Numerical Investigations of Dynamic Stall Control

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Florin FRUNZULICA

2014-04-01

Full Text Available In this paper we investigated numerically the dynamic stall phenomenon and the possibilities to control it, with application to vertical axis wind turbines (for urban users. The Phenomenon appear at low tip speed ratio (TSR<4 and it has a great impact on structural integrity of the wind turbine and power performances. For this reason we performed a computational study of dynamic stall around NACA 0012 airfoil in pitching motion at relative low Reynolds number (105. Also, we performed the same analysis for four flow control methods: two passive (Gurney flap and slot and two active (blowing jet on the rounded trailing edge and synthetic jet periodically activated. The Results are compared to those of an existing experimental case test.

Multi-Stakeholder Case Prioritization in Digital Investigations

Directory of Open Access Journals (Sweden)

Joshua I. James

2014-09-01

Full Text Available This work examines the problem of case prioritization in digital investigations for better utilization of limited criminal investigation resources. Current methods of case prioritization, as well as observed prioritization methods used in digital forensic investigation laboratories are examined. After, a multi-stakeholder approach to case prioritization is given that may help reduce reputational risk to digital forensic laboratories while improving resource allocation. A survey is given that shows differing opinions of investigation priority between Law Enforcement and the public that is used in the development of a prioritization model. Finally, an example case is given to demonstrate the practicality of the proposed method.

Case-control studies in neurosurgery.

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Nesvick, Cody L; Thompson, Clinton J; Boop, Frederick A; Klimo, Paul

2014-08-01

Observational studies, such as cohort and case-control studies, are valuable instruments in evidence-based medicine. Case-control studies, in particular, are becoming increasingly popular in the neurosurgical literature due to their low cost and relative ease of execution; however, no one has yet systematically assessed these types of studies for quality in methodology and reporting. The authors performed a literature search using PubMed/MEDLINE to identify all studies that explicitly identified themselves as "case-control" and were published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Each paper was evaluated for 22 descriptive variables and then categorized as having either met or missed the basic definition of a case-control study. All studies that evaluated risk factors for a well-defined outcome were considered true case-control studies. The authors sought to identify key features or phrases that were or were not predictive of a true case-control study. Those papers that satisfied the definition were further evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. The search detected 67 papers that met the inclusion criteria, of which 32 (48%) represented true case-control studies. The frequency of true case-control studies has not changed with time. Use of odds ratios (ORs) and logistic regression (LR) analysis were strong positive predictors of true case-control studies (for odds ratios, OR 15.33 and 95% CI 4.52-51.97; for logistic regression analysis, OR 8.77 and 95% CI 2.69-28.56). Conversely, negative predictors included focus on a procedure/intervention (OR 0.35, 95% CI 0.13-0.998) and use of the word "outcome" in the Results section (OR 0.23, 95% CI 0.082-0.65). After exclusion of nested case-control studies, the negative correlation between focus on a procedure

Pilot case-control study of paediatric falls from windows.

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Johnston, Brian D; Quistberg, D Alexander; Shandro, Jamie R; Partridge, Rebecca L; Song, Hyun Rae; Ebel, Beth E

2011-12-01

Unintentional falls from windows are an important cause of paediatric morbidity. There have been no controlled studies to identify modifiable environmental risk factors for window falls in young children. The authors have piloted a case-control study to test procedures for case identification, subject enrolment, and environmental data collection. Case windows were identified when a child 0-9 years old presented for care after a fall from that window. Control windows were identified (1) from the child's home and (2) from the home of an age- and gender-matched child seeking care for an injury diagnosis not related to a window fall. Study staff visited enrolled homes to collect window measurements and conduct window screen performance tests. The authors enrolled and collected data on 18 case windows, 18 in-home controls, and 14 matched community controls. Six potential community controls were contacted for every one enrolled. Families who completed the home visit viewed study procedures positively. Case windows were more likely than community controls to be horizontal sliders (100% vs 50%), to have deeper sills (6.28 vs 4.31 inches), to be higher above the exterior surface (183 vs 82 inches), and to have screens that failed below a threshold derived from the static pressure of a 3-year-old leaning against the mesh (60.0% vs 16.7%). Case windows varied very little from in-home controls. Case-control methodology can be used to study risk factors for paediatric falls from windows. Recruitment of community controls is challenging but essential, because in-home controls tend to be over-matched on important variables. A home visit allows direct measurement of window type, height, sill depth, and screen performance. These variables should all be investigated in subsequent, larger studies covering major housing markets.

Case-control studies in diabetes. Do they really use a case-control design?

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Ramos, Analía; Mendoza, Lilian Cristina; Rabasa, Fernanda; Bolíbar, Ignasi; Puig, Teresa; Corcoy, Rosa

2017-07-01

Studies defined as case-control do not always use this design. We aimed to estimate the frequency of mislabelled case-control studies in published articles in the area of diabetes and to identify the predictors of incorrect labelling. We searched Medline and Web of Science for articles with "diabetes" and "case control" in title and filtered for language (English/Romance) and period (January 2010-December 2014). Inclusion criteria were: (1) statement to use a case-control design in title, (2) to be a final full-length publication and (3) to have original data in the area of diabetes. Three independent reviewers went through titles, looked for full texts and reviewed them. Discrepancies were settled with a fourth reviewer. Expert epidemiologist advice was requested in case of doubt. case-control mislabelling; addressed predictors: publication year, journal impact factor and journal subject. proportion of mislabelled CC articles and assessment of predictors by multivariate logistic regression analysis. We retrieved 362 articles, 251 of them fulfilling inclusion criteria. The proportion of mislabelled CC studies was 43.8% (confidence interval 95% 37.7-50.0%). Most mislabelled studies had a cross-sectional design (82.7%). Predictors of mislabelling were publication year, journal impact factor and journal area. A relevant subset of studies defined as case-control in the area of diabetes correspond to mislabelled cross-sectional studies. Incorrect labelling misleads readers regarding the interpretation of results and the cause-effect hypothesis. Researchers, reviewers and editors should be aware of and commit to settle this issue.

Source-case investigation of Mycobacterium wolinskyi cardiac surgical site infection.

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Dupont, C; Terru, D; Aguilhon, S; Frapier, J-M; Paquis, M-P; Morquin, D; Lamy, B; Godreuil, S; Parer, S; Lotthé, A; Jumas-Bilak, E; Romano-Bertrand, S

2016-07-01

The non-tuberculous mycobacteria (NTM) Mycobacterium wolinskyi caused bacteraemia and massive colonization of an aortic prosthesis in a patient 16 days after cardiac surgery, necessitating repeat surgery and targeted antimicrobial chemotherapy. The infection control team investigated the source and conditions of infection. Peri-operative management of the patient complied with recommendations. The environmental investigation showed that although M. wolinskyi was not recovered, diverse NTM species were present in water from point-of-use taps and heater-cooler units for extracorporeal circulation. This case and increasing evidence of emerging NTM infections in cardiac surgery led to the implementation of infection control procedures in cardiac surgery wards. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Risk factors associated with lipomyelomeningocele: a case-control study.

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Esmaeili, Arash; Hanaei, Sara; Fadakar, Kaveh; Dadkhah, Sahar; Arjipour, Mahdi; Habibi, Zohreh; Nejat, Farideh; El Khashab, Mostafa

2013-01-01

In general, it seems that both genetic and environmental factors play important roles in the induction of neural tube defects. Lipomyelomeningocele (LipoMMC) is a rather common type of closed neural tube defect, but only limited studies have investigated the potential risk factors of this anomaly. Therefore, the purpose of this case-control study was to investigate the risk factors involved in LipoMMC formation. Various risk factors were evaluated in 35 children between 1 month and 10 years of age with LipoMMC in a hospital-based case-control study. The 2 control arms consisted of 35 children with myelomeningocele (MMC group) and 35 children with congenital anomalies other than central nervous system problems (control group). All groups were matched for age and visited the same hospital. A structured questionnaire was used for the collection of all data, including the mothers' weight and height during pregnancy, education, reproductive history, previous abortions, and socioeconomic status, as well as the parents' consanguinity and family history of the same anomalies. Univariate analysis of the children with LipoMMC compared to the control group showed that the use of periconceptional folic acid supplementation was significantly lower in the MMC and LipoMMC groups compared to the control group. In addition, comparison of the MMC and control groups revealed statistically significant differences regarding the use of folic acid and maternal obesity. In multivariate analysis, use of folic acid in the periconceptional period and during the first trimester was an independent risk factor for LipoMMC and MMC. Furthermore, maternal obesity was a significantly positive risk factor for MMC. The probable risk factors for LipoMMC were investigated in this case-control study. Consumption of folic acid in the periconceptional period and during the first trimester is an independent protective factor against LipoMMC. It seems that larger studies are needed to examine other possible

Outbreak of acute renal failure in Panama in 2006: a case-control study.

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Rentz, E Danielle; Lewis, Lauren; Mujica, Oscar J; Barr, Dana B; Schier, Joshua G; Weerasekera, Gayanga; Kuklenyik, Peter; McGeehin, Michael; Osterloh, John; Wamsley, Jacob; Lum, Washington; Alleyne, Camilo; Sosa, Nestor; Motta, Jorge; Rubin, Carol

2008-10-01

In September 2006, a Panamanian physician reported an unusual number of patients with unexplained acute renal failure frequently accompanied by severe neurological dysfunction. Twelve (57%) of 21 patients had died of the illness. This paper describes the investigation into the cause of the illness and the source of the outbreak. Case-control and laboratory investigations were implemented. Case patients (with acute renal failure of unknown etiology and serum creatinine > 2 mg/dl) were individually matched to hospitalized controls for age (+/- 5 years), sex and admission date (< 2 days before the case patient). Questionnaire and biological data were collected. The main outcome measure was the odds of ingesting prescription cough syrup in cases and controls. Forty-two case patients and 140 control patients participated. The median age of cases was 68 years (range: 25-91 years); 64% were male. After controlling for pre-existing hypertension and renal disease and the use of angiotensin-converting enzyme inhibitors, a significant association was found between ingestion of prescription cough syrup and illness onset (adjusted odds ratio: 31.0, 95% confidence interval: 6.93-138). Laboratory analyses confirmed the presence of diethylene glycol (DEG) in biological samples from case patients, 8% DEG contamination in cough syrup samples and 22% contamination in the glycerin used to prepare the cough syrup. The source of the outbreak was DEG-contaminated cough syrup. This investigation led to the recall of approximately 60 000 bottles of contaminated cough syrup, widespread screening of potentially exposed consumers and treatment of over 100 affected patients.

Role of U.S. animal control agencies in equine neglect, cruelty, and abandonment investigations.

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Stull, C L; Holcomb, K E

2014-05-01

Every state in the United States has regulations prohibiting acts of neglect and cruelty against animals. Local law enforcement and animal control agencies are responsible in many communities to enforce these statutes. As society's perception of horses has changed from their origin as livestock to companion animals in modern times, owners have transitioned their care and management. The goal of this study was to identify the role and capacities of local animal control services in the United States that investigate equine neglect, cruelty, and abandonment investigations and to identify challenges and outcomes of the investigations. A 128-question online survey was accessible for animal agencies to complete. Comprehensive questions included their capacity for investigating equine cases, funding, housing for horses, and causes and outcomes of investigations. Respondents also were asked to select a single case and provide detailed information on the condition of horses, seizure and custody procedures, costs, and prosecution proceedings. A total of 165 respondents from 26 states completed all or the majority of the questions. A total of 6,864 equine investigations were initiated between 2007 and 2009 by 90 agencies, which extrapolates to 38 investigations annually per agency. A typical agency has an average annual budget of $740,000, employs 7 animal control officers, and spends about $10,000 annually on equine cases. Neglect was ranked as the most common reason for investigation. Owner ignorance, economic hardship, and lack of responsibility were the highest ranked causes of neglect and cruelty. Individual cases were provided by 91 agencies concerning 749 equines. The physical condition of the horse was the primary factor of investigation, and low body condition, parasite infestation, and compromised dental condition were present in most seized horses. Over half of the equine owners previously had been investigated or charged with neglect or cruelty of animals or were

Field-based random sampling without a sampling frame: control selection for a case-control study in rural Africa.

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Crampin, A C; Mwinuka, V; Malema, S S; Glynn, J R; Fine, P E

2001-01-01

Selection bias, particularly of controls, is common in case-control studies and may materially affect the results. Methods of control selection should be tailored both for the risk factors and disease under investigation and for the population being studied. We present here a control selection method devised for a case-control study of tuberculosis in rural Africa (Karonga, northern Malawi) that selects an age/sex frequency-matched random sample of the population, with a geographical distribution in proportion to the population density. We also present an audit of the selection process, and discuss the potential of this method in other settings.

Investigation on the use digital controls instead of PID analog controls in the level control of steam generators of nuclear power PWR

International Nuclear Information System (INIS)

Alvarenga, Marco Antonio Bayout

2012-01-01

The aim of this study is to identify current alternatives for the implementation of digital controllers in the level control of steam generators of nuclear power PWR (Pressurized Water Reaetor). It is intended to identify the types of digital controls that are available from the theoretical and conceptual viewpoints for this purpose. We investigate the advantages and disadvantages of each controller model. From this assessment are pointed the most suitable models in hierarchical scale. This evaluation also serves to suggest possible types of control installation as a whole, where the level control of the steam generators becomes just one of many controls that are part of the plant. In this case, the use of digital controls allows the non-linear and multivariable treatment which is characteristic of complex systems, such as the nuclear power generation. The treatment of nonlinearities and multivariable aspects allows a more detailed study of the stability of these plants when they are subject to transients or several accidents, such as the case of losing external power of transients. In the specific case of steam generators, the instabilities result from the emergence of the shrink and swell phenomenas, depending on the load variations of thermonuclear plant. The application of several types and digital controllers, considering these inherent characteristics of the level control of steam generators, allows to infer which types of controllers are more appropriate to treat instabilities of this type and to make conjectures in its use for the cases of more complex instabilities, considering the integration of all nucleus-plant controls.

An epidemiological investigation of the early phase of the porcine epidemic diarrhea (PED) outbreak in Canadian swine herds in 2014: A case-control study.

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Perri, Amanda M; Poljak, Zvonimir; Dewey, Cate; Harding, John C S; O'Sullivan, Terri L

2018-02-01

The first case of porcine epidemic diarrhea (PED) in Canada was diagnosed in January 2014 in Ontario, approximately 9 months after PED emerged in the United States. An early investigation of the Canadian outbreak suspected that the probable source of the virus was contaminated feed. The objective of this study was to evaluate the role of feed and other possible factors in the early phase of the PED outbreak in Canadian swine herds. The study period of interest for this case-control study was January 22nd to March 1st, 2014. A case herd was defined as a swine herd with a confirmed positive laboratory diagnostic test (RT-PCR) results for PED virus, along with pigs exhibiting typical clinical signs at the herd level during the study period. A questionnaire was administered to participating producers from the 22 Canadian swine herds enrolled (n = 9 case and n = 13 control herds). Case herd producers were asked to provide information from the initial day of onset of clinical signs and 30 days prior to that day. Control herds were matched to a case herd on the basis of province, herd type and approximate size. The period of interest for a control herd was matched to the initial day of clinical signs of PED for the case herd, along with the 30 days prior to this day. The questionnaire questions focused on herd demographics, biosecurity protocols, live animal movements onto and off sites, deadstock movements, feed and people movements for both the case and control herds. The questionnaire for control herds were based on their matched case's period of interest, and together with case herds formed a matched stratum. Multivariable exact conditional logistic regression and mixed multivariable logistic regression models, with the matched stratum as a random effect, were used to assess the association between various risk factors and the odds of PED introduction into a herd. After adjusting for biosecurity practices, the odds of a PED occurrence was 38.1 (95% CI: 2

Investigation of Pertussis Cases in a Texas County, 2008-2012.

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Staudt, Amanda; Mangla, Anil T; Alamgir, Hasanat

2015-07-01

Within the past 25 years, there has been a dramatic increase in the incidence of pertussis cases in the United States. As such, this investigation reports on the high-risk groups and describes risk factors of pertussis cases in a large Texas county. This study was a cross-sectional analysis of data collected by health department employees using the Texas Department of State Health Service's Pertussis Case Track Record, which is the standard investigation form for collecting vital information on pertussis cases. We extracted and analyzed county-level data for a 5-year period (2008-2012). The study population at risk included all current residents in this county, and cases included all who were clinically diagnosed as having confirmed or probable pertussis cases that were reported to the health department according to the Centers for Disease Control and Prevention case definition. The vaccination status of a case was defined as fully vaccinated, partially vaccinated, or not vaccinated. A total of 198 probable and confirmed pertussis cases were included in this analysis. Most of the cases were infants younger than 1 year old (n = 107). The largest category of cases was not vaccinated and of the rest, 32.8% were partially vaccinated, 17.2% had unknown vaccination status, and 13.1% were fully vaccinated. Only 48 (24.2%) sources of exposure were identified and they included fathers (14.6%), sisters (14.6%), brothers (14.6%), other children (14.6%), and mothers (12.5%). Many sources of exposure (n = 26, 54.1%) were unaware of their vaccination history. Hispanics accounted for 84.5% of cases in the younger than 1 year old group and 88.9% of cases were in the 1 to 2 years old group. With respect to race/ethnicity and vaccination status of the cases, 39.46% of Hispanics, 32% of whites, and 50% of blacks were reported to be unvaccinated. Increasing pertussis vaccination coverage among children, as well as providing booster shots to adults with special attention on the

Can iridology detect susceptibility to cancer? A prospective case-controlled study.

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Münstedt, Karsten; El-Safadi, Samer; Brück, Friedel; Zygmunt, Marek; Hackethal, Andreas; Tinneberg, Hans-Rudolf

2005-06-01

This prospective case-control study aimed to investigate the value of iridology as a diagnostic tool in detecting some common cancers. One hundred ten (110) subjects were enrolled in the study: 68 subjects had histologically proven cancers of the breast, ovary, uterus, prostate, or colorectum, and 42 were control subjects. All subjects were examined by an experienced practitioner of iridology, who was unaware of their gender or medical details. He was allowed to suggest up to five diagnoses for each subject and his results were then compared with each subject's medical diagnosis to determine the accuracy of iridology in detecting malignancy. Iridology identified the correct diagnosis in only 3 cases (sensitivity, 0.04). Iridology was of no value in diagnosing the cancers investigated in this study.

Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study.

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Higdon, Melissa M; Hammitt, Laura L; Deloria Knoll, Maria; Baggett, Henry C; Brooks, W Abdullah; Howie, Stephen R C; Kotloff, Karen L; Levine, Orin S; Madhi, Shabir A; Murdoch, David R; Scott, J Anthony G; Thea, Donald M; Driscoll, Amanda J; Karron, Ruth A; Park, Daniel E; Prosperi, Christine; Zeger, Scott L; O'Brien, Katherine L; Feikin, Daniel R

2017-06-15

Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Accounting for control mislabeling in case-control biomarker studies.

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Rantalainen, Mattias; Holmes, Chris C

2011-12-02

In biomarker discovery studies, uncertainty associated with case and control labels is often overlooked. By omitting to take into account label uncertainty, model parameters and the predictive risk can become biased, sometimes severely. The most common situation is when the control set contains an unknown number of undiagnosed, or future, cases. This has a marked impact in situations where the model needs to be well-calibrated, e.g., when the prediction performance of a biomarker panel is evaluated. Failing to account for class label uncertainty may lead to underestimation of classification performance and bias in parameter estimates. This can further impact on meta-analysis for combining evidence from multiple studies. Using a simulation study, we outline how conventional statistical models can be modified to address class label uncertainty leading to well-calibrated prediction performance estimates and reduced bias in meta-analysis. We focus on the problem of mislabeled control subjects in case-control studies, i.e., when some of the control subjects are undiagnosed cases, although the procedures we report are generic. The uncertainty in control status is a particular situation common in biomarker discovery studies in the context of genomic and molecular epidemiology, where control subjects are commonly sampled from the general population with an established expected disease incidence rate.

Selective serotonin reuptake inhibitors and gastrointestinal bleeding: a case-control study.

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Alfonso Carvajal

Full Text Available BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs have been associated with upper gastrointestinal (GI bleeding. Given their worldwide use, even small risks account for a large number of cases. This study has been conducted with carefully collected information to further investigate the relationship between SSRIs and upper GI bleeding. METHODS: We conducted a case-control study in hospitals in Spain and in Italy. Cases were patients aged ≥18 years with a primary diagnosis of acute upper GI bleeding diagnosed by endoscopy; three controls were matched by sex, age, date of admission (within 3 months and hospital among patients who were admitted for elective surgery for non-painful disorders. Exposures to SSRIs, other antidepressants and other drugs were defined as any use of these drugs in the 7 days before the day on which upper gastrointestinal bleeding started (index day. RESULTS: 581 cases of upper GI bleeding and 1358 controls were considered eligible for the study; no differences in age or sex distribution were observed between cases and controls after matching. Overall, 4.0% of the cases and 3.3% of controls used an SSRI antidepressant in the week before the index day. No significant risk of upper GI bleeding was encountered for SSRI antidepressants (adjusted odds ratio, 1.06, 95% CI, 0.57-1.96 or for whichever other grouping of antidepressants. CONCLUSIONS: The results of this case-control study showed no significant increase in upper GI bleeding with SSRIs and provide good evidence that the magnitude of any increase in risk is not greater than 2.

Case-control study of mesothelioma in the shipyard industry

International Nuclear Information System (INIS)

Correa-Villasenor, A.

1987-01-01

A nested case-control study was undertaken to investigate the relationship between occupational exposures to asbestos and low-level gamma radiation and mesothelioma. One hundred nineteen cases and four hundred fifty-two latency-matched controls were selected. Analyses were conducted using the conditional maximum likelihood estimate of the odds ratio and conditional logistic regression for matched sets. The results from the analyses revealed a relationship between asbestos exposure and mesothelioma; the strength of this relationship increased with the intensity and duration of the asbestos exposure. Exposure to low-level gamma radiation was also associated with an increased risk of mesothelioma. There was no interaction between asbestos and radiation. Shipyard employment in non-asbestos jobs and male gender were also found to be associated with mesothelioma

Hypothyroidism among SLE patients: Case-control study.

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Watad, Abdulla; Mahroum, Naim; Whitby, Aaron; Gertel, Smadar; Comaneshter, Doron; Cohen, Arnon D; Amital, Howard

2016-05-01

The prevalence of hypothyroidism in SLE patients varies considerably and early reports were mainly based on small cohorts. To investigate the association between SLE and hypothyroidism. Patients with SLE were compared with age and sex-matched controls regarding the proportion of hypothyroidism in a case-control study. Chi-square and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study was performed utilizing the medical database of Clalit Health Services. The study included 5018 patients with SLE and 25,090 age and sex-matched controls. The proportion of hypothyroidism in patients with SLE was increased compared with the prevalence in controls (15.58% and 5.75%, respectively, Phypothyroidism (odds ratio 2.644, 95% confidence interval 2.405-2.908). Patients with SLE have a greater proportion of hypothyroidism than matched controls. Therefore, physicians treating patients with SLE should be aware of the possibility of thyroid dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

Importance of Multifaceted Approaches in Infection Control: A Practical Experience from an Outbreak Investigation.

Directory of Open Access Journals (Sweden)

Nina Katharina Stock

Full Text Available This study presents the results of a multidisciplinary, nosocomial MRSA outbreak investigation in an 8-bed medical intensive care unit (ICU. The identification of seven MRSA positive patients in the beginning of 2014 led to the closure of the ward for several weeks. A multidisciplinary, retrospective investigation was initiated in order to identify the reason and the source for the outbreak, describe MRSA transmission in the department and identify limitations in infection control.The investigation comprised an epidemiological description of MRSA cases from 2012 to 2014 and a characterization of MRSA isolates, including phage-, spa- and PFGE-typing. Additionally, MRSA screening was performed from the hospital staff and the environment. To identify the reason for the outbreak, work-related, psychological and behavioral factors were investigated by impartial audits and staff interviews.Thirty-one MRSA cases were registered during the study period, and 36 isolates were investigated. Molecular typing determined the outbreak strain (phage type 54/812, PFGE type A4, spa type t003 and identified the probable index case. Nasal carriage in one employee and a high environmental contamination with the outbreak strain was documented. Important gaps in nursing procedures and general management were identified. Elevated stress levels and communication problems preceded the outbreak. Compliance with hand hygiene and isolation procedures was evaluated as appropriate.This study demonstrates the complexity of controlling hospital-associated infections. The combined use of different typing methods is beneficial for outbreak investigations. Psychological, behavioral and other work-related factors have an important impact on the spread of nosocomial pathogens. These factors should be addressed and integrated in routine infection control practice.

Identification and medical utilization of incident cases of alcohol dependence: A population-based case-control study.

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Pan, Chun-Hung; Li, Min-Shan; Yang, Tien-Wey; Huang, Ming-Chyi; Su, Sheng-Shiang; Hung, Yen-Ni; Chen, Chiao-Chicy; Kuo, Chian-Jue

2018-05-05

Patients with alcohol dependence (AD) often seek help from medical professionals due to alcohol-related diseases, but the overall distribution of medical specialties identifying new AD cases is unclear. We investigated how such cases were identified and how medical resources were utilized before the identification of AD in a nationwide cohort. We enrolled a population-based cohort (N = 1,000,000) using the National Health Insurance Research Database of Taiwan; 8181 cases with incident AD were retrieved between January 1, 2000, and December 31, 2010. For this nested case-control study, four controls were matched for age and sex with each case based on risk-set sampling. We measured various dimensions of medical utilization before AD was diagnosed, including department visited, physical comorbidity, and medication used. Conditional logistic regression was used for estimating the variables associated with AD. Patients living in less urbanized areas who were unemployed were more likely to develop AD. The highest proportions (34.2%) of AD cases were identified in the internal medicine department, followed by the emergency (22.3%) and psychiatry (18.7%) departments. AD patients had a higher risk of comorbid chronic hepatic disease (adjusted RR = 2.72, p identification of AD than controls. AD patients also had greater numbers of hospital admissions than controls, including non-psychiatric and psychiatric hospitalizations. Outpatient visit numbers were similar for AD patients and controls. The findings indicate that clinicians providing care in diverse medical settings should be prepared to screen for unhealthy alcohol use and to mitigate its detrimental effects. Copyright © 2018 Elsevier B.V. All rights reserved.

Health issues in the Arab American community. Male infertility in Lebanon: a case-controlled study.

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Kobeissi, Loulou; Inhorn, Marcia C

2007-01-01

The impact of risk factors, such as consanguinity and familial clustering, reproductive infections, traumas, and diseases, lifestyle factors and occupational and war exposures on male infertility, was investigated in a case-controlled study conducted in Lebanon. One-hundred-twenty males and 100 controls of Lebanese, Syrian or Lebanese-Palestinian descents were selected from two in-vitro fertilization (IVF) clinics located in Beirut, Lebanon. All cases suffered from impaired sperm count and function, according to World Health Organization guidelines for semen analysis. Controls were the fertile husbands of infertile women. Data were collected using a semi-structured interview, laboratory blood testing and the results of the most recent semen analysis. Univariate, bivariate and multivariate logistic regression analyses were used for data analysis, along with checks for effect modification and control of confounders. Consanguinity and the familial clustering of male infertility cases, as well as reproductive illnesses and war exposures were independently significant risk factors for male infertility. The odds of having infertility problems in the immediate family were 2.6 times higher in cases than controls. The odds of reproductive illness were 2 times higher in cases than controls. The odds of war exposures were 1.57 times higher in cases than controls. Occupational exposures, such as smoking and caffeine intake, were not shown to be important risk factors. This case-controlled study highlights the importance of investigating the etiology of male infertility in Middle Eastern communities. It suggests the need to expand research on male reproductive health in the Middle East in order to improve the prevention and management of male infertility and other male reproductive health problems.

Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study

OpenAIRE

Cristina Lopez-del Burgo; Alfredo Gea; Jokin de Irala; Miguel A. Martínez-González; Jorge E. Chavarro; Estefania Toledo

2015-01-01

The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the ...

Study Design for a Case Control Investigation of Cellular Telephones and Other Risk Factors for Brain Tumors in Adults

International Nuclear Information System (INIS)

Inskip, P.D.; Hatch, E.E.; Stewart, P.A.; Heineman, E.F.; Ziegler, R.G.; Dosemeci, M.; Parry, D.; Rothman, N.; Boice, J.D. Jr.; Wilcosky, T.C.; Watson, D.J.; Shapiro, W.R.; Selker, R.G.; Fine, H.A.; Black, P. McL.; Loeffler, J.S.; Linet, M.S.

1999-01-01

The aetiology of brain tumours is poorly understood. Due, in part, to public concern about a postulated relationship between the use of cellular telephones or other increasingly prevalent environmental exposures and the incidence of brain cancer in adults, the National Cancer Institute is collaborating with three US hospitals in a comprehensive case control study of malignant and benign brain tumours. Factors under consideration include use of cellular phones and other wireless communication devices, workplace exposures to chemical agents and electromagnetic fields, dietary factors, family history of tumours, genetic determinants of susceptibility, home appliance use, reproductive history and hormonal exposures, viruses, medical and dental exposure to ionising radiation, and other aspects of medical history. Approximately 800 newly diagnosed brain tumour cases and 800 controls were enrolled at hospitals in Boston, Phoenix and Pittsburgh from 1994 to 1998. Cases include all adults (age ≥ 18 y) newly diagnosed with a histologically confirmed intracranial glioma, histologically confirmed intracranial meningioma or acoustic neuroma. Controls are patients admitted to the same hospitals as the cases, and treated for any of a variety of non-malignant conditions. Key features of the study include its large size, the emphasis on rapid ascertainment of incident cases and interview of study subjects rather than surrogate respondents, the use of detailed, job-specific questions developed by industrial hygienists to ascertain occupational exposures, and the storage of blood samples for future evaluation of inherited susceptibility, biomarkers of exposure and gene environment interactions. (author)

The Association Between Urban Tree Cover and Gun Assault: A Case-Control and Case-Crossover Study.

Science.gov (United States)

Kondo, Michelle C; South, Eugenia C; Branas, Charles C; Richmond, Therese S; Wiebe, Douglas J

2017-08-01

Green space and vegetation may play a protective role against urban violence. We investigated whether being near urban tree cover during outdoor activities was related to being assaulted with a gun. We conducted geographic information systems-assisted interviews with boys and men aged 10-24 years in Philadelphia, Pennsylvania, including 135 patients who had been shot with a firearm and 274 community controls, during 2008-2011. Each subject reported a step-by-step mapped account of where and with whom they traveled over a full day from waking until being assaulted or going to bed. Geocoded path points were overlaid on mapped layers representing tree locations and place-specific characteristics. Conditional logistic regressions were used to compare case subjects versus controls (case-control) and case subjects at the time of injury versus times earlier that day (case-crossover). When comparing cases at the time of assault to controls matched at the same time of day, being under tree cover was inversely associated with gunshot assault (odds ratio (OR) = 0.70, 95% confidence interval (CI): 0.55, 0.88), especially in low-income areas (OR = 0.69, 95% CI: 0.54, 0.87). Case-crossover models confirmed this inverse association overall (OR = 0.55, 95% CI: 0.34, 0.89) and in low-income areas (OR = 0.54, 95% CI: 0.33, 0.88). Urban greening and tree cover may hold promise as proactive strategies to decrease urban violence. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Exposure to pistachio pesticides and stillbirth: a case-control study.

Science.gov (United States)

Razi, Saeid; Rezaeian, Mohsen; Dehkordi, Fatemeh Ghani; Manshoori, Azita; Goujani, Reza; Vazirinejad, Reza

2016-01-01

Stillbirth is an undesirable outcome of pregnancy. In light of the increasing use of pesticides and growing concerns about the possible health effects of agricultural pesticides, we investigated the effect of exposure to pistachio pesticides on stillbirth in pregnant mothers. This case-control study was conducted in Rafsanjan, Iran from 2011 to 2012. A total of 125 females who had a recent stillbirth were included as the case group, and 250 controls were selected from females who had a recent live birth. For each case, two controls with the nearest propensity score to the case were selected. Data were collected using a protocol developed by the researcher that involved interviewing respondents and reviewing their medical records. Conditional multivariate and univariate logistic regression analysis were performed and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The ORs of stillbirth in mothers living in pistachio gardens and those who were exposed to sprayed pesticides, in comparison to the controls, were 14.1 (95% CI, 3.3 to 63.4) and 5.0 (95% CI, 1.2 to 28.6), respectively. No significant differences were found in stillbirth rates according to the distance between the mother's residence and a pistachio garden or involvement in agricultural activities. The results of our study showed that exposure to pistachio pesticides during pregnancy may increase the likelihood of stillbirth in mothers.

Use of oral cholera vaccines in an outbreak in Vietnam: a case control study.

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Dang Duc Anh

Full Text Available BACKGROUND: Killed oral cholera vaccines (OCVs are available but not used routinely for cholera control except in Vietnam, which produces its own vaccine. In 2007-2008, unprecedented cholera outbreaks occurred in the capital, Hanoi, prompting immunization in two districts. In an outbreak investigation, we assessed the effectiveness of killed OCV use after a cholera outbreak began. METHODOLOGY/PRINCIPAL FINDINGS: From 16 to 28 January 2008, vaccination campaigns with the Vietnamese killed OCV were held in two districts of Hanoi. No cholera cases were detected from 5 February to 4 March 2008, after which cases were again identified. Beginning 8 April 2008, residents of four districts of Hanoi admitted to one of five hospitals for acute diarrhea with onset after 5 March 2008 were recruited for a matched, hospital-based, case-control outbreak investigation. Cases were matched by hospital, admission date, district, gender, and age to controls admitted for non-diarrheal conditions. Subjects from the two vaccinated districts were evaluated to determine vaccine effectiveness. 54 case-control pairs from the vaccinated districts were included in the analysis. There were 8 (15% and 16 (30% vaccine recipients among cases and controls, respectively. The vaccine was 76% protective against cholera in this setting (95% CI 5% to 94%, P = 0.042 after adjusting for intake of dog meat or raw vegetables and not drinking boiled or bottled water most of the time. CONCLUSIONS/SIGNIFICANCE: This is the first study to explore the effectiveness of the reactive use of killed OCVs during a cholera outbreak. Our findings suggest that killed OCVs may have a role in controlling cholera outbreaks.

A Note on Penalized Regression Spline Estimation in the Secondary Analysis of Case-Control Data

KAUST Repository

Gazioglu, Suzan

2013-05-25

Primary analysis of case-control studies focuses on the relationship between disease (D) and a set of covariates of interest (Y, X). A secondary application of the case-control study, often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated due to the case-control sampling, and to avoid the biased sampling that arises from the design, it is typical to use the control data only. In this paper, we develop penalized regression spline methodology that uses all the data, and improves precision of estimation compared to using only the controls. A simulation study and an empirical example are used to illustrate the methodology.

A Note on Penalized Regression Spline Estimation in the Secondary Analysis of Case-Control Data

KAUST Repository

Gazioglu, Suzan; Wei, Jiawei; Jennings, Elizabeth M.; Carroll, Raymond J.

2013-01-01

Primary analysis of case-control studies focuses on the relationship between disease (D) and a set of covariates of interest (Y, X). A secondary application of the case-control study, often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated due to the case-control sampling, and to avoid the biased sampling that arises from the design, it is typical to use the control data only. In this paper, we develop penalized regression spline methodology that uses all the data, and improves precision of estimation compared to using only the controls. A simulation study and an empirical example are used to illustrate the methodology.

External radiotherapy prior to thyroid cancer: A case-control study

International Nuclear Information System (INIS)

Hallquist, A.; Loefroth, P.O.; Hardell, L.

1993-01-01

The aim of this investigation was to study previous radiotherapy of malignant diseases as a risk factor for thyroid cancer. By using the Swedish Cancer Registry all cases of thyroid cancer with another malignant disease at least one year previously and living within the catchment area of the hospital were traced. During 1959-1989 a total of 1056 cases of thyroid cancer were identified. Of these, 37 had had another previous malignant disease and they constituted the cases in this study. As controls four persons with at least two malignant diseases, thyroid cancer excluded, were selected for each case from the same cancer registry. Ten (27.0%) of the 37 patients with thyroid cancer as a second tumor had earlier been irradiated with the treatment dose including the thyroid gland as compared with 34 (24.5%) of the 139 control patients. Eight of the ten cases with previous irradiation of the thyroid gland had papillary cancer. The median latency was 13 years. The estimated radiation dose in the thyroid varied between 3 and 40 Gy. External radiotherapy gave a crude odds ratio of 1.1 with 95% confidence interval = 0.5-2.8 for thyroid cancer. The weighted odds ratio was calculated to 2.3 with confidence interval = 0.5-8.9. This case-control study gave a nonsignificantly increased odds ratio for thyroid cancer in patients with external radiotherapy including the thyroid gland. 26 refs., 4 tabs

Low maternal folate concentrations and maternal MTHFR C677T polymorphism are associated with an increased risk for neural tube defects in offspring: a case-control study among Pakistani case and control mothers.

Science.gov (United States)

Nauman, Nuzhat; Jalali, Samina; Shami, Sajjad; Rafiq, Shireen; Große, Greta; Hilger, Alina C; Zhang, Rhong; Mansoor, Saira; Ludwig, Michael; Reutter, Heiko

2018-01-01

There is considerable evidence that periconceptional maternal folate deficiency and coding variants in maternal genes coding for critical enzymes in the folate pathway are associated with neural tube defects (NTDs) in offspring. In a case-control study we investigated C677T polymorphism in the 5,10- methylenetetrahydrofolate reductase (MTHFR) gene in case and control mothers of Pakistani origin, and compared these with the respective maternal folate concentrations measured at the time of delivery. A case-control study was conducted among 109 case and 100 control mothers identified through the Holy Family Hospital Rawalpindi, Quaid-i-Azam University, Islamabad, Pakistan. Red blood cell (RBC) and serum folate concentrations and MTHFRC677T polymorphism were compared between case and control mothers. Mean RBC folate and serum folate concentrations were significantly lower in cases compared with control mothers (pcases compared with control mothers (CC vs TT pcases compared with control mothers (C vs T pCase mothers with 677CT or 677TT genotypes had significantly lower serum (pstudy provides further evidence that maternal folate deficiency and MTHFRC677T polymorphism might be associated with an increased risk for NTDs in offspring. Our results are limited by the fact that maternal folate concentrations were not obtained during the periconceptional period, but at delivery. Further analyses, including maternal folate levels during the periconceptional period, are warranted.

Effect of alpha amylase on early childhood caries: a matched case-control study

OpenAIRE

Mojarad, Farzad; Department of Pediatric Dentistry, School of Dentistry, Hamadan University of Medical Sciences, Hamadan; Fazlollahifar, Samira; Department of Pediatric Dentistry, School of Dentistry, Hamadan University of Medical Sciences, Hamadan; Poorolajal, Jalal; Research Center for Health Sciences, Department of Epidemiology & Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan; Hajilooi, Mehrdad; Department of Pathology, School of Dentistry, Hamadan University of Medical Sciences, Hamadan

2013-01-01

Objectives: There are a few studies addressing the relationship between salivary alpha-amylase and dental caries. This study was implemented in order to investigate the effect of salivary alpha-amylase level on early childhood caries (ECC).Materials and Methods: In this matched case-control study, which was carried out from November 2011 to March 2012 in Hamadan City, the west of Iran, mean levels of salivary alpha-amylase of 84 ECC-active cases were compared to that of 84 ECC-free controls u...

Investigation of Energy-Efficient Supermarket Display Cases

Energy Technology Data Exchange (ETDEWEB)

Walker, D.H.

2005-01-21

contributing about 3/4 of that fraction. Consequently, the focus of this investigation has tilted toward the open, vertical, multi-deck medium temperature case type. Various technologies and control methods are energy efficiency measures (EEMs) that could be applied to display cases and result in the reduction of the refrigeration load and of the energy consumption of the supermarket refrigeration system. An extensive evaluation of the EEMs was conducted in order to select those that met the following criteria: (1) Near-term implementation--All EEMs considered could be implemented with existing refrigeration hardware and technology. (2) Potential for energy-efficiency improvements--Energy savings and/or refrigeration load reduction must be obtained by the implementation of the EEM. (3) Enhancement of the ability to maintain target product temperature--Proper operation of the display case and maintenance of the stored product temperature could not be compromised by the use of the EEM. The energy impact of a number of viable display case EEMs was quantified by performing whole building hourly simulations. A special version of the U.S. Department of Energy's (DOE-2.3) program was used to develop a model of a supermarket. The model was then calibrated using available end-use monitored data to increase confidence in simulation results.

Risk factors for Buruli ulcer in Côte d'Ivoire: Results of a case-control ...

African Journals Online (AJOL)

A case-control study was carried out in 3 highly endemic regions of Côte d'Ivoire to study risk factors for Buruli ulcer. A case was defined as a Buruli ulcer occurring less than one year before the date of survey, resident in one of the regions investigated and there was no history of Buruli ulcer illness. Controls were selected ...

Psychosocial and Psychiatric Factors Associated with Adolescent Suicide: A Case-Control Psychological Autopsy Study

Science.gov (United States)

Portzky, Gwendolyn; Audenaert, Kurt; van Heeringen, Kees

2009-01-01

This study aimed at the investigation of psychosocial and psychiatric risk factors of adolescent suicide by means of a case-control psychological autopsy study. Relatives and other informants of 19 suicide victims and 19 matched psychiatric controls were interviewed by means of a semi-structured interview schedule. Psychiatric controls included…

Case-Control Studies of Sporadic Enteric Infections: A Review and Discussion of Studies Conducted Internationally from 1990 to 2009

Science.gov (United States)

Fullerton, Kathleen E.; Scallan, Elaine; Kirk, Martyn D.; Mahon, Barbara E.; Angulo, Frederick J.; de Valk, Henriette; van Pelt, Wilfrid; Gauci, Charmaine; Hauri, Anja M.; Majowicz, Shannon; O’Brien, Sarah J.

2015-01-01

Epidemiologists have used case-control studies to investigate enteric disease outbreaks for many decades. Increasingly, case-control studies are also used to investigate risk factors for sporadic (not outbreak-associated) disease. While the same basic approach is used, there are important differences between outbreak and sporadic disease settings that need to be considered in the design and implementation of the case-control study for sporadic disease. Through the International Collaboration on Enteric Disease “Burden of Illness” Studies (the International Collaboration), we reviewed 79 case-control studies of sporadic enteric infections caused by nine pathogens that were conducted in 22 countries and published from 1990 through to 2009. We highlight important methodological and study design issues (including case definition, control selection, and exposure assessment) and discuss how approaches to the study of sporadic enteric disease have changed over the last 20 years (e.g., making use of more sensitive case definitions, databases of controls, and computer-assisted interviewing). As our understanding of sporadic enteric infections grows, methods and topics for case-control studies are expected to continue to evolve; for example, advances in understanding of the role of immunity can be used to improve control selection, the apparent protective effects of certain foods can be further explored, and case-control studies can be used to provide population-based measures of the burden of disease. PMID:22443481

Exposure to pistachio pesticides and stillbirth: a case-control study

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Saeid Razi

2016-04-01

Full Text Available OBJECTIVES Stillbirth is an undesirable outcome of pregnancy. In light of the increasing use of pesticides and growing concerns about the possible health effects of agricultural pesticides, we investigated the effect of exposure to pistachio pesticides on stillbirth in pregnant mothers. METHODS This case-control study was conducted in Rafsanjan, Iran from 2011 to 2012. A total of 125 females who had a recent stillbirth were included as the case group, and 250 controls were selected from females who had a recent live birth. For each case, two controls with the nearest propensity score to the case were selected. Data were collected using a protocol developed by the researcher that involved interviewing respondents and reviewing their medical records. Conditional multivariate and univariate logistic regression analysis were performed and odds ratios (ORs and 95% confidence intervals (CIs were calculated. RESULTS The ORs of stillbirth in mothers living in pistachio gardens and those who were exposed to sprayed pesticides, in comparison to the controls, were 14.1 (95% CI, 3.3 to 63.4 and 5.0 (95% CI, 1.2 to 28.6, respectively. No significant differences were found in stillbirth rates according to the distance between the mother’s residence and a pistachio garden or involvement in agricultural activities. CONCLUSIONS The results of our study showed that exposure to pistachio pesticides during pregnancy may increase the likelihood of stillbirth in mothers.

Forensic investigation of suicide cases in major Greek correctional facilities.

Science.gov (United States)

Sakelliadis, E I; Vlachodimitropoulos, D G; Goutas, N D; Panousi, P I; Logiopoulou, A-P I; Delicha, E M; Spiliopoulou, C A

2013-11-01

According to Greek legislation the medico-legal investigation of deaths occurring in prisons is mandatory. Furthermore, in cases of suicide or of suspected suicide the contribution of medico-legal investigation is of grave importance. The current paper addresses the medico-legal investigation of suicide cases in Greek correctional facilities and aims to describe the current situation. Our study consists of the meticulous research in the data records of major Greek correctional facilities, for the time period 1999-2010. Official permission was obtained by the Hellenic Ministry of Justice, which provided us the access to the records. Data was also collected from the Piraeus Forensic Service, from the Department of Pathological Anatomy of the University of Athens and finally from our own records. Measures were taken to respect the anonymity of the cases. Data was collected for the social, penal, medical history as well as for the medico-legal investigation. It appears that 85.7% of suicide cases were transferred to the Prisoner's Hospital (p < 0.0001), the forensic pathologist who conducted the PME did not perform scene investigation in none of the 70 suicide cases. In a total of 70 cases, histopathological examination, was requested only in 30 cases (42.9%). Hanging was the preferred method for those who committed suicide, followed by the poisoning due to psychoactive substances. Understanding the mistakes made during the forensic investigation of suicide cases inside correctional facilities is necessary, in order to prevent them from occurring again in the future, by implementing appropriate new policies and guidelines. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Association Between Zolpidem Use and Glaucoma Risk: A Taiwanese Population-Based Case-Control Study

OpenAIRE

Ho, Yi-Hao; Chang, Yue-Cune; Huang, Wei-Cheng; Chen, Hsin-Yi; Lin, Che-Chen; Sung, Fung-Chang

2015-01-01

Background To date, the relationship between zolpidem use and subsequent risk of glaucoma in a Taiwanese population has not been assessed. Methods We used data from the National Health Insurance system to investigate whether zolpidem use was related to glaucoma risk. A 1:4 matched case-control study was conducted. The cases were patients newly diagnosed with glaucoma from 2001 to 2010. The controls were randomly selected non-glaucoma subjects matched by sex and age (?5 years). Zolpidem exposu...

Investigation of piloting aids for manual control of hypersonic maneuvers

Science.gov (United States)

Raney, David L.; Phillips, Michael R.; Person, Lee H., Jr.

1995-01-01

An investigation of piloting aids designed to provide precise maneuver control for an air-breathing hypersonic vehicle is described. Stringent constraints and nonintuitive high-speed flight effects associated with maneuvering in the hypersonic regime raise the question of whether manual control of such a vehicle should even be considered. The objectives of this research were to determine the extent of manual control that is desirable for a vehicle maneuvering in this regime and to identify the form of aids that must be supplied to the pilot to make such control feasible. A piloted real-time motion-based simulation of a hypersonic vehicle concept was used for this study, and the investigation focused on a single representative cruise turn maneuver. Piloting aids, which consisted of an auto throttle, throttle director, autopilot, flight director, and two head-up display configurations, were developed and evaluated. Two longitudinal control response types consisting of a rate-command/attitude-hold system and a load factor-rate/load-factor-hold system were also compared. The complete set of piloting aids, which consisted of the autothrottle, throttle director, and flight director, improved the average Cooper-Harper flying qualities ratings from 8 to 2.6, even though identical inner-loop stability and control augmentation was provided in all cases. The flight director was determined to be the most critical of these aids, and the cruise turn maneuver was unachievable to adequate performance specifications in the absence of this flight director.

Criminal investigations in child protective services cases: an empirical analysis.

Science.gov (United States)

Cross, Theodore P; Chuang, Emmeline; Helton, Jesse J; Lux, Emily A

2015-05-01

This study analyzed the frequency and correlates of criminal investigation of child maltreatment in cases investigated by child protective service (CPS), using national probability data from the National Survey of Child and Adolescent Well-Being. Criminal investigations were conducted in slightly more than 25% of cases. Communities varied substantially in percentage criminally investigated. Sexual abuse was the most frequent type of maltreatment criminally investigated followed by physical abuse. Logistic regression results indicated that criminal investigations were more likely when caseworkers perceived greater harm and more evidence; when CPS conducted an investigation rather than an assessment; when a parent or a legal guardian reported the maltreatment; and when cases were located in communities in which CPS and police had a memorandum of understanding (MOU) governing coordination. Most variation between communities in criminal investigation remained unexplained. The findings suggest the potential of MOUs for communities wanting to increase criminal investigation. © The Author(s) 2014.

Qat use and esophageal cancer in Ethiopia: A pilot case-control study.

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Maria E Leon

and religion differing between cases and controls. A large case-control study with enrolment of EC cases and carefully matched controls at health facilities from high-risk areas in the countryside, where the majority of cases occur, is needed to further investigate the association between qat use and EC.

A case-control study of Yersinia enterocolitica infections in Auckland.

Science.gov (United States)

Satterthwaite, P; Pritchard, K; Floyd, D; Law, B

1999-10-01

To identify major risk factors for Yersinia enterocolitica (YE) and identify measures to reduce YE infections. A prospective case control study, group age matched, using 186 cases of YE identified by community pathology laboratories and 379 randomly selected controls. Conducted between April 1995 and June 1996 in Auckland, New Zealand. Face-to-face interviews used a standardised questionnaire examining exposures to factors potentially associated with YE infections including untreated water, unreticulated sewerage, consumption of selected foods, selected food handling practices and socio-demographic factors. Multivariate logistic regression was used to calculate adjusted odds ratios for the potential risk factors. Population attributable risk (PAR) was calculated for significant exposures. Having more than two people living in the home was more common among cases than controls (OR = 2.2). Town supply water (OR = 0.2), reticulated sewerage (OR = 0.34) and looking after a young child (OR = 0.51) were significantly less common. Of the meats, only pork (OR = 1.34) had a higher consumption rate, while bacon (OR = 0.75) and smallgoods (OR = 0.73) were consumed less frequently by cases than controls. Eating food from a sandwich bar was more frequent among cases (OR = 1.18). Fruit and vegetable consumption was marginally less (OR = 0.98). The population attributable risk of these factors was 0.89, implying that 89% of YE would be eliminated if adverse exposures were removed. The risk of YE illness is increased by contact with untreated water, unreticulated sewerage and consumption of pork. Investigation of non-town water supply, informal sewerage systems and methods of preparation and consumption of pork are recommended to determine how YE enters the human food chain.

Pesticide Exposure and Head and Neck Cancers: A Case-Control Study in an Agricultural Region

Directory of Open Access Journals (Sweden)

Maryam Amizadeh

2017-09-01

Full Text Available Introduction: Causes of head and neck cancers (HNCs are multifactorial, and few studies have investigated the association between chemical exposure and HNCs. The objective of this study was to investigate associations between HNCs, agricultural occupations, and pesticide exposure. The potential for the accumulation of pesticides in the adipose tissue of patients was also investigated.   Materials and Methods: A structured questionnaire was used to collect information on demographics, occupation, and exposure to pesticides in a hospital-based case-control study. Pesticide residue in the adipose tissue of the neck in both cases and controls was also monitored via gas chromatography–mass spectroscopy.   Results: Thirty-one HNC cases were included in this study as well as 32 gender-, age-, and smoking-matched controls. An agricultural occupation was associated with HNC (odds ratio [OR], 3.26; 95% confidence interval [CI], 1.13–9.43 after controlling for age, sex, and smoking. Pesticide exposure was associated with total HNC cases (OR, 7.45; 95% CI, 1.78–3.07 and larynx cancer (OR, 9.33; 95% CI, 1.65–52.68. A dose-response pattern was observed for HNC cases (P=0.06 and larynx cancer (P=0.01. In tracing the pesticide residue, five chlorinated pesticides, namely dichlorodiphenyltrichloroethane (DDT, dichlorodipheny-ldichloroethane (DDD, dichlorodiphenyldichloroethylene (DDE, dieldrin, and lindane, were identified in the adipose tissue. Chlorinated pesticide detection was significantly associated with HNC (OR, 3.91; 95% CI 0.9–0.16.9.   Conclusion: HNCs were found to be associated with pesticide exposure after controlling for confounders. A high education level was identified as a modifying factor decreasing the risk of HNCs. Further studies with larger number of subjects are recommended to assess these relationships in greater detail.

A case-control study of risk factors for bovine cysticercosis in Danish cattle herds

DEFF Research Database (Denmark)

Calvo Artavia, Francisco Fernando; Nielsen, Liza Rosenbaum; Dahl, J.

2013-01-01

than in countries with few lightly infected cases per year. The aim of the present case-control study was to quantify associations between potential herd-level risk factors and BC in Danish cattle herds. Risk factors can be used in the design of a risk-based meat inspection system targeted towards...... a questionnaire and register data from the Danish Cattle Database were grouped into meaningful variables and used to investigate the risk factors for BC using a multivariable logistic regression model. Case herds were almost three times more likely than control herds to let all or most animals out grazing. Case...... the animals with the highest risk of BC. Cases (n = 77) included herds that hosted at least one animal diagnosed with BC at meat inspection, from 2006 to 2010. Control herds (n = 231) consisted of randomly selected herds that had not hosted any animals diagnosed with BC between 2004 and 2010. The answers from...

Weight, height, body mass index and risk of breast cancer in postmenopausal women: a case-control study

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Vahdaninia Mariam

2008-09-01

Full Text Available Abstract Background Many women in Iran have a relatively high body mass index. To investigate whether the condition contributes to excess breast cancer cases, a case-control study was conducted to assess the relationships between anthropometric variables and breast cancer risk in Tehran, Iran. Methods All incident cases of breast cancer in the Iranian Centre for Breast Cancer (ICBC were identified through the case records. Eligible cases were all postmenopausal women with histological confirmed diagnosis of breast cancer during 1996 to year 2000. Controls were randomly selected postmenopausal women attending the ICBC for clinical breast examination during the same period. The body mass index (BMI was calculated based on weights and heights as measured by the ICBC nursing staff. Both tests for trend and logistic regression analysis were performed to calculate odds ratios and 95% confidence intervals as measures of relative risk. Results In all, 116 breast cancer cases and 116 controls were studied. There were no significant differences between cases and control with regard to most independent variables studied. However, a significant difference was observed between cases and controls indicating that the mean BMI was higher in cases as compared to controls (P = 0.004. Performing logistic regression analysis while controlling for age, age at menopause, family history of breast cancer and parity, the results showed that women with a BMI in the obese range had a three fold increased risk of breast cancer [odds ratio (OR = 3.21, 95% confidence interval (CI: 1.15–8.47]. Conclusion The results suggest that obesity in postmenopausal women could increase risk of breast cancer and it merits further investigation in populations such as Iran where it seems that many women are short in height, and have a relatively high body mass index.

Investigation of an isolated case of human Crimean–Congo hemorrhagic fever in Central Uganda, 2015

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Stephen Balinandi

2018-03-01

Full Text Available Background: Crimean–Congo hemorrhagic fever (CCHF is the most geographically widespread tick-borne viral infection. Outbreaks of CCHF in sub-Saharan Africa are largely undetected and thus under-reported. On November 9, 2015, the National Viral Hemorrhagic Fever Laboratory at the Uganda Virus Research Institute received an alert for a suspect VHF case in a 33-year-old male who presented with VHF compatible signs and symptoms at Mengo Hospital in Kampala. Methods: A blood sample from the suspect patient was tested by RT-PCR for CCHF and found positive. Serological testing on sequential blood specimens collected from this patient showed increasing anti-CCHFV IgM antibody titers, confirming recent infection. Repeat sampling of the confirmed case post recovery showed high titers for anti-CCHFV-specific IgG. An epidemiological outbreak investigation was initiated following the initial RT-PCR positive detection to identify any additional suspect cases. Results: Only a single acute case of CCHF was detected from this outbreak. No additional acute CCHF cases were identified following field investigations. Environmental investigations collected 53 tick samples, with only 1, a Boophilus decoloratus, having detectable CCHFV RNA by RT-PCR. Full-length genomic sequencing on a viral isolate from the index human case showed the virus to be related to the DRC (Africa 2 lineage. Conclusions: This is the fourth confirmed CCHF outbreak in Uganda within 2 years after more than 50 years of no reported human CCHF cases in this country. Our investigations reaffirm the endemicity of CCHFV in Uganda, and show that exposure to ticks poses a significant risk for human infection. These findings also reflect the importance of having an established national VHF surveillance system and diagnostic capacity in a developing country like Uganda, in order to identify the first cases of VHF outbreaks and rapidly respond to reduce secondary cases. Additional efforts should focus on

Investigation of suspected TRALI cases in 2006–2011

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Marjeta Maček Kvanka

2012-12-01

Methods: In 2006–2011, eight suspected TRALI cases that met consensus clinical criteria and had chest radiograph were investigated in the Blood Transfusion Center of Slovenia. Patients and all donors of blood components transfused within 6 hours before the onset of acute respiratory distress were investigated for leukocyte antibodies against HLA class I and II antigens, and antibodies against neutrophil antigens HNA. All cases were investigated for patient, donor and blood component characteristics. In cooperation with clinicians, chest radiographs and alternative risk factors for acute lung injury (ALI were evaluated.

Prevalence of Periodontitis in Patients with Established Rheumatoid Arthritis: A Swedish Population Based Case-Control Study

Science.gov (United States)

Eriksson, Kaja; Nise, Lena; Kats, Anna; Luttropp, Elin; Catrina, Anca Irinel; Askling, Johan; Jansson, Leif; Alfredsson, Lars; Klareskog, Lars; Lundberg, Karin; Yucel-Lindberg, Tülay

2016-01-01

Introduction The possible hypothesis of a link between periodontitis and rheumatoid arthritis (RA), specifically anti-citrullinated protein antibody (ACPA) positive RA, prompted us to investigate the prevalence of periodontitis in the Swedish Epidemiological Investigation of RA (EIRA), a well-characterised population-based RA case-control cohort. Methods Periodontal status of 2,740 RA cases and 3,942 matched controls was retrieved through linking EIRA with the National Dental Health Registry (DHR), where dental diagnostic- and treatment codes on the adult Swedish population have been registered. Dental records from 100 cases and controls were reviewed to validate the periodontal diagnostic codes in DHR. Results The reviewed dental records confirmed 90% of the periodontitis diagnoses in DHR among RA cases, and 88% among controls. We found the positive predictive value of periodontitis diagnoses in the DHR to be 89% (95% CI 78 to 95%) with a sensitivity of 77% (95% CI: 65 to 86%). In total, 86% of EIRA participants were identified in DHR. The risk for periodontitis increased by age and current smoking status in both cases as well as controls. No significant differences in prevalence of periodontal disease in terms of gingivitis, periodontitis, peri-implantitis or increased risk for periodontitis or peri-implantitis were observed between RA cases and controls. In addition, there was no difference on the basis of seropositivity, ACPA or rheumatoid factor (RF), among patients with RA. Conclusions Our data verify that smoking and ageing are risk factors for periodontitis, both in RA and controls. We found no evidence of an increased prevalence of periodontitis in patients with established RA compared to healthy controls, and no differences based on ACPA or RF status among RA subjects. PMID:27203435

Experimental Investigation on Aerodynamic Control of a Wing with Distributed Plasma Actuators

International Nuclear Information System (INIS)

Han Menghu; Li Jun; Liang Hua; Zhao Guangyin; Niu Zhongguo

2015-01-01

Experimental investigation of active flow control on the aerodynamic performance of a flying wing is conducted. Subsonic wind tunnel tests are performed using a model of a 35° swept flying wing with an nanosecond dielectric barrier discharge (NS-DBD) plasma actuator, which is installed symmetrically on the wing leading edge. The lift and drag coefficient, lift-to-drag ratio and pitching moment coefficient are tested by a six-component force balance for a range of angles of attack. The results indicate that a 44.5% increase in the lift coefficient, a 34.2% decrease in the drag coefficient and a 22.4% increase in the maximum lift-to-drag ratio can be achieved as compared with the baseline case. The effects of several actuation parameters are also investigated, and the results show that control efficiency demonstrates a strong dependence on actuation location and frequency. Furthermore, we highlight the use of distributed plasma actuators at the leading edge to enhance the aerodynamic performance, giving insight into the different mechanism of separation control and vortex control, which shows tremendous potential in practical flow control for a broad range of angles of attack. (paper)

Thyrotropin receptor autoantibodies and early miscarriages in patients with Hashimoto thyroiditis: a case-control study.

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Toulis, Konstantinos A; Goulis, Dimitrios G; Tsolakidou, Konstantina; Hilidis, Ilias; Fragkos, Marios; Polyzos, Stergios A; Gerofotis, Antonios; Kita, Marina; Bili, Helen; Vavilis, Dimitrios; Daniilidis, Michail; Tarlatzis, Basil C; Papadimas, Ioannis

2013-08-01

We have previously hypothesized that early miscarriage in women with Hashimoto thyroiditis might be the result of a cross-reactivity process, in which blocking autoantibodies against thyrotropin receptor (TSHr-Ab) antagonize hCG action on its receptor on the corpus luteum. To test this hypothesis from the clinical perspective, we investigated the presence of TSHr-Ab in Hashimoto thyroiditis patients with apparently unexplained, first-trimester recurrent miscarriages compared to that in Hashimoto thyroiditis patients with documented normal fertility. A total of 86 subjects (43 cases and 43 age-matched controls) were finally included in a case-control study. No difference in the prevalence of TSHr-Ab positivity was detected between cases and controls (Fisher's exact test, p value = 1.00). In patients with recurrent miscarriages, TSHr-Ab concentrations did not predict the number of miscarriages (univariate linear regression, p value = 0.08). These results were robust in sensitivity analyses, including only cases with full investigation or those with three or more miscarriages. We conclude that no role could be advocated for TSHr-Ab in the aetiology of recurrent miscarriages in women with Hashimoto thyroiditis.

Risk factors associated with hantavirosis fatality: a regional analysis from a case-control study in Brazil

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Maria Cristina Antunes Willemann

2014-01-01

Full Text Available Introduction: In Brazil, hantavirus cardiopulmonary syndrome (HCPS has a high lethality rate that varies by region. This study aimed to identify the risk factors associated with fatal hantavirosis. Methods: This study was a case-control study that included all laboratory confirmed cases of hantavirosis. The cases were stratified by the different Brazilian regions using data from the Notifiable Diseases Information System. “Cases” were patients who progressed to death, whereas “controls” were patients who were cured. The odds ratio (OR and the adjusted OR were calculated. Results: Overall, 158 cases and 281 controls were included in this study. In the Midwest region, the cases were 60% less likely to present with flank pain, and the time between the beginning of symptoms and death was shorter than the time between the beginning of symptoms and a cure. In the Southeast region, the cases were 60% less likely to present with thrombocytopenia or reside in rural areas compared to those who progressed to a cure. Additionally, the cases sought medical assistance, notification and investigation more quickly than the controls. In the Southern region, the cases that died were 70% less likely to be male compared to the controls. Conclusions: HCPS manifests with nonspecific symptoms, and there are few published studies related to the condition, so determining a patient's therapeutic strategy is difficult. This study presents findings from different Brazilian regions and highlights the need for further investigations to improve comprehension about regional risk factors associated with hantavirosis and to reduce morbimortality.

Waterparks are high risk for cryptosporidiosis: A case-control study in Victoria, 2015.

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de Gooyer, Tanyth E; Gregory, Joy; Easton, Marion; Stephens, Nicola; Fearnley, Emily; Kirk, Martyn

2017-06-30

An increase in notifications of cryptosporidiosis was observed in Victoria between March and April 2015. Cases mostly resided in one metropolitan region and hypothesis-generating interviews identified common exposures to aquatic facilities. We conducted a case-control study to determine exposure source(s) and facilitate control measures. Laboratory-confirmed cases of cryptosporidiosis from the region of interest notified between 1 March and 23 April 2015 were included. Controls residing in the same region were recruited from participants in a population health survey and frequency matched (2 per case) by age group. Details of exposure to potential risk factors were collected using a standardised telephone questionnaire for the 14-days prior to illness for cases, and an analogous exposure period for controls. Univariable and multivariable logistic regression were used to determine risk factors associated with illness using STATA SE 13.1. Thirty cases and 66 controls were included in the study. Half the cases were less than 12 years of age and 62% were female. Illness was most strongly associated with recreational water exposure at any waterpark (adjusted odds ratio (aOR)=73.5; 95% confidence interval (CI):6.74-802), and specifically at Victorian waterparks (aOR=45.6; 95% CI:5.20-399). Cases were linked with attendance at either a waterpark in the region or an adjacent region. As a result of this investigation, hyperchlorination was completed at identified facilities and swim hygiene information distributed. This study reinforces the potential for recreational water facilities, particularly waterparks, to act as a transmission source of Cryptosporidium infections. Continued communication to patrons is required to ensure healthy swimming practice in Victorian aquatic facilities.

Evaluation of TB Case Finding through Systematic Contact Investigation, Chhattisgarh, India

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Kshitij Khaparde

2015-01-01

Full Text Available Rationale. Contact investigation is an established tool for early case detection of tuberculosis (TB. In India, contact investigation is not often conducted, despite national policy, and the yield of contact investigation is not well described. Objective. To determine the yield of evaluating household contacts of sputum smear-positive TB cases in Rajnandgaon district, Chhattisgarh, India. Methods. Among 14 public health care facilities with sputum smear microscopy services, home visits were conducted to identify household contacts of all registered sputum smear-positive TB cases. We used a standardized protocol to screen for clinical symptoms suggestive of active TB with additional referral for chest radiograph and sputa collection. Results. From December 2010 to May 2011, 1,556 household contacts of 312 sputum smear-positive TB cases were identified, of which 148 (9.5% were symptomatic. Among these, 109 (73.6% were evaluated by sputum examination resulting in 11 cases (10.1% of sputum smear-positive TB and 4 cases (3.6% of smear-negative TB. Household visits contributed additional 63% TB cases compared to passive case detection alone. Conclusion. A standard procedure for conducting household contact investigation identified additional TB cases in the community and offered an opportunity to initiate isoniazid chemoprophylaxis among children.

Mild asthma and chronic bronchitis seem to influence functional exercise capacity: a multi-case control study.

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Marcon, Alessandro; Girardi, Paolo; Ferrari, Marcello; Olivieri, Mario; Accordini, Simone; Bombieri, Cristina; Bortolami, Oscar; Braggion, Marco; Cappa, Veronica; Cazzoletti, Lucia; Locatelli, Francesca; Nicolis, Morena; Perbellini, Luigi; Sembeni, Silvia; Verlato, Giuseppe; Zanolin, Maria Elisabetta; de Marco, Roberto

2013-01-01

In the Genes Environment Interaction in Respiratory Diseases population-based multi-case control study, we investigated whether asthma, chronic bronchitis (CB) and rhinitis were associated with a reduced 6-minute walk distance (6MWD), and whether the 6MWD determinants were similar for subjects with/without respiratory diseases. Cases of asthma (n = 360), CB (n = 120), rhinitis (n = 203) and controls (no respiratory diseases: n = 302) were recruited. The variation in the 6MWD across the groups was analyzed by ANCOVA, adjusting for gender, age, height, weight and comorbidity. The 6MWD determinants were studied by linear regression, and heterogeneity across the cases and controls was investigated. The 6MWD differed across cases and controls (p = 0.01). It was shorter for cases of asthma (-17.1, 95% CI -28.3 to -5.8 m) and CB (-20.7, 95% CI: -36.6 to -4.8 m) than for controls (604 ± 68 m on average), but not for cases of rhinitis. The negative association between age and the 6MWD was significant for cases of CB, but not for the other groups (p = 0.001). Even at the level of severity found in the general population, asthma and CB could influence the 6MWD, which seems to reflect the functional exercise level for daily physical activities. The negative association between ageing and the 6MWD was particularly strong in subjects with CB. Our report adds to the mounting evidence that CB is not a trivial condition, especially in the ageing adult population, and it supports the importance of monitoring functional capacity and of physical reconditioning in mild asthma. Copyright © 2013 S. Karger AG, Basel.

Investigating sexual problems, psychological distress and quality of life in female patients with Takotsubo cardiomyopathy: A prospective case-control study.

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Saffari, Mohsen; Lin, Chung-Ying; Broström, Anders; Mårtensson, Jan; Malm, Dan; Burri, Andrea; Fridlund, Bengt; Pakpour, Amir H

2017-10-01

Takotsubo cardiomyopathy (TSCM) has detrimental effects on both physical and psychological health of sufferers. However, little is known whether TSCM also affects sexual functioning in female patients. The aim of this study was to investigate psychological distress (depression and anxiety), health-related quality of life, and sexual functioning in women with TSCM and compare them with women with acute myocardial infarction and with healthy controls. A three group prospective case-control design was used. Female patients with TSCM or acute myocardial infarction, as well as healthy controls (94 in each group), were recruited across eight Iranian university hospitals. Data were collected at baseline and after six and 18 months using the Hospital Anxiety and Depression Scale, the Short Form-12, the Female Sexual Function Index and the Female Sexual Distress Scale. Multilevel logistic regression was conducted. The TSCM group showed worst sexual functioning and the highest level of anxiety and depression at baseline ( pquality of life at baseline, which was lower in both groups compared with the healthy controls ( pquality of life showed a significant change over time, especially in the TSCM group, with health-related quality of life decreasing, while anxiety and depression were increasing. Compared with the acute myocardial infarction and healthy control groups, the TSCM group showed a higher prevalence of sexual problems (odds ratios = 3.10 and 2.28, respectively) across time. Moreover, sexual functioning was found to be a mediator between anxiety and health-related quality of life in the TSCM group. Depression, anxiety, health-related quality of life, and sexual dysfunction tend to increase over time in female patients with TSCM; thus, healthcare providers should pay attention to these problems and provide appropriate treatment where necessary.

Exposure to antiepileptic drugs and the risk of hip fracture: a case-control study

DEFF Research Database (Denmark)

Tsiropoulos, Ioannis; Andersen, Morten; Nymark, Tine

2008-01-01

PURPOSE: To investigate whether the use of antiepileptic drugs (AEDs) increases the risk of hip fracture. METHODS: We performed a case-control study using data from the Funen County (population 2004: 475,000) hip fracture register. Cases (n = 7,557) were all patients admitted to county hospitals...... with a hip fracture during the period 1996-2004. Controls (n = 27,575) were frequency matched by age and gender. Information on use of AEDs, other drugs, and hospital contacts was available from local registers. Odds ratios (ORs) with 95% confidence intervals (CI) for hip fracture were estimated...

Leptospira Exposure and Gardeners: A Case-Control Seroprevalence Study

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Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

2016-01-01

Background Leptospira can be found in soil. However, it is unclear whether occupational exposure to soil may represent a risk for Leptospira infection in humans. Therefore, we sought to determine the association of Leptospira IgG seroprevalence with the occupation of gardener, and to determine the epidemiological characteristics of gardeners associated with Leptospira exposure. Methods We performed a case-control study in 168 gardeners and 168 age- and gender-matched control subjects without gardening occupation in Durango City, Mexico. The seroprevalence of anti-Leptospira IgG antibodies in cases and controls was determined using an enzyme immunoassay. Bivariate and multivariate analyses were used to assess the association of Leptospira exposure and the characteristics of the gardeners. Results Anti-Leptospira IgG antibodies were found in 10 (6%) of 168 gardeners and in 15 (8.9%) of 168 control subjects (odds ratio (OR): 0.64; 95% confidence interval (CI): 0.28 - 1.48; P = 0.40). Multivariate analysis showed that Leptospira seropositivity was positively associated with female gender (OR: 5.82; 95% CI: 1.11 - 30.46; P = 0.03), and negatively associated with eating while working (OR: 0.21; 95% CI: 0.05 - 0.87; P = 0.03). In addition, multivariate analysis showed that high anti-Leptospira levels were associated with consumption of boar meat (OR: 28.00; 95% CI: 1.20 - 648.80; P = 0.03). Conclusions This is the first case-control study of Leptospira exposure in gardeners. Results do not support an association of Leptospira exposure with the occupation of gardener. However, further studies to confirm the lack of this association are needed. The potential role of consumption of boar meat in Leptospira infection deserves further investigation. PMID:26668679

Association between smoking habits and acne vulgaris. A case-control study

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Alice Mannocci

2012-09-01

Full Text Available

Background: acne vulgaris, is one of the most common skin disorder. Previous studies about the role of smoke in the pathogenesis of acne reported contradictory results. The aim of this study was to conduct a case-control study investigating the relationship between tobacco smoking and acne.

Methods: a case-control study was performed during the period September 2009 - February 2010. A questionnaire was administrated to each participant, to assess the association acne - smoke. Cases were outpatients of the Dermatologic Ambulatory of the “Fiorini” Hospital, Sapienza University of Rome (Italy. Controls were age and gender-matched to the cases. The ratio cases-controls was 1:2. A univariate and a multiple logistic regression analysis were conducted; Odds Ratio (OR and the relative 95% confidence interval (95%CI were assessed. The statistical significance was set at p < 0.05.

Results: crude OR for the association acne - smoke was 7.26 (IC=2.27-23.18; adjusted OR for sex and age was 5.47 (IC=1.67-17.97. Of 93 cases, 6 had a severe grade of acne (6.5%, 19 had an intermediate grade of acne (20.4%, and 68 had a mild grade of acne (73.1%. No one of the smokers had a severe grade of acne, one had an intermediate grade of acne and 11 had mild acne; these differences are not statistically significant.

Conclusions: the association between acne and smoke shows an increased risk (OR=7.26 with a statistically significant CI. Moreover, people ≥ 18 years of age have twice the risk compared to persons < 18 years of age (OR=2.31.

Gingivitis and periodontitis as a risk factor for stroke: A case-control study in the Iranian population.

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Hashemipour, Maryam Alsadat; Afshar, Afsaneh Jahanshahi; Borna, Roya; Seddighi, Behnas; Motamedi, Amin

2013-09-01

Periodontitis and gingivitis are one of the most infectious diseases in human. Several studies have been carried out on dependence of periodontitis and stroke. The aim of this study was to investigate the gingivitis and periodontitis as a risk factor for stroke in Iranian population. A case-control study was conducted on 100 patients suffering from stroke as case group, and 100 hospitalized patients as control group. The case group included 42 males and 58 females, and in control group there were 44 males and 56 females. Using a University of North Carolina-15 manual probe, the clinical attachment level, the distance between the cemento-enamel junction and the probed base of the periodontal pocket, were recorded by gingival and periodontal indexes. The data were analyzed by multiple logistic regressions, Chi-square test, Fisher's test, t-test, Man Whitney, and SPSS11.5 software program. P > 0.05 was considered as significant. The case group included 42 males and 58 females, and in control group 44 males and 56 females were included. In this investigation, the average of gingival index in men and women of case group was 1.22 ± 0.55 and 1.31 ± 0.55, respectively. This study showed that the average of gingival index in case group was more than control group. Periodontal index in both groups in men was more than women. The moderate and severe periodontitis in case group were more than that of control group (P = 0.003, P = 0.001). The result of this study shows that there is a significant relation between stroke and periodontal index; however, there isn't any significant relation between stroke and gingival index.

A case-control study on risk of changing food consumption for colorectal cancer.

Science.gov (United States)

Zhang, Bing; Li, Xiangping; Nakama, Hidenori; Zhang, Xing; Wei, Ning; Zhang, Xiulan; Zhang, Leshan

2002-01-01

To investigate the relative risk factor of food items for colorectal cancer in four time periods through a case-control study in a Chinese rural area. Colorectal cancer patients diagnosed at a county cancer center, Hebei Province, China, and non-cancer outpatients with similar age, sex, and place of residence were selected for cases and controls, respectively. There were 102 (93.6%) colorectal cancer patients and 99 (90.8%) outpatients being the cases and controls, respectively in the present investigation, who agreed to be interviewed about their food intake, during a 20-year period, through a food frequency questionnaire. The risks of intake of different food items and lifestyle for colorectal cancer were compared between cases and controls. During the 20-year period, diets of both cases and controls changed with increase in intake of animal foods and fruits, and alcohol consumption tended to increase. In the food items, milk intake showed a protective effect in both males and females, and the odds ratios were 0.38 (95% CI 0.16-0.90) and 0.28 (95% CI 0.10-0.81) for males and females, respectively. A reduced risk of fruit intake could be seen in males, while a reduced risk of vegetables could be observed in females. Meat intake and saturated fats were the prominent risk factors for colorectal cancer in males and females, respectively. A comparison of life habits, showed that tea drinking had a consistent protective effect in females, and the odds ratios were 0.21 (0.08-0.58), 0.23 (0.08-0.67), 0.25 (0.10-0.64), and 0.11 (0.04-0.30) for periods of 20-, 10-, 5-years ago, and current time, respectively. These findings indicate that change in food consumption is strongly associated with a change in risk of colorectal cancer, and dietary meat has increased the risk of colorectal cancer. Increase in the consumption of milk and fruits may be a significant measure for colorectal cancer prevention in low-incidence areas.

Sensory impairments and wrist fractures: A case-control study

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Bergthora Baldursdottir

2017-12-01

Full Text Available Objectives: To investigate vestibular function, foot sensation, postural control and functional abilities, and to evaluate whether these variables are associated with fall-related wrist fracture. Methods: A case-control study was conducted with 98 subjects, age range 50–75 years, who had sustained a fall-related wrist fracture. Forty-eight sex-, age- and physical activity-matched individuals, with no previous history of wrist fracture, served as controls. Measurements included: head-shake test (HST, tuning fork, biothesiometer, Semmes-Weinstein monofilaments (MF, Sensory Organization Test (SOT, Five-Times-Sit-to-Stand Test (FTSTS, 10-m walk test (10MWT, Activities-specific Balance Confidence (ABC, and the Dizziness Handicap Inventory (DHI scales. Logistic regression models were used to determine associations of variables with a fall-related wrist fracture. Results: Vestibular asymmetry was apparent in 82% of wrist fracture subjects and 63% of controls (p = 0.012. Plantar pressure sensation (p <0.001, SOT composite scores (p < 0.001, 10MWT (p <0.001, FTSTS (p <0.001, ABC (p <0.001 and DHI (p <0.005 were significantly poorer among cases than controls. A positive HST (odds ratio (OR 5.424; p = 0.008 and monofilament sensation (OR 3.886; p = 0.014 showed the strongest associations with having a fall-related wrist fracture. Conclusion: Asymmetrical vestibular function and reduced plantar pressure sensation are associated with fall-related wrist fractures among the ageing population. These factors are potential targets for future interventions.

Psychiatric comorbidity may not predict suicide during and after hospitalization. A nested case-control study with blinded raters.

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Walby, Fredrik A; Odegaard, Erik; Mehlum, Lars

2006-06-01

To investigate the differential impact of DSM-IV axis-I and axis-II disorders on completed suicide and to study if psychiatric comorbidity increases the risk of suicide in currently and previously hospitalized psychiatric patients. A nested case-control design based on case notes from 136 suicides and 166 matched controls. All cases and controls were rediagnosed using the SCID-CV for axis-I and the DSM-IV criteria for axis-II disorders and the inter-rater reliability was satisfactory. Raters were blind to the case and control status and the original hospital diagnoses. Depressive disorders and bipolar disorders were associated with an increased risk of suicide. No such effect was found for comorbidity between axis-I disorders and for comorbidity between axis-I and axis-II disorders. Psychiatric diagnoses, although made using a structured and criteria-based approach, was based on information recorded in case notes. Axis-II comorbidity could only be investigated at an aggregated level. Psychiatric comorbidity did not predict suicide in this sample. Mood disorders did, however, increase the risk significantly independent of history of previous suicide attempts. Both findings can inform identification and treatment of patients at high risk for completed suicide.

A population-based case-control study on statin exposure and risk of acute diverticular disease.

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Sköldberg, Filip; Svensson, Tobias; Olén, Ola; Hjern, Fredrik; Schmidt, Peter T; Ljung, Rickard

2016-01-01

A reduced risk of perforated diverticular disease among individuals with current statin exposure has been reported. The aim of the present study was to investigate whether statins reduce the risk of acute diverticular disease. A nation-wide population-based case-control study was performed, including 13,127 cases hospitalised during 2006-2010 with a first-time diagnosis of colonic diverticular disease, and 128,442 control subjects (matched for sex, age, county of residence and calendar year). Emergency surgery, assumed to be a proxy for complicated diverticulitis, was performed on 906 of the cases during the index admission, with 8818 matched controls. Statin exposure was classified as "current" or "former" if a statin prescription was last dispensed ≤ 125 days or >125 days before index date, respectively. The association between statin exposure and acute diverticular disease was investigated by conditional logistic regression, including models adjusting for country of birth, educational level, marital status, comorbidities, nonsteroidal anti-inflammatory drug/steroid exposure and healthcare utilisation. A total of 1959 cases (14.9%) and 16,456 controls (12.8%) were current statin users (crude OR 1.23 [95% CI 1.17-1.30]; fully adjusted OR 1.00 [0.94-1.06]). One hundred and thirty-two of the cases subjected to surgery (14.6%), and 1441 of the corresponding controls (16.3%) were current statin users (crude OR 0.89 [95% CI 0.73-1.08]; fully adjusted OR 0.70 [0.55-0.89]). The results do not indicate that statins affect the development of symptomatic diverticular disease in general. However, current statin use was associated with a reduced risk of emergency surgery for diverticular disease.

Selection of population controls for a Salmonella case-control study in the UK using a market research panel and web-survey provides time and resource savings.

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Mook, P; Kanagarajah, S; Maguire, H; Adak, G K; Dabrera, G; Waldram, A; Freeman, R; Charlett, A; Oliver, I

2016-04-01

Timely recruitment of population controls in infectious disease outbreak investigations is challenging. We evaluated the timeliness and cost of using a market research panel as a sampling frame for recruiting controls in a case-control study during an outbreak of Salmonella Mikawasima in the UK in 2013. We deployed a web-survey by email to targeted members of a market research panel (panel controls) in parallel to the outbreak control team interviewing randomly selected public health staff by telephone and completing paper-based questionnaires (staff controls). Recruitment and completion of exposure history web-surveys for panel controls (n = 123) took 14 h compared to 15 days for staff controls (n = 82). The average staff-time cost per questionnaire for staff controls was £13·13 compared to an invoiced cost of £3·60 per panel control. Differences in the distribution of some exposures existed between these control groups but case-control studies using each group found that illness was associated with consumption of chicken outside of the home and chicken from local butchers. Recruiting market research panel controls offers time and resource savings. More rapid investigations would enable more prompt implementation of control measures. We recommend that this method of recruiting controls is considered in future investigations and assessed further to better understand strengths and limitations.

Risk factors associated with sick leave due to work-related injuries in Dutch farmers: an exploratory case-control study

NARCIS (Netherlands)

Hartman, E.; Frankena, K.; Oude Vrielink, H.H.E.; Nielen, M.; Metz, J.H.M.; Huirne, R.B.M.

2004-01-01

Using data from an insurance company, the occurrence of sick leave among Dutch farmers due to work-related injuries, and the epidemiological risk factors were investigated. In this case-control study the cases had filed a sick leave claim for work-related injury from 19982001 and the controls had

Population versus hospital controls for case-control studies on cancers in Chinese hospitals.

Science.gov (United States)

Li, Lin; Zhang, Min; Holman, D'Arcy

2011-12-15

Correct control selection is crucial to the internal validity of case-control studies. Little information exists on differences between population and hospital controls in case-control studies on cancers in Chinese hospital setting. We conducted three parallel case-control studies on leukemia, breast and colorectal cancers in China between 2009 and 2010, using population and hospital controls to separately match 540 incident cases by age, gender and residency at a 1:1 ratio. Demographic and lifestyle factors were measured using a validated questionnaire in face-to-face interview. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using conditional logistic regression analyses. The two control groups had closely similar exposure distributions of 15 out of 16 factors, with the only exception being that hospital controls were less likely to have a BMI ≥ 25 (OR = 0.71, 95% CI: 0.54, 0.93). For exposure of green tea drinking, the adjusted ORs (95% CIs) comparing green tealeaves intake ≥ 1000 grams annually with non-drinkers were 0.51 (0.31, 0.83) and 0.21 (0.27, 0.74) for three cancers combined, 0.06 (0.01, 0.61) and 0.07 (0.01, 0.47) for breast cancer, 0.52 (0.29, 0.94) and 0.45 (0.25, 0.82) for colorectal cancer, 0.65 (0.08, 5.63) and 0.57 (0.07, 4.79) for leukemia using hospital and population controls respectively. The study found that hospital controls were comparable with population controls for most demographic characteristics and lifestyle factors measured, but there was a slight difference between the two control groups. Hospital outpatients provide a satisfactory control group in hospital-based case-control study in the Chinese hospital setting.

Population versus hospital controls for case-control studies on cancers in Chinese hospitals

Directory of Open Access Journals (Sweden)

Li Lin

2011-12-01

Full Text Available Abstract Background Correct control selection is crucial to the internal validity of case-control studies. Little information exists on differences between population and hospital controls in case-control studies on cancers in Chinese hospital setting. Methods We conducted three parallel case-control studies on leukemia, breast and colorectal cancers in China between 2009 and 2010, using population and hospital controls to separately match 540 incident cases by age, gender and residency at a 1:1 ratio. Demographic and lifestyle factors were measured using a validated questionnaire in face-to-face interview. Odds ratios (ORs and 95% confidence intervals (CIs were obtained using conditional logistic regression analyses. Results The two control groups had closely similar exposure distributions of 15 out of 16 factors, with the only exception being that hospital controls were less likely to have a BMI ≥ 25 (OR = 0.71, 95% CI: 0.54, 0.93. For exposure of green tea drinking, the adjusted ORs (95% CIs comparing green tealeaves intake ≥ 1000 grams annually with non-drinkers were 0.51 (0.31, 0.83 and 0.21 (0.27, 0.74 for three cancers combined, 0.06 (0.01, 0.61 and 0.07 (0.01, 0.47 for breast cancer, 0.52 (0.29, 0.94 and 0.45 (0.25, 0.82 for colorectal cancer, 0.65 (0.08, 5.63 and 0.57 (0.07, 4.79 for leukemia using hospital and population controls respectively. Conclusions The study found that hospital controls were comparable with population controls for most demographic characteristics and lifestyle factors measured, but there was a slight difference between the two control groups. Hospital outpatients provide a satisfactory control group in hospital-based case-control study in the Chinese hospital setting.

Case Studies in Modelling, Control in Food Processes.

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Glassey, J; Barone, A; Montague, G A; Sabou, V

This chapter discusses the importance of modelling and control in increasing food process efficiency and ensuring product quality. Various approaches to both modelling and control in food processing are set in the context of the specific challenges in this industrial sector and latest developments in each area are discussed. Three industrial case studies are used to demonstrate the benefits of advanced measurement, modelling and control in food processes. The first case study illustrates the use of knowledge elicitation from expert operators in the process for the manufacture of potato chips (French fries) and the consequent improvements in process control to increase the consistency of the resulting product. The second case study highlights the economic benefits of tighter control of an important process parameter, moisture content, in potato crisp (chips) manufacture. The final case study describes the use of NIR spectroscopy in ensuring effective mixing of dry multicomponent mixtures and pastes. Practical implementation tips and infrastructure requirements are also discussed.

Ultrasound biomicroscopy and iris pigment dispersion: a case--control study.

Science.gov (United States)

Mora, P; Sangermani, C; Ghirardini, S; Carta, A; Ungaro, N; Gandolfi, Sa

2010-04-01

The study involved eyes affected by pigment dispersion syndrome (PDS) or pigmentary glaucoma (PG) investigated by ultrasound biomicroscopy (UBM). Different irido-corneal parameters were assessed and compared with those from healthy controls. The aim was to investigate the capacity of the UBM in differentiating the cases and, potentially, in confirming the pathogenic mechanisms. Patients with a first diagnosis of PDS or PG were included. A cohort of healthy volunteers matched for sex, age and refractive errors was recruited. All underwent UBM examination: the following parameters were assessed in relaxed and stimulated accommodative state in one eye: iris-lens contact (ILC), irido-corneal angle (ICA) and iris concavity (IC). A receiver operating characteristic (ROC) analysis assessed the ability of UBM to discriminate between subjects with and without PDS/PG. There were 24 eyes in the case group: four diagnosed as PG and the remaining 20 as PDS. There were 25 eyes in the control group. The two groups were statistically superimposable except for baseline intraocular pressure, which was higher in the case group (p=0.0001). All UBM parameters were statistically different between the two groups. ICA in near vision was the best-performing parameter, reaching a sensitivity (=specificity) of 0.875 with a cut-off at 53.0 degrees . The second most sensitive parameter was IC, still in near vision. All UBM parameters examined were statistically different between the two groups. ROC analysis showed ICA and IC in near vision to be the most discriminatory parameters. This evidence confirms the importance of iris movements in inducing the particular features of PDS/PG.

The relationship between maternal periodontitis and preterm low birth weight: A case-control study

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Satheesh Mannem

2011-01-01

Full Text Available Background: The relationship between periodontal diseases in pregnancy and children born prematurely or with low birth weight has been increasingly investigated, showing positive and negative results, respectively. Objective: To evaluate the association between Maternal Periodontitis and Preterm delivery or Low Birth Weight. Materials and Methods: In this case-control study, 104 pregnant women without systemic disease or other risk factors for preterm labor were chosen. The control group (n = 52 had term labor (infants ≥37 weeks and the case group (n = 52 had preterm labor (infants <37 weeks. Plaque index, bleeding index, and birth weight were measured. Results: The data of plaque index (cases 1.21±0.56; controls 0.63±0.31, bleeding index (cases, 2.08±0.62; controls, 1.52±0.61, birth weight (cases, 2.01±0.36; controls 2.87±0.32, and Probing Pocket Depth (PPD ≥4mm and Clinical Attachment Level (CAL ≥3mm in at least 4 teeth (odds ratio 137.50, P value < 0.0001 revealed a statistically significant difference between the two groups P< 0.05. Conclusions: A noticeable relationship between periodontal health and duration of pregnancy; periodontal disease could be a risk factor for preterm labor. Oral hygiene maintenance should be a part of prenatal care protocol.

Quality control in the neutron activation analysis of biological markers for selenium in epidemiological investigations

International Nuclear Information System (INIS)

Morris, J.S.; Ngwenyama, R.A.; Guthrie, J.M.; Brockman, J.D.; Spate, V.L.; Robertson, J.D.

2008-01-01

Instrumental neutron activation analysis is routinely used at the MURR to quantify selenium in prospectively-collected biologic markers including blood serum and toenails. These specimens are typically collected from well-defined cohort populations participating in investigations assessing selenium intake and incidence of chronic disease endpoints. These epidemiological investigations, whether observational (case-control) or clinical (intervention), typically generate thousands of samples. The purpose of this paper is to assess, through evaluation of quality control results, if the achievable accuracy and precision in the measurement of selenium using NAA is adequate to determine a relative risk of 1.2 at high confidence in epidemiological studies. (author)

Relationship of Psychosocial Risk Factors, Certain Personality Traits and Myocardial Infarction in Indians: A Case-control Study.

Science.gov (United States)

Gupta, Rajni; Kishore, Jugal; Bansal, Yogesh; Daga, Mk; Jiloha, Rc; Singal, Rajeev; Ingle, Gk

2011-07-01

To investigate the relationship of psychosocial factors (lack of social support, stress and subjective well-being) and personality traits with myocardial infarction (MI). A case-control study involving 100 cases and 100 matched controls was conducted in Lok Nayak Hospital, New Delhi. Stress over 1 year was significantly higher in cases (P introvert (P < 0.001) personalities. Certain personality traits and recent stress may be important risk factors of MI, especially in Indians. The finding may have implications on the preventive strategies planned for MI patients.

Oestrogen receptor α gene haplotype and postmenopausal breast cancer risk: a case control study

International Nuclear Information System (INIS)

Wedrén, Sara; Stiger, Fredrik; Persson, Ingemar; Baron, John; Weiderpass, Elisabete; Lovmar, Lovisa; Humphreys, Keith; Magnusson, Cecilia; Melhus, Håkan; Syvänen, Ann-Christine; Kindmark, Andreas; Landegren, Ulf; Fermér, Maria Lagerström

2004-01-01

Oestrogen receptor α, which mediates the effect of oestrogen in target tissues, is genetically polymorphic. Because breast cancer development is dependent on oestrogenic influence, we have investigated whether polymorphisms in the oestrogen receptor α gene (ESR1) are associated with breast cancer risk. We genotyped breast cancer cases and age-matched population controls for one microsatellite marker and four single-nucleotide polymorphisms (SNPs) in ESR1. The numbers of genotyped cases and controls for each marker were as follows: TA n , 1514 cases and 1514 controls; c.454-397C → T, 1557 cases and 1512 controls; c.454-351A → G, 1556 cases and 1512 controls; c.729C → T, 1562 cases and 1513 controls; c.975C → G, 1562 cases and 1513 controls. Using logistic regression models, we calculated odds ratios (ORs) and 95% confidence intervals (CIs). Haplotype effects were estimated in an exploratory analysis, using expectation-maximisation algorithms for case-control study data. There were no compelling associations between single polymorphic loci and breast cancer risk. In haplotype analyses, a common haplotype of the c.454-351A → G or c.454-397C → T and c.975C → G SNPs appeared to be associated with an increased risk for ductal breast cancer: one copy of the c.454-351A → G and c.975C → G haplotype entailed an OR of 1.19 (95% CI 1.06–1.33) and two copies with an OR of 1.42 (95% CI 1.15–1.77), compared with no copies, under a model of multiplicative penetrance. The association with the c.454-397C → T and c.975C → G haplotypes was similar. Our data indicated that these haplotypes were more influential in women with a high body mass index. Adjustment for multiple comparisons rendered the associations statistically non-significant. We found suggestions of an association between common haplotypes in ESR1 and the risk for ductal breast cancer that is stronger in heavy women

Risk factors for cataract: A case control study

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Ughade Suresh

1998-01-01

Full Text Available The present study was designed as a hospital-based, group-matched, case-control investigation into the risk factors associated with age-related cataract in central India. The study included 262 cases of age-related cataract and an equal number of controls. A total of 21 risk factors were evaluated: namely, low socioeconomic status (SES, illiteracy, marital status, history of diarrhoea, history of diabetes, glaucoma, use of cholinesterase inhibitors, steroids, spironolactone, nifedipine, analgesics, myopia early in life, renal failure, heavy smoking, heavy alcohol consumption, hypertension, low body mass index (BMI, use of cheaper cooking fuel, working in direct sunlight, family history of cataract, and occupational exposure. In univariate analysis, except marital status, low BMI, renal failure, use of steroids, spironolactone, analgesics, and occupational exposure, all 14 other risk factors were found significantly associated with age-related cataract. Unconditional multiple logistic regression analysis confirmed the significance of low SES, illiteracy, history of diarrhoea, diabetes, glaucoma, myopia, smoking, hypertension and cheap cooking fuel. The etiological role of these risk factors in the outcome of cataract is confirmed by the estimates of attributable risk proportion. The estimates of population attributable risk proportion for these factors highlight the impact of elimination of these risk factors on the reduction of cataract in this population.

Investigations of respiratory control systems simulation

Science.gov (United States)

Gallagher, R. R.

1973-01-01

The Grodins' respiratory control model was investigated and it was determined that the following modifications were necessary before the model would be adaptable for current research efforts: (1) the controller equation must be modified to allow for integration of the respiratory system model with other physiological systems; (2) the system must be more closely correlated to the salient physiological functionings; (3) the respiratory frequency and the heart rate should be expanded to illustrate other physiological relationships and dependencies; and (4) the model should be adapted to particular individuals through a better defined set of initial parameter values in addition to relating these parameter values to the desired environmental conditions. Several of Milhorn's respiratory control models were also investigated in hopes of using some of their features as modifications for Grodins' model.

Nitrates in municipal drinking water and non-Hodgkin lymphoma: an ecological cancer case-control study in Taiwan.

Science.gov (United States)

Chang, Chih-Ching; Tsai, Shang-Shyue; Wu, Trong-Neng; Yang, Chun-Yuh

2010-01-01

The relationship between nitrate levels in drinking water and increased risk of non-Hodgkin lymphoma (NHL) development has been inconclusive. A matched cancer case-control and a nitrate ecology study was used to investigate the association between mortality attributed to NHL and nitrate exposure from Taiwan's drinking water. All deaths due to NHL in Taiwan residents from 2000 through 2006 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. Data on nitrate-nitrogen (NO(3)-N) levels of drinking water throughout Taiwan were collected from the Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was presumed to be the source of the subject's nitrate exposure via drinking water. The adjusted odds ratios (OR) for NHL death for those with high nitrate levels in their drinking water, as compared to the lowest tertile, were 1.02 (0.87-1.2) and 1.05 (0.89-1.24), respectively. The results of the present study show that there was no statistically significant association between nitrates in drinking water at levels in this investigation and increased risk of death attributed to NHL.

Cardiovascular drugs and the risk of suicide: a nested case-control study

DEFF Research Database (Denmark)

Callréus, Torbjörn; Agerskov Andersen, Ulla; Hallas, Jesper

2007-01-01

OBJECTIVE: During the past 30 years, various cardiovascular drugs have been implicated as causes of depression or suicide. Although the evidence for causal relationships has generally been conflicting, both beta-blockers and angiotensin-converting-enzyme inhibitors (ACE-inhibitors) have been...... related to depression. Lipid-lowering therapies and calcium-channel blockers have also been linked to an increased risk of suicide. In this study, we investigated the possible association between the use of cardiovascular drugs and suicide using population-based register data. METHODS: We performed...... a nested case-control study in the county of Funen, Denmark, that consisted of 743 cases of completed suicide identified in a Death Registry for the period 1991-1998 and 14,860 age- and sex-matched controls. Information on previous drug use was retrieved from prescription data and the association between...

[Research and control of relapse tuberculosis cases].

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Yamagishi, Fumio; Toyota, Makoto

2009-12-01

were recognized more significantly in male cases aged 70's. In the cases that deviated from the standard treatment and that became impossible to use rifampicin, it should be careful to emergence of isoniazid resistance. 3. The current status of the recurrence tuberculosis cases in Tokyo: Michiko NAGAMINE (Specific Disease Control Section, Tokyo Metropolitan Government Bureau of Social Welfare and Public Health). As for the background of the patient whose disease has relapsed, unstable elements are observed. After any symptom, more patients are diagnosed as a relapse case rather than finding by a medical check up. And more than half are related to homeless or life without fixed address. Their status of insurance is the livelihood protection, no insurance or the national health insurance. By RFLP analysis in Shinjuku city, some clusters have recurrent cases, one of clusters has both a relapse and exogenous reinfection. This is able to elucidate an infectious state. Like this, the analysis of each cluster can help effective countermeasures. 4. Recurrence of tuberculosis in the City of Yokohama between 2004 and 2008: Michihiko YOSHIDA (Shinagawa Public Health Center), Takahiro TOYOZAWA (Yokohama Public Health Center). To identify the TB recurrence rate, we studied a cohort of 40 cases (treatment completion 36 cases, interruption 4 cases) of whom had a previous history of TB treatment including isoniazid and rifampicin. The time for relapse was 7.9 +/- 8.6 years and the overall relapse rate was 0.6% (0.47-0.7%). Our study suggested the relapse was almost equal to the low incident countries but the long-term follow-up and surveillance data should be carefully evaluated. 5. Comparison of the retreatment cases of pulmonary tuberculosis: Yuka SASAKI (National Hospital Organization Chiba-East National Hospital). To investigate the factors of the retreatment of pulmonary tuberculosis, 134 retreatment cases were studied. The factors leading to retreatment were cavitary and large

Some investigations on the use of ultrasonics in travelling bubble cavitation control

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Chatterjee, Dhiman; Arakeri, Vijay H.

2004-04-01

In this paper we report results from some investigations on the use of ultrasonics in controlling travelling bubble cavitation. Control of this type of cavitation, generated using a venturi device, has been achieved by manipulation of potential nuclei using a piezoelectric device, termed the Ultrasonic Nuclei Manipulator (UNM). The performance of the UNM, activated in continuous-wave (CW) and pulsed modes, has been studied over a range of dissolved gas concentration (C). The performance under CW-excitation is found to depend sensitively on C, with lack of control in near-saturated water samples. Failure to control cavitation at C ≈ 1 under CW-excitation is suggested to be a result of bubble growth by rectified diffusion under these conditions. The pulsed mode of excitation of the UNM, in such cases, seems to be a very promising alternative. Further improvement is observed by using two piezoelectric crystals, one driven in the CW-mode and the second in pulsed mode, as the UNM. Through carefully designed experimentation, this has been traced to the movement of nuclei under the influence of Bjerknes forces. Besides reduction of noise, other measures of control have been identified and investigated. For example, it has been found that the maximum velocity achievable at the venturi throat can be increased from about 15 m s(-1) to about 22 m s(-1) with nuclei manipulation using ultrasonics.

Use of a total traffic count metric to investigate the impact of roadways on asthma severity: a case-control study

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deVos Annemarie JBM

2011-06-01

Full Text Available Abstract Background This study had two principal objectives: (i to investigate the relationship between asthma severity and proximity to major roadways in Perth, Western Australia; (ii to demonstrate a more accurate method of exposure assessment for traffic pollutants using an innovative GIS-based measure that fully integrates all traffic densities around subject residences. Methods We conducted a spatial case-control study, in which 'cases' were defined as individuals aged under 19 years of age with more severe asthma (defined here as two or more emergency department contacts with asthma in a defined 5-year period versus age- and gender-matched 'controls' with less severe asthma (defined here as one emergency department contact for asthma. Traffic exposures were measured using a GIS-based approach to determine the lengths of the roads falling within a buffer area, and then multiplying them by their respective traffic counts. Results We examined the spatial relationship between emergency department contacts for asthma at three different buffer sizes: 50 metres, 100 metres and 150 metres. No effect was noted for the 50 metre buffer (OR = 1.07; 95% CI: 0.91-1.26, but elevated odds ratios were observed with for crude (unadjusted estimates OR = 1.21 (95% CI: 1.00-1.46 for 100 metre buffers and OR = 1.25 (95% CI: 1.02-1.54 for 150 metre buffers. For adjusted risk estimates, only the 150 metre buffer yielded a statistically significant finding (OR = 1.24; 95% CI:1.00-1.52. Conclusions Our study revealed a significant 24% increase in the risk of experiencing multiple emergency department contacts for asthma for every log-unit of traffic exposure. This study provides support for the hypothesis that traffic related air pollution increases the frequency of health service contacts for asthma. This study used advanced GIS techniques to establish traffic-weighted buffer zones around the geocoded residential location of subjects to provide an accurate

Dietary intake of folate and riboflavin, MTHFR C677T Genotype, and colorectal adenoma risk: a Dutch case-control study

NARCIS (Netherlands)

Donk, van den M.; Buijsse, G.M.; Berg, van den S.W.; Ocké, M.C.; Harryvan, J.L.; Nagengast, F.M.; Kok, F.J.; Kampman, E.

2005-01-01

We investigated the associations between dietary intake of folate and vitamin B2, MTHFR C677T genotype, and colorectal adenomas in a Dutch case-control study. Data of cases with at least one histologically confirmed colorectal adenoma (n = 768) and controls with no history of any type of colorectal

Splenectomy Correlates With Increased Risk of Acute Pancreatitis: A Case-Control Study in Taiwan

Science.gov (United States)

Lai, Shih-Wei; Lin, Cheng-Li; Liao, Kuan-Fu

2016-01-01

Objective The objective of the study was to investigate the association between splenectomy and acute pancreatitis. Methods We conducted a case-control study using the database of the Taiwan National Health Insurance Program. We included 7666 subjects aged 20–84 years with first-time acute pancreatitis during the period of 1998–2011 as cases and 30 664 randomly selected subjects without acute pancreatitis as controls. Both cases and controls were matched for sex, age, and index year of acute pancreatitis diagnosis. The association of acute pancreatitis with splenectomy was examined using a multivariable unconditional logistic regression model and reported as an odds ratio and its 95% confidence interval (CI). Results After adjustment for covariables, the adjusted odds ratio of acute pancreatitis was 2.90 for subjects with splenectomy (95% CI, 1.39–6.05) compared with subjects without splenectomy. Conclusions Splenectomy is associated with acute pancreatitis. Further studies are necessary to clarify the underlying mechanism. PMID:27087607

Investigation of Airfoil Aeroacoustics with Blowing Control Mechanism

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Baha ZAFER

2016-11-01

Full Text Available In this investigation, it is dealt with computational aero-acoustic analysis of an airfoil with jet blowing. The airfoil shape is selected as NACA0015 profile with jet blowing on upper surface. The calculations of analysis are done by using commercial finite volume solver. The k-ε turbulence model is used for the turbulence modeling and the Ffowcs Williams and Hawking acoustic analogy model is run for determination of acoustic data. The numerical results are compared with experimental data for computed Sound Pressure Level without jet blowing and well agreement is observed. In the case of jet blowing, the effects of different jet angle, velocity ratio and angle of attack on airfoil are investigated and noise levels of non jet cases and jet blowing cases are studied.

Case-control study of lung cancer among workers at a uranium processing plant

International Nuclear Information System (INIS)

Cookfair, D.L.

1982-01-01

The purpose of this case-control study was to investigate the relationship between exposure to radiation resulting from the inhalation of uranium dust and the dust of uranium-bearing compounds and death due to lung cancer. Cases and controls were chosen from a cohort of white male workers employed at one uranium processing plant during World War II. The 330 cases consisted of all lung cancer deaths occurring in the cohort between 1943 and 1973. Level of exposure to radiation and other potential workplace carcinogens was determined for each worker using process manuals, industrial hygiene reports, air monitoring data and individual work histories. Smoking status and information regarding medical variables was determined from employee medical records. Cumulative radiation lung dose among study population members ranged from 0 to 75 rads. Data were analyzed using Mantel-Haenszel stratified analysis and logistic regression. Relative risk was found to increase with increasing level of lung dose exposure even after controlling for age, smoking status and other workplace exposures, but only for those who were over the age of 44 when first exposed. A statistically significant excess in risk was found for men in this hire age group with a cumulative lung dose of 20 rads or more. The risk associated with the overall work environment was also investigated using a summary measure of total workplace exposure called chemical rank. A similar relationship existed between chemical rank and lung cancer to that found for cumulative lung dose and lung cancer

Patterned genital injury in cases of rape - A case-control study

DEFF Research Database (Denmark)

Astrup, Birgitte Schmidt; Ravn, Pernille; Thomsen, Jørgen Lange

2013-01-01

A pattern of genital injury that separates trauma seen in sexual assault cases from trauma seen following consensual sexual intercourse has been a matter of debate. This study aimed at clarifying the question by eliminating as many confounders as possible in a prospective, case-control setup. A t...

Effectiveness of malaria control interventions in Madagascar: a nationwide case-control survey.

Science.gov (United States)

Kesteman, Thomas; Randrianarivelojosia, Milijaona; Raharimanga, Vaomalala; Randrianasolo, Laurence; Piola, Patrice; Rogier, Christophe

2016-02-11

Madagascar, as other malaria endemic countries, depends mainly on international funding for the implementation of malaria control interventions (MCI). As these funds no longer increase, policy makers need to know whether these MCI actually provide the expected protection. This study aimed at measuring the effectiveness of MCI deployed in all transmission patterns of Madagascar in 2012-2013 against the occurrence of clinical malaria cases. From September 2012 to August 2013, patients consulting for non-complicated malaria in 31 sentinel health centres (SHC) were asked to answer a short questionnaire about long-lasting insecticidal nets (LLIN) use, indoor residual spraying (IRS) in the household and intermittent preventive treatment of pregnant women (IPTp) intake. Controls were healthy all-ages individuals sampled from a concurrent cross-sectional survey conducted in areas surrounding the SHC. Cases and controls were retained in the database if they were resident of the same communes. The association between Plasmodium infection and exposure to MCI was calculated by multivariate multilevel models, and the protective effectiveness (PE) of an intervention was defined as 1 minus the odds ratio of this association. Data about 841 cases (out of 6760 cases observed in SHC) and 8284 controls was collected. The regular use of LLIN provided a significant 51 % PE (95 % CI [16-71]) in multivariate analysis, excluding in one transmission pattern where PE was -11 % (95 % CI [-251 to 65]) in univariate analysis. The PE of IRS was 51 % (95 % CI [31-65]), and the PE of exposure to both regular use of LLIN and IRS was 72 % (95 % CI [28-89]) in multivariate analyses. Vector control interventions avoided yearly over 100,000 clinical cases of malaria in Madagascar. The maternal PE of IPTp was 73 %. In Madagascar, LLIN and IRS had good PE against clinical malaria. These results may apply to other countries with similar transmission profiles, but such case-control surveys could be

Investigation of established genetic risk variants for glioma in prediagnostic samples from a population-based nested case-control study.

Science.gov (United States)

Wibom, Carl; Späth, Florentin; Dahlin, Anna M; Langseth, Hilde; Hovig, Eivind; Rajaraman, Preetha; Johannesen, Tom Børge; Andersson, Ulrika; Melin, Beatrice

2015-05-01

Although glioma etiology is poorly understood in general, growing evidence indicates a genetic component. Four large genome-wide association studies (GWAS) have linked common genetic variants with an increased glioma risk. However, to date, these studies are based largely on a case-control design, where cases have been recruited at the time of or after diagnosis. They may therefore suffer from a degree of survival bias, introduced when rapidly fatal cases are not included. To confirm glioma risk variants in a prospective setting, we have analyzed 11 previously identified risk variants in a set of prediagnostic serum samples with 598 cases and 595 matched controls. Serum samples were acquired from The Janus Serum Bank, a Norwegian population-based biobank reserved for cancer research. We confirmed the association with glioma risk for variants within five genomic regions: 8q24.21 (CCDC26), 9p21.3 (CDKN2B-AS1), 11q23.3 (PHLDB1), 17p13.1 (TP53), and 20q13.33 (RTEL1). However, previously identified risk variants within the 7p11.2 (EGFR) region were not confirmed by this study. Our results indicate that the risk variants that were confirmed by this study are truly associated with glioma risk and may, consequently, affect gliomagenesis. Though the lack of positive confirmation of EGFR risk variants may be attributable to relatively limited statistical power, it nevertheless raises the question whether they truly are risk variants or markers for glioma prognosis. Our findings indicate the need for further studies to clarify the role of glioma risk loci with respect to prolonged survival versus etiology. ©2015 American Association for Cancer Research.

Case-control study of amyotrophic lateral sclerosis

Energy Technology Data Exchange (ETDEWEB)

Deapen, D.M.; Henderson, B.E.

1986-05-01

The authors conducted a study of 518 amyotrophic lateral sclerosis patients identified between 1977 and 1979 and 518 controls to investigate putative risk factors for this disease. Occupations at risk of electrical exposure were reported more often by patients (odds ratio (OR) = 3.8, 95% confidence interval (CI) = 1.4-13.0) as were electrical shocks producing unconsciousness (OR = 2.8, 95% CI = 1.0-9.9). Although an overall excess of physical trauma associated with unconsciousness was observed in the amyotrophic lateral sclerosis patients (OR = 1.6, 95% CI = 1.0-2.4), the effect was inversely associated with duration of the unconscious episodes, suggesting an effect of recall bias. Only slight differences were found for surgical traumata to the nervous system. Parkinsonism was reported more often among first degree relatives of cases (OR = 2.7, 95% CI = 1.1-7.6). The frequencies of prior poliomyelitis or other central nervous system diseases were similar for patients and controls. Occupational exposure to selected toxic substances was similar for patients and controls except for the manufacture of plastics (OR = 3.7, 95% CI = 1.0-20.5), although few details of these exposures were provided. No differences in occupations with exposure to animal skins or hides were observed.

HLA-C -35kb expression SNP is associated with differential control of β-HPV infection in squamous cell carcinoma cases and controls.

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Karin A Vineretsky

Full Text Available A single nucleotide polymorphism (SNP 35 kb upstream of the HLA-C gene is associated with HLA-C expression, and the high expressing genotype (CC has been associated with HIV-I control. HLA-C is unique among the classical MHC class I molecules for its role in the control of viral infections and recognition of abnormal or missing self. This immunosurveillance is central to the pathogenesis of non-melanoma skin cancer (NMSC, and of squamous cell carcinoma (SCC in particular. While sun exposure is a major risk factor for these cancers, cutaneous infections with genus β-HPV have been implicated in the development of SCC. We hypothesized that the high expression HLA-C genotype is associated with β-HPV infections. Therefore, we investigated the association between β-HPV serology and the -35 kb SNP (rs9264942 in a population-based case-control study of 510 SCC cases and 608 controls. Among controls, the high expression -35 kb SNP genotype (CC reduced the likelihood of positive serology for multiple (≥2 β-HPV infections (OR = 0.49, 95% CI: 0.25-0.97, and β-HPV species 2 infection (OR = 0.43, 95% CI: 0.23-0.79. However, no association with β-HPV status was observed among SCC cases. Our findings suggest that underlying immunogenotype plays an important role in differential control of β-HPV in SCC cases and controls.

Advantages of the nested case-control design in diagnostic research

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Hoes Arno W

2008-07-01

Full Text Available Abstract Background Despite its benefits, it is uncommon to apply the nested case-control design in diagnostic research. We aim to show advantages of this design for diagnostic accuracy studies. Methods We used data from a full cross-sectional diagnostic study comprising a cohort of 1295 consecutive patients who were selected on their suspicion of having deep vein thrombosis (DVT. We draw nested case-control samples from the full study population with case:control ratios of 1:1, 1:2, 1:3 and 1:4 (per ratio 100 samples were taken. We calculated diagnostic accuracy estimates for two tests that are used to detect DVT in clinical practice. Results Estimates of diagnostic accuracy in the nested case-control samples were very similar to those in the full study population. For example, for each case:control ratio, the positive predictive value of the D-dimer test was 0.30 in the full study population and 0.30 in the nested case-control samples (median of the 100 samples. As expected, variability of the estimates decreased with increasing sample size. Conclusion Our findings support the view that the nested case-control study is a valid and efficient design for diagnostic studies and should also be (reappraised in current guidelines on diagnostic accuracy research.

HPV and cofactors for invasive cervical cancer in Morocco: a multicentre case-control study.

Science.gov (United States)

Berraho, Mohamed; Amarti-Riffi, Afaf; El-Mzibri, Mohammed; Bezad, Rachid; Benjaafar, Noureddine; Benideer, Abdelatif; Matar, Noureddine; Qmichou, Zinab; Abda, Naima; Attaleb, Mohammed; Znati, Kaoutar; El Fatemi, Hind; Bendahhou, Karima; Obtel, Majdouline; Filali Adib, Abdelhai; Mathoulin-Pelissier, Simone; Nejjari, Chakib

2017-06-20

Limited national information is available in Morocco on the prevalence and distribution of HPV-sub-types of cervical cancer and the role of other risk factors. The aim was to determine the frequency of HPV-sub-types of cervical cancer in Morocco and investigate risk factors for this disease. Between November 2009 and April 2012 a multicentre case-control study was carried out. A total of 144 cases of cervical cancer and 288 age-matched controls were included. Odds-ratios and corresponding confidence-intervals were computed by conditional logistic regression models. Current HPV infection was detected in 92.5% of cases and 13.9% of controls. HPV16 was the most common type for both cases and controls. Very strong associations between HPV-sub-types and cervical cancer were observed: total-HPV (OR = 39), HPV16 (OR = 49), HPV18 (OR = 31), and multiple infections (OR = 13). Education, high parity, sexual intercourse during menstruation, history of sexually transmitted infections, and husband's multiple sexual partners were also significantly associated with cervical cancer in the multivariate analysis. Our results could be used to establish a primary prevention program and to prioritize limited screening to women who have specific characteristics that may put them at an increased risk of cervical cancer.

Occupational Lifting Tasks and Retinal Detachment in Non-Myopics and Myopics: Extended Analysis of a Case-control Study

OpenAIRE

Mattioli, Stefano; Curti, Stefania; De Fazio, Rocco; Cooke, Robin Mt; Zanardi, Francesca; Bonfiglioli, Roberta; Farioli, Andrea; Violante, Francesco S.

2012-01-01

Objectives: Lifting heavy weights involves the Valsalva manoeuvre, which leads to intraocular pressure spikes. We used data from a case-control study to further investigate the hypothesis that occupational lifting is a risk factor for retinal detachment. Methods: The study population included 48 cases (patients operated for retinal detachment) and 84 controls (outpatients attending an eye clinic). The odds ratios (OR) of idiopathic retinal detachment were estimated with a logistic regressi...

A case-control study of the association between ulcerative colitis and hyperthyroidism in an Asian population.

Science.gov (United States)

Tsai, Ming-Chieh; Lin, Herng-Ching; Lee, Cha-Ze

2017-06-01

Ulcerative colitis (UC) is a chronic relapsing inflammatory disease with significant clinical diversity. However, the aetiology, pathogenesis and optimal treatment of UC remain unclear. The purpose of this case-control study was to investigate the association between previously diagnosed hyperthyroidism and UC using a large population-based data set in Taiwan. The data for this population-based case-control study were retrieved from the Taiwan Longitudinal Health Insurance Database 2005. We included 2709 patients with UC as cases and 8127 sex- and age-matched patients without UC as controls. A conditional logistic regression analysis was conducted to compute the odds ratio (OR) and corresponding 95% confidence interval (CI) for the association between UC and prior hyperthyroidism. We found that, in total, 327 of the 10 836 sampled patients (3.02%) had previously been diagnosed with hyperthyroidism. There was a higher proportion of prior hyperthyroidism among cases than controls (4.10% vs 2.66%, Phyperthyroidism was 1.57 (95% CI=1.24-1.98) compared to controls. Similarly, after adjusting for monthly income, geographic location and urbanization level, cases were still more likely to have previously been diagnosed with hyperthyroidism than controls (OR=1.61, 95% CI=1.27-2.05). Furthermore, we analysed the ORs of prior hyperthyroidism between cases and controls according to age group. We found that of the youngest group of sampled patients (18-39 years), cases had the greatest adjusted OR for having previously been diagnosed with hyperthyroidism than controls (OR=1.98, 95% CI=1.04-3.79). This study demonstrated an association between UC and hyperthyroidism. © 2017 John Wiley & Sons Ltd.

Medical records documentation of constipation preceding Parkinson disease: A case-control study.

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Savica, R; Carlin, J M; Grossardt, B R; Bower, J H; Ahlskog, J E; Maraganore, D M; Bharucha, A E; Rocca, W A

2009-11-24

Parkinson disease (PD) may affect the autonomic nervous system and may cause constipation; however, few studies have explored constipation preceding the motor onset of PD. We investigated constipation preceding PD using a case-control study design in a population-based sample. Using the medical records-linkage system of the Rochester Epidemiology Project, we identified 196 subjects who developed PD in Olmsted County, MN, from 1976 through 1995. Each incident case was matched by age (+/-1 year) and sex to a general population control. We reviewed the complete medical records of cases and controls in the medical records-linkage system to ascertain the occurrence of constipation preceding the onset of PD (or index year). Constipation preceding PD or the index year was more common in cases than in controls (odds ratio [OR] 2.48; 95% confidence interval [CI] 1.49 to 4.11; p = 0.0005). This association remained significant after adjusting for smoking and coffee consumption (ever vs never), and after excluding constipation possibly induced by drugs. In addition, the association remained significant in analyses restricted to constipation documented 20 or more years before the onset of motor symptoms of PD. Although the association was stronger in women than in men and in patients with PD with rest tremor compared with patients with PD without rest tremor, these differences were not significant. Our findings suggest that constipation occurring as early as 20 or more years before the onset of motor symptoms is associated with an increased risk of Parkinson disease.

Targeting the initial investigation and management in cases of acute pulmonary embolism.

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Moore, Nicholas; Hawkins, Peter

2013-01-01

It was noted by consultants in our hospital that the early investigation of suspected pulmonary embolism (PE) lacked structure. This was causing delays in definitive diagnosis and early management. The resulting unnecessary use of investigation was also wasting resources. In particular, the inappropriate use of serum d-dimer tests was causing concern. The National Institute of Clinical Excellence (NICE) guidelines recommend use of the 2-level Well's score to target investigation in suspected PE. A baseline audit against the NICE guideline revealed that Well's scores were rarely used (only calculated in 12% of cases) and confirmed the suspicion that early investigation was poorly targeted. This project intervened using educational talks promoting the use of Well's scores in cases of suspected PE. Well's score proformas were placed in the emergency department and emergency assessment unit for reference. Their availability was advertised. This significantly increased the use of Well's scores (46% vs 11%, p<0.001). Fewer patients underwent unnecessary d-dimer measurements in cases of likely PE (65% vs 86%). Initial investigation was more targeted in cases where a Well's score had been calculated than in cases without a Well's score. For example, significantly fewer unnecessary d-dimer tests were performed in these cases (45% vs 100%, p<0.05). The cost of unnecessary investigation in suspected PE is not only significant financially but also in the resulting delay in definitive diagnosis and management for the patient. The simple intervention used here was effective in addressing this problem.

Correlation of Serum Zinc Level with Simple Febrile Seizures: A Hospital based Prospective Case Control Study

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Imran Gattoo

2015-04-01

Full Text Available Background: Febrile seizures are one of the most common neurological conditions of childhood. It seems that zinc deficiency is associated with increased risk of febrile seizures.Aim: To estimate the serum Zinc level in children with simple Febrile seizures and to find the correlation between serum zinc level and simple Febrile seizures.Materials and Methods: The proposed study was a hospital based prospective case control study which included infants and children aged between 6 months to 5 years, at Post Graduate Department of Pediatrics, (SMGS Hospital, GMC Jammu, northern India. A total of 200 infants and children fulfilling the inclusion criteria were included. Patients were divided into 100(cases in Group A with simple febrile seizure and 100(controls in Group B of children with acute febrile illness without seizure. All patients were subjected to detailed history and thorough clinical examination followed by relevant investigations.Results: Our study had slight male prepondance of 62% in cases and 58% in controls . Mean serum zinc level in cases was 61.53±15.87 ugm/dl and in controls it was 71.90+18.50 ugm/dl .Serum zinc level was found significantly low in cases of simple febrile seizures as compaired to controls ,with p value of

Sustainability Strategy and Management Control Systems in Family Firms. Evidence from a Case Study

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Fabio Caputo

2017-06-01

Full Text Available The aim of this paper is to investigate how the integration of new forms of sustainable control systems (SCSs and traditional management control systems (MCSs, and the use of these control systems affect the integration of sustainability within organizational strategy. A qualitative case study based on a longitudinal investigation of an Italian family firm operating in an environment-sensitive context, the intermodal transport industry, has been used to trace the company’s pathway to sustainability integration based on the Gond et al. framework. The paper enriches the Gond et al. conceptualization providing evidence of the external and internal factors relevant in affecting the organization’s pathway towards sustainability integration. To the best of the authors’ knowledge, the present study is the first analysis that investigates the integration of sustainability into organizational strategy in the context of family firms, from the point of view of performance management systems (PMSs.

Organizing pneumonia and occupational and environmental risk factors: a case-control study.

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Jobard, Stéphanie; Chaigne, Benjamin; Marchand-Adam, Sylvain; Lasfargues, Gérard; Diot, Elisabeth

2017-11-01

A single-center case-control study was carried out to investigate the relationship between occupational and environmental exposure and organizing pneumonia (OP). Thirty-seven cases of OP, including 25 cases of cryptogenic OP, and 111 controls were included. Occupational exposure was assessed retrospectively by an industrial hygienist and an occupational physician, through semi-quantitative estimates of exposure. An exposure score was calculated for each subject, based on probability, intensity, daily frequency, and duration of exposure for each period of employment. The final cumulative exposure score was obtained by summing exposure scores for all periods of employment. Significant associations with all-cause OP were observed for exposure to tetrachloroethylene (OR 13.33, CI 95% 1.44-123.5) and silica (OR 6.61, CI 95% 1.16-37.71). A significant association with cryptogenic OP was observed only for tetrachloroethylene (OR 31.6, CI 95% 1.64-610.8). No associations were found for environmental exposure. Despite its low statistical power, this work suggests that occupational risk factors could be involved in OP.

Investigation of active structural intensity control in finite beams: theory and experiment

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Audrain; Masson; Berry

2000-08-01

An investigation of structural intensity control is presented in this paper. As opposed to previous work, the instantaneous intensity is completely taken into account in the control algorithm, i.e., all the terms are considered in the real-time control process and, in particular, the evanescent waves are considered in this approach. A finite difference approach using five accelerometers is used as the sensing scheme. A feedforward filtered-X least mean square algorithm is adapted to this energy-based control problem, involving a nonpositive definite quadratic form in general. In this respect, the approach is limited to cases where the geometry is such that the intensity component will have the same sign for the control source and the primary disturbance. Results from numerical simulations are first presented to illustrate the benefit of using a cost function based on structural intensity. Experimental validation of the approach is conducted on a free-free beam covered with viscoelastic material. A comparison is made between classical acceleration control and structural intensity control and the performance of both approaches is presented. These results confirm that using intensity control allows the error sensors to be placed closer to the control source and the primary disturbance, while preserving a good control performance.

Case-control study of genus-beta human papillomaviruses in plucked eyebrow hairs and cutaneous squamous cell carcinoma.

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Iannacone, Michelle R; Gheit, Tarik; Pfister, Herbert; Giuliano, Anna R; Messina, Jane L; Fenske, Neil A; Cherpelis, Basil S; Sondak, Vernon K; Roetzheim, Richard G; Silling, Steffi; Pawlita, Michael; Tommasino, Massimo; Rollison, Dana E

2014-05-01

Cutaneous human papillomaviruses (HPV) have been reported in cutaneous squamous cell carcinoma (SCC). We conducted a clinic-based case-control study to investigate the association between genus-beta HPV DNA in eyebrow hairs (EBH) and SCC. EBH from 168 SCC cases and 290 controls were genotyped for genus-beta HPV DNA. SCC tumors from a subset of cases (n = 142) were also genotyped. Viral load was determined in a subset of specimens positive for a single HPV type. Associations with SCC were estimated by odds ratios (OR) and 95% confidence intervals (CI) adjusted for age and sex using logistic regression. Statistical tests were two-sided. EBH DNA prevalence was greater in cases (87%) than controls (73%) (p genus-beta types tested, when accounting for DNA for the same HPV type in the tumor (ORs = 3.44-76.50). Compared to controls, the mean viral DNA load in EBH among the selected cases was greater for HPV5, HPV8 and HPV24, but lower for HPV38. SCC cases were more likely than controls to have HPV DNA+ EBH for single and multiple HPV types, providing additional support for the potential role of genus-beta HPV infections in SCC development. © 2013 UICC.

Assessment of global phase uncertainty in case-control studies

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van Houwelingen Hans C

2009-09-01

Full Text Available Abstract Background In haplotype-based candidate gene studies a problem is that the genotype data are unphased, which results in haplotype ambiguity. The measure 1 quantifies haplotype predictability from genotype data. It is computed for each individual haplotype, and for a measure of global relative efficiency a minimum value is suggested. Alternatively, we developed methods directly based on the information content of haplotype frequency estimates to obtain global relative efficiency measures: and based on A- and D-optimality, respectively. All three methods are designed for single populations; they can be applied in cases only, controls only or the whole data. Therefore they are not necessarily optimal for haplotype testing in case-control studies. Results A new global relative efficiency measure was derived to maximize power of a simple test statistic that compares haplotype frequencies in cases and controls. Application to real data showed that our proposed method gave a clear and summarizing measure for the case-control study conducted. Additionally this measure might be used for selection of individuals, who have the highest potential for improving power by resolving phase ambiguity. Conclusion Instead of using relative efficiency measure for cases only, controls only or their combined data, we link uncertainty measure to case-control studies directly. Hence, our global efficiency measure might be useful to assess whether data are informative or have enough power for estimation of a specific haplotype risk.

Thyroid cancer in French Polynesia: a population based case control study

International Nuclear Information System (INIS)

Brindel, P.; Doyon, F.; Adjadj, E.; Vathaire, F. de; Drozdovitch, V.; Bouville, A.; Paoaafaite, J.; Teuri, J.

2006-01-01

Full text of publication follows: Because a previous study had shown that registered thyroid cancer incidence is higher among natives of French Polynesia (FP) than in other Maori populations from Hawaii and New-Zealand, a case-control study of thyroid cancer coordinated by Unit 605 of INSERM was conducted in FP. The main objective was to assess the potential role of atmospheric nuclear weapons tests performed by France between 1966 and 1974 on such a high incidence. The study included 600 subjects born and residing in FP: 229 cases of differentiated thyroid carcinoma diagnosed between 1979 and 2004, aged up to 30 years old at start of nuclear weapons testing and 371 control s matched on gender and birth date randomly selected from t he FP registry of births. Face to face interviews were conducted from 2002 to 2004 by specialized investigators native from FP who received a specific formation for this study. Addresses were collected from the territorial medical insurance, which covers all the inhabitants, whatever their professional status. Detailed information about nutrition at time of interview and at the end of adolescence was collected by means of a semi-quantitative method using pictures. Data concerning residence, hormonal and reproductive life, familial and personal background of thyroid pathologies and cancers, and professional and environmental exposure to carcinogens were also collected. For each study subject, radiation thyroid dose was estimated taking into account residential history and dietary habits of the subject and deposition densities of radionuclides reconstructed for each island where the subject resided during the testing period. The iodine intake will be estimated from the dietary questionnaire, as well as from mass-spectrometry measurements of stable iodine in nail clippings, which were collected during the interviews. Among the 229 cases, 89% were females, 54% declared themselves as of pure Maori origin, another 36% of Maori-Asian or Maori

Role of nutrition in pre-eclampsia and eclampsia cases, a case control study

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Punyatoya Bej

2014-12-01

Full Text Available Background: Preeclampsia and eclampsia during pregnancy contribute to maternal and fetal morbidity as well as mortality. The identification of the role of maternal nutrition during pregnancy will help in reducing morbidity and mortality. Aims & Objective: The objective of this study is to find out the role of nutrition, in the form of total calorie, protein, fruits, iron, folic acid and calcium intake in the development of preeclampsia and eclampsia among pregnant women in a tertiary level hospital. Material Methods: After ethical approval and informed consent, 122 women who delivered beyond 22 weeks of gestation and diagnosed as preeclampsia or eclampsia were selected. Simultaneously, 122 controls with no diagnosis of preeclampsia or eclampsia were selected from the post natal ward. Cases and controls were administered the same pre-tested questionnaire containing questions related to food and micronutrient intake by cases and control. Results: Logistic regression was applied in the statistical analysis. The factors that were found to be significant predictors of risk for development of preeclampsia and eclampsia were higher calorie intake (adjusted Odds Ratio (OR 14.12 [6.41-43.23] P < 0.001, less protein intake (adjusted OR 3.87 [1.97-8.01] P < 0.001 during pregnancy. Fruits intake in both cases and controls were similar. 77.9% of cases and 84.4% of controls had taken iron tablets during their antenatal period. 75.4% of cases and 82.8% of controls had taken calcium tablets during their antenatal period. Iron and calcium intake is not significantly associated with development of preeclampsia and eclampsia. Conclusion: Higher calorie intake and less protein intake during pregnancy were associated with development of preeclampsia and eclampsia. Fruits intake, iron and calcium intake were not associated with development of preeclampsia and eclampsia

Homocyst(e)ine and cardiovascular disease: a systematic review of the evidence with special emphasis on case-control studies and nested case-control studies.

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Ford, Earl S; Smith, S Jay; Stroup, Donna F; Steinberg, Karen K; Mueller, Patricia W; Thacker, Stephen B

2002-02-01

Elevated concentrations of homocyst(e)ine are thought to increase the risk of vascular diseases including coronary heart disease and cerebrovascular disease. We searched MEDLINE (1966-1999), EMBASE (1974-1999), SciSearch (1974- 1999), and Dissertation Abstracts (1999) for articles and theses about homocyst(e)ine concentration and coronary heart disease and cerebrovascular disease. We included 57 publications (3 cohort studies, 12 nested case-control studies, 42 case-control studies) that reported results on 5518 people with coronary heart disease (11,068 control subjects) and 1817 people with cerebrovascular disease (4787 control subjects) in our analysis. For coronary heart disease, the summary odds ratios (OR) for a 5-micromol/l increase in homocyst(e)ine concentration were 1.06 (95% CI : 0.99-1.13) for 2 publications of cohort studies, 1.23 (95% CI : 1.07-1.41) for 10 publications of nested case-control studies, and 1.70 (95% CI : 1.50-1.93) for 26 publications of case-control studies. For cerebrovascular disease, the summary OR for a 5-micromol/l increase in homocyst(e)ine concentration were 1.10 (95% CI : 0.94-1.28) for 2 publications of cohort studies, 1.58 (95% CI : 1.35-1.85) for 5 publications of nested case-control studies, and 2.16 (95% CI : 1.65-2.82) for 17 publications of case-control studies. Prospective studies offer weaker support than case-control studies for an association between homocyst(e)ine concentration and cardiovascular disease. Although other lines of evidence support a role for homocyst(e)ine in the pathogenesis of cardiovascular disease, more information from prospective epidemiological studies or clinical trials is needed to clarify this role.

Robust estimation for homoscedastic regression in the secondary analysis of case-control data

KAUST Repository

Wei, Jiawei; Carroll, Raymond J.; Mü ller, Ursula U.; Keilegom, Ingrid Van; Chatterjee, Nilanjan

2012-01-01

Primary analysis of case-control studies focuses on the relationship between disease D and a set of covariates of interest (Y, X). A secondary application of the case-control study, which is often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated owing to the case-control sampling, where the regression of Y on X is different from what it is in the population. Previous work has assumed a parametric distribution for Y given X and derived semiparametric efficient estimation and inference without any distributional assumptions about X. We take up the issue of estimation of a regression function when Y given X follows a homoscedastic regression model, but otherwise the distribution of Y is unspecified. The semiparametric efficient approaches can be used to construct semiparametric efficient estimates, but they suffer from a lack of robustness to the assumed model for Y given X. We take an entirely different approach. We show how to estimate the regression parameters consistently even if the assumed model for Y given X is incorrect, and thus the estimates are model robust. For this we make the assumption that the disease rate is known or well estimated. The assumption can be dropped when the disease is rare, which is typically so for most case-control studies, and the estimation algorithm simplifies. Simulations and empirical examples are used to illustrate the approach.

Robust estimation for homoscedastic regression in the secondary analysis of case-control data

KAUST Repository

Wei, Jiawei

2012-12-04

Primary analysis of case-control studies focuses on the relationship between disease D and a set of covariates of interest (Y, X). A secondary application of the case-control study, which is often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated owing to the case-control sampling, where the regression of Y on X is different from what it is in the population. Previous work has assumed a parametric distribution for Y given X and derived semiparametric efficient estimation and inference without any distributional assumptions about X. We take up the issue of estimation of a regression function when Y given X follows a homoscedastic regression model, but otherwise the distribution of Y is unspecified. The semiparametric efficient approaches can be used to construct semiparametric efficient estimates, but they suffer from a lack of robustness to the assumed model for Y given X. We take an entirely different approach. We show how to estimate the regression parameters consistently even if the assumed model for Y given X is incorrect, and thus the estimates are model robust. For this we make the assumption that the disease rate is known or well estimated. The assumption can be dropped when the disease is rare, which is typically so for most case-control studies, and the estimation algorithm simplifies. Simulations and empirical examples are used to illustrate the approach.

Residential traffic noise exposure and vestibular schwannoma - a Danish case-control study.

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Roswall, Nina; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Schüz, Joachim; Johansen, Christoffer; Jensen, Steen Solvang; Raaschou-Nielsen, Ole; Sørensen, Mette

2017-10-01

Few risk factors for sporadic vestibular schwannoma (VS) are known. Several studies have proposed an increased risk with occupational noise exposure, whereas no studies have investigated residential traffic noise exposure as a risk factor. The present study investigated if residential traffic noise was associated with vestibular schwannoma in a large, population-based Danish case-control study. We identified 1454 VS cases, age above 30 years at diagnosis, between 1990 and 2007. For each case, we selected two random population controls, matched on sex and year of birth. Road and railway traffic noise at the residence was calculated for all present and historical addresses between 1987 and index date. Associations between traffic noise and risk for VS were estimated using conditional logistic regression, adjusted for education, disposable personal income, cohabitation status, railway noise exposure, municipal population density, and municipal income. A two-year time-weighted mean road traffic noise exposure was associated with an adjusted odds ratio of 0.92 (0.82-1.03) for developing VS, per 10 dB increment. There was no clear trend in categorical analyses. Similarly, linear and categorical analyses of residential railway noise did not suggest an association. We found no interaction with demographics, year of diagnosis, individual and municipal socioeconomic variables, and railway noise exposure. The results did not differ by tumor side, spread or size. The present study does not suggest an association between residential traffic noise and VS.

Common carotid artery intima-media thickness and brain infarction : the Etude du Profil Génétique de l'Infarctus Cérébral (GENIC) case-control study. The GENIC Investigators.

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Touboul, P J; Elbaz, A; Koller, C; Lucas, C; Adraï, V; Chédru, F; Amarenco, P

2000-07-18

BACKGROUND-The use of intima-media thickness (IMT) as an outcome measure in observational studies and intervention trials relies on the view that it reflects early stages of atherosclerosis and cardiovascular risk. There is little knowledge concerning the relation between IMT and brain infarction (BI). METHODS AND RESULTS-We investigated the relation of IMT with BI and its subtypes in 470 cases and 463 controls. Cases with BI proven by MRI were consecutively recruited and classified into subtypes by cause of BI. Controls were recruited among individuals hospitalized at the same institutions and matched for age, sex, and center. IMT was measured at the far wall of both common carotid arteries (CCA) using an automatic detection system. Adventitia-to-adventitia diameters and CCA-IMT were measured on transverse views; lumen diameter was computed using these measures. Mean (+/-SEM) CCA-IMT was higher in cases (0.797+/-0.006 mm) than in controls (0.735+/-0.006 mm; P<0. 0001). This difference remained after adjustment for lumen diameter and when analyses were restricted to subjects free of previous cardiovascular or cerebrovascular history. The difference in CCA-IMT between cases and controls was significant in the main subtypes. The risk of BI increased continuously with increasing CCA-IMT. The odds ratio per SD increase (0.150 mm) was 1.82 (95% confidence interval, 1.54 to 2.15); adjustment for cardiovascular risk factors slightly attenuated this relation (odds ratio, 1.73; 95% confidence interval, 1.45 to 2.07). CONCLUSIONS-An increased CCA-IMT was associated with BI, both overall and in the main subtypes. An increased IMT may help select patients at high risk for BI.

What factors play a role in preventing self-immolation?Results from a case-control study in Iran

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Hosein Karim

2015-07-01

Full Text Available Abstract: Background: To investigate factors related to prevention of self-immolation in west of Iran. Methods: In a case-control study, 30 consecutive cases of deliberate self-inflicted burns admitted to the regional burn center (Imam Khomeini hospital in Kermanshah province, Iran were compared with controls selected from the community and matched by sex, age,district-county of residence, and rural vs urban living environment. The following characteristics relevant to preventing self immolation were collected from all cases and controls: main domestic fuel used in the household, awareness about complications of burn injuries, and use of counseling services. Results: Descriptive analyses revealed that kerosene was the main domestic fuel in the household for 83% of cases. Not surprisingly, the main means of self-immolation in 93% of the patients was kerosene, with other fuels such as petrol and domestic gas used in remaining cases. The majority of cases and controls were aware of the potential complications of burn injuries. Use of counseling services was more common in controls. Conclusions: All three aspects of preventing self-immolation – having kerosene and other fuels in the home, being aware of the complications of burn injuries, and using counseling services were present in both the cases and controls. This suggests a large portion of residents in rural Iran are potential self-immolation victims. Increasing preventive strategies may reduce risk of suicide by self-immolation.

Helicopter internal noise control: Three case histories

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Edwards, B. D.; Cox, C. R.

1978-01-01

Case histories are described in which measurable improvements in the cabin noise environments of the Bell 214B, 206B, and 222 were realized. These case histories trace the noise control efforts followed in each vehicle. Among the design approaches considered, the addition of a fluid pulsation damper in a hydraulic system and the installation of elastomeric engine mounts are highlighted. It is concluded that substantial weight savings result when the major interior noise sources are controlled by design, both in altering the noise producing mechanism and interrupting the sound transmission paths.

Risk factors for acute Toxoplasma gondii diseases in Taiwan: a population-based case-control study.

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Ting-Yi Chiang

Full Text Available Although human toxoplasmosis is a notifiable disease in Taiwan since 2007, little is known about its risk factors. This study aimed to investigate the risk factors for acute Toxoplasma gondii diseases in Taiwan. We conducted a nationwide population-based case-control study. Cases of acute human toxoplasmosis notified to the Taiwan Centers for Diseases Control (Taipei, Taiwan during 2008-2013 were compared with controls that were randomly selected from healthy T. gondii-seronegative blood donors who participated in a nationwide T. gondii seroepidemiologic study during 2009-2010. Cases and controls were matched according to age, gender and residency at an 1:8 ratio. Structured questionnaires were used to gather information regarding risk factors. A total of 30 laboratory-confirmed acute T. gondii disease cases and 224 controls were enrolled. The most common clinical manifestation of the cases was flu-like symptoms (n = 20, followed by central nervous system disease (n = 4, ocular diseases (n = 3, abortion (n = 2, and congenital infection (n = 1. Multivariate conditional logistic regression showed that raw clam consumption (adjusted odds ratio [OR] = 3.7; 95% confidence interval [CI] = 1.4-9.9 and having a cat in the household (adjusted OR = 2.9; 95% CI = 1.1-7.9 were two independent risk factors for acute T. gondii disease. We conclude that raw shellfish consumption and domestic cat exposure were risk factors for acquiring acute T. gondii diseases in Taiwan. This finding may guide future research and control policies.

Toxocara infection in psychiatric inpatients: a case control seroprevalence study.

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Cosme Alvarado-Esquivel

Full Text Available BACKGROUND: There is poor knowledge about the epidemiology of toxocariasis in psychiatric patients. AIMS: Determine the seroepidemiology of Toxocara infection in psychiatric patients. METHODS: Through a case-control seroprevalence study, 128 psychiatric inpatients and 276 control subjects were compared for the presence of anti-Toxocara IgG antibodies in Durango, Mexico. Socio-demographic, clinical, and behavioral characteristics of inpatients associated with toxocariasis were also investigated. RESULTS: Six of the 128 (4.7% psychiatric inpatients, and 3 (1.1% of the 276 controls were positive for anti-Toxocara IgG antibodies (P = 0.03. Stratification by age showed that Toxocara seroprevalence was significantly (P = 0.02 higher in patients aged ≤50 years old (6/90∶6.7% than controls of the same age (2/163∶1.2%. While Toxocara seroprevalence was similar in patients and controls aged >50 years old. Stratification by gender showed that Toxocara seroprevalence was significantly (P = 0.03 higher in female patients (2/37∶5.4% than in female controls (0/166∶0%. No statistically significant associations between Toxocara seropositivity and clinical characteristics were found. In contrast, Toxocara seropositivity was associated with consumption of goat meat and raw sea snail. CONCLUSIONS: This is the first report of toxocariasis in psychiatric inpatients in Mexico. Further studies with larger sample sizes are needed to elucidate the association of toxocariasis with psychiatric diseases. The role of the consumption of goat meat and raw sea snail in the transmission of Toxocara deserve further investigation.

A Case-Control Study of the Role of Human Papillomavirus in Oesophageal Squamous Cell Carcinoma in Australia

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Surabhi S. Liyanage

2014-01-01

Full Text Available Objective. We investigate the prevalence of human papillomavirus (HPV in oesophageal squamous cell carcinoma (OSCC tissues compared to oesophageal tissue from healthy controls, in an Australian cohort. Methods. We conducted a hospital-based case-control study of 99 patients with OSCC and 100 healthy controls to examine the presence of HPV DNA. Paraffin tissues were tested using the PapType high-risk HPV detection and genotyping kit and with INNO-LiPA HPV Genotyping Extra. The biopsy samples were tested for HPV using a PCR-ELISA method based on the L1 consensus primer set PGMY09-PGMY11. Results. HPV DNA of the oncogenic genotype 16 was detected in 1/99 case specimens, a rate of 1010 per 100,000 (95% CI: 30–5500. All control specimens were negative for HPV. Significantly higher rates of smoking, other aerodigestive cancers, and mortality were seen among cases than controls. A pooled analysis of this study and the only other Australian case-control study found that 9/321 cases and 0/155 controls were positive for HPV. The pooled odds ratio for HPV being a risk factor for OSCC was 9.35 (95% CI: 0.47–190.33. Conclusion. Our results suggest that in this multifactorial cancer HPV may be an additional risk factor; although a larger, better powered study is needed.

Matched case-control studies: a review of reported statistical methodology

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Niven DJ

2012-04-01

Full Text Available Daniel J Niven1, Luc R Berthiaume2, Gordon H Fick1, Kevin B Laupland11Department of Critical Care Medicine, Peter Lougheed Centre, Calgary, 2Department of Community Health Sciences, University of Calgary, Calgary, Alberta, CanadaBackground: Case-control studies are a common and efficient means of studying rare diseases or illnesses with long latency periods. Matching of cases and controls is frequently employed to control the effects of known potential confounding variables. The analysis of matched data requires specific statistical methods.Methods: The objective of this study was to determine the proportion of published, peer reviewed matched case-control studies that used statistical methods appropriate for matched data. Using a comprehensive set of search criteria we identified 37 matched case-control studies for detailed analysis.Results: Among these 37 articles, only 16 studies were analyzed with proper statistical techniques (43%. Studies that were properly analyzed were more likely to have included case patients with cancer and cardiovascular disease compared to those that did not use proper statistics (10/16 or 63%, versus 5/21 or 24%, P = 0.02. They were also more likely to have matched multiple controls for each case (14/16 or 88%, versus 13/21 or 62%, P = 0.08. In addition, studies with properly analyzed data were more likely to have been published in a journal with an impact factor listed in the top 100 according to the Journal Citation Reports index (12/16 or 69%, versus 1/21 or 5%, P ≤ 0.0001.Conclusion: The findings of this study raise concern that the majority of matched case-control studies report results that are derived from improper statistical analyses. This may lead to errors in estimating the relationship between a disease and exposure, as well as the incorrect adaptation of emerging medical literature.Keywords: case-control, matched, dependent data, statistics

Two-stage case-control association study of dopamine-related genes and migraine

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Pardo Julio

2009-09-01

Full Text Available Abstract Background We previously reported risk haplotypes for two genes related with serotonin and dopamine metabolism: MAOA in migraine without aura and DDC in migraine with aura. Herein we investigate the contribution to migraine susceptibility of eight additional genes involved in dopamine neurotransmission. Methods We performed a two-stage case-control association study of 50 tag single nucleotide polymorphisms (SNPs, selected according to genetic coverage parameters. The first analysis consisted of 263 patients and 274 controls and the replication study was composed by 259 cases and 287 controls. All cases were diagnosed according to ICHD-II criteria, were Spanish Caucasian, and were sex-matched with control subjects. Results Single-marker analysis of the first population identified nominal associations of five genes with migraine. After applying a false discovery rate correction of 10%, the differences remained significant only for DRD2 (rs2283265 and TH (rs2070762. Multiple-marker analysis identified a five-marker T-C-G-C-G (rs12363125-rs2283265-rs2242592-rs1554929-rs2234689 risk haplotype in DRD2 and a two-marker A-C (rs6356-rs2070762 risk haplotype in TH that remained significant after correction by permutations. These results, however, were not replicated in the second independent cohort. Conclusion The present study does not support the involvement of the DRD1, DRD2, DRD3, DRD5, DBH, COMT, SLC6A3 and TH genes in the genetic predisposition to migraine in the Spanish population.

Outbreak of Ampicillin/Piperacillin-Resistant Klebsiella Pneumoniae in a Neonatal Intensive Care Unit (NICU): Investigation and Control Measures

OpenAIRE

Fabbri, Giuliana; Panico, Manuela; Dallolio, Laura; Suzzi, Roberta; Ciccia, Matilde; Sandri, Fabrizio; Farruggia, Patrizia

2013-01-01

Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs). The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infection...

A case-control study of visual acuity in onychocryptosis.

LENUS (Irish Health Repository)

Hogan, Aisling M

2012-02-01

BACKGROUND: There are many theories surrounding the etiology of ingrown toenails (IGTN). Few factors have been formally assessed, but it is widely accepted that a poor nail cutting technique has a causative role. AIM: To investigate the hypothesis that decreased visual acuity may lead to inadequate nail cutting and the formation of IGTN. METHODS: A prospective case-control study was performed. Near and distance visual acuity were tested on a population with IGTN (n = 19) and compared with that of an age- and sex-matched control cohort (n = 24) who underwent epidermal cyst excision in the same tertiary referral center. Comparisons of visual acuity were made between groups by Mann-Whitney U-test. Differences were taken to be significant if P < 0.05. Institutional Review Board approval was sought and granted. RESULTS: No significant difference in visual acuity (near or distance) was demonstrated between patients with IGTN and the control group (P = 0.33). CONCLUSION: Visual acuity does not appear to play a significant role in the development of IGTN.

Pesticide exposure and lymphohaematopoietic cancers: a case-control study in an agricultural region (Larissa, Thessaly, Greece).

Science.gov (United States)

Kokouva, Maria; Bitsolas, Nikolaos; Hadjigeorgiou, Georgios M; Rachiotis, George; Papadoulis, Nikolaos; Hadjichristodoulou, Christos

2011-01-04

The causality of lymphohaematopoietic cancers (LHC) is multifactorial and studies investigating the association between chemical exposure and LHC have produced variable results. The aim of this study was to investigate the relationships between exposure to pesticides and LHC in an agricultural region of Greece. A structured questionnaire was employed in a hospital-based case control study to gather information on demographics, occupation, exposure to pesticides, agricultural practices, family and medical history and smoking. To control for confounders, backward conditional and multinomial logistic regression analyses were used. To assess the dose-response relationship between exposure and disease, the chi-square test for trend was used. Three hundred and fifty-four (354) histologically confirmed LHC cases diagnosed from 2004 to 2006 and 455 sex- and age-matched controls were included in the study. Pesticide exposure was associated with total LHC cases (OR 1.46, 95% CI 1.05-2.04), myelodysplastic syndrome (MDS) (OR 1.87, 95% CI 1.00-3.51) and leukaemia (OR 2.14, 95% CI 1.09-4.20). A dose-response pattern was observed for total LHC cases (P = 0.004), MDS (P = 0.024) and leukaemia (P = 0.002). Pesticide exposure was independently associated with total LHC cases (OR 1.41, 95% CI 1.00 - 2.00) and leukaemia (OR 2.05, 95% CI 1.02-4.12) after controlling for age, smoking and family history (cancers, LHC and immunological disorders). Smoking during application of pesticides was strongly associated with total LHC cases (OR 3.29, 95% CI 1.81-5.98), MDS (OR 3.67, 95% CI 1.18-12.11), leukaemia (OR 10.15, 95% CI 2.15-65.69) and lymphoma (OR 2.72, 95% CI 1.02-8.00). This association was even stronger for total LHC cases (OR 18.18, 95% CI 2.38-381.17) when eating simultaneously with pesticide application. Lymphohaematopoietic cancers were associated with pesticide exposure after controlling for confounders. Smoking and eating during pesticide application were identified as

Radiation exposure and central nervous system cancers: A case-control study among workers at two nuclear facilities

International Nuclear Information System (INIS)

Carpenter, A.V.; Flanders, W.D.; Frome, E.L.; Crawford-Brown, D.J.; Fry, S.A.

1987-03-01

A nested case-control study was conducted among workers employed between 1943 and 1977 at two nuclear facilities to investigate the possible association of primary malignant neoplasms of the central nervous system (CNS) with occupational exposure to ionizing radiation from external and internal sources. Eighty-nine white male and female workers, who according to the information on death certificates dies of primary CNS cancers, were identified as cases. Four matched controls were selected for each case. External radiation exposure data were available from film badge readings for individual workers, whereas radiation dose to lung from internally deposited radionuclides, mainly uranium, was estimated from area and personnel monitoring data and was used in analyses in lieu of the dose to the brain. Matched sets were included in the analyses only if information was available for the case and at least one of the corresponding controls. Thus, the analyses of external radiation included 27 cases and 90 matched controls, and 47 cases and 120 matched controls were analyzed for the effects of radiation from internally deposited uranium. No association was observed between deaths fron CNS cancers and occupational exposure to ionizing radiation from external or internal sources. However, due to the small number of monitored subjects and low doses, a weak association could not be ruled out. 43 refs., 1 fig., 15 tabs

Association between group A beta-haemolytic streptococci and vulvovaginitis in adult women: a case-control study.

Science.gov (United States)

Bruins, M J; Damoiseaux, R A M J; Ruijs, G J H M

2009-08-01

Guidelines for the management of vaginal discharge mention Candida albicans, Trichomonas vaginalis, bacterial vaginosis, Chlamydia trachomatis and Neisseria gonorrhoeae as causes and do not recommend full microbiological culture. The role of non-group B beta-haemolytic streptococci in vaginal cultures is unclear, except for group A streptococci that are known to cause vulvovaginitis in children. In a case-control study, we investigated the association between non-group B beta-haemolytic streptococci and vulvovaginitis in adult women. Cases were women with recurrent vaginal discharge from whom a sample was cultured. Controls were asymptomatic women who consented to submitting a vaginal swab. Group A streptococci were isolated from 49 (4.9%) of 1,010 cases and not from the 206 controls (P < 0.01). Isolation rates of group C, F and G streptococci were low and did not differ statistically between cases and controls. Group A beta-haemolytic streptococci are associated with vaginal discharge in adult women. The other non-group B streptococci require more study. For the adequate management of vaginal discharge, culturing is necessary if initial treatment fails. Guidelines should be amended according to these results.

Intrapartum electrocardiogram alteration in fetuses with congenital heart disease: a case-control study.

Science.gov (United States)

Gay, Estelle; Bornallet, Géraldine; Gaucherand, Pascal; Doret, Muriel

2015-11-01

To assess if the fetal electrocardiogram especially ST segment is modified by congenital heart diseases: modifications in frequencies of the different ST events and modifications in signal quality. A retrospective case-control study, comparing frequencies of the different ST events and the quality of the signal between fetuses with congenital heart diseases and fetuses without congenital heart disease. From 2000 to 2011, fifty-eight fetuses with congenital heart disease had their heart rate recording using a STAN device during labor. Control group was fetuses who were born just before a case and had a STAN as a second line for intrapartum surveillance. Cases and controls were matched on parity, gestational age at birth, presence of growth restriction and umbilical artery pH. Frequencies of the different ST event and quality of the signal were first analyzed for the global labor recording, and then separately for the first and the second phase of labor. No statistically significant difference in ST event frequencies between fetuses with congenital heart disease and the control group was found. Regarding the quality of the signal, 11.49% (±18.82) of recording time is a signal loss for fetus with congenital heart disease whereas only 5.18% (±10.67) for the control group (p=0.028). This is the first study investigating for intrapartum electrocardiogram modification in fetus with congenital heart disease. Congenital heart diseases do not modify frequencies of ST events. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Screening detected celiac disease in children with type 1 diabetes mellitus : Effect on the clinical course - (A case control study)

NARCIS (Netherlands)

Rami, B; Sumnik, Z; Schober, E; Waldhor, T; Battelino, T; Bratanic, N; Kurti, K; Lebl, J; Limbert, C; Madacsy, L; Odink, RJH; Paskova, M; Soltesz, G

Objective: To investigate clinical and metabolic characteristics of diabetic children with screening detected celiac disease in a multicenter case-control study. Methods: Cases: 98 diabetic patients were diagnosed as having silent celiac disease by screening with endomysial antibodies and subsequent

Dengue infection and miscarriage: a prospective case control study.

Directory of Open Access Journals (Sweden)

Peng Chiong Tan

Full Text Available BACKGROUND: Dengue is the most prevalent mosquito borne infection worldwide. Vertical transmissions after maternal dengue infection to the fetus and pregnancy losses in relation to dengue illness have been reported. The relationship of dengue to miscarriage is not known. METHOD: We aimed to establish the relationship of recent dengue infection and miscarriage. Women who presented with miscarriage (up to 22 weeks gestation to our hospital were approached to participate in the study. For each case of miscarriage, we recruited 3 controls with viable pregnancies at a similar gestation. A brief questionnaire on recent febrile illness and prior dengue infection was answered. Blood was drawn from participants, processed and the frozen serum was stored. Stored sera were thawed and then tested in batches with dengue specific IgM capture ELISA, dengue non-structural protein 1 (NS1 antigen and dengue specific IgG ELISA tests. Controls remained in the analysis if their pregnancies continued beyond 22 weeks gestation. Tests were run on 116 case and 341 control sera. One case (a misdiagnosed viable early pregnancy plus 45 controls (39 lost to follow up and six subsequent late miscarriages were excluded from analysis. FINDINGS: Dengue specific IgM or dengue NS1 antigen (indicating recent dengue infection was positive in 6/115 (5·2% cases and 5/296 (1·7% controls RR 3·1 (95% CI 1·0-10 P = 0·047. Maternal age, gestational age, parity and ethnicity were dissimilar between cases and controls. After adjustments for these factors, recent dengue infection remained significantly more frequently detected in cases than controls (AOR 4·2 95% CI 1·2-14 P = 0·023. INTERPRETATION: Recent dengue infections were more frequently detected in women presenting with miscarriage than in controls whose pregnancies were viable. After adjustments for confounders, the positive association remained.

Comparison of two control groups for estimation of oral cholera vaccine effectiveness using a case-control study design.

Science.gov (United States)

Franke, Molly F; Jerome, J Gregory; Matias, Wilfredo R; Ternier, Ralph; Hilaire, Isabelle J; Harris, Jason B; Ivers, Louise C

2017-10-13

Case-control studies to quantify oral cholera vaccine effectiveness (VE) often rely on neighbors without diarrhea as community controls. Test-negative controls can be easily recruited and may minimize bias due to differential health-seeking behavior and recall. We compared VE estimates derived from community and test-negative controls and conducted bias-indicator analyses to assess potential bias with community controls. From October 2012 through November 2016, patients with acute watery diarrhea were recruited from cholera treatment centers in rural Haiti. Cholera cases had a positive stool culture. Non-cholera diarrhea cases (test-negative controls and non-cholera diarrhea cases for bias-indicator analyses) had a negative culture and rapid test. Up to four community controls were matched to diarrhea cases by age group, time, and neighborhood. Primary analyses included 181 cholera cases, 157 non-cholera diarrhea cases, 716 VE community controls and 625 bias-indicator community controls. VE for self-reported vaccination with two doses was consistent across the two control groups, with statistically significant VE estimates ranging from 72 to 74%. Sensitivity analyses revealed similar, though somewhat attenuated estimates for self-reported two dose VE. Bias-indicator estimates were consistently less than one, with VE estimates ranging from 19 to 43%, some of which were statistically significant. OCV estimates from case-control analyses using community and test-negative controls were similar. While bias-indicator analyses suggested possible over-estimation of VE estimates using community controls, test-negative analyses suggested this bias, if present, was minimal. Test-negative controls can be a valid low-cost and time-efficient alternative to community controls for OCV effectiveness estimation and may be especially relevant in emergency situations. Copyright © 2017. Published by Elsevier Ltd.

Case-control study on uveal melanoma (RIFA: rational and design

Directory of Open Access Journals (Sweden)

Schmidt-Pokrzywniak Andrea

2004-08-01

Full Text Available Abstract Background Although a rare disease, uveal melanoma is the most common primary intraocular malignancy in adults, with an incidence rate of up to 1.0 per 100,000 persons per year in Europe. Only a few consistent risk factors have been identified for this disease. We present the study design of an ongoing incident case-control study on uveal melanoma (acronym: RIFA study that focuses on radiofrequency radiation as transmitted by radio sets and wireless telephones, occupational risk factors, phenotypical characteristics, and UV radiation. Methods/Design We conduct a case-control study to identify the role of different exposures in the development of uveal melanoma. The cases of uveal melanoma were identified at the Division of Ophthalmology, University of Essen, a referral centre for tumours of the eye. We recruit three control groups: population controls, controls sampled from those ophthalmologists who referred cases to the Division of Ophthalmology, University of Duisburg-Essen, and sibling controls. For each case the controls are matched on sex and age (five year groups, except for sibling controls. The data are collected from the study participants by short self-administered questionnaire and by telephone interview. During and at the end of the field phase, the data are quality-checked. To estimate the effect of exposures on uveal melanoma risk, we will use conditional logistic regression that accounts for the matching factors and allows to control for potential confounding.

Public Health Economic Burden Associated with Two Single Measles Case Investigations - Colorado, 2016-2017.

Science.gov (United States)

Marx, Grace E; Chase, Jennifer; Jasperse, Joseph; Stinson, Kaylan; McDonald, Carol E; Runfola, Janine K; Jaskunas, Jillian; Hite, Donna; Barnes, Meghan; Askenazi, Michele; Albanese, Bernadette

2017-11-24

During July 2016-January 2017, two unrelated measles cases were identified in the Denver, Colorado area after patients traveled to countries with endemic measles transmission. Each case resulted in multiple exposures at health care facilities and public venues, and activated an immediate and complex response by local and state public health agencies, with activities led by the Tri-County Health Department (TCHD), which serves Adams, Arapahoe, and Douglas counties. To track the economic burden associated with investigating and responding to single measles cases, personnel hours and supply costs incurred during each investigation were tracked prospectively. No secondary cases of measles were identified in either investigation. Postexposure prophylaxis (PEP) was administered to 31 contacts involving the first case; no contacts of the second case were eligible for PEP because of a delay in diagnosing measles disease. Public health costs of disease investigation in the first and second case were estimated at $49,769 and $18,423, respectively. Single measles cases prompted coordinated public health action and were costly and resource-intensive for local public health agencies.

[Lack of association between MMR vaccination and the incidence of autism in children: a case-control study].

Science.gov (United States)

Mrozek-Budzyn, Dorota; Kiełtyka, Agnieszka; Majewska, Renata

2009-01-01

The matched case-control study has been undertook to investigate whether measles, mumps, and rubella (MMR) vaccine may be casually associated with autism in children. Cases were children to 14-year old with diagnosis of core autism or atypical autism. Controls were matched on age, sex and general practice. The 96 cases and 192 controls were included. The study provides strong evidence against association of autism with both MMR and a single measles individual vaccine. Additionally children vaccinated with MMR, regardless of age of vaccination (to 18th, 24th and 36th month of life), had risk equal half of that of single measles vaccinated (for vaccinated to 18th month OR=0.41 95%PU: 0.20-0.85). Our findings confirm that MMR vaccination is not associated with an increased risk of autism in children.

A case-control study of hormonal exposures as etiologic factors for ALS in women : Euro-MOTOR

NARCIS (Netherlands)

Rooney, James P K; Visser, Anne E; D'Ovidio, Fabrizio; Vermeulen, Roel; Beghi, Ettore; Chio, Adriano; Veldink, Jan H.; Logroscino, Giancarlo; van den Berg, Leonard H.; Hardiman, Orla

2017-01-01

OBJECTIVE: To investigate the role of hormonal risk factors for amyotrophic lateral sclerosis (ALS) among women from 3 European countries. METHODS: ALS cases and matched controls were recruited over 4 years in Ireland, Italy, and the Netherlands. Hormonal exposures, including reproductive history,

Haplotype-based case-control study between human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 gene and cerebral infarction.

Science.gov (United States)

Naganuma, Takahiro; Nakayama, Tomohiro; Sato, Naoyuki; Fu, Zhenyan; Yamaguchi, Mai; Soma, Masayoshi; Aoi, Noriko; Usami, Ron; Doba, Nobutaka; Hinohara, Shigeaki

2009-10-01

The aim of this study was to investigate the relationship between cerebral infarction (CI) and the human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/REF-1) gene using single-nucleotide polymorphisms (SNPs) and a haplotype-based case-control study. We selected 5 SNPs in the human APE1/REF1 gene (rs1760944, rs3136814, rs17111967, rs3136817 and rs1130409), and performed case-control studies in 177 CI patients and 309 control subjects. rs17111967 was found to have no heterogeneity in Japanese. The overall distribution of the haplotype-based case-control study constructed by rs1760944, rs3136814 and rs1130409 showed a significant difference. The frequency of the G-C-T haplotype was significantly higher in the CI group than in the control group (2.5% vs. 0.0%, p>0.001). Based on the results of the haplotype-based case-control-study, the G-C-T haplotype may be a genetic marker of CI, and the APE1/REF-1 gene may be a CI susceptibility gene.

Detection of erythrovirus B19 in thyroidectomy specimens from Graves' disease patients: a case-control study.

Science.gov (United States)

Page, Cyril; Hoffmann, Thomas Walter; Benzerdjeb, Nassim; Duverlie, Gilles; Sevestre, Henri; Desailloud, Rachel

2013-08-01

Environmental factors, such as viruses, are thought to contribute to the development of thyroid autoimmunity. Erythrovirus B19 (EVB19) is suspected to be involved in Hashimoto's thyroiditis, but no direct evidence is available concerning the role of EVB19 infection in Graves' disease. The objective of this study was to investigate whether the presence of EVB19 is more frequent in thyroidectomy specimens of patients undergoing thyroidectomy for Graves' disease (cases) than for multinodular thyroid (controls). Serum and thyroidectomy specimens were prospectively collected from 64 patients referred for total thyroidectomy over a 5-year period (2007-2011) and were investigated retrospectively and blindly for circulating EVB19 DNA by q-PCR (Qiagen), and for EVB19 thyrocyte infection by immunochemistry (VP2-Antibody, Dako). EVB19 serology was also determined. General clinical and laboratory data were collected. Twenty patients were referred for Graves' disease and 44 patients were referred for non-autoimmune multinodular thyroid. Patients with thyroid cancer were excluded. Ten percent of Graves' disease patients and 27.7% of control patients had positive staining of thyrocytes for EVB19 antibodies (ns). EVB19-positive and EVB19-negative cases did not differ. EVB19-positive controls were older than EVB19-negative controls (mean age: 57.5 [35-74] vs. 45 [28-80] years, P=0.03) No case of acute EVB19 infection was identified. EVB19-positive serology was more frequent in controls than in Graves' disease patients (88% vs. 45%, PGraves' disease patients than in controls. Further studies are needed to determine the role of EVB19 infection in thyroid diseases. Copyright © 2013 Wiley Periodicals, Inc.

Mobile phone base stations and early childhood cancers: case-control study.

Science.gov (United States)

Elliott, Paul; Toledano, Mireille B; Bennett, J; Beale, L; de Hoogh, K; Best, N; Briggs, D J

2010-06-22

To investigate the risk of early childhood cancers associated with the mother's exposure to radiofrequency from and proximity to macrocell mobile phone base stations (masts) during pregnancy. Case-control study. Cancer registry and national birth register data in Great Britain. 1397 cases of cancer in children aged 0-4 from national cancer registry 1999-2001 and 5588 birth controls from national birth register, individually matched by sex and date of birth (four controls per case). Incidence of cancers of the brain and central nervous system, leukaemia, and non-Hodgkin's lymphomas, and all cancers combined, adjusted for small area measures of education level, socioeconomic deprivation, population density, and population mixing. Mean distance of registered address at birth from a macrocell base station, based on a national database of 76,890 base station antennas in 1996-2001, was similar for cases and controls (1107 (SD 1131) m v 1073 (SD 1130) m, P=0.31), as was total power output of base stations within 700 m of the address (2.89 (SD 5.9) kW v 3.00 (SD 6.0) kW, P=0.54) and modelled power density (-30.3 (SD 21.7) dBm v -29.7 (SD 21.5) dBm, P=0.41). For modelled power density at the address at birth, compared with the lowest exposure category the adjusted odds ratios were 1.01 (95% confidence interval 0.87 to 1.18) in the intermediate and 1.02 (0.88 to 1.20) in the highest exposure category for all cancers (P=0.79 for trend), 0.97 (0.69 to 1.37) and 0.76 (0.51 to 1.12), respectively, for brain and central nervous system cancers (P=0.33 for trend), and 1.16 (0.90 to 1.48) and 1.03 (0.79 to 1.34) for leukaemia and non-Hodgkin's lymphoma (P=0.51 for trend). There is no association between risk of early childhood cancers and estimates of the mother's exposure to mobile phone base stations during pregnancy.

Struggling doctors in specialist training: a case control study

DEFF Research Database (Denmark)

O'Neill, Lotte; Norberg, Karen; Thomsen, Maria

), or transferred (i.e. had unplanned changes in place of training/ward due to failure to thrive or due to inadequate development of competences), or dropped out (i.e. were dismissed from, had resigned from, or changed their speciality). Controls were a random sample of doctors in the source population, who were......Abstract summary The aim of this cummulative incidence case-control study was to examine: if struggling trainees in medical specialist training (cases) tended to struggle already in medical school or not compared to non-struggling controls, and which performance indicators during medical school...... seemed to predict struggling in postgraduate education if any. The study design is rooted in epidemiological methodology. Struggling doctors in specialist training: a case-control study. It has been reported in the international literature, that around 3-10% of doctors in post-garduate specialist...

Colon cancer controls versus population controls in case-control studies of occupational risk factors

DEFF Research Database (Denmark)

Kaerlev, Linda; Lynge, Elsebeth; Sabroe, Svend

2004-01-01

are interchangeable with the experience for population controls. Patient controls may even be preferable from population controls under certain conditions. In this study we examine if colon cancer patients can serve as surrogates for proper population controls in case-control studies of occupational risk factors...... about occupational, medical and life style conditions. RESULTS: No statistical significant difference for educational level, medical history or smoking status was seen between the two control groups. There was evidence of a higher alcohol intake, less frequent work as a farmer and less exposure...... to pesticides among colon cancer controls. CONCLUSIONS: Use of colon cancer controls may provide valid exposure estimates in studies of many occupational risk factors for cancer, but not for studies on exposure related to farming....

Individual socioeconomic status and breast cancer diagnostic stages: a French case-control study.

Science.gov (United States)

Orsini, Mattea; Trétarre, Brigitte; Daurès, Jean-Pierre; Bessaoud, Faiza

2016-06-01

Health inequalities have increased over the last 30 years. Our goal was to investigate the relationship between low individual socioeconomic status and poor breast cancer prognosis. Our hypothesis was: low socioeconomic status patients have a higher risk of being diagnosed with late stage breast cancer than high socioeconomic status ones due to delayed diagnosis. We conducted a matched case-control study on 619 women with breast cancer, living in the Hérault, a French administrative area. Both Cases and Controls were recruited among invasive cases diagnosed in 2011 and 2012 and treated in Hérault care centers. Cases were defined as patients with advanced stages. Controls were composed of early stage patients. Individual socioeconomic status was assessed using a validated individual score adapted to the French population and health care system. We observed that low socioeconomic status patients have a 2-fold risk of having late stage breast cancer regardless of cancer characteristics and detection mode (screening vs. clinical signs). One reason explaining those results could be that low socioeconomic status patients have less regular follow-up which can lead to later and poorer diagnosis. Follow-up is improved for women with a better awareness of breast cancer. Health policy makers could reduce health inequalities by reducing the delay in breast cancer diagnosis for low socioeconomic status women. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Investigation of and Response to 2 Plague Cases, Yosemite National Park, California, USA, 2015.

Science.gov (United States)

Danforth, Mary; Novak, Mark; Petersen, Jeannine; Mead, Paul; Kingry, Luke; Weinburke, Matthew; Buttke, Danielle; Hacker, Gregory; Tucker, James; Niemela, Michael; Jackson, Bryan; Padgett, Kerry; Liebman, Kelly; Vugia, Duc; Kramer, Vicki

2016-12-01

In August 2015, plague was diagnosed for 2 persons who had visited Yosemite National Park in California, USA. One case was septicemic and the other bubonic. Subsequent environmental investigation identified probable locations of exposure for each patient and evidence of epizootic plague in other areas of the park. Transmission of Yersinia pestis was detected by testing rodent serum, fleas, and rodent carcasses. The environmental investigation and whole-genome multilocus sequence typing of Y. pestis isolates from the patients and environmental samples indicated that the patients had been exposed in different locations and that at least 2 distinct strains of Y. pestis were circulating among vector-host populations in the area. Public education efforts and insecticide applications in select areas to control rodent fleas probably reduced the risk for plague transmission to park visitors and staff.

The environment as an unrecognized reservoir for community-associated methicillin resistant Staphylococcus aureus USA300: a case-control study.

Directory of Open Access Journals (Sweden)

Anne-Catrin Uhlemann

Full Text Available BACKGROUND: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA infections are spreading, but the source of infections in non-epidemic settings remains poorly defined. METHODS: We carried out a community-based, case-control study investigating socio-demographic risk factors and infectious reservoirs associated with MRSA infections. Case patients presented with CA-MRSA infections to a New York hospital. Age-matched controls without infections were randomly selected from the hospital's Dental Clinic patient population. During a home visit, case and control subjects completed a questionnaire, nasal swabs were collected from index respondents and household members and standardized environmental surfaces were swabbed. Genotyping was performed on S. aureus isolates. RESULTS: We enrolled 95 case and 95 control subjects. Cases more frequently reported diabetes mellitus and a higher number of skin infections among household members. Among case households, 53 (56% were environmentally contaminated with S. aureus, compared to 36 (38% control households (p = .02. MRSA was detected on fomites in 30 (32% case households and 5 (5%; p<.001 control households. More case patients, 20 (21% were nasally colonized with MRSA than were control indexes, 2 (2%; p<.001. In a subgroup analysis, the clinical isolate (predominantly USA300, was more commonly detected on environmental surfaces in case households with recurrent MRSA infections (16/36, 44% than those without (14/58, 24%, p = .04. CONCLUSIONS: The higher frequency of environmental contamination of case households with S. aureus in general and MRSA in particular implicates this as a potential reservoir for recolonization and increased risk of infection. Environmental colonization may contribute to the community spread of epidemic strains such as USA300.

Attention deficit hyperactivity disorder in children with primary monosymptomatic nocturnal enuresis: A case-control study

Directory of Open Access Journals (Sweden)

Parsa Yousefichaijan

2016-01-01

Full Text Available Attention deficit hyperactivity disorder (ADHD is one of the most common childhood neurological disorders. The aim of this study was to investigate ADHD in children with primary monosymptomatic nocturnal enuresis (PMNE and compare it with healthy children. A total of 100 five to 16-year-old children with PMNE and 100 healthy children without NE were included in this case-control study as the cases and control groups, respectively. Subjects were selected from children who were referred to the pediatric clinic of the Amir Kabir Hospital of Arak, Iran, based on inclusion and exclusion criteria. ADHD was diagnosed by Conner′s Parent Rating Scale-48 and the Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria and was confirmed by consultation with a psychiatrist. Data were analyzed by binomial test using SPSS18. ADHD inattentive type was observed in 16 cases (16% with PMNE and five controls (5% (P = 0.01. Despite these significant differences in the case and control groups, 25 (25% and 16 (16% children were affected by ADHD hyperactive-impulsive type (P = 0.08 and 15 (15% and 16 (16% children were affected by ADHD mixed type (P = 0.84, respectively. ADHD inattentive type in children with PMNE was significantly more common than that in healthy children. The observed correlation between ADHD inattentive type and PMNE makes psychological counseling mandatory in children with PMNE.

National outbreak of Salmonella Enteritidis phage type 14b in England, September to December 2009: case-control study.

Science.gov (United States)

Janmohamed, K; Zenner, D; Little, C; Lane, C; Wain, J; Charlett, A; Adak, B; Morgan, D

2011-04-14

We conducted an unmatched retrospective case–control study to investigate an upsurge of non-travel-related sporadic cases of infection with Salmonella enterica subsp. enterica serotype Enteritidis phage type 14b with antimicrobial resistance to nalidixic acid and partial resistance to ciprofloxacin (S. Enteritidis PT 14b NxCp(L)) that was reported in England from 1 September to 31 December 2009. We analysed data from 63 cases and 108 controls to determine whether cases had the same sources of infection as those found through investigation of 16 concurrent local foodborne outbreaks in England and Wales. Multivariable logistic regression analysis adjusting for age and sex identified food consumption at restaurants serving Chinese or Thai cuisine (odds ratio (OR): 4.4; 95% CI: 1.3–14.8; p=0.02), egg consumed away from home (OR: 5.1; 95% CI: 1.3–21.2; p=0.02) and eating vegetarian foods away from home (OR: 14.6; 95% CI: 2.1–99; p=0.006) as significant risk factors for infection with S. Enteritidis PT 14b NxCp(L). These findings concurred with those from the investigation of the16 outbreaks, which identified the same Salmonella strain in eggs from a specified source outside the United Kingdom. The findings led to a prohibition of imports from this source, in order to control the outbreak.

Fragrance allergy and quality of life - a case-control study.

Science.gov (United States)

Heisterberg, Maria V; Menné, Torkil; Johansen, Jeanne D

2014-02-01

Fragrance ingredients can cause contact allergy, which may affect quality of life (QoL). However, few studies have investigated this topic. To investigate QoL life among subjects with a fragrance allergy as compared with other eczema patients. A case-control survey was sent to subjects with a positive patch test reaction to a fragrance ingredient/marker (n = 550) and to a control group (n = 1100). It contained questions on eczema and the newly developed fragrance QoL index. Participants had been consecutively patch tested at Gentofte University Hospital (2000-2010). The response rate was 65.7%. Information on patch test data was retrieved from the National Contact Dermatitis Database. An increase in impairment of QoL was observed in women with fragrance allergy as compared with the control group (p = 0.042), which was not found among men. Several factors played a significant role in impairment of QoL in women: (i) number of fragrance allergies, (ii) severity of the patch test reaction, (iii) age combined with recent diagnosis; and (iv) allergy to specific fragrance ingredients/markers. Fragrance-allergic subjects are just as affected in their QoL as other eczema patients. However, women, and in particular recently diagnosed young women, seem to be more impaired in their QoL than other eczema patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

77 FR 45378 - Guidelines for Cases Requiring On-Scene Death Investigation

Science.gov (United States)

2012-07-31

... DEPARTMENT OF JUSTICE Office of Justice Programs [OJP (NIJ) Docket No. 1600] Guidelines for Cases... entitled, ``Guidelines for Cases Requiring On-Scene Death Investigation''. The opportunity to provide comments on this document is open to coroner/medical examiner office representatives, law enforcement...

The importance of the supportive control environment for internal audit effectiveness – the case of Croatian companies

OpenAIRE

Barišić, Ivana; Tušek, Boris

2016-01-01

The paper investigates whether a supportive control environment is associated with the internal audit effectiveness and what characteristics of a control environment are important in this respect. A survey was conducted via a questionnaire on 54 mostly large companies in Croatia. Appropriate methods of statistical analysis were used in order to analyse the survey results. According to the research results, in the case of a supportive control environment there is a greater ch...

Suspected survivor bias in case-control studies: stratify on survival time and use a negative control.

Science.gov (United States)

van Rein, Nienke; Cannegieter, Suzanne C; Rosendaal, Frits R; Reitsma, Pieter H; Lijfering, Willem M

2014-02-01

Selection bias in case-control studies occurs when control selection is inappropriate. However, selection bias due to improper case sampling is less well recognized. We describe how to recognize survivor bias (i.e., selection on exposed cases) and illustrate this with an example study. A case-control study was used to analyze the effect of statins on major bleedings during treatment with vitamin K antagonists. A total of 110 patients who experienced such bleedings were included 18-1,018 days after the bleeding complication and matched to 220 controls. A protective association of major bleeding for exposure to statins (odds ratio [OR]: 0.56; 95% confidence interval: 0.29-1.08) was found, which did not become stronger after adjustment for confounding factors. These observations lead us to suspect survivor bias. To identify this bias, results were stratified on time between bleeding event and inclusion, and repeated for a negative control (an exposure not related to survival): blood group non-O. The ORs for exposure to statins increased gradually to 1.37 with shorter time between outcome and inclusion, whereas ORs for the negative control remained constant, confirming our hypothesis. We recommend the presented method to check for overoptimistic results, that is, survivor bias in case-control studies. Copyright © 2014 Elsevier Inc. All rights reserved.

An intronic single-nucleotide polymorphism (rs13217795) in FOXO3 is associated with asthma and allergic rhinitis: a case-case-control study.

Science.gov (United States)

Amarin, Justin Z; Naffa, Randa G; Suradi, Haya H; Alsaket, Yousof M; Obeidat, Nathir M; Mahafza, Tareq M; Zihlif, Malek A

2017-11-15

Asthma and allergic rhinitis are respiratory diseases with a significant global burden. Forkhead box O3 (FOXO3) is a gene involved in the etiology of a number of respiratory diseases. The objective of this study is to assess the association of rs13217795, an intronic FOXO3 single-nucleotide polymorphism, with asthma and allergic rhinitis. In this case-case-control genetic association study, genotyping was conducted using the PCR-RFLP method. Genotype-based associations were investigated under the general, recessive, and dominant models of disease penetrance using binomial logistic regression; and, allele-based associations were tested using Pearson's chi-squared test. The final study population consisted of 94 controls, 124 asthmatics, and 110 allergic rhinitis patients. The general and recessive models of disease penetrance were statistically significant for both case-control comparisons. Under the general model, the odds of the asthma phenotype were 1.46 (0.64 to 3.34) and 3.42 (1.37 to 8.57) times higher in heterozygotes and derived allele homozygotes, respectively, compared to ancestral allele homozygotes. The corresponding odds ratios for the allergic rhinitis phenotype were 1.05 (0.46 to 2.40) and 2.35 (0.96 to 5.73), respectively. The dominant model of disease penetrance was not statistically significant. The minor allele in all study groups was the ancestral allele, with a frequency of 0.49 in controls. There was no deviation from Hardy-Weinberg equilibrium in controls. Both case-control allele-based associations were statistically significant. Herein we present the first report of the association between rs13217795 and allergic rhinitis, and the first independent verification of the association between rs13217795 and asthma. Marker selection in future genetic association studies of asthma and allergic rhinitis should include functional polymorphisms in linkage disequilibrium with rs13217795.

Outbreak investigation and control case report of brucellosis: Experience from livestock research centre, Mpwapwa, Tanzania

Directory of Open Access Journals (Sweden)

Gabriel M. Shirima

2014-11-01

Full Text Available Brucellosis screening was conducted between 2005 and 2010 at the National Livestock Research Institute headquarters, Mpwapwa, Tanzania, following an abortion storm in cattle. The initial screening targeted breeding herds; 483 cattle were screened using the Rose Bengal Plate Test (RBPT followed by the Competitive Enzyme-linked Immunosorbent Assay (c-ELISA as a confirmatory test. The seropositivity on c-ELISA was 28.95% in 2005; it subsequently declined to 6.72%, 1.17%, 0.16% and 0.00% in 2006, 2007, 2009 and 2010, respectively. Brucella seropositivity was not detected in goats. Seropositivity declined following institution of stringent control measures that included: gradual culling of seropositive animals through slaughter; isolation and confinement of pregnant cows close to calving; proper disposal of placentas and aborted foetuses; the use of the S19 vaccine; and restricted introduction of new animals. It was thought that the source of this outbreak was likely to have been from the introduction of infected animals from another farm. Furthermore, humans were found with brucellosis antibodies. Out of 120 people screened, 12 (10% were confirmed seropositive to brucella antigen exposure by c-ELISA analysis. The majority of the seropositive individuals (80% were milkers and animal handlers from the farm. Nine individuals had clinical signs suggestive of brucellosis. All cases received medical attention from the district hospital. This achievement in livestock and human health showed that it is possible to control brucellosis in dairy farms, compared to pastoral and agro-pastoral farms, thus providing evidence to adopt these strategies in dairy farms thought to be at risk.

An Investigation Into Why Lighting Controls Fail in Buildings

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Bernard Doyle

2012-04-01

Full Text Available The project began as a post-occupancy evaluation of lighting controls installed in a range of buildings, including a public office building, a shopping centre and a primary school. Actual controlled lighting consumption was to be compared against past billing or simulated energy consumption. However, when the research began it was found that the controls had been removed from two out of the three buildings. Further research proved that it was not unusual for lighting controls to be disconnected following installation. This raised a much bigger research question- why were the controls disconnected and what were the factors governing success or failure of these systems? To answer this new question a new methodology to that first envisaged had to be established. Investigating the reasons for disconnection could only be achieved by discussion with those involved. To find out what people know, or think, it is necessary to ask them. Interviewing was used to address the new research question. It was found that little research exists on long-term performance analysis of lighting controls. A framework was created to determine if there is correlation between past findings and the reasons for failure in the case studies. It should be noted that there were minimal findings into the failure of lighting controls systems in buildings in Ireland, which prompted possible additional reasons for the failure of these systems, e.g. differing usage patterns, availability of useful daylight. The research that followed posed many challenges requiring the use of qualitative data in an engineering environment. In order to answer the research question, a clearly-defined and wellstructured methodology was required. It was concluded from the research that the conceptual framework used was appropriate and that the methods were fit for purpose.Some of the findings included: • Maintenance costs are comparitively high • Misinterpretation of commissioning processes �

The Relationship between Chronic Constipation and Urinary Tract Infection in Children: A Case-Control Clinical Study

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Gholamreza Sarvari

2017-09-01

Full Text Available Background Urinary tract infection (UTI is one of the most common bacterial infections in children, if not diagnosed leads to serious complications such as hypertension, chronic renal failure and renal scar. Constipation is one of the main risk factors for recurrent UTI. The aim of present study was to investigate the relationship between chronic constipation and urinary tract infection in children. Materials and Methods In this case-control study 105 patients with functional chronic constipation as case group, compared with 104 children without chronic constipation as control. The control group was matched according to gender and age. The prevalence of UTI in children with and without constipation as well as their improvement was compared after treatment. Results The prevalence of UTI in case and control groups was 13.3% and 6.7%, respectively (P=0.17. The prevalence of UTI in case group decreased to 3.8% after treatment of constipation. Escherichia coli (E coli was the most commonly isolated organism in both groups. Conclusion Results of present study showed that despite of no significant urinary tract infection incidence between children with constipation and those without constipation, the constipation should still be considered as a predisposing risk factor for the UTI occurrence.

Laboratory Processes for Confirmation of Lymphogranuloma Venereum Infection During a 2015 Investigation of a Cluster of Cases in the United States.

Science.gov (United States)

Kersh, Ellen N; Pillay, Allan; de Voux, Alex; Chen, Cheng

2017-11-01

In September 2015, the Centers for Disease Control and Prevention were notified of a suspected outbreak investigation of lymphogranuloma venereum (LGV) cases by the Michigan Department of Health and Human Services. The Centers for Disease Control and Prevention offered support with a laboratory-developed polymerase chain reaction test for LGV. This note describes the laboratory workflow and procedures used for the laboratory confirmation of LGV infection.

Risk factors associated with non-alcoholic fatty liver disease in subjects from primary care units. A case-control study

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Bernad Jesús

2008-10-01

Full Text Available Abstract Background Non alcoholic fatty liver disease (NAFL consists in the accumulation of fat vacuoles in the cytoplasm of hepatocytes. Many etiologic factors are associated with NAFL, such as, the metabolic syndrome factors, medications, bariatric surgery, nutritional disorders. However, very little information is available on the clinical relevance of this disorder as a health problem in the general population. Methods and design The aim of the study is establish the risk factors most frequently associated with NAFL in a general adult population assigned to the primary care units and to investigate the relationship between each component of the metabolic syndrome and the risk of having a NAFL. A population based case-control, observational and multicenter study will be carried out in 18 primary care units from the "Area de Gestión del Barcelonés Nord y Maresme" (Barcelona attending a population of 360,000 inhabitants and will include 326 cases and 370 controls. Cases are defined as all subjects fulfilling the inclusion criteria and with evidence of fatty liver in an abdominal ultrasonography performed for any reason. One control will be randomly selected for each case from the population, matched for age, gender and primary care center. Controls with fatty liver or other liver diseases will be excluded. All cases and controls will be asked about previous hepatic diseases, consumption of alcohol, smoking and drugs, and a physical examination, biochemical analyses including liver function tests, the different components of the metabolic syndrome and the HAIR score will also be performed. Paired controls will also undergo an abdominal ultrasonography. Discussion This study will attempt to determine the factors most frequently associated with the presence of NAFL investigate the relationship between the metabolic syndrome and the risk of fatty liver and study the influence of the different primary care professionals in avoiding the evolution

A case-control study of risk factors for epithelial ovarian cancer

Directory of Open Access Journals (Sweden)

Ghaem Maghami Noori F

2001-09-01

Full Text Available Ovarian cancer is second prevalent cancer among gynecologic malignancies and the most common type of ovarian cancer is epithelial form (85-90 percent. To detect the risk factors for the epithelial ovarian cancer, a case-control study was conducted in Valieasr hospital in 1988. In this study, 118 cases with epithelial ovarian cancer (according histological records and 240 controls without any gynecological cancer in gynecologic clinic had been interviewed. For data analysis, T-test, Chi2 test and logistic regression have been used at a =0.05 as level of significance. The mean age in cases was 50±13 and in controls was 49.9±12 years, without significant different. The mean number of pregnancies and parity in cases was less than controls, significantly (P<0.03. The mean months of breast feeding in cases was less than controls (54.9±71.2 versus 82.4±62.7 (P<0.001. The cases had a lower mean age of menarch than controls (P=0.03. 58 percent of cases and 21.3 percent of controls hadn't used any contraception methods (P=0.00001. The mean years of contraception was significantly less in cases versus controls (P<0.001. The odds ratio for epithelial ovarian cancer was 0.24 (95 percent CI: 0.13-0.48 in OCP users, 0.47 (95 percent CI: 0.005-0.43 in TL method, and was 0.41 (95 percent CI: 0.22-0.76 in other contraception methods, relative to women who hadn't used any contraception methods. This study reveals that epithelial ovarian cancer risk increases significantly with earlier menarch, decreasing number of pregnancy, deliveries duration of breast feeding and use of contraception methods. Use of contraception pill and tubal ligation method decreases risk of epithelial ovarian cancer.

The Misconception of Case-Control Studies in the Plastic Surgery Literature: A Literature Audit.

Science.gov (United States)

Hatchell, Alexandra C; Farrokhyar, Forough; Choi, Matthew

2017-06-01

Case-control study designs are commonly used. However, many published case-control studies are not true case-controls and are in fact mislabeled. The purpose of this study was to identify all case-control studies published in the top three plastic surgery journals over the past 10 years, assess which were truly case-control studies, clarify the actual design of the articles, and address common misconceptions. MEDLINE, Embase, and Web of Science databases were searched for case-control studies in the three highest-impact factor plastic surgery journals (2005 to 2015). Two independent reviewers screened the resulting titles, abstracts, and methods, if applicable, to identify articles labeled as case-control studies. These articles were appraised and classified as true case-control studies or non-case-control studies. The authors found 28 articles labeled as case-control studies. However, only six of these articles (21 percent) were truly case-control designs. Of the 22 incorrectly labeled studies, one (5 percent) was a randomized controlled trial, three (14 percent) were nonrandomized trials, two (9 percent) were prospective comparative cohort designs, 14 (64 percent) were retrospective comparative cohort designs, and two (9 percent) were cross-sectional designs. The mislabeling was worse in recent years, despite increases in evidence-based medicine awareness. The majority of published case-control studies are not in fact case-control studies. This misunderstanding is worsening with time. Most of these studies are actually comparative cohort designs. However, some studies are truly clinical trials and thus a higher level of evidence than originally proposed.

Reducing selection bias in case-control studies from rare disease registries.

Science.gov (United States)

Cole, J Alexander; Taylor, John S; Hangartner, Thomas N; Weinreb, Neal J; Mistry, Pramod K; Khan, Aneal

2011-09-12

In clinical research of rare diseases, where small patient numbers and disease heterogeneity limit study design options, registries are a valuable resource for demographic and outcome information. However, in contrast to prospective, randomized clinical trials, the observational design of registries is prone to introduce selection bias and negatively impact the validity of data analyses. The objective of the study was to demonstrate the utility of case-control matching and the risk-set method in order to control bias in data from a rare disease registry. Data from the International Collaborative Gaucher Group (ICGG) Gaucher Registry were used as an example. A case-control matching analysis using the risk-set method was conducted to identify two groups of patients with type 1 Gaucher disease in the ICGG Gaucher Registry: patients with avascular osteonecrosis (AVN) and those without AVN. The frequency distributions of gender, decade of birth, treatment status, and splenectomy status were presented for cases and controls before and after matching. Odds ratios (and 95% confidence intervals) were calculated for each variable before and after matching. The application of case-control matching methodology results in cohorts of cases (i.e., patients with AVN) and controls (i.e., patients without AVN) who have comparable distributions for four common parameters used in subject selection: gender, year of birth (age), treatment status, and splenectomy status. Matching resulted in odds ratios of approximately 1.00, indicating no bias. We demonstrated bias in case-control selection in subjects from a prototype rare disease registry and used case-control matching to minimize this bias. Therefore, this approach appears useful to study cohorts of heterogeneous patients in rare disease registries.

Potential of public transit as a transportation control measure: Case studies

Energy Technology Data Exchange (ETDEWEB)

Sillings, M.

1998-07-01

This report is the final product of the Clean Air Project of the National Association of Regional Councils/NARC. It documents a nationwide study of transit projects and programs initiated in the wake of the 1990 Clean Air Act Amendments/CAAA and the Intermodal Surface Transportation Efficiency Act of 1991/ISTEA. The study purpose was to assess the experience, limitations, and value of public transit as a potential transportation control measure/TCM, i.e., generates significant air quality benefits by eliminating or reducing emissions from motor vehicles. Four in-depth case studies and six additional projects featured as innovations in transportation are offered as examples investigating the potential of transit as a TCM. These case studies and innovations highlight the efforts of ten metropolitan areas and transit agencies which have succeed in developing and implementing innovative transit strategies.

Pituitary tumor risk in relation to mobile phone use: A case-control study.

Science.gov (United States)

Shrestha, Mithila; Raitanen, Jani; Salminen, Tiina; Lahkola, Anna; Auvinen, Anssi

2015-01-01

The number of mobile phone users has grown rapidly, which has generated mounting public concern regarding possible health hazards. This study aims to assess pituitary tumor risk, as it has rarely been investigated. A case-control study was conducted with 80 eligible cases identified from all five university hospitals in Finland and frequency-matched 240 controls from the national population register. Controls were matched to cases by age, sex, region of residence and date of interview. A detailed history of mobile phone use was obtained using a structured interview. Several indicators of mobile phone use were assessed using conditional logistic regression. A reduced odds ratio was seen among regular mobile phone users [OR 0.39, 95% confidence interval (CI) 0.21, 0.72] relative to never/non-regular users, possibly reflecting methodological limitations. Pituitary tumor risk was not increased after 10 or more years since first use (OR 0.69, 95% CI 0.25, 1.89). The risk was not increased in relation to duration, cumulative hours of use, or cumulative number of calls. The results were similar for analog and digital phones. We found no excess risk associated with self-reported short- or medium-term use of mobile phones. This is consistent with most of the published studies. However, uncertainties remained for longer duration of use, as a very small proportion of study participants reported use beyond 10 years.

Investigation of and Response to 2 Plague Cases, Yosemite National Park, California, USA, 2015

Science.gov (United States)

Danforth, Mary; Novak, Mark; Petersen, Jeannine; Mead, Paul; Kingry, Luke; Weinburke, Matthew; Buttke, Danielle; Hacker, Gregory; Tucker, James; Niemela, Michael; Jackson, Bryan; Padgett, Kerry; Liebman, Kelly; Vugia, Duc

2016-01-01

In August 2015, plague was diagnosed for 2 persons who had visited Yosemite National Park in California, USA. One case was septicemic and the other bubonic. Subsequent environmental investigation identified probable locations of exposure for each patient and evidence of epizootic plague in other areas of the park. Transmission of Yersinia pestis was detected by testing rodent serum, fleas, and rodent carcasses. The environmental investigation and whole-genome multilocus sequence typing of Y. pestis isolates from the patients and environmental samples indicated that the patients had been exposed in different locations and that at least 2 distinct strains of Y. pestis were circulating among vector–host populations in the area. Public education efforts and insecticide applications in select areas to control rodent fleas probably reduced the risk for plague transmission to park visitors and staff. PMID:27870634

Possible environmental, occupational, and other etiologic factors for Parkinson's disease: a case-control study in Germany.

Science.gov (United States)

Seidler, A; Hellenbrand, W; Robra, B P; Vieregge, P; Nischan, P; Joerg, J; Oertel, W H; Ulm, G; Schneider, E

1996-05-01

In a case-control study, we investigated the possible etiologic relevance to Parkinson's disease (PD) of rural factors such as farming activity, pesticide exposures, well-water drinking, and animal contacts; toxicologic exposures such as wood preservatives, heavy metals, and solvents; general anesthesia; head trauma; and differences in the intrauterine environment. We recruited 380 patients in nine German clinics, 379 neighborhood control subjects, and 376 regional control subjects in the largest case-control study investigating such factors and collected data in structured personal interviews using conditional logistic regression to control for educational status and cigarette smoking. The latter was strongly inversely associated with PD. There were significantly elevated odds ratios (OR) for pesticide use, in particular, for organochlorines and alkylated phosphates, but no association was present between PD and other rural factors. A significantly elevated OR was present for exposure to wood preservatives. Subjective assessment by the probands indicated that exposure to some heavy metals, solvents, exhaust fumes, and carbon monoxide was significantly more frequent among patients than control subjects, but this was not confirmed by a parallel assessment of job histories according to a job exposure matrix. Patients had undergone general anesthesia and suffered severe head trauma more often than control subjects, but a dose-response gradient was not present. Patients reported a significantly larger number of amalgam-filled teeth before their illness than control subjects. The frequency of premature births and birth order did not differ between patients and control subjects. Patients reported significantly more relatives affected with PD than control subjects. These results support a role for environmental and genetic factors in the etiology of PD.

Case-control study of gadodiamide-related nephrogenic systemic fibrosis

DEFF Research Database (Denmark)

Marckmann, Peter; Skov, Lone; Rossen, Kristian

2007-01-01

exposed to gadodiamide develop nephrogenic systemic fibrosis. METHODS: We conducted a case-control study of 19 histologically verified cases and 19 sex- and age-matched controls. All subjects had chronic renal failure when exposed to gadodiamide. Clinical, biochemical and pharmacological data were.......02). CONCLUSIONS: Increasing cumulative gadodiamide exposure, high-dose epoietin-beta treatment, and higher serum concentrations of ionized calcium and phosphate increase the risk of gadodiamide-related nephrogenic systemic fibrosis in renal failure patients. Severe cases seem to develop primarily among patients......BACKGROUND: Nephrogenic systemic fibrosis may be caused by gadolinium (Gd)-containing magnetic resonance imaging contrast agents. Most reported cases were associated with one particular agent, gadodiamide. Yet, unidentified cofactors might explain why only a minority of renal failure patients...

Lifestyle Factors and Gender-Specific Risk of Stroke in Adults with Diabetes Mellitus: A Case-Control Study.

Science.gov (United States)

Guo, Jian; Guan, Tianjia; Shen, Ying; Chao, Baohua; Li, Mei; Wang, Longde; Liu, Yuanli

2018-07-01

The lifestyle interventions are effective preventive measures for stroke in general population, and the stroke risk with lifestyle factors may be modified by gender, health conditions, etc. Therefore, we conducted a case-control study to investigate the gender-specific association between stroke risk and lifestyle factors in adults with diabetes based on the China National Stroke Screening Survey. Structured questionnaires were used to collect demographic data and information regarding lifestyle factors, history of chronic medical conditions, and family history of stroke and the status of treatment. The case group comprised individuals diagnosed with first-ever stroke in 2013-2014 screening period. Their corresponding controls (frequency-matched for age group and urban/rural ratio) were randomly selected from individuals with diabetes without stroke. There were 170 total stroke cases (500 controls) and 152 ischemic stroke cases (456 controls) among men with diabetes, and 183 total stroke cases (549 controls) and 168 ischemic stroke cases (504 controls) among women with diabetes. We found that physical inactivity was significantly associated with increased risk of total stroke (odds ratio [OR] = 1.50, 95% confidence interval [CI] 1.02-2.21) and of ischemic stroke (OR = 1.57, 95% CI 1.04-2.36) in women with diabetes. We found no significant association of smoking, overweight/obesity, or physical inactivity with risk of total or ischemic stroke in men with diabetes. Among the lifestyle factors of smoking, overweight/obesity, and physical inactivity, physical inactivity might increase the risk of total and ischemic stroke in women with diabetes. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Opium consumption and risk of bladder cancer: A case-control analysis.

Science.gov (United States)

Hosseini, Seyyed Yousof; Safarinejad, Mohammad Reza; Amini, Erfan; Hooshyar, Hassan

2010-01-01

We evaluated the relationship between opium consumption and bladder cancer (BC) in a case-control study of an Iranian population. In a hospital-based case-control study of 179 patients with BC and 179 cancer-free controls frequency-matched by age, sex, and smoking status, we investigated the relationship between opium consumption and BC. A comprehensive epidemiologic interview was conducted on all participants to collect personal information, such as demographics and smoking status. Overall, we found significant age, sex, cigarette smoking adjusted association between BC risk and opium consumption, [odds ratio (OR) = 4.60; 95% confidence interval (CI) = 3.53-6.28]. The elevated risk was more evident in older individuals (OR = 5.42; 95% CI, 4.12-7.28) than younger individuals (OR = 3.65; 95% CI, 2.76-4.76) (P = 0.01). Heavy smokers with the opium consumption exhibited a 6-fold elevated risk for BC (OR = 6.16; 95% CI, 3.34-8.32) (P = 0.0001). When stratified according to different grades of BC, a 3.4-fold increased risk was associated with the opium consumption in grade III with an OR of 3.44 (95% CI, 2.82-8.28) (P = 0.001). A similar but slightly higher risk was also seen in case of grade IV tumors (OR = 3.86; 95% CI, 2.14-10.16) (P = 0.001). Invasive bladder tumors were more common among the opiates users (OR = 2.6; 95% CI, 1.44-5.42) (P = 0.01). Cumulative risk of BC in women with opium consumption (OR = 4.10 95% CI, 3.54-5.88) (P = 0.001) was slightly less than in men (OR = 5.10 95% CI, 3.54-5.88) (P = 0.0001). Based on Pearson correlations, the risk of BC significantly correlated with opium dependence duration (r = 0.74, P = 0.001), type of opiate used (r = 0.65, P = 0.001), and simultaneous cigarette smoking (r = 0.74, P = 0.0001). The results indicated that there is about 5-fold increase in risk of developing this cancer in the presence of opium consumption. Further research is needed to investigate the functional implications of the opium consumption in BC

Associated factors with attention deficit hyperactivity disorder (ADHD): a case-control study.

Science.gov (United States)

Malek, Ayyoub; Amiri, Shahrokh; Sadegfard, Majid; Abdi, Salman; Amini, Saeedeh

2012-09-01

The current study attempted to investigate factors associated with attention deficit hyperactivity disorder (ADHD) in children without co-morbidities. In this case-control study, 164 ADHD children who attended the Child and Adolescent Psychiatric Clinics of Tabriz University of Medical Sciences, Iran were compared with 166 normal children selected in a random-cluster method from primary and secondary schools. Clinical interviews based on DSM-IV-TR using K-SADS were used to diagnose ADHD cases and to select the control group. Participants were matched for age. We used chi-square and binary logistic regression for data analysis. Among the associated factors with ADHD were gender and maternal employment. Boys (OR 0.54; 95% confidence interval: 0.34 - 0.86) and those children with working mothers (OR 0.16: 95% confidence interval: 0.06 - 0.86) suffered more from ADHD. The birth season, family size, birth order, and parental kinship were not among risk factors for ADHD. The results of the study show that maternal employment and male gender are among the associated risk factors for ADHD.

Lung and bladder cancer among Danish urban bus drivers and tramway employees: a nested case-control study.

Science.gov (United States)

Soll-Johanning, Helle; Bach, Elsa; Jensen, Steen S

2003-02-01

The combustion of fossil fuels produces small amounts of mutagenic and carcinogenic compounds. We investigated the association between employment and lung and bladder cancer in Danish bus drivers and tramway employees. We carried out a nested case-control study of 153 lung and 84 bladder cancer cases, and 606 controls sampled in a cohort of 18 174 bus drivers or tramway employees employed in Copenhagen during the period 1900-1994. The cases and controls or their next of kin were interviewed about smoking, along with occupational and residential history. An exposure index based on which bus routes the bus drivers had mainly been driving was established. Relative risks (RRs) were estimated by conditional logistic regression. The analysis showed decreasing risk for lung cancer with increasing years of employment as a bus driver (RR = 0.97 for each added year, 95% confidence interval = 0.96-0.99). The air pollution index based on main bus for the bus drivers showed no positive correlation with risk.

A case-control evaluation of fungiform papillae density in burning mouth syndrome.

Science.gov (United States)

Naud, Jason M; Benca, Laura; Drangsholt, Mark T; LeResche, Linda; Coldwell, Susan E

2018-04-01

It has been hypothesized that high fungiform papillae density may be a risk factor for developing the taste and pain alterations characteristic of burning mouth syndrome. Evaluate whether fungiform papillae density, taste sensitivity, and mechanical pain sensitivity differ between burning mouth syndrome cases and controls. This case-control study compared cases diagnosed with primary burning mouth syndrome with pain-free controls. Participants (17 female cases and 23 female controls) rated the intensity of sucrose, sodium chloride, citric acid, and quinine applied separately to each side of the anterior tongue and sampled whole mouth. Mechanical pain sensitivity was assessed separately for each side of the tongue using weighted pins. Digital photographs of participants' tongues were used to count fungiform papillae. Burning mouth syndrome cases had increased whole mouth taste intensity. Cases also had increased sensitivity to quinine on the anterior tongue, as well as increased mechanical pain sensitivity on the anterior tongue. Fungiform papillae density did not differ significantly between cases and controls. Fungiform papillae density on the left and right sides of the tongue were correlated in controls; however, there was no left/right side correlation in cases. Cases had increased pain and taste perception on the anterior tongue. The lack of correlation between left and right fungiform papillae density in cases may be an indication of asymmetrical lingual innervation in these patients. 3b. Laryngoscope, 128:841-846, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Inverse association between yerba mate consumption and idiopathic Parkinson's disease. A case-control study.

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Gatto, Emilia Mabel; Melcon, Carlos; Parisi, Virginia L; Bartoloni, Leonardo; Gonzalez, Claudio D

2015-09-15

Yerba mate tea is a very common beverage in some countries of South America. We conducted a case-control study on an individual basis using hospital records to investigate the association between Parkinson's disease (PD) and yerba mate intake. A case was defined as an age of ≥ 40 years with ≥ 1 year of PD. Each case was individually matched by two controls. Exposure was measured by yerba mate consumption, coffee, tea, and alcohol intake and smoking status. The sample consisted of 223 PD patients (mean age 68 years and mean disease duration 7.3 years) and 406 controls. There was an inverse association between yerba mate "bombilla" consumption and PD (OR 0.64, 95% CI: 0.54-0.76, p=0.00001). A multivariate analysis with a logistic regression adjusted by sex, alcohol intake and smoking provided the following results: yerba mate (OR 0.63, 95% CI: 0.53-0.76), tea (OR 0.60, 95% CI: 0.42-0.86), coffee (OR 0.51, 95% CI: 0.35-0.73). We found an inverse association between yerba mate consumption and PD. These results led us to hypothesize that yerba mate may have a potential protective role in the development of PD. Copyright © 2015 Elsevier B.V. All rights reserved.

Residential radon exposure and lung cancer risk in Misasa, Japan. A case-control study

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Sobue, Tomotaka; Lee, Valerie S.; Ye, Weimin; Tanooka, Hiroshi; Mifune, Masaaki; Suyama, Akihiko; Koga, Taeko; Morishima, Hiroshige; Kondo, Sohei

2000-01-01

In order to investigate an association between residential radon exposure and risk of lung cancer, a case-control study was conducted in Misasa Town, Tottori Prefecture, Japan. The case series consisted of 28 people who had died of lung cancer in the years 1976-96 and 36 controls chosen randomly from the residents in 1976, matched by sex and year of birth. Individual residential radon concentrations were measured for 1 year with alpha track detectors. The average radon concentration was 46 Bq/m 3 for cases and 51 Bq/m 3 for controls. Compared to the level of 24 or less Bq/m 3 , the adjusted odds ratios of lung cancer associated with radon levels of 25-49, 50-99 and 100 or more Bq/m 3 , were 1.13 (95% confidence interval; 0.29-4.40), 1.23 (0.16-9.39) and 0.25 (0.03-2.33), respectively. None of the estimates showed statistical significance, due to small sample size. When the subjects were limited to only include residents of more than 30 years, the estimates did not change substantially. This study did not find that the risk pattern of lung cancer, possibly associated with residential radon exposure, in Misasa Town differed from patterns observed in other countries. (author)

Candidate gene analysis of spontaneous preterm delivery: New insights from re-analysis of a case-control study using case-parent triads and control-mother dyads

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Myking Solveig

2011-12-01

Full Text Available Abstract Background Spontaneous preterm delivery (PTD has a multifactorial etiology with evidence of a genetic contribution to its pathogenesis. A number of candidate gene case-control studies have been performed on spontaneous PTD, but the results have been inconsistent, and do not fully assess the role of how two genotypes can impact outcome. To elucidate this latter point we re-analyzed data from a previously published case-control candidate gene study, using a case-parent triad design and a hybrid design combining case-parent triads and control-mother dyads. These methods offer a robust approach to genetic association studies for PTD compared to traditional case-control designs. Methods The study participants were obtained from the Norwegian Mother and Child Cohort Study (MoBa. A total of 196 case triads and 211 control dyads were selected for the analysis. A case-parent triad design as well as a hybrid design was used to analyze 1,326 SNPs from 159 candidate genes. We compared our results to those from a previous case-control study on the same samples. Haplotypes were analyzed using a sliding window of three SNPs and a pathway analysis was performed to gain biological insight into the pathophysiology of preterm delivery. Results The most consistent significant fetal gene across all analyses was COL5A2. The functionally similar COL5A1 was significant when combining fetal and maternal genotypes. PON1 was significant with analytical approaches for single locus association of fetal genes alone, but was possibly confounded by maternal effects. Focal adhesion (hsa04510, Cell Communication (hsa01430 and ECM receptor interaction (hsa04512 were the most constant significant pathways. Conclusion This study suggests a fetal association of COL5A2 and a combined fetal-maternal association of COL5A1 with spontaneous PTD. In addition, the pathway analysis implied interactions of genes affecting cell communication and extracellular matrix.

Appendectomy and Risk of Subsequent Diverticular Disease Requiring Hospitalization: A Population-Based Case-Control Study.

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Sköldberg, Filip; Olén, Ola; Ekbom, Anders; Schmidt, Peter T

2018-07-01

Appendicitis and acute diverticulitis share clinical features and are both influenced by genetic and environmental factors. Appendectomy has been positively associated with diverticular disease in hospital-based case-control studies. The aim of the present study was to investigate, in a population-based setting, whether appendectomy, with or without appendicitis, is associated with an altered risk of hospitalization with diverticular disease. This was a population-based case-control study. The study was based on national healthcare and population registers. We studied 41,988 individuals hospitalized between 2000 and 2010 with a first-time diagnosis of colonic diverticular disease and 413,115 matched control subjects. The association between appendectomy with or without appendicitis and diverticular disease was investigated by conditional logistic regression, including a model adjusting for hospital use. A total of 2813 cases (6.7%) and 19,037 controls (4.6%) had a previous record of appendectomy (appendectomy with acute appendicitis: adjusted OR = 1.31 (95% CI, 1.24-1.39); without appendicitis: adjusted OR = 1.30 (95% CI, 1.23-1.38)). Appendectomy was most strongly associated with an increased risk of diverticular disease within 1 year (with appendicitis: adjusted OR = 2.26 (95% CI, 1.61-3.16); without appendicitis: adjusted OR = 3.98 (95% CI, 2.71-5.83)), but the association was still present ≥20 years after appendectomy (with appendicitis: adjusted OR = 1.22 (95% CI, 1.12-1.32); without appendicitis: adjusted OR = 1.19 (95% CI, 1.10-1.28)). Detailed clinical information on the cases was not available. There were unmeasured potential confounders, such as smoking and dietary factors. The findings are consistent with a hypothesis of appendectomy causing an increased risk of diverticular disease, for example, by affecting the mucosal immune system or the gut microbiome. However, several other mechanisms may contribute to, or account for, the positive association

Reducing selection bias in case-control studies from rare disease registries

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Mistry Pramod K

2011-09-01

Full Text Available Abstract Background In clinical research of rare diseases, where small patient numbers and disease heterogeneity limit study design options, registries are a valuable resource for demographic and outcome information. However, in contrast to prospective, randomized clinical trials, the observational design of registries is prone to introduce selection bias and negatively impact the validity of data analyses. The objective of the study was to demonstrate the utility of case-control matching and the risk-set method in order to control bias in data from a rare disease registry. Data from the International Collaborative Gaucher Group (ICGG Gaucher Registry were used as an example. Methods A case-control matching analysis using the risk-set method was conducted to identify two groups of patients with type 1 Gaucher disease in the ICGG Gaucher Registry: patients with avascular osteonecrosis (AVN and those without AVN. The frequency distributions of gender, decade of birth, treatment status, and splenectomy status were presented for cases and controls before and after matching. Odds ratios (and 95% confidence intervals were calculated for each variable before and after matching. Results The application of case-control matching methodology results in cohorts of cases (i.e., patients with AVN and controls (i.e., patients without AVN who have comparable distributions for four common parameters used in subject selection: gender, year of birth (age, treatment status, and splenectomy status. Matching resulted in odds ratios of approximately 1.00, indicating no bias. Conclusions We demonstrated bias in case-control selection in subjects from a prototype rare disease registry and used case-control matching to minimize this bias. Therefore, this approach appears useful to study cohorts of heterogeneous patients in rare disease registries.

Delayed sleep phase cases and controls

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Nievergelt Caroline M

2008-04-01

Full Text Available Abstract Background Delayed sleep phase disorder (DSPD is a condition in which patients have difficulty falling asleep before the early morning hours and commonly have trouble awakening before late morning or even early afternoon. Several studies have suggested that variations in habitual bedtime are 40–50% heritable. Methods We recruited a case series of 205 participants, along with 221 controls (DSPD-C with normal sleep, roughly matched for age, gender, and ancestry. A representative sample of San Diego adults recruited some years before was already available to confirm the control group. Both DSPD and DSPD-C provided blood or saliva samples for DNA and completed extensive questionnaires about sleep habits, sleep history, family history, sleep quality, morningness-eveningness traits, depression, mania, and seasonality of symptoms. The DSPD group wore wrist actigraphs for a median of 13.2 days. The representative sample collected previously had undergone actigraphic recordings, from which 48 hours of data were generally available. Results The DSPD and DSPD-C samples showed almost no overlap on morningness-eveningness scores. DSPD cases went to bed and arose about 3 hours later than the DSPD-C and the representative sample. DSPD cases reported more difficulties with sleep, poorer sleep quality, and more depression, but there was no significant difference in a history of mania. DSPD cases reported more family history of late bedtimes, but female DSPD reported that their fathers' bedtimes were later than the fathers of male DSPD. Conclusion These results indicate a DSPD phenotype is familial and associated with unipolar depression.

The Toxicology Investigators Consortium Case Registry--the 2014 Experience.

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Rhyee, Sean H; Farrugia, Lynn; Campleman, Sharan L; Wax, Paul M; Brent, Jeffrey

2015-12-01

The Toxicology Investigators Consortium (ToxIC) Case Registry was established in 2010 by the American College of Medical Toxicology. The Registry includes all medical toxicology consultations performed at participating sites. The Registry was queried for all cases entered between January 1 and December 31, 2014. Specific data reviewed for analysis included demographics (age, gender, ethnicity), source of consultation, reasons for consultation, agents involved in toxicological exposures, signs, symptoms, clinical findings, fatalities, and treatment. In 2014, 9172 cases were entered in the Registry across 47 active member sites. Females accounted for 51.1 % of cases. The majority (65.1 %) of cases were adults between the ages of 19 and 65. Caucasians made up the largest identified ethnic group (48.9 %). Most Registry cases originated from the inpatient setting (93.5 %), with a large majority of these consultations coming from the emergency department or inpatient admission services. Intentional and unintentional pharmaceutical exposures continued to be the most frequent reasons for consultation, accounting for 61.7 % of cases. Among cases of intentional pharmaceutical exposure, 62.4 % were associated with a self-harm attempt. Non-pharmaceutical exposures accounted for 14.1 % of Registry cases. Similar to the past years, non-opioid analgesics, sedative-hypnotics, and opioids were the most commonly encountered agents. Clinical signs or symptoms were noted in 81.9 % of cases. There were 89 recorded fatalities (0.97 %). Medical treatment (e.g., antidotes, antivenom, chelators, supportive care) was rendered in 62.3 % of cases. Patient demographics and exposure characteristics in 2014 Registry cases remain similar to prior years. The majority of consultations arose in the acute care setting (emergency department or inpatient) and involved exposures to pharmaceutical products. Among exposures, non-opioid analgesics, sedative/hypnotics, and opioids were the most frequently

Outbreak of Ampicillin/Piperacillin-Resistant Klebsiella Pneumoniae in a Neonatal Intensive Care Unit (NICU: Investigation and Control Measures

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Patrizia Farruggia

2013-02-01

Full Text Available Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs. The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infections sustained by ampicillin/piperacillin-resistant Klebsiella pneumoniae were observed over a two-month period. One culture obtained from a 12% saccarose multiple-dose solution allowed the growth of Klebsiella pneumoniae. During the inspections performed by the Hospital Infection Control Team, using the check-list for the evaluation of the NICU staff compliance to the infection control measures, several breaches in the infection control policy were identified and control measures were adopted. In our case the definition of a specific check-list led to the adoption of the correct control measures. Further studies would be helpful in order to develop a standard check-list able to identify critical flows in the adhesion to the guidelines. It could be used in different NICUs and allow to obtain reproducible levels of infection control.

Outbreak of ampicillin/piperacillin-resistant Klebsiella pneumoniae in a neonatal intensive care unit (NICU): investigation and control measures.

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Fabbri, Giuliana; Panico, Manuela; Dallolio, Laura; Suzzi, Roberta; Ciccia, Matilde; Sandri, Fabrizio; Farruggia, Patrizia

2013-02-26

Klebsiella pneumoniae is a frequent cause of infectious outbreaks in Neonatal Intensive Care Units (NICUs). The aim of this paper is to describe an outbreak occurred in a 13-bed NICU and the control measures adopted in order to interrupt the chain of transmission. We described the microbiological investigations, the NICU staff compliance to the infection control measures by means of a specifically designed check-list and the control measures adopted. Six cases of primary bloodstream infections sustained by ampicillin/piperacillin-resistant Klebsiella pneumoniae were observed over a two-month period. One culture obtained from a 12% saccarose multiple-dose solution allowed the growth of Klebsiella pneumoniae. During the inspections performed by the Hospital Infection Control Team, using the check-list for the evaluation of the NICU staff compliance to the infection control measures, several breaches in the infection control policy were identified and control measures were adopted. In our case the definition of a specific check-list led to the adoption of the correct control measures. Further studies would be helpful in order to develop a standard check-list able to identify critical flows in the adhesion to the guidelines. It could be used in different NICUs and allow to obtain reproducible levels of infection control.

Neurocognitive performance in family-based and case-control studies of schizophrenia

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Gur, Ruben C.; Braff, David L.; Calkins, Monica E.; Dobie, Dorcas J.; Freedman, Robert; Green, Michael F.; Greenwood, Tiffany A.; Lazzeroni, Laura C.; Light, Gregory A.; Nuechterlein, Keith H.; Olincy, Ann; Radant, Allen D.; Seidman, Larry J.; Siever, Larry J.; Silverman, Jeremy M.; Sprock, Joyce; Stone, William S.; Sugar, Catherine A.; Swerdlow, Neal R.; Tsuang, Debby W.; Tsuang, Ming T.; Turetsky, Bruce I.; Gur, Raquel E.

2014-01-01

Background Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. Methods The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Results Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Conclusions Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs. PMID:25432636

Neurocognitive performance in family-based and case-control studies of schizophrenia.

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Gur, Ruben C; Braff, David L; Calkins, Monica E; Dobie, Dorcas J; Freedman, Robert; Green, Michael F; Greenwood, Tiffany A; Lazzeroni, Laura C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Gur, Raquel E

2015-04-01

Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs.

Chronic autoimmune disorders are increased in coeliac disease: A case-control study.

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Bibbò, Stefano; Pes, Giovanni Mario; Usai-Satta, Paolo; Salis, Roberta; Soro, Sara; Quarta Colosso, Bianca Maria; Dore, Maria Pina

2017-11-01

Coeliac disease (CD) is an autoimmune disorder of the small bowel associated with increased risk of additional autoimmune diseases (ADs).To investigate the prevalence of ADs in a population of adult coeliac patients.This was a retrospective case-control study. Data from coeliac patients and controls referred to a tertiary center between 2013 and 2016 were collected. The frequency of ADs and the unadjusted and adjusted odds ratios (ORs) for age, gender, disease duration, and body mass index with their 95% confidence intervals (CIs) were evaluated.Two hundred fifty-five patients with CD (median age 37.1 years; 206 women) were matched with 250 controls. ADs were more frequent (35.3%) in coeliac patients than in controls (15.2%). Adjusted ORs for the presence of only 1, at least 1, and more than 1 AD were 3.13 (95% CI 1.81-5.42, P disease. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Factors associated with tuberculosis cases in Semarang District, Indonesia: case-control study performed in the area where case detection rate was extremely low.

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Rahayu, Sri Ratna; Katsuyama, Hironobu; Demura, Masashi; Katsuyama, Midori; Ota, Yoko; Tanii, Hideji; Higashi, Tomomi; Semadi, Ngakan Putu Djaja; Saijoh, Kiyofumi

2015-07-01

Indonesia is ranked as the 4th highest contributor to tuberculosis (TB) in the world. Semarang District in Central Java displays extremely low case detection rate (CDR), possibly contributing to the local prevalence of TB. A case-control study was performed to explore the factors that cause such low CDR. We recruited 129 TB cases and 83 controls that visited the same centers and were not diagnosed with TB. The cases had 7.5 ± 2.3 symptoms/person on average, indicating the delay in diagnosis because the controls only displayed 1.0 ± 1.7. The multiple logistic regression analysis comparing the cases/controls extracted following factors as a risk to have TB: farmer, close contact with TB patients, ignorance of whether Bacillus Calmette-Guérin (BCG) was accepted or no, smoking, low income, a lot of people living in the same room, irregular hand wash before meals, not wash hands after blow, soil floor, and no sunlight and no ventilation in the house. Neither the cases nor the controls knew the symptoms and how to avoid TB infection, which probably caused the delay in diagnosis. It is difficult to change the current living conditions. Thus, the amendment of the community-based education program of TB seems to be required.

Risk factors for measles among adults in Tianjin, China: Who should be controls in a case-control study?

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Wagner, Abram L; Boulton, Matthew L; Gillespie, Brenda W; Zhang, Ying; Ding, Yaxing; Carlson, Bradley F; Luo, Xiaoyan; Montgomery, JoLynn P; Wang, Xiexiu

2017-01-01

Control groups in previous case-control studies of vaccine-preventable diseases have included people immune to disease. This study examines risk factors for measles acquisition among adults 20 to 49 years of age in Tianjin, China, and compares findings using measles IgG antibody-negative controls to all controls, both IgG-negative and IgG-positive. Measles cases were sampled from a disease registry, and controls were enrolled from community registries in Tianjin, China, 2011-2015. Through a best subsets selection procedure, we compared which variables were selected at different model sizes when using IgG-negative controls or all controls. We entered risk factors for measles in two separate logistic regression models: one with measles IgG-negative controls and the other with all controls. The study included 384 measles cases and 1,596 community controls (194 IgG-negative). Visiting a hospital was an important risk factor. For specialty hospitals, the odds ratio (OR) was 4.53 (95% confidence interval (CI): 1.28, 16.03) using IgG-negative controls, and OR = 5.27 (95% CI: 2.73, 10.18) using all controls. Variables, such as age or length of time in Tianjin, were differentially selected depending on the control group. Individuals living in Tianjin ≤3 years had 2.87 (95% CI: 1.46, 5.66) times greater odds of measles case status compared to all controls, but this relationship was not apparent for IgG-negative controls. We recommend that case-control studies examining risk factors for infectious diseases, particularly in the context of transmission dynamics, consider antibody-negative controls as the gold standard.

A Methodology for Investigating Adaptive Postural Control

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McDonald, P. V.; Riccio, G. E.

1999-01-01

Our research on postural control and human-environment interactions provides an appropriate scientific foundation for understanding the skill of mass handling by astronauts in weightless conditions (e.g., extravehicular activity or EVA). We conducted an investigation of such skills in NASA's principal mass-handling simulator, the Precision Air-Bearing Floor, at the Johnson Space Center. We have studied skilled movement-body within a multidisciplinary context that draws on concepts and methods from biological and behavioral sciences (e.g., psychology, kinesiology and neurophysiology) as well as bioengineering. Our multidisciplinary research has led to the development of measures, for manual interactions between individuals and the substantial environment, that plausibly are observable by human sensory systems. We consider these methods to be the most important general contribution of our EVA investigation. We describe our perspective as control theoretic because it draws more on fundamental concepts about control systems in engineering than it does on working constructs from the subdisciplines of biomechanics and motor control in the bio-behavioral sciences. At the same time, we have attempted to identify the theoretical underpinnings of control-systems engineering that are most relevant to control by human beings. We believe that these underpinnings are implicit in the assumptions that cut across diverse methods in control-systems engineering, especially the various methods associated with "nonlinear control", "fuzzy control," and "adaptive control" in engineering. Our methods are based on these theoretical foundations rather than on the mathematical formalisms that are associated with particular methods in control-systems engineering. The most important aspects of the human-environment interaction in our investigation of mass handling are the functional consequences that body configuration and stability have for the pick up of information or the achievement of

A case-control study of risk factors associated with scrub typhus infection in Beijing, China.

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Yanning Lyu

Full Text Available To investigate the risk factors of scrub typhus infection in Beijing, China, a case-control study was carried out. Cases (n = 56 were defined as persons who were diagnosed by PCR and serological method within three years. Three neighborhood control subjects were selected by matching for age and occupation. Living at the edge of the village, living in the houses near grassland, vegetable field or ditch, house yard without cement floor, piling weeds in the house or yard, all of these were risk factors for scrub typhus infection. Working in vegetable fields and hilly areas, and harvesting in autumn posed the highest risks, with odds ratios (ORs and 95% confidence intervals (CIs of 3.7 (1.1-11.9, 8.2 (1.4-49.5, and 17.2 (5.1-57.9, respectively. These results would be useful for the establishment of a detail control strategy for scrub typhus infection in Beijing, China.

Leukaemia incidence among workers in the shoe and boot manufacturing industry: a case-control study

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Forand Steven P

2004-08-01

Full Text Available Abstract Background Previous reports have indicated an excess of leukaemia in Broome County, New York, particularly in the Town of Union. Surveillance of cancer incidence data indicates that a large proportion of these cases occurred among males ages 65 and older. Shoe and boot manufacturing has been the largest single industry in this area throughout much of the past century. Occupational studies from Europe suggest a link between leukaemia and employment in the shoe and boot manufacturing industry. However, researchers have not found a positive association between leukaemia and employment in the shoe industry among workers in the United States. Methods A matched case-control study was conducted to investigate the association between leukaemia incidence among males 65 and older and employment in the shoe and boot manufacturing industry. Thirty-six cases of leukaemia occurring between 1981–1990; among males age 65 and older; residing in the town of Union met the study case criteria. Death certificates were obtained for each of the cases. These were matched to death certificates of 144 controls on date of death and date of birth +/- 1 year. Death certificates were then examined to determine the employer and occupation of each study subject. Conditional logistic regression was used to determine the risk of leukaemia among those working in the industry. Results The risk of both leukaemia (OR = 1.47; 95% CI 0.70, 3.09 and acute myeloid leukaemia (OR = 1.19; 95% CI 0.33, 4.28 were elevated among those employed in the shoe and boot manufacturing industry, however neither was statistically significant. Conclusion The results, though suggestive of an association between leukaemia and employment in the shoe and boot manufacturing industry, were not statistically conclusive due mainly to limited study power. Several additional limitations may also have prevented the observance of more conclusive findings. Better exposure assessment, information on

A case-control study on risk factors of breast cancer in Han Chinese women.

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Liu, Li-Yuan; Wang, Fei; Cui, Shu-De; Tian, Fu-Guo; Fan, Zhi-Min; Geng, Cui-Zhi; Cao, Xu-Chen; Yang, Zhen-Lin; Wang, Xiang; Liang, Hong; Wang, Shu; Jiang, Hong-Chuan; Duan, Xue-Ning; Wang, Hai-Bo; Li, Guo-Lou; Wang, Qi-Tang; Zhang, Jian-Guo; Jin, Feng; Tang, Jin-Hai; Li, Liang; Zhu, Shi-Guang; Zuo, Wen-Shu; Yu, Li-Xiang; Xiang, Yu-Juan; Zhou, Fei; Li, Liang; Zhang, Qiang; Fu, Qin-Ye; Ma, Zhong-Bing; Gao, De-Zong; Li, Yu-Yang; Liu, Lu; Ye, Chun-Miao; Wang, Yong-Jiu; Zhou, Wen-Zhong; Yu, Zhi-Gang

2017-11-14

This study aimed to investigate risk factors associated with breast cancer among Han Chinese women in northern and eastern China. A matched case-control study involving 1489 patients with breast cancer and 1489 controls was conducted across 21 hospitals in 11 provinces in China, from April 2012 to April 2013. We developed a structured questionnaire to record information from face-to-face interviews with participants. Student's t-tests, Pearson's chi-square tests, and univariate and multivariate conditional logistic regression analyses were used to identify variables with significant differences between the case and control groups. Ten variables were identified (P ratio, menopause, family history of breast cancer, present life satisfaction, sleep satisfaction, milk products, behavior prevention scores, and awareness of breast cancer. We identified a comprehensive range of factors related to breast cancer, among which several manageable factors may contribute to breast cancer prevention. Further prospective studies concerning psychological interventions, sleep regulation, health guidance, and physical exercise are required. A screening model for high-risk populations should be put on the agenda.

Investigation of a national outbreak of STEC Escherichia coli O157 using online consumer panel control methods: Great Britain, October 2014.

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Sinclair, C; Jenkins, C; Warburton, F; Adak, G K; Harris, J P

2017-04-01

In October 2014, Public Health England (PHE) identified cases of Shiga toxin-producing Escherichia coli (STEC) serogroup O157 sharing a multiple locus variable-number tandem repeat analysis (MLVA) profile. We conducted a case-control study using multivariable logistic regression to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CI) testing a range of exposures. Cases were defined as laboratory-confirmed STEC O157 with the implicated MLVA profile, were UK residents aged ⩾18 years with symptom onset between 25 September and 30 October 2014, and had no history of travel abroad within 5 days of symptom onset. One hundred and two cases were identified. Cases were mostly female (65%; median age 49, range 2-92 years). It was the second largest outbreak seen in England, to date, and a case-control study was conducted using market research panel controls and online survey methods. These methods were instrumental in the rapid data collection and analysis necessary to allow traceback investigations for short shelf-life products. This is a new method of control recruitment and this is the first in which it was a standalone recruitment method. The case-control study suggested a strong association between consumption of a ready-to-eat food and disease (aOR 28, 95% CI 5·0-157) from one retailer. No reactive microbiological testing of food items during the outbreak was possible due to the short shelf-life of the product. Collaboration with industrial bodies is needed to ensure timely traceback exercises to identify contamination events and initiate appropriate and focused microbiological testing and implement control measures.

A case-control study assessing depression in patients with periodontitis

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Shiyamali Sundararajan

2017-01-01

Full Text Available Background: Chronic periodontitis is an inflammatory disease of the supporting structures of the tooth. One of the important non-oral risk factors for periodontitis is psychosocial stress and depression. Depression affects oral health by affecting the immune system through its effects on hypothalamic pituitary axis system. Periodontal inflammatory surface area (PISA is a system used to assess inflammatory burden in the periodontal tissue. Aim: The aim of this study is to assess the relationship between PISA and depression. Settings and Design: The design of the study is case-control study. Materials and Methods: The study design is a case-control study with forty patients each in case and control groups. The periodontal inflammatory level was assessed by PISA system and the levels of depression was assessed by using Beck's Depression Inventory (BDI. Statistical Analysis: Student's t-test was used to compare PISA and BDI scores. The BDI score (mean ± standard deviation [SD] for controls was 12.75 ± 6.82 compared to 22.73 ± 4.40 for the cases. The comparison (t = 7.78 was statistically significant at P < 0.0001. The PISA score (mean ± SD for controls was 210.47 ± 76.80 compared to the PISA score of 1069.50 ± 204.21 for cases which was statistically significant (t = 24.90; P < 0.0001. Results: Significantly higher BDI scores were observed in patients with chronic periodontitis than healthy controls. Conclusion: This study clearly reveals a significant association between the severity of depression and inflammatory burden.

Benchmarking of industrial control systems via case-based reasoning

International Nuclear Information System (INIS)

Hadjiiski, M.; Boshnakov, K.; Georgiev, Z.

2013-01-01

Full text: The recent development of information and communication technologies enables the establishment of virtual consultation centers related to the control of specific processes that are widely presented worldwide as the location of the installations does not have influence on the results. The centers can provide consultations regarding the quality of the process control and overall enterprise management as correction factors such as weather conditions, product or service and associated technology, production level, quality of feedstock used and others can be also taken into account. The benchmarking technique is chosen as a tool for analyzing and comparing the quality of the assessed control systems in individual plants. It is a process of gathering, analyzing and comparing data on the characteristics of comparable units to assess and compare these characteristics and improve the performance of the particular process, enterprise or organization. By comparing the different processes and the adoption of the best practices energy efficiency could be improved and hence the competitiveness of the participating organizations will increase. In the presented work algorithm for benchmarking and parametric optimization of a given control system is developed by applying the approaches of Case-Based Reasoning (CBR) and Data Envelopment Analysis (DEA). Expert knowledge and approaches for optimal tuning of control systems are combined. Two of the most common systems for automatic control of different variables in the case of biological wastewater treatment are presented and discussed. Based on analysis of the processes, different cases are defined. By using DEA analysis the relative efficiencies of 10 systems for automatic control of dissolved oxygen are estimated. The designed and implemented in the current work CBR and DEA are applicable for the purposed of virtual consultation centers. Key words: benchmarking technique, energy efficiency, Case-Based Reasoning (CBR

Determinants of impaired growth among hospitalized children: a case-control study

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Marilia de Carvalho Lima

Full Text Available CONTEXT: Protein energy malnutrition constitutes a public health problem, especially in less affluent countries. The identification of amenable predictive risk factors is of major importance for policy makers to plan interventions to reduce infant malnutrition. OBJECTIVE: To identify risk factors for protein energy malnutrition among hospitalized low-income children aged 6 to 24 months. TYPE OF STUDY: Case-control study. SETTING: Two public hospitals in Recife, Brazil. PARTICIPANTS: The cases were 124 infants with length-for-age below the 10th percentile of the National Center for Health Statistics curve and the controls were 241 infants with length-for-age equal to or above the 10th percentile who were recruited in the same infirmary. METHODS: Cases and controls were compared in relation to a variety of sociodemographic, environmental and reproductive factors, and their healthcare, previous feeding practice and morbidity. Logistic regression analysis was used to investigate the net effect of risk factors on infant malnutrition, after adjusting for potential confounding variables. RESULTS: The mother's age, possession of a TV set, type of water supply, family size and location of the home were significantly associated with child malnutrition in the bivariate analysis. However, these associations lost their significance after adjusting for other explanatory variables in the hierarchical logistic regression analysis. This analysis showed that low birth weight contributed the largest risk for impaired growth. Increased risks of infant malnutrition were also significantly associated with households that had no toilet facilities or refrigerator, high parity for the mother, no breastfeeding of the infant, inadequate vaccination coverage and previous hospitalization for diarrhea and pneumonia. DISCUSSION: The literature shows that chronic malnutrition, as assessed by low length-for-age indexes, is often related to low income. However, this was not the

Propensity score matching for selection of local areas as controls for evaluation of effects of alcohol policies in case series and quasi case-control designs.

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de Vocht, F; Campbell, R; Brennan, A; Mooney, J; Angus, C; Hickman, M

2016-03-01

Area-level public health interventions can be difficult to evaluate using natural experiments. We describe the use of propensity score matching (PSM) to select control local authority areas (LAU) to evaluate the public health impact of alcohol policies for (1) prospective evaluation of alcohol policies using area-level data, and (2) a novel two-stage quasi case-control design. Ecological. Alcohol-related indicator data (Local Alcohol Profiles for England, PHE Health Profiles and ONS data) were linked at LAU level. Six LAUs (Blackpool, Bradford, Bristol, Ipswich, Islington, and Newcastle-upon-Tyne) as sample intervention or case areas were matched to two control LAUs each using PSM. For the quasi case-control study a second stage was added aimed at obtaining maximum contrast in outcomes based on propensity scores. Matching was evaluated based on average standardized absolute mean differences (ASAM) and variable-specific P-values after matching. The six LAUs were matched to suitable control areas (with ASAM 0.05 indicating good matching) for a prospective evaluation study that sought areas that were similar at baseline in order to assess whether a change in intervention exposure led to a change in the outcome (alcohol related harm). PSM also generated appropriate matches for a quasi case-control study--whereby the contrast in health outcomes between cases and control areas needed to be optimized in order to assess retrospectively whether differences in intervention exposure were associated with the outcome. The use of PSM for area-level alcohol policy evaluation, but also for other public health interventions, will improve the value of these evaluations by objective and quantitative selection of the most appropriate control areas. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Investigating Science Collaboratively: A Case Study of Group Learning

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Zinicola, Debra A.

2009-01-01

Discussions of one urban middle school group of students who were investigating scientific phenomena were analyzed; this study was conducted to discern if and how peer interaction contributes to learning. Through a social constructivist lens, case study methodology, we examined conceptual change among group members. Data about science talk was…

Possibility of environmentally-safe casing soil disinfection for control of cobweb disease of button mushroom

OpenAIRE

Potočnik Ivana; Rekanović Emil; Stepnović Miloš; Milijašević-Marčić Svetlana; Todorović Biljana; Nikolić-Bujanović Ljiljana; Čekerevac Milan

2014-01-01

The soil-borne pathogen Cladobotryum dendroides causes cobweb disease of button mushroom (Agaricus bisporus) and its significant yield losses. Casing soil disinfection by toxic formaldehyde is a widespread practice. The aim of this study was to investigate the potential of two environmentally friendly substances, colloidal silver and peracetic acid, against C. dendroides. Their biological efficacy (impact on mushroom yield), effectiveness (disease control) ...

Investigation of Plasminogen Activator Inhibitor-1 (PAI-1) 4G/5G promoter polymorphism in Indian venous thrombosis patients: A case-control study.

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Prabhudesai, Aniket; Shetty, Shrimati; Ghosh, Kanjaksha; Kulkarni, Bipin

2017-09-01

The role of PAI-1 4G/5G polymorphism in venous thrombosis has been contradictory. PAI-1 4G/4G genotype is associated with elevated levels of PAI-1 resulting in a hypofibrinolytic state and a higher thrombotic risk. In this study, the distribution of genotypes and frequency of alleles of the 4G/5G polymorphism of PAI-1 gene in Indian patients with different types of venous thrombosis was investigated for its role in development of thrombosis. A total of 87 portal vein thrombosis (PVT), 71 Budd-Chiari syndrome (BCS), 156 cerebral vein thrombosis (CVT), and 163 deep vein thrombosis (DVT) patients were studied alongside 251 healthy controls for the PAI-1 4G/5G polymorphism by allele-specific PCR. Frequency of 4G/4G genotype was higher in all groups in comparison with controls. 4G/4G was associated with PVT risk (OR=2.51, 95% CI=1.29-4.96, P=.0075), BCS risk (OR=5.98, 95% CI=2.68-13.42, P<.0001), and DVT risk (OR=1.75, 95% CI=0.98-3.02, P=.0225). This is the first case-control study from India establishing PAI-1 4G/4G as a strong risk factor for abdominal thrombosis (PVT and BCS). Statistically significant association was not found between 4G/4G genotype and CVT risk. PAI-1 4G/4G is a strong risk factor for venous thrombosis in Indian patients and should be included in laboratory testing panel of thrombophilia. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

On the Analysis of Case-Control Studies in Cluster-correlated Data Settings.

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Haneuse, Sebastien; Rivera-Rodriguez, Claudia

2018-01-01

In resource-limited settings, long-term evaluation of national antiretroviral treatment (ART) programs often relies on aggregated data, the analysis of which may be subject to ecological bias. As researchers and policy makers consider evaluating individual-level outcomes such as treatment adherence or mortality, the well-known case-control design is appealing in that it provides efficiency gains over random sampling. In the context that motivates this article, valid estimation and inference requires acknowledging any clustering, although, to our knowledge, no statistical methods have been published for the analysis of case-control data for which the underlying population exhibits clustering. Furthermore, in the specific context of an ongoing collaboration in Malawi, rather than performing case-control sampling across all clinics, case-control sampling within clinics has been suggested as a more practical strategy. To our knowledge, although similar outcome-dependent sampling schemes have been described in the literature, a case-control design specific to correlated data settings is new. In this article, we describe this design, discuss balanced versus unbalanced sampling techniques, and provide a general approach to analyzing case-control studies in cluster-correlated settings based on inverse probability-weighted generalized estimating equations. Inference is based on a robust sandwich estimator with correlation parameters estimated to ensure appropriate accounting of the outcome-dependent sampling scheme. We conduct comprehensive simulations, based in part on real data on a sample of N = 78,155 program registrants in Malawi between 2005 and 2007, to evaluate small-sample operating characteristics and potential trade-offs associated with standard case-control sampling or when case-control sampling is performed within clusters.

Retrospective exposure assessment and quality control in an international multi-centre case-control study

DEFF Research Database (Denmark)

Tinnerberg, H; Heikkilä, P; Huici-Montagud, A

2003-01-01

The paper presents the exposure assessment method and quality control procedure used in an international, multi-centre case-control study within a joint Nordic and Italian cohort. This study was conducted to evaluate whether occupational exposure to carcinogens influenced the predictivity of high...... was higher among the original assessors (the assessor from the same country as the subject) than the average prevalence assessed by the other four in the quality control round. The original assessors classified more job situations as exposed than the others. Several reasons for this are plausible: real...... country-specific differences, differences in information available to the home assessor and the others and misunderstandings or difficulties in translation of information. To ensure the consistency of exposure assessments in international retrospective case-control studies it is important to have a well...

Social capital and adverse treatment outcomes of tuberculosis: a case-control study.

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Deshmukh, P R; Mundra, A; Dawale, A

2017-08-01

'Social capital' refers to social norms, relationships, networks and values that affect the functioning and development of society. Social capital influences health positively, but its role in the treatment outcomes of tuberculosis (TB) is not known. To study the role of social capital in determining adverse TB treatment outcomes. Of 516 patients registered under the Revised National Tuberculosis Control Programme in 2014 in Wardha Tuberculosis Unit, Wardha, India, we included 88 patients with adverse treatment outcomes as cases and 187 controls from among those without adverse outcomes. Multiple logistic regression was used to compare standardised Z-scores. A greater proportion of controls than cases belonged to higher quartiles of social capital and its domains than cases, and the mean standardised Z-score was also consistently higher among controls than cases. Respectively 47% and 15% of cases and controls were in the poorest quartile of social capital, whereas respectively 10% and 33% of cases and controls were in the richest quartile. Each unit increase in Z-score of overall social capital reduced the odds of adverse treatment outcomes by 63.1%. Appropriate interventions for building social capital for TB patients and linking them with the programme would improve programme performance.

Risk Factors for Anemia in Pregnancy: A Case Control Study

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Rutuja Pundkar

2017-12-01

Full Text Available Background: Aim of the study was to find the risk factors leading to Anemia in pregnancy. The main objective was to study the various sociodemographic factors leading to anemia. And to assess the knowledge about anemia among study participants. Material and methods: The present Case control study was carried out at Primary Health Centre, to determine the risk factors leading to anemia in pregnancy. A total of 308 pregnant females were registered. Among them two groups were made, group I cases and group II controls. Each group had 50 cases each. Laboratory test were done and females having hemoglobin less than 11mg/dl were considered anemic. Anemic females were considered cases and females having Hb >11mg/dl were considered controls. Data analysis was done using SPSS software. Results: The overall mean haemoglobin (Hb was 11.55g/dL in controls, whereas it was seen that among the cases it was 9.58g/dL.It would seem that diet, family size, education, social class, gravida and parity are associated with anemia in pregnancy. Conclusion: After adjusting for all the possible covariates there seems to be significant association between Hb levels and age group, education level, family size, diet, gravida and parity.

Primary health care utilization prior to suicide: a retrospective case-control study among active-duty military personnel.

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Hochman, Eldar; Shelef, Leah; Mann, J John; Portugese, Shirly; Krivoy, Amir; Shoval, Gal; Weiser, Mark; Fruchter, Eyal

2014-08-01

About 45% of civilians who died by suicide had contact with a doctor within 1 month of death. Thus, educating primary care physicians (PCP) to detect and mitigate depression is an important suicide-prevention strategy. However, the PCP consulting rate before suicide has not been examined in a military population. We investigated the utilization of primary health care and mental health services by active-duty military personnel suicide cases prior to death in comparison to matched military controls. All suicides (N = 170) were extracted from a cohort of all active-duty Israeli military male personnel between 2002 and 2012. Applying a retrospective, nested case-control design, we compared primary care services utilization by suicide cases with demographic and occupationally matched military controls (N = 500). Whereas 38.3% of suicide cases contacted a PCP within the last month before death, only 27.6% of suicide cases contacted a mental health specialist during their entire service time. The PCP contact rate within 1 month before death or index day did not differ between suicide cases and military controls (38.3% vs. 33.8%, χ²₁ = 1.05, P = .3). More suicide cases contacted a mental health specialist within service time than did military controls (27.6% vs. 13.6%, χ²₁ = 10.85, P = .001). Even though PCP contact rate by military personnel who died by suicide is slightly lower than that reported for civilians who died by suicide prior to their death, it is higher than mental health specialist contact rate and higher than that by age-matched civilians who died by suicide. These results imply that PCPs education is a viable approach to suicide prevention in a military setting. © Copyright 2014 Physicians Postgraduate Press, Inc.

Investigation of phase-wise voltage regulator control logics for compensating voltage deviations in an experimental low voltage network

DEFF Research Database (Denmark)

Hu, Junjie; Zecchino, Antonio; Marinelli, Mattia

2016-01-01

This paper investigates the control logics of an on-load tap-changer (OLTC) transformer by means of an experimental system validation. The experimental low-voltage unbalanced system consists of a decoupled single-phase OLTC transformer, a 75-metre 16 mm2 cable, a controllable single-phase resistive...... load and an electric vehicle, which has the vehicle-to-grid function. Three control logics of the OLTC transformer are described in the study. The three control logics are classified based on their control objectives and control inputs, which include network currents and voltages, and can be measured...... either locally or remotely. To evaluate and compare the control performances of the three control logics, all the tests use the same loading profiles. The experimental results indicate that the modified line compensation control can regulate voltage in a safe band in the case of various load...

Mechanical reliability of falling systems. Case of control rods of nuclear reactors

International Nuclear Information System (INIS)

Rezkallah, B.

1991-05-01

After having briefly recalled the main principles adopted for nuclear reactor safety (barrier based method, emergency stop system, emergency cooling system) and how control rod operation anomalies are described, this research thesis first gives an overview of knowledge in the field of reliability (principles, qualitative and quantitative methods, failure trees, performance function, shock modelling and mode analysis). Then, the author presents the modelling of the drop and rotation of a control rod. The computation technique is the modal synthesis. The author highlights the influence of physical (friction, initial conditions) and numerical (modal truncation) parameters. He reports a probabilistic analysis of the problem and proposes a stochastic model for the different shock forces (notably friction). He compares the results with those obtained with the DEMT software. The last part reports the investigation of a rare case: the jamming or untimely stop of the control rod device

Association of HCV with diabetes mellitus: an Egyptian case-control study

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Esmat Gamal G

2011-07-01

Full Text Available Abstract Background The highest Hepatitis C Virus (HCV prevalence in the world occurs in Egypt. Several studies from different parts of the world have found that 13% to 33% of patients with chronic HCV have associated diabetes, mostly type II Diabetes Mellitus (DM. In Egypt the prevalence of DM is 25.4% among HCV patients. Therefore, it is important to identify the magnitude of the problem of diabetes in order to optimize the treatment of chronic hepatitis C. Methods The objective of this case-control study was to evaluate the prevalence of DM and other extrahepatic (EH manifestations among patients with different HCV morbidity stages including asymptomatic, chronic hepatic and cirrhotic patients. In this study, 289 HCV patients older than 18 were selected as cases. Also, 289 healthy controls were included. Laboratory investigations including Liver Function tests (LFT and blood glucose level were done. Also serological assays including cryoglobulin profile, rheumatoid factor, antinuclear antibody, HCV-PCR were performed. Results Out of 289 HCV cases, 40 (13.84% were diabetic. Out of 289 healthy controls, 12 (4.15% were diabetic. It was found that the diabetic HCV group mean age was [48.1 (± 9.2]. Males and urbanians represented 72.5% and 85% respectively. Lower level of education was manifested in 52.5% and 87.5% were married. In the nondiabetic HCV group mean age was [40.7 (± 10.4]. Males and urbanians represented 71.5% and 655% respectively. secondary and higher level of education was attained in 55.4% and 76.7% were married. Comparing between the diabetic HCV group and the non diabetic HCV group, age, residence and alcohol drinking were the only significant factors affecting the incidence of diabetes between the two groups. There was no significant difference regarding sonar findings although cirrhosis was more prevalent among diabetic HCV cases and the fibrosis score was higher in diabetic HCV patients than among the non diabetic HCV cases

Genetic variation at CYP3A is associated with age at menarche and breast cancer risk: a case-control study

OpenAIRE

Johnson, N. (Nichola); Dudbridge, Frank; Orr, Nick; Gibson, Lorna; Jones, Michael; Schoemaker, Minouk; Folkerd, E.J. (Elizabeth J.); Haynes, B.P. (Ben P.); Hopper, John; Southey, Melissa; Dite, G.S. (Gillian S.); Apicella, C. (Carmel); Schmidt, Marjanka; Broeks, Annegien; Veer, Laura

2014-01-01

textabstractINTRODUCTION: We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years.METHODS: We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breas...

Genetic variation at CYP3A is associated with age at menarche and breast cancer risk: A case-control study

OpenAIRE

Johnson, Nichola; Dudbridge, Frank; Orr, Nick; Gibson, Lorna; Jones, Michael; Schoemaker, Minouk; Folkerd, E.J. (Elizabeth J.); Haynes, B.P. (Ben P.); Hopper, John; Southey, Melissa; Dite, Gillian; Apicella, Carmel; Schmidt, Marjanka; Broeks, Annegien; Veer, Laura

2014-01-01

textabstractIntroduction: We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years. Methods: We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Brea...

Serum Taurine and Stroke Risk in Women: A Prospective, Nested Case-Control Study

Science.gov (United States)

Wu, Fen; Koenig, Karen L.; Zeleniuch-Jacquotte, Anne; Jonas, Saran; Afanasyeva, Yelena; Wójcik, Oktawia P.; Costa, Max; Chen, Yu

2016-01-01

Background Taurine (2-aminoethanesulfonic acid), a conditionally essential sulfur-containing amino acid, is mainly obtained from diet in humans. Experimental studies have shown that taurine’s main biological actions include bile salt conjugation, blood pressure regulation, anti-oxidation, and anti-inflammation. Methods We conducted a prospective case-control study nested in the New York University Women’s Health Study, a cohort study involving 14,274 women enrolled since 1985. Taurine was measured in pre-diagnostic serum samples of 241 stroke cases and 479 matched controls. Results There was no statistically significant association between serum taurine and stroke risk in the overall study population. The adjusted ORs for stroke were 1.0 (reference), 0.87 (95% CI, 0.59–1.28), and 1.03 (95% CI, 0.69–1.54) in increasing tertiles of taurine (64.3–126.6, 126.7–152.9, and 153.0–308.5 nmol/mL, respectively). A significant inverse association between serum taurine and stroke risk was observed among never smokers, with an adjusted OR of 0.66 (95% CI, 0.37–1.18) and 0.50 (95% CI, 0.26–0.94) for the second and third tertile, respectively (p for trend = 0.01), but not among past or current smokers (p for interaction taurine and stroke risk, although a protective effect was observed in never smokers, which requires further investigation. Taurine, Stroke, Epidemiology, Prospective, Case-control study, NYUWHS. PMID:26866594

Human papillomavirus (HPV) infection in a case-control study of oral squamous cell carcinoma and its increasing trend in northeastern Thailand.

Science.gov (United States)

Phusingha, Pensiri; Ekalaksananan, Tipaya; Vatanasapt, Patravoot; Loyha, Kulchaya; Promthet, Supannee; Kongyingyoes, Bunkerd; Patarapadungkit, Natcha; Chuerduangphui, Jureeporn; Pientong, Chamsai

2017-06-01

Human papillomavirus (HPV) is an independent risk factor for development of oral squamous cell carcinoma (OSCC). This study aimed to investigate the role of HPV infection and the trend in percentage of HPV-associated OSCC over a 5-year period in northeastern Thailand. In this case-control study, 91 exfoliated oral cell samples and 80 lesion cell samples from OSCC cases and exfoliated oral cells from 100 age/gender-matched controls were collected. HPV infection was investigated by PCR using GP5+/GP6+ primers followed by HPV genotyping using reverse line blot hybridization. Quantitative RT-PCR was used to evaluate HPV oncogene transcription. Temporal trends of HPV infection were evaluated in archived formalin-fixed paraffin-embedded (FFPE) OSCC tissues using in situ hybridization. HPV DNA was found in 17.5% (14/80) of lesion samples from OSCC cases and 29.7% (27/91) of exfoliated oral cell samples from the same cases. These values were significantly higher than in exfoliated oral cell samples from controls (13%, 13/100). HPV-16 was the genotype most frequently found in OSCC cases (92.8%, 13/14 infected cases). Interestingly, HPV oncogene mRNA expression was detected and correlated with OSCC cases (P cases were positive for HPV E6/E7 mRNA expression. There was a trend of increasing percentage of HPV-associated OSCC from 2005 to 2010. This was especially so for females with well-differentiated tumors in specific tongue sub-sites. We suggest that HPV infection plays an important role in oral carcinogenesis in northeastern Thailand. © 2016 Wiley Periodicals, Inc.

Developmental origins of polycystic ovary syndrome (PCOS), a case control study comparing birth weight in women with PCOS and control group.

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Sadrzadeh, Sheda; Painter, Rebecca C; Lambalk, Cornelis B

2016-10-01

Evidence from various epidemiological studies and experimental animal studies has linked adverse intrauterine circumstances with health problems in adult life. This field of investigation is known as Developmental Origins of Health and Disease (DOHaD). Studies investigating the relation between developing polycystic ovary syndrome (PCOS) in adulthood and birth weight have yielded inconsistent results: PCOS is described more often in women with low birth weight and high birth weight, while other studies have failed to establish any relation. In this retrospective case-control study, we evaluated whether women diagnosed with PCOS had lower birth weight compared to women with a regular menstrual cycle (controls). Binary logistic regression models were used to analyze the data and correct for known confounders. About 65 women with PCOS and 96 controls were recruited for this purpose. The average birth weight of PCOS women (3357 g) did not differ from the average birth weight of controls (3409 g). Mean age at menarche differed significantly between groups, 13.7  years and 12.8  years (p = 0.006), respectively, for PCOS women and controls. In conclusion, we could not confirm the effect of adverse intrauterine conditions, reflected in birth weight, on developing PCOS.

Children with pertussis inform the investigation of other pertussis cases among contacts

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Rodrigues Laura C

2007-05-01

Full Text Available Abstract Background The number of reported pertussis has increased in the last two decades. However, many cases of pertussis may be underreported or not diagnosed. The World Health Organization estimates that pertussis causes 200.000 – 400.000 deaths each year, most deaths are in infants and in developing countries. Infants with pertussis can indicate an undetected source cases in the community. Methods At a University Hospital in Brazil individuals that had frequent contacts with a child with confirmed pertussis (the index case and had recent history of cough were enrolled into the study. Nasopharyngeal swabs were collected from every contact that had cough within the last 21 days. Cases confirmation followed the guidelines of the Center for Disease Control and Prevention – Atlanta, U.S.A. Results Pertussis diagnosis was confirmed in 51 children, (considered the index cases. Among the index cases, 72.5% (37/51 were under 6 months of age; culture for Bordetella pertussis was positive in 78.4% (40/51. Pertussis was confirmed in 39% (107/276 of the contacts of 51 index cases. Among these contacts identified as a pertussis case, 40.2% (43/107 were between 6 months and 111/2 years of age and 59.8% (64/107 were older than 111/2 years of age. Pertussis was confirmed by culture in 11.2% (12/107 of them and by epidemiologic linkage in 88.8% (95/107. Each index case allowed identifying two new cases of pertussis. Conclusion Public health authorities should consider implementing early recognition of pertussis index cases and searching for pertussis cases among the contacts. Treatment of the cases and prophylaxis of the contacts is fundamental to control outbreaks in the community.

The impact of glaucoma on quality of life in Ethiopia: a case-control study.

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Ayele, Fisseha A; Zeraye, Banchamelak; Assefa, Yared; Legesse, Kbrom; Azale, Telake; Burton, Matthew J

2017-12-13

Glaucoma is a chronic disease characterized by irreversible optic nerve damage and visual field loss that leads to visual impairment and blindness; ultimately limiting personal independence and compromising overall quality of life of affected individuals. There is paucity of information on how glaucoma affects the quality of life of patients in low and middle-income countries where resources for both diagnosis and treatment of such conditions are limited. In this study we investigate the impact of glaucoma on quality of life in Ethiopian patients. The quality of life of 307 glaucoma patients and 76 normal controls that were frequency matched to the age and sex profiles of the cases was assessed using Amharic version of Glaucoma Quality of Life -15 questionnaire. Linear regression models and the t-test were employed to compare significant differences in GQL-15 scores and to generate mean and mean differences between cases and controls respectively. The mean GQL-15 score in the glaucoma cases was substantially higher (indicating poorer quality of life) than the controls [cases 46.3 (95% CI, 28.8-63.8) and controls 18.6 (95% CI, 15.2-22.0), p glaucoma had significantly higher scores than the controls. Poorer quality of life was associated with age ≥ 71 years old 51.1 (95%CI, 26.2-75.9), rural residence 55.7 (95%CI, 49.9-61.5), monthly income of glaucoma (50.9; 95%CI, 43.6-58.3). These glaucoma patients, including those with normal visual acuity and early disease, had poorer quality of life compared to normal controls. Older age, rural residence, low income and more advanced disease were significantly associated with poorer quality of life. There is a need to increase awareness of the impact of glaucoma among clinicians, patients and their families, for a better understanding of the impact this disease has on a person's life.

A prevalence-based association test for case-control studies.

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Ryckman, Kelli K; Jiang, Lan; Li, Chun; Bartlett, Jacquelaine; Haines, Jonathan L; Williams, Scott M

2008-11-01

Genetic association is often determined in case-control studies by the differential distribution of alleles or genotypes. Recent work has demonstrated that association can also be assessed by deviations from the expected distributions of alleles or genotypes. Specifically, multiple methods motivated by the principles of Hardy-Weinberg equilibrium (HWE) have been developed. However, these methods do not take into account many of the assumptions of HWE. Therefore, we have developed a prevalence-based association test (PRAT) as an alternative method for detecting association in case-control studies. This method, also motivated by the principles of HWE, uses an estimated population allele frequency to generate expected genotype frequencies instead of using the case and control frequencies separately. Our method often has greater power, under a wide variety of genetic models, to detect association than genotypic, allelic or Cochran-Armitage trend association tests. Therefore, we propose PRAT as a powerful alternative method of testing for association.

Caval filter implantation under MRI control - experimental in vitro and in vivo investigations

International Nuclear Information System (INIS)

Neuerburg, J.; Buecker, A.; Adam, G.; Leenen, M.; Guenther, R.W.; Hurtak, M.S.W.

1997-01-01

Purpose: An instrument has been developed for the introduction of caval filters which can be used with MRI; it has been investigated in in vitro and in in vivo experiments. Material and method: The ferromagnetic components of a commercially available instrument for the femoral introduction of the MR-eye TM Tulip IVC filter were changed for similar, non-ferromagnetic parts and the lock and dilator marked with dysprosium oxide rings. The instrument was used in a flow phantom and in animal experiments (two domestic pigs) in order to insert filters under MRI control on a 1.5 T Philips Gyroscan with integrated mobile digital subtraction angiography. Results: Both in vitro and in vivo, the introducer, catheter and caval filter could be identified by MRI and positioned under MRI control. The position of the filter as indicated by MRI corresponded with radiological and macroscopic findings in all cases (5 phantoms, 2 pigs). Conclusion: The early experimental results indicate that percutaneous introduction of caval filters with placement under MRI control is possible. (orig.) [de

Detection of Pneumocystis DNA in samples from patients suspected of bacterial pneumonia--a case-control study

DEFF Research Database (Denmark)

Helweg-Larsen, Jannik; Jensen, Jørgen Skov; Dohn, Birthe

2002-01-01

Pneumocystis jiroveci (formerly known as P. carinii f.sp. hominis) is an opportunistic fungus that causes Pneumocystis pneumonia (PCP) in immunocompromised individuals. Pneumocystis jiroveci can be detected by polymerase chain reaction (PCR). To investigate the clinical importance of a positive P...... Pneumocystis-PCR among HIV-uninfected patients suspected of bacterial pneumonia, a retrospective matched case-control study was conducted....

The case for moderate gun control.

Science.gov (United States)

DeGrazia, David

2014-03-01

In addressing the shape of appropriate gun policy, this essay assumes for the sake of discussion that there is a legal and moral right to private gun ownership. My thesis is that, against the background of this right, the most defensible policy approach in the United States would feature moderate gun control. The first section summarizes the American gun control status quo and characterizes what I call "moderate gun control." The next section states and rebuts six leading arguments against this general approach to gun policy. The section that follows presents a positive case for moderate gun control that emphasizes safety in the home and society as well as rights whose enforcement entails some limits or qualifications on the right to bear arms. A final section shows how the recommended gun regulations address legitimate purposes, rather than imposing arbitrary restrictions on gun rights, and offers concluding reflections.

An outbreak of vancomycin-resistant Enterococcus faecium in an acute care pediatric hospital: Lessons from environmental screening and a case-control study

Science.gov (United States)

Drews, Steven J; Richardson, Susan E; Wray, Rick; Freeman, Renee; Goldman, Carol; Streitenberger, Laurie; Stevens, Derek; Goia, Cristina; Kovach, Danuta; Brophy, Jason; Matlow, Anne G

2008-01-01

BACKGROUND The present study describes a vancomycin-resistant enterococci (VRE) outbreak investigation and a case-control study to identify risk factors for VRE acquisition in a tertiary care pediatric hospital. OBJECTIVE To report an outbreak investigation and a case-control study to identify risk factors for VRE colonization or infection in hospitalized children. METHODS Screening for VRE cases was performed by culture or polymerase chain reaction. A case-control study of VRE-colonized patients was undertaken. Environmental screening was performed using standard culture and susceptibility methods, with pulsed-field gel electrophoresis to determine relationships between VRE isolates. Statistical analysis was performed using SAS version 9.0 (SAS Institute Inc, USA). RESULTS Thirty-four VRE-positive cases were identified on 10 wards between February 28, 2005, and May 27, 2005. Pulsed-field gel electrophoresis analysis confirmed a single outbreak strain that was also isolated from a video game found on one affected ward. Multivariate analysis identified cephalosporin use as the major risk factor for VRE colonization. CONCLUSIONS In the present study outbreak, VRE colonization was significantly associated with cephalosporin use. Because shared recreational items and environmental surfaces may be colonized by VRE, they warrant particular attention in housekeeping protocols, particularly in pediatric institutions. PMID:19412380

The Relationship between Maternal Diseases during Pregnancy and Low Birth Weight: a Nested Case-Control Study in Rural Areas of Kurdistan Province (West of Iran

Directory of Open Access Journals (Sweden)

Ghobad Moradi

2017-08-01

Full Text Available Background: Low birth weight (LBW is considered as one of the important health indicators in evaluating prenatal care as well as determining scale of infants' health in the society. The study aimed to investigate maternal diseases during pregnancy and its impact on LBW in rural areas of Kurdistan province, Iran. Materials and Methods: This study was conducted in nested case-control study method in rural areas of Kurdistan province- Iran in 2015-2016. In this study, 182 infants less than 2,500gr as case and 364 infants weighing 2,500 g and more as control were entered the study. Information about case and control groups was extracted by investigating records of pregnant women care. Data was analyzed using software Stata-12 with point and interval estimation of odds ratio (OR using conditional logistic regression. Results: The results of single-variable analysis of conditional logistic regression showed that there is a statistical relationship between blood pressure during pregnancy, iron deficiency anemia, mother's thyroid problems, oral and dental problems, and history of bleeding during pregnancy in case and control groups (P

Maternal age and Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

NARCIS (Netherlands)

W.A. Rocca; C.M. van Duijn (Cornelia); D.G. Clayton (David); V. Chandra; L. Fratiglioni (Laura); A.B. Graves; A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; J.A. Mortimer; S.L. Shalat; H. Soininen; A. Hofman (Albert)

1991-01-01

textabstractTo investigate the possible association between Alzheimer's disease and late maternal age at index birth, we conducted a collaborative re-analysis of existing case-control data sets. Of the 11 studies participating in the EURODEM project, four were included in the analyses regarding

Increasing levels of free thyroxine as a risk factor for a first venous thrombosis: a case-control study

NARCIS (Netherlands)

van Zaane, Bregje; Squizzato, Alessandro; Huijgen, Roeland; van Zanten, Anton P.; Fliers, Eric; Cannegieter, Suzanne C.; Büller, Harry R.; Gerdes, Victor E. A.; Brandjes, Dees P. M.

2010-01-01

A hypercoagulable state exists in hyperthyroidism, but the association with venous thrombosis (VT) is not fully explored. We aimed to investigate VT risk for different plasma levels of thyroid hormones and thyroid antibodies. We used a case-control study on leg vein thrombosis conducted between

Risk factors for posterior vitreous detachment: a case-control study.

Science.gov (United States)

Chuo, Jean Y; Lee, Tracy Y Y; Hollands, Hussein; Morris, Andrew H; Reyes, Romina C; Rossiter, Jonathan D; Meredith, Sarah P; Maberley, David A L

2006-12-01

To identify possible risk factors for the development of posterior vitreous detachment (PVD). Retrospective case-control study. A total of 138 cases with PVD and 114 age-matched controls were accrued from two different sites. Demographic, medical, ocular, and lifestyle data were obtained through chart review, questionnaires, and clinical examination. A 108-item semiquantitative food frequency questionnaire was also used to estimate macro- and micronutrient intake. Univariate and multivariate regression analyses were employed to identify variables significantly associated with the main outcome measure of PVD. Subgroup analysis of gender-specific variables was performed. Among all patients, multivariate regression analysis demonstrated female gender (odds ratio [OR] = 2.01, P = .016), myopic refraction (OR = 4.32, P < .0005), and higher intake of vitamin B6 (OR = 2.61, P = .001) to be associated with PVD after controlling for age. In the subgroup analysis of women, menopause (OR = 18.2, P < .0005), myopic refraction (OR = 3.42, P = .01), and higher intake of vitamin B6 (OR = 3.92, P = .005) were associated with PVD. Specifically, there was a significant association between vitamin B6 and PVD amongst premenopausal women but not amongst postmenopausal women. An association between PVD and menopause has not been documented previously. We suspect that high estrogen levels seen in premenopausal women may be protective against PVD and that hormonal changes associated with menopause may lead to changes in the vitreous, predisposing to PVD. Higher levels of intake of vitamin B6 were also associated with the development of PVD in premenopausal women possibly through an anti-estrogen effect. These findings should be investigated further with prospective studies.

Determinants of podoconiosis, a case control study | Feleke ...

African Journals Online (AJOL)

The sample size was calculated using Epi-info soft ware: 95% CI, 85% power, control to case ratio of 2:1, expected frequency of barefoot among controls 50%, odds ratio of 1.5 and non-response rate of 10% yielding 1148 study participants. Binary logistic regression was used to identify the determinants of Podoconiosis.

Neospora caninum versus Brucella spp. exposure among dairy cattle in Ethiopia: a case control study.

Science.gov (United States)

Asmare, Kassahun

2014-08-01

This case-control study aimed at assessing the relative association of Neospora caninum and Brucella species exposure with reproductive disorders. The study was carried out between October 2011 and June 2012 on 731 dairy cows sampled from 150 dairy farms in selected 17 conurbations of Ethiopia. Two hundred sixty-six of the cows were categorized as cases based on their history of abortion or stillbirth while the remaining 465 were controls. The presence of antibody to N. caninum was screened using indirect ELISA, while Brucella spp. exposure was assayed serially using Rose Bengal Plate Test and Complement Fixation Test. Exposure to N. caninum was more frequently observed among cases (23.8%) than controls (12.7%), while no significant difference (p > 0.05) was noted for Brucella exposure between the two groups. Moreover, the proportion of cows with disorders like retention of fetal membrane, endometritis and increased inter-calving period were significantly higher (p Brucella spp. exposure. However, neither N. caninum nor Brucella spp. could explain the majority (73.2%) of the reported abortions and stillbirths in cattle. Hence, this observation underscores the need for more intensive investigation on the identification of causes of the aforementioned disorders in dairy cattle of Ethiopia.

Shrinkage Estimators for Robust and Efficient Inference in Haplotype-Based Case-Control Studies

KAUST Repository

Chen, Yi-Hau; Chatterjee, Nilanjan; Carroll, Raymond J.

2009-01-01

Case-control association studies often aim to investigate the role of genes and gene-environment interactions in terms of the underlying haplotypes (i.e., the combinations of alleles at multiple genetic loci along chromosomal regions). The goal of this article is to develop robust but efficient approaches to the estimation of disease odds-ratio parameters associated with haplotypes and haplotype-environment interactions. We consider "shrinkage" estimation techniques that can adaptively relax the model assumptions of Hardy-Weinberg-Equilibrium and gene-environment independence required by recently proposed efficient "retrospective" methods. Our proposal involves first development of a novel retrospective approach to the analysis of case-control data, one that is robust to the nature of the gene-environment distribution in the underlying population. Next, it involves shrinkage of the robust retrospective estimator toward a more precise, but model-dependent, retrospective estimator using novel empirical Bayes and penalized regression techniques. Methods for variance estimation are proposed based on asymptotic theories. Simulations and two data examples illustrate both the robustness and efficiency of the proposed methods.

Shrinkage Estimators for Robust and Efficient Inference in Haplotype-Based Case-Control Studies

KAUST Repository

Chen, Yi-Hau

2009-03-01

Case-control association studies often aim to investigate the role of genes and gene-environment interactions in terms of the underlying haplotypes (i.e., the combinations of alleles at multiple genetic loci along chromosomal regions). The goal of this article is to develop robust but efficient approaches to the estimation of disease odds-ratio parameters associated with haplotypes and haplotype-environment interactions. We consider "shrinkage" estimation techniques that can adaptively relax the model assumptions of Hardy-Weinberg-Equilibrium and gene-environment independence required by recently proposed efficient "retrospective" methods. Our proposal involves first development of a novel retrospective approach to the analysis of case-control data, one that is robust to the nature of the gene-environment distribution in the underlying population. Next, it involves shrinkage of the robust retrospective estimator toward a more precise, but model-dependent, retrospective estimator using novel empirical Bayes and penalized regression techniques. Methods for variance estimation are proposed based on asymptotic theories. Simulations and two data examples illustrate both the robustness and efficiency of the proposed methods.

Environment And Genetics in Lung cancer Etiology (EAGLE study: An integrative population-based case-control study of lung cancer

Directory of Open Access Journals (Sweden)

Colombi Antonio

2008-06-01

Full Text Available Abstract Background Lung cancer is the leading cause of cancer mortality worldwide. Tobacco smoking is its primary cause, and yet the precise molecular alterations induced by smoking in lung tissue that lead to lung cancer and impact survival have remained obscure. A new framework of research is needed to address the challenges offered by this complex disease. Methods/Design We designed a large population-based case-control study that combines a traditional molecular epidemiology design with a more integrative approach to investigate the dynamic process that begins with smoking initiation, proceeds through dependency/smoking persistence, continues with lung cancer development and ends with progression to disseminated disease or response to therapy and survival. The study allows the integration of data from multiple sources in the same subjects (risk factors, germline variation, genomic alterations in tumors, and clinical endpoints to tackle the disease etiology from different angles. Before beginning the study, we conducted a phone survey and pilot investigations to identify the best approach to ensure an acceptable participation in the study from cases and controls. Between 2002 and 2005, we enrolled 2101 incident primary lung cancer cases and 2120 population controls, with 86.6% and 72.4% participation rate, respectively, from a catchment area including 216 municipalities in the Lombardy region of Italy. Lung cancer cases were enrolled in 13 hospitals and population controls were randomly sampled from the area to match the cases by age, gender and residence. Detailed epidemiological information and biospecimens were collected from each participant, and clinical data and tissue specimens from the cases. Collection of follow-up data on treatment and survival is ongoing. Discussion EAGLE is a new population-based case-control study that explores the full spectrum of lung cancer etiology, from smoking addiction to lung cancer outcome, through

Investigation on the use digital controls instead of PID analog controls in the level control of steam generators of nuclear power PWR; Investigacao sobre o uso de controladores digitais em substituicao aos controladores analogicos PID para o controle de nivel de geradores de vapor de centrais nucleares PWR

Energy Technology Data Exchange (ETDEWEB)

Alvarenga, Marco Antonio Bayout

2012-07-01

The aim of this study is to identify current alternatives for the implementation of digital controllers in the level control of steam generators of nuclear power PWR (Pressurized Water Reaetor). It is intended to identify the types of digital controls that are available from the theoretical and conceptual viewpoints for this purpose. We investigate the advantages and disadvantages of each controller model. From this assessment are pointed the most suitable models in hierarchical scale. This evaluation also serves to suggest possible types of control installation as a whole, where the level control of the steam generators becomes just one of many controls that are part of the plant. In this case, the use of digital controls allows the non-linear and multivariable treatment which is characteristic of complex systems, such as the nuclear power generation. The treatment of nonlinearities and multivariable aspects allows a more detailed study of the stability of these plants when they are subject to transients or several accidents, such as the case of losing external power of transients. In the specific case of steam generators, the instabilities result from the emergence of the shrink and swell phenomenas, depending on the load variations of thermonuclear plant. The application of several types and digital controllers, considering these inherent characteristics of the level control of steam generators, allows to infer which types of controllers are more appropriate to treat instabilities of this type and to make conjectures in its use for the cases of more complex instabilities, considering the integration of all nucleus-plant controls.

Doses in radiation accidents investigated by chromosome aberration analysis XVI: A review of cases investigated, 1985

International Nuclear Information System (INIS)

Lloyd, D.C.; Edwards, A.A.; Prosser, J.S.; Moquet, J.E.; Finnon, P.

1986-04-01

During 1985, 28 cases of suspected overexposure to ionising radiation were referred to NRPB for investigation by cytogenetic analysis, and the results are presented in this report. Of the 28 cases, 17 were associated with industrial radiography, 9 from major nuclear organisations and 2 from research, education and health institutions. In 20 cases, no biological indication of overexposure was found. The remaining 8 cases all arose from industrial uses of radiation. The highest overexposure to a sealed source in 1985 ws about 0.4 Gy from an 192 Ir source that became detached from its winding mechanism. Two serious incidents involving unsealed sources are also described; an accidental ingestion of 125 I, for which cytogenetic analysis is of limited relevance, and an inhalation of droplets of tritiated water. The latter also produced a committed dose equivalent of about 0.4 Sv, the estimates from cytogenetic analysis and urine analysis being in good agreement. (author)

Nitrate in drinking water and risk of death from bladder cancer: an ecological case-control study in Taiwan.

Science.gov (United States)

Chiu, Hui-Fen; Tsai, Shang-Shyue; Yang, Chun-Yuh

2007-06-01

The relationship between nitrate levels in drinking water and bladder cancer development is controversial. A matched cancer case-control with nitrate ecology study was used to investigate the association between bladder cancer mortality occurrence and nitrate exposure from Taiwan drinking water. All bladder cancer deaths of Taiwan residents from 1999 through 2003 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth,and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on nitrate-nitrogen (NO3-N) levels in drinking water throughout Taiwan were collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was assumed to be the source of the subject's nitrate exposure via drinking water. The adjusted odds ratios for bladder cancer death for those with high nitrate levels in their drinking water were 1.76 (1.28-2.42) and 1.96 (1.41-2.72) as compared to the lowest tertile. The results of the present study show that there was a significant positive relationship between the levels of nitrate in drinking water and risk of death from bladder cancer.

The Toxicology Investigators Consortium Case Registry-the 2015 Experience.

Science.gov (United States)

Farrugia, Lynn A; Rhyee, Sean H; Campleman, Sharan L; Ruha, Anne-Michelle; Weigand, Timothy; Wax, Paul M; Brent, Jeffrey

2016-09-01

The American College of Medical Toxicology established the Toxicology Investigators Consortium (ToxIC) Case Registry in 2010. The Registry contains all medical toxicology consultations performed at participating sites. The Registry has continued to grow since its inception, and as of December 31, 2015, contains 43,099 cases. This is the sixth annual report of the ToxIC Registry, summarizing the additional 8115 cases entered in 2015. Cases were identified by a query of the Registry for all cases entered between January 1 and December 31, 2015. Specific data reviewed for analysis included demographics (age, race, gender), source of consultation, reason for consultation, agents and agent classes involved in exposures, signs, symptoms, clinical findings, fatalities, and treatment. By the end of 2015, there were 50 active sites, consisting of 101 separate health-care facilities; 51.2 % of cases involved females. Adults between the ages of 19 and 65 made up the majority (64.2 %) of Registry cases. Caucasian race was the most commonly reported (55.6 %); 9.6 % of cases were identified as Hispanic ethnicity. Inpatient and emergency department referrals were by far the most common referral sources (92.9 %). Intentional pharmaceutical exposures remained the most frequent reason for consultation, making up 52.3 % of cases. Of these intentional pharmaceutical exposures, 69 % represented an attempt at self-harm, and 85.6 % of these were a suicide attempt. Nonopioid analgesics, sedative-hypnotics, and antidepressant agents were the most commonly reported agent classes in 2015. Almost one-third of Registry cases involved a diagnosed toxidrome (32.8 %), with a sedative-hypnotic toxidrome being the most frequently described. Significant vital sign abnormalities were recorded in 25.3 % of cases. There were 98 fatalities reported in the Registry (1.2 %). Adverse drug reactions were reported in 4.3 % of cases. Toxicological treatment was given in 65.3 % of cases, with 33.0�

One Critical Case in Singularly Perturbed Control Problems

Science.gov (United States)

Sobolev, Vladimir

2017-02-01

The aim of the paper is to describe the special critical case in the theory of singularly perturbed optimal control problems. We reduce the original singularly perturbed problem to a regularized one such that the existence of slow integral manifolds can be established by means of the standard theory. We illustrate our approach by an example of control problem.

Risk Factors Profile of Shoulder Dystocia in Oman: A Case Control Study

OpenAIRE

Maha M. Al-Khaduri; Rania Mohammed Abudraz; Sayed G. Rizvi; Yahya M. Al-Farsi

2014-01-01

Objective: This study aimed to assess the risk factor profile of shoulder dystocia and associated neonatal complications in Oman, a developing Arab country. Methods: A retrospective case-control study was conducted among 111 cases with dystocia and 111 controls, identified during 1994-2006 period in a tertiary care hospital in Oman. Controls were randomly selected among women who did not have dystocia, and were matched to cases on the day of delivery. Data related to potential risk factor...

Relationship of psychosocial risk factors, certain personality traits and myocardial infarction in Indians: A case-control study

Directory of Open Access Journals (Sweden)

Rajni Gupta

2011-01-01

Full Text Available Objective: To investigate the relationship of psychosocial factors (lack of social support, stress and subjective well-being and personality traits with myocardial infarction (MI. Materials and Methods: A case-control study involving 100 cases and 100 matched controls was conducted in Lok Nayak Hospital, New Delhi. Results: Stress over 1 year was significantly higher in cases (P < 0.001. However, difference was not significant when scores of social support (P = 0.2, Presumptive Stressful Life Event (PSLE over lifetime (P = 0.058 and subjective well-being (P = 0.987 were compared. MI was significantly associated with hyperactive (P < 0.001, dominant (P = 0.03, egoistic (P < 0.001 and introvert (P < 0.001 personalities. Conclusion: Certain personality traits and recent stress may be important risk factors of MI, especially in Indians. The finding may have implications on the preventive strategies planned for MI patients.

Naevi as a risk factor for basal cell carcinoma in Caucasians: a Danish case-control study

DEFF Research Database (Denmark)

Lock-Andersen, J; Drzewiecki, K T; Wulf, H C

1999-01-01

The number of melanocytic naevi in Caucasians is related to previous exposure to the sun and is a well-documented major risk factor for cutaneous malignant melanoma. Basal cell carcinoma, which is the most common form of skin cancer, has also been shown to be related to exposure to the sun....... To investigate whether the number of common naevi is a risk factor for basal cell carcinoma in Caucasians we performed whole-body counting of naevi > or =2 mm in a Danish case-control study with 145 cases of primary basal cell carcinoma and 119 controls matched on age, gender and place of residence. Naevi were...... recorded according to size and body region and the skin phototype was assessed. There was no correlation between self-reported skin type and the number of naevi. Females with basal cell carcinoma had more naevi than did female controls (median number of naevi: 65 and 32, respectively) while males...

Autism in children and correlates in Lebanon: a pilot case-control study.

Science.gov (United States)

Hamadé, Aline; Salameh, Pascale; Medlej-Hashim, Myrna; Hajj-Moussa, Elie; Saadallah-Zeidan, Nina; Rizk, Francine

2013-09-17

Autism spectrum disorder (ASD) is a neurological disorder typically appearing before the age of three. The exact cause of autism remains uncertain, and several factors may be involved in its onset: genetic factors and possible environmental factors. The aim of this study was to assess the correlates of autism in the Lebanese population. We investigated the association of autism with several factors in 86 autism cases from specialized schools for children with developmental disabilities and 172 control children from regular public schools in the same regions. Several risk factors for autism were investigated after comparison with a cohort control on parental age, sex, maternal unhappy feeling during pregnancy, consanguineous marriage, and province of residence. The Chi-square test was used to compare nominal variables, and Fisher exact test was used in case expected values within cells were inferior to five. For quantitative variables, we used t-test to compare means between two groups, after checking their distribution normality. For multivariate analysis, we used a forward stepwise likelihood ratio logistic regression. We observed male predominance (79.1%) among autistic infants. There was a significant association between autism and older parents age (OR=1.27), male sex (OR=3.38), unhappy maternal feeling during pregnancy (OR=5.77), living close to industry (OR=6.58), previous childhood infection (OR=8.85), but none concerning maternal age, paternal age and consanguinity. In this pilot epidemiological study of autism in Lebanon, we found several prenatal and perinatal risk factors for autism that could be modified.

Intrapartum amnioinfusion in meconium-stained liquor: a case-control study.

Science.gov (United States)

Bansal, Neeta; Gupta, Vineeta; Nanda, Anuja; Chaudhary, Priyanka; Tandon, Archna; Behl, Neelima

2013-06-01

The aim of this study was to investigate perinatal outcome and the rate of cesarean section (CS) following intrapartum amnioinfusion in women with meconium-stained amniotic fluid (MSAF). A total of 100 women at term in labor with meconium were randomized to infuse transcervical intrapartum amnioinfusion with saline (50) and routine obstetrical care (50). Perinatal outcome and obstetric outcome were recorded and analyzed in both groups by means of Chi-square test. The CS rate due to fetal distress was 40.0 % in the control group and 20.0 % in the study group. The difference was statistically significant (P Amnioinfusion in cases of meconium-stained liquor significantly improved neonatal outcome and CS rate without increasing any maternal and fetal complications.

Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study.

Science.gov (United States)

Huang, Jiaqi; Zagai, Ulrika; Hallmans, Göran; Nyrén, Olof; Engstrand, Lars; Stolzenberg-Solomon, Rachael; Duell, Eric J; Overvad, Kim; Katzke, Verena A; Kaaks, Rudolf; Jenab, Mazda; Park, Jin Young; Murillo, Raul; Trichopoulou, Antonia; Lagiou, Pagona; Bamia, Christina; Bradbury, Kathryn E; Riboli, Elio; Aune, Dagfinn; Tsilidis, Konstantinos K; Capellá, Gabriel; Agudo, Antonio; Krogh, Vittorio; Palli, Domenico; Panico, Salvatore; Weiderpass, Elisabete; Tjønneland, Anne; Olsen, Anja; Martínez, Begoña; Redondo-Sanchez, Daniel; Chirlaque, Maria-Dolores; Hm Peeters, Petra; Regnér, Sara; Lindkvist, Björn; Naccarati, Alessio; Ardanaz, Eva; Larrañaga, Nerea; Boutron-Ruault, Marie-Christine; Rebours, Vinciane; Barré, Amélie; Bueno-de-Mesquita, H B As; Ye, Weimin

2017-04-15

The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case-control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non-significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction cancer risk in western European populations. However, the suggested association between chronic corpus atrophic gastritis and pancreatic cancer risk warrants independent verification in future studies, and, if confirmed, further studies on the underlying mechanisms. © 2016 UICC.

Distribution of ABO and Rh Blood Groups in Patients With Keratoconus: A Case-Control Study.

Science.gov (United States)

Naderan, Mohammad; Rajabi, Mohammad Taher; Shoar, Saeed; Kamaleddin, Mohammad Amin; Naderan, Morteza; Rezagholizadeh, Farzaneh; Zolfaghari, Masoome; Pahlevani, Rozhin

2015-07-01

Association of keratoconus (KC) with genetic predisposition and environmental factors has been well documented. However, no single study has investigated the possible relationship between ABO and Rh blood groups and KC. A case-control study was designed in a university hospital enrolling 214 patients with KC in the case group and equal number of age- and sex-matched healthy subjects in the control group. Primary characteristics, ABO blood group, and Rh factors were compared between the two groups. Topographic findings of KC eyes and the severity of the diseases were investigated according to the distribution of the blood groups. Blood group O and Rh(+) phenotype were most frequent in both groups. There was no significant difference between the two groups in terms of ABO blood groups or Rh factors. Mean keratometery (K), central corneal thickness, thinnest corneal thickness, flat K, steep K, sphere and cylinder, spherical equivalent, and uncorrected visual acuity were all similar between ABO blood groups and Rh(+) and Rh(-) groups. However, the best spectacle-corrected visual acuity (BCVA) had the highest value in AB blood group (0.35 ± 0.22 logMAR, P=0.005). Moreover, the blood group AB revealed the highest frequency for grade 3 KC, followed by grades 1, 2, and 4 (P=0.003). We observed no significant excess of any particular blood group among KC cases compared with healthy subjects. Except BCVA, none of the keratometric or topographic findings was significantly different between blood groups.

Nosocomial outbreak of staphylococcal scalded skin syndrome in neonates: epidemiological investigation and control.

Science.gov (United States)

El Helali, N; Carbonne, A; Naas, T; Kerneis, S; Fresco, O; Giovangrandi, Y; Fortineau, N; Nordmann, P; Astagneau, P

2005-10-01

Over a three-month period, 13 neonates developed staphylococcal scalded skin syndrome (SSSS) in a maternity unit, between four and 18 days after their birth. An epidemiological and descriptive study followed by a case-control study was performed. A case was defined as a neonate with blistering or peeling skin, and exfoliative toxin A Staphylococcus aureus positive cultures. Controls were selected at random from the asymptomatic, non-colonized neonates born on the same day as the cases. All staff members and all neonates born during the outbreak period were screened for carriage by nasal swabs and umbilical swabs, respectively. S. aureus isolates were polymerase chain reaction (PCR) screened for etA gene and genotyped by pulsed-field gel electrophoresis (PFGE). Two clusters of eight and five cases were identified. Receiving more than one early umbilical care procedure by the same ancillary nurse was the only risk factor identified in the case-control study (odds ratio=15, 95% confidence intervals 2-328). The ancillary nurse suffered from chronic dermatitis on her hands that favoured S. aureus carriage. Exfoliative-toxin-A-producing strains, as evidenced by PCR and indistinguishable by PFGE, were isolated from all but one of the SSSS cases, from four asymptomatic neonates, from two staff members and from the ancillary nurse's hands. Removal of the ancillary nurse from duty, infection control measures (isolation precautions, chlorhexidine handwashing and barrier protections), and treatment of the carriers (nasal mupirocin and chlorhexidine showers) led to control of the epidemic. In conclusion, this study emphasizes the need for tight surveillance of chronic dermatitis in healthcare workers.

78 FR 6834 - Certain Cases for Portable Electronic Devices; Institution of Investigation

Science.gov (United States)

2013-01-31

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-867] Certain Cases for Portable Electronic Devices; Institution of Investigation AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on...

Brain-relevant antibodies in first-episode psychosis: a matched case-control study.

Science.gov (United States)

Gaughran, Fiona; Lally, John; Beck, Katherine; McCormack, Ruaidhri; Gardner-Sood, Poonam; Coutinho, Ester; Jacobson, Leslie; Lang, Bethan; Sainz-Fuertes, Ricardo; Papanastasiou, Evangelos; Di Forti, Marta; Nicholson, Tim; Vincent, Angela; Murray, Robin M

2018-06-01

There has been much recent excitement about the possibility that some cases of psychosis may be wholly due to brain-reactive antibodies, with antibodies to N-methyl-D-aspartate receptor (NMDAR) and the voltage-gated potassium channel (VGKC)-complex reported in a few patients with first-episode psychosis (FEP). Participants were recruited from psychiatric services in South London, UK, from 2009 to 2011 as part of the Genetics and Psychosis study. We conducted a case-control study to examine NMDAR and VGKC-complex antibody levels and rates of antibody positivity in 96 patients presenting with FEP and 98 controls matched for age and sex. Leucine-rich glioma inactiviated-1 (LGI1) and contactin-associated protein (CASPR) antibodies were also measured. Notably, patients with suspicion of organic disease were excluded. VGKC-complex antibodies were found in both cases (n = 3) and controls (n = 2). NMDAR antibody positivity was seen in one case and one control. Either LGI1-Abs or CASPR2-Abs were found in three cases and three controls. Neuronal antibody staining, consistent with the above results or indicating potential novel antigens, was overall positive in four patients but also in six controls. Overall, antibody positivity was at low levels only and not higher in cases than in controls. This case-control study of the prevalence of antibodies in FEP does not provide evidence to support the hypothesis that FEP is associated with an immune-mediated process in a subgroup of patients. Nevertheless, as other bio-clinical factors may influence the effect of such antibodies in a given individual, and patients with organic neurological disease may be misdiagnosed as FEP, the field requires more research to put these findings in context.

Epilepsy and risk of suicide: a population-based case-control study

DEFF Research Database (Denmark)

Christensen, Jakob; Vestergaard, Mogens; Mortensen, Preben Bo

2007-01-01

by sex, birth year, and calendar date, were assigned to each suicide case. FINDINGS: We identified 21 169 cases of suicide and 423 128 controls. 492 (2.32%) individuals who committed suicide had epilepsy compared with 3140 (0.74%) controls, corresponding to a three times higher risk (rate ratio [RR] 3...

Investigation of actuator debonding effects on active control in smart composite laminates

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Bin Huang

2015-04-01

Full Text Available This article presents a numerical study of active vibration control of smart composite laminates in the presence of actuator debonding failures. A comparison between the smart composite laminates with healthy actuator and various partially debonded actuator cases is performed to investigate the debonding effects on the vibration suppression. The improved layerwise theory with Heaviside’s unit step function is adopted to model the displacement field with actuator debonding failure. The higher order electric potential field is adopted to describe the potential variation through the thickness. The finite element method–based formulations are derived using the plate element, taking into consideration the electro-mechanical coupling effect. The reduced-order model is represented by the state-space form and further for the vibration suppression using a simple constant gain velocity feedback control strategy. For the purpose of demonstration, a 16-layer cross-ply substrate laminate ([0/90]4s is employed for the numerical study. The results show that the actuator debonding affects the closed-loop frequencies, active damping ratios, and efficiency of vibration suppression.

Harnessing case isolation and ring vaccination to control Ebola.

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Chad Wells

2015-05-01

Full Text Available As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy candidate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine. To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest that if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolation alone. The marginal benefit of ring vaccination is predicted to be greatest in settings where there are more contacts per individual, greater clustering among individuals, when contact tracing has low efficacy or vaccination confers post-exposure protection. In such settings, ring vaccination can avert up to an additional 8% of Ebola cases. Accordingly, ring vaccination is predicted to offer a moderately beneficial supplement to ongoing non-pharmaceutical Ebola control efforts.

Harnessing case isolation and ring vaccination to control Ebola.

Science.gov (United States)

Wells, Chad; Yamin, Dan; Ndeffo-Mbah, Martial L; Wenzel, Natasha; Gaffney, Stephen G; Townsend, Jeffrey P; Meyers, Lauren Ancel; Fallah, Mosoka; Nyenswah, Tolbert G; Altice, Frederick L; Atkins, Katherine E; Galvani, Alison P

2015-05-01

As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy candidate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine. To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest that if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolation alone. The marginal benefit of ring vaccination is predicted to be greatest in settings where there are more contacts per individual, greater clustering among individuals, when contact tracing has low efficacy or vaccination confers post-exposure protection. In such settings, ring vaccination can avert up to an additional 8% of Ebola cases. Accordingly, ring vaccination is predicted to offer a moderately beneficial supplement to ongoing non-pharmaceutical Ebola control efforts.

The role of acupuncture in controlling the gagging reflex using a review of ten cases.

Science.gov (United States)

Fiske, J; Dickinson, C

2001-06-09

The gagging reflex is a physiological reaction which safeguards the airway from foreign bodies. In some people this response is exaggerated to the extent that the acceptance/provision of dental treatment is not possible. The aim of this paper is to review the role of acupuncture in controlling gagging as a safe, cheap, quick and relatively non-invasive technique. Ten people agreed to try ear acupuncture to control gagging during dental treatment. Prior to treatment the severity of gagging was assessed. Acupuncture needles were inserted into a specific anti-gagging point on each ear, manipulated briefly and left in situ. Dental treatment was then carried out and the effectiveness of the acupuncture in preventing gagging was assessed. After treatment, the needles were removed and the patient discharged. All acupuncture was carried out by a dentist trained in its use. Four people had a severe gag reflex which made treatment impossible and six had a very severe reflex which made treatment impossible and affected their dental attendance. Ear acupuncture completely controlled the gag reflex in eight cases (23 treatment episodes) and partially controlled the reflex in two cases (two treatment episodes). Dental treatment could be carried out in all cases and at all visits. The cost of materials was 0.2 pounds per person per visit. Additional clinical time was in the order of 2-3 minutes. There were no adverse reactions to the technique and, on all occasions, patients were fit to leave the surgery and travel home unaccompanied. Ear acupuncture was successful in controlling the gag reflex. It is a safe, quick, inexpensive and relatively noninvasive technique. A controlled clinical trial is required to investigate any placebo effect.

Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study.

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Lopez-del Burgo, Cristina; Gea, Alfredo; de Irala, Jokin; Martínez-González, Miguel A; Chavarro, Jorge E; Toledo, Estefania

2015-07-27

The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72-1.51). No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72-1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82-1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84-1.64) was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women's fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously.

Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study

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Cristina Lopez-del Burgo

2015-07-01

Full Text Available The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72–1.51. No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72–1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82–1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84–1.64 was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women’s fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously.

Periodontal disease and spontaneous preterm birth: a case control study

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Eley Barry

2006-07-01

Full Text Available Abstract Background Several studies have suggested an association between periodontal disease and prematurity but this finding has not been consistently observed. Methods Case control study. Cases (n = 50 were women who had delivered after spontaneous preterm labor at Results There was no difference in the proportion of sites with significant attachment loss (≥3 mm: Cases-3.2%, Controls-2.2% p = 0.21. The gingival crevicular fluid concentrations of elastase and gingipain were elevated in cases vs. controls 238.8 uU/ul vs. 159.6 uU/ul p = .007 and 2.70 uU/ul vs. 1.56 uU/ul p = .001. On multivariate analysis, the mean log concentration of elastase, but not of gingipain, remained a significant predictor of preterm labor p = .0.015. Conclusion We found no evidence that clinical periodontal disease is associated with spontaneous preterm birth. Elevated gingival crevicular fluid levels of elastase were associated with preterm birth but further research is needed before this can be assumed to be a causal relationship.

Design control and scientific investigations: Is there any linkage?

International Nuclear Information System (INIS)

Richards, R.R.

1995-01-01

The quality assurance requirements that apply to the effort to achieve safe transportation, storage, and disposal of high-level nuclear waste specify that ''design control'' be applied to design activities. That effort also involves extensive scientific investigation activities to, among other things, develop information that may be used in engineering design activities. Individuals who are charged with the implementation of such quality assurance requirements have come to a variety of conclusions about whether there is any firm linkage between design control and the conduct of scientific investigations. This paper contends that there is a reasonable and necessary linkage between ''design control'' and scientific activities, though not a connection that has traditionally been made and not one addressed in the QA standards for radioactive waste management programs

Analgesics use and ESRD in younger age: a case-control study

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Moehner Sabine

2007-12-01

Full Text Available Abstract Background An ad hoc peer-review committee was jointly appointed by Drug Authorities and Industry in Germany, Austria and Switzerland in 1999/2000 to review the evidence for a causal relation between phenacetin-free analgesics and nephropathy. The committee found the evidence as inconclusive and requested a new case-control study of adequate design. Methods We performed a population-based case-control study with incident cases of end-stage renal disease (ESRD under the age of 50 years and four age and sex-matched neighborhood controls in 170 dialysis centers (153 in Germany, and 17 in Austria from January 1, 2001 to December 31, 2004. Data on lifetime medical history, risk factors, treatment, job exposure and intake of analgesics were obtained in a standardized face-to-face interview using memory aids to enhance accuracy. Study design, study performance, analysis plan, and study report were approved by an independent international advisory committee and by the Drug Authorities involved. Unconditional logistic regression analyses were performed. Results The analysis included 907 cases and 3,622 controls who had never used phenacetin-containing analgesics in their lifetime. The use of high cumulative lifetime dose (3rd tertile of analgesics in the period up to five years before dialysis was not associated with later ESRD. Adjusted odds ratios with 95% confidence intervals were 0.8 (0.7 – 1.0 and 1.0 (0.8 – 1.3 for ever- compared with no or low use and high use compared with low use, respectively. The same results were found for all analgesics and for mono-, and combination preparations with and without caffeine. No increased risk was shown in analyses stratifying for dose and duration. Dose-response analyses showed that analgesic use was not associated with an increased risk for ESRD up to 3.5 kg cumulative lifetime dose (98 % of the cases with ESRD. While the large subgroup of users with a lifetime dose up to 0.5 kg (278 cases and

Apolipoprotein E in Temporal Lobe Epilepsy: A Case-Control Study

Science.gov (United States)

Kumar, Amit; Tripathi, Manjari; Pandey, Ravindra M.; Ramakrishnan, Lakshmy; Srinivas, M.; Luthra, Kalpana

2006-01-01

Purpose: To investigate the relationship of apolipoprotein E (apoE) genotype, plasma levels of apoE and lipids in temporal lobe epilepsy (TLE) patients in Asian Indians. Status of plasma levels of Apo E in epilepsy patients has not been reported till date. Methods: ApoE gene polymorphism was analyzed in 58 patients with temporal lobe epilepsy (TLE) and 57 age and sex approximated controls using Polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). Levels of plasma apoE and lipids were measured using ELISA and enzymatic kits respectively. Results: The distribution of ApoE genotype in epilepsy patients and controls was comparable. Higher levels of plasma ApoE were observed in TLE patients as compared to controls (p = 0.0001). Individuals with plasma levels of apoE > 190 mg/L were at 20 times higher odds (95%CI = 2.46–163.34, p = 0.005), while those with levels of apoE between 150–190 mg/L were at 4.9 times higher odds (95% CI = 1.85–13.9, p = 0.001), to develop TLE. Conclusions: We have observed for the first time, high levels of plasma apoE in epilepsy patients. The findings of this case-control study suggest that apolipoprotein E may play an important role in epilepsy. PMID:17264404

Gender-specific suicide risk factors: a case-control study of individuals with major depressive disorder.

Science.gov (United States)

Dalca, Ioana Mioara; McGirr, Alexander; Renaud, Johanne; Turecki, Gustavo

2013-12-01

Available information on risk for suicide completion in females is limited and often extrapolated from studies conducted in males. However, the validity of extending to females risk factors identified among male suicide cases is unclear. In this study, we aimed to investigate clinical and behavioral risk factors for suicide among female depressed patients and compare them to similar factors among male depressed patients. We identified 201 suicide completers (160 male and 41 female) who died during an episode of major depressive disorder (MDD). Cases were compared to 127 living patients with MDD (88 male and 39 female). All subjects were characterized for Axis I and II diagnoses using the Structured Clinical Interview for DSM-IV Axis I Disorders and Structured Clinical Interview for DSM-IV Axis II Personality Disorders according to the DSM-IV, as well as behavioral and temperament dimensions using proxy-based interviews. The primary outcome was measures of impulsive and impulsive-aggressive behaviors. Compared to controls, male, but not female suicide cases had higher levels of impulsive aggression (P suicide cases from controls. However, nonimpulsive aggression and impulsive aggression were correlated constructs in males (r = 0.297; P suicide, such as alcohol and substance dependence, cluster B disorders, and elevated hostility and aggression, were replicated in the pooled-sex analyses, and, though not statistically significant in discriminating between suicide cases and controls by gender, maintained strong group differences. Males and females share many risk factors for suicide in MDD, yet alcohol dependence is much more specific though less sensitive among depressed females. Nonimpulsive aggression is part of a diathesis for suicide in females, which is distinct from the well-characterized impulsive aggression that is consistently reported in a portion of male suicide cases. © Copyright 2013 Physicians Postgraduate Press, Inc.

Ethnic variations in severe maternal morbidity in the UK- a case control study.

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Manisha Nair

Full Text Available Previous studies showed a higher risk of maternal morbidity amongst black and other minority ethnic (BME groups, but were unable to investigate whether this excess risk was concentrated within specific BME groups in the UK. Our aim was to analyse the specific risks and to investigate reasons for any disparity.Unmatched case-control analysis using data from the United Kingdom Obstetric Surveillance System (UKOSS, February 2005-January 2013. Cases were 1,753 women who experienced severe morbidity during the peripartum period. Controls were 3,310 women who delivered immediately before the cases in the same hospital. Multivariable logistic regression modelling was used to adjust for known confounders and to understand their effects.Compared with white European women, the odds of severe maternal morbidity were 83% higher among black African women (adjusted odds ratio (aOR = 1.83; 95% Confidence Interval (CI = 1.39-2.40, 80% higher among black Caribbean (aOR = 1.80; 95% CI = 1.14-2.82, 74% higher in Bangladeshi (aOR = 1.74; 95% CI = 1.05-2.88, 56% higher in other non-whites (non-Asian (aOR = 1.56; 95% CI = 1.05-2.33 and 43% higher among Pakistani women (aOR = 1.43; 95% CI = 1.07-1.92. There was no evidence of substantial confounding. Anaemia in current pregnancy, previous pregnancy problems, inadequate utilisation of antenatal care, pre-existing medical conditions, parity>3, and being younger and older were independent risk factors but, the odds of severe maternal morbidity did not differ by socioeconomic status, between smokers and non-smokers or by BMI.This national study demonstrates an increased risk of severe maternal morbidity among women of ethnic minority backgrounds which could not be explained by known risk factors for severe maternal morbidity.

Management Control in Inter-organizational Relationships: The Case of Franchises

OpenAIRE

Magdalena Cordobés Madueño; Pilar Soldevila García

2015-01-01

There is great interest in the role of management control on theoretical and practical developments within the field of Inter-organizational Relations. This research aims to contribute at verifying how relationships between firms affect the management control tools used, as illustrated in a specific case: the relationship between the franchisor and its franchisees, which has not received much attention to date. As indicated by previous research, case studies can be helpful to determine the...

Case-control study of fetal microchimerism and breast cancer.

Directory of Open Access Journals (Sweden)

Vijayakrishna K Gadi

2008-03-01

Full Text Available Prior pregnancy is known to protect against development of breast cancer. Recent studies have demonstrated that pregnancy has the capacity to establish small numbers of immunologically active fetal-derived cells in the mother, a phenomenon known as fetal microchimerism (FMc. We asked whether presence of FMc, routinely acquired during pregnancy, is a protective factor for breast cancer.DNA extracts from peripheral blood specimens were obtained from a population-based case-control study of risk factors for breast cancer in women 21 to 45 years old. Specimens were tested with quantitative PCR for presence and concentrations of male DNA presumed to derive from prior pregnancies with a male fetus. Odds ratios (OR and 95% confidence intervals (CI were estimated with consideration of multiple established reproductive and environmental risk factors for breast cancer. FMc results were generated on 99 parous women, 54 with primary invasive breast cancer and 45 general population controls. FMc prevalence was 56% (25/45 and 26% (14/54 in controls and cases, respectively. Women harboring FMc were less likely to have had breast cancer (OR = 0.29, 95% CI 0.11-0.83; p = 0.02, adjusting for age, number of children, birth of a son, history of miscarriage, and total DNA tested. In addition, FMc concentrations were higher in controls versus cases (p = 0.01. Median concentrations were 2 (0-78 and 0 (0-374 fetal genomes/10(6 maternal genomes in controls and cases, respectively.Results suggest that the enigma of why some parous women are not afforded protection from breast cancer by pregnancy might in part be explained by differences in FMc. Mechanistic studies of FMc-derived protection against breast cancer are warranted.

[A case-control study on association between OAS1 polymorphism and susceptibility to spontaneous preterm birth and preterm premature rupture of membranes].

Science.gov (United States)

Yang, Xiao; Zhang, Xiao-Ai; Wu, Zhi-Hao; Peng, Wei; Zhu, Li-Na; Wang, Yan

2015-09-01

To investigate the association between the genetic polymorphism of 2',5'-oligoadenylate synthetase 1 (OAS1) and susceptibility to spontaneous preterm birth (SPTB) and preterm premature rupture of membranes (PPROM). The case-control study consisted of 599 preterm infants including 171 cases of PPROM, and 673 full-term infants without maternal histories of SPTB and PPROM as controls. The single nucleotide polymorphism (SNP) at OAS1 intron 5, rs10774671, was analyzed by polymerase chain reaction-restriction fragment length polymorphism. No significant differences were observed between the case and control groups in the frequencies of genotypes (AA, GA, and GG) and alleles (A and G) of OAS1 rs10774671. When the case group was divided into two subgroups with or without PPROM, no significant differences in the genotype and allele frequencies were found between each subgroup and the control group. When the case group was divided into three subgroups with different gestational ages at SPTB, no significant differences in the genotype and allele frequencies were detected between each subgroup and the control group. No association is identified between OAS1 SNP and susceptibility to SPTB and PPROM.

Birth order and sibship size: evaluation of the role of selection bias in a case-control study of non-Hodgkin's lymphoma.

Science.gov (United States)

Mensah, F K; Willett, E V; Simpson, J; Smith, A G; Roman, E

2007-09-15

Substantial heterogeneity has been observed among case-control studies investigating associations between non-Hodgkin's lymphoma and familial characteristics, such as birth order and sibship size. The potential role of selection bias in explaining such heterogeneity is considered within this study. Selection bias according to familial characteristics and socioeconomic status is investigated within a United Kingdom-based case-control study of non-Hodgkin's lymphoma diagnosed during 1998-2001. Reported distributions of birth order and maternal age are each compared with expected reference distributions derived using national birth statistics from the United Kingdom. A method is detailed in which yearly data are used to derive expected distributions, taking account of variability in birth statistics over time. Census data are used to reweight both the case and control study populations such that they are comparable with the general population with regard to socioeconomic status. The authors found little support for an association between non-Hodgkin's lymphoma and birth order or family size and little evidence for an influence of selection bias. However, the findings suggest that between-study heterogeneity could be explained by selection biases that influence the demographic characteristics of participants.

Analysis of Clinical Cohort Data Using Nested Case-control and Case-cohort Sampling Designs. A Powerful and Economical Tool.

Science.gov (United States)

Ohneberg, K; Wolkewitz, M; Beyersmann, J; Palomar-Martinez, M; Olaechea-Astigarraga, P; Alvarez-Lerma, F; Schumacher, M

2015-01-01

Sampling from a large cohort in order to derive a subsample that would be sufficient for statistical analysis is a frequently used method for handling large data sets in epidemiological studies with limited resources for exposure measurement. For clinical studies however, when interest is in the influence of a potential risk factor, cohort studies are often the first choice with all individuals entering the analysis. Our aim is to close the gap between epidemiological and clinical studies with respect to design and power considerations. Schoenfeld's formula for the number of events required for a Cox' proportional hazards model is fundamental. Our objective is to compare the power of analyzing the full cohort and the power of a nested case-control and a case-cohort design. We compare formulas for power for sampling designs and cohort studies. In our data example we simultaneously apply a nested case-control design with a varying number of controls matched to each case, a case cohort design with varying subcohort size, a random subsample and a full cohort analysis. For each design we calculate the standard error for estimated regression coefficients and the mean number of distinct persons, for whom covariate information is required. The formula for the power of a nested case-control design and the power of a case-cohort design is directly connected to the power of a cohort study using the well known Schoenfeld formula. The loss in precision of parameter estimates is relatively small compared to the saving in resources. Nested case-control and case-cohort studies, but not random subsamples yield an attractive alternative for analyzing clinical studies in the situation of a low event rate. Power calculations can be conducted straightforwardly to quantify the loss of power compared to the savings in the num-ber of patients using a sampling design instead of analyzing the full cohort.

Health service utilisation and investigations before diagnosis of cancer of unknown primary (CUP): A population-based nested case-control study in Australian Government Department of Veterans' Affairs clients.

Science.gov (United States)

Vajdic, Claire M; Schaffer, Andrea L; Dobbins, Timothy A; Ward, Robyn L; Er, Chuang C; Pearson, Sallie-Anne

2015-08-01

Population-based data on the use of health services and diagnostic investigations for patients with cancer of unknown primary (CUP) is scarce. It is uncertain whether the pathways to diagnosis are different for CUP compared to other cancers. We performed a population-based nested matched case-control study using linked routinely collected records for Australian Government Department of Veterans' Affairs clients, 2004-2007. We compared health care consultations, hospitalisations, emergency department visits, and diagnostic procedures in the three months prior and the month of diagnosis for 281 clients registered with a diagnosis of CUP (C809) and 1102 controls randomly selected from clients registered with a first diagnosis of metastatic cancer of known primary. Overall, the median age at cancer diagnosis was 83 years. CUP patients were slightly older and had significantly more comorbidities prior to diagnosis than those with known primary. Compared to known primary, a diagnosis of CUP was significantly more likely after an emergency department visit, less specialist input, fewer invasive diagnostic procedures such as resection or endoscopy, and more non-invasive procedures such as magnetic resonance imaging. There were no differences in primary care or allied health consultations and hospitalisations. This health care pathway suggests delayed recognition of cancer and scope for improvement in the medical management of high-risk individuals presenting to primary care. The pattern of diagnostic investigations reveals under-investigation in some CUP patients but this is likely to reflect recognition of limited treatment options and poor prognosis and is consistent with clinical guidelines. Copyright © 2015 Commonwealth of Australia. Published by Elsevier Ltd.. All rights reserved.

Violence against Women and Gastroschisis: A Case-Control Study

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Daniel Ruiz

2013-10-01

Full Text Available Background: Gastroschisis, a birth defect characterized by herniated fetal abdominal wall, occurs more commonly in infants born to teenage and young mothers. Ischemia of the vascular vitelline vessels is the likely mechanism of pathogenesis. Given that chronic stress and violence against women are risk factors for cardiovascular disease we explored whether these may represent risk factors for gastroschisis, when they occur during pregnancy. A case-control study was conducted, with 15 incident cases of children born with gastroschisis in the Region of Murcia, Spain, from December 2007 to June 2013. Forty concurrent controls were recruited at gestation weeks 20–24 or post-partum. All mothers of cases and controls completed a comprehensive, in-person, ‘green sheet’ questionnaire on environmental exposures. Results: Mothers of children with gastroschisis were younger, smoked more cigarettes per week relative to controls, were exposed to higher amounts of illegal drugs, and suffered from domestic violence more frequently than the controls. Multivariable logistic regression analysis highlights periconceptional ‘gender-related violence’ (OR: 16.6, 95% CI 2.7 to 101.7 and younger maternal age (OR 1.1, 95% CI 1.0–1.3. Conclusions: Violence against pregnant women is associated with birth defects, and should be studied in more depth as a cause-effect teratogenic. Psychosocial risk factors, including gender-based violence, are important for insuring the health and safety of the pregnant mother and the fetus.

[Investigation of the presence of Mycobacterium tuberculosis in the lymph node aspirates of the suspected tularemia lymphadenitis cases].

Science.gov (United States)

Albayrak, Nurhan; Celebi, Bekir; Kavas, Semra; Simşek, Hülya; Kılıç, Selçuk; Sezen, Figen; Arslantürk, Ahmet

2014-01-01

Recently reports of cervical tuberculous lymphadenitis and oropharyngeal tularemia which are the most common infectious causes of granulomatous lymphadenitis, have been significantly increased in Turkey. The differentiation of cervical tuberculous lymphadenitis and oropharyngeal tularemia is usually confusing on the basis of clinical and histopathological findings. Thus, in tularemia endemic areas, the patients are more commonly evaluated in terms of tularemia lymphadenitis leaving tuberculosis out. The aim of this study was to investigate the presence of Mycobacterium tuberculosis in cervical lymph node aspirates, obtained from tularemia suspected cases. A total of 105 oropharyngeal tularemia-suspected cases which were found negative for Francisella tularensis by bacteriological (culture), molecular (PCR) and serological (microagglutination) methods, were included in the study. The samples had been previously studied at National Tularemia Reference Laboratory, Turkish Public Health Institution, between 2009-2011. The study samples were evaluated in terms of M.tuberculosis by culture and real-time PCR (rtPCR) methods in the National Tuberculosis Reference Laboratory. Both Lowenstein-Jensen (LJ) medium and liquid-based MGIT (BD, USA) automated culture system were used for mycobacterial culture. Samples that yielded mycobacterial growth were identified as M.tuberculosis by immunochromotographic test (BD, USA). The lymph node aspirates of 65 patients who were F.tularensis PCR negative but antibody positive, were used as the control group. As a result, M.tuberculosis was found to be positive in 9 (8.6%) of 105 tularemia-negative lymph node aspirates, sent to our laboratory from different geographic regions for the investigation of tularemia. Six of the M.tuberculosis positive cases were male and the age range of the patients was 26-85 years. The presence of M.tuberculosis was detected only by culture in two samples, only by rtPCR in five samples and both by culture and

Case-control study of congenital malformations and occupational exposure to low-level ionizing radiation

International Nuclear Information System (INIS)

Sever, L.E.; Gilbert, E.S.; Hessol, N.A.; McIntyre, J.M.

1988-01-01

In a case-control study, the authors investigated the association of parental occupational exposure to low-level external whole-body penetrating ionizing radiation and risk of congenital malformations in their offspring. Cases and controls were ascertained from births in two counties in southeastern Washington State, where the Hanford Site has been a major employer. A unique feature of this study was the linking of quantitative individual measurement of external whole-body penetrating ionizing radiation exposure of employees at the Hanford Site, using personal dosimeters, and the disease outcome, congenital malformations. The study population included 672 malformation cases and 977 matched controls from births occurring from 1957 through 1980. Twelve specific malformation types were analyzed for evidence of association with employment of the parents at Hanford and with occupational exposure to ionizing radiation. Two defects, congenital dislocation of the hip and tracheoesophageal fistula, showed statistically significant associations with employment of the parents at Hanford, but not with parental radiation exposure. Neural tube defects showed a significant association with parental preconception exposure, on the basis of a small number of cases. Eleven other defects, including Down syndrome, for which an association with radiation was considered most likely, showed no evidence of such an association. When all malformations were analyzed as a group, there was no evidence of an association with employment of the parents at Hanford, but the relation of parental exposure to radiation before conception was in the positive direction (one-tailed p value between 0.05 and 0.10). Given the number of statistical tests conducted, some or all of the observed positive correlations are likely to represent false positive findings. 30 references

Sympathetic skin response in multiple sclerosis: a meta-analysis of case-control studies.

Science.gov (United States)

Margaritella, Nicolò; Mendozzi, Laura; Garegnani, Massimo; Gilardi, Elisabetta; Nemni, Raffaello; Pugnetti, Luigi

2018-01-01

The usefulness of sympathetic skin responses (SSR) in multiple sclerosis (MS) has been advocated by several studies in the last 20 years; however, due to a great heterogeneity of findings, a comprehensive meta-analysis of case-control studies is in order to pinpoint consistencies and investigate the causes of discrepancies. We searched MEDLINE, EMBASE and Cochrane databases for case-control studies comparing SSR absence frequency and latency between patients with MS and healthy controls. Thirteen eligible studies including 415 MS patients and 331 healthy controls were identified. The pooled analysis showed that SSR can be always obtained in healthy controls while 34% of patients had absent SSRs in at least one limb (95% CI 22-47%; p studies (I 2  = 90.3%). Patients' age explained 22% of the overall variability and positive correlations were found with Expanded Disability Status Scale and disease duration. The pooled mean difference of SSR latency showed a significant increase in patients on both upper (193 ms; 95% CI 120-270 ms) and lower (350 ms; 95% CI 190-510 ms) extremities. We tested the discriminatory value of SSR latency thresholds defined as the 95% confidence interval (CI) upper bound of the healthy controls, and validated the results on a new dataset. The lower limb threshold of 1.964 s produces the best results in terms of sensitivity 0.86, specificity 0.67, positive predicted value 0.75 and negative predicted value 0.80. Despite a considerable heterogeneity of findings, there is evidence that SSR is a useful tool in MS.

Case history of controlling a landslide at Panluo open-pit mine in China

Science.gov (United States)

Wei, Zuoan; Yin, Guangzhi; Wan, Ling; Shen, Louyan

2008-04-01

Controlling of landsides safely and economically is a great challenge to mine operators because landslides are major geological problems especially in open-pit mines. In this paper, a case history at Panluo open-pit mine is presented in detail to share the experiences and lessons with mine operators. Panluo open-pit mine is located in the southwestern Fujian province of China. It is the largest open-pit iron mine in the Fujian province and was planned in 1965 and is in full operation from 1978. In July 1990, an earthquake of magnitude 5.3 in Taiwan Strait and big rainstorms impacted the mine slope, causing tension cracks and rather large-scale failures, and forming a U-shaped landslide. Total potential volume was estimated to be up to 1.0 × 106 m3. This directly threatened the mine production. In order to protect the mine production and the dwellers’ safety around, a dynamic comprehensive method was implemented including geotechnical investigations, in-situ testing and monitoring, stability analysis, and many mitigation and preventive measures. These measures slowed down the development and further occurrence of the landslide. The results showed that the landslides were still active, it was slowed with the control measures and moved rapidly with rainfall and mining down. However, no catastrophic accidents occurred and the pit mining was continued till it was closed at the elevation of 887 m in 2000. As a successful case of landslide control at an open-pit mine for 10 years, this paper reports the controlling measures in details. These experiences of landslide control may be beneficial to other similar mines for landslide control.

Investigating power control in autonomous power systems with increasing wind power penetration

Energy Technology Data Exchange (ETDEWEB)

Margaris, Ioannis D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Hansen, Anca D.; Sorensen, Poul [Risoe National Laboratory, Roskilde (Denmark). Wind Energy Dept.; Hatziargyriou, Nikos D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Public Power Corporation S.A., Athens (Greece)

2009-07-01

Increasing levels of wind penetration in autonomous power systems has set intensively high standards with respect to wind turbine technology during the last years. Special features of non-interconnected power systems make security issues rather critical, as the operation of large wind farms like conventional power plants is becoming a necessity. This paper includes the study case of Rhodos island, in Greece, where rapidly increasing wind penetration has started to impose serious security issues for the immediate future. The scenarios studied here correspond to reference year of study 2012 and include wind farms with three different wind turbine technologies - namely Doubly Fed Induction Generator (DFIG), Permanent Magnet Synchronous Generator (PMSG) and Active Stall Induction Generator (ASIG) based wind turbines. Aggregated models of the wind farms are being used and results for different load cases are being analyzed and discussed. The ability of wind farms to assist in some of the power system control services traditionally carried out by conventional synchronous generation is being investigated and discussed. The power grid of the island, including speed governors and automatic voltage regulators, is simulated in the dedicated power system simulation program Power Factory from DIgSILENT. (orig.)

Forensic Polygraph in Crime Investigation: A Case Study

Directory of Open Access Journals (Sweden)

Aabad Ayoub

2016-06-01

Full Text Available A polygraph is an instrument that measures and records physiological changes inside the body. In the absence of a valid physical evidence, polygraphy may be a useful technique to verify truthfulness or detect deception. The present study was conducted to determine the truthfulness of a suspect in a murder case that was referred to PFSA for a polygraph examination. The stomach contents of the examinee and the hyoid bone of the vicvtim were submitted to the department of toxicology and forensic pathology at the PFSA, respectively. In the present study, integrated zone comparison technique (IZCT and forensic assessment interview technique (FAINT designed for specific and multi issue testing were used to examine the suspect. Computerized Academy for Scientific Investigative training (ASIT Algorithm and weighted scoring were applied in IZCT and FAINT scoring, respectively. The suspect of this murder case was brought to PFSA for polygraph examination. During the initial interview, the suspect denied any involvement in the said case. However, after complete polygraph examination, the suspect was proven to have been deceptive and later on confessed to police officials. The polygraph examination of the suspect proved him deceptive which was later confirmed by his confession. His stomach did not contain any toxic/ sedative material.

Experimental investigation of an accelerometer controlled automatic braking system

Science.gov (United States)

Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

1972-01-01

An investigation was made to determine the feasibility of an automatic braking system for arresting the motion of an airplane by sensing and controlling braked wheel decelerations. The system was tested on a rotating drum dynamometer by using an automotive tire, wheel, and disk-brake assembly under conditions which included two tire loadings, wet and dry surfaces, and a range of ground speeds up to 70 knots. The controlling parameters were the rates at which brake pressure was applied and released and the Command Deceleration Level which governed the wheel deceleration by controlling the brake operation. Limited tests were also made with the automatic braking system installed on a ground vehicle in an effort to provide a more realistic proof of its feasibility. The results of this investigation indicate that a braking system which utilizes wheel decelerations as the control variable to restrict tire slip is feasible and capable of adapting to rapidly changing surface conditions.

Maternal complication prevention: evidence from a case-control study in southwest Nigeria

Directory of Open Access Journals (Sweden)

Kayode O. Osungbade

2014-12-01

Full Text Available Background: The importance of strengthening maternal health services as a preventive intervention for morbidities and complications during pregnancy and delivery in developing countries cannot be over-emphasised, since use of prenatal health services improves maternal health outcomes. Aim: This study investigated differences in risk factors for maternal complications in booked and unbooked pregnant women in Nigeria, and provided evidence for their prevention. Setting: The study was carried out in a postnatal ward in a secondary health facility. Methods: This was a case-control study involving booked and unbooked pregnant women who had delivered. Consecutive enrolment of all unbooked pregnant women (cases was done, and one booked pregnant woman (control was enrolled and matched for age with each of these. Both groups were interviewed using a questionnaire, whilst records of delivery were extracted from the hospital files. Findings were subjected to logistical regression at a significance level of p < 0.05. Results: Booked women had a lower median length of labour (10 hours compared to unbooked women (13 hours. More women in the booked control group (139; 35.1% than in the unbooked case group (96; 23.6% reported at least one type of morbidity during the index pregnancy (p = 0.0004. Booking status was associated with a likelihood of spontaneous vaginal delivery. Young maternal age, low education, rural residence and low socio-economic status were associated with less likelihood of using prenatal services. Young maternal age, low education and intervention in the delivery were associated with a likelihood of experiencing a complication of delivery. Conclusion: Strengthening antenatal and secondary healthcare services as short- and mediumterm measures might be cost-effective as a preventive strategy in complications of pregnancy,whilst socio-economic dimensions of health are accorded priority in the long term.

Evaluation of two methods for assessing gene-environment interactions using data from the Danish case-control study of facial clefts

DEFF Research Database (Denmark)

Etheredge, Analee J; Christensen, Kaare; Del Junco, Deborah

2005-01-01

BACKGROUND: Epidemiological investigations have begun to consider gene-environment (GE) interactions as potential risk factors for many diseases, including several different birth defects. However, traditional methodological approaches for the analysis of case-control data tend to have low power ...

Postnatal risk factors for testicular cancer: The EPSAM case-control study.

Science.gov (United States)

Moirano, Giovenale; Zugna, Daniela; Grasso, Chiara; Mirabelli, Dario; Lista, Patrizia; Ciuffreda, Libero; Segnan, Nereo; Merletti, Franco; Richiardi, Lorenzo

2017-11-01

Testicular cancer is considered to originate from an impaired differentiation of fetal germ cells, but puberty could represent another time window of susceptibility. Our study aimed at investigating the association between environmental exposures acting during puberty/adolescence (13-19 years of age) and the risk of testicular cancer. We used data of the EPSAM study, a case-control study on germ-cell testicular cancer conducted in the province of Turin, Italy, involving cases diagnosed between 1997 and 2008. Histologically confirmed cases (n = 255) and controls (n = 459) completed a postal questionnaire focusing in particular on the pubertal period (namely age 13 years) with questions on physical activity (competitive sports, gardening), lifestyle (alcohol consumption, smoking), occupational history and medical conditions. All analyses were adjusted for the matching variables, cryptorchidism and educational level. Having done at least one competitive sport during puberty (odds ratio [OR]: 0.72, 95% confidence interval: 0.52-1.00), gardening activities during puberty (OR: 0.62, 0.42-0.94) and having a lower weight than peers during puberty (OR: 0.64, 0.42-0.97) were all inversely associated with the risk of testicular cancer. No evidence of association between smoking or alcohol consumption during puberty and the risk of testicular cancer was observed. Regarding agriculture-related occupations, we found an association with the risk of testicular cancer both for occasional jobs during puberty (OR: 2.40, 95% CI: 1.08-5.29) and ever employment in adolescence (OR: 2.59, 95% CI: 0.83-8.10). Our results suggest that postnatal exposures could play a role in testicular cancer aetiology, at least when acting in puberty or adolescence. © 2017 UICC.

Identifying risk factors for blindness from primary open-angle glaucoma by race: a case-control study.

Science.gov (United States)

Williams, Andrew M; Huang, Wei; Muir, Kelly W; Stinnett, Sandra S; Stone, Jordan S; Rosdahl, Jullia A

2018-01-01

To examine the factors associated with blindness from primary open-angle glaucoma (POAG) among black and white patients at our institution. For this retrospective, case-control study, patients legally blind from POAG ("cases") were matched on age, race, and gender with non-blind POAG patients ("controls"). Thirty-seven black case-control pairs and 19 white case-control pairs were included in this study. Clinical variables were compared at initial presentation and over the course of follow-up. Black case-control pairs and white case-control pairs had similar characteristics at presentation, including cup-to-disc ratio and number of glaucoma medications. However, over the course of follow-up, black cases underwent significantly more glaucoma surgeries than matched controls (2.4 versus 1.2, p =0.001), whereas white cases and controls had no significant difference in glaucoma operations (0.9 versus 0.6, p =0.139). Our analysis found that glaucoma surgery is associated with blindness in black patients (odds ratio [OR] 1.6, 95% CI 1.1-2.2) but not in white patients (OR 1.5, 95% CI 0.7-3.2). Black and white case-control pairs with POAG shared similar risk factors for blindness at presentation. However, over the follow-up period, black cases required significantly more glaucoma surgeries compared to black controls, whereas there was no significant difference in surgery between white cases and controls. There was no difference in medication changes in either case-control set.

Toxoplasma gondii seroprevalence and association with equine protozoal myeloencephalitis: A case-control study of Californian horses.

Science.gov (United States)

James, K E; Smith, W A; Packham, A E; Conrad, P A; Pusterla, N

2017-06-01

While toxoplasmosis is not commonly considered a clinical disease of equines, previous seroprevalence studies have reported differing background rates of Toxoplasma gondii infection in horses globally. The objective of this study was to evaluate possible associations between T. gondii seroprevalence and clinical signs of equine protozoal myeloencephalitis (EPM) in horses. Using a case-control study design, 720 Californian horses with neurologic signs compatible with EPM were compared to healthy, non-neurologic horses for the presence of T. gondii antibodies (using indirect fluorescent antibody tests [IFAT]). Toxoplasma gondii seroprevalence among cases and controls was determined at standard serum cut-offs: 40, 80, 160, 320, and 640. At a T. gondii titre cut-off of 320, horses with clinical signs compatible with EPM had 3.55 times the odds of a seropositive test compared to those without clinical signs (Pequines. Serologic testing of cerebrospinal fluid and isolation of T. gondii in EPM suspect cases should be considered. Future studies investigating the relationship between T. gondii and EPM are warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Individual external exposures from Nevada Test Site fallout for Utah leukemia cases and controls

International Nuclear Information System (INIS)

Lloyd, R.D.; Gren, D.C.; Simon, S.L.; Wrenn, M.E.; Hawthorne, H.A.; Lotz, T.M.; Stevens, W.; Till, J.E.

1990-01-01

External gamma-ray exposures from fallout originating at the Nevada Test Site (NTS) have been assigned to 6,507 individual subjects (1,177 leukemia cases and 5,330 control subjects) who died as Utah residents between 1952 and 1981. Leukemia cases were identified, confirmed, and classified by cell type from the Utah Cancer Registry, Utah State vital records, and medical records. Residential histories were obtained from the Deceased Membership File (DMF) of the Church of Jesus Christ of Latter-day Saints (LDS), supplemented by information from the LDS Church Census Records that were taken in 1950, 1955, and 1960-62. Control subjects were selected randomly within age strata from the DMF and were frequency-matched to the cases by age at death and for sex. Individual radiation exposures were assigned as a function of residence location and time interval for each residence during the fallout period (1951-1958) using geographic exposure data taken from the literature. Temporal distribution of exposure for subjects who resided in more than one locality or who were born or died during the fallout period was determined from data of other investigators. Calculated gamma-ray exposures for each place of residence were summed for each subject to yield the exposure to fallout from the NTS

A case-control study of risk factors for equine influenza spread onto horse premises during the 2007 epidemic in Australia.

Science.gov (United States)

Firestone, Simon M; Schemann, Kathrin A; Toribio, Jenny-Ann L M L; Ward, Michael P; Dhand, Navneet K

2011-06-01

The 2007 epidemic of equine influenza in Australia provided an opportunity to investigate the effectiveness of on-farm biosecurity measures in preventing the spread of a novel pathogen in a largely naive population. We conducted a case-control study of 200 horse premises from highly affected regions of the state of New South Wales (NSW), to investigate risk factors for the spread of equine influenza onto horse premises, specifically, non-compliance with biosecurity measures recommended to horse owners by the relevant animal health authority, the NSW Department of Primary Industries. The study was restricted to cases occurring during the first seven weeks of the epidemic, a period prior to vaccination and the relaxation of some movement restrictions. Case and control premises were selected from a laboratory testing dataset and interviews were conducted with horse owners and managers on premises between July and November 2009. The proximity of premises to the nearest infected premises was the factor most strongly associated with case status. Case premises were more likely than control premises to be within 5 km and beyond 10 km of an infected premises. Having a footbath in place on the premises before any horses were infected was associated with a nearly four-fold reduction in odds of infection (odds ratio=0.27; 95% confidence interval: 0.09, 0.83). This protective association may have reflected overall premises biosecurity standards related to the fomite transmission of equine influenza. Compliance with certain on-farm biosecurity practices seemingly prevented horses on premises in high risk areas being infected with equine influenza during the 2007 outbreak in Australia. In future outbreaks, in addition to broader disease control measures, on-farm biosecurity practices should be adopted by horse owners and managers to prevent equine influenza spread. Copyright © 2011 Elsevier B.V. All rights reserved.

Investigator's Guide to Missing Child Cases. For Law-Enforcement Officers Locating Missing Children. Second Edition.

Science.gov (United States)

Patterson, John C.

This booklet provides guidance to law enforcement officers investigating missing children cases, whether through parental kidnappings, abductions by strangers, runaway or "throwaway" cases, and those in which the circumstances are unknown. The guide describes, step-by-step, the investigative process required for each of the four types of missing…

Radon and Lung Cancer Case-Control Study in Middle Ural

International Nuclear Information System (INIS)

Kirdin, I.A.; Lezhnin, V.L.; Yarmoshenko, I.V.; Ekidin, A.

2001-01-01

Full text: The pilot phase of radon and lung cancer case-control study has been performed in Karpinsk and Pervouralsk towns of Middle Ural region of Russia. The case group consists of 341 persons with lung cancer and living in that towns at least five previous years. The lung cancer diagnoses were carefully verified by instrumental techniques and 70% of its were morphologically validated. The persons for the control group (448) were chosen from the population living in that towns at least five years taking into account the age and sex. The special epidemiological questionnaire was developed which includes the items by the groups of factors as follow: clinical data, social factors, chronic lung diseases, life habit, tobacco smoking, alcohol drinking, diet preference etc. The epidemiological questionnaires were fulfilled for each member of case and control groups. Radon gas concentration and thoron equilibrium equivalent concentration measurements had been performed using nuclear track detectors and grab sampling accordingly in the dwellings of case and control groups members. By preliminary estimation the odds ratios are 1, 0.91, 1.2, 1.1 in the ranges of radon and thoron equilibrium equivalent concentration 0-6, 3-13, 13-36 and 36-370 Bq/m 3 respectively. The deeper and more rigorous analysis as well as different independent approaches will be discussed in the paper.(author)

Tuberculosis and diabetes mellitus in the Republic of Kiribati: a case-control study.

Science.gov (United States)

Viney, K; Cavanaugh, J; Kienene, T; Harley, D; Kelly, P M; Sleigh, A; O'Connor, J; Mase, S

2015-05-01

To better inform local management of TB-diabetes collaborative activities, we aimed to determine the prevalence of diabetes among persons with and without TB and to determine the association between TB and diabetes in Kiribati, a Pacific Island nation. We compared consecutively enrolled TB cases to a group of randomly selected community controls without evidence of TB. Diabetes was diagnosed by HbA1c, and clinical and demographic data were collected. A tuberculin skin test was administered to controls. The chi-square test was used to assess significance in differences between cases and controls. We also calculated an odds ratio, with 95% confidence intervals, for the odds of diabetes among cases relative to controls. Unweighted multivariate logistic regression was performed to adjust for the effects of age and sex. A total of 275 TB cases and 499 controls were enrolled. The diabetes prevalence in cases (101, 37%) was significantly greater than in controls (94, 19%) (adjusted odds ratio: 2.8; 95% CI 2.0-4.1). Fifty-five percent (108) of all diabetic diagnoses were new; this proportion was higher among controls (64.8%) than cases (46.5%). Five patients with TB were screened to detect one patient with diabetes. There is a strong association between TB and diabetes in Kiribati and bidirectional screening should be conducted in this setting. © 2015 John Wiley & Sons Ltd.

Effect of anterior cervical osteophyte in poststroke dysphagia: a case-control study.

Science.gov (United States)

Kim, Youngkook; Park, Geun-Young; Seo, Yu Jung; Im, Sun

2015-07-01

To investigate whether the concomitant presence of anterior cervical osteophytes can influence the severity and outcome of patients with poststroke dysphagia. Retrospective case-control study. Hospital. A total of 40 participants were identified (N=40). Patients with poststroke dysphagia with anterior cervical osteophytes (n=20) were identified and matched by age, sex, location, and laterality of the stroke lesion to a poststroke dysphagia control group with no anterior cervical osteophytes (n=20). Not applicable. Videofluoroscopic swallowing study, Functional Oral Intake Scale (FOIS), and Penetration-Aspiration Scale results assessed within the first month of stroke were analyzed. The FOIS at 6 months was recorded, and severity of dysphagia was compared between the 2 groups. The case group had larger degrees of postswallow residues in the valleculae and pyriform sinuses (P=.020 and Pdysphagia (OR=15.375; 95% CI, 3.195-infinity). The presence of anterior cervical osteophytes, which may cause mechanical obstruction and interfere with residue clearance at the valleculae and pyriform sinuses and result in more postswallow aspiration, may influence initial severity and outcome of poststroke dysphagia. The presence of anterior cervical osteophytes may be considered an important clinical condition that may affect poststroke dysphagia rehabilitation. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Laryngeal sarcoidosis: a case-control study.

Science.gov (United States)

Duchemann, Boris; Lavolé, Armelle; Naccache, Jean-Marc; Nunes, Hilario; Benzakin, Sylvain; Lefevre, Marine; Kambouchner, Marianne; Périé, Sophie; Valeyre, Dominique; Cadranel, Jacques

2014-10-20

We undertook a study on a series of laryngeal sarcoidosis (LS), a very rare and often threatening localization to better specify laryngeal manifestations, sarcoidosis clinical expression and long-term follow-up. This was a retrospective case-control study. All LS patients from two French centers were included and compared to sarcoidosis patients without laryngeal localization with two controls for one patient. Twelve consecutive LS patients were recruited between 1993 and 2011. LS revealed sarcoidosis in eight cases (67%). The most common symptoms were hoarseness (77%), inspiratory dyspnea (38%) and dysphagia (38%). Epidemiological characterisics were not different. Extrapulmonary localizations were significantly more common in LS patients than in controls (92% vs. 54%, p=0.02), particularly lupus pernio (25% vs. 0%, p=0.03) and nasosinusal involvement (83% vs. 4%, p<0.01) while thoracic involvement was less frequent (58% vs 100%, p < 0.01). Treatment rates were higher in the LS group (92% vs. 58%, p=0.04), and treatment duration was longer (median: 81 vs. 13 months, p=0.04), with frequent long-term treatment (67%, N=8/12). Two patients underwent surgery. One patient needed temporary tracheostomy during the course of the disease; Remission rates were lower in LS patients (9% vs. 58% at 2 years p<0.01). Eventually, there was no death nor definitive tracheotomy. LS is a rare condition that is often associated to other loco-regional localizations. LS are often difficult to manage. Survival is good but may require a medico-surgical approach.

ALCOHOL CONSUMPTION WITH FAMILY PATTERN RELATED TO STRONG PERSONALITIES: A CASE-CONTROL STUDY IN MARRIED ROMANIAN STUDENTS.

Science.gov (United States)

Petrescu, Cristina

2016-01-01

In the study conducted the aim was to investigate strong personalities (SP) related to alcohol consumption in married students from Romania. Consisted in 2 samples: a case-sample (23 alcohol consumer students with a family pattern of weekly consumption, 47.8% male and 52.2% female, aged 21-29 years) and a control-sample (42 no-alcohol consumer students without a family pattern of consumption, 26.2% male and 73.8% female, aged 21-29 years), selected from a sample of 176 married students. An observational inquiry (case-control) consisted in applying 2 questionnaires: Health Questionnaire (60 items, 7: Q43-Q49 -alcohol consumption) and Strong Personalities Questionnaire (88 items, alpha-Crohnbach index-0.823). Statistical analysis was performed by the aid of SPSS 20 Program. For alcohol consumer students with weekly pattern of consumption the main reason of alcohol consumption was curiosity (60.9%) and the most frequent consumed alcohol was beer (38.6%, 500-3000 ml/week). Personalities' profiles revealed V-hyperthymic, III-hyperperseverant and X-emotive strong personalities (SP) as being symptomatic (over 50% symptomatic level-SL) for both samples, with a difference (control-case) for X-emotive SP (71.7% students--57.1% students, respectively). I-demonstrative, VII-cyclothymic and IV-unruly SP presented a difference between case (symptomatic: 61.8%; 61.8% and 61.8% students, respectively) and control (symptomatic: 36.8%; 37.5% and 45% students, respectively) samples. A statistically significant difference case-control samples was demonstrated for I-Demonstrative (item S29: chi square chi2 = 10.65; Sig.0.002; gamma correlation gamma=0.73; Sig.0.002) and for X-emotive (item S25: chi2 = 8.76; gamma = -0.66; Sig.0.003) SP. In conclusion, a relation SP-alcohol consumption in married students is suggested.

Looking for Celiac Disease in Italian Women with Endometriosis: A Case Control Study

Directory of Open Access Journals (Sweden)

Luca Santoro

2014-01-01

Full Text Available In the last years, a potential link between endometriosis and celiac disease has been hypothesized since these disorders share some similarities, specifically concerning a potential role of oxidative stress, inflammation, and immunological dysfunctions. We investigated the prevalence of celiac disease among Italian women with endometriosis with respect to general population. Consecutive women with a laparoscopic and histological confirmed diagnosis of endometriosis were enrolled; female nurses of our institution, without a known history of endometriosis, were enrolled as controls. IgA endomysial and tissue transglutaminase antibodies measurement and serum total IgA dosage were performed in both groups. An upper digestive endoscopy with an intestinal biopsy was performed in case of antibodies positivity. Presence of infertility, miscarriage, coexistence of other autoimmune diseases, and family history of autoimmune diseases was also investigated in all subjects. Celiac disease was diagnosed in 5 of 223 women with endometriosis and in 2 of 246 controls (2.2% versus 0.8%; P=0.265. Patients with endometriosis showed a largely higher rate of infertility compared to control group (27.4% versus 2.4%; P<0.001. Our results confirm that also in Italian population an increased prevalence of celiac disease among patients with endometriosis is found, although this trend does not reach the statistical significance.

Maximum likelihood estimation for Cox's regression model under nested case-control sampling

DEFF Research Database (Denmark)

Scheike, Thomas Harder; Juul, Anders

2004-01-01

-like growth factor I was associated with ischemic heart disease. The study was based on a population of 3784 Danes and 231 cases of ischemic heart disease where controls were matched on age and gender. We illustrate the use of the MLE for these data and show how the maximum likelihood framework can be used......Nested case-control sampling is designed to reduce the costs of large cohort studies. It is important to estimate the parameters of interest as efficiently as possible. We present a new maximum likelihood estimator (MLE) for nested case-control sampling in the context of Cox's proportional hazards...... model. The MLE is computed by the EM-algorithm, which is easy to implement in the proportional hazards setting. Standard errors are estimated by a numerical profile likelihood approach based on EM aided differentiation. The work was motivated by a nested case-control study that hypothesized that insulin...

Risk factors for acute asthma in tropical America: a case-control study in the City of Esmeraldas, Ecuador.

Science.gov (United States)

Ardura-Garcia, Cristina; Vaca, Maritza; Oviedo, Gisela; Sandoval, Carlos; Workman, Lisa; Schuyler, Alexander J; Perzanowski, Matthew S; Platts-Mills, Thomas A E; Cooper, Philip J

2015-08-01

Despite the high asthma rates described in Latin America, asthma risk factors in poor urban settings are not well established. We investigated risk factors for acute asthma among Ecuadorian children. A matched case-control study was carried out in a public hospital serving a coastal city. Children with acute asthma were age- and sex-matched to non-asthmatics. A questionnaire was administered, and blood, as well as stool, and nasopharyngeal swabs were collected. Sixty cases and 119 controls aged 5-15 were evaluated. High proportions of cases were atopic with population-attributable fractions for atopy of 68.5% for sIgE and 57.2% for SPT. Acute asthma risk increased with greater titers of mite IgE (3.51-50 kU/l vs. 50kU/l vs. Asthma risk was significantly independently associated with bronchiolitis (adj. OR: 38.9, 95% CI 3.26-465), parental educational level (adj. OR 1.26, 95% CI: 1.08-1.46), and presence of sIgE (adj. OR: 36.7, 95% CI: 4.00-337), while a reduced risk was associated with current contact with pets (adj. OR: 0.07, 95% CI: 0.01-0.56). Rhinovirus infection was more frequent in cases (cases 35.6% vs. controls 7.8%, p = 0.002). None of the cases were on maintenance therapy with inhaled corticosteroids and most relied on emergency department for control. A high proportion of children presenting to a public hospital with acute asthma were allergic to mite, particularly at high IgE titer. Poor asthma control resulted in overuse of emergency care. © 2015 The Authors. Pediatric Allergy and Immunology Published by John Wiley & Sons Ltd.

ICOS gene polymorphisms are associated with sporadic breast cancer: a case-control study

International Nuclear Information System (INIS)

Xu, Fengyan; Li, Dalin; Zhang, Qiujin; Fu, Zhenkun; Zhang, Jie; Yuan, Weiguang; Chen, Shuang; Pang, Da; Li, Dianjun

2011-01-01

Inducible costimulator (ICOS), a costimulatory molecular of the CD28 family, provides positive signal to enhance T cell proliferation. Its abnormal expression can disturb the immune response and entail an increased risk of cancer. To investigate whether single nucleotide polymorphisms (SNPs) in the ICOS gene are associated with sporadic breast cancer susceptibility and progression in Chinese women, a case-control study was conducted. In the study cohort, we genotyped five SNPs (rs11889031, rs10932029, rs4675374, rs10183087 and rs10932037) in ICOS gene among 609 breast cancer patients and 665 age-matched healthy controls. Furthermore, the positive results were replicated in an independent validation cohort of 619 patients and 682 age-matched healthy controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotypes. In rs10932029, compared with TT genotype and T allele, the CT genotype and C allele showed a significantly increased risk of breast cancer (P = 0.030, OR = 1.467, 95% CI 1.037-2.077; P = 0.017, OR = 1.481, 95% CI 1.070-2.049, respectively), and the associations were also significant in the validation cohort (P = 0.002, OR = 1.693, 95% CI 1.211-2.357; P = 0.003, OR = 1.607, 95% CI 1.171-2.204, respectively). Haplotype analysis showed that CTCAC haplotype containing rs10932029 T allele had a lower frequency in cases than in controls (P = 0.015), whereas haplotype CCCAC containing rs10932029 C allele was more common in cases than in controls (P = 0.013). In the analysis of clinicopathologic features, rs11889031 CT genotype and T allele were associated with progesterone receptor (PR) status and lymph node metastasis, which were further supported by our validation cohort. Moreover, some haplotypes were associated with estrogen receptor (ER) and PR statuses. These results indicate that ICOS gene polymorphisms may affect the risk of breast cancer and show that some SNPs are associated with breast cancer

Investigation of Genetic Disturbances in Oxygen Sensing and Erythropoietin Signaling Pathways in Cases of Idiopathic Erythrocytosis

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Carla Luana Dinardo

2013-01-01

Full Text Available Background. Idiopathic erythrocytosis is the term reserved for cases with unexplained origins of abnormally increased hemoglobin after initial investigation. Extensive molecular investigation of genes associated with oxygen sensing and erythropoietin signaling pathways, in those cases, usually involves sequencing all of their exons and it may be time consuming. Aim. To perform a strategy for molecular investigation of patients with idiopathic erythrocytosis regarding oxygen sensing and erythropoietin signaling pathways. Methods. Samples of patients with idiopathic erythrocytosis were evaluated for the EPOR, VHL, PHD2, and HIF-2α genes using bidirectional sequencing of their hotspots. Results. One case was associated with HIF-2α mutation. Sequencing did not identify any pathogenic mutation in 4 of 5 cases studied in any of the studied genes. Three known nonpathogenic polymorphisms were found (VHL p.P25L, rs35460768; HIF-2α p.N636N, rs35606117; HIF-2α p.P579P, rs184760160. Conclusion. Extensive molecular investigation of cases considered as idiopathic erythrocytosis does not frequently change the treatment of the patient. However, we propose a complementary molecular investigation of those cases comprising genes associated with erythrocytosis phenotype to meet both academic and genetic counseling purposes.

Salivary and microbiological parameters of chronic periodontitis subjects with and without type 2 diabetes mellitus: a case-control study

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José Roberto CORTELLI

Full Text Available Background: Several studies have investigated the differences in salivary parameters and microbial composition between diabetic and non-diabetic patients, however, specific differences are still not clear mainly due to the effects of confounder. Aim: The aim of this case-control study was to evaluate the salivary and microbial parameters of chronic periodontitis subjects with and without type 2 diabetes mellitus. Material and method: This case-control study included 60 chronic periodontitis subjects, 30 diabetics (case group and 30 non-diabetics (control group, paired according to periodontitis severity, gender and age. Stimulated whole saliva was collected from all volunteers to measure the salivary pH and the salivary flow rate. Bacterial samples were collected with paper points from periodontal sites showing the deepest periodontal pocket depth associated with the highest clinical attachment loss. The frequency of A. actinomycetemcomitans, P. intermedia, P. gingivalis, T. forsythia and C. rectus was evaluated by PCR. Data was statistically analyzed by Student's t, Mann-Whitney and Chi-square (p<0.05. Result: Diabetic subjects showed higher salivary glucose levels and lower stimulated flow rates in comparison to non-diabetic controls. P. gingivalis and T. forsythia were the most frequent pathogens (p<0.05. Bacterial frequency did not differ between case and control groups. Conclusion: Diabetes status influenced salivary glucose levels and flow rate. Within the same severity of chronic periodontitis, diabetic subjects did not show higher frequency of periodontal pathogens in comparison to their paired controls.

Risk Factors for Campylobacteriosis of Chicken, Ruminant, and Environmental Origin: A Combined Case-Control and Source Attribution Analysis

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Wagenaar, Jaap A.; de Boer, Albert G.; Havelaar, Arie H.; Friesema, Ingrid H. M.; French, Nigel P.; Busani, Luca; van Pelt, Wilfrid

2012-01-01

Background Campylobacteriosis contributes strongly to the disease burden of food-borne pathogens. Case-control studies are limited in attributing human infections to the different reservoirs because they can only trace back to the points of exposure, which may not point to the original reservoirs because of cross-contamination. Human Campylobacter infections can be attributed to specific reservoirs by estimating the extent of subtype sharing between strains from humans and reservoirs using multilocus sequence typing (MLST). Methodology/Principal Findings We investigated risk factors for human campylobacteriosis caused by Campylobacter strains attributed to different reservoirs. Sequence types (STs) were determined for 696 C. jejuni and 41 C. coli strains from endemic human cases included in a case-control study. The asymmetric island model, a population genetics approach for modeling Campylobacter evolution and transmission, attributed these cases to four putative animal reservoirs (chicken, cattle, sheep, pig) and to the environment (water, sand, wild birds) considered as a proxy for other unidentified reservoirs. Most cases were attributed to chicken (66%) and cattle (21%), identified as the main reservoirs in The Netherlands. Consuming chicken was a risk factor for campylobacteriosis caused by chicken-associated STs, whereas consuming beef and pork were protective. Risk factors for campylobacteriosis caused by ruminant-associated STs were contact with animals, barbecuing in non-urban areas, consumption of tripe, and never/seldom chicken consumption. Consuming game and swimming in a domestic swimming pool during springtime were risk factors for campylobacteriosis caused by environment-associated STs. Infections with chicken- and ruminant-associated STs were only partially explained by food-borne transmission; direct contact and environmental pathways were also important. Conclusion/Significance This is the first case-control study in which risk factors for

Risk factors for campylobacteriosis of chicken, ruminant, and environmental origin: a combined case-control and source attribution analysis.

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Lapo Mughini Gras

Full Text Available BACKGROUND: Campylobacteriosis contributes strongly to the disease burden of food-borne pathogens. Case-control studies are limited in attributing human infections to the different reservoirs because they can only trace back to the points of exposure, which may not point to the original reservoirs because of cross-contamination. Human Campylobacter infections can be attributed to specific reservoirs by estimating the extent of subtype sharing between strains from humans and reservoirs using multilocus sequence typing (MLST. METHODOLOGY/PRINCIPAL FINDINGS: We investigated risk factors for human campylobacteriosis caused by Campylobacter strains attributed to different reservoirs. Sequence types (STs were determined for 696 C. jejuni and 41 C. coli strains from endemic human cases included in a case-control study. The asymmetric island model, a population genetics approach for modeling Campylobacter evolution and transmission, attributed these cases to four putative animal reservoirs (chicken, cattle, sheep, pig and to the environment (water, sand, wild birds considered as a proxy for other unidentified reservoirs. Most cases were attributed to chicken (66% and cattle (21%, identified as the main reservoirs in The Netherlands. Consuming chicken was a risk factor for campylobacteriosis caused by chicken-associated STs, whereas consuming beef and pork were protective. Risk factors for campylobacteriosis caused by ruminant-associated STs were contact with animals, barbecuing in non-urban areas, consumption of tripe, and never/seldom chicken consumption. Consuming game and swimming in a domestic swimming pool during springtime were risk factors for campylobacteriosis caused by environment-associated STs. Infections with chicken- and ruminant-associated STs were only partially explained by food-borne transmission; direct contact and environmental pathways were also important. CONCLUSION/SIGNIFICANCE: This is the first case-control study in which risk

Dietary patterns, goitrogenic food, and thyroid cancer: a case-control study in French Polynesia.

Science.gov (United States)

Cléro, Énora; Doyon, Françoise; Chungue, Vaïana; Rachédi, Frédérique; Boissin, Jean-Louis; Sebbag, Joseph; Shan, Larrys; Rubino, Carole; de Vathaire, Florent

2012-01-01

French Polynesia has one of the world's highest thyroid cancer incidence rates. A case-control study among native residents of French Polynesia included 229 cases of differentiated thyroid cancer diagnosed between 1979 and 2004, and 371 population controls. Dietary patterns and goitrogenic food consumption (cabbage, cassava) were analyzed. We used a factor analysis to identify dietary patterns and a conditional logistic regression analysis to investigate the association between dietary patterns or food items and thyroid cancer risk. Two distinct dietary patterns were identified: traditional Polynesian and Western. A nonsignificant inverse association was observed between the traditional Polynesian dietary pattern and thyroid cancer risk. The Western pattern was not associated with thyroid cancer risk. Cassava consumption was significantly associated with a decreased risk of thyroid cancer. In conclusion, a traditional Polynesian dietary pattern led to a weak reduced risk of thyroid cancer in French Polynesia. The protective effect of cassava on this cancer does not seem to be substantially different from that of cabbage, which was the main goitrogenic food studied to date.

Risk of tinnitus in patients with sleep apnea: A nationwide, population-based, case-control study.

Science.gov (United States)

Koo, Malcolm; Hwang, Juen-Haur

2017-09-01

To investigate the risk of tinnitus in patients with sleep disturbance or sleep apnea. Case control study. We identified 21,798 middle-aged and elderly patients with otolaryngologist-diagnosed tinnitus between January 1, 2000, and December 31, 2012, from the Longitudinal Health Insurance Database 2000 of the Taiwan National Health Insurance Research Database. A total of 108,990 controls were also identified from the same database based on frequency-matching on 10-year age interval, sex, and year of index date of the cases. Diagnoses of sleep disturbance (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] codes 780.50, 780.52, 307.4) and sleep apnea (ICD-9-CM codes 780.51, 780.53, 780.57) in the cases and controls prior to the index date were assessed. The risks of tinnitus in patients with sleep disturbance and sleep apnea were separately evaluated with multivariate logistic regression analyses. The mean age of the total 130,788 patients was 59.8 years, and 47% of them were males. The risk of tinnitus was higher in patients with sleep disturbance compared to those without the condition (adjusted odds ratio [OR] = 1.13, 95% confidence interval [CI] [95% CI] = 1.11-1.17), and the risk of tinnitus was higher in patients with sleep apnea compared to those without the condition (adjusted OR = 1.36, 95% CI = 1.16-1.60). In this population-based, case-control study, the risk of tinnitus was found to be significantly higher among middle-aged and elderly Taiwanese patients with sleep disturbances, especially with sleep apnea. 3b. Laryngoscope, 127:2171-2175, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

A case-control study on the association of hepatitis B virus infection and hepatocellular carcinoma in Northeast Brazil

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Cotrim Helma

1992-01-01

Full Text Available Hepatitis B virus (HBV serological markers were investigated in 40 incident cases of hepatocellular carcinoma (HCC and in two age and sex matched control groups, comprising 40 patients with other cancers and 80 healthy individuals, resident in Bahia, Brazil. Serologic tests were done by radioimmunoassay. The study observed high proportion of seropositivity to HBsAg (42.5% and of those presenting HBsAg or antiHBc (65.0% among HCC cases, higher in men than women and in those aged 17 to 30 years old. HBsAg seropositivity among HCC patients was greater than in the control group with other cancers (7.5% and in healthy controls (2.5%, corresponding to odds ratio estimates of 15.0 (95% CI 3.29, 68.30 and 33.0 (95% CI 9.13, 119.28, both statistically significant. HBeAg was not observed and antiHBe was present in 41.2% of cases, suggesting the absence of viral replication, possibly with viral DNA intergration into the hepatocyte genome. The presence of cirrhosis was associated with HBsAg seropositivity among HCC cases. A history of chronic alcoholism is shown to be more frequently related to those cases with cirrhosis. This study highlights the relevant association between HCC and HBV in Northeast Brazil, particularly for young individuals, and the high risk of development of HCC for HBsAg carriers.

Association between renal cysts and abdominal aortic aneurysm: A case-control study

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Hélio Miguel de Azevêdo Bião Veiga

Full Text Available Summary Objective: To investigate the positive association between the presence of simple renal cysts (SRCs and abdominal aortic aneurysm (AAA. Method: In a retrospective case-control study including subjects aged > 50 years, we evaluated the incidence of SRCs on computed tomography (CT scan. We compared 91 consecutive patients with AAA referred from the Division of Vascular Surgery and 396 patients without AAA, randomly selected after being matched by age and gender from 3,186 consecutive patients who underwent abdominal CT. SRC was defined as a round or oval low-attenuation lesion with a thin wall and size > 4 mm on CT without obvious evidence of radiographic enhancement or septations. Patients were considered as having AAA if the size of aorta was greater than 3.0 cm. Results: Patients with AAA and without AAA were similar in terms of age (67.9± 8.41 vs. 68.5±9.13 years (p=0.889 and gender (71.4 vs. 71.2% of male subjects, respectively (p=0.999. There was no difference in the prevalence of SRC between case and controls. Among individuals with AAA, 38 (41.8%; [95CI 32.5-52.6] had renal cysts compared to 148 (37.4%; [95CI 32.7-42.2] in the control group (p=0.473, with a prevalence ratio (PR of 1.16 (95CI 0.80-1.68. Conclusion: We found no significant differences in the prevalence of SRCs among patients with AAA and controls. Our findings suggest that the presence of SRCs is not a risk factor or a marker for AAA.

Obstacles to action in arthritis: a community case-control study.

Science.gov (United States)

Hutton, Ingrid; Gamble, Greg; McLean, Grant; Butcher, Hugh; Gow, Peter; Dalbeth, Nicola

2009-07-01

Despite the benefits of physical activity, people with arthritis are less active than the general population. The aim of this study was to determine the motivators and obstacles to physical activity for adults with arthritis. Participants were identified from the Obstacles to Action Study, a community based study of 8163 adults, which explored barriers and motivators to physical activity. A 1:1 case-control study was designed; cases were identified as those participants who reported arthritis (n = 1106). Each case was matched with an age, sex and ethnicity-matched non-arthritis control (n = 1106). Cases were less likely to achieve recommended physical activity targets (58.8% vs. 68.1% P = 0.00001). Furthermore, fewer people with arthritis believed that physical activity would help them lead healthy lives (86.7% vs. 91.3% P = 0.006) or viewed physical activity as a priority (53.8% vs. 59.8% P = 0.005). Cases were less confident in their abilities to try a new activity (37.1% vs. 43.7% P = 0.002) or maintain a healthy weight (65.0% vs. 74.3% P = 0.00001). Cases also reported greater negative impact scores for barriers to activity, particularly arthritis, accessibility, cost and discomfort while exercising. Motivators and environmental barriers to activity were similar for cases and controls. These findings persisted after adjusting for educational level, body mass index and comorbidities. People with arthritis are less active and demonstrate different attitudes toward physical activity. Although people with arthritis identify similar environmental barriers, they have different psychosocial barriers. In order to design effective physical activity programs for people with arthritis, these barriers must be specifically addressed.

Night shift work and chronic lymphocytic leukemia in the MCC-Spain case-control study.

Science.gov (United States)

Costas, Laura; Benavente, Yolanda; Olmedo-Requena, Rocío; Casabonne, Delphine; Robles, Claudia; Gonzalez-Barca, Eva-Maria; de la Banda, Esmeralda; Alonso, Esther; Aymerich, Marta; Tardón, Adonina; Marcos-Gragera, Rafael; Gimeno-Vázquez, Eva; Gómez-Acebo, Inés; Papantoniou, Kyriaki; Castaño-Vinyals, Gemma; Aragonés, Nuria; Pollán, Marina; Kogevinas, Manolis; de Sanjosé, Silvia

2016-11-01

Chronic lymphocytic leukemia (CLL) has few known modifiable risk factors. Recently, circadian disruption has been proposed as a potential contributor to lymphoid neoplasms' etiology. Serum melatonin levels have been found to be significantly lower in CLL subjects compared with healthy controls, and also, CLL prognosis has been related to alterations in the circadian molecular signaling. We performed the first investigation of an association between night shift work and CLL in 321 incident CLL cases and 1728 population-based controls in five areas of Spain. Participants were interviewed face-to-face by trained interviewers to collect information on sociodemographic factors, familial, medical and occupational history, including work shifts and other lifestyle factors. We used logistic regression models adjusted for potential confounders to estimate odds ratios (OR) and 95% confidence intervals (CI). Seventy-nine cases (25%) and 339 controls (20%) had performed night work. Overall, working in night shifts was not associated with CLL (OR = 1.06; 95% CI = 0.78-1.45, compared with day work). However, long-term night shift (>20 years) was positively associated with CLL (OR(tertile 3 vs . day-work)  = 1.77; 95% = 1.14-2.74), although no linear trend was observed (P trend = 0.18). This association was observed among those with rotating (OR(tertile 3 vs . day-work)  = 2.29; 95% CI = 1.33-3.92; P trend = 0.07), but not permanent night shifts (OR(tertile 3 vs . day-work) = 1.16; 95% CI = 0.60-2.25; P trend = 0.86). The association between CLL and long-term rotating night shift warrants further investigation. © 2016 UICC.

Maximum likelihood estimation for Cox's regression model under nested case-control sampling

DEFF Research Database (Denmark)

Scheike, Thomas; Juul, Anders

2004-01-01

Nested case-control sampling is designed to reduce the costs of large cohort studies. It is important to estimate the parameters of interest as efficiently as possible. We present a new maximum likelihood estimator (MLE) for nested case-control sampling in the context of Cox's proportional hazard...

Hygiene behaviour and hospitalized severe childhood diarrhoea: a case-control study.

Science.gov (United States)

Baltazar, J C; Tiglao, T V; Tempongko, S B

1993-01-01

The relationship between personal and domestic hygiene behaviour and hospitalized childhood diarrhoea was examined in a case-control study of 356 cases and 357 controls from low-income families in metropolitan Manila. Indices of hygiene behaviour were defined for overall cleanliness, kitchen hygiene, and living conditions. Only the indices for overall cleanliness and kitchen hygiene were significantly associated with diarrhoea. An increasing excess risk of hospitalization with severe diarrhoea was noted as the ratings for standards of hygiene became lower, and this excess risk persisted even after controlling for confounding variables. The implications of our findings for the control of diarrhoeal disease are discussed.

Prolonged outbreak of Serratia marcescens in Tartu University Hospital: a case-control study.

Science.gov (United States)

Adamson, Vivika; Mitt, Piret; Pisarev, Heti; Metsvaht, Tuuli; Telling, Kaidi; Naaber, Paul; Maimets, Matti

2012-10-31

The aim of our study was to investigate and control an outbreak and identify risk factors for colonization and infection with Serratia marcescens in two departments in Tartu University Hospital. The retrospective case-control study was conducted from July 2005 to December 2006. Molecular typing by pulsed field gel electrophoresis was used to confirm the relatedness of Serratia marcescens strains. Samples from the environment and from the hands of personnel were cultured. The outbreak involved 210 patients, 61 (29%) developed an infection, among them 16 were invasive infections. Multivariate analysis identified gestational age, arterial catheter use and antibiotic treatment as independent risk factors for colonization and infection with Serratia marcescens. Molecular typing was performed on 83 Serratia marcescens strains, 81 of them were identical and 2 strains were different. Given the occasionally severe consequences of Serratia marcescens in infants, early implementation of aggressive infection control measures involving patients and mothers as well as the personnel is of utmost importance.

Root-cause Investigation for No Setback Initiation at Liquid Zone Control Unit Perturbation in CANDU6 Reactor

Energy Technology Data Exchange (ETDEWEB)

Park, Donghwan; Kim, Youngae; Kim, Sungmin [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Liquid zone control system (LZCS) is one of the indigenous systems in CANDU type reactor for reactor reactivity control. The LZCS is filled with light water and used to provide a continuous fine control of the reactivity and the reactor power level. This system is also designed to accomplish spatial control of the power distribution, automatically, which prevents xenon induced power oscillations. As the tilt control term is phased out, it is replaced by a level control term, which tends to drive the individual zone levels towards the average level of all the zones. Most of CANDU reactors have been experienced these events. Generally setback or stepback conditions are on when variables of spatial control off, high zone power, etc. are reached to the initiating conditions before ROP trip. But the condition of setback or stepback is not initiated before ROP trip sometime. In this study the root-causes for this event are investigated, and the impact assessment is performed by physics computational modeling. To investigate the root-cause of ROP trip before initiating setback at abnormal operating condition, some LZC perturbation models were simulated and investigated the neutron flux readings of zone detector and ROP detector. Two root-causes were founded. The first, flux variation by water level change is more gradual than other zones due to design characteristics in zone 03. The second, ROP detector (SDS no. 2 3G) in the near zone 03 is very sensitive below 40% of water level due to ROP detector installed position. Even though setback is initiated earlier than ROP trip in case of zone 03 perturbation, ROP trip will be occurred because power decreasing rate is very slow(0.1%/sec) on setback condition.

Effectiveness of oral polio vaccination against paralytic poliomyelitis: a matched case-control study in Somalia.

Science.gov (United States)

Mahamud, Abdirahman; Kamadjeu, Raoul; Webeck, Jenna; Mbaeyi, Chukwuma; Baranyikwa, Marie Therese; Birungi, Julianne; Nurbile, Yassin; Ehrhardt, Derek; Shukla, Hemant; Chatterjee, Anirban; Mulugeta, Abraham

2014-11-01

After the last case of type 1 wild poliovirus (WPV1) was reported in 2007, Somalia experienced another outbreak of WPV1 (189 cases) in 2013. We conducted a retrospective, matched case-control study to evaluate the vaccine effectiveness (VE) of oral polio vaccine (OPV). We retrieved information from the Somalia Surveillance Database. A case was defined as any case of acute flaccid paralysis (AFP) with virological confirmation of WPV1. We selected two groups of controls for each case: non-polio AFP cases ("NPAFP controls") matched to WPV1 cases by age, date of onset of paralysis and region; and asymptomatic "neighborhood controls," matched by age. Using conditional logistic regression, we estimated the VE of OPV as (1-odds ratio)×100. We matched 99 WPV cases with 99 NPAFP controls and 134 WPV1 cases with 268 neighborhood controls. Using NPAFP controls, the overall VE was 70% (95% confidence interval [CI], 37-86), 59% (2-83) among 1-3 dose recipients, 77% (95% CI, 46-91) among ≥4 dose recipients. In neighborhood controls, the overall VE was 95% (95% CI, 84-98), 92% (72-98) among 1-3 dose recipients, and 97% (89-99) among ≥4 dose recipients. When the analysis was limited to cases and controls ≤24 months old, the overall VE in NPAFP and neighborhood controls was 95% (95% CI, 65-99) and 97% (95% CI, 76-100), respectively. Among individuals who were fully vaccinated with OPV, vaccination was effective at preventing WPV1 in Somalia. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Predictors and outcomes of superior mesenteric artery syndrome in patients with constipation: a prospective, nested case-control study.

Science.gov (United States)

Xu, Lin; Yu, Wen-Kui; Lin, Zhi-Liang; Jiang, Jun; Feng, Xiao-Bo; Li, Ning

2014-10-01

Superior mesenteric artery (SMA) syndrome may occur in patients with constipation, whereas the association between these two distinct diseases has not been confirmed yet. We investigated the incidence, risk factors and treatment strategy associated with SMA syndrome in constipated patients. We conducted a prospective nested case-control study from a 9-year hospitalization cohort (n=973). Cases were matched to controls 1:4 on factors of age and gender. Cases developed SMA syndrome in long term follow-up (n=26) and controls did not (n=104). Independent risk factors were identified by using univariate analysis and conditional logistic regression analysis. Enteral nutritional support was applied in all cases and its curative effect was evaluated by retrospective analysis. The incidence of SMA syndrome was 2.67%. The risk factors under scrutiny were body mass index (BMI)≤18 (odds ratio (OR) 2.89, 95% CI 1.14 to 9.31) and abnormal colon transit time (OR 3.57, 95% CI 1.36 to 9.35). Twenty-two patients recovered after treatment of nutritional support, and the success rate of conservative treatment was 84.6%. BMI≤18 and prolonged colon transit time both were risk factors associated with SMA syndrome in constipated patients. Enteral nutritional support should be adopted as the first-line treatment for this condition.

Selection of controls in case-control studies on maternal medication use and risk of birth defects

NARCIS (Netherlands)

Bakker, M.K.; de Walle, H.E.; Dequito, A.; van den Berg, P.B.; de Jong-van den Berg, L.T.

BACKGROUND:: In case-control studies on teratogenic risks of maternal drug use during pregnancy, the use of normal or malformed controls may lead to recall-bias or selection bias. This can be avoided by using controls with a genetic disorder. However, researchers are hesitant to use these as

Knee movement patterns of injured and uninjured adolescent basketball players when landing from a jump: a case-control study.

Science.gov (United States)

Louw, Quinette; Grimmer, Karen; Vaughan, Christopher

2006-03-07

A common knee injury mechanism sustained during basketball is landing badly from a jump. Landing is a complex task and requires good coordination, dynamic muscle control and flexibility. For adolescents whose coordination and motor control has not fully matured, landing badly from a jump can present a significant risk for injury. There is currently limited biomechanical information regarding the lower limb kinetics of adolescents when jumping, specifically regarding jump kinematics comparing injured with uninjured adolescents. This study reports on an investigation of biomechanical differences in landing patterns of uninjured and injured adolescent basketball players. A matched case-control study design was employed. Twenty-two basketball players aged 14-16 years participated in the study: eleven previously knee-injured and eleven uninjured players matched with cases for age, gender, weight, height and years of play, and playing for the same club. Six high-speed, three-dimensional Vicon 370 cameras (120 Hz), Vicon biomechanical software and SAS Version 8 software were employed to analyse landing patterns when subjects performed a "jump shot". Linear correlations determined functional relationships between the biomechanical performance of lower limb joints, and paired t-tests determined differences between the normalised peak biomechanical parameters. The average peak vertical ground reaction forces between the cases and controls were similar. The average peak ground reaction forces between the cases and controls were moderately correlated (r = -0.47). The control (uninjured) players had significantly greater hip and knee flexion angles and significantly greater eccentric activity on landing than the uninjured cases (p jump, at different ages and physical developmental stages, would assist clinicians and coaches to identify players with inappropriate knee performance comparable to their age or developmental stage.

An Outbreak of Vancomycin-Resistant Enterococcus faecium in an Acute Care Pediatric Hospital: Lessons from Environmental Screening and a Case-Control Study

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Steven J Drews

2008-01-01

Full Text Available BACKGROUND: The present study describes a vancomycin-resistant enterococci (VRE outbreak investigation and a case-control study to identify risk factors for VRE acquisition in a tertiary care pediatric hospital.

Internal audit: the expert in providing comfort to the audit committee. The case of risk management and internal control

OpenAIRE

G. SARENS; I. DE BEELDE

2006-01-01

This study investigates to what extent audit committees feel uncomfortable about risk management and internal control, and focuses on how internal audit can be the expert in providing comfort in these areas, building upon the sociology of professions literature. Four case studies reveal that audit committees need comfort with respect to the control environment. Thanks to their internal position, their familiarity with the company, and their position close to people across the company, interna...

White rice consumption and risk of esophageal cancer in Xinjiang Uyghur Autonomous Region, northwest China: a case-control study

OpenAIRE

Tang, Li; Xu, Fenglian; Zhang, Taotao; Lei, Jun; Binns, Colin W.; Lee, Andy H.

2015-01-01

This study investigated the association between white rice consumption and the risk of esophageal cancer in remote northwest China, where the cancer incidence is known to be high. A case-control study was conducted during 2008?2009 in Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China. Participants were 359 incident esophageal cancer patients and 380 hospital-based controls. Information on habitual white rice consumption was obtained by personal interview using a validated semi-qu...

[Application of nested case-control study on safe evaluation of post-marketing traditional Chinese medicine injection].

Science.gov (United States)

Xiao, Ying; Zhao, Yubin; Xie, Yanming

2011-10-01

The nested case-control study design (or the case-control in a cohort study) is described here as a new study design used in safe evaluation of post-marketing traditional Chinese medicine injection. In the nested case-control study, cases of a disease that occur in a defined cohort are identified and, for each, a specified number of matched controls is selected from among those in the cohort who have not developed the disease by the time of disease occurrence in the case. For many research questions, the nested case-control design potentially offers impressive reductions in costs and efforts of data collection and analysis compared with the full cohort approach, with relatively minor loss in statistical efficiency. The nested case-control design is particularly advantageous for studies in safe evaluation of post-marketing traditional Chinese medicine injection. Some examples of the application of nested case-control study were given.

Risk factors for neural tube defects in Riyadh City, Saudi Arabia: Case-control study.

Science.gov (United States)

Salih, Mustafa A M; Murshid, Waleed R; Mohamed, Ashry Gad; Ignacio, Lena C; de Jesus, Julie E; Baabbad, Rubana; El Bushra, Hassan M

2014-01-01

Both genetic and non-genetic environmental factors are involved in the etiology of neural tube defects (NTD) which affect 0.5-2/1000 pregnancies worldwide. This study aimed to explore the risk factors for the development of NTD in Saudi population, and highlight identifiable and preventable causes. Similar studies are scarce in similar populations ofthe Arabian Peninsula and North Africa. This is an unmatched concurrent case-control study including NTD cases born at King Khalid University Hospital, Riyadh during a 4-year period (2002-2006). The case-control study included 25 cases and 125 controls (case: control ratio of 1:5). Years of formal education, employment, household environment (including availability of air conditioning) and rate of parental consanguinity did not differ between mothers of cases and controls. Significantly higher proportion of mothers of cases had history of stillbirth compared to control mothers (16% vs 4.1%, P=0.02). Also family history of hydrocephalus and congenital anomalies were more prevalent in cases than controls (P values=0.0000 and 0.003, respectively). There was significant protective effect of periconceptional folic acid consumption both prior to conception (OR 0.02, 95% CI 0.00-0.07) and during the first 6 weeks of conception (OR 0.13, 95% CI 0.04-0.39). Further research, including a larger cohort, is required to enable ascertainment of gene-nutrient and gene environment interactions associated with NTD in Saudi Arabia.

The lack of selection bias in a snowball sampled case-control study on drug abuse.

Science.gov (United States)

Lopes, C S; Rodrigues, L C; Sichieri, R

1996-12-01

Friend controls in matched case-control studies can be a potential source of bias based on the assumption that friends are more likely to share exposure factors. This study evaluates the role of selection bias in a case-control study that used the snowball sampling method based on friendship for the selection of cases and controls. The cases selected fro the study were drug abusers located in the community. Exposure was defined by the presence of at least one psychiatric diagnosis. Psychiatric and drug abuse/dependence diagnoses were made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. Cases and controls were matched on sex, age and friendship. The measurement of selection bias was made through the comparison of the proportion of exposed controls selected by exposed cases (p1) with the proportion of exposed controls selected by unexposed cases (p2). If p1 = p2 then, selection bias should not occur. The observed distribution of the 185 matched pairs having at least one psychiatric disorder showed a p1 value of 0.52 and a p2 value of 0.51, indicating no selection bias in this study. Our findings support the idea that the use of friend controls can produce a valid basis for a case-control study.

Case-control study of genetic and environmental influences on premature death of adult adoptees.

Science.gov (United States)

Petersen, Liselotte; Nielsen, Gert G; Andersen, Per Kragh; Sørensen, Thorkild I A

2002-08-01

Genetic and environmental influence on risk of premature death in adulthood was investigated by estimating the associations in total and cause-specific mortality of adult Danish adoptees and their biological and adoptive parents. Among all 14,427 nonfamilial adoptions formally granted in Denmark during the period 1923 through 1947, we identified 976 case families in which the adoptee died before a fixed date. As control families, we selected 976 families where the adoptees were alive on that date, and matched to the case adoptees with regard to gender and year and month of birth. The data were viewed as a cohort of case parents and a cohort of control parents, and lifetime distributions in the two cohorts were compared using a Cox regression, stratified with regard to the matching variables: gender and year of birth. In the main analyses, the sample was restricted with regard to birth year of the adoptees, and age of transfer to the adoptive parents, and age at death was restricted to the same range for parents and offspring (25-64 years) in order to consider a symmetric lifetime distribution. This reduces the sample to 459 case families and 738 control families. Various truncations, restrictions, and stratifications were used in order to examine the robustness of the results. The results showed a higher mortality among biological parents who had children dying in the age range 25 through 64 years, and this was significant for death from natural causes, infectious causes, vascular causes, and from all causes combined. There were no significant effects for the adoptive parents. This study supports that there are moderate genetic influences on the risk of dying prematurely in adulthood, and only a small, if any, effect of the family environment. Copyright 2002 Wiley-Liss, Inc.

Risk factors for gallbladder cancer: a case-control study.

Science.gov (United States)

Jain, Kajal; Sreenivas, V; Velpandian, T; Kapil, Umesh; Garg, Pramod Kumar

2013-04-01

Risk factors for gallbladder cancer (GBC) except gallstones are not well known. The objective was to study the risk factors for GBC. In a case-control study, 200 patients with GBC, 200 healthy controls and 200 gallstones patients as diseased controls were included prospectively. The risk factors studied were related to socioeconomic profile, life style, reproduction, diet and bile acids. On comparing GBC patients (mean age 51.7 years; 130 females) with healthy controls, risk factors were chemical exposure [odd ratios (OR): 7.0 (2.7-18.2); p < 0.001)], family history of gallstones [OR: 5.3 (1.5-18.9); p < 0.01)], tobacco [OR: 4.1 (1.8-9.7); p < 0.001)], fried foods [OR: 3.1 (1.7-5.6); p < 0.001], joint family [OR: 3.2 (1.7-6.2); p < 0.001], long interval between meals [OR: 1.4 (1.2-1.6); p < 0.001] and residence in Gangetic belt [OR: 3.3 (1.8-6.2); p < 0.001]. On comparing GBC cases with gallstone controls, risk factors were female gender [OR: 2.4 (1.3-4.3); p = 0.004], residence in Gangetic belt [OR: 2.3 (1.2-4.4); p = 0.012], fried foods [OR: 2.5 (1.4-4.4); p < 0.001], diabetes [OR: 2.7 (1.2-6.4); p = 0.02)], tobacco [OR 3.8 (1.7-8.1); p < 0.001)] and joint family [OR: 2.1 (1.2-3.4); p = 0.004]. The ratio of secondary to primary bile acids was significantly higher in GBC cases than gallstone controls (20.8 vs. 0.44). Fried foods, tobacco, chemical exposure, family history of gallstones, residence in Gangetic belt and secondary bile acids were significant risk factors for GBC. Copyright © 2012 UICC.

Heat and nuclear radiation as risk factors for male infertility: results of a French case-control study

International Nuclear Information System (INIS)

Thonneau, P.F.; Rachou, E.; Ducot, B.; Multigner, L.; Velez de la Calle, J.P.; Le Martelot, M.T.

1998-01-01

Very few studies have investigated the possible effects of environmental radiation and heat exposure on male reproductive function. We conducted a case control study to evaluate the various infertility risk factors in the military population of the french town of Brest to investigate an apparently high incidence of infertility in couples in which the man may have been exposed to occupational nuclear radiation. These findings suggest that in addition to well known medical factors, 'potential' exposure to heat or nuclear radiation could also be risk factors for infertility. (N.C.)

A case-control study of wicket spikes using video-EEG monitoring.

Science.gov (United States)

Vallabhaneni, Maya; Baldassari, Laura E; Scribner, James T; Cho, Yong Won; Motamedi, Gholam K

2013-01-01

To investigate clinical characteristics associated with wicket spikes in patients undergoing long-term video-EEG monitoring. A case-control study was performed in 479 patients undergoing video-EEG monitoring, with 3 age- (±3 years) and gender-matched controls per patient with wicket spikes. Logistic regression was utilized to investigate the association between wicket spikes and other factors, including conditions that have been previously associated with wicket spikes. Wicket spikes were recorded in 48 patients. There was a significantly higher prevalence of dizziness/vertigo (p=0.002), headaches (p=0.005), migraine (p=0.015), and seizures (p=0.016) in patients with wickets. The majority of patients with wicket spikes did not exhibit epileptiform activity on EEG; however, patients with history of seizures were more likely to have wickets (p=0.017). There was no significant difference in the prevalence of psychogenic non-epileptic seizures between the groups. Wickets were more common on the left, during sleep, and more likely to be first recorded on day 1-2 of monitoring. Patients with wicket spikes are more likely to have dizziness/vertigo, headaches, migraine, and seizures. Patients with history of seizures are more likely to have wickets. The prevalence of psychogenic non-epileptic seizures is not significantly higher in patients with wickets. Copyright © 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Lumbar lordosis and pars interarticularis fractures: a case-control study

International Nuclear Information System (INIS)

Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P.

2012-01-01

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Lumbar lordosis and pars interarticularis fractures: a case-control study

Energy Technology Data Exchange (ETDEWEB)

Bugg, William G; Lewis, Mark; Juette, Arne; Cahir, John G; Toms, Andoni P [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

2012-07-15

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Lumbar lordosis and pars interarticularis fractures: a case-control study

Energy Technology Data Exchange (ETDEWEB)

Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P. [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

2012-07-15

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Low dose irradiation and risk of leukaemia: A case-control study

International Nuclear Information System (INIS)

Chobanova, N.; Bayrakova, A.

1997-01-01

The effect of low dose irradiation (medical X-ray diagnostic) on the developing of leukaemias in adults is investigated. The influence of non-radiation agents (occupational exposure to chemical carcinogens, past viral infections, family aggregations) to leukaemias are considered also. During this retrospective study 228 patients have been examined with the following diagnosis: acute myeloid leukaemia, chronic myelogenous leukaemias, myelodisplastic syndrome and non-Hodgkin lymphoma (diagnosed between 1991-1993). Each case has been matched with two controls. Statistically significant increase has been found in the risk of developing leukaemias after X-ray diagnostic irradiation (OR = 1.98, 95% CI = 1.14 ./. 3.46). Exposure to chemical agents is also associated with significant increase in the risk (OR = 1.98, 95% CI = 1.25 ./. 2.86). (author)

Hyperthyroidism association with SLE, lessons from real-life data--A case-control study.

Science.gov (United States)

Watad, Abdulla; Cohen, Arnon D; Comaneshter, Doron; Tekes-Manova, Dorit; Amital, Howard

2016-01-01

Despite the frequently encountered association between thyroid disease and systemic lupus erythematosus (SLE) is well known, it is of surprise that only several reports compromised of small population size support this observation. To investigate the association of comorbid SLE and hyperthyroidism. Using the database of the largest health maintenance organization (HMO) in Israel, the Clalit Health Services, we searched for the co-existence of SLE and hyperthyroidism. Patients with SLE were compared with age- and sex-matched controls regarding the prevalence of hyperthyroidism in a case-control study. Chi-square and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study included 5018 patients with SLE and 25,090 age- and sex- matched controls. The prevalence of hyperthyroidism in patients with SLE was increased compared with the prevalence in controls (2.59% and 0.91%, respectively, p hyperthyroidism (odds ratio 2.52, 95% confidence interval 2.028-3.137). Patients with SLE have a greater prevalence of hyperthyroidism than matched controls. Therefore, physicians treating patients with SLE should be aware of this possibility of this thyroid dysfunction.

Early pregnancy peripheral blood gene expression and risk of preterm delivery: a nested case control study

Directory of Open Access Journals (Sweden)

Muhie Seid Y

2009-12-01

Full Text Available Abstract Background Preterm delivery (PTD is a significant public health problem associated with greater risk of mortality and morbidity in infants and mothers. Pathophysiologic processes that may lead to PTD start early in pregnancy. We investigated early pregnancy peripheral blood global gene expression and PTD risk. Methods As part of a prospective study, ribonucleic acid was extracted from blood samples (collected at 16 weeks gestational age from 14 women who had PTD (cases and 16 women who delivered at term (controls. Gene expressions were measured using the GeneChip® Human Genome U133 Plus 2.0 Array. Student's T-test and fold change analysis were used to identify differentially expressed genes. We used hierarchical clustering and principle components analysis to characterize signature gene expression patterns among cases and controls. Pathway and promoter sequence analyses were used to investigate functions and functional relationships as well as regulatory regions of differentially expressed genes. Results A total of 209 genes, including potential candidate genes (e.g. PTGDS, prostaglandin D2 synthase 21 kDa, were differentially expressed. A set of these genes achieved accurate pre-diagnostic separation of cases and controls. These genes participate in functions related to immune system and inflammation, organ development, metabolism (lipid, carbohydrate and amino acid and cell signaling. Binding sites of putative transcription factors such as EGR1 (early growth response 1, TFAP2A (transcription factor AP2A, Sp1 (specificity protein 1 and Sp3 (specificity protein 3 were over represented in promoter regions of differentially expressed genes. Real-time PCR confirmed microarray expression measurements of selected genes. Conclusions PTD is associated with maternal early pregnancy peripheral blood gene expression changes. Maternal early pregnancy peripheral blood gene expression patterns may be useful for better understanding of PTD

A case-control study of risk factors for male infertility in Southern ...

African Journals Online (AJOL)

Aim: The purpose of this study was to evaluate the association between selected potential socio-demographic and behavioural risk factors and infertility in Nigeria males. Methods: The study consisted of cases and controls. The cases were 150 males with proven male infertility, while the controls were 150 fertile males with ...

Hygiene behaviour and hospitalized severe childhood diarrhoea: a case-control study.

OpenAIRE

Baltazar, J. C.; Tiglao, T. V.; Tempongko, S. B.

1993-01-01

The relationship between personal and domestic hygiene behaviour and hospitalized childhood diarrhoea was examined in a case-control study of 356 cases and 357 controls from low-income families in metropolitan Manila. Indices of hygiene behaviour were defined for overall cleanliness, kitchen hygiene, and living conditions. Only the indices for overall cleanliness and kitchen hygiene were significantly associated with diarrhoea. An increasing excess risk of hospitalization with severe diarrhoe...

Piloting a programme tool to evaluate malaria case investigation and reactive case detection activities: results from 3 settings in the Asia Pacific.

Science.gov (United States)

Cotter, Chris; Sudathip, Prayuth; Herdiana, Herdiana; Cao, Yuanyuan; Liu, Yaobao; Luo, Alex; Ranasinghe, Neil; Bennett, Adam; Cao, Jun; Gosling, Roly D

2017-08-22

Case investigation and reactive case detection (RACD) activities are widely-used in low transmission settings to determine the suspected origin of infection and identify and treat malaria infections nearby to the index patient household. Case investigation and RACD activities are time and resource intensive, include methodologies that vary across eliminating settings, and have no standardized metrics or tools available to monitor and evaluate them. In response to this gap, a simple programme tool was developed for monitoring and evaluating (M&E) RACD activities and piloted by national malaria programmes. During the development phase, four modules of the RACD M&E tool were created to assess and evaluate key case investigation and RACD activities and costs. A pilot phase was then carried out by programme implementers between 2013 and 2015, during which malaria surveillance teams in three different settings (China, Indonesia, Thailand) piloted the tool over a period of 3 months each. This study describes summary results of the pilots and feasibility and impact of the tool on programmes. All three study areas implemented the RACD M&E tool modules, and pilot users reported the tool and evaluation process were helpful to identify gaps in RACD programme activities. In the 45 health facilities evaluated, 71.8% (97/135; min 35.3-max 100.0%) of the proper notification and reporting forms and 20.0% (27/135; min 0.0-max 100.0%) of standard operating procedures (SOPs) were available to support malaria elimination activities. The tool highlighted gaps in reporting key data indicators on the completeness for malaria case reporting (98.8%; min 93.3-max 100.0%), case investigations (65.6%; min 61.8-max 78.4%) and RACD activities (70.0%; min 64.7-max 100.0%). Evaluation of the SOPs showed that knowledge and practices of malaria personnel varied within and between study areas. Average monthly costs for conducting case investigation and RACD activities showed variation between study

Characteristics and prognosis of pneumococcal endocarditis: a case-control study.

Science.gov (United States)

Daudin, M; Tattevin, P; Lelong, B; Flecher, E; Lavoué, S; Piau, C; Ingels, A; Chapron, A; Daubert, J-C; Revest, M

2016-06-01

Case series have suggested that pneumococcal endocarditis is a rare disease, mostly reported in patients with co-morbidities but no underlying valve disease, with a rapid progression to heart failure, and high mortality. We performed a case-control study of 28 patients with pneumococcal endocarditis (cases), and 56 patients with non-pneumococcal endocarditis (controls), not matched for sex and age, during the years 1991-2013, in one referral centre. Alcoholism (39.3% versus 10.7%; p endocarditis. Cardiac surgery was required in 64.3% of patients with pneumococcal endocarditis, much earlier than in patients with non-pneumococcal endocarditis (mean time from symptom onset, 14.1 ± 18.2 versus 69.0 ± 61.1 days). In-hospital mortality rates were similar (7.1% versus 12.5%). Streptococcus pneumoniae causes rapidly progressive endocarditis requiring life-saving early cardiac surgery in most cases. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Can routine chest radiography be used to diagnose mild COPD? A nested case-control study.

Science.gov (United States)

den Harder, A M; Snoek, A M; Leiner, T; Suyker, W J; de Heer, L M; Budde, R P J; Lammers, J W J; de Jong, P A; Gondrie, M J A

2017-07-01

To determine whether mild stage chronic obstructive pulmonary disease (COPD) can be detected on chest radiography without substantial overdiagnosis. A retrospective nested case-control study (case:control, 1:1) was performed in 783 patients scheduled for cardiothoracic surgery who underwent both spirometry and a chest radiograph preoperative. Diagnostic accuracy of chest radiography for diagnosing mild COPD was investigated using objective measurements and overall appearance specific for COPD on chest radiography. Inter-observer variability was investigated and variables with a kappa >0.40 as well as baseline characteristics were used to make a diagnostic model which was aimed at achieving a high positive predictive value (PPV). Twenty percent (155/783) had COPD. The PPV of overall appearance specific for COPD alone was low (37-55%). Factors in the diagnostic model were age, type of surgery, gender, distance of the right diaphragm apex to the first rib, retrosternal space, sternodiaphragmatic angle, maximum height right diaphragm (lateral view) and subjective impression of COPD (using both views). The model resulted in a PPV of 100%, negative predictive value (NPV) of 82%, sensitivity of 10% and specificity of 100% with an area under the curve of 0.811. Detection of mild COPD without substantial overdiagnosis was not feasible on chest radiographs in our cohort. Copyright © 2017 Elsevier B.V. All rights reserved.

Active control and sound synthesis--two different ways to investigate the influence of the modal parameters of a guitar on its sound.

Science.gov (United States)

Benacchio, Simon; Mamou-Mani, Adrien; Chomette, Baptiste; Finel, Victor

2016-03-01

The vibrational behavior of musical instruments is usually studied using physical modeling and simulations. Recently, active control has proven its efficiency to experimentally modify the dynamical behavior of musical instruments. This approach could also be used as an experimental tool to systematically study fine physical phenomena. This paper proposes to use modal active control as an alternative to sound simulation to study the complex case of the coupling between classical guitar strings and soundboard. A comparison between modal active control and sound simulation investigates the advantages, the drawbacks, and the limits of these two approaches.

Neonatal encephalopathy and socioeconomic status: population-based case-control study.

Science.gov (United States)

Blume, Heidi K; Loch, Christian M; Li, Christopher I

2007-07-01

To investigate the association between maternal socioeconomic status and the risk of encephalopathy in full-term newborns. Population-based case-control study. Washington State births from 1994 through 2002 recorded in the linked Washington State Birth Registry and Comprehensive Hospital Abstract Reporting System. Cases (n = 1060) were singleton full-term newborns with Comprehensive Hospital Abstract Reporting System International Classification of Diseases, Ninth Revision diagnoses of seizures, birth asphyxia, central nervous system dysfunction, or cerebral irritability. Control cases (n = 5330) were singleton full-term newborns selected from the same database. Main Exposures Socioeconomic status was defined by median income of the census tract of the mother's residence, number of years of maternal educational achievement, or maternal insurance status. Odds ratios estimating the risk of encephalopathy associated with disadvantaged socioeconomic status were calculated in 3 separate analyses using multivariate adjusted logistic regression. Newborns of mothers living in neighborhoods in which residents have a low median income were at increased risk of encephalopathy compared with newborns in neighborhoods in which residents have a median income more than 3 times the poverty level (adjusted odds ratio, 1.9; 95% confidence interval, 1.5-2.3). There was also a trend for increasing risk of encephalopathy associated with decreasing neighborhood income (PNewborns of mothers with less than 12 years of educational achievement had a higher risk of encephalopathy compared with newborns of mothers with more than 16 years of educational achievement (adjusted odds ratio, 1.7; 95% confidence interval, 1.3-2.3). Newborns of mothers receiving public insurance also had a higher risk of encephalopathy compared with newborns of mothers who have commercial insurance (adjusted odds ratio, 1.4; 95% confidence interval, 1.2-1.7). Disadvantaged socioeconomic status was independently

Periodontal disease as a risk factor for adverse pregnancy outcomes: a systematic review and meta-analysis of case-control studies.

Science.gov (United States)

Corbella, Stefano; Taschieri, Silvio; Francetti, Luca; De Siena, Francesca; Del Fabbro, Massimo

2012-07-01

Periodontal disease is a highly prevalent group of illnesses of microbial etiology, whose consequence is a severe breakdown of tooth-supporting structures. A link between periodontal infection and several systemic conditions, among which adverse pregnancy outcomes, has been suggested in the recent years. The aim of this review based on case-control studies was to evaluate if periodontal disease could be considered as a risk factor for preterm birth, low birth-weight and preterm low birth-weight. An electronic search (via Pubmed) was performed for case-control studies investigating the relationship between periodontal disease and adverse pregnancy outcomes. From the initially retrieved 417 articles, 17 case-control studies, accounting for a total of 10,148 patients, were included in the review and in the meta-analysis. The estimated odds ratio was 1.78 (CI 95%: 1.58, 2.01) for preterm birth, 1.82 (CI 95%: 1.51, 1.20) for low birth-weight and 3.00 (CI 95%: 1.93, 4.68) for preterm low birth-weight. Despite the results of the analysis of pooled data suggested a link between periodontal diseases and adverse pregnancy outcomes, the presence of important confounders, whose effect could not be addressed, prevents a validation of the meta-analysis outcomes. Further more accurate investigations based on individual data analysis could give a better insight into the topic of the present review.

Birth outcomes of cases with isolated atrial septal defect type II--a population-based case-control study.

Science.gov (United States)

Vereczkey, Attila; Kósa, Zsolt; Csáky-Szunyogh, Melinda; Urbán, Róbert; Czeizel, Andrew E

2013-07-01

In general, epidemiological studies have evaluated cases with congenital cardiovascular abnormalities together. The aim of this study is to describe the birth outcomes of cases with isolated/single atrial septal defect type II (ASD-II, i.e. only a fossa ovalis defect) after surgical correction or lethal outcome in the light of maternal sociodemographic data. Comparison of birth outcomes and maternal characteristics of cases with ASD-II and controls without defect. The population-based Hungarian Case-Control Surveillance of Congenital Abnormalities. Hungarian newborn infants with or without ASD-II. Medically recorded birth outcomes, maternal age and birth order were evaluated. Marital and employment status was based on maternal information. The lifestyle factors were analyzed in a subsample of mothers visited at home based on a personal interview with mothers and their close relatives, and the family consensus was accepted. Mean gestational age at delivery and birthweight, rate of preterm birth and low birthweight, maternal age, birth order, marital and employment status. The evaluation of 471 cases with ASD-II and 38,151 controls without any defects showed a female excess in cases with ASD-II, having shorter gestational age and lower mean birthweight, and thus a higher rate of preterm births and low birthweight. Intrauterine growth restriction and shorter gestational age were found in cases with ASD-II, particularly in female children. These factors may have a general developmental process in which there was not closure of the foramen ovale, thus echocardiographic screening of these babies might be of value. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica © 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

Risk factors for unintentional poisoning in children aged 1-3 years in NSW Australia: a case-control study.

Science.gov (United States)

Schmertmann, Marcia; Williamson, Ann; Black, Deborah; Wilson, Leigh

2013-05-24

Unintentional poisoning in young children is an important public health issue. Age pattern studies have demonstrated that children aged 1-3 years have the highest levels of poisoning risk among children aged 0-4 years, yet little research has been conducted regarding risk factors specific to this three-year age group and the methodologies employed varied greatly. The purpose of the current study is to investigate a broad range of potential risk factors for unintentional poisoning in children aged 1-3 years using appropriate methodologies. Four groups of children, one case group (children who had experienced a poisoning event) and three control groups (children who had been 'injured', 'sick' or who were 'healthy'), and their mothers (mother-child dyads) were enrolled into a case-control study. All mother-child dyads participated in a 1.5-hour child developmental screening and observation, with mothers responding to a series of questionnaires at home. Data were analysed as three case-control pairs with multivariate analyses used to control for age and sex differences between child cases and controls. Five risk factors were included in the final multivariate models for one or more case-control pairs. All three models found that children whose mothers used more positive control in their interactions during a structured task had higher odds of poisoning. Two models showed that maternal psychiatric distress increased poisoning risk (poisoning-injury and poisoning-healthy). Individual models identified the following variables as risk factors: less proximal maternal supervision during risk taking activities (poisoning-injury), medicinal substances stored in more accessible locations in bathrooms (poisoning-sick) and lower total parenting stress (poisoning-healthy). The findings of this study indicate that the nature of the caregiver-child relationship and caregiver attributes play an important role in influencing poisoning risk. Further research is warranted to explore the

A case-control study of risk of leukaemia in relation to mobile phone use.

Science.gov (United States)

Cooke, R; Laing, S; Swerdlow, A J

2010-11-23

Mobile phone use is now ubiquitous, and scientific reviews have recommended research into its relation to leukaemia risk, but no large studies have been conducted. In a case-control study in South East England to investigate the relation of acute and non-lymphocytic leukaemia risk to mobile phone use, 806 cases with leukaemia incident 2003-2009 at ages 18-59 years (50% of those identified as eligible) and 585 non-blood relatives as controls (provided by 392 cases) were interviewed about mobile phone use and other potentially aetiological variables. No association was found between regular mobile phone use and risk of leukaemia (odds ratio (OR)=1.06, 95% confidence interval (CI)=0.76, 1.46). Analyses of risk in relation to years since first use, lifetime years of use, cumulative number of calls and cumulative hours of use produced no significantly raised risks, and there was no evidence of any trends. A non-significantly raised risk was found in people who first used a phone 15 or more years ago (OR=1.87, 95% CI=0.96, 3.63). Separate analyses of analogue and digital phone use and leukaemia subtype produced similar results to those overall. This study suggests that use of mobile phones does not increase leukaemia risk, although the possibility of an effect after long-term use, while biologically unlikely, remains open.

FRF-based structural damage detection of controlled buildings with podium structures: Experimental investigation

Science.gov (United States)

Xu, Y. L.; Huang, Q.; Zhan, S.; Su, Z. Q.; Liu, H. J.

2014-06-01

How to use control devices to enhance system identification and damage detection in relation to a structure that requires both vibration control and structural health monitoring is an interesting yet practical topic. In this study, the possibility of using the added stiffness provided by control devices and frequency response functions (FRFs) to detect damage in a building complex was explored experimentally. Scale models of a 12-storey main building and a 3-storey podium structure were built to represent a building complex. Given that the connection between the main building and the podium structure is most susceptible to damage, damage to the building complex was experimentally simulated by changing the connection stiffness. To simulate the added stiffness provided by a semi-active friction damper, a steel circular ring was designed and used to add the related stiffness to the building complex. By varying the connection stiffness using an eccentric wheel excitation system and by adding or not adding the circular ring, eight cases were investigated and eight sets of FRFs were measured. The experimental results were used to detect damage (changes in connection stiffness) using a recently proposed FRF-based damage detection method. The experimental results showed that the FRF-based damage detection method could satisfactorily locate and quantify damage.

Case Control Study of Impulsivity, Aggression, Pesticide Exposure and Suicide Attempts Using Pesticides among Farmers.

Science.gov (United States)

Lyu, Chun Ping; Pei, Jian Ru; Beseler, L Cheryl; Li, Yu Ling; Li, Jian Hui; Ren, Ming; Stallones, Lorann; Ren, Shu Ping

2018-03-01

A case-control study was conducted to investigate associations between organophosphate pesticide (OP) exposure, aggression, impulsivity, and attempted suicide. Questionnaires were used to collect information; impulsivity and aggression were measured by the Barratt Impulsivity Scale (BIS) and the Aggression Inventory (AI). A greater number of OP symptoms was associated with an increased odds of a suicide attempt after adjusting for marital status and income (OR = 1.45; CI 1.14-1.86). Attempted suicide was significantly associated with high impulsivity scores (means: 72.4 vs. 60.6, P controls and scored higher on scales of impulsivity and aggression. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

The Glioma International Case-Control Study

DEFF Research Database (Denmark)

Amirian, E. Susan; Armstrong, Georgina N; Zhou, Renke

2016-01-01

Decades of research have established only a few etiological factors for glioma, which is a rare and highly fatal brain cancer. Common methodological challenges among glioma studies include small sample sizes, heterogeneity of tumor subtypes, and retrospective exposure assessment. Here, we briefly...... describe the Glioma International Case-Control (GICC) Study (recruitment, 2010-2013), a study being conducted by the Genetic Epidemiology of Glioma International Consortium that integrates data from multiple data collection sites, uses a common protocol and questionnaire, and includes biospecimen...

Control and non-progression of HIV-1 infection in sub-Saharan Africa: A case and review

Directory of Open Access Journals (Sweden)

P Patel

2012-08-01

Full Text Available Elite and viraemic controllers represent unique subsets of HIV-infected patients who may also be long-term non-progressors (LTNPs. LNTPs constitute an estimated 1 - 15% of the total HIV-positive population in the USA and Europe, but less is known about their epidemiology in sub-Saharan Africa. Though the exact mechanisms for long-term non-progression appear to be numerous and are still under investigation, research on elite controllers may hold the key to new therapeutics and vaccine development. The clinical management of such patients can be challenging, as there are no standard guidelines for treatment, particularly in resource-limited settings. We describe the case of an HIV-infected Botswanan man who is likely an elite or viraemic controller.

Clinical implications of antiretroviral drug interactions with warfarin: a case-control study.

Science.gov (United States)

Esterly, John S; Darin, Kristin M; Gerzenshtein, Lana; Othman, Fidah; Postelnick, Michael J; Scarsi, Kimberly K

2013-06-01

Warfarin, a frequently prescribed anticoagulant with a narrow therapeutic index, is susceptible to drug-drug interactions with antiretroviral therapy (ART). This study compared the warfarin maintenance dose (WMD) between patients receiving and not receiving ART and evaluated predictors of warfarin dosage among those on ART. This was a case-control (1:2) study. Cases were HIV-infected patients receiving warfarin and protease inhibitor (PI)- and/or non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Controls were randomly selected HIV-uninfected patients receiving warfarin. The WMD was compared between cases and controls and between cases on varying ART regimens. Bivariate comparisons were performed and a linear regression model was developed to identify predictors of WMD. We identified 18 case and 36 control patients eligible for inclusion. Cases were younger than controls (mean age: 45.8 versus 63.1 years, P African American (50.0% versus 22.2%, P=0.04). ART was classified as PI-based (n=9), NNRTI-based (n=7) and PI + NNRTI-based (n=2). The WMD (mean ± SD) differed between cases and controls (8.6  ±  3.4 mg versus 5.1 ± 1.5 mg, P ART regimens (PI: 8.8  ±  4.5 mg; NNRTI: 8.6   ± 1.8 mg; PI + NNRTI: 7.3  ±  3.3 mg; P = 0.86). Race and ritonavir dose were independent predictors of WMD, predicting an increase of 3.9 mg (95% CI: 0.88-6.98, P = 0.02) if a patient was African American or 3.7 mg (95% CI: 0.53-6.89, P = 0.03) if the total daily ritonavir dose was 200 mg. The required WMD was significantly higher in patients receiving ART. Prompt dose titration to achieve a higher WMD with vigilant monitoring may be required due to these drug-drug interactions.

Childhood risk factors in Korean women with anorexia nervosa: two sets of case-control studies with retrospective comparisons.

Science.gov (United States)

Kim, Youl-Ri; Heo, Si Young; Kang, Heechan; Song, Ki Jun; Treasure, Janet

2010-11-01

The aim of this study was to investigate the characteristics of the risk factors for anorexia nervosa (AN) in Korean women. Two sets of case-control comparisons were conducted, in which 52 women with lifetime AN from Seoul, S. Korea, were compared with 108 Korean healthy controls and also with 42 women with lifetime AN from the UK in terms of their childhood risk factors. A questionnaire designed to conduct a retrospective assessment of the childhood risk factors was administered to all participants. The Korean AN women were more likely to report premorbid anxiety, perfectionism, and emotional undereating and were less likely to report having supportive figures in their childhood than the Korean healthy controls. There were no overall differences in the childhood risk factors between the Korean and British women with AN. Premorbid anxiety, perfectionism, less social support, and emotional undereating merit attention as risk factors in Korean AN. The current results are informative, but an epidemiologically robust prospective case-control study would be needed to validate these findings. © 2009 by Wiley Periodicals, Inc.

Three cases of radiation esophagitis controlled with proton pump inhibitor

Energy Technology Data Exchange (ETDEWEB)

Murakami, Ryuji; Saito, Ryuichi; Miyazaki, Toshiyuki [Kumamoto Red Cross Hospital (Japan)

2002-04-01

Radiation esophagitis sometimes interrupts the radiation therapy due to swallowing pain and dysplasia. We experienced three cases of radiation-induced esophagitis controlled with proton pump inhibitor (PPI). These cases suggested etiologic relationship radiation esophagitis and gastroesophageal reflux disease (GERD). We should consider PPI as treatment option for radiation esophagitis. (author)

Case-based e-learning to improve the attitude of medical students towards occupational health, a randomised controlled trial.

Science.gov (United States)

Smits, P B A; de Graaf, L; Radon, K; de Boer, A G; Bos, N R; van Dijk, F J H; Verbeek, J H A M

2012-04-01

Undergraduate medical teaching in occupational health (OH) is a challenge in universities around the world. Case-based e-learning with an attractive clinical context could improve the attitude of medical students towards OH. The study question is whether case-based e-learning for medical students is more effective in improving knowledge, satisfaction and a positive attitude towards OH than non-case-based textbook learning. Participants, 141 second year medical students, were randomised to either case-based e-learning or text-based learning. Outcome measures were knowledge, satisfaction and attitude towards OH, measured at baseline, directly after the intervention, after 1 week and at 3-month follow-up. Of the 141 participants, 130 (92%) completed the questionnaires at short-term follow-up and 41 (29%) at 3-month follow-up. At short-term follow-up, intervention and control groups did not show a significant difference in knowledge nor satisfaction but attitude towards OH was significantly more negative in the intervention group (F=4.041, p=0.047). At 3-month follow-up, there were no significant differences between intervention and control groups for knowledge, satisfaction and attitude. We found a significant decrease in favourable attitude during the internship in the experimental group compared with the control group. There were no significant differences in knowledge or satisfaction between case-based e-learning and text-based learning. The attitude towards OH should be further investigated as an outcome of educational programmes.

Allergies and risk of pancreatic cancer: a pooled analysis from the Pancreatic Cancer Case-Control Consortium.

Science.gov (United States)

Olson, Sara H; Hsu, Meier; Satagopan, Jaya M; Maisonneuve, Patrick; Silverman, Debra T; Lucenteforte, Ersilia; Anderson, Kristin E; Borgida, Ayelet; Bracci, Paige M; Bueno-de-Mesquita, H Bas; Cotterchio, Michelle; Dai, Qi; Duell, Eric J; Fontham, Elizabeth H; Gallinger, Steven; Holly, Elizabeth A; Ji, Bu-Tian; Kurtz, Robert C; La Vecchia, Carlo; Lowenfels, Albert B; Luckett, Brian; Ludwig, Emmy; Petersen, Gloria M; Polesel, Jerry; Seminara, Daniela; Strayer, Lori; Talamini, Renato

2013-09-01

In order to quantify the risk of pancreatic cancer associated with history of any allergy and specific allergies, to investigate differences in the association with risk according to age, gender, smoking status, or body mass index, and to study the influence of age at onset, we pooled data from 10 case-control studies. In total, there were 3,567 cases and 9,145 controls. Study-specific odds ratios and 95% confidence intervals were calculated by using unconditional logistic regression adjusted for age, gender, smoking status, and body mass index. Between-study heterogeneity was assessed by using the Cochran Q statistic. Study-specific odds ratios were pooled by using a random-effects model. The odds ratio for any allergy was 0.79 (95% confidence interval (CI): 0.62, 1.00) with heterogeneity among studies (P allergies or asthma. There were no major differences among subgroups defined by age, gender, smoking status, or body mass index. Older age at onset of allergies was slightly more protective than earlier age.

Studies of CTNNBL1 and FDFT1 variants and measures of obesity: analyses of quantitative traits and case-control studies in 18,014 Danes

DEFF Research Database (Denmark)

Andreasen, Camilla Helene; Mogensen, Mette Sloth; Borch-Johnsen, Knut

2009-01-01

of obesity-related quantitative traits, and case-control studies in large study samples of Danes. METHODS: The FDFT1 rs7001819, CTNNBL1 rs6013029 and rs6020846 were genotyped, using TaqMan allelic discrimination, in a combined study sample comprising 18,014 participants ascertained from; the population...... and a previous study. FDFT1 rs7001819 showed no association with obesity, neither when analysing quantitative traits nor when performing case-control studies of obesity.......). The most significantly associating variants within CTNNBL1 including rs6013029 and rs6020846 were additionally confirmed to associate with morbid obesity in a French Caucasian case-control sample. The aim of this study was to investigate the impact of these three variants on obesity, through analyses...

Effects of interleukin-1 receptor antagonist (IL-1Ra) gene 86 bp VNTR polymorphism on recurrent pregnancy loss: a case-control study.

Science.gov (United States)

Hajizadeh, Yasamin Sayed; Emami, Elina; Nottagh, Marina; Amini, Zahra; Maroufi, Nazila Fathi; Azimian, Saba Haj; Isazadeh, Alireza

2017-05-26

Objective Recurrent pregnancy loss (RPL) is a heterogeneous disease which is defined as two or more consecutive fetal losses during early pregnancy. Interleukin-1 receptor antagonist (IL-1Ra) is a anti-inflammatory cytokine, which inhibits IL-1 activity by binding to its receptors. The aim of this study was to investigate the association between RPL and IL-1Ra intron 2 polymorphism (86 bp VNTR) in Iranian women. Materials and methods In this case control study, genetic polymorphism was studied in 140 RPL patients and 140 healthy women as controls. Genomic DNA was extracted from the blood samples and polymorphism analysis was performed using the polymerase chain reaction (PCR) method. Finally, the data obtained were analyzed by statistical software. Results We found an increased frequency of the IL-1Ra 1/1 genotype in the case group compared to the control group. Whereas, the frequency of IL-1Ra genotype 1/2 was higher in control group than in the case group. However, we did not observe an association between IL-1Ra 86 bp VNTR polymorphism in intron 2 and RPL patients (p > 0.05). Conclusion IL-1Ra VNTR polymorphism may not be a genetic factor for RPL. However, investigation of IL-1Ra polymorphism was recommended in other populations and patients with recurrent pregnancy loss.

Use of methimazole and risk of acute pancreatitis: A case-control study in Taiwan.

Science.gov (United States)

Lai, Shih-Wei; Lin, Cheng-Li; Liao, Kuan-Fu

2016-01-01

Some cases of acute pancreatitis have been reported to be associated with use of methimazole. The aim of this study was to investigate the relationship between use of methimazole and risk of acute pancreatitis on the basis of a systematic analysis. This was a population-based case-control study analyzing the database of the Taiwan National Health Insurance Program. There were 5764 individuals aged 20-84 years with a first attack of acute pancreatitis from 1998 to 2011 as the cases and 23,056 randomly selected sex- and age-matched individuals without acute pancreatitis as the controls. Use of methimazole was categorized as "never use" and "ever use." We estimated the relative risk of acute pancreatitis associated with the use of methimazole by calculating the odds ratio (OR) with 95% confidence interval (CI) using a multivariable logistic regression model. After adjustment for confounding factors, the OR of acute pancreatitis was 0.91 in individuals with ever use of methimazole, when compared with individuals with never use of methimazole (95% CI, 0.60-1.38). Unlike methimazole use, alcohol-related disease, biliary stone, cardiovascular disease, chronic obstructive pulmonary disease, diabetes mellitus, hepatitis B, hepatitis C, and hypertriglyceridemia were factors significantly associated with acute pancreatitis. Our study does not detect a substantial association between the use of methimazole and risk of acute pancreatitis on the basis of systematic analysis. There appears to be a discrepancy between case reports and our systematic analysis about the association between the use of methimazole and risk of acute pancreatitis.

Risk factors for idiopathic orbital inflammation: a case-control study

NARCIS (Netherlands)

Bijlsma, Ward R.; van Gils, Carla H.; Paridaens, Dion; Mourits, Maarten P.; Kalmann, Rachel

2011-01-01

Objective To identify risk factors involved in the development of idiopathic orbital inflammation (IOI). Methods Case-control study of 69 adults who had had a first episode of IOI and 296 adult controls with rhegmatogenous retinal detachment (RD) selected from three orbital centres in The

Dietary inflammation potential and postmenopausal breast cancer risk in a German case-control study.

Science.gov (United States)

Ge, Isabell; Rudolph, Anja; Shivappa, Nitin; Flesch-Janys, Dieter; Hébert, James R; Chang-Claude, Jenny

2015-08-01

Unhealthy dietary habits can increase the risk for serious medical conditions, such as cancer, yet the association between diet and breast cancer remains unclear. We investigated whether individual diets based on their inflammatory potential are associated with postmenopausal breast cancer risk by employing an energy-adjusted dietary inflammation index. In a German population-based case-control study, 2887 postmenopausal breast cancer patients (aged 50-74 years, first diagnosed between 2002 and 2005) and 5512 healthy age-matched controls provided information on dietary habits for the year prior to diagnosis (cases) or recruitment (controls) using a 176-items food frequency questionnaire. Associations between the energy-adjusted dietary inflammation index (E-DII) score (both as continuous variable and in quintiles) and risk for breast cancer were assessed using conditional logistic regression adjusted for potential confounders. No significant associations between the E-DII score and postmenopausal breast cancer risk were observed (adjusted OR Q5 vs Q1: 1.01, 95% CI: 0.86-1.17). Associations did not differ by estrogen receptor/progesterone receptor status (ER + PR+: adjusted OR Q5 vs Q1: 1.06, 95% CI: 0.88-1.27; ER + or PR+: OR Q5 vs Q1: 1,07, 95% CI: 0.79-1.45; ER-PR-: OR Q5 vs Q1: 0.87 95% CI: 0.63-1.20). Our results regarding E-DII are consistent with previous studies reporting a lack of association between C-reactive protein, a marker of systemic inflammation, and postmenopausal breast cancer risk. The findings may reflect a real absence of association between dietary inflammatory potential and postmenopausal cancer risk or an underestimation of association due to recall bias. Further investigation is warranted in cohort studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

An investigation of twenty-one cases of low-frequency noise complaints

DEFF Research Database (Denmark)

Pedersen, Christian Sejer; Møller, Henrik; Persson-Waye, Kerstin

2007-01-01

Twenty-one cases of low-frequency noise complaints were thoroughly investigated with the aim of answering the question whether it is real physical sound or low-frequency tinnitus that causes the annoyance. Noise recordings were made in the homes of the complainants taking the spatial variation...

Mental illness, poverty and stigma in India: a case-control study.

Science.gov (United States)

Trani, Jean-Francois; Bakhshi, Parul; Kuhlberg, Jill; Narayanan, Sreelatha S; Venkataraman, Hemalatha; Mishra, Nagendra N; Groce, Nora E; Jadhav, Sushrut; Deshpande, Smita

2015-02-23

To assess the effect of experienced stigma on depth of multidimensional poverty of persons with severe mental illness (PSMI) in Delhi, India, controlling for gender, age and caste. Matching case (hospital)-control (population) study. University Hospital (cases) and National Capital Region (controls), India. A case-control study was conducted from November 2011 to June 2012. 647 cases diagnosed with schizophrenia or affective disorders were recruited and 647 individuals of same age, sex and location of residence were matched as controls at a ratio of 1:2:1. Individuals who refused consent or provided incomplete interview were excluded. Higher risk of poverty due to stigma among PSMI. 38.5% of PSMI compared with 22.2% of controls were found poor on six dimensions or more. The difference in multidimensional poverty index was 69% between groups with employment and income of the main contributors. Multidimensional poverty was strongly associated with stigma (OR 2.60, 95% CI 1.27 to 5.31), scheduled castes/scheduled tribes/other backward castes (2.39, 1.39 to 4.08), mental illness (2.07, 1.25 to 3.41) and female gender (1.87, 1.36 to 2.58). A significant interaction between stigma, mental illness and gender or caste indicates female PSMI or PSMI from 'lower castes' were more likely to be poor due to stigma than male controls (ppoverty linked to SMI are pervasive and intertwined. In particular for low caste and women, it is a strong predictor of poverty. Exclusion from employment linked to negative attitudes and lack of income are the highest contributors to multidimensional poverty, increasing the burden for the family. Mental health professionals need to be aware of and address these issues. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Control selection and confounding factors: A lesson from a Japanese case-control study to examine acellular pertussis vaccine effectiveness.

Science.gov (United States)

Ohfuji, Satoko; Okada, Kenji; Nakano, Takashi; Ito, Hiroaki; Hara, Megumi; Kuroki, Haruo; Hirota, Yoshio

2017-08-24

When using a case-control study design to examine vaccine effectiveness, both the selection of control subjects and the consideration of potential confounders must be the important issues to ensure accurate results. In this report, we described our experience from a case-control study conducted to evaluate the effectiveness of acellular pertussis vaccine combined with diphtheria-tetanus toxoids (DTaP vaccine). Newly diagnosed pertussis cases and age- and sex-matched friend-controls were enrolled, and the history of DTaP vaccination was compared between groups. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of vaccination for development of pertussis. After adjustment for potential confounders, four doses of DTaP vaccination showed a lower OR for pediatrician-diagnosed pertussis (OR=0.11, 95% CI, 0.01-0.99). In addition, the decreasing OR of four doses vaccination was more pronounced for laboratory-confirmed pertussis (OR=0.07, 95%CI, 0.01-0.82). Besides, positive association with pertussis was observed in subjects with a history of steroid treatment (OR=5.67) and those with a recent contact with a lasting cough (OR=4.12). When using a case-control study to evaluate the effectiveness of vaccines, particularly those for uncommon infectious diseases such as pertussis, the use of friend-controls may be optimal due to the fact that they shared a similar experience for exposure to the pathogen as the cases. In addition, to assess vaccine effectiveness as accurately as possible, the effects of confounding should be adequately controlled with a matching or analysis technique. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

A case-control analysis on the association between erectile dysfunction and sudden sensorineural hearing loss in Taiwan.

Science.gov (United States)

Keller, Joseph J; Chen, Yi-Kuang; Lin, Herng-Ching

2012-05-01

Although the cause of sudden sensorineural hearing loss (SSNHL) is yet to be elucidated, many theories have been proposed regarding potentially contributory etiologies. One increasingly well-supported theory purports an underlying vascular pathomechanism. If this is the case, SSNHL may also associate with conditions comorbid with vascular diseases, such as erectile dysfunction (ED). However, no studies to date have investigated the association between ED and SSNHL. This study set out to estimate a putative association between ED and having been previously diagnosed with SSNHL using a population-based dataset with a case-control design. This study used administrative claim data from the Taiwan National Health Insurance program. We identified 4,504 patients with ED as the study group and randomly selected 22,520 patients as the comparison group. Conditional logistic regression was used to examine the association between ED and having previously received a diagnosis of SSNHL. The prevalence and risk of SSNHL between cases and controls were calculated. Of the sampled patients, 41 (0.15%) had been diagnosed with SSNHL before the index date; 22 (0.49% of the cases) were from the study group and 19 (0.08% of controls) were from the control group. Conditional logistic regression analysis revealed that after adjusting for the patient's monthly income, geographic location, hypertension, diabetes, hyperlipidemia, coronary heart disease, obesity, and alcohol abuse/alcohol dependence syndrome status, patients with ED were more likely than controls to have been diagnosed with SSNHL before the index date (odds ratio = 6.06, 95% confidence interval = 3.25-11.29). There was an association between ED and prior SSNHL. The results of this study add to the evidence supporting an underlying vascular pathomechanism regarding the development of SSNHL and highlight a need for clinicians dealing with SSNHL patients to be alert to the development of ED. © 2012 International Society for

Association of Serum Uric Acid with Preeclampsia: A Case Control Study

Directory of Open Access Journals (Sweden)

Razia Sultana

2013-07-01

Full Text Available Background: Preeclampsia (PE is still one of the important causes of maternal and fetal mortality in Bangladesh. Many researches have been done to identify a unique screening test that would predict the risk of developing PE before the classic symptoms appear. One of the most accessible and easiest screening tests is serum uric acid measurement. Numerous studies have demonstrated a relation between elevated maternal serum uric acid levels and adverse maternal and fetal outcome. Among several pathophysiologic factors the most commonly accepted explanation for hyperuricemia in PE is increased reabsorption and decreased excretion of uric acid.Objective: The aim of the present study was to assess the association of serum uric acid with preeclampsia.Materials and method: A case control study was conducted in the department of Biochemistry, Dhaka Medical College, Dhaka from July 2010 to June 2011. A total number of 100 pregnant women in third trimester of pregnancy attending in Obstetrics and Gynaecology department of Dhaka Medical College Hospital were selected purposively as study subjects. Among them 50 pregnant women with preeclampsia were selected as cases and 50 normal healthy pregnant women as controls.Results: Most of the study subjects were within 21 – 30 years of age group and mean age in case and control was 24.06±3.71 and 24.66±3.22 years respectively, which was not statistically different. Mean gestational age in case and control was 33.50±2.55 weeks and 33.60±2.95 weeks respectively, which was also not statistically different. Among the study subjects majority was primi in both groups (case 76%, contol 58% showing no statistical significance. Majority of the subjects in both groups were irregular in their antenatal checkup (case 52%, contol 40%. Uric acid concentration was measured in all the study subjects. The mean serum uric acid concentration in cases and controls were 7.01±1.90 mg/dl and 4.55±1.63 mg/dl respectively. This

On distributed parameter control systems in the abnormal case and in the case of nonoperator equality constraints

Directory of Open Access Journals (Sweden)

Urszula Ledzewicz

1993-01-01

Full Text Available In this paper, a general distributed parameter control problem in Banach spaces with integral cost functional and with given initial and terminal data is considered. An extension of the Dubovitskii-Milyutin method to the case of nonregular operator equality constraints, based on Avakov's generalization of the Lusternik theorem, is presented. This result is applied to obtain an extension of the Extremum Principle for the case of abnormal optimal control problems. Then a version of this problem with nonoperator equality constraints is discussed and the Extremum Principle for this problem is presented.

Importance of Internal Audit and Internal Control in an organization - Case Study

OpenAIRE

Bubilek, Olga

2017-01-01

This research is a descriptive case study of a company. It presents concepts of the internal audit and internal control based on an example of a Finnish company. The research examines the role and importance that internal audit and internal controls have in an organization. The main research question is “What is the role and importance of internal audit and internal control in an organization” Additional sub-questions relating to the case company that will allow for better understanding of...

Dietary and lifestyle characteristics of colorectal cancer in Jordan: a case-control study.

Science.gov (United States)

Arafa, Mostafa A; Waly, Mostafa I; Jriesat, Sahar; Al Khafajei, Ahmed; Sallam, Sunny

2011-01-01

We evaluated dietary pattern and lifestyle characteristics of patients with colorectal cancer (CRC) in Jordan. The case-control study included 220 recently diagnosed CRC cases and 220 age and gender matched healthy subjects as a control group. The participating CRC cases had lower dietary intake of fibre, folate, vitamin B12, β-carotene, vitamin C and selenium as compared to controls (P<0.05). The frequency of consumption of fruits and vegetables was also lower among CRC cases, while the frequency of consumption of red meat and saturated fat was higher and positively associated with CRC risk. Furthermore, family history for CRC played a positive role and the majority of CRC cases and controls had a low physical activity level. A sedentary lifestyle and a diet low in fruits and vegetables, and high in animal red meat and saturated fat, appeared associated with CRC among the studied Jordanian subjects. This is consistent with the reported CRC studies in developed nations indicating global causal effects for this tumour type.

High risk human papillomavirus in the periodontium : A case control study

Directory of Open Access Journals (Sweden)

Anna Shipilova

2017-01-01

Full Text Available Background: Human papilloma viruses (HPVs are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. It is thought that the periodontium could be a reservoir for HPV. Aims: 1. Detection of Human Papilloma virus (HPV in periodontal pocket as well as gingival of patients having localized chronic periodontitis and gingival sulcus of periodontally healthy subjects. 2. Quantitative estimation of E6 and E7 mRNA in subjects showing presence of HPV3. To assess whether periodontal pocket is a reservoir for HPV. Settings and Design: This case-control study included 30 subjects with localized chronic Periodontitis (cases and 30 periodontally healthy subjects (controls. Two samples were taken from cases, one from periodontal pocket and one from gingival sulcus and one sample was taken from controls. Methods and Materials: Samples were collected in the form of pocket scrapings and gingival sulcus scrapings from cases and controls respectively. These samples were sent in storage media for identification and estimation of E6/E7 mRNA of HPV using in situ hybridization and flow cytometry. Statistical analysis: Statistical analysis was done by using, mean, percentage and Chi Square test. A statistical package SPSS version 13.0 was used to analyze the data. P value < 0.05 was considered as statistically significant. Results: pocket samples as well as sulcus samples for both cases and controls were found to contain HPV E6/E7 mRNAInterpretation and Conclusion: Presence of HPV E6/E7 mRNA in periodontium supports the hypothesis that periodontal tissues serve as a reservoir for latent HPV and there may be a synergy between oral cancer, periodontitis and HPV. However prospective studies are required to further explore this link.

Load consequences when sweeping blades - A case study of a 5 MW pitch controlled wind turbine

Energy Technology Data Exchange (ETDEWEB)

Verelst, D.R.S.; Larsen, Torben J.

2010-08-15

The generic 5 MW NREL wind turbine model is used in Risoe's aeroelastic simulator HAWC2 to investigate 120 different swept blade configurations (forward and backward sweep). Sensitivity for 2 different controllers is considered as well. Backward sweep results in a pitch to feather torsional moment of the blade, effectively reducing blade twist angles under increased loading. This behaviour results in decreased flap-wise fatigue and extreme loads, an increase for edge-wise fatigue loading and status quo or slight decrease in extreme loads (depending on the controller). Tower base and shaft-end bending moments are reduced as well. Forward sweep leads to an increase in angle of attack under loading. For a pitch controlled turbine this leads to an increase in fatigue and extreme loading in all cases. A controller inflicted instability is present for the more extreme forward swept cases. Due to the shape of considered sweep curves, an inherent and significant increase in torsional blade root bending moment is noted. A boomerang shaped sweep curve is proposed to counteract this problematic increased loading. Controller sensitivity shows that adding sweep affects some loadings differently. Power output is reduced for backward sweep since the blade twist is optimized as a rigid structure, ignoring the torsional deformations which for a swept blade can be significant. (author)

External adjustment of unmeasured confounders in a case-control study of benzodiazepine use and cancer risk

DEFF Research Database (Denmark)

Thygesen, Lau Caspar; Pottegård, Anton; Ersbøll, Annette Kjaer

2017-01-01

AIMS: Previous studies have reported diverging results on the association between benzodiazepine use and cancer risk. METHODS: We investigated this association in a matched case-control study including incident cancer cases during 2002-2009 in the Danish Cancer Registry (n = 94 923) and age......% confidence interval 1.00-1.19) and for smoking-related cancers from 1.20 to 1.10 (95% confidence interval 1.00-1.21). CONCLUSION: We conclude that the increased risk observed in the solely register-based study could partly be attributed to unmeasured confounding....... PSs were used: The error-prone PS using register-based confounders and the calibrated PS based on both register- and survey-based confounders, retrieved from the Health Interview Survey. RESULTS: Register-based data showed that cancer cases had more diagnoses, higher comorbidity score and more co...

Association between Myocardial Infarction and Periodontitis: a Meta-Analysis of Case-Control Studies

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Quan Shi

2016-11-01

Full Text Available AbstractBackground and Objective: Many clinical researches have been carried out to investigate the relationship between myocardial infarction (MI and periodontitis. Despite most of them indicated that the periodontitis may be associated with an increased risk of MI, the findings and study types of these studies have been inconsistent. The goal of this meta-analysis was to critically assess the strength of the association between MI and periodontitis in case-control studies.Methods: PubMed and the Cochrane Library were searched for eligible case-control studies reporting relevant parameters that compared periodontal status between MI and control subjects. The odds ratios (ORs and 95% confidence intervals (CIs from each study were pooled to estimate the strength of the association between MI and periodontitis. The mean differences and 95% CIs for periodontal-related parameters were calculated to determine their overall effects.Results: Seventeen studies including a total of 3456 MI patients and 3875 non-MI control subjects were included. The pooled OR for the association between MI and periodontitis was 2.531 (95% CI: 1.927-3.324. The mean differences (95% CIs for clinical attachment loss, probing depth, bleeding on probing, plaque index, and the number of missing teeth were 1.000 (0.726-1.247, 1.209 (0.538-1.880, 0.342 (0.129-0.555, 0.383 (0.205-0.560, and 4.122 (2.012-6.232, respectively. Conclusion: With the current evidence, the results support the presence of a significant association between MI and periodontitis. Moreover, MI patients had worse periodontal and oral hygiene status and fewer teeth than did control subjects. More high-quality and well-designed studies focusing on the casual relationship between MI and periodontitis should be conducted in the future.

The association between Anoplocephala perfoliata and colic in Swedish horses--a case control study.

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Back, H; Nyman, A; Osterman Lind, E

2013-11-08

A case-control study was performed to investigate the association between colic of all types in Swedish horses and infection with the equine tapeworm Anoplocephala perfoliata. Colic cases were defined by clinical signs consistent with the presence of abdominal pain, and the control horses had no signs of colic within the last year but attended a clinic for other reasons. Blood and fecal samples were collected by veterinarian from 67 horses with signs of colic and 67 control horses. The sera were analyzed using serodiagnostic assay anti-12/13 kDa IgG(T) ELISA. The fecal samples, 30 g from each horse, were analyzed with a modified sugar salt flotation method with a density of 1.280. A significant association was found between the presence of A. perfoliata eggs in feces and colic with a 16 times higher risk of colic if eggs had been observed in fecal samples. However, there was no significant association between colic and the median OD-values in the serological diagnosis, nor when recommended cut-offs were used. The study concludes that A. perfoliata is a risk factor for colic in Swedish horses and it suggests that the modified flotation method can be used as a diagnostic tool for identifying horses at risk. Copyright © 2013. Published by Elsevier B.V.

Association between zolpidem use and glaucoma risk: a Taiwanese population-based case-control study.

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Ho, Yi-Hao; Chang, Yue-Cune; Huang, Wei-Cheng; Chen, Hsin-Yi; Lin, Che-Chen; Sung, Fung-Chang

2015-01-01

To date, the relationship between zolpidem use and subsequent risk of glaucoma in a Taiwanese population has not been assessed. We used data from the National Health Insurance system to investigate whether zolpidem use was related to glaucoma risk. A 1:4 matched case-control study was conducted. The cases were patients newly diagnosed with glaucoma from 2001 to 2010. The controls were randomly selected non-glaucoma subjects matched by sex and age (± 5 years). Zolpidem exposure and/or the average dosage of zolpidem used (mg/year) were evaluated. Medical comorbidities were considered as confounding factors. Multiple logistic regression models were used to evaluate the potential risk of zolpidem exposure on glaucoma with/without adjustment for the effects of confounding variables. The exposure rate of zolpidem use in the glaucoma group was significantly higher than that of the control group (2.8% vs. 2.0%, P zolpidem use vs. those without was 1.19 (95% confidence interval [CI], 1.02-1.38). Compared to non-zolpidem users, zolpidem users with an average dose of more than 200 mg/year had significantly increased risk of glaucoma (OR 1.31, 95% CI 1.03-1.68). This study suggests that the use of zolpidem might increase the risk of subsequent glaucoma. Further confirmatory studies are recommended to clarify this important issue.

Sample size calculations for case-control studies

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This R package can be used to calculate the required samples size for unconditional multivariate analyses of unmatched case-control studies. The sample sizes are for a scalar exposure effect, such as binary, ordinal or continuous exposures. The sample sizes can also be computed for scalar interaction effects. The analyses account for the effects of potential confounder variables that are also included in the multivariate logistic model.

High risk human papillomavirus in the periodontium : A case control study.

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Shipilova, Anna; Dayakar, Manjunath Mundoor; Gupta, Dinesh

2017-01-01

Human papilloma viruses (HPVs) are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. It is thought that the periodontium could be a reservoir for HPV. 1. Detection of Human Papilloma virus (HPV) in periodontal pocket as well as gingival of patients having localized chronic periodontitis and gingival sulcus of periodontally healthy subjects. 2. Quantitative estimation of E6 and E7 mRNA in subjects showing presence of HPV3. To assess whether periodontal pocket is a reservoir for HPV. This case-control study included 30 subjects with localized chronic Periodontitis (cases) and 30 periodontally healthy subjects (controls). Two samples were taken from cases, one from periodontal pocket and one from gingival sulcus and one sample was taken from controls. Samples were collected in the form of pocket scrapings and gingival sulcus scrapings from cases and controls respectively. These samples were sent in storage media for identification and estimation of E6/E7 mRNA of HPV using in situ hybridization and flow cytometry. Statistical analysis was done by using, mean, percentage and Chi Square test. A statistical package SPSS version 13.0 was used to analyze the data. P value oral cancer, periodontitis and HPV. However prospective studies are required to further explore this link.

Posture control and the risk of industrial accident: a stabilographic investigation in a naval shipyard.

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Moll van Charante, A W; Snijders, C J; Mulder, P G

1991-10-01

In a previous case-control study on the effect of impaired perceptual acuity on the risk of industrial injuries at a naval shipyard, three factors which might influence the perception and processing of sensory impressions--alcohol consumption, hearing loss exceeding 20 decibels (dB) and exposure to noise exceeding 82 dB(A)--were found to contribute to the risk of injury. According to recent reports, these factors can all lead to impaired posture control. Because in general about 40% of all accidents are associated with falling, tripping, slipping and the like, a supplementary study has been carried out to unravel possible confounding effects of posture control on these three risk factors. Cases (who had suffered two or more accidents during the preceding 4 years) and controls (who had been accident-free in the same period) were compared as regards posture control measured during silence or noise. No significant difference in posture control was found between cases and controls, either in silence or during exposure to heavy noise.

Putative periodontopathic bacteria and herpesviruses in pregnant women: a case-control study

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Lu, Haixia; Zhu, Ce; Li, Fei; Xu, Wei; Tao, Danying; Feng, Xiping

2016-01-01

Little is known about herpesvirus and putative periodontopathic bacteria in maternal chronic periodontitis. The present case-control study aimed to explore the potential relationship between putative periodontopathic bacteria and herpesviruses in maternal chronic periodontitis.Saliva samples were collected from 36 pregnant women with chronic periodontitis (cases) and 36 pregnant women with healthy periodontal status (controls). Six putative periodontopathic bacteria (Porphyromonas gingivalis ...

Risk Factors for Sporadic Domestically Acquired Campylobacter Infections in Norway 2010-2011: A National Prospective Case-Control Study.

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Emily MacDonald

Full Text Available Campylobacteriosis is the most frequently reported food- and waterborne infection in Norway. We investigated the risk factors for sporadic Campylobacter infections in Norway in order to identify areas where control and prevention measures could be improved.A national prospective case-control study of factors associated with Campylobacter infection was conducted from July 2010 to September 2011. Cases were recruited from the Norwegian Surveillance System of Communicable Diseases (MSIS. Controls were randomly selected from the Norwegian Population Registry. Cases and controls were mailed a paper questionnaire with a prepaid return envelope. Univariable analyses using logistic regression were conducted for all exposures. A final parsimonious multivariable model was developed using regularized/penalized logistic regression, and adjusted odds ratios were calculated.A total of 995 cases and 1501 controls were included in the study (response proportion 55% and 30%, respectively. Exposures that had significant increases in odds of Campylobacter infection in multivariable analysis were drinking water directly from river, stream, or lake (OR: 2.96, drinking purchased bottled water (OR: 1.78, eating chicken (1.69, eating meat that was undercooked (OR: 1.77, eating food made on a barbecue (OR: 1.55, living on a farm with livestock (OR: 1.74, having a dog in the household (OR: 1.39, and having household water supply serving fewer than 20 houses (OR: 1.92.Consumption of poultry and untreated water remain important sources of Campylobacter infection in Norway, despite ongoing control efforts. The results justify the need for strengthening education for consumers and food handlers about the risks of cross-contamination when preparing poultry and with consuming raw or undercooked chicken. The public should also be reminded to take precautions when drinking untreated water in nature and ensure continued vigilance in order to protect and maintain the quality of

Risk Factors for Sporadic Domestically Acquired Campylobacter Infections in Norway 2010-2011: A National Prospective Case-Control Study.

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MacDonald, Emily; White, Richard; Mexia, Ricardo; Bruun, Tone; Kapperud, Georg; Lange, Heidi; Nygård, Karin; Vold, Line

2015-01-01

Campylobacteriosis is the most frequently reported food- and waterborne infection in Norway. We investigated the risk factors for sporadic Campylobacter infections in Norway in order to identify areas where control and prevention measures could be improved. A national prospective case-control study of factors associated with Campylobacter infection was conducted from July 2010 to September 2011. Cases were recruited from the Norwegian Surveillance System of Communicable Diseases (MSIS). Controls were randomly selected from the Norwegian Population Registry. Cases and controls were mailed a paper questionnaire with a prepaid return envelope. Univariable analyses using logistic regression were conducted for all exposures. A final parsimonious multivariable model was developed using regularized/penalized logistic regression, and adjusted odds ratios were calculated. A total of 995 cases and 1501 controls were included in the study (response proportion 55% and 30%, respectively). Exposures that had significant increases in odds of Campylobacter infection in multivariable analysis were drinking water directly from river, stream, or lake (OR: 2.96), drinking purchased bottled water (OR: 1.78), eating chicken (1.69), eating meat that was undercooked (OR: 1.77), eating food made on a barbecue (OR: 1.55), living on a farm with livestock (OR: 1.74), having a dog in the household (OR: 1.39), and having household water supply serving fewer than 20 houses (OR: 1.92). Consumption of poultry and untreated water remain important sources of Campylobacter infection in Norway, despite ongoing control efforts. The results justify the need for strengthening education for consumers and food handlers about the risks of cross-contamination when preparing poultry and with consuming raw or undercooked chicken. The public should also be reminded to take precautions when drinking untreated water in nature and ensure continued vigilance in order to protect and maintain the quality of water

The effects of umbilical cord entanglement upon labor management and fetal health: retrospective case control study.

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Buyukkayaci Duman, Nuriye; Topuz, Senay; Bostanci, Mehmet Omer; Gorkem, Umit; Yuksel Kocak, Derya; Togrul, Cihan; Gungor, Tayfun

2018-03-01

This retrospective study aimed at determining prognostic factors that paved the way for umbilical cord entanglement (UCE) and the effects of UCE upon labor management and fetal health. Sixty women who gave term birth with head presentation and received UCE diagnosis following birth composed the case group while another 60 women with the same characteristics who were selected with randomized sampling method and who did not develop UCE comprised the control group. The data obtained were processed with SPSS 22.0 statistical program. T test was used for comparing demographic and obstetric data and mean birth weight of babies in the case group and control group. For comparing data on active labor management and fetal health, numbers, percentages and chi-square test were used. Also for comparing values case: 58.3.0%; control: 21.7%), vacuum assisted vaginal delivery (case: 20.0%; control: 3.3%), forceps assisted vaginal delivery (case: 8.3%; control: 1.7%), fetal distress (case: 60.0%; control: 25.0%), amniotic fluid meconium (case: 58.3%; control: 21.7%), APGAR score less than 7 at the 1st minute (case: 58.3%; control: 21.7%) and APGAR score less than 7 at the 5th minute were higher in the women in the case group than the women in the control group (p < 0.05). UCE increased rates of interventional birth, emergent cesarean delivery, vacuum assisted vaginal delivery, forceps assisted vaginal delivery, amniotic fluid meconium and fetal distress.

Hospital-treated mental and behavioral disorders and risk of Alzheimer's disease: A nationwide nested case-control study.

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Tapiainen, V; Hartikainen, S; Taipale, H; Tiihonen, J; Tolppanen, A-M

2017-06-01

Studies investigating psychiatric disorders as Alzheimer's disease (AD) risk factors have yielded heterogeneous findings. Differences in time windows between the exposure and outcome could be one explanation. We examined whether (1) mental and behavioral disorders in general or (2) specific mental and behavioral disorder categories increase the risk of AD and (3) how the width of the time window between the exposure and outcome affects the results. A nationwide nested case-control study of all Finnish clinically verified AD cases, alive in 2005 and their age, sex and region of residence matched controls (n of case-control pairs 27,948). History of hospital-treated mental and behavioral disorders was available since 1972. Altogether 6.9% (n=1932) of the AD cases and 6.4% (n=1784) of controls had a history of any mental and behavioral disorder. Having any mental and behavioral disorder (adjusted OR=1.07, 95% CI=1.00-1.16) or depression/other mood disorder (adjusted OR=1.17, 95% CI=1.05-1.30) were associated with higher risk of AD with 5-year time window but not with 10-year time window (adjusted OR, 95% CI 0.99, 0.91-1.08 for any disorder and 1.08, 0.96-1.23 for depression). The associations between mental and behavioral disorders and AD were modest and dependent on the time window. Therefore, some of the disorders may represent misdiagnosed prodromal symptoms of AD, which underlines the importance of proper differential diagnostics among older persons. These findings also highlight the importance of appropriate time window in psychiatric and neuroepidemiology research. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Plasma carotenoids, vitamin C, retinol and tocopherols levels and pancreatic cancer risk within the European Prospective Investigation into Cancer and Nutrition: a nested case-control study: plasma micronutrients and pancreatic cancer risk.

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Jeurnink, Suzanne M; Ros, Martine M; Leenders, Max; van Duijnhoven, Franzel J B; Siersema, Peter D; Jansen, Eugene H J M; van Gils, Carla H; Bakker, Marije F; Overvad, Kim; Roswall, Nina; Tjønneland, Anne; Boutron-Ruault, Marie-Christine; Racine, Antoine; Cadeau, Claire; Grote, Verena; Kaaks, Rudolf; Aleksandrova, Krasimira; Boeing, Heiner; Trichopoulou, Antonia; Benetou, Vasiliki; Valanou, Elisavet; Palli, Domenico; Krogh, Vittorio; Vineis, Paolo; Tumino, Rosario; Mattiello, Amalia; Weiderpass, Elisabete; Skeie, Guri; Castaño, José María Huerta; Duell, Eric J; Barricarte, Aurelio; Molina-Montes, Esther; Argüelles, Marcial; Dorronsoro, Mire; Johansen, Dorthe; Lindkvist, Björn; Sund, Malin; Crowe, Francesca L; Khaw, Kay-Tee; Jenab, Mazda; Fedirko, Veronika; Riboli, E; Bueno-de-Mesquita, H B

2015-03-15

Evidence of a protective effect of several antioxidants and other nutrients on pancreatic cancer risk is inconsistent. The aim of this study was to investigate the association for prediagnostic plasma levels of carotenoids, vitamin C, retinol and tocopherols with risk of pancreatic cancer in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC). 446 incident exocrine pancreatic cancer cases were matched to 446 controls by age at blood collection, study center, sex, date and time of blood collection, fasting status and hormone use. Plasma carotenoids (α- and β-carotene, lycopene, β-cryptoxanthin, canthaxanthin, zeaxanthin and lutein), α- and γ-tocopherol and retinol were measured by reverse phase high-performance liquid chromatography and plasma vitamin C by a colorimetric assay. Incidence rate ratios (IRRs) with 95% confidence intervals (95%CIs) for pancreatic cancer risk were estimated using a conditional logistic regression analysis, adjusted for smoking status, smoking duration and intensity, waist circumference, cotinine levels and diabetes status. Inverse associations with pancreatic cancer risk were found for plasma β-carotene (IRR highest vs. lowest quartile 0.52, 95%CI 0.31-0.88, p for trend = 0.02), zeaxanthin (IRR highest vs. lowest quartile 0.53, 95%CI 0.30-0.94, p for trend = 0.06) and α-tocopherol (IRR highest vs. lowest quartile 0.62, 95%CI 0.39-0.99, p for trend = 0.08. For α- and β-carotene, lutein, sum of carotenoids and γ-tocopherol, heterogeneity between geographical regions was observed. In conclusion, our results show that higher plasma concentrations of β-carotene, zeaxanthin and α-tocopherol may be inversely associated with risk of pancreatic cancer, but further studies are warranted. © 2014 UICC.

Differential epidemiology of Salmonella Typhi and Paratyphi A in Kathmandu, Nepal: a matched case control investigation in a highly endemic enteric fever setting.

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Abhilasha Karkey

Full Text Available Enteric fever, a systemic infection caused by the bacteria Salmonella Typhi and Salmonella Paratyphi A, is endemic in Kathmandu, Nepal. Previous work identified proximity to poor quality water sources as a community-level risk for infection. Here, we sought to examine individual-level risk factors related to hygiene and sanitation to improve our understanding of the epidemiology of enteric fever in this setting.A matched case-control analysis was performed through enrollment of 103 blood culture positive enteric fever patients and 294 afebrile community-based age and gender-matched controls. A detailed questionnaire was administered to both cases and controls and the association between enteric fever infection and potential exposures were examined through conditional logistic regression. Several behavioral practices were identified as protective against infection with enteric fever, including water storage and hygienic habits. Additionally, we found that exposures related to poor water and socioeconomic status are more influential in the risk of infection with S. Typhi, whereas food consumption habits and migration play more of a role in risk of S. Paratyphi A infection.Our work suggests that S. Typhi and S. Paratyphi A follow different routes of infection in this highly endemic setting and that sustained exposure to both serovars probably leads to the development of passive immunity. In the absence of a polyvalent vaccine against S. Typhi and S. Paratyphi A, we advocate better systems for water treatment and storage, improvements in the quality of street food, and vaccination with currently available S. Typhi vaccines.

Aetiology of handball injuries : a case-control study

NARCIS (Netherlands)

Dirx, M.; Bouter, L. M.; de Geus, G. H.

This article presents the results of a case-control study regarding the background to handball injuries among players of 12 years and older. Data were collected by means of a written questionnaire on the nature, location and direct causes of the injuries as well as information on risk factors.

How valid is the prenatal estrogen excess hypothesis of testicular germ cell cancer? A case control study on hormone-related factors.

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Dieckmann, K P; Endsin, G; Pichlmeier, U

2001-12-01

The prenatal estrogen excess hypothesis postulates abnormally high estrogen levels during pregnancy which predispose the developing gonad to testicular germ cell cancer (GCT) in adulthood. As no direct measurements are possible to support this hypothesis, evidence must come from clinical and epidemiological observations. The present study looked to surrogate parameters that purportedly point to high estrogenic influence in utero. In a case-control study design, 418 cases with GCT were compared to 636 controls having fractures, injuries or nephrolithiasis. A second comparison was done with 120 men suffering from malignant melanoma. The following factors were investigated: maternal and paternal age at birth of proband, birth-order, distribution of brothers and sisters in sibs of patients, sibship size, status of being a twin, status of being a singleton child, handedness, and frequency of breast cancer in mothers and sisters. Status of being a twin was significantly associated with GCT risk (OR 2.41; 95% CI 1.04- 5.63) if compared to men with fractures or stones. Comparison with melanoma controls showed only a nonsignificant trend. Frequency of breast cancer was insignificantly higher in mothers of GCT patients. Maternal age above 30 years was associated with decreased risk of GCT, which is contradictory to the hypothesis. No other parameter was significantly different in cases and controls. The present investigation failed to produce evidence for the estrogen excess hypothesis. Obviously, the parameters tested are only weak indicators of estrogenic influence during embryogenesis. Thus, the sample size and statistical power of the trial might have been too low to show any significant association. But, assessing the negative results of this study in light of equally negative results in previous investigations, the estrogen excess hypothesis still remains to be hypothetic.

Internet-based control recruitment for a case-control study of major risk factors for stroke in Korea: lessons from the experience.

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Park, Jong-Moo; Cho, Yong-Jin; Lee, Kyung Bok; Park, Tai Hwan; Lee, Soo Joo; Han, Moon-Ku; Ko, Youngchai; Lee, Jun; Cha, Jae-Kwan; Lee, Byung-Chul; Yu, Kyung-Ho; Oh, Mi-Sun; Lee, Ji Sung; Lee, Juneyoung; Bae, Hee-Joon

2014-01-01

This study aimed to estimate the population-attributable risks (PARs) of 9 major risk factors for stroke in Korea through a case-control study and to test the feasibility and validity of internet-based control recruitment. From April 2008 to September 2009, controls were enrolled via internet after providing consent for participation through a web-based survey. The cases included patients who were admitted to the participating centers due to acute stroke or transient ischemic attack within 7 days of onset during the study period. Each control was age- and sex-matched with 2 cases. Adjusted odd ratios, age-standardized prevalence, and PARs were estimated for the 9 major risk factors using the prevalence of risk factors in the control group and the age and sex characteristics from Korea's national census data. In total, 1041 controls were matched to 2082 stroke cases. Because of a shortage of elderly controls in the internet-based recruitment, 248 controls were recruited off-line. The PARs were 23.44%, 10.95%, 51.32%, and 6.35% for hypertension, diabetes, smoking, and stroke history, respectively. Hypercholesterolemia, atrial fibrillation, obesity, coronary heart disease, and a family history of stroke were not associated with stroke. Comparison with education and religion of the control group with that mentioned in the national census data showed a notable difference. The study results imply that internet-based control recruitment for a case-control study requires careful selection of risk factors with high self-awareness and effective strategies to facilitate the recruitment of elderly participants. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Factors associated with anti-tuberculosis medication adverse effects: a case-control study in Lima, Peru.

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Chung-Delgado, Kocfa; Revilla-Montag, Alejandro; Guillen-Bravo, Sonia; Velez-Segovia, Eduardo; Soria-Montoya, Andrea; Nuñez-Garbin, Alexandra; Silva-Caso, Wilmer; Bernabe-Ortiz, Antonio

2011-01-01

Long-term exposure to anti-tuberculosis medication increases risk of adverse drug reactions and toxicity. The objective of this investigation was to determine factors associated with anti-tuberculosis adverse drug reactions in Lima, Peru, with special emphasis on MDR-TB medication, HIV infection, diabetes, age and tobacco use. A case-control study was performed using information from Peruvian TB Programme. A case was defined as having reported an anti-TB adverse drug reaction during 2005-2010 with appropriate notification on clinical records. Controls were defined as not having reported a side effect, receiving anti-TB therapy during the same time that the case had appeared. Crude, and age- and sex-adjusted models were calculated using odds ratios (OR) and 95% confidence intervals (95%CI). A multivariable model was created to look for independent factors associated with side effect from anti-TB therapy. A total of 720 patients (144 cases and 576 controls) were analyzed. In our multivariable model, age, especially those over 40 years (OR = 3.93; 95%CI: 1.65-9.35), overweight/obesity (OR = 2.13; 95%CI: 1.17-3.89), anemia (OR = 2.10; IC95%: 1.13-3.92), MDR-TB medication (OR = 11.1; 95%CI: 6.29-19.6), and smoking (OR = 2.00; 95%CI: 1.03-3.87) were independently associated with adverse drug reactions. Old age, anemia, MDR-TB medication, overweight/obesity status, and smoking history are independent risk factors associated with anti-tuberculosis adverse drug reactions. Patients with these risk factors should be monitored during the anti-TB therapy. A comprehensive clinical history and additional medical exams, including hematocrit and HIV-ELISA, might be useful to identify these patients.

Factors associated with anti-tuberculosis medication adverse effects: a case-control study in Lima, Peru.

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Kocfa Chung-Delgado

Full Text Available BACKGROUND: Long-term exposure to anti-tuberculosis medication increases risk of adverse drug reactions and toxicity. The objective of this investigation was to determine factors associated with anti-tuberculosis adverse drug reactions in Lima, Peru, with special emphasis on MDR-TB medication, HIV infection, diabetes, age and tobacco use. METHODOLOGY AND RESULTS: A case-control study was performed using information from Peruvian TB Programme. A case was defined as having reported an anti-TB adverse drug reaction during 2005-2010 with appropriate notification on clinical records. Controls were defined as not having reported a side effect, receiving anti-TB therapy during the same time that the case had appeared. Crude, and age- and sex-adjusted models were calculated using odds ratios (OR and 95% confidence intervals (95%CI. A multivariable model was created to look for independent factors associated with side effect from anti-TB therapy. A total of 720 patients (144 cases and 576 controls were analyzed. In our multivariable model, age, especially those over 40 years (OR = 3.93; 95%CI: 1.65-9.35, overweight/obesity (OR = 2.13; 95%CI: 1.17-3.89, anemia (OR = 2.10; IC95%: 1.13-3.92, MDR-TB medication (OR = 11.1; 95%CI: 6.29-19.6, and smoking (OR = 2.00; 95%CI: 1.03-3.87 were independently associated with adverse drug reactions. CONCLUSIONS: Old age, anemia, MDR-TB medication, overweight/obesity status, and smoking history are independent risk factors associated with anti-tuberculosis adverse drug reactions. Patients with these risk factors should be monitored during the anti-TB therapy. A comprehensive clinical history and additional medical exams, including hematocrit and HIV-ELISA, might be useful to identify these patients.

Circulating folate levels and colorectal adenoma: a case-control study and a meta-analysis.

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Park, Yeong Mi; Youn, Jiyoung; Cho, Chang Ho; Kim, Sung Hi; Lee, Jung Eun

2017-10-01

The relationship between folate and colorectal neoplasia remains controversial. We examined the association between serum folate concentrations and colorectal adenomas in a case-control study of Korean adults and conducted a meta-analysis. Our case-control study included 113 pairs of case and control who underwent colonoscopy and provided blood samples. We used multivariable conditional logistic regression models to obtain the odds ratios and 95% confidence interval (CIs). For meta-analysis, we identified the relevant studies by searching the PubMed database up to February 2017, included our case-control study and combined the study-specific relative risks (RRs) using a random-effects model. In this case-control study, we included 58 men and 55 women with colorectal adenomas and sex and fasting status matched the controls. We did not find any significant association between the serum folate levels and colorectal adenomas in either men or women. For meta-analysis, a total of eleven studies were included in our analysis and classified into two groups; polyp clearance group (PC) for the studies that included participants who underwent endoscopies and had their polyps removed at baseline; and no polyp clearance group (NPC) for the studies that included participants whose histories of endoscopies were unknown or who underwent their first endoscopies. Four PC (1,311 cases and 1,672 non-cases) and eight NPC studies (3,501 cases and 11,347 non-cases) were included. The combined RRs (95% CIs) comparing the bottom with the top categories of circulating folate levels were 1.07 (0.97-1.18) for the NPC group but 1.45 (1.16-1.74) for the PC group. Low circulating folate levels were associated with new adenoma formation.

Multilingual home environment and specific language impairment: a case-control study in Chinese children.

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Cheuk, Daniel Ka Leung; Wong, Virginia; Leung, Gabriel Matthew

2005-07-01

Specific language impairment (SLI) is a common developmental disorder in young children. To investigate the association between multilingual home environment and SLI, we conducted a case-control study in Hong Kong Chinese children over a 4-year period in the Duchess of Kent Children's Hospital. Consecutive medical records of all new referrals below 5 years of age were reviewed and children diagnosed with SLI (case) were compared with those referred with other developmental and behavioural problems who had been assessed as having normal language and overall development (control) using the Griffiths Mental Developmental Scale. SLI was defined as those with a language quotient more than one standard deviation below the mean and below the general developmental quotient in children with normal general developmental quotient, but without neurological or other organic diseases. We used binary and ordinal logistic regression to assess any association between SLI and multilingual exposure at home, adjusting for age and gender of subjects, parental age, education level and occupational status, number of siblings, family history of language delay and main caregiver at home. Multivariable linear regression was used to examine the effect of covariates on the language comprehension and expression standard scores assessed by the Reynell Developmental Language Scale. A total of 326 cases and 304 controls were included. The mean ages of cases and controls were 2.56 and 2.89 years respectively. Boys predominated in both groups (cases, 75.2%; controls, 60.2%). The children were exposed to between one and four languages at home, the major ones being Cantonese Chinese followed by English. The adjusted odds ratio (OR) of SLI was 2.94; [95% confidence interval (CI) 1.82, 4.74] for multilingual compared with monolingual exposure. A significant linear dose-response relationship was found (OR of SLI = 2.58 [1.72, 3.88] for each additional language to which the child was exposed). Male

Association between Zika virus infection and microcephaly in Brazil, January to May, 2016: preliminary report of a case-control study.

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de Araújo, Thalia Velho Barreto; Rodrigues, Laura Cunha; de Alencar Ximenes, Ricardo Arraes; de Barros Miranda-Filho, Demócrito; Montarroyos, Ulisses Ramos; de Melo, Ana Paula Lopes; Valongueiro, Sandra; de Albuquerque, Maria de Fátima Pessoa Militão; Souza, Wayner Vieira; Braga, Cynthia; Filho, Sinval Pinto Brandão; Cordeiro, Marli Tenório; Vazquez, Enrique; Di Cavalcanti Souza Cruz, Danielle; Henriques, Cláudio Maierovitch Pessanha; Bezerra, Luciana Caroline Albuquerque; da Silva Castanha, Priscila Mayrelle; Dhalia, Rafael; Marques-Júnior, Ernesto Torres Azevedo; Martelli, Celina Maria Turchi

2016-12-01

The microcephaly epidemic, which started in Brazil in 2015, was declared a Public Health Emergency of International Concern by WHO in 2016. We report the preliminary results of a case-control study investigating the association between microcephaly and Zika virus infection during pregnancy. We did this case-control study in eight public hospitals in Recife, Brazil. Cases were neonates with microcephaly. Two controls (neonates without microcephaly), matched by expected date of delivery and area of residence, were selected for each case. Serum samples of cases and controls and cerebrospinal fluid samples of cases were tested for Zika virus-specific IgM and by quantitative RT-PCR. Laboratory-confirmed Zika virus infection during pregnancy was defined as detection of Zika virus-specific IgM or a positive RT-PCR result in neonates. Maternal serum samples were tested by plaque reduction neutralisation assay for Zika virus and dengue virus. We estimated crude odds ratios (ORs) and 95% CIs using a median unbiased estimator for binary data in an unconditional logistic regression model. We estimated ORs separately for cases with and without radiological evidence of brain abnormalities. Between Jan 15, 2016, and May 2, 2016, we prospectively recruited 32 cases and 62 controls. 24 (80%) of 30 mothers of cases had Zika virus infection compared with 39 (64%) of 61 mothers of controls (p=0·12). 13 (41%) of 32 cases and none of 62 controls had laboratory-confirmed Zika virus infection; crude overall OR 55·5 (95% CI 8·6-∞); OR 113·3 (95% CI 14·5-∞) for seven cases with brain abnormalities; and OR 24·7 (95% CI 2·9-∞) for four cases without brain abnormalities. Our data suggest that the microcephaly epidemic is a result of congenital Zika virus infection. We await further data from this ongoing study to assess other potential risk factors and to confirm the strength of association in a larger sample size. Brazilian Ministry of Health, Pan American Health Organization

Knee movement patterns of injured and uninjured adolescent basketball players when landing from a jump: A case-control study

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Grimmer Karen

2006-03-01

Full Text Available Abstract Background A common knee injury mechanism sustained during basketball is landing badly from a jump. Landing is a complex task and requires good coordination, dynamic muscle control and flexibility. For adolescents whose coordination and motor control has not fully matured, landing badly from a jump can present a significant risk for injury. There is currently limited biomechanical information regarding the lower limb kinetics of adolescents when jumping, specifically regarding jump kinematics comparing injured with uninjured adolescents. This study reports on an investigation of biomechanical differences in landing patterns of uninjured and injured adolescent basketball players. Methods A matched case-control study design was employed. Twenty-two basketball players aged 14–16 years participated in the study: eleven previously knee-injured and eleven uninjured players matched with cases for age, gender, weight, height and years of play, and playing for the same club. Six high-speed, three-dimensional Vicon 370 cameras (120 Hz, Vicon biomechanical software and SAS Version 8 software were employed to analyse landing patterns when subjects performed a "jump shot". Linear correlations determined functional relationships between the biomechanical performance of lower limb joints, and paired t-tests determined differences between the normalised peak biomechanical parameters. Results The average peak vertical ground reaction forces between the cases and controls were similar. The average peak ground reaction forces between the cases and controls were moderately correlated (r = -0.47. The control (uninjured players had significantly greater hip and knee flexion angles and significantly greater eccentric activity on landing than the uninjured cases (p Conclusion The findings of the study indicate that players with a history of knee injuries had biomechanically compromised landing techniques when compared with uninjured players matched for

Environmental and occupational risk factors for progressive supranuclear palsy: Case-control study.

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Litvan, Irene; Lees, Peter S J; Cunningham, Christopher R; Rai, Shesh N; Cambon, Alexander C; Standaert, David G; Marras, Connie; Juncos, Jorge; Riley, David; Reich, Stephen; Hall, Deborah; Kluger, Benzi; Bordelon, Yvette; Shprecher, David R

2016-05-01

The cause of progressive supranuclear palsy (PSP) is largely unknown. Based on evidence for impaired mitochondrial activity in PSP, we hypothesized that the disease may be related to exposure to environmental toxins, some of which are mitochondrial inhibitors. This multicenter case-control study included 284 incident PSP cases of 350 cases and 284 age-, sex-, and race-matched controls primarily from the same geographical areas. All subjects were administered standardized interviews to obtain data on demographics, residential history, and lifetime occupational history. An industrial hygienist and a toxicologist unaware of case status assessed occupational histories to estimate past exposure to metals, pesticides, organic solvents, and other chemicals. Cases and controls were similar on demographic factors. In unadjusted analyses, PSP was associated with lower education, lower income, more smoking pack-years, more years of drinking well water, more years living on a farm, more years living 1 mile from an agricultural region, more transportation jobs, and more jobs with exposure to metals in general. However, in adjusted models, only more years of drinking well water was significantly associated with PSP. There was an inverse association with having a college degree. We did not find evidence for a specific causative chemical exposure; higher number of years of drinking well water is a risk factor for PSP. This result remained significant after adjusting for income, smoking, education and occupational exposures. This is the first case-control study to demonstrate PSP is associated with environmental factors. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

The effect of N-acetyl cysteine (NAC) on aluminum phosphide poisoning inducing cardiovascular toxicity: a case-control study.

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Taghaddosinejad, Fakhreddin; Farzaneh, Esmaeil; Ghazanfari-Nasrabad, Mahdi; Eizadi-Mood, Nastaran; Hajihosseini, Morteza; Mehrpour, Omid

2016-01-01

Aluminum phosphide (AlP) is a very effective indoor and outdoor pesticide. We investigated the effects of N-acetyl cysteine (NAC) on the survival time, hemodynamics, and cardiac biochemical parameters at various time intervals in some cases of AlP poisoning. This research was a case-control study to evaluate 63 AlP poisoned patients during 2010-2012. Patients with cardiovascular complications of AlP to be treated with intravenous NAC plus conventional treatment were considered as the case group and compared with patients who did not receive NAC. NAC infusion was administered to the case group at 300 mg/kg for 20 h. The data gathered included age, sex, heart rate, Systolic blood pressure (SBP), creatine phosphokinase (CPK), creatine kinase MB (CK-MB), and ECG at the admission time and 12, 18, and 24 h after admission. Analysis of repeated measures was performed to check the variability of parameters over time. The mean ages in the case and control groups were 26.65 ± 1.06 (19-37 years) and 28.39 ± 1.11 (18-37 years), respectively (P = 0.266). Most of the patients were female (56.5%). CK-MB means were significantly different between the two groups, but no differences between the other variables were observed. Also, CK-MB, CPK, heart rate, and systolic blood pressure means became significantly different over time (0, 12, 18, and 24 h) in both groups (P managed by the positive role of NAC as the biochemical index of cardiotoxicity was found to elevate in both the case and control groups. Therefore, for the management protocol optimization, NAC evaluation should be done in further cases.

Smoking, alcohol, and coffee consumption preceding Parkinson's disease: a case-control study.

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Benedetti, M D; Bower, J H; Maraganore, D M; McDonnell, S K; Peterson, B J; Ahlskog, J E; Schaid, D J; Rocca, W A

2000-11-14

To study the association of PD with preceding smoking, alcohol, and coffee consumption using a case-control design. The authors used the medical records linkage system of the Rochester Epidemiology Project to identify 196 subjects who developed PD in Olmsted County, MN, during the years 1976 to 1995. Each incident case was matched by age (+/-1 year) and sex to a general population control subject. The authors reviewed the complete medical records of cases and control subjects to abstract exposure information. For coffee consumption, the authors found an OR of 0.35 (95% CI = 0.16 to 0.78, p = 0.01), a dose-effect trend (p = 0.003), and a later age at PD onset in cases who drank coffee compared with those who never did (median 72 versus 64 years; p = 0.0002). The inverse association with coffee remained significant after adjustment for education, smoking, and alcohol drinking and was restricted to PD cases with onset at age coffee drinking and PD; however, this association does not imply that coffee has a direct protective effect against PD. Alternative explanations for the association should be considered.

Genetic susceptibility loci, environmental exposures, and Parkinson's disease: a case-control study of gene-environment interactions.

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Chung, Sun Ju; Armasu, Sebastian M; Anderson, Kari J; Biernacka, Joanna M; Lesnick, Timothy G; Rider, David N; Cunningham, Julie M; Ahlskog, J Eric; Frigerio, Roberta; Maraganore, Demetrius M