mice bearing tumor. The results showed that labelled rate of 125 I was 73.8%, the specific activity was 18.2 PBq/mol, the radiochemical purity (RCP) was over 98% and remained 96.3% after 48 days stored at -80 degree C. The specific binding of 125 I-VIP to the SGC7901 cell was inhibited by VIP in dose dependence in the competition experiment. The radioactivity of tumor was higher than that of muscles in all phases (P<0.05-0.01), the peak activity of tumor occurred at 30 min (3.58 +- 0.48ID%/g) and the peak ratio of T/N occurred at 60 min after the injection. The activity of lungs was obviously higher than that of blood, the intestine was always in low level. Most of the activity in the body was mainly eliminated from kidney. The present study demonstrated that the radioactive labelled VIP is a promising agent for tumor VIP receptor scintigraphy

Dgroup: DG00900 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available hydrochloride (JAN) ... Neuropsychiatric agent ... DG01941 ... Benzamide antipsychotic ... DG01478 ... Dopamine antagonis...t ... DG01474 ... Dopamine D2-receptor antagonist ATC code: N05AL02 Antipsychotic, Neuroleptic, Dopamine D2 receptor antagonist Benzamide derivative DRD2 [HSA:1813] [KO:K04145] ...

Quantitative Analysis of HER2 Receptor Expression In Vivo by Near-Infrared Optical Imaging

Directory of Open Access Journals (Sweden)

Victor Chernomordik

2010-07-01

Full Text Available Human epidermal growth factor receptor 2 (HER2 overexpression in breast cancers is associated with poor prognosis and resistance to therapy. Current techniques for estimating this important characteristic use ex vivo assays that require tissue biopsies. We suggest a novel noninvasive method to characterize HER2 expression in vivo, using optical imaging, based on HER2-specific probes (albumin-binding domain–fused-(ZHER2:3422-Cys Affibody molecules [Affibody AB, Solna, Sweden], labeled with Alexa Fluor 750 [Molecular Probes, Invitrogen, Carlsbad, CA] that could be used concomitantly with HER2-targeted therapy. Subcutaneous tumor xenografts, expressing different levels of HER2, were imaged with a near-infrared fluorescence small-animal imaging system at several times postinjection of the probe. The compartmental ligand-receptor model was used to calculate HER2 expression from imaging data. Correlation between HER2 amplification/overexpression in tumor cells and parameters, directly estimated from the sequence of optical images, was observed (eg, experimental data for BT474 xenografts indicate that initial slope, characterizing the temporal dependence of the fluorescence intensity detected in the tumor, linearly depends on the HER2 expression, as measured ex vivo by an enzyme-linked immunosorbent assay for the same tumor. The results obtained from tumors expressing different levels of HER2 substantiate a similar relationship between the initial slope and HER2 amplification/overexpression. This work shows that optical imaging, combined with mathematical modeling, allows noninvasive monitoring of HER2 expression in vivo.

Tratamento farmacológico de acatisia induzida por antipsicóticos Pharmacological treatment of neuroleptic-induced akathisia

Directory of Open Access Journals (Sweden)

Adriano Resende Lima

2001-06-01

Full Text Available INTRODUÇÃO: A acatisia induzida por antipsicóticos é um transtorno de movimento relacionado ao sistema motor e caracterizado por sensação subjetiva de inquietude interna, irritabilidade ou disforia que podem ser intensas. Associa-se à sensação física e objetiva de desassossego e a movimentos não discinéticos. Esse efeito adverso pode predispor à pobre adesão ao tratamento e, conseqüentemente, favorecer recaídas. Assim, a escolha do melhor tratamento contribui para o alívio do sofrimento dos pacientes e favorece o melhor prognóstico. OBJETIVOS: Avaliar a eficácia e a tolerabilidade dos betabloqueadores, benzodiazepínicos e anticolinérgicos, comparados ao placebo e entre si, no tratamento de acatisia induzida por antipsicóticos, independente de idade ou diagnóstico psiquiátrico. MÉTODOS: Todos os estudos controlados, obtidos a partir das estratégias de busca que compararam betabloqueadores de ação central, benzodiazepínicos ou anticolinérgicos ao placebo e entre si, independente de sexo, idade ou diagnóstico psiquiátrico, foram considerados para esta atualização. Até março de 1999, foram consultadas sete bases de dados eletrônicos, sendo também examinadas as referências bibliográficas dos artigos selecionados. RESULTADOS: São apresentados 22 estudos controlados, sendo 13 comparando betabloqueadores, benzodiazepínicos e anticolinérgicos ao placebo e nove comparando diretamente as intervenções entre si. CONCLUSÕES: As três intervenções farmacológicas demonstraram eficácia superior comparadas ao placebo. Betabloqueadores de ação central mostraram-se mais eficazes, quando comparados a betabloqueadores de ação periférica, benzodiazepínicos e anticolinérgicos.INTRODUCTION: Neuroleptic-induced akathisia is a movement disorder related to the motor system characterized by complaints of inner restlessness, mental uneasiness, or dysphoria, all of which can be intense. Restlessness and non

Synthesis and evaluation of [11C]Cimbi-806 as a potential PET ligand for 5-HT₇ receptor imaging

DEFF Research Database (Denmark)

Herth, Matthias Manfred; Hansen, Hanne Demant; Ettrup, Anders Janusz

2012-01-01

)-N,N-dimethylethanamine ([(11)C]Cimbi-806) as a radioligand for imaging brain 5-HT(7) receptors with positron emission tomography (PET). Precursor and reference compound was synthesized and subsequent (11)C-labelling with [(11)C]methyltriflate produced [(11)C]Cimbi-806 in specific activities ranging from 50 to 300 GBq...... of appropriate in vivo blocking with a 5-HT(7) receptor selective compounds renders the conclusion that [(11)C]Cimbi-806 is not an appropriate PET radioligand for imaging the 5-HT(7) receptor in vivo....

Revealing dynamically-organized receptor ion channel clusters in live cells by a correlated electric recording and super-resolution single-molecule imaging approach.

Science.gov (United States)

Yadav, Rajeev; Lu, H Peter

2018-03-28

The N-methyl-d-aspartate (NMDA) receptor ion-channel is activated by the binding of ligands, along with the application of action potential, important for synaptic transmission and memory functions. Despite substantial knowledge of the structure and function, the gating mechanism of the NMDA receptor ion channel for electric on-off signals is still a topic of debate. We investigate the NMDA receptor partition distribution and the associated channel's open-close electric signal trajectories using a combined approach of correlating single-molecule fluorescence photo-bleaching, single-molecule super-resolution imaging, and single-channel electric patch-clamp recording. Identifying the compositions of NMDA receptors, their spatial organization and distributions over live cell membranes, we observe that NMDA receptors are organized inhomogeneously: nearly half of the receptor proteins are individually dispersed; whereas others exist in heterogeneous clusters of around 50 nm in size as well as co-localized within the diffraction limited imaging area. We demonstrate that inhomogeneous interactions and partitions of the NMDA receptors can be a cause of the heterogeneous gating mechanism of NMDA receptors in living cells. Furthermore, comparing the imaging results with the ion-channel electric current recording, we propose that the clustered NMDA receptors may be responsible for the variation in the current amplitude observed in the on-off two-state ion-channel electric signal trajectories. Our findings shed new light on the fundamental structure-function mechanism of NMDA receptors and present a conceptual advancement of the ion-channel mechanism in living cells.

Multivariate cluster analysis of dynamic iodine-123 iodobenzamide SPET dopamine D{sub 2}receptor images in schizophrenia

Energy Technology Data Exchange (ETDEWEB)

Acton, P.D. [Inst. of Nuclear Medicine, Univ. Coll. London Medical School, London (United Kingdom); Pilowsky, L.S. [Institute of Psychiatry, London (United Kingdom); Costa, D.C. [Inst. of Nuclear Medicine, Univ. Coll. London Medical School, London (United Kingdom); Ell, P.J. [Inst. of Nuclear Medicine, Univ. Coll. London Medical School, London (United Kingdom)

1997-02-01

This paper describes the application of a multivariate statistical technique to investigate striatal dopamine D{sub 2}receptor concentrations measured by iodine-123 iodobenzamide ({sup 123}I-IBZM) single-photon emission tomography (SPET). This technique enables the automatic segmentation of dynamic nuclear medicine images based on the underlying time-activity curves present in the data. Once the time-activity curves have been extracted, each pixel can be mapped back on to the underlying distribution, considerably reducing image noise. Cluster analysis has been verified using computer simulations and phantom studies. The technique has been applied to SPET images of dopamine D {sub 2}receptors in a total of 20 healthy and 20 schizophrenic volunteers (22 male, 18 female), using the ligand {sup 123}I-IBZM. Following automatic image segmentation, the concentration of striatal dopamine D {sub 2}receptors shows a significant left-sided asymmetry in male schizophrenics compared with male controls. The mean left-minus-right laterality index for controls is -1.52 (95% CI -3.72-0.66) and for patients 4.04 (95% CI 1.07-7.01). Analysis of variance shows a case-by-sex-by-side interaction, with F=10.01, P=0.005. We can now demonstrate that the previously observed male sex-specific D {sub 2}receptor asymmetry in schizophrenia, which had failed to attain statistical significance, is valid. Cluster analysis of dynamic nuclear medicine studies provides a powerful tool for automatic segmentation and noise reduction of the images, removing much of the subjectivity inherent in region-of-interest analysis. The observed striatal D {sub 2}asymmetry could reflect long hypothesized disruptions in dopamine-rich cortico-striatal-limbic circuits in schizophrenic males. (orig.). With 4 figs., 2 tabs.

Stimulatory effect of the D2 antagonist sulpiride on glucose utilization in dopaminergic regions of rat brain

Energy Technology Data Exchange (ETDEWEB)

Pizzolato, G; Soncrant, T T; Larson, D M; Rapoport, S I

1987-08-01

Local cerebral glucose utilization (LCGU) was measured, using the quantitative autoradiographic (/sup 14/C)2-deoxy-D-glucose method, in 56 brain regions of 3-month-old, awake Fischer-344 rats, after intraperitoneal administration of sulpiride (SULP) 100 mg/kg. SULP, an atypical neuroleptic, is a selective antagonist of D2 dopamine receptors. LCGU was reduced in a few nondopaminergic regions at 1 h after drug administration. Thereafter, SULP progressively elevated LCGU in many other regions. At 3 h, LCGU was elevated in 23% of the regions examined, most of which are related to the CNS dopaminergic system (caudate-putamen, nucleus accumbens, olfactory tubercle, lateral habenula, median eminence, paraventricular hypothalamic nucleus). Increases of LCGU were observed also in the suprachiasmatic nucleus, lateral geniculate, and inferior olive. These effects of SULP on LCGU differ from the effects of the typical neuroleptic haloperidol, which produces widespread decreases in LCGU in the rat brain. Selective actions on different subpopulations of dopamine receptors may explain the different effects of the two neuroleptics on brain metabolism, which correspond to their different clinical and behavioral actions.

Paliperidone Inducing Concomitantly Syndrome of Inappropriate Antidiuretic Hormone, Neuroleptic Malignant Syndrome, and Rhabdomyolysis

Directory of Open Access Journals (Sweden)

Jaspinder Kaur

2016-01-01

Full Text Available Paliperidone, an active metabolite of risperidone, is a new atypical antipsychotic agent. Syndrome of inappropriate antidiuretic hormone (SIADH, neuroleptic malignant syndrome (NMS, and rhabdomyolysis are the uncommon side effects of psychotropic drugs. We report a case of 35-year-old male with schizoaffective disorder who was admitted for acute-on-chronic exacerbation of his psychotic disorder for which intramuscular paliperidone 234 mg injection was given. Two days later, the patient developed hyponatremic seizures secondary to SIADH which was treated with hypertonic saline. On the third day, he developed high grade fever and severe muscle rigidity with raised creatine phosphokinase (CPK and liver enzymes levels. He was treated with dantrolene 100 mg, bromocriptine 2.5 mg, and lorazepam 2 mg. Our patient required management of the three rare conditions following treatment with paliperidone. This case highlights the need for health care providers to be aware of the rare, potentially life threatening but preventable hyponatremia, NMS, and rhabdomyolysis as a possible adverse effect of paliperidone.

Peptides and receptors in image-guided therapy: theranostics for neuroendocrine neoplasms.

Science.gov (United States)

Baum, Richard P; Kulkarni, Harshad R; Carreras, Cecilia

2012-05-01

Theranostics of neuroendocrine neoplasms (NENs) based on molecular imaging using receptor positron emission tomography/computed tomography (PET/CT) with (68)Ga-labeled somatostatin (SMS) analogs and molecular radiotherapy applying peptide receptor radionuclide therapy (PRRNT) with (90)Y- and/or (177)Lu-labeled peptides has paved the way to personalized medicine. SMS receptor PET/CT enables very accurate detection of NENs and their metastases with high diagnostic sensitivity and specificity and provides quantitative, reproducible data that can be used for selecting patients for PRRNT and evaluation of therapy response. Among other advantages are the fast imaging protocol (total study time, 60-90 minutes), low radiation burden (10-12 mSv), flexibility in daily use, and lower cost than octreotide scintigraphy. As we move toward personalized medicine, the diagnostic information obtained from PET/CT must be improved, that is, by fast routine quantification of lesions. PRRNT is highly effective for the treatment of NENs, even in very advanced cases, and lends a benefit in overall survival of several years. In addition, significant improvement in clinical symptoms and excellent palliation can be achieved. In patients with progressive NENs, fractionated, personalized PRRNT with lower doses of radioactivity given over a longer period (Bad Berka Concept) results in good therapeutic responses. By this concept, severe hematologic and/or renal toxicity can be reduced or completely avoided, and the quality of life can be improved. Sequential (DUO-PRRNT) and concurrent (TANDEM-PRRNT) administrations of radiopeptides are more effective in progressive NEN than using either radionuclide alone. PRRNT should only be performed at specialized centers, as NEN patients need highly individualized interdisciplinary treatment and long-term care. Copyright © 2012 Elsevier Inc. All rights reserved.

Evaluation of an image receptor for computed radiography system in mammography

International Nuclear Information System (INIS)

Dantas, Marcelino V.A.; Rosado, Paulo H.G.; Santana, Priscila C.; Alvarenga, Frederico L.; Nogueira, Maria S.

2009-01-01

In this work, the performance of an image receptor for computed radiography system, Kodak CR850, was assessed through tests, recommended by the European protocol, with a specific image plate for mammography where were analyzed the Contrast-to-noise ratio (CNR) and uniformity and linearity of detector. The CNRs were 14.1, 11.7, 10.3, 8.4, 7.1 and 5.9 for 2, 3, 4, 5, 6 and 7 cm polymethylmethacrylate (PMMA) thickness, respectively. The linearity between detector response and dose, obtained a correlation coefficient (R 2 ) greater than 0.99, and the maximum variation found in the detector uniformity calculation was 3.94 in the lower right corner. (author)

Gd-EDDA/HYNIC-RGD as an MR molecular probe imaging integrin alphanubeta3 receptor-expressed tumor-MR molecular imaging of angiogenesis.

Science.gov (United States)

Huo, Tianlong; Du, Xiangke; Zhang, Sen; Liu, Xia; Li, Xubing

2010-02-01

The aim of this study is to develop a novel MR probe containing arginine-glycine-aspartic acid (RGD) motif for imaging integrin alphanubeta3 receptor-expressed tumor. Commercially available HYNIC-RGD conjugated with co-ligand EDDA was labeled with Gd(3+), and the mixture was isolated and purified by solid phase extract (SPE) to get the entire probe Gd-EDDA/HYNIC-RGD. Human hepatocellular carcinoma (HHCC) cell line BEL-7402 was cultured and the cells harvested and suspended in serum-free Dulbecco's modified Eagle medium (DMEM) were subcutaneously inoculated into athymic nude mice for tumor growth. In vitro cell binding assay to integrin alphanubeta3 receptor and cell viability experiments were conducted. The in vivo imaging of the three arms of xenografts were performed by MR scan with a dedicated animal coil at time points of 0, 30, 60, 90min and 24-h post-intravenous injection (p.i.). Three arms of nude mice then were sacrificed for histological examination to confirm the imaging results. Gd-EDDA/HYNIC-RGD was successfully isolated by SPE and validity was verified on signal enhancement through in vitro and in vivo experiments. The nude mice model bearing HHCC was well established. There was approx. 30% signal enhancement on T1WI FSE images at 90min post-intravenous injection of the Gd-EDDA/HYNIC-RGD compared with baseline, and the signal to time curve is straightforward over time in the span of 0-90min p.i., while the control arms do not show this tendency. Gd-EDDA/HYNIC-RGD has the potential to serve as an MR probe detecting integrin alphanubeta3 receptor-expressed tumor. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.

PET/CT imaging of human somatostatin receptor 2 (hsstr2) as reporter gene for gene therapy

International Nuclear Information System (INIS)

Hofmann, M.; Gazdhar, A.; Weitzel, T.; Schmid, R.; Krause, T.

2006-01-01

Localized information on region-selective gene expression in small animals is widely obtained by use of reporter genes inducing light emission. Using these reporter genes for imaging deep inside the human body fluorescent probes are hindered by attenuation, scattering and possible fluorescence quenching. This can be overcome by use of radio-peptide receptors as reporter genes. Therefore, the feasibility of the somatostatin receptor 2 expression vector system for expression imaging was checked against a control vector containing luciferase gene. For in vivo transduction of vector DNA into the rat forelimb muscles the in vivo electroporation technique was chosen because of its high regio-selectivity. The gene expression was imaged by high-sensitive CCD camera (luciferase activity) and by PET/CT using a Ga-68-DOTATOC as radio peptide probe. The relative sstr2 expression was enhanced by gene transduction at maximum to a factor of 15. The PET/CT images could be fully quantified. The above demonstrated feasibility of radio-peptide PET/CT reporter gene imaging may serve in the future as a tool for full quantitative understanding of regional gene expression, especially in large animals and humans

PET/CT imaging of human somatostatin receptor 2 (hsstr2) as reporter gene for gene therapy

Energy Technology Data Exchange (ETDEWEB)

Hofmann, M. [Molecular Imaging and Therapy Group (MIT-Bern), Clinic of Nuclear Medicine, Inselspital, Medical School Bern (Switzerland)]. E-mail: Michael.Hofmann@insel.ch; Gazdhar, A. [Division of Pulmonary Medicine, University Hospital Bern (Switzerland); Weitzel, T. [Molecular Imaging and Therapy Group (MIT-Bern), Clinic of Nuclear Medicine, Inselspital, Medical School Bern (Switzerland); Schmid, R. [Division of Thoracic Surgery, University Hospital Bern (Switzerland); Krause, T. [Molecular Imaging and Therapy Group (MIT-Bern), Clinic of Nuclear Medicine, Inselspital, Medical School Bern (Switzerland)

2006-12-20

Localized information on region-selective gene expression in small animals is widely obtained by use of reporter genes inducing light emission. Using these reporter genes for imaging deep inside the human body fluorescent probes are hindered by attenuation, scattering and possible fluorescence quenching. This can be overcome by use of radio-peptide receptors as reporter genes. Therefore, the feasibility of the somatostatin receptor 2 expression vector system for expression imaging was checked against a control vector containing luciferase gene. For in vivo transduction of vector DNA into the rat forelimb muscles the in vivo electroporation technique was chosen because of its high regio-selectivity. The gene expression was imaged by high-sensitive CCD camera (luciferase activity) and by PET/CT using a Ga-68-DOTATOC as radio peptide probe. The relative sstr2 expression was enhanced by gene transduction at maximum to a factor of 15. The PET/CT images could be fully quantified. The above demonstrated feasibility of radio-peptide PET/CT reporter gene imaging may serve in the future as a tool for full quantitative understanding of regional gene expression, especially in large animals and human000.

Pharmacological evaluation of halogenated and non-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles as D(2) and 5-HT(2A) receptor ligands.

Science.gov (United States)

Tomić, Mirko; Vasković, Djurdjica; Tovilović, Gordana; Andrić, Deana; Penjišević, Jelena; Kostić-Rajačić, Sladjana

2011-05-01

Five groups of previously synthesized and initially screened non-substituted and 4-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles were estimated for their in-vitro binding affinities at the rat D(2) , 5-HT(2A) , and α(1) -adrenergic receptors. Among all these compounds, 2-methoxyphenyl and 2-chlorophenyl piperazines demonstrate the highest affinities for the tested receptors. The effects of 4-halogenation of benzimidazoles reveal that substitution with bromine may greatly increase the affinity of the compounds for the studied receptors, while the effect of substitution with chlorine is less remarkable. Most of the tested components show 5-HT(2A)/D(2) pK(i) binding ratios slightly above or less than 1, while only 4-chloro-6-(2-{4-[3-(trifluoromethyl)phenyl]piperazin-1-yl}ethyl)-1H-benzimidazole expresses an appropriate higher binding ratio (1.14), which was indicated for atypical neuroleptics. This compound exhibits a non-cataleptic action in rats and prevents d-amphetamine-induced hyperlocomotion in mice, which suggest its atypical antipsychotic potency. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

124I-Epidepride: A PET radiotracer for extended imaging of dopamine D2/D3 receptors

International Nuclear Information System (INIS)

Pandey, Suresh; Venugopal, Archana; Kant, Ritu; Coleman, Robert; Mukherjee, Jogeshwar

2014-01-01

Objectives: A new radiotracer, 124 I-epidepride, has been developed for the imaging of dopamine D2/3 receptors (D2/3Rs). 124 I-Epidepride (half-life of 124 I = 4.2 days) allows imaging over extended periods compared to 18 F-fallypride (half-life of 18 F = 0.076 days) and may maximize visualization of D2/3Rs in the brain and pancreas (allowing clearance from adjacent organs). D2/3Rs are also present in pancreatic islets where they co-localize with insulin to produce granules and may serve as a surrogate marker for imaging diabetes. Methods: 124 I-Epidepride was synthesized using N-[[(2S)-1-ethylpyrrolidin-2-yl]methyl]-5-tributyltin-2, 3-dimethoxybenzamide and 124 I-iodide under no carrier added condition. Rats were used for in vitro and in vivo imaging. Brain slices were incubated with 124 I-epidepride (0.75 μCi/cc) and nonspecific binding measured with 10 μM haloperidol. Autoradiograms were analyzed by OptiQuant. 124 I-Epidepride (0.2 to 0.3 mCi, iv) was administered to rats and brain uptake at 3 hours, 24 hours, and 48 hours post injection was evaluated. Results: 124 I-Epidepride was obtained with 50% radiochemical yield and high radiochemical purity (> 95%). 124 I-Epidepride localized in the striatum with a striatum to cerebellum ratio of 10. Binding was displaced by dopamine and haloperidol. Brain slices demonstrated localization of 124 I-epidepride up until 48 hours in the striatum. However, the extent of binding was reduced significantly. Conclusions: 124 I-Epidepride is a new radiotracer suitable for extended imaging of dopamine D2/3 receptors and may have applications in imaging of receptors in the brain and monitoring pancreatic islet cell grafting

Fluorescence lifetime FRET imaging of receptor-ligand complexes in tumor cells in vitro and in vivo

Science.gov (United States)

Rudkouskaya, Alena; Sinsuebphon, Nattawut; Intes, Xavier; Mazurkiewicz, Joseph E.; Barroso, Margarida

2017-02-01

To guide the development of targeted therapies with improved efficacy and accelerated clinical acceptance, novel imaging methodologies need to be established. Toward this goal, fluorescence lifetime Förster resonance energy transfer (FLIM-FRET) imaging assays capitalize on the ability of antibodies or protein ligands to bind dimerized membrane bound receptors to measure their target engagement levels in cancer cells. Conventional FLIM FRET microscopy has been widely applied at visible wavelengths to detect protein-protein interactions in vitro. However, operation at these wavelengths restricts imaging quality and ability to quantitate lifetime changes in in vivo small animal optical imaging due to high auto-fluorescence and light scattering. Here, we have analyzed the uptake of iron-bound transferrin (Tf) probes into human breast cancer cells using FLIM-FRET microscopy in the visible and near-infrared (NIR) range. The development of NIR FLIM FRET microscopy allows for the use of quantitative lifetime-based molecular assays to measure drug-target engagement levels at multiple scales: from in vitro microscopy to in vivo small animal optical imaging (macroscopy). This novel approach can be extended to other receptors, currently targeted in oncology. Hence, lifetime-based molecular imaging can find numerous applications in drug delivery and targeted therapy assessment and optimization.

In vivo stem cell tracking with imageable nanoparticles that bind bioorthogonal chemical receptors on the stem cell surface.

Science.gov (United States)

Lee, Sangmin; Yoon, Hwa In; Na, Jin Hee; Jeon, Sangmin; Lim, Seungho; Koo, Heebeom; Han, Sang-Soo; Kang, Sun-Woong; Park, Soon-Jung; Moon, Sung-Hwan; Park, Jae Hyung; Cho, Yong Woo; Kim, Byung-Soo; Kim, Sang Kyoon; Lee, Taekwan; Kim, Dongkyu; Lee, Seulki; Pomper, Martin G; Kwon, Ick Chan; Kim, Kwangmeyung

2017-09-01

It is urgently necessary to develop reliable non-invasive stem cell imaging technology for tracking the in vivo fate of transplanted stem cells in living subjects. Herein, we developed a simple and well controlled stem cell imaging method through a combination of metabolic glycoengineering and bioorthogonal copper-free click chemistry. Firstly, the exogenous chemical receptors containing azide (-N 3 ) groups were generated on the surfaces of stem cells through metabolic glycoengineering using metabolic precursor, tetra-acetylated N-azidoacetyl-d-mannosamine(Ac 4 ManNAz). Next, bicyclo[6.1.0]nonyne-modified glycol chitosan nanoparticles (BCN-CNPs) were prepared as imageable nanoparticles to deliver different imaging agents. Cy5.5, iron oxide nanoparticles and gold nanoparticles were conjugated or encapsulated to BCN-CNPs for optical, MR and CT imaging, respectively. These imageable nanoparticles bound chemical receptors on the Ac 4 ManNAz-treated stem cell surface specifically via bioorthogonal copper-free click chemistry. Then they were rapidly taken up by the cell membrane turn-over mechanism resulting in higher endocytic capacity compared non-specific uptake of nanoparticles. During in vivo animal test, BCN-CNP-Cy5.5-labeled stem cells could be continuously tracked by non-invasive optical imaging over 15 days. Furthermore, BCN-CNP-IRON- and BCN-CNP-GOLD-labeled stem cells could be efficiently visualized using in vivo MR and CT imaging demonstrating utility of our stem cell labeling method using chemical receptors. These results conclude that our method based on metabolic glycoengineering and bioorthogonal copper-free click chemistry can stably label stem cells with diverse imageable nanoparticles representing great potential as new stem cell imaging technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

THE USE OF POSITRON EMISSION TOMOGRAPHY IN IDENTIFYING AND QUANTIFYING RECEPTORS INVOLVED IN SCHIZOPHRENIA.

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VOLKOW,N.D.; WOLF,A.P.

1991-01-01

Schizophrenia is a devasting mental disorder that is the focus of a great deal of research. Some symptoms of the disease, such as auditory hallucinations and delusions, can be ameliorated with drug treatment, whereas other symptoms, such as social withdrawal and cognitive decline, remain uncontrolled. It is possible that these latter symptoms that are often termed ''negative symptoms'' are the result of anatomical and neurochemical abnormalities, whereas those symptoms of the disease such as auditory hallucinations that are termed ''positive symptoms'' may be a result of only neurochemical disorders. The drugs used to treat schizophrenia are designated neuroleptics. The term neuroleptic was chosen to emphasize the similarity of pharmacological profiles of drugs with entirely different chemical structures. Especially prominent features of the effects of neuroleptics include the following: a state of affective indifference; a decrease in locomotor activity; a decrease in excitation, agitation, and aggressiveness; and an antipsychotic action in patients with acute as well as chronic psychoses.

Malignant Neuroleptic Syndrome following Deep Brain Stimulation Surgery of Globus Pallidus Pars Internus in Cerebral Palsy

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Jae Meen Lee

2016-02-01

Full Text Available Neuroleptic malignant syndrome (NMS is a rare but potentially lethal outcome caused by sudden discontinuation or dose reduction of dopaminergic agents. We report an extremely rare case of NMS after deep brain stimulation (DBS surgery in a cerebral palsy (CP patient without the withdrawal of dopaminergic agents. A 19-year-old girl with CP was admitted for DBS due to medically refractory dystonia and rigidity. Dopaminergic agents were not stopped preoperatively. DBS was performed uneventfully under monitored anesthesia. Dopaminergic medication was continued during the postoperative period. She manifested spasticity and muscle rigidity, and was high fever resistant to anti-pyretic drugs at 2 h postoperative. At postoperative 20 h, she suffered cardiac arrest and expired, despite vigorous cardiopulmonary resuscitation. NMS should be considered for hyperthermia and severe spasticity in CP patients after DBS surgery, irrespective of continued dopaminergic medication.

In vivo (/sup 3/H)flunitrazepam binding: imaging of receptor regulation

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Ciliax, B.J.; Penney, J.B. Jr.; Young, A.B.

1986-08-01

The use of (/sup 3/H)flunitrazepam as a ligand to measure alterations in benzodiazepine receptors in vivo in rats was investigated. Animals were injected with (/sup 3/H)flunitrazepam i.v., arterial samples of (/sup 3/H)flunitrazepam were obtained and, later, the animals were sacrificed to assay brain binding. (/sup 3/H)flunitrazepam enters the brain rapidly and binds to benzodiazepine receptors. About two-thirds of this binding is blocked by predosing the animals with 5 mg/kg of clonazepam. The amount of remaining (nonspecific) binding correlates very well (r = 0.88) with the amount of radioactivity found in plasma at the time of death. A series of rats were lesioned unilaterally with kainic acid in the caudate-putamen several months before the infusion of (/sup 3/H)flunitrazepam. In vivo autoradiography in lesioned rats showed that benzodiazepine binding in globus pallidus and substantia nigra on the side of the lesion was increased significantly as compared to the intact side. The observed changes in benzodiazepine binding were similar to those observed previously in lesioned rats using in vitro techniques. Thus, benzodiazepine receptor regulation can be imaged quantitatively using in vivo binding techniques.

[99mTc]O2-AMD3100 as a SPECT tracer for CXCR4 receptor imaging

International Nuclear Information System (INIS)

Hartimath, Siddesh V.; Domanska, Urszula M.; Walenkamp, Annemiek M.E.; Dierckx, Rudi A.J.O.; Vries, Erik F.J. de

2013-01-01

Purpose: CXCR4 plays an important role in HIV infection, tumor progression, neurogenesis, and inflammation. In-vivo imaging of CXCR4 could provide more insight in the role of this receptor in health and disease. The aim of this study was to investigate [ 99m Tc]O 2 -AMD3100 as a potential SPECT tracer for imaging of CXCR4. Method: AMD3100 was labelled with [ 99m Tc]pertechnetate. A cysteine challenge assay was performed to test the tracer stability. Heterologous and homologous receptor binding assay and internalization assay were performed in CXCR4 expressing Jurkat-T cells. Ex vivo biodistribution was studied in healthy mice at 30, 60, and 120 min after tracer injection. Tumor uptake of the tracer was determined by microSPECT imaging in nude mice xenografted with human PC-3 prostate tumor. Specificity of tracer uptake was determined by blocking studies using an excess of unlabelled AMD3100. Results: AMD3100 was labelled with technetium-99 m with a radiochemical yield of > 98%. The tracer was stable in PBS and mouse plasma for at least 6 h at 37 °C. Heterologous and homologous binding assays with AMD3100 showed IC 50 values of 240 ± 10 μM, and 92 ± 5 μM for [ 125 I]SDF-1α and [ 99m Tc]O 2 -AMD3100 respectively, with negligible receptor internalisation. The tracer showed high uptake in liver, lungs, spleen, thymus, intestine and bone. Blocking dose of AMD3100.8HCl (20 mg/kg) decreased the uptake in these organs (p 99m Tc]O 2 -AMD3100 showed specific tumor accumulation in mice bearing PC-3 xenografts model. Time activity curves (TAC) in AMD3100 pre-treated animals tracer showed 1.7 times less tumor uptake as compared to control animals (p 99m Tc]O 2 -AMD3100 is readily labelled, is stable in plasma and displays a favourable binding affinity for the CXCR4 receptors. [ 99m Tc O 2 -AMD3100 shows specific binding in organs with high CXCR4 expression and in CXCR4 positive tumors. These results justify further evaluation of this radiopharmaceutical as a potential

Time-Resolved Spectroscopy and Near Infrared Imaging for Prostate Cancer Detection: Receptor-targeted and Native Biomarker

Science.gov (United States)

Pu, Yang

Optical spectroscopy and imaging using near-infrared (NIR) light provides powerful tools for non-invasive detection of cancer in tissue. Optical techniques are capable of quantitative reconstructions maps of tissue absorption and scattering properties, thus can map in vivo the differences in the content of certain marker chromophores and/or fluorophores in normal and cancerous tissues (for example: water, tryptophan, collagen and NADH contents). Potential clinical applications of optical spectroscopy and imaging include functional tumor detection and photothermal therapeutics. Optical spectroscopy and imaging apply contrasts from intrinsic tissue chromophores such as water, collagen and NADH, and extrinsic optical contrast agents such as Indocyanine Green (ICG) to distinguish disease tissue from the normal one. Fluorescence spectroscopy and imaging also gives high sensitivity and specificity for biomedical diagnosis. Recent developments on specific-targeting fluorophores such as small receptor-targeted dye-peptide conjugate contrast agent offer high contrast between normal and cancerous tissues hence provide promising future for early tumour detection. This thesis focus on a study to distinguish the cancerous prostate tissue from the normal prostate tissues with enhancement of specific receptor-targeted prostate cancer contrast agents using optical spectroscopy and imaging techniques. The scattering and absorption coefficients, and anisotropy factor of cancerous and normal prostate tissues were investigated first as the basis for the biomedical diagnostic and optical imaging. Understanding the receptors over-expressed prostate cancer cells and molecular target mechanism of ligand, two small ICG-derivative dye-peptides, namely Cypate-Bombesin Peptide Analogue Conjugate (Cybesin) and Cypate-Octreotate Peptide Conjugate (Cytate), were applied to study their clinical potential for human prostate cancer detection. In this work, the steady-state and time

Identification and super-resolution imaging of ligand-activated receptor dimers in live cells

Science.gov (United States)

Winckler, Pascale; Lartigue, Lydia; Giannone, Gregory; de Giorgi, Francesca; Ichas, François; Sibarita, Jean-Baptiste; Lounis, Brahim; Cognet, Laurent

2013-08-01

Molecular interactions are key to many chemical and biological processes like protein function. In many signaling processes they occur in sub-cellular areas displaying nanoscale organizations and involving molecular assemblies. The nanometric dimensions and the dynamic nature of the interactions make their investigations complex in live cells. While super-resolution fluorescence microscopies offer live-cell molecular imaging with sub-wavelength resolutions, they lack specificity for distinguishing interacting molecule populations. Here we combine super-resolution microscopy and single-molecule Förster Resonance Energy Transfer (FRET) to identify dimers of receptors induced by ligand binding and provide super-resolved images of their membrane distribution in live cells. By developing a two-color universal-Point-Accumulation-In-the-Nanoscale-Topography (uPAINT) method, dimers of epidermal growth factor receptors (EGFR) activated by EGF are studied at ultra-high densities, revealing preferential cell-edge sub-localization. This methodology which is specifically devoted to the study of molecules in interaction, may find other applications in biological systems where understanding of molecular organization is crucial.

Long-Term Haloperidol Treatment Prolongs QT Interval and Increases Expression of Sigma 1 and IP3 Receptors in Guinea Pig Hearts.

Science.gov (United States)

Stracina, Tibor; Slaninova, Iva; Polanska, Hana; Axmanova, Martina; Olejnickova, Veronika; Konecny, Petr; Masarik, Michal; Krizanova, Olga; Novakova, Marie

2015-07-01

Haloperidol is a neuroleptic drug used for a medication of various psychoses and deliria. Its administration is frequently accompanied by cardiovascular side effects, expressed as QT interval prolongation and occurrence of even lethal arrhythmias. Despite these side effects, haloperidol is still prescribed in Europe in clinical practice. Haloperidol binds to sigma receptors that are coupled with inositol 1,4,5-trisphosphate (IP3) receptors. Sigma receptors are expressed in various tissues, including heart muscle, and they modulate potassium channels. Together with IP3 receptors, sigma receptors are also involved in calcium handling in various tissues. Therefore, the present work aimed to study the effects of long-term haloperidol administration on the cardiac function. Haloperidol (2 mg/kg once a day) or vehiculum was administered by intraperitoneal injection to guinea pigs for 21 consecutive days. We measured the responsiveness of the hearts isolated from the haloperidol-treated animals to additional application of haloperidol. Expression of the sigma 1 receptor and IP3 receptors was studied by real time-PCR and immunohistochemical analyses. Haloperidol treatment caused the significant decrease in the relative heart rate and the prolongation of QT interval of the isolated hearts from the haloperidol-treated animals, compared to the hearts isolated from control animals. The expression of sigma 1 and IP3 type 1 and type 2 receptors was increased in both atria of the haloperidol-treated animals but not in ventricles. The modulation of sigma 1 and IP3 receptors may lead to altered calcium handling in cardiomyocytes and thus contribute to changed sensitivity of cardiac cells to arrhythmias.

Olanzapine versus typical neuroleptics for schizophrenia: evaluation of social and economic costs

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Giorgio Mariani

2006-06-01

Full Text Available An important number of publications is reporting results from health outcomes studies comparing atypical antipsychotics (AA with typical neuroleptics (TN over 1 year of observation. Our study has prolonged the period observation of the economical and social outcomes to 4 years: 31 patients with schizophrenia were observed retrospectively during two years of TN treatment and then followed during 2 more years of olanzapine treatment after naturalistic switch. The results show a general reduction of health care interventions (territory and hospital during the olanzapine treatment period. Global costs during olanzapine treatment were lower than during TN treatment (10506 euros with TN vs 6193 euros with olanzapine over 2 years. The social outcome, measured through the registration of the number of working days in the two periods of the study (retrospective with TN and prospective with olanzapine, was better during olanzapine treatment, probably due to increased patient compliance to the rehabilitative activities offered by the Department of Mental Health. In our experience, olanzapine appeared to dominate TN treatment, as its higher acquisition costs were offset by the reduction of territorial and nosocomial health care interventions over two years of observation, and associated with higher involvement in rehabilitative and social activities.

Development of gamma emitting receptor-binding radiotracers for imaging the brain and pancreas. Progress report, February 1983-September 1984

International Nuclear Information System (INIS)

Reba, R.C.

1984-01-01

The possibility of measuring the change in receptor concentration as a function of disease by external imaging was investigated. The structure-binding-relationship which provides optimal localization of radiolabelled antagonist of the muscarinic acetylcholine receptors in the brain was studied. These relationships were also studied with respect to localization in the pancreas

In vitro and in vivo evaluation of [123I]IBZM: a potential CNS D-2 dopamine receptor imaging agent

International Nuclear Information System (INIS)

Kung, H.F.; Pan, S.; Kung, M.P.; Billings, J.; Kasliwal, R.; Reilley, J.; Alavi, A.

1989-01-01

In vitro binding characteristics of a CNS dopamine D-2 receptor imaging agent, (S)-N-[(1-ethyl-2-pyrrolidinyl)] methyl-2-hydroxy-3-iodo-6-methoxybenzamide [( 125 I]IBZM), was carried out in rats. Also brain images, as well as organ biodistribution were determined in a monkey following the administration of 123 I-labeled compound. The S-(-)-I[ 125 I]IBZM showed high specific dopamine D-2 receptor binding in rat striatum (Kd = 0.426 +/- 0.082 nM, Bmax = 480 +/- 22 fmol/mg of protein). Competition of various ligands for the IBZM binding displayed the following rank order of potency: spiperone greater than S(-)IBZM much greater than R(+)IBZM greater than or equal to S(-)BZM greater than dopamine greater than ketanserin greater than SCH-23390 much greater than propranolol, norepinephrine, serotonin. In vivo planar images of a monkey injected with [ 123 I]IBZM demonstrated a high concentration in basal ganglia of brain. The ratios of activity in the basal ganglia to cerebellum and the cortex to cerebellum in monkey brain were 4.93 and 1.44, respectively, at 120 min postinjection. These preliminary results indicate that [ 123 I]IBZM is a potentially promising imaging agent for the investigation of dopamine D-2 receptors in humans

Asialoglycoprotein-receptor-targeted hepatocyte imaging using {sup 99m}Tc galactosylated chitosan

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Kim, Eun-Mi [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Jeong, Hwan-Jeong [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of)]. E-mail: jayjeong@chonbuk.ac.kr; Kim, Se-Lim [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Sohn, Myung-Hee [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Nah, Jae-Woon [Division of Applied Materials Engineering, Department of Polymer Science and Engineering, Sunchon National University, Sunchon, Jeonnam (Korea, Republic of); Bom, Hee-Seung [Department of Nuclear Medicine, Chonnam National University School of Medicine, Gwangju (Korea, Republic of); Park, In-Kyu [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of); Cho, Chong-Su [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of)

2006-05-15

This study investigated the usefulness of {sup 99m}Tc hydrazinonicotinamide-galactosylated chitosan (HGC) in hepatocyte imaging. HGC was obtained by coupling the galactose moiety of both lactobionic acid and succinimidyl 6-hydrazinonicotinate hydrochloride (succinimidyl HYNIC). The coupled product was then radiolabeled with {sup 99m}Tc using stannous chloride and tricine as reducing agent and coligand, respectively. Labeling efficiency was >90% both in room temperature and in serum up to 24 h after injection. The hepatic uptake properties of {sup 99m}Tc HGC were studied in Balb/C mice. {sup 99m}Tc HGC and {sup 99m}Tc hydrazinonicotinamide chitosan (HC) were intravenously injected into mice, with receptor binding identified by coinjection with 9 and 14 mg of free galactose. Images were acquired with a {gamma}-camera. After injection via the tail vein of the mice, {sup 99m}Tc HGC showed high selectivity for the liver, while {sup 99m}Tc HC without a galactose group showed low liver uptake. In addition, the hepatic uptake of {sup 99m}Tc HGC was blocked by coinjection of free galactose. Tissue distribution was determined at three different times (10, 60 and 120 min). The liver accumulated 13.16{+-}2.72%, 16.11{+-}5.70% and 16.55{+-}2.28% of the injected dose per gram at 10, 60 and 120 min after injection, respectively. {sup 99m}Tc HGC showed specific and rapid targeting of hepatocytes. It is a promising receptor-specific radiopharmaceutical with potential applications in liver imaging for the evaluation of hepatocytic function.

DOTA-PESIN, a DOTA-conjugated bombesin derivative designed for the imaging and targeted radionuclide treatment of bombesin receptor-positive tumours

International Nuclear Information System (INIS)

Zhang, Hanwen; Maecke, Helmut R.; Schuhmacher, Jochen; Eisenhut, Michael; Waser, Beatrice; Reubi, Jean Claude; Wild, Damian

2007-01-01

We aimed at designing and developing a novel bombesin analogue, DOTA-PEG 4 -BN(7-14) (DOTA-PESIN), with the goal of labelling it with 67/68 Ga and 177 Lu for diagnosis and radionuclide therapy of prostate and other human cancers overexpressing bombesin receptors. The 8-amino acid peptide bombesin (7-14) was coupled to the macrocyclic chelator DOTA via the spacer 15-amino-4,7,10,13-tetraoxapentadecanoic acid (PEG 4 ). The conjugate was complexed with Ga(III) and Lu(III) salts. The GRP receptor affinity and the bombesin receptor subtype profile were determined in human tumour specimens expressing the three bombesin receptor subtypes. Internalisation and efflux studies were performed with the human GRP receptor cell line PC-3. Xenografted nude mice were used for biodistribution. [Ga III /Lu III ]-DOTA-PESIN showed good affinity to GRP and neuromedin B receptors but no affinity to BB3. [ 67 Ga/ 177 Lu]-DOTA-PESIN internalised rapidly into PC-3 cells whereas the efflux from PC-3 cells was relatively slow. In vivo experiments showed a high and specific tumour uptake and good retention of [ 67 Ga/ 177 Lu]-DOTA-PESIN. [ 67 Ga/ 177 Lu]-DOTA-PESIN highly accumulated in GRP receptor-expressing mouse pancreas. The uptake specificity was demonstrated by blocking tumour uptake and pancreas uptake. Fast clearance was found from blood and all non-target organs except the kidneys. High tumour-to-normal tissue ratios were achieved, which increased with time. PET imaging with [ 68 Ga]-DOTA-PESIN was successful in visualising the tumour at 1 h post injection. Planar scintigraphic imaging showed that the 177 Lu-labelled peptide remained in the tumour even 3 days post injection. The newly designed ligands have high potential with regard to PET and SPECT imaging with 68/67 Ga and targeted radionuclide therapy with 177 Lu. (orig.)

Olanzapine-induced neuroleptic malignant syndrome in a patient with bipolar affective disorder: Does quetiapine holds the solution?

Directory of Open Access Journals (Sweden)

Praveen Tripathi

2013-01-01

Full Text Available Neuroleptic Malignant Syndrome (NMS is a rare, severe and life threatening condition induced by antipsychotic medications. It is commonly encountered with the use of first generation antipsychotics, however cases of NMS have been reported with the use of second generation antipsychotics like Olanzapine, Risperidone, Paliperidone, Aripiprazole, Ziprasidone, Amisulpride, Quetiapine and Clozapine, though the incidence of such reports is rare. Due to decreased use of first generation antipsychotics, NMS is reported less frequently now a days. In this case report- we highlight the management issues of a patient suffering from bipolar affective disorder, who had developed NMS following intramuscular injection of haloperidol, which was withdrawn and olanzapine was given later on. The patient had again developed NMS with olanzapine. Finally the patient was managed with modified electroconvulsive therapy and discharged on Lithium carbonate and Quetiapine.

[Treatment of attention deficit disorders in adulthood using psychostimulants and low-dose neuroleptics--a critical case report].

Science.gov (United States)

Schmidt, L G; Schlünder, M; Reischies, F M

1988-03-01

Psychiatric research and therapy recently evinced increasing interest in patients suffering from attention deficit disorder. "Attention deficit disorder" is a category of mental disorders listed in DSM III, with a separate diagnostic subgroup for attention deficit disorders persisting in adults who had been hyperkinetic in childhood ("attention deficit disorder-residual type"); however, this does not feature in a corresponding manner in the ICD 9 version. Since there are practically no therapy studies in existence within the ICD range that can be relevant for such disorders, we studied the treatment of an adult patient with the psychostimulant fenetylline under clinical conditions and found a significant improvement in attention performance. However, on integration in a long-term day-clinic rehabilitation programme we found that low-dose neuroleptic treatment was on the whole of greater benefit than fenetylline treatment.

Application of 5-hydroxytryptamine receptor imaging for study of neuropsychiatric disorders and brain functions

International Nuclear Information System (INIS)

Qiu Chun; Guan Yihui

2011-01-01

In the central nervous system, the widely distributed 5-hydroxytryptamine (5-HT)receptors are involved in regulating a large number of psychological and physiological functions, including mood, sleep, endocrine and autonomic nervous system. Abnormal 5-HT transmission has been implicated in a variety of neuropsychiatric disorders, such as pain, depression and epilepsy. With the development of radioligands, non-invasive nuclear imaging technique with exquisite sensitivity and specificity has been applied for delineation of neurotransmitter function in vivo. It does great benefit for researches of these diseases and development of drugs. This review provided an overview of 5-HT receptors radioligands and recent findings. (authors)

Gd-EDDA/HYNIC-RGD as an MR molecular probe imaging integrin ανβ3 receptor-expressed tumor-MR molecular imaging of angiogenesis

International Nuclear Information System (INIS)

Huo Tianlong; Du Xiangke; Zhang Sen; Liu Xia; Li Xubing

2010-01-01

Rationale and objective: The aim of this study is to develop a novel MR probe containing arginine-glycine-aspartic acid (RGD) motif for imaging integrin ανβ3 receptor-expressed tumor. Materials and methods: Commercially available HYNIC-RGD conjugated with co-ligand EDDA was labeled with Gd 3+ , and the mixture was isolated and purified by solid phase extract (SPE) to get the entire probe Gd-EDDA/HYNIC-RGD. Human hepatocellular carcinoma (HHCC) cell line BEL-7402 was cultured and the cells harvested and suspended in serum-free Dulbecco's modified Eagle medium (DMEM) were subcutaneously inoculated into athymic nude mice for tumor growth. In vitro cell binding assay to integrin ανβ3 receptor and cell viability experiments were conducted. The in vivo imaging of the three arms of xenografts were performed by MR scan with a dedicated animal coil at time points of 0, 30, 60, 90 min and 24-h post-intravenous injection (p.i.). Three arms of nude mice then were sacrificed for histological examination to confirm the imaging results. Results: Gd-EDDA/HYNIC-RGD was successfully isolated by SPE and validity was verified on signal enhancement through in vitro and in vivo experiments. The nude mice model bearing HHCC was well established. There was approx. 30% signal enhancement on T1WI FSE images at 90 min post-intravenous injection of the Gd-EDDA/HYNIC-RGD compared with baseline, and the signal to time curve is straightforward over time in the span of 0-90 min p.i., while the control arms do not show this tendency. Conclusion: Gd-EDDA/HYNIC-RGD has the potential to serve as an MR probe detecting integrin ανβ3 receptor-expressed tumor.

Gd-EDDA/HYNIC-RGD as an MR molecular probe imaging integrin {alpha}{nu}{beta}3 receptor-expressed tumor-MR molecular imaging of angiogenesis

Energy Technology Data Exchange (ETDEWEB)

Huo Tianlong [Peking University People' s Hospital, Radiology Department, 11 Xizhimen South Street, Xicheng District, Beijing 100044 (China)], E-mail: huotianlong@bjmu.edu.cn; Du Xiangke [Peking University People' s Hospital, Radiology Department, 11 Xizhimen South Street, Xicheng District, Beijing 100044 (China)], E-mail: duxk@263.net; Zhang Sen [Peking University People' s Hospital, Radiology Department, 11 Xizhimen South Street, Xicheng District, Beijing 100044 (China)], E-mail: skagerrak_s@yahoo.com.cn; Liu Xia [Peking University People' s Hospital, Radiology Department, 11 Xizhimen South Street, Xicheng District, Beijing 100044 (China)], E-mail: iamliuxia@126.com; Li Xubing [Peking University People' s Hospital, Radiology Department, 11 Xizhimen South Street, Xicheng District, Beijing 100044 (China)], E-mail: lixb@bjmu.edu.cn

2010-02-15

Rationale and objective: The aim of this study is to develop a novel MR probe containing arginine-glycine-aspartic acid (RGD) motif for imaging integrin {alpha}{nu}{beta}3 receptor-expressed tumor. Materials and methods: Commercially available HYNIC-RGD conjugated with co-ligand EDDA was labeled with Gd{sup 3+}, and the mixture was isolated and purified by solid phase extract (SPE) to get the entire probe Gd-EDDA/HYNIC-RGD. Human hepatocellular carcinoma (HHCC) cell line BEL-7402 was cultured and the cells harvested and suspended in serum-free Dulbecco's modified Eagle medium (DMEM) were subcutaneously inoculated into athymic nude mice for tumor growth. In vitro cell binding assay to integrin {alpha}{nu}{beta}3 receptor and cell viability experiments were conducted. The in vivo imaging of the three arms of xenografts were performed by MR scan with a dedicated animal coil at time points of 0, 30, 60, 90 min and 24-h post-intravenous injection (p.i.). Three arms of nude mice then were sacrificed for histological examination to confirm the imaging results. Results: Gd-EDDA/HYNIC-RGD was successfully isolated by SPE and validity was verified on signal enhancement through in vitro and in vivo experiments. The nude mice model bearing HHCC was well established. There was approx. 30% signal enhancement on T1WI FSE images at 90 min post-intravenous injection of the Gd-EDDA/HYNIC-RGD compared with baseline, and the signal to time curve is straightforward over time in the span of 0-90 min p.i., while the control arms do not show this tendency. Conclusion: Gd-EDDA/HYNIC-RGD has the potential to serve as an MR probe detecting integrin {alpha}{nu}{beta}3 receptor-expressed tumor.

Megavoltage cone-beam computed tomography using a high-efficiency image receptor

International Nuclear Information System (INIS)

Seppi, Ed J.; Munro, Peter; Johnsen, Stan W.; Shapiro, Ed G.; Tognina, Carlo; Jones, Dan; Pavkovich, John M.; Webb, Chris; Mollov, Ivan; Partain, Larry D.; Colbeth, Rick E.

2003-01-01

Purpose: To develop an image receptor capable of forming high-quality megavoltage CT images using modest radiation doses. Methods and Materials: A flat-panel imaging system consisting of a conventional flat-panel sensor attached to a thick CsI scintillator has been fabricated. The scintillator consists of individual CsI crystals 8 mm thick by 0.38 mm x 0.38-mm pitch. Five sides of each crystal are coated with a reflecting powder/epoxy mixture, and the sixth side is in contact with the flat-panel sensor. A timing interface coordinates acquisition by the imaging system and pulsing of the linear accelerator. With this interface, as little as one accelerator pulse (0.023 cGy at the isocenter) can be used to form projection images. Different CT phantoms irradiated by a 6-MV X-ray beam have been imaged to evaluate the performance of the imaging system. The phantoms have been mounted on a rotating stage and rotated while 360 projection images are acquired in 48 s. These projections have been reconstructed using the Feldkamp cone-beam CT reconstruction algorithm. Results and Discussion: Using an irradiation of 16 cGy (360 projections x 0.046 cGy/projection), the contrast resolution is ∼1% for large objects. High-contrast structures as small as 1.2 mm are clearly visible. The reconstructed CT values are linear (R 2 =0.98) for electron densities between 0.001 and 2.16 g/cm 3 , and the reconstruction time for a 512 x 512 x 512 data set is 6 min. Images of an anthropomorphic phantom show that soft-tissue structures such as the heart, lung, kidneys, and liver are visible in the reconstructed images (16 cGy, 5-mm-thick slices). Conclusions: The acquisition of megavoltage CT images with soft-tissue contrast is possible with irradiations as small as 16 cGy

Glutamatergic neurotransmission modulation and the mechanisms of antipsychotic atypicality.

Science.gov (United States)

Heresco-Levy, Uriel

2003-10-01

The neurotransmission mediated by the excitatory amino acids (EAA) glutamate (GLU) and aspartate is of interest to the pharmacotherapy of psychosis due to its role in neurodevelopment and neurotoxicity, its complex interactions with dopaminergic and other neurotransmitter systems and its pivotal importance in recent models of schizophrenia. Accumulating evidence indicates that modulation of glutamatergic neurotransmission may play an important role in the mechanisms of action of atypical antipsychotic drugs. The principles of the phencyclidine (PCP) model of schizophrenia suggest that conventional neuroleptics cannot counteract all aspects of schizophrenia symptomatology, while a more favorable outcome, including anti-negative and cognitive symptoms effects, would be expected with the use of treatment modalities targeting glutamatergic neurotransmission. Clozapine and other presently used atypical antipsychotics differ from conventional neuroleptics in the way they affect various aspects of glutamatergic receptors function. In this context, a specific hypothesis suggesting an agonistic role of clozapine at the N-methyl-D-aspartate (NMDA) subtype of GLU receptors has been postulated. Furthermore, the results of the first generation of clinical trials with glycine (GLY) site agonists of the NMDA receptor in schizophrenia suggest that this type of compounds (1) have efficacy and side effects profiles different than those of conventional neuroleptics and (2) differ in their synergic effects when used in addition to conventional neuroleptics versus clozapine and possibly additional atypical antipsychotics. These findings (1) bring further support to the hypothesis that glutamatergic effects may play an important role in the mechanism of action of atypical antipsychotics, (2) help explain the unique clinical profile of clozapine, and (3) suggest that GLY site agonists of the NMDA receptor may represent a new class of atypical antipsychotic medication. Future research in

Severe ischemic colitis following olanzapine use: a Case Report

Directory of Open Access Journals (Sweden)

Samuel Raimundo Fernandes

Full Text Available Ischemic colitis is the most common subtype of intestinal ischemia usually resulting from vasospasm, vessel occlusion or mesenteric hypoperfusion. Neuroleptics have seldom been linked to ischemic colitis by blocking peripheral anticholinergic and antiserotonergic receptors inducing severe gastrointestinal paresis. We report a young patient with severe ischemic colitis requiring surgery due to necrosis of the bowel. After exclusion of other potential causes, olanzapine was admitted as the cause of ischemia. Clinicians should be aware of how to recognize and treat the potentially life-threatening effects of neuroleptics.

SPET imaging of central muscarinic receptors with (R,R)[123I]-I-QNB: methodological considerations

International Nuclear Information System (INIS)

Norbury, R.; Travis, M.J.; Erlandsson, K.; Waddington, W.; Owens, J.; Ell, P.J.; Murphy, D.G.

2004-01-01

Investigations on the effect of normal healthy ageing on the muscarinic system have shown conflicting results. Also, in vivo determination of muscarinic receptor binding has been hampered by a lack of subtype selective ligands and differences in methods used for quantification of receptor densities. Recent in vitro and in vivo work with the muscarinic antagonist (R,R)-I-QNB indicates this ligand has selectivity for m 1 and m 4 muscarinic receptor subtypes. Therefore, we used (R,R)[ 123 I]-I-QNB and single photon emission tomography to study brain m 1 and m 4 muscarinic receptors in 25 healthy female subjects (11 younger subjects, age range 26-32 years and 14 older subjects, age range 57-82 years). Our aims were to ascertain the viability of tracer administration and imaging within the same day, and to evaluate whether normalization to whole brain, compared to normalization to cerebellum, could alter the clinical interpretation of results. Images were analyzed using the simplified reference tissue model and by two ratio methods: normalization to whole brain and normalization to cerebellum. Significant correlations were observed between kinetic analysis and normalization to cerebellum, but not to whole brain. Both the kinetic analysis and normalization to cerebellum showed age-related reductions in muscarinic binding in frontal, orbitofrontal, and parietal regions. Normalization to whole brain, however, failed to detect age-related changes in any region. Here we show that, for this radiotracer, normalizing to a region of negligible specific binding (cerebellum) significantly improves sensitivity when compared to global normalization

The analytical of radiochemical purity of tumor receptor imaging agent 99Tcm-octreotide

International Nuclear Information System (INIS)

Wang Xufu; Zuo Shuyao; Shao Wenbo; Wang Guoming; Sun Jianwen; Zhang Qin

2003-01-01

The radiochemical purity of tumor receptor imaging agent 99 Tc m -octreotide is measured by High Pressure Liquid Chromatography (HPLC) and two systems of chromatography combining method of silver stain. The results show that the radiochemical purity of 98 Tc m -octreotide measured by both methods are effective and correct. It can separate 99 Tc m -octreotide from other radioactive compositions correctly and effectively

The clinical impact of a combined gamma camera/CT imaging system on somatostatin receptor imaging of neuroendocrine tumours

International Nuclear Information System (INIS)

Hillel, P.G.; Beek, E.J.R. van; Taylor, C.; Lorenz, E.; Bax, N.D.S.; Prakash, V.; Tindale, W.B.

2006-01-01

AIM: With a combined gamma camera/CT imaging system, CT images are obtained which are inherently registered to the emission images and can be used for the attenuation correction of SPECT and for mapping the functional information from these nuclear medicine tomograms onto anatomy. The aim of this study was to evaluate the clinical impact of SPECT/CT using such a system for somatostatin receptor imaging (SRI) of neuroendocrine tumours. MATERIALS AND METHODS: SPECT/CT imaging with 111 In-Pentetreotide was performed on 29 consecutive patients, the majority of whom had carcinoid disease. All SPECT images were first reported in isolation and then re-reported with the addition of the CT images for functional anatomical mapping (FAM). RESULTS: Fifteen of the 29 SPECT images were reported as abnormal, and in 11 of these abnormal images (73%) FAM was found to either establish a previously unknown location (7/11) or change the location (4/11) of at least one lesion. The revised location could be independently confirmed in 64% of these cases. Confirmation of location was not possible in the other patients due to either a lack of other relevant investigations, or the fact that lesions seen in the SPECT images were not apparent in the other investigations. FAM affected patient management in 64% of the cases where the additional anatomical information caused a change in the reported location of lesions. CONCLUSION: These results imply that FAM can improve the reporting accuracy for SPECT SRI with significant impact on patient management

[11C]WAY-100635 PET imaging of 5-HT1A receptor binding in patients with temporal lobe epilepsy

International Nuclear Information System (INIS)

Sasai, Taeko; Matsuura, Masato; Itou, Shigeo; Suhara, Tetsuya; Yahata, Noriaki; Okubo, Yoshiro

2006-01-01

To understand the role of 5-HT in human temporal lobe epilepsy, here we measured 5-HT 1A receptor binding potential by positron emission tomography (PET) with [carbonyl- 11 C]WAY100635, a selective 5-HT 1A receptor antagonist, in patients with temporal lobe epilepsy and normal controls. Twelve patients with temporal lobe epilepsy and seventeen healthy controls participated in the study. For each subject, we conducted PET and magnetic resonance imaging (MRI), by which we measured the 5-HT 1A receptor binding potential, the R1-value, a relative indicator of cerebral blood flow in regions of interest, and the volume of gray matter. Patients with temporal lobe epilepsy showed significantly reduced 5-HT 1A receptor binding potential in the temporal lobe. The laterality of the reduction was coincided with the epileptogenic foci estimated by a scalp electroencephalography (EEG). In contrast, the R1-value and gray matter volume showed no difference between the patient and control groups. Our study revealed that 5-HT 1A receptor binding was reduced significantly at the epileptogenic foci. We suggest that PET imaging with [carbonyl- 11 C]WAY100635 is potentially a useful non-invasive method for determining the epileptogenic foci. (author)

Cyclopentadienyl tricarbonyl complexes of 99mTc for the in vivo imaging of the serotonin 5-HT 1a receptor in the brain

International Nuclear Information System (INIS)

Saidi, Mouldi; Trabelsi, Adel; MEKNI, Abdelkader; Kretzschmar, M.; Sefert, S.; Bergmann, R.; Pietzsch, H.-J.

2005-01-01

The present interest in the 5-HT 1a receptor is due to its implicated role in several major neuropsychiatric disorders such as depression, eating disorders and anxiety. For the diagnosis of these pathophysiological processes it is important to have radioligands in hand able to specifically bind on the 5-HT 1a receptor in order to allow brain imaging. due to the optimal radiation properties of 99mTc there is a considerable interest in the development of 99mTc radiopharmaceuticals for imaging serotonergic CNS receptors using single-photon emission tomography (SPET). Here we introduce two cyclopentadienyl technitium tricarbonyl conjugates of piperidine derivatives which show high accumulation of radioactivity in brain areas rich in 5-HT 1a receptors

Dopamine denervation does not alter in vivo 3H-spiperone binding in rat striatum: implications for external imaging of dopamine receptors in Parkinson's disease

International Nuclear Information System (INIS)

Bennett, J.P. Jr.; Wooten, G.F.

1986-01-01

Striatal particulate preparations, both from rats with lesion-induced striatal dopamine (DA) loss and from some striatal dopamine (DA) loss and from some patients with Parkinson's disease, exhibit increased 3 H-neuroleptic binding, which is interpreted to be the mechanism of denervation-induced behavioral supersensitivity to dopaminergic compounds. After intravenous 3 H-spiperone ( 3 H-SP) administration to rats with unilateral nigral lesions, we found no differences in accumulation of total or particulate-bound 3 H-SP in dopamine-denervated compared with intact striata. 3 H-SP in vivo binds to less than 10% of striatal sites labeled by 3 H-SP incubated with striatal particulate preparations in vitro. Quantitative autoradiography of 3 H-SP binding to striatal sections in vitro also failed to reveal any effects of dopamine denervation. 3 H-SP bound to striatal sites in vivo dissociates more slowly than that bound to striatal particulate preparations labeled in vitro. Striatal binding properties of 3 H-SP administered in vivo are quite different from the same kinetic binding parameters estimated in vitro using crude membrane preparations of striatum. In addition, striatal binding of in vivo-administered 3H-SP is not affected by prior lesion of the substantia nigra, which results in profound ipsilateral striatal dopamine depletion. Thus, behavioral supersensitivity to dopaminergic compounds may not be associated with altered striatal binding properties for dopamine receptor ligands in vivo

Catatonia, neuroleptic malignant syndrome, and cotard syndrome in a 22-year-old woman: a case report.

Science.gov (United States)

Weiss, C; Santander, J; Torres, R

2013-01-01

The following case study describes a 22-year-old woman with depression and symptoms of psychosis who developed neuroleptic malignant syndrome after using Risperidone, thus requiring life support equipment and Bromocriptine, later recovering after seven days. From a psychiatric and neurological point of view, however, the persistence of catatonic syndrome and Cotard syndrome delusions was observed, based on assertions such as "I do not have a heart," "my heart is not beating," "I can not breathe," "I am breaking apart," "I have no head" (ideas of negation) and statements about the patient being responsible for the "death of the whole world" (ideas of enormity). Brain NMR revealed leukoencephalopathy, interpreted as scar lesions caused by perinatal neurological damage, after discarding other pathologies. The patient responded well to electroconvulsive therapy after 11 sessions. Organic vulnerability to these syndromes, as well as their coexistence and clinical differentiation is discussed in the light of the data observed.

Catatonia, Neuroleptic Malignant Syndrome, and Cotard Syndrome in a 22-Year-Old Woman: A Case Report

Directory of Open Access Journals (Sweden)

C. Weiss

2013-01-01

Full Text Available The following case study describes a 22-year-old woman with depression and symptoms of psychosis who developed neuroleptic malignant syndrome after using Risperidone, thus requiring life support equipment and Bromocriptine, later recovering after seven days. From a psychiatric and neurological point of view, however, the persistence of catatonic syndrome and Cotard syndrome delusions was observed, based on assertions such as “I do not have a heart,” “my heart is not beating,” “I can not breathe,” “I am breaking apart,” “I have no head” (ideas of negation and statements about the patient being responsible for the “death of the whole world” (ideas of enormity. Brain NMR revealed leukoencephalopathy, interpreted as scar lesions caused by perinatal neurological damage, after discarding other pathologies. The patient responded well to electroconvulsive therapy after 11 sessions. Organic vulnerability to these syndromes, as well as their coexistence and clinical differentiation is discussed in the light of the data observed.

Nicotinic receptor imaging with F-18 A85380 PET in Alzheimer's disease and normal ageing

International Nuclear Information System (INIS)

Bottlaender, M.; Maziere, B.; Pappata, S.; Dolle, F.; Rowe, C.; Tochon-Danguy, H.; Reutens, D.; Chan, G.; Woodward, M.

2002-01-01

Full text: Central nicotinic acetylcholine receptors (nAChR) mediate excitatory neurotransmission and contribute to a variety of brain functions including learning and memory. Post mortem studies in patients with Alzheimer's disease have revealed losses of nAChR from the neocortex and hippocampal formation with ligand binding studies showing a reduction of over 50% compared to normal elderly brains in the temporal cortex and hippocampus (Sabbagh 1998). This is consistent with the loss of cholinergic neurones that has been well documented in this condition. Nicotinic AChR are predominantly located presynaptically on the cholinergic neurones. Consequently the ability to image and quantify these receptors may provide a measure of cholinergic loss and therefore a test for the early diagnosis of Alzheimer's disease and for monitoring therapy designed' to preserve cholinergic neurones. Aging is known to effect nAChR (Hellstrom-Lindahl 2000) so this variable must be quantified and incorporated into analysis of the scans. Nicotinic receptors also have important modulatory effects on glutamate, dopamine, serotonin and noradrenaline release and profound receptor loss has been documented in Parkinson's disease and Diffuse Lewy Body disease in addition to AD. Abnormalities in the alpha 7 subtype have been reported in schizophrenia. Imaging studies of nAChR have been hampered by the lack of a suitable tracer for in-vivo imaging. Nicotine itself labelled with carbon-11 for PET imaging has been used but has been shown to reflect regional cerebral blood flow not nAChR due to high nonspecific binding (Nyback et al, 1994). Potent nAChR ligands such as Epibatidine have been very useful for in-vitro studies but are too toxic for routine human use due to strong activation of nAChR including those in the sympathetic ganglia (A3B4 subtype). Recently, the Abbott Laboratories developed A85380 (3-[2(S)-2- azetidinylmethoxyl]pyridine) an azetidine derivative of the 3-pyridyl ethers that has

Preclinical evaluation of "1"1"1In-DOTA-Bombesin analogue for peptide receptor targeted imaging

International Nuclear Information System (INIS)

Salgueiro, C.; Castiglia, S.G. de; Tesan, F.; Salgueiro, M.J.

2017-01-01

Peptide receptors are very important targets for imaging and therapy. The bombesin family is becoming significant, in special the gastrine-releasing peptide receptor (GRPr) that has been found in Prostate and Breast tumors. The aim of this work is to label [DOTA-Pro1,Tyr4] BN with "1"1"1InCl3 and study its efficacy in normal and tumor animals. Radiolabeling experiences were made to find the best peptide : radionuclide relationship. The radiochemical purity was determined by Sep-pak C18 cartridge (Waters) and ITLC-SG using 50mM EDTA in 0.1M ammonium acetate (pH 5.5) and 3.5%(v/v) ammonia/methanol 1:1. Gamma imaging studies were made 24 hs after injection of the product in control rats. On the other hand gamma imaging studies were made at 24 hs in tumor bearing nude mice too. The tumor was induced by subcutaneous injection of PC3 cells. For biodistribution studies animals were sacrificed and blood, pancreas, intestine, kidneys, liver, lungs, femoral muscle and tumor were analyzed. The results were expressed as %ID/g of tissue. Radiolabeling experiments allowed us to obtain an stable product with >95% of radiochemical purity and 5.78MBq/nmol of specific activity, with a ratio of 13μg peptide per In-111 mCi. The normal and tumor animals imaging show physiological uptake in kidneys and a biodistribution according to bibliography. A specific uptake is evidenced in tumor. Our results show a radiochemical stable compound for 48 hs and suitable for GRPr imaging. (authors) [es

EGF receptor targeted tumor imaging with biotin-PEG-EGF linked to 99mTc-HYNIC labeled avidin and streptavidin

International Nuclear Information System (INIS)

Jung, Kyung-Ho; Park, Jin Won; Paik, Jin-Young; Quach, Cung Hoa Thien; Choe, Yearn Seong; Lee, Kyung-Han

2012-01-01

Introduction: As direct radiolabeled peptides suffer limitations for in vivo imaging, we investigated the usefulness of radioloabeled avidin and streptavidin as cores to link peptide ligands for targeted tumor imaging. Methods: Human epidermal growth factor (EGF) was site specifically conjugated with a single PEG-biotin molecule and linked to 99m Tc-HYNIC labeled avidin-FITC (Av) or streptavidin-Cy5.5 (Sav). Receptor targeting was verified in vitro, and in vivo pharmacokinetic and biodistribution profiles were studied in normal mice. Scintigraphic imaging was performed in MDA-MB-468 breast tumor xenografted nude mice. Results: Whereas both 99m Tc-Av-EGF and 99m Tc-Sav-EGF retained receptor-specific binding in vitro, the two probes substantially diverged in pharmacokinetic and biodistribution behavior in vivo. 99m Tc-Av-EGF was rapidly eliminated from the circulation with a T1/2 of 4.3 min, and showed intense hepatic accumulation but poor tumor uptake (0.6%ID/gm at 4 h). 99m Tc-Sav-EGF displayed favorable in vivo profiles of longer circulation (T1/2β, 51.5 min) and lower nonspecific uptake that resulted in higher tumor uptake (3.8 %ID/gm) and clear tumor visualization at 15 h. Conclusion: 99m Tc-HYNIC labeled streptavidin linked with growth factor peptides may be useful as a protein-ligand complex for targeted imaging of tumor receptors.

Radiolabeled cetuximab: dose optimization for epidermal growth factor receptor imaging in a head-and-neck squamous cell carcinoma model

NARCIS (Netherlands)

Hoeben, B.A.W.; Molkenboer-Kuenen, J.D.M.; Oyen, W.J.G.; Peeters, W.J.M.; Kaanders, J.H.A.M.; Bussink, J.; Boerman, O.C.

2011-01-01

Noninvasive imaging of the epidermal growth factor receptor (EGFR) in head-and-neck squamous cell carcinoma could be of value to select patients for EGFR-targeted therapy. We assessed dose optimization of (111) Indium-DTPA-cetuximab ((111) In-cetuximab) for EGFR imaging in a head-and-neck squamous

On the clinical impact of cerebral dopamine D{sub 2} receptor scintigraphy; Zur klinischen Wertigkeit der zerebralen Dopamin-D{sub 2}-Rezeptorszintigraphie

Energy Technology Data Exchange (ETDEWEB)

Larisch, R. [Duesseldorf Univ. (Germany). Klinik fuer Nuklearmedizin; Klimke, A. [Duesseldorf Univ. (Germany). Psychiatrische Klinik

1998-12-31

The present review describes findings and clinical indications for the dopamine D{sub 2} receptor scintigraphy. Methods for the examination of D{sub 2} receptors are positron emission tomography (PET) using {sup 11}C- or {sup 18}F-labelled butyrophenones or benzamides or single photon emission tomography (SPECT) using {sup 123}I-iodobenzamide (IBZM) respectively. The most important indication in neurology is the differential diagnosis of Parkinsonism: Patients with early Parkinson`s disease show an increased D{sub 2} receptor binding (D{sub 2}-RB) compared to control subjects. However, patients suffering from Steele-Richardson-Olszewski-Syndrome or Multiple System Atrophy show a decreased D{sub 2}-RB and are generally non-responsive to treatment. Postsynaptic blockade of D{sub 2} receptors results in a drug induced Parkinsonian syndrome, which can be diagnosed by D{sub 2} scintigraphy. Further possible indications occur in psychiatry: The assessment of receptor occupancy is useful in schizophrenic patients treated with neuroleptics. Additionally, D{sub 2} receptor scintigraphy might help to clarify the differential diagnosis between neuroleptic malignant syndrome and lethal catatonia. The method might be useful for supervising neurobiochemical changes in drug dependency and during withdrawal. Assessment of dopamine D{sub 2} receptor binding can simplify the choice of therapy in depressive disorder: Patients showing a low D{sub 2} binding are likely to improve following an antidepressive drug treatment whereas sleep deprivation is promising in patients with high D{sub 2} binding. (orig.) [Deutsch] Die vorliegende Arbeit gibt eine Uebersicht ueber Befunde und klinische Indikationen zur Dopamin-D{sub 2}-Rezeptorszintigraphie. Methoden zur Untersuchung der D{sub 2}-Rezeptoren sind die Positronen-Emissions-Tomographie (PET) mit {sup 11}C- oder {sup 18}F-markierten Butyrophenonen oder Benzamiden oder die Einzelphotonen-Emissions-Tomographie (SPECT) mit {sup 123}I

Improved localization of cellular membrane receptors using combined fluorescence microscopy and simultaneous topography and recognition imaging

International Nuclear Information System (INIS)

Duman, M; Pfleger, M; Chtcheglova, L A; Neundlinger, I; Bozna, B L; Ebner, A; Schuetz, G J; Hinterdorfer, P; Zhu, R; Mayer, B; Rankl, C; Moertelmaier, M; Kada, G; Kienberger, F; Salio, M; Shepherd, D; Polzella, P; Cerundolo, V; Dieudonne, M

2010-01-01

The combination of fluorescence microscopy and atomic force microscopy has a great potential in single-molecule-detection applications, overcoming many of the limitations coming from each individual technique. Here we present a new platform of combined fluorescence and simultaneous topography and recognition imaging (TREC) for improved localization of cellular receptors. Green fluorescent protein (GFP) labeled human sodium-glucose cotransporter (hSGLT1) expressed Chinese Hamster Ovary (CHO) cells and endothelial cells (MyEnd) from mouse myocardium stained with phalloidin-rhodamine were used as cell systems to study AFM topography and fluorescence microscopy on the same surface area. Topographical AFM images revealed membrane features such as lamellipodia, cytoskeleton fibers, F-actin filaments and small globular structures with heights ranging from 20 to 30 nm. Combined fluorescence and TREC imaging was applied to detect density, distribution and localization of YFP-labeled CD1d molecules on α-galactosylceramide (αGalCer)-loaded THP1 cells. While the expression level, distribution and localization of CD1d molecules on THP1 cells were detected with fluorescence microscopy, the nanoscale distribution of binding sites was investigated with molecular recognition imaging by using a chemically modified AFM tip. Using TREC on the inverted light microscope, the recognition sites of cell receptors were detected in recognition images with domain sizes ranging from ∼ 25 to ∼ 160 nm, with the smaller domains corresponding to a single CD1d molecule.

Improved localization of cellular membrane receptors using combined fluorescence microscopy and simultaneous topography and recognition imaging

Energy Technology Data Exchange (ETDEWEB)

Duman, M; Pfleger, M; Chtcheglova, L A; Neundlinger, I; Bozna, B L; Ebner, A; Schuetz, G J; Hinterdorfer, P [Institute for Biophysics, University of Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Zhu, R; Mayer, B [Christian Doppler Laboratory for Nanoscopic Methods in Biophysics, Institute for Biophysics, University of Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Rankl, C; Moertelmaier, M; Kada, G; Kienberger, F [Agilent Technologies Austria GmbH, Aubrunnerweg 11, A-4040 Linz (Austria); Salio, M; Shepherd, D; Polzella, P; Cerundolo, V [Cancer Research UK Tumor Immunology Group, Weatherall Institute of Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX3 9DS (United Kingdom); Dieudonne, M, E-mail: ferry_kienberger@agilent.com [Agilent Technologies Belgium, Wingepark 51, Rotselaar, AN B-3110 (Belgium)

2010-03-19

The combination of fluorescence microscopy and atomic force microscopy has a great potential in single-molecule-detection applications, overcoming many of the limitations coming from each individual technique. Here we present a new platform of combined fluorescence and simultaneous topography and recognition imaging (TREC) for improved localization of cellular receptors. Green fluorescent protein (GFP) labeled human sodium-glucose cotransporter (hSGLT1) expressed Chinese Hamster Ovary (CHO) cells and endothelial cells (MyEnd) from mouse myocardium stained with phalloidin-rhodamine were used as cell systems to study AFM topography and fluorescence microscopy on the same surface area. Topographical AFM images revealed membrane features such as lamellipodia, cytoskeleton fibers, F-actin filaments and small globular structures with heights ranging from 20 to 30 nm. Combined fluorescence and TREC imaging was applied to detect density, distribution and localization of YFP-labeled CD1d molecules on {alpha}-galactosylceramide ({alpha}GalCer)-loaded THP1 cells. While the expression level, distribution and localization of CD1d molecules on THP1 cells were detected with fluorescence microscopy, the nanoscale distribution of binding sites was investigated with molecular recognition imaging by using a chemically modified AFM tip. Using TREC on the inverted light microscope, the recognition sites of cell receptors were detected in recognition images with domain sizes ranging from {approx} 25 to {approx} 160 nm, with the smaller domains corresponding to a single CD1d molecule.

Genetic Imaging of the Association of Oxytocin Receptor Gene (OXTR Polymorphisms with Positive Maternal Parenting

Directory of Open Access Journals (Sweden)

Kalina J. Michalska

2014-02-01

Full Text Available Background: Well-validated models of maternal behavior in small-brain mammals posit a central role of oxytocin in parenting, by reducing stress and enhancing the reward value of social interactions with offspring. In contrast, human studies are only beginning to gain insights into how oxytocin modulates maternal behavior and affiliation. Methods: To explore associations between oxytocin receptor genes and maternal parenting behavior in humans, we conducted a genetic imaging study of women selected to exhibit a wide range of observed parenting when their children were 4-6 years old. Results: In response to child stimuli during functional magnetic resonance imaging, hemodynamic responses in brain regions that mediate affect, reward, and social behavior were significantly correlated with observed positive parenting. Furthermore, single nucleotide polymorphisms (rs53576 and rs1042778 in the gene encoding the oxytocin receptor were significantly associated with both positive parenting and hemodynamic responses to child stimuli in orbitofrontal cortex, anterior cingulate cortex and hippocampus. Conclusions: These findings contribute to the emerging literature on the role of oxytocin in human social behavior and support the feasibility of tracing biological pathways from genes to neural regions to positive maternal parenting behaviors in humans using genetic imaging methods.

Development of an image analysis screen for estrogen receptor alpha (ERα) ligands through measurement of nuclear translocation dynamics.

Science.gov (United States)

Dull, Angie; Goncharova, Ekaterina; Hager, Gordon; McMahon, James B

2010-11-01

We have developed a robust high-content assay to screen for novel estrogen receptor alpha (ERα) agonists and antagonists by quantitation of cytoplasmic to nuclear translocation of an estrogen receptor chimera in 384-well plates. The screen utilizes a green fluorescent protein tagged-glucocorticoid/estrogen receptor (GFP-GRER) chimera which consisted of the N-terminus of the glucocorticoid receptor fused to the human ER ligand binding domain. The GFP-GRER exhibited cytoplasmic localization in the absence of ERα ligands, and translocated to the nucleus in response to stimulation with ERα agonists or antagonists. The BD Pathway 435 imaging system was used for image acquisition, analysis of translocation dynamics, and cytotoxicity measurements. The assay was validated with known ERα agonists and antagonists, and the Library of Pharmacologically Active Compounds (LOPAC 1280). Additionally, screening of crude natural product extracts demonstrated the robustness of the assay, and the ability to quantitate the effects of toxicity on nuclear translocation dynamics. The GFP-GRER nuclear translocation assay was very robust, with z' values >0.7, CVs screening of natural product extracts. This assay has been developed for future primary screening of synthetic, pure natural products, and natural product extracts libraries available at the National Cancer Institute at Frederick. Copyright © 2010 Elsevier Ltd. All rights reserved.

Neuroleptic malignant-like syndrome with a slight elevation of creatine-kinase levels and respiratory failure in a patient with Parkinson's disease

Directory of Open Access Journals (Sweden)

Wei L

2014-02-01

Full Text Available Li Wei,1,2 Yinghui Chen1,2 1Department of Neurology, Jinshan Hospital, 2Department of Neurology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China Abstract: Neuroleptic malignant-like syndrome (NMLS is a rare but catastrophic complication of drug treatment for Parkinson's disease (PD. Sudden withdrawal and abrupt reduction of antiparkinsonian drugs are major risk factors. Just as its name suggests, the clinical features of NMLS are similar to neuroleptic malignant syndrome, which is a dangerous adverse response to antipsychotic drugs. Both of these conditions can present with hyperthermia, marked muscle rigidity, altered consciousness, autonomic dysfunction, and elevated serum creatine-kinase (CK levels. However, we describe a special NMLS case with a slight elevation of CK levels and respiratory failure in the full course of her treatment. The patient, a 68-year-old woman with a 4-years history of Parkinson's disease, presented with hyperthermia and severe muscular rigidity. During the course of her treatment, her maximum temperature was extremely high (above 41°C. At the beginning, the diagnosis of NMLS secondary to dopamine decrease was difficult to make, because her initial blood examination revealed that her serum CK levels were mildly elevated and decreased to normal range rapidly. Although antiparkinsonian drugs and supportive treatment were applied, the patient developed an acute respiratory failure in the early course of treatment. This case report highlights that when confronted with Parkinson's patients with high body temperature and muscle rigidity, NMLS should be taken into consideration even if there is no CK elevation. Likewise, the need for supportive care is essential, because its complications are severe, even such as respiratory failure. Keywords: antiparkinsonian drugs, creatine kinase, parkinsonism–hyperpyrexia syndrome, respiratory failure

Radioiodination of central nerves system dopamine D2 receptor imaging agent. IBZM preparation and preclinical study

International Nuclear Information System (INIS)

Lin Yansong; Lin Xiangtong; Hu Mingyang; Pan Shangren; Wang Bocheng

1996-01-01

To study preparation of central nerves system dopamine D2 imaging agent 131 I-IBZM and its preclinical investigation, peracetic acid was used as the oxidant for preparing radioiodinated 125 I-IBZM and 131 I-IBZM, D2 binding properties of IBZM were examined by in vitro binding saturation analysis, rat whole body and regional brain biodistribution, rat brain autoradiography and rabbit SPECT static imaging, etc. The results are: 1. The radiolabelling yields of 125 I-IBZM and 131 I-IBZM were 84.18% +- 3.06% and 78.50% +- 3.47%. The radiochemical purity were over 95% after being isolated by HPLC; and were over 90% after being isolated by organic extraction. 2. Scatchard plot of D2 receptor saturation binding analysis showed: K d = 0.53 +- 0.06 nmol/L, B max = 466.45 +- 45.88 fmol/mg protein. 3. The rat brain autoradiography and analysis showed that there was high 125 I-IBZM uptake in striatal area 2 hr after injection, the striatal/cerebellum ratio was 6.22 +- 0.48; the high 125 -IBZM uptake can be blocked by haloperidol--a special dopamine D2 receptor antagonist. 4. 131 I-IBZM rat biodistribution and rabbit SPECT planar imaging showed good initial brain uptake and retention, the initial uptake of rat brain was 1.893 +- 0.147% ID/g at 2 min and 1.044 +- 0.135% ID/g at 60 min. The results showed that the radioiodinated IBZM had high affinity, saturation and specificity to rat's and rabbit's central nerves system dopamine D2 receptors

Triple-color super-resolution imaging of live cells: resolving submicroscopic receptor organization in the plasma membrane.

Science.gov (United States)

Wilmes, Stephan; Staufenbiel, Markus; Lisse, Domenik; Richter, Christian P; Beutel, Oliver; Busch, Karin B; Hess, Samuel T; Piehler, Jacob

2012-05-14

In living color: efficient intracellular covalent labeling of proteins with a photoswitchable dye using the HaloTag for dSTORM super-resolution imaging in live cells is described. The dynamics of cellular nanostructures at the plasma membrane were monitored with a time resolution of a few seconds. In combination with dual-color FPALM imaging, submicroscopic receptor organization within the context of the membrane skeleton was resolved. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Olanzapine-Induced Diabetic Ketoacidosis and Neuroleptic Malignant Syndrome with Rhabdomyolysis: A Case Report

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Young Kyoung Sa

2013-03-01

Full Text Available Atypical antipsychotics have replaced conventional antipsychotics in the treatment of schizophrenia because they have less of a propensity to cause undesirable neurologic adverse events including extrapyramidal symptoms, tardive dyskinesia, and neuroleptic malignant syndrome (NMS. However, atypical antipsychotics have been known to result in various metabolic complications such as impaired glucose tolerance, diabetes and even diabetic ketoacidosis (DKA. In addition, a number of NMS cases have been reported in patients treated with atypical antipsychotics, although the absolute incidence of neurologic side effects is currently significantly low. Here, we report a patient who simultaneously developed DKA, acute renal failure and NMS with rhabdomyolysis after olanzapine treatment. Olanzapine-induced metabolic complications and NMS were dramatically improved with cessation of the olanzapine treatment and initiation of supportive management including fluid therapy, hemodialysis, and intensive glycemic control using insulin. At short-term follow-up, insulin secretion was markedly recovered as evidenced by a restoration of serum C-peptide level, and the patient no longer required any hypoglycemic medications. Despite the dramatic increase in the use of atypical antipsychotics treatment, individualized treatments along with careful monitoring may be prudent for high risk or vulnerable patients in order to avoid the development of metabolic side effects.

DOTA-PESIN, a DOTA-conjugated bombesin derivative designed for the imaging and targeted radionuclide treatment of bombesin receptor-positive tumours

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Zhang, Hanwen; Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Department of Radiology, Basel (Switzerland); Schuhmacher, Jochen; Eisenhut, Michael [German Cancer Research Centre, Department of Radiopharmaceutical Chemistry, Heidelberg (Germany); Waser, Beatrice; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, P.O. Box 62, Berne (Switzerland); Wild, Damian [University Hospital, Clinic and Institute of Nuclear Medicine, Department of Radiology, Basel (Switzerland)

2007-08-15

We aimed at designing and developing a novel bombesin analogue, DOTA-PEG{sub 4}-BN(7-14) (DOTA-PESIN), with the goal of labelling it with {sup 67/68}Ga and {sup 177}Lu for diagnosis and radionuclide therapy of prostate and other human cancers overexpressing bombesin receptors. The 8-amino acid peptide bombesin (7-14) was coupled to the macrocyclic chelator DOTA via the spacer 15-amino-4,7,10,13-tetraoxapentadecanoic acid (PEG{sub 4}). The conjugate was complexed with Ga(III) and Lu(III) salts. The GRP receptor affinity and the bombesin receptor subtype profile were determined in human tumour specimens expressing the three bombesin receptor subtypes. Internalisation and efflux studies were performed with the human GRP receptor cell line PC-3. Xenografted nude mice were used for biodistribution. [Ga{sup III}/Lu{sup III}]-DOTA-PESIN showed good affinity to GRP and neuromedin B receptors but no affinity to BB3. [{sup 67}Ga/{sup 177}Lu]-DOTA-PESIN internalised rapidly into PC-3 cells whereas the efflux from PC-3 cells was relatively slow. In vivo experiments showed a high and specific tumour uptake and good retention of [{sup 67}Ga/{sup 177}Lu]-DOTA-PESIN. [{sup 67}Ga/{sup 177}Lu]-DOTA-PESIN highly accumulated in GRP receptor-expressing mouse pancreas. The uptake specificity was demonstrated by blocking tumour uptake and pancreas uptake. Fast clearance was found from blood and all non-target organs except the kidneys. High tumour-to-normal tissue ratios were achieved, which increased with time. PET imaging with [{sup 68}Ga]-DOTA-PESIN was successful in visualising the tumour at 1 h post injection. Planar scintigraphic imaging showed that the {sup 177}Lu-labelled peptide remained in the tumour even 3 days post injection. The newly designed ligands have high potential with regard to PET and SPECT imaging with {sup 68/67}Ga and targeted radionuclide therapy with {sup 177}Lu. (orig.)

In vivo characterization of radioiodinated (+)-2-[4-(4-iodophenyl) piperidino] cyclohexanol as a potential σ-1 receptor imaging agent

International Nuclear Information System (INIS)

Akhter, Nasima; Shiba, Kazuhiro; Ogawa, Kazuma; Kinuya, Seigo; Nakajima, Kenichi; Mori, Hirofumi

2007-01-01

In this study, the (+)-enantiomer of radioiodinated 2-[4-(4-iodophenyl)piperidino]cyclohexanol [(+)-[ 125 I]-p-iodovesamicol] [(+)-[ 125 I]pIV], which is reported to bind with high affinity to σ-1 receptors in vitro, was tested for its usefulness in imaging σ-1 receptors in the central nervous system (CNS) in vivo. In biodistribution studies, significant amounts (approximately 3% of the injected dose) of (+)-[ 125 I]pIV accumulated in rat brain, and its retention was prolonged. In blocking studies, the accumulation of (+)-[ 125 I]pIV in the rat brain was significantly reduced by the coadministration of σ-ligands such as pentazocine (5.0 μmol), haloperidol (0.5 μmol) or SA4503 (0.5 μmol). The blocking effect of pentazocine (selective σ-1 ligand) was similar to the blocking effects of SA4503 and haloperidol [nonselective σ (σ-1 and σ-2) ligands]. Ex vivo autoradiography of the rat brain at 45 min following intravenous injection of (+)-[ 125 I]pIV showed high localization in brain areas rich in σ-1 receptors. Thus, the distribution of (+)-[ 125 I]pIV was thought to bind to σ-1 receptors in the CNS in vivo. These results indicate that radioiodinated (+)-pIV may have the potential to image σ-1 receptors in vivo

Biodistribution and dosimetry in humans of two inverse agonists to image cannabinoid CB1 receptors using positron emission tomography

International Nuclear Information System (INIS)

Terry, Garth E.; Hirvonen, Jussi; Liow, Jeih-San; Seneca, Nicholas; Morse, Cheryl L.; Pike, Victor W.; Innis, Robert B.; Tauscher, Johannes T.; Schaus, John M.; Phebus, Lee; Felder, Christian C.; Halldin, Christer

2010-01-01

Cannabinoid subtype 1 (CB 1 ) receptors are found in nearly every organ in the body, may be involved in several neuropsychiatric and metabolic disorders, and are therefore an active target for pharmacotherapy and biomarker development. We recently reported brain imaging of CB 1 receptors with two PET radioligands: 11 C-MePPEP and 18 F-FMPEP-d 2 . Here we describe the biodistribution and dosimetry estimates for these two radioligands. Seven healthy subjects (four men and three women) underwent whole-body PET scans for 120 min after injection with 11 C-MePPEP. Another seven healthy subjects (two men and five women) underwent whole-body PET scans for 300 min after injection with 18 F-FMPEP-d 2 . Residence times were acquired from regions of interest drawn on tomographic images of visually identifiable organs for both radioligands and from radioactivity excreted in urine for 18 F-FMPEP-d 2 . The effective doses of 11 C-MePPEP and 18 F-FMPEP-d 2 are 4.6 and 19.7 μSv/MBq, respectively. Both radioligands demonstrated high uptake of radioactivity in liver, lung, and brain shortly after injection and accumulated radioactivity in bone marrow towards the end of the scan. After injection of 11 C-MePPEP, radioactivity apparently underwent hepatobiliary excretion only, while radioactivity from 18 F-FMPEP-d 2 showed both hepatobiliary and urinary excretion. 11 C-MePPEP and 18 F-FMPEP-d 2 yield an effective dose similar to other PET radioligands labeled with either 11 C or 18 F. The high uptake in brain confirms the utility of these two radioligands to image CB 1 receptors in brain, and both may also be useful to image CB 1 receptors in the periphery. (orig.)

Differential expression of growth factor receptors and membrane-bound tumor markers for imaging in male and female breast cancer.

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Jeroen F Vermeulen

Full Text Available INTRODUCTION: Male breast cancer accounts for 0.5-1% of all breast cancers and is generally diagnosed at higher stage than female breast cancers and therefore might benefit from earlier detection and targeted therapy. Except for HER2 and EGFR, little is known about expression of growth factor receptors in male breast cancer. We therefore investigated expression profiles of growth factor receptors and membrane-bound tumor markers in male breast cancer and gynecomastia, in comparison with female breast cancer. METHODS: Tissue microarrays containing 133 male breast cancer and 32 gynecomastia cases were stained by immunohistochemistry for a panel of membrane-bound targets and compared with data on 266 female breast cancers. RESULTS: Growth factor receptors were variably expressed in 4.5% (MET up to 38.5% (IGF1-R of male breast cancers. Compared to female breast cancer, IGF1-R and carbonic anhydrase 12 (CAXII were more frequently and CD44v6, MET and FGFR2 less frequently expressed in male breast cancer. Expression of EGFR, HER2, CAIX, and GLUT1 was not significantly different between male and female breast cancer. Further, 48.1% of male breast cancers expressed at least one and 18.0% expressed multiple growth factor receptors. Since individual membrane receptors are expressed in only half of male breast cancers, a panel of membrane markers will be required for molecular imaging strategies to reach sensitivity. A potential panel of markers for molecular imaging, consisting of EGFR, IGF1-R, FGFR2, CD44v6, CAXII, GLUT1, and CD44v6 was positive in 77% of male breast cancers, comparable to female breast cancers. CONCLUSIONS: Expression patterns of growth factor receptors and hypoxia membrane proteins in male breast cancer are different from female breast cancer. For molecular imaging strategies, a putative panel consisting of markers for EGFR, IGF1-R, FGFR2, GLUT1, CAXII, CD44v6 was positive in 77% of cases and might be considered for development of

Triazolam-induced modulation of muscarinic acetylcholine receptor in living brain slices as revealed by a new positron-based imaging technique

International Nuclear Information System (INIS)

Murata, T.; Matsumura, K.; Onoe, H.; Watanabe, Y.; Sihver, S.; Sihver, W.; Langstroem, B.; Bergstroem, M.; Yonekura, Y.

1997-01-01

The effect of triazolam, a potent benzodiazepine (BZ) agonist, on muscarinic acetylcholinergic receptor (mAChR) binding was investigated in living brain slices by use of a novel positron-based imaging technique. Fresh rat brain slices were incubated with [ 11 C]N-methyl-4-piperidylbenzilate ([ 11 C]NMPB), a mAChR antagonist, in oxygenated Krebs-Ringer solution at 37 degree C. During incubation, time-resolved imaging of [ 11 C]NMPB binding in the slices was constructed on the storage phosphor screens. Addition of triazolam (1 μM) plus muscimol (30 μM), a GABA A receptor agonist, to the incubation mixture decreased the specific binding of [ 11 C]NMPB. Ro15-1788, a BZ receptor antagonist, prevented this effect, indicating that the effect was exerted through the GABA A /BZ receptor complex. These results demonstrated that stimulation of the GABA A /BZ receptor lowers the affinity of the mAChR for its ligand, which may underlie the BZ-induced amnesia, a serious clinical side effect of BZ. No such effect in the P2-fraction instead implies that the integrity of the neuronal cells and/or their environment is prerequisite for the modulation of mAChR by GABA A /BZ stimulation. (author)

Development of radiotracers for imaging NR2B subtype NMDA receptors with positron emission tomography

International Nuclear Information System (INIS)

Labas, R.

2007-01-01

The aim of this thesis was to develop new radioactive tracers for imaging NR2B subtype NMDA receptors with positron emission tomography. Several compounds including 4-(4-fluoro-benzyl)piperidine and presenting interesting in vivo biological properties were the object of a labelling with a positrons emitter atom ( 11 C or 18 F)

Dopamine D2 receptor occupancy in normal humans treated with a novel antipsychotic drug YKP1358 measured by PET and [11c]raclopride

International Nuclear Information System (INIS)

Lee, J. S.; Kim, S. J.; Lee, K. J.; Kim, E.; Yu, K. S.; Jang, I. J.; Kwon, J. S.; Kang, W. J.; Jeong, J. M.; Lee, D. S.; Chung, J. K.; Lee, M. C.

2005-01-01

YKP1358 is a novel serotonin (5-HT 2A ) and dopamine (D 2 ) antagonist, and fitted the general profile of an atypical neuroleptic agent in preclinical studies. The time course of D 2 receptor occupancy in the brain of living human after a single oral dose of YKP1358 was measured using PET and related to the plasma drug levels. A single oral dose, dose escalation (100 mg, 200 mg, and 250 mg), open-label study was performed in 9 healthy male volunteers (3 per each dose) using the [ 11 C]raclopried PET. After the baseline scan, each subject was studied at 2, 5, and 10 hours after the single administration of YKP1358. Blood samples for evaluation of plasma concentration of YKP1358 were also taken at various time points (0-32 hours post-dose). Binding potential (BP) of [ 11 C]raclopride in the putamen was estimated with simplified reference tissue model and percent reduction of the BP was calculated to obtain the D 2 receptor occupancy. BP parametric image was generated using a pixel-wise Logan noninvasive plot. T max of plasma concentration-time profiles was 0.67 hours, and elimination half-life was 5.71, 7.46, and 8.58 hours in 100 mg, 200 mg, and 250 mg dosing groups, respectively. D 2 receptor occupancy of YKP1358 was 60 to 80% at 2 hours, 40 to 60% at 5 hours, and 20 to 50% at 10 hours. The relationship of plasma concentration and D 2 receptor occupancy of YKP1358 was well predicted by Emax model, and Emax was 100 %, EC50 was 8.9 (=1.1) ng/mI, and Hills coefficient was 0.525. PK profile of YKP1358 showed individual variation, but the D 2 receptor occupancy was less variable and well predicted by an Emax model. Since D 2 antagonists show therapeutic effects at 50 to 80% D 2 occupancy and the EC50 of YKP1358 is less than 10 ng/ml, doses of YKP1358 which maintain plasma concentrations above 10 ng/ml are expected to show therapeutic effects

STRATEGIES FOR QUANTIFYING PET IMAGING DATA FROM TRACER STUDIES OF BRAIN RECEPTORS AND ENZYMES.

Energy Technology Data Exchange (ETDEWEB)

Logan, J.

2001-04-02

A description of some of the methods used in neuroreceptor imaging to distinguish changes in receptor availability has been presented in this chapter. It is necessary to look beyond regional uptake of the tracer since uptake generally is affected by factors other than the number of receptors for which the tracer has affinity. An exception is the infusion method producing an equilibrium state. The techniques vary in complexity some requiring arterial blood measurements of unmetabolized tracer and multiple time uptake data. Others require only a few plasma and uptake measurements and those based on a reference region require no plasma measurements. We have outlined some of the limitations of the different methods. Laruelle (1999) has pointed out that test/retest studies to which various methods can be applied are crucial in determining the optimal method for a particular study. The choice of method will also depend upon the application. In a clinical setting, methods not involving arterial blood sampling are generally preferred. In the future techniques for externally measuring arterial plasma radioactivity with only a few blood samples for metabolite correction will extend the modeling options of clinical PET. Also since parametric images can provide information beyond that of ROI analysis, improved techniques for generating such images will be important, particularly for ligands requiring more than a one-compartment model. Techniques such as the wavelet transform proposed by Turkheimer et al. (2000) may prove to be important in reducing noise and improving quantitation.

Cholinergic Receptor Binding in Alzheimer Disease and Healthy Aging: Assessment In Vivo with Positron Emission Tomography Imaging.

Science.gov (United States)

Sultzer, David L; Melrose, Rebecca J; Riskin-Jones, Hannah; Narvaez, Theresa A; Veliz, Joseph; Ando, Timothy K; Juarez, Kevin O; Harwood, Dylan G; Brody, Arthur L; Mandelkern, Mark A

2017-04-01

To compare regional nicotinic cholinergic receptor binding in older adults with Alzheimer disease (AD) and healthy older adults in vivo and to assess relationships between receptor binding and clinical symptoms. Using cross-sectional positron emission tomography (PET) neuroimaging and structured clinical assessment, outpatients with mild to moderate AD (N = 24) and healthy older adults without cognitive complaints (C group; N = 22) were studied. PET imaging of α4β2* nicotinic cholinergic receptor binding using 2-[ 18 F]fluoro-3-(2(S)azetidinylmethoxy)pyridine (2FA) and clinical measures of global cognition, attention/processing speed, verbal memory, visuospatial memory, and neuropsychiatric symptoms were used. 2FA binding was lower in the AD group compared with the C group in the medial thalamus, medial temporal cortex, anterior cingulate, insula/opercula, inferior caudate, and brainstem (p healthy older adults, lower receptor binding may be associated with slower processing speed. Cholinergic receptor binding in vivo may reveal links to other key brain changes associated with aging and AD and may provide a potential molecular treatment target. Published by Elsevier Inc.

Striatal adenosine A2A receptor-mediated positron emission tomographic imaging in 6-hydroxydopamine-lesioned rats using [18F]-MRS5425

International Nuclear Information System (INIS)

Bhattacharjee, Abesh Kumar; Lang Lixin; Jacobson, Orit; Shinkre, Bidhan; Ma Ying; Niu Gang; Trenkle, William C.; Jacobson, Kenneth A.; Chen Xiaoyuan; Kiesewetter, Dale O.

2011-01-01

Introduction: A 2A receptors are expressed in the basal ganglia, specifically in striatopallidal GABAergic neurons in the striatum (caudate-putamen). This brain region undergoes degeneration of presynaptic dopamine projections and depletion of dopamine in Parkinson's disease. We developed an 18 F-labeled A 2A analog radiotracer ([ 18 F]-MRS5425) for A 2A receptor imaging using positron emission tomography (PET). We hypothesized that this tracer could image A 2A receptor changes in the rat model for Parkinson's disease, which is created following unilateral injection of the monoaminergic toxin 6-hydroxydopamine (6-OHDA) into the substantia nigra. Methods: [ 18 F]-MRS5425 was injected intravenously in anesthetized rats, and PET imaging data were collected. Image-derived percentage injected doses per gram (%ID/g) in regions of interest was measured in the striatum of normal rats and in rats unilaterally lesioned with 6-OHDA after intravenous administration of saline (baseline), D 2 agonist quinpirole (1.0 mg/kg) or D 2 antagonist raclopride (6.0 mg/kg). Results: Baseline %ID/g reached a maximum at 90 s and maintained plateau for 3.5 min, and then declined slowly thereafter. In 6-OHDA-lesioned rats, %ID/g was significantly higher in the lesioned side compared to the intact side, and the baseline total %ID/g (data from both hemispheres were combined) was significantly higher compared to quinpirole stimulation starting from 4.5 min until the end of acquisition at 30 min. Raclopride did not produce any change in uptake compared to baseline or between the hemispheres. Conclusion: Thus, increase of A 2A receptor-mediated uptake of radioactive MRS5425 could be a superior molecular target for Parkinson's imaging.

Radioiodination of central nerves system dopamine D2 receptor imaging agent. IBZM preparation and preclinical study

Energy Technology Data Exchange (ETDEWEB)

Yansong, Lin; Xiangtong, Lin; Mingyang, Hu; Shangren, Pan; Bocheng, Wang [Huashan Hospital of Shanghai Medical Univ., Shanghai (China)

1996-11-01

To study preparation of central nerves system dopamine D2 imaging agent {sup 131}I-IBZM and its preclinical investigation, peracetic acid was used as the oxidant for preparing radioiodinated {sup 125}I-IBZM and {sup 131}I-IBZM, D2 binding properties of IBZM were examined by in vitro binding saturation analysis, rat whole body and regional brain biodistribution, rat brain autoradiography and rabbit SPECT static imaging, etc. The results are: 1. The radiolabelling yields of {sup 125}I-IBZM and {sup 131}I-IBZM were 84.18% +- 3.06% and 78.50% +- 3.47%. The radiochemical purity were over 95% after being isolated by HPLC; and were over 90% after being isolated by organic extraction. 2. Scatchard plot of D2 receptor saturation binding analysis showed: K{sub d} = 0.53 +- 0.06 nmol/L, B{sub max} = 466.45 +- 45.88 fmol/mg protein. 3. The rat brain autoradiography and analysis showed that there was high {sup 125}I-IBZM uptake in striatal area 2 hr after injection, the striatal/cerebellum ratio was 6.22 +- 0.48; the high {sup 125}-IBZM uptake can be blocked by haloperidol--a special dopamine D2 receptor antagonist. 4. {sup 131}I-IBZM rat biodistribution and rabbit SPECT planar imaging showed good initial brain uptake and retention, the initial uptake of rat brain was 1.893 +- 0.147% ID/g at 2 min and 1.044 +- 0.135% ID/g at 60 min. The results showed that the radioiodinated IBZM had high affinity, saturation and specificity to rat`s and rabbit`s central nerves system dopamine D2 receptors.

No evidence for a major gene effect of the dopamine D{sub 4} receptor gene in the susceptibility to Gilles de la Tourette Syndrome in five Canadian families

Energy Technology Data Exchange (ETDEWEB)

Barr, C.L.; Wigg, K.G.; Tsui, Lap-Chee [Univ. of Toronto, Ontario (Canada)] [and others

1996-05-31

Gilles de la Tourette Syndrome (TS) is a neuropsychiatric disorder characterized by both motor and vocal tics affecting approximately 1/10,000 females and 1/2000 males. Because of the success of neuroleptics and other agents interacting with the dopaminergic system in the suppression of tics, a defect in the dopamine system has been hypothesized in the etiology of TS. In this paper we test the hypothesis that the dopamine D{sub 4} receptor (DRD44) is linked to the genetic susceptibility to TS in five families. We tested three polymorphisms in the DRD4 gene and a polymorphism in the closely linked locus, tyrosine hydroxylase (TH). We found no evidence for linkage of DRD4 or TH to TS using an autosomal dominant model with reduced penetrance or using non-parametric methods. The presence of a mutation that results in a truncated non-functional D{sub 4} receptor protein was also tested for, but was not observed in these families. 36 refs., 1 tab.

Synthesis and Preliminary Evaluation of a 2-Oxoquinoline Carboxylic Acid Derivative for PET Imaging the Cannabinoid Type 2 Receptor

Directory of Open Access Journals (Sweden)

Linjing Mu

2014-03-01

Full Text Available Cannabinoid receptor subtype 2 (CB2 has been shown to be up-regulated in activated microglia and therefore plays an important role in neuroinflammatory and neurodegenerative diseases such as multiple sclerosis, amyotrophic lateral sclerosis and Alzheimer’s disease. The CB2 receptor is therefore considered as a very promising target for therapeutic approaches as well as for imaging. A promising 2-oxoquinoline derivative designated KP23 was synthesized and radiolabeled and its potential as a ligand for PET imaging the CB2 receptor was evaluated. [11C]KP23 was obtained in 10%–25% radiochemical yield (decay corrected and 99% radiochemical purity. It showed high stability in phosphate buffer, rat and mouse plasma. In vitro autoradiography of rat and mouse spleen slices, as spleen expresses a high physiological expression of CB2 receptors, demonstrated that [11C]KP23 exhibits specific binding towards CB2. High spleen uptake of [11C]KP23 was observed in dynamic in vivo PET studies with Wistar rats. In conclusion, [11C]KP23 showed promising in vitro and in vivo characteristics. Further evaluation with diseased animal model which has higher CB2 expression levels in the brain is warranted.

Gastrin-releasing peptide receptor-targeted gadolinium oxide-based multifunctional nanoparticles for dual magnetic resonance/fluorescent molecular imaging of prostate cancer

Directory of Open Access Journals (Sweden)

Cui DT

2017-09-01

Full Text Available Danting Cui,1 Xiaodan Lu,1 Chenggong Yan,1 Xiang Liu,1 Meirong Hou,1 Qi Xia,2 Yikai Xu,1 Ruiyuan Liu2,3 1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, People’s Republic of China; 2School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, People’s Republic of China; 3School of Biomedical Engineering, Southern Medical University, Guangzhou, People’s Republic of China Abstract: Bombesin (BBN, an analog of gastrin-releasing peptide (GRP, specifically binds to GRP receptors, which are overexpressed in human prostate cancer (PC. Here, we synthesized a BBN-modified gadolinium oxide (Gd2O3 nanoprobe containing fluorescein (Gd2O3-5(6-carboxyfluorescein [FI]-polyethylene glycol [PEG]-BBN for targeted magnetic resonance (MR/optical dual-modality imaging of PC. The Gd2O3-FI-PEG-BBN nanoparticles exhibited a relatively uniform particle size with an average diameter of 52.3 nm and spherical morphology as depicted by transmission electron microscopy. The longitudinal relaxivity (r1 of Gd2O3-FI-PEG-BBN (r1 =4.23 mM–1s–1 is comparable to that of clinically used Magnevist (Gd-DTPA. Fluorescence microscopy and in vitro cellular MRI demonstrated GRP receptor-specific and enhanced cellular uptake of the Gd2O3-FI-PEG-BBN in PC-3 tumor cells. Moreover, Gd2O3-FI-PEG-BBN showed more remarkable contrast enhancement than the corresponding nontargeted Gd2O3-FI-PEG according to in vivo MRI and fluorescent imaging. Tumor immunohistochemical analysis further demonstrated improved accumulation of the targeted nanoprobe in tumors. BBN-conjugated Gd2O3 may be a promising nanoplatform for simultaneous GRP receptor-targeted molecular cancer diagnosis and antitumor drug delivery in future clinical applications. Keywords: magnetic resonance imaging, gadolinium oxide, bombesin, gastrin-releasing peptide receptor, molecular imaging

Biodistribution and dosimetry in humans of two inverse agonists to image cannabinoid CB{sub 1} receptors using positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Terry, Garth E. [National Institute of Mental Health, Molecular Imaging Branch, Bethesda, MD (United States); Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Stockholm (Sweden); Hirvonen, Jussi; Liow, Jeih-San; Seneca, Nicholas; Morse, Cheryl L.; Pike, Victor W.; Innis, Robert B. [National Institute of Mental Health, Molecular Imaging Branch, Bethesda, MD (United States); Tauscher, Johannes T.; Schaus, John M.; Phebus, Lee; Felder, Christian C. [Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN (United States); Halldin, Christer [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Stockholm (Sweden)

2010-08-15

Cannabinoid subtype 1 (CB{sub 1}) receptors are found in nearly every organ in the body, may be involved in several neuropsychiatric and metabolic disorders, and are therefore an active target for pharmacotherapy and biomarker development. We recently reported brain imaging of CB{sub 1} receptors with two PET radioligands: {sup 11}C-MePPEP and {sup 18}F-FMPEP-d{sub 2}. Here we describe the biodistribution and dosimetry estimates for these two radioligands. Seven healthy subjects (four men and three women) underwent whole-body PET scans for 120 min after injection with {sup 11}C-MePPEP. Another seven healthy subjects (two men and five women) underwent whole-body PET scans for 300 min after injection with {sup 18}F-FMPEP-d{sub 2}. Residence times were acquired from regions of interest drawn on tomographic images of visually identifiable organs for both radioligands and from radioactivity excreted in urine for {sup 18}F-FMPEP-d{sub 2}. The effective doses of {sup 11}C-MePPEP and {sup 18}F-FMPEP-d{sub 2} are 4.6 and 19.7 {mu}Sv/MBq, respectively. Both radioligands demonstrated high uptake of radioactivity in liver, lung, and brain shortly after injection and accumulated radioactivity in bone marrow towards the end of the scan. After injection of {sup 11}C-MePPEP, radioactivity apparently underwent hepatobiliary excretion only, while radioactivity from {sup 18}F-FMPEP-d{sub 2} showed both hepatobiliary and urinary excretion. {sup 11}C-MePPEP and {sup 18}F-FMPEP-d{sub 2} yield an effective dose similar to other PET radioligands labeled with either {sup 11}C or {sup 18}F. The high uptake in brain confirms the utility of these two radioligands to image CB{sub 1} receptors in brain, and both may also be useful to image CB{sub 1} receptors in the periphery. (orig.)

Serotonin type-1A receptor imaging in depression

International Nuclear Information System (INIS)

Drevets, Wayne C.; Frank, Ellen; Price, Julie C.; Kupfer, David J.; Greer, Phil J.; Mathis, Chester

2000-01-01

Regional 5-hydroxytryptamine 1A (5-HT 1A ) receptor binding potential (BP) of depressed subjects with primary, recurrent, familial mood disorders was compared to that of healthy controls by using positron emission tomography and [carbonyl- 11 C]WAY-100635 {[ 11 C]N-(2-(4-(2-methoxyphenyl)-1-piperazin-1-yl)ethyl)-N-(2-pyridyl) cyclohexanecarboxamide}. The mean 5-HT 1A receptor BP was reduced 42% in the midbrain raphe and 25-33% in limbic and neocortical areas in the mesiotemporal, occipital, and parietal cortex. The magnitude of these abnormalities was most prominent in bipolar depressives and unipolar depressives who had bipolar relatives. These abnormal reductions in 5-HT 1A receptor BP are consistent with in vivo evidence that 5-HT 1A receptor sensitivity is reduced in major depressive disorder and postmortem data showing a widespread deficit of 5-HT 1A receptor expression in primary mood disorders

Characterization of high specific activity [16 alpha-123I]Iodo-17 beta-estradiol as an estrogen receptor-specific radioligand capable of imaging estrogen receptor-positive tumors

International Nuclear Information System (INIS)

Pavlik, E.J.; Nelson, K.; Gallion, H.H.; van Nagell, J.R. Jr.; Donaldson, E.S.; Shih, W.J.; Spicer, J.A.; Preston, D.F.; Baranczuk, R.J.; Kenady, D.E.

1990-01-01

16 alpha-[123I]Iodo-17 beta-estradiol (16 alpha-[123I]E2) has been characterized for use as a selective radioligand for estrogen receptor (ERc) that is capable of generating in situ images of ERc-positive tumors. High specific activity 16 alpha-[123I]E2 (7,500-10,000 Ci/mmol) was used in all determinations. Radiochemical purity was determined by thin layer chromatography, and the selectivity of radioligand for ERc was evaluated using size exclusion high performance liquid chromatography on ERc prepared from rodent uteri. Efficiencies of radioidination approaching 100% were achieved, and excellent receptor selectivity was obtained even when the efficiency of radioiodination was as low as 10%. Low radiochemical purity was always associated with poor selectivity for ERc. No new radioligand species was generated during the course of radiodecay; however, reduced binding over time, even when increased activity was used to compensate for radiodecay, indicated that the formation of a radioinert competitor does occur. 16 alpha-[123I]E2 demonstrated stable, high affinity binding to ERc and was concentrated by ERc-positive tissues. After injecting 16 alpha-[123I]E2 in vivo, images of ERc-containing tissues were obtained, including rabbit reproductive tract and dimethylbenzanthracene-induced tumors. The demonstrations of ERc selectivity and image formation both indicate that 16 alpha-[123I]E2 should have promise as a useful new radiopharmaceutical for imaging ERc-positive cancers

Initial clinical experiences with dopamine D2 receptor imaging by means of 2'-iodospiperone and single-photon emission computed tomography

International Nuclear Information System (INIS)

Yonekura, Yoshiharu; Saji, Hideo; Iwasaki, Yasushi

1995-01-01

Dopamine D 2 receptor imaging was performed with 123 I labeled 2'-iodospiperone (2'-ISP) and single-photon emission computed tomography (SPECT) in 9 patients: 4 with idiopathic Parkinson's disease, 2 with parkinsonism, 1 with Wilson's disease and 2 with pituitary tumor, and the results were compared with the data for 9 normal subjects. Following an intravenous injection of 123 I-2'-ISP, early (within 30 min) and late (between 2 and 4 hr) SPECT images were obtained by means of a multi-detector SPECT scanner or a rotating gamma camera. In normal subjects, early SPECT images demonstrated uniform distribution of radioactivity in the cerebral gray matter and cerebellum reflecting regional cerebral blood flow, whereas late SPECT images showed high radioactivity only in the basal ganglia. All the patients with Parkinson's disease also demonstrated symmetrical basal ganglia uptake in the late SPECT images, but it was diminished in parkinsonism and Wilson's disease. One patient with a growth hormone-producing pituitary tumor had a positive uptake in the tumor. These preliminary clinical data demonstrated that 2'-ISP can be used for SPECT imaging of D 2 dopamine receptors and may be of clinical value for the diagnosis and planning of the treatment of neurological diseases. (author)

Development of a Tc-99m labeled sigma-2 receptor-specific ligand as a potential breast tumor imaging agent

International Nuclear Information System (INIS)

Choi, Seok-Rye; Yang, Biao; Ploessl, Karl; Chumpradit, Sumalee; Wey, Shiaw-Pyng; Acton, Paul D.; Wheeler, Kenneth; Mach, Robert H.; Kung, Hank F.

2001-01-01

A novel in vivo imaging agent, 99m Tc labeled [(N-[2-((3'-N'-propyl-[3,3,1]aza-bicyclononan-3α-yl)(2''-methoxy-5- methyl-phenylcarbamate) (2-mercaptoethyl)amino)acetyl]-2-aminoethanethiolato] technetium(V) oxide), [ 99m Tc]2, displaying specific binding towards sigma-2 receptors was prepared and characterized. In vitro binding assays showed that the rhenium surrogate of [ 99m Tc]2, Re-2, displayed excellent binding affinity and selectivity towards sigma-2 receptors (K i = 2,723 and 22 nM for sigma-1 and sigma-2 receptor, respectively). Preparation of [ 99m Tc]2 was achieved by heating the S-protected starting material, 1, in the presence of acid, reducing agent (stannous glucoheptonate) and sodium [ 99m Tc]pertechnetate. The lipophilic racemic mixture was successfully prepared in 10 to 50% yield and the radiochemical purity was >98%. Separation of the isomers, peak A and peak B, was successfully achieved by using a chiralpak AD column eluted with an isocratic solvent (n-hexane/isopropanol; 3:1; v/v). The peak A and peak B appear to co-elute with the isomers of the surrogate, Re-2, under the same HPLC condition. Biodistribution studies in tumor bearing mice (mouse mammary adenocarcinoma, cell line 66, which is known to over-express sigma-2 receptors) showed that the racemic [ 99m Tc]2 localized in the tumor. Uptake in the tumor was 2.11, 1.30 and 1.11 %dose/gram at 1, 4 and 8 hr post iv injection, respectively, suggesting good uptake and retention in the tumor cells. The tumor uptake was significantly, but incompletely, blocked (about 25-30% blockage) by co-injection of 'cold' (+)pentazocine or haloperidol (1 mg/Kg). A majority of the radioactivity localized in the tumor tissue was extractable (>60%), and the HPLC analysis showed that it is the original compound, racemic [ 99m Tc]2 (>98% pure). The distribution of the purified peak A and peak B was determined in the same tumor bearing mice at 4 hr post iv injection. The tumor uptake was similar for both isomers

Skeletal effects of central nervous system active drugs: anxiolytics, sedatives, antidepressants, lithium and neuroleptics.

Science.gov (United States)

Vestergaard, Peter

2008-09-01

Many central nervous system active drugs can alter postural balance, increasing the risk of fractures. Anxiolytics and sedatives include the benzodiazepines, and these have been associated with a limited increase in the risk of fractures, even at low doses, probably from an increased risk of falls. No systematic differences have been shown between benzodiazepines with long and short half-lives. Although the increase in risk of fractures was limited, care must still be taken when prescribing for older fall-prone subjects at risk of osteoporosis. Neuroleptics may be associated with a decrease in bone mineral density and a very limited increase in fracture risk. Antidepressants are associated with a dose-dependent increase in the risk of fractures. The increase in relative risk of fractures seems to be larger with selective serotonin reuptake inhibitors (SSRIs) than with tricyclic antidepressants. The reason for this is not known but may be linked to serotonin effects on bone cells and the risk of falls. With the wide use of SSRIs, more research is needed. Lithium is associated with a decrease in the risk of fractures. This may be linked to its effects on the Wnt glycoprotein family, which is a specialised signalling system for certain cell types.

[Applying Neuman's Systems Model to a neuroleptic malignant syndrome psychiatric patient and his caregiver].

Science.gov (United States)

Wang, Shu-Mi; Lai, Chien-Yu

2010-04-01

This article describes a nurse's experience using Neuman's Systems Model to care for a chronic psychiatric patient and his caregiver. The patient was diagnosed as suffering from neuroleptic malignant syndrome (NMS). Nursing care described in this article was administered from October 23 to December 4, 2007. The patient developed NMS in the third month of a three-month period of hospitalization, which endangered his life as well as the health of his caregiver. Nursing care was provided to the patient and his caregiver based on Neuman's Systems Model, which included assessments of intrapersonal, interpersonal, and extra-personal forces as well as of environmental factors affecting the health of the patient and his caregiver. The four nursing care issues identified included: existing self-care deficit, sensory/perceptual alteration, sleep pattern disturbance, and caregiver role strain. Following Neuman's systems model, primary, secondary, and tertiary prevention were used to strengthen the flexible lines of defense, internal lines of resistance, and supporting existing strengths of both patient and caregiver, as well as to conserve client system energy. Significant improvements in patient and caregiver abilities were apparent in nursing intervention outcomes. This experience shows the Neuman's systems model to be an efficient model in psychiatric nursing care.

Serotonin type-1A receptor imaging in depression

Energy Technology Data Exchange (ETDEWEB)

Drevets, Wayne C. E-mail: drevets@pet.upmc.edu; Frank, Ellen; Price, Julie C.; Kupfer, David J.; Greer, Phil J.; Mathis, Chester

2000-07-01

Regional 5-hydroxytryptamine{sub 1A} (5-HT{sub 1A}) receptor binding potential (BP) of depressed subjects with primary, recurrent, familial mood disorders was compared to that of healthy controls by using positron emission tomography and [carbonyl-{sup 11}C]WAY-100635 {l_brace}[{sup 11}C]N-(2-(4-(2-methoxyphenyl)-1-piperazin-1-yl)ethyl)-N-(2-pyridyl) cyclohexanecarboxamide{r_brace}. The mean 5-HT{sub 1A} receptor BP was reduced 42% in the midbrain raphe and 25-33% in limbic and neocortical areas in the mesiotemporal, occipital, and parietal cortex. The magnitude of these abnormalities was most prominent in bipolar depressives and unipolar depressives who had bipolar relatives. These abnormal reductions in 5-HT{sub 1A} receptor BP are consistent with in vivo evidence that 5-HT{sub 1A} receptor sensitivity is reduced in major depressive disorder and postmortem data showing a widespread deficit of 5-HT{sub 1A} receptor expression in primary mood disorders.

99mTc labelled peptides for imaging of peripheral receptors

International Nuclear Information System (INIS)

Mustanser, J.; Anjum, A.

2001-01-01

Several peptides are being used as radiopharmaceuticals for receptor imaging scintigraphy. The peptide receptors are found in the tumours of various sites in the human body. Somatostatin is one of those, which is expressed by a variety of tumours say in brain cortex, medullary carcinoma of thyroid, adrenal glands, pancreas and gut. Therefore neuropeptides based on somatostatin analogues are labelled with different radionuclide, 123 I and 111 In. Efforts are underway to label RC-160 (an analogue of somatostatin) with 99m Tc because of its favourable radiation dosimetry, short half-life, low price, high count rate and better diagnostic efficacy. In this project various methods of labelling RC-160 with different radionuclides 125 I and 99m Tc have been studied in detail. Radioiodination of RC-160 was tried with 125 I using the iodogen method as directed and then with Chloramine T method. Labelling of RC-160 peptide with 99m Tc was done using two different aspects. Direct labelling with 99m Tc and indirect labelling with 99m Tc using double chelating agents. Radiochemical quality control was carried out applying instant thin layer chromatography using ITLC-SG strips in 85% of methanol. Later the HPLC analysis was used for its evaluation. To label RC-160 with 99m Tc the approach of direct labelling was attempted first. 46% labelling could be achieved with 95% of radiochemical purity. The biodistribution of 99m Tc-RC-160 complex in rats has also been studied to determine uptake in various sites of somatostatin receptors. Eventually, attempt was made to synthesize biomolecule by conjugating Boc protected RC-160 with benzoyl MAG-3. As a result 80% of Boc-RC-160 went under conjugation with benzoyl MAG-3. (author)

Morphological Imaging in the Localization of Neuroendocrine Gastroenteropancreatic Tumors Found by Somatostatin Receptor Scintigraphy

International Nuclear Information System (INIS)

Saga, T.; Doi, R.; Endo, K.; Shimatsu, A.; Koizumi, K.; Ichikawa, T.; Yamamoto, K.; Noguchi, S.; Ishibashi, M.; Machinami, R.; Nakamura, K.; Sakahara, H.

2005-01-01

Purpose: To evaluate the necessity of morphological images (MI) in reading somatostatin receptor scintigraphy (SRS) in patients with suspected neuroendocrine gastroenteropancreatic (GEP) tumors. Material and Methods: A Japanese multicenter clinical trial of SRS was conducted in 40 patients with suspected GEP tumors. Three experienced radiologists interpreted the images in three separate sessions in a blinded manner (1: SRS images alone, 2: MI alone, 3: SRS and MI analyzed simultaneously), and the reading results of each session were compared. In addition, the diagnostic abilities of SRS, MI and SRS alone and simultaneous SRS and MI readings were compared for patients where final diagnosis was obtained. Results: SRS detected more suspected lesions (positive or inconclusive uptake) than morphological images did (51 vs 27 lesions), but included many physiological uptakes detected as positive or inconclusive uptakes. Combined reading of SRS and morphological images helped to correctly recognize these physiological uptakes, and also helped in determining the anatomical localization of the abnormal uptakes. Combined reading of SRS and morphological images gave the highest diagnostic impact. Conclusion: The sensitivity of SRS with regard to GEP is high. However the specificity is very low. Morphologic imaging is necessary for the exclusion of physiological uptake and correct anatomic location of an abnormal tracer uptake. The combined reading of SRS and morphologic imaging studies gives the highest diagnostic impact

Synthesis and biological evaluation of carbon-11- and fluorine-18-labeled 2-oxoquinoline derivatives for type 2 cannabinoid receptor positron emission tomography imaging

International Nuclear Information System (INIS)

Evens, Nele; Muccioli, Giulio G.; Houbrechts, Nele; Lambert, Didier M.; Verbruggen, Alfons M.; Van Laere, Koen; Bormans, Guy M.

2009-01-01

Introduction: The type 2 cannabinoid (CB 2 ) receptor is part of the endocannabinoid system and has been suggested as a mediator of several central and peripheral inflammatory processes. Imaging of the CB 2 receptor has been unsuccessful so far. We synthesized and evaluated a carbon-11- and a fluorine-18-labeled 2-oxoquinoline derivative as new PET tracers with high specificity and affinity for the CB 2 receptor. Methods: Two 2-oxoquinoline derivatives were synthesized and radiolabeled with either carbon-11 or fluorine-18. Their affinity and selectivity for the human CB 2 receptor were determined. Biological evaluation was done by biodistribution, radiometabolite and autoradiography studies in mice. Results: In vitro studies showed that both compounds are high affinity CB 2 -specific inverse agonists. Biodistribution study of the tracers in mice showed a high in vivo initial brain uptake and fast brain washout, in accordance with the low CB 2 receptor expression levels in normal brain. A persistently high in vivo binding to the spleen was observed, which was inhibited by pretreatment with two structurally unrelated CB 2 selective inverse agonists. In vitro autoradiography studies with the radioligands confirmed CB 2 -specific binding to the mouse spleen. Conclusion: We synthesized two novel CB 2 receptor PET tracers that show high affinity/selectivity for CB 2 receptors. Both tracers show favourable characteristics as radioligands for central and peripheral in vivo visualization of the CB 2 receptor and are promising candidates for primate and human CB 2 PET imaging.

Tumor-associated macrophages in glioblastoma multiforme-a suitable target for somatostatin receptor-based imaging and therapy?

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Constantin Lapa

Full Text Available Glioblastoma multiforme (GBM is the most common primary brain tumor in adults. Tumor-associated macrophages (TAM have been shown to promote malignant growth and to correlate with poor prognosis. [1,4,7,10-tetraazacyclododecane-NN',N″,N'″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE labeled with Gallium-68 selectively binds to somatostatin receptor 2A (SSTR2A which is specifically expressed and up-regulated in activated macrophages. On the other hand, the role of SSTR2A expression on the cell surface of glioma cells has not been fully elucidated yet. The aim of this study was to non-invasively assess SSTR2A expression of both glioma cells as well as macrophages in GBM.15 samples of patient-derived GBM were stained immunohistochemically for macrophage infiltration (CD68, proliferative activity (Ki67 as well as expression of SSTR2A. Anti-CD45 staining was performed to distinguish between resident microglia and tumor-infiltrating macrophages. In a subcohort, positron emission tomography (PET imaging using 68Ga-DOTATATE was performed and the semiquantitatively evaluated tracer uptake was compared to the results of immunohistochemistry.The amount of microglia/macrophages ranged from 50% in the tumor samples with the vast majority being resident microglial cells. A strong SSTR2A immunostaining was observed in endothelial cells of proliferating vessels, in neurons and neuropile. Only faint immunostaining was identified on isolated microglial and tumor cells. Somatostatin receptor imaging revealed areas of increased tracer accumulation in every patient. However, retention of the tracer did not correlate with immunohistochemical staining patterns.SSTR2A seems not to be overexpressed in GBM samples tested, neither on the cell surface of resident microglia or infiltrating macrophages, nor on the surface of tumor cells. These data suggest that somatostatin receptor directed imaging and treatment strategies are less promising in GBM.

Anti-N-methyl-D-aspartate receptor encephalitis concomitant with multifocal subcortical white matter lesions on magnetic resonance imaging: a case report and review of the literature.

Science.gov (United States)

Wang, Rui-Jin; Chen, Bu-Dong; Qi, Dong

2015-07-08

Anti-N-methyl-D-aspartate receptor encephalitis is a severe autoimmune disorder characterized by severe psychiatric symptoms, seizures, decreased consciousness, autonomic dysregulation, and dyskinesias. Multifocal subcortical white matter lesions on fluid-attenuated inversion recovery and diffuse weighted images have rarely been reported in previous literature, and serial magnetic resonance imaging changes after plasma exchange have not been presented before. A previously healthy 24-year-old Chinese woman presented with acute psychiatric symptoms characterized by fear and agitation followed by decreased consciousness, dyskinesias, and seizures. Magnetic resonance imaging revealed hyperintense lesions on fluid-attenuated inversion recovery and diffuse weighted images in bilateral subcortical white matter. Cerebrospinal fluid analysis revealed a mild pleocytosis with lymphocytic predominance. Protein and glucose levels were normal. Aquaporin-4 antibodies in serum and cerebrospinal fluid were negative. Identification of anti-N-methyl-D-aspartate receptor antibodies in serum and cerebrospinal fluid confirmed the diagnosis of anti-N-methyl-D-aspartate receptor encephalitis. She was initially treated with combined intravenous immunoglobulin and methylprednisolone without improvement. Plasma exchange was then initiated with good response; the patient made a full recovery after several cycles of plasma exchange. Repeat magnetic resonance imaging performed 1 month after plasma exchange showed partial resolution of the hyperintense lesions in bilateral subcortical white matter, and follow-up magnetic resonance imaging 2 months after plasma exchange showed complete resolution. Anti-N-methyl-D-aspartate receptor encephalitis may be concomitant with multifocal subcortical white matter lesions. Such lesions may resolve after appropriate immunotherapy.

Development of a Ga-68 labeled triptorelin analog for GnRH receptor imaging

Energy Technology Data Exchange (ETDEWEB)

Zoghi, Masoumeh; Niazi, Ali [Islamic Azad Univ., Arak (Iran, Islamic Republic of). Dept. of Chemistry; Jalilian, Amir R.; Johari-daha, Fariba; Alirezapour, Behrouz [Nuclear Science and Technology Research Institute (NSTRI) (Iran, Islamic Republic of). Radiation Application Research School; Ramezanpour, Sorour [K.N. Toosi Univ. of Technology, Tehran (Iran, Islamic Republic of). Peptide Chemistry Research Center

2016-08-01

Optimized total synthesis, radiolabeling and quality control of [{sup 68}Ga]-DOTA-Hyd-TRP as an efficient and possible PET radiotracer for GnRH receptor imaging in various tumors is of great interest. DOTA-Hyd-TRP was synthesized using solid phase peptide synthesis followed by conjugation to DOTA using pSCN-Bn-DOTA. [{sup 68}Ga]-DOTA-Hyd-TRP was prepared using generator-based [{sup 68}Ga]GaCl{sub 3} and DOTA-Hyd-TRP under optimized conditions for time, temperature, ligand amount, gallium content and column cartridge purification followed by proper formulation. The biodistribution of the tracer in rats was studied using tissue counting up to 120 min. [{sup 68}Ga]-DOTA-Hyd-TRP was prepared at optimized conditions in 5-7 min at 95 C followed by separation using C{sub 18} cartridge (radiochemical purity ∼99 ± 0.88% ITLC, > 99% HPLC, specific activity: 300 ± 15 MBq/nM). The biodistribution of the tracer demonstrated high kidney uptake of the tracer in 10-20 min as well as significant testicular uptake consistent with reported GnRH receptor mappings. Block test studies by triptorelin pretreatment of the animals prior to tracer administration demonstrated significant specific uptake in receptor rich organs including testes and stomach.

Molecular imaging with 68Ga-SSTR PET/CT and correlation to immunohistochemistry of somatostatin receptors in neuroendocrine tumours

International Nuclear Information System (INIS)

Kaemmerer, Daniel; Haugvik, Sven-Petter; Hommann, Merten; Peter, Luisa; Lupp, Amelie; Schulz, Stefan; Saenger, Joerg; Prasad, Vikas; Kulkarni, Harshad; Baum, Richard Paul

2011-01-01

Somatostatin receptors (SSTR) are known for an overexpression in gastroenteropancreatic neuroendocrine tumours (GEP-NET). The aim of the present study was to find out if the receptor density predicted by the semi-quantitative parameters generated from the static positron emission tomography (PET/CT) correlated with the in vitro immunohistochemistry using a novel rabbit monoclonal anti-SSTR2A antibody (clone UMB-1) for specific SSTR2A immunohistochemistry and polyclonal antibodies for SSTR1 and 3-5. Overall 14 surgical specimens generated from 34 histologically documented GEP-NET patients were correlated with the preoperative 68 Ga-DOTA-NOC PET/CT. Quantitative assessment of the receptor density was done using the immunoreactive score (IRS) of Remmele and Stegner; the additional 4-point IRS classification for immunohistochemistry and standardized uptake values (SUV max and SUV mean ) were used for PET/CT. The IRS for SSTR2A and SSTR5 correlated highly significant with the SUV max on the PET/CT (p mean (p max on the 68 Ga-DOTA-NOC PET/CT scans is concordant with the affinity profile of 68 Ga-DOTA-NOC to the SSTR subtypes and demonstrates the excellent qualification of somatostatin analogues in the diagnostics of NET. This study correlating somatostatin receptor imaging using 68 Ga-DOTA-NOC PET/CT with immunohistochemically analysed SSTR also underlines the approval of therapy using somatostatin analogues, follow-up imaging as well as radionuclide therapy. (orig.)

Biodistribution and dosimetry of iodine-123-labelled Z-MIVE: an oestrogen receptor radioligand for breast cancer imaging

NARCIS (Netherlands)

Rijks, L. J.; Busemann Sokole, E.; Stabin, M. G.; de Bruin, K.; Janssen, A. G.; van Royen, E. A.

1998-01-01

This study reports on the distribution and radiation dosimetry of iodine-123-labelled cis-11beta-methoxy-17alpha-iodovinyloestradiol (Z-[123I]MIVE), a promising radioligand for imaging of oestrogen receptors (ERs) in human breast cancer. Whole-body scans were performed up to 24 h after intravenous

Class side effects: decreased pressure in the lower oesophageal and the pyloric sphincters after the administration of dopamine antagonists, neuroleptics, anti-emetics, L-NAME, pentadecapeptide BPC 157 and L-arginine.

Science.gov (United States)

Belosic Halle, Zeljka; Vlainic, Josipa; Drmic, Domagoj; Strinic, Dean; Luetic, Kresimir; Sucic, Mario; Medvidovic-Grubisic, Maria; Pavelic Turudic, Tatjana; Petrovic, Igor; Seiwerth, Sven; Sikiric, Predrag

2017-05-17

The ulcerogenic potential of dopamine antagonists and L-NAME in rats provides unresolved issues of anti-emetic neuroleptic application in both patients and experimental studies. Therefore, in a 1-week study, we examined the pressures within the lower oesophageal and the pyloric sphincters in rats [assessed manometrically (cm H 2 O)] after dopamine neuroleptics/prokinetics, L-NAME, L-arginine and stable gastric pentadecapeptide BPC 157 were administered alone and/or in combination. Medication (/kg) was given once daily intraperitoneally throughout the 7 days, with the last dose at 24 h before pressure assessment. Given as individual agents to healthy rats, all dopamine antagonists (central [haloperidol (6.25 mg, 16 mg, 25 mg), fluphenazine (5 mg), levomepromazine (50 mg), chlorpromazine (10 mg), quetiapine (10 mg), olanzapine (5 mg), clozapine (100 mg), sulpiride (160 mg), metoclopramide (25 mg)) and peripheral(domperidone (10 mg)], L-NAME (5 mg) and L-arginine (100 mg) decreased the pressure within both sphincters. As a common effect, this decreased pressure was rescued, dose-dependently, by BPC 157 (10 µg, 10 ng) (also note that L-arginine and L-NAME given together antagonized each other's responses). With haloperidol, L-NAME worsened both the lower oesophageal and the pyloric sphincter pressure, while L-arginine ameliorated lower oesophageal sphincter but not pyloric sphincter pressure, and antagonized L-NAME effect. With domperidone, L-arginine originally had no effect, while L-NAME worsened pyloric sphincter pressure. This effect was opposed by L-arginine. All these effects were further reversed towards a stronger beneficial effect, close to normal pressure values, by the addition of BPC 157. In addition, NO level was determined in plasma, sphincters and brain tissue. Thiobarbituric acid reactive substances (TBARS) were also assessed. Haloperidol increased NO levels (in both sphincters, the plasma and brain), consistently producing increased

Imaging dopamine D3 receptors in the human brain with positron emission tomography, [11C]PHNO, and a selective D3 receptor antagonist.

Science.gov (United States)

Searle, Graham; Beaver, John D; Comley, Robert A; Bani, Massimo; Tziortzi, Andri; Slifstein, Mark; Mugnaini, Manolo; Griffante, Cristiana; Wilson, Alan A; Merlo-Pich, Emilio; Houle, Sylvain; Gunn, Roger; Rabiner, Eugenii A; Laruelle, Marc

2010-08-15

Dopamine D(3) receptors are involved in the pathophysiology of several neuropsychiatric conditions. [(11)C]-(+)-PHNO is a radiolabeled D(2) and D(3) agonist, suitable for imaging the agonist binding sites (denoted D(2HIGH) and D(3)) of these receptors with positron emission tomography (PET). PET studies in nonhuman primates documented that, in vivo, [(11)C]-(+)-PHNO displays a relative selectivity for D(3) compared with D(2HIGH) receptor sites and that the [(11)C]-(+)-PHNO signal is enriched in D(3) contribution compared with conventional ligands such as [(11)C] raclopride. To define the D(3) contribution (f(PHNO)(D3)) to [(11)C]-(+)-PHNO binding potential (BP(ND)) in healthy humans, 52 PET scans were obtained in 19 healthy volunteers at baseline and following oral administration of various doses of the selective D(3) receptor antagonist, GSK598809. The impact of GSK598809 on [(11)C]-(+)-PHNO was regionally selective. In dorsal regions of the striatum, GSK598809 did not significantly affect [(11)C]-(+)-PHNO BP(ND) (f(PHNO)(D3) approximately 0%). Conversely, in the substantia nigra, GSK598809 dose-dependently reduced [(11)C]-(+)-PHNO binding to nonspecific level (f(PHNO)(D3) approximately 100%). In ventral striatum (VST), globus pallidus and thalamus (THA), [(11)C]-(+)-PHNO BP(ND) was attributable to a combination of D(2HIGH) and D(3) receptor sites, with f(PHNO)(D3) of 26%, 67% and 46%, respectively. D(3) receptor binding potential (BP(ND)(D3)) was highest in globus pallidus (1.90) and substantial nigra (1.39), with lower levels in VST (.77) and THA (.18) and negligible levels in dorsal striatum. This study elucidated the pharmacologic nature of the [(11)C]-(+)-PHNO signal in healthy subjects and provided the first quantification of D(3) receptor availability with PET in the living human brain. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Application of photoshop-based image analysis to quantification of hormone receptor expression in breast cancer.

Science.gov (United States)

Lehr, H A; Mankoff, D A; Corwin, D; Santeusanio, G; Gown, A M

1997-11-01

The benefit of quantifying estrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer is well established. However, in routine breast cancer diagnosis, receptor expression is often quantified in arbitrary scores with high inter- and intraobserver variability. In this study we tested the validity of an image analysis system employing inexpensive, commercially available computer software on a personal computer. In a series of 28 invasive ductal breast cancers, immunohistochemical determinations of ER and PR were performed, along with biochemical analyses on fresh tumor homogenates, by the dextran-coated charcoal technique (DCC) and by enzyme immunoassay (EIA). From each immunohistochemical slide, three representative tumor fields (x20 objective) were captured and digitized with a Macintosh personal computer. Using the tools of Photoshop software, optical density plots of tumor cell nuclei were generated and, after background subtraction, were used as an index of immunostaining intensity. This immunostaining index showed a strong semilogarithmic correlation with biochemical receptor assessments of ER (DCC, r = 0.70, p < 0.001; EIA, r = 0.76, p < 0.001) and even better of PR (DCC, r = 0.86; p < 0.01; EIA, r = 0.80, p < 0.001). A strong linear correlation of ER and PR quantification was also seen between DCC and EIA techniques (ER, r = 0.62, p < 0.001; PR, r = 0.92, p < 0.001). This study demonstrates that a simple, inexpensive, commercially available software program can be accurately applied to the quantification of immunohistochemical hormone receptor studies.

Molecular Imaging of Hepatocellular Carcinoma Xenografts with Epidermal Growth Factor Receptor Targeted Affibody Probes

Directory of Open Access Journals (Sweden)

Ping Zhao

2013-01-01

Full Text Available Hepatocellular carcinoma (HCC is a highly aggressive and lethal cancer. It is typically asymptomatic at the early stage, with only 10%–20% of HCC patients being diagnosed early enough for appropriate surgical treatment. The delayed diagnosis of HCC is associated with limited treatment options and much lower survival rates. Therefore, the early and accurate detection of HCC is crucial to improve its currently dismal prognosis. The epidermal growth factor receptor (EGFR has been reported to be involved in HCC tumorigenesis and to represent an attractive target for HCC imaging and therapy. In this study, an affibody molecule, Ac-Cys-ZEGFR:1907, targeting the extracellular domain of EGFR, was used for the first time to assess its potential to detect HCC xenografts. By evaluating radio- or fluorescent-labeled Ac-Cys-ZEGFR:1907 as a probe for positron emission tomography (PET or optical imaging of HCC, subcutaneous EGFR-positive HCC xenografts were found to be successfully imaged by the PET probe. Thus, affibody-based PET imaging of EGFR provides a promising approach for detecting HCC in vivo.

Kindling: A Model for the Development of Tardive Dyskinesia?

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B. Glenthøj

1988-01-01

Full Text Available Tardive dyskinesia (TD from long-term neuroleptic treatment may be irreversible; therefore prevention has become a major concern. A controversial issue with regard to the clinical use of neuroleptic drugs is the possible influence on the development of TD of drug holidays. The major characteristics of kindling, theories of TD and the role of multiplicity in the development of TD are described. Some clinical studies point to interruption of neuroleptic therapy being a risk factor for development of irreversible TD. Induction of dyskinesia in non-human primates has been demonstrated after repeated administration of haloperidol. Rodent studies have not been conclusive. Several experimental results link TD with kindling: both conditions involve repeated stimulations, both seem to involve increased receptor responsiveness and in both conditions does depression in GABA transmission in SNR (substantia nigra; pars reticulata play an important role. It is concluded that the kindling hypothesis is relevant to the investigation of TD.

Quantification of GABAA receptors in the rat brain with [123I]Iomazenil SPECT from factor analysis-denoised images

International Nuclear Information System (INIS)

Tsartsalis, Stergios; Moulin-Sallanon, Marcelle; Dumas, Noé; Tournier, Benjamin B.; Ghezzi, Catherine; Charnay, Yves; Ginovart, Nathalie; Millet, Philippe

2014-01-01

Purpose: In vivo imaging of GABA A receptors is essential for the comprehension of psychiatric disorders in which the GABAergic system is implicated. Small animal SPECT provides a modality for in vivo imaging of the GABAergic system in rodents using [ 123 I]Iomazenil, an antagonist of the GABA A receptor. The goal of this work is to describe and evaluate different quantitative reference tissue methods that enable reliable binding potential (BP) estimations in the rat brain to be obtained. Methods: Five male Sprague–Dawley rats were used for [ 123 I]Iomazenil brain SPECT scans. Binding parameters were obtained with a one-tissue compartment model (1TC), a constrained two-tissue compartment model (2TC c ), the two-step Simplified Reference Tissue Model (SRTM2), Logan graphical analysis and analysis of delayed-activity images. In addition, we employed factor analysis (FA) to deal with noise in data. Results: BP ND obtained with SRTM2, Logan graphical analysis and delayed-activity analysis was highly correlated with BP F values obtained with 2TC c (r = 0.954 and 0.945 respectively, p c and SRTM2 in raw and FA-denoised images (r = 0.961 and 0.909 respectively, p ND values from raw images while scans of only 70 min are sufficient from FA-denoised images. These images are also associated with significantly lower standard errors of 2TC c and SRTM2 BP values. Conclusion: Reference tissue methods such as SRTM2 and Logan graphical analysis can provide equally reliable BP ND values from rat brain [ 123 I]Iomazenil SPECT. Acquisitions, however, can be much less time-consuming either with analysis of delayed activity obtained from a 20-minute scan 50 min after tracer injection or with FA-denoising of images

Treatment of generalized anxiety disorder: comparison of a new beta-blocking drug (CGP 361 A), low-dose neuroleptic (flupenthixol), and placebo.

Science.gov (United States)

Bjerrum, H; Allerup, P; Thunedborg, K; Jakobsen, K; Bech, P

1992-09-01

In an attempt to evaluate an alternative drug treatment to benzodiazepines in generalized anxiety disorders, a placebo controlled trial was carried out with a new beta-adrenergic blocker (CPG 361 A). A low-dosage neuroleptic (flupenthixol) was included as a reference drug. Depending on the clinical assessment scales the placebo treatment resulted in moderate to excellent improvement in 36% to 56% of the patients after four weeks of treatment. The active drugs generally had a higher improvement range (from 31% to 80%). The global improvement scale was found to be better than the other scales in discriminating between placebo (50% improvement) and the active drugs (CGP 361 A brought about 78% improvement and flupenthixol brought about 80% improvement). However, only for flupenthixol was the difference of statistical significance.

Clinically compliant spatial and temporal imaging of chimeric antigen receptor T-cells.

Science.gov (United States)

Emami-Shahri, Nia; Foster, Julie; Kashani, Roxana; Gazinska, Patrycja; Cook, Celia; Sosabowski, Jane; Maher, John; Papa, Sophie

2018-03-14

The unprecedented efficacy of chimeric antigen receptor (CAR) T-cell immunotherapy of CD19 + B-cell malignancy has established a new therapeutic pillar of hematology-oncology. Nonetheless, formidable challenges remain for the attainment of comparable success in patients with solid tumors. To accelerate progress and rapidly characterize emerging toxicities, systems that permit the repeated and non-invasive assessment of CAR T-cell bio-distribution would be invaluable. An ideal solution would entail the use of a non-immunogenic reporter that mediates specific uptake of an inexpensive, non-toxic and clinically established imaging tracer by CAR T cells. Here we show the utility of the human sodium iodide symporter (hNIS) for the temporal and spatial monitoring of CAR T-cell behavior in a cancer-bearing host. This system provides a clinically compliant toolkit for high-resolution serial imaging of CAR T cells in vivo, addressing a fundamental unmet need for future clinical development in the field.

Receptor-targeted metalloradiopharmaceuticals. Final technical report

International Nuclear Information System (INIS)

Green, Mark A.

2000-01-01

Copper (II) and platinum (II) coordination complexes were prepared and characterized. These complexes were designed to afford structural homology with steroidal and non-steroidal estrogens for possible use as receptor-targeted radiopharmaceuticals. While weak affinity for the estrogen receptor was detectable, none would appear to have sufficient receptor-affinity for estrogen-receptor-targeted imaging or therapy

In vivo type 2 cannabinoid receptor-targeted tumor optical imaging using a near infrared fluorescent probe.

Science.gov (United States)

Zhang, Shaojuan; Shao, Pin; Bai, Mingfeng

2013-11-20

The type 2 cannabinoid receptor (CB2R) plays a vital role in carcinogenesis and progression and is emerging as a therapeutic target for cancers. However, the exact role of CB2R in cancer progression and therapy remains unclear. This has driven the increasing efforts to study CB2R and cancers using molecular imaging tools. In addition, many types of cancers overexpress CB2R, and the expression levels of CB2R appear to be associated with tumor aggressiveness. Such upregulation of the receptor in cancer cells provides opportunities for CB2R-targeted imaging with high contrast and for therapy with low side effects. In the present study, we report the first in vivo tumor-targeted optical imaging using a novel CB2R-targeted near-infrared probe. In vitro cell fluorescent imaging and a competitive binding assay indicated specific binding of NIR760-mbc94 to CB2R in CB2-mid delayed brain tumor (DBT) cells. NIR760-mbc94 also preferentially labeled CB2-mid DBT tumors in vivo, with a 3.7-fold tumor-to-normal contrast enhancement at 72 h postinjection, whereas the fluorescence signal from the tumors of the mice treated with NIR760 free dye was nearly at the background level at the same time point. SR144528, a CB2R competitor, significantly inhibited tumor uptake of NIR760-mbc94, indicating that NIR760-mbc94 binds to CB2R specifically. In summary, NIR760-mbc94 specifically binds to CB2R in vitro and in vivo and appears to be a promising molecular tool that may have great potential for use in diagnostic imaging of CB2R-positive cancers and therapeutic monitoring as well as in elucidating the role of CB2R in cancer progression and therapy.

Initial clinical experiences with dopamine D{sub 2} receptor imaging by means of 2`-iodospiperone and single-photon emission computed tomography

Energy Technology Data Exchange (ETDEWEB)

Yonekura, Yoshiharu [Fukui Medical Schoool, Matsuoka (Japan). Biomedical Imaging Research Center; Saji, Hideo; Iwasaki, Yasushi [and others

1995-08-01

Dopamine D{sub 2} receptor imaging was performed with {sup 123}I labeled 2`-iodospiperone (2`-ISP) and single-photon emission computed tomography (SPECT) in 9 patients: 4 with idiopathic Parkinson`s disease, 2 with parkinsonism, 1 with Wilson`s disease and 2 with pituitary tumor, and the results were compared with the data for 9 normal subjects. Following an intravenous injection of {sup 123}I-2`-ISP, early (within 30 min) and late (between 2 and 4 hr) SPECT images were obtained by means of a multi-detector SPECT scanner or a rotating gamma camera. In normal subjects, early SPECT images demonstrated uniform distribution of radioactivity in the cerebral gray matter and cerebellum reflecting regional cerebral blood flow, whereas late SPECT images showed high radioactivity only in the basal ganglia. All the patients with Parkinson`s disease also demonstrated symmetrical basal ganglia uptake in the late SPECT images, but it was diminished in parkinsonism and Wilson`s disease. One patient with a growth hormone-producing pituitary tumor had a positive uptake in the tumor. These preliminary clinical data demonstrated that 2`-ISP can be used for SPECT imaging of D{sub 2} dopamine receptors and may be of clinical value for the diagnosis and planning of the treatment of neurological diseases. (author).

Guideline for PET/CT imaging of neuroendocrine neoplasms withGa-DOTA-conjugated somatostatin receptor targeting peptides andF-DOPA

DEFF Research Database (Denmark)

Bozkurt, Murat Fani; Virgolini, Irene; Balogova, Sona

2017-01-01

PURPOSE & METHODS: Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing......, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using68Ga-DOTA-conjugated peptides, as well as18F-DOPA imaging for various neuroendocrine neoplasms. RESULTS & CONCLUSION: The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with68Ga...

Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

International Nuclear Information System (INIS)

Waser, Beatrice; Reubi, Jean Claude

2014-01-01

Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. For the somatostatin receptor targeting of tumours, however, it was recently reported that antagonist tracers were superior to agonist tracers. The present study therefore evaluated various forms of the 125 iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracer for the in vitro visualization of GLP-1 receptor-expressing tissues in rats and humans and compared it with the agonist tracer 125 I-GLP-1(7-36)amide. Receptor autoradiography studies with 125 I-GLP-1(7-36)amide agonist or 125 I-BH-exendin(9-39) antagonist radioligands were performed in human and rat tissues. The antagonist 125 I-BH-exendin(9-39) labelled at lysine 19 identifies all human and rat GLP-1 target tissues and GLP-1 receptor-expressing tumours. Binding is of high affinity and is comparable in all tested tissues in its binding properties with the agonist tracer 125 I-GLP-1(7-36)amide. For comparison, 125 I-BH-exendin(9-39) with the BH labelled at lysine 4 did identify the GLP-1 receptor in rat tissues but not in human tissues. The GLP-1 receptor antagonist exendin(9-39) labelled with 125 I-BH at lysine 19 is an excellent GLP-1 radioligand that identifies human and rat GLP-1 receptors in normal and tumoural tissues. It may therefore be the molecular basis to develop suitable GLP-1 receptor antagonist radioligands for in vivo imaging of GLP-1 receptor-expressing tissues in patients. (orig.)

Neuroleptic malignant syndrome: A review of the clinical/diagnostic features and report of a case without fever

Directory of Open Access Journals (Sweden)

Okwudili Obayi

2017-01-01

Full Text Available Neuroleptic malignant syndrome (NMS is an uncommon but potentially fatal idiosyncratic reaction characterized by the development of altered consciousness, hyperthermia, autonomic dysfunction, and muscular rigidity on exposure to antipsychotic (or some other psychotropic medications. It is a medical emergency that requires early prompt identification and intervention. Fever is a predominant symptom in NMS. However, there have been reports that the classical high temperature usually associated with NMS may, on rare occasions, be absent. Case presentation This review and case report focus on the clinical/diagnostic features of NMS and a report of an unusual case without the classical high grade fever in a 27- year old male patient with schizophrenia who had been on high doses of multiple typical and atypical antipsychotic drugs. Conclusion This case report serves to remind clinicians of the essential features in the diagnosis of NMS and supports earlier reports that the classical high temperature usually associated with NMS may, on rare occasions, be absent and that would not exclude the diagnosis.

Striatal adenosine A{sub 2A} receptor-mediated positron emission tomographic imaging in 6-hydroxydopamine-lesioned rats using [{sup 18}F]-MRS5425

Energy Technology Data Exchange (ETDEWEB)

Bhattacharjee, Abesh Kumar; Lang Lixin; Jacobson, Orit [Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892 (United States); Shinkre, Bidhan [Chemical Biology Unit, Laboratory of Cell Biochemistry and Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892 (United States); Ma Ying [Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892 (United States); Niu Gang [Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892 (United States); Department of Radiology and Imaging Sciences, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Trenkle, William C. [Chemical Biology Unit, Laboratory of Cell Biochemistry and Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892 (United States); Jacobson, Kenneth A. [Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892 (United States); Chen Xiaoyuan [Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892 (United States); Kiesewetter, Dale O., E-mail: dk7k@nih.gov [Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892 (United States)

2011-08-15

Introduction: A{sub 2A} receptors are expressed in the basal ganglia, specifically in striatopallidal GABAergic neurons in the striatum (caudate-putamen). This brain region undergoes degeneration of presynaptic dopamine projections and depletion of dopamine in Parkinson's disease. We developed an {sup 18}F-labeled A{sub 2A} analog radiotracer ([{sup 18}F]-MRS5425) for A{sub 2A} receptor imaging using positron emission tomography (PET). We hypothesized that this tracer could image A{sub 2A} receptor changes in the rat model for Parkinson's disease, which is created following unilateral injection of the monoaminergic toxin 6-hydroxydopamine (6-OHDA) into the substantia nigra. Methods: [{sup 18}F]-MRS5425 was injected intravenously in anesthetized rats, and PET imaging data were collected. Image-derived percentage injected doses per gram (%ID/g) in regions of interest was measured in the striatum of normal rats and in rats unilaterally lesioned with 6-OHDA after intravenous administration of saline (baseline), D{sub 2} agonist quinpirole (1.0 mg/kg) or D{sub 2} antagonist raclopride (6.0 mg/kg). Results: Baseline %ID/g reached a maximum at 90 s and maintained plateau for 3.5 min, and then declined slowly thereafter. In 6-OHDA-lesioned rats, %ID/g was significantly higher in the lesioned side compared to the intact side, and the baseline total %ID/g (data from both hemispheres were combined) was significantly higher compared to quinpirole stimulation starting from 4.5 min until the end of acquisition at 30 min. Raclopride did not produce any change in uptake compared to baseline or between the hemispheres. Conclusion: Thus, increase of A{sub 2A} receptor-mediated uptake of radioactive MRS5425 could be a superior molecular target for Parkinson's imaging.

[18F]Fluoroethylflumazenil: a novel tracer for PET imaging of human benzodiazepine receptors

International Nuclear Information System (INIS)

Gruender, G.; Lange-Asschenfeldt, C.; Vernaleken, I.; Lueddens, H.; Siessmeier, T.; Buchholz, H.-G.; Bartenstein, P.; Stoeter, P.; Drzezga, A.; Roesch, F.

2001-01-01

5-(2'-[ 18 F]Fluoroethyl)flumazenil ([ 18 F]FEF) is a fluorine-18 labelled positron emission tomography (PET) tracer for central benzodiazepine receptors. Compared with the established [ 11 C]flumazenil, it has the advantage of the longer half-life of the fluorine-18 label. After optimisation of its synthesis and determination of its in vitro receptor affinities, we performed first PET studies in humans. PET studies in seven healthy human volunteers were performed on a Siemens ECAT EXACT whole-body scanner after injection of 100-280 MBq [ 18 F]FEF. In two subjects, a second PET scan was conducted after pretreatment with unlabelled flumazenil (1 mg or 2.5 mg i.v., 3 min before tracer injection). A third subject was studied both with [ 18 F]FEF and with [ 11 C]flumazenil. Brain radioactivity was measured for 60-90 min p.i. and analysed with a region of interest-oriented approach and on a voxelwise basis with spectral analysis. Plasma radioactivity was determined from arterial blood samples and metabolites were determined by high-performance liquid chromatography. In human brain, maximum radioactivity accumulation was observed 4±2 min p.i., with a fast clearance kinetics resulting in 50% and 20% of maximal activities at about 10 and 30 min, respectively. [ 18 F]FEF uptake followed the known central benzodiazepine receptor distribution in the human brain (occipital cortex >temporal cortex >cerebellum >thalamus >pons). Pretreatment with unlabelled flumazenil resulted in reduced tracer uptake in all brain areas except for receptor-free reference regions like the pons. Parametric images of distribution volume and binding potential generated on a voxelwise basis revealed two- to three-fold lower in vivo receptor binding of [ 18 F]FEF compared with [ 11 C]flumazenil, while relative uptake of [ 18 F]FEF was higher in the cerebellum, most likely owing to its relatively higher affinity for benzodiazepine receptors containing the α6 subunit. Metabolism of [ 18 F]FEF was very

Long-term treatment with haloperidol affects neuropeptide S and NPSR mRNA levels in the rat brain.

Science.gov (United States)

Palasz, Artur; Rojczyk, Ewa; Golyszny, Milosz; Filipczyk, Lukasz; Worthington, John J; Wiaderkiewicz, Ryszard

2016-04-01

The brainstem-derived neuropeptide S (NPS) has a multidirectional regulatory activity, especially as a potent anxiolytic factor. Accumulating data suggests that neuroleptics affect peptidergic signalling in various brain structures. However, there is no information regarding the influence of haloperidol on NPS and NPS receptor (NPSR) expression. We assessed NPS and NPSR mRNA levels in brains of rats treated with haloperidol using quantitative real-time polymerase chain reaction. Chronic haloperidol treatment (4 weeks) led to a striking upregulation of NPS and NPSR expression in the rat brainstem. Conversely, the NPSR mRNA expression was decreased in the hippocampus and striatum. This stark increase of NPS in response to haloperidol treatment supports the hypothesis that this neuropeptide is involved in the dopamine-dependent anxiolytic actions of neuroleptics and possibly also in the pathophysiology of mental disorders. Furthermore, our findings underline the complex nature of potential interactions between dopamine receptors and brain peptidergic pathways, which has potential clinical applications.

Novel one-pot one-step synthesis of 2'-[(18)F]fluoroflumazenil (FFMZ) for benzodiazepine receptor imaging.

Science.gov (United States)

Yoon, Young Hyun; Jeong, Jae Min; Kim, Hyung Woo; Hong, Sung Hyun; Lee, Yun-Sang; Kil, Hee Sup; Chi, Dae Yoon; Lee, Dong Soo; Chung, June-Key; Lee, Myung Chul

2003-07-01

We describe the synthesis of 2'-[(18)F]fluoroflumazenil (FFMZ), which differs from the typically used [(18)F]fluoroethylflumazenil (FEFMZ) for benzodiazepine receptor imaging. For one-pot one-step labeling, the precursors, 2'-tosyloxyflumazenil (TFMZ) and 2'-mesyloxyflumazenil (MFMZ), were synthesized in three steps. The precursors were successfully labeled with no-carrier-added (18)F-fluoride which was activated by repeated azeotropic distillation with Kryptofix 2.2.2./potassium carbonate in MeCN. An automated system for labeling and purification of [(18)F]FFMZ was developed. Labeling efficiency and radiochemical purity of [(18)F]FFMZ after synthesis by the automated system were 68% and 98%, respectively. Specific binding of [(18)F]FFMZ to central benzodiazepine receptor of rats was demonstrated by phosphoimaging.

Novel one-pot one-step synthesis of 2'-[18F]fluoroflumazenil (FFMZ) for benzodiazepine receptor imaging

International Nuclear Information System (INIS)

Young, Hyun Yoon; Jae, Min Jeong; Hyung, Woo Kim; Sung, Hyun Hong; Lee, Yun-Sang; Hee, Sup Kil; Dae, Yoon Chi; Dong, Soo Lee; Chung, June-Key; Myung, Chul Lee

2003-01-01

We describe the synthesis of 2'-[ 18 F]fluoroflumazenil (FFMZ), which differs from the typically used [ 18 F]fluoroethylflumazenil (FEFMZ) for benzodiazepine receptor imaging. For one-pot one-step labeling, the precursors, 2'-tosyloxyflumazenil (TFMZ) and 2'-mesyloxyflumazenil (MFMZ), were synthesized in three steps. The precursors were successfully labeled with no-carrier-added 18 F-fluoride which was activated by repeated azeotropic distillation with Kryptofix 2.2.2./potassium carbonate in MeCN. An automated system for labeling and purification of [ 18 F]FFMZ was developed. Labeling efficiency and radiochemical purity of [ 18 F]FFMZ after synthesis by the automated system were 68% and 98%, respectively. Specific binding of [ 18 F]FFMZ to central benzodiazepine receptor of rats was demonstrated by phosphoimaging

Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

Energy Technology Data Exchange (ETDEWEB)

Waser, Beatrice; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, PO Box 62, Berne (Switzerland)

2014-06-15

Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. For the somatostatin receptor targeting of tumours, however, it was recently reported that antagonist tracers were superior to agonist tracers. The present study therefore evaluated various forms of the {sup 125}iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracer for the in vitro visualization of GLP-1 receptor-expressing tissues in rats and humans and compared it with the agonist tracer {sup 125}I-GLP-1(7-36)amide. Receptor autoradiography studies with {sup 125}I-GLP-1(7-36)amide agonist or {sup 125}I-BH-exendin(9-39) antagonist radioligands were performed in human and rat tissues. The antagonist {sup 125}I-BH-exendin(9-39) labelled at lysine 19 identifies all human and rat GLP-1 target tissues and GLP-1 receptor-expressing tumours. Binding is of high affinity and is comparable in all tested tissues in its binding properties with the agonist tracer {sup 125}I-GLP-1(7-36)amide. For comparison, {sup 125}I-BH-exendin(9-39) with the BH labelled at lysine 4 did identify the GLP-1 receptor in rat tissues but not in human tissues. The GLP-1 receptor antagonist exendin(9-39) labelled with {sup 125}I-BH at lysine 19 is an excellent GLP-1 radioligand that identifies human and rat GLP-1 receptors in normal and tumoural tissues. It may therefore be the molecular basis to develop suitable GLP-1 receptor antagonist radioligands for in vivo imaging of GLP-1 receptor-expressing tissues in patients. (orig.)

Positron Emission Tomographic Imaging of the Cannabinoid Type 1 Receptor System with [11C]OMAR ([11C]JHU75528: Improvements in Image Quantification Using Wild-Type and Knockout Mice

Directory of Open Access Journals (Sweden)

Raúl Herance

2011-11-01

Full Text Available In this study, we assessed the feasibility of using positron emission tomography (PET and the tracer [11C]OMAR ([11C]JHU75528, an analogue of rimonabant, to study the brain cannabinoid type 1 (CB1 receptor system. Wild-type (WT andCB1 knockout (KO animals were imaged at baseline and after pretreatment with blocking doses of rimonabant. Brain uptake in WT animals was higher (50% than in KO animals in baseline conditions. After pretreatment with rimonabant, WT uptake lowered to the level of KO animals. The results of this study support the feasibility of using PET with the radiotracer [11C]JHU75528 to image the brain CB1 receptor system in mice. In addition, this methodology can be used to assess the effect of new drugs in preclinical studies using genetically manipulated animals.

PET imaging of urokinase-type plasminogen activator receptor (uPAR) in prostate cancer

DEFF Research Database (Denmark)

Skovgaard, Dorthe; Persson, Morten; Kjaer, Andreas

2016-01-01

Overexpression of urokinase-type plasminogen activator receptors (uPAR) represents an important biomarker for aggressiveness in most common malignant diseases, including prostate cancer (PC). Accordingly, uPAR expression either assessed directly in malignant PC tissue or assessed directly in plasma...... and prognostic imaging method. In this review, we will focus on the recent development of uPAR PET and the relevance within prostate cancer imaging. Novel antibody and small-molecule radiotracers-targeting uPAR, including a series of uPAR-targeting PET ligands, based on the high affinity peptide ligand AE105......, have been synthesized and tested in vitro and in vivo in preclinical murine xenograft models and, recently, in a first-ever clinical uPAR PET study in cancer patients, including patients with PC. In this phase I study, a high and specific uptake of the tracer 64Cu-DOTA-AE105 was found in both primary...

A Case Report of Lipid-Rich Carcinoma of the Breast Including Histological Characteristics and Intrinsic Subtype Profile

Directory of Open Access Journals (Sweden)

Ayako Kimura

2011-05-01

Full Text Available A 57-year-old Japanese woman with schizophrenia, who had received long-term treatment with neuroleptics, noticed a painless, pea-sized lump in her right breast. She was admitted to our hospital and a malignant tumor was diagnosed. The patient underwent a conservative radical mastectomy (Patey’s operation. The excised tumor measured 2.0 × 1.2 × 1.1 cm in diameter, and its cut surface was grayish-white. Histologically, tumor cells with clear to foamy cytoplasm were invariably Oil Red O-positive and periodic acid Schiff-negative with or without diastase digestion. The tumor was diagnosed as a lipid-rich carcinoma accompanied by an in situ component. Neuroleptics increase serum prolactin levels by interfering with dopaminergic inhibition of prolactin secretion. Immunohistochemical analysis revealed that, although prolactin was not detected, the tumor cells expressed prolactin receptor, indicating prolactin as the genesis of this neoplasm. In immunohistochemical intrinsic subtype analysis, the tumor was negative for estrogen receptor, progesterone receptor, human epidermal growth factor receptor 1 and 2, and basal cytokeratins (CK5, CK6, and CK14, indicating an unclassified (all-marker negative subtype. Axillary lymph nodes were free of metastasis (stage I, and the patient has been well for 20 years without any evidence of recurrence.

Imaging of a glioma using peripheral benzodiazepine receptor ligands

Energy Technology Data Exchange (ETDEWEB)

Starosta-Rubinstein, S.; Ciliax, B.J.; Penney, J.B.; McKeever, P.; Young, A.B.

1987-02-01

Two types of benzodiazepine receptors have been demonstrated in mammalian tissues, one which is localized on neuronal elements in brain and the other, on glial cells and in peripheral tissues such as kidney. In vivo administration of /sup 3/H-labeled PK 11195 (1-(2-chlorophenyl-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide) or (/sup 3/H)flunitrazepam with 5 mg of clonazepam per kg to rats with intracranial C6 gliomas resulted in high levels of tritiated-drug binding to the tumor as shown by quantitative autoradiography. Pharmacological studies indicated that the bound drugs labeled the peripheral benzodiazepine binding site. Binding to the peripheral benzodiazepine site was confirmed primarily to malignant cells with little binding to adjacent normal brain tissue or to necrotic tissue. Tumor cell binding was completely inhibited by preadministration of the peripheral benzodiazepine blocking agent PK 11195 at 5 mg/kg. The centrally selective benzodiazepine ligand clonazepam had no effect on PK 11195 binding to the tumor cells. When binding to other tumor cell lines grown in nude mice and nude athymic rats was evaluated, little or no peripheral benzodiazepine binding was detected on human pheochromocytoma (RN1) and neuroblastoma (SK-N-MC, SK-N-SH) tumor cells, respectively. However, high densities of peripheral benzodiazepine binding sites were observed on tumors derived from a human glioma cell line (ATCC HTB 14, U-87 MG). The presence of high concentrations of specific peripheral benzodiazepine receptors on glial tumors suggests that human primary central nervous system tumors could be imaged and diagnosed using peripheral benzodiazepine ligands labeled with positron- or gamma-emitting isotopes.

(-)-N-[11C]propyl-norapomorphine: a positron-labeled dopamine agonist for PET imaging of D2 receptors

International Nuclear Information System (INIS)

Hwang, Dah-Ren; Kegeles, Lawrence S.; Laruelle, Marc

2000-01-01

Imaging neuroreceptors with radiolabeled agonists might provide valuable information on the in vivo agonist affinity states of receptors of interest. We report here the radiosynthesis, biodistribution in rodents, and imaging studies in baboons of [ 11 C]-labeled (-)-N-propyl-norapomorphine [(-)-NPA]. (-)-[ 11 C]NPA was prepared by reacting norapomorphine with [ 11 C]propionyl chloride and a lithium aluminum hydride reduction. [ 11 C]Propionyl chloride was prepared by reacting [ 11 C]CO 2 with ethylmagnesium bromide, followed by reacting with phthaloyl chloride. The radiochemical yield of (-)-[ 11 C]NPA was 2.5% at end of synthesis (EOS), and the synthesis time was 60 min. The specific activity was 1700±1900 mCi/μmol ( N=7; ranged 110-5200 mCi/μmol at EOS). Rodent biodistribution studies showed high uptake of [ 11 C](-)-NPA in D 2 receptor-rich areas, and the striatum/cerebellum ratios were 1.7, 3.4, and 4.4 at 5 min, 30 min, and 60 min postinjection, respectively. Pretreating the animals with haloperidol (1 mg/kg) decreased the striatum/cerebellum ratio at 30 min postinjection to 1.3. (-)-[ 11 C]NPA was also evaluated via baboon positron emission tomography (PET) studies. Under control conditions ( N=4), rapid uptake of the tracer was observed and the striatum/cerebellum ratio reached 2.86±0.15 at 45 min postinjection. Following haloperidol pretreatment (0.2 mg/kg IV), the striatum/cerebellum ratio was 1.29 at 45 min postinjection. The result demonstrated the existence of specific binding of this new tracer to the D 2 receptor. To our knowledge, the current finding of a striatum/cerebellum ratio of 2.8 in baboon was the highest reported with a radiolabeled D 2 agonist. (-)-[ 11 C]NPA is a promising new D 2 agonist PET tracer for probing D 2 receptors in vivo using PET

(-)-N-[(11)C]propyl-norapomorphine: a positron-labeled dopamine agonist for PET imaging of D(2) receptors.

Science.gov (United States)

Hwang, D R; Kegeles, L S; Laruelle, M

2000-08-01

Imaging neuroreceptors with radiolabeled agonists might provide valuable information on the in vivo agonist affinity states of receptors of interest. We report here the radiosynthesis, biodistribution in rodents, and imaging studies in baboons of [(11)C]-labeled (-)-N-propyl-norapomorphine [(-)-NPA]. (-)-[(11)C]NPA was prepared by reacting norapomorphine with [(11)C]propionyl chloride and a lithium aluminum hydride reduction. [(11)C]Propionyl chloride was prepared by reacting [(11)C]CO(2) with ethylmagnesium bromide, followed by reacting with phthaloyl chloride. The radiochemical yield of (-)-[(11)C]NPA was 2.5% at end of synthesis (EOS), and the synthesis time was 60 min. The specific activity was 1700+/-1900 mCi/micromol ( N=7; ranged 110-5200 mCi/micromol at EOS). Rodent biodistribution studies showed high uptake of [(11)C](-)-NPA in D(2) receptor-rich areas, and the striatum/cerebellum ratios were 1.7, 3.4, and 4.4 at 5 min, 30 min, and 60 min postinjection, respectively. Pretreating the animals with haloperidol (1 mg/kg) decreased the striatum/cerebellum ratio at 30 min postinjection to 1.3. (-)-[(11)C]NPA was also evaluated via baboon positron emission tomography (PET) studies. Under control conditions ( N=4), rapid uptake of the tracer was observed and the striatum/cerebellum ratio reached 2.86+/-0.15 at 45 min postinjection. Following haloperidol pretreatment (0.2 mg/kg IV), the striatum/cerebellum ratio was 1.29 at 45 min postinjection. The result demonstrated the existence of specific binding of this new tracer to the D(2) receptor. To our knowledge, the current finding of a striatum/cerebellum ratio of 2.8 in baboon was the highest reported with a radiolabeled D(2) agonist. (-)-[(11)C]NPA is a promising new D(2) agonist PET tracer for probing D(2) receptors in vivo using PET.

Synthesis and 131I labelling of epidepride as a dopamine D2 receptor imaging agent

International Nuclear Information System (INIS)

Yang Min; Hu Mingyang; Pei Zhuguo; Wang Bocheng; Zhou Xingqin

2001-01-01

S-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-iodo-2, 3-dimethoxybenzamide (Epidepride) and its iodine labeling precursor S-(-)-N-[(1-Ethyl-2-pyrrolidinyl)methyl]-5-tributyltin-2, 3-dimethoxybenzamide are synthesized from 3-methoxy salicylic acid. The labeling precursor is labeled with 131 I by hydrogen peroxide method, and 131 I-epidepride is gained, its radiolabelling yield (RLY) and the radiochemical purity (RCP) are all over 95%. The RCP of 131 I-epidepride is over 90% under 4 degree C after 15 days. 131 I-epidepride has high affinity to dopamine D 2 receptor. The striatal uptake can be blocked completely by spiperone. The striatum and cerebellum uptake ratio can reach 237 at 320 min in rats. The results show that 131 I-epidepride may be used as a dopamine D 2 receptor imaging agent for SPECT

(/sup 76/Br)Bromolisuride: a new tool for quantitative in vivo imaging of D-2 dopamine receptors

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Maziere, B; Loc' h, C; Stulzaft, O; Ottaviani, M; Comar, D; Maziere, M; Hantraye, P

1986-08-15

Bromolisuride, an ergoline derivative, was labeled with the positron emitter radionuclide, bromine 76. In vitro and in vivo binding and competition studies in rats demonstrated a high affinity (K/sub D/ = 0.3 nM) and a high specificity of this new radioligand for D-2 dopamine receptors. PET kinetic studies in baboons showed an accumulation of (/sup 76/Br)bromolisuride in the striatum which reached a maximum 30 min post-injection and which could be displaced by haloperidol. All these results indicated that this new ligand is certainly suitable for the non-invasive in vivo quantitative imaging of D-2 dopamine receptor sites in human brain. 20 refs.; 6 figs.; 1 table.

Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors.

Science.gov (United States)

Linares, Andrea; Couling, Leena E; Carrera, Eduardo J; Speth, Robert C

2016-06-07

This protocol describes receptor binding patterns for Angiotensin II (Ang II) in the rat brain using a radioligand specific for Ang II receptors to perform receptor autoradiographic mapping. Tissue specimens are harvested and stored at -80 °C. A cryostat is used to coronally section the tissue (brain) and thaw-mount the sections onto charged slides. The slide-mounted tissue sections are incubated in (125)I-SI-Ang II to radiolabel Ang II receptors. Adjacent slides are separated into two sets: 'non-specific binding' (NSP) in the presence of a receptor saturating concentration of non-radiolabeled Ang II, or an AT1 Ang II receptor subtype (AT1R) selective Ang II receptor antagonist, and 'total binding' with no AT1R antagonist. A saturating concentration of AT2 Ang II receptor subtype (AT2R) antagonist (PD123319, 10 µM) is also present in the incubation buffer to limit (125)I-SI-Ang II binding to the AT1R subtype. During a 30 min pre-incubation at ~22 °C, NSP slides are exposed to 10 µM PD123319 and losartan, while 'total binding' slides are exposed to 10 µM PD123319. Slides are then incubated with (125)I-SI-Ang II in the presence of PD123319 for 'total binding', and PD123319 and losartan for NSP in assay buffer, followed by several 'washes' in buffer, and water to remove salt and non-specifically bound radioligand. The slides are dried using blow-dryers, then exposed to autoradiography film using a specialized film and cassette. The film is developed and the images are scanned into a computer for visual and quantitative densitometry using a proprietary imaging system and a spreadsheet. An additional set of slides are thionin-stained for histological comparisons. The advantage of using receptor autoradiography is the ability to visualize Ang II receptors in situ, within a section of a tissue specimen, and anatomically identify the region of the tissue by comparing it to an adjacent histological reference section.

In vivo binding and autoradiographic imaging of (+)-3-[125I]Iodo-MK-801 to the NMDA receptor-channel complex in rat brain

International Nuclear Information System (INIS)

Gibson, R.E.; Burns, H.D.; Thorpe, H.H.; Waisi Eng; Ransom, R.; Solomon, H.

1992-01-01

Radioiodinated (+)-3-Iodo-MK-801 is a high affinity radioligand for the N-methyl-D-aspartate (NMDA) receptor-channel complex. We have demonstrated in vivo localization in the CNS of rat which is stereoselective and blocked by coinjection of unlabeled MK-801. Autoradiography indicates localization in vivo which is in concordance with in vitro autoradiographic studies. These results indicate that radioiodinated (+)-3-Iodo-MK-801 is a useful probe for in vitro and in vivo autoradiographic studies and suggest that radioligands for the NMDA receptor may be developed which will provide in vivo images of receptor distribution in man. (author)

Measurements, in vivo, of parameters of the dopamine system

International Nuclear Information System (INIS)

Friedman, A.M.; DeJesus, O.T.; Dinerstein, R.; Revenaugh, J.

1983-01-01

This paper discusses methods of measuring important parameters of the dopamine system in the living animal by use of PET techniques. One primary concern is the density and binding affinity of post-synaptic neuroreceptors. A second concern is the activity of neurons. In vivo, this is generally related to the turnover of neurotransmitter and can also be related to the uptake of precursor compounds by the neurons. If the transmitter and neuroleptic compound compete for the same binding sites (on the receptor molecule) these two effects are interwoven and are not easily isolated. It appears that the movement of neuroleptic drugs from the brain is slow enough to allow equilibrium to be maintained between ligand and receptor, especially after some time for the initial washout and translocation in the brain. To test the consequences of equilibrium binding and the possible use of the model for measurement of receptor densities by emission tomography we have modified Clark's equilibrium model of ligand binding. In this note we will describe the solutions of the equations and some comparisons of the predictions of the model with data, as well as its application to tomographic measurements

Physiologic basics and clinical experience with somatostatin-receptor-scintigraphy

International Nuclear Information System (INIS)

Henze, E.; Eberhardt, J.U.; Bohuslavizki, K.H.

1994-01-01

The introduction of radiolabelled octreotide, an analogon to the receptor binding hormone Somatostatin, has markedly increased the ability to detect structures and tumours carrying somatostatin receptors by nuclear medicine imaging with high sensitivity and specificity. It has been shown that in vitro receptor density and in vivo scintigraphic results correlate well in particular in tumours of neuroendocrine origin of the GI tract such as insulinomas, gastrinomas, glucagonomas, carcionoids, but also in paragangliomas, small cell lung cancer and meningiomas. As receptors were also shown to be present on so called activated leucocytes granulomas, lymphomas and autoimmune disease have been imaged with octreotide successfully. The specific tracer (In-111-DTPA-D-PHE-Octreotide, Octreoscan R ) is rapidly cleared from the blood pool by the kidneys and, partially, via the liver providing a high target to background ratio. Physiologic uptake is usually observed in the pituitary and thyroid glands, in spleen and liver. Optimum tracer accumulation for tumour scintigraphy is seen on the 24-h-images with the best target to background ratios. Additional SPECT-imaging is recommended in particular in the abdominal regions. The sensitivity in imaging the above named tumours ranges from 70 up to 100%. In-111 octreotide imaging is of diagnostic impact both for the primary diagnostic evaluation as well as for detecting or excluding secondary manifestations in known tumour sites. Of specific value is the information on relative receptor density in the tumour to be treated as may be obtained by quantitative In-111 octreotide imaging for decision making whether or not to use cold octreotide (Sandostatin R ) as a receptor blocking drug for therapy as well as for treatment follow-up studies. (author)

A Non-imaging High Throughput Approach to Chemical Library Screening at the Unmodified Adenosine-A3 Receptor in Living Cells

Directory of Open Access Journals (Sweden)

Maria Augusta Arruda

2017-12-01

Full Text Available Recent advances in fluorescent ligand technology have enabled the study of G protein-coupled receptors in their native environment without the need for genetic modification such as addition of N-terminal fluorescent or bioluminescent tags. Here, we have used a non-imaging plate reader (PHERAstar FS to monitor the binding of fluorescent ligands to the human adenosine-A3 receptor (A3AR; CA200645 and AV039, stably expressed in CHO-K1 cells. To verify that this method was suitable for the study of other GPCRs, assays at the human adenosine-A1 receptor, and β1 and β2 adrenoceptors (β1AR and β2AR; BODIPY-TMR-CGP-12177 were also carried out. Affinity values determined for the binding of the fluorescent ligands CA200645 and AV039 to A3AR for a range of classical adenosine receptor antagonists were consistent with A3AR pharmacology and correlated well (R2 = 0.94 with equivalent data obtained using a confocal imaging plate reader (ImageXpress Ultra. The binding of BODIPY-TMR-CGP-12177 to the β1AR was potently inhibited by low concentrations of the β1-selective antagonist CGP 20712A (pKi 9.68 but not by the β2-selective antagonist ICI 118551(pKi 7.40. Furthermore, in experiments conducted in CHO K1 cells expressing the β2AR this affinity order was reversed with ICI 118551 showing the highest affinity (pKi 8.73 and CGP20712A (pKi 5.68 the lowest affinity. To determine whether the faster data acquisition of the non-imaging plate reader (~3 min per 96-well plate was suitable for high throughput screening (HTS, we screened the LOPAC library for inhibitors of the binding of CA200645 to the A3AR. From the initial 1,263 compounds evaluated, 67 hits (defined as those that inhibited the total binding of 25 nM CA200645 by ≥40% were identified. All compounds within the library that had medium to high affinity for the A3AR (pKi ≥6 were successfully identified. We found three novel compounds in the library that displayed unexpected sub-micromolar affinity

Synthesis and 125I labelling of a precursor for imaging nicotinic acetylcholine receptors

International Nuclear Information System (INIS)

Liu Yuxia; Liu Ning; Yang Yuanyou; Zan Liangbiao; Liao Jiali; Jin Jiannan; Sichuan Univ., Chengdu

2006-01-01

Nicotinic Acetylcholine Receptors (nAChRs) are involved in various pharmacological effects or diseases, such as Alzheimer's Disease, Parkinson's Disease and tobacco addiction. It will be very appealing to image nAChRs in vivo, diagnose and treat the above diseases, and probe the mechanism of nAChRs in tobacco addiction if the suitable radioactive labeled compound can be synthesized. In this study, (s)-5-(tri-butylstannyl)-3{[1-(tert-butoxycarbonyl)-2-azetidinyl]methoxy} pyridine, a precursor for imaging nAChRs, was synthesized with commercial 2-furfurylamine and (s)-2-azetidinecarboxylic acid as starting materials, and was further labeled with 125/123 I. The whole procedure for radiosynthesis needs 50-55 min and more than 30% of the 125 I are found in the purified 5-[ 125 I]-A-85380. Even staying for 3 days at room temperature in vitro, the purified 5-[ 125 I]-I-85380 can maintain its stability, with a radiochemical purity of more than 95%. (authors)

Hydrotherapy as a possible neuroleptic and sedative treatment.

Science.gov (United States)

Shevchuk, Nikolai A

2008-01-01

Psychotic symptoms such as delusions and hallucinations can have a devastating effect on a patient's social functioning. Since psychosis is rarely congenital, it is possible that lifestyle factors play a role in its etiology. This paper offers a hypothesis that some of these factors could be: (a) A lifestyle lacking evolutionarily conserved stressors such as frequent exposure to heat and/or cold, resulting in a lack of "thermal exercise" which could lead to malfunctioning of the brain. (b) Partial retention and absorption of toxic waste in the colon, as described in more detail below. (c) Genetic makeup that makes a person vulnerable to the above conditions. To test the hypothesis, three types of hydrotherapy are proposed (to be tested separately) as a putative neuroleptic treatment: head-out hot showers, adapted cold showers (twice daily each), and colon hydrotherapy (every 3-12 weeks, which also includes a dietary change according to Harvard's Healthy Eating Pyramid). The following is supporting evidence: Dopaminergic transmission in the mesolimbic pathway is involved in central processing of pain and negative stimuli (e.g. stress-induced analgesia) in addition to its role in the pathophysiology of psychosis. It is also known that if a neural pathway can perform two different functions, then the execution of one function will often suppress the other (e.g. gate control theory of pain). Thus, a pain-based therapy, such as a moderately hot shower, could have a "crowding out" effect on pathological processes within the mesolimbic system. In addition, hyperthermia is known to induce fatigue and depress activity of the frontal cortex (the sedative effect). As described previously, an adapted cold shower could work as a mild electroshock applied to the sensory cortex and, therefore, it might have an antipsychotic effect similar to that of electroconvulsive therapy. Additionally, a cold shower is a vivid example of stress-induced analgesia and would also be expected to

Agonist and antagonist actions of antipsychotic agents at 5-HT1A receptors: a [35S]GTPgammaS binding study.

Science.gov (United States)

Newman-Tancredi, A; Gavaudan, S; Conte, C; Chaput, C; Touzard, M; Verrièle, L; Audinot, V; Millan, M J

1998-08-21

Recombinant human (h) 5-HT1A receptor-mediated G-protein activation was characterised in membranes of transfected Chinese hamster ovary (CHO) cells by use of guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]GTPgammaS binding). The potency and efficacy of 21 5-HT receptor agonists and antagonists was determined. The agonists, 5-CT (carboxamidotryptamine) and flesinoxan displayed high affinity (subnanomolar Ki values) and high efficacy (Emax > 90%, relative to 5-HT = 100%). In contrast, ipsapirone, zalospirone and buspirone displayed partial agonist activity. EC50s for agonist stimulation of [35S]GTPgammaS binding correlated well with Ki values from competition binding (r = +0.99). Among the compounds tested for antagonist activity, methiothepin and (+)butaclamol exhibited 'inverse agonist' behaviour, inhibiting basal [35S]GTPgammaS binding. The actions of 17 antipsychotic agents were investigated. Clozapine and several putatively 'atypical' antipsychotic agents, including ziprasidone, quetiapine and tiospirone, exhibited partial agonist activity and marked affinity at h5-HT1A receptors, similar to their affinity at hD2 dopamine receptors. In contrast, risperidone and sertindole displayed low affinity at h5-HT1A receptors and behaved as 'neutral' antagonists, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Likewise the 'typical' neuroleptics, haloperidol, pimozide, raclopride and chlorpromazine exhibited relatively low affinity and 'neutral' antagonist activity at h5-HT1A receptors with Ki values which correlated with their respective Kb values. The present data show that (i) [35S]GTPgammaS binding is an effective method to evaluate the efficacy and potency of agonists and antagonists at recombinant human 5-HT1A receptors. (ii) Like clozapine, several putatively 'atypical' antipsychotic drugs display balanced serotonin h5-HT1A/dopamine hD2 receptor affinity and partial agonist activity at h5-HT1A receptors. (iii) Several 'typical' and some putatively 'atypical

Development of radioiodinated receptor ligands for cerebral single photon emission tomography

International Nuclear Information System (INIS)

Knapp, F.F. Jr.; McPherson, D.W.

1992-01-01

In the last decade the use of radiolabeled ligands for the imaging of cerebral receptors by emission computed tomography (ECT) has seen rapid growth. The opportunity to routinely perform cerebral single photon emission tomography (SPET) with iodine-123-labeled ligands depends on the availability of receptor ligands into which iodine can be introduced without decreasing the required high target receptor specificity. The use of iodine-123-labeled receptor-specific ligands also depends on the availability of high purity iodine-123 at reasonable costs and the necessary imaging instrumentation. In this paper, the development and current stage of evaluation of various iodine-123-labeled ligands for SPET imaging of dopaminergic, serotonergic and muscarinic acetylcholinergic receptor classes are discussed

Development of an inflammation imaging tracer, 111In-DOTA-DAPTA, targeting chemokine receptor CCR5 and preliminary evaluation in an ApoE-/- atherosclerosis mouse model.

Science.gov (United States)

Wei, Lihui; Petryk, Julia; Gaudet, Chantal; Kamkar, Maryam; Gan, Wei; Duan, Yin; Ruddy, Terrence D

2018-02-07

Chemokine receptor 5 (CCR5) plays an important role in atherosclerosis. Our objective was to develop a SPECT tracer targeting CCR5 for imaging plaque inflammation by radiolabeling D-Ala-peptide T-amide (DAPTA), a CCR5 antagonist, with 111 In. 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) conjugated DAPTA (DOTA-DAPTA) was labeled with 111 In. Cell uptake studies were conducted in U87-CD4-CCR5 and U87-MG cells. Biodistribution was determined in C57BL/6 mice. Autoradiography, en face and Oil Red O (ORO) imaging studies were performed in ApoE -/- mice. DOTA-DAPTA was radiolabeled with 111 In with high radiochemical purity (> 98%) and specific activity (70 MBq·nmol). 111 In-DOTA-DAPTA exhibited fast blood and renal clearance and high spleen uptake. The U87-CD4-CCR5 cells had significantly higher uptake in comparison to the U87-MG cells. The cell uptake was reduced by three times with DAPTA, indicating the receptor specificity of the uptake. Autoradiographic images showed significantly higher lesion uptake of 111 In-DOTA-DAPTA in ApoE -/- mice than that in C57BL/6 mice. The tracer uptake in 4 month old ApoE -/- high fat diet (HFD) mice with blocking agent was twofold lower than the same mice without the blocking agent, demonstrating the specificity of the tracer for the CCR5 receptor. 111 In-DOTA-DAPTA, specifically targeting chemokine receptor CCR5, is a potential SPECT agent for imaging inflammation in atherosclerosis.

Knock-In Mice with NOP-eGFP Receptors Identify Receptor Cellular and Regional Localization.

Science.gov (United States)

Ozawa, Akihiko; Brunori, Gloria; Mercatelli, Daniela; Wu, Jinhua; Cippitelli, Andrea; Zou, Bende; Xie, Xinmin Simon; Williams, Melissa; Zaveri, Nurulain T; Low, Sarah; Scherrer, Grégory; Kieffer, Brigitte L; Toll, Lawrence

2015-08-19

The nociceptin/orphanin FQ (NOP) receptor, the fourth member of the opioid receptor family, is involved in many processes common to the opioid receptors including pain and drug abuse. To better characterize receptor location and trafficking, knock-in mice were created by inserting the gene encoding enhanced green fluorescent protein (eGFP) into the NOP receptor gene (Oprl1) and producing mice expressing a functional NOP-eGFP C-terminal fusion in place of the native NOP receptor. The NOP-eGFP receptor was present in brain of homozygous knock-in animals in concentrations somewhat higher than in wild-type mice and was functional when tested for stimulation of [(35)S]GTPγS binding in vitro and in patch-clamp electrophysiology in dorsal root ganglia (DRG) neurons and hippocampal slices. Inhibition of morphine analgesia was equivalent when tested in knock-in and wild-type mice. Imaging revealed detailed neuroanatomy in brain, spinal cord, and DRG and was generally consistent with in vitro autoradiographic imaging of receptor location. Multicolor immunohistochemistry identified cells coexpressing various spinal cord and DRG cellular markers, as well as coexpression with μ-opioid receptors in DRG and brain regions. Both in tissue slices and primary cultures, the NOP-eGFP receptors appear throughout the cell body and in processes. These knock-in mice have NOP receptors that function both in vitro and in vivo and appear to be an exceptional tool to study receptor neuroanatomy and correlate with NOP receptor function. The NOP receptor, the fourth member of the opioid receptor family, is involved in pain, drug abuse, and a number of other CNS processes. The regional and cellular distribution has been difficult to determine due to lack of validated antibodies for immunohistochemical analysis. To provide a new tool for the investigation of receptor localization, we have produced knock-in mice with a fluorescent-tagged NOP receptor in place of the native NOP receptor. These

Strategies for Imaging Androgen Receptor Signaling Pathway in Prostate Cancer: Implications for Hormonal Manipulation and Radiation Treatment

Directory of Open Access Journals (Sweden)

Gravina Giovanni Luca

2013-01-01

Full Text Available Prostate cancer (Pca is a heterogeneous disease; its etiology appears to be related to genetic and epigenetic factors. Radiotherapy and hormone manipulation are effective treatments, but many tumors will progress despite these treatments. Molecular imaging provides novel opportunities for image-guided optimization and management of these treatment modalities. Here we reviewed the advances in targeted imaging of key biomarkers of androgen receptor signaling pathways. A computerized search was performed to identify all relevant studies in Medline up to 2013. There are well-known limitations and inaccuracies of current imaging approaches for monitoring biological changes governing tumor progression. The close integration of molecular biology and clinical imaging could ease the development of new molecular imaging agents providing novel tools to monitor a number of biological events that, until a few years ago, were studied by conventional molecular assays. Advances in translational research may represent the next step in improving the oncological outcome of men with Pca who remain at high risk for systemic failure. This aim may be obtained by combining the anatomical properties of conventional imaging modalities with biological information to better predict tumor response to conventional treatments.

Novel Chemical Strategies for Labeling Small Molecule Ligands for Androgen, Progestin, and Peroxisome Proliferator-Activated Receptors for Imaging Prostate and Breast Cancer and the Heart

International Nuclear Information System (INIS)

Katzenellenbogen, John A.

2007-01-01

Summary of Progress The specific aims of this project can be summarized as follows: Aim 1: Prepare and evaluate radiolabeled ligands for the peroxisome proliferator-activated receptor γ (PPARγ), a new nuclear hormone receptor target for tumor imaging and hormone therapy. Aim 2: Prepare steroids labeled with a cyclopentadienyl tricarbonyl technetium or rhenium unit. Aim 3: Prepare and evaluate other organometallic systems of novel design as ligand mimics and halogenated ligands for nuclear hormone receptor-based tumor imaging. As is described in detail in the report, we made excellent progress on all three of these aims; the highlights of our progress are the following: (1) we have prepared the first fluorine-18 labeled analogs of ligands for the PPARγ receptor and used these in tissue distribution studies in rats; (2) we have developed three new methods for the synthesis of cyclopentadienyltricarbonyl rhenium and technetium (CpRe(CO)3 and CpTc(CO)3) systems and we have adapted these to the synthesis of steroids labeled with these metals, as well as ligands for other receptor systems; (3) we have prepared a number of fluorine-18 labeled steroidal and non-steroidal androgens and measured their tissue distribution in rats; (4) we have prepared iodine and bromine-labeled progestins with high progesterone receptor binding affinity; and (5) we have prepared inorganic metal tricarbonyl complexes and steroid receptor ligands in which the metal tricarbonyl unit is an integral part off the ligand core

[7α-18F]fluoro-17α-methyl-5α-dihydrotestosterone: a ligand for androgen receptor-mediated imaging of prostate cancer

International Nuclear Information System (INIS)

Garg, Pradeep K.; Labaree, David C.; Hoyte, Robert M.; Hochberg, Richard B.

2001-01-01

We have synthesized a 18 F-labeled androgen, [7α- 18 F]fluoro-17α-methyl-5α-dihydrotestosterone, in a no-carrier-added radiosynthesis by exchange of 18 F- (tetrabutylammonium fluoride) with the 7β-tosyloxy of 17α-methyl-5α-dihydrotestosterone. The nonradioactive steroid binds with high affinity and specificity to the androgen receptor and binds poorly, if at all, to other steroid receptors and plasma sex hormone binding globulin. The 7α- 18 F-androgen concentrates markedly in the prostate of rats by an androgen receptor-dependent mechanism. It is likely that [7α- 18 F]fluoro-17α-methyl-5α-dihydrotestosterone will be an excellent positron emission tomography imaging agent for prostate cancer

[18F]fluoromethylated phenyl-pyrroles and 7-azaindole analog as potential dopamine D4 receptor imaging agents

International Nuclear Information System (INIS)

Ji, D. Y.; Oh, S. Z.; Choi, Y. S.; Lee, K. C.; Kim, S. E.; Choi, Y.; Lee, K. H.; Kim, B. T.

1997-01-01

An association between the dopamine D 4 receptor and schizophrenia was recently suggested and the D 4 receptor antagonists may thus have potential in elucidating the role of the receptor in schizophrenic patients. The purpose of this study was to develop some of these antagonists as potential dopamine D 4 receptor imaging agents for PET. We have prepared 1-(3-[ 18 F]fluoromethylphenyl)-3-([4-(pyridin-2-yl)piperazin-1-yl)methyl) pyrrole (1), 1-(3-[ 18 F]fluoromethylphenyl)-3-([4-(pyridin-2-yl)piperazin-1-yl)methyl) pyrrole (2), and 3-([4-(4-[ 18 F]fluoro methylbenzyl)piperazin-1-yl)methyl)-1H-pyrrolo(2,3,-b)pyridine (3) as potential imaging agents for the dopamine D 4 receptor for PET. The compounds [ 18 F]1 and [ 18 F]2 were prepared by coupling of (3-[ 18 F]fluoromethylphenyl)-pyrrol-1- yl-3-aldehyde and the piperazine moiety in the presence of NaBH 3 CN. The [ 18 F]fluorinated aldehyde was obtained in 60-85% yield by the displacement of the corresponding mesylate with F-18-(THF, 90 .deg. C, 5 min). HPLC purification (Alltech Econosil C-18 columm, 250 x 10 mm, 35: 65 = 0.1M NH 4 CI 2 H : CH 3 OH, 4 ml/min, t R =26.6 min) gave the [ 18 F]1 and [ 18 F]2 in 7-12% yield. In the case of azaindole 3, a methlene link was inserted between the piperazinyl and a fluoromethyl phenyl group. Radiochemical synthesis of the [ 18 F]3 was carried out by coupling of the piperazne moiety and [ 18 F]fluoromethylbenzyl mesylate in the presence of NEt 3 (3:1-CH 3 CN: DMF, 120 .deg. C, 30 min). Purification was carried out by HPLC using a C-18 column (Alltech Econosil, 50 x 10 mm, 100% 0.1M NH 4 CO 2 H for 5 min followed by 40:60=0.1 M NH 4 CO 2 H : MeOH, 4 ml/min t R =28.7 min). The time of synthesis including HPLC purification was 100 min. The overall yield of [ 18 F]3 was 10-15% with a radiochemical purity better than 97% and a specific activity greater than 1000 ci/mmol

Cerebrospinal fluid endorphins in schizophrenia

International Nuclear Information System (INIS)

Rimon, R.; Terenius, L.; Kampman, R.

1980-01-01

Opioid-receptor-active material, endorphins, has been measured in cerebrospinal fluid samples obtained from schizophrenics. A chromatographic procedure isolated the Fraction I endorphin which was quantitated in a receptorassay. At least two cerebrospinal fluid samples were obtained from each patient, at day 0 with no medication and at days 30 and 60 after medication with fluphenazine under standardized conditions. Three series of patients were included: acute schizophrenics (n=11); re-entry schizophrenics (n=7) who have previously been treated with neuroleptics but were readmitted to hospital usually as a consequence of stopped medication, and chronic schizophrenics (n=9) who had been without neuroleptics for at least 2 weeks prior to day 0. At day 0, 6/9 acute cases, 4/6 of re-entry and 2/9 chronic cases had endorphin levels above the range of healthy volunteers. The levels in chronic cases were significantly lower than those in acute cases. Treatment with neuroleptics significantly lowered the endorphin levels in acute cases. These results confirm and extend previous observations. (author)

Evaluation of transcriptional activity of the oestrogen receptor with sodium iodide symporter as an imaging reporter gene.

Science.gov (United States)

Kang, Joo Hyun; Chung, June-Key; Lee, Yong Jin; Kim, Kwang Il; Jeong, Jae Min; Lee, Dong Soo; Lee, Myung Chul

2006-10-01

Oestrogen receptors are ligand-dependent transcription factors whose activity is modulated either by oestrogens or by an alternative signalling pathway. Oestrogen receptors interact via a specific DNA-binding domain, the oestrogen responsive element (ERE), in the promoter region of sensitive genes. This binding leads to an initiation of gene expression and hormonal effects. To determine the transcriptional activity of the oestrogen receptor, we developed a molecular imaging system using sodium iodide symporter (NIS) as a reporter gene. The NIS reporter gene was placed under the control of an artificial ERE derived from pERE-TA-SEAP and named as pERE-NIS. pERE-NIS was transferred to MCF-7, human breast cancer cells, which highly expressed oestrogen receptor-alpha with lipofectamine. Stably expressing cells were generated by selection with G418 for 14 days. After treatment of 17beta-oestradiol and tamoxifen with serial doses, the (125)I uptake was measured for the determination of NIS expression. The inhibition of NIS activity was performed with 50 micromol x l(-1) potassium perchlorate. The MCF7/pERE-NIS treated with 17beta-oestradiol accumulated (125)I up to 70-80% higher than did non-treated cells. NIS expression was increased according to increasing doses of 17beta-oestradiol. MCF7/pERE-NIS treated with tamoxifen also accumulated (125)I up to 50% higher than did non-treated cells. Potassium perchlorate completely inhibited (125)I uptake. When MDA-MB231 cells, the oestrogen receptor-negative breast cancer cells, were transfected with pERE-NIS, (125)I uptake of MDA-MB-231/pERE-NIS did not increase. This pERE-NIS reporter system is sufficiently sensitive for monitoring transcriptional activity of the oestrogen receptor. Therefore, cis-enhancer reporter systems with ERE will be applicable to the development of a novel selective oestrogen receptor modulator with low toxicity and high efficacy.

MicroPET imaging of 5-HT{sub 1A} receptors in rat brain: a test-retest [{sup 18}F]MPPF study

Energy Technology Data Exchange (ETDEWEB)

Aznavour, Nicolas [McGill University, Department of Psychiatry, Montreal, QC (Canada)]|[Laboratory of Neuroenergetics and Cellular Dynamics, EPFL, SV, BMI, Lausanne (Switzerland); Benkelfat, Chawki; Gravel, Paul [McGill University, Department of Psychiatry, Montreal, QC (Canada)]|[McGill University, Department of Neurology and Neurosurgery, Montreal, QC (Canada); Aliaga, Antonio [McGill University, Department of Small Animal Imaging Laboratory, Montreal, QC (Canada); Rosa-Neto, Pedro [Douglas Hospital, Molecular NeuroImaging Laboratory, Montreal, QC (Canada); Bedell, Barry [McGill University, Department of Neurology and Neurosurgery, Montreal, QC (Canada)]|[McGill University, Department of Small Animal Imaging Laboratory, Montreal, QC (Canada); Zimmer, Luc [CERMEP, ANIMAGE Department, Lyon (France)]|[Universite Lyon 1 and CNRS, Lyon (France); Descarries, Laurent [Universite de Montreal, Department of Pathology and Cell Biology, Montreal, QC (Canada)]|[Universite de Montreal, Department of Physiology, Montreal, QC (Canada)]|[Universite de Montreal, GRSNC, Montreal, QC (Canada)

2009-01-15

Earlier studies have shown that positron emission tomography (PET) imaging with the radioligand [{sup 18}F]MPPF allows for measuring the binding potential of serotonin 5-hydroxytryptamine{sub 1A} (5-HT{sub 1A}) receptors in different regions of animal and human brain, including that of 5-HT{sub 1A} autoreceptors in the raphe nuclei. In the present study, we sought to determine if such data could be obtained in rat, with a microPET (R4, Concorde Microsystems). Scans from isoflurane-anaesthetised rats (n = 18, including six test-retest) were co-registered with magnetic resonance imaging data, and binding potential, blood to plasma ratio and radiotracer efflux were estimated according to a simplified reference tissue model. Values of binding potential for hippocampus (1.2), entorhinal cortex (1.1), septum (1.1), medial prefrontal cortex (1.0), amygdala (0.8), raphe nuclei (0.6), paraventricular hypothalamic nucleus (0.5) and raphe obscurus (0.5) were comparable to those previously measured with PET in cats, non-human primates or humans. Test-retest variability was in the order of 10% in the larger brain regions (hippocampus, medial prefrontal and entorhinal cortex) and less than 20% in small nuclei such as the septum and the paraventricular hypothalamic, basolateral amygdaloid and raphe nuclei. MicroPET brain imaging of 5-HT{sub 1A} receptors with [{sup 18}F]MPPF thus represents a promising avenue for investigating 5-HT{sub 1A} receptor function in rat. (orig.)

In vivo quantitative imaging of dopamine receptors in human brain using positron emission tomography and (XWBr)bromospiperone

Energy Technology Data Exchange (ETDEWEB)

Maziere, B; Loc' h, C; Barton, J -C; Sgouropoulos, P; Duquesnoy, N; Antona, R d' ; Cambon, H

1985-08-27

The brain regional distribution and kinetics of (XWBr)bromospiperone, a derivative of a neuroleptic (spiperone) labeled with the positron emitter bromine-76, were studied by time-of-flight tomography after i.v. injection in man. In a control subject the kinetic distribution study showed an accumulation of radioactivity which reached a maximum 3 h postinjection in the frontal cortex and cerebellum regions and 4-5 h postinjection in the basal ganglia. Thereafter the striatal activity remained essentially constant over a period of 25 h. In a group of 13 control subjects, the mean value for the striatum-to-cerebellum ratio, at 4.5 h postinjection, was 1.84 (S.D. 0.21). In two schizophrenics treated with high doses of haloperidol, this ratio was found to be only 1.22. These data indicate that radiolabeled bromospiperone is very suitable for human pharmacological or pathological investigations of the central dopaminergic system. (Auth.). 20 refs.; 3 figs.; 1 table.

Heterogeneity of triple-negative breast cancer: mammographic, US, and MR imaging features according to androgen receptor expression

Energy Technology Data Exchange (ETDEWEB)

Bae, Min Sun; Song, Sung Eun; Kim, Won Hwa; Lee, Su Hyun; Moon, Woo Kyung [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Park, So Yeon; Park, In-Ae [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Han, Wonshik; Noh, Dong-Young [Seoul National University College of Medicine, Department of Surgery, Seoul (Korea, Republic of)

2014-09-16

Our aim was to determine whether triple-negative breast cancers (TNBCs) with and without androgen receptor (AR) expression have distinguishing imaging features on mammography, breast ultrasound (US), and magnetic resonance (MR) imaging. AR expression was assessed immunohistochemically in 125 patients with TNBC from a consecutive series of 1,086 operable invasive breast cancers. Two experienced radiologists blinded to clinicopathological findings reviewed all imaging studies in consensus using the BI-RADS lexicon. The imaging and pathological features of 33 AR-positive TNBCs were compared with those of 92 AR-negative TNBCs. The presence of mammographic calcifications with or without a mass (p < 0.001), non-mass enhancement on MR imaging (p < 0.001), and masses with irregular shape or spiculated margins on US (p < 0.001 and p = 0.002) and MR imaging (p = 0.001 and p < 0.001) were significantly associated with AR-positive TNBC. Compared with AR-negative TNBC, AR-positive TNBC was more likely to have a ductal carcinoma in situ component (59.8 % vs. 90.9 %, p = 0.001) and low Ki-67 expression (30.4 % vs. 51.5 %, p = 0.030). AR-positive and AR-negative TNBCs have different imaging features, and certain imaging findings can be useful to predict AR status in TNBC. (orig.)

Receptors for Projection Radiography. Chapter 7

Energy Technology Data Exchange (ETDEWEB)

Rowlands, J. A. [Thunder Bay Regional Research Institute, Thunder Bay (Canada); Neitzel, U. [Philips Healthcare, Hamburg (Germany)

2014-09-15

X ray images are formed as shadows of the interior of the body. Since it is not yet practical to focus X rays, an X ray receptor has to be larger than the body part to be imaged. Thus, the first challenge in making an X ray receptor is the need to image a large area. A second challenge is to make a system that has an image quality as good as that allowed by the physics, i.e. permits the detection of objects whose size and contrast are limited only by the quantum statistics (see Section 4.6). This means absorbing most of the X ray quanta and using these in an efficient, i.e. a quantum noise limited, manner, while providing adequate spatial resolution simultaneously.

99m Tc-anti-epidermal growth factor receptor nanobody for tumor imaging.

Science.gov (United States)

Piramoon, Majid; Hosseinimehr, Seyed Jalal; Omidfar, Kobra; Noaparast, Zohreh; Abedi, Seyed Mohammad

2017-04-01

Nanobodies are important biomolecules for tumor targeting. In this study, we synthesized and labeled anti-epidermal growth factor receptor (EGFR) nanobody OA-cb6 with 99m Tc(CO) 3 + and evaluated its characteristics for targeting the EGFR in the A431 human epidermal carcinoma cell line. Nanobody radiolabeling was achieved with high yield and radiochemical purity, and the radioconjugate was stable. Biodistribution results in nude mice exhibited a favorable tumor-to-muscle ratio at 4-hr postinjection, and tumor location was visualized at 4 hr after injection of radiolabeled nanobody. Our result showed that the OA-cb6- 99m Tc-tricarbonyl radiolabeled nanobody is a promising radiolabeled biomolecule for tumor imaging in cancers with high EGFR overexpression. © 2016 John Wiley & Sons A/S.

Does elevating image receptor increase breast receptor footprint and improve pressure balance?

International Nuclear Information System (INIS)

Smith, H.; Szczepura, K.; Mercer, C.; Maxwell, A.; Hogg, P.

2015-01-01

There is no consensus in the literature regarding the image receptor (IR) position for the cradio-caudal projection in mammography. Some literature indicates the IR should be positioned to the infra mammary fold (IMF); other literature suggests the IR be raised 2 cm relative to the IMF. Using 16 female volunteers (32 breasts) and a pressure sensitive mat we investigated breast footprint and pressure balance with IR at IMF and IR 2 cm above the IMF. Breast area on IR and paddle and interface pressure between IR/breast and paddle/breast were recorded. A uniformity index (UI) gave a measure of pressure balance between IR/breast and paddle/breast. IR breast footprint increases significantly by 13.81 cm 2 (p < 0.02) when IR is raised by 2 cm. UI reduces from 0.4 to 0.00 (p = 0.04) when positioned at IMF +2 cm demonstrating an improved pressure balance. Practitioners should consider raising the IR by 2 cm relative to the IMF in clinical practice. Further work is suggested to investigate the effects of practitioner variability and breast asymmetry. - Highlights: • Experimental study. • 16 female volunteers/32 breasts. • Compares two methods of conducting the cranio-caudal project. • Provides sufficient evidence to indicate which method is likely to be superior. • Has value to clinical mammography.

Microultrasound Molecular Imaging of Vascular Endothelial Growth Factor Receptor 2 in a Mouse Model of Tumor Angiogenesis

Directory of Open Access Journals (Sweden)

Joshua J. Rychak

2007-09-01

Full Text Available High-frequency microultrasound imaging of tumor progression in mice enables noninvasive anatomic and functional imaging at excellent spatial and temporal resolution, although microultrasonography alone does not offer molecular scale data. In the current study, we investigated the use of microbubble ultrasound contrast agents bearing targeting ligands specific for molecular markers of tumor angiogenesis using high-frequency microultrasound imaging. A xenograft tumor model in the mouse was used to image vascular endothelial growth factor receptor 2 (VEGFR-2 expression with microbubbles conjugated to an anti-VEGFR-2 monoclonal antibody or an isotype control. Microultrasound imaging was accomplished at a center frequency of 40 MHz, which provided lateral and axial resolutions of 40 and 90 μm, respectively. The B-mode (two-dimensional mode acoustic signal from microbubbles bound to the molecular target was determined by an ultrasound-based destruction-subtraction scheme. Quantification of the adherent microbubble fraction in nine tumor-bearing mice revealed significant retention of VEGFR-2-targeted microbubbles relative to control-targeted microbubbles. These data demonstrate that contrast-enhanced microultrasound imaging is a useful method for assessing molecular expression of tumor angiogenesis in mice at high resolution.

111In-cetuximab-F(ab')2 SPECT imaging for quantification of accessible epidermal growth factor receptors (EGFR) in HNSCC xenografts

NARCIS (Netherlands)

Dijk, L.K. van; Hoeben, B.A.W.; Stegeman, H.; Kaanders, J.H.A.M.; Franssen, G.M.; Boerman, O.C.; Bussink, J.

2013-01-01

BACKGROUND AND PURPOSE: Immunohistochemical epidermal growth factor receptor (EGFR) expression does not correlate with treatment response in head and neck squamous cell carcinomas (HNSCC). Aim was to apply the tracer (111)In-cetuximab-F(ab')2 for EGFR microSPECT imaging and to investigate if tracer

Preparation and in vitro evaluation of folate-receptor-targeted SPION–polymer micelle hybrids for MRI contrast enhancement in cancer imaging

International Nuclear Information System (INIS)

Mahajan, Shveta; Choudhary, Veena; Koul, Veena; Shishodia, Gauri; Bharti, Alok C

2013-01-01

Polymer–SPION hybrids were investigated for receptor-mediated localization in tumour tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared by high-temperature decomposition of iron acetylacetonate were monodisperse (9.27 ± 3.37 nm), with high saturation magnetization of 76.8 emu g −1 . Amphiphilic copolymers prepared from methyl methacrylate and PEG methacrylate by atom transfer radical polymerization were conjugated with folic acid (for folate-receptor specificity). The folate-conjugated polymer had a low critical micellar concentration (0.4 mg l −1 ), indicating stability of the micellar formulation. SPION–polymeric micelle clusters were prepared by desolvation of the SPION dispersion/polymer solution in water. Magnetic resonance imaging of the formulation revealed very good contrast enhancement, with transverse (T 2 ) relaxivity of 260.4 mM −1 s −1 . The biological evaluation of the SPION micelles included cellular viability assay (MTT) and uptake in HeLa cells. These studies demonstrated the potential use of these nanoplatforms for imaging and targeting. (paper)

Preparation and in vitro evaluation of folate-receptor-targeted SPION-polymer micelle hybrids for MRI contrast enhancement in cancer imaging

Science.gov (United States)

Mahajan, Shveta; Koul, Veena; Choudhary, Veena; Shishodia, Gauri; Bharti, Alok C.

2013-01-01

Polymer-SPION hybrids were investigated for receptor-mediated localization in tumour tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared by high-temperature decomposition of iron acetylacetonate were monodisperse (9.27 ± 3.37 nm), with high saturation magnetization of 76.8 emu g-1. Amphiphilic copolymers prepared from methyl methacrylate and PEG methacrylate by atom transfer radical polymerization were conjugated with folic acid (for folate-receptor specificity). The folate-conjugated polymer had a low critical micellar concentration (0.4 mg l-1), indicating stability of the micellar formulation. SPION-polymeric micelle clusters were prepared by desolvation of the SPION dispersion/polymer solution in water. Magnetic resonance imaging of the formulation revealed very good contrast enhancement, with transverse (T2) relaxivity of 260.4 mM-1 s-1. The biological evaluation of the SPION micelles included cellular viability assay (MTT) and uptake in HeLa cells. These studies demonstrated the potential use of these nanoplatforms for imaging and targeting.

Multifunctional molecular imaging probes for estrogen receptors. 99mTc labeled diethylstilbestrol (DES) conjugated, cuinp quantum dot nanoparticles (DESCIP)

International Nuclear Information System (INIS)

Payam Moharrami; Perihan Unak; Ozge Kozgus Guldu; Medine, E.I.; Gul Gumuser; Elvan Sayit Bilgin; Omer Aras

2017-01-01

A theranostic nanoparticle was synthesized based on diethylstilbestrol conjugated with phosphate, copper, and indium (DESCIP) and labelled with 99m Tc which can be used for SPECT imaging of ER-enriched cancers. In vitro biological activity of 99m Tc-DESCIP was examined in breast adenocarcinoma cells (MCF-7), prostatic carcinoma cells (PC-3), and pulmonary epithelial cells (A-549). In vivo lymph node imaging was performed in normal and receptor blocked female New Zealand rabbits. Results demonstrated that 99m Tc-DESCIP and DESCIP has potential for imaging ER-enriched tumors such as breast and prostate tumors, and their metastases in the lung, as well as improving management for their therapies. (author)

Somatostatin receptor expression in Merkel cell carcinoma as target for molecular imaging

International Nuclear Information System (INIS)

Buder, Kristina; Becker, Jürgen C; Lapa, Constantin; Kreissl, Michael C; Schirbel, Andreas; Herrmann, Ken; Schnack, Alexander; Bröcker, Eva-Bettina; Goebeler, Matthias; Buck, Andreas K

2014-01-01

Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment. To non-invasively assess SSTR expression in MCC using PET and the radiotracers [ 68 Ga]DOTA-D-Phe 1 -Tyr 3 -octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT). SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73% for nodal metastases, 100% for bone, and 67% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13%). SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management

Optical Molecular Imaging of Epidermal Growth Factor Receptor Expression to Improve Detection of Oral Neoplasia

Directory of Open Access Journals (Sweden)

Nitin Nitin

2009-06-01

Full Text Available Background: The development of noninvasive molecular imaging approaches has the potential to improve management of cancer. Methods: In this study, we demonstrate the potential of noninvasive topical delivery of an epidermal growth factor-Alexa 647 (EGF-Alexa 647 conjugate to image changes in epidermal growth factor receptor expression associated with oral neoplasia. We report a series of preclinical analyses to evaluate the optical contrast achieved after topical delivery of EGF-Alexa 647 in a variety of model systems, including cells, three-dimensional tissue cultures, and intact human tissue specimens using wide-field and high-resolution fluorescence imaging. Data were collected from 17 different oral cancer patients: eight pairs of normal and abnormal biopsies and nine resected tumors were examined. Results: The EGF-dye conjugate can be uniformly delivered throughout the oral epithelium with a penetration depth exceeding 500 µm and incubation time of less than 30 minutes. After EGF-Alexa 647 incubation, the presence of oral neoplasia is associated with a 1.5- to 6.9-fold increase in fluorescence contrast compared with grossly normal mucosa from the same patient with both wide-field and high-resolution fluorescence imaging. Conclusions: Results illustrate the potential of EGF-targeted fluorescent agents for in vivo molecular imaging, a technique that may aid in the diagnosis and characterization of oral neoplasia and allow real-time detection of tumor margins.

Benzodiazepine receptor imaging with iomazenil SPECT in aphasic patients with cerebral infarction

Energy Technology Data Exchange (ETDEWEB)

Koshi, Yasuhiko; Kitamura, Shin; Ohyama, Masashi [Nippon Medical School, Tokyo (Japan)] (and others)

1999-08-01

To investigate the relationship between prognosis of aphasia and neuronal damage in the cerebral cortex, we evaluated the distribution of central-type benzodiazepine receptor (BZR) binding in post-stroke aphasics with [{sup 123}I]iomazenil and SPECT. We performed iomazenil SPECT in six aphasic patients (aged from 45 to 75 years; all right-handed) with unilateral left cerebral infarction. Three patients showed signs of Broca's aphasia and the other three Wernicke's aphasia. Cerebral blood flow (CBF) imaging was performed with [{sup 123}I]iodoamphetamine (IMP). The regions of interest (ROIs) on both images were set in the cerebral cortex, cerebellar cortex and language relevant area in both hemispheres. Three patients were classified in the mild prognosis group and the other three in the moderate prognosis group. The left language-relevant area was more closely concerned with the difference in aphasic symptoms than the right one in both BZR and CBF distribution, but the ipsilateral to the contralateral ratio (I/C ratio) in the language-relevant areas in the BZR distribution was significantly lower in the moderate prognosis group than in the mild prognosis group, although no difference was seen for these values between the two groups in the CBF distribution. These results suggest that BZR imaging, which makes possible an increase in neuronal cell viability in the cerebral cortex, is useful not only for clarifying the aphasic symptoms but also for evaluating the prognosis of aphasia in patients with cerebral infarction. (author)

Benzodiazepine receptor imaging with iomazenil SPECT in aphasic patients with cerebral infarction

International Nuclear Information System (INIS)

Koshi, Yasuhiko; Kitamura, Shin; Ohyama, Masashi

1999-01-01

To investigate the relationship between prognosis of aphasia and neuronal damage in the cerebral cortex, we evaluated the distribution of central-type benzodiazepine receptor (BZR) binding in post-stroke aphasics with [ 123 I]iomazenil and SPECT. We performed iomazenil SPECT in six aphasic patients (aged from 45 to 75 years; all right-handed) with unilateral left cerebral infarction. Three patients showed signs of Broca's aphasia and the other three Wernicke's aphasia. Cerebral blood flow (CBF) imaging was performed with [ 123 I]iodoamphetamine (IMP). The regions of interest (ROIs) on both images were set in the cerebral cortex, cerebellar cortex and language relevant area in both hemispheres. Three patients were classified in the mild prognosis group and the other three in the moderate prognosis group. The left language-relevant area was more closely concerned with the difference in aphasic symptoms than the right one in both BZR and CBF distribution, but the ipsilateral to the contralateral ratio (I/C ratio) in the language-relevant areas in the BZR distribution was significantly lower in the moderate prognosis group than in the mild prognosis group, although no difference was seen for these values between the two groups in the CBF distribution. These results suggest that BZR imaging, which makes possible an increase in neuronal cell viability in the cerebral cortex, is useful not only for clarifying the aphasic symptoms but also for evaluating the prognosis of aphasia in patients with cerebral infarction. (author)

Development and evaluation of a novel radioiodinated vesamicol analog as a sigma receptor imaging agent.

Science.gov (United States)

Ogawa, Kazuma; Kanbara, Hiroya; Shiba, Kazuhiro; Kitamura, Yoji; Kozaka, Takashi; Kiwada, Tatsuto; Odani, Akira

2012-09-28

Sigma receptors are highly expressed in human tumors and should be appropriate targets for developing tumor imaging agents. Previously, we synthesized a vesamicol analog, (+)-2-[4-(4-iodophenyl)piperidino]cyclohexanol ((+)-pIV), with a high affinity for sigma receptors and prepared radioiodinated (+)-pIV. As a result, (+)-[125I]pIV showed high tumor uptake in biodistribution experiments. However, the accumulation of radioactivity in normal tissues, such as the liver, was high. We supposed that some parts of the accumulation of (+)-pIV in the liver should be because of its high lipophilicity, and prepared and evaluated a more hydrophilic radiolabeled vesamicol analog, (+)-4-[1-(2-hydroxycyclohexyl)piperidine-4-yl]-2-iodophenol ((+)-IV-OH). (+)-[125I]IV-OH was prepared by the chloramine T method from the precursor. The partition coefficient of (+)-[125I]IV-OH was measured. Biodistribution experiments were performed by intravenous administration of a mixed solution of (+)-[125I]IV-OH and (+)-[131I]pIV into DU-145 tumor-bearing mice. Blocking studies were performed by intravenous injection of (+)-[125I]IV-OH mixed with an excess amount of ligand into DU-145 tumor-bearing mice. The hydrophilicity of (+)-[125I]IV-OH was much higher than that of (+)-[125I]pIV. In biodistribution experiments, (+)-[125I]IV-OH and (+)-[131I]pIV showed high uptake in tumor tissues at 10-min post-injection. Although (+)-[131I]pIV tended to be retained in most tissues, (+)-[125I]IV-OH was cleared from most tissues. In the liver, the radioactivity level of (+)-[125I]IV-OH was significantly lower at all time points compared to those of (+)-[131I]pIV. In the blocking studies, co-injection of an excess amount of sigma ligands resulted in significant decreases of tumor/blood uptake ratios after injection of (+)-[125I]IV-OH. The results indicate that radioiodinated (+)-IV-OH holds a potential as a sigma receptor imaging agent.

In vivo imaging of GABAA receptors using sequential whole-volume iodine-123 iomazenil single-photon emission tomography

International Nuclear Information System (INIS)

Busatto, G.F.; Pilowsky, L.S.; Costa, D.C.; Ell, P.J.; Lingford-Hughes, A.; Kerwin, R.W.

1995-01-01

Using a brain-dedicated triple-headed single-photon emission tomography (SPET) system, a sequential whole-volume imaging protocol has been devised to evaluate the regional distribution of iodine-123 iomazenil binding to GABA A receptors in the entire brain. The protocol was piloted in eight normal volunteers (seven males and one female; mean age, 24.8±3.9 years). The patterns obtained were largely compatible with the known distribution of GABA A receptors in the brain as reported in autoradiographic studies, with cerebral cortical regions, particularly the occipital and frontal cortices, displaying the highest 123 I-iomazenil uptake. Measures of time to peak uptake and tracer washout rates presented with the same pattern of regional variation, with later times to peak and slower washout rates in cortical regions compared to other brain areas. Semiquantitative analysis of the data using white matter/ventricle regions as reference demonstrated a plateau of specific 123 I-iomazenil binding in neocortical and cerebellar regions from 60-75 min onwards. These data demonstrate the feasibility of sequential, dynamic whole-volume 123 I-iomazenil SPET imaging. The protocol may be particularly useful in the investigation of neuropsychiatric conditions which are likely to involve more than one focus of GABA abnormalities, such as anxiety disorders and schizophrenia. (orig.)

Preliminary genetic imaging study of the association between estrogen receptor-α gene polymorphisms and harsh human maternal parenting.

Science.gov (United States)

Lahey, Benjamin B; Michalska, Kalina J; Liu, Chunyu; Chen, Qi; Hipwell, Alison E; Chronis-Tuscano, Andrea; Waldman, Irwin D; Decety, Jean

2012-09-06

A failure of neural changes initiated by the estrogen surge in late pregnancy to reverse the valence of infant stimuli from aversive to rewarding is associated with dysfunctional maternal behavior in nonhuman mammals. Estrogen receptor-α plays the crucial role in mediating these neural effects of estrogen priming. This preliminary study examines associations between estrogen receptor-α gene polymorphisms and human maternal behavior. Two polymorphisms were associated with human negative maternal parenting. Furthermore, hemodynamic responses in functional magnetic resonance imaging to child stimuli in neural regions associated with social cognition fully mediated the association between genetic variation and negative parenting. This suggests testable hypotheses regarding a biological pathway between genetic variants and dysfunctional human maternal parenting. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Molecular imaging of neuroendocrine tumors using {sup 68}Ga-labeled peptides (Somatostatin receptor PET/CT); Molekulare Bildgebung neuroendokriner Tumoren mit {sup 68}Ga-markierten Peptiden (Somatostatinrezeptor-PET/CT)

Energy Technology Data Exchange (ETDEWEB)

Baum, R.P.; Prasad, V. [Zentralklinik Bad Berka GmbH (Germany). Klinik fuer Nuklearmedizin/PET-Zentrum; Hoersch, D. [Zentralklinik Bad Berka GmbH (Germany). Klinik fuer Innere Medizin, Gastroenterologie, Onkologie, Endokrionologie

2009-06-15

Receptor PET/CT using {sup 68}Ga-labeled somatostatin analogues (DOTA-NOC, DOTA-TOC or DOTA-TATE) enables the highly sensitive molecular imaging of neuroendocrine tumors (NETs) based on the expression of somatostatin receptors and even the detection of receptor subtypes. Our experience after more than 3000 studies shows that receptor PET/CT has a significantly higher tumor detection rate than conventional scintigraphy (even in SPECT/CT technique), and that tumor lesions can be very accurately localized. By calculating standardized uptake values (SUV) - which are reproducible and investigator-independent - patients can be selected for peptide receptor radiotherapy and also the course after therapy can be controlled. Receptor-PET/CT is the most sensitive imaging modality for the detection of unknown primary tumors (CUP syndrome), which is especially true for the detection of neuroendocrine tumors of the pancreas and small bowel; whole-body staging (''one stop shop'') as well as restaging and selection of patients for peptide receptor radiotherapy can be performed using a patient-friendly procedure (examination finished within one hour) exposing the patient to less radiation than whole-body CT scanning. The {sup 68}Ge/{sup 68}Ga generator has proved very reliable over the years - even in a hospital environment. The effective costs for {sup 68}Ga labeled somatostatin analogues might be less than for scintigraphic agents, provided a certain number of studies per year are performed. The development of new tumor-specific peptides as well as of other DOTA- or NOTA-coupled radiopharmaceuticals opens a new avenue into the future: finally, the {sup 68}Ga generator could play a similar important role for PET/CT as did the {sup 99m}Tc-Generator for conventional gamma camera imaging over the last decades. (orig.)

Molecular imaging with {sup 68}Ga-SSTR PET/CT and correlation to immunohistochemistry of somatostatin receptors in neuroendocrine tumours

Energy Technology Data Exchange (ETDEWEB)

Kaemmerer, Daniel; Haugvik, Sven-Petter; Hommann, Merten [Zentralklinik Bad Berka GmbH, Department of General and Visceral Surgery, Bad Berka (Germany); Peter, Luisa; Lupp, Amelie; Schulz, Stefan [University of Jena, Department of Pharmacology and Toxicology, Jena (Germany); Saenger, Joerg [Laboratory of Pathology and Cytology, Bad Berka (Germany); Prasad, Vikas; Kulkarni, Harshad; Baum, Richard Paul [Zentralklinik Bad Berka, Department of Nuclear Medicine and Center for PET, Bad Berka (Germany)

2011-09-15

Somatostatin receptors (SSTR) are known for an overexpression in gastroenteropancreatic neuroendocrine tumours (GEP-NET). The aim of the present study was to find out if the receptor density predicted by the semi-quantitative parameters generated from the static positron emission tomography (PET/CT) correlated with the in vitro immunohistochemistry using a novel rabbit monoclonal anti-SSTR2A antibody (clone UMB-1) for specific SSTR2A immunohistochemistry and polyclonal antibodies for SSTR1 and 3-5. Overall 14 surgical specimens generated from 34 histologically documented GEP-NET patients were correlated with the preoperative {sup 68}Ga-DOTA-NOC PET/CT. Quantitative assessment of the receptor density was done using the immunoreactive score (IRS) of Remmele and Stegner; the additional 4-point IRS classification for immunohistochemistry and standardized uptake values (SUV{sub max} and SUV{sub mean}) were used for PET/CT. The IRS for SSTR2A and SSTR5 correlated highly significant with the SUV{sub max} on the PET/CT (p < 0.001; p < 0.05) and the IRS for SSTR2A with the SUV{sub mean} (p < 0.013). The level of SSTR2A score correlated significantly with chromogranin A staining and indirectly to the tumour grading. The highly significant correlation between SSTR2A and SSTR5 and the SUV{sub max} on the {sup 68}Ga-DOTA-NOC PET/CT scans is concordant with the affinity profile of {sup 68}Ga-DOTA-NOC to the SSTR subtypes and demonstrates the excellent qualification of somatostatin analogues in the diagnostics of NET. This study correlating somatostatin receptor imaging using {sup 68}Ga-DOTA-NOC PET/CT with immunohistochemically analysed SSTR also underlines the approval of therapy using somatostatin analogues, follow-up imaging as well as radionuclide therapy. (orig.)

Neurokinin-3 Receptor Binding in Guinea Pig, Monkey, and Human Brain: In Vitro and in Vivo Imaging Using the Novel Radioligand, [18F]Lu AF10628.

Science.gov (United States)

Varnäs, Katarina; Finnema, Sjoerd J; Stepanov, Vladimir; Takano, Akihiro; Tóth, Miklós; Svedberg, Marie; Møller Nielsen, Søren; Khanzhin, Nikolay A; Juhl, Karsten; Bang-Andersen, Benny; Halldin, Christer; Farde, Lars

2016-08-01

Previous autoradiography studies have suggested a marked interspecies variation in the neuroanatomical localization and expression levels of the neurokinin 3 receptor, with high density in the brain of rat, gerbil, and guinea pig, but at the time offered no conclusive evidence for its presence in the human brain. Hitherto available radioligands have displayed low affinity for the human neurokinin 3 receptor relative to the rodent homologue and may thus not be optimal for cross-species analyses of the expression of this protein. A novel neurokinin 3 receptor radioligand, [(18)F]Lu AF10628 ((S)-N-(cyclobutyl(3-fluorophenyl)methyl)-8-fluoro-2-((3-[(18)F]-fluoropropyl)amino)-3-methyl-1-oxo-1,2-dihydroisoquinoline-4-carboxamide), was synthesized and used for autoradiography studies in cryosections from guinea pig, monkey, and human brain as well as for positron emission tomography studies in guinea pig and monkey. The results confirmed previous observations of interspecies variation in the neurokinin 3 receptor brain localization with more extensive distribution in guinea pig than in primate brain. In the human brain, specific binding to the neurokinin 3 receptor was highest in the amygdala and in the hypothalamus and very low in other regions examined. Positron emission tomography imaging showed a pattern consistent with that observed using autoradiography. The radioactivity was, however, found to accumulate in skull bone, which limits the use of this radioligand for in vivo quantification of neurokinin 3 receptor binding. Species differences in the brain distribution of neurokinin 3 receptors should be considered when using animal models for predicting human neurokinin 3 receptor pharmacology. For positron emission tomography imaging of brain neurokinin 3 receptors, additional work is required to develop a radioligand with more favorable in vivo properties. © The Author 2016. Published by Oxford University Press on behalf of CINP.

[¹¹C]-(+)-PHNO PET imaging of dopamine D(2/3) receptors in Parkinson's disease with impulse control disorders.

Science.gov (United States)

Payer, Doris E; Guttman, Mark; Kish, Stephen J; Tong, Junchao; Strafella, Antonio; Zack, Martin; Adams, John R; Rusjan, Pablo; Houle, Sylvain; Furukawa, Yoshiaki; Wilson, Alan A; Boileau, Isabelle

2015-02-01

Dopamine agonist medications with high affinity for the D3 dopamine receptor are commonly used to treat Parkinson's disease, and have been associated with pathological behaviors categorized under the umbrella of impulse control disorders (ICD). The aim of this study was to investigate whether ICD in Parkinson's patients are associated with greater D3 dopamine receptor availability. We used positron emission tomography (PET) radioligand imaging with the D3 dopamine receptor preferring agonist [¹¹C]-(+)-propyl-hexahydro-naphtho-oxazin (PHNO) in Parkinson's patients with (n = 11) and without (n = 21) ICD, and age-, sex-, and education-matched healthy control subjects (n = 18). Contrary to hypotheses, [¹¹C]-(+)-PHNO binding in D3 -rich brain areas was not elevated in Parkinson's patients with ICD compared with those without; instead, [¹¹C]-(+)-PHNO binding in ventral striatum was 20% lower (P = 0.011), correlating with two measures of ICD severity (r = -0.8 and -0.9), which may reflect higher dopamine tone in ventral striatum. In dorsal striatum, where [¹¹C]-(+)-PHNO binding is associated with D2 receptor levels, [¹¹C]-(+)-PHNO binding was elevated across patients compared with controls. We conclude that although D3 dopamine receptors have been linked to the occurrence of ICD in Parkinson's patients. Our findings do not support the hypothesis that D3 receptor levels are elevated in Parkinson's patients with ICD. We also did not find ICD-related abnormalities in D2 receptor levels. Our findings argue against the possibility that differences in D2/3 receptor levels can account for the development of ICD in PD; however, we cannot rule out that differences in dopamine levels (particularly in ventral striatum) may be involved. © 2015 International Parkinson and Movement Disorder Society.

[68Ga]pentixafor for CXCR4 imaging in a PC-3 prostate cancer xenograft model - comparison with [18F]FDG PET/CT, MRI and ex vivo receptor expression.

Science.gov (United States)

Schwarzenböck, Sarah M; Stenzel, Jan; Otto, Thomas; Helldorff, Heike V; Bergner, Carina; Kurth, Jens; Polei, Stefan; Lindner, Tobias; Rauer, Romina; Hohn, Alexander; Hakenberg, Oliver W; Wester, Hans J; Vollmar, Brigitte; Krause, Bernd J

2017-11-10

The aim was to characterize the properties of [ 68 Ga]Pentixafor as tracer for prostate cancer imaging in a PC-3 prostate cancer xenograft mouse model and to investigate its correlation with [ 18 F]FDG PET/CT, magnetic resonance imaging (MRI) and ex vivo analyses. Static [ 68 Ga]Pentixafor and [ 18 F]FDG PET as well as morphological/ diffusion weighted MRI and 1 H MR spectroscopy was performed. Imaging data were correlated with ex vivo biodistribution and CXCR4 expression in PC-3 tumors (immunohistochemistry (IHC), mRNA analysis). Flow cytometry was performed for evaluation of localization of CXCR4 receptors ( in vitro PC-3 cell experiments). Tumor uptake of [ 68 Ga]Pentixafor was significantly lower compared to [ 18 F]FDG. Ex vivo CXCR4 mRNA expression of tumors was shown by PCR. Only faint tumor CXCR4 expression was shown by IHC (immuno reactive score of 3). Accordingly, flow cytometry of PC-3 cells revealed only a faint signal, cell membrane permeabilisation showed a slight signal increase. There was no significant correlation of [ 68 Ga]Pentixafor tumor uptake and ex vivo receptor expression. Spectroscopy showed typical spectra of prostate cancer. PC-3 tumor uptake of [ 68 Ga]Pentixafor was existent but lower compared to [ 18 F]FDG. No significant correlation of ex vivo tumor CXCR4 receptor expression and [ 68 Ga]Pentixafor tumor uptake was shown. CXCR4 receptor expression on the surface of PC-3 cells was existent but rather low possibly explaining the limited [ 68 Ga]Pentixafor tumor uptake; receptor localization in the interior of PC-3 cells is presumable as shown by cell membrane permeabilisation. Further studies are necessary to define the role of [ 68 Ga]Pentixafor in prostate cancer imaging.

Fundamental study on brain receptor mapping by neuronuclear medicine imaging. Quantitation of receptor autoradiography in the rat brain

Energy Technology Data Exchange (ETDEWEB)

Tsuji, Shiro

1988-04-01

The usefulness of autoradiography in the quantitation of the rat brain receptor was evaluated. H-3 spiperone, H-3 quinuclidinyl benzylate (QNB), H-3 muscimol, H-3 diprenorphine, H-3 ketanserin, and H-3 dihydroalprenolol hydrochloride were used for autoradiography. Satisfactory autoradiograms with these H-3 labeled ligants were obtained for incubation time, washing time, and binding curve. The video digitizer system was the most suitable in autoradiography. Using appropriate conditions for the ligand-receptor interaction, receptor autoradiography and in vitro receptor assay were concordant as for the the number of maximum binding sites (Bmax) of the muscarinic acetylcholine receptor and equilibrium dissociation constant (Kd) of its antagonist, H-3 QNB. Receptor autoradiography with high spatial resolution allowed the comparison of Bmax and Kd in the brain. To improve conventional Scatchard analysis, used in the estimation of Bmax and Kd, a new mathematical method was developed for estimating individual rate constants and Bmax on the basis of time courses of association and dissociation. Using the new mathematical method, apparent equilibrium dissociation rate constant was in good agreement with that from a non-isomerization model. Autoradiography may provide a clue for the basic data on brain receptor mapping by a promising emission computerized tomography in neuropsychiatric diseases. (Namekawa, K.).

Radiolabeled pertuzumab for imaging of human epidermal growth factor receptor 2 expression in ovarian cancer

Energy Technology Data Exchange (ETDEWEB)

Jiang, Dawei [Shenzhen University, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen (China); University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Im, Hyung-Jun [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Seoul National University, Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Sun, Haiyan; Cho, Steve Y. [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Valdovinos, Hector F.; England, Christopher G.; Ehlerding, Emily B.; Nickles, Robert J. [University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); Lee, Dong Soo [Seoul National University, Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Huang, Peng [Shenzhen University, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen (China); Cai, Weibo [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States)

2017-08-15

Human epidermal growth factor receptor 2 (HER2) is over-expressed in over 30% of ovarian cancer cases, playing an essential role in tumorigenesis and metastasis. Non-invasive imaging of HER2 is of great interest for physicians as a mean to better detect and monitor the progression of ovarian cancer. In this study, HER2 was assessed as a biomarker for ovarian cancer imaging using {sup 64}Cu-labeled pertuzumab for immunoPET imaging. HER2 expression and binding were examined in three ovarian cancer cell lines (SKOV3, OVCAR3, Caov3) using in vitro techniques, including western blot and saturation binding assays. PET imaging and biodistribution studies in subcutaneous models of ovarian cancer were performed for non-invasive in vivo evaluation of HER2 expression. Additionally, orthotopic models were employed to further validate the imaging capability of {sup 64}Cu-NOTA-pertuzumab. HER2 expression was highest in SKOV3 cells, while OVCAR3 and Caov3 displayed lower HER2 expression. {sup 64}Cu-NOTA-pertuzumab showed high specificity for HER2 (K{sub a} = 3.1 ± 0.6 nM) in SKOV3. In subcutaneous tumors, PET imaging revealed tumor uptake of 41.8 ± 3.8, 10.5 ± 3.9, and 12.1 ± 2.3%ID/g at 48 h post-injection for SKOV3, OVCAR3, and Caov3, respectively (n = 3). In orthotopic models, PET imaging with {sup 64}Cu-NOTA-pertuzumab allowed for rapid and clear delineation of both primary and small peritoneal metastases in HER2-expressing ovarian cancer. {sup 64}Cu-NOTA-pertuzumab is an effective PET tracer for the non-invasive imaging of HER2 expression in vivo, rendering it a potential tracer for treatment monitoring and improved patient stratification. (orig.)

A fundamental study on brain receptor mapping by neuronuclear medicine imaging

International Nuclear Information System (INIS)

Tsuji, Shiro

1988-01-01

The usefulness of autoradiography in the quantitation of the rat brain receptor was evaluated. H-3 spiperone, H-3 quinuclidinyl benzylate (QNB), H-3 muscimol, H-3 diprenorphine, H-3 ketanserin, and H-3 dihydroalprenolol hydrochloride were used for autoradiography. Satisfactory autoradiograms with these H-3 labeled ligants were obtained for incubation time, washing time, and binding curve. The video digitizer system was the most suitable in autoradiography. Using appropriate conditions for the ligand-receptor interaction, receptor autoradiography and in vitro receptor assay were concordant as for the the number of maximum binding sites (Bmax) of the muscarinic acetylcholine receptor and equilibrium dissociation constant (Kd) of its antagonist, H-3 QNB. Receptor autoradiography with high spatial resolution allowed the comparison of Bmax and Kd in the brain. To improve conventional Scatchard analysis, used in the estimation of Bmax and Kd, a new mathematical method was developed for estimating individual rate constants and Bmax on the basis of time courses of association and dissociation. Using the new mathematical method, apparent equilibrium dissociation rate constant was in good agreement with that from a non-isomerization model. Autoradiography may provide a clue for the basic data on brain receptor mapping by a promising emission computerized tomography in neuropsychiatric diseases. (Namekawa, K.)

Nuclear Medicine Imaging of Neuroendocrine Tumors

NARCIS (Netherlands)

Brabander, Tessa; Kwekkeboom, Dik J.; Feelders, Richard A.; Brouwers, Adrienne H.; Teunissen, Jaap J. M.; Papotti, M; DeHerder, WW

2015-01-01

An important role is reserved for nuclear imaging techniques in the imaging of neuroendocrine tumors (NETs). Somatostatin receptor scintigraphy (SRS) with In-111-DTPA-octreotide is currently the most important tracer in the diagnosis, staging and selection for peptide receptor radionuclide therapy

Urokinase-type plasminogen activator receptor (uPAR), tissue factor (TF) and epidermal growth factor receptor (EGFR)

DEFF Research Database (Denmark)

Christensen, Anders; Kiss, Katalin; Lelkaitis, Giedrius

2017-01-01

Background: Tumor-specific biomarkers are a prerequisite for the development of targeted imaging and therapy in oral squamous cell carcinoma (OSCC). urokinase-type Plasminogen Activator Receptor (uPAR), Tissue Factor (TF) and Epidermal Growth Factor Receptor (EGFR) are three biomarkers that exhib...... with a reduced survival. uPAR seems to be a prognostic biomarker in oral cancer....

Synthesis of 99mTc-oxybutynin for M3-receptor-mediated imaging of urinary bladder

International Nuclear Information System (INIS)

Moustapha, M.E.; Benha University, Benha; Motaleb, M.A.; Ibrahim, I.T.

2011-01-01

Radiolabeling of oxybutynin, a muscarinic acetylcholine (mACh) receptor antagonist agent with 99m Tc is of considerable interest for imaging of urinary bladder. This study is aimed to optimize radiolabeling yield of oxybutynin with 99m Tc using SnCl 2 x 2H 2 O as a reducing agent with respect to factors that affect the reaction conditions such as oxybutynin amount, stannous chloride amount, reaction time and pH of the reaction mixture. In vitro stability of the radiolabeled complex was checked and it was found to be stable for up to 8 h. 99m Tc-oxybutynin was injected via subcutaneous and intravenous administration routes into normal Sprague-Dawley rats. Biodistribution studies have revealed that 99m Tc-oxybutynin exhibits high affinity and specificity for the muscarinic M 3 subtype located on the smooth muscle of urinary bladder relative to the M 1 and M 2 subtypes of the G protein coupled receptor (GPCR) superfamily. In vivo uptake of subcutaneous 99m Tc-oxybutynin in urinary bladder was 19.6 ± 0.42% ID at 0.5 h, whereas in intravenous administration route the accumulation in the urinary bladder was found to be 9.4 ± 0.31% ID at 0.5 h post injection. Administration of cold oxybutynin effectively blocked urinary bladder uptake and further confirms the high specificity of this complex for the M 3 receptor. (author)

Molecular MR Imaging Probes

OpenAIRE

MAHMOOD, UMAR; JOSEPHSON, LEE

2005-01-01

Magnetic resonance imaging (MRI) has been successfully applied to many of the applications of molecular imaging. This review discusses by example some of the advances in areas such as multimodality MR-optical agents, receptor imaging, apoptosis imaging, angiogenesis imaging, noninvasive cell tracking, and imaging of MR marker genes.

Rapid Visualization of Human Tumor Xenografts through Optical Imaging with a Near-Infrared Fluorescent Anti–Epidermal Growth Factor Receptor Nanobody

Directory of Open Access Journals (Sweden)

Sabrina Oliveira

2012-01-01

Full Text Available Given that overexpression of the epidermal growth factor receptor (EGFR is found in many types of human epithelial cancers, noninvasive molecular imaging of this receptor is of great interest. A number of studies have employed monoclonal antibodies as probes; however, their characteristic long half-life in the bloodstream has encouraged the development of smaller probes. In this study, an anti-EGFR nanobody-based probe was developed and tested in comparison with cetuximab for application in optical molecular imaging. To this aim, the anti-EGFR nanobody 7D12 and cetuximab were conjugated to the near-infrared fluorophore IRDye800CW. 7D12-IR allowed the visualization of tumors as early as 30 minutes postinjection, whereas with cetuximab-IR, no signal above background was observed at the tumor site. Quantification of the IR-conjugated proteins in the tumors revealed ≈ 17% of injected dose per gram 2 hours after injection of 7D12-IR, which was significantly higher than the tumor uptake obtained 24 hours after injection of cetuximab-IR. This difference is associated with the superior penetration and distribution of 7D12-IR within the tumor. These results demonstrate that this anti-EGFR nanobody conjugated to the NIR fluorophore has excellent properties for rapid preclinical optical imaging, which holds promise for its future use as a complementary diagnostic tool in humans.

Ionotropic crustacean olfactory receptors.

Directory of Open Access Journals (Sweden)

Elizabeth A Corey

Full Text Available The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs, the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs, as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling.

Relationship of neuromotor disturbances to psychosis symptoms in first-episode neuroleptic-naive schizophrenia patients.

Science.gov (United States)

Cortese, Leonardo; Caligiuri, Michael P; Malla, Ashok K; Manchanda, Rahul; Takhar, Jatinder; Haricharan, Raj

2005-06-01

From the very inception of the modern diagnostic scheme for psychotic disorders, abnormalities in motor function have been observed in these conditions. Despite convergence from multiple areas of research supporting the notion that multiple frontal-subcortical circuits regulate motor and limbic behavior, the precise relationship between motor abnormalities and psychopathology has not been elucidated. The goals of this study were to examine the prevalence of extrapyramidal signs (EPS) in first-episode schizophrenia patients and their relationships to three psychopathological dimensions (positive psychosis syndrome, negative syndrome, and disorganization). We assessed EPS using traditional observer-based as well as quantitative instrumental measures in 39 neuroleptic-naive first-episode schizophrenia subjects. Subjects were followed for 6 months after initiating antipsychotic treatment to examine the stability of motor-limbic relationships. Four main findings emerged from this study. First, depending on the measure used the prevalence of dyskinesia prior to treatment ranged from 13% to 20%. The prevalence of parkinsonism ranged from 18% to 28%. Second, severity of dyskinesia was associated with the positive psychotic syndrome; whereas parkinsonism was associated with the positive psychosis, negative syndrome and disorganization. Third, psychopathology improved significantly across all symptom dimensions following antipsychotic treatment, while EPS remained stable. This suggests that some motor abnormalities in schizophrenia may reflect trait characteristics. Fourth, abnormalities on the pre-treatment instrumental measure of parkinsonism predicted greater improvement on positive psychosis symptoms following treatment (p=0.008). Our findings support the notion that neuromotor disturbances may be a core feature of schizophrenia in a substantial proportion of patients and implicate multiple fronto-striatal circuits regulating limbic and neuromotor behavior in

Harnessing Integrative Omics to Facilitate Molecular Imaging of the Human Epidermal Growth Factor Receptor Family for Precision Medicine.

Science.gov (United States)

Pool, Martin; de Boer, H Rudolf; Hooge, Marjolijn N Lub-de; van Vugt, Marcel A T M; de Vries, Elisabeth G E

2017-01-01

Cancer is a growing problem worldwide. The cause of death in cancer patients is often due to treatment-resistant metastatic disease. Many molecularly targeted anticancer drugs have been developed against 'oncogenic driver' pathways. However, these treatments are usually only effective in properly selected patients. Resistance to molecularly targeted drugs through selective pressure on acquired mutations or molecular rewiring can hinder their effectiveness. This review summarizes how molecular imaging techniques can potentially facilitate the optimal implementation of targeted agents. Using the human epidermal growth factor receptor (HER) family as a model in (pre)clinical studies, we illustrate how molecular imaging may be employed to characterize whole body target expression as well as monitor drug effectiveness and the emergence of tumor resistance. We further discuss how an integrative omics discovery platform could guide the selection of 'effect sensors' - new molecular imaging targets - which are dynamic markers that indicate treatment effectiveness or resistance.

Quantitative Time-Resolved Fluorescence Imaging of Androgen Receptor and Prostate-Specific Antigen in Prostate Tissue Sections.

Science.gov (United States)

Krzyzanowska, Agnieszka; Lippolis, Giuseppe; Helczynski, Leszek; Anand, Aseem; Peltola, Mari; Pettersson, Kim; Lilja, Hans; Bjartell, Anders

2016-05-01

Androgen receptor (AR) and prostate-specific antigen (PSA) are expressed in the prostate and are involved in prostate cancer (PCa). The aim of this study was to develop reliable protocols for reproducible quantification of AR and PSA in benign and malignant prostate tissue using time-resolved fluorescence (TRF) imaging techniques. AR and PSA were detected with TRF in tissue microarrays from 91 PCa patients. p63/ alpha-methylacyl-CoA racemase (AMACR) staining on consecutive sections was used to categorize tissue areas as benign or cancerous. Automated image analysis was used to quantify staining intensity. AR intensity was significantly higher in AMACR+ and lower in AMACR- cancer areas as compared with benign epithelium. The PSA intensity was significantly lower in cancer areas, particularly in AMACR- glands. The AR/PSA ratio varied significantly in the AMACR+ tumor cells as compared with benign glands. There was a trend of more rapid disease progression in patients with higher AR/PSA ratios in the AMACR- areas. This study demonstrates the feasibility of developing reproducible protocols for TRF imaging and automated image analysis to study the expression of AR and PSA in benign and malignant prostate. It also highlighted the differences in AR and PSA protein expression within AMACR- and AMACR+ cancer regions. © 2016 The Histochemical Society.

Development of radiolabeled probes directed against sigma-1 receptors

International Nuclear Information System (INIS)

Ogawa, Kazuma; Masuda, Ryohei; Shiba, Kazuhiro

2017-01-01

It has been reported that sigma-1 receptors regulate the release of signaling substances in the central nervous systems and are related to various diseases, such as schizophrenia, stress disorders, dementia, amyotrophic lateral sclerosis (ALS), and cancer. If the quantification of the sigma-1 receptors is possible, the pathophysiology, the stage, and the early detection of the diseases could be understandable. Molecular imaging using Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) and radioactive probes makes noninvasive quantification of the in vivo metabolism and function possible. Currently, only nuclear medicine diagnosis using PET or SPECT can quantify the sigma-1 receptors. Therefore, there is great expectation for the development of molecular probes to image the sigma-1 receptors specifically. In this paper, we introduce our research on the development of radiohalogen-labeled molecular probes directed against the sigma-1 receptors. (author)

High-resolution imaging of brain 5-HT{sub 1B} receptors in the rhesus monkey using [{sup 11}C]P943

Energy Technology Data Exchange (ETDEWEB)

Nabulsi, Nabeel; Huang Yiyun; Weinzimmer, David; Ropchan, Jim; Frost, James J. [Yale PET Center, Department of Diagnostic Radiology and Psychiatry, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520-8048 (United States); McCarthy, Timothy [Pfizer Global R and D, Groton, CT 06340 (United States); Carson, Richard E.; Ding Yushin [Yale PET Center, Department of Diagnostic Radiology and Psychiatry, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520-8048 (United States)

2010-02-15

The serotonin 5-HT{sub 1B} receptors regulate the release of serotonin and are involved in various disease states, including depression and schizophrenia. The goal of the study was to evaluate a high affinity and high selectivity antagonist, [{sup 11}C]P943, as a positron emission tomography (PET) tracer for imaging the 5-HT{sub 1B} receptor. [{sup 11}C]P943 was synthesized via N-methylation of the precursor with [{sup 11}C]methyl iodide or [{sup 11}C]methyl triflate using automated modules. The average radiochemical yield was approx. 10% with radiochemical purity of >99% and specific activity of 8.8{+-}3.6 mCi/nmol at the end-of-synthesis (n=37). PET imaging was performed in non-human primates with a high-resolution research tomograph scanner with a bolus/infusion paradigm. Binding potential (BP{sub ND}) was calculated using the equilibrium ratios of regions to cerebellum. The tracer uptake was highest in the globus pallidus and occipital cortex, moderate in basal ganglia and thalamus, and lowest in the cerebellum, which is consistent with the known brain distribution of 5-HT{sub 1B} receptors. Infusion of tracer at different specific activities (by adding various amount of unlabeled P943) reduced BP{sub ND} values in a dose-dependent manner, demonstrating the saturability of the tracer binding. Blocking studies with GR127935 (2 mg/kg iv), a selective 5-HT{sub 1B}/5-HT{sub 1D} antagonist, resulted in reduction of BP{sub ND} values by 42-95% across regions; for an example, in occipital region from 0.71 to 0.03, indicating a complete blockade. These results demonstrate the saturability and specificity of [{sup 11}C]P943 for 5-HT{sub 1B} receptors, suggesting its suitability as a PET radiotracer for in vivo evaluations of the 5-HT{sub 1B} receptor system in humans.

Increased GABA-A receptor binding and reduced connectivity at the motor cortex in children with hemiplegic cerebral palsy: a multimodal investigation using 18F-fluoroflumazenil PET, immunohistochemistry, and MR imaging.

Science.gov (United States)

Park, Hae-Jeong; Kim, Chul Hoon; Park, Eun Sook; Park, Bumhee; Oh, So Ra; Oh, Maeng-Keun; Park, Chang Il; Lee, Jong Doo

2013-08-01

γ-aminobutyric acid (GABA)-A receptor-mediated neural transmission is important to promote practice-dependent plasticity after brain injury. This study investigated alterations in GABA-A receptor binding and functional and anatomic connectivity within the motor cortex in children with cerebral palsy (CP). We conducted (18)F-fluoroflumazenil PET on children with hemiplegic CP to investigate whether in vivo GABA-A receptor binding is altered in the ipsilateral or contralateral hemisphere of the lesion site. To evaluate changes in the GABA-A receptor subunit after prenatal brain injury, we performed GABA-A receptor immunohistochemistry using rat pups with a diffuse hypoxic ischemic insult. We also performed diffusion tensor MR imaging and resting-state functional MR imaging on the same children with hemiplegic CP to investigate alterations in anatomic and functional connectivity at the motor cortex with increased GABA-A receptor binding. In children with hemiplegic CP, the (18)F-fluoroflumazenil binding potential was increased within the ipsilateral motor cortex. GABA-A receptors with the α1 subunit were highly expressed exclusively within cortical layers III, IV, and VI of the motor cortex in rat pups. The motor cortex with increased GABA-A receptor binding in children with hemiplegic CP had reduced thalamocortical and corticocortical connectivity, which might be linked to increased GABA-A receptor distribution in cortical layers in rats. Increased expression of the GABA-A receptor α1 subunit within the ipsilateral motor cortex may be an important adaptive mechanism after prenatal brain injury in children with CP but may be associated with improper functional connectivity after birth and have adverse effects on the development of motor plasticity.

Regional blockade by neuroleptic drugs of in vivo 3H-spiperone binding in the rat brain. Relation to blockade of apomorphine induced hyperactivity and stereotypies

International Nuclear Information System (INIS)

Koehler, C.; Haglund, L.; Oegren, S.-O.; Aengeby, T.

1981-01-01

The regional prevention by neuroleptic drugs of specific in vivo 3 H-spiperone binding was studied in the rat brain. L-sulpiride, thioridazine and clozapine were found to reduce the 3 H-spiperone bindings selectively in the olfactory tubercle, septum, substantia nigra and frontal cortex but not the striatum at dose levels which preferentially block apomorphine (APO) induced hyperactivity. The maximal prevention of specific 3 H-spiperone binding by l-sulpiride and clozapine reached 60-80% in the former structures while the displacement of striatal 3 H-spiperone binding did not exceed 40%. In contrast to l-sulpiride, thioridazine and clozapine both chlorpromazine and haloperidol reduced the 3 H-spiperone binding to the same extent in all regions studied. Chlorpromazine and haloperidol were potent in prevention of striatal 3 H-spiperone binding in vivo which reached 60-80% in this structure. (Author)

Imaging Dose-dependent Pharmacokinetics of an RGD-Fluorescent Dye Conjugate Targeted to αvβ3 Receptor Expressed in Kaposi's Sarcoma

Directory of Open Access Journals (Sweden)

Sunkuk Kwon

2005-04-01

Full Text Available Dynamic fluorescence images were obtained from xenografts bearing a subcutaneous human Kaposi's sarcoma (KS1767 immediately following the intravenous injection of an integrin-receptor targeting Cy5.5-c(KRGDf at a dose ranging from 0.75 to 6 nmol/mouse. The fluorescence images were acquired using an intensified charge-coupled device system and were analyzed with a three-compartment pharmacokinetic (PK model to determine uptake parameters in the tumor and normal tissue regions of interest as a function of administered dose. Our results show that the uptake of Cy5.5-c(KRGDf in tumor regions were: (i significantly greater than the contralateral normal tissue regions; (ii linearly increased with dose of Cy5.5-c(KRGDf up to 1.5 nmol/mouse; and (iii blocked by preinjection of c(KRGDf. Above doses of 1.5 nmol/mouse, the uptake no longer increased with dose, suggesting integrin receptor saturation. In normal tissues, the PK uptake parameters were not influenced by Cy5.5-c(KRGDf dose nor by the preadministration of c(KRGDf.

A radiogallium-DOTA-based bivalent peptidic ligand targeting a chemokine receptor, CXCR4, for tumor imaging.

Science.gov (United States)

Sano, Kohei; Masuda, Ryo; Hisada, Hayato; Oishi, Shinya; Shimokawa, Kenta; Ono, Masahiro; Fujii, Nobutaka; Saji, Hideo; Mukai, Takahiro

2014-03-01

We have developed a novel radiogallium (Ga)-DOTA-based bivalent peptidic ligand targeting a chemokine receptor, CXCR4, for tumor imaging. A CXCR4 imaging probe with two CXCR4 antagonists (Ac-TZ14011) on Ga-DOTA core, Ga-DOTA-TZ2, was synthesized, and the affinity and binding to CXCR4 was evaluated in CXCR4 expressing cells in vitro. The affinity of Ga-DOTA-TZ2 for CXCR4 was 20-fold greater than the corresponding monovalent probe, Ga-DOTA-TZ1. (67)Ga-DOTA-TZ2 showed the significantly higher accumulation in CXCR4-expressing tumor cells compared with (67)Ga-DOTA-TZ1, suggesting the bivalent effect enhances its binding to CXCR4. The incorporation of two CXCR4 antagonists to Ga-DOTA could be effective in detecting CXCR4-expressing tumors. Copyright © 2014 Elsevier Ltd. All rights reserved.

N-(N-benzylpiperidin-4-yl)-2-[18F]fluorobenzamide: A potential ligand for PET imaging of σ receptors

International Nuclear Information System (INIS)

Shiue Chyngyann; Shiue, Grace G.; Zhang, Sue X.; Wilder, Susan; Greenberg, Joel H.; Benard, Francois; Wortman, Jeffrey A.; Alavi, Abass A.

1997-01-01

Four nitro- and fluorobenzamides (1-4) have been synthesized in good yields from nitro- and fluoro-substituted benzoyl chloride with 4-amino-1-benzylpiperidine. In vitro studies showed that these compounds have high affinities to σ receptors. N-(N-Benzylpiperidin-4-yl)-2-fluorobenzamide (3), in particular, bound to σ receptors with high affinity (K i = 3.4 nM, guinea pig brain membranes) and high selectivity (σ-2/σ-1 = 120). It was, therefore, labeled with 18 F and evaluated as a σ receptor radioligand. N-(N-Benzylpiperidin-4-yl)-2-[ 18 F]fluorobenzamide (3a) was synthesized in one step by nucleophilic substitution of the 2-nitro precursor (1) with [ 18 F]fluoride in DMSO at 140 deg. C for 20 min followed by purification with HPLC in 4-10% yield (decay corrected). The synthesis time was 90 min and the specific activity was 0.4-1.0 Ci/μmol. Tissue distribution in mice revealed that the uptakes of 3a in the brain, heart, liver, lungs, spleen, kidneys and small intestine were high, and the radioactivity in these organs remained constant from 60 to 120 min post-injection. The radioactivity in the bone did not significantly increase, suggesting in vivo defluorination may not be the major route of metabolism of 3a in mice. Blocking studies with haloperidol in rats indicated that the uptake of compound 3a in the rat brain was selective to haloperidol-sensitive σ sites. These results suggest that compound 3a is a potent σ receptor radioligand and may be a potential ligand for PET imaging of σ receptors in humans

Change of central cholinergic receptors following lesions of nucleus basalis magnocellularis in rats: search for an imaging index suitable for the early detection of Alzheimer's disease

International Nuclear Information System (INIS)

Ogawa, Mikako; Iida, Yasuhiko; Nakagawa, Masaki; Kuge, Yugi; Kawashima, Hidekazu; Tominaga, Akiko; Ueda, Masashi; Magata, Yasuhiro; Saji, Hideo

2006-01-01

Cholinergic system in the central nervous system is involved in the memory function. Thus, because the dysfunction of cholinergic system that project to the cerebral cortex from nucleus basalis of Meynert (nbM) would be implicated in the memory function deficits in Alzheimer's disease (AD), evaluating cholinergic function may be useful for the early detection of AD. In this study, because the nucleus basalis magnocellularis (NBM) in rats is equivalent to nbM in human, we investigated the change in cholinergic receptors in the frontal cortex of rats with unilateral lesion to the NBM to find an appropriate index for the early detection of AD using techniques of nuclear medicine. The right NBM was injected with ibotenic acid. [ 18 F]FDG-PET images were obtained 3 days later. Some rats were sacrificed at 1 week, whereas others were subjected to a second [ 18 F]FDG-PET at 4 weeks then sacrificed for membrane preparation. The prepared membranes were subjected to radioreceptor assays to measure the density of nicotinic and muscarinic acetylcholine receptors. Glucose metabolism had decreased on the damaged side compared to the control side at 3 days, but at 4 weeks, there was no difference between the sides. Nicotinic acetylcholine receptors had significantly decreased in density compared to the control side at both 1 and 4 weeks. However, muscarinic receptors were not affected. These results suggested that neuronal dysfunction in AD could be diagnosed at an early stage by imaging nicotinic acetylcholine receptors

Antagonism by supidimide of haloperidol-induced augmentation of [3H]-spiperone binding in rat striatum

International Nuclear Information System (INIS)

Hennies, H.H.; Hess, V.; Flohe, L.

1984-01-01

Rats were treated for two weeks with haloperidol alone or with additional test drugs and the D 2 receptor density in the striatum was investigated after a drug-free period of five days. The D 2 receptor system as analysed by [ 3 H]-spinerone binding was best characterized by a model with two binding sites of different affinity. Chronic haloperidol treatment substantially augmented the total binding capacity 2-(2-Oxo-3-piperidyl)-1,2-benzisothiazoline-3-one-1,1-dioxide (supidimide), a functional synergist of neuroleptics in acute experiments, surprisingly antagonized the haloperidol-induced receptor augmentation, whereas other CNS depressants (diazepam and phenobarbital) were ineffective. (orig./MG) [de

Antagonism by supidimide of haloperidol-induced augmentation of (/sup 3/H)-spiperone binding in rat striatum

Energy Technology Data Exchange (ETDEWEB)

Hennies, H H; Hess, V; Flohe, L

1984-01-01

Rats were treated for two weeks with haloperidol alone or with additional test drugs and the D/sub 2/ receptor density in the striatum was investigated after a drug-free period of five days. The D/sub 2/ receptor system as analysed by (/sup 3/H)-spinerone binding was best characterized by a model with two binding sites of different affinity. Chronic haloperidol treatment substantially augmented the total binding capacity 2-(2-Oxo-3-piperidyl)-1,2-benzisothiazoline-3-one-1,1-dioxide (supidimide), a functional synergist of neuroleptics in acute experiments, surprisingly antagonized the haloperidol-induced receptor augmentation, whereas other CNS depressants (diazepam and phenobarbital) were ineffective.

Synthesis, radiolabeling and bioevaluation of a novel arylpiperazine derivative containing triazole as a 5-HT1A receptor imaging agents

International Nuclear Information System (INIS)

Hassanzadeh, Leila; Erfani, Mostafa; Najafi, Reza; Shafiei, Mohammad; Amini, Mohsen; Shafiee, Abbass; Ebrahimi, Seyed Esmaeil Sadat

2013-01-01

Introduction: It has been recognized that serotonin plays a main role in various pathological conditions such as anxiety, depression, aggressiveness, schizophrenia, suicidal behavior, panic and autism. 1-(2-Methoxyphenyl) piperazine pharmacophore, a fragment of the true 5-HT 1A antagonist WAY100635, is found in numerous selective 5-HT 1A imaging agents. In this paper, we have reported the synthesis of a novel derivative of 1-(2-methoxyphenyl) piperazine that is labeled with 99m Tc (CO) 3 via click chemistry. Methods: The bidentate alkyne, propargylglycine was reacted with phenyl piperazine triazole derivative in the presence of a catalytic amount of Cu (I) to form tridentate ligand. The ligand was radiolabeled with the precursor [ 99m Tc] [(H 2 O) 3 (CO) 3 ] + and characterized by HPLC. The bioevaluation of radio labeled ligand was carried out in rats. Results: Triazole complex was labeled by 99m Tc-tricarbonyl and its radiochemical yield was more than > 95% which was determined by HPLC. In vivo stability studies in human serum albumin show a 93% ratio of complex after a 24 h period. The calculated partition coefficient (logP) was 0.34 ± 0.02. Receptor binding assays indicated about 70% specific binding of radioligand to 5-HT 1A receptors. Biodistribution studies have shown brain hippocampus uptake of 0.40 ± 0.08 %ID/g at 30 min post injection. Conclusions: Results indicate that this 99m Tc-tricabonyl-arylpiperazine derivative has specific binding to 5-HT 1A receptors and presented suitable characters for its use as a CNS imaging agent

In vivo imaging of GABA{sub A} receptors using sequential whole-volume iodine-123 iomazenil single-photon emission tomography

Energy Technology Data Exchange (ETDEWEB)

Busatto, G.F. [Dept. of Psychological Medicine, Inst. of Psychiatry, London (United Kingdom); Pilowsky, L.S. [Dept. of Psychological Medicine, Inst. of Psychiatry, London (United Kingdom); Costa, D.C. [Inst. of Nuclear Medicine, University Coll. and Middlesex School of Medicine, London (United Kingdom); Ell, P.J. [Inst. of Nuclear Medicine, University Coll. and Middlesex School of Medicine, London (United Kingdom); Lingford-Hughes, A. [Dept. of Psychological Medicine, Inst. of Psychiatry, London (United Kingdom); Kerwin, R.W. [Dept. of Psychological Medicine, Inst. of Psychiatry, London (United Kingdom)

1995-01-01

Using a brain-dedicated triple-headed single-photon emission tomography (SPET) system, a sequential whole-volume imaging protocol has been devised to evaluate the regional distribution of iodine-123 iomazenil binding to GABA{sub A} receptors in the entire brain. The protocol was piloted in eight normal volunteers (seven males and one female; mean age, 24.8{+-}3.9 years). The patterns obtained were largely compatible with the known distribution of GABA{sub A} receptors in the brain as reported in autoradiographic studies, with cerebral cortical regions, particularly the occipital and frontal cortices, displaying the highest {sup 123}I-iomazenil uptake. Measures of time to peak uptake and tracer washout rates presented with the same pattern of regional variation, with later times to peak and slower washout rates in cortical regions compared to other brain areas. Semiquantitative analysis of the data using white matter/ventricle regions as reference demonstrated a plateau of specific {sup 123}I-iomazenil binding in neocortical and cerebellar regions from 60-75 min onwards. These data demonstrate the feasibility of sequential, dynamic whole-volume {sup 123}I-iomazenil SPET imaging. The protocol may be particularly useful in the investigation of neuropsychiatric conditions which are likely to involve more than one focus of GABA abnormalities, such as anxiety disorders and schizophrenia. (orig.)

Serotonin-1A receptor imaging in recurrent depression: replication and literature review

International Nuclear Information System (INIS)

Drevets, Wayne C.; Thase, Michael E.; Moses-Kolko, Eydie L.; Price, Julie; Frank, Ellen; Kupfer, David J.; Mathis, Chester

2007-01-01

Introduction: Serotonin-1A receptor (5-HT 1A R) function appears to be decreased in major depressive disorder (MDD) based on physiological responses to 5-HT 1A R agonists in vivo and to 5-HT 1A R binding in brain tissues postmortem or antemortem. We have previously assessed 5-HT 1A R binding potential (BP) in depression using positron emission tomography (PET) and [carbonyl- 11 C]WAY-100635, and we have demonstrated reduced 5-HT 1A R BP in the mesiotemporal cortex (MTC) and raphe in depressives with primary recurrent familial mood disorders (n=12) versus controls (n=8) [Drevets WC, Frank E, Price JC, Kupfer DJ, Holt D, Greer PJ, Huang Y, Gautier C, Mathis C. PET imaging of serotonin 1A receptor binding in depression. Biol Psychiatry 1999;46(10):1375-87]. These findings were replicated by some, but not other, studies performed in depressed samples that were more generally selected using criteria for MDD. In the current study, we attempted to replicate our previous findings in an independent sample of subjects selected according to the criteria for primary recurrent depression applied in our prior study. Methods: Using PET and [carbonyl- 11 C]WAY-100635, 5-HT 1A R BP was assessed in 16 depressed subjects and 8 healthy controls. Results: Mean 5-HT 1A R BP was reduced by 26% in the MTC (P 1A R binding were similar to those found postmortem in 5-HT 1A R mRNA concentrations in the hippocampus in MDD [Lopez JF, Chalmers DT, Little KY, Watson SJ. Regulation of serotonin 1A, glucocorticoid, and mineralocorticoid receptor in rat and human hippocampus: implications for neurobiology of depression. Biol Psychiatry 1998;43:547-73] and in 5-HT 1A R-binding capacity in the raphe in depressed suicide victims [Arango V, Underwood MD, Boldrini M, Tamir H, Kassir SA, Hsiung S, Chen JJ, Mann JJ. Serotonin 1A receptors, serotonin transporter binding and serotonin transporter mRNA expression in the brainstem of depressed suicide victims. Neuropsychopharmacology 2001;25(6):892-903]. There

A2A-D2 receptor-receptor interaction modulates gliotransmitter release from striatal astrocyte processes.

Science.gov (United States)

Cervetto, Chiara; Venturini, Arianna; Passalacqua, Mario; Guidolin, Diego; Genedani, Susanna; Fuxe, Kjell; Borroto-Esquela, Dasiel O; Cortelli, Pietro; Woods, Amina; Maura, Guido; Marcoli, Manuela; Agnati, Luigi F

2017-01-01

Evidence for striatal A2A-D2 heterodimers has led to a new perspective on molecular mechanisms involved in schizophrenia and Parkinson's disease. Despite the increasing recognition of astrocytes' participation in neuropsychiatric disease vulnerability, involvement of striatal astrocytes in A2A and D2 receptor signal transmission has never been explored. Here, we investigated the presence of D2 and A2A receptors in isolated astrocyte processes prepared from adult rat striatum by confocal imaging; the effects of receptor activation were measured on the 4-aminopyridine-evoked release of glutamate from the processes. Confocal analysis showed that A2A and D2 receptors were co-expressed on the same astrocyte processes. Evidence for A2A-D2 receptor-receptor interactions was obtained by measuring the release of the gliotransmitter glutamate: D2 receptors inhibited the glutamate release, while activation of A2A receptors, per se ineffective, abolished the effect of D2 receptor activation. The synthetic D2 peptide VLRRRRKRVN corresponding to the receptor region involved in electrostatic interaction underlying A2A-D2 heteromerization abolished the ability of the A2A receptor to antagonize the D2 receptor-mediated effect. Together, the findings are consistent with heteromerization of native striatal astrocytic A2A-D2 receptors that via allosteric receptor-receptor interactions could play a role in the control of striatal glutamatergic transmission. These new findings suggest possible new pathogenic mechanisms and/or therapeutic approaches to neuropsychiatric disorders. © 2016 International Society for Neurochemistry.

Preliminary studies of 99mTc-memantine derivatives for NMDA receptor imaging

International Nuclear Information System (INIS)

Zhou Xingqin; Zhang Jiankang; Yan Chenglong; Cao Guoxian; Zhang Rongjun; Cai Gangming; Jiang Mengjun; Wang Songpei

2012-01-01

Introduction: Novel technetium-labeled ligands, 99m Tc-NCAM and 99m Tc-NHAM were developed from the N-methyl-D-aspartate (NMDA) receptor agonist memantine as a lead compound by coupling with N 2 S 2 . This study evaluated the binding affinity and specificity of the ligands for the NMDA receptor. Methods: Ligand biodistribution and uptake specificity in the brain were investigated in mice. Binding affinity and specificity were determined by radioligand receptor binding assay. Three antagonists were used for competitive binding analysis. In addition, uptake of the complexes into SH-SY5Y nerve cells was evaluated. Results: The radiochemical purity of 99m Tc-labeled ligands was more than 95%. Analysis of brain regional uptake showed higher concentration in the frontal lobe and specific uptake in the hippocampus. 99m Tc-NCAM reached a higher target to nontarget ratio than 99m Tc-NHAM. The results indicated that 99m Tc-NCAM bound to a single site on the NMDA receptor with a K d of 701.21 nmol/l and a B max of 62.47 nmol/mg. Specific inhibitors of the NMDA receptor, ketamine and dizocilpine, but not the dopamine D 2 and 5HT 1A receptor partial agonist aripiprazole, inhibited specific binding of 99m Tc-NCAM to the NMDA receptor. Cell physiology experiments showed that NCAM can increase the viability of SH-SY5Y cells after glutamate-induced injury. Conclusions: The new radioligand 99m Tc-NCAM has good affinity for and specific binding to the NMDA receptor, and easily crosses the blood–brain barrier; suggesting that it might be a potentially useful tracer for NMDA receptor expression.

Fundamental study on nuclear medicine imaging of cholinergic innervation in the brain; Changes of neurotransmitter and receptor in animal model of Alzheimer's disease

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Hiroshi; Kinuya, Keiko; Sumiya, Hisashi; Hisada, Kinichi [Kanazawa Univ. (Japan). School of Medicine; Tsuji, Shiro; Terada, Hitoshi; Shiba, Kazuhiro; Mori, Hirofumi

1990-10-01

A fundamental study was performed on the nuclear medicine imaging of cholinergic innervation in the brain. In a cholinergic denervation model prepared by producing an unilateral basal forebrain lesion in the rat, which is reported to be one of animal models of Alzheimer' disease, quantitative determination of acetylcholine in parietal cortices revealed statistically significant 31% decrease on an average in the ipsilateral side relative to the contralateral side to the lesion. In vitro receptor autoradiography showed no significant differences in total, M{sub 1}, and M{sub 2} muscarinic acetylcholine receptors between the ipsilateral and contralateral cortices to the lesion. Simultaneous mapping of presynaptic cholinergic innervation using {sup 3}H-2-(4-phenylpiperidino) cyclohexanol (AH5183) demonstrated significant 14% decrease of AH5183 binding on an average in the ipsilateral relative to the contralateral fronto-parieto-temporal cortices to the lesion. These results suggest that AH5183 is a promising ligand for mapping cholinergic innervation in nuclear medicine imaging. (author).

Preclinical evaluation and quantification of [(18)F]MK-9470 as a radioligand for PET imaging of the type 1 cannabinoid receptor in rat brain

OpenAIRE

Casteels, Cindy; Koole, Michel; Celen, Sofie; Bormans, Guy; Van Laere, Koen

2012-01-01

PURPOSE: [(18)F]MK-9470 is an inverse agonist for the type 1 cannabinoid (CB1) receptor allowing its use in PET imaging. We characterized the kinetics of [(18)F]MK-9470 and evaluated its ability to quantify CB1 receptor availability in the rat brain. METHODS: Dynamic small-animal PET scans with [(18)F]MK-9470 were performed in Wistar rats on a FOCUS-220 system for up to 10 h. Both plasma and perfused brain homogenates were analysed using HPLC to quantify radiometabolites. Displacement and blo...

Synthesis and binding characteristics of N-(1-naphthyl)-N'-(3-[125I]-iodophenyl)-N'-methylguanidine ([125I]-CNS 1261): a potential SPECT agent for imaging NMDA receptor activation

International Nuclear Information System (INIS)

Owens, Jonathan; Tebbutt, Andrew A.; McGregor, Ailsa L.; Kodama, K.; Magar, Sharad S.; Perlman, Michael E.; Robins, David J.; Durant, Graham J.; McCulloch, James

2000-01-01

N-(1-Naphthyl)-N'-(3-[ 125 I]-iodophenyl)-N'-methylguanidine ([ 125 I]-CNS 1261) was synthesized as a potential radioligand to image N-methyl-D-aspartate (NMDA) receptor activation. [ 125 I]-CNS 1261 was prepared by radioiodination of N-(1-naphthyl)-N'-(3-tributylstannylphenyl)-N'-methylguanidine using Na 125 I and peracetic acid. [ 125 I]-CNS 1261 uptake in vivo reflected NMDA receptor distribution in normal rat brain, whereas in ischemic rat brain, uptake was markedly increased in areas of NMDA receptor activation. Radiolabeled CNS 1261 appears to be a good candidate for further development as a single photon emission computed tomography tracer in the investigation of NMDA receptor activation in cerebral ischemia

Preclinical evaluation of a positron emitting progestin ([18F]fluoro-16 alpha-methyl-19-norprogesterone) for imaging progesterone receptor positive tumours with positron emission tomography

NARCIS (Netherlands)

Verhagen, Aalt; Luurtsema, Gert; PESSER, JW; DEGROOT, TJ; OOSTERHUIS, JW; Vaalburg, Willem; Wouda, S.

Three 21-fluoro-progestins were investigated as potential imaging agents for the in vivo assessment of human progesterone receptor positive neoplasms with positron emission tomography. In competitive binding assays these compounds demonstrated high specificity, competing only for progesterone

Experimental study of 99mTc-NGA--a imaging agent of hepatic asialo-glycoprotein receptor

International Nuclear Information System (INIS)

Zhang Rongjun; Jin Jian; Liang Gaolin; Wan Weixing; Li Wenxin; Tao Yonghui; Hu Mingyang

2001-01-01

Galactosyl neo-glycol-albumin (NGA), a specific ligand of asialo-glycoprotein receptor (ASGPR), was synthesized and identified. FITC-HSA and FITC-NGA was prepared by the method of Marshal. NGA was labeled directly with Na 99m TcO 4 . Contrasted with FITC-HSA, FITC-NGA was analyzed with flow cytometry (FCM). The results of FCM analysis showed that the amounts of ASGPR on the surface of normal hepatic cells, chronic injured ones and carcinoma ones was different obviously. Their values of MIF were 228.7, 5.81 and 1.13 respectively. The worse the hepatic cell was injured, the lower the values of MIF decreased. The amounts of ASGPR on the surface of per normal hepatic cell was about 8 x 10 6 . The ASGPRs on 1 x 10 6 hepatic cells can be saturated by 0.4 μg FITC-NGA, and the combination of ASGPR with FITC-NGA can be inhibited by 50 times amounts of NGA. It showed that NGA is a specific ligand of ASGPR. Biodistribution in mice showed that 99m Tc-NGA could be up taken specifically by liver of mice, and had the characteristic of saturation. The radioactivities of other organs were all low, and that of intestinal tract increased with time. The liver imaging of normal and model animals showed that the rates of blood clearance of normal animals were higher than that of liver injured model animal and the imaging could be inhibited by excessive NGA; The simple kinetics analysis indicated that comparing the normal animals and the model animals, the time-radioactivity curves of both hearts and livers were obviously different. The values of receptor index (LHL15) were 0.980 +- 0.010 and 0.949 +- 0.025 (n = 6), respectively

Guideline for PET/CT imaging of neuroendocrine neoplasms with {sup 68}Ga-DOTA-conjugated somatostatin receptor targeting peptides and {sup 18}F-DOPA

Energy Technology Data Exchange (ETDEWEB)

Bozkurt, Murat Fani [Hacettepe University Faculty of Medicine Department of Nuclear Medicine, Ankara (Turkey); Virgolini, Irene; Decristoforo, Clemens [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Balogova, Sona [Comenius University and St. Elisabeth Oncology Institute, Department of Nuclear Medicine, Bratislava (Slovakia); Tenon Hospital AP-HP and Universite Pierre et Marie Curie, Department of Nuclear Medicine, Paris (France); Beheshti, Mohsen [St. Vincent' s Hospital, PET-CT Center, Department of Nuclear Medicine and Endocrinology, Linz (Austria); Paracelsus Medical University, Department of Nuclear Medicine, Salzburg (Austria); Rubello, Domenico [Santa Maria della Misericordia Hospital, Department of Nuclear Medicine, PET Center and Medical Physics and Radiology, Rovigo (Italy); Ambrosini, Valentina; Fanti, Stefano [University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Bologna (Italy); Kjaer, Andreas [National University Hospital and University of Copenhagen, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Delgado-Bolton, Roberto [San Pedro Hospital and Centre for Biomedical Research of La Rioja (CIBIR), Department of Diagnostic Imaging (Radiology) and Nuclear Medicine, Logrono (Spain); Kunikowska, Jolanta [Medical University of Warsaw, Nuclear Medicine, Warsaw (Poland); Oyen, Wim J.G. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London (United Kingdom); Chiti, Arturo [Humanitas University, Nuclear Medicine Department, Rozzano, MI (Italy); Giammarile, Francesco [University of Lyon, Nuclear Medicine, Lyon (France)

2017-08-15

Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using {sup 68}Ga-DOTA-conjugated peptides, as well as {sup 18}F-DOPA imaging for various neuroendocrine neoplasms. The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with {sup 68}Ga-conjugated peptides has been revised and updated with the relevant and recent literature in the field with contribution of distinguished experts. (orig.)

Visualization of Tumor Angiogenesis Using MR Imaging Contrast Agent Gd-DTPA-anti-VEGF Receptor 2 Antibody Conjugate in a Mouse Tumor Model

International Nuclear Information System (INIS)

Jun, Hong Young; Yin, Hong Hua; Kim, Sun Hee; Park, Seong Hoon; Kim, Hun Soo; Yoon Kwon Ha Yoon

2010-01-01

To visualize tumor angiogenesis using the MRI contrast agent, Gd- DTPA-anti-VEGF receptor 2 antibody conjugate, with a 4.7-Tesla MRI instrument in a mouse model. We designed a tumor angiogenesis-targeting T1 contrast agent that was prepared by the bioconjugation of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and an anti-vascular endothelial growth factor receptor-2 (VEGFR2) antibody. The specific binding of the agent complex to cells that express VEGFR2 was examined in cultured murine endothelial cells (MS-1 cells) with a 4.7-Tesla magnetic resonance imaging scanner. Angiogenesis-specific T1 enhancement was imaged with the Gd-DTPA-anti-VEGFR2 antibody conjugate using a CT-26 adenocarcinoma tumor model in eight mice. As a control, the use of the Gd-DTPA-anti-rat immunoglobulin G (Gd-DTPA-anti-rat IgG) was imaged with a tumor model in eight mice. Statistical significance was assessed using the Mann-Whitney test. Tumor tissue was examined by immunohistochemical analysis. The Gd-DTPA-anti-VEGFR2 antibody conjugate showed predominant binding to cultured endothelial cells that expressed a high level of VEGFR2. Signal enhancement was approximately three-fold for in vivo T1-weighted MR imaging with the use of the Gd-DTPA-anti-VEGFR2 antibody conjugate as compared with the Gd-DTPA-rat IgG in the mouse tumor model (p < 0.05). VEGFR2 expression in CT-26 tumor vessels was demonstrated using immunohistochemical staining. MR imaging using the Gd-DTPA-anti-VEGFR2 antibody conjugate as a contrast agent is useful in visualizing noninvasively tumor angiogenesis in a murine tumor model

Visualization of Tumor Angiogenesis Using MR Imaging Contrast Agent Gd-DTPA-anti-VEGF Receptor 2 Antibody Conjugate in a Mouse Tumor Model

Energy Technology Data Exchange (ETDEWEB)

Jun, Hong Young; Yin, Hong Hua; Kim, Sun Hee; Park, Seong Hoon; Kim, Hun Soo; Yoon Kwon Ha Yoon [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

2010-08-15

To visualize tumor angiogenesis using the MRI contrast agent, Gd- DTPA-anti-VEGF receptor 2 antibody conjugate, with a 4.7-Tesla MRI instrument in a mouse model. We designed a tumor angiogenesis-targeting T1 contrast agent that was prepared by the bioconjugation of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and an anti-vascular endothelial growth factor receptor-2 (VEGFR2) antibody. The specific binding of the agent complex to cells that express VEGFR2 was examined in cultured murine endothelial cells (MS-1 cells) with a 4.7-Tesla magnetic resonance imaging scanner. Angiogenesis-specific T1 enhancement was imaged with the Gd-DTPA-anti-VEGFR2 antibody conjugate using a CT-26 adenocarcinoma tumor model in eight mice. As a control, the use of the Gd-DTPA-anti-rat immunoglobulin G (Gd-DTPA-anti-rat IgG) was imaged with a tumor model in eight mice. Statistical significance was assessed using the Mann-Whitney test. Tumor tissue was examined by immunohistochemical analysis. The Gd-DTPA-anti-VEGFR2 antibody conjugate showed predominant binding to cultured endothelial cells that expressed a high level of VEGFR2. Signal enhancement was approximately three-fold for in vivo T1-weighted MR imaging with the use of the Gd-DTPA-anti-VEGFR2 antibody conjugate as compared with the Gd-DTPA-rat IgG in the mouse tumor model (p < 0.05). VEGFR2 expression in CT-26 tumor vessels was demonstrated using immunohistochemical staining. MR imaging using the Gd-DTPA-anti-VEGFR2 antibody conjugate as a contrast agent is useful in visualizing noninvasively tumor angiogenesis in a murine tumor model

SSTR-Mediated Imaging in Breast Cancer: Is There a Role for Radiolabeled Somatostatin Receptor Antagonists?

Science.gov (United States)

Dalm, Simone U; Haeck, Joost; Doeswijk, Gabriela N; de Blois, Erik; de Jong, Marion; van Deurzen, Carolien H M

2017-10-01

Recent studies have shown enhanced tumor targeting by novel somatostatin receptor (SSTR) antagonists compared with clinically widely used agonists. However, these results have been obtained mostly in neuroendocrine tumors, and only limited data are available for cancer types with lower SSTR expression, including breast cancer (BC). To date, two studies have reported higher binding of the antagonist than the agonist in BC, but in both studies only a limited number of cases were evaluated. In this preclinical study, we further investigated whether the application of an SSTR antagonist can improve SSTR-mediated BC imaging in a large panel of BC specimens. We also generated an in vivo BC mouse model and performed SPECT/MRI and biodistribution studies. Methods: Binding of 111 In-DOTA-Tyr 3 -octreotate (SSTR agonist) and 111 In-DOTA-JR11 (SSTR antagonist) to 40 human BC specimens was compared using in vitro autoradiography. SSTR2 immunostaining was performed to confirm SSTR2 expression of the tumor cells. Furthermore, binding of the radiolabeled SSTR agonist and antagonist was analyzed in tissue material from 6 patient-derived xenografts. One patient-derived xenograft, the estrogen receptor-positive model T126, was chosen to generate in vivo mouse models containing orthotopic breast tumors for in vivo SPECT/MRI and biodistribution studies after injection with 177 Lu-DOTA-Tyr 3 -octreotate or 177 Lu-DOTA-JR11. Results: 111 In-DOTA-JR11 binding to human BC tissue was significantly higher than 111 In-DOTA-Tyr 3 -octreotate binding ( P < 0.001). The median ratio of antagonist binding versus agonist binding was 3.39 (interquartile range, 2-5). SSTR2 immunostaining confirmed SSTR2 expression on the tumor cells. SPECT/MRI of the mouse model found better tumor visualization with the antagonist. This result was in line with the significantly higher tumor uptake of the radiolabeled antagonist than of the agonist as measured in biodistribution studies 285 min after radiotracer

Progress on the application of ligand receptor binding assays in radiopharmaceuticals

International Nuclear Information System (INIS)

Zhou Xue; Qian Jinping; Kong Aiying; Zhu Lin

2010-01-01

Receptor binding assay is an important drug screening method, which can quickly and inexpensively study the interactions between the targeted receptor and the potential ligands in vitro and provide the information of the relative binding affinity of ligand-receptor. The imaging of many radiopharmaceuticals is based on highly selective radioligand-receptor binding. The technique plays an important role in the design and screening of receptor-targeting radiopharmaceuticals. (authors)

The Z-isomer of 11 beta-methoxy-17 alpha-[123I]iodovinylestradiol is a promising radioligand for estrogen receptor imaging in human breast cancer

NARCIS (Netherlands)

Rijks, L. J.; Boer, G. J.; Endert, E.; de Bruin, K.; Janssen, A. G.; van Royen, E. A.

1997-01-01

The potential of both stereoisomers of 11 beta-methoxy-17 alpha-[123I] iodovinylestradiol (E- and Z-[123I]MIVE) as suitable radioligands for imaging of estrogen receptor (ER)-positive human breast tumours was studied. The 17 alpha-[123I]iodovinylestradiol derivatives were prepared stereospecifically

N-(N-benzylpiperidin-4-yl)-2-[{sup 18}F]fluorobenzamide: A potential ligand for PET imaging of {sigma} receptors

Energy Technology Data Exchange (ETDEWEB)

Chyngyann, Shiue; Shiue, Grace G; Zhang, Sue X; Wilder, Susan; Greenberg, Joel H; Benard, Francois; Wortman, Jeffrey A; Alavi, Abass A

1997-10-01

Four nitro- and fluorobenzamides (1-4) have been synthesized in good yields from nitro- and fluoro-substituted benzoyl chloride with 4-amino-1-benzylpiperidine. In vitro studies showed that these compounds have high affinities to {sigma} receptors. N-(N-Benzylpiperidin-4-yl)-2-fluorobenzamide (3), in particular, bound to {sigma} receptors with high affinity (K{sub i} = 3.4 nM, guinea pig brain membranes) and high selectivity ({sigma}-2/{sigma}-1 = 120). It was, therefore, labeled with {sup 18}F and evaluated as a {sigma} receptor radioligand. N-(N-Benzylpiperidin-4-yl)-2-[{sup 18}F]fluorobenzamide (3a) was synthesized in one step by nucleophilic substitution of the 2-nitro precursor (1) with [{sup 18}F]fluoride in DMSO at 140 deg. C for 20 min followed by purification with HPLC in 4-10% yield (decay corrected). The synthesis time was 90 min and the specific activity was 0.4-1.0 Ci/{mu}mol. Tissue distribution in mice revealed that the uptakes of 3a in the brain, heart, liver, lungs, spleen, kidneys and small intestine were high, and the radioactivity in these organs remained constant from 60 to 120 min post-injection. The radioactivity in the bone did not significantly increase, suggesting in vivo defluorination may not be the major route of metabolism of 3a in mice. Blocking studies with haloperidol in rats indicated that the uptake of compound 3a in the rat brain was selective to haloperidol-sensitive {sigma} sites. These results suggest that compound 3a is a potent {sigma} receptor radioligand and may be a potential ligand for PET imaging of {sigma} receptors in humans.

Facial morphometry of Ecuadorian patients with growth hormone receptor deficiency/Laron syndrome.

Science.gov (United States)

Schaefer, G B; Rosenbloom, A L; Guevara-Aguirre, J; Campbell, E A; Ullrich, F; Patil, K; Frias, J L

1994-01-01

Facial morphometry using computerised image analysis was performed on patients with growth hormone receptor deficiency (Laron syndrome) from an inbred population of southern Ecuador. Morphometrics were compared for 49 patients, 70 unaffected relatives, and 14 unrelated persons. Patients with growth hormone receptor deficiency showed significant decreases in measures of vertical facial growth as compared to unaffected relatives and unrelated persons with short stature from other causes. This report validates and quantifies the clinical impression of foreshortened facies in growth hormone receptor deficiency. Images PMID:7815422

Vitamin B6 versus mianserin and placebo in acute neuroleptic-induced akathisia: a randomized, double-blind, controlled study.

Science.gov (United States)

Miodownik, Chanoch; Lerner, Vladimir; Statsenko, Nikolay; Dwolatzky, Tzvi; Nemets, Boris; Berzak, Elina; Bergman, Joseph

2006-01-01

Treatment strategies against acute neuroleptic-induced akathisia (NIA) include anticholinergic (antimuscarinic) agents, dopamine agonists, GABAergic agents, beta-blockers, benzodiazepines, and serotonin antagonists. However, many patients who have acute akathisia fail to respond. In previous studies, mianserin and vitamin B6 were found to be effective in the treatment of acute akathisia. The purpose of this study was to compare the efficacy of B(6), mianserin and placebo in the treatment of acute NIA. Sixty schizophrenia and schizoaffective inpatients who have NIA were randomly divided to receive vitamin B(6) 1,200 mg/d, mianserin 15 mg/d, or placebo for 5 days, in a double-blind design. The Barnes Akathisia Rating Scale, Brief Psychiatric Rating Scale, and Clinical Global Impression were used to assess the severity of NIA and psychotic symptoms. The assessment was made at baseline and daily for the duration of the study. Compared with the placebo group, the vitamin B(6)-treated and mianserin-treated patients showed a significant improvement in the subjective (P vitamin B(6) group (13/23, 56%) as well as in the mianserin groups (13/20, 65%), and in only one patient in the placebo group (1/17, 6%; P vitamin B(6) and mianserin suggests that the pathophysiology of acute NIA is heterogeneous with the various subtypes of acute NIA responding differently to the various pharmacological approaches.

A retrospective analysis of cases with neuroleptic malignant syndrome and an evaluation of risk factors for mortality.

Science.gov (United States)

Sahin, Aynur; Cicek, Mustafa; Gonenc Cekic, Ozgen; Gunaydin, Mucahit; Aykut, Demet Saglam; Tatli, Ozgur; Karaca, Yunus; Arici, Mualla Aylin

2017-12-01

Neuroleptic malignant syndrome (NMS) is a neurological emergency rarely encountered in clinical practice but with a high mortality rate. Cases associated with atypical antipsychotic use or termination of dopamine agonists have been seen in recent years. The purpose of this study was to assess the presence of risk factors for mortality by investigating all clinical and laboratory characteristics of cases with NMS. This descriptive, cross-sectional study retrospectively investigated all clinical and laboratory characteristics by scanning the ICD-10 codes of patients presenting to the XXXX Faculty of Medicine Emergency Department and diagnosed with NMS between 2006 and 2016. Patients were divided into surviving and non-surviving groups, and the data elicited were subjected to statistical comparisons. The mean age of the 18 patients diagnosed with NMS was 46.9 ± 4.8 years, and 50% were women. In addition to antipsychotics among the drugs leading to NMS, the syndrome also developed as a result of levodopa withdrawal in three patients and metoclopramide use in one patient. Statistically significant differences were determined between the surviving and non-surviving patients in terms of blood pressure, blood urea nitrogen (BUN), creatine kinase (CK) and mean platelet volume (MPV) values (p ≤ 0.05). In this study the most common agent that cause NMS was atypical antipsychotics. Also advanced age, increased blood pressure and serum CK, BUN and MPV values were identified as potential risk factors for mortality in NMS.

Serotonin-1A receptor gene polymorphism and the ability of antipsychotic drugs to improve attention in schizophrenia.

Science.gov (United States)

Sumiyoshi, Tomiki; Tsunoda, Masahiko; Higuchi, Yuko; Itoh, Toru; Seo, Tomonori; Itoh, Hiroko; Suzuki, Michio; Kurachi, Masayoshi

2010-05-01

The purpose of this study was to determine if the functional single nucleotide polymorphisms of rs6259 C(-1019)G in the promoter region, which regulates serotonin 5-HT(1A) receptor transcription, affects the ability of antipsychotic drugs to improve attention in patients with schizophrenia. Subjects were neuroleptic-free and meeting DSM-IV-TR criteria for schizophrenia. Psychopathology and attention were evaluated with the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS) at baseline and 3 months after treatment with atypical antipsychotic drugs (AAPDs). DNA was extracted from peripheral blood following standard procedures. Genotyping was performed with HS-Taq assay (LaboPass). Data were available from 30 subjects (male/female=19/11), in which 17 had the CC genotype, three had the GG genotype, and 10 were heterozygous. The 3-month treatment with AAPDs was associated with significant improvements in positive and negative symptoms, but not attention as measured by SANS-Attention subscale in the entire subject group. There were no significant differences in the degree of improvements of SAPS and SANS scores between the CC genotype group and the (C/G plus G/G) combined group. On the other hand, improvement of attention was significantly greater for the former group compared to the latter group (P<0.016), suggesting a detrimental influence of the G-allele. These results provide additional support to the role of 5-HT(1A) receptors in some of the cognitive disturbances of schizophrenia. Further studies with a larger number of subjects are warranted.

Positron Emission Tomography (PET) Imaging of Opioid Receptors

NARCIS (Netherlands)

van Waarde, Aren; Absalom, Anthony; Visser, Anniek; Dierckx, Rudi; Dierckx, Rudi AJO; Otte, Andreas; De Vries, Erik FJ; Van Waarde, Aren; Luiten, Paul GM

2014-01-01

The opioid system consists of opioid receptors (which mediate the actions of opium), their endogenous ligands (the enkephalins, endorphins, endomorphins, dynorphin, and nociceptin), and the proteins involved in opioid production, transport, and degradation. PET tracers for the various opioid

Preparation and evaluation of 99mTc-EDDA/HYNIC-[Lys 3]-bombesin for imaging gastrin-releasing peptide receptor-positive tumours.

Science.gov (United States)

Ferro-Flores, Guillermina; Arteaga de Murphy, Consuelo; Rodriguez-Cortés, Jeanette; Pedraza-López, Martha; Ramírez-Iglesias, María Teresa

2006-04-01

Bombesin is a peptide that was initially isolated from frog skin and which belongs to a large group of neuropeptides with many biological functions. The human equivalent is gastrin-releasing peptide (GRP), whose receptors are over-expressed in a variety of malignant tumours. To prepare a HYNIC-[Lys 3]-bombesin analogue that could be easily labelled with 99mTc from lyophilized kit formulations and to evaluate its potential as an imaging agent for GRP receptor-positive tumours. HYNIC was conjugated to the epsilon-amino group of Lys 3 residue at the N-terminal region of bombesin via succinimidyl-N-Boc-HYNIC at pH 9.0. 99mTc labelling was performed by addition of sodium pertechnetate solution and 0.2 M phosphate buffer pH 7.0 to a lyophilized formulation. Stability studies were carried out by reversed phase HPLC and ITLC-SG analyses in serum and cysteine solutions. In-vitro internalization was tested using human prostate cancer PC-3 cells with blocked and non-blocked receptors. Biodistribution and tumour uptake were determined in PC-3 tumour-bearing nude mice. 99mTc-EDDA/HYNIC-[Lys 3]-bombesin was obtained with radiochemical purities >93% and high specific activity ( approximately 0.1 GBq.nmol). Results of in-vitro studies demonstrated a high stability in serum and cysteine solutions, specific cell receptor binding and rapid internalization. Biodistribution data showed a rapid blood clearance, with predominantly renal excretion and specific binding towards GRP receptor-positive tissues such as pancreas and PC-3 tumours. 99mTc-EDDA/HYNIC-[Lys 3]-bombesin obtained from lyophilized kit formulations has promising characteristics for the diagnosis of malignant tumours that over-express the GRP receptor.

Dual integrin and gastrin-releasing peptide receptor targeted tumor imaging using 18F-labeled PEGylated RGD-bombesin heterodimer 18F-FB-PEG3-Glu-RGD-BBN.

Science.gov (United States)

Liu, Zhaofei; Yan, Yongjun; Chin, Frederic T; Wang, Fan; Chen, Xiaoyuan

2009-01-22

Radiolabeled RGD and bombesin peptides have been extensively investigated for tumor integrin alpha(v)beta(3) and GRPR imaging, respectively. Due to the fact that many tumors are both integrin and GRPR positive, we designed and synthesized a heterodimeric peptide Glu-RGD-BBN, which is expected to be advantageous over the monomeric peptides for dual-receptor targeting. A PEG(3) spacer was attached to the glutamate alpha-amino group of Glu-RGD-BBN to enhance the (18)F labeling yield and to improve the in vivo kinetics. PEG(3)-Glu-RGD-BBN possesses the comparable GRPR and integrin alpha(v)beta(3) receptor-binding affinities as the corresponding monomers, respectively. The dual-receptor targeting properties of (18)F-FB-PEG(3)-Glu-RGD-BBN were observed in PC-3 tumor model. (18)F-FB-PEG(3)-Glu-RGD-BBN with high tumor contrast and favorable pharmacokinetics is a promising PET tracer for dual integrin and GRPR positive tumor imaging. This heterodimer strategy may also be an applicable method to develop other molecules with improved in vitro and in vivo characterizations for tumor diagnosis and therapy.

Evaluation of (64)Cu-labeled DOTA-D-Phe(1)-Tyr (3)-octreotide ((64)Cu-DOTA-TOC) for imaging somatostatin receptor-expressing tumors.

Science.gov (United States)

Hanaoka, Hirofumi; Tominaga, Hideyuki; Yamada, Keiich; Paudyal, Pramila; Iida, Yasuhiko; Watanabe, Shigeki; Paudyal, Bishnuhari; Higuchi, Tetsuya; Oriuchi, Noboru; Endo, Keigo

2009-08-01

In-111 ((111)In)-labeled octreotide has been clinically used for imaging somatostatin receptor-positive tumors, and radiolabeled octreotide analogs for positron emission tomography (PET) have been developed. Cu-64 ((64)Cu; half-life, 12.7 h) is an attractive radionuclide for PET imaging and is produced with high specific activity using a small biomedical cyclotron. The aim of this study is to produce and fundamentally examine a (64)Cu-labeled octreotide analog, (64)Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-D: -Phe(1)-Tyr(3)-octreotide ((64)Cu-DOTA-TOC). (64)Cu produced using a biomedical cyclotron was reacted with DOTA-TOC for 30 min at 45 degrees C. The stability of (64)Cu-DOTA-TOC was evaluated in vitro (incubated with serum) and in vivo (blood collected after administration) by HPLC analysis. Biodistribution studies were performed in normal mice by administration of mixed solution of (64)Cu-DOTA-TOC and (111)In-DOTA-TOC and somatostatin receptor-positive U87MG tumor-bearing mice by administration of (64)Cu-DOTA-TOC or (64)Cu-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid-octreotide ((64)Cu-TETA-OC). The tumor was imaged using (64)Cu-DOTA-TOC, (64)Cu-TETA-OC, and FDG with an animal PET scanner. (64)Cu-DOTA-TOC can be produced in amounts sufficient for clinical study with high radiochemical yield. (64)Cu-DOTA-TOC was stable in vitro, but time-dependent transchelation to protein was observed after injection into mice. In biodistribution studies, the radioactivity of (64)Cu was higher than that of (111)In in all organs except kidney. In tumor-bearing mice, (64)Cu-DOTA-TOC showed a high accumulation in the tumor, and the tumor-to-blood ratio reached as high as 8.81 +/- 1.17 at 6 h after administration. (64)Cu-DOTA-TOC showed significantly higher accumulation in the tumor than (64)Cu-TETA-OC. (64)Cu-DOTA-TOC PET showed a very clear image of the tumor, which was comparable to that of (18)F-FDG PET and very similar to that of (64)Cu

Evaluation of 64Cu-labeled DOTA-D-Phe1-Tyr3-octreotide (64Cu-DOTA-TOC) for imaging somatostatin receptor-expressing tumors

International Nuclear Information System (INIS)

Hanaoka, Hirofumi; Tominaga, Hideyuki; Yamada, Keiich

2009-01-01

In-111 ( 111 In)-labeled octreotide has been clinically used for imaging somatostatin receptor-positive tumors, and radiolabeled octreotide analogs for positron emission tomography (PET) have been developed. Cu-64 ( 64 Cu; half-life, 12.7 h) is an attractive radionuclide for PET imaging and is produced with high specific activity using a small biomedical cyclotron. The aim of this study is to produce and fundamentally examine a 64 Cu-labeled octreotide analog, 64 Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-D-Phe 1 -Tyr 3 -octreotide ( 64 Cu-DOTA-TOC). 64 Cu produced using a biomedical cyclotron was reacted with DOTA-TOC for 30 min at 45 deg C. The stability of 64 Cu-DOTA-TOC was evaluated in vitro (incubated with serum) and in vivo (blood collected after administration) by high performance liquid chromatography (HPLC) analysis. Biodistribution studies were performed in normal mice by administration of mixed solution of 64 Cu-DOTA-TOC and 111 In-DOTA-TOC and somatostatin receptor-positive U87MG tumor-bearing mice by administration of 64 Cu-DOTA-TOC or 64 Cu-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid-octreotide ( 64 Cu-TETA-OC). The tumor was imaged using 64 Cu-DOTA-TOC, 64 Cu-TETA-OC, and fluorodeoxyglucose (FDG) with an animal PET scanner. 64 Cu-DOTA-TOC can be produced in amounts sufficient for clinical study with high radiochemical yield. 64 Cu-DOTA-TOC was stable in vitro, but time-dependent transchelation to protein was observed after injection into mice. In biodistribution studies, the radioactivity of 64 Cu was higher than that of 111 In in all organs except kidney. In tumor-bearing mice, 64 Cu-DOTA-TOC showed a high accumulation in the tumor, and the tumor-to-blood ratio reached as high as 8.81±1.17 at 6 h after administration. 64 Cu-DOTA-TOC showed significantly higher accumulation in the tumor than 64 Cu-TETA-OC. 64 Cu-DOTA-TOC PET showed a very clear image of the tumor, which was comparable to that of 18 F-FDG PET and

Regional blockade by neuroleptic drugs of in vivo /sup 3/H-spiperone binding in the rat brain. Relation to blockade of apomorphine induced hyperactivity and stereotypies

Energy Technology Data Exchange (ETDEWEB)

Koehler, C; Haglund, L; Oegren, S O; Aengeby, T [Astra Lackemedel AB, Soedertaelje (Sweden). Dept. of Pharmacology

1981-01-01

The regional prevention by neuroleptic drugs of specific in vivo /sup 3/H-spiperone binding was studied in the rat brain. L-sulpiride, thioridazine and clozapine were found to reduce the /sup 3/H-spiperone bindings selectively in the olfactory tubercle, septum, substantia nigra and frontal cortex but not the striatum at dose levels which preferentially block apomorphine (APO) induced hyperactivity. The maximal prevention of specific /sup 3/H-spiperone binding by l-sulpiride and clozapine reached 60-80% in the former structures while the displacement of striatal /sup 3/H-spiperone binding did not exceed 40%. In contrast to l-sulpiride, thioridazine and clozapine both chlorpromazine and haloperidol reduced the /sup 3/H-spiperone binding to the same extent in all regions studied. Chlorpromazine and haloperidol were potent in prevention of striatal /sup 3/H-spiperone binding in vivo which reached 60-80% in this structure.

A magnetic resonance imaging study in first-episode disorganized-type patients with schizophrenia

International Nuclear Information System (INIS)

Ohnuma, Tohru; Kimura, Michihiro; Takahashi, Tadashi; Iwamoto, Norihiko; Arai, Heii

1997-01-01

Although a number of radiological studies have suggested that brains of patients suffering from schizophrenia have morphological abnormalities, the results are inconsistent. In the present study, in order to examine the brain, morphological features of homogeneous schizophrenics' brain magnetic resonance imagings (MRI) were taken, before neuroleptic treatment, from subjects suffering from disorganized-type schizophrenia, (DOS) during their first episodes. Results showed that DOS had significantly smaller indices for bilateral frontal gray matter (GM), left hippocampal formation (HF), left parahippocampal gray matter (PHGM) and left cingulate gyrus gray matter (CGM) than normal controls. These findings support the previous computed tomography (CT) and MRI studies on schizophrenic brains, although the subjects were not defined as disorganized-type, and may suggest the involvement of a neurocircuit between the bilateral frontal lobe and the left side of limbic system in the first-episode DOS group. (author). 54 refs

Boronic acids for fluorescence imaging of carbohydrates.

Science.gov (United States)

Sun, Xiaolong; Zhai, Wenlei; Fossey, John S; James, Tony D

2016-02-28

"Fluorescence imaging" is a particularly exciting and rapidly developing area of research; the annual number of publications in the area has increased ten-fold over the last decade. The rapid increase of interest in fluorescence imaging will necessitate the development of an increasing number of molecular receptors and binding agents in order to meet the demand in this rapidly expanding area. Carbohydrate biomarkers are particularly important targets for fluorescence imaging given their pivotal role in numerous important biological events, including the development and progression of many diseases. Therefore, the development of new fluorescent receptors and binding agents for carbohydrates is and will be increasing in demand. This review highlights the development of fluorescence imaging agents based on boronic acids a particularly promising class of receptors given their strong and selective binding with carbohydrates in aqueous media.

Imaging opiate receptors by positron tomography (PET): Evaluation by displacement of 3-Acetyl-6-Deoxy-6-Beta-/sup 18/F-flouronaltrexone with active and inactive naloxone

International Nuclear Information System (INIS)

Larson, S.M.; Channing, M.A.; Rice, K.R.; Pert, C.B.; Eckelman, W.C.; Burke, T.R.; Bennett, J.M.; Carson, R.E.; Di Chiro, G.

1985-01-01

We recently reported the development of a new radiopharmaceutical for in vivo PET imaging of opiate receptors, 3-acetyl-6-deoxy-6-Beta-/sup 18/F-fluoronaltrexone: 3-acetylcyclofoxy, or /sup 18/F-ACF. These studies involved displacement of /sup 18/F-ACF from sites of uptake in the baboon sub-cortical gray matter, and provided strong proof of the opiate receptor specificity of the tracer. We now report on the anatomic localization of /sup 18/F-ACF in the sub-cortical grapy matter of baboon, and the kinetics of uptake and displacement of the tracer. /sup 18/F-ACF was prepared from the known 3-acetyl-6-alpha-naltrexol via the triflate, using /sup 18/F produced by neutron bombardment of /sup 6/Li/sub 2/CO/sub 3/. Anesthetized baboons were imaged after injection of /sup 18/F-ACF (sp.ac.=20Ci/mmol), using the NIH NEUROPET, a high resolution PET scanner. After bolus injection, the initial distribution to brain was rapid with peak uptake at 6 minutes post-injection. Clearance from opiate receptor rich regions of thalamus and basal ganglia was gradual, but after injection of active (but not after inactive), naloxone, clearance from these regions more than doubled. In non-opiate rich regions, (e.g. cerebellum), the predominant component of clearance was equally rapid with or without the active naloxone. Displacement studies of positron labelled ligands provide a powerful tool for non-invasive study of opiate receptor in living primates

Piracetam reverses haloperidol-induced catalepsy in mice

OpenAIRE

SALAM, Omar Abdel; NADA, Somaia

2014-01-01

To investigate the memory-enhancing drugs piracetam, vinpocetine, and ginkgo biloba for their ability to reduce catalepsy in mice treated with haloperidol. Haloperidol is a classic neuroleptic drug that induces motor abnormalities and cognitive impairment due to a blockade of dopamine D2 receptors in the striatum. Materials and methods: Catalepsy was induced by intraperitoneal haloperidol (2 mg/kg) administration. The drugs being tested were either administered intraperitoneally (IP) along ...

Molecular Imaging and Precision Medicine in Breast Cancer.

Science.gov (United States)

Chudgar, Amy V; Mankoff, David A

2017-01-01

Precision medicine, basing treatment approaches on patient traits and specific molecular features of disease processes, has an important role in the management of patients with breast cancer as targeted therapies continue to improve. PET imaging offers noninvasive information that is complementary to traditional tissue biomarkers, including information about tumor burden, tumor metabolism, receptor status, and proliferation. Several PET agents that image breast cancer receptors can visually demonstrate the extent and heterogeneity of receptor-positive disease and help predict which tumors are likely to respond to targeted treatments. This review presents applications of PET imaging in the targeted treatment of breast cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Radiosynthesis and evaluation of 11C-CIMBI-5 as a 5-HT2A receptor agonist radioligand for PET

DEFF Research Database (Denmark)

Ettrup, Anders; Palner, Mikael; Gillings, Nic

2010-01-01

PET brain imaging of the serotonin 2A (5-hydroxytryptamine 2A, or 5-HT(2A)) receptor has been widely used in clinical studies, and currently, several well-validated radiolabeled antagonist tracers are used for in vivo imaging of the cerebral 5-HT(2A) receptor. Access to 5-HT(2A) receptor agonist...... PET tracers would, however, enable imaging of the active, high-affinity state of receptors, which may provide a more meaningful assessment of membrane-bound receptors. In this study, we radiolabel the high-affinity 5-HT(2A) receptor agonist 2-(4-iodo-2,5-dimethoxyphenyl)-N-(2-[(11)C-OCH(3......)]methoxybenzyl)ethanamine ((11)C-CIMBI-5) and investigate its potential as a PET tracer....

Correlation of breast cancer subtypes, based on estrogen receptor, progesterone receptor, and HER2, with functional imaging parameters from {sup 68}Ga-RGD PET/CT and {sup 18}F-FDG PET/CT

Energy Technology Data Exchange (ETDEWEB)

Yoon, Hai-Jeon [Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, The Institute of Radiation Medicine, Seoul (Korea, Republic of); Ewha Womans University School of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Kang, Keon Wook; Jeong, Jae Min; Chung, June-Key [Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Biomedical Sciences, Seoul (Korea, Republic of); Seoul National University College of Medicine, The Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Chun, In Kook [Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Kangwon National University Hospital, Department of Nuclear Medicine, Chuncheon, Kangwon-Do (Korea, Republic of); Cho, Nariya [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of); Im, Seock-Ah [Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Jeong, Sunjoo [Dankook University, Department of Molecular Biology, Yongin (Korea, Republic of); Lee, Song [Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, The Institute of Radiation Medicine, Seoul (Korea, Republic of); Jung, Kyeong Cheon [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Lee, Yun-Sang [Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Lee, Dong Soo [Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, The Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University, Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul (Korea, Republic of); Moon, Woo Kyung [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Biomedical Sciences, Seoul (Korea, Republic of); Seoul National University College of Medicine, The Institute of Radiation Medicine, Seoul (Korea, Republic of)

2014-08-15

Imaging biomarkers from functional imaging modalities were assessed as potential surrogate markers of disease status. Specifically, in this prospective study, we investigated the relationships between functional imaging parameters and histological prognostic factors and breast cancer subtypes. In total, 43 patients with large or locally advanced invasive ductal carcinoma (IDC) were analyzed (47.6 ± 7.5 years old). {sup 68}Ga-Labeled arginine-glycine-aspartic acid (RGD) and {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) were performed. The maximum and average standardized uptake values (SUV{sub max} and SUV{sub avg}) from RGD PET/CT and SUV{sub max} and SUV{sub avg} from FDG PET/CT were the imaging parameters used. For histological prognostic factors, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression was identified using immunohistochemistry (IHC) or fluorescent in situ hybridization (FISH). Four breast cancer subtypes, based on ER/PR and HER2 expression (ER/PR+,Her2-, ER/PR+,Her2+, ER/PR-,Her2+, and ER/PR-,Her2-), were considered. Quantitative FDG PET parameters were significantly higher in the ER-negative group (15.88 ± 8.73 vs 10.48 ± 6.01, p = 0.02 for SUV{sub max}; 9.40 ± 5.19 vs 5.92 ± 4.09, p = 0.02 for SUV{sub avg}) and the PR-negative group (8.37 ± 4.94 vs 4.79 ± 3.93, p = 0.03 for SUV{sub avg}). Quantitative RGD PET parameters were significantly higher in the HER2-positive group (2.42 ± 0.59 vs 2.90 ± 0.75, p = 0.04 for SUV{sub max}; 1.60 ± 0.38 vs 1.95 ± 0.53, p = 0.04 for SUV{sub avg}) and showed a significant positive correlation with the HER2/CEP17 ratio (r = 0.38, p = 0.03 for SUV{sub max} and r = 0.46, p < 0.01 for SUV{sub avg}). FDG PET parameters showed significantly higher values in the ER/PR-,Her2- subgroup versus the ER/PR+,Her2- or ER/PR+,Her2+ subgroups, while RGD PET parameters showed significantly lower values in the ER

Effect of the dopamine D1-like receptor antagonist SCH 23390 on the microstructure of ingestive behaviour in water-deprived rats licking for water and NaCl solutions.

Science.gov (United States)

Galistu, Adriana; D'Aquila, Paolo S

2012-01-18

The analysis of licking microstructure provides measures, size and number of licking bouts, which might reveal, respectively, reward evaluation and behavioural activation. Based on the different effects of the dopamine D1-like and D2-like receptor antagonists SCH 23390 and raclopride on licking for sucrose, in particular the failure of the former to reduce bout size and the ability of the latter to induce a within-session decrement of bout number resembling either reward devaluation or neuroleptics on instrumental responding, we suggested that activation of reward-associated responses depends on dopamine D1-like receptor stimulation, and its level is updated on the basis of a dopamine D2-like receptor-mediated reward evaluation. Consistent results were obtained in a study examining the effect of dopamine D2-like receptor antagonism in rats licking for NaCl solutions and water. In this study, we examined the effects of the dopamine D1-like receptor antagonist SCH 23390 (0, 10, 20 and 40 μg/kg) on the microstructure of licking for water and sodium chloride solutions (0.075 M, 0.15 M, 0.3 M) in 12 h water deprived rats. Rats were exposed to each solution for 60 s either after the first lick or after 3 min that the animals were placed in the chambers. Bout size, but not bout number, was decreased at the highest NaCl concentration. SCH 23390 produced a decrease of bout number and of lick number mainly due to the decreased number of subjects engaging in licking behaviour, and failed to reduce bout size for Na Cl and water at a dose which increased the latency to the 1st lick but did not affect the intra-bout lick rate. In agreement with previous observations, these results suggest that dopamine D1-like receptors play an important role in the activation of reward-oriented responses. Copyright © 2011 Elsevier Inc. All rights reserved.

Synthesis, radiolabeling and bioevaluation of a novel arylpiperazine derivative containing triazole as a 5-HT{sub 1A} receptor imaging agents

Energy Technology Data Exchange (ETDEWEB)

Hassanzadeh, Leila [Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Erfani, Mostafa; Najafi, Reza; Shafiei, Mohammad [Nuclear Science Research School, Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran (AEOI), end of Karegar Ave., Tehran (Iran, Islamic Republic of); Amini, Mohsen; Shafiee, Abbass [Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ebrahimi, Seyed Esmaeil Sadat, E-mail: sesebrahimi@yahoo.com [Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2013-02-15

Introduction: It has been recognized that serotonin plays a main role in various pathological conditions such as anxiety, depression, aggressiveness, schizophrenia, suicidal behavior, panic and autism. 1-(2-Methoxyphenyl) piperazine pharmacophore, a fragment of the true 5-HT{sub 1A} antagonist WAY100635, is found in numerous selective 5-HT{sub 1A} imaging agents. In this paper, we have reported the synthesis of a novel derivative of 1-(2-methoxyphenyl) piperazine that is labeled with {sup 99m}Tc (CO){sub 3} via click chemistry. Methods: The bidentate alkyne, propargylglycine was reacted with phenyl piperazine triazole derivative in the presence of a catalytic amount of Cu (I) to form tridentate ligand. The ligand was radiolabeled with the precursor [{sup 99m}Tc] [(H{sub 2}O){sub 3} (CO){sub 3}]{sup +} and characterized by HPLC. The bioevaluation of radio labeled ligand was carried out in rats. Results: Triazole complex was labeled by {sup 99m}Tc-tricarbonyl and its radiochemical yield was more than > 95% which was determined by HPLC. In vivo stability studies in human serum albumin show a 93% ratio of complex after a 24 h period. The calculated partition coefficient (logP) was 0.34 ± 0.02. Receptor binding assays indicated about 70% specific binding of radioligand to 5-HT{sub 1A} receptors. Biodistribution studies have shown brain hippocampus uptake of 0.40 ± 0.08 %ID/g at 30 min post injection. Conclusions: Results indicate that this {sup 99m}Tc-tricabonyl-arylpiperazine derivative has specific binding to 5-HT{sub 1A} receptors and presented suitable characters for its use as a CNS imaging agent.

Downstream reporter gene imaging for signal transduction pathway of dopamine type 2 receptor

International Nuclear Information System (INIS)

Le, Uyenchi N.; Min, Jung Joon; Moon, Sung Min; Bom, Hee Seung

2004-01-01

The Dopamine 2 receptor (D2R) signal pathway regulates gene expression by phosphorylation of proteins including cAMP reponse element-binding protein (CREB), a transcription factor. In this study, we developed a reporter strategy using the GAL4 fusion CREB to assess the phosphorylation of CREB, one of the targets of the D2R signal transduction pathway. We used three plasmids: GAL4 fusion transactivator (pCMV-CREB), firefly luciferase reporter with GAL4 binding sites (pG5-FLUC), and D2R plasmid (pCMV-D2R). Group 1 293T cells were transiently transfected with pCMV-CREB and pG5-FLUC, and group 2 cells were transfected with all three plasmids. Transfected cells were stimulated with different concentrations of dopamine (0-200 M). For animal studies, group 1 and 2 cells (1x10 6 ) were subcutaneously injected on the left and right thigh of six nude mice, respectively. Dopamine stimiulation was performed with intraperitoneal injection of L-DOPA incombination with carbidopa, a peripheral DOPA decarboxylase inhibitor. Bioluminescence optical imaging studies were performed before and after L-DOPA injection. In cell culture studies, group 1 cells showed strong luciferase activity which implies direct activation of the signaling pathway due to growth factors contained in culture medium. Group 2 cells showed strong luciferase activity and a further increase after administration of dopamine. In animal studies, group 1 and 2 cells showed bioluminescence signal before L-DOPA injection, but signal from group 2 cells significantly increased 12 h after L-DOPA injection. The signal from group 1 cells disappeared thereafter, but group 2 cells continued to show signal until 36 h of L-DOPA injection. This study demonstrates imaging of the D2R signal transduction pathway and should be useful for noninvasive imaging of downstream effects of G-coupled protein pathways

Dual-purpose linker for alpha helix stabilization and imaging agent conjugation to glucagon-like peptide-1 receptor ligands.

Science.gov (United States)

Zhang, Liang; Navaratna, Tejas; Liao, Jianshan; Thurber, Greg M

2015-02-18

Peptides display many characteristics of efficient imaging agents such as rapid targeting, fast background clearance, and low non-specific cellular uptake. However, poor stability, low affinity, and loss of binding after labeling often preclude their use in vivo. Using glucagon-like peptide-1 receptor (GLP-1R) ligands exendin and GLP-1 as a model system, we designed a novel α-helix-stabilizing linker to simultaneously address these limitations. The stabilized and labeled peptides showed an increase in helicity, improved protease resistance, negligible loss or an improvement in binding affinity, and excellent in vivo targeting. The ease of incorporating azidohomoalanine in peptides and efficient reaction with the dialkyne linker enable this technique to potentially be used as a general method for labeling α helices. This strategy should be useful for imaging beta cells in diabetes research and in developing and testing other peptide targeting agents.

A Mixed Presentation of Serotonin Syndrome vs Neuroleptic Malignant Syndrome in a 12-Year-Old Boy.

Science.gov (United States)

Sun, Christie; Sweet, Hannah; Minns, Alicia B; Shapiro, Desiree; Jenkins, Willough

2018-04-24

Neuroleptic malignant syndrome (NMS) and serotonin syndrome (SS) are serious medical conditions associated with commonly prescribed psychiatric medications. Although the mechanisms differ, they can be clinically difficult to distinguish. We report a case of a pediatric patient with complicated psychiatric history that developed features of both syndromes in the setting of polypharmacy. A 12-year-old boy with a history of developmental delay, attention-deficit hyperactivity disorder, and posttraumatic stress disorder presented to the emergency department with behavior changes consisting of delayed reactions, gait instability, drooling, and slowed movements. Ten days before presentation, his outpatient psychiatrist had made multiple medication changes including discontinuation of cyproheptadine (an appetite stimulant) and initiation of aripiprazole. On arrival, the patient was noted to be tachycardia and hypertensive for age. He was disoriented, intermittently agitated, and tremulous with increased tonicity, clonus in the lower extremities, and mydriasis. He was supportively treated with lorazepam and intravenous fluids while discontinuing potential offending agents. His course was complicated by hypertension and agitation managed with dexmedetomidine infusion and benzodiazepines. His mental status, tremors, and laboratory values began to improve over the next 2 days, and eventually transitioned to the inpatient psychiatric unit on hospital day 7. Diagnosis of NMS or SS can be difficult when there is overlap between syndromes, particularly in the setting of multiple potential offending agents or underlying developmental delay. In addition, pediatric patients may present atypically as compared with adult patients with the same condition. The use of antipsychotic medications for young children with behavioral problems has risen dramatically in the last decade, increasing their risk for developing SS or NMS.

99mTc labelled peptides for imaging of peripheral receptors. Final report of a co-ordinated research project. 1995-1999

International Nuclear Information System (INIS)

2001-04-01

99m Tc radiopharmaceuticals have remained the workhorse of diagnostic nuclear medicine over the last three decades ever since the introduction of the gamma camera as the main imaging instrument. Due to the near ideal nuclear properties such as gamma energy, half-life, lack of beta radiation and easy availability as a convenient generator system at an affordable cost of 99m Tc, it can be reasonably anticipated that 99m Tc will continue to retain this position in the foreseeable future. To a large extent this has been possible because of the successful development, over the years, of 99m Tc radiopharmaceuticals as substitutes for other clinically well established agents. Examples of these success stories are 99m Tc substitutes for 131 I hippuran and rose bengal 201 Tl and 123 I brain perfusion agents, which have come to be known collectively as 'second generation 99m Tc radiopharmaceuticals'. It should be acknowledged that each one of these developments was a result of innovative and sustained research and development efforts by scientists from different parts of the world. Concurrently these research efforts have made significant contributions to better understanding of the radiochemistry and co-ordination chemistry of 99m Tc. The radiopharmaceutical scientists are now in a much better position to design, prepare and evaluate 99m Tc complexes for specific applications. Building on this capability, the next step is development of 99m Tc substitutes for receptor specific radiopharmaceuticals, which have established clinical potential. Efforts in this direction are already ongoing and the work during the last decade on 99m Tc labelling of monoclonal antibodies can be considered the beginning of these 'third generation 99m Tc radiopharmaceuticals'. The International Atomic Energy Agency (IAEA) had organized two co-ordinated research projects (CRPs) in the past covering 99m Tc second generation agents and 99m Tc monoclonal antibodies, and the results were published in

Targeted functional imaging of estrogen receptors with 99mTc-GAP-EDL

International Nuclear Information System (INIS)

Takahashi, Nobukazu; Yang, David J.; Kohanim, Saady; Oh, Chang-Sok; Yu, Dong-Fang; Azhdarinia, Ali; Kurihara, Hiroaki; Kim, E.E.; Zhang, Xiaochun; Chang, Joe Y.

2007-01-01

To evaluate the feasibility of using 99m Tc-glutamate peptide-estradiol in functional imaging of estrogen receptor-positive [ER(+)] diseases. 3-Aminoethyl estradiol (EDL) was conjugated to glutamate peptide (GAP) to yield GAP-EDL. Cellular uptake studies of 99m Tc-GAP-EDL were conducted in ER(+) cell lines (MCF-7, 13762 and T47D). To demonstrate whether GAP-EDL increases MAP kinase activation, Western blot analysis of GAP-EDL was performed in 13762 cells. Biodistribution was conducted in nine rats with 13762 breast tumors at 0.5-4 h. Each rat was administered 99m Tc-GAP-EDL. Two animal models (rats and rabbits) were created to ascertain whether tumor uptake of 99m Tc-GAP-EDL was via an ER-mediated process. In the tumor model, breast tumor-bearing rats were pretreated with diethylstilbestrol (DES) 1 h prior to receiving 99m Tc-GAP-EDL. In the endometriosis model, part of the rabbit uterine tissue was dissected and grafted to the peritoneal wall. The rabbit was administered with 99m Tc-GAP-EDL. There was a 10-40% reduction in uptake of 99m Tc-GAP-EDL in cells treated with DES or tamoxifen compared with untreated cells. Western blot analysis showed an ERK1/2 phosphorylation process with GAP-EDL. Biodistribution studies showed that tumor uptake and tumor-to-muscle count density ratio in 99m Tc-GAP-EDL groups were significantly higher than those in 99m Tc-GAP groups at 4 h. Among 99m Tc-GAP-EDL groups, region of interest analysis of images showed that tumor-to muscle ratios were decreased in blocking groups. In the endometriosis model, the grafted uterine tissue could be visualized by 99m Tc-GAP-EDL. Cellular or tumor uptake of 99m Tc-GAP-EDL occurs via an ER-mediated process. 99m Tc-GAP-EDL is a useful agent for imaging functional ER(+) disease. (orig.)

Simultaneous topography and recognition imaging: physical aspects and optimal imaging conditions

International Nuclear Information System (INIS)

Preiner, Johannes; Ebner, Andreas; Zhu Rong; Hinterdorfer, Peter; Chtcheglova, Lilia

2009-01-01

Simultaneous topography and recognition imaging (TREC) allows for the investigation of receptor distributions on natural biological surfaces under physiological conditions. Based on atomic force microscopy (AFM) in combination with a cantilever tip carrying a ligand molecule, it enables us to sense topography and recognition of receptor molecules simultaneously with nanometre accuracy. In this study we introduce optimized handling conditions and investigate the physical properties of the cantilever-tip-sample ensemble, which is essential for the interpretation of the experimental data gained from this technique. In contrast to conventional AFM methods, TREC is based on a more sophisticated feedback loop, which enables us to discriminate topographical contributions from recognition events in the AFM cantilever motion. The features of this feedback loop were investigated through a detailed analysis of the topography and recognition data obtained on a model protein system. Single avidin molecules immobilized on a mica substrate were imaged with an AFM tip functionalized with a biotinylated IgG. A simple procedure for adjusting the optimal amplitude for TREC imaging is described by exploiting the sharp localization of the TREC signal within a small range of oscillation amplitudes. This procedure can also be used for proving the specificity of the detected receptor-ligand interactions. For understanding and eliminating topographical crosstalk in the recognition images we developed a simple theoretical model, which nicely explains its origin and its dependence on the excitation frequency.

A retrospective analysis of cases with neuroleptic malignant syndrome and an evaluation of risk factors for mortality

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Aynur Sahin

2017-12-01

Full Text Available Objective: Neuroleptic malignant syndrome (NMS is a neurological emergency rarely encountered in clinical practice but with a high mortality rate. Cases associated with atypical antipsychotic use or termination of dopamine agonists have been seen in recent years. The purpose of this study was to assess the presence of risk factors for mortality by investigating all clinical and laboratory characteristics of cases with NMS. Material and methods: This descriptive, cross-sectional study retrospectively investigated all clinical and laboratory characteristics by scanning the ICD-10 codes of patients presenting to the XXXX Faculty of Medicine Emergency Department and diagnosed with NMS between 2006 and 2016. Patients were divided into surviving and non-surviving groups, and the data elicited were subjected to statistical comparisons. Results: The mean age of the 18 patients diagnosed with NMS was 46.9 ± 4.8 years, and 50% were women. In addition to antipsychotics among the drugs leading to NMS, the syndrome also developed as a result of levodopa withdrawal in three patients and metoclopramide use in one patient. Statistically significant differences were determined between the surviving and non-surviving patients in terms of blood pressure, blood urea nitrogen (BUN, creatine kinase (CK and mean platelet volume (MPV values (p ≤ 0.05. Conclusion: In this study the most common agent that cause NMS was atypical antipsychotics. Also advanced age, increased blood pressure and serum CK, BUN and MPV values were identified as potential risk factors for mortality in NMS.

Imaging the β-adrenergic receptor. II: [F-18]-fluoroalkyl derivatives of carazolol

International Nuclear Information System (INIS)

Kinsey, B.M.; Tewson, T.J.

1990-01-01

Carazolol is a ligand with one of the highest association constants known for the β-adrenergic receptor and presumably has one of the slowest rates of dissociation from the receptor. The authors have prepared a [F-18]-fluoroalkyl derivative of carazolol which the authors believe will be useful in the in vivo detection and measurement of the β-adrenergic receptor. The synthesis is based upon the formation of a hydrazole from cyclohexanedione and para-[2-hydroxyethyl]phenylhydrazine followed by Fischer indole synthesis, dehydrogenation and side chain addition to give the protected hydroxyethylcarazolol derivative 1

In vivo imaging of oxidative stress in the kidney of diabetic mice and its normalization by angiotensin II type 1 receptor blocker

International Nuclear Information System (INIS)

Sonta, Toshiyo; Inoguchi, Toyoshi; Matsumoto, Shingo; Yasukawa, Keiji; Inuo, Mieko; Tsubouchi, Hirotaka; Sonoda, Noriyuki; Kobayashi, Kunihisa; Utsumi, Hideo; Nawata, Hajime

2005-01-01

This study was undertaken to evaluate oxidative stress in the kidney of diabetic mice by electron spin resonance (ESR) imaging technique. Oxidative stress in the kidney was evaluated as organ-specific reducing activity with the signal decay rates of carbamoyl-PROXYL probe using ESR imaging. The signal decay rates were significantly faster in corresponding image pixels of the kidneys of streptozotocin-induced diabetic mice than in those of controls. This technique further demonstrated that administration of angiotensin II type 1 receptor blocker (ARB), olmesartan (5 mg/kg), completely restored the signal decay rates in the diabetic kidneys to control values. In conclusion, this study provided for the first time the in vivo evidence for increased oxidative stress in the kidneys of diabetic mice and its normalization by ARB as evaluated by ESR imaging. This technique would be useful as a means of further elucidating the role of oxidative stress in diabetic nephropathy

Small-Animal Imaging Using Diffuse Fluorescence Tomography.

Science.gov (United States)

Davis, Scott C; Tichauer, Kenneth M

2016-01-01

Diffuse fluorescence tomography (DFT) has been developed to image the spatial distribution of fluorescence-tagged tracers in living tissue. This capability facilitates the recovery of any number of functional parameters, including enzymatic activity, receptor density, blood flow, and gene expression. However, deploying DFT effectively is complex and often requires years of know-how, especially for newer mutlimodal systems that combine DFT with conventional imaging systems. In this chapter, we step through the process of using MRI-DFT imaging of a receptor-targeted tracer in small animals.

Assessment of chitosan-affected metabolic response by peroxisome proliferator-activated receptor bioluminescent imaging-guided transcriptomic analysis.

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Chia-Hung Kao

Full Text Available Chitosan has been widely used in food industry as a weight-loss aid and a cholesterol-lowering agent. Previous studies have shown that chitosan affects metabolic responses and contributes to anti-diabetic, hypocholesteremic, and blood glucose-lowering effects; however, the in vivo targeting sites and mechanisms of chitosan remain to be clarified. In this study, we constructed transgenic mice, which carried the luciferase genes driven by peroxisome proliferator-activated receptor (PPAR, a key regulator of fatty acid and glucose metabolism. Bioluminescent imaging of PPAR transgenic mice was applied to report the organs that chitosan acted on, and gene expression profiles of chitosan-targeted organs were further analyzed to elucidate the mechanisms of chitosan. Bioluminescent imaging showed that constitutive PPAR activities were detected in brain and gastrointestinal tract. Administration of chitosan significantly activated the PPAR activities in brain and stomach. Microarray analysis of brain and stomach showed that several pathways involved in lipid and glucose metabolism were regulated by chitosan. Moreover, the expression levels of metabolism-associated genes like apolipoprotein B (apoB and ghrelin genes were down-regulated by chitosan. In conclusion, these findings suggested the feasibility of PPAR bioluminescent imaging-guided transcriptomic analysis on the evaluation of chitosan-affected metabolic responses in vivo. Moreover, we newly identified that downregulated expression of apoB and ghrelin genes were novel mechanisms for chitosan-affected metabolic responses in vivo.

3-D Image Analysis of Fluorescent Drug Binding

Directory of Open Access Journals (Sweden)

M. Raquel Miquel

2005-01-01

Full Text Available Fluorescent ligands provide the means of studying receptors in whole tissues using confocal laser scanning microscopy and have advantages over antibody- or non-fluorescence-based method. Confocal microscopy provides large volumes of images to be measured. Histogram analysis of 3-D image volumes is proposed as a method of graphically displaying large amounts of volumetric image data to be quickly analyzed and compared. The fluorescent ligand BODIPY FL-prazosin (QAPB was used in mouse aorta. Histogram analysis reports the amount of ligand-receptor binding under different conditions and the technique is sensitive enough to detect changes in receptor availability after antagonist incubation or genetic manipulations. QAPB binding was concentration dependent, causing concentration-related rightward shifts in the histogram. In the presence of 10 μM phenoxybenzamine (blocking agent, the QAPB (50 nM histogram overlaps the autofluorescence curve. The histogram obtained for the 1D knockout aorta lay to the left of that of control and 1B knockout aorta, indicating a reduction in 1D receptors. We have shown, for the first time, that it is possible to graphically display binding of a fluorescent drug to a biological tissue. Although our application is specific to adrenergic receptors, the general method could be applied to any volumetric, fluorescence-image-based assay.

Brain 18F-FDG, 18F-florbtaben PET/CT, 123I-FP-CIT SPECT and cardiac 123I-MBG imaging for diagnosis of a 'cerebral type' of Lewy Body disease

International Nuclear Information System (INIS)

Gucht, Axel Van Der; Bélissant, Ophélie; Rabu, Corenti; Cottereau, Anne-Ségolène; Evangelista, Eva; Chalaye, Julia; Bonnot-Lours, Sophie; Fénelon, Gilles; Itti, Emmanuel; De Langavant, Laurent Cleret

2016-01-01

A 67-year-old man was referred for fluctuating neuropsychiatric symptoms, featuring depression, delirious episodes, recurrent visual hallucinations and catatonic syndrome associated with cognitive decline. No parkinsonism was found clinically even under neuroleptic treatment. 18 F-FDG PET/CT showed hypometabolism in the posterior associative cortex including the occipital cortex, suggesting Lewy body dementia, but 123 I-FP-CIT SPECT was normal and cardiac 123 I-MIBG imaging showed no signs of sympathetic denervation. Alzheimer's disease was excluded by a normal 18 F-florbetaben PET/CT. This report suggests a rare case of α-synucleinopathy without brainstem involvement, referred to as 'cerebral type' of Lewy body disease

Comparison in animal models of 18F-spiroperidol and 18F-haloperidol: potential agents for imaging the dopamine receptor

International Nuclear Information System (INIS)

Welch, M.J.; Kilbourn, M.R.; Mathias, C.J.; Mintun, M.A.; Raichle, M.E.

1983-01-01

Fluorine-18-labeled haloperidol and spiroperidol have been prepared by an exchange reaction using the corresponding non-labeled compound or the nitro analog. Studies in rats have shown that the distribution of labeled spiroperidol has a high striatum to cerebellum ratio which is not observed with haloperidol. A ratio of 10.66 +/- 1.6 is obtained two hours after administration of the 18 F-spiroperidol. When 18 F-spiroperidol was administered to a baboon and tomographic images obtained, the dopamine receptor rich areas were clearly visualized two hours after administration

Adenosine A{sub 2A} receptor imaging with [{sup 11}C]KF18446 PET in the rat brain after quinolinic acid lesion. Comparison with the dopamine receptor imaging

Energy Technology Data Exchange (ETDEWEB)

Ishiwata, Kiichi; Ogi, Nobuo; Hayakawa, Nobutaka [Tokyo Metropolitan Inst. of Gerontology, Tokyo (Japan). Positron Medical Center] [and others

2002-11-01

We proposed [{sup 11}C]KF18446 as a selective radioligand for mapping the adenosine A{sub 2A} receptors being highly enriched in the striatum by positron emission tomography (PET). In the present study, we investigated whether [{sup 11}C]KF18446 PET can detect the change in the striatal adenosine A{sub 2A} receptors in the rat after unilateral injection of an excitotoxin quinolinic acid into the striatum, a Huntington's disease model, to demonstrate the usefulness of [{sup 11}C]KF18446. The extent of the striatal lesion was identified based on MRI, to which the PET was co-registered. The binding potential of [{sup 11}C]KF18446 significantly decreased in the quinolinic acid-lesioned striatum. The decrease was comparable to the decrease in the potential of [{sup 11}C] raclopride binding to dopamine D{sub 2} receptors in the lesioned striatum, but seemed to be larger than the decrease in the potential of [{sup 11}C]SCH23390 binding to dopamine D{sub 1} receptors. Ex vivo and in vitro autoradiography validated the PET signals. We concluded that [{sup 11}C]KF18446 PET can detect change in the adenosine A{sub 2A} receptors in the rat model, and will provide a new diagnostic tool for characterizing post-synaptic striatopallidal neurons in the stratum. (author)

Determination of optimal acquisition time of [18F]FCWAY PET for imaging serotonin 1A receptors in the healthy male subjects

International Nuclear Information System (INIS)

Yong Choi, Jae; Lee, Minkyung; Jeon, Tae Joo; Choi, Soo-Hee; Choi, Ye Ji; Lee, Yu Kyung; Kim, Jae-Jin; Ryu, Young Hoon

2014-01-01

The purpose of this research is to find optimal acquisition time point of [ 18 F]FCWAY PET for the assessment of serotonin 1A receptor (5-HT 1A ) density. To achieve this goal, we examined the specific-to-nonspecific ratios in various brain regions. The cerebellum has very few 5-HT 1A receptors in the brain, so we set this region as the reference tissue. As a result, specific-to-nonspecific binding ratios in the frontal, temporal cortex and the hippocampus were steadily increased at 90 min after injection and remained stable at 120 min. In addition, the binding ratio of the late time was significantly higher than that of the previous time points. From these results, we recommend that 90 min p.i. is a better single time point for the analysis rather than previous time points for assessing [ 18 F]FCWAY binding to 5-HT 1A receptors. - Highlights: • For routine clinical study, PET protocol should be conducted on a single time point with short imaging acquisition. • The specific-to-nonspecific ratios in the various brain regions were calculated. • Optimal [ 18 F]FCWAY PET acquisition time point was proposed

Biokinetics and dosimetry of 99m Tc-EDDA/HYNIC-[Lys3]-bombesin in humans: imaging of GRP receptors

International Nuclear Information System (INIS)

Santos C, C.L.; Ferro F, G.; Murphy, C.A de; Cardena, E.; Pichardo R, P.

2007-01-01

Full text: Bombesin (BN) receptor subtype 2 (GRP-r) is over-expressed on various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently we reported the 99- mTc-EDDA/HYNIC-[Lys 3 ]-Bombesin ( 99m Tc-HYNIC-BN) complex as a new radiopharmaceutical with high stability in human serum, specific cell GRP-receptor binding and rapid internalization. The aim of this study was to evaluate the 99m Tc-HYNIC-BN biokinetics and dosimetry in 5-healthy and 3-breast cancer women. Whole-body images were acquired at 20, 90, 180 min and 24 h after 99m Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source' organs on each time frame. The same set of ROIs was used for all 8 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-HYNIC-BN time activity curves in each organ, to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed a rapid radiopharmaceutical blood clearance with predominantly renal excretion and minimal hepatobiliary elimination. 99m Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in breast cancer lesions and well differentiated from GRP-r expression in lungs and airways with normal GRP-r density (ratio 3:1). The equivalent doses for a study using 370 MBq were 7.38±1.68, 0.59±0.08, 2.07±0.60, 0.58±0.1, 0.75±0.09 and 0.43±0.07 mSv for kidneys, liver, lungs, ovaries, pancreas and red marrow respectively. The effective dose was 1.64±0.25 mSv which is comparable with the doses known for most of the 99m Tc radiopharmaceutical studies in nuclear medicine. (Author)

Technetium-99m spiperone dithiocarbamate: a potential radiopharmaceutical for dopamine receptor imaging with SPECT

Energy Technology Data Exchange (ETDEWEB)

Ballinger, J R; Gulenchyn, K Y; Hassan, M N [Ottawa Civic Hospital (Canada). Div. of Nuclear Medicine and Neurology; Ottawa Univ., ON (Canada))

1989-01-01

Spiperone dithiocarbamate (SPDC) was prepared by reacting spiperone with carbon disulfide followed by sodium hydroxide. SPDC was labelled with {sup 99m}Tc by reduction of pertechnetate with formamidine sulfinic acid or sodium pertechnetate with formamidine sulfinic acid or sodium dithionite at alkaline pH, resulting in {similar to} 40% incorporation of {sup 99m}Tc. The lipophilic complex was conveniently isolated at high specific activity and high radiochemical purity by extraction into dichloromethane, which was then evaporated and the residue was redissolved in a 1:3 mixture of ethanol and saline containing 0.1mg/ml gentisic acid. Biodistribution studies following i.p. injection in rats showed low uptake of radioactivity in the brain, but striatum/cortex and striatum/cerebellum ratios were reduced by pretreatment with haloperidol. This agent may allow imaging of dopamine D-2 receptors using single-photon emission computed tomography (SPECT). (author).

Molecular imaging of σ receptors: synthesis and evaluation of the potent σ1 selective radioligand [18F]fluspidine

International Nuclear Information System (INIS)

Fischer, Steffen; Hiller, Achim; Deuther-Conrad, Winnie; Scheunemann, Matthias; Steinbach, Joerg; Brust, Peter; Wiese, Christian; Grosse Maestrup, Eva; Schepmann, Dirk; Wuensch, Bernhard

2011-01-01

Neuroimaging of σ 1 receptors in the human brain has been proposed for the investigation of the pathophysiology of neurodegenerative and psychiatric diseases. However, there is a lack of suitable 18 F-labelled PET radioligands for that purpose. The selective σ 1 receptor ligand [ 18 F]fluspidine (1'-benzyl-3-(2-[ 18 F]fluoroethyl)-3H-spiro[[2]benzofuran-1,4'-piperidine]) was synthesized by nucleophilic 18 F - substitution of the tosyl precursor. In vitro receptor binding affinity and selectivity were assessed by radioligand competition in tissue homogenate and autoradiographic approaches. In female CD-1 mice, in vivo properties of [ 18 F]fluspidine were evaluated by ex vivo brain section imaging and organ distribution of intravenously administered radiotracer. Target specificity was validated by organ distribution of [ 18 F]fluspidine after treatment with 1 mg/kg i.p. of the σ receptor antagonist haloperidol or the emopamil binding protein (EBP) inhibitor tamoxifen. In vitro metabolic stability and in vivo metabolism were investigated by LC-MS n and radio-HPLC analysis. [ 18 F]Fluspidine was obtained with a radiochemical yield of 35-45%, a radiochemical purity of ≥ 99.6% and a specific activity of 150-350 GBq/μmol (n = 6) within a total synthesis time of 90-120 min. In vitro, fluspidine bound specifically and with high affinity to σ 1 receptors (K i = 0.59 nM). In mice, [ 18 F]fluspidine rapidly accumulated in brain with uptake values of 3.9 and 4.7%ID/g and brain to blood ratios of 7 and 13 at 5 and 30 min after intravenous application of the radiotracer, respectively. By ex vivo autoradiography of brain slices, resemblance between binding site occupancy of [ 18 F]fluspidine and the expression of σ 1 receptors was shown. The radiotracer uptake in the brain as well as in peripheral σ 1 receptor expressing organs was significantly inhibited by haloperidol but not by tamoxifen. Incubation with rat liver microsomes led to a fast biotransformation of

Evaluation of radiolabeled ML04, a putative irreversible inhibitor of epidermal growth factor receptor, as a bioprobe for PET imaging of EGFR-overexpressing tumors

International Nuclear Information System (INIS)

Abourbeh, Galith; Dissoki, Samar; Jacobson, Orit; Litchi, Amir; Daniel, Revital Ben; Laki, Desirediu; Levitzki, Alexander; Mishani, Eyal

2007-01-01

Overexpression of epidermal growth factor receptor (EGFR) has been implicated in tumor development and malignancy. Evaluating the degree of EGFR expression in tumors could aid in identifying patients for EGFR-targeted therapies and in monitoring treatment. Nevertheless, no currently available assay can reliably quantify receptor content in tumors. Radiolabeled inhibitors of EGFR-TK could be developed as bioprobes for positron emission tomography imaging. Such imaging agents would not only provide a noninvasive quantitative measurement of EGFR content in tumors but also serve as radionuclide carriers for targeted radiotherapy. The potency, reversibility, selectivity and specific binding characteristics of ML04, an alleged irreversible inhibitor of EGFR, were established in vitro. The distribution of the F-18-labeled compound and the extent of EGFR-specific tumor uptake were evaluated in tumor-bearing mice. ML04 demonstrated potent, irreversible and selective inhibition of EGFR, combined with specific binding to the receptor in intact cells. In vivo distribution of the radiolabeled compound revealed tumor/blood and tumor/muscle activity uptake ratios of about 7 and 5, respectively, 3 h following administration of a radiotracer. Nevertheless, only minor EGFR-specific uptake of the compound was detected in these studies, using either EGFR-negative tumors or blocking studies as controls. To improve the in vivo performance of ML04, administration via prolonged intravenous infusion is proposed. Detailed pharmacokinetic characterization of this bioprobe could assist in the development of a kinetic model that would afford accurate measurement of EGFR content in tumors

Imaging of persistent cAMP signaling by internalized G protein-coupled receptors.

Science.gov (United States)

Calebiro, Davide; Nikolaev, Viacheslav O; Lohse, Martin J

2010-07-01

G protein-coupled receptors (GPCRs) are the largest family of plasma membrane receptors. They mediate the effects of several endogenous cues and serve as important pharmacological targets. Although many biochemical events involved in GPCR signaling have been characterized in great detail, little is known about their spatiotemporal dynamics in living cells. The recent advent of optical methods based on fluorescent resonance energy transfer allows, for the first time, to directly monitor GPCR signaling in living cells. Utilizing these methods, it has been recently possible to show that the receptors for two protein/peptide hormones, the TSH and the parathyroid hormone, continue signaling to cAMP after their internalization into endosomes. This type of intracellular signaling is persistent and apparently triggers specific cellular outcomes. Here, we review these recent data and explain the optical methods used for such studies. Based on these findings, we propose a revision of the current model of the GPCR-cAMP signaling pathway to accommodate receptor signaling at endosomes.

Brain penetrant small molecule 18F-GnRH receptor (GnRH-R) antagonists: Synthesis and preliminary positron emission tomography imaging in rats

International Nuclear Information System (INIS)

Olberg, Dag E.; Bauer, Nadine; Andressen, Kjetil W.; Hjørnevik, Trine; Cumming, Paul; Levy, Finn O.; Klaveness, Jo; Haraldsen, Ira; Sutcliffe, Julie L.

2016-01-01

Introduction: The gonadotropin releasing hormone receptor (GnRH-R) has a well-described neuroendocrine function in the anterior pituitary. However, little is known about its function in the central nervous system (CNS), where it is most abundantly expressed in hippocampus and amygdala. Since peptide ligands based upon the endogenous decapetide GnRH do not pass the blood–brain-barrier, we are seeking a high-affinity small molecule GnRH-R ligand suitable for brain imaging by positron emission tomography. We have previously reported the radiosynthesis and in vitro evaluation of two novel [ 18 F]fluorinated GnRH-R ligands belonging to the furamide class of antagonists, with molecular weight less than 500 Da. We now extend this work using palladium coupling for the synthesis of four novel radioligands, with putatively reduced polar surface area and hydrophilicity relative to the two previously described compounds, and report the uptake of these 18 F-labeled compounds in brain of living rats. Methods: We synthesized reference standards of the small molecule GnRH-R antagonists as well as mesylate precursors for 18 F-labeling. The antagonists were tested for binding affinity for both human and rat GnRH-R. Serum and blood stability in vitro and in vivo were studied. Biodistribution and PET imaging studies were performed in male rats in order to assess brain penetration in vivo. Results: A palladium coupling methodology served for the synthesis of four novel fluorinated furamide GnRH receptor antagonists with reduced heteroatomic count. Radioligand binding assays in vitro revealed subnanomolar affinity of the new fluorinated compounds for both human and rat GnRH-R. The 18 F-GnRH antagonists were synthesized from the corresponding mesylate precursors in 5–15% overall radiochemical yield. The radiolabeled compounds demonstrated good in vivo stability. PET imaging with the 18 F-radiotracers in naive rats showed good permeability into brain and rapid washout, but absence of

Serotonin-1A receptor imaging in recurrent depression: replication and literature review

Energy Technology Data Exchange (ETDEWEB)

Drevets, Wayne C. [Mood and Anxiety Disorders Program, MINH Molecular Imaging Branch, Bethesda, MD 20892 (United States); Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 19213 (United States); Department of Radiology, University of Pittsburgh, Pittsburgh, PA 19213 (United States)], E-mail: drevetsw@mail.nih.gov; Thase, Michael E. [Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 19213 (United States); Department of Psychiatry, University of Pennsylvania, School of Medicine and Philadelphia Veterans Affairs Medical Center, Philadelphia, PA 19104 (United States); Moses-Kolko, Eydie L. [Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 19213 (United States); Price, Julie [Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 19213 (United States); Department of Radiology, University of Pittsburgh, Pittsburgh, PA 19213 (United States); Frank, Ellen; Kupfer, David J. [Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 19213 (United States); Mathis, Chester [Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 19213 (United States); Department of Radiology, University of Pittsburgh, Pittsburgh, PA 19213 (United States)

2007-10-15

Introduction: Serotonin-1A receptor (5-HT{sub 1A}R) function appears to be decreased in major depressive disorder (MDD) based on physiological responses to 5-HT{sub 1A}R agonists in vivo and to 5-HT{sub 1A}R binding in brain tissues postmortem or antemortem. We have previously assessed 5-HT{sub 1A}R binding potential (BP) in depression using positron emission tomography (PET) and [carbonyl-{sup 11}C]WAY-100635, and we have demonstrated reduced 5-HT{sub 1A}R BP in the mesiotemporal cortex (MTC) and raphe in depressives with primary recurrent familial mood disorders (n=12) versus controls (n=8) [Drevets WC, Frank E, Price JC, Kupfer DJ, Holt D, Greer PJ, Huang Y, Gautier C, Mathis C. PET imaging of serotonin 1A receptor binding in depression. Biol Psychiatry 1999;46(10):1375-87]. These findings were replicated by some, but not other, studies performed in depressed samples that were more generally selected using criteria for MDD. In the current study, we attempted to replicate our previous findings in an independent sample of subjects selected according to the criteria for primary recurrent depression applied in our prior study. Methods: Using PET and [carbonyl-{sup 11}C]WAY-100635, 5-HT{sub 1A}R BP was assessed in 16 depressed subjects and 8 healthy controls. Results: Mean 5-HT{sub 1A}R BP was reduced by 26% in the MTC (P < .005) and by 43% in the raphe (P < .001) in depressives versus controls. Conclusions: These data replicate our original findings, which showed that BP was reduced by 27% in the MTC (P < .025) and by 42% in the raphe (P < .02) in depression. The magnitudes of these reductions in 5-HT{sub 1A}R binding were similar to those found postmortem in 5-HT{sub 1A}R mRNA concentrations in the hippocampus in MDD [Lopez JF, Chalmers DT, Little KY, Watson SJ. Regulation of serotonin 1A, glucocorticoid, and mineralocorticoid receptor in rat and human hippocampus: implications for neurobiology of depression. Biol Psychiatry 1998;43:547-73] and in 5-HT{sub 1A

Cancer Stratification by Molecular Imaging

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Justus Weber

2015-03-01

Full Text Available The lack of specificity of traditional cytotoxic drugs has triggered the development of anticancer agents that selectively address specific molecular targets. An intrinsic property of these specialized drugs is their limited applicability for specific patient subgroups. Consequently, the generation of information about tumor characteristics is the key to exploit the potential of these drugs. Currently, cancer stratification relies on three approaches: Gene expression analysis and cancer proteomics, immunohistochemistry and molecular imaging. In order to enable the precise localization of functionally expressed targets, molecular imaging combines highly selective biomarkers and intense signal sources. Thus, cancer stratification and localization are performed simultaneously. Many cancer types are characterized by altered receptor expression, such as somatostatin receptors, folate receptors or Her2 (human epidermal growth factor receptor 2. Similar correlations are also known for a multitude of transporters, such as glucose transporters, amino acid transporters or hNIS (human sodium iodide symporter, as well as cell specific proteins, such as the prostate specific membrane antigen, integrins, and CD20. This review provides a comprehensive description of the methods, targets and agents used in molecular imaging, to outline their application for cancer stratification. Emphasis is placed on radiotracers which are used to identify altered expression patterns of cancer associated markers.

Estimate the time varying brain receptor occupancy in PET imaging experiments using non-linear fixed and mixed effect modeling approach

International Nuclear Information System (INIS)

Zamuner, Stefano; Gomeni, Roberto; Bye, Alan