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Sample records for acute intermittent porphyria

  1. Feigning Acute Intermittent Porphyria

    Rania Elkhatib; Modupe Idowu; Gregory S. Brown; Jaber, Yasmeen M.; Reid, Matthew B.; Cheryl Person

    2014-01-01

    Acute intermittent porphyria (AIP) is an autosomal dominant genetic defect in heme synthesis. Patients with this illness can have episodic life-threatening attacks characterized by abdominal pain, neurological deficits, and psychiatric symptoms. Feigning this illness has not been reported in the English language literature to date. Here, we report on a patient who presented to the hospital with an acute attack of porphyria requesting opiates. Diligent assessment of extensive prior treatment r...

  2. Acute Intermittent Porphyria (AIP)

    ... sold as Panhematin ® , from Recordati Rare Diseases. Most hospitals do not stock it. Therefore the pharmacy must be notified at the time the patient’s ... the Acute Porphyrias - Clarification of Testing Results** Important Update ... & Immunology, University Hospital of Wales, for assistance in the preparation of ...

  3. Autonomic neuropathy in acute intermittent porphyria.

    Laiwah, A C; Macphee, G. J.; P Boyle; Moore, M R; Goldberg, A

    1985-01-01

    Autonomic function was assessed in subjects with acute intermittent porphyria and age- and sex-matched controls using five different bedside tests of cardiovascular reflexes. During the acute attack both parasympathetic and sympathetic tests were impaired, but subsequently improved during remission. Early parasympathetic dysfunction was also detected during remission and in latent asymptomatic acute intermittent porphyria.

  4. Cardiac calcification in acute intermittent porphyria

    Tanmoy Ghatak

    2011-01-01

    Full Text Available Aetiology of pericardial calcifications can be multifactorial. Tuberculosis has been reported as the most common cause. Other known causes include uraemia, asbestosis, post-traumatic or postoperative. We report a rare case of pericardial calcification seen in a patient with established acute intermittent porphyria. A direct causal relationship cannot be established between porphyria and pericardial calcification, but it may be due to deposition of the porphyrin in the pericardium.

  5. Cardiac calcification in acute intermittent porphyria

    Tanmoy Ghatak; Afzal Azim; Arvind K Baronia; Banani Poddar

    2011-01-01

    Aetiology of pericardial calcifications can be multifactorial. Tuberculosis has been reported as the most common cause. Other known causes include uraemia, asbestosis, post-traumatic or postoperative. We report a rare case of pericardial calcification seen in a patient with established acute intermittent porphyria. A direct causal relationship cannot be established between porphyria and pericardial calcification, but it may be due to deposition of the porphyrin in the pericardium.

  6. Acute intermittent porphyria in the puerperium

    Sparić Radmila

    2010-01-01

    Full Text Available Introduction. Acute intermittent porphyria emerges as a result of partial defect of porphobilinogen deaminase and is manifested by repeated episodes of somatic, psychiatric and neurological disorders. The disease is conducted via the autosomaldominant gene of variable penetration, so most of the carriers never experience seizures. Timely making of diagnosis, screening of blood relatives of the patient and education of patients on avoidance of provoking factors are the key to adequate treatment. Case Outline. A 23-year-old patient having born the third child was hospitalized due to pains in the abdomen and convulsive seizures nine days after the vaginal delivery. At admittance, she suffered a generalized convulsive seizure of clonic-tonic type. The patient immediately underwent a complete clinical, laboratory, bacteriological and ultrasound examination. Bearing in mind the fact that the patient had several convulsive seizures even after the given neurological therapy, haem-arginate was introduced into therapy during four days. The administration of haem-arginate led to the normalization of blood pressure, pulse and bowel function. The administration of haem-arginate led to the normalization of blood pressure, pulse and bowel function. The patient was treated by a team of doctors, in the intensive care ward, with the use of medicaments, which are allowed in the case of acute porphyria. Sixteen days after the admittance, with clean neurological status and gynaecological and ultra-sound findings, she was released for ambulatory treatment. Conclusion. The presented case exhibits the gravity of making a diagnosis of acute intermittent porphyria in puerperium and the necessity of multi-disciplinary approach in treating this disease. Acute intermittent porphyria should be considered in cases of ambiguous abdominal pain, as well as in patients having abdominal pains followed by neuro-psychiatric disorders.

  7. Post- Partum Acute Intermittent Porphyria - A Case Report

    Gaurav Tomar

    2010-02-01

    Full Text Available Porphyrias are inherited disorders, each involving a specific enzyme in heme biosynthetic pathways. Acute intermittent porphyria, one of the hepatic porphyria is the most severe form of the disease, with gastrointestinal and neuropsychiatric manifestations. Proper management will dramatically improve the outcome in this otherwise debilitating and potentially life-threatening disease.

  8. Post- Partum Acute Intermittent Porphyria - A Case Report

    Gaurav Tomar; Ashish Sethi; TC Kriplani; Neeraj Narang

    2010-01-01

    Porphyrias are inherited disorders, each involving a specific enzyme in heme biosynthetic pathways. Acute intermittent porphyria, one of the hepatic porphyria is the most severe form of the disease, with gastrointestinal and neuropsychiatric manifestations. Proper management will dramatically improve the outcome in this otherwise debilitating and potentially life-threatening disease.

  9. Acute intermittent porphyria: Diagnosis per chance

    Soundravally R

    2008-10-01

    Full Text Available Objectives: To report a case of acute intermittent porphyria (AIP diagnosed by chance during routine investigations. Clinical Presentation and Intervention: A 21-year-old female presented with vague gastrointestinal symptoms. Upon admission, she was disoriented. Later she developed generalized seizures and was treated with phenytoin, but the condition worsened. Upon investigation, her liver function, renal function, blood sugar level and electrolytes were within normal limits. When kept for routine laboratory testing, the color change in urine prompted us to investigate for porphyria. It was positive for phorphobilinogen (PBG and urophorphyrin. Since AIP had been diagnosed, the initial treatment with phenytoin was discontinued with a favorable outcome. A screening test for PBG in urine by Ehrlich′s reagent was performed on the patient′s mother and was positive. Conclusion: A high degree of suspicion at the laboratory can also determine the diagnosis of AIP, which is often missed by the clinician.

  10. Epidemiological, clinical anf pathogenetic studies of acute intermittent porphyria

    Bylesjö, Ingemar

    2008-01-01

    Porphyrias are inherited metabolic disorders characterised by an impairment of heme biosynthesis. Acute intermittent porphyria (AIP) is the most common of the acute porphyrias in Sweden. Acute attacks of AIP are characterised by neuro-psychiatric symptoms, including epileptic seizures. Environmental and acquired factors are related to the induction of symptoms. Acute attacks of AIP are treated with high doses of glucose and/or hematin infusions. The pathogenesis of the neuro-psychiatric sympt...

  11. Acute Intermittent Porphyria Associated with Respiratory Failure: A Multidisciplinary Approach

    Mayra Gonçalves Menegueti; Alkmim-Teixeira Gil Cezar; Karin Aparecida Casarini; Kátia Simone Muniz Cordeiro; Anibal Basile-Filho; Olindo Assis Martins-Filho; Maria Auxiliadora-Martins

    2011-01-01

    Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroen...

  12. Acute intermittent porphyria, women and sex hormones. Screening for hepatocellular carcinoma in porphyria

    Innala, Eva

    2010-01-01

    Background:   Porphyrias are inherited disorders with impaired heme biosynthesis. Acute intermittent porphyria (AIP) is the most common porphyria in Sweden. AIP attacks may be life-threatening. Female sex hormones are regarded as important precipitating factors. Hepatocellular carcinoma (HCC) is a severe complication in the older AIP population. The aim of the thesis was to describe the clinical expression of AIP in women, experience of hormonal contraception and hormonal replacement therapie...

  13. Differential diagnosis of acute abdominal pain – acute intermittent porphyria

    Mislav Klobučić; Duška Šklebar; Renata Ivanac; Dragica Vrabec Matković; Anita Jug-Klobučić; Ivan Šklebar

    2011-01-01

    Acute intermittent porphyria (AIP) is a rare autosomal dominant disorder of heme biosynthesis in liver due to deficiency of porphobilinogen deaminase enzyme. Clinically, AIP is dominatedby a colicky type pain, which does not subside after taking usual analgesics. Additional frequent symptoms are vomiting, hypertension, peripheral neuropathy, seizures, depression, delirium and coma. This paper reported a case of a twenty-fi- ve-year-old female patient, who had undergone a period of six days be...

  14. Acute Intermittent Porphyria Associated with Respiratory Failure: A Multidisciplinary Approach

    Mayra Gonçalves Menegueti

    2011-01-01

    Full Text Available Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroenterological disorders on patients whose routine investigation tests are normal, especially when precipitating factors exist. Intensive care measures and a multidisciplinary team approach are essential.

  15. Acute intermittent porphyria associated with respiratory failure: a multidisciplinary approach.

    Menegueti, Mayra Gonçalves; Gil Cezar, Alkmim-Teixeira; Casarini, Karin Aparecida; Muniz Cordeiro, Kátia Simone; Basile-Filho, Anibal; Martins-Filho, Olindo Assis; Auxiliadora-Martins, Maria

    2011-01-01

    Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroenterological disorders on patients whose routine investigation tests are normal, especially when precipitating factors exist. Intensive care measures and a multidisciplinary team approach are essential. PMID:21687623

  16. Acute Intermittent Porphyria Associated with Respiratory Failure: A Multidisciplinary Approach

    Menegueti, Mayra Gonçalves; Gil Cezar, Alkmim-Teixeira; Casarini, Karin Aparecida; Muniz Cordeiro, Kátia Simone; Basile-Filho, Anibal; Martins-Filho, Olindo Assis; Auxiliadora-Martins, Maria

    2011-01-01

    Despite being challenging, delivery of effective nursing care to patients with acute intermittent porphyria is a matter of utmost importance. In this paper, the diversity of symptoms and the difficult diagnosis of this condition are emphasized, and details concerning the treatment of this disorder in the intensive care unit are presented. We believe that acute intermittent porphyria should be borne in mind during performance of differential diagnosis of neurological, psychiatric, and gastroenterological disorders on patients whose routine investigation tests are normal, especially when precipitating factors exist. Intensive care measures and a multidisciplinary team approach are essential. PMID:21687623

  17. Acute intermittent porphyria: Diagnostic dilemma and treatment options

    Mohan Deep Kaur; Nita Hazarika; Namita Saraswat; Rajesh Sood

    2015-01-01

    Acute intermittent porphyria (AIP) presents with diverse group of symptoms making its early diagnosis difficult. Delaying diagnosis and treatment of AIP can be fatal or can cause long term or permanent neurological damage. We present here a case report of AIP where the diagnosis was missed. The diversity of symptoms and details concerning the treatment options for AIP are discussed.

  18. Differential diagnosis of acute abdominal pain – acute intermittent porphyria

    Mislav Klobučić

    2011-08-01

    Full Text Available Acute intermittent porphyria (AIP is a rare autosomal dominant disorder of heme biosynthesis in liver due to deficiency of porphobilinogen deaminase enzyme. Clinically, AIP is dominatedby a colicky type pain, which does not subside after taking usual analgesics. Additional frequent symptoms are vomiting, hypertension, peripheral neuropathy, seizures, depression, delirium and coma. This paper reported a case of a twenty-fi- ve-year-old female patient, who had undergone a period of six days between the first presentationto the medical department and the diagnosis confirmation. It has accentuated possible mistakes in symptomatic therapy administration as well as dangers of a delayed diagnosis.

  19. Acute intermittent porphyria and pregnancy: an obstetric challenge

    Pragati Meena

    2016-02-01

    Full Text Available Acute intermittent porphyria is a rare autosomal dominant disease caused by a mutation in the gene coding for the porphobillinogen deaminase enzymes in heam biosynthesis. The disease manifests as acute attacks of neuropsychiatric dysfunction and neurovisceral manifestations presenting as acute abdomen. In pregnancy, 54% patient has exacerbation of attacks in the form of seizures and acute abdomen occurs due to hormonal changes. Prevalence of acute intermittent porphyria is 1-2/200000 in general. Here we report a case of 36 year old women, G4P1L2A2 presenting at 10+4 weeks of gestation requesting pregnancy termination. Patient was diagnosed as case of acute intermittent porphyria with porphyic polyneuropathy 6 months back. At that time her main symptoms were acute pain abdomen with numbness and weakness in all four limbs. Her urinary porphobillinogen and 5 ALA raised. Her CECT of brain and nerve conduction studies were normal. Since then she is on Tablet Gabapentin 300 mg H.S. She underwent successful pregnancy termination by suction and evacuation under spinal anesthesia and she refused for copper-T insertion. Only safe drugs were used for procedure and she was discharged with advice of barrier contraception. [Int J Reprod Contracept Obstet Gynecol 2016; 5(2.000: 542-544

  20. Late Acute Intermittent Porphyria Attack In A Patient With Type 2 Diabetes

    Toma Nicoleta; Stancu Maria M.; Savu Octavian

    2015-01-01

    Background. Acute intermittent porphyria (AIP) is a hereditary metabolic aberration resulting from a partial defect in the activity of the enzyme porphobilinogen deaminase (PBDG) during the course of haeme synthesis. Diabetic metabolism may attenuate the episodes of porphyria related symptoms.

  1. Communication with acute intermittent porphyria patients who have tracheostomy

    Sevda Arslan

    2013-07-01

    Full Text Available Objective: Introducing acute intermittent porphyria disease and investigating the communication techniques for acute intermittent porphyria patients who have tracheostomyCase Report: 26 years old woman patient consulted to the hospital when she was 13 years old with nausea and vomiting complaints. In 2008, because of respiratory arrest, tracheostomy was implemented to the patient who had acute intermittent porphyria diagnose. The patient had two bullous lesions on the left hand and hyperpigmentation’s on the face and legs. As a result of metabolic acidosis (because of urine disease, the patient was taken to dialysis. After six months of dialysis, hypernatremia was found in the laboratory tests (Na: 85.Period of acute crisis developed In the patient with hypertension, atrophy in the muscles, fainting, abdominal pain, nausea, vomiting and diarrhea. Because of serious diarrhea, TPN was started for the patient who was fed with gavage before. Laboratory test results are Na:126, K:8.1, BUN:23.83, Urine:51, Creatinine:0.94, Leukocyte:20.4, erytrocyte:2.22, Hb:6.87g/dl, Hct: %20.9, Plt:106. Result: It is really difficult to communicate with these patients with lifespan limited because of an extremely severe clinical condition and tracheostomy.

  2. Tissue-specific splicing mutation in acute intermittent porphyria

    An inherited deficiency of porphobilinogen deaminase in humans is responsible for the autosomal dominant disease acute intermittent porphyria. Different classes of mutations have been described at the protein level suggesting that this is a heterogeneous disease. It was previously demonstrated that porphobilinogen deaminase is encoded by two distinct mRNA species expressed in a tissue-specific manner. Analysis of the genomic sequences indicated that these two mRNAs are transcribed from two promoters and only differ in their first exon. The first mutation identified in the human porphobilinogen deaminase gene is a single-base substitution (G → A) in the canonical 5' splice donor site of intron 1. This mutation leads to a particular subtype of acute intermittent porphyria characterized by the restriction of the enzymatic defect to nonerythropoietic tissues. Hybridization analysis using olignonucleotide probes after in vitro amplification of genomic DNA offers another possibility of detecting asymptomatic carriers of the mutation in affected families

  3. Tissue-specific splicing mutation in acute intermittent porphyria

    Grandchamp, B.; Picat, C. (Laboratoire de Genetique Moleculaire, Paris (France)); Mignotte, V.; Romeo, P.H.; Goossens, M. (Institut National de la Sante et de la Recherche Medicale, Creteil (France)); Wilson, J.H.P.; Sandkuyl, L. (Erasmus Univ., Rotterdam (Netherlands)); Te Velde, K. (Saint Geertruiden Hospital, Deventer (Netherlands)); Nordmann, Y. (Hopital Louis Mourier, Colombes (France))

    1989-01-01

    An inherited deficiency of porphobilinogen deaminase in humans is responsible for the autosomal dominant disease acute intermittent porphyria. Different classes of mutations have been described at the protein level suggesting that this is a heterogeneous disease. It was previously demonstrated that porphobilinogen deaminase is encoded by two distinct mRNA species expressed in a tissue-specific manner. Analysis of the genomic sequences indicated that these two mRNAs are transcribed from two promoters and only differ in their first exon. The first mutation identified in the human porphobilinogen deaminase gene is a single-base substitution (G {yields} A) in the canonical 5{prime} splice donor site of intron 1. This mutation leads to a particular subtype of acute intermittent porphyria characterized by the restriction of the enzymatic defect to nonerythropoietic tissues. Hybridization analysis using olignonucleotide probes after in vitro amplification of genomic DNA offers another possibility of detecting asymptomatic carriers of the mutation in affected families.

  4. Liver transplantation for acute intermittent porphyria:a viable treatment?

    Faisal S Dar; Koji Asai; Ali Raza Haque; Thomas Cherian; Mohamed Rela; Nigel Heaton

    2010-01-01

    BACKGROUND:Acute intermittent porphyria (AIP) is the most common hepatic porphyria. Its clinical presentation includes severe disabling and life-threatening neurovisceral symptoms and acute psychiatric symptoms. These symptoms result from the overproduction and accumulation of porphyrin precursors, 5-aminoleuvulinic acid (ALA) and porphobilinogen (PBG). The effect of medical treatment is transient and is not effective once irreversible neurological damage has occurred. Liver transplantation (LT) replaces hepatic enzymes and can restore normal excretion of ALA and PBG and prevent acute attacks. METHOD:Two cases of LT for AIP were identiifed retro-spectively from a prospectively maintained LT database. RESULT:LT was successful with resolution of AIP in two patients who suffered from repeated acute attacks. CONCLUSION:LT can correct the underlying metabolic abnormality in AIP and improves quality of life signiifcantly.

  5. An update of clinical management of acute intermittent porphyria

    Pischik E

    2015-09-01

    Full Text Available Elena Pischik,1,2 Raili Kauppinen,11Porphyria Research Unit, Division of Endocrinology, Department of Medicine, University Central Hospital of Helsinki, Helsinki, Finland; 2Department of Neurology, Consultative and Diagnostic Centre with Polyclinics, St Petersburg, Russia Abstract: Acute intermittent porphyria (AIP is due to a deficiency of the third enzyme, the hydroxymethylbilane synthase, in heme biosynthesis. It manifests with occasional neuropsychiatric crises associated with overproduction of porphyrin precursors, aminolevulinic acid and porphobilinogen. The clinical criteria of an acute attack include the paroxysmal nature and various combinations of symptoms, such as abdominal pain, autonomic dysfunction, hyponatremia, muscle weakness, or mental symptoms, in the absence of other obvious causes. Intensive abdominal pain without peritoneal signs, acute peripheral neuropathy, and encephalopathy usually with seizures or psychosis are the key symptoms indicating possible acute porphyria. More than fivefold elevation of urinary porphobilinogen excretion together with typical symptoms of an acute attack is sufficient to start a treatment. Currently, the prognosis of the patients with AIP is good, but physicians should be aware of a potentially fatal outcome of the disease. Mutation screening and identification of type of acute porphyria can be done at the quiescent phase of the disease. The management of patients with AIP include following strategies: A, during an acute attack: 1 treatment with heme preparations, if an acute attack is severe or moderate; 2 symptomatic treatment of autonomic dysfunctions, polyneuropathy and encephalopathy; 3 exclusion of precipitating factors; and 4 adequate nutrition and fluid therapy. B, during remission: 1 exclusion of precipitating factors (education of patients and family doctors, 2 information about on-line drug lists, and 3 mutation screening for family members and education about precipitating factors in

  6. Antinuclear antibodies and the diagnosis of systemic lupus erythematosus in patients with acute intermittent porphyria.

    Allard, S A; Charles, P. J.; Herrick, A. L.; McColl, K E; Scott, J. T.

    1990-01-01

    To investigate the previously postulated association of systemic lupus erythematosus (SLE) and porphyria 38 patients with various types of porphyria were investigated for clinical and laboratory evidence of a connective tissue disease. Antinuclear antibodies (ANAs) were found in 8/15 (53%) patients with acute intermittent porphyria. These patients were more likely to have had a recent acute attack of porphyria, but only one patient had clinical evidence of SLE. Antinuclear antibodies were not...

  7. Psychosocial Aspects of Predictive Genetic Testing for Acute Intermittent Porphyria in Norwegian Minors

    Andersen, Janice; Sandberg, Sverre; Raaheim, Maalfrid; Gjengedal, Eva

    2011-01-01

    Objective: The Norwegian Porphyria Centre routinely offers genetic counselling and predictive genetic testing in families diagnosed with porphyria. The aim of this study was to investigate the subjective experiences of adolescents and young adults who were genetically tested for acute intermittent porphyria (AIP) as minors. What were the psychosocial consequences and how were these handled?

  8. Red cell survival and sequestration in acute intermittent porphyria

    Life span and sequestration of red cells have been studied in twenty one proved cases of acute intermittent porphyria of different age and sex group from Bikaner District, Rajasthan State (India). Chromium-51 labelled red cells were used in the study and the excess count method of Bughe Jones and Szur was used to calculate the index of sequestration. The mean apparent half survival time of erythrocytes in the control subjects was 25.9 +- 2.9 (S.D.) days and the same in the prophyria patients was 27.0 +- 3.8 days. This shows that the life span of red cells is normal in both the patient and the control. Excess destruction of red blood cells was found to take place in either spleen or liver in the disease and no excess accumulation of erythrocytes occurred over spleen as compared to liver. (M.G.B.)

  9. Late Acute Intermittent Porphyria Attack In A Patient With Type 2 Diabetes

    Toma Nicoleta

    2015-06-01

    Full Text Available Background. Acute intermittent porphyria (AIP is a hereditary metabolic aberration resulting from a partial defect in the activity of the enzyme porphobilinogen deaminase (PBDG during the course of haeme synthesis. Diabetic metabolism may attenuate the episodes of porphyria related symptoms.

  10. Acute intermittent porphyria in two patients on anticonvulsant therapy and with normal erythrocyte porphobilinogen deaminase activity.

    Herrick, A. L.; McColl, K E; Moore, M R; Brodie, M J; Adamson, A R; Goldberg, A

    1989-01-01

    1. Acute intermittent porphyria (AIP) is sometimes termed a 'pharmacogenetic' disease. patients with genetic deficiency of the enzyme porphobilinogen deaminase are liable to develop acute attacks of porphyria if exposed to a variety of drugs. 2. Two patients are reported who had no evidence of deficiency of erythrocyte porphobilinogen deaminase yet developed typical attacks of AIP while on anticonvulsant therapy. 3. Normal activity of erythrocyte porphobilinogen deaminase does not completely ...

  11. Abdominal pain and syndrome of inappropriate antidiuretic hormone secretion as clinical presentation of acute intermittent porphyria.

    Valle Feijóo, M L; Bermúdez Sanjurjo, J R; González Vázquez, L; Rey Martínez, M; de la Fuente Aguado, J

    2015-01-01

    Acute intermittent porphyria (AIP) is a rare condition characterized by abdominal pain and a wide range of nonspecific symptoms. We report the case of a woman with abdominal pain and syndrome of inappropriate antidiuretic hormone secretion (SIADH) as clinical presentation of AIP. The diagnosis was achieved through the etiologic study of the SIADH. PMID:25796467

  12. Acute intermittent porphyria caused by novel mutation in HMBS gene, misdiagnosed as cholecystitis

    Alfadhel M

    2014-11-01

    Full Text Available Majid Alfadhel,1,3 Neam Saleh,2 Helal Alenazi,2 Henry Baffoe-Bonnie21Division of Genetics, Department of Pediatrics, 2Division of General Medicine, Department of Medicine, King Abdulaziz Medical City, Riyadh, Kingdom of Saudi Arabia; 3College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi ArabiaBackground: Acute intermittent porphyria (AIP is an autosomal dominant neurovisceral inherited disorder due to a defect in the heme biosynthesis pathway. Misdiagnosis of the porphyrias is not uncommon.Case report: We present a case of a 26-year-old female with suspected acute cholecystitis, mental status changes, and seizures. Biochemical and molecular investigations confirmed the diagnosis of AIP by findings of elevated urinary porphobilinogen, 5-aminolevulinic acid, and total porphyrins. DNA molecular testing showed a novel heterozygous mutation (c. 760delC p.L254X in the exon11 of the HMBS gene. To the best of our knowledge, this is the first report of a misdiagnosis of AIP presenting with acute cholecystitis.Conclusion: Clinicians are alerted to consider the possibility of AIP in an adult presenting with an acute abdomen, features of cholecystitis, and neuropsychiatric manifestations.Keywords: porphyria, cholecystitis, acute abdomen, acute intermittent porphyria, HMBS gene, hydroxymethylbilane synthase

  13. Anesthetic management of vaginal tear repair during early puerperium in a patient with acute intermittent porphyria

    Mahmood Ghazanwy

    2014-04-01

    Full Text Available A 26 year old female with history of acute intermittent porphyria (AIP was scheduled for vaginal tear repair after delivering her first baby. Raised blood pressure during her antenatal period was safely treated with α-methyl dopa. Her preoperative examination revealed no symptoms suggestive of acute exacerbation of AIP. Anesthesia was induced with fentanyl and propofol, and a proseal laryngeal mask airway (LMA was inserted and maintained with intermittent propofol and inhalation of isoflurane in nitrous oxide and oxygen. Her intraoperative and postoperative period remained uneventful.

  14. Acute intermittent porphyria presenting with neurological emergency: Review of six cases

    Kochar Dhanpat

    2007-01-01

    Full Text Available Acute intermittent porphyria presenting with short duration of gastrointestinal symptoms followed by rapidly progressive fulminant neurological syndrome during first attack is relatively uncommon. It is a neurological emergency and mimics many other psychiatric and medical disorders and can be fatal if it remains undiagnosed and untreated. Further, specific treatment in the form of Heme arginate is not universally available and very costly, so high clinical suspicion and early diagnosis and management of acute attack and prevention of further attacks are very important. We report a series of six cases who presented with convulsion and/or polyneuropathy early in the course of disease to highlight this fact.

  15. Acute intermittent porphyria: comorbidity and shared familial risks with schizophrenia and bipolar disorder in Sweden.

    Cederlöf, Martin; Bergen, Sarah E; Larsson, Henrik; Landén, Mikael; Lichtenstein, Paul

    2015-12-01

    Acute intermittent porphyria (AIP) has been associated with schizophrenia in some studies, but prior research is limited by the absence of comparison populations. Here, we linked Swedish registers to examine the risk of schizophrenia and bipolar disorder in 717 individuals diagnosed with AIP and their first-degree relatives, compared with matched individuals without AIP and their first-degree relatives. Individuals with AIP had a fourfold increased risk of schizophrenia or bipolar disorder. Similarly, relatives of individuals with AIP had double the risk of schizophrenia or bipolar disorder, suggesting that these associations may be as a result of common genetic influences. PMID:26494868

  16. Anesthetic implication of tricuspid valve replacement in a patient with acute intermittent porphyria.

    Saberi, Kianoush; Salehi, Mehrdad; Rahmanian, Mehrzad; Bakhshandeh, Ali Reza; Mahlabani, Mohammad

    2016-01-01

    Facing a patient with acute intermittent porphyria (AIP), there is narrow safety margin which circumscribe all the therapeutic actions including choice of drugs. This would become even more complicated when it comes to a stressful and drug-dependent process like a cardiopulmonary bypass. According to author's researches, no specific AIP case of tricuspid valve (TV) replacement is reported recently. Furthermore, fast-track anesthesia was safely used in this 37-year-old male known the case of AIP, who was a candidate for TV replacement and removing the port catheter. The patient was extubated subsequently, only 3 h after entering the Intensive Care Unit. PMID:27052088

  17. Anesthetic implication of tricuspid valve replacement in a patient with acute intermittent porphyria

    Kianoush Saberi

    2016-01-01

    Full Text Available Facing a patient with acute intermittent porphyria (AIP, there is narrow safety margin which circumscribe all the therapeutic actions including choice of drugs. This would become even more complicated when it comes to a stressful and drug-dependent process like a cardiopulmonary bypass. According to author′s researches, no specific AIP case of tricuspid valve (TV replacement is reported recently. Furthermore, fast-track anesthesia was safely used in this 37-year-old male known the case of AIP, who was a candidate for TV replacement and removing the port catheter. The patient was extubated subsequently, only 3 h after entering the Intensive Care Unit.

  18. A family with accute intermittent porphyria

    Porphyrias are inherited defects in heme metabolism that result in excessive secretion of porphyrins and porphyrin precursors. Porphyrias can be classified into acute, (neuropsychiatric), cutaneous and mixed forms. There are seven main types of porphyrias, acute intermittent porphyria and plumboporphyria are predominantly neuropsychiatric, congenital erythropoietic porphyria, porphyria cutanea tarda and erythropoietic protoporphyria have predominantly cutaneous manifestations and hereditary coproporphyria and variegate porphyria are classified as mixed as they both have neuropsychiatric and cutaneous features. They cause life-threatening attacks of neurovisceral symptoms that mimic many other acute medical and psychiatric conditions. Lack of clinical recognition often delays effective treatment and inappropriate diagnostic tests may lead to misdiagnosis and inappropriate treatment. Although the specific enzyme and gene defect have been identified, diagnosis and treatment of these disorders present formidable challenges because their signs and symptoms mimic other common conditions. We present a case report of a 13 years old girl who suffers from acute intermittent porphyria and the family tree showing all members who suffer from it. (author)

  19. Acute intermittent porphyria with syndrome of inappropriate antidiuretic hormone secretion (SIADH and neurological crisis, successfully treated with haemodialysis

    P. S. Singh

    2014-04-01

    Full Text Available We report a 35 years old male, a case of Acute Intermittent Porphyria (AIP with Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH and neurological crisis for its rarity. Since specific parenteral medication (hemin was not available, patient was empirically treated with haemodialysis with satisfactory outcome. [Int J Res Med Sci 2014; 2(2.000: 795-797

  20. Acute hepatic porphyria and hepatocellular carcinoma.

    Kauppinen, R.; Mustajoki, P

    1988-01-01

    In this study we examined the case histories of 163 living and 82 deceased adult Finnish patients with acute hepatic porphyria. There were 184 patients with acute intermittent porphyria and 61 patients with variegate porphyria. Among the 124 of the 163 living patients, who were traced 1984-1985, no hepatocellular carcinoma was found. Among the 82 deceased patients the cause of death was porphyria in 29 (36%), cardiovascular disease in 23 (29%) and hepatocellular carcinoma in 7 (9%). Of the 7 ...

  1. MR imaging of acute intermittent porphyria mimicking reversible posterior leukoencephalopathy syndrome

    Utz, N.; Kinkel, B.; Hedde, J.P.; Bewermeyer, H. [Staedtisches Krankenhaus Koeln-Merheim, Koeln (Germany). Neurologische Klinik

    2001-12-01

    Reversible posterior leukoencephalopathy syndrome (PLS) is characterized by headache, altered mental function, visual disturbances and seizures. Neuroimaging studies suggest a white-matter oedema, predominantly in the posterior parietal-temporal-occipital regions of the brain. We present the case of a 30-year-old woman who had suffered her first attack of acute intermittent porphyria (AIP). Following 1 week of abdominal pain she developed several generalized seizures, and hallucinations, and exhibited a progressive deterioration of the consciousness. T2-weighted images, especially fluid-attenuated inversion recovery (FLAIR) sequences showed bilateral lesions in the posterior frontal, parietal and occipital cortex and subcortical white matter. Following treatment with haematin and a high carbohydrate diet the patient's condition improved. Follow-up magnetic resonance imaging (MRI) revealed complete resolution of the lesions. To our knowledge, this is the first report concerning a completely reversible PLS in AIP. (orig.)

  2. MR imaging of acute intermittent porphyria mimicking reversible posterior leukoencephalopathy syndrome

    Reversible posterior leukoencephalopathy syndrome (PLS) is characterized by headache, altered mental function, visual disturbances and seizures. Neuroimaging studies suggest a white-matter oedema, predominantly in the posterior parietal-temporal-occipital regions of the brain. We present the case of a 30-year-old woman who had suffered her first attack of acute intermittent porphyria (AIP). Following 1 week of abdominal pain she developed several generalized seizures, and hallucinations, and exhibited a progressive deterioration of the consciousness. T2-weighted images, especially fluid-attenuated inversion recovery (FLAIR) sequences showed bilateral lesions in the posterior frontal, parietal and occipital cortex and subcortical white matter. Following treatment with haematin and a high carbohydrate diet the patient's condition improved. Follow-up magnetic resonance imaging (MRI) revealed complete resolution of the lesions. To our knowledge, this is the first report concerning a completely reversible PLS in AIP. (orig.)

  3. High prevalence of and potential mechanisms for chronic kidney disease in patients with acute intermittent porphyria.

    Pallet, Nicolas; Mami, Iadh; Schmitt, Caroline; Karim, Zoubida; François, Arnaud; Rabant, Marion; Nochy, Dominique; Gouya, Laurent; Deybach, Jean-Charles; Xu-Dubois, Yichum; Thervet, Eric; Puy, Hervé; Karras, Alexandre

    2015-08-01

    Acute intermittent porphyria (AIP) is a genetic disorder of the synthesis of heme caused by a deficiency in hydroxymethylbilane synthase (HMBS), leading to the overproduction of the porphyrin precursors δ-aminolevulinic acid and porphobilinogen. The aim of this study is to describe the clinical and biological characteristics, the renal pathology, and the cellular mechanisms of chronic kidney disease associated with AIP. A total of 415 patients with HMBS deficiency followed up in the French Porphyria Center were enrolled in 2003 in a population-based study. A follow-up study was conducted in 2013, assessing patients for clinical, biological, and histological parameters. In vitro models were used to determine whether porphyrin precursors promote tubular and endothelial cytotoxicity. Chronic kidney disease occurred in up to 59% of the symptomatic AIP patients, with a decline in the glomerular filtration rate of ~1 ml/min per 1.73 m(2) annually. Proteinuria was absent in the vast majority of the cases. The renal pathology was a chronic tubulointerstitial nephropathy, associated with a fibrous intimal hyperplasia and focal cortical atrophy. Our experimental data provide evidence that porphyrin precursors promote endoplasmic reticulum stress, apoptosis, and epithelial phenotypic changes in proximal tubular cells. In conclusion, the diagnosis of chronic kidney disease associated with AIP should be considered in cases of chronic tubulointerstitial nephropathy and/or focal cortical atrophy with severe proliferative arteriosclerosis. PMID:25830761

  4. Spectrum of emergency department presentation in patients of acute intermittent porphyria: Experience from a North Indian tertiary care center

    Kumar Susheel

    2010-01-01

    Full Text Available Of the porphyrias, acute intermittent porphyria (AIP is the most frequently encountered porphyria. The clinical characterestics of thirteen patients of AIP who presented to the Emergency Department were analyzed. The most common precipitating factor was drugs. Eleven patients presented with pain abdomen. Neurological manifestations included: Seizures in six and motor weakness in six. Of the four patients with hyponatremia, three had associated neuropathy and the fourth patient demonstrated a severe course marked by pontine-extrapontine myelinolysis and profound adrenergic activity. In conclusion, even though AIP is less frequently reported from India the emergency physicians should be vigilant to exclude the diagnostic possibility of AIP in a patient with an appropriate clinical setting.

  5. Characterization of the Porphobilinogen Deaminase Deficiency in Acute Intermittent Porphyria: IMMUNOLOGIC EVIDENCE FOR HETEROGENEITY OF THE GENETIC DEFECT

    Anderson, Peter M.; Reddy, Raman M.; Anderson, Karl E.; Desnick, Robert J

    1981-01-01

    The molecular pathology of the porphobilinogen (PBG)-deaminase deficiency in heterozygotes for acute intermittent porphyria (AIP) was investigated by means of biochemical and immunologic techniques. The stable enzyme-substrate intermediates (A, B, C, D, and E) of PBG-deaminase were separated by anion-exchange chromatography of erythrocyte lysates from heterozygotes for AIP and normal individuals. In normal lysates, the intermediates eluted in a characteristic pattern with decreasing amounts o...

  6. Glucose Effect in the Acute Porphyrias

    ... You are here Home Diet and Nutrition The glucose effect in acute porphyrias The disorders Acute Intermittent ... are treated initially with the administration of carbohydrate/glucose. This therapy has its basis in the ability ...

  7. Mitochondrial energetic defects in muscle and brain of a Hmbs-/- mouse model of acute intermittent porphyria.

    Homedan, Chadi; Schmitt, Caroline; Laafi, Jihane; Gueguen, Naïg; Desquiret-Dumas, Valérie; Lenglet, Hugo; Karim, Zoubida; Gouya, Laurent; Deybach, Jean-Charles; Simard, Gilles; Puy, Hervé; Malthièry, Yves; Reynier, Pascal

    2015-09-01

    Acute intermittent porphyria (AIP), an autosomal dominant metabolic disease (MIM #176000), is due to a deficiency of hydroxymethylbilane synthase (HMBS), which catalyzes the third step of the heme biosynthetic pathway. The clinical expression of the disease is mainly neurological, involving the autonomous, central and peripheral nervous systems. We explored mitochondrial oxidative phosphorylation (OXPHOS) in the brain and skeletal muscle of the Hmbs(-/-) mouse model first in the basal state (BS), and then after induction of the disease with phenobarbital and treatment with heme arginate (HA). The modification of the respiratory parameters, determined in mice in the BS, reflected a spontaneous metabolic energetic adaptation to HMBS deficiency. Phenobarbital induced a sharp alteration of the oxidative metabolism with a significant decrease of ATP production in skeletal muscle that was restored by treatment with HA. This OXPHOS defect was due to deficiencies in complexes I and II in the skeletal muscle whereas all four respiratory chain complexes were affected in the brain. To date, the pathogenesis of AIP has been mainly attributed to the neurotoxicity of aminolevulinic acid and heme deficiency. Our results show that mitochondrial energetic failure also plays an important role in the expression of the disease. PMID:26071363

  8. Intensive care management of patients with acute intermittent porphyria: Clinical report of four cases and review of literature

    Mehta Madhur

    2010-01-01

    Full Text Available Acute intermittent porphyria (AIP, the most common and the most severe form of acute hepatic porphyria, is an autosomal dominant condition. It results from lower-than-normal levels (less than 50% of porphobilinogen (PBG deaminase. Patients may present commonly with gastrointestinal complaints and neuropsychiatric manifestations. Diagnosis may be confirmed with the presence of intermediary metabolites of haem synthesis, amino levulinic acid (ALA and PBG in urine or with specific enzyme assays. Abdominal pain is the most common symptom (90%. Peripheral polyneuropathy, primarily motor with flaccid paresis of proximal musculature, with or without autonomic involvement, is characteristic. Respiratory failure necessitates ventilator and intensive care support. Avoidance of precipitating factors and the use of haem preparations and intravenous dextrose form the basis of management. Gabapentin and propofol, rather than the conventional antiepileptics appear to be the appropriate choice for seizure control. Here, we present intensive care management of four cases of AIP with varying clinical presentation.

  9. Acute intermittent porphyria leading to posterior reversible encephalopathy syndrome (PRES): a rare cause of abdominal pain and seizures.

    Dagens, Andrew; Gilhooley, Michael James

    2016-01-01

    Acute intermittent porphyria (AIP) is an inherited deficiency in the haem biosynthesis pathway. AIP is rare, affecting around 1 in 75 000 people. Acute attacks are characterised by abdominal pain associated with autonomic, neurological and psychiatric symptoms. AIP is rarely associated with posterior reversible encephalopathy syndrome (PRES). PRES is a clinicoradiological condition caused by the failure of the posterior circulation to autoregulate, resulting in cerebral oedema, headaches, nausea and seizures. This association is important because drugs used in the management of seizures may worsen an attack of AIP. This article describes a case of AIP and PRES in a young woman. PMID:27277587

  10. A novel mutation in the porphobilinogen deaminase gene in an extended Chinese family with acute intermittent porphyria.

    Yang, Jing; Wang, Honglian; Yin, Kunlun; Hua, Baolai; Zhu, Tienan; Zhao, Yongqiang; Guo, Shubin; Yu, Xuezhong; Wu, Wei; Zhou, Zhou

    2015-07-10

    Acute intermittent porphyria (AIP) is an autosomal dominant disorder caused by a partial deficiency of porphobilinogen deaminase (PBGD), the third enzyme of the heme biosynthetic pathway. Establishing accurate diagnoses of the patient and asymptomatic family members with AIP involves identifying the PBGD enzyme mutations directly. Genetic testing provides a precise diagnosis for the patient and other asymptomatic family members, and thereby proper treatments can be initiated to prevent the disease from progressing. In this study, we report a novel PBGD missense mutation, A G-to-C, at the position 988 resulting in Alanine to Proline (Ala330Pro), in a Chinese family. PMID:25870942

  11. Haplotype Analysis of Norwegian and Swedish Patients with Acute Intermittent Porphyria (AIP: Extreme Haplotype Heterogeneity for the Mutation R116W

    Kjersti Tjensvoll

    2003-01-01

    Full Text Available Acute intermittent porphyria (AIP, the most common of the acute porphyrias, is caused by mutations in the gene encoding hydroxymethylbilane synthase (HMBS also called porphobilinogen deaminase (PBGD. The mutation spectrum in the HMBS gene is characterized by a majority of family specific mutations. Among the exceptions are R116W and W198X, with high prevalence in both the Dutch and Swedish populations. These two mutations were also detected in unrelated Norwegian patients. Thus, Norwegian and Swedish patients were haplotyped using closely linked flanking microsatellites and intragenic single nucleotide polymorphisms (SNPs to see if the high frequency of these two mutations is due to a founder effect. Twelve intragenic SNPs were determined by a method based on fluorescent restriction enzyme fingerprinting single-strand conformation polymorphism (F-REF-SSCP.

  12. A novel 3-base deletion (IVS3+2_4delTGG of the hydroxymethylbilane synthase gene in a Brazilian patient with acute intermittent porphyria

    Georgina Severo Ribeiro

    2007-01-01

    Full Text Available Acute intermittent porphyria (AIP, OMIM 176000 is an autosomal dominant metabolic disease caused by mutations in the gene encoding hydroxymethylbilane synthase (HMBS; EC 4.3.1.8; formely named porphobilinogen deaminase, PBGD, mapped to chromosome 11q23.3. We describe a novel mutation of the HMBS gene, a de novo 3-base deletion in the splicing donor site of intron 3 (IVS3+2_4delTGG in a woman affected by AIP. RT-PCR analysis revealed an abnormal HMBS mRNA, compatible with exon 3 skipping.

  13. Acute intermittent porphyria

    Syal, Kartik; Bhatt, Rashmi; Singh, Surinder; Ohri, Anil

    2015-01-01

    These discussions are selected from the weekly staff conferences in the Department of Medicine, University of California Medical Center, San Francisco. Taken from transcriptions, they are prepared by Drs. Martin J. Cline and Hibbard E. Williams, Assistant Professors of Medicine, under the direction of Dr. Lloyd H. Smith, Jr., Professor of Medicine and Chairman of the Department of Medicine.

  14. Porfiria aguda intermitente: relato de caso e revisão da literatura Acute intermittent porphyria: case report and review of the literature

    Daniela von Ah Lopes

    2008-12-01

    caso de porfiria aguda intermitente no pós-operatório de cirurgia bariátrica.Acute intermittent porphyria is an unusual pathology with potentially severe consequences when not early detected. Among the possible causes of porphyric crises decrease of caloric intake has been described. A case of acute intermittent porphyria in the late postoperative period of a bariatric surgery performed for treatment of obesity is reported. A review of the diagnostic aspects and management of this pathology in the intensive care unit follows. A 31 year old woman was admitted in the intensive care unit three weeks after a bariatric surgery, with decreased level of consciousness and respiratory distress. The patient evolved with psychomotor agitation, mental confusion, abdominal pain and proximal tetraparesis. Diagnosis investigation disclosed severe hyponatremia (92mEq/L, hypomagnesemia, hypophosfatemia and hypocalcemia and cloudy urine without hematuria. Acute porphyria was suspected and the urine test detected high delta amino-levulinic acid and porphobilinogen. Treatment consisted of a correction of electrolyte disturbances and high carbohydrate intake. Hematin and heme arginate were not used, due to the difficulty to acquire the medication. After 8 months the patient progressed with full recovery of muscle strength and a clinical improvement. Acute intermittent porphyria has signs and symptoms common to several clinical, neurological, psychiatric and gastroenterological pathologies, which complicate diagnosis. Therefore, acute intermittent porphyria should be included in the differential diagnosis of neurological, psychiatric and gastroenterological alterations when results of all other exams are normal. Attention must be given to patients undergoing surgery mainly bariatric that, in addition to procedure stress, substantially limit the total caloric intake, potentially triggering crises. Review of literature did not disclose any report of acute intermittent porphyria crisis

  15. Markers for vulnerability in acute porphyria. A hypothesis paper.

    Thunell, S; Andersson, C; Carlmark, B; Floderus, Y; Grönqvist, S O; Harper, P; Henrichson, A; Lindh, U

    1995-04-01

    Previously symptomatic and permanently asymptomatic carriers of a gene mutation for acute intermittent porphyria as well as matched controls were screened with regard to a series of variables of possible relevance to the development of porphyric symptoms. The basis for the study was a concept of acute porphyria as a condition of a permanent system overload of oxidative stress, with long term effects on hepatic and renal tissue, and with instances of periodic overload of free radicals giving rise to acute neurologic involvement. Leukocyte concentrations of manganese, calcium, iron and zinc, as well as erythrocyte calcium differed between the groups, acute intermittent porphyria gene carriers, irrespective of previous porphyric illness, showing significantly higher levels than the controls. Manganese was found to be the most discriminative component of all the 78 variables investigated, accounting for about 98 per cent of the variance between the groups. An increment, by a factor of four, in cellular manganese is suggestive of an increase, in acute intermittent porphyria, of a manganese associated enzyme, e.g. glutamine synthetase, pyruvate carboxylase or mitochondrial superoxide dismutase. The best fit into the model considered is provided by a theory focused on superoxide dismutase, induced in response to superoxide anion radical produced from aminolaevulinic acid. In porphyria gene carriers seemingly resistant to porphyric manifestations, an increase in potentially prooxidant cellular iron is matched by a proportional increment in manganese, i.e. presumably by a corresponding mitochondrial superoxide dismutase induction. This mechanism is not operative in porphyric individuals prone to development of neuropsychiatric symptoms. In acute intermittent porphyria with a history of porphyric illness there is a positive correlation between erythrocyte manganese and serum folate and a negative correlation between leukocyte ferrochelatase activity and serum cobalamin

  16. Acute intermittent porphyria: A single-base deletion and a nonsense mutation in the human hydroxymethylbilane synthase gene, predicting truncations of the enzyme polypeptide

    Lee, G.L.; Astrin, K.H.; Desnick, R.J. [Mount Sinai School of Medicine, New York, NY (United States)

    1995-08-28

    Acute intermittent porphyria (AIP) is an autosomal-dominant inborn error of metabolism that results from the half-normal activity of the third enzyme in the heme biosynthetic pathway, hydroxymethylbilane synthase (HMB-synthase). AIP is an ecogenetic condition, since the life-threatening acute attacks are precipitated by various factors, including drugs, alcohol, fasting, and certain hormones. Biochemical diagnosis is problematic, and the identification of mutations in the HMB-synthase gene provides accurate detection of presymptomatic heterozygotes, permitting avoidance of the acute precipitating factors. By direct solid-phase sequencing, two mutations causing AIP were identified, an adenine deletion at position 629 in exon 11(629delA), which alters the reading frame and predicts premature truncation of the enzyme protein after amino acid 255, and a nonsense mutation in exon 12 (R225X). These mutations were confirmed by either restriction enzyme analysis or family studies of symptomatic patients, permitting accurate presymptomatic diagnosis of affected relatives. 29 refs., 2 figs.

  17. A novel mutation, IVS2-2AgG, associated with acute intermittent porphyria in a Chinese family.

    Jiao, Huang; Xianfeng, Zhang; Hui, Han; Yuhong, Zhan; Chu, Zhang

    2015-08-01

    Porphyria is a group of disorders caused by the accumulation of porphyrin and porphyrin precursors due to the abnormalities in certain enzymes that normally participate in the production of haem. We report a case of a woman with severe menstruation-related abdominal pain, hyponatraemia, and psychiatric symptoms. Excessive porphobilinogen was found in her urine. A new mutation in intron 2 (IVS2-2Ag→G), which had never previously been reported in patients with porphyria or in healthy Chinese population, was identified in the heterozygous state in the patient and her mother. PMID:26228342

  18. High frequency of mutations in exon 10 of the porphobilinogen deaminase gene in patients with a CRIM-positive subtype of acute intermittent porphyria

    Gu, X.F.; Rooij, F. de; Voortman, G.; Velde, K.T.; Nordmann, Y.; Grandchamp, B.

    1992-09-01

    Acute intermittent porphyria (AIP) is an autosomal dominant disease characterized by a partial deficiency of porphobilinogen (PBG) deaminase. Different subtypes of the disease have been defined, and more than 10 different mutations have been described. The authors focused their study on exon 10, since they previously found that three different mutations were located in this exon and that two of them seemed to be relatively common. They used denaturing gradient gel electrophoresis (DGGE) after in vitro amplification to detect all possible mutations in exon 10 in 41 unrelated AIP patients. In about one-fourth of these patients they could distinguish three abnormal migration patterns, indicating the presence of various mutations. Additional sequencing demonstrated the presence of three different single-base substitutions. Two of these mutations had already been described. A third one consisted of a C-to-T transition located at position 499 of the PBG deaminase mRNA and resulted in an Arg-to-Trp substitution. All three mutations were found in patients with crossreacting immunological material (CRIM)-positive forms of AlP. The high frequency of these mutations make DGGE analysis of exon 10 a useful approach allowing the direct detection of the DNA abnormality in most of the families with the CRIM-positive subtype of AlP. 23 refs., 3 figs., 1 tab.

  19. Liver Transplantation in the Management of Porphyria

    Singal, Ashwani K.; Parker, Charles; Bowden, Christine; Thapar, Manish; Liu, Lawrence; McGuire, Brendan M.

    2014-01-01

    Porphyrias are a group of eight metabolic disorders, each resulting from a mutation that affects an enzyme of the heme biosynthetic pathway. Porphyrias are classified as hepatic or erythropoietic, depending upon the site where the gene defect is predominantly expressed. Clinical phenotypes are classified as follows: (1) acute porphyrias with neurovisceral symptoms: acute intermittent porphyria; delta amino-levulinic acid hydratase deficiency porphyria; hereditary coproporphyria; and variegate...

  20. Acute Porphyria in a Patient with Arnold Chiari Malformation

    Shen, Jianbin; O’Keefe, Kevin; Webb, Lisa B.; DeGirolamo, Angela

    2015-01-01

    Patient: Female, 33 Final Diagnosis: Acute porphyria Symptoms: Abdominal pain • alternating bowel habits Medication: Metronidazole • bactrim • oxybutynin Clinical Procedure: EMG • porhyria workup Specialty: Neurology Objective: Rare disease Background: Acute porphyria and Arnold Chiari malformation are both uncommon genetic disorders without known association. The insidious onset, non-specific clinical manifestations, and precipitating factors often cause diagnosis of acute porphyria to be mi...

  1. Acute porphyrias: clinical spectrum of hodpitalized patients

    To determine characteristics, clinical features and triggers of acute porphyria in hospitalized patients presenting to a tertiary care center in Pakistan. Case records of 26 patients hospitalized with diagnosis were identified through computerized hospital patients data. The diagnosis of acute porphyria was based on pertinent clinical features and laboratory investigations after exclusion of other alternative diagnosis and patients previously diagnosed as porphyric. The data was analyzed through SPSS software version 11.0. Twelve patients (46.2%) were males. Mean age was 21 years. Most common manifestation were gastrointestinal (n=22; 88.5%) followed by neurological symptoms (n=14; 54%). Neurological manifestations included seizures (n=9; 34.6%) and neuropathy (n=6; 23%). One patient presented with depression and insomnia. Family history was positive in (n=8; 30.8%). Eighteen (69%) had history of previous attacks at their presentation to the hospital. Most common precipitating factor was eating outside (n=18; 69%). Porphyrias are uncommon and cryptic group of diseases. This study shows a slightly different gender distribution, earlier onset of symptoms, higher number of neuropsychiatric symptoms (especially seizures), more distal neuropathies and different precipitant in the studied subset of patients than described previously in the western studies. (author)

  2. Porphyria

    ... How is porphyria diagnosed? How is porphyria treated? Eating, Diet, and Nutrition Points to Remember Clinical Trials What are porphyrias? Porphyrias are rare disorders that affect mainly the skin or nervous system and may cause abdominal pain. These disorders are usually inherited, meaning ...

  3. Chester porphyria: a clinical study of a new form of acute porphyria.

    Qadiri, M R; Church, S. E.; McColl, K E; Moore, M R; Youngs, G. R.

    1986-01-01

    Acute porphyria afflicts a large kindred in Chester that stems from a marriage in 1896 that has produced 200 descendants; this is the largest porphyric kindred to be identified in the United Kingdom. Six members aged 51 or under died from the condition over the past eight years. The diagnosis of porphyria was overlooked in some as the symptoms may mimic those of other acute illnesses, so that incomplete or incorrect death certificates have been issued. Psychosis, hypertension, and renal compl...

  4. Porphyria

    Porphyrias are a group of genetic disorders caused by problems with how your body makes a substance ... carries oxygen. There are two main types of porphyrias. One affects the skin and the other affects ...

  5. Safety of general anaesthesia and surgery in acute hepatic porphyria.

    Dover, S B; Plenderleith, L; Moore, M R; McColl, K E

    1994-01-01

    Patients with acute hepatic porphyria are denied essential operations because of concern that general anaesthesia and surgery will precipitate a life threatening porphyric crisis. This study assessed the safety of surgery under general anaesthesia in these patients. A combined prospective and retrospective case note study, with a biochemical study, was conducted in 25 patients with acute hepatic porphyria undergoing 38 surgical operations. Clinical outcome measures were survival and occurrenc...

  6. Epidemiological study of the Danish Acute Intermittent Porphyriapopulation

    Brusgaard, Klaus

    The aim of our study was to describe the occurrence of Acute Intermittent Porphyria (AIP) in Denmark demographically, genetically and biochemically.The study was based on a database of porphobilinogen deaminase (PBGD) mutations detected in the period of 2000-2010. A total of 148 individuals were...... the study period. PBGD mutations were detected by standard exon and splice site sequencing procedures.The biochemical diagnosis of an acute porphyria attack was based on a PBG/creatinine ratio of ≥5.0 mmol/mol (reference interval 0.0–0.8 mmol/mol). Demographic distribution and prevalence: Region of......, 19 (26%) women). The total amount of measurements of biochemistry significant for acute porphyria attack in the registration period was 366, which corresponds to an average of 15 (1-83) per individual (32 (2-83) among the men, 9 (1-41) among the women) The 14 individuals who died during the...

  7. Porphyria in Sweden.

    Thunell, S; Floderus, Y; Henrichson, A; Harper, P

    2006-01-01

    In a brief survey the work of Swedish porphyrinologists through time is presented, from the organic chemist Jakob Berzelius 1840 to the molecular biologists of today. The building up in Stockholm of a Swedish national competence centre for porphyria is touched upon and the emergence of a computerized national register on the porphyria gene carriers in the country described. Figures for the prevalences of the seven different forms of porphyria diagnosed in Sweden are given. The geographical distribution of gene mutation spectra is shown for the most frequent form, acute intermittent porphyria. The organisation at Porphyria Centre Sweden of its diagnostic and consultative services is described, as is the decentralized model for porphyria care applied in the form of a clinical network covering the long and sparsely populated country. The ideas and activities of the Swedish Porphyria Patients' Association are presented. Its focus on protection-by-information of the porphyria gene carrier against maltreatment in health service contacts, and against other exposures to environmental threats to his or her health, is discussed. The combined efforts of the national porphyria centre and the patients' association have resulted in early and accurate diagnosis of most of the porphyria gene carriers in the country. The information to the carriers and to the health service regarding the mechanisms of the diseases and the importance of avoiding exposure to disease triggering environmental factors have greatly reduced porphyric morbidity. In the case of the acute porphyrias, by this programme and after the introduction of heme arginate in the therapy, mortality in the acute phase has become extremely rare in Sweden. In contrast, probably due to greater awareness of the high risk for liver cancer in acute porphyrias the number of hepatoma cases diagnosed has increased. The current research activities at the Porphyria Centre which aim at finding ways to substitute the mutated gene in

  8. Audit of the Use of Regular Haem Arginate Infusions in Patients with Acute Porphyria to Prevent Recurrent Symptoms

    Marsden, Joanne T.; Guppy, Simon; Stein, Penelope; Cox, Timothy M.; Badminton, Michael; Gardiner, Tricia; Barth, Julian H; Stewart, M. Felicity; Rees, David C.

    2015-01-01

    The National Acute Porphyria Service (NAPS) provides acute care support and clinical advice for patients in England with active acute porphyria requiring haem arginate treatment and patients with recurrent acute attacks.

  9. Cutaneous Porphyrias

    Christiansen, Anne L; Aagaard, Lise; Krag, Aleksander; Rasmussen, Lars M; Bygum, Anette

    2016-01-01

    Porphyrias are rare diseases caused by altered haem synthesis leading to the accumulation of different haem intermediates. Neurovisceral attacks may occur in acute porphyrias, while photosensitivity is the presenting symptom in cutaneous porphyrias. We present here an overview of symptoms and a...... flowchart for the diagnosis of cutaneous porphyrias, with recommendations for monitoring and an update of treatment options. From the Danish Porphyria Register, we present the incidences and approximate prevalences of cutaneous porphyrias within the last 25 years. A total of 650 patients with porphyria...... cutanea tarda were identified, 73 with erythropoietic protoporphyria, 9 with variegate porphyria, 4 with hereditary coproporphyria and one with congenital erythropoietic porphyria. The total incidence of all porphyrias was ~0.52/100,000 per year....

  10. Danos ao DNA promovidos por ácido 5-aminolevulínico: possível associação com o desenvolvimento de carcinoma hepatocelular em portadores de porfiria aguda intermitente DNA damage induced by 5-aminolevulinic acid: a possible association with the development of hepatocellular carcinoma in acute intermittent porphyria patients

    Janice Onuki

    2002-07-01

    Full Text Available 5-Aminolevulinic acid (ALA is a heme precursor accumulated in acute intermittent porphyria (AIP, which might be associated with hepatocellular carcinoma (HCC in symptomatic patients. Under metal catalyzed oxidation, ALA and its cyclic dimerization product, 3,6-dihydropyrazine-2,5-dipropanoic acid, produce reactive oxygen species that damage plasmid and calf thymus DNA bases, increase the steady state level of 8-oxo-7,8-dihydro-2´-deoxyguanosine in liver DNA and promote mitochondrial DNA damage. The final product of ALA, 4,5-dioxovaleric acid (DOVA, is able to alkylate guanine moieties, producing adducts. ALA and DOVA are mutagenic in bacteria. This review shows an up-to-date literature data that reinforce the hypothesis that the DNA damage induced by ALA may be associated with the development of HCC in AIP patients.

  11. [Neurocutaneous porphyrias].

    Frank, J

    2016-03-01

    Porphyrias comprise a heterogeneous group of predominantly genetically determined metabolic diseases which are due to a dysfunction in heme biosynthesis. Variegate porphyria and hereditary coproporphyria are referred to as neurocutaneous porphyrias because affected patients can develop both cutaneous symptoms on light-exposed body sites and potentially life-threatening acute neurovisceral symptoms, thereby mimicking several other diseases. In this overview, we provide an update on pathogenesis, clinical manifestation, diagnosis, and therapy of these two types of porphyria. PMID:26743053

  12. The little imitator--porphyria: a neuropsychiatric disorder.

    Crimlisk, H L

    1997-01-01

    Three common subtypes of porphyria give rise to neuropsychiatric disorders; acute intermittent porphyria, variegate porphyria, and coproporphyria. The second two also give rise to cutaneous symptoms. Neurological or psychiatric symptoms occur in most acute attacks, and may mimic many other disorders. The diagnosis may be missed because it is not even considered or because of technical problems, such as sample collection and storage, and interpretation of results. A negative screening test doe...

  13. Porphyria and anorexia: cause and effect

    Martins, Carlos R.; Bandeira, Barbara E.S.; Martinez, Alberto R. M.; Dalgalarrondo, Paulo; França, Marcondes C.

    2014-01-01

    Porphyrias are hereditary disorders related to impaired biosynthesis of heme and characterized by multisystemic manifestations. Acute intermittent porphyria (AIP) is the most common acute subtype of the disease, and often associated with psychiatric symptoms. We here report a patient who developed acute flaccid paralysis after remarkable weight loss, which was related to an eating disorder (anorexia nervosa). After an extensive neurologic workup, he was diagnosed with AIP. This case emphasize...

  14. Clinically Important Features of Porphyrin and Heme Metabolism and the Porphyrias

    Siddesh Besur

    2014-11-01

    Full Text Available Heme, like chlorophyll, is a primordial molecule and is one of the fundamental pigments of life. Disorders of normal heme synthesis may cause human diseases, including certain anemias (X-linked sideroblastic anemias and porphyrias. Porphyrias are classified as hepatic and erythropoietic porphyrias based on the organ system in which heme precursors (5-aminolevulinic acid (ALA, porphobilinogen and porphyrins are chiefly overproduced. The hepatic porphyrias are further subdivided into acute porphyrias and chronic hepatic porphyrias. The acute porphyrias include acute intermittent, hereditary copro-, variegate and ALA dehydratase deficiency porphyria. Chronic hepatic porphyrias include porphyria cutanea tarda and hepatoerythropoietic porphyria. The erythropoietic porphyrias include congenital erythropoietic porphyria (Gűnther’s disease and erythropoietic protoporphyria. In this review, we summarize the key features of normal heme synthesis and its differing regulation in liver versus bone marrow. In both organs, principal regulation is exerted at the level of the first and rate-controlling enzyme, but by different molecules (heme in the liver and iron in the bone marrow. We also describe salient clinical, laboratory and genetic features of the eight types of porphyria.

  15. MRI reveals reversible lesions resembling posterior reversible encephalopathy in porphyria

    We report a 20-year-old woman who had an attack of acute intermittent porphyria with seizures, hallucinations, autonomic and somatic neuropathy. T2-weighted MRI revealed multiple lesions which were no longer visible 3 months later. We suggest a similar mechanism to posterior reversible encephalopathy underlying cerebral symptoms in porphyria. (orig.)

  16. MRI reveals reversible lesions resembling posterior reversible encephalopathy in porphyria

    Celik, M. [Huesrev Gerede c, 128/4 Tesvikiye, 80690 Istanbul (Turkey); Department of Neurology, Sisli Etfal Education and Research Hospital, Sisli Etfal S., Sisli, Istanbul (Turkey); Forta, H.; Babacan, G. [Department of Neurology, Sisli Etfal Education and Research Hospital, Sisli Etfal S., Sisli, Istanbul (Turkey); Dalkilic, Tuerker [Department of Neurosurgery, Sisli Etfal Education and Research Hospital, Sisli Etfal S., Sisli, Istanbul (Turkey)

    2002-10-01

    We report a 20-year-old woman who had an attack of acute intermittent porphyria with seizures, hallucinations, autonomic and somatic neuropathy. T2-weighted MRI revealed multiple lesions which were no longer visible 3 months later. We suggest a similar mechanism to posterior reversible encephalopathy underlying cerebral symptoms in porphyria. (orig.)

  17. Porphyria Presenting as Diffuse Encephalopathy

    J Gordon Millichap

    2005-05-01

    Full Text Available An 18-year-old female presenting with seizures, myalgias, abdominal pain, headache and vomiting had multiple large contrast-enhancing white matter lesions on MRI and was diagnosed with acute intermittent porphyria (AIP, in a report from the Department of Neurology, Mayo Clinic, Rochester, MN.

  18. A case of fatal acute intermittent porphyria: laboratory diagnosis and pathogenesis considerations / Un caz fatal de porfirie acută intermitentă: diagnostic de laborator şi consideraţii patogenice

    Bălaşa Rodica

    2014-09-01

    Full Text Available Porfiria acută intermitentă (PAI este o boală metabolică, cu transmitere autosomal dominantă, cu alterarea căii de biosinteză a hemului prin deficitul enzimei porphobilinogen (PBG dezaminaza. Acest diagnostic trebuie să fie evocate în toate cazurile de adultii care prezintă simptome inexplicabile, dar cu unele caracteristici clinice sugestive: femei cu vârstă reproductivă, dureri abdominale, slăbiciune musculară, hiponatremie prelungită şi severă, urină închisă la culoare sau roşie.

  19. Studies in laboratory animals to assess the safety of anti-inflammatory agents in acute porphyria.

    McColl, K E; Thompson, G G; Moore, M R

    1987-01-01

    The safety of various anti-inflammatory drugs in acute porphyria was assessed by examining their effect on rat hepatic haem synthesis. Azapropazone, chloroquine, and gold increased delta-aminolaevulinic acid (ALA) synthase activity, indicating that they are liable to precipitate porphyric crises. Aspirin, ibuprofen, indomethacin, ketoprofen, flurbiprofen, phenylbutazone, naproxen, prednisolone, and penicillamine did not increase ALA synthase activity and should be safe in porphyria. Though th...

  20. Light-induced depigmentation in planarians models the pathophysiology of acute porphyrias.

    Stubenhaus, Bradford M; Dustin, John P; Neverett, Emily R; Beaudry, Megan S; Nadeau, Leanna E; Burk-McCoy, Ethan; He, Xinwen; Pearson, Bret J; Pellettieri, Jason

    2016-01-01

    Porphyrias are disorders of heme metabolism frequently characterized by extreme photosensitivity. This symptom results from accumulation of porphyrins, tetrapyrrole intermediates in heme biosynthesis that generate reactive oxygen species when exposed to light, in the skin of affected individuals. Here we report that in addition to producing an ommochrome body pigment, the planarian flatworm Schmidtea mediterranea generates porphyrins in its subepithelial pigment cells under physiological conditions, and that this leads to pigment cell loss when animals are exposed to intense visible light. Remarkably, porphyrin biosynthesis and light-induced depigmentation are enhanced by starvation, recapitulating a common feature of some porphyrias - decreased nutrient intake precipitates an acute manifestation of the disease. Our results establish planarians as an experimentally tractable animal model for research into the pathophysiology of acute porphyrias, and potentially for the identification of novel pharmacological interventions capable of alleviating porphyrin-mediated photosensitivity or decoupling dieting and fasting from disease pathogenesis. PMID:27240733

  1. 表现为可逆性后部白质脑病综合征的急性间歇性卟啉病(附1例报告)%Acute intermittent porphyria appeaed as reversible posterior leukoencephalopathy syndrome ( report of 1 case)

    高海凤; 鲁琳; 李永秋

    2012-01-01

    Objective To explore the clinical features of acute intermittent porphyria ( AIP) apperaed as reversible posterior leukoencephalopathy syndrome (RPLS). Methods The clinical date of one AIP patient apperaed as RPLS was retrospectively analyzed. Results This patient was a young woman. The main clinical manifastations were abdominal pain, seizures, psychological symptoms and autonomie nervous dysfunction. The laboratory examination showed hyponatremia, hypochloridemia and uroporphyrin positive. The MR1 indicate diffusely lesions located in bilateral posterior frontal lobe, parital and temporal lobe and bilateral cerebellar hemisphere, which were low signals in T, WI and high signals in T2WI and Flair imaging. The symptom was improved after treated with high volume of glucose and adenosine triphosphate, and the symptomatic treatments like correcting electrolyte turbulence etc. The reexamination of MRI showed the lesions were almost disappeared. Conclusions AIP is a rare cause of RPLS. The AIP patient apperaed as RPLS may suffer abdominal pain and nervous and psychological symptoms. Urine test and MRI may be helpful to diagnose.%目的 探讨表现为可逆性白质脑病综合征(RPLs)的急性间歇性卟啉病(AIP)的临床特点.方法 回顾性分析1例表现为RPLS的AIP患者的临床资料.结果 本例患者为青年女性,临床表现为腹痛、癫痫发作、精神症状、植物神经受累表现,检查发现低钠、低氯血症,尿卟啉定性阳性;头颅MRI示两侧额叶后部、顶叶、颞叶皮质和两侧小脑半球弥漫对称性片状异常信号,T1WI为等或低信号,T2WI及Flair序列呈高信号.经高糖、三磷酸腺苷以及纠正电解质紊乱等治疗后症状改善.复查头颅MRI示病变基本消失.结论 AIP是RPLS的罕见原因之一.表现为RPLS的AIP可有腹痛和神经精神症状等,尿检和影像学检查对诊断有帮助.

  2. Porphyria and anorexia: cause and effect.

    Martins, Carlos R; Bandeira, Barbara E S; Martinez, Alberto R M; Dalgalarrondo, Paulo; França, Marcondes C

    2014-12-01

    Porphyrias are hereditary disorders related to impaired biosynthesis of heme and characterized by multisystemic manifestations. Acute intermittent porphyria (AIP) is the most common acute subtype of the disease, and often associated with psychiatric symptoms. We here report a patient who developed acute flaccid paralysis after remarkable weight loss, which was related to an eating disorder (anorexia nervosa). After an extensive neurologic workup, he was diagnosed with AIP. This case emphasizes a deleterious vicious cycle between AIP and anorexia: porphyria may lead to anorexia and the carbohydrate restriction may lead to recurrent porphyric attacks. Therefore, an interruption of this cycle with psychiatric approaches to the eating disorders is crucial for long-term therapeutic efficacy. PMID:25988062

  3. Light-induced depigmentation in planarians models the pathophysiology of acute porphyrias

    Stubenhaus, Bradford M; Dustin, John P; Neverett, Emily R; Beaudry, Megan S; Nadeau, Leanna E; Burk-McCoy, Ethan; He, Xinwen; Pearson, Bret J; Pellettieri, Jason

    2016-01-01

    Porphyrias are disorders of heme metabolism frequently characterized by extreme photosensitivity. This symptom results from accumulation of porphyrins, tetrapyrrole intermediates in heme biosynthesis that generate reactive oxygen species when exposed to light, in the skin of affected individuals. Here we report that in addition to producing an ommochrome body pigment, the planarian flatworm Schmidtea mediterranea generates porphyrins in its subepithelial pigment cells under physiological conditions, and that this leads to pigment cell loss when animals are exposed to intense visible light. Remarkably, porphyrin biosynthesis and light-induced depigmentation are enhanced by starvation, recapitulating a common feature of some porphyrias – decreased nutrient intake precipitates an acute manifestation of the disease. Our results establish planarians as an experimentally tractable animal model for research into the pathophysiology of acute porphyrias, and potentially for the identification of novel pharmacological interventions capable of alleviating porphyrin-mediated photosensitivity or decoupling dieting and fasting from disease pathogenesis. DOI: http://dx.doi.org/10.7554/eLife.14175.001 PMID:27240733

  4. Porphyrias: A 2015 update.

    Karim, Zoubida; Lyoumi, Said; Nicolas, Gael; Deybach, Jean-Charles; Gouya, Laurent; Puy, Hervé

    2015-09-01

    The hereditary porphyrias comprise a group of eight metabolic disorders of the heme biosynthesis pathway. Each porphyria is caused by abnormal function at a separate enzymatic step resulting in a specific accumulation of heme precursors. Porphyrias are classified as hepatic or erythropoietic, based on the organ system in which heme precursors (δ-aminolevulinic acid [ALA], porphobilinogen and porphyrins) are overproduced. Clinically, porphyrias are characterized by acute neurovisceral symptoms, skin lesions or both. However, most if not all the porphyrias impair hepatic or gastrointestinal function. Acute hepatic porphyrias present with severe abdominal pain, nausea, constipation, confusion and seizure, which may be life threatening, and patients are at risk of hepatocellular carcinoma without cirrhosis. Porphyria Cutanea presents with skin fragility and blisters, and patients are at risk of hepatocellular carcinoma with liver iron overload. Erythropoietic protoporphyria and X-linked protoporphyria present with acute painful photosensitivity, and patients are at risk of acute liver failure. Altogether, porphyrias are still underdiagnosed, but once they are suspected, early diagnosis based on measurement of biochemical metabolites that accumulate in the blood, urine, or feces is essential so specific treatment can be started as soon as possible and long-term liver complications are prevented. Screening families to identify presymptomatic carriers is also crucial to prevent overt disease and chronic hepatic complications. PMID:26142871

  5. Audit of the Use of Regular Haem Arginate Infusions in Patients with Acute Porphyria to Prevent Recurrent Symptoms.

    Marsden, Joanne T; Guppy, Simon; Stein, Penelope; Cox, Timothy M; Badminton, Michael; Gardiner, Tricia; Barth, Julian H; Stewart, M Felicity; Rees, David C

    2015-01-01

    The National Acute Porphyria Service (NAPS) provides acute care support and clinical advice for patients in England with active acute porphyria requiring haem arginate treatment and patients with recurrent acute attacks.This audit examined the benefits and complications of regular haem arginate treatment started with prophylactic intent to reduce the frequency of recurrent acute attacks in a group of patients managed through NAPS. We included 22 patients (21 female and 1 male) and returned information on diagnosis, indications for prophylactic infusions, frequency and dose, analgesia, activity and employment and complications including thromboembolic disease and iron overload.The median age at presentation with porphyria was 21 years (range 9-44), with acute abdominal pain as the predominant symptom. Patients had a median of 12 (1-400) attacks before starting prophylaxis and had received a median of 52 (0-1,350) doses of haem arginate. The median age at starting prophylaxis was 28 years (13-58) with a median delay of 4 years (0.5-37) between presentation and prophylaxis. The frequency of prophylactic haem arginate varied from 1 to 8 per month, and 67% patients were documented as having a reduction in pain frequency on prophylaxis. Only one patient developed clinically significant iron overload and required iron chelation, but the number of venous access devices required varied from 1 to 15, with each device lasting a median of 1.2 years before requiring replacement. Six patients stopped haem arginate and in three this was because their symptoms had improved. Prophylactic haem arginate appears to be beneficial in patients with recurrent acute porphyria symptoms, but maintaining central venous access may prove challenging. PMID:25762493

  6. [Porphyrias and haem related disorders].

    Peoc'h, K; Martin-Schmitt, C; Talbi, N; Deybach, J-C; Gouya, L; Puy, H

    2016-03-01

    The hereditary porphyrias comprise a group of eight metabolic disorders of the haem biosynthesis pathway characterised by acute neurovisceral symptoms, skin lesions or both. Each porphyria is caused by abnormal function of a separate enzymatic step resulting in a specific accumulation of haem precursors. Seven porphyrias are the consequence of a partial enzyme deficiency while a gain of function mechanism has been recently characterised in a novel porphyria. Acute porphyrias present with severe abdominal pain, nausea, constipation, confusion and seizure, which may be life threatening. Cutaneous porphyrias can be present with either acute painful photosensitivity or skin fragility and blisters. Rare recessive porphyrias usually manifest in early childhood with either severe chronic neurological symptoms or chronic haemolysis and severe cutaneous photosensitivity. Porphyrias are still underdiagnosed, but once they are suspected, and depending on the clinical presentation, a specific and simple front line test allows the diagnosis in all symptomatic patients. Diagnosis is essential to institute as soon as possible a specific treatment. Screening families to identify presymptomatic carriers is crucial to prevent chronic complications and overt disease by counselling on avoiding potential precipitants. PMID:26774916

  7. Porphyria Cutanea Tarda: A rare metabolic condition in India

    B S Roopa; R Gurumoorthi; Ponnusankar Sivasankaran

    2015-01-01

    Porphyria cutanea tarda (PCT) is the most frequent type of porphyria worldwide and presents with skin symptoms only. Porphyrias are a group of eight panethnic inherited metabolic disorders of heme biosynthesis. Porphyria can affect peripheral, autonomic, and central nervous systems.In porphyria conditions there is accumulation of the hemeprecursor′s 5-aminolaevulinic acid, porphobilinogen, and porphyrins; which are associated with characteristic clinical feature with acute neurovisceral attac...

  8. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Lindsay B. Baker

    2015-07-01

    Full Text Available Intermittent sports (e.g., team sports are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h. Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1 potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2 the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3 what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports. Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before

  9. Severe porphyric neuropathy--importance of screening for porphyria in Guillain-Barré syndrome.

    Schutte, Clara-Maria; van der Meyden, Cornelius H; van Niekerk, Linette; Kakaza, Mandisa; van Coller, Riaan; Ueckermann, Veronica; Oosthuizen, Nicky M

    2016-01-01

    The hepatic porphyrias are a group of rare metabolic disorders, each of which is associated with a specific enzymatic alteration in the haem biosynthesis pathway. In South Africa (SA), a high incidence of variegate porphyria (VP) is seen as a result of a founder effect, but acute intermittent porphyria (AIP) is also encountered. The development of acute neurovisceral attacks is related to environmental factors, including medications, hormones and diet. A possible manifestation of a severe attack is rapidly progressing quadriparesis, which may mimic Guillain-Barré syndrome. We present four such cases, highlighting that acute porphyria should be considered in the differential diagnosis of Guillain-Barré syndrome. Three patients presented to Steve Biko Academic Hospital, Pretoria, SA, with progressive quadriparesis, and one to a private hospital with acute abdominal pain followed by rapidly progressive quadriparesis. Two patients had started antiretroviral therapy before the development of symptoms, and one had started antituberculosis therapy. All patients had marked weakness with depressed reflexes, and showed varying degrees of confusion. An initial diagnosis of Guillain-Barré syndrome led to administration of intravenous immunoglobulins in two patients. On testing for porphyria, it was found that two patients had AIP and two VP. Electrophysiological investigations revealed severe mainly motor axonal neuropathy in all. Two patients deteriorated to the point of requiring mechanical ventilation, and one of them died due to complications of critical illness. Haemin was administered to three patients, but the process of obtaining this medication was slow, which delayed the recommended early administration. The surviving patients showed minimal recovery and remained severely disabled. Porphyric neuropathy should always be considered as a differential diagnosis in a patient with an acute neuropathy, especially in SA. Absence of abdominal pain does not exclude the

  10. Porphyria Cutanea Tarda

    ... Favorite Name: Category: Share: Yes No, Keep Private Porphyria Cutanea Tarda Share | A porphyria is blood disorder in which cells fail to ... the substance (heme) that gives blood its color. Porphyria Cutanea Tarda, also called PCT, is the most ...

  11. Porphyria Cutanea Tarda: A rare metabolic condition in India

    B S Roopa

    2015-01-01

    Full Text Available Porphyria cutanea tarda (PCT is the most frequent type of porphyria worldwide and presents with skin symptoms only. Porphyrias are a group of eight panethnic inherited metabolic disorders of heme biosynthesis. Porphyria can affect peripheral, autonomic, and central nervous systems.In porphyria conditions there is accumulation of the hemeprecursor′s 5-aminolaevulinic acid, porphobilinogen, and porphyrins; which are associated with characteristic clinical feature with acute neurovisceral attacks and skin lesions. Variegate porphyria, hereditary coproporphyria, and PCT share the same chronic cutaneous photosensitivity. Some drugs will also induce acute attack of porphyria. This report summarizes the management of PCT with a focus on the signs and symptoms and finding that might help and prevent unnecessary medications.

  12. Neuropsychiatric porphyria in patients with refractory epilepsy: report of three cases

    Winkler, A.; T. Peters; Elwes, R.

    2005-01-01

    Objectives: Although epileptic seizures are an infrequent feature of acute attacks of the neuropsychiatric porphyrias, there are no significant reports of porphyria in chronic epilepsy. This paper attempts to redress the balance.

  13. Preclinical Development of a Subcutaneous ALAS1 RNAi Therapeutic for Treatment of Hepatic Porphyrias Using Circulating RNA Quantification.

    Chan, Amy; Liebow, Abigail; Yasuda, Makiko; Gan, Lin; Racie, Tim; Maier, Martin; Kuchimanchi, Satya; Foster, Don; Milstein, Stuart; Charisse, Klaus; Sehgal, Alfica; Manoharan, Muthiah; Meyers, Rachel; Fitzgerald, Kevin; Simon, Amy; Desnick, Robert J; Querbes, William

    2015-01-01

    The acute hepatic porphyrias are caused by inherited enzymatic deficiencies in the heme biosynthesis pathway. Induction of the first enzyme 5-aminolevulinic acid synthase 1 (ALAS1) by triggers such as fasting or drug exposure can lead to accumulation of neurotoxic heme intermediates that cause disease symptoms. We have demonstrated that hepatic ALAS1 silencing using siRNA in a lipid nanoparticle effectively prevents and treats induced attacks in a mouse model of acute intermittent porphyria. Herein, we report the development of ALN-AS1, an investigational GalNAc-conjugated RNAi therapeutic targeting ALAS1. One challenge in advancing ALN-AS1 to patients is the inability to detect liver ALAS1 mRNA in the absence of liver biopsies. We here describe a less invasive circulating extracellular RNA detection assay to monitor RNAi drug activity in serum and urine. A striking correlation in ALAS1 mRNA was observed across liver, serum, and urine in both rodents and nonhuman primates (NHPs) following treatment with ALN-AS1. Moreover, in donor-matched human urine and serum, we demonstrate a notable correspondence in ALAS1 levels, minimal interday assay variability, low interpatient variability from serial sample collections, and the ability to distinguish between healthy volunteers and porphyria patients with induced ALAS1 levels. The collective data highlight the potential utility of this assay in the clinical development of ALN-AS1, and in broadening our understanding of acute hepatic porphyrias disease pathophysiology. PMID:26528940

  14. Excess risk of adverse pregnancy outcomes in women with porphyria: a population-based cohort study

    Tollånes, Mette Christophersen; Aarsand, Aasne Karine; Sandberg, Sverre

    2010-01-01

    The porphyrias comprise a heterogeneous group of rare, primarily hereditary, metabolic diseases caused by a partial deficiency in one of the eight enzymes involved in the heme biosynthesis. Our aim was to assess whether acute or cutaneous porphyria has been associated with excess risks of adverse pregnancy outcomes. A population-based cohort study was designed by record linkage between the Norwegian Porphyria Register, covering 70% of all known porphyria patients in Norway, and the Medical Bi...

  15. Acute interstitial nephritis induced by intermittent use of Rifampicin in patient with Brucellosis

    Acute oliguric renal failure (ARF) developed in a patient 2 days after she was started on intermittent anti-Brucella therapy including rifampicin. The clinical picture was compatible with acute allergic interstitial nephritis. Renal histology revealed mainly acute tubular necrosis with mild tubulo-intertitial mononuclear cellular infiltrate. Intermittent therapy, as in our patient, has been the major factor in the development of rifampicin induced ARF in cases reviewed in literature. (author)

  16. Disease: H00202 [KEGG MEDICUS

    Full Text Available H00202 Hepatic porphyria, including: Porphyria Cutanea Tarda (PCT); VHepatoerythropoietic porphyria...; Acute Intermittent Porphyria (AIP); Variegate porphyria (VP); ALA-dehydratase deficiency porphyria... (ALADP); Hereditary Coproporphyria (HCP) Hepatic porphyrias are diseases due to marked deficiencies... of enzymes in the heme biosynthetic pathway. Clinical manifestations in porphyria... 176000 176200 121300 125270 PMID:14995910 Kauppinen R Molecular diagnostics of acute intermittent porphyria

  17. Porphyria cutanea tarda

    Bygum, A; Brandrup, F; Christiansen, L; Petersen, N E

    2000-01-01

    Porphyria cutanea tarda (PCT), the most common porphyria disease, is characterized by blistering and skin fragility of sun-exposed skin. The symptoms are caused by lowered activity of uroporphyrinogen decarboxylase (URO-D) resulting in accumulation of water-soluble porphyrins in the skin. Most PCT...

  18. Rapid screening test for porphyria diagnosis using fluorescence spectroscopy

    Lang, A.; Stepp, H.; Homann, C.; Hennig, G.; Brittenham, G. M.; Vogeser, M.

    2015-07-01

    Porphyrias are rare genetic metabolic disorders, which result from deficiencies of enzymes in the heme biosynthesis pathway. Depending on the enzyme defect, different types of porphyrins and heme precursors accumulate for the different porphyria diseases in erythrocytes, liver, blood plasma, urine and stool. Patients with acute hepatic porphyrias can suffer from acute neuropathic attacks, which can lead to death when undiagnosed, but show only unspecific clinical symptoms such as abdominal pain. Therefore, in addition to chromatographic methods, a rapid screening test is required to allow for immediate identification and treatment of these patients. In this study, fluorescence spectroscopic measurements were conducted on blood plasma and phantom material, mimicking the composition of blood plasma of porphyria patients. Hydrochloric acid was used to differentiate the occurring porphyrins (uroporphyrin-III and coproporphyrin-III) spectroscopically despite their initially overlapping excitation spectra. Plasma phantom mixtures were measured using dual wavelength excitation and the corresponding concentrations of uroporphyrin-III and coproporphyrin-III were determined. Additionally, three plasma samples of porphyria patients were examined and traces of coproporphyrin-III and uroporphyrin-III were identified. This study may therefore help to establish a rapid screening test method with spectroscopic differentiation of the occurring porphyrins, which consequently allows for the distinction of different porphyrias. This may be a valuable tool for clinical porphyria diagnosis and rapid or immediate treatment.

  19. Diet and Nutrition in Porphyria

    ... You are here Home About Porphyria Diet and Nutrition A proper diet is important to all individuals, ... alter food intake. Therefore, attention to diet and nutrition is important in almost any disease. Porphyrias are ...

  20. Clinical and genetic features of variegate porphyria in a Chinese patient

    2001-01-01

    @@Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented.

  1. [Solarium-induced pseudoporphyria and variegate porphyria as rare differential diagnoses of porphyria cutanea tarda].

    Kochs, C; Mühlenstädt, E; Neumann, N J; Hanneken, S

    2009-10-01

    Three patients presented with typical porphyria cutanea tarda-like vesicles, erosions and scars as well as increased fragility, primarily on the back of the hands. In two of the three, porphyrin workup was normal. Skin biopsy was compatible with porphyria cutanea tarda (PCT) or pseudoporphyria. The common aspect in the patients' history was the frequent use of solaria for many years, so that UV-induced pseudoporphyria was diagnosed. Treatment was strict abstention from UV radiation and regular dermatologic controls for signs of skin damage. Porphyrin analysis in the third patient showed normal excretion of total urine porphyrins and precursors; however, fecal porphyrins were elevated with dominating coproporphyrins in HPLC and the plasma fluorescence scan yielded a peak at 625 nm. Subsequent mutation analysis showed a mutation in the protoporphyrinogen oxidase gene, thereby confirming the diagnosis of variegate porphyria. Five months after the initial diagnosis the patient presented with the first acute attack. Further investigations revealed a metastasized carcinoma of the colon, which probably triggered the acute attack. Our cases show rare differential diagnoses in patients presenting with typical PCT-like skin lesions. The discrimination between porphyria cutanea tarda and its differential diagnoses is very important since it has an important impact not only on the treatment modality but also on the course and the prognosis of the disease. PMID:19756434

  2. Functional Characterization of Five Protoporphyrinogen oxidase Missense Mutations Found in Argentinean Variegate Porphyria Patients

    Méndez, Manuel; Granata, Barbara X.; Jiménez, María J. Morán; Parera, Victoria E.; Batlle, Alcira; De Salamanca, Rafael Enríquez; Rossetti, María V.

    2011-01-01

    A partial deficiency in protoporphyrinogen oxidase (PPOX) produces the acute/cutaneous (or mixed) variegate porphyria (VP), the third most frequent porphyria in Argentina. This autosomal dominant disorder is clinically characterized by skin lesions and/or acute neurovisceral attacks. The precise diagnosis of patients with a symptomatic VP is essential to provide accurate treatment. It is also critical to identify asymptomatic relatives to avoid precipitating factors and prevent acute attacks.

  3. Diaphragm long-term facilitation following acute intermittent hypoxia during wakefulness and sleep

    Terada, J.; Mitchell, G.S.

    2011-01-01

    Acute intermittent hypoxia (AIH) elicits a form of respiratory plasticity known as long-term facilitation (LTF). Here, we tested four hypotheses in unanesthetized, spontaneously breathing rats using radiotelemetry for EEG and diaphragm electromyography (Dia EMG) activity: 1) AIH induces LTF in Dia EMG activity; 2) diaphragm LTF (Dia LTF) is more robust during sleep vs. wakefulness; 3) AIH (or repetitive AIH) disrupts natural sleep-wake architecture; and 4) preconditioning with daily AIH (dAIH...

  4. LIPOPOLYSACCHARIDE ATTENUATES PHRENIC LONG-TERM FACILITATION FOLLOWING ACUTE INTERMITTENT HYPOXIA

    Vinit, Stéphane; Windelborn, James A; Mitchell, Gordon S.

    2011-01-01

    Lipopolysaccharide (LPS) induces inflammatory responses, including microglial activation in the central nervous system. Since LPS impairs certain forms of hippocampal and spinal neuroplasticity, we hypothesized that LPS would impair phrenic long-term facilitation (pLTF) following acute intermittent hypoxia (AIH) in outbred Sprague-Dawley (SD) and inbred Lewis (L) rats.. Approximately three hours following a single LPS injection (i.p.), the phrenic response during hypoxic episodes is reduced i...

  5. Sleep state dependence of ventilatory long-term facilitation following acute intermittent hypoxia in Lewis rats

    Nakamura, A.; Olson, E B; Terada, J.; Wenninger, J. M.; Bisgard, G. E.; Mitchell, G.S.

    2010-01-01

    Ventilatory long-term facilitation (vLTF) is a form of respiratory plasticity induced by acute intermittent hypoxia (AIH). Although vLTF has been reported in unanesthetized animals, little is known concerning the effects of vigilance state on vLTF expression. We hypothesized that AIH-induced vLTF is preferentially expressed in sleeping vs. awake male Lewis rats. Vigilance state was assessed in unanesthetized rats with chronically implanted EEG and nuchal EMG electrodes, while tidal volume, fr...

  6. [Porphyria cutanea tara].

    Merk, H F

    2016-03-01

    Porphyria cutanea tara (PCT) has a prevelance of about 40 new diagnoses per 1 million people per year and is the most frequently occurring type of porphyria worldwide. Inhibition of the uroporphyrinogen decarboxylase (UROD) is the main cause of the disease, which can be the result of a heterozygous or homozygous mutation of the UROD gene; however, xenobiotics or other diseases may play an important role for the precipitation of the disease. Risk factors include alcohol, estrogen, iron overload, and hemochromatosis, hepatitis C or poisoning, e.g., with polyhalogenated aromatic compounds such as hexachlorobenzene. Signs and symptoms are blisters, skin fragility, erosions hyperpigmentation, sclerodermoid plaques. Therapy includes sun protection, prevention of risk factors, phlebotomy, and chloroquine. PMID:26743054

  7. Gene-environmental interactions: Lessons from porphyria

    Sassa, Shigeru

    2003-01-01

    The porphyrias are uncommon, complex, and fascinating metabolic conditions, caused by deficiencies in the activities of the enzymes of the heme biosynthetic pathway. Two cardinal symptoms of the porphyrias are cutaneous photosensitivity and neurologic disturbances. Molecular analysis of gene defects has shown that there are multiple and heterogeneous mutations in each porphyria. Patients with symptomatic porphyria can suffer greatly, and, in rare cases, may die. While congenital porphyrias ar...

  8. Effects of Acutely Intermittent Hypoxic Exposure on Running Economy and Physical Performance in Basketball Players.

    Kilding, Andrew E; Dobson, Bryan P; Ikeda, Erika

    2016-07-01

    Kilding, AE, Dobson, BP, and Ikeda, E. Effects of acutely intermittent hypoxic exposure on running economy and physical performance in basketball players. J Strength Cond Res 30(7): 2033-2042, 2016-The aim of this study was to determine the effect of short duration intermittent hypoxic exposure (IHE) on physical performance in basketball players. Using a single-blind placebo-controlled group design, 14 trained basketball players were subjected to 15 days of passive short duration IHE (n = 7), or normoxic control (CON, n = 7), using a biofeedback nitrogen dilution device. A range of physiological, performance, and hematological variables were measured at baseline, and 10 days after IHE. After intervention, the IHE group, relative to the CON group, exhibited improvements in the Yo-Yo intermittent recovery level 1 (+4.8 ± 1.6%; effect size [ES]: 1.0 ± 0.4) and repeated high-intensity exercise test performance (-3.5 ± 1.6%; ES: -0.4 ± 0.2). Changes in hematological parameters were minimal, although soluble transferrin receptor increased after IHE (+9.2 ± 10.1%; ES: 0.3 ± 0.3). Running economy at 11 km·h (-9.0 ± 9.7%; ES: -0.7 ± 0.7) and 13 km·h was improved (-8.2 ± 6.9%; ES: -0.7 ± 0.5), but changes to V[Combining Dot Above]O2peak, HRpeak, and lactate were unclear. In summary, acutely IHE resulted in worthwhile changes in physical performance tests among competitive basketball players. However, physiological measures explaining the performance enhancement were in most part unclear. PMID:26677826

  9. Phase II study of profiromycin vs mitomycin-C utilizing acute intermittent schedules.

    Baker, L H; Izbicki, R M; Vaitkevicius, V K

    1976-01-01

    A randomized prosective study of Mitomycin-C and its N-methyl derivative, Porfiromycin, was conducted. Thirty-two patients with disseminated gastrointestinal cancer or other disseminated abdominal adenocarcinoma were treated with Mitomycin-C; 31 patients received Porfiromycin. Both drugs were given by acute intermittent bolus schedule (Mitomucin-C , 22.5 mg/M2 or Porfiromycin, 75 mg/M2 every 6--8 weeks as a single bolus i.v. injection). Eleven patients (34%) who received Mitomycin-C entered into partial remission. In 10 of the 31 patients (32%) receiving Porfiromycin, partial remission occured. Analysis by tumor type demonstrated that in the Mitomycin-C treated group responses occured in 4 of 12 patients with colorectal carcinoma, in 4 of 9 with upper GI cancers, and in 3 of 11 with ovarian cancer. Correspondingly in Porfiromycin group responses occured in 2 of 12 colorectal carcinoma patients, in 3 of 7 upper GI cancer patients, and in 5 of 12 ovarian cancer patients. Both drugs produced significant myelosuppression; however, Porfiromycin toxicity appeared more cumulative. Further clinical trial of Mitomycin in an acute intermittent bolus schedule appears justified. PMID:958162

  10. Congenital erythropoietic porphyria in three siblings.

    Bari, Arfan Ul

    2007-01-01

    Congenital erythropoietic porphyria is a rare autosomal recessive disorder that usually presents with marked skin photosensitivity, hypertrichosis, blistering, scarring, milia formation and dyspigmentation of the photo-exposed areas. Three adult siblings (two sisters and one brother) are presented here with variable degree of skin manifestations. During early childhood, all the siblings started showing signs of photosensitivity with darkening of urine color followed by skin blistering over the face and hands. The oldest showed severe sclerodermiform mutilation and the youngest exhibited an initial involvement with hypertrichosis. None of them had any history of convulsions, acute abdominal pain or joint pain. Woods lamp examination and laboratory investigations confirmed the diagnosis. PMID:17921617

  11. Congenital erythropoietic porphyria in three siblings

    Bari Arfan Ul

    2007-01-01

    Full Text Available Congenital erythropoietic porphyria is a rare autosomal recessive disorder that usually presents with marked skin photosensitivity, hypertrichosis, blistering, scarring, milia formation and dyspigmentation of the photo-exposed areas. Three adult siblings (two sisters and one brother are presented here with variable degree of skin manifestations. During early childhood, all the siblings started showing signs of photosensitivity with darkening of urine color followed by skin blistering over the face and hands. The oldest showed severe sclerodermiform mutilation and the youngest exhibited an initial involvement with hypertrichosis. None of them had any history of convulsions, acute abdominal pain or joint pain. Woods lamp examination and laboratory investigations confirmed the diagnosis.

  12. Diagnostic Value of 99mTc-DISIDA hepatobiliary Scintigraphy in Patients with Acute or Intermittent Common Bile Duct Obstruction

    We examined patients with suspected acute or intermittent biliary obstruction using hepatobiliary scintigraphy, ultrasonography and contrast cholangiography. Of 16 patients with confirmed common bile duct obstruction, sonography and scintigraphy disagreed in 8(50%). Scintigraphy revealed partial or complete common bile duct obstruction in 13 patients (81.3%) and 6 of them had no evidence of dilated biliary trees. It is concluded that disagreement between sonography and scintigraphy is not rare in patients with acute or intermittent biliary obstruction and hepatobiliary scintigraphy is useful in diagnosing obstruction prior to ductal dilatation.

  13. [Diagnosis of the porphyrias : From A (as in aminolevulinic acid) to Z (as in zinc protoporphyrin)].

    Kürten, V; Neumann, N J; Frank, J

    2016-03-01

    The porphyrias comprise a clinically, biochemically, and genetically heterogeneous group of predominantly hereditary metabolic disorders resulting from a dysfunction along the heme biosynthetic pathway. Whereas most variants can manifest with different cutaneous symptoms, some types only reveal life-threatening acute neurovisceral attacks. Therefore, interdisciplinary care of these patients is advisable. In this article, we provide an overview of characteristic clinical and laboratory findings in the various forms of porphyria and a diagnostic algorithm. PMID:26743052

  14. Erythrodontia in congenital erythropoietic porphyria

    Rashmi Bhavasar

    2011-01-01

    Full Text Available Congenital erythropoietic porphyria (CEP is one of the rarest of porphyrias occurring worldwide. CEP is a very rare genetic autosomal recessive disease, with mutation in the gene that codifies uroporphyrinogen-III synthase, leading to porphyrin accumulation in many tissues, with marked skin photosensitivity, hemolytic anemia with splenomegaly and a decreased life expectancy. We report a case of Günther′s disease in view of its rarity along with a description of this interesting condition. An 18-month-old female baby with clinical, hematological and biochemical profile of CEP was reported with marked skin photosensitivity over face and hands. She had erythrodontia with delayed eruption of teeth. When evaluating erythrodontia of uncertain cause, we advocate maintaining a high degree of awareness for porphyria, especially for CEP as it is the rarest among porphyria and is a life-threatening condition.

  15. New developments in erythropoietic porphyrias.

    Darwich, E; Herrero, C

    2013-04-01

    In recent years, important advances have been made in our understanding of the genetics of porphyrias, particularly with respect to erythropoietic protoporphyria (EPP) and congenital erythropoietic porphyria (CEP), 2 forms of erythropoietic porphyria no longer considered to be monogenic. The identification of mutations in genes not previously associated with these disorders as causative factors or modulators of severity has helped to explain the presence of genotypic and phenotypic differences between patients carrying the same mutations. These advances have also led to the identification of causative genetic defects in patients who, based on molecular studies, had no mutations in the uroporphyrinogen III synthase gene UROS (in CEP) or in the ferrochelatase gene FECH (in EPP). Better understanding and characterization of the genetics of porphyrias will allow us to determine genotypic and phenotypic correlations and improve the molecular classification of these diseases, which will have both practical and prognostic implications. PMID:22766189

  16. Porphyria: Pathophysiology, diagnosis, and treatment.

    Gasson, Tracy; Klein, Kathleen

    2015-08-15

    Porphyrias are inherited metabolic disorders that involve alterations in enzymes utilized in the heme biosynthetic pathway. Most of these conditions are inherited; however, some are believed to be acquired through environmental exposures. Patients with porhyrias often present with a wide range of clinical symptoms, making it difficult to diagnose. Treatments vary depending on clinical presentation. A thorough and detailed history is essential and key to discovering a porphyria diagnosis. PMID:26180905

  17. Porphyria cutanea tarda responding to spirulina

    Pavithran K; Nair P

    1992-01-01

    A male patient of porphyria cutanea tarda responded to oral spirulina - an alga rich in beta - carotene. The beta - carotene in the spirulina quenches the singlet oxygen which is responsible for the tissue damage in porphyria-associated photosensitivity.

  18. Porphyria Cutanea Tarda and Agent Orange

    ... ZIP code here Porphyria Cutanea Tarda and Agent Orange VA presumes porphyria cutanea tarda (PCT) is related to Veterans' exposure to Agent Orange or other herbicides during military service when the ...

  19. Porphyria cutanea tarda and Sjogren's syndrome *

    Fang, Su; Sun, Xiao Jie; Wang, ZanFeng; Song, DanYang; LI, TIENAN

    2014-01-01

    Porphyria cutanea tarda is prevalent in connective tissue disease, common in systemic lupus erythematosus. However, the co-existence of primary sjogren's syndrome and porphyria cutanea tarda is rare and poses diagnostic and therapeutic challenges. We report a case of porphyria cutanea tarda associated with primary sjogren's syndrome.

  20. Sleep state dependence of ventilatory long-term facilitation following acute intermittent hypoxia in Lewis rats.

    Nakamura, A; Olson, E B; Terada, J; Wenninger, J M; Bisgard, G E; Mitchell, G S

    2010-08-01

    Ventilatory long-term facilitation (vLTF) is a form of respiratory plasticity induced by acute intermittent hypoxia (AIH). Although vLTF has been reported in unanesthetized animals, little is known concerning the effects of vigilance state on vLTF expression. We hypothesized that AIH-induced vLTF is preferentially expressed in sleeping vs. awake male Lewis rats. Vigilance state was assessed in unanesthetized rats with chronically implanted EEG and nuchal EMG electrodes, while tidal volume, frequency, minute ventilation (Ve), and CO(2) production were measured via plethysmography, before, during, and after AIH (five 5-min episodes of 10.5% O(2) separated by 5-min normoxic intervals), acute sustained hypoxia (25 min of 10.5% O(2)), or a sham protocol without hypoxia. Vigilance state was classified as quiet wakefulness (QW), light and deep non-rapid eye movement (NREM) sleep (l-NREM and d-NREM sleep, respectively), or rapid eye movement sleep. Ventilatory variables were normalized to pretreatment baseline values in the same vigilance state. During d-NREM sleep, vLTF was observed as a progressive increase in Ve post-AIH (27 + or - 5% average, 30-60 min post-AIH). In association, Ve/Vco(2) (36 + or - 2%), tidal volume (14 + or - 2%), and frequency (7 + or - 2%) were increased 30-60 min post-AIH during d-NREM sleep. vLTF was significant but less robust during l-NREM sleep, was minimal during QW, and was not observed following acute sustained hypoxia or sham protocols in any vigilance state. Thus, vLTF is state-dependent and pattern-sensitive in unanesthetized Lewis rats, with the greatest effects during d-NREM sleep. Although the physiological significance of vLTF is not clear, its greatest significance to ventilatory control is most likely during sleep. PMID:20360430

  1. Chronic intermittent hypoxia alters ventilatory and metabolic responses to acute hypoxia in rats.

    Morgan, Barbara J; Adrian, Russell; Wang, Zun-Yi; Bates, Melissa L; Dopp, John M

    2016-05-15

    We determined the effects of chronic exposure to intermittent hypoxia (CIH) on chemoreflex control of ventilation in conscious animals. Adult male Sprague-Dawley rats were exposed to CIH [nadir oxygen saturation (SpO2), 75%; 15 events/h; 10 h/day] or normoxia (NORM) for 21 days. We assessed the following responses to acute, graded hypoxia before and after exposures: ventilation (V̇e, via barometric plethysmography), V̇o2 and V̇co2 (analysis of expired air), heart rate (HR), and SpO2 (pulse oximetry via neck collar). We quantified hypoxia-induced chemoreceptor sensitivity by calculating the stimulus-response relationship between SpO2 and the ventilatory equivalent for V̇co2 (linear regression). An additional aim was to determine whether CIH causes proliferation of carotid body glomus cells (using bromodeoxyuridine). CIH exposure increased the slope of the V̇e/V̇co2/SpO2 relationship and caused hyperventilation in normoxia. Bromodeoxyuridine staining was comparable in CIH and NORM. Thus our CIH paradigm augmented hypoxic chemosensitivity without causing glomus cell proliferation. PMID:26917692

  2. Clinical Characteristics and 30-Day Outcomes of Intermittent Hemodialysis for Acute Kidney Injury in an African Intensive Care Unit

    Arthur Kwizera; Janat Tumukunde; Lameck Ssemogerere; Emmanuel Ayebale; Peter Agaba; Jamali Yakubu; Aggrey Lubikire; Mary Nabukenya; Robert Kalyesubula

    2016-01-01

    Introduction. Acute kidney injury (AKI) is a common occurrence in the intensive care unit (ICU). Studies have looked at outcomes of renal replacement therapy using intermittent haemodialysis (IHD) in ICUs with varying results. Little is known about the outcomes of using IHD in resource-limited settings where continuous renal replacement therapy (CRRT) is limited. We sought to determine outcomes of IHD among critically ill patients admitted to a low-income country ICU. Methods. A retrospective...

  3. Hepatoerythropoietic porphyria precipitated by viral hepatitis.

    Hift, R J; Meissner, P N; Todd, G.

    1993-01-01

    Porphyria cutanea tarda (PCT), the condition resulting from a deficiency of hepatic uroporphyrinogen decarboxylase activity, is the commonest form of porphyria. Both acquired and familial form exist and are commonly associated in adults with liver disease and hepatic iron overload. The condition is extremely rare in children; most cases of childhood PCT are familial and some particularly severe cases have been shown to have a hepatoerythropoietic porphyria or homozygous uroporphyrinogen decar...

  4. PORPHYRIA : THE DISEASE THAT CALLS FOR AWARENESS

    Ravi R; Swati D

    2015-01-01

    Porphyria is a relatively uncommon condition and it should be considered in patients presenting with atypical medical , psychiatric , or surgical history. Paucity of clinical recognition of porphyria often delays diagnosis and consequently treatment. Also , signs and symptoms mimic other common medical and surgical conditions. So , awareness of porphyria alon g with proper and accurate diagnostic tests in conjunction could be of great boon to su...

  5. Repetitive acute intermittent hypoxia increases growth/neurotrophic factor expression in non-respiratory motor neurons.

    Satriotomo, I; Nichols, N L; Dale, E A; Emery, A T; Dahlberg, J M; Mitchell, G S

    2016-05-13

    Repetitive acute intermittent hypoxia (rAIH) increases growth/trophic factor expression in respiratory motor neurons, thereby eliciting spinal respiratory motor plasticity and/or neuroprotection. Here we demonstrate that rAIH effects are not unique to respiratory motor neurons, but are also expressed in non-respiratory, spinal alpha motor neurons and upper motor neurons of the motor cortex. In specific, we used immunohistochemistry and immunofluorescence to assess growth/trophic factor protein expression in spinal sections from rats exposed to AIH three times per week for 10weeks (3×wAIH). 3×wAIH increased brain-derived neurotrophic factor (BDNF), its high-affinity receptor, tropomyosin receptor kinase B (TrkB), and phosphorylated TrkB (pTrkB) immunoreactivity in putative alpha motor neurons of spinal cervical 7 (C7) and lumbar 3 (L3) segments, as well as in upper motor neurons of the primary motor cortex (M1). 3×wAIH also increased immunoreactivity of vascular endothelial growth factor A (VEGFA), the high-affinity VEGFA receptor (VEGFR-2) and an important VEGF gene regulator, hypoxia-inducible factor-1α (HIF-1α). Thus, rAIH effects on growth/trophic factors are characteristic of non-respiratory as well as respiratory motor neurons. rAIH may be a useful tool in the treatment of disorders causing paralysis, such as spinal injury and motor neuron disease, as a pretreatment to enhance motor neuron survival during disease, or as preconditioning for cell-transplant therapies. PMID:26944605

  6. Diaphragm long-term facilitation following acute intermittent hypoxia during wakefulness and sleep.

    Terada, J; Mitchell, G S

    2011-05-01

    Acute intermittent hypoxia (AIH) elicits a form of respiratory plasticity known as long-term facilitation (LTF). Here, we tested four hypotheses in unanesthetized, spontaneously breathing rats using radiotelemetry for EEG and diaphragm electromyography (Dia EMG) activity: 1) AIH induces LTF in Dia EMG activity; 2) diaphragm LTF (Dia LTF) is more robust during sleep vs. wakefulness; 3) AIH (or repetitive AIH) disrupts natural sleep-wake architecture; and 4) preconditioning with daily AIH (dAIH) for 7 days enhances Dia LTF. Sleep-wake states and Dia EMG were monitored before (60 min), during, and after (60 min) AIH (10, 5-min hypoxic episodes, 5-min normoxic intervals; n = 9), time control (continuous normoxia, n = 8), and AIH following dAIH preconditioning for 7 days (n = 7). Dia EMG activities during quiet wakefulness (QW), rapid eye movement (REM), and non-REM (NREM) sleep were analyzed and normalized to pre-AIH values in the same state. During NREM sleep, diaphragm amplitude (25.1 ± 4.6%), frequency (16.4 ± 4.7%), and minute diaphragm activity (amplitude × frequency; 45.2 ± 6.6%) increased above baseline 0-60 min post-AIH (all P 0.05). We conclude that 1) AIH induces Dia LTF during NREM sleep and wakefulness; 2) Dia LTF is greater in NREM sleep vs. QW and is abolished during REM sleep; 3) AIH and repetitive AIH disrupt natural sleep patterns; and 4) Dia LTF is unaffected by dAIH. The capacity for plasticity in spinal pump muscles during sleep and wakefulness suggests an important role in the neural control of breathing. PMID:21372099

  7. Porphyria and pregnancy. Case report

    Noemí Martínez

    2011-03-01

    Full Text Available The porphyrias are a group of diseases caused by a deficiency of enzymes responsible for the synthesis of heme, that can lead to severe disease that requires early diagnosis to avoid complications. The frequency of the disease is low and its association with pregnancy unusual, but it is a good time for patients carrying develop the disease or suffer an exacerbation of the same, hence the vital importance of prophylaxis of the factors risk.

  8. Porphyria and pregnancy. Case report

    Noemí Martínez

    2011-04-01

    Full Text Available The porphyrias are a group of diseases caused by a deficiency of enzymes responsible for the synthesis of heme, that can lead to severe disease that requires early diagnosis to avoid complications. The frequency of the disease is low and its association with pregnancy unusual, but it is a good time for patients carrying develop the disease or suffer an exacerbation of the same, hence the vital importance of prophylaxis of the factors risk.

  9. Porphyria cutanea tarda responding to spirulina

    Pavithran K

    1992-01-01

    Full Text Available A male patient of porphyria cutanea tarda responded to oral spirulina - an alga rich in beta - carotene. The beta - carotene in the spirulina quenches the singlet oxygen which is responsible for the tissue damage in porphyria-associated photosensitivity.

  10. Effect of Acute Intermittent CPAP Depressurization during Sleep in Obese Patients

    Jun, Jonathan C.; Unnikrishnan, Dileep; Schneider, Hartmut; Kirkness, Jason; Schwartz, Alan R.; Philip L. Smith; Polotsky, Vsevolod Y.

    2016-01-01

    Background Obstructive Sleep Apnea (OSA) describes intermittent collapse of the airway during sleep, for which continuous positive airway pressure (CPAP) is often prescribed for treatment. Prior studies suggest that discontinuation of CPAP leads to a gradual, rather than immediate return of baseline severity of OSA. The objective of this study was to determine the extent of OSA recurrence during short intervals of CPAP depressurization during sleep. Methods Nine obese (BMI = 40.4 ± 3.5) subje...

  11. PORPHYRIA : THE DISEASE THAT CALLS FOR AWARENESS

    Ravi R

    2015-01-01

    Full Text Available Porphyria is a relatively uncommon condition and it should be considered in patients presenting with atypical medical , psychiatric , or surgical history. Paucity of clinical recognition of porphyria often delays diagnosis and consequently treatment. Also , signs and symptoms mimic other common medical and surgical conditions. So , awareness of porphyria alon g with proper and accurate diagnostic tests in conjunction could be of great boon to surpass the formidable challenges put forth by porphyric patients. Here , we present a case of 24 year old woman who suffers from porphyria and ultimately dies because of inappropriateness in diagnosis on the part of physicians which is due to lack of awareness and strong clinically suspicious eye.

  12. Congenital erythropoietic porphyria with hemolytic anemia

    Massod Qazi

    2005-01-01

    Full Text Available A 15 year old boy with clinical, hematological and biochemical profile of congenital erythropoietic porphyria with hemolytic anemia is being reported in view of the rarity of this condition.

  13. Porphyria: A Suitable Case for Teaching.

    Hawkey, Roy

    1990-01-01

    The porphyrias are a family of genetic disorders whose genetics and biochemistry are largely identified. Background information on these diseases are discussed including porphyrins, gene expression, population genetics, and historical significance. (CW)

  14. Intermittent Exposure to Social Defeat and Open-field Test in Rats : Acute and Long-term Effects on ECG, Body Temperature and Physical Activity

    Sgoifo, Andrea; Pozzato, Chiara; Meerlo, Peter; Costoli, Tania; Manghi, Massimo; Stilli, Donatella; Olivetti, Giorgio; Musso, Ezio

    2002-01-01

    This study investigated the effects of exposure to an intermittent homotypic stressor on: (i) habituation of acute autonomic responsivity (i.e. cardiac sympathovagal balance and susceptibility to arrhythmias), and (ii) circadian rhythmicity of heart rate, body temperature, and physical activity. Aft

  15. Sporadic porphyria cutanea tarda due to haemochromatosis

    Geus, Hilde; Dees, A.

    2006-01-01

    textabstractHaemochromatosis is a hereditary iron-overload syndrome caused by increased intestinal iron absorption and characterised by accumulation of potentially toxic iron in the tissues. Sometimes this disease presents as a cutanea porphyria. We describe a patient with joint complaints and blistering skin lesions on sun-exposed skin. After identifying the porphyria cutanea tarda by urine analysis we found that the serum activity of uroporphyrinogen decarboxylase (UROD) was normal, meaning...

  16. Clinical Characteristics and 30-Day Outcomes of Intermittent Hemodialysis for Acute Kidney Injury in an African Intensive Care Unit

    Tumukunde, Janat; Ssemogerere, Lameck; Ayebale, Emmanuel; Agaba, Peter; Yakubu, Jamali; Lubikire, Aggrey; Nabukenya, Mary

    2016-01-01

    Introduction. Acute kidney injury (AKI) is a common occurrence in the intensive care unit (ICU). Studies have looked at outcomes of renal replacement therapy using intermittent haemodialysis (IHD) in ICUs with varying results. Little is known about the outcomes of using IHD in resource-limited settings where continuous renal replacement therapy (CRRT) is limited. We sought to determine outcomes of IHD among critically ill patients admitted to a low-income country ICU. Methods. A retrospective review of patient records was conducted. Patients admitted to the ICU who underwent IHD for AKI were included in the study. Patients' demographic and clinical characteristics, cause of AKI, laboratory parameters, haemodialysis characteristics, and survival were interpreted and analyzed. Primary outcome was mortality. Results. Of 62 patients, 40 had complete records. Median age of patients was 38.5 years. Etiologic diagnoses associated with AKI included sepsis, malaria, and ARDS. Mortality was 52.5%. APACHE II (OR 4.550; 95% CI 1.2–17.5, p = 0.028), mechanical ventilation (OR 13.063; 95% CI 2.3–72, p = 0.003), and need for vasopressors (OR 16.8; 95% CI 3.4–82.6, p = 0.001) had statistically significant association with mortality. Conclusion. IHD may be a feasible alternative for RRT in critically ill haemodynamically stable patients in low resource settings where CRRT may not be available. PMID:27042657

  17. The effects of acute intermittent hypoxia on cardiovascular parameters in normotensive and chronic hypobaric hypoxia-induced hypertensive rabbits.

    Yaman, Muhittin O; Guner, Ibrahim; Uzun, Hafize; Sahin, Gulderen; Yelmen, Nermin

    2014-01-01

    The effects of both chronic hypoxia and acute intermittent hypoxia (AIH) on cardiovascular system are unclear. We designed this study to develop a rabbit model of hypertension by exposure to chronic hypobaric hypoxia (CHH) and to investigate the effects of AIH on hypertensive rabbits. Present study was performed in 13 albino rabbits that divided into CHH and control groups. To develop hypertension, the rabbits were placed in a hypobaric chamber (390 mmHg; 22 hours/day, 30 days). Afterwards, AIH protocol was applied (8% FIO2 (Fraction of Inspired Oxygen) 1 min + 5 min normoxia, 20 cycles, 2 hours) to rabbits anesthetized with urethane and alpha-chloralose. Mean arterial pressure (MAP), heart rate (HR) and hematocrit values have been determined. Also asymmetric dimethylarginine (ADMA), endothelial nitric oxide synthase (eNOS), endothelin-1 and norepinephrine values have been analyzed in blood. We developed a model of hypertension in rabbits via exposure to severe CHH and we believe that ADMA is an important parameter in the development and permanence of CHH-induced hypertension. The main finding of this sudy was the depressor effect of AIH on blood pressure and heart rate in CHH- induced hypertension model. Finally, we believe that AIH protocol may be applicable for prevention and treatment of hypertension if properly developed. PMID:24448370

  18. Congenital erythropoietic porphyria: Two case reports

    Sankha Koley

    2011-01-01

    Full Text Available Porphyrias form a group of disorders caused due to defects in the haem synthetic pathway. Congenital erythropoietic porphyia (CEP is the rarest of the bullous porphyrias (less than 200 cases have been reported till recent times and a clinician may not see a case during his professional life. We present two cases of CEP. One child with CEP presented with typical infancy-onset blistering, photosensitivity, red urine, and erythrodontia, with hypertrichosis of the upper arms and back. The other child of CEP presented with childhood-onset blistering, mutilation, and hypertrichosis on the face.

  19. Enzymatic and immunological studies of uroporphyrinogen decarboxylase in familial porphyria cutanea tarda and hepatoerythropoietic porphyria.

    De Verneuil, H.; Beaumont, C; Deybach, J C; Nordmann, Y; Sfar, Z; Kastally, R

    1984-01-01

    Uroporphyrinogen decarboxylase activity was measured in hemoglobin-free lysates from two patients with hepatoerythropoietic porphyria (HEP) and from 12 unrelated patients with familial porphyria cutanea tarda (PCT). In HEP patients, enzyme activities were 5% of normal, and familial studies clearly confirmed that patients with HEP are cases of homozygous PCT. Immunoreactive uroporphyrinogen decarboxylase was measured by developing a direct and noncompetitive enzyme immunoassay (EIA). For the 1...

  20. Establishing a network of specialist Porphyria centres - effects on diagnostic activities and services

    Tollånes Mette C; Aarsand Aasne K; Villanger Jørild Haugen; Støle Egil; Deybach Jean-Charles; Marsden Joanne; To-Figueras Jordi; Sandberg Sverre

    2012-01-01

    Abstract Background The porphyrias are a heterogeneous group of rare metabolic diseases. The full spectrum of porphyria diagnostics is usually performed by specialized porphyria laboratories or centres. The European Porphyria Initiative (EPI), a collaborative network of porphyria centres formed in 2001, evolved in 2007 into the European Porphyria Network (EPNET), where participating centres are required to adhere to agreed quality criteria. The aim of this study was to examine the state and d...

  1. Intermittent exposure to social defeat and open-field test in rats: acute and long-term effects on ECG, body temperature and physical activity.

    Sgoifo, Andrea; Pozzato, Chiara; Meerlo, Peter; Costoli, Tania; Manghi, Massimo; Stilli, Donatella; Olivetti, Giorgio; Musso, Ezio

    2002-02-01

    This study investigated the effects of exposure to an intermittent homotypic stressor on: (i) habituation of acute autonomic responsivity (i.e. cardiac sympathovagal balance and susceptibility to arrhythmias), and (ii) circadian rhythmicity of heart rate, body temperature, and physical activity. After implantation of a transmitter for the radiotelemetric recording of electrocardiogram (ECG), body temperature and physical activity, adult male rats (Rattus norvegicus, Wild Type Groningen strain) were repeatedly exposed (10 consecutive times, on alternate days) to either a social stressor (defeat by a con-specific, n = 15) or an open-field, control challenge (transfer to a new cage; n = 8). ECGs, body temperature and physical activity were continuously recorded in baseline, test and recovery periods (each lasting 15 min), at the 1st and 10th episodes of both defeat and open-field challenge. The circadian rhythms of heart rate, body temperature and physical activity were monitored before (5 days), during (16 days) and after (21 days) the intermittent stress protocol. This study indicates that there is no clear habituation of either acute cardiac autonomic responsivity (as estimated by means of time-domain indexes of heart rate variability) or arrhythmia occurrence to a brief, intermittent, homotypic challenge, regardless of the nature of the stressor (social or non-social). On the other hand, rats exposed to social challenge also failed to show adaptation of acute temperature and activity stress responsiveness, whereas rats facing open-field challenge developed habituation of activity and sensitization of temperature responses. Repeated social challenge produced remarkable reductions of the heart rate circadian rhythm amplitude (this effect being significantly greater than that produced by intermittent open-field), but only minor changes in the daily rhythms of body temperature and physical activity. PMID:12171764

  2. Intermittent use of amifostine during postoperative radiochemotherapy and acute toxicity in rectal cancer patients

    From September 1997 through October 1998, 30 patients with stage II/III rectal cancer underwent postoperative radiochemotherapy at our department. All patients had undergone curative (R0) resection and received 50.4 Gy to the pelvis with a 3-field technique using a belly board followed by a boost of 5.4 Gy to the presacral space in conventional fractionation with 1.8 Gy per fraction. 5-FU chemotherapy was administered as 120-hours continuous infusion in the first and fifth radiation week via a central venous catheter in a daily dosage of 1000 mg/m2. All patients were offered to participate in a phase-II study using additional amifostine. Fifteen patients participated and received 500 mg amifostine daily on chemotherapy days (days 1 to 5 and 29 to 33) immediately prior to the daily radiation fraction. Fifteen patients did not participate and served as non-randomized control. The study was approved by the ethical committee of the Martin-Luter-University and informed consent was obtained from all patients. Results: The distribution of patients' characteristics and prognostic parameters was comparable in both groups. Side effects of amifostine were mild and included hypotension (53% grade I, 7% grade II) and nausea (47% grade I, 13% grade II). Antiemetics were not routinely used. All patients completed radiochemotherapy plus amifostine without unplanned breaks or dose reductions. One patients developed a cerebral infraction which was considered to be not related to the use of amifostine. As compared to the non-randomized control group, patients with additional amifostine had less acute skin and bowel toxicity (maximum erythema score 1.47±0.64 without vs 0.87±0.52 with amifostine, p=0.009 and maximum diarrhea score 1.07±1.03 vs 0.40±0.63, p=0.044). Oral 5-FU-related mucositis and hematological toxicity were not significantly different. (orig.)

  3. Herbicide-induced experimental variegate porphyria in mice: tissue porphyrinogen accumulation and response to porphyrogenic drugs.

    Krijt, J; Stranska, P; Maruna, P; Vokurka, M; Sanitrak, J

    1997-01-01

    Administration of oxadiazon or oxyfluorfen (1000 ppm in the diet) to male BALB/c mice for 9 days resulted in experimental porphyria, resembling the acute phase of human variegate porphyria. Urinary concentrations of 5-aminolevulinic acid and porphobilinogen reached 1500 and 3000 mumol/L, respectively. Both herbicides caused a decrease of protoporphyrinogen oxidase activity in liver and kidney. Brain protoporphyrinogen oxidase activity was not altered. Liver and kidney porphyrin content increased to 11 and 17 nmol/g, respectively (control mice, 2 nmol/g). Over 50% of liver and kidney porphyrins were in the reduced (porphyrinogen) form. Bile of oxadiazon-treated mice contained 700 nmol/mL of protoporphyrinogen (control mice, 15 nmol/mL). Porphyrin content of the trigeminal nerve increased from 1 nmol/g in control animals to 11 nmol/g in oxadiazon-treated animals, suggesting a possible contribution of peripheral nerve porphyrins to porphyric neuropathy. Mice treated with 125 ppm of oxadiazon in the diet for 9 days excreted moderately elevated levels of porphobilinogen in urine (control mice, less than 50 mumol/L; treated mice, 330 mumol/L). Administration of phenobarbital or phenytoin (single injections on days 7, 8, and 9) increased the urinary porphobilinogen concentration to 3500 mumol/L. This response to porphyrogenic drugs resembles the response observed in human acute porphyrias. PMID:9431441

  4. Intermittent use of amifostine during postoperative radiochemotherapy and acute toxicity in rectal cancer patients

    Dunst, J.; Semlin, S.; Pigorsch, S.; Mueller, A.C.; Reese, T. [Halle-Wittenberg Univ., Halle (Germany). Abt. fuer Radiotherapie

    2000-09-01

    From September 1997 through October 1998, 30 patients with stage II/III rectal cancer underwent postoperative radiochemotherapy at our department. All patients had undergone curative (R0) resection and received 50.4 Gy to the pelvis with a 3-field technique using a belly board followed by a boost of 5.4 Gy to the presacral space in conventional fractionation with 1.8 Gy per fraction. 5-FU chemotherapy was administered as 120-hours continuous infusion in the first and fifth radiation week via a central venous catheter in a daily dosage of 1000 mg/m{sup 2}. All patients were offered to participate in a phase-II study using additional amifostine. Fifteen patients participated and received 500 mg amifostine daily on chemotherapy days (days 1 to 5 and 29 to 33) immediately prior to the daily radiation fraction. Fifteen patients did not participate and served as non-randomized control. The study was approved by the ethical committee of the Martin-Luter-University and informed consent was obtained from all patients. Results: The distribution of patients' characteristics and prognostic parameters was comparable in both groups. Side effects of amifostine were mild and included hypotension (53% grade I, 7% grade II) and nausea (47% grade I, 13% grade II). Antiemetics were not routinely used. All patients completed radiochemotherapy plus amifostine without unplanned breaks or dose reductions. One patients developed a cerebral infraction which was considered to be not related to the use of amifostine. As compared to the non-randomized control group, patients with additional amifostine had less acute skin and bowel toxicity (maximum erythema score 1.47{+-}0.64 without vs 0.87{+-}0.52 with amifostine, p=0.009 and maximum diarrhea score 1.07{+-}1.03 vs 0.40{+-}0.63, p=0.044). Oral 5-FU-related mucositis and hematological toxicity were not significantly different. (orig.) [German] Zwischen September 1997 und Oktober 1998 wurden 15 Patienten mit postoperativer

  5. Porphyria cutanea tarda in a HIV- positive patient.

    Franzon, Valéria Aparecida Zanela; Mikilita, Emanuella Stella; Camelo, Fernanda Henriques; Camargo, Rosana

    2016-01-01

    This is a case report about Porphyria cutanea tarda (PCT) and its relationship with the infection caused by the human immunodeficiency virus (HIV). Cutaneous porphyria is an illness caused by enzymatic modification that results in partial deficiency of uroporphyrinogen decarboxylase (Urod), which may be hereditary or acquired. Several studies suggest that HIV infection associated with cofactors might trigger the development of porphyria cutanea tarda. In this case report, we present a patient infected with HIV, who after the introduction of antiretroviral therapy (ART) enjoyed clinical improvement of porphyria cutanea tarda symptoms. PMID:27579753

  6. Porphyria cutanea tarda in a HIV- positive patient*

    Franzon, Valéria Aparecida Zanela; Mikilita, Emanuella Stella; Camelo, Fernanda Henriques; Camargo, Rosana

    2016-01-01

    This is a case report about Porphyria cutanea tarda (PCT) and its relationship with the infection caused by the human immunodeficiency virus (HIV). Cutaneous porphyria is an illness caused by enzymatic modification that results in partial deficiency of uroporphyrinogen decarboxylase (Urod), which may be hereditary or acquired. Several studies suggest that HIV infection associated with cofactors might trigger the development of porphyria cutanea tarda. In this case report, we present a patient infected with HIV, who after the introduction of antiretroviral therapy (ART) enjoyed clinical improvement of porphyria cutanea tarda symptoms. PMID:27579753

  7. Energy intermittency

    Sorensen, Bent

    2014-01-01

    The first book to consider intermittency as a key point of an energy system, Energy Intermittency describes different levels of variability for traditional and renewable energy sources, presenting detailed solutions for handling energy intermittency through trade, collaboration, demand management, and active energy storage. Addressing energy supply intermittency systematically, this practical text:Analyzes typical time-distributions and intervals between episodes of demand-supply mismatch and explores their dependence on system layouts and energy source characteristicsSimulates scenarios regar

  8. Human Immunodeficiency Virus Associated Sporadic Nonfamilial Porphyria Cutanea Tarda.

    Guha, Sibashish Kamal; Bandyopadhyay, Debabrata; Saha, Abanti; Lal, Niharika Ranjan

    2016-01-01

    Porphyria cutanea tarda (PCT), a relatively uncommon metabolic disease, is the most common cutaneous porphyria. Here, we present the case of a patient diagnosed with sporadic, nonfamilial PCT that presented with classical cutaneous findings and multiple risk factors, including alcohol abuse, human immunodeficiency virus/AIDS, that have been strongly associated with the sporadic form of PCT. PMID:27293254

  9. Human immunodeficiency virus associated sporadic nonfamilial porphyria cutanea tarda

    Sibashish Kamal Guha; Debabrata Bandyopadhyay; Abanti Saha; Niharika Ranjan Lal

    2016-01-01

    Porphyria cutanea tarda (PCT), a relatively uncommon metabolic disease, is the most common cutaneous porphyria. Here, we present the case of a patient diagnosed with sporadic, nonfamilial PCT that presented with classical cutaneous findings and multiple risk factors, including alcohol abuse, human immunodeficiency virus/AIDS, that have been strongly associated with the sporadic form of PCT.

  10. Human Immunodeficiency Virus Associated Sporadic Nonfamilial Porphyria Cutanea Tarda

    Guha, Sibashish Kamal; Bandyopadhyay, Debabrata; Saha, Abanti; Lal, Niharika Ranjan

    2016-01-01

    Porphyria cutanea tarda (PCT), a relatively uncommon metabolic disease, is the most common cutaneous porphyria. Here, we present the case of a patient diagnosed with sporadic, nonfamilial PCT that presented with classical cutaneous findings and multiple risk factors, including alcohol abuse, human immunodeficiency virus/AIDS, that have been strongly associated with the sporadic form of PCT.

  11. Acute Flaccid paralysis in adults: Our experience

    Rupesh Kaushik

    2014-01-01

    Full Text Available Acute flaccid paralysis (AFP is a complex clinical syndrome with a broad array of potential etiologies that vary with age. We present our experience of acute onset lower motor neuron paralysis. Materials and Methods: One hundred and thirty-three consecutive adult patients presenting with weakness of duration less than four weeks over 12 months period were enrolled. Detailed history, clinical examination, and relevant investigations according to a pre-defined diagnostic algorithm were carried out. The patients were followed through their hospital stay till discharge or death. Results: The mean age was 33.27 (range 13-89 years with male preponderance (67.7%. The most common etiology was neuroparalytic snake envenomation (51.9%, followed by Guillain Barre syndrome (33.1%, constituting 85% of all patients. Hypokalemic paralysis (7.5% and acute intermittent porphyria (4.5% were the other important conditions. We did not encounter any case of acute polio mylitis in adults. In-hospital mortality due to respiratory paralysis was 9%. Conclusion: Neuroparalytic snakebite and Guillain Barre syndrome were the most common causes of acute flaccid paralysis in adults in our study.

  12. Porphyria and radiotherapy: yet a constellation of risk?

    Background: little is known concerning the relation of porphyrias to radiation treatment for cancer. The recent literature does not report negative outcomes at least in single cases of breast cancer, bladder cancer or in a patient with lymphoma. Theoretically, there is a risk for radiation treatment in cases of porphyrias. Case report: two patients with porphyria are described who underwent radiotherapy for glioblastoma multiforme. Case histories, radiation treatment data and the proof of porphyria are given in detail. The patients received a concomitant radiochemotherapy with infusions of ACNU [1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-(2-chloroethyl)-3-nitrosourea] every 6 weeks. The total radiation doses at the ICRU point were 60 and 38 Gy, respectively, given in single daily fractions of 2 Gy. Results: both patients responded well as far as objective tumor regression is concerned but died early after 7 and 1.5 months following diagnosis. The first patient experienced a large brain necrosis and deterioration of her porphyria. The second patient died of cardiopulmonary insufficiency still during radiotherapy with persistent or even increased signs of porphyria. The tumor showed extensive necrosis already after 38 Gy. Conclusion: in view of annotations in the literature and this case report, caution is advised as for irradiation of brain or nervous tissues in case of porphyrias. Molecular biology data seems to support this warning to some extent. (orig.)

  13. HAART: a risk factor for development of porphyria cutanea tarda?

    Fred Bernardes Filho

    2012-12-01

    Full Text Available Porphyria cutanea tarda (PCT is caused by inherited or acquired partial deficiency of the uroporphyrinogen-decarboxylase (Uro-D enzyme activity. It is the most common form of porphyria. The main triggering factors to the development of porphyria cutanea tarda are alcohol, hepatitis C virus and human immunodeficiency virus. There are several reports of PCT associated with drugs, among them, antiretroviral therapy. We describe three HIV-positive patients, which showed photosensitivity as well as the emergence of tense blisters on sun-exposed areas during the use of highly active antiretroviral therapy (HAART and discuss the possibility of PCT after the use of these drugs by those patients.

  14. Acute intermittent hypoxia-induced expression of Brain-Derived Neurotrophic Factor is disrupted in the brainstem of mecp2 null mice

    Vermehren-Schmaedick, Anke; Jenkins, Victoria K.; Knopp, Sharon J.; Balkowiec, Agnieszka; Bissonnette, John M.

    2012-01-01

    Rett syndrome is a neurodevelopmental disorder caused by loss of function mutations in the gene encoding the transcription factor methyl-CpG-binding protein 2 (MeCP2). One of its targets is the gene encoding brain-derived neurotrophic factor (bdnf). In vitro studies using cultured neurons have produced conflicting results with respect to the role of MeCP2 in BDNF expression. Acute intermittent hypoxia (AIH) induces plasticity in the respiratory system characterized by long-term facilitation of phrenic nerve amplitude. This paradigm induces an increase in BDNF protein. We hypothesized that AIH leads to augmentation of BDNF transcription in respiratory-related areas of the brainstem and that MeCP2 is necessary for this process. Wild-type and mecp2 null (mecp2−/y) mice were subjected to three 5-min episodes of exposure to 8% O2/4% CO2/88% N2, delivered at 5-min intervals. Normoxia control wild-type and mecp2 null mice were exposed to room air for the total length of time, i.e. 30 min. Following a recovery in room air, the pons and medulla were rapidly removed. Expression of BDNF protein and transcripts were determined by ELISA and quantitative PCR, respectively. AIH induced a significant increase in BDNF protein in the pons and medulla, and in mRNA transcript levels in the pons of wild-type animals. In contrast, there were no significant changes in either BDNF protein or transcripts in the pons or medulla of mice lacking Mecp2. The results indicate that Mecp2 is required for regulation of BDNF expression by acute intermittent hypoxia in vivo. PMID:22297041

  15. Acute intermittent hypoxia-induced expression of brain-derived neurotrophic factor is disrupted in the brainstem of methyl-CpG-binding protein 2 null mice.

    Vermehren-Schmaedick, A; Jenkins, V K; Knopp, S J; Balkowiec, A; Bissonnette, J M

    2012-03-29

    Rett syndrome is a neurodevelopmental disorder caused by loss-of-function mutations in the gene encoding the transcription factor methyl-CpG-binding protein 2 (MeCP2). One of its targets is the gene encoding brain-derived neurotrophic factor (bdnf). In vitro studies using cultured neurons have produced conflicting results with respect to the role of MeCP2 in BDNF expression. Acute intermittent hypoxia (AIH) induces plasticity in the respiratory system characterized by long-term facilitation of phrenic nerve amplitude. This paradigm induces an increase in BDNF protein. We hypothesized that AIH leads to augmentation of BDNF transcription in respiratory-related areas of the brainstem and that MeCP2 is necessary for this process. Wild-type and mecp2 null (mecp2(-/y)) mice were subjected to three 5-min episodes of exposure to 8% O(2)/4% CO(2)/88% N(2), delivered at 5-min intervals. Normoxia control wild-type and mecp2 null mice were exposed to room air for the total length of time, that is, 30 min. Following a recovery in room air, the pons and medulla were rapidly removed. Expression of BDNF protein and transcripts were determined by ELISA and quantitative PCR, respectively. AIH induced a significant increase in BDNF protein in the pons and medulla, and in mRNA transcript levels in the pons of wild-type animals. In contrast, there were no significant changes in either BDNF protein or transcripts in the pons or medulla of mice lacking MeCP2. The results indicate that MeCP2 is required for regulation of BDNF expression by acute intermittent hypoxia in vivo. PMID:22297041

  16. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    Chang SC

    2016-05-01

    Full Text Available Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. Objective: We evaluated pressure-regulated volume control (PRVC ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Patients and methods: Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation – volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2–4 hours and 48 hours. Results: Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2, and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2 levels. The pH and PaCO2 levels at 2–4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both; after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05. Vital signs during 2–4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05. The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2–4 hours and 48

  17. A case of congenital erythropoietic porphyria without hemolysis

    Arun K De

    2013-01-01

    Full Text Available Porphyrias are group of disorders caused by deficiency of the enzymes in heme synthetic pathway. Congenital erythropoietic porphyria (CEP is an extremely rare disease with mutation in the gene that codes for uroporphyrinogen III synthase leading to accumulation of porphyrin in different tissues and marked cutaneous photosensitivity. Here, we describe a case of CEP with infancy onset blistering, photosensitivity, red colored urine and teeth along with scarring but without any feature of hemolysis.

  18. Terpene-induced porphyria and the illness of Vincent van Gogh

    Lambrecht, R.; Cable, E.; Cable, J.; Clements, E.; Donohue, S.; Greene, Y.; Srivastava, K.; Arnold, W.; Bonkovsky, H. (Univ. of Massachusetts Medical Center, Worcester (United States) Univ. of Kansas Medical Center, Kansas City (United States))

    1992-01-01

    Vincent van Gogh suffered from recurrent bouts of an illness that may have been acute porphyria and abused camphor and alcohol, the latter particularly in the form of absinthe, a liqueur distilled from wormwood that was popular in 19th C France. To learn whether camphor or terpenes found in absinthe are porphyrogenic, the authors studied them in cultures of chick embryo liver cells. All were found to be porphyrogenic, especially in the presence of deferoxamine. The terpenes also induced the activity and protein amount of 5-aminolevulinate synthase and heme oxygenase, and induced activities of benzphetamine demethylase. The degree of porphyrin and enzyme induction produced by 1mM camphor was similar to that produced by 50uM glutethimide, a potent porphyrogen. Potency of pinene and thujone were lower. Camphor and glutethimide both produced accumulations of 8- and 7-COOH porphyrins, whereas pinene and thujone produced 4- and 2-COOH porphyrin accumulation. The authors conclude that camphor, pinen and thujone are porphyrogenic, cable of exacerbating acute porphyria, and may have done so in van Gogh.

  19. Predicting Changes in High-Intensity Intermittent Running Performance with Acute Responses to Short Jump Rope Workouts in Children

    Martin Buchheit

    2014-09-01

    Full Text Available The aims of the present study were to 1 examine whether individual HR and RPE responses to a jump rope workout could be used to predict changes in high-intensity intermittent running performance in young athletes, and 2 examine the effect of using different methods to determine a smallest worthwhile change (SWC on the interpretation of group-average and individual changes in the variables. Before and after an 8-week high-intensity training program, 13 children athletes (10.6 ± 0.9 yr performed a high-intensity running test (30-15 Intermittent Fitness Test, VIFT and three jump rope workouts, where HR and RPE were collected. The SWC was defined as either 1/5th of the between-subjects standard deviation or the variable typical error (CV. After training, the large ~9% improvement in VIFT was very likely, irrespective of the SWC. Standardized changes were greater for RPE (very likely-to-almost certain, ~30-60% changes, ~4-16 times >SWC than for HR (likely-to-very likely, ~2-6% changes, ~1-6 times >SWC responses. Using the CV as the SWC lead to the smallest and greatest changes for HR and RPE, respectively. The predictive value for individual performance changes tended to be better for HR (74-92% than RPE (69%, and greater when using the CV as the SWC. The predictive value for no-performance change was low for both measures (<26%. Substantial decreases in HR and RPE responses to short jump rope workouts can predict substantial improvements in high-intensity running performance at the individual level. Using the CV of test measures as the SWC might be the better option.

  20. A Case of Porphyria Cutanea Tarda in a Patient Undergoing Dialysis

    Ayşegül Güney; Ayşın Köktürk; Ayşe Polat

    2010-01-01

    Porphyrinogens are the building blocks of all the hemoproteins, such as hemoglobin and the cytochrome enzymes. In certain inherited and acquired disease states, called the porphyrias, these intermediate metabolites of hemoglobin synthesis are increased. Porphyria cutanea tarda is the most common type of porphyria. It is characterized by photosensitivity resulting in bullae, especially on sun-exposed parts. Liver diseases, kidney diseases, hepatitis C virus infection concomitant with porphyria...

  1. Acute and delayed effects of intermittant ozone on cardiovascular and thermoregulatory responses of young and aged rats

    Ozone (03) is associated with cardiovascular and respiratory diseases. The aged population is considered to be more sensitive to air pollutants but relatively few studies have demonstrated increased susceptibility in animal models of aging. To study the acute and delayed physiolo...

  2. Acute effects of resistance exercise and intermittent intense aerobic exercise on blood cell count and oxidative stress in trained middle-aged women

    The aim of this study was to compare the effect of an intermittent intense aerobic exercise session and a resistance exercise session on blood cell counts and oxidative stress parameters in middle-aged women. Thirty-four women were selected and divided into three groups: RE group (performing 60 min of resistance exercises, N = 12), spinning group (performing 60 min of spinning, N = 12), and control group (not exercising regularly, N = 10). In both exercise groups, lymphocytes and monocytes decreased after 1-h recuperation (post-exercise) compared to immediately after exercise (P < 0.05). Immediately after exercise, in both exercised groups, a significant increase in TBARS (from 16.5 ± 2 to 25 ± 2 for the spinning group and from 18.6 ± 1 to 28.2 ± 3 nmol MDA/mL serum for the RE group) and protein carbonyl (from 1.0 ± 0.3 to 1.6 ± 0.2 for the spinning group and from 0.9 ± 0.2 to 1.5 ± 0.2 nmol/mg protein for the RE group) was observed (P < 0.05). A decrease in antioxidant activities (non-protein sulfhydryl, superoxide dismutase, catalase) was also demonstrated with a negative correlation between damage markers and antioxidant body defenses (P < 0.05). These results indicate that an acute bout of intermittent or anaerobic exercise induces immune suppression and increases the production of reactive oxygen species, causing oxidative stress in middle-aged and trained women. Furthermore, we demonstrated that trained women show improved antioxidant capacity and lower oxidative damage than sedentary ones, demonstrating the benefits of chronic regular physical activity

  3. A Case of Porphyria Cutanea Tarda in a Patient Undergoing Dialysis

    Ayşegül Güney

    2010-09-01

    Full Text Available Porphyrinogens are the building blocks of all the hemoproteins, such as hemoglobin and the cytochrome enzymes. In certain inherited and acquired disease states, called the porphyrias, these intermediate metabolites of hemoglobin synthesis are increased. Porphyria cutanea tarda is the most common type of porphyria. It is characterized by photosensitivity resulting in bullae, especially on sun-exposed parts. Liver diseases, kidney diseases, hepatitis C virus infection concomitant with porphyria cutanea tarda have been reported. We reported porphyria in a patient undergoing dialysis.

  4. The acute effects of intermittent treadmill running on hunger and plasma acylated ghrelin concentration in individuals with obesity

    Gholipour M

    2011-05-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Body weight is regulated by both food intake and energy expenditure. Ghrelin, a hormone produced by the stomach and pancreas, enhances appetite. This study was undertaken to determine the effects of intermittent treadmill running on acylated ghrelin and appetite in individuals with obesity."n"nMethods : Nine inactive male students, with a mean age of 20.56±0.48 yrs, a body mass index of 32.68±0.84 kg/m2 and a maximum oxygen uptake of 34.21±1.48 ml/kg/min, participated in the study in two trials (control and exercise in a counterbalanced, randomized design. The protocol included intermittent running with a constant intensity at 65% of VO2 max on a treadmill. Blood samples were collected before, during, and 2h after cessation of the exercise."n"nResults : Acylated ghrelin concentrations and hunger ratings decreased significantly in the second phase and remained lower than baseline (P=0.006 and P=0.002, respectively at the end of the exercise. The total area under the curve values and hunger ratings (all P<0.0005 were significantly lower in the exercise trial compared with the control state. Similarly, growth hormone rose significantly at the second phase and remained higher than baseline (P=0.033 at the

  5. Genetic and biochemical studies in Argentinean patients with variegate porphyria

    Giudice Jimena

    2008-06-01

    Full Text Available Abstract Background A partial deficiency in Protoporphyrinogen oxidase (PPOX produces the mixed disorder Variegate Porphyria (VP, the second acute porphyria more frequent in Argentina. Identification of patients with an overt VP is absolutely important because treatment depends on an accurate diagnosis but more critical is the identification of asymptomatic relatives to avoid acute attacks which may progress to death. Methods We have studied at molecular level 18 new Argentinean patients biochemically diagnosed as VP. PPOX gene was amplified in one or in twelve PCR reactions. All coding exons, flanking intronic and promoter regions were manual or automatically sequenced. For RT-PCR studies RNA was retrotranscripted, amplified and sequenced. PPOX activity in those families carrying a new and uncharacterized mutation was performed. Results All affected individuals harboured mutations in heterozygous state. Nine novel mutations and 3 already reported mutations were identified. Six of the novel mutations were single nucleotide substitutions, 2 were small deletions and one a small insertion. Three single nucleotide substitutions and the insertion were at exon-intron boundaries. Two of the single nucleotide substitutions, c.471G>A and c.807G>A and the insertion (c.388+3insT were close to the splice donor sites in exons 5, 7 and intron 4 respectively. The other single nucleotide substitution was a transversion in the last base of intron 7, g.3912G>C (c.808-1G>C so altering the consensus acceptor splice site. However, only in the first case the abnormal band showing the skipping of exon 5 was detected. The other single nucleotide substitutions were transversions: c.101A>T, c.995G>C and c.670 T>G that result in p.E34V, p.G332A and W224G aminoacid substitutions in exons 3, 10 and 7 respectively. Activity measurements indicate that these mutations reduced about 50% PPOX activity and also that they co-segregate with this reduced activity value. Two

  6. Comparison of the effects of growth hormone on acylated ghrelin and following acute intermittent exercise in two levels of obesity

    Majid Gholipour

    2013-08-01

    Full Text Available Background: The prevalence of obesity has risen enormously over the past few decad-es. Both food intake (Appetite and energy expenditure can influence body weight. Acylated ghrelin enhances appetite, and its plasma level is suppressed by growth horm-one. The present study, examines the effects of an intermittent exercise with progress-ive intensities on acylated ghrelin, appetite, and growth hormone in inactive male students with two levels of obesity.Methods: Eleven inactive males were allocated into two groups on the basis of their body mass index (BMI. Six subjects in group one, BMI= 31.18±0.92 kg/m2, and five subjects in group two, BMI= 36.94±2.25 kg/m2, ran on the treadmill with progressive intensities of 50, 60, 70 and 80% of VO2max for 10, 10, 5, and 2 min respectively. Blood samples were collected before the exercise (as the resting values, after each workload (during the exercise, and at 30, 60, and 120 min (during recovery.Results: Plasma acylated ghrelin concentrations and hunger ratings in two groups were decreased and remained significantly lower than resting values (P=0.008 and P=0.002 respectively at the end of the trial and there was no significant differences between groups. Growth hormone levels in two groups were increased and remained significant-ly higher than resting values (groups one P=0.012, group two P=0.005 at the end of the trial and there was no significant differences between groups. In addition, there were no significant differences between area under the curves (AUC values over total periods for acylated ghrelin, hunger ratings, and growth hormone in two groups.Conclusion: These findings indicate that individuals with two levels of obesity have the same response to the different intensities of treadmill running and two hours thereafter during recovery period, which can be considered for designing a more effective weighting loss training program.

  7. [Porphyria cutanea tarda: the benefit of additional diagnostics].

    Vossen, Allard R J V; Boesten, Lianne S M; Siersema, Peter D; Nellen, Ruud G L

    2016-01-01

    The porphyrias are a clinically and genetically heterogeneous group of relatively rare metabolic diseases that result from disorders in the biosynthesis of haeme. Porphyria cutanea tarda (PCT) is the most common type, accounting for 80-90% of all porphyrias, and is essentially an acquired disease, although PCT can also occur on a familial basis. We describe a 71-year-old female and a 62-year-old male patient, both of whom had several risk factors for developing PCT, ranging from iron overload due to a mutation in the hereditary haemochromatosis protein (HFE) gene, alcohol use, smoking, and exogenous oestrogen, to persistent hepatitis C infection. The clinical relevance of the several diagnostic modalities is important in PCT. Diagnostic evaluation is important in order to confirm the diagnosis, but also to evaluate the treatment response in the context of long-term follow-up in the prevention of late complications of PCT, i.e. hepatocellular carcinoma. PMID:26840933

  8. Multiple hepatic foci in latent porphyria cutanea tarda

    A 41-year-old patient with latent porphyria cutanea tarda is described; 8 years after mastectomy for carcinoma, sonography and CT showed multiple hepatic foci, which were at first interpreted as liver metastases. A liver biopsy was carried out during laparoscopy and u/v fluorescence and subsequent laboratory tests confirmed the diagnosis of porphyria cutanea tarda. Treatment with Resochin produced almost complete resolution of the liver abnormalities within 9 months. Magnetic resonance tomography using proton-weighted SE sequences showed a few foci of high signal intensity. (orig.)

  9. Multiple hepatic foci in latent porphyria cutanea tarda

    Kerjes, W.; Harder, T.; Steudel, A.; Hartlapp, J.H.

    1988-02-01

    A 41-year-old patient with latent porphyria cutanea tarda is described; 8 years after mastectomy for carcinoma, sonography and CT showed multiple hepatic foci, which were at first interpreted as liver metastases. A liver biopsy was carried out during laparoscopy and u/v fluorescence and subsequent laboratory tests confirmed the diagnosis of porphyria cutanea tarda. Treatment with Resochin produced almost complete resolution of the liver abnormalities within 9 months. Magnetic resonance tomography using proton-weighted SE sequences showed a few foci of high signal intensity.

  10. Chronic Intermittent Ethanol Exposure Enhances the Excitability and Synaptic Plasticity of Lateral Orbitofrontal Cortex Neurons and Induces a Tolerance to the Acute Inhibitory Actions of Ethanol.

    Nimitvilai, Sudarat; Lopez, Marcelo F; Mulholland, Patrick J; Woodward, John J

    2016-03-01

    Alcoholism is associated with changes in brain reward and control systems, including the prefrontal cortex. In prefrontal areas, the orbitofrontal cortex (OFC) has been suggested to have an important role in the development of alcohol-abuse disorders and studies from this laboratory demonstrate that OFC-mediated behaviors are impaired in alcohol-dependent animals. However, it is not known whether chronic alcohol (ethanol) exposure alters the fundamental properties of OFC neurons. In this study, mice were exposed to repeated cycles of chronic intermittent ethanol (CIE) exposure to induce dependence and whole-cell patch-clamp electrophysiology was used to examine the effects of CIE treatment on lateral OFC (lOFC) neuron excitability, synaptic transmission, and plasticity. Repeated cycles of CIE exposure and withdrawal enhanced current-evoked action potential (AP) spiking and this was accompanied by a reduction in the after-hyperpolarization and a decrease in the functional activity of SK channels. CIE mice also showed an increase in the AMPA/NMDA ratio, and this was associated with an increase in GluA1/GluA2 AMPA receptor expression and a decrease in GluN2B NMDA receptor subunits. Following CIE treatment, lOFC neurons displayed a persistent long-term potentiation of glutamatergic synaptic transmission following a spike-timing-dependent protocol. Lastly, CIE treatment diminished the inhibitory effect of acute ethanol on AP spiking of lOFC neurons and reduced expression of the GlyT1 transporter. Taken together, these results suggest that chronic exposure to ethanol leads to enhanced intrinsic excitability and glutamatergic synaptic signaling of lOFC neurons. These alterations may contribute to the impairment of OFC-dependent behaviors in alcohol-dependent individuals. PMID:26286839

  11. Porphyria Cutanea Tarda with Constrictive Pericarditis: A Rare Association

    Jyotika Kalsy; Mughda Sharma; Nidhi Sharma; Kaur Jasleen

    2012-01-01

    Porphyria cutanea tarda(PCT) is characterised by photosensitivity and bulla formation on photoexposed parts which heals with scaring and pigmentation. PCT is frequently associated with diabetes mellitus, lupus erythematosus and hepetitis C virus infection. We are reporting and Indian patient of PCT associated with pericarditis which is very rare.

  12. Intermittent hyperthyreosis

    Intermittent hyperthyreosis occurs under various forms of stress, especially heat stress. The clinician may diagnose such cases as masked or apathetic hyperthyroidism or 'forme fruste' hyperthyreosis or thyroid autonomy. As most routine and standard tests may here yield inconsistent results, it is the patients' anamnesis which may provide the clue. Our Bioclimatology Unit has now seen over 100 cases in which thyroid hypersensitivity towards heat was the most prominent syndrome: 10-15% of weather-sensitive patients are affected. The patients complain before or during heat spells of such contradictory symptoms as insomnia, irritability, tension, tachycardia, palpitations, precordial pain, dyspnoe, flushes with sweating or chills, tremor, abdominal pain or diarrhea, polyuria or pollakisuria, weight loss in spite of ravenous appetite, fatigue, exhaustion, depression, adynamia, lack of concentration and confusion. Determination of urinary neurohormones allows a differential diagnosis, intermittent hyperthyreosis being characterized by three cardinal symptoms: tachycardia - every case with more than 80 pulse beats being suspect (not specific); urinary histamine - every case excreting more than 90 μg/day being suspect. Again the drawback of this test is its lack of specificity, as histamine may also be increased in cases of allergy and spondylitis; urinary thyroxine - every case excreting more than 20 μg/day T-4 being suspect. This is the only specific test. Therapy should make use of lithium carbonate and betablockers. Propyl thiouracil is rarely required. (orig.)

  13. Porphyrias associated with malignant tumors: Results of treatment with ionizing irradiation

    Schaffer, Moshe; Schaffer, Pamela Manuela; Panzer, M.; Wilkowski, R; Dühmke, Eckhart

    2001-01-01

    Background: Porphyrin metabolism disorders, known as porphyria, represent inherited or acquired diseases. The development of porphyria due to light sensibility occurs especially with exposure to wavelengths in the range of 300-700 nm. Skin reactions and neurovisceral dysfunctions are known side effects of ionizing irradiation. It can be postulated that during or after ionizing irradiation treatment of patients affected with tumor and porphyria, severe side effects might appear, in contrast to...

  14. Precipitating factors of porphyria cutanea tarda in Brazil with emphasis on hemochromatosis gene (HFE) mutations. Study of 60 patients*

    Vieira, Fatima Mendonça Jorge; NAKHLE Maria Cristina; Abrantes-Lemos, Clarice Pires; Cançado, Eduardo Luiz Rachid; dos Reis, Vitor Manoel Silva

    2013-01-01

    BACKGROUND Porphyria cutanea tarda is the most common form of porphyria, characterized by the decreased activity of the uroporphyrinogen decarboxylase enzyme. Several reports associated HFE gene mutations of hereditary hemochromatosis with porphyria cutanea tarda worldwide, although up to date only one study has been conducted in Brazil. OBJECTIVES Investigation of porphyria cutanea tarda association with C282Y and H63D mutations in the HFE gene. Identification of precipitating factors (hepat...

  15. 38 CFR 3.813 - Interim benefits for disability or death due to chloracne or porphyria cutanea tarda.

    2010-07-01

    ... disability or death due to chloracne or porphyria cutanea tarda. 3.813 Section 3.813 Pensions, Bonuses, and... porphyria cutanea tarda. (a) Disability benefits. Except as provided in paragraph (c) of this section, a... Vietnam era, and who suffers from chloracne or porphyria cutanea tarda which became manifest within...

  16. Congenital erythropoietic porphyria in an African hedgehog (Atelerix albiventris).

    Wolff, Carlos; Corradini, Paulina; Cortés, Galaxia

    2005-06-01

    A 6-mo-old, male African hedgehog (Atelerix albiventris) presented with a history of pink urine and demonstrating pink-colored teeth and mild hepatomegaly on examination. Urinalysis revealed no physical, chemical, or cellular abnormalities other than a pink color and fluorescence under ultraviolet light (UV). Also under UV, intense fluorescence of teeth, feet, and spines was noted. Porphyria was suspected. Spectrophotometric evaluation of urine showed extremely elevated levels of copro- and uroporphyrins. Analysis of the urine by thin-layer chromatography showed an abnormal pattern of excreted porphyrin intermediates. Urine high-performance thin-layer chromatography showed that excreted porphyrins were 90-95% of the type-I isomeric form, suggestive of congenital erythropoietic porphyria. PMID:17323578

  17. Intermittent hypoxia and neurorehabilitation.

    Gonzalez-Rothi, Elisa J; Lee, Kun-Ze; Dale, Erica A; Reier, Paul J; Mitchell, Gordon S; Fuller, David D

    2015-12-15

    In recent years, it has become clear that brief, repeated presentations of hypoxia [i.e., acute intermittent hypoxia (AIH)] can boost the efficacy of more traditional therapeutic strategies in certain cases of neurologic dysfunction. This hypothesis derives from a series of studies in animal models and human subjects performed over the past 35 yr. In 1980, Millhorn et al. (Millhorn DE, Eldridge FL, Waldrop TG. Respir Physiol 41: 87-103, 1980) showed that electrical stimulation of carotid chemoafferent neurons produced a persistent, serotonin-dependent increase in phrenic motor output that outlasts the stimulus for more than 90 min (i.e., a "respiratory memory"). AIH elicits similar phrenic "long-term facilitation" (LTF) by a mechanism that requires cervical spinal serotonin receptor activation and de novo protein synthesis. From 2003 to present, a series of studies demonstrated that AIH can induce neuroplasticity in the injured spinal cord, causing functional recovery of breathing capacity after cervical spinal injury. Subsequently, it was demonstrated that repeated AIH (rAIH) can induce recovery of limb function, and the functional benefits of rAIH are greatest when paired with task-specific training. Since uncontrolled and/or prolonged intermittent hypoxia can elicit pathophysiology, a challenge of intermittent hypoxia research is to ensure that therapeutic protocols are well below the threshold for pathogenesis. This is possible since many low dose rAIH protocols have induced functional benefits without evidence of pathology. We propose that carefully controlled rAIH is a safe and noninvasive modality that can be paired with other neurorehabilitative strategies including traditional activity-based physical therapy or cell-based therapies such as intraspinal transplantation of neural progenitors. PMID:25997947

  18. Radiological features in congenital erythropoietic porphyria (Gunther's disease)

    Gunther's disease or congenital erythropoietic porphyria is a rare and severe disorder comprising cutaneous and haemolytic symptoms. Photocutaneous lesions are responsible for scleroderma-like calcifications and deformities of the extremities visible on X-rays. Hemolytic manifestations lead to diffuse major osteopenia. Soft tissue calcifications of the fingers can be seen even in young patients. One case reported here is the first illustration of intracranial calcifications located on dura-mater and calvarium. (orig.)

  19. Uroporphyrinogen decarboxylase gene mutations in Danish patients with porphyria cutanea tarda

    Christiansen, L; Bygum, A; Jensen, A; Brandrup, F; Thomsen, K; Hørder, Mogens; Petersen, N E

    2000-01-01

    Decreased uroporphyrinogen decarboxylase (UROD) activity is a characteristic feature of the most common of the porphyrias, porphyria cutanea tarda (PCT). A subgroup of the clinically overt PCT cases is associated with mutations in the gene encoding UROD and inherited as an autosomal-dominant trait...

  20. Feline porphyria associated with anemia, severe hepatic disease, and renal calculi

    Schnier, Jonathan J.; Hanna, Paul

    2010-01-01

    A 13-year-old, neutered male domestic cat presented with signs of weight loss, anemia, and hepatomegaly. Pathognomonic signs of porphyria were identified. Charcoal-like renal calculi and severe liver changes were observed, neither of which has been previously reported in association with feline porphyria.

  1. Porphyria and radiotherapy: yet a constellation of risk?; Porphyrie und Radiotherapie: doch eine Risikokonstellation?

    Rhomberg, W. [Abt. fuer Radioonkologie, Landeskrankenhaus, Feldkirch (Austria); Offner, F.A. [Abt. fuer Pathologie, Landeskrankenhaus, Feldkirch (Austria)

    2005-06-01

    Background: little is known concerning the relation of porphyrias to radiation treatment for cancer. The recent literature does not report negative outcomes at least in single cases of breast cancer, bladder cancer or in a patient with lymphoma. Theoretically, there is a risk for radiation treatment in cases of porphyrias. Case report: two patients with porphyria are described who underwent radiotherapy for glioblastoma multiforme. Case histories, radiation treatment data and the proof of porphyria are given in detail. The patients received a concomitant radiochemotherapy with infusions of ACNU [1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-(2-chloroethyl)-3-nitrosourea] every 6 weeks. The total radiation doses at the ICRU point were 60 and 38 Gy, respectively, given in single daily fractions of 2 Gy. Results: both patients responded well as far as objective tumor regression is concerned but died early after 7 and 1.5 months following diagnosis. The first patient experienced a large brain necrosis and deterioration of her porphyria. The second patient died of cardiopulmonary insufficiency still during radiotherapy with persistent or even increased signs of porphyria. The tumor showed extensive necrosis already after 38 Gy. Conclusion: in view of annotations in the literature and this case report, caution is advised as for irradiation of brain or nervous tissues in case of porphyrias. Molecular biology data seems to support this warning to some extent. (orig.)

  2. Allogeneic corneoscleral limbus tissue transplantation for treatment of the necrosis in porphyria eye disease

    Feng; Yan; Yan; Lu; Jie; Yin; Feng; Jiang; Zhen-Ping; Huang

    2014-01-01

    · Porphyria cutanea tarda(PCT) with ocular complications are rarely reported. To the best of our knowledge, no reports exist on allogeneic corneoscleral limbus tissue transplantation for treatment of these.Amniotic membrane grafting had been performed in their patient suffering from porphyria eye disease, but necrosis developed in the grafts. Nevertheless, in our patient, allogeneic corneoscleral limbus transplantation prevented necrosis from development at corneoscleral limbus. So we considered that the allogeneic corneoscleral limbus transplantation might be an option to repair the necrosis in porphyria eye disease with avoiding sunlight and using artificial tear drops.

  3. Porfiria cutânea tardia Porphyria cutanea tarda

    Fátima Mendonça Jorge Vieira

    2006-12-01

    Full Text Available Trata-se de revisão sobre a porfiria cutânea tardia em que são abordados a fisiopatogenia, as características clínicas, as doenças associadas, os fatores desencadeantes, a bioquímica, a histopatologia, a microscopia eletrônica, a microscopia de imunofluorescência e o tratamento da doença.This is a review article of porphyria cutanea tarda addressing pathophysiology, clinical features, associated conditions, triggering factors, biochemistry, histopathology, electronic microscopy, immunofluorescence microscopy and treatment of the disease.

  4. Congenital Erythropoietic Porphyria With Calcific Constrictive Pericarditis: A Case Report and Brief Review of Literature.

    Chowdhury, Ujjwal K; Patel, Kartik; Seth, Sandeep; Ray, Ruma; Jagia, Priya; Sahu, Manoj

    2015-10-01

    An 18-year-old boy with congenital erythropoietic porphyria and calcific constrictive pericarditis underwent total pericardiectomy. The cause of pericardial calcification could be deposition of porphyrins in the pericardium. Surgical importance of this rare condition is highlighted. PMID:26467880

  5. Adult-onset congenital erythropoietic porphyria (Günther's disease) presenting with thrombocytopenia.

    Murphy, A.; Gibson, G; Elder, G H; Otridge, B A; Murphy, G M

    1995-01-01

    Cutaneous signs of Günther's disease (congenital erythropoietic porphyria) developing 5 years after the onset of symptomatic thrombocytopenia are described in a 65-year-old man. Persistent thrombocytopenia unresponsive to corticosteroids and immunoglobulin necessitated a splenectomy.

  6. Allogeneic corneoscleral limbus tissue transplantation for treatment of the necrosis in porphyria eye disease

    2014-01-01

    Porphyria cutanea tarda (PCT) with ocular complications are rarely reported. To the best of our knowledge, no reports exist on allogeneic corneoscleral limbus tissue transplantation for treatment of these. Amniotic membrane grafting had been performed in their patient suffering from porphyria eye disease, but necrosis developed in the grafts. Nevertheless, in our patient, allogeneic corneoscleral limbus transplantation prevented necrosis from development at corneoscleral limbus. So we conside...

  7. Porphyria Cutanea Tarda Masquerading as Epidermolysis Bullosa Acquisita: A Report of Two Cases

    Deen, Kristyn; Wu, Jason

    2015-01-01

    Porphyria cutanea tarda (PCT) is the most common type of porphyria worldwide and is often initially diagnosed when cutaneous manifestations arise. We present two patients where misdiagnosis of PCT occurred due to the condition masquerading as epidermolysis bullosa acquisita histologically. In patients with undifferentiated bullous/erosive skin conditions occurring in photo-distributed regions, PCT should be considered in the differential diagnosis irrespective of histopathological findings on...

  8. Intermittent Explosive Disorder

    Lut Tamam; Meliha Zengin Eroglu; Ozlem Paltaci

    2011-01-01

    Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etio...

  9. INTERMITTENT DEGRADATION AND SCHIZOTYPY

    Roché, Matthew W.; Silverstein, Steven M.; Lenzenweger, Mark F.

    2015-01-01

    Intermittent degradation refers to transient detrimental disruptions in task performance. This phenomenon has been repeatedly observed in the performance data of patients with schizophrenia. Whether intermittent degradation is a feature of the liability for schizophrenia (i.e., schizotypy) is an open question. Further, the specificity of intermittent degradation to schizotypy has yet to be investigated. To address these questions, 92 undergraduate participants completed a battery of self-repo...

  10. A molecular study of congenital erythropoietic porphyria in cattle

    Agerholm, J S; Thulstrup, P W; Bjerrum, M J; Bendixen, Christian; Jørgensen, C B; Fredholm, M

    2012-01-01

    is segregating in a manner consistent with autosomal recessive inheritance. Biochemical analyses demonstrated accumulation of uroporphyrin, thus confirming that it is indeed insufficient activity of UROS which is the cause of the disease. We have therefore sequenced all nine exons of UROS in affected......Previous studies have shown that congenital erythropoietic porphyria (CEP) in cattle is caused by an inherited deficiency of the enzyme uroporphyrinogen III synthase (UROS) encoded by the UROS gene. In this study, we have established the pedigree of an extended Holstein family in which the disease...... and non-affected individuals without detecting any potential causative mutations. However, a single nucleotide polymorphism (SNP) located within the spliceosome attachment region in intron 8 of UROS is shown to segregate with the disease allele. Our study supports the hypothesis that CEP in cattle is...

  11. Further discussion concerning porphyria cutanea tarda and TCDD exposure

    Jones, R.E.; Chelsky, M.

    Past reports have correlated a diagnosis of porphyria cutanea tarda (PCT) with exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Re-examination of the literature, however, has caused us to question the conclusion of a relationship between acquired PCT and TCDD. The major considerations at issue were: (1) whether the diagnostic label of PCT was applied excessively to cases with findings that are nonspecific; (2) whether the clinical conditions suggestive of PCT were likely results of exposure to another chemical, for example hexachlorobenzene (HCB); and (3) whether a causal link between PCT and TCDD is reasonably substantiated by the facts. Based on the re-evaluation of the literature, the known effects of HCB and TCDD, and the follow-up results from the chemical plant, the authors submit that HCB alone, or HCB in combination with other polychlorinated aromatic hydrocarbons, may have been responsible for the effects observed and the subsequent correlation to PCT.

  12. Advances in understanding the pathogenesis of congenital erythropoietic porphyria.

    Di Pierro, Elena; Brancaleoni, Valentina; Granata, Francesca

    2016-05-01

    Congenital erythropoietic porphyria (CEP) is a rare genetic disease resulting from the remarkable deficient activity of uroporphyrinogen III synthase, the fourth enzyme of the haem biosynthetic pathway. This enzyme defect results in overproduction of the non-physiological and pathogenic porphyrin isomers, uroporphyrin I and coproporphyrin I. The predominant clinical characteristics of CEP include bullous cutaneous photosensitivity to visible light from early infancy, progressive photomutilation and chronic haemolytic anaemia. The severity of clinical manifestations is markedly heterogeneous among patients; and interdependence between disease severity and porphyrin amount in the tissues has been pointed out. A more pronounced endogenous production of porphyrins concomitant to activation of ALAS2, the first and rate-limiting of the haem synthesis enzymes in erythroid cells, has also been reported. CEP is inherited as autosomal recessive or X-linked trait due to mutations in UROS or GATA1 genes; however an involvement of other causative or modifier genes cannot be ruled out. PMID:26969896

  13. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    Chang SC; Shi JD; Fu CP; Wu X; Li SQ

    2016-01-01

    Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive car...

  14. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    Chang, Su Chi

    2016-01-01

    Suchi Chang,1 Jindong Shi,2 Cuiping Fu,1 Xu Wu,1 Shanqun Li1 1Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, 2Department of Respiratory Medicine, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, People’s Republic of China Background: COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Inten...

  15. ROTURA DEL SEPTO INTERVENTRICULAR DESPUÉS DE INFARTO AGUDO DE MIOCARDIO CON APERTURA Y CIERRE INTERMITENTES / Interventricular septal rupture after acute myocardial infarction with intermittent opening and closing

    Jorge L. Alonso Freire

    2013-01-01

    Full Text Available Resumen La rotura del septo interventricular es una grave complicación en pacientes que sufren infarto agudo de miocardio. Se presenta aproximadamente en el 1 % de los pacientes infartados, su mortalidad es elevada y el tratamiento de elección es la reparación quirúrgica. Se presenta un paciente anciano que ingresó en la Unidad de Cuidados Intensivos por infarto agudo de miocardio de cara anterior, que recibió tratamiento trombolítico con estreptokinasa recombinante cubana y 24 horas más tarde, presentó deterioro hemodinámico con cambios electrocardiográficos y aparición de soplo sistólico en la punta. Se realizó una ecocardiografía que mostró un defecto del septo interventricular con apertura y cierre intermitentes. Horas más tarde el paciente falleció por insuficiencia cardiocirculatoria, a pesar del tratamiento. Se presentan las imágenes ecocardiográficas y la pieza anatómica. Lo inusual del presente caso fue la apertura y el cierre intermitentes del defecto interventricular. No se encontró ningún informe similar a en las bases de datos bibliográficas consultadas. / Abstract Ventricular septum rupture is a serious complication in patients with acute myocardial infarction. It occurs in approximately 1% of heart attack patients; its mortality rate is high and surgical repair is the treatment of choice. The case of an elderly male patient who was admitted to the Intensive Care Unit for acute anterior myocardial infarction is reported. This patient received thrombolytic therapy with Cuban recombinant streptokinase and 24 hours later presented hemodynamic deterioration with electrocardiographic changes and appearance of systolic murmur at the apex. Echocardiography was performed which showed a ventricular septal defect with intermittent opening and closing. Despite treatment, the patient died of circulatory failure hours later. Echocardiographic images and the anatomical specimen are shown. What was unusual in this case was

  16. Familial and sporadic porphyria cutanea tarda: clinical and biochemical features and risk factors in 152 patients.

    Muñoz-Santos, Carlos; Guilabert, Antonio; Moreno, Nemesio; To-Figueras, Jordi; Badenas, Celia; Darwich, Esteve; Herrero, Carmen

    2010-03-01

    Porphyria cutanea tarda is the most frequent porphyria and occurs in both sporadic and familial forms. We conducted the current study in a series of 152 consecutive patients with porphyria cutanea tarda attending the Porphyria Unit of the Hospital Clinic of Barcelona, Spain, to update the clinical manifestations of the disease and to study the sex differences, the proportion of familial forms, and the role of different risk factors in this population. Patients were classified as familial and sporadic cases according to erythrocyte uroporphyrinogen-decarboxylase activity and uroporphyrinogen-decarboxylase genotyping. In our cohort, skin fragility and blisters on the hands were the most frequent clinical manifestations. Women more frequently had facial hypertrichosis (84.8%; p = 0.004), affected areas other than the hands and face (33.3%; p = 0.008), and pruritus (27.3%; p = 0.041) compared with men. Of our patients, 11.8% did not present the typical clinical onset of the disease, with facial hypertrichosis and hyperpigmentation the more frequent complaints in these cases. Analysis of risk factors showed a high prevalence of hepatitis C virus infection (65.8%) and alcohol abuse (59.9%), both being more frequent in men (p < 0.001). Hepatitis C virus infection was the only risk factor that showed differences between the sporadic and familial forms in the logistic regression model (odds ratio, 0.05; 95% confidence interval, 0.006-0.46). In conclusion, atypical forms of presentation of porphyria cutanea tarda should be considered in order to prevent delayed diagnosis. We note the sustained role of hepatitis C virus infection in the precipitation of sporadic porphyria cutanea tarda. Therefore, in countries with a high prevalence of hepatitis C virus infection, the absence of such infection in a patient with porphyria cutanea tarda may suggest a possible familial case. PMID:20517178

  17. Partial protoporphyrinogen oxidase (PPOX gene deletions, due to different Alu-mediated mechanisms, identified by MLPA analysis in patients with variegate porphyria

    Barbaro Michela

    2013-01-01

    Full Text Available Abstract Variegate porphyria (VP is an autosomal dominantly inherited hepatic porphyria. The genetic defect in the PPOX gene leads to a partial defect of protoporphyrinogen oxidase, the penultimate enzyme of heme biosynthesis. Affected individuals can develop cutaneous symptoms in sun-exposed areas of the skin and/or neuropsychiatric acute attacks. The identification of the genetic defect in VP families is of crucial importance to detect the carrier status which allows counseling to prevent potentially life threatening neurovisceral attacks, usually triggered by factors such as certain drugs, alcohol or fasting. In a total of 31 Swedish VP families sequence analysis had identified a genetic defect in 26. In the remaining five families an extended genetic investigation was necessary. After the development of a synthetic probe set, MLPA analysis to screen for single exon deletions/duplications was performed. We describe here, for the first time, two partial deletions within the PPOX gene detected by MLPA analysis. One deletion affects exon 5 and 6 (c.339-197_616+320del1099 and has been identified in four families, most probably after a founder effect. The other extends from exon 5 to exon 9 (c.339-350_987+229del2609 and was found in one family. We show that both deletions are mediated by Alu repeats. Our findings emphasize the usefulness of MLPA analysis as a complement to PPOX gene sequencing analysis for comprehensive genetic diagnostics in patients with VP.

  18. Intermittent Explosive Disorder

    Lut Tamam

    2011-09-01

    Full Text Available Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etiological studies displayed the role of both psychosocial factors like childhood traumas and biological factors like dysfunctional neurotransmitter systems and genetics. In differential diagnosis of the disorder, disorders involving agression as a symptom such as alcohol and drug intoxication, antisocial and borderline personality disorders, personality changes due to general medical conditions and behavioral disorder should be considered. A combination of pharmacological and psychotherapeutic approaches are suggested in the treatment of the disorder. This article briefly reviews the historical background, diagnostic criteria, epidemiology, etiology and treatment of intermittent explosive disorder.

  19. Forecasting intermittent demand

    Teunter, R.H.; Duncan, L

    2006-01-01

    Methods for forecasting intermittent demand are compared using a large data-set from the UK Royal Air Force (RAF). Several important results are found. First, we show that the traditional per period forecast error measures are not appropriate for intermittent demand, even though they are consistently used in the literature. Second, by comparing target service levels to achieved service levels when inventory decisions are based on demand forecasts, we show that Croston's method (and a variant)...

  20. Intermittency in particle physics

    This thesis presents an analysis of intermittency as it appears in high energy multiparticle production. Momentum space particle distributions are scale invariant and fluctuate from events to events. This phenomenon originates from Hydrodynamics. Some results about hydrodynamics intermittency are by the way deduced using random diffusion processes and the Landau-Ginzburg equation. A phenomenological approach utilizing random cascading models is used to describe the morphology and intermittent features of particle distributions. Along these lines, a thorough study of random cascades is performed. The origin of intermittent fluctuation is to be found within the Framework of Quantum Field Theory. Indeed intermittency is intimately linked to the perturbative cascade of Quantum Chromodynamics. The long distance behaviour of perturbative QCD is intermittent at the leading collinear logarithm approximation. Moreover fluctuations of matter density along the rapidity axis suggest that the gluon cascade undergoes a phase transition towards a valley landscape where gluons are prone to get clumped within small regions. This is compatible with the so-called preconfinement

  1. Vinyl chloride-induced hepatic coproporphyrinuria with transition to chronic hepatic porphyria

    Doss, M.; Lange, C.E.; Veltman, G.

    1984-02-15

    A chronic hepatic disorder of porphyrin metabolism was found in 36 workers with vinyl chloride (VC)-induced hepatic injury following long-time industrial exposure. Pathologic porphyrinuria, especially secondary coproporphyrinuria with transition to subclinical chronic hepatic porphyria, is a consistent pathobiochemical parameter for the recognition of VC hepatic lesions. The porphyrinuria is of diagnostic value for the incipient toxic phase. Erythrocyte uroporphyrinogen decarboxylase activity studied in six cases with initial chronic hepatic porphyria was normal, suggesting that VC affects only this enzyme in the liver.

  2. Porphyria cutanea tarda in a chronic hemodialysis patient

    Labidi Jannet

    2010-01-01

    Full Text Available End-stage renal failure and long-term hemodialysis (HD treatment promote the development of genetically conditioned porphyria cutanea tarda (PCT. Iron overload is often asso-ciated with this disease and is thought to play a role in its pathogenesis. We report a case of HD-related PCT, which improved with deferoxamine treatment. A 33-year-old woman, with end-stage renal failure on HD since 1998, presented with a history of blisters on the face and dorsum of the hands, of several months duration. Laboratory analysis showed: hemoglobin 10.4 g/dL; a moderate hepatic cytolysis; ferritin 1300 μg/L (Nl: 8-120 μg/L and negative serology for HIV, HBV and HCV. Porphyrin analyses showed a PCT pattern. Skin biopsy findings and direct immunofluo-rescence were consistent with PCT. The patient received deferoxamine (40 mg/kg intravenously every week for 6 weeks which led to dramatic improvement of the symptoms. Several treatments are proposed in the management of dialysis-related PCT. This case confirms that deferoxamine can induce rapid and prolonged remission.

  3. Are renewable energies intermittent?

    This article outlines that renewable energies, notably photovoltaic and wind energy, are not that intermittent. Besides the fact that their operation is progressive (they do not pass from nothing to one), the fact they are distributed among the territory means that, when considering them all, the production is smoothed at the territory scale. They are in fact more varying than intermittent and they are smoothed and predictable. On the other side, thermal plants are regularly stopped, for maintenance for example. It states that in absence of wind or sun, fossil energies can be replaced by hydraulic energy and nuclear energy

  4. Intermittency and random matrices

    Sokoloff, Dmitry; Illarionov, E. A.

    2015-08-01

    A spectacular phenomenon of intermittency, i.e. a progressive growth of higher statistical moments of a physical field excited by an instability in a random medium, attracted the attention of Zeldovich in the last years of his life. At that time, the mathematical aspects underlying the physical description of this phenomenon were still under development and relations between various findings in the field remained obscure. Contemporary results from the theory of the product of independent random matrices (the Furstenberg theory) allowed the elaboration of the phenomenon of intermittency in a systematic way. We consider applications of the Furstenberg theory to some problems in cosmology and dynamo theory.

  5. Porphyria cutanea tarda associated with autoimmune hypothyroidism, vitiligo and alopecia universalis.

    Sabán, J; Rodríguez-García, J L; Gil, J; País, J R; Medina, S

    1991-12-01

    The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient. PMID:1803247

  6. Difficult diagnosis in a dermatologist's practice (description of a clinical case of late cutaneous porphyria

    Utz S.R.

    2015-09-01

    Full Text Available The article presents a case report of clinical observations of late cutaneous porphyria in a 50-years old patient. The data of the etiology, pathogenesis and clinical picture are summarized. A differential diagnosis with vulgar disease, acquired epidermolysis bullosa and pseudoporphyria. The results of a successful comprehensive treatment of disease by drugs quinoline series, systemic glucocorticosteroids, phlebotomy.

  7. Difficult diagnosis in a dermatologist's practice (description of a clinical case of late cutaneous porphyria)

    Utz S.R.; Bakulev A.L.; Slesarenko N.A.; Eremina M.G.; Muratova D.S.

    2015-01-01

    The article presents a case report of clinical observations of late cutaneous porphyria in a 50-years old patient. The data of the etiology, pathogenesis and clinical picture are summarized. A differential diagnosis with vulgar disease, acquired epidermolysis bullosa and pseudoporphyria. The results of a successful comprehensive treatment of disease by drugs quinoline series, systemic glucocorticosteroids, phlebotomy.

  8. Zooplankton intermittency and turbulence

    Schmitt, François G.

    2010-05-01

    Planktonic organisms usually live in a turbulent world. Since marine turbulence is characterized by very high Reynolds numbers, it possesses very intermittent fluctuations which in turn affect marine life. We consider here such influence on zooplankton on 2 aspects. First we consider zooplankton motion in the lab. Many copepods display swimming abilities. More and more species have been recently recorded using normal or high speed cameras, and many trajectories have been extracted from these movies and are now available for analysis. These trajectories can be complex, stochastic, with random switching from low velocity to high velocity events and even jumps. These complex trajectories show that an adequate modeling is necessary to understand and characterize them. Here we review the results published in the literature on copepod trajectories. We discuss the random walk, Levy walk modeling and introduce also multifractal random walks. We discuss the way to discriminate between these different walks using experimental data. Stochastic simulations will be performed to illustrate the different families. Second, we consider zooplankton contact rates in the framework of intermittent turbulence. Intermittency may have influence on plankton contact rates. We consider the Particle Stokes number of copepods, in a intermediate dissipation range affected by intermittent fluctuations. We show that they may display preferential concentration effects, and we consider the influence on contact rates of this effect in the intermediate dissipation range.

  9. Effect of intermittent hypercapnia on respiratory control in rat pups.

    Steggerda, Justin A; Mayer, Catherine A; Martin, Richard J; Wilson, Christopher G

    2010-01-01

    Preterm infants are subject to fluctuations in blood gas status associated with immature respiratory control. Intermittent hypoxia during early postnatal life has been shown to increase chemoreceptor sensitivity and destabilize the breathing pattern; however, intermittent hypercapnia remains poorly studied. Therefore, to test the hypothesis that intermittent hypercapnia results in altered respiratory control, we examined the effects of daily exposure to intermittent hypercapnia on the ventilatory response to subsequent hypercapnic and hypoxic exposure in neonatal rat pups. Exposure cycles consisted of 5 min of intermittent hypercapnia (5% CO(2), 21% O(2), balance N(2)) followed by 10 min of normoxia. Rat pups were exposed to 18 exposure cycles each day for 1 week, from postnatal day 7 to 14. We analyzed diaphragm electromyograms (EMGs) from pups exposed to subsequent acute hypercapnic (5% CO(2)) and hypoxic (12% O(2)) challenges. In response to a subsequent hypercapnia challenge, there was no significant difference in the ventilatory response between control and intermittent hypercapnia-exposed groups. In contrast, intermittent hypercapnia-exposed rat pups showed an enhanced ventilatory response to hypoxic challenge with an increase in minute EMG to 118 +/- 14% of baseline versus 107 +/- 13% for control pups (p < 0.05). We speculate that prior hypercapnic exposure may increase peripheral chemoreceptor response to subsequent hypoxic exposures and result in perturbed neonatal respiratory control. PMID:19752577

  10. The decrease in uroporphyrinogen decarboxylase activity induced by ethanol predisposes rats to the development of porphyria and accelerates xenobiotic-triggered porphyria, regardless of hepatic damage

    Ríos de Molina M.C.

    2002-01-01

    Full Text Available We evaluated the porphyrinogenic ability of ethanol (20% in drinking water per se, its effect on the development of sporadic porphyria cutanea tarda induced by hexachlorobenzene in female Wistar rats (170-190 g, N = 8/group, and the relationship with hepatic damage. Twenty-five percent of the animals receiving ethanol increased up to 14-, 25-, and 4.5-fold the urinary excretion of delta-aminolevulinate, porphobilinogen, and porphyrins, respectively. Ethanol exacerbated the precursor excretions elicited by hexachlorobenzene. Hepatic porphyrin levels increased by hexachlorobenzene treatment, while this parameter only increased (up to 90-fold in some of the animals that received ethanol alone. Ethanol reduced the activities of uroporphyrinogen decarboxylase, delta-aminolevulinate dehydrase and ferrochelatase. In the ethanol group, many of the animals showed a 30% decrease in uroporphyrinogen activity; in the ethanol + hexachlorobenzene group, this decrease occurred before the one caused by hexachlorobenzene alone. Ethanol exacerbated the effects of hexachlorobenzene, among others, on the rate-limiting enzyme delta-aminolevulinate synthetase. The plasma activities of enzymes that are markers of hepatic damage were similar in all drug-treated groups. These results indicate that 1 ethanol exacerbates the biochemical manifestation of sporadic hexachlorobenzene-induced porphyria cutanea tarda; 2 ethanol per se affects several enzymatic and excretion parameters of the heme metabolic pathway; 3 since not all the animals were affected to the same extent, ethanol seems to be a porphyrinogenic agent only when there is a predisposition, and 4 hepatic damage showed no correlation with the development of porphyria cutanea tarda.

  11. Uroporphyrinogen decarboxylase: Complete human gene sequence and molecular study of three families with hepatoerythropoietic porphyria

    Moran-Jimenez, M.J.; Ged, C.; Verneuil, H. de [Universite de Bordeaux (France)] [and others

    1996-04-01

    A deficiency in uroporphyrinogen decarboxylase (UROD) enzyme activity, the fifth enzyme of the heme biosynthetic pathway, is found in patients with sporadic porphyria cutanea tarda (s-PCT), familial porphyria cutanea tarda (f-PCT), and hepatoerythropoietic porphyria (HEP). Subnormal UROD activity is due to mutations of the UROD gene in both f-PCT and HEP, but no mutations have been found in s-PCT. Genetic analysis has determined that f-PCT is transmitted as an autosomal dominant trait. In contrast, HEP, a severe form of cutaneous porphyria, is transmitted as an autosomal recessive trait. HEP is characterized by a profound deficiency of UROD activity, and the disease is usually manifest in childhood. In this study, a strategy was designed to identify alleles responsible for the HEP phenotype in three unrelated families. Mutations of UROD were identified by direct sequencing of four amplified fragments that contained the entire coding sequence of the UROD gene. Two new missense mutations were observed at the homoallelic state: P62L (proline-to-leucine substitution at codon 62) in a Portuguese family and Y311C (tyrosine-to-cysteine substitution at codon 311) in an Italian family. A third mutation, G281E, was observed in a Spanish family. This mutation has been previously described in three families from Spain and one from Tunisia. In the Spanish family described in this report, a paternal uncle of the proband developed clinically overt PCT as an adult and proved to be heterozygous for the G281E mutation. Mutant cDNAs corresponding to the P62L and Y311C changes detected in these families were created by site-directed mutagenesis. Recombinant proteins proved to have subnormal enzyme activity, and the Y311C mutant was thermolabile. 24 refs., 7 figs., 4 tabs.

  12. Radiological features in congenital erythropoietic porphyria (Gunther's disease). Report of three cases

    Levesque, M.; Legmann, P.; Le Cloirec, A.; Deybach, J.C.; Nordmann, Y.

    1988-01-01

    Gunther's disease or congenital erythropoietic porphyria is a rare and severe disorder comprising cutaneous and haemolytic symptoms. Photocutaneous lesions are responsible for scleroderma-like calcifications and deformities of the extremities visible on X-rays. Hemolytic manifestations lead to diffuse major osteopenia. Soft tissue calcifications of the fingers can be seen even in young patients. One case reported here is the first illustration of intracranial calcifications located on dura-mater and calvarium.

  13. Ultraviolet light induced changes in the organization of mitotic chromosomes in porphyria cutanea tarda

    Chromosome decondensation or attenuation can be induced with ultraviolet light, particularly in the presence of inhibitors of semiconservative DNA synthesis, such as hydroxyurea. The rate of decondensation of metaphase chromosomes from lymphocyte cultures of healthy controls and patients with porphyria cutanea tarda has been compared after ultraviolet irradiation in the presence of hydroxyurea. Chromosomes of the patients attenuated more readily than the control ones at all UV doses. The possibilities causing such differences in the profile of chromosome decondensation are discussed

  14. Forecast combinations for intermittent demand

    Fotios PETROPOULOS; Kourentzes, Nikos

    2015-01-01

    Intermittent demand is characterised by infrequent demand arrivals, where many periods have zero demand, coupled with varied demand sizes. The dual source of variation renders forecasting for intermittent demand a very challenging task. Many researchers have focused on the development of specialised methods for intermittent demand. However, apart from a case study on hierarchical forecasting, the effects of combining, which is a standard practice for regular demand, have not been investigated...

  15. Fate in intermittent claudication

    Jelnes, Rolf; Gaardsting, O; Hougaard Jensen, K;

    1986-01-01

    The fate of 257 consecutive patients (100 women) aged 36-85 years (mean 65) first seen with intermittent claudication in 1977 was analysed after a mean of 6.5 (SD 0.5) years. When first seen none of the patients complained of rest pain or had ulcers or gangrenous lesions on the feet. At follow up...... 113 of the patients (44%) had died. Causes of death were no different from those in the general population. Mortality was twice that of the general population matched for age and sex. Mortality among the men was twice that among the women. In men under 60 mortality was four times that expected. The...

  16. Studies on the role of the Ah receptor in hexachloro-benzene-induced porphyria

    Many of the effects of hexachlorobenzene (HCB) resemble those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), whose effects are initiated by its binding to the AH receptor, the regulatory gene product of the Ah locus. I investigated the ability of HCB to interact with the AH receptor and the involvement of this protein in HCB-induced porphyria. The induction of two cytochrome P450 isozymes regulated by the Ah locus was also examined in light of their possible role in the pathogenesis of HCB- and TCDD-induced porphyria. HCB competitively inhibited the in vitro specific binding of [3H]-TCDD to the rat hepatic Ah receptor (KI = 2.1 μM) without affecting the solubility of [3H]TCDD. Following the administration of HCB to rats, the number of [3H]TCDD specific binding sites was reduced by up to 40%. HCB induced cytochromes P450b, P450e, P450c, and P450d, confirming that it is a mixed-type P450 inducer. The presence of porphyria in mice was assessed by measuring urinary and hepatic porphyrins and hepatic uroporphyrinogen decarboxylase activity

  17. Studies on the role of the Ah receptor in hexachloro-benzene-induced porphyria

    Hahn, M.E.

    1987-01-01

    Many of the effects of hexachlorobenzene (HCB) resemble those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), whose effects are initiated by its binding to the AH receptor, the regulatory gene product of the Ah locus. I investigated the ability of HCB to interact with the AH receptor and the involvement of this protein in HCB-induced porphyria. The induction of two cytochrome P450 isozymes regulated by the Ah locus was also examined in light of their possible role in the pathogenesis of HCB- and TCDD-induced porphyria. HCB competitively inhibited the in vitro specific binding of ({sup 3}H)-TCDD to the rat hepatic Ah receptor (K{sub I} = 2.1 {mu}M) without affecting the solubility of ({sup 3}H)TCDD. Following the administration of HCB to rats, the number of ({sup 3}H)TCDD specific binding sites was reduced by up to 40%. HCB induced cytochromes P450b, P450e, P450c, and P450d, confirming that it is a mixed-type P450 inducer. The presence of porphyria in mice was assessed by measuring urinary and hepatic porphyrins and hepatic uroporphyrinogen decarboxylase activity.

  18. Interventions for intermittent exotropia

    Hatt, Sarah R; Gnanaraj, Lawrence

    2014-01-01

    Background The clinical management of intermittent exotropia has been discussed extensively in the literature, yet there remains a lack of clarity regarding indications for intervention, the most effective form of treatment and whether or not there is an optimal time in the evolution of the disease at which any treatment should be carried out. Objectives The objective of this review was to analyse the effects of various surgical and non-surgical treatments in randomised trials of participants with intermittent exotropia, and to report intervention criteria and determine the significance of factors such as age with respect to outcome. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 4, 2012), MEDLINE (January 1966 to May 2012), EMBASE (January 1980 to May 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to May 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 4 May 2012. We are no longer searching the UK Clinical Trials Gateway (UKCTG) for this review. We manually searched the British Orthoptic Journal up to 2002, and the proceedings of the European Strabismological Association (ESA), International Strabismological Association (ISA) and American Academy of Paediatric Ophthalmology and Strabismus meeting (AAPOS) up to 2001. We contacted researchers who are active in the field for information about further published or unpublished studies. Selection criteria We included randomised controlled trials of any surgical or non-surgical treatment for intermittent exotropia. Data collection and

  19. Instantons and intermittency

    Falkovich, G; Lebedev, V; Migdal, A

    1995-01-01

    We propose the new method for finding the non-Gaussian tails of probability distribution function (PDF) for solutions of a stochastic differential equation, such as convection equation for a passive scalar, random driven Navier-Stokes equation etc. Existence of such tails is generally regarded as a manifestation of intermittency phenomenon. Our formalism is based on the WKB approximation in the functional integral for the conditional probability of large fluctuation. We argue that the main contribution to the functional integral is given by a coupled field-force configuration -- {\\em instanton}. As an example, we examine the correlation functions of the passive scalar u advected by a large-scale velocity field \\delta-correlated in time. We find the instanton determining the tails of the generating functional and show that it is different from the instanton that determines the probability distribution function of high powers of u. We discuss the simplest instantons for the Navier-Stokes equation.

  20. Effects of Cold Modality Application With Static and Intermittent Pneumatic Compression on Tissue Temperature and Systemic Cardiovascular Responses

    Holwerda, Seth W.; Trowbridge, Cynthia A.; Womochel, Kathryn S.; Keller, David M.

    2013-01-01

    Background: In the therapeutic setting, cryotherapy with varying levels of intermittent cyclical compression often replaces an ice bag and elastic wrap. However, little is known about the cardiovascular strain and tissue temperature decreases associated with cooling and intermittent compression. Hypothesis: The authors hypothesized that higher levels of intermittent compression will result in greater reductions of tissue temperature and that all cold modalities will cause acute increases in c...

  1. Bandagem reversível do tronco pulmonar IV: análise da hipertrofia aguda do ventrículo direito em modelo experimental de sobrecarga intermitente IV Pulmonary trunk reversible banding: analysis of right ventricle acute hypertrophy in an intermittent loading experimental model

    Acrisio Sales Valente

    2008-03-01

    Full Text Available OBJETIVO: A bandagem ajustável do tronco pulmonar (TP pode proporcionar treinamento ventricular mais fisiológico para cirurgia de Jatene em dois estágios. Este estudo experimental analisa a hipertrofia aguda (96 horas do ventrículo direito (VD submetido à sobrecarga sistólica intermitente. MÉTODOS: Cinco grupos de sete cabritos jovens foram dispostos conforme o tempo de sobrecarga sistólica do VD (0, 24, 48, 72 e 96 horas. O grupo zero hora funcionou como grupo controle. Avaliações ecocardiográficas e hemodinâmicas foram feitas diariamente. Os animais foram sacrificados para avaliação do conteúdo de água e pesagem das massas cardíacas. RESULTADOS: Houve aumento da espessura do VD a partir de 48 horas de treinamento (pOBJECTIVES: Adjustable pulmonary trunk (PT banding device may induce a more physiologic ventricle retraining for the two-stage Jatene operation. This experimental study evaluates the acute hypertrophy (96 hours of the right ventricle (RV submitted to an intermittent pressure overload. METHODS: Five groups of seven young goats were distributed according to RV intermittent systolic overload duration (0, 24, 48, 72 and 96 hours. The zero-hour group served as a control group. Echocardiographic and hemodynamic evaluations were performed daily. After completing the training program for each group, the animals were sacrificed for water content and cardiac masses evaluation. RESULTS: There was a significant increase in RV free wall thickness starting with the 48-hour group (p<0.05. However, a decreased RV ejection fraction, associated with an important RV dilation and a significant increase in the RV volume to mass ratio was observed at 24-hour training period, when compared to 96-hour period (p=0.003, with subsequent recovery throughout the protocol. A 104.7% increase in RV mass was observed in the 96-hour group, as compared to the control group, with no differences in water content between these two groups. The daily mean

  2. Intermedia and Intermittency

    Veres Bálint

    2014-12-01

    Full Text Available It is commonly known that medial reflections have been initiated by attempts to secure the borders of discrete medial forms and to define the modus operandi of each essentialized medial area. Later on, the focus of study has shifted to plurimedial formations and the interactions between predefined medial genres. In the last few decades, taxonomic approaches to various multi-, inter-, and transmedial phenomena dominated the discussions, which offered invaluable support in mapping the terrain, but at the same time hindered the analysis of the ephemeral, time-dependent aspects of plurimedial operations. While we explore the properties of each medial configuration, we lose sight of the actual historical drivers that produce ever-new configurations. My thesis is that any discourse on intermediality should be paralleled by a discourse on cultural intermittency, and consequently, media studies should involve an approach that focuses on the “ecosystem” of the constantly renewing media configurations from the point of view of their vitalizing potential and capability to trigger heightened experiences. This approach draws much inspiration from K. Ludwig Pfeiffer’s media anthropology that gives orientation in my paper.

  3. Porphyria cutanea tarda as a complication of therapy for chronic hepatitis C

    Azim, James; McCurdy, Heather; Moseley, Richard H.

    2008-01-01

    There is a strong association between porphyria cutanea tarda (PCT) and chronic viral hepatitis C. Therapy for chronic viral hepatitis C may improve PCT. However, there are only a few reports of the de novo development of PCT during therapy for chronic viral hepatitis C. We describe the development of PCT in a 56-year-old patient with chronic viral hepatitis C after 12 wk of peginterferon/ribavirin therapy. In addition, the patient was homozygous for the H63D hereditary hemochromatosis gene (...

  4. Porphyria cutanea tarda in a human immunodeficiency virus-infected patient: A rare scenario in India

    Ramesh M. Bhat

    2014-01-01

    Full Text Available A 30-year-old unmarried, heterosexual male presented with an 8-month history of tense blistering skin lesions over the hands. Physical examination revealed facial hypertrichosis and multiple erosions with crusts and scars over the dorsum of both hands. Woods lamp examination of the urine, histopathology and urinary porphyrin levels were suggestive of porphyria cutanea tarda (PCT. The patient responded well to hydroxychloroquine and antiretroviral drugs. This case report calls for a detailed evaluation and HIV testing in every patient with PCT.

  5. Intermittency Growth in Fluid Turbulence

    ZHU Jian-Zhou

    2006-01-01

    @@ Measurement and phenomenological analyses of intermittency growth in an experimental turbulent pipe flow and numerical turbulence are performed, for which working definitions such as degree, increment, and growth rate of intermittency are introduced with the help of quasiscaling theory. The logarithmic-normal inertial scaling model is extended to quasiscaling as the second-order truncation of the Taylor expansion and is used for studying the intermittency growth problem. The extended self-similarity properties are shown to be not consistent with the monotonicity of the third order local quasiscaling exponent and the nonmonotonic behaviour of the intermittency growth rate as a result of bottleneck. Digestions of the results with scale-dependent multifractals are provided.

  6. Intermittency in spiral Poiseuille flow

    The results of an experimental study on intermittent spiral vortices observed in a counter-rotating Taylor-Couette system with an additional axial through flow, i.e. Spiral-Poiseuille flow, are presented. Convectively unstable upstream propagating spiral vortices appear in the laminar basic flow from an oscillatory instability and in general become absolutely unstable at higher inner cylinder Reynolds number. It is found that at Reynolds numbers above the absolute stability border the spiral vortices become unstable and a complex flow state showing intermittent bursts appears. The intermittent flow state is characterised by an irregular alternation between clearly distinguishable 'laminar' phases corresponding to up-and downstream propagating spiral vortices as well as propagating Taylor vortices. For a sufficiently high rate of axial through flow it is found that intermittency can occur directly from the convectively unstable regime of the upstream propagating spiral vortices

  7. Spinal Plasticity following Intermittent Hypoxia: Implications for Spinal Injury

    Dale-Nagle, Erica A.; Hoffman, Michael S.; MacFarlane, Peter M.; Satriotomo, Irawan; Lovett-Barr, Mary Rachael; Vinit, Stéphane; Mitchell, Gordon S.

    2010-01-01

    Plasticity is a fundamental property of the neural system controlling breathing. One frequently studied model of respiratory plasticity is long-term facilitation of phrenic motor output (pLTF) following acute intermittent hypoxia (AIH). pLTF arises from spinal plasticity, increasing respiratory motor output through a mechanism that requires new synthesis of brain derived neurotrophic factor (BDNF), activation of its high affinity receptor, tropomyosin-related kinase B (TrkB) and extracellular...

  8. High-Intensity Intermittent Exercise: Effect on Young People's Cardiometabolic Health and Cognition.

    Cooper, Simon B; Dring, Karah J; Nevill, Mary E

    2016-01-01

    With only a quarter of young people currently meeting physical activity guidelines, two key areas of concern are the effects of exercise on cardiometabolic health and cognition. Despite the fact that physical activity in young people is typically high intensity and intermittent in nature, much of the literature examines traditional endurance-type exercise. This review provides an update on the effects of high-intensity intermittent exercise on young people's cardiometabolic health and cognition. High-intensity intermittent exercise has acute beneficial effects on endothelial function and postprandial lipemia and chronic positive effects on weight management. In addition, there is emerging evidence regarding chronic benefits on the blood lipid profile, blood pressure, and proinflammatory and anti-inflammatory cytokines. Furthermore, emerging evidence suggests beneficial acute and chronic effects of high-intensity intermittent exercise on cognition. However, further research is required in both cardiometabolic health and cognition, particularly regarding the impact of school-based interventions in adolescents. PMID:27399821

  9. Intermittency in 197Au fragmentation

    The concept of factorial moments was applied to an analysis of the dynamical fluctuations in the charge distributions of the fragments emitted from gold nuclei with energies 10.6 and < 1.0 GeV/n interacting with emulsion nuclei. Clear evidence for intermittent fluctuations has been found in an analysis using all the particles released from the gold projectile, with a stronger effect observed below 1 GeV/n than at 10.6 GeV/n. For the full data sets, however, the intermittency effect was found to be very sensitive to the singly charged particles, and neglecting these particles strongly reduces the intermittency signal. When the analysis is restricted to the multiply charged fragments, an intermittency effect is revealed only for multifragmentation events, although one that is enhanced as compared to the analysis of all, singly and multiply charged, particles. The properties of the anomalous fractal dimensions suggest a sequential decay mechanism, rather than the existence of possible critical behaviour in the process of nuclear fragmentation. The likely influence of the charge conservation effects and the finite size of decaying systems on the observed intermittency signals was pointed out. (author). 37 refs, 9 figs, 5 tabs

  10. Elastic wave turbulence and intermittency

    Chibbaro, Sergio; Josserand, Christophe

    2016-07-01

    We investigate the onset of intermittency for vibrating elastic plate turbulence in the framework of the weak wave turbulence theory using a numerical approach. The spectrum of the displacement field and the structure functions of the fluctuations are computed for different forcing amplitudes. At low forcing, the spectrum predicted by the theory is observed, while the fluctuations are consistent with Gaussian statistics. When the forcing is increased, the spectrum varies at large scales, corresponding to the oscillations of nonlinear structures made of ridges delimited by d cones. In this regime, the fluctuations exhibit small-scale intermittency that can be fitted via a multifractal model. The analysis of the nonlinear frequency shows that the intermittency is linked to the breakdown of the weak turbulence at large scales only.

  11. Bursts in intermittent aeolian saltation

    Carneiro, M V; Herrmann, H J

    2014-01-01

    Close to the onset of Aeolian particle transport through saltation we find in wind tunnel experiments a regime of intermittent flux characterized by bursts of activity. Scaling laws are observed in the time delay between each burst and in the measurements of the wind fluctuations at the critical Shields number $\\theta_c$. The time delay between each burst decreases on average with the increase of the Shields number until saltation becomes non-intermittent and the sand flux becomes continuous. A numerical model for saltation including the wind-entrainment from the turbulent fluctuations can reproduce these observations and gives insight about their origin. We present here also for the first time measurements showing that with feeding it becomes possible to sustain intermittent flux even below the threshold $\\theta_c$ for natural saltation initiation.

  12. Anesthesia for hemicolectomy in a known porphyric with cecal malignancy

    B K Naithani

    2015-01-01

    Full Text Available Intraoperative management of a known acute intermittent porphyria patient is a challenge requiring awareness of factors, which trigger an acute crisis, clinical features of a porphyric attack, knowledge of safe pharmacologic intervention, and preparedness for reintubation and ventilatory support. The classical signs of a porphyric crisis such as pain abdomen, vomiting and neuropsychiatric symptoms are masked under general anesthesia and can be confused with postoperative pain and vomiting and postoperative cognitive dysfunction, especially for intra-abdominal surgeries. Eternal vigilance for onset of an acute crisis is imperative. After a crisis of acute intermittent porphyria, residual paresis may persist for years in the absence of further attacks.

  13. Intermittent control of coexisting attractors.

    Liu, Yang; Wiercigroch, Marian; Ing, James; Pavlovskaia, Ekaterina

    2013-06-28

    This paper proposes a new control method applicable for a class of non-autonomous dynamical systems that naturally exhibit coexisting attractors. The central idea is based on knowledge of a system's basins of attraction, with control actions being applied intermittently in the time domain when the actual trajectory satisfies a proximity constraint with regards to the desired trajectory. This intermittent control uses an impulsive force to perturb one of the system attractors in order to switch the system response onto another attractor. This is carried out by bringing the perturbed state into the desired basin of attraction. The method has been applied to control both smooth and non-smooth systems, with the Duffing and impact oscillators used as examples. The strength of the intermittent control force is also considered, and a constrained intermittent control law is introduced to investigate the effect of limited control force on the efficiency of the controller. It is shown that increasing the duration of the control action and/or the number of control actuations allows one to successfully switch between the stable attractors using a lower control force. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method. PMID:23690639

  14. Intermittency patterns in hadron multiproduction

    Short-range fluctuations in rapidity are observed in high energy multiproduction of hadrons. Using a factorial moment method, we show how to isolate non-statistical fluctuations and discuss some model predictions. Models including a space-time cascade of cluster decays are expected to lead to fluctuation patterns typical of intermittency whereas the dual parton model gives a very different steady behaviour

  15. A rare case of puberty onset congenital erythropoietic porphyria with ophthalmological manifestations

    Debjani Mishra

    2016-01-01

    Full Text Available A 27-year-old male patient was presented with foreign body sensation in both the eyes for 2 years duration and blisters followed by scarring and pigmentation in the photo-exposed areas of the body over the previous 12 years. His urine was reddish colored for the previous year. On examination, there was scarring, hyper-pigmentation of photo-exposed parts of the body along with resorption of the distal phalanges of fingers in both hands except the smallest digit which had onycholysis. Ocular examination indicated scleral necrosis in the interpalpebral areas in both eyes and bilateral dry eye. Hematological examination indicated a picture suggestive of hemolytic anemia. Abdominal ultrasonography indicated an enlarged spleen. These clinical features are suggestive of puberty onset congenital erythropoietic porphyria with ophthalmological manifestations.

  16. A Rare Case of Puberty Onset Congenital Erythropoietic Porphyria with Ophthalmological Manifestations.

    Debjani, Mishra; Somnath, Mukhopadhyay

    2016-01-01

    A 27-year-old male patient was presented with foreign body sensation in both the eyes for 2 years duration and blisters followed by scarring and pigmentation in the photo-exposed areas of the body over the previous 12 years. His urine was reddish colored for the previous year. On examination, there was scarring, hyper-pigmentation of photo-exposed parts of the body along with resorption of the distal phalanges of fingers in both hands except the smallest digit which had onycholysis. Ocular examination indicated scleral necrosis in the interpalpebral areas in both eyes and bilateral dry eye. Hematological examination indicated a picture suggestive of hemolytic anemia. Abdominal ultrasonography indicated an enlarged spleen. These clinical features are suggestive of puberty onset congenital erythropoietic porphyria with ophthalmological manifestations. PMID:26957860

  17. Porphyria cutanea tarda as a complication of therapy for chronic hepatitis C

    James Azim; Heather McCurdy; Richard H Moseley

    2008-01-01

    There is a strong association between porphyria cutanea tarda (PCT) and chronic viral hepatitis C. Therapy for chronic viral hepatitis C may improve PCT. However, there are only a few reports of the de novo development of PCT during therapy for chronic viral hepatitis C. We describe the development of PCT in a 56-year-old patient with chronic viral hepatitis C after 12 wk of peginterferon/ribavirin therapy. In addition, the patient was homozygous for the H63D hereditary hemochromatosis gene (HFE) mutation. The association of PCT with chronic viral hepatitis C and the possible role of hepatic iron overload and ribavirin-induced hemolytic anemia in the development of PCT during therapy for chronic viral hepatitis C are discussed.

  18. Methodological foundations for physical rehabilitation of patients on intermittent asthma.

    Grigus I.M.

    2011-05-01

    Full Text Available The aim was to improve the physical rehabilitation of patients with intermittent bronchial asthma exacerbation by applying the pathogenetic modes of physical activity and a range of physical therapeutic factors. A total of 70 patients with intermittent asthma in the acute stage. In the hospital carried out a specific program of physical rehabilitation, including the modified methods of therapeutic physical culture and physiotherapy facilities. The use of physical rehabilitation resulted in a reduction of assault period of the disease, significantly improved the physical performance of patients. In all cases of physical rehabilitation program achieved full control of the disease, significantly improves the quality of life of patients, did not occur in the treatment of patients with only medicines.

  19. Accumulation of uroporphyrin does not provoke further inhibition of liver uroporphyrinogen decarboxylase activity in hexachlorobenzene-induced porphyria.

    Adjarov, D G; Elder, G H

    1986-01-01

    The inhibition of uroporphyrinogen decarboxylase (Uro-D) is the basic pathogenetic mechanism in porphyria caused by hexachlorobenzene (HCB). This study aimed to establish whether hepatic accumulation of uroporphyrin in this porphyria could provoke a further decrease of Uro-D activity. Male C57Bl/6 mice were treated for 8 weeks with a diet containing 0.02% HCB. In some of them the deposition of liver porphyrins was additionally increased by intraperitoneal application of delta-aminolaevulinic acid (ALA). Uro-D activity was determined by measuring unconverted substrate uroporphyrinogen after its oxidation to uroporphyrin by reversed-phase high performance liquid chromatography. The value of endogenously formed uroporphyrin was also obtained from the sample by subtraction, using a blank assay. HCB treatment resulted in reduced activity of hepatic Uro-D, but this activity was not significantly less in animals loaded with ALA than in non-loaded mice. Uroporphyrin deposition tended to decrease 6 weeks after withdrawal of HCB, but the activity of Uro-D was still markedly inhibited. There was no evidence that the accumulation of uroporphyrin promoted a supplementary decrease of Uro-D activity in HCB porphyria. PMID:3596742

  20. Acute lymphocytic Leukemia masquerading as acute osteomyelitis

    Two children each developed a focal destructive bone lesion accompanied by intermittent fever, swelling, tenderness and elevated ESR. Blood counts were normal; bone marrow aspiration showed acute leukemia. The bone lesions healed in both patients after anti-leukemic therapy. We suggest that the similar roentgenographic appearance of osteomyelitis, bone infarction and focal destructive lesions in leukemia probably reflects a common, basically ischemic process of bone. (orig.)

  1. Intermittent exotropia: Surgical treatment strategies

    Jai Aditya Kelkar

    2015-01-01

    Full Text Available Surgical management of intermittent exotropias (IXTs is ambiguous, with techniques of management varying widely between institutions. This review aims to examine available literature on the surgical management of IXT. A literature search was performed using PubMed, Web of Knowledge, LILACS, and the University of Liverpool Orthoptic Journals and Conference Transactions Database. All English-language papers published between 1958 and the present day were considered.

  2. Power-constrained intermittent control

    Gawthrop, Peter J.; Wagg, David J; Neild, Simon A; Wang, Liuping

    2013-01-01

    In this article, input power, as opposed to the usual input amplitude, constraints are introduced in the context of intermittent control. They are shown to result in a combination of quadratic optimisation and quadratic constraints. The main motivation for considering input power constraints is its similarity with semi-active control. Such methods are commonly used to provide damping in mechanical systems and structures. It is shown that semi-active control can be re-expressed and generalised...

  3. Lattice splitting under intermittent flows

    Schläpfer, Markus; Trantopoulos, Konstantinos

    2010-01-01

    We study the splitting of regular square lattices subject to stochastic intermittent flows. Various flow patterns are produced by different groupings of the nodes, based on their random alternation between two possible states. The resulting flows on the lattices decrease with the number of groups according to a power law. By Monte Carlo simulations we reveal how the time span until the occurrence of a splitting depends on the flow patterns. Increasing the flow fluctuation frequency shortens t...

  4. Intermittent torsion of accessory hepatic lobe: An unusual cause of recurrent right upper quadrant pain

    An accessory lobe of the liver is a rare congenital anomaly that can undergo torsion and present as an acute surgical emergency. It is rarely diagnosed preoperatively. We report the preoperative utility of CT scan and MRI in the diagnosis and surgical planning of a case of intermittent accessory hepatic lobe torsion

  5. Intermittent torsion of accessory hepatic lobe: An unusual cause of recurrent right upper quadrant pain

    Jambhekar Kedar

    2010-01-01

    Full Text Available An accessory lobe of the liver is a rare congenital anomaly that can undergo torsion and present as an acute surgical emergency. It is rarely diagnosed preoperatively. We report the preoperative utility of CT scan and MRI in the diagnosis and surgical planning of a case of intermittent accessory hepatic lobe torsion.

  6. Long-term tolerability of telcagepant for acute treatment of migraine in a randomized trial

    Connor, Kathryn M; Aurora, Sheena K; Loeys, Tom; Ashina, Messoud; Jones, Christopher; Giezek, Hilde; Massaad, Rachid; Williams-Diaz, Angela; Lines, Christopher; Ho, Tony W

    2011-01-01

    To evaluate the long-term tolerability of telcagepant for acute treatment of intermittent migraine attacks. Background.- Telcagepant is a calcitonin gene-related peptide (CGRP) receptor antagonist being investigated for the acute treatment of migraine....

  7. Hexachlorobenzene impairs glucose metabolism in a rat model of porphyria cutanea tarda: a mechanistic approach

    Mazzetti, Marta Blanca; Taira, Maria Cristina; Lelli, Sandra Marcela; Viale, Leonor Carmen San Martin de [Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428BGA, Ciudad Autonoma Buenos Aires (Argentina); Dascal, Eduardo; Basabe, Juan Carlos [Centro de Investigaciones Endocrinologicas (CEDIE). Hospital de Ninos, Dr. Ricardo Gutierrez, C1425EDF, Ciudad Autonoma Buenos Aires (Argentina)

    2004-01-01

    Hexachlobenzene (HCB), one of the most persistent environmental pollutants, induces porphyria cutanea tarda (PCT). The aim of this work was to analyze the effect of HCB on some aspects of glucose metabolism, particularly those related to its neosynthesis in vivo. For this purpose, a time-course study on gluconeogenic enzymes, pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G-6-Pase) and on pyruvate kinase (PK), a glycolytic enzyme, was carried out. Plasma glucose and insulin levels, hepatic glycogen, tryptophan contents, and the pancreatic insulin secretion pattern stimulated by glucose were investigated. Oxidative stress and heme pathway parameters were also evaluated. HCB treatment decreased PC, PEPCK, and G-6-Pase activities. The effect was observed at an early time point and grew as the treatment progressed. Loss of 60, 56, and 37%, respectively, was noted at the end of the treatment when a considerable amount of porphyrins had accumulated in the liver as a result of drastic blockage of uroporphyrinogen decarboxylase (URO-D) (95% inhibition). The plasma glucose level was reduced (one-third loss), while storage of hepatic glucose was stimulated in a time-dependent way by HCB treatment. A decay in the normal plasma insulin level was observed as fungicide intoxication progressed (twice to four times lower). However, normal insulin secretion of perifused pancreatic Langerhans islets stimulated by glucose during the 3rd and 6th weeks of treatment did not prove to be significantly affected. HCB promoted a time-dependent increase in urinary chemiluminiscence (fourfold) and hepatic malondialdehide (MDA) content (fivefold), while the liver tryptophan level was only raised at the longest intoxication times. These results would suggest that HCB treatment does not cause a primary alteration in the mechanism of pancreatic insulin secretion and that the changes induced by the fungicide on insulin levels would be an adaptative

  8. Bifurcations and intermittent magnetic activity

    The sequence of equilibria of two-dimensional reduced magnetohydrodynamics has been studied as a function of the tearing mode stability parameter Δ'. After a symmetry-breaking bifurcation occurring at Δ' ∼ 0, which originates a state with a small magnetic island, the system undergoes a second bifurcation, of tangent type, at Δ' ∼ 1. Above this value, no stationary solutions with small islands exist. The system rapidly develops an island of macroscopic size. This general property is proposed as a basic ingredient of the intermittent events observed in magnetically confined plasmas. (author)

  9. Bifurcations and intermittent magnetic activity

    Tebaldi, C.; Ottaviani, M.; Porcelli, F. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1996-04-01

    The sequence of equilibria of two-dimensional reduced magnetohydrodynamics has been studied as a function of the tearing mode stability parameter {Delta}`. After a symmetry-breaking bifurcation occurring at {Delta}` {approx} 0, which originates a state with a small magnetic island, the system undergoes a second bifurcation, of tangent type, at {Delta}` {approx} 1. Above this value, no stationary solutions with small islands exist. The system rapidly develops an island of macroscopic size. This general property is proposed as a basic ingredient of the intermittent events observed in magnetically confined plasmas. (author).

  10. Improved Intermittency Analysis of Individual Events

    Janik, R. A.; Ziaja, B.

    1998-01-01

    Recent progress on the event-by-event analysis of intermittent data by R. A. Janik and myself is reported. The intermittency analysis of single event data (particle moments) in multiparticle production is improved, taking into account corrections due to the reconstruction of history of a particle cascade. This approach is tested within the framework of the $\\alpha$-model.}

  11. The Yo-Yo intermittent recovery test

    Bangsbo, Jens; Iaia, F. Marcello; Krustrup, Peter

    2008-01-01

    The two Yo-Yo intermittent recovery (IR) tests evaluate an individual's ability to repeatedly perform intense exercise. The Yo-Yo IR level 1 (Yo-Yo IR1) test focuses on the capacity to carry out intermittent exercise leading to a maximal activation of the aerobic system, whereas Yo-Yo IR level 2 ...

  12. Radiation characteristics of intermittence exhaust noise

    ZHAO Shengdun; SHANG Chunyang; ZHAO Zhigang; SHI Weixiang

    2000-01-01

    Aerodynamic characteristics, the noise characteristics in the course of intermittence exhaust are investigated and the expressions for sound pressure level of the noise generated by single-pole source and quadrupole source in the intermittence exhaust noise are established. The effects of all parameters in pneumatic system on the noise are also comprehensively studied.

  13. Molecular heterogeneity of familial porphyria cutanea tarda in Spain: characterization of 10 novel mutations in the UROD gene

    Méndez, Manuel; Poblete-Gutiérrez, Pamela; García-Bravo, María; Wiederholt, T.; Morán-Jiménez, María Josefa; Merk, H. F.; Garrido Astray, María Concepción; Frank, Jorge; Fontanellas, Antonio; Enríquez de Salamanca, Rafael

    2007-01-01

    Porphyria cutanea tarda (PCT) results from decreased hepatic uroporphyrinogen decarboxylase (UROD) activity. In the majority of patients, the disease is sporadic (S-PCT or type I) and the enzyme deficiency is limited to the liver. Familial PCT (F-PCT or type II) is observed in 20-30% of patients in whom mutations on one allele of the UROD gene reduce UROD activity by approximately 50% in all tissues. Another variant of PCT (type III) is characterized by family history of the disease although ...

  14. Porphyria cutanea tarda associated with HFE C282Y homozygosity, iron overload, and use of a contraceptive vaginal ring.

    Barton, James C; Edwards, Corwin Q

    2016-01-01

    Porphyria cutanea tarda (PCT) is characterized by decreased uroporphyrinogen decarboxylase activity in hepatocytes, uroporphyrin I and heptacarboxyl porphyrin III accumulation, photosensitivity dermatitis, and increased storage iron. In women, estrogen therapy, including oral contraceptives, postmenopausal hormone replacement, and tamoxifen for breast cancer treatment, is a risk factor for PCT. We report the case of a woman who presented with PCT, HFE C282Y homozygosity, and hepatic iron overload and was using a contraceptive vaginal ring containing ethinyl estradiol, an estrogen. We discuss this case in the context of characteristics of other persons with PCT, including common HFE mutations, iron overload, and estrogen exposure. PMID:26908385

  15. Porphyria cutanea tarda associated with HFE C282Y homozygosity, iron overload, and use of a contraceptive vaginal ring

    James C. Barton

    2016-02-01

    Full Text Available Porphyria cutanea tarda (PCT is characterized by decreased uroporphyrinogen decarboxylase activity in hepatocytes, uroporphyrin I and heptacarboxyl porphyrin III accumulation, photosensitivity dermatitis, and increased storage iron. In women, estrogen therapy, including oral contraceptives, postmenopausal hormone replacement, and tamoxifen for breast cancer treatment, is a risk factor for PCT. We report the case of a woman who presented with PCT, HFE C282Y homozygosity, and hepatic iron overload and was using a contraceptive vaginal ring containing ethinyl estradiol, an estrogen. We discuss this case in the context of characteristics of other persons with PCT, including common HFE mutations, iron overload, and estrogen exposure.

  16. Kinetic intermittency in magnetized plasma turbulence

    Teaca, Bogdan; Told, Daniel; Jenko, Frank

    2016-01-01

    We employ magnetized plasma turbulence, described by a gyrokinetic formalism in an interval ranging from the end of the fluid scales to the electron gyroradius, to introduce the first study of kinetic intermittency, in which nonlinear structures formed directly in the distribution functions are analyzed by accounting for velocity space correlations generated by linear (Landau resonance) and nonlinear phase mixing. Electron structures are found to be strongly intermittent and dominated by linear phase mixing, while nonlinear phase mixing dominates the weakly intermittent ions. This is the first time spatial intermittency and linear phase mixing are shown to be self-consistently linked for the electrons and, as the magnetic field follows the intermittency of the electrons at small scales, explain why magnetic islands are places dominated by Landau damping in steady state turbulence.

  17. Intermittent dystonia in Hartnup disease.

    Darras, B T; Ampola, M G; Dietz, W H; Gilmore, H E

    1989-01-01

    A 6-month-old girl developed intermittent dystonic posture of the legs and eczematous dermatitis without ataxia. Qualitative and quantitative urine amino acid testing confirmed the diagnosis of Hartnup disease. Cranial computed tomography, electroencephalogram, electromyogram/nerve conduction study, posterior tibial somatosensory evoked potentials, 24-hour electroencephalographic telemetry, and metrizamide myelogram were normal. Spinal fluid hydroxy-indoleacetic acid concentration was less than or equal to 2 S.D. of normal; oral tryptophan loading (70 mg/kg) resulted in a two-fold rise in cerebrospinal fluid 5-hydroxy-indoleacetic acid concentration. Tryptophan administered alone or with nicotinic acid failed to improve the dystonia; however, trihexyphenidyl (1-2 mg/kg/day) dramatically improved it. Hartnup disease should be considered in children with unexplained dystonia. PMID:2712944

  18. Anisotropic Intermittency of Magnetohydrodynamic Turbulence

    Osman, K T; Chapman, S C; Hnat, B

    2013-01-01

    A higher-order multiscale analysis of spatial anisotropy in inertial range magnetohydrodynamic turbulence is presented using measurements from the STEREO spacecraft in fast ambient solar wind. We show for the first time that, when measuring parallel to the local magnetic field direction, the full statistical signature of the magnetic and Els\\"asser field fluctuations is that of a non-Gaussian globally scale-invariant process. This is distinct from the classic multi-exponent statistics observed when the local magnetic field is perpendicular to the flow direction. These observations are interpreted as evidence for the weakness, or absence, of a parallel magnetofluid turbulence energy cascade. As such, these results present strong observational constraints on the statistical nature of intermittency in turbulent plasmas.

  19. Optical diagnostics of intermittent flows

    Okulov, V.L.; Naumov, I.V.; Sørensen, Jens Nørkær

    2007-01-01

    image velocimetry, frequently give erroneous results, especially for the transition flow and developed nonstationary flow. However, their combined use in diagnostics of unsteady (intermittent) flows significantly improves both the temporal and spatial resolution of measurements. Such a complex approach......The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle...... is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for...

  20. Analytical approach to continuous and intermittent bottleneck flows

    Helbing, D.; Johansson, A.; Mathiesen, Joachim Kaj; Jensen, M.H.; Hansen, A.

    2006-01-01

    Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20......Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20...

  1. Scleral necrosis in congenital erythropoietic porphyria: A case report and review of the literature

    Shweta Agarwal

    2015-01-01

    Full Text Available A 28-year-old presented with complaints of severe pain and redness in the left eye since 2 weeks. He had similar complaints in the right eye 2 years back for which he had undergone a scleral patch graft. Best corrected visual acuity was 20/20 in both eyes. The right had a well vascularized scleral graft and rest of the anterior segment was normal. The left eye had inferior conjunctival congestion with an area of the scleral melt with uveal show just temporal to the limbus in the interpalbebral area. The cornea was clear and anterior chamber was quiet in the left eye. Applanation tonometry and fundus evaluation were normal in both eyes. Physical examination revealed hyperpigmented skin lesion, hypertrichosis and absorption of distal phalanges. Laboratory, ocular and physical findings confirmed the diagnosis of congenital erythropoietic porphyria. He was on oral steroids 40 mg/day since 2 weeks and topical antibiotics and lubricants. He was advised to continue the same and was taken up for scleral patch graft with fibrin glue in the left eye. Postoperatively he was continued on topical and oral steroids and lubricants.3 weeks later the left eye had stabilized however patient came with a melt in the right eye. Since it was an early melt, we went ahead with cyanoacrylate glue and bandage contact lens in the right eye and started him on topical steroids for the right eye also. Three months later both the eyes were stable, and the patient was gradually tapered off the steroids.

  2. Scleral necrosis in congenital erythropoietic porphyria: A case report and review of the literature.

    Agarwal, Shweta; Majumder, Parthopratim Dutta; Srinivasan, Bhaskar; Iyer, Geetha

    2015-01-01

    A 28-year-old presented with complaints of severe pain and redness in the left eye since 2 weeks. He had similar complaints in the right eye 2 years back for which he had undergone a scleral patch graft. Best corrected visual acuity was 20/20 in both eyes. The right had a well vascularized scleral graft and rest of the anterior segment was normal. The left eye had inferior conjunctival congestion with an area of the scleral melt with uveal show just temporal to the limbus in the interpalbebral area. The cornea was clear and anterior chamber was quiet in the left eye. Applanation tonometry and fundus evaluation were normal in both eyes. Physical examination revealed hyperpigmented skin lesion, hypertrichosis and absorption of distal phalanges. Laboratory, ocular and physical findings confirmed the diagnosis of congenital erythropoietic porphyria. He was on oral steroids 40 mg/day since 2 weeks and topical antibiotics and lubricants. He was advised to continue the same and was taken up for scleral patch graft with fibrin glue in the left eye. Postoperatively he was continued on topical and oral steroids and lubricants.3 weeks later the left eye had stabilized however patient came with a melt in the right eye. Since it was an early melt, we went ahead with cyanoacrylate glue and bandage contact lens in the right eye and started him on topical steroids for the right eye also. Three months later both the eyes were stable, and the patient was gradually tapered off the steroids. PMID:26903733

  3. An unhappy triad: Hemochromatosis, porphyria cutanea tarda and hepatocellular carcinoma-A case report

    Martina T Mogl; Andreas Pascher; Sabine J Presser; Michael Schwabe; Peter Neuhaus; Natascha C Nuessler

    2007-01-01

    Liver fibrosis and cirrhosis are predisposing factors for the development of hepatocellular carcinoma (HCC). Hemosiderosis has also been described to trigger carcinogenesis. A significant iron overload, as found in hereditary hemochromatosis (HHC), is a risk factor for HCC and may also promote the symptoms of porphyria cutanea tarda (PCT). A 68-year old male patient presented to our clinic with a suspected HCC,elevated alpha-fetoprotein but normal liver function tests. He reported a 25 year-old history of vitiligo upon exposure to sunlight. The patient underwent an extended left hemihepatectomy, and the recovery was uneventful, with the exception of a persistent hyperbilirubinemia. Perfusion problems and extrahepatic cholestasis were ruled out by CT-scan with angiography and MR-cholangiopancreatography. However, MRI showed an iron overload. Histology confirmed the HCC (pT3, pN0, G3, R0) and revealed a portal fibrosis and hemosiderosis. Based on the skin lesions we suspected a PCT that was confirmed by laboratory tests showing elevated porphyrin, uroporphyrin, coproporphyrin and porphobilinogen. Concurrently, molecular diagnostics revealed homozygosity for the C282Y mutation within the hemochromatosis HFE gene. After phlebotomy and normalization of liver function tests the patient was discharged. This is the first case ever showing the unusual combination of HCC in a fibrotic liver with HHC and PCT. This diagnosis not only warrants oncological follow-up but also symptomatic therapy to normalize iron metabolism and thereby improve liver function and alleviate the symptoms of HHC and PCT. Thus progression of fibrosis may be prevented and liver regeneration supported.

  4. Assessing Relative Volatility/Intermittency/Energy Dissipation

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko; Schmiegel, Jürgen

    process in particular. While this estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, we apply it also to energy price data. Moreover, we develop a probabilistic asymptotic theory for relative power variations of Brownian semistationary......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency even when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  5. Fluctuations and intermittency in fragment size distributions

    The intermittency signal on the size frequency of fragments found in various fragmenting systems is reconsidered. This signal extracted from a factorial moment analysis was interpreted as a genuine intermittency. The conclusion is that the signal found in earlier works and interpreted as an intermittency behaviour results from both the power law of the mean size fragment distribution and from the finite width of the multiplicity distribution. Any partition of integers exhibiting these two features will provide a similar signal. (author). 38 refs., 9 figs

  6. Intermittent sea-level acceleration

    Olivieri, M.; Spada, G.

    2013-10-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.

  7. Intermittency in Human Heart Rate Variability

    Intermittency in time series of the time intervals between heart beats (RR intervals) extracted from 24 hour (portable) ECG is found for some cases of humans with arrhythmia. Laminar phases are found by sweeping a short (5 intervals) time window through the time series and calculating the standard deviation of the series in each window. 8 of the 18 arrhythmia cases studied had a bimodal distribution of the standard deviation values indicating some kind of intermittency. The distribution of lengths of the laminar phases identifies the intermittency obtained in human heart rate variability as Type 1 in the Pomeau and Manneville classification. Although the arrhythmia cases studied were medically very different - in those instances that intermittency did occur the probability distributions of laminar phase lengths were strikingly similar. (author)

  8. Improved Intermittency Analysis of Single Event Data

    Janik, R. A.; Ziaja, B.

    1998-01-01

    The intermittency analysis of single event data (particle moments) in multiparticle production is improved, taking into account corrections due to the reconstruction of history of a particle cascade. This approach is tested within the framework of the $\\alpha$-model.

  9. Scalings of intermittent structures in magnetohydrodynamic turbulence

    Zhdankin, Vladimir; Uzdensky, Dmitri A

    2016-01-01

    Turbulence is ubiquitous in plasmas, leading to rich dynamics characterized by irregularity, irreversibility, energy fluctuations across many scales, and energy transfer across many scales. Another fundamental and generic feature of turbulence, although sometimes overlooked, is the inhomogeneous dissipation of energy in space and in time. This is a consequence of intermittency, the scale-dependent inhomogeneity of dynamics caused by fluctuations in the turbulent cascade. Intermittency causes turbulent plasmas to self-organize into coherent dissipative structures, which may govern heating, diffusion, particle acceleration, and radiation emissions. In this paper, we present recent progress on understanding intermittency in incompressible magnetohydrodynamic turbulence with a strong guide field. We focus on the statistical analysis of intermittent dissipative structures, which occupy a small fraction of the volume but arguably account for the majority of energy dissipation. We show that, in our numerical simulat...

  10. Intermittent cyclophosphamide in refractory rheumatoid arthritis

    Hørslev-Petersen, Kim; Beyer, Jannie M; Helin, Pekka

    1983-01-01

    Three patients with refractory rheumatoid arthritis were treated with oral cyclophosphamide; in two cases this was supplemented with pulse treatment with methylprednisolone. Long term remission was induced in all three patients and was sustained until follow up at least nine months after the methylprednisolone was stopped. Leucopenia occurred but resolved when cyclophosphamide was reduced from daily to intermittent dosing. Intermittent treatment with cyclophosphamide, possibly in conjunction ...

  11. Insights from Intermittent Binocular Rivalry and EEG

    Pitts, Michael A.; Juliane eBritz

    2011-01-01

    Novel stimulation and analytical approaches employed in EEG studies of ambiguous figures have recently been applied to binocular rivalry. The combination of intermittent stimulus presentation and EEG source imaging has begun to shed new light on the neural underpinnings of binocular rivalry. Here, we review the basics of the intermittent paradigm and highlight methodological issues important for interpreting previous results and designing future experiments. We then outline current analytical...

  12. Origin of intermittency in the fragmentation models

    Intermittency has been much discussed for momentum distribution of produced particles in ultrarelativistic collisions of leptons, hadrons and nuclei. More recently, scale invariant fluctuations has been found in the fragment-charge distribution following the decay of hot nuclear residuum. In this review the origin of intermittent fluctuations is discussed in cluster fragmentation models such as the percolation model and the fragmentation-inactivation binary cascading model. (author) 21 refs., 4 figs

  13. Scalings of intermittent structures in magnetohydrodynamic turbulence

    Zhdankin, Vladimir; Boldyrev, Stanislav; Uzdensky, Dmitri A.

    2016-05-01

    Turbulence is ubiquitous in plasmas, leading to rich dynamics characterized by irregularity, irreversibility, energy fluctuations across many scales, and energy transfer across many scales. Another fundamental and generic feature of turbulence, although sometimes overlooked, is the inhomogeneous dissipation of energy in space and in time. This is a consequence of intermittency, the scale-dependent inhomogeneity of dynamics caused by fluctuations in the turbulent cascade. Intermittency causes turbulent plasmas to self-organize into coherent dissipative structures, which may govern heating, diffusion, particle acceleration, and radiation emissions. In this paper, we present recent progress on understanding intermittency in incompressible magnetohydrodynamic turbulence with a strong guide field. We focus on the statistical analysis of intermittent dissipative structures, which occupy a small fraction of the volume but arguably account for the majority of energy dissipation. We show that, in our numerical simulations, intermittent structures in the current density, vorticity, and Elsässer vorticities all have nearly identical statistical properties. We propose phenomenological explanations for the scalings based on general considerations of Elsässer vorticity structures. Finally, we examine the broader implications of intermittency for astrophysical systems.

  14. Human apolipoprotein E4 targeted replacement in mice reveals increased susceptibility to sleep disruption and intermittent hypoxia

    Kaushal, Navita; Ramesh, Vijay; Gozal, David

    2012-01-01

    Intermittent hypoxia (IH) and sleep fragmentation (SF) are major manifestations of sleep apnea, a frequent condition in aging humans. Sleep perturbations are frequent in Alzheimer's disease (AD) and may underlie the progression of disease. We hypothesized that acute short-term IH, SF, and their combination (IH+SF) may reveal unique susceptibility in sleep integrity in a murine model of AD. The effects of acute IH, SF, and IH+SF on sleep architecture, delta power, sleep latency, and core body ...

  15. CORRECTION ON "CHRONIC INTERMITTENT ANOXIA...".

    Halstead, W C

    1945-08-10

    The writer is embarrassed by his discovery that in revising a manuscript entitled "Chronic Intermittent Anoxia and Impairment of Peripheral Vision," an important paragraph was inadvertently omitted from the version which appeared in Science for June 15, 1945. In checking back it becomes evident that the omission arose in the author's final copy, and that the editors of Science are in no way responsible. The paragraph which should have been inserted between the two paragraphs of column 2, page 615, is as follows: Serial determinations of alveolar gas tensions for each visual test day were carried out on sixteen of the twenty subjects by Dr. Wright Adams, but no relationship could be established with the impairment of peripheral vision. Similarly, in a smaller number of subjects no clear relationship could be established between the visual effect and renal vascular changes (Dr. Alf S. Alving), cardio-vascular changes (Dr. Emmet B. Bay), blood chemistry (Dr. Guzmán E. S. Barrón), psychiatric changes (Dr. Hugh T. Carmichael), electroencephalograms (Dr. Theodore Case), peripheral blood flow (Dr. Milton Landowne), certain metabolic effects (Drs. Henry T. Ricketts and A. Hughes Bryan), and certain additional neuropsychological indicators. Through omission of the above paragraph, inadequate representation was given to the scope of the total war research project in which the psychological studies carried out by the writer constituted one aspect. In addition to their particular lines of investigation, each of the above men contributed generously of specialized knowledge and of time and energy to insure adequate clinical supervision of the experimental subjects and a valid interpretation of the impairment of peripheral vision as reported. PMID:17802440

  16. Intermittent Noise Induces Physiological Stress in a Coastal Marine Fish.

    Tye A Nichols

    Full Text Available Anthropogenic noise in the ocean has increased substantially in recent decades, and motorized vessels produce what is likely the most common form of underwater noise pollution. Noise has the potential to induce physiological stress in marine fishes, which may have negative ecological consequences. In this study, physiological effects of increased noise (playback of boat noise recorded in the field on a coastal marine fish (the giant kelpfish, Heterostichus rostratus were investigated by measuring the stress responses (cortisol concentration of fish to increased noise of various temporal dynamics and noise levels. Giant kelpfish exhibited acute stress responses when exposed to intermittent noise, but not to continuous noise or control conditions (playback of recorded natural ambient sound. These results suggest that variability in the acoustic environment may be more important than the period of noise exposure for inducing stress in a marine fish, and provide information regarding noise levels at which physiological responses occur.

  17. Opinion Paper: 'Likelihood-ratio' and 'odds' applied to monitoring of patients as a supplement to 'reference change value' (RCV)

    Petersen, Per Hyltoft; Sandberg, Sverre; Iglesias, Natàlia; Sölétormos, György; Aarsand, Aasne Karine; Brandslund, Ivan; Jørgensen, Lone G M

    2007-01-01

    acute intermittent porphyria, where increasing excretion of porphobilinogen is characteristic for an attack. The within-subject biological variation is estimated to 25%, which for two measurements gives a variation of 35% for measured differences. Three pre-test probabilities are assumed and illustrate...

  18. Congenital erythropoietic porphyria with two mutations of the uroporphyrinogen III synthase gene (Cys73Arg, Thr228Met

    Zoran Gucev

    2011-01-01

    Full Text Available Congenital erythropoietic porphyria (CEP is an autosomal recessive inborn error of metabolism that results from the markedly deficient activity of uroporphyrinogen III synthase (UROS. We describe a 14-year-old girl with red urine since infancy, progressive blistering and scarring of the skin, and moderate hemolytic anemia. After years of skin damage, her face is mutilated; she has a bald patch on the scalp, hypertrichosis of the neck, areas of skin darkening, and limited joint movements of the hands. Total urine excretion and fecal total porphyrin were both markedly raised above normal levels. Sequencing of the UROS gene identified two mutations causing CEP (Cys73Arg, Thr228Met. The patient lesions are progressing. Bone marrow transplantation and/or gene therapy are proposed as the next steps in her treatment. In brief, we describe a CEP with confirmed two pathogenic mutations, severe phenotype and discuss the various treatment options available.

  19. Protective Effects of Covalent Cross-Linking on Proteolysis of Human Coproporphyrinogen Oxidase and Implications for Porphyria

    Ahmed W. Jafri

    2008-01-01

    Full Text Available The effects of covalent cross-linkers on the enzyme, coproporphyrinogen oxidase, had been previously studied but their role in protecting the enzyme from protease cleavage has not been evaluated. Therefore, we examined how the cross-linker bis (sulfosuccinimidyl suberate (BS3 affects the ability of trypsin to digest purified, wild type recombinant human coproporphyrinogen oxidase and selected mutants. Following incubation, the apparent molecular weights of peptides were evaluated by SDS-PAGE and enzymatic activity was assessed by spectroscopy following HPLC. For both wild type and mutants, the results indicated that the cross-linker was indeed able to protect against trypsin digestion relative to the enzyme incubated with trypsin in the absence of the cross-linker. These data have implications for the episodic nature of porphyria.

  20. Dynamics of desynchronized episodes in intermittent synchronization

    Leonid L Rubchinsky

    2014-06-01

    Full Text Available Intermittent synchronization is observed in a variety of different experimental settings in physics and beyond and is an established research topic in nonlinear dynamics. When coupled oscillators exhibit relatively weak, intermittent synchrony, the trajectory in the phase space spends a substantial fraction of time away from a vicinity of a synchronized state. Thus to describe and understand the observed dynamics one may consider both synchronized episodes and desynchronized episodes (the episodes when oscillators are not synchronous. This mini-review discusses recent developments in this area. We explain how one can consider variation in synchrony on the very short time-scales, provided that there is some degree of overall synchrony. We show how to implement this approach in the case of intermittent phase locking, review several recent examples of the application of these ideas to experimental data and modeling systems, and discuss when and why these methods may be useful.

  1. Assessing relative volatility/intermittency/energy dissipation

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko S.; Schmiegel, Jürgen

    2014-01-01

    process in particular. This estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, but it is also applicable in other areas. We develop a probabilistic asymptotic theory for realised relative power variations of Brownian semistationary processes......, and introduce inference methods based on the theory. We also discuss how to extend the asymptotic theory to other classes of processes exhibiting stochastic volatility/intermittency. As an empirical application, we study relative energy dissipation in data of atmospheric turbulence.......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...

  2. Magnetic field generation by intermittent convection

    Chertovskih, R; Chimanski, E V

    2016-01-01

    Magnetic field generation by convective flows in transition to weak turbulence is studied numerically. By fixing the Prandtl number at P=0.3 and varying the Rayleigh number (Ra) as a control parameter in three-dimensional Rayleigh-Benard convection of an electrically conducting fluid, a recently reported route to hyperchaos involving quasiperiodic regimes, crises and chaotic intermittent attractors is followed, and the critical magnetic Prandtl number ($P_m^c$) for dynamo action is determined as a function of Ra. A mechanism for the onset of on-off intermittency in the magnetic energy is described, the most beneficial convective regimes for dynamo action are identified, and how intermittency affects the dependence of $P_m^c$ on Ra is discussed.

  3. Intermittent versus continuous androgen deprivation therapy.

    Higano, Celestia S

    2014-05-01

    Androgen deprivation therapy (ADT) has been the standard of care for metastatic prostate cancer for decades; however, the choice of continuous or intermittent administration is a matter of debate. Two large phase III trials have reported results comparing these 2 forms of ADT administration. The National Cancer Institute of Canada (NCIC) PR-7 trial studied men with an increasing prostate-specific antigen (PSA) level and no evidence of metastatic disease after definitive or salvage radiation therapy and radical prostatectomy. The Southwest Oncology Group 9346 trial studied men with newly diagnosed hormone-sensitive metastatic disease. The primary end point in both trials was overall survival with a noninferiority design. The NCIC trial showed that the overall survival in men treated with intermittent ADT was not inferior to that of men treated with continuous ADT, but the SWOG trial was inconclusive regarding noninferiority. Certain domains of quality of life were better in the intermittent arms of both trials. If using ADT in the setting of biochemical relapse, intermittent ADT should be strongly considered over continuous ADT, except perhaps in patients with Gleason score of 8 or higher. In men with metastatic disease, continuous ADT remains the standard of care, because the SWOG trial did not establish noninferiority of intermittent ADT with respect to survival. However, for those with significant side effects from ADT, establishing the risk group, as determined by PSA value after 7 months of ADT or the presence of pain at diagnosis, may help guide the choice of intermittent versus continuous ADT in men with metastatic disease. PMID:24812139

  4. Intermittent heat exposure and thirst in rats

    Barney, Christopher C.; Kuhrt, David M.

    2016-01-01

    Abstract Adequate water intake, supporting both cardiovascular function and evaporative cooling, is a critical factor in mitigating the effects of heat waves, which are expected to increase with global warming. However, the regulation of water intake during periods of intermittent heat exposure is not well understood. In this study, the effects of access to water or no access during intermittent heat exposure were assessed using male Sprague‐Dawley rats exposed to 37.5°C for 4 h/day. After 7 ...

  5. Porfiria cutânea tarda e lúpus eritematoso sistêmico Porphyria cutanea tarda and systemic lupus erythematosus

    Leticia Haendchen

    2011-02-01

    Full Text Available A associação de lúpus eritematoso sistêmico e porfiria, embora rara, é conhecida de longa data. Ela obriga o médico a realizar um cuidadoso diagnóstico diferencial das lesões bolhosas nesses pacientes e tomar cuidados com a prescrição de certas drogas, como a cloroquina. Esta, nas doses habituais para tratamento do lúpus, pode causar hepatotoxicidade em pacientes com porfiria. Descreve-se o caso de uma paciente com lúpus que desenvolveu lesões bolhosas compatíveis com porfiria cutânea tardia.The co-existence of systemic lupus erythematosus and porphyria although rare has been known for a long time. This association forces the physician to make a careful differential diagnosis of the bullous lesions that might appear in such patients and to be careful when prescribing certain drugs such as chloroquine. This drug, when used in the regular doses for treating lupus, may cause hepatotoxicity in patients.suffering from porphyria. It is described here the case of a patient with lupus who developed bullous lesions compatible with porphyria cutanea tarda.

  6. Intermittent demand : Linking forecasting to inventory obsolescence

    Teunter, Ruud H.; Syntetos, Aris A.; Babai, M. Zied

    2011-01-01

    The standard method to forecast intermittent demand is that by Croston. This method is available in ERP-type solutions such as SAP and specialised forecasting software packages (e.g. Forecast Pro), and often applied in practice. It uses exponential smoothing to separately update the estimated demand

  7. Clean Intermittent Catheterization in the School Setting

    Katrancha, Elizabeth D.

    2008-01-01

    Spina bifida (SB) is a neural tube defect that causes many physical and mental disabilities. Bowel and bladder incontinence is the disability seen most often in these students that requires the school nurse's attention. Clean intermittent catheterization (CIC) provides the student with SB a vehicle to reach a satisfactory level of continence,…

  8. UNSTEADY DISPERSION IN RANDOM INTERMITTENT FLOW

    The longitudinal dispersion coefficient of a conservative tracer was calculated from flow tests in a dead-end pipe loop system. Flow conditions for these tests ranged from laminar to transitional flow, and from steady to intermittent and random. Two static mixers linked in series...

  9. Bus Lanes with Intermittent Priority: Screening Formulae and an Evaluation

    Eichler, Michael; Daganzo, Carlos F.

    2005-01-01

    This paper evaluates strategies for operating buses on signal-controlled arterials using special lanes that are made intermittently available to general traffic. The advantage of special bus lanes, intermittent or dedicated, is that they free buses from traffic interference; the disadvantage is that they disrupt traffic. We find that intermittent lanes, unlike dedicated ones, do not significantly reduce street capacity. Intermittence, however, increases the average traffic density at which th...

  10. Effect of Intermittent Hypercapnia on Respiratory Control in Rat Pups

    Steggerda, Justin A.; Mayer, Catherine A; Martin, Richard J.; Wilson, Christopher G.

    2009-01-01

    Preterm infants are subject to fluctuations in blood gas status associated with immature respiratory control. Intermittent hypoxia during early postnatal life has been shown to increase chemoreceptor sensitivity and destabilize the breathing pattern; however, intermittent hypercapnia remains poorly studied. Therefore, to test the hypothesis that intermittent hypercapnia results in altered respiratory control, we examined the effects of daily exposure to intermittent hypercapnia on the ventila...

  11. Intermittent heat exposure and thirst in rats.

    Barney, Christopher C; Kuhrt, David M

    2016-04-01

    Adequate water intake, supporting both cardiovascular function and evaporative cooling, is a critical factor in mitigating the effects of heat waves, which are expected to increase with global warming. However, the regulation of water intake during periods of intermittent heat exposure is not well understood. In this study, the effects of access to water or no access during intermittent heat exposure were assessed using male Sprague-Dawley rats exposed to 37.5°C for 4 h/day. After 7 days of intermittent heat exposure, reductions in evaporative water loss were observed in all animals and reductions in water intake following heat exposure occurred as the days of heat exposure increased. Rats that were not allowed water during the 7 days of exposure had decreased rehydration levels, however, rats allowed access to water increased water intake during exposure and exhibited higher overall rehydration levels over the same time period. Peripheral administration of angiotensinII, mimicking activation of volemic thirst, or hypertonic saline solution, activating intracellular thirst, did not result in alteration of water intake in rats exposed to heat with access to water compared to control rats. In contrast, rats exposed to heat without access to water had reduced water intake after administration of hypertonic saline and increased water intake after administration of angiotensinIIcompared to control rats. These experiments demonstrate that thirst responses to intermittent heat exposure are altered by providing water during heat exposure and that intermittent heat exposure without access to water alters drinking responses to both intracellular and extracellular thirst challenges. PMID:27095836

  12. Intermittent Aeration in Biological Treatment of Wastewater

    H. Doan

    2009-01-01

    Full Text Available Problem statement: E-coating process is widely used to provide a protective coating layer on metal parts in the automotive and metal finishing industry. The wastewater from the coating process contains organic compounds that are used in the cleaning, pretreatment and coating steps. Organic pollutants can be removed biologically. In the aerobic biological treatment, water aeration accounts for a significant portion of the total operating cost of the treatment process. Intermittent aeration is thus of benefit since it would reduce the energy consumption in the wastewater treatment. In the present study, wastewater from an electro-coating process was treated biologically using a packed column as an aerator where the wastewater was aerated by a countercurrent air flow. The objective was to obtain an optimum aeration cycle. Approach: Intermittent aeration time was varied at different preset cycles. An operational optimum of the aeration time (or air-water contacting time in the column was determined from the BOD5 removal after a certain treatment period. For continuous aeration of the wastewater, the air-liquid contacting time in the column was 52 min for 24 h of treatment. A unit energy consumption for pumping liquid and air, which was defined as the energy consumption per percent BOD5 removed, was used as a criterion to determine the optimum contacting time. Results: Optimum air-liquid contacting times were found to be about 38, 26 and 22 min for the treatment times of 24, 48 and 72 h, consecutively. This indicates that 27-58% saving on the unit energy consumption can be achieved using intermittent aeration of the wastewater. On the basis of the overall BOD5 removal, 17% and 23% savings in energy were observed with the intermittent aeration as compared to the continuous aeration of the wastewater for 48 and 72 h. Conclusion: The results obtained indicate that an appropriate intermittent aeration cycle can bring about a substantial energy saving

  13. Porfiria cutánea tardía: Reporte de 5 casos Porphyria cutanea tarda: Five cases report

    J L Iribas

    2008-03-01

    Full Text Available La PCT es la más común de las porfirias. Es una fotodermatosis que resulta de la deficiencia de la UPD, enzima perteneciente a la vía de síntesis del hemo. Presentamos la evolución de cinco casos de PCT; cuatro de PCT familiar y uno de PCT esporádica. En dos de los pacientes pertenecientes al grupo de PCT tipo II, encontramos como factor de riesgo, el consumo de alcohol, y en la paciente con PCT tipo I se detectó serología positiva para VHC. Todos los pacientes fueron tratados con cloroquina y flebotomías repetidas. Rápidamente se detectó mejoría clínica y bioquímica. Se observó que la porfirinuria continuó en descenso aún luego de suspendida la terapéutica. Tres de los pacientes con PCT familiar persisten en remisión clínica y con ausenciade recaídas tras más de 10 años de seguimiento. Aconsejamos en pacientes que padecen PCT la búsqueda de factores asociados (VHC, HIV, genes de HH y desencadenantes exógenos (consumo excesivo de alcohol, hierro en la dieta e ingesta de estrógenos que de ser controlados o evitados, junto con el tratamiento oportuno, contribuyen a un satisfactorio control de la enfermedad.The porphyria cutanea tarda is the most frequent porphyria, it is a photodermatosis secondary to uroporphyrinogen decarboxylase deficiency; this enzyme belongs to the haem synthesis pathway. We present on this paper the evolution of five cases of PCT, four of them with familiar type and one of them sporadic type. In two patients belonging to PCT type II, we found alcohol addiction as a serious risk, while on the other patients PCT type I we found HCV positive serology. All patients were treated with chloroquine and phlebotomies. We could observe a good response not only clinical but biochemical. We could also see that the porphyrins urinary level continued descending once the drug was withdrew. Three of the patients with familiar PCT remains in clinical remission without any relapses in ten years of control. We advice

  14. Comparison in continuous or intermittent intravenous injections of furosemide in patients with acute decompensated heart failure%急性失代偿性心力衰竭患者连续与间歇注射呋塞米的对比研究

    陈瑜; 季顺民; 丁卫东

    2013-01-01

    Objective To discuss the curative effects of continuous intravenous injection (cIV) or intermittent intravenous injection (iIV) of furosemide in the patients with acute decompensated heart failure (ADHF). Methods The patients with ADHF (n=56) were chosen from the Nanmo Health Center, Hai’an County of Nantong City of Jiangsu Province from Jun. 2011 to Nov. 2012, and then divided into cIV group (n=26) and iIV group (n=30). The primary end point was net urine output (nUOP)/24 h, and secondary end points included nUOP/furosemide, total urine output (tUOP)/24 h, tUOP/furosemide, weight loss during the study, additional treatment for ADHF, continuing time of drug administration, hospitalization days and safety reviewing (electrolyte loss and hemodynamic instability). Results The levels of nUOP and tUOP [nUOP:(2098±1132) mL vs. (1575±1100) mL, P=0.086;tUOP:(3726± 1121) mL vs. (2955±1267) mL, P=0.019], and tUOP/furosemide [(38.6±31.0) mL/mg vs. (22.2±12.5) mL/mg, P=0.021] were higher in cIV group than those in iIV group. The other indexes, including nUOP/furosemide, weight loss during the study, additional treatment for ADHF, continuing time of drug administration, and safety had no differences between two groups, and average body weight had no significant difference in two groups before and after treatment. The hospitalization time was shorter in cIV group than that in iIV group [(6.9±3.7) vs. (10.9±8.3 days), P=0.006]. Conclusion cIV has better curative effect than iIV on the clinical symptoms such as anhelation in ADHF patients, and patients’ tolerance is higher.%目的:比较连续(cIV)或间歇(iIV)静注给予呋塞米对急性失代偿性心力衰竭(ADHF)患者的疗效和安全性的差异。方法纳入2011年6月~2012年11月江苏省南通市海安县南莫中心卫生院ADHF患者56例,其中26例采用cIV方式给药的患者纳入cIV组,30例采用iIV方式给药的患者纳入iIV组,主要终点为每日净尿量(nUOP)

  15. Radial evolution of solar wind intermittency in the inner heliosphere

    Bruno, R; Sorriso-Valvo, L; Bavassano, B

    2003-01-01

    We analyzed intermittency in the solar wind, as observed on the ecliptic plane, looking at magnetic field and velocity fluctuations between 0.3 and 1 AU, for both fast and slow wind and for compressive and directional fluctuations. Our analysis focused on the property that probability distribution functions of a fluctuating field affected by intermittency become more and more peaked at smaller and smaller scales. Since the peakedness of a distribution is measured by its flatness factor we studied the behavior of this parameter for different scales to estimate the degree of intermittency of our time series. We confirmed that both magnetic field and velocity fluctuations are rather intermittent and that compressive magnetic fluctuations are generally more intermittent than the corresponding velocity fluctuations. In addition, we observed that compressive fluctuations are always more intermittent than directional fluctuations and that while slow wind intermittency does not depend on the radial distance from the ...

  16. Insights from intermittent binocular rivalry and EEG

    Michael A Pitts

    2011-09-01

    Full Text Available Novel stimulation and analytical approaches employed in EEG studies of ambiguous figures have recently been applied to binocular rivalry. The combination of intermittent stimulus presentation and EEG source imaging has begun to shed new light on the neural underpinnings of binocular rivalry. Here, we review the basics of the intermittent paradigm and highlight methodological issues important for interpreting previous results and designing future experiments. We then outline current analytical approaches, including EEG microstates, event-related potentials, and statistically-based source estimation, and propose a spatio-temporal model that integrates findings from several studies. Finally, we discuss the advantages and limitations of using binocular rivalry as a tool to investigate the neural basis of perceptual awareness.

  17. Game performance and intermittent hypoxic training.

    Hinckson, E A; Hamlin, M J; Wood, M R; Hopkins, W G

    2007-08-01

    Live high-train low altitude exposure simulated by hypoxic devices may improve athletic performance. In this study, intermittent normobaric hypoxia was achieved with the GO2altitude hypoxicator to determine its effects on sea level performance in rugby players. Ten players were randomly assigned to two groups. Players in each group received 14 sessions of either hypoxic (10-15% O(2)) or normoxic (21% O(2)) exposure at rest over 14 consecutive days in a single blind fashion. Various performance measures were obtained consecutively in a single testing session pre- and post-exposure. Effects of hypoxic exposure on maximum speed and sprint times were trivial (rugby simulation, hypoxic exposure produced impairments of peak power in two scrums (15%, +/-8%; 9%, +/-7%) and impairments of time in offensive sprints (7%, +/-8%) and tackle sprints (11%, +/-9%). Pending further research, rugby players would be unwise to use normobaric intermittent hypoxic exposure to prepare for games at sea level. PMID:17311807

  18. Stochastic resonance in on-off intermittency

    Stochastic resonance (SR) is studied in chaotic systems exhibiting on-off intermittency (OOI). They include a discrete-time system - the logistic map with the control parameter varying randomly in time and a continuous time system - chaotic oscillators just below the synchronisation threshold. As a weak additive or multiplicative periodic forcing is added to such systems, the signal-to-noise ratio (SNR) exhibits a maximum as a function of the intermittency control parameter. In all cases SNR shows dependence on the forcing frequency. In the case of additive periodic forcing in continuous-time systems a distinct minimum of SNR is observed when the periodic forcing frequency is close to the characteristic frequency of chaotic oscillations of the system. In the case of multiplicative periodic forcing this dependence retains even for very small frequencies; this is a result of a very long characteristic time scale, typical of systems with OOI. (author)

  19. Intermittent enhancement in chronic nodular calcified neurocysticercosis

    Martin Oselkin, MD

    2015-01-01

    Full Text Available Neurocysticercosis (NCC is the most common cause of new onset seizures and epilepsy in the developing and tropical world. There has been a marked increase in domestic cases of diseases traditionally associated with developing countries, and now NCC should be high on a radiologist's differential diagnosis list for a patient with seizures. Radiologic findings of NCC correlate with the parasite's life cycle within the host. The calcified granulomas signify the final stage (nodular calcified as nonenhancing punctate calcifications on imaging and are traditionally known to remain without enhancement. Here we describe a unique case of intermittent enhancement of a cortical calcified nodule secondary to NCC that was followed for over 10 years. Radiologists must challenge the traditionally accepted progression of imaging findings and accept that calcified nodules of chronic NCC may intermittently enhance.

  20. Intermittent tracking of flat plate collectors

    A theoretical analysis of different intervals of intermittent two-axis tracking of the sun, on the amount of annual energy received by flat-plate collectors, has been carried out. The analysis was done for Ipoh, a city near the university at a latitude of 40 34 North in Malaysia. For the analysis, a computer program was developed to calculate the solar insulation according to the interval settings, considering ASHRAE Standard Sky assumption. Both direct and diffused components of solar radiation have been considered. The tracking system was targeted for flat plate collectors where the degree of tracking accuracy would be much lower Hence, the tracking mechanism will be much simpler and lower in costs. Results showed that by a 3-hour intermittent tracking, a flat-plate collector could get as much as 35% more annual energy than a fixed one. The 3-hour interval tracking greatly simplifies the gear mechanism from the motor to the solar collector. (Author)

  1. A simple model for turbulence intermittencies

    Rimbert, Nicolas

    2009-01-01

    Whether turbulence intermittencies shall be described by a log-Poisson, a log-stable pdf or other distributions is still debated nowadays. In this paper, a bridge between polymer physics, self-avoiding walk and random vortex stretching is established which may help in getting a new insight on this topics. Actually a very simple relationship between stability index of the stable law and the well known Flory exponent stemming from polymer physics is established. Moreover the scaling of turbulence intermittencies with Reynolds number is also obtained and the overall picture is very close to Tennekes' simple model for the fine scale structure of turbulence [Phys. Fluids, 11, 3 (1968)] : vortex tubes of Kolmogorov length width are bend by bigger vortices of Taylor length scale. This thus results in both a simple and sound model with no fitting parameter needed.

  2. Intermittency exponent of the turbulent energy cascade

    We consider the turbulent energy dissipation from one-dimensional records in experiments using air and gaseous helium at cryogenic temperatures, and obtain the intermittency exponent via the two-point correlation function of the energy dissipation. The air data are obtained in a number of flows in a wind tunnel and the atmospheric boundary layer at a height of about 35 m above the ground. The helium data correspond to the centerline of a jet exhausting into a container. The air data on the intermittency exponent are consistent with each other and with a trend that increases with the Taylor microscale Reynolds number, Rλ, of up to about 1000 and saturates thereafter. On the other hand, the helium data cluster around a constant value at nearly all Rλ, this being about half of the asymptotic value for the air data. Some possible explanation is offered for this anomaly. (author)

  3. Correcting intermittent central suppression improves binocular marksmanship.

    Hussey, Eric S

    2007-04-01

    Intermittent central suppression (ICS) is a defect in normal binocular (two-eyed) vision that causes confusion in visual detail. ICS is a repetitive intermittent loss of visual sensation in the central area of vision. As the central vision of either eye "turns on and off", aiming errors in sight can occur that must be corrected when both eyes are seeing again. Any aiming errors in sight might be expected to interfere with marksmanship during two-eyed seeing. We compared monocular (one-eyed, patched) and binocular (two-eyed) marksmanship with pistol shooting with an Army ROTC cadet before and after successful therapy for diagnosed ICS. Pretreatment, monocular marksmanship was significantly better than binocular marksmanship, suggesting defective binocularity reduced accuracy. After treatment for ICS, binocular and monocular marksmanship were essentially the same. Results confirmed predictions that with increased visual stability from correcting the suppression, binocular and monocular marksmanship accuracies should merge. PMID:17484315

  4. Scaling and Intermittency in Animal Behavior

    Harnos, A; Lawrence, A B; Vattay, G

    1999-01-01

    Scale-invariant spatial or temporal patterns and Lévy flight motion have been observed in a large variety of biological systems. It has been argued that animals in general might perform Lévy flight motion with power law distribution of times between two changes of the direction of motion. Here we study the temporal behaviour of nesting gilts. The time spent by a gilt in a given form of activity has power law probability distribution without finite average. Further analysis reveals intermittent eruption of certain periodic behavioural sequences which are responsible for the scaling behaviour and indicates the existence of a critical state. We show that this behaviour is in close analogy with temporal sequences of velocity found in turbulent flows, where random and regular sequences alternate and form an intermittent sequence.

  5. Intermittence and roughening of periodic elastic media

    We analyze intermittence and roughening of an elastic interface or domain wall pinned in a periodic potential, in the presence of random-bond disorder in 1+1 and 2+1 dimensions. Though the ensemble average behavior is smooth, the typical behavior of a large sample is intermittent, and does not self-average to a smooth behavior. Instead, large fluctuations occur in the mean location of the interface and the onset of interface roughening is via an extensive fluctuation which leads to a jump in the roughness of order λ, the period of the potential. Analytical arguments based on extreme statistics are given for the number of the minima of the periodicity visited by the interface and for the roughening crossover, which is confirmed by extensive exact ground state calculations

  6. Intermittent permeation of cylindrical nanopores by water

    Allen, Rosalind; Melchionna, Simone; Hansen, Jean-Pierre

    2002-01-01

    Molecular Dynamics simulations of water molecules in nanometre sized cylindrical channels connecting two reservoirs show that the permeation of water is very sensitive to the channel radius and to electric polarization of the embedding material. At threshold, the permeation is {\\emph{intermittent}} on a nanosecond timescale, and strongly enhanced by the presence of an ion inside the channel, providing a possible mechanism for gating. Confined water remains surprisingly fluid and bulk-like. It...

  7. Intermittent chaotic chimeras for coupled rotators

    Olmi, Simona; Martens, Erik Andreas; Thutupalli, Shashi; Torcini, Alessandro

    2015-01-01

    wo symmetrically coupled populations of N oscillators with inertia m display chaotic solutions with broken symmetry similar to experimental observations with mechanical pendulums. In particular, we report evidence of intermittent chaotic chimeras, where one population is synchronized and the othe...... jumps erratically between laminar and turbulent phases. These states have finite lifetimes diverging as a power law with N and m. Lyapunov analyses reveal chaotic properties in quantitative agreement with theoretical predictions for globally coupled dissipative systems....

  8. Intermittency Studies in Directed Bond Percolation

    Henkel, Malte; Peschanski, Robert

    1992-01-01

    The self-similar cluster fluctuations of directed bond percolation at the percolation threshold are studied using techniques borrowed from inter\\-mit\\-ten\\-cy-related analysis in multi-particle production. Numerical simulations based on the factorial moments for large $1+1$-dimensional lattices allow to handle statistical and boundary effects and show the existence of weak but definite intermittency patterns. The extracted fractal dimensions are in agreement with scaling arguments leading to ...

  9. Intermittent Aeration in Biological Treatment of Wastewater

    Doan, H.; Lohi, A.

    2009-01-01

    Problem statement: E-coating process is widely used to provide a protective coating layer on metal parts in the automotive and metal finishing industry. The wastewater from the coating process contains organic compounds that are used in the cleaning, pretreatment and coating steps. Organic pollutants can be removed biologically. In the aerobic biological treatment, water aeration accounts for a significant portion of the total operating cost of the treatment process. Intermittent aeration is ...

  10. Sampling for Intermittent Shorts in Electron Tubes

    Hurford, Allen F.

    1967-01-01

    The primary purpose of sampling is to provide data from which a decision can be made to accept or reject the lot from which the sample was drawn. However, if the lot contains both permanent and intermittent defects, this decision may be biased in addition to the known sampling risks by these data to the extent that they are themselves no longer certainties but rather, probabilities.

  11. Long-range forecasting of intermittent streamflow

    F. F. van Ogtrop; R. W. Vervoort; Heller, G. Z.; D. M. Stasinopoulos; Rigby, R. A.

    2011-01-01

    Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a statistical model to forecast streamflow up to 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS) to determine the probability of f...

  12. Intermittent relaxation in hierarchical energy landscapes

    Fischer, Andreas; Sibani, Paolo; Hoffmann, Karl Heinz

    2007-01-01

    We numerically simulate a thermalization process in an energy landscape with hierarchically organized metastable states. The initial configuration is chosen to have a large energy excess, relative to the thermal equilibrium value at the running temperature. We show that the initial energy surplus is dissipated in a series of intermittent bursts, or quakes, whose rate decreases as the inverse of the age of the system. In addition, one observes energy fluctuations with a zero centered Gaussian ...

  13. Global spectral structures of intermittent chaos

    Power spectra of intermittent chaos near its onset point is formulated in order to clarify fluctuations of periodic laminar motions caused by turbulent bursts. It is shown that the power spectra exhibit eminent peaks at selected frequencies mω0 with m = 0,1,2, ... and an eigenfrequency ω0 of the laminar motions. The peak at zero frequency is produced by fluctuations of durations of the laminar motions, whereas the peaks at nonzero frequencies are generated by jumps of phase shifts of the laminar motions by bursts. The shape of each peak turns out to obey an inverse-power law 1/|ω-mω0|ζm with a universal exponent ζm. For the type I intermittency caused by the saddle-node bifurcation, ζ0 = 1, ζ1 = 2 under normal reinjections, whereas ζ0 = ζm = 1 if reinjections are restricted to the upper half of a narrow channel of the tangent map. For the type III intermittency caused by the inverted period-doubling bifurcation, ζm = 3/2 for m ≥ 1. (author)

  14. Intermittent control of unstable multivariate systems.

    Loram, I; Gawthrop, P; Gollee, H

    2015-08-01

    A sensorimotor architecture inspired from biological, vertebrate control should (i) explain the interface between high dimensional sensory analysis, low dimensional goals and high dimensional motor mechanisms and (ii) provide both stability and flexibility. Our interest concerns whether single-input-single-output intermittent control (SISO_IC) generalized to multivariable intermittent control (MIC) can meet these requirements.We base MIC on the continuous-time observer-predictorstate-feedback architecture. MIC uses event detection. A system matched hold (SMH), using the underlying continuoustime optimal control design, generates multivariate open-loop control signals between samples of the predicted state. Combined, this serial process provides a single-channel of control with optimised sensor fusion and motor synergies. Quadratic programming provides constrained, optimised equilibrium control design to handle unphysical configurations, redundancy and provides minimum, necessary reduction of open loop instability through optimised joint impedance. In this multivariate form, dimensionality is linked to goals rather than neuromuscular or sensory degrees of freedom. The biological and engineering rationale for intermittent rather than continuous multivariate control, is that the generalised hold sustains open loop predictive control while the open loop interval provides time within the feedback loop for online centralised, state dependent optimisation and selection. PMID:26736539

  15. Glucose-6-Phosphate Dehydrogenase Deficiency and Haemoglobin Drop after Sulphadoxine-Pyrimethamine Use for Intermittent Preventive Treatment of Malaria during Pregnancy in Ghana – A Cohort Study

    Owusu, Ruth; Asante, Kwaku Poku; Mahama, Emmanuel; Awini, Elizabeth; Anyorigiya, Thomas; Dosoo, David; Amu, Alberta; Jakpa, Gabriel; Ofei, Emmanuel; Segbaya, Sylvester; Oduro, Abraham Rexford; Gyapong, Margaret; Hodgson, Abraham; Bart-Plange, Constance; Owusu-Agyei, Seth

    2015-01-01

    Background Sulphadoxine-Pyrimethamine (SP) is still the only recommended antimalarial for use in intermittent preventive treatment of malaria during pregnancy (IPTp) in some malaria endemic countries including Ghana. SP has the potential to cause acute haemolysis in G6PD deficient people resulting in significant haemoglobin (Hb) drop but there is limited data on post SP-IPTp Hb drop. This study determined the difference, if any in proportions of women with significant acute haemoglobin drop b...

  16. Acute pollution of recipients in urban areas

    Rauch, W.; Harremoës, P.

    1997-01-01

    Oxygen and ammonia concentration are key parameters of acute water pollution in urban rivers. These two abiotic parameters are statistically assessed for a historical rain series by means of a simplified deterministic model of the integrated drainage system. Continuous simulation of the system...... performance indicates that acute water pollution is caused by intermittent discharges from both sewer system and wastewater treatment plant. Neglecting one of them in the evaluation of the environmental impact gives a wrong impression of total system behavior. Detention basins and alternative operational...... modes in the treatment plant under wet weather loading have a limited positive effect for minimizing acute water pollution. (C) 1997 IAWQ. Published by Elsevier Science Ltd....

  17. The interactions of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) and 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) in TCDD-induced porphyria

    Yao, Cheng Catsby.

    1989-01-01

    Halogenated aryl hydrocarbon(HAH)-induced porphyria is caused by alteration of porphyrin metabolism and results in the accumulation of hepatic and urinary porphyrins. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (75 {mu}/kg) caused significant increases of hepatic porphyrin levels in C57BL/6 male, female and ovariectomized female, and C57BL/10 male mice 3 weeks after treatment. In contrast, 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) was inactive at a dose of 750 {mu}mol/kg. Cotreatment with MCDF (750 {mu}mol/kg) and 2,3,7,8-TCDD (75 {mu}g/kg) resulted in partial antagonism of 2,3,7,8-TCDD-induced porphyrin accumulation in female but not in male mice. In female C57BL/6 mice, 2,3,7,8-TCDD-induced porphyria was accompanied by the induction of hepatic microsomal aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) activities and the inhibition of uroporphyrinogen decarboxylase (UROD) activity. MCDF (750 {mu}mol/kg) did not significantly affect these enzyme activities. In coadministration studies, MCDF partially antagonized 2,3,7,8-TCDD-induced hepatic porphyrin accumulation but did not affect the activities of hepatic AHH, EROD or UROD. These results demonstrate that the induction of the monooxygenase enzyme activities and the inhibition of UROD activity by 2,3,7,8-TCDD and the development of porphyria are not coordinately regulated in C57BL/6 female mice. In cultured chick embryo hepatocytes, 2,3,7,8-TCDD caused a significant increase in porphyrin levels and induced AHH and EROD activities. MCDF and Aroclor 1254 partially antagonized the 2,3,7,8-TCDD induced AHH and EROD activities but not the porphyrin accumulation.

  18. UNSTEADY INTERMITTENT FLOW IN A ROTATING CURVED PIPE

    YIN Jian-an; SHEN Xin-rong; CHEN Hua-jun; ZHANG Ben-zhao

    2004-01-01

    The effects of rotation and intermittent fre quency on the flow transition of secondary flow and, main flow were examined in detail. Certain hitherto unknown flow patterns were found. A numerical study was performed to study the characteristics of unsteady intermittent flow in a rotating curved pipe. Due to the rotation, both the Coriolis force and the centrifugal force could contribute to the unsteady intermittent flow and some complicated phenomena can be found. The results indicate that the unsteady intermittent flow are mainly characterized by five parameters: the Dean number Dn , the curvatureκ, the maximal force ratio F (of the Coriolis force to the centrifugal force in a cycle), the intermittent frequency parameter η(the ratio of a pulslating time to the cycle period), and the Womersley number α. Present works shows the natures of the unsteady intermittent flow in a rotating curved pipe.

  19. Hovering and intermittent flight in birds

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound (∼0.3 kg) and small birds with rounded wings do not use intermittent glides.

  20. Hovering and intermittent flight in birds

    Tobalske, Bret W, E-mail: bret.tobalske@mso.umt.ed [Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, MT 59812 (United States)

    2010-12-15

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound ({approx}0.3 kg) and small birds with rounded wings do not use intermittent glides.

  1. Regionalization of patterns of flow intermittence from gauging station records

    Snelder, T.H.; Datry, T.; Lamouroux, N.; Larned, S. T.; E. Sauquet; Pella, H.; C. Catalogne

    2013-01-01

    Understanding large-scale patterns in flow intermittence is important for effective water resource management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times-series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero-flow) in each year of record (FREQ; yr−1)...

  2. Intermittent Microwave Drying of Wheat (Triticum aestivum L.) Seeds

    Yan Li; Tao Zhang; Chenglai Wu; Chunqing Zhang

    2014-01-01

    The purpose of present study was to characterize the intermittent microwave drying of wheat seeds. Results revealed that microwave on time percentage (MOTP) and initial moisture content were the main parameters which influenced the intermittent microwave drying rate and the germination capacity of dried seeds. Best intermittent microwave drying (power: 800 W; seed sample weight: 100 g, microwave on time in each cycle: 32 s) without significantly decreasing the germination rate was...

  3. Spatio-temporal intermittency on the sandpile

    The self-organized critical state exhibited by a sandpile model is shown to correspond to motion on an attractor characterized by an invariant distribution of the height variable. The largest Lyapunov exponent is equal to zero. The model nonetheless displays intermittent chaos, with a multifractal distribution of local expansion coefficients in history space. Laminar spatio-temporal regions are interrupted by chaotic bursts caused by avalanches. We introduce the concept of local histories in configuration space and show that their expansion parameters also exhibit a multifractal distribution in time and space. (author). 22 refs, 5 figs

  4. Intermittency pattern of fluctuations in nuclear multifragmentation

    The method of scaled factorial moments is used to study fluctuations of the fragment size distribution in the percolation model and in nuclear multifragmentation following the breakup of the high energy nuclei in the nuclear emulsion. The percolation model accounts well for the fluctuations in the nuclear fragmentation process. An intermittent pattern of fluctuations is found in the data suggesting a self-similarity in the fragment size distribution and a random character for the scaling law. However, no evidence of the critical behaviour in nuclear multifragmentation is found. (orig.)

  5. Reduction in intermittent transport by shearing

    The intermittent transport due to coherent structures (streamers) is shown to be dramatically reduced by the shearing of mean flow in passive scalar field model, with the scaling ∝Ω-3. Here, Ω is the shearing rate of the mean flow. This reduction is much stronger than that in turbulent transport (∝Ω-1) [Kim and Diamond, Phys. Rev. Lett. 91, 075001 (2003)] in the same model. Implications for the transition from low to high confinement (L-H transition) are discussed

  6. Acute Bronchitis

    ... of bronchitis: acute and chronic. Most cases of acute bronchitis get better within several days. But your cough ... that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when people ...

  7. Intermittent lag synchronization in a driven system of coupled oscillators

    Alexander N Pisarchik; Rider Jaimes-Reátegui

    2005-04-01

    We study intermittent lag synchronization in a system of two identical mutually coupled Duffing oscillators with parametric modulation in one of them. This phenomenon in a periodically forced system can be seen as intermittent jump from phase to lag synchronization, during which the chaotic trajectory visits a periodic orbit closely. We demonstrate different types of intermittent lag synchronizations, that occur in the vicinity of saddle-node bifurcations where the system changes its dynamical state, and characterize the simplest case of period-one intermittent lag synchronization.

  8. Projective synchronization of a hyperchaotic system via periodically intermittent control

    Huang Jun-Jian; Li Chuan-Dong; Zhang Wei; Wei Peng-Cheng

    2012-01-01

    We further study the projective synchronization of a new hyperchaotic system.Different from the most existing methods,intermittent control is applied to chaotic synchronization in the present paper.We formulate the intermittent control system that governs the dynamics of the projective synchronization error,then derive the sufficient conditions for the exponential stability of intermittent control system by using the Lyapunov stability theory,and finally establish the periodically intermittent controller according to the stability criterion by which the projective synchronization is expected to be achieved.The analytical results are also demonstrated by several numerical simulations.

  9. Sustained acclimatization in Chilean mine workers subjected to chronic intermittent hypoxia.

    Farias, Jorge G; Osorio, Jorge; Soto, Gustavo; Brito, Julio; Siques, Patricia; Reyes, Juan G

    2006-01-01

    Farias, Jorge G., Jorge Osorio, Gustavo Soto, Julio Brito, Patricia Siques, and Juan G. Reyes. Sustained acclimatization in Chilean mine workers subjected to chronic intermittent hypoxia. High Alt. Med. Biol. 7:302-306, 2006--We wanted to know if sea-level mine workers exposed previously to chronic intermittent hypoxia reached a steady acclimatization at 36 months under hypobaric hypoxia. An intermittently exposed group of mine workers (IE, n = 25) were subjected to submaximal exercise (100 W) at 4500 m. Their systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and hemoglobin oxygen saturation (HbSatO(2)) were monitored. Two comparison groups of unacclimatized sea-level workers (n = 17) were studied. A nonexposed group (NE) performed 5 min of submaximal exercise at sea level. Some kind of exercise was performed both by an acutely exposed group (AE) and IE group at 4500 m. No statistical differences were found for HR, SBP, and DBP (p > 0.05) during exercise between IE and AE groups. Resting HbSatO(2) of IE (87 +/- 6%) was lower than NE (97 +/- 3%) (p < 0.05), but was higher than AE (82 +/- 4%) (p < 0.05). In the exercise condition, HbSatO(2) of IE (85 +/- 5%) was lower than NE (95 +/- 3%) (p < 0.05), but was higher than AE (76 +/- 2%) (p < 0.05). These responses were maintained through the 6 months of the study period. Thus, mine workers subjected to intermittent hypobaric condition for 3 years showed a good degree of acclimatization that was maintained through time. PMID:17173515

  10. Soren Kierkegaard (1813-55): a bicentennial pathographical review.

    Schioldann, Johan; Søgaard, Ib

    2013-12-01

    Researchers in the fields of psychology, psychiatry, medicine and theology have made exhaustive efforts to shed light on the elusive biography/pathography of the great Danish philosopher Søren Kierkegaard (1813-55). This 'bicentennial' article reviews his main pathographical diagnoses of, respectively, possible manic-depressive [bipolar] disease, epilepsy, complex partial seizure disorder, Landry-Guillain-Barré's acute ascending paralysis, acute intermittent porphyria with possible psychiatric manifestations, and syphilidophobia. PMID:24573750

  11. Intermittent preventive treatment of malaria in pregnancy

    Mbonye, A.K.; Bygbjerg, Ib Christian; Magnussen, Pascal

    2008-01-01

    OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non-randomized comm......OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non......-randomized community trial was implemented in 21 community clusters (intervention) and four clusters where health units provided routine IPTp (control). The primary outcome measures were access and adherence to IPTp, number of malaria episodes, prevalence of anaemia, and birth weight. Numbers of live births, abortions......, still births, and maternal and child deaths were secondary endpoints. FINDINGS: 1404 (67.5%) of 2081 with the new delivery system received two doses of sulfadoxine-pyrimethamine versus 281 (39.9%) of 704 with health units (P < 0.0001). The prevalence of malaria episodes decreased from 906 (49.5%) of...

  12. Strain intermittency in shape-memory alloys

    Balandraud, Xavier; Barrera, Noemi; Biscari, Paolo; Grédiac, Michel; Zanzotto, Giovanni

    2015-05-01

    We study experimentally the intermittent progress of the mechanically induced martensitic transformation in a Cu-Al-Be single crystal through a full-field measurement technique: the grid method. We utilize an in-house, specially designed gravity-based device, wherein a system controlled by water pumps applies a perfectly monotonic uniaxial load through very small force increments. The sample exhibits hysteretic superelastic behavior during the forward and reverse cubic-monoclinic transformation, produced by the evolution of the strain field of the phase microstructures. The in-plane linear strain components are measured on the sample surface during the loading cycle, and we characterize the strain intermittency in a number of ways, showing the emergence of power-law behavior for the strain avalanching over almost six decades of magnitude. We also describe the nonstationarity and the asymmetry observed in the forward versus reverse transformation. The present experimental approach, which allows for the monitoring of the reversible martensitic transformation both locally and globally in the crystal, proves useful and enhances our capabilities in the analysis and possible control of transition-related phenomena in shape-memory alloys.

  13. Shearing of Materials with Intermittent Joints

    Gerolymatou, Eleni; Triantafyllidis, Theodoros

    2016-07-01

    The strength of fractures is much lower as a rule than that of intact rock. As a result they play a controlling part in the mechanical behaviour in general and the failure in particular of rock mass. Though a large volume of experimental data is available on the shear resistance of joints, as well as on the propagation of single cracks, the same is not true for the mechanical behaviour of intermittent joints. The experimental data available in this case are limited and the strength of rock mass with intermittent joints is usually modelled using averaged values of cohesion or assuming the fractures to be continuous. In the present work, the results of simple shear tests on a series of gypsum specimens with pre-existing cracks are presented. Twelve different crack orientations and two normal stresses were tested. The hypothesis of averaged cohesion and the theory of fracture mechanics are used to reproduce the results. It is found that fracture mechanics provides a more suitable model for the experimental results, especially when crack interaction is taken into account.

  14. Regionalization of patterns of flow intermittence from gauging station records

    T. H. Snelder

    2013-01-01

    Full Text Available Understanding large-scale patterns in flow intermittence is important for effective water resource management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times-series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero-flow in each year of record (FREQ; yr−1, and the total number of zero-flow days in each year of record (DUR; days. These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr−1, and the mean duration of zero-flow periods (mDUR; days. Approximately 20% of stations had recorded at least one zero-flow period. Dissimilarities between pairs of gauges calculated from the annual times-series (FREQ and DUR and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero-flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used Random Forest (RF models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35. Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also catchment area, shape and slope. However, we suggest that the fair-to-poor performance of the classification models is because intermittence is also controlled by

  15. Chronic intermittent hypoxia and obstructive sleep apnea: an experimental and clinical approach

    Sforza E

    2016-04-01

    Full Text Available Emilia Sforza, Fréderic Roche Service de Physiologie Clinique et de l'Exercice, Pole NOL, CHU, EA SNA-EPIS 4607, Faculté de Médecine J. Lisfranc, UJM Saint-Etienne, Université de Lyon, Saint-Etienne, France Abstract: Obstructive sleep apnea (OSA is a prevalent sleep disorder considered as an independent risk factor for cardiovascular consequences, such as systemic arterial hypertension, ischemic heart disease, cardiac arrhythmias, metabolic disorders, and cognitive dysfunction. The pathogenesis of OSA-related consequence is assumed to be chronic intermittent hypoxia (IH inducing alterations at the molecular level, oxidative stress, persistent systemic inflammation, oxygen sensor activation, and increase of sympathetic activity. Overall, these mechanisms have an effect on vessel permeability and are considered to be important factors for explaining vascular, metabolic, and cognitive OSA-related consequences. The present review attempts to examine together the research paradigms and clinical studies on the effect of acute and chronic IH and the potential link with OSA. We firstly describe the literature data on the mechanisms activated by acute and chronic IH at the experimental level, which are very helpful and beneficial to explaining OSA consequences. Then, we describe in detail the effect of IH in patients with OSA that we can consider "the human model" of chronic IH. In this way, we can better understand the specific pathophysiological mechanisms proposed to explain the consequences of IH in OSA. Keywords: hypoxia, intermittent hypoxia, experimental studies, obstructive sleep apnea

  16. Intermittent Versus Continuous Phototherapy for Reducing Neonatal Hyperbilirubinemia

    Nikoo Niknafs; Bahare Bahman-Bijari; Mohammad Hossein Torabinejad; Abdol-Ali Mortazavi; Pedram Niknafs

    2008-01-01

    Objective: Clinical studies comparing intermittent versus continuous phototherapy for reducing neonatal hyperbilirubinemia have produced conflicting results. This study was conducted to compare the efficacy of intermittent with continuous phototherapy. Methods: This study was performed on 114 neonates with indirect hyperbilirubinemia. Inclusion criteria were body weight above 2000 grams, absence of other concomitant diseases, and hyperbilirubinemia neither requiring intensive phototherapy nor...

  17. Bound by Children: Intermittent Cohabitation and Living Together Apart

    Cross-Barnet, Caitlin; Cherlin, Andrew; Burton, Linda

    2011-01-01

    In this article, we examine variations in low-income mothers' patterns of intermittent cohabitation and the voluntary and involuntary nature of these unions. Intermittent cohabitation involves couples living together and separating in repeating cycles. Using Three-City Study ethnographic data, we identified 45 low-income mothers involved in these…

  18. Intermittent versus Continuous Physiotherapy in Children with Cerebral Palsy

    Christiansen, Annette Sandahl; Lange, Christa

    2008-01-01

    The aim of this study was to compare the effect of the delivery of the same amount of intermittent versus continuous physiotherapy given to children with cerebral palsy (CP). This was organized either in an intermittent regime four times a week for 4 weeks alternating with a 6-week treatment pause, or a continuous once or twice a week regime, both…

  19. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    2010-04-01

    ... providing mechanical ventilation at a preset rate. (b) Classification. Class II (performance standards). ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent mandatory ventilation attachment. 868... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  20. Human stick balancing: an intermittent control explanation.

    Gawthrop, Peter; Lee, Kwee-Yum; Halaki, Mark; O'Dwyer, Nicholas

    2013-12-01

    intermittent, and therefore, the continuous-time strategy cannot be correct. However, the model of intermittent control used in this paper is based on the virtual pivot continuous-time control scheme, handles time delays and moreover masquerades as the underlying continuous-time controller. In addition, the event-driven properties of intermittent control can explain experimentally observed variability. PMID:23943300

  1. Intermittent drying of beans in a spouted bed

    C. A. Oliveira

    2007-12-01

    Full Text Available Carioca beans are a highly nutritious grain, in terms of the amount of protein, iron and potassium as well as carbohydrates and fiber and as a source of vitamins. The moisture content of recently picked beans is too high for good preservation and storage, resulting in the need for drying before packaging. In this work, the drying of Carioca beans in a laboratory scale spouted bed under intermittent conditions of the drying air was experimentally analyzed. Experiments carried out consisted of two types of intermittent regime: intermittence in the spout regime, referred to as spouted/fixed bed and intermittence of the air supply to the bed, called spouted bed/rest. The results were compared to those for bean drying in a spouted bed dryer without intermittence.

  2. Finite dissipation and intermittency in magnetohydrodynamics

    Mininni, P D

    2009-01-01

    We present an analysis of data stemming from numerical simulations of decaying magnetohydrodynamic (MHD) turbulence up to grid resolution of 1536^3 points and up to Taylor Reynolds number of 1200. The initial conditions are such that the initial velocity and magnetic fields are helical and in equipartition, while their correlation is negligible. Analyzing the data at the peak of dissipation, we show that the dissipation in MHD seems to asymptote to a constant as the Reynolds number increases, thereby strengthening the possibility of fast reconnection events in the solar environment for very large Reynolds numbers. Furthermore, intermittency of MHD flows, as determined by the spectrum of anomalous exponents of structure functions of the velocity and the magnetic field, is stronger than for fluids, confirming earlier results; however, we also find that there is a measurable difference between the exponents of the velocity and those of the magnetic field, as observed recently in the solar wind. Finally, we discu...

  3. Muscle coordination changes during intermittent cycling sprints.

    Billaut, François; Basset, Fabien A; Falgairette, Guy

    2005-06-01

    Maximal muscle power is reported to decrease during explosive cyclical exercises owing to metabolic disturbances, muscle damage, and adjustments in the efferent neural command. The aim of the present study was to analyze the influence of inter-muscle coordination in fatigue occurrence during 10 intermittent 6-s cycling sprints, with 30-s recovery through electromyographic activity (EMG). Results showed a decrease in peak power output with sprint repetitions (sprint 1 versus sprint 10: -11%, Pversus sprint 10: -90.2 ms, Pcycling sprints of short duration, decreased possibly due to the inability of muscles to maintain maximal force. This reduction in maximal power output occurred in parallel to changes in the muscle coordination pattern after fatigue. PMID:15862899

  4. Scintillation-Induced Intermittency in SETI

    Cordes, J M; Sagan, Carl Edward; Cordes, James M.; Sagan, Carl

    1997-01-01

    We consider interstellar scintillations as a cause of intermittency in radio signals from extraterrestrial intelligence (ETI). We demonstrate that scintillations are very likely to allow initial detections of narrowband signals from distant sources (> 100 pc), while making redetections improbable. We consider three models in order to assess the non-repeating, narrowband events found in recent SETI and to analyze large surveys in general: (I) Radiometer noise; (II) A population of constant Galactic sources undergoing interstellar scintillation,; and (III) Real, transient signals (or hardware errors) of either terrestrial or ET origin. We apply likelihood and Bayesian tests of the models to The Planetary Society/Harvard META data. We find that Models II and III are both highly preferred to Model I, but that Models II and III are about equally likely. Ruling out Model II in favor of Model III requires many more reobservations than were conducted in META *or* the reobservation threshold must be much lower than wa...

  5. Voltage Stability Evaluation Incorporating Wind Power Intermittency

    Libao SHI; Yang ZHAO; Yixin NI; Liangzhong YAO; Masoud BAZARGAN

    2013-01-01

    A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly,the power output modelings of three types of wind turbines are discussed.Secondly,the Jensen model is employed to simulate the wind farm with the wake effect.The Monte Carlo based technique is used to conduct the voltage stability evaluation incorporating the randomness of the wind speed based on the Weibull probability distribution.Thirdly,the relative sensitivity index (RSI) is calculated to identify weak buses during analysis.Finally,case studies with different simulation scenarios are carried out.Some statistical results involving weakness probability,expected value and variance of RSI as well as preliminary conclusions are drawn based on numerical simulation results.

  6. Towards an intermittency-friendly energy system

    Blarke, Morten

    2012-01-01

    capitulating as wind power penetration levels are moving above 25%; some operators are retiring cogeneration units entirely, while other operators are making way for heat-only boilers. This development is jeopardizing the system-wide energy, economic, and environmental benefits that distributed cogeneration......Distributed cogeneration has played a key role in the implementation of sustainable energy policies for three decades. However, increasing penetration levels of intermittent renewables is challenging that position. The paradigmatic case of West Denmark indicates that distributed operators are...... still has to offer. The solution is for distributed operators to adapt their technology and operational strategies to achieve a better co-existence between cogeneration and wind power. Four options for doing so are analysed including a new concept that integrates a high pressure compression heat pump...

  7. Turbulent mixing: the roots of intermittency

    Mixing in fully developed incompressible turbulent flows is known to lead to a cascade of discontinuity fronts of passive scalar fields; these fronts make the tracer fields strongly intermittent and give rise to an anomalous scaling of structure functions. Here, a simple model, essentially a one-dimensional (1D) variant of Baker's map, is developed, which captures the main mechanism responsible for the emergence of the discontinuities. The model is studied both numerically and analytically. In particular, the structure function scaling exponent ζp is derived; for the Kolmogorov turbulence, ζp=2/3 log3(p+1). The analytical findings are consistent with simulations, and explain the results of a series of numerical and experimental studies

  8. Clinical relevance of intermittent tumour blood flow

    One of the goals of translational cancer research is to understand basic 'phenomena' so that tumour response to therapy can be improved. One such phenomenon is intermittent tumour blood flow. The impact of the transient hypoxia that results from decreased tumour blood flow is now beginning to be appreciated in preclinical systems, and also receiving some attention in clinical practise. Thus in this article we review the nature and frequency of microregional blood flow changes in preclinical and clinical tumours and examine the impact of those changes on response to both radiotherapy and chemotherapy. Additionally, the implications of non-constant blood flow for both the growth of the unperturbed tumour and the regrowth of surviving tumour clonogens during and after therapy are examined

  9. Scale Dependence of Spatiotemporal Intermittence of Rain

    Kundu, Prasun K.; Siddani, Ravi K.

    2011-01-01

    It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

  10. Acute Abdominal Pain Secondary to Chilaiditi Syndrome

    Buicko, Jessica L.; Miguel Lopez-Viego; David Kang; Lopez, Michael A.; Pan, Andrew S.

    2013-01-01

    Chilaiditi syndrome is a rare condition occurring in 0.025% to 0.28% of the population. In these patients, the colon is displaced and caught between the liver and the right hemidiaphragm. Patients' symptoms can range from asymptomatic to acute intermittent bowel obstruction. Diagnosis is best achieved with CT imaging. Identification of Chilaiditi syndrome is clinically significant as it can lead to many significant complications such as volvulus, perforation, and bowel obstruction. If the pat...

  11. Intermittent drinking, oxytocin and human health.

    Pruimboom, L; Reheis, D

    2016-07-01

    Looking at a waterhole, it is surprising that so many animals share the same space without visible signs of anxiety or aggression. Although waterholes are the preferred feeding locations of large carnivores, waterholes are shared by all type of herbivores of all sizes and shapes, including elephants. Recent research shows that the homeostatic disturbances leading to the "thirst feeling" not only activate specific substances regulating water and mineral household, but also the "trust and love" hormone oxytocin, while decreasing the production of the typical stress hormone cortisol. People using drugs, seem to be in search for oxytocin, as evidenced in studies with individuals on drugs such as ecstasy and gamma-hydroxybyturate. Hot environment, drought and increased sweating also activate specific oxytocin-producing parts of the hypothalamus, just as breastfeeding does in mother and infant. Water homeostasis is the only allostatic system activating trust neuro-anatomy and we suggest that this is due to the fact that all animals depend on water, whereas food type is species specific. Our hypothesis; regulating drinking behaviour through intermittent bulk drinking could increase oxytocin signalling, recover human trust and increase health by down-regulation of stress axis activity and inflammatory activity of the immune system. Intermittent bulk drinking should be defined as water (including tea and coffee) drinking up to a feeling of satiety and regulated by a mild feeling of thirst. This would mean that people would not drink less quantity but less frequently and that's how all animals, but also human newborns behave. It is the latter group, which is probably the only group of humans with a normal fluid homeostasis. PMID:27241263

  12. Identification of intermittent control in man and machine.

    Loram, Ian D; van de Kamp, Cornelis; Gollee, Henrik; Gawthrop, Peter J

    2012-09-01

    Regulation by negative feedback is fundamental to engineering and biological processes. Biological regulation is usually explained using continuous feedback models from both classical and modern control theory. An alternative control paradigm, intermittent control, has also been suggested as a model for biological control systems, particularly those involving the central nervous system. However, at present, there is no identification method explicitly formulated to distinguish intermittent from continuous control; here, we present such a method. The identification experiment uses a special paired-step set-point sequence. The corresponding data analysis use a conventional ARMA model to relate a theoretically derived equivalent set-point to control signal; the novelty lies in sequentially and iteratively adjusting the timing of the steps of this equivalent set-point to optimize the linear time-invariant fit. The method was verified using realistic simulation data and was found to robustly distinguish not only between continuous and intermittent control but also between event-driven intermittent and clock-driven intermittent control. When applied to human pursuit tracking, event-driven intermittent control was identified, with an intermittent interval of 260-310 ms (n = 6, p < 0.05). This new identification method is applicable for machine and biological applications. PMID:22491973

  13. Mixing and diffusion in intermittent overturning turbulence

    Redondo, Jose M.; Mahjoub, Otman B.; Gonzalez-Nieto, Pilar L.; Lawry, Andrew

    2014-05-01

    The improvements in experimental methods and high resolution image analysis are nowadays able to detect subtle changes in the structure of the turbulence over a wide range of temporal and spatial scales [1], we compare the scaling shown by different mixing fronts driven by buoyancy that form a Rayleigh-Taylor mixing front. We use PIV and density front tracking in several experimental configurations akin to geophysical overturning [2-7]. We parametrize the role of unstable stratification by means of the Atwood number and compare both the scaling and the multifractal and the maximum local fractal structure functions of the different markers used to visualize the front. Both reactive and passive scalar tracers are used to investigate the mixing structure and the intermittency of the flow. Different initial conditions are compared and the mixing efficiency of the overal turbulent process evaluated [6-7]. An interesting approach, relating the Multi-Fractal dimension spectra, the intermittency and the spectral exponent is to find relationships that may be used to parameterise the sub-grid turbulence in terms of generalized diffusivities [4 ] that take into account the topology and the self-similarity of the Mixing RT and RM flows. As an example, a relationship between the diffusivity, the exponent β, the intermittency μ, and D(i), may be found for the volume fraction or the concentration, at the same time other locally measured parameters such as the enstrophy or the gradient alignment as well as their multi-fractal structures may turn out to be physically relevant indicators of the local turbulence and the mixing. Several methods of deriving local eddy diffusivity and local entrainment should give more realistic estimates of the spatial/temporal non-homogeneities (and intermittencies in the Kolmogorov 62 sense obtained as spatial correlations of the turbulent dissipation, or from structure functions) and these values may be used to parameterise turbulence at a variety

  14. Acute Pancreatitis and Pregnancy

    ... Acute Pancreatitis > Acute Pancreatitis and Pregnancy test Acute Pancreatitis and Pregnancy Timothy Gardner, MD Acute pancreatitis is ... of acute pancreatitis in pregnancy. Reasons for Acute Pancreatitis and Pregnancy While acute pancreatitis is responsible for ...

  15. Photoluminescence intermittency of semiconductor quantum dots in dielectric environments

    Isaac, A.

    2006-08-11

    The experimental studies presented in this thesis deal with the photoluminescence intermittency of semiconductor quantum dots in different dielectric environments. Detailed analysis of intermittency statistics from single capped CdSe/ZnS, uncapped CdSe and water dispersed CdSe/ZnS QDs in different matrices provide experimental evidence for the model of photoionization with a charge ejected into the surrounding matrix as the source of PL intermittency phenomenon. We propose a self-trapping model to explain the increase of dark state lifetimes with the dielectric constant of the matrix. (orig.)

  16. Evaluation of continuous and intermittent myocardial topical negative pressure

    Lindstedt, Sandra; Malmsjö, Malin; Gesslein, Bodil;

    2008-01-01

    Topical negative pressure, commonly used in wound therapy, has been shown to increase blood flow and stimulate angiogenesis in subcutaneous tissue and skeletal muscle. In wound therapy, intermittent negative pressure is often preferred to continuous negative pressure as tissue exposed to...... intermittent therapy shows twice as much granulation tissue formation than that exposed to continuous pressure after 2 weeks of therapy. The present study was designed to elucidate the differences in microvascular blood flow in the left anterior descending artery area between continuous and intermittent...... myocardial topical negative pressure of -50 mmHg....

  17. Two-particle description of turbulence, Markov property, and intermittency

    It is shown that the hypothesis of independent increments for velocity, which is widely used by many authors [e.g., A. M. Obukhov, Adv. Geophys. 6, 113 (1959)] in the Lagrangian description of turbulence, is inconsistent with the Navier--Stokes equations in a fundamental way. A more general Lagrangian description of turbulent velocity such as the Markov process with dependent increments, which recognizes the condition of incompressibility and the important phenomenon of intermittency, is proposed. A model of intermittent relative motion of fluid particles in turbulent flow is presented. The high-order Lagrangian moments and the probability distribution are obtained. The distribution for the intermittent vorticity is also proposed

  18. Intermittent Renewable Management Pilot Phase 2

    Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Homan, Gregory [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Anderson, Robert [Olivine, Inc., San Ramon, CA (United States); Hernandez, John [Pacific Gas & Electric Company, San Francisco, CA (United States)

    2015-04-01

    The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with direct participation of third-parties and customers including customer acceptance; market transformation challenges (wholesale market, technology); technical and operational feasibility; and value to the rate payers, DR resource owners and the utility on providing an enabling mechanism for DR resources into the wholesale markets. The customer had the option of committing to either three contiguous hour blocks for 24 days or six contiguous hours for 12 days a month with day-ahead notification that aligned with the CAISO integrated forward market. As a result of their being available, the customer was paid $10/ kilowatt (kW)-month for capacity in addition to CAISO energy settlements. The participants were limited to no more than a 2 megawatt (MW) capacity with a six-month commitment. Four participants successfully engaged in the pilot. In this report, we provide the description of the pilot, participant performance results, costs and value to participants as well as outline some of the issues encountered through the pilot. Results show that participants chose to participate with storage and the value of CAISO settlements were significantly lower than the capacity payments provided by the utility as incentive payments. In addition, this pilot revealed issues both on the participant side and system operations side. These issues are summarized in the report.The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with

  19. Bronchitis - acute

    ... sharing features on this page, please enable JavaScript. Acute bronchitis is swelling and inflammation in the main passages ... present only for a short time. Causes When acute bronchitis occurs, it almost always comes after having a ...

  20. Bronchitis - acute

    Acute bronchitis is swelling and inflammation in the main passages that carry air to the lungs. The swelling narrows ... makes it harder to breathe. Another symptom of bronchitis is a cough. Acute means the symptoms have ...

  1. Acute Bronchitis

    Bronchitis is an inflammation of the bronchial tubes, the airways that carry air to your lungs. It ... chest tightness. There are two main types of bronchitis: acute and chronic. Most cases of acute bronchitis ...

  2. Análise de variáveis fisiológicas de adolescentes com diagnóstico clínico de asma leve intermitente ou leve persistente quando submetidos a hipóxia aguda e teste de esforço máximo Analysis of physiological variables during acute hypoxia and maximal stress test in adolescents clinically diagnosed with mild intermittent or mild persistent asthma

    Martin Maldonado

    2011-12-01

    -sectional study involving 48 adolescents (12-14 years of age who were divided into three groups: mild intermittent asthma (MIA, n = 12; mild persistent asthma (MPA, n = 12; and control (n = 24. All subjects were induced to acute hypoxia and were submitted to maximal stress testing. Anthropometric data were collected, and functional variables were assessed before and after the maximal stress test. During acute hypoxia, the time to a decrease in SpO2 and the time to recovery of SpO2 (at rest were determined. RESULTS: No significant differences were found among the groups regarding the anthropometric variables or regarding the ventilatory variables during the stress test. Significant differences were found in oxygen half-saturation pressure of hemoglobin prior to the test and in PaO2 prior to the test between the MPA and control groups (p = 0.0279 and p = 0.0116, respectively, as was in the oxygen extraction tension prior to the test between the MIA and MPA groups (p = 0.0419. There were no significant differences in terms of the SpO2 times under any of the conditions studied. Oxygen consumption and respiratory efficiency were similar among the groups. The use of a bronchodilator provided no significant benefit during the hypoxia test. No correlations were found between the hypoxia test results and the physiological variables. CONCLUSIONS: Our findings suggest that adolescents with mild persistent asthma have a greater capacity to adapt to hypoxia than do those with other types of asthma.

  3. Acute pancreatitis

    Bo-Guang Fan; Åke Andrén-Sandberg

    2010-01-01

    Background : Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims : The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods : We reviewed the English-language literature (Medline) addressing pancreatitis. Results : Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingest...

  4. Acute pancreatitis

    Bo-Guang Fan; Åke Andrén-Sandberg

    2010-01-01

    Background: Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims: The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods: We reviewed the English-language literature (Medline) addressing pancreatitis. Results: Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion....

  5. Long-range forecasting of intermittent streamflow

    F. F. van Ogtrop

    2011-01-01

    Full Text Available Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a probabilistic statistical model to forecast streamflow 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill.

  6. Defense styles in Intermittent Explosive Disorder.

    Puhalla, Alexander A; McCloskey, Michael S; Brickman, Lauren J; Fauber, Robert; Coccaro, Emil F

    2016-04-30

    The overreliance on immature and/or neurotic defense mechanisms, as opposed to more mature defensive functioning has been linked to several psychiatric disorders. However, to date, the role of defense styles among individuals with Intermittent Explosive Disorder (IED) has not been examined. Given that individuals with IED display difficulties controlling their anger and aggression, one might expect these individuals to exhibit more immature and less mature defense styles. The current study compared participants with IED to a personality disorder (PD) comparison group, as well as to healthy volunteers (HV) on the Defense Style Questionnaire, a self-report measure that assesses the extent to which individuals endorse using mature, immature, and neurotic defense styles. Subjects with IED had significantly higher scores than both comparison groups on immature defense styles and exhibited lower scores on mature defense mechanisms. Hierarchical regression of significant defense style subscales showed that higher levels of acting out and lower levels of sublimation uniquely discriminated participants with IED from the PD and HV comparison groups. PMID:27086223

  7. Optimal Intermittent Reorientation in Insect Navigation

    Peleg, Orit; Mahadevan, Lakshminarayanan; Applied Math Lab Team

    2015-03-01

    The process of navigation is often accompanied by several cognitive demanding activities, such as motor control, locomotion planning, and multi-sensory acquisition and integration. Organisms with limited cognitive resources must therefore multitask and develop optimal schemes to dynamically allocate resources to the different tasks. An extreme example of task alternations during navigation is the hallmark of ball rolling dung beetles. The beetles need to roll their dung-ball along a straight path away from the dung pile where intense competition occurs. Before initiating a roll, dung beetles climb on top of the ball and rotate about their vertical axis. This action serves as an orientation mechanism that allows them to set an initial bearing, and to regain this bearing if they experience an unintentional disturbance along the way. We developed a model inspired by the beetle's navigational scheme, where an agent performs a random walk intermittent by reorientation events, in which its heading direction is corrected. We show that the resultant paths are a characteristic of correlated diffusion in short time scale, and biased diffusion in the long time scale. We identify optimal alternation schemes and characterize their robustness upon introducing noisy sensory acquisition and rough environmental conditions.

  8. Finite dissipation and intermittency in magnetohydrodynamics.

    Mininni, P D; Pouquet, A

    2009-08-01

    We present an analysis of data stemming from numerical simulations of decaying magnetohydrodynamic (MHD) turbulence up to grid resolution of 1536(3) points and up to Taylor Reynolds number of approximately 1200 . The initial conditions are such that the initial velocity and magnetic fields are helical and in equipartition, while their correlation is negligible. Analyzing the data at the peak of dissipation, we show that the dissipation in MHD seems to asymptote to a constant as the Reynolds number increases, thereby strengthening the possibility of fast reconnection events in the solar environment for very large Reynolds numbers. Furthermore, intermittency of MHD flows, as determined by the spectrum of anomalous exponents of structure functions of the velocity and the magnetic field, is stronger than that of fluids, confirming earlier results; however, we also find that there is a measurable difference between the exponents of the velocity and those of the magnetic field, reminiscent of recent solar wind observations. Finally, we discuss the spectral scaling laws that arise in this flow. PMID:19792189

  9. Long-range forecasting of intermittent streamflow

    F. F. van Ogtrop

    2011-11-01

    Full Text Available Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a statistical model to forecast streamflow up to 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 6 and 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill.

  10. Intermittency is a consequence of turbulent transport in nonlinear systems

    Newell, Benno Rumpf Alan C.

    2003-01-01

    Intermittent high-amplitude structures emerge in a damped and driven discrete nonlinear Schroedinger equation whose solutions transport both energy and particles from sources to sinks. These coherent structures are necessary for any solution that has statistically stationary transport properties.

  11. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery

    Rajsrinivas Parthasarathy

    2016-01-01

    Full Text Available Embryonic carotid – basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of the anterior and posterior cerebral arteries in this patient with a persistent left trigeminal artery and 75% stenosis of the left internal carotid artery (ICA. The symptom of intermittent vertigo resolved with carotid endarterectomy. Decreased flow across the stenotic segment of the ICA which subserved the posterior circulation resulted in basilar insufficiency. Hypoperfusion to the flocculonodular lobe supplied by the anterior inferior cerebellar artery is a likely cause for the intermittent vertigo.

  12. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery

    Parthasarathy, Rajsrinivas; Derksen, Carol; Saqqur, Maher; Khan, Khurshid

    2016-01-01

    Embryonic carotid – basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of the anterior and posterior cerebral arteries in this patient with a persistent left trigeminal artery and 75% stenosis of the left internal carotid artery (ICA). The symptom of intermittent vertigo resolved with carotid endarterectomy. Decreased flow across the stenotic segment of the ICA which subserved the posterior circulation resulted in basilar insufficiency. Hypoperfusion to the flocculonodular lobe supplied by the anterior inferior cerebellar artery is a likely cause for the intermittent vertigo. PMID:26933370

  13. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery.

    Parthasarathy, Rajsrinivas; Derksen, Carol; Saqqur, Maher; Khan, Khurshid

    2016-01-01

    Embryonic carotid - basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of the anterior and posterior cerebral arteries in this patient with a persistent left trigeminal artery and 75% stenosis of the left internal carotid artery (ICA). The symptom of intermittent vertigo resolved with carotid endarterectomy. Decreased flow across the stenotic segment of the ICA which subserved the posterior circulation resulted in basilar insufficiency. Hypoperfusion to the flocculonodular lobe supplied by the anterior inferior cerebellar artery is a likely cause for the intermittent vertigo. PMID:26933370

  14. Experimental evidence for directed percolation in spatiotemporal intermittency

    Rupp, Peter; Richter, Reinhard; Rehberg, Ingo

    2002-01-01

    A new experimental system showing a transition to spatiotemporal intermittency is presented. It consists of a ring of hundred oscillating ferrofluidic spikes. The measured critical exponents of the system agree with those obtained from a theoretical model of directed percolation.

  15. Sensing and characterization of EMI during intermittent connector anomalies

    National Aeronautics and Space Administration — This paper presents a new on-line methodology for detecting intermittent disconnection failures. The detection principle operates on the fundamental Lorentz Law...

  16. Intermittent Turbulence in the Very Stable Ekman Layer

    Barnard, James C.

    2001-01-05

    INTERMITTENT TURBULENCE IN THE VERY STABLE EKMAN LAYER This study describes a Direct Numerical Simulation (DNS) of a very stable Ekman layer in which a constant downward heat flux is applied at the lower boundary, thus cooling the fluid above. Numerical experiments were performed in which the strength of the imposed heat flux was varied. For downward heat fluxes above a certain critical value the turbulence becomes intermittent and, as the heat flux increases beyond this value, the flow tends to relaminarize because of the very strong ambient stratification. We adopt Mahrt?s (1999) definition of the very stable boundary layer as a boundary layer in which intermittent, rather than continuous turbulence, is observed. Numerical experiments were used to test various hypothesis of where in ?stability parameter space? the very stable boundary layer is found. These experiments support the findings of Howell and Sun (1999) that the boundary layer will exhibit intermittency and therefore be categorized as ?very stable?, when the stability parameter, z/L, exceeds unity. Another marker for the very stable boundary layer, Derbyshire?s (1990) maximum heat flux criterion, was also examined. Using a case study drawn from the simulations where turbulence intermittency was observed, the mechanism that causes the intermittence was investigated. It was found that patchy turbulence originates from a vigorous inflectional, Ekman-like instability -- a roll cell -- that lifts colder air over warmer air. The resulting convective instability causes an intense burst of turbulence. This turbulence is short-lived because the lifting motion of the roll cell, as well as the roll cell itself, is partially destroyed after the patchy turbulence is generated. Examples of intermittent turbulence obtained from the simulations appear to be consistent with observations of intermittency even though the Reynolds number of the DNS is relatively low (400).

  17. Drift Intermittent Synchronization and Controllability in a Simple Model

    XIE Bai-Song; YU Ming-Young

    2005-01-01

    A simple model of three coupled oscillators as an approximation of main modes behaviors in a spatial extended system is proposed. Multi-looping generalized synchronization and drift intermittent lag phase synchronization phenomena are found in this simple model. For a certain of parameters in which chaotic-like intermittent behavior exhibit the amplitudes and phases of three modes are controlled to be synchronized states via coupling them with an external periodic mode.

  18. The Prismatic Effect on Stereoacuity in Intermittent Exotropia

    Choi, Kyoung Sub; Chung, Seung Ah; Lee, Kyu Sung; Lee, Jong Bok

    2009-01-01

    Purpose To evaluate the effect of acrylic refractive prism and Fresnel membrane prism on stereoacuity in intermittent exotropia. Materials and Methods Stereoacuities of fifty-two patients (mean age, 12.4 years; range 6 to 45 years) with intermittent exotropia were measured using the Titmus and TNO stereotests, while they wore prisms of varying power on nonfixating eye or evenly on each eye. Results Stereoacuities were significantly reduced with increasing prism power for both prisms, ranging ...

  19. Identification of intermittent control in man and machine

    Loram, Ian D.; van de Kamp, Cornelis; Gollee, Henrik; Gawthrop, Peter J.

    2012-01-01

    Regulation by negative feedback is fundamental to engineering and biological processes. Biological regulation is usually explained using continuous feedback models from both classical and modern control theory. An alternative control paradigm, intermittent control, has also been suggested as a model for biological control systems, particularly those involving the central nervous system. However, at present, there is no identification method explicitly formulated to distinguish intermittent fr...

  20. Non-locality and Intermittency in 3D Turbulence

    Laval, J. -P.; B. Dubrulle; Nazarenko, S.(Russian Federal Nuclear Center (VNIIEF), Sarov, Russia)

    2001-01-01

    Numerical simulations are used to determine the influence of the non-local and local interactions on the intermittency corrections in the scaling properties of 3D turbulence. We show that neglect of local interactions leads to an enhanced small-scale energy spectrum and to a significantly larger number of very intense vortices (tornadoes) and stronger intermittency. On the other hand, neglect of the non-local interactions results in even stronger small-scale spectrum but significantly weaker ...

  1. INTERMITTENT CLONAZEPAM IN THE PREVENTION OF RECURRENT FEBRILE SEIZURES

    Touran MAHMOUDIAN; Omid YAGHINI; Shirin BAJOGHLI

    2010-01-01

    ObjectiveTo evaluate the efficacy and common side effects of intermittent clonazepam in febrile  seizures.Materials & MethodsThis study was an experimental trial designed to determine the efficacy of intermittent clonazepam in febrile seizures .Thirty patients with an age range of 6 months to 5 years (60% male, 40% female) were studied. Children with a history of psychomotor delay, abnormal  neurological examination, a history of antiepileptic drug consumption, and afebrile seizures were excl...

  2. Intermittent Reinforcement and the Persistence of Behavior: Experimental Evidence

    Robin M. Hogarth; Villeval, Marie-Claire

    2010-01-01

    Whereas economists have made extensive studies of the impact of levels of incentives on behavior, they have paid little attention to the effects of regularity and frequency of incentives. We contrasted three ways of rewarding participants in a real-effort experiment in which individuals had to decide when to exit the situation : a continuous reinforcement schedule (all periods paid) ; a fixed intermittent reinforcement schedule (one out of three periods paid) ; and a random intermittent reinf...

  3. Intermittency and solitons in the driven dissipative nonlinear Schroedinger equation

    Moon, H. T.; Goldman, M. V.

    1984-01-01

    The cubic nonlinear Schroedinger equation, in the presence of driving and Landau damping, is studied numerically. As the pump intensity is increased, the system exhibits a transition from intermittency to a two-torus to chaos. The laminar phase of the intermittency is also a two-torus motion which corresponds in physical space to two identical solitons of amplitude determined by a power-balance equation.

  4. Decarbonizing electricity generation with intermittent sources of energy

    Ambec, Stefan; Crampes, Claude

    2015-01-01

    We examine the impact of public policies that aim to decarbonate electricity production by replacing fossil fuel energy by intermittent renewable sources, namely wind and solar power. We consider a model of energy investment and production with two sources of energy: one is clean but intermittent (e.g. wind), whereas the other one is reliable but polluting (e.g. coal). A carbon tax decreases electricity production while simultaneously increasing investment in wind power. This tax may however ...

  5. The minimum transition hypothesis for intermittent hierarchical motor control

    Amir eKarniel

    2013-02-01

    Full Text Available In intermittent control, instead of continuously calculating the control signal, the controller occasionally changes this signal at certain sparse points in time. The control law may include feedback, adaptation, optimization, or any other control strategies. When, where, and how does the brain employ intermittency as it controls movement? These are open questions in motor neuroscience. Evidence for intermittency in human motor control has been repeatedly observed in the neural control of movement literature. Moreover, some researchers have provided theoretical models to address intermittency. Even so, the vast majority of current models, and I would dare to say the dogma in most of the current motor neuroscience literature involves continuous control. In this paper, I focus on an area in which intermittent control has not yet been thoroughly considered, the structure of muscle synergies. A synergy in the muscle space is a group of muscles activated together by a single neural command. Under the assumption that the motor control is intermittent, I present the minimum transition hypothesis and its predictions with regards to the structure of muscle synergies. The minimum transitions hypothesis (MTH asserts that the purpose of synergies is to minimize the effort of the higher level in the hierarchy by minimizing the number of transitions in an intermittent control signal. The implications of the MTH are not only for the structure of the muscle synergies but also to the intermittent and hierarchical nature of the motor system, with various predictions as to the process of skill learning, and important implications to the design of brain machine interfaces and human robot interaction.

  6. Regionalization of patterns of flow intermittence from gauging station records

    Snelder, T.H.; Datry, T.; Lamouroux, N.; Larned, S. T.; E. Sauquet; Pella, H.; C. Catalogne

    2013-01-01

    Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times...

  7. Intermittency of quasi-static magnetohydrodynamic turbulence: A wavelet viewpoint

    Intermittency of quasi-static magnetohydrodynamic (MHD) turbulence in an imposed magnetic field is examined, using three-dimensional orthonormal wavelets. The wavelet analysis is applied to two turbulent MHD flows computed by direct numerical simulation with 5123 grid points and with different intensities of the imposed magnetic field. It is found that the imposed magnetic field leads to a substantial amplification of intermittency of the flow, especially in the direction of the imposed magnetic field.

  8. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery

    Rajsrinivas Parthasarathy; Carol Derksen; Maher Saqqur; Khurshid Khan

    2016-01-01

    Embryonic carotid – basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of th...

  9. Liquid fallback and the performance of intermittent gas-lift

    Santos, Odair G.; Alhanati, Francisco J.S.; Bordalo, Sergio N. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Petroleo

    1998-07-01

    The study of liquid fallback in intermittent gas-lift methods shows that the impact of the fallback is misinterpreted in the literature. An explanation of the dynamics of this phenomena is presented as a contribution to a better understanding of the process. The economic analysis of gas-lift plants demonstrates the sensitivity of the performance to the correct evaluation of the effect of the fallback, when ranking the best intermittent methods. (author)

  10. Characteristics of spatiotemporal intermittency in two phase flows

    The characteristics of temporal and spatiotemporal intermittent, or slug flow, in two phase flashing flows are analyzed in the context of intermittency transition to chaos. Particularly, the possibility of occurence of generic intermittency routes (Types I, II and III) is investigated in the presence of density wave instability in the system and conclusive evidence for the occurrence of Types I and III is presented. Particularly important is the prediction of the mean slug length and the slug length distribution since the slug flow represents an unfavorable flow regime for gas-liquid transportation in pipes. Identification of two generic intermittency routes automatically gives a quantitative prediction concerning the length distribution of laminar and turbulent (slug) phases. Spatiotemporal analysis, based on the bi-othogonal decoposition and concepts from information theory, provides quantitative characterization and prediction of slug flows and possible mechanism of transition from spatiotemporal intermittency to spatiotemporal chaos (turbulence) is outlined. The analysis of the intermittency in two-phase flows was performed on the experimental data obtained in the study of natural circulation instabilities during small break loss-of-coolant accident. 7 refs., 14 figs

  11. Modeling of Flow Transition Using an Intermittency Transport Equation

    Suzen, Y. B.; Huang, P. G.

    1999-01-01

    A new transport equation for intermittency factor is proposed to model transitional flows. The intermittent behavior of the transitional flows is incorporated into the computations by modifying the eddy viscosity, mu(sub t), obtainable from a turbulence model, with the intermittency factor, gamma: mu(sub t, sup *) = gamma.mu(sub t). In this paper, Menter's SST model (Menter, 1994) is employed to compute mu(sub t) and other turbulent quantities. The proposed intermittency transport equation can be considered as a blending of two models - Steelant and Dick (1996) and Cho and Chung (1992). The former was proposed for near-wall flows and was designed to reproduce the streamwise variation of the intermittency factor in the transition zone following Dhawan and Narasimha correlation (Dhawan and Narasimha, 1958) and the latter was proposed for free shear flows and was used to provide a realistic cross-stream variation of the intermittency profile. The new model was used to predict the T3 series experiments assembled by Savill (1993a, 1993b) including flows with different freestream turbulence intensities and two pressure-gradient cases. For all test cases good agreements between the computed results and the experimental data are observed.

  12. Acute pancreatitis

    Bo-Guang Fan

    2010-05-01

    Full Text Available Background: Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims: The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods: We reviewed the English-language literature (Medline addressing pancreatitis. Results: Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion. There are a number of important issues regarding clinical highlights in the classification, treatment and prognosis of acute pancreatitis, and treatment options for complications of acute pancreatitis including pancreatic pseudocysts. Conclusions: Multidisciplinary approach should be used for the management of the patient with acute pancreatitis.

  13. Acute pancreatitis

    Bo-Guang Fan

    2010-01-01

    Full Text Available Background : Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims : The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods : We reviewed the English-language literature (Medline addressing pancreatitis. Results : Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion. There are a number of important issues regarding clinical highlights in the classification, treatment and prognosis of acute pancreatitis, and treatment options for complications of acute pancreatitis including pancreatic pseudocysts. Conclusions : Multidisciplinary approach should be used for the management of the patient with acute pancreatitis.

  14. Regionalization of patterns of flow intermittence from gauging station records

    T. H. Snelder

    2013-07-01

    Full Text Available Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero flow in each year of record (FREQ; yr−1, and the total number of zero-flow days in each year of record (DUR; days. These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr−1, and the mean duration of zero-flow periods (mDUR; days. Approximately 20% of stations had recorded at least one zero-flow period in their record. Dissimilarities between pairs of gauges calculated from the annual times series (FREQ and DUR and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used random forest (RF models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35. Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also

  15. Management of intermittent angle closure glaucoma with Nd: yag laser iridotomy as a primary procedure

    To assess the efficacy and complications of Nd: YAG laser iridotomy in patients with intermittent (sub-acute) angle closure glaucoma. Twenty-five eyes of twenty-three patients with periodic (intermittent) angle closure, selected in outpatient department, were kept on pilocarpine until YAG laser iridotomy was performed. After YAG laser iridotomy oral acetazolamide and topical dexamethasone was used to control post laser rise of IOP and inflammation respectively. Patency of iridotomy was confirmed and intra-ocular pressure was measured one hour after the procedure. Immediate complication, if any, was noted. Follow-up was done for six months. Prophylactic laser iridotomy was done in fellow eye with occludable angle. Levene's test for equality of variance and t-test for equality of means were used for statistical analysis. This study revealed a significant difference in IOP before and after YAG laser iridotomy (p = .002). Complete follow-up of 6 months was possible in 25 eyes of 23 subjects. After YAG Laser iridotomy, 21 (84%) eyes showed negative provocative test, intraocular pressure below 19mm Hg without medication and anterior chamber angle no more occludable and were labeled successful. Iridotomy remained patent in 96% of eyes. Iridotomy failed to reduce IOP in 4 (16%) eyes. The complications were minimal and transient. (author)

  16. The Effects of Montmorency Tart Cherry Concentrate Supplementation on Recovery Following Prolonged, Intermittent Exercise.

    Bell, Phillip G; Stevenson, Emma; Davison, Gareth W; Howatson, Glyn

    2016-01-01

    This study investigated Montmorency tart cherry concentrate (MC) supplementation on markers of recovery following prolonged, intermittent sprint activity. Sixteen semi-professional, male soccer players, who had dietary restrictions imposed for the duration of the study, were divided into two equal groups and consumed either MC or placebo (PLA) supplementation for eight consecutive days (30 mL twice per day). On day 5, participants completed an adapted version of the Loughborough Intermittent Shuttle Test (LISTADAPT). Maximal voluntary isometric contraction (MVIC), 20 m Sprint, counter movement jump (CMJ), agility and muscle soreness (DOMS) were assessed at baseline, and 24, 48 and 72 h post-exercise. Measures of inflammation (IL-1-β, IL-6, IL-8, TNF-α, hsCRP), muscle damage (CK) and oxidative stress (LOOH) were analysed at baseline and 1, 3, 5, 24, 48 and 72 h post-exercise. Performance indices (MVIC, CMJ and agility) recovered faster and muscle soreness (DOMS) ratings were lower in the MC group (p < 0.05). Additionally, the acute inflammatory response (IL-6) was attenuated in the MC group. There were no effects for LOOH and CK. These findings suggest MC is efficacious in accelerating recovery following prolonged, repeat sprint activity, such as soccer and rugby, and lends further evidence that polyphenol-rich foods like MC are effective in accelerating recovery following various types of strenuous exercise. PMID:27455316

  17. Intermittency and Topology of Shock Induced Mixing

    Tellez, Jackson; Redondo, Jose M.; Ben Mahjoub, Otman; Malik, Nadeem; Vila, Teresa

    2016-04-01

    The advance of a Rayleigh-Taylor front is described in Linden & Redondo (1991),[1-3] and may be shown to follow a quadratic law in time where the width of the growing region of instability depends on the local mixing efficiency of the different density fluids that accelerate against each other g is the acceleration and A is the Atwood number defined as the diference of densities divided by their sum. This results show the independence of the large amplitude structures on the initial conditions the width of the mixing region depends also on the intermittency of the turbulence. Then dimensional analysis may also depend on the relevant reduced acceleration driven time and the molecular reactive time akin to Damkholer number and the fractal structure of the contact zone [2,4]. Detailed experiments and simulations on RT and RM shock induced fronts analized with respect to structure functions are able to determine which mechanisms are most effective in local mixing which increase the effective fractal dimension, as well as the effect of higher order geometrical parameters, such as the structure functions, in non-homogeneous fluids (Mahjoub et al 1998)[5]. The structure of a Mixing blob shows a relatively sharp head with most of the mixing taking place at the sides due to what seems to be shear instability very similar to the Kelvin-Helmholtz instabilities, but with sideways accelerations. The formation of the blobs and spikes with their secondary instabilities produces a turbulent cascade, evident just after about 1 non-dimensional time unit, from a virtual time origin that takes into account the linear growth phase, as can be seen by the growth of the fractal dimension for different volume fractions. Two-dimensional cuts of the 3D flow also show that vortex flows have closed or spiral streamlines around their core. Examples of such flows can be also seen in the laboratory, for example at the interface of atwo-layer stratified fluid in a tank in which case streamlines

  18. The response of interleukin-6 and soluble interleukin-6 receptor isoforms following intermittent high intensity and continuous moderate intensity cycling

    Leggate, Melanie; Nowell, Mari A.; Jones, Simon A.; Nimmo, Myra A.

    2010-01-01

    As interleukin-6 (IL-6), its soluble receptor (sIL-6R), and the IL-6/sIL-6R complex is transiently elevated in response to prolonged moderate-intensity exercise, this study investigated how these levels would be modulated by an acute bout of high-intensity intermittent (HIIT) exercise in comparison to continuous moderate-intensity exercise (MOD). This study also investigated the expression of the differentially spliced sIL-6R (DS-sIL-6R) in response to exercise. Eleven healthy males completed...

  19. Neuropathic pain in hereditary coproporphyria

    Chen, Guan-Liang; Yang, Deng-Ho; Wu, Jeng-Yuau; Kuo, Chia-Wen; Hsu, Wen-Hsiu

    2013-01-01

    Acute porphyrias are rare diseases with varying incidences worldwide. These diseases are disorders of heme biosynthesis characterized by acute attacks of neurological symptoms. Acute porphyria should be considered in patients with unexplained abdominal pain or neurological damage. Clinical manifestations of acute porphyria are nonspecific and are associated with multiple organ systems. This report examines a rare case of an uncommon type of acute porphyria in a patient with an initial present...

  20. Effects of continuous and intermittent exercise on executive function in children aged 8-10 years.

    Lambrick, Danielle; Stoner, Lee; Grigg, Rebecca; Faulkner, James

    2016-09-01

    Understanding the effects of acute exercise on executive function in prepubescent children may be important for the enhancement of school performance. This study assessed the effect of an acute bout of continuous (CONT) or intermittent (INT), moderate-intensity treadmill exercise on executive function in young children. Twenty healthy children, mean (SD); age: 8.8 (0.8) years; height: 140 (9) cm; weight: 36 (11) kg; boys: n = 9, performed a graded-exercise test to determine maximal oxygen uptake, and two 15-min submaximal bouts of treadmill exercise; protocols were either CONT or INT. During CONT, participants ran at 90% of gas exchange threshold. During INT, participants performed six consecutive 2.5 min blocks of exercise, which were designed to reflect children's typical activity patterns, comprising 45 s at a heavy intensity, 33 s at a moderate intensity, 10 s at a severe intensity, and 62 s at a low intensity. Participants performed the Stroop task before the submaximal exercise bouts and after, at 1-, 15-, and 30-min intervals. Near-infrared spectroscopy (NIRS) measured cerebral perfusion and oxygenation. Regardless of condition, Stroop performance was improved at 1 min after compared to before, 54.9 (9.8) s versus 57.9 (11) s, respectively, p Stroop performance for INT only (49%, p exercise, of either an intermittent or continuous nature, improves executive function in children, and effects are maintained for ≤ 30 min following exercise cessation. Accordingly, it is recommended that children should engage in physical activity during periods of school recess. PMID:27314635

  1. Cardioprotective adaptation of rats to intermittent hypobaric hypoxia is accompanied by the increased association of hexokinase with mitochondria.

    Waskova-Arnostova, Petra; Elsnicova, Barbara; Kasparova, Dita; Hornikova, Daniela; Kolar, Frantisek; Novotny, Jiri; Zurmanova, Jitka

    2015-12-15

    Chronic hypoxia increases the myocardial resistance to acute ischemia-reperfusion injury by affecting the mitochondrial redox balance. Hexokinase (HK) bears a high potential to suppress the excessive formation of reactive oxygen species because of its increased association with mitochondria, thereby inhibiting the membrane permeability transition pore opening and preventing cell death. The purpose of this study was to determine the effect of severe intermittent hypobaric hypoxia (7,000 m, 8 h/day, 5 wk) on the function and colocalization of HK isoforms with mitochondria in the left (LV) and right ventricles of rat myocardium. The real-time RT-PCR, Western blot, enzyme coupled assay, and quantitative immunofluorescence techniques were used. Our results showed significantly elevated expression of HK isoforms (HK1 and HK2) in the hypoxic LV. In addition, intermittent hypoxia increased the total HK activity and the association of HK isoforms with mitochondria in both ventricles. These findings suggest that HK may contribute to the cardioprotective phenotype induced by adaptation to severe intermittent hypobaric hypoxia. PMID:26494452

  2. Intermittent single point machining of brittle materials

    Marsh, E

    1999-12-07

    A series of tests were undertaken to explore diamond tool wear in the intermittent cutting of brittle materials, specifically silicon. The tests were carried out on a plain way No. 3 Moore machine base equipped as a flycutter with a motorized Professional Instruments 4R air bearing spindle. The diamond tools were made by Edge Technologies with known crystal orientation and composition and sharpened with either an abrasive or chemical process, depending on the individual test. The flycutting machine configuration allowed precise control over the angle at which the tool engages the anisotropic silicon workpiece. In contrast, the crystallographic orientation of the silicon workpiece changes continuously during on-axis turning. As a result, it is possible to flycut a workpiece in cutting directions that are known to be easy or hard. All cuts were run in the 100 plane of the silicon, with a slight angle deliberately introduced to ensure that the 100 plane is engaged in ''up-cutting'' which lengthens the tool life. A Kistler 9256 dynamometer was used to measure the cutting forces in order to gain insight into the material removal process and tool wear during testing. The dynamometer provides high bandwidth force measurement with milli-Newton resolution and good thermal stability. After many successive passes over the workpiece, it was observed that the cutting forces grow at a rate that is roughly proportional to the degradation of the workpiece surface finish. The exact relationship between cutting force growth and surface finish degradation was not quantified because of the problems associated with measuring surface finish in situ. However, a series of witness marks were made during testing in an aluminum sample that clearly show the development of wear flats on the tool nose profile as the forces grow and the surface finish worsens. The test results show that workpieces requiring on the order of two miles of track length can be made with low tool

  3. Intermittent attendance at breast cancer screening

    Padraic Fleming

    2013-09-01

    Full Text Available Background. To determine why women skip rounds and factors influencing return of previous non attenders (PNAs to breast screening. Design and methods. Retrospective, quantitative, structured questionnaire posted to 2500 women. First PNAs did not attend their first screening appointment in 2007/2008 but then attended in 2010; First Controls first attended in 2010 without missed previous appointments. Women who attended screening in 2006 or earlier then skipped a round but returned in 2010 were Subsequent PNAs; Subsequent Controls attended all appointments.Results. More First Controls than First PNAs had family history of cancer (72.7% vs 63.2%; P=0.003; breast cancer (31.3% vs 24.8%; P=0.04. More PNAs lived rurally; more First PNAs had 3rd level education (33.2% vs 23.6%; P=0.002 and fewer had private insurance than First Controls (57.7% vs 64.8%; P=0.04. Excellent/good health was reported in First PNAs and First Controls (82.9% vs 83.2%, but fewer Subsequent PNAs than Subsequent Controls (72.7% vs 84.9%; P=0.000. Common considerations at time of missed appointment were had mammogram elsewhere (33% First PNA and postponed to next round (16% First PNA, 18.8% Subsequent PNA. Considerations when returning to screening were similar for First PNAs and Subsequent PNAs: I am older (35.4%, 29.6%, I made sure I remembered (29%, 23.6%, could reschedule (17.6%, 20.6%, illness of more concern (16.5%, 19%. More First PNAs stated my family/friends advised (22.3% vs 15.2% or my GP (12.6% vs 4.6% advised me to attend, heard good things about BreastCheck (28.8% vs 13.6%.Conclusions. Intermittent attenders do not fit socio-demographic patterns of non-attenders; GP recommendation and word of mouth were important in women’s return to screening. Fear and anxiety seem to act as a screening facilitator rather than an inhibitor.

  4. Aerodynamics of intermittent bounds in flying birds

    Tobalske, Bret W.; Hearn, Jason W. D.; Warrick, Douglas R.

    sagittal plane during upstroke of flapping flight, we hypothesize that body lift is produced during flapping phases. Future efforts to model the mechanics of intermittent flight should take into account that flap-bounding birds may support up to 20% of their weight even with their wings fully flexed.

  5. Mathematically modelling and controlling prostate cancer under intermittent hormone therapy

    Yoshito Hirata; Gouhei Tanaka; Nicholas Bruchovsky; Kazuyuki Aihara

    2012-01-01

    In this review,we summarize our recently developed mathematical models that predict the effects of intermittent androgen suppression therapy on prostate cancer (PCa).Although hormone therapy for PCa shows remarkable results at the beginning of treatment,cancer cells frequently acquire the ability to grow without androgens during long-term therapy,resulting in an eventual relapse.To circumvent hormone resistance,intermittent androgen suppression was investigated as an alternative treatment option.However,at the present time,it is not possible to select an optimal schedule of on- and off-treatment cycles for any given patient.In addition,clinical trials have revealed that intermittent androgen suppression is effective for some patients but not for others.To resolve these two problems,we have developed mathematical models for PCa under intermittent androgen suppression.The mathematical models not only explain the mechanisms of intermittent androgen suppression but also provide an optimal treatment schedule for the on- and off-treatment periods.

  6. Entropic-Skins Geometry to Describe Wall Turbulence Intermittency

    Diogo Queiros-Conde

    2015-04-01

    Full Text Available In order to describe the phenomenon of intermittency in wall turbulence and, more particularly, the behaviour of moments  and and intermittency exponents ζP with the order p and distance to the wall, we developed a new geometrical framework called “entropic-skins geometry” based on the notion of scale-entropy which is here applied to an experimental database of boundary layer flows. Each moment has its own spatial multi-scale support Ωp (“skin”. The model assumes the existence of a hierarchy of multi-scale sets Ωp ranged from the “bulk” to the “crest”. The crest noted characterizes the geometrical support where the most intermittent (the highest fluctuations in energy dissipation occur; the bulk is the geometrical support for the whole range of fluctuations. The model assumes then the existence of a dynamical flux through the hierarchy of skins. The specific case where skins display a fractal structure is investigated. Bulk fractal dimension  and crest dimension  are linked by a scale-entropy flux defining a reversibility efficiency  (d is the embedding dimension. The model, initially developed for homogeneous and isotropic turbulent flows, is applied here to wall bounded turbulence where intermittency exponents are measured by extended self-similarity. We obtained for intermittency exponents the analytical expression with γ ≈ 0.36 in agreement with experimental results.

  7. Intermittency on simultaneous observations of riometer at several Antarctic locations

    Ovalle, E. M.; Foppiano, A. J.; Stepanova, M. V.; Weatherwax, A. T.

    2016-03-01

    It is well known that auroral radio wave absorption, as measured by riometers, consists of periods of relative quiescence which are interrupted by short bursts of activity. Such patterns in activity are observed in systems ranging from the stock market to turbulence, i.e. they exhibit intermittency. In the case of the auroral absorption it has also been found that intermittency strongly depends on the magnetic local time, being largest in the night-time sector. This can be interpreted as indicating that the precipitating particles responsible of the absorption exhibit intermittency, especially near the substorm eye, where the level of turbulence increases. Here, we analyse simultaneous observations of riometer absorption at seven Antarctic locations, to determine whether they exhibit intermittency. We determine the Probability Distribution Functions of the fluctuations of riometer absorption for absorption events larger than 0.1 dB, as well as those for the time-intervals between absorption events. Observations are for locations within the austral auroral absorption zone and on the polar cap. It is found that the parameters of a power law used to describe the calculated PDFs are consistent with the formation of coherent structures being more frequent within the auroral zone, as a manifestation of intermittency.

  8. Study on Intermittent Irrigation for Paddy Rice: II. Crop Responses

    2001-01-01

    Effect of intermittent irrigation on the production of paddy rice was studied in a well-puddled paddy field with four treatments and 2 replicates: continuous flooding irrigation (CFI), and intermittent irrigation II-0, II-1 and II-2, in which plants were re-irrigated when the soil water potential fell below 0, -10, and -20 kPa, respectively, at soil depth of about 5 cm. Results showed that the reduction in soil water potential to about -10 or -20 kPa did not significantly affect the number of grains and the percentage of ripened grains. While, a lower crop growth rate (CGR) resulted from a decrease in the net assimilation rate (NAR) during intermittent irrigation II-1 and II-2, and there was also a reduction in the leaf area index (LAI) during intermittent irrigation II-2. Senescence of lower leaves on stems was promoted in treatments II-1 and II-2 at the ripening stage. Early senescence at ripening stage and water stress around midday decreased the rate of photosynthesis in leaves, causing the lower NAR. These physiological responses of the plants were responsible for the reduction in the dry matter production and grain yield in the intermittent irrigation treatments.

  9. Success of Surgical Correction in Constant and Intermittent Exotropias

    Objective: To evaluate the success rate of surgical corrections of constant and intermittent exotropias. Study Design: A case series. Place and Duration of Study: Al-Ibrahim Eye Hospital, Karachi, from July 2011 to December 2012. Methodology: Patients having primary exotropia (deviation 15 - 45 prism diopters [PD]) were included. Patients with either constant exotropia or basic intermittent exotropia underwent unilateral surgery of lateral rectus recession (maximum up to 10 mm) and medial rectus resection (up to 6 mm). Similarly, when patients had intermittent distance exotropia, underwent bilateral lateral rectus recession (maximum up to 10 mm). Final outcome was considered at the end of 2 months at which achievement of A /sup 2/ 10 PD of exotropia was considered as a success. Results: Out of 248 patients, 170 (68.5%) had either constant exotropia or basic intermittent exotropia, while 78 (31.5%) had intermittent distance exotropia. Mean angle of deviation before surgery was 49.23 prism diopters while after surgery, mean angle of deviation was 8.54 prism diopters. Overall success rate was 81.45% (n=202). In case of unilateral lateral rectus recession and medial rectus resection surgery, the success rate was 85.14% while success rate in case of bilateral lateral rectus recession was 65.21% (p=0.001). Conclusion: Unilateral lateral rectus recession and medial rectus resection for surgical correction of exotropia had better surgical success rate as compared to bilateral lateral rectus recession. (author)

  10. Swirl effects on external intermittency in turbulent jets

    Highlights: ► Modelling and Simulation of Intermittent Turbulent Flows. ► Swirl Effects on External Intermittency. ► Gaussian and Non-Gaussian Probability Density Distribution. - Abstract: In this paper we present the modelled results of velocity and mixture fraction intermittency for selected isothermal swirling jet flows using Large Eddy Simulation (LES). The modelled problems considered three different swirl numbers S = 0.3, 0.54 and 0.8 respectively. The probability density functions (pdfs) and intermittency of velocity and mixture fraction are presented. The simulations capture well complex flow features such as centre jet precession, a bluff body stabilised recirculation zone, and swirl induced vortex breakdown and also describe the effects of far field flow as well as scalar distributions. The calculated probability density distributions exhibit changes from a Gaussian to a delta function with increased radial distance from the jet centreline, and also a non-Gaussian shape on the jet centreline near the precession region. The radial variation of the intermittency shows differences between results with increased swirl number, especially inside the downstream swirl-induced recirculation region.

  11. Intermittent synchronization in a network of bursting neurons

    Park, Choongseok; Rubchinsky, Leonid L.

    2011-09-01

    Synchronized oscillations in networks of inhibitory and excitatory coupled bursting neurons are common in a variety of neural systems from central pattern generators to human brain circuits. One example of the latter is the subcortical network of the basal ganglia, formed by excitatory and inhibitory bursters of the subthalamic nucleus and globus pallidus, involved in motor control and affected in Parkinson's disease. Recent experiments have demonstrated the intermittent nature of the phase-locking of neural activity in this network. Here, we explore one potential mechanism to explain the intermittent phase-locking in a network. We simplify the network to obtain a model of two inhibitory coupled elements and explore its dynamics. We used geometric analysis and singular perturbation methods for dynamical systems to reduce the full model to a simpler set of equations. Mathematical analysis was completed using three slow variables with two different time scales. Intermittently, synchronous oscillations are generated by overlapped spiking which crucially depends on the geometry of the slow phase plane and the interplay between slow variables as well as the strength of synapses. Two slow variables are responsible for the generation of activity patterns with overlapped spiking, and the other slower variable enhances the robustness of an irregular and intermittent activity pattern. While the analyzed network and the explored mechanism of intermittent synchrony appear to be quite generic, the results of this analysis can be used to trace particular values of biophysical parameters (synaptic strength and parameters of calcium dynamics), which are known to be impacted in Parkinson's disease.

  12. Scaling the Thrust Production and Energetics of Inviscid Intermittent Swimming

    Akoz, Emre; Moored, Keith

    2015-11-01

    Many fish have adopted an intermittent swimming gait sometimes referred as a burst-and-coast behavior. By using this gait, fish have been estimated at reducing their energetic cost of swimming by about 50%. Lighthill proposed that the skin friction drag of an undulating body can be around 400% greater than a rigidly-held coasting body, which may explain the energetic savings of intermittent swimming. Recent studies have confirmed the increase in skin friction drag over an undulating body, however, the increase is on the order of 20-70%. This more modest gain in skin friction drag is not sufficient to lead to the observed energy savings. Motivated by these observations, we investigate the inviscid mechanisms behind intermittent swimming for parameters typical of biology. We see that there is an energy savings at a fixed swimming speed for intermittent swimming as compared to continuous swimming. Then we consider three questions: What is the nature of the inviscid mechanism that leads to the observed energy savings, how do the forces and energetics of intermittent swimming scale with the swimming parameters, and what are the limitations to the benefit? Supported by the Office of Naval Research under Program Director Dr. Bob Brizzola, MURI grant number N00014-14-1-0533.

  13. Complex economic dynamics: Chaotic saddle, crisis and intermittency

    Complex economic dynamics is studied by a forced oscillator model of business cycles. The technique of numerical modeling is applied to characterize the fundamental properties of complex economic systems which exhibit multiscale and multistability behaviors, as well as coexistence of order and chaos. In particular, we focus on the dynamics and structure of unstable periodic orbits and chaotic saddles within a periodic window of the bifurcation diagram, at the onset of a saddle-node bifurcation and of an attractor merging crisis, and in the chaotic regions associated with type-I intermittency and crisis-induced intermittency, in non-linear economic cycles. Inside a periodic window, chaotic saddles are responsible for the transient motion preceding convergence to a periodic or a chaotic attractor. The links between chaotic saddles, crisis and intermittency in complex economic dynamics are discussed. We show that a chaotic attractor is composed of chaotic saddles and unstable periodic orbits located in the gap regions of chaotic saddles. Non-linear modeling of economic chaotic saddle, crisis and intermittency can improve our understanding of the dynamics of financial intermittency observed in stock market and foreign exchange market. Characterization of the complex dynamics of economic systems is a powerful tool for pattern recognition and forecasting of business and financial cycles, as well as for optimization of management strategy and decision technology

  14. Subacute fulminant hepatic failure with intermittent fever

    Cong-Xin Chen; Bo Liu; Yong Hu; Joyce E. Johnson; Yi-Wei Tang

    2009-01-01

    BACKGROUND:Viral hepatitis B accounts for over 80%of acute hepatic failures in China and the patients die mainly of its complications. A patient with hepatic failure and fever is not uncommon, whereas repeated fever is rare. METHODS:A 32-year-old female was diagnosed with subacute hepatic failure and hepatitis B viral infection because of hyperbilirubinemia, coagulopathy, hepatic encephalopathy, serum anti-HBs-positive without hepatitis B vaccination, and typical intrahepatic pathological features of chronic hepatitis B. Plasma exchange was administered twice and she awoke with hyperbilirubinemia and discontinuous fever. RESULTS:Urethritis was conifrmed and medication-induced fever and/or spontaneous bacterial peritonitis (Gram-negative bacillus infection) was suspected. The patient was treated with antibiotics, steroids and a Chinese herbal medicine, matrine, for three months and she recovered. CONCLUSION:The survival rate of patients with hepatic failure might be improved with comprehensive supporting measures and appropriate, timely management of com-plications.

  15. Congenital Erythropoietic Porphyria (CEP)

    ... and some types of artificial light, such as fluorescent lights (photosensitivity). After exposure to light, the photo-activated ... and some types of artificial light, such as fluorescent lights (photosensitivity). However, they typically do not have the ...

  16. Genetics Home Reference: porphyria

    ... Aug 16;143(4):316. Citation on PubMed Badminton MN, Elder GH. Molecular mechanisms of dominant expression ... SD, Ducamp S, Gouya L, Grandchamp B, Beaumont C, Badminton MN, Elder GH, Holme SA, Anstey AV, Parker ...

  17. Porphyria Cutanea Tarda (PCT)

    ... liver tests are generally abnormal even in PCT patients without Hepatitis C infection. Diagnosis The preferred screening test for ... 2016 Chicago Patient Meeting date: Dec 6, 2015 Patient Education Meeting in Orlando Florida » More upcoming events John ...

  18. Learning about Porphyria

    ... Care Online Health Resources For Health Professionals Competency & Curricular Resources Genetics 101 Genomic Medicine and Health Care ... by a specific abnormality in the heme production process. Heme is a chemical compound that contains iron ...

  19. Intermittency in e+e- and lepton-hadron collisions

    The intermittency data in e+e- and lepton-hadron collisions are reviewed. The power-law behavior of the moments has been established by various e+e- experiments and a μp experiment. The intermittency in the two-dimensional space of rapidity and azimuthal angle is much stronger than in the rapidity space only. The neutrino-nucleus data indicate significant effects from nuclear reinteractions. The LUND parton shower model fits the data better than the matrix element model without special retuning. The relations among the moments of different orders are in good agreement with the predictions by the negative binomial and pure birth distributions. The origin of the intermittency in e+e- and μp collisions is consistent with the self-similar cascade mechanism of jet formation. 11 refs., 7 figs

  20. Horizontal Visibility graphs generated by type-II intermittency

    In this contribution we study the onset of chaos via type-II intermittency within the framework of Horizontal Visibility graph theory. We construct graphs associated to time series generated by an iterated map close to a Neimark–Sacker bifurcation and study, both numerically and analytically, their main topological properties. We find well defined equivalences between the main statistical properties of intermittent series (scaling of laminar trends and Lyapunov exponent) and those of the resulting graphs, and accordingly construct a graph-theoretical description of type-II intermittency. We finally recast this theory into a graph-theoretical renormalization group (RG) framework, and show that the fixed point structure of RG flow diagram separates regular, critical and chaotic dynamics. (paper)

  1. Temporal Intermittency of Energy Dissipation in Magnetohydrodynamic Turbulence

    Zhdankin, Vladimir; Boldyrev, Stanislav

    2015-01-01

    Energy dissipation in magnetohydrodynamic (MHD) turbulence is known to be highly intermittent in space, being concentrated in sheet-like coherent structures. Much less is known about intermittency in time, another fundamental aspect of turbulence which has great importance for observations of solar flares and other space/astrophysical phenomena. In this Letter, we investigate the temporal intermittency of energy dissipation in numerical simulations of MHD turbulence. We consider four-dimensional spatiotemporal structures, "flare events", responsible for a large fraction of the energy dissipation. We find that although the flare events are often highly complex, they exhibit robust power-law distributions and scaling relations. We find that the probability distribution of dissipated energy has a power law index close to -1.75, similar to observations of solar flares, indicating that intense dissipative events dominate the heating of the system. We also discuss the temporal asymmetry of flare events as a signatu...

  2. Multiparticle correlations and intermittency in high energy collisions

    The analysis of the intermittency signal observed in high energy experiments is presented using multiparticle distributions and correlation functions. The effect of the dimensional projection of the multiparticle distributions on one or two-dimensional subspace is discussed. The structure of the multiparticle cumulants is analyzed for the DELPHI e+e- annihilation data. The model of spatiotemporal intermittency is discussed in details and is shown to reproduce qualitatively the dependence of the intermittency strength on the target and projectile nuclei. A 1-dimensional (1D) cellular-automaton and a 1D forest-fire model is studied. On the example of the noncritical 1D Ising model the difficulties of the scaled factorial moment (SFM) method in extracting genuine scaling behaviour is illustrated. All these studies could serve as tools to test the sensibility of the SFM method as used in the analysis of the high energy production. (K.A.) 122 refs.; 38 figs.; 3 tabs

  3. Intermittency in Fractal Fourier Hydrodynamics: Lessons from the Burgers Equation

    Buzzicotti, Michele; Frisch, Uriel; Ray, Samriddhi Sankar

    2016-01-01

    We present theoretical and numerical results for the one-dimensional stochastically forced Burgers equation decimated on a fractal Fourier set of dimension $D$. We investigate the robustness of the energy transfer mechanism and of the small-scale statistical fluctuations by changing $D$. We find that a very small percentage of mode-reduction ($D \\lesssim 1$) is enough to destroy most of the characteristics of the original non-decimated equation. In particular, we observe a suppression of intermittent fluctuations for $D <1$ and a quasi-singular transition from the fully intermittent ($D=1$) to the non-intermittent case for $D \\lesssim 1$. Our results indicate that the existence of strong localized structures (shocks) in the one-dimensional Burgers equation is the result of highly entangled correlations amongst all Fourier modes.

  4. Scenedesmus dimorphus biofilm: Photoefficiency and biomass production under intermittent lighting.

    Toninelli, Andrea Efrem; Wang, Junfeng; Liu, Mingshen; Wu, Hong; Liu, Tianzhong

    2016-01-01

    This study investigated the effect of intermittent lighting on the growth performances of a Scenedesmus dimorphus biofilm. Flashing light effect (FLE) is common in traditional suspended cultures of microalgae; yet, publications about this phenomenon, in the context of biofilm cultivation, are scarce. In this work we demonstrate that, thanks to intermittent illumination, it is possible for attached cultivations to fulfill FLE, improve photoefficiency and productivity as well as providing protection from photoinhibition using much lower flashing light frequencies than those usually required with suspended cultures. Medium frequency intermittent lighting (0.1 Hz) guaranteed excellent light integration resulting in 9.13 g m(-2) d(-1) biomass productivity, which was 8.9% higher than with continuous lighting. Results showed that a light fraction value of 0.5 always improved photoefficiency values as related to continuous light with a 118.8% maximum increase. PMID:27561323

  5. Bladder emptying by intermittent electrical stimulation of the pudendal nerve

    Boggs, Joseph W.; Wenzel, Brian J.; Gustafson, Kenneth J.; Grill, Warren M.

    2006-03-01

    Persons with a suprasacral spinal cord injury cannot empty their bladder voluntarily. Bladder emptying can be restored by intermittent electrical stimulation of the sacral nerve roots (SR) to cause bladder contraction. However, this therapy requires sensory nerve transection to prevent dyssynergic contraction of the external urethral sphincter (EUS). Stimulation of the compound pudendal nerve trunk (PN) activates spinal micturition circuitry, leading to a reflex bladder contraction without a reflex EUS contraction. The present study determined if PN stimulation could produce bladder emptying without nerve transection in cats anesthetized with α-chloralose. With all nerves intact, intermittent PN stimulation emptied the bladder (64 ± 14% of initial volume, n = 37 across six cats) more effectively than either distention-evoked micturition (40 ± 19%, p 0.10), indicating that PN stimulation was not limited by bladder-sphincter dyssynergia. Intermittent PN stimulation holds promise for restoring bladder emptying following spinal injury without requiring nerve transection.

  6. Intermittent Microwave Drying of Wheat (Triticum aestivum L. Seeds

    Yan Li

    2014-02-01

    Full Text Available The purpose of present study was to characterize the intermittent microwave drying of wheat seeds. Results revealed that microwave on time percentage (MOTP and initial moisture content were the main parameters which influenced the intermittent microwave drying rate and the germination capacity of dried seeds. Best intermittent microwave drying (power: 800 W; seed sample weight: 100 g, microwave on time in each cycle: 32 s without significantly decreasing the germination rate was obtained at initial moisture content≤ 20.3% along with 20% MOTP. While, if initial moisture content of seeds was ≤ 16.7%, the seeds can be dried more rapidly using MOTP 30% without affecting germination capacity. The results obtained from this study would provide technical basis to select optimal wheat seed processing and design seed drying equipments.

  7. Environmental heat stress, hyperammonemia and nucleotide metabolism during intermittent exercise

    Mohr, Magni; Rasmussen, Peter; Drust, Barry;

    2006-01-01

    glycogen, CP, ATP and IMP levels were similar across trials. In conclusion, altered levels of "classical peripheral fatiguing agents" does apparently not explain the reduced capacity for performing repeated sprints following intermittent exercise in the heat, whereas the augmented systemic NH3 response may......Abstract  This study investigated the influence of environmental heat stress on ammonia (NH3) accumulation in relation to nucleotide metabolism and fatigue during intermittent exercise. Eight males performed 40 min of intermittent exercise (15 s at 306±22 W alternating with 15 s of unloaded cycling......) followed by five 15 s all-out sprints. Control trials were conducted in a 20°C environment while heat stress trials were performed at an ambient temperature of 40°C. Muscle biopsies and venous blood samples were obtained at rest, after 40 min of exercise and following the maximal sprints. Following...

  8. Intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats.

    Chen, Xiaofei; Zhao, Tong; Huang, Xin; Wu, Liying; Wu, Kuiwu; Fan, Ming; Zhu, Lingling

    2016-05-01

    Increasing studies have shown protective effects of intermittent hypoxia on brain injury and heart ischemia. However, the effect of intermittent hypoxia on blood glucose metabolism, especially in diabetic conditions, is rarely observed. The aim of this study was to investigate whether intermittent hypoxia influences blood glucose metabolism in type 1 diabetic rats. Streptozotocin-induced diabetic adult rats and age-matched control rats were treated with intermittent hypoxia (at an altitude of 3 km, 4 h per day for 3 weeks) or normoxia as control. Fasting blood glucose, body weight, plasma fructosamine, plasma insulin, homeostasis model assessment of insulin resistance (HOMA-IR), pancreas β-cell mass, and hepatic and soleus glycogen were measured. Compared with diabetic rats before treatment, the level of fasting blood glucose in diabetic rats after normoxic treatment was increased (19.88 ± 5.69 mmol/L vs. 14.79 ± 5.84 mmol/L, p  0.05). Meanwhile, fasting blood glucose in diabetic rats after hypoxic treatment was also lower than that in diabetic rats after normoxic treatment (13.14 ± 5.77 mmol/L vs. 19.88 ± 5.69 mmol/L, pintermittent hypoxia was significantly lower than that in diabetic rats receiving normoxia (1.28 ± 0.11 vs. 1.39 ± 0.11, p intermittent hypoxia showed effect on the increase of soleus glycogen but not hepatic glycogen. We conclude that intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats and its regulation on muscular glycogenesis may play a role in the underlying mechanism. PMID:26902078

  9. Intermittent spray cooling: A new technology for controlling surface temperature

    In this work, intermittent spray cooling is proposed as a new technological concept to remove heat fluxes with good performance and introduce the potential use of advanced control techniques in the development of thermal management systems. The objective of this research work is to provide further insight into the physics involved in the heat transfer process triggered by the impact of an intermittent spray, and further investigate the effects of injection system parameters, such as the frequency of injection, pulse duration, initial wall temperature, pressure of injection and impingement distance, on the intermittent cooling system's performance. The results include a brief description of the spray intermittent behavior, an analysis on its thermal response and an evaluation of its performance. The 'duty cycle', defined as the percentage of the cyclic time during which the cooling liquid is injected, is found to be the main parameter enabling a more accurate control of the cooling process. The experiments reported evidence that small duty cycles promote heat removal by phase-change. With larger duty cycles, the effect of reducing the time lag between consecutive injections is a greater interaction between cycles, eventually leading to the formation of a thin liquid film. As the duty cycle evolves toward the continuous spray condition, the cooling system's thermal response improves, but phase-change is mitigated, affecting the system's performance. Intermittent spray cooling is also compared with continuous spray cooling experiments and liquid savings has been estimated by 10-90% for the same energetic efficiencies reported in the literature. Finally, general guidelines are outlined for the design of thermal management systems based on intermittent spray cooling

  10. Risk Quantification Associated with Wind Energy Intermittency in California

    George, Sam O; Nguyen, Scott V

    2010-01-01

    As compared to load demand, frequent wind energy intermittencies produce large short-term (sub 1-hr to 3-hr) deficits (and surpluses) in the energy supply. These intermittent deficits pose systemic and structural risks that will likely lead to energy deficits that have significant reliability implications for energy system operators and consumers. This work provides a toolset to help policy makers quantify these first-order risks. The thinking methodology / framework shows that increasing wind energy penetration significantly increases the risk of loss in California. In addition, the work presents holistic risk tables as a general innovation to help decision makers quickly grasp the full impact of risk.

  11. Challenges to Cabin Humidity Removal Presented by Intermittent Condensing Conditions

    vonJouanne, Roger G.; Williams, David E.

    2007-01-01

    On-orbit temperature and humidity control (THC) is more easily accomplished when the THC hardware is either consistently dry (i.e., no humidity control is occurring), or consistently wet. The system is especially challenged when intermittent wet/dry conditions occur. The first six years of on-orbit ISS operations have revealed specific concerns within the THC system, specifically in the condensing heat exchanger and the downstream air/water separator. Failed or degraded hardware has been returned to ground and investigated. This paper presents the investigation findings, and the recommended hardware and procedural revisions to prevent and recover from the effects of intermittent condensing conditions.

  12. Influence of beetroot juice supplementation on intermittent exercise performance

    Wylie, Lee J.; Bailey, Stephen J.; Kelly, James; Blackwell, James R.; Vanhatalo, Anni; Andrew M. Jones

    2015-01-01

    Purpose This study tested the hypothesis that nitrate (NO3 −) supplementation would improve performance during high-intensity intermittent exercise featuring different work and recovery intervals. Method Ten male team-sport players completed high-intensity intermittent cycling tests during separate 5-day supplementation periods with NO3 −-rich beetroot juice (BR; 8.2 mmol NO3 − day−1) and NO3 −-depleted beetroot juice (PL; 0.08 mmol NO3 − day−1). Subjects completed: twenty-four 6-s all-out sp...

  13. Intermittent characteristics in coupling between turbulence and zonal flows

    An extended application of Gabour's wavelet to bicoherence analysis succeeds in resolving the instantaneous structure of three wave couplings between disparate scale electric field fluctuations in the high temperature core in a toroidal plasma device named the compact helical system. The obtained results quantify an intermittent linkage between turbulence and zonal flows-a highlighted issue in the present plasma research. This is the first demonstration that the intermittent nature of the three wave coupling should underlie the turbulence power modulation due to zonal flows

  14. Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults.

    Cherif, Anissa; Roelands, Bart; Meeusen, Romain; Chamari, Karim

    2016-01-01

    The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits. PMID:26438184

  15. Study of drying of small diameter Larch lumbers with intermittent heating

    GUO Ming-hui; ZHAO Xi-ping

    2006-01-01

    Intermittent heating for drying of small diameter Larch lumbers is investigated experimentally. The lumbers were dried using an experimental drying schedule. Moisture content (MC) of the lumber was continuously recorded and final drying defects were examined. The drying curves showed that the drying rate was a constant in the early stage of intermittent heating drying and decreased evidently when the MC was about 18% ( intermittent 2h) and 20% (intermittent 6h). The drying quality reached the second (intermittent 2h) and first grade (intermittent 6h) of the Chinese National Standard. The visual drying defects, especially the check extent along grains were reduced with intermittent heating. When the intermittent time increased, the effect was more obvious.

  16. Radial evolution of intermittency of density fluctuations in the fast solar wind

    Bruno, R; Primavera, L; Pietropaolo, E; D'Amicis, R; Sorriso-Valvo, L; Carbone, V; Malara, F; Veltri, P

    2014-01-01

    We study the radial evolution of intermittency of density fluctuations in the fast solar wind. The study is performed analyzing the plasma density measurements provided by Helios 2 in the inner heliosphere between $0.3$ and $0.9$ AU. The analysis is carried out by means of a complete set of diagnostic tools, including the flatness factor at different time scales to estimate intermittency, the Kolmogorov-Smirnov test to estimate the degree of intermittency, and the Fourier transform to estimate the power spectral densities of these fluctuations. Density fluctuations within fast wind are rather intermittent and their level of intermittency, together with the amplitude of intermittent events, decreases with distance from the Sun, at odds with intermittency of both magnetic field and all the other plasma parameters. Furthermore, the intermittent events are strongly correlated, exhibiting temporal clustering. This indicates that the mechanism underlying their generation departs from a time-varying Poisson process....

  17. Impacts of Urbanization and Intermittent Flow on Macroinvertebrates in Headwater Stream

    Recent Supreme Court cases have brought increased attention to the contribution of intermittent waters to the health of downstream ecosystems. However, there is still limited knowledge on what factors are shaping these frequently disturbed intermittent stream communities. The obj...

  18. Intermittent versus continuous administration of growth hormone treatment.

    Hakeem, V; Hindmarsh, P. C.; Brook, C G

    1993-01-01

    Growth hormone treatment given by daily injection was compared with growth hormone given for three weeks of every four. All children had received recombinant human growth hormone for two years before randomisation. Growth velocity decreased in both groups in years one and two of the study but the effect was significantly greater in the group receiving intermittent growth hormone.

  19. INTERMITTENT CLONAZEPAM IN THE PREVENTION OF RECURRENT FEBRILE SEIZURES

    Touran MAHMOUDIAN

    2010-10-01

    Full Text Available ObjectiveTo evaluate the efficacy and common side effects of intermittent clonazepam in febrile  seizures.Materials & MethodsThis study was an experimental trial designed to determine the efficacy of intermittent clonazepam in febrile seizures .Thirty patients with an age range of 6 months to 5 years (60% male, 40% female were studied. Children with a history of psychomotor delay, abnormal  neurological examination, a history of antiepileptic drug consumption, and afebrile seizures were excluded from the study. Patients received a single dose of prophylactic Clonazepam (0.05 mg/kg/ day on the first day of febrile illness and twice daily during the course of fever.An antipyretic medication (Acetaminophen was advised if fever exceeded 38oC. Patients were followed up for one year after the study inclusion date.ResultsThree patients were excluded from study since they didnot follow the tritment and three patients experienced afebrile seizures. Twenty four patients had 162 febrile episodes during the course of the study and all patients were seizure-free after 1 year.ConclusionClonazepam was 100% effective but lethargy and ataxia were common side effects in patients. Fortunately, their parents continued treatment because they had prior awareness of the  possible side effects of clonazepam. Clonazepam is efficacious as an intermittent therapy for febrile seizures if parents are informed of its side effects.Keywords: recurrent febrile seizures, clonazepam, intermittent prophylaxis

  20. Serum bilirubin kinetics in intermittent phototherapy of physiological jaundice.

    Lau, S. P.; Fung, K P

    1984-01-01

    Thirty four term babies with physiological jaundice were subjected to continuous phototherapy and to two regimens of intermittent phototherapy. The difference in serum bilirubin kinetics between the three groups of treated babies was insignificant; a schedule of one in four hours of irradiation achieved the same treatment effect as continuous phototherapy.

  1. Intermittent Versus Continuous Phototherapy for Reducing Neonatal Hyperbilirubinemia

    Nikoo Niknafs

    2008-09-01

    Full Text Available Objective: Clinical studies comparing intermittent versus continuous phototherapy for reducing neonatal hyperbilirubinemia have produced conflicting results. This study was conducted to compare the efficacy of intermittent with continuous phototherapy. Methods: This study was performed on 114 neonates with indirect hyperbilirubinemia. Inclusion criteria were body weight above 2000 grams, absence of other concomitant diseases, and hyperbilirubinemia neither requiring intensive phototherapy nor exceeding the range of exchange transfusion. The neonates were randomly divided into two groups. Continuous phototherapy group received phototherapy on and off for 2 hours and half an hour respectively and the intermittent phototherapy group on and off for one hour. The phototherapy units were identical and serum total bilirubin levels were measured every 12 hours after starting phototherapy. Findings: Two groups were matched regarding weight and risk factors such as ABO and Rh incompatibility. The difference of total serum bilirubin levels between two groups was insignificant at the start of phototherapy and also after 12, 24, 36 and 48 hours (P>0.2.Conclusion: Intermittent phototherapy defined as one hour on and one hour off is as effective as continuous phototherapy defined as 2 hours on and half an hour off, in reducing total serum bilirubin level in full term babies.

  2. Critical exponents of directed percolation measured in spatiotemporal intermittency

    Rupp, Peter; Richter, Reinhard; Rehberg, Ingo

    2002-01-01

    A new experimental system showing a transition to spatiotemporal intermittency is presented. It consists of a ring of hundred oscillating ferrofluidic spikes. Four of five of the measured critical exponents of the system agree with those obtained from a theoretical model of directed percolation.

  3. Why and how to normalize the factorial moments of intermittency

    The normalization of factorial moments of intermittency, which is often the subject of controverses, is justified and (re-)derived from the general assumption of multi-Poissonian statistical noise in the production of particles at high-energy. Correction factors for the horizontal vs. Vertical analyses are derived in general cases, including the factorial multi-bin correlation moments

  4. Intermittency in multihadron production: An analysis using stochastic theories

    Multiplicity data of the NA22, KLM, and UA1 collaborations are analysed by means of probability distributions derived in the framework of pure birth stochastic equations. The intermittent behaviour of the KLM and UA1 data is well reproduced by the theory. A comparison with the negative binomial distribution is also made. 19 refs., 3 figs., 1 tab. (Authors)

  5. Intermittent breeding as a cost of site fidelity

    Bruinzeel, Louis

    2007-01-01

    Intermittent breeding (skipping a breeding season) can be the result of an adaptive decision by a focal individual, trading current reproductive success in favour of future reproductive success (residual reproductive value hypothesis). In contrast, an individual can also be forced by conspecifics to

  6. Drug therapy for improving walking distance in intermittent claudication

    Momsen, Anne-Mette; Jensen, M B; Norager, C B;

    2009-01-01

    To evaluate the efficacy of pharmacological interventions in improving walking capacity and health-related quality of life for people with intermittent claudication. DATASOURCES: We searched Medline, EMBASE, Cochrane library and relevant websites for studies published from the start of the...

  7. Two-scale analysis of intermittency in fully developed turbulence

    Badii, R.; Talkner, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    A self-affinity test for turbulent time series is applied to experimental data for the estimation of intermittency exponents. The method employs exact relations satisfied by joint expectations of observables computed across two different length scales. One of these constitutes a verification tool for the existence and the extent of the inertial range. (author) 2 figs., 13 refs.

  8. Optimizing supervised exercise therapy for patients with intermittent claudication

    Nicolaï, Saskia P A; Hendriks, Erik J M; Prins, Martin H; Teijink, Joep A W; van Asselt, Thea

    2010-01-01

    BACKGROUND: The first-line intervention for intermittent claudication is usually supervised exercise therapy (SET). The literature describes a range of exercise programs varying in setting, duration, and content. The purpose of the present study was to examine the exercise protocols offered and to i

  9. Chronic Salmonella eimsbuettel septicaemia presenting with intermittent sweats and haematuria.

    Lowes, J A; Clark, A J; Britten, K. E.

    1980-01-01

    An unusual presentation is reported of salmonellosis, frank haematuria and chronic septicaemia arising during an outbreak of food poisoning caused by Salmonella eimsbuettel. The patient whose gut was colonized gave a history of chronic pyrexia and weight loss and suffered an intermittent urinary infection but had no gastroenteritis.

  10. Giant urethral stone in a patient using clean intermittant catheterization

    Abdullah Gedik

    2011-06-01

    Full Text Available Urethral stone is a rare entity in clinical practice. Primary urethral stone happening directly in urethra is even rare, and it usually occurs as a result frequent urinary infection, urethral stricture and trauma.While the application of clear intermittant catheterization reliably protects bladder function, in long term use, it may cause various complications.In this case, we discussed giant urethral stone in a patient who has been acting clean intermittent catheterization regularly and without problem fort he last five years and who has had total loss of sensation in this lower extremity as a result of falling from height. Considering that the urethral calibration, in the patient acting clean intermittent catheterization is interesting, the giant urethra stone as much as examined such a case has not been presented in literature.In the patient acting clean intermittent catheterization and having loss of urethral sensation and with neurogenic bladder, we call attention to urethral pathologies the symptoms of which were seeing late

  11. Teaching Intermittent Self-Catheterization Skills to Mentally Retarded Children.

    Tarnowski, Kenneth J.; Drabman, Ronald S.

    1987-01-01

    In an A-B design with replication, the efficacy of a behavioral training program for teaching two mildly retarded six-year-old children intermittent self-catheterization skills was demonstrated. Component skills were task-analyzed and trained via a graduated prompting procedure. (Author/DB)

  12. Reliability, Availability, and Maintainability of Intermittently-usedRepairable Systems

    P.S. Rajpal

    2007-03-01

    Full Text Available A composite measure comprising linear combination of reliability, availability, andmaintainability (CMRAM is proposed for an intermittently-used complex repairable system,namely a transport helicopter. The failure data are fitted in Weibull distribution for overlappingintervals of operating time to capture the effect of recent maintenance and other actions. Evaluationof CMRAM is helpful in formulating future operational and maintenance strategies.

  13. Reliability, Availability, and Maintainability of Intermittently-usedRepairable Systems

    P.S. Rajpal; K.S. Shishodia; G.S. Sekhon

    2007-01-01

    A composite measure comprising linear combination of reliability, availability, andmaintainability (CMRAM) is proposed for an intermittently-used complex repairable system,namely a transport helicopter. The failure data are fitted in Weibull distribution for overlappingintervals of operating time to capture the effect of recent maintenance and other actions. Evaluationof CMRAM is helpful in formulating future operational and maintenance strategies.

  14. Transition to turbulence, intermittence, and fluctuation in vortices

    This paper shows that the mechanism of coalescence of the vortices is decisive in turbulent flows with moderately large Reynolds numbers irrespective of the number of dimensions. A comparison of the calculations of this study with experimental data shows that the flows remain transitional (intermittent) up to very large values of the Reynolds number

  15. Intermittent activity of radio sources. Accretion instabilities and jet precession

    Kunert-Bajraszewska, M.; Janiuk, A.; Siemiginowska, A.; Gawronski, M.

    2010-01-01

    We consider the radiation pressure instability operating on short timescales 10^3 - 10^6 years in the accretion disk around a supermassive black hole as the origin of the intermittent activity of radio sources. We test whether this instability can be responsible for short ages (

  16. Intermittency and multifractional Brownian character of geomagnetic time series

    G. Consolini

    2013-07-01

    Full Text Available The Earth's magnetosphere exhibits a complex behavior in response to the solar wind conditions. This behavior, which is described in terms of mutifractional Brownian motions, could be the consequence of the occurrence of dynamical phase transitions. On the other hand, it has been shown that the dynamics of the geomagnetic signals is also characterized by intermittency at the smallest temporal scales. Here, we focus on the existence of a possible relationship in the geomagnetic time series between the multifractional Brownian motion character and the occurrence of intermittency. In detail, we investigate the multifractional nature of two long time series of the horizontal intensity of the Earth's magnetic field as measured at L'Aquila Geomagnetic Observatory during two years (2001 and 2008, which correspond to different conditions of solar activity. We propose a possible double origin of the intermittent character of the small-scale magnetic field fluctuations, which is related to both the multifractional nature of the geomagnetic field and the intermittent character of the disturbance level. Our results suggest a more complex nature of the geomagnetic response to solar wind changes than previously thought.

  17. From quantum fields to fractal structures: intermittency in particle physics

    Some features and theoretical interpretations of the intermittency phenomenon observed in high-energy multi-particle production are recalled. One develops on the various connections found with fractal structuration of fluctuations in turbulence, spin-glass physics and aggregation phenomena described by the non-linear Smoluchowski equation. This may lead to a new approach to quantum field properties

  18. Muscle Fatigue during Intermittent Exercise in Individuals with Mental Retardation

    Zafeiridis, Andreas; Giagazoglou, Paraskevi; Dipla, Konstantina; Salonikidis, Konstantinos; Karra, Chrisanthi; Kellis, Eleftherios

    2010-01-01

    This study examined fatigue profile during intermittent exercise in 10 men with mild to moderate mental retardation (MR) and 10 men without mental retardation (C). They performed 4 x 30 s maximal knee extensions and flexions with 1-min rest on an isokinetic dynamometer. Peak torque of flexors (PTFL) and extensors (PTEX), total work (TW), and…

  19. Acute pancreatitis

    ... page: //medlineplus.gov/ency/article/000287.htm Acute pancreatitis To use the sharing features on this page, ... fatty foods after the attack has improved. Outlook (Prognosis) Most cases go away in a week. However, ...

  20. Acute Pericarditis

    ... Sugar Control Helps Fight Diabetic Eye Disease Are 'Workaholics' Prone to OCD, Anxiety? ALL NEWS > Resources First ... cancer, or heart surgery, the fluid is blood. Causes Acute pericarditis usually results from infection or other ...

  1. Acute Abdominal Pain Secondary to Chilaiditi Syndrome

    Pan, Andrew S.; Lopez, Michael A.; Buicko, Jessica L.; Lopez-Viego, Miguel

    2013-01-01

    Chilaiditi syndrome is a rare condition occurring in 0.025% to 0.28% of the population. In these patients, the colon is displaced and caught between the liver and the right hemidiaphragm. Patients' symptoms can range from asymptomatic to acute intermittent bowel obstruction. Diagnosis is best achieved with CT imaging. Identification of Chilaiditi syndrome is clinically significant as it can lead to many significant complications such as volvulus, perforation, and bowel obstruction. If the patient is symptomatic, treatment is usually conservative. Surgery is rarely indicated with indications including ischemia and failure of resolution with conservative management. PMID:23936720

  2. Acute Abdominal Pain Secondary to Chilaiditi Syndrome

    David Kang

    2013-01-01

    Full Text Available Chilaiditi syndrome is a rare condition occurring in 0.025% to 0.28% of the population. In these patients, the colon is displaced and caught between the liver and the right hemidiaphragm. Patients' symptoms can range from asymptomatic to acute intermittent bowel obstruction. Diagnosis is best achieved with CT imaging. Identification of Chilaiditi syndrome is clinically significant as it can lead to many significant complications such as volvulus, perforation, and bowel obstruction. If the patient is symptomatic, treatment is usually conservative. Surgery is rarely indicated with indications including ischemia and failure of resolution with conservative management.

  3. DEMAND CATEGORISATION, FORECASTING, AND INVENTORY CONTROL FOR INTERMITTENT DEMAND ITEMS

    E. Babiloni

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: It is commonly assumed that intermittent demand appears randomly, with many periods without demand; but that when it does appear, it tends to be higher than unit size. Basic and well-known forecasting techniques and stock policies perform very poorly with intermittent demand, making new approaches necessary. To select the appropriate inventory management policy, it is important to understand the demand pattern for the items, especially when demand is intermittent. The use of a forecasting method designed for an intermittent demand pattern, such as Croston’s method, is required instead of a simpler and more common approach such as exponential smoothing. The starting point is to establish taxonomic rules to select efficiently the most appropriate forecasting and stock control policy to cope with thousands of items found in real environments. This paper contributes to the state of the art in: (i categorisation of the demand pattern; (ii methods to forecast intermittent demand; and (iii stock control methods for items with intermittent demand patterns. The paper first presents a structured literature review to introduce managers to the theoretical research about how to deal with intermittent demand items in both forecasting and stock control methods, and then it points out some research gaps for future development for the three topics.

    AFRIKAANSE OPSOMMING: Daar word algemeen aanvaar dat intermitterende vraag op toevalswyse voorkom, met verskeie periodes waar daar geen vraag is nie. Wanneer die vraag dan wel materialiseer, oorskry dit dikwels die eenheidsgrootte. Die bekende vooruitskattingstegnieke en voorraadbeleidstellings het min sukses waar intermitterende vraag voorkom, sodat nuwe benaderings nodig is om die problem aan te spreek. Om ‘n geskikte voorraadbestuur-beleid te selekteer, is dit noodsaaklik om die vraagpatroon van die items te verstaan, juis in gevalle van intermitterende patrone. Die gebruik van

  4. Randomized double-blind placebo-controlled crossover study of caffeine in patients with intermittent claudication

    Momsen, A H; Jensen, M B; Norager, C B;

    2010-01-01

    Intermittent claudication is a disabling symptom of peripheral arterial disease for which few medical treatments are available. This study investigated the effect of caffeine on physical capacity in patients with intermittent claudication.......Intermittent claudication is a disabling symptom of peripheral arterial disease for which few medical treatments are available. This study investigated the effect of caffeine on physical capacity in patients with intermittent claudication....

  5. Porfiria eritropoética congénita em bovino no estado de Minas Gerais Bovine congenital erythropoietic porphyria in the state of Minas Gerais, Brazil

    Mary Suzan Varaschin

    1998-12-01

    Full Text Available Relata-se um caso de porfiria eritropoética congênita em um bovino Holandês Preto e Branco, fêmea, de 9 meses de idade, proveniente da cidade de Machado, MG. O quadro clínico caracterizava-se pela presença de lesões crônicas de fotossensibilizaçâo observadas nas partes não pigmentadas do corpo, que apareceram após a exposição do animal à luz solar, aos 4 meses de idade. Além da fotossensibilizaçâo, as alterações macroscópicas mais evidentes foram coloração marrom-avermelhada dos ossos e marrom-rosada dos dentes, causadas pela deposição de porfirina.A case of bovine congenital erythropoietic porphyria in a 9-month-old Holstein female, from Machado, Minas Gerais, Brazil is described. The calf showed chronic cutaneous photosensitization, limited to white-haired areas, when exposed to sun-light. Reddish-brown discoloration of bones and brownish-pink discoloration of teeth, caused by deposition of porphyrin, were observed.

  6. Characterizing spatial and temporal patterns of intermittent rivers

    de Vries, Stefan B.; Hoeve, Jasper; Sauquet, Eric; Leigh, Catherine; Bonada, Núria; Fike, Kimberly; Dahm, Clifford; Booij, Martijn J.; Datry, Thibault

    2015-04-01

    Intermittent rivers (IRs) support high biodiversity due to their dynamic alternations between terrestrial and aquatic phases. They represent a large proportion of the river network. However the current knowledge on these ecosystems is limited. The international research project "Intermittent River Biodiversity Analysis and Synthesis" (IRBAS, www.irbas.fr) aims to collect and analyze data on IR biodiversity from France, Spain, North America and Australia. These activities ultimately should help in identifying relationships between flow regime components and ecological responses. The IRBAS project will provide guidelines for policy-makers and resource managers for effective water and habitat management, restoration and preservation. This work examines one of the aspects in the IRBAS project: studying the large-scale spatial distribution of IRs as well as the year-to-year variability of zero-flow events. IRs were described by two variables: the frequency of periods without flow (FREQ) per time period (months or years) and the total number of zero-flow days (DUR) in a specified time window (month or year). Daily discharge data from more than 1700 gauging stations with no significant human influence on flow were collected from France, Spain, Australia and conterminous United States. A minimum length of 30 years of data starting from 1970 was required with less than 5% of missing data. Climate data for France and Australia were also collected. A classification of perennial versus intermittent rivers was defined, with 455 stations out of the 1684 considered "intermittent", i.e. the gauging station records had, on average, at least 5 zero-flow days per year. The analysis of the subset of IRs showed that: - Greater than 50% of the IRs in the database is located in Australia, where only 35% of the stations are considered perennial. In Spain the proportion of IRs reaches 25%. The proportion of intermittent rivers in France (7%) is certainly underestimated as a consequence of

  7. Acute dyspnea

    Radiodiagnosis is applied to determine the causes of acute dyspnea. Acute dyspnea is shown to aggravate the course of pulmonary diseases (bronchial asthma, obstructive bronchitis, pulmonary edema, throboembolism of pulmonary arteries etc) and cardiovascular diseases (desiseas of myocardium). The main tasks of radiodiagnosis are to determine volume and state of the lungs, localization and type of pulmonary injuries, to verify heart disease and to reveal concomitant complications

  8. Bronchitis (acute)

    Wark, Peter

    2008-01-01

    Acute bronchitis, with transient inflammation of the trachea and major bronchi, affects over 40/1000 adults a year in the UK. The causes are usually considered to be infective, but only around half of people have identifiable pathogens.The role of smoking or environmental tobacco smoke inhalation in predisposing to acute bronchitis is unclear.A third of people may have longer-term symptoms or recurrence.

  9. Demographics and frequency of the intermittently upturned omentum at CT

    Objectives: To describe the demographics and frequency of the intermittently upturned omentum at CT. Methods: We retrospectively reviewed abdominal CT scans of 336 consecutive patients (189 men and 147 women) who were imaged between June 1 and June 17, 2010 and who had prior comparison scans. Readers recorded the presence or absence of an intermittently upturned omentum, defined as a thick rind of fat interposed between the liver and the anterior abdominal wall seen on one but not the other scan. At chart review, we recorded patient demographics and other clinical characteristics (prior surgical history, presence of cirrhosis). Results: An intermittently upturned omentum was found in 10 of 336 (3.0%) patients. An intermittently upturned omentum was seen more commonly in men than in women (9 of 189 men, or 4.8% versus 1 of 147 women, or 0.7%, p = 0.047) and in cirrhotics (4 of 37 cirrhotics, or 10.8% versus 6 of 299 non-cirrhotics, or 2.0%, p = 0.023). In a sub-analysis of patients without prior abdominal surgery, this finding was again seen more commonly in men than women (7 of 163 men, or 4.3% versus 0 of 134 women, or 0%, p = 0.018) and in cirrhotics (3 of 33 cirrhotics, or 9.1% versus 4 of 264 non-cirrhotics, or 1.5%, p = 0.032). Conclusions: An intermittently upturned omentum is not uncommon and is more frequently seen in men and in patients with cirrhosis who may have a larger anterior hepatic space

  10. The influence of continuous and intermittent traffic noise on sleep

    Eberhardt, J. L.; Stråle, L.-O.; Berlin, M. H.

    1987-08-01

    The effects of road traffic noise on sleep were studied in the laboratory using nine young male adults (aged 20-26). The subjects were exposed to noise with different temporal characteristics: (i) continuous traffic noise of 36 dB(A) or 45 dB(A), (ii) intermittent noise of 50 truck passages with L pmax = 45 dB(A) ( L eq = 29 dB(A)) or L pmax = 55 dB(A) ( L eq = 36 dB(A)), and (iii) a combination of continuous (45 dB(A)) and intermittent ( L pmax = 55 dB(A)) traffic noise. For one noise condition (intermittent 55 dB(A)) the effect of the use of ear plugs was also studied. The intermittent noise of L pmax = 45 dB(A) caused transitions towards lighter sleep, whereas 55 dB(A) was needed to induce awakening effects. It could be shown that the probability for arousal reactions depends on the emergence of the noise peaks from the background, rather than the absolute noise peak level. Continuous traffic noise of 45 dB(A) caused REM sleep deficits, while intermittent traffic noise of L pmax = 45 dB(A) caused stage III+IV deficits. The night with ear plugs was virtually undisturbed. After nights with REM sleep deficits the subjective sleep quality was rated lower and mood was influenced adversely. For the types of exposure used in the present investigation L eq alone is not an adequate descriptor of the noise dose, relating to the sleep disturbances observed. From the present experiment, together with other existing data, it might be concluded that the WHO recommendation of L eq = 35 dB(A) is adequate, but should be supplemented with a maximum noise level, as expressed for example in L pmax or LI, that should not be exceeded.

  11. [Acute oliguric renal failure and haemolytic anaemia following infectious mononucleosis].

    Brkovic, Natasa; Jørgensen, Kit Riegels; Rosenbæk, Jeppe Bakkestrøm; Pedersen, Erling Bjerregaard

    2015-11-01

    A 19-year-old man was admitted to hospital due to fatigue, nausea, abdominal pain and faint. He was pale and icteric, awake with sufficient respiration and circulation. He had infectious mononucleosis complicated with acute oliguric renal failure and severe haemolytic anaemia with a positive Coombs test. He had a cold agglutinin syndrome. The treatment comprised intermittent haemodialysis, plasmapheresis and heating. He recovered completely after two months. PMID:26573947

  12. Acute stress is detrimental to heart regeneration in zebrafish

    Sallin, Pauline; Jaźwińska, Anna

    2016-01-01

    Psychological stress is one of the factors associated with human cardiovascular disease. Here, we demonstrate that acute perceived stress impairs the natural capacity of heart regeneration in zebrafish. Beside physical and chemical disturbances, intermittent crowding triggered an increase in cortisol secretion and blocked the replacement of fibrotic tissue with new myocardium. Pharmacological simulation of stress by pulse treatment with dexamethasone/adrenaline reproduced the regenerati...

  13. Acute myelogenous leukemia (AML) - children

    Acute myelogenous leukemia - children; AML; Acute myeloid leukemia - children; Acute granulocytic leukemia - children; Acute myeloblastic leukemia - children; Acute non-lymphocytic leukemia (ANLL) - children

  14. Synthesis of Intermittent-Motion Linkages with Slight Difference in Length Between Links

    CHEN Xin-bo; YU Zhen

    2006-01-01

    The design of intermittent-motion linkages using traditional methods iS usually complicated.In this paper,(1)a new method for realizing intermittent motion,using linkages with a slight difference in length between links,is studied;(2)some new types of intermittent-motion linkages and their software for visual analysis and design are developed;and(3)influences of some design parameters on intermittent.motion characteristics are clarifled.Results confirmed that the theory and the software are useful,making the synthesis of intermittent-motion linkages clear and easy.

  15. RENAL REPLACEMENT THERAPY IN ACUTE KIDNEY FAILURE - AN OVERVIEW

    Treesa P. Varghese

    2014-10-01

    Full Text Available Renal failure is the loss of renal function, either acute or chronic, that results in azotemia and syndrome of uremia. Acute renal failure, is also known as acute kidney injury (AKI, is defined as an abrupt (within 48 hours reduction in kidney function. The initial management of acute kidney failure involves treating the underlying cause, stopping nephrotoxic drugs and ensuring that the patient is euvolaemic with an adequate mean arterial blood pressure. However, no specific treatments have been shown to reverse the course AKF so Renal Replacement Therapy (RRT is the cornerstone of further management. RRT therapy can be administrated either intermittently or continuously. Multiple modalities of RRT are currently available. The purpose of this review is to familiarize different modalities of RRT for blood purification.

  16. On the intermittent character of interplanetary magnetic field fluctuations

    Bruno, Roberto; Chapman, Sandra; Hnat, Bogdan; Noullez, Alain; Sorriso-Valvo, Luca; 10.1063/1.2711429

    2009-01-01

    Interplanetary magnetic field magnitude fluctuations are notoriously more intermittent than velocity fluctuations in both fast and slow wind. This behaviour has been interpreted in terms of the anomalous scaling observed in passive scalars in fully developed hydrodynamic turbulence. In this paper, the strong intermittent nature of the interplanetary magnetic field is briefly discussed comparing results performed during different phases of the solar cycle. The scaling properties of the interplanetary magnetic field magnitude show solar cycle variation that can be distinguished in the scaling exponents revealed by structure functions. The scaling exponents observed around solar maximum coincide, within the errors, to those measured for passive scalars in hydrodynamic turbulence. However, it is also found that the values are not universal in the sense that the solar cycle variation may be reflected in dependence on the structure of the velocity field.

  17. Turbulence and intermittent transport at the boundary of magnetized plasmas

    Garcia, O.E.; Naulin, V.; Nielsen, A.H.;

    2005-01-01

    Numerical fluid simulations of interchange turbulence for geometry and parameters relevant to the boundary region of magnetically confined plasmas are shown to result in intermittent transport qualitatively similar to recent experimental measurements. The two-dimensional simulation domain features...... a forcing region with spatially localized sources of particles and heat outside which losses due to the motion along open magnetic-field lines dominate, corresponding to the edge region and the scrape-off layer, respectively. Turbulent states reveal intermittent eruptions of hot plasma from the edge...... formation of blob structures is thus related to profile variations, which are here triggered in a quasiperiodic manner by a global dynamical regulation due to the self-sustained sheared flows. (C) 2005 American Institute of Physics....

  18. Intermittency-friendly and high-efficiency cogeneration

    Blarke, Morten; Dotzauer, Erik

    2011-01-01

    This paper develops, implements, and applies a mathematical model for economic unit dispatch for a novel cogeneration concept (CHP-HP-FG-CS (CHP with compression heat pump and cold storage using flue gas heat)) that increases the plant’s operational flexibility. The CHP-HP-FG-CS concept is a high-efficiency...... and widely applicable option in distributed cogeneration better supporting the co-existence between cogenerators and intermittent renewables in the energy system. The concept involves integrating an efficient high-temperature compression heat pump that uses only waste heat recovered from flue gases as...... cogeneration plant. It is found that CHP-HP-FG-CS offers significant reductions in fuel consumption (−8.9%) and operational production costs (−11.4%). The plant’s fuel-to-energy efficiency increases from 88.9 to 95.5%, which is state-of-the-art. The plant’s intermittency-friendliness coefficient Rc improves...

  19. Intermittency in fractal Fourier hydrodynamics: Lessons from the Burgers equation.

    Buzzicotti, Michele; Biferale, Luca; Frisch, Uriel; Ray, Samriddhi Sankar

    2016-03-01

    We present theoretical and numerical results for the one-dimensional stochastically forced Burgers equation decimated on a fractal Fourier set of dimension D. We investigate the robustness of the energy transfer mechanism and of the small-scale statistical fluctuations by changing D. We find that a very small percentage of mode-reduction (D ≲ 1) is enough to destroy most of the characteristics of the original nondecimated equation. In particular, we observe a suppression of intermittent fluctuations for D < 1 and a quasisingular transition from the fully intermittent (D=1) to the nonintermittent case for D ≲ 1. Our results indicate that the existence of strong localized structures (shocks) in the one-dimensional Burgers equation is the result of highly entangled correlations amongst all Fourier modes. PMID:27078449

  20. Ensuring patient adherence to clean intermittent self-catheterization

    Seth JH

    2014-02-01

    Full Text Available Jai H Seth, Collette Haslam, Jalesh N Panicker Department of Uro-Neurology, University College London Institute of Neurology and the National Hospital for Neurology and Neurosurgery, London, UK Abstract: Patient performance of clean intermittent self-catheterization is a crucial component of the management of incomplete bladder emptying, which can arise from a variety of conditions. This allows patients to have more control over their bladder emptying, and avoids the inconveniences that come with an indwelling urethral catheter. There are, however, barriers that patients face when performing this task which may ultimately limit adherence. In this article, these barriers are discussed in more detail with potential solutions to counter them. Keywords: clean intermittent self-catheterization, catheters, barriers, compliance, adherence

  1. Continuous use of intermittent bladder catheterization - can social support contribute?

    Marjoyre Anne Lindozo Lopes

    2014-06-01

    Full Text Available OBJECTIVE: to investigate the factors affecting the adequate continuous use of intermittent catheterization and its relation with social support.METHOD: sectional, descriptive and correlational study involving 49 patients with neuropathic bladder caused by spinal cord injury.RESULTS: almost all (92% participants continued the intermittent catheterization, but 46.9% made some changes in the technique. The complications (28.6% of the sample were mainly infection and vesicolithiasis. There were high scores for social support in relation to people that were part of the patient's social support.CONCLUSION: All of them noticed great support from the family, but not from the society in general. The difficulties were related to the lack of equipment and inadequate infrastructure, leading to changes that increased urologic complications.

  2. Intermittent-flow coefficients of a poppet valve

    Waldron, C D

    1939-01-01

    Flow coefficients were determined for the inlet valve of a modern air-cooled cylinder during operation of the valve. The cylinder head with valves was mounted on a large tank that could be evacuated. Operating the valve with a rotating cam allowed air to flow through the valve into the evacuated tank. The change of pressure in the tank was a measure of the amount of air flowing though the valve in a given number of cycles. The flow coefficients were determined from the pressure across the valve, the quantity of air flowing, and the valve-lift curve. Coefficients were measured with lifts of 0.1 to 0.6 inch and speeds of 130 to 1,200 r.p.m. The results obtained with intermittent flow were compared with the results of tests made with steady flow through this cylinder head. This comparison indicated that steady-flow coefficients can be used for intermittent flow.

  3. Intermittency and correlations in hadronic $Z^0$ decays

    Abbiendi, G; Alexander, Gideon; Allison, J; Altekamp, N; Anderson, K J; Anderson, S; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Bechtluft, J; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Blobel, Volker; Bloodworth, Ian J; Bock, P; Böhme, J; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Davis, R; De Jong, S; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Fiedler, F; Fierro, M; Fleck, I; Folman, R; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gascon, J; Gascon-Shotkin, S M; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Gibson, V; Gibson, W R; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herndon, M; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hobson, P R; Hoch, M; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanzaki, J I; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lautenschlager, S R; Lawson, I; Layter, J G; Lazic, D; Lee, A M; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Liu, D; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Markopoulos, C; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Menke, S; Merritt, F S; Mes, H; Meyer, J; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mir, R; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Oreglia, M J; Orito, S; Pálinkás, J; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poffenberger, P R; Poli, B; Polok, J; Przybycien, M B; Rembser, C; Rick, Hartmut; Robertson, S; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Sittler, A; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Sproston, M; Stahl, A; Stephens, K; Steuerer, J; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trigger, I; Trócsányi, Z L; Tsur, E; Turcot, A S; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; Wagner, A; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wermes, N; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Yekutieli, G; Zacek, V; Zer-Zion, D

    1999-01-01

    A multidimensional study of local multiplicity fluctuations and multiparticle correlations of hadrons produced in Z decays is performed. The study is based on the data sample of more than 4 million events recorded with the OPAL detector at LEP. The fluctuations and correlations are analysed in terms of the normalized scaled factorial moments and cumulants up to the fifth order. The moments are observed to have intermittency-like behaviour, which is found to be more pronounced with increasing dimension. The large data sample allows for the first time a study of the factorial cumulants in e+e- annihilation. The analysis of the cumulants shows the existence of genuine multiparticle correlations with a strong intermittency rise up to higher orders. These correlations are found to be stronger in higher dimensions. The decomposition of the factorial moments into lower-order correlations that the dynamical fluctuations have important contributions from genuine many-particle correlations. The Monte Carlo models JETSE...

  4. Intermittency in an optomechanical cavity near a subcritical Hopf bifurcation

    Suchoi, Oren; Ella, Lior; Shtempluk, Oleg; Buks, Eyal

    2014-09-01

    We experimentally study an optomechanical cavity consisting of an oscillating mechanical resonator embedded in a superconducting microwave transmission line cavity. Tunable optomechanical coupling between the mechanical resonator and the microwave cavity is introduced by positioning a niobium-coated single-mode optical fiber above the mechanical resonator. The capacitance between the mechanical resonator and the coated fiber gives rise to optomechanical coupling, which can be controlled by varying the fiber-resonator distance. We study radiation-pressure-induced self-excited oscillation as a function of microwave driving parameters (frequency and power). Intermittency between limit-cycle and steady-state behaviors is observed with blue-detuned driving frequency. The experimental results are accounted for by a model that takes into account the Duffing-like nonlinearity of the microwave cavity. A stability analysis reveals a subcritical Hopf bifurcation near the region where intermittency is observed.

  5. A search of the 'Wow' locale for intermittent radio signals

    Gray, Robert H.

    1994-12-01

    In 1977 a search for extraterrestrial intelligence (SETI) at Ohio State University (OSU) recorded a strong signal near the 21-cm hydrogen line, which displayed several characteristics that might be expected of a candidate interstellar radio signal. This event was not repeatable with the OSC meridian transit radio telescope but could have been due to an intermittent source, which would be difficult to reobserve with a transit instrument. This article reports a search for the OSU signal using the fully steerable Harvard-Smithsonian 26-m radio telescope, tracking for up to 4 hr at a time to improve the chances of detecting an intermittent source. Despite higher sensitivity and longer cumulative observations, no signals resembling the OSU event were found.

  6. The constraints imposed to European grids by intermittent electricity injection

    Intermittent renewables, such as solar or wind energy, induce additional difficulties for the transmission and distribution network management. The renewable electricity injected into the grid results in lower prices on the spot electricity market. Such a situation has both advantages and drawbacks for the end-user. The industrial consumer will partly benefit from a lower market price, whereas at the same time subsidies paid by the domestic consumer will be higher. The additional cost associated with intermittent electricity amounts to the difference between the purchase price paid to the producers of the renewable electricity (feed-in-tariffs) and the selling price on the day-ahead market With lower spot prices the difference increases. Consequently the generous subsidies to renewables due to the FIT System should be cut and a new energy policy to promote renewables must be implemented within the European Union. A common management of the European networks may largely contribute to improve the system. (author)

  7. S-SPRAY ROUTING PROTOCOL FOR INTERMITTENTLY CONNECTED MOBILE NETWORKS

    S. Ramesh

    2013-09-01

    Full Text Available The Intermittently Connected Mobile Networks (ICMN is a disconnected mobile network where a complete connectivity never exists. The intermittent connectivity is due to the dense nature of the network. The dense nature is mainly due to the high mobility of the nodes in the network. Routing in such a sparse network is arduous. Due to the disconnected attribute of the network, the encounter of the suspicious nodes in the network also remains a tedious task. In this paper, we put forward a secure routing that aids in detecting and preventing intrusion of malicious nodes. The routing process is made adorable through Spray and Wait (SNW. Since ICMN is prompt to higher delays certain authentication series are used to enable secure communication within the network. The amalgamation of SNW with authentication series leads a novel routing protocol named S-Spray (Secured-Spray which is highly secure.

  8. Effect of intermittent sitting time on acute postprandial lipemia in children

    Kara Ross

    2015-06-01

    Conclusion: When sitting was interrupted by short bouts of moderate intensity exercise there was a reduction in triglyceride concentrations in eight out of 12 participants. Possible reasons to account for the difference in response may include sexual maturation, gender differences, genetic conditions, or the rate of digestion and intestinal absorption.

  9. Risk factors for acute urinary retention requiring temporary intermittent catheterization after prostate brachytherapy: a prospective study

    Purpose: We prospectively investigated prognostic factors for men undergoing transperineal radioactive seed implantation for prostate cancer at the University of Washington. Methods and Materials: Between February and April, 1998, 62 consecutive unselected patients were prospectively followed after brachytherapy for early-stage prostate adenocarcinoma. Pretreatment variables included age, American Urological Association (AUA) score, uroflowimetry, and prostate volume by ultrasound. Nonrandomized variables included hormonal therapy, seed type, and use of pelvic radiotherapy. Patients were contacted by phone at one week postoperatively and at one-month intervals thereafter. Follow-up continued until all patients provided the date of last catheterization. Results: Urinary retention rate at one week was 34% (21 of 63 patients). At one month, 29%; at three months, 18%; and at six months, 10%. Preoperative flow rate and post-void residual did not predict for retention (p=.48 and p=.58). Use of alpha blockers, hormonal therapy, type of seed (103Pd or 1251), or external beam radiotherapy had no impact on risk of retention at any followup point. Preimplant volume and AUA score predicted for retention on univariate analysis, but on multivariate analysis only postimplant volume remained significant (p=.02) for predicting retention risk and duration. Conclusion: Patients with large prostate size (>36 g) and higher AUA score (>10) appear to be at greater risk of risk of retention as well as duration of retention as defined in our study. Further investigation will be needed to clarify the risk of urinary retention for men undergoing brachytherapy

  10. Prolapsed bilateral ureteroceles leading to intermittent outflow obstruction.

    Stunell, H

    2012-02-01

    A ureterocele refers to a cystic dilatation of the distal ureter. It may be unilateral or bilateral and may be associated with a duplex system in some cases. We present an unusual case where a young patient was found to have large bilateral ureteroceles which prolapsed into the urethra, causing intermittent incontinence and obstruction. We discuss the case and review the literature concerning this rare anomaly.

  11. Low Dose Intermittent Isotretinoin Therapy in Moderate Acne Vulgaris

    Belçın İzol; Emel Bülbül Başkan; Zübeyde Başar; Şükran Tunalı; Hayriye Sarıcaoğlu

    2012-01-01

    Objective: In this study, we aimed to investigate the efficiency and side effects of intermittent low dose isotretinoin therapy in moderate acne. Materials and Methods: Patients followed up at our acne outpatient clinic between September 2007 and April 2009 were evaluated. Those treated with 20 mg/day isotretinoin three times a week were included in the study. Relevant data were recorded from patient files. We recorded the age and weight of the cases, duration of acne, previous treatments, ac...

  12. Intermittent ion trajectories and focusing in spherical inertial electromagnetic confinement

    Performance of spherical magnetic electrostatic confinement fusion is analyzed. Magnetic field lines in spherical cusps provide a chaotic scattering system that improves the ion focusing due to synergetic effect of intermittent ion trajectories. Confined ions are bounced within electrostatic well reflecting from magnetic barriers shaped by convex field lines. The concept offers a means of enhancing ion reactivity provided by caustic formation that are resulted from an intersection of ion orbits within confinement volume. Parameters of the experimental device are estimated. (author)

  13. Intermittent recombinant TSH injections prevent ovariectomy-induced bone loss

    Sun, Li; Vukicevic, Slobodan; Baliram, Ramkumarie; Yang, Guozhe; Sendak, Rebecca; McPherson, John; Zhu, Ling-ling; Iqbal, Jameel; Latif, Rauf; Natrajan, Arjun; Arabi, Ario; Yamoah, Kosj; Moonga, Baljit S.; Gabet, Yankel; Davies, Terry F.

    2008-01-01

    We recently described the direct effects of thyroid-stimulating hormone (TSH) on bone and suggested that the bone loss in hyperthyroidism, hitherto attributed solely to elevated thyroid hormone levels, could at least in part arise from accompanying decrements in serum TSH. Recent studies on both mice and human subjects provide compelling evidence that thyroid hormones and TSH have the opposite effects on the skeleton. Here, we show that TSH, when injected intermittently into rodents, even at ...

  14. The experience of aggressive outbursts in intermittent explosive disorder

    Kulper, Daniel A.; Kleiman, Evan M.; McCloskey, Michael S.; Berman, Mitchell E.; Coccaro, Emil F.

    2014-01-01

    Conceptualizations of Intermittent Explosive Disorder (IED) have suffered from a scarcity of research investigating the subjective experience and phenomenology of the aggressive outbursts among those with IED relative to those who partake in more normative forms of aggression. Furthermore, though some studies have shown that individuals with IED are more impaired and have a poorer quality of life, few studies looked at negative outcomes specific to an individual with IED’s aggressive behavior...

  15. Intermittent control models of human standing: similarities and differences

    Gawthrop, Peter; Loram, Ian; Gollee, Henrik; Lakie, Martin

    2014-01-01

    Two architectures of intermittent control are compared and contrasted in the context of the single inverted pendulum model often used for describing standing in humans. The architectures are similar insofar as they use periods of open-loop control punctuated by switching events when crossing a switching surface to keep the system state trajectories close to trajectories leading to equilibrium. The architectures differ in two significant ways. Firstly, in one case, the open-loop control trajec...

  16. Functional independence measure in patients with intermittent claudication

    Caroline Shihara de Assis; Letícia de Carvalho Batista; Nelson Wolosker; Antonio Eduardo Zerati; Rita de Cassia Gengo e Silva

    2015-01-01

    AbstractOBJECTIVEOf this study were to evaluate the functional independence of patients with intermittent claudication and to verify its association with sociodemographic and clinical variables, walking ability and physical activity level.METHODThis was a descriptive, exploratory, cross-sectional study with a quantitative approach. Fifty participants (66.4 years; 68% male) were recruited from Claudication Unit of a tertiary hospital. Functional Independence Measure were used to evaluate funct...

  17. Tester Detects Steady-Short Or Intermittent-Open Circuits

    Anderson, Bobby L.

    1990-01-01

    Momentary open circuits or steady short circuits trigger buzzer. Simple, portable, lightweight testing circuit sounds long-duration alarm when it detects steady short circuit or momentary open circuit in coaxial cable or other two-conductor transmission line. Tester sensitive to discontinuities lasting 10 microseconds or longer. Used extensively for detecting intermittent open shorts in accelerometer and extensometer cables. Also used as ordinary buzzer-type continuity checker to detect steady short or open circuits.

  18. Intermittent contact mode piezoresponse force microscopy in a liquid environment

    Rodriguez, Brian J [Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Jesse, Stephen; Kalinin, Sergei V [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Habelitz, Stefan [Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, CA 94143 (United States); Proksch, Roger [Asylum Research, Santa Barbara, CA 93117 (United States)], E-mail: brian.rodriguez@ucd.ie, E-mail: sergei2@ornl.gov

    2009-05-13

    Probing electromechanical coupling in biological systems and electroactive molecules requires high resolution functional imaging. Here, we investigate the feasibility of intermittent contact mode piezoresponse force microscopy based on simultaneous mechanical and electrical probe modulation. It is shown that imaging at frequencies corresponding to the first contact resonance in liquid allows contrast consistent with the electromechanical signal to be obtained for model ferroelectric systems and piezoelectric tooth dentin.

  19. Intermittent-contact mode piezoresponse force microscopy in liquid environment

    Rodriguez, Brian J [ORNL; Jesse, Stephen [ORNL; Habelitz, S. [University of California, San Francisco; Kalinin, Sergei V [ORNL

    2009-01-01

    Probing electromechanical coupling in biological systems and electroactive molecules requires high-resolution imaging. Here, we investigate the feasibility of intermittent contact mode piezoresponse force microscopy based on simultaneous mechanical and electrical probe modulation. It is shown that the combination of (a) imaging at frequencies corresponding to the first contact resonance in (b) liquid allows contrast consistent with electromechanical signal to be obtained on model ferroelectric perovskites and tooth dentin.

  20. Intermittent contact mode piezoresponse force microscopy in a liquid environment

    Rodriguez, Brian [University College, Dublin; Jesse, Stephen [ORNL; Habelitz, S. [University of California, San Francisco; Proksch, Roger [Asylum Research, Santa Barbara, CA; Kalinin, Sergei V [ORNL

    2009-01-01

    Probing electromechanical coupling in biological systems and electroactive molecules requires high resolution functional imaging. Here, we investigate the feasibility of intermittent contact mode piezoresponse force microscopy based on simultaneous mechanical and electrical probe modulation. It is shown that imaging at frequencies corresponding to the first contact resonance in liquid allows contrast consistent with the electromechanical signal to be obtained for model ferroelectric systems and piezoelectric tooth dentin