			Home About us Contact

Epidemiological Investigations (epidemiological + investigation)

Distribution by Scientific Domains

Medical Sciences	62%
Life Sciences	33%

Selected Abstracts

Patients' conceptions of the cause of their rheumatoid arthritis: A qualitative study

MUSCULOSKELETAL CARE, Issue 4 2009
MScN, Ulrika Bergsten RN
Abstract Background:,Patients' perspective of the causes and consequences of rheumatoid arthritis (RA) can conflict with that of healthcare professionals and lead to misunderstanding, difficulties in management and a poorer outcome. Objectives:,The aim of this study was to describe the variation in how patients' conceive the cause of their RA. Methods:,An open written question from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study, aimed at patients recently diagnosed with RA, was answered by 38 strategically selected patients during 2003 and analysed using the phenomenographic approach. Results:,Two descriptive categories and six concepts emerged: the category ,consequences beyond personal control' comprised not having a clue, being exposed to climatic change, being genetically exposed and unexpected effects of events; the category ,overloaded circumstances' involved work and family-related strain. Consequences beyond personal control implied that the patients could not prevent the disease and expressed their lack of understanding as to why they contracted it. Overloaded circumstances were described as strained situations that were both work and family related and could be influenced by the patient. Conclusions:,The patient's perspective of the cause of their RA includes aspects that complement the current pathogenetic models and should therefore be considered in the management of the disease. When dealing with rheumatic diseases, it is necessary to be aware of the patient's perspectives in order to new management strategies. In addition to epidemiological studies, further studies of patients' own experience are needed in order to achieve a more tailored care model. Copyright © 2009 John Wiley & Sons, Ltd [source]

Gene,environment interaction between the DRB1 shared epitope and smoking in the risk of anti,citrullinated protein antibody,positive rheumatoid arthritis: All alleles are important

ARTHRITIS & RHEUMATISM, Issue 6 2009
Emeli Lundström
Objective An interaction effect for developing rheumatoid arthritis (RA) was previously observed between HLA,DRB1 shared epitope (SE) alleles and smoking. We aimed to further investigate this interaction between distinct SE alleles and smoking regarding the risk of developing RA with and without anti,citrullinated protein antibodies (ACPAs). Methods We used data regarding smoking habits and HLA,DRB1 genotypes from 1,319 patients and 943 controls from the Epidemiological Investigation of Rheumatoid Arthritis, in which 972 patients and 488 controls were SE positive. Subsequently, 759 patients and 328 controls were subtyped for specific alleles within the DRB1*04 group. Odds ratios with 95% confidence intervals (95% CIs) were calculated by means of logistic regression. Interaction was evaluated by calculating attributable proportion due to interaction, with 95% CIs. Results A strong interaction between smoking and SE alleles in the development of ACPA-positive RA was observed for all DRB1*04 SE alleles taken as a group (relative risk [RR] 8.7 [95% CI 5.7,13.1]) and for the *0401 and *0404 alleles (RR 8.9 [95% CI 5.8,13.5]) and the *01 and *10 alleles (RR 4.9 [95% CI 3.0,7.8]) as specific, separate groups, with similar strength of interaction for the different groups (attributable proportion due to interaction 0.4 [95% CI 0.2,0.6], 0.5 [95% CI 0.3,0.7], and 0.6 [95% CI 0.4,0.8], respectively). Conclusion There is a statistically significant interaction between distinct DRB1 SE alleles and smoking in the development of ACPA-positive RA. Interaction occurs with the *04 group as well as the *01/*10 group, demonstrating that regardless of fine specificity, all SE alleles strongly interact with smoking in conferring an increased risk of ACPA-positive RA. [source]

Opposing effects of HLA,DRB1*13 alleles on the risk of developing anti,citrullinated protein antibody,positive and anti,citrullinated protein antibody,negative rheumatoid arthritis

ARTHRITIS & RHEUMATISM, Issue 4 2009
Emeli Lundström
Objective The effect of non,shared epitope HLA,DRB1 alleles on rheumatoid arthritis (RA) is poorly understood. This study was undertaken to investigate the effects of several HLA,DRB1 alleles, independent of the shared epitope, on the risk of developing anti,citrullinated protein antibody (ACPA),positive or ACPA-negative RA in a large case,control study. Methods HLA typing for the DRB1 gene was performed in 1,352 patients with RA and 922 controls from the Swedish Epidemiological Investigation of Rheumatoid Arthritis study. Relative risks (RRs) and 95% confidence intervals (95% CIs) were calculated. Results DRB1*13 was found to protect against ACPA-positive RA when stratifying for the shared epitope and using a dominant genetic model (RR 0.41 [95% CI 0.26,0.64]). Furthermore, DRB1*13 neutralized the effect of the shared epitope in ACPA-positive RA (RR 3.91 [95% CI 3.04,5.02] in patients who had the shared epitope but not DRB1*13, and RR 1.22 [95% CI 0.81,1.83] in patients with both the shared epitope and DRB1*13, as compared with patients negative for both the shared epitope and DRB1*13). However, we did not replicate the previous published risk of ACPA-negative RA conferred by DRB1*03 when a dominant genetic model was used (RR 1.29 [95% CI 0.91,1.82]). Similarly, no significant effect of DRB1*03 on RR for ACPA-negative RA was seen using the recessive genetic model (RR 1.18 [95% CI 0.6,2.4]). In contrast, the combination of DRB1*03 and DRB1*13 was significantly associated with increased risk of developing ACPA-negative RA (RR 2.07 [95% CI 1.17,3.67]). Conclusion Our findings indicate that the DRB1*13 allele plays a dual role in the development of RA, by protecting against ACPA-positive RA but, in combination with DRB1*03, increasing the risk of ACPA-negative RA. [source]

Different patterns of associations with anti,citrullinated protein antibody,positive and anti,citrullinated protein antibody,negative rheumatoid arthritis in the extended major histocompatibility complex region

ARTHRITIS & RHEUMATISM, Issue 1 2009
Bo Ding
Objective To identify additional variants in the major histocompatibility complex (MHC) region that independently contribute to risk in 2 disease subsets of rheumatoid arthritis (RA) defined according to the presence or absence of antibodies to citrullinated protein antigens (ACPAs). Methods In a multistep analytical strategy using unmatched as well as matched analyses to adjust for HLA,DRB1 genotype, we analyzed 2,221 single-nucleotide polymorphisms (SNPs) spanning 10.7 Mb, from 6p22.2 to 6p21.31, across the MHC. For ACPA-positive RA, we analyzed samples from the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA) and the North American Rheumatoid Arthritis Consortium (NARAC) studies (totaling 1,255 cases and 1,719 controls). For ACPA-negative RA, we used samples from the EIRA study (640 cases and 670 controls). Plink and SAS statistical packages were used to conduct all statistical analyses. Results A total of 299 SNPs reached locus-wide significance (P < 2.3 × 10,5) for ACPA-positive RA, whereas surprisingly, no SNPs reached this significance for ACPA-negative RA. For ACPA-positive RA, we adjusted for known DRB1 risk alleles and identified additional independent associations with SNPs near HLA,DPB1 (rs3117213; odds ratio 1.42 [95% confidence interval 1.17,1.73], Pcombined = 0.0003 for the strongest association). Conclusion There are distinct genetic patterns of MHC associations in the 2 disease subsets of RA defined according to ACPA status. HLA,DPB1 is an independent risk locus for ACPA-positive RA. We did not identify any associations with SNPs within the MHC for ACPA-negative RA. [source]

An outbreak of HBV and HCV infection in a paediatric oncology ward: Epidemiological investigations and prevention of further spread

JOURNAL OF MEDICAL VIROLOGY, Issue 3 2003
Uga Dumpis
Abstract Hospital-acquired hepatitis B (HBV) and C virus (HCV) infections continue to occur despite increased awareness of this problem among the medical community. One hundred six patients were infected in a haematology oncology ward for children, over the time period 1996 to 2000. Serum samples from 45 such patients and 3 from infected medical personnel were used for nucleic acid amplification. HBV core, as well as HCV core and hypervariable region 1 (HVR1) nucleotide sequences, were analysed by phylogenetic tree analysis, in order to characterise the epidemiological pattern of viral transmission on the ward. Samples from 32 patients were positive for HBV-DNA or HCV-RNA by PCR. Ten patients were positive for both markers. Seventeen out of twenty-three HCV core gene sequences were found to be evolutionarily related and clustered separately from other local sequences in the phylogenetic tree, indicating nosocomial transmission. This was confirmed by analysis of HVR1 gene sequences. One nurse and one physician from the ward were HCV RNA positive, but their HCV sequences were not related evolutionarily to those of the patient cluster. Fifteen out of nineteen HBV core gene sequences were also clustered together and were positioned separately in the relevant tree. Epidemiological investigation excluded a common source infection and indicated that spread of infection was most likely due to inappropriate infection control measures on the ward. No obvious risk factors for transmission were identified during the retrospective survey in patients with related sequences, except use of multidose vials for saline and poor staff compliance with routine hand hygiene procedures. The preventive measures that were introduced reduced the incidence of infection significantly. No new cases of HBV infection and only three anti-HCV seroconversions occurred over a period of 19 months. The introduction and maintenance of strict prevention measures over a 2 year period, combined with HBV vaccination, reduced significantly the incidence of new HCV and HBV infections. J. Med. Virol. 69:331,338, 2003. © 2003 Wiley-Liss, Inc. [source]

Epidemiological investigation of Sudden Infant Death Syndrome infants , recommendations for future studies

CHILD: CARE, HEALTH AND DEVELOPMENT, Issue 2002
P. Blair
Abstract In recent years the study of infant care practices within the sleeping environment has proved to be the single most important set of observations for reducing the risk of Sudden Infant Death Syndrome (SIDS). To further reduce the number of deaths and resolve the debate on safe infant care practice, a closer scrutiny of this environment is required. However, anecdotal observation from uncontrolled death-scene investigations and a reluctance to diagnose SIDS because of adverse social conditions or circumstantial evidence at the time of death is undermining future research. To investigate SIDS now means investigating the wider umbrella of all Sudden Unexpected Deaths in Infancy (SUDI) because of the potential for misdiagnosis. In trying to find out why SIDS infants die we have increasingly been forced to search for why infants survive in the first few months of life and it is this comparative component of epidemiological observation that has saved so many lives. A death-scene investigation is vital to any planned future investigation of SIDS but equally essential is a sleep-scene investigation of surviving infants to put any findings into context. SIDS infants are no longer scattered across the social strata and the cot is not the only environment in which they are found, social deprivation and use of the parental bed are now more discernable. Future studies should therefore reflect these changes with a second control group of surviving infants more closely matched to the type of environment in which SIDS infants might be found. [source]

An outbreak of HBV and HCV infection in a paediatric oncology ward: Epidemiological investigations and prevention of further spread

Aetiology of stillbirth: unexplored is not unexplained

AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 5 2007
Mary-Anne Measey
Abstract Objective: To describe the rate of and demographic factors associated with fetal postmortem investigation and to classify the cause of all fetal deaths that underwent postmortem investigation. To compare the proportion of deaths remaining unexplained after postmortem investigation with estimates derived from death certificates. Method: All fetal deaths in Western Australia (WA) from 1990 to 1999 were identified. These data were used to calculate postmortem rates and describe the characteristics of women consenting to postmortems. A multidisciplinary team classified the cause of all deaths that underwent postmortem investigation using the Perinatal Society of Australia and New Zealand Perinatal Death Classification System. The proportion of deaths that were unexplained was compared with estimates based on death certificates. Results: Of the 1,619 fetal deaths recorded for 1990 to 1999, 49% (n=789) underwent complete postmortem investigation. Based on investigations, 22% of the 789 fetal deaths were unexplained and a further 18% were identified as having fetal growth restriction. Based on death certificates, 42% were unexplained and 65% were later explained by postmortem investigation. Conclusion and Implications: Postmortem investigation rates are low. They reveal a cause of death for the majority of cases that are unexplained clinically. Epidemiological investigations of unexplained fetal death based on cases not subject to complete postmortem investigation may lead to inaccurate conclusions. A standardised definition for unexplained fetal deaths that distinguishes between cases with detailed investigation and those with limited or no investigation is needed. [source]

Evaluating the usefulness of spa typing, in comparison with pulsed-field gel electrophoresis, for epidemiological typing of methicillin-resistant Staphylococcus aureus in a low-prevalence region in Sweden 2000,2004

CLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2010
A. C. Petersson
Clin Microbiol Infect 2010; 16: 456,462 Abstract The usefulness of spa typing was evaluated in relation to pulsed-field gel electrophoresis (PFGE), as a tool for epidemiological typing of methicillin-resistant Staphylococcus aureus (MRSA) in a low-prevalence region in southern Sweden. Bacterial isolates from 216 MRSA cases, newly identified in 2000,2004, were studied. The isolates were obtained from infected patients (31%), and from colonized individuals found by screening (69%). In total, 49 spa types and 73 PFGE patterns were identified. The discriminatory power of spa typing was lower (94.9 ± 1.8%) than that of PFGE (97.3 ± 1.2%). For two spa types (t002 and t008) the Panton,Valentine leukocidin results added useful discriminatory information. The most common spa types were t044 (n = 31; four PFGE patterns), t002 (n = 24; 10 PFGE patterns), t067 (n = 12; four PFGE patterns), t050 (n = 12; one PFGE pattern), and t324 (n = 11; one PFGE pattern). Epidemiological investigations identified 91 single cases and 39 transmission chains, each involving two to 13 cases. All the transmission chains were held together both by spa and PFGE typing. Among the 91 single-case isolates, 33 spa types and 50 PFGE patterns were unique (matchless) at the time of identification. The low prevalence of MRSA, the low number of outbreaks, and the wide spectrum of strains due to frequent acquisitions abroad (49% of the cases), makes spa typing a useful complement to epidemiological investigations in our setting. However, we still recommend the continued use of PFGE for further discrimination of isolates with identical spa types when epidemiological data can not exclude possible transmission. [source]

Genotypic variability and persistence of Legionella pneumophila PFGE patterns in 34 cooling towers from two different areas

ENVIRONMENTAL MICROBIOLOGY, Issue 2 2008
Inma Sanchez
Summary Genotypic variability and clonal persistence are important concepts in molecular epidemiology as they facilitate the search for the source of sporadic cases or outbreaks of legionellosis. We studied the genotypic variability and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns over time (period > 6 months) in 34 positive cooling towers from two different areas. In area A, radius of 70 km, 52 indistinguishable PFGE patterns were differentiated among the 27 cooling towers. In 13 cooling towers we observed , 2 PFGE patterns. Each cooling tower had its own indistinguishable Legionella PFGE pattern which was not shared with any other cooling tower. In area B, radius of 1 km, 10 indistinguishable PFGE patterns were obtained from the seven cooling towers. In four, we observed , 2 PFGE patterns. Three of these 10 indistinguishable PFGE patterns were shared by more than one cooling tower. In 27 of 34 cooling towers the same PFGE pattern was recovered after 6 months to up to 5 years of follow-up. The large genotypic diversity of Legionella observed in the cooling towers aids in the investigation of community outbreaks of Legionnaires' disease. However, shared patterns in small areas may confound the epidemiological investigation. The persistence of some PFGE patterns in cooling towers makes the recovery of the Legionella isolate causing the outbreak possible over time. [source]

The risk of a horse-and-rider partnership falling on the crosscountry phase of eventing competitions

EQUINE VETERINARY JOURNAL, Issue 2 2006
J. K. Murray
Summary Reasons for performing study: Fatalities resulting from horse falls occurring during the cross-country phase of eventing competitions initiated epidemiological investigation of the risk factors associated with horse falls. Objectives: To identify variables that increased or decreased the risk of a horse fall during the cross-country phase of an eventing competition. Methods: Data were collected from randomly selected British Eventing competitions held in Great Britain during 2001 and 2002. Data were obtained for 173 cases (jumping efforts resulting in a fall of the horse-and-rider partnership) and 503 matched controls (jumping efforts not resulting in a fall). The risk of falling was modelled using conditional logistic regression. Results: An increased risk of a horse fall was associated with jumping into or out of water; taking off from good-to-soft, soft or heavy ground; fences with a drop landing; nonangled fences with a spread ,2 m; and angled fences. Other risk factors included riders who knew that they were in the lead within the competition before the cross-country phase; an inappropriate speed of approach to the fence (too fast or too slow); horse-and-rider partnerships that had not incurred refusals at earlier fences; and riders who received cross-country tuition. Conclusions: This study has identified modifiable course- and fence-level risk factors for horse falls during the cross-country phase of eventing competitions. The risk of horse and rider injury at eventing competitions should be reduced by 3 simple measures; maintaining good to firm take-off surfaces at fences, reducing the base spread of fences to <2 m and reducing the use of fences at which horses are required to jump into or out of water. Risk reduction arising from course and fence modification needs to be confirmed by intervention studies. Potential relevance: Knowledge of factors that increase or decrease the risk of a horse fall can be used by UK governing bodies of the sport to reduce the risk of horse falls on the cross-country phase of eventing competitions, and reduce the risk of horse and rider injuries and fatalities. As one in 3 horses that fall injure themselves and one in 100 horse falls results in fatality to the horse, we suggest that immediate consideration is given to these recommendations. [source]

Issues in the epidemiological investigation of dry mouth

GERODONTOLOGY, Issue 2 2005
W. Murray Thomson
Despite decades of research, much remains unanswered about the epidemiology of dry mouth. This review aims to provide an overview of the condition's epidemiology and the issues to consider when planning an epidemiological study of dry mouth. The latter can be broadly grouped into: study design; sampling and statistical power considerations; the measurement of dry mouth; and the selection, nature and measurement of relevant exposure measures, including medications and potential confounding variables. Each of these is discussed, in order to provide guidance for prospective researchers based on experience with past research. Finally, an agenda for further epidemiological research into dry mouth is proposed. [source]

Phylogenetic analysis indicates transmission of hepatitis C virus from an infected orthopedic surgeon to a patient

JOURNAL OF MEDICAL VIROLOGY, Issue 4 2002
R. Stefan Ross
Abstract During recent years, a controversial discussion has emerged in the medical community on the real number and possible public health implications of hepatitis C virus (HCV) transmissions from infected medical staff to susceptible patients. We report here on molecular virological and epidemiological analyses involving 229 patients who underwent exposure-prone operations by an HCV-infected orthopedic surgeon. Of the 229 individuals affected, 207 could be tested. Three were positive for HCV antibodies. Molecular and epidemiological investigation revealed that two of them were not infected by the surgeon. The third patient, a 50-year-old man, underwent complicated total hip arthroplasty with trochanteric osteotomy. He harbored an HCV 2b isolate that in phylogenetic analysis of the hypervariable region 1 (HVR 1) was closely related to the HCV strain recovered from the infected surgeon, indicating that HCV-provider-to-patient transmission occurred intraoperatively. To our knowledge, this is the first documented case of HCV transmission by an orthopedic surgeon. The recorded transmission rate of 0.48% (95% confidence interval: 0.09,2.68%) was within the same range reported previously for the spread of hepatitis B virus during orthopedic procedures. Since the result of our investigation sustains the notion that patients may contract HCV from infected health-care workers during exposure-prone procedures, a series of further retrospective exercises is needed to assess more precisely the risk of HCV provider-to-patient transmission and to delineate from these studies recommendations for the guidance and management of HCV-infected medical personnel. J. Med. Virol. 66:461,467, 2002. © 2002 Wiley-Liss, Inc. [source]

Development of an oligonucleotide microarray method for Salmonella serotyping

MICROBIAL BIOTECHNOLOGY, Issue 6 2008
B. Tankouo-Sandjong
Summary Adequate identification of Salmonella enterica serovars is a prerequisite for any epidemiological investigation. This is traditionally obtained via a combination of biochemical and serological typing. However, primary strain isolation and traditional serotyping is time-consuming and faster methods would be desirable. A microarray, based on two housekeeping and two virulence marker genes (atpD, gyrB, fliC and fljB), has been developed for the detection and identification of the two species of Salmonella (S. enterica and S. bongori), the five subspecies of S. enterica (II, IIIa, IIIb, IV, VI) and 43 S. enterica ssp. enterica serovars (covering the most prevalent ones in Austria and the UK). A comprehensive set of probes (n = 240), forming 119 probe units, was developed based on the corresponding sequences of 148 Salmonella strains, successfully validated with 57 Salmonella strains and subsequently evaluated with 35 blind samples including isolated serotypes and mixtures of different serotypes. Results demonstrated a strong discriminatory ability of the microarray among Salmonella serovars. Threshold for detection was 1 colony forming unit per 25 g of food sample following overnight (14 h) enrichment. [source]

Risk of silicosis in cohorts of Chinese tin and tungsten miners and pottery workers (II): Workplace-specific silica particle surface composition,,

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2005
J. Harrison
Abstract Background It is hypothesized that surface occlusion by alumino-silicate affects the toxic activity of silica particles in respirable dust. In conjunction with an epidemiological investigation of silicosis disease risk in Chinese tin and tungsten mine and pottery workplaces, we analyzed respirable silica dusts using a multiple-voltage scanning electron microscopy,energy dispersive X-ray spectroscopy (MVSEM-EDS). Methods Forty-seven samples of respirable sized dust were collected on filters from 13 worksites and were analyzed by MVSEM-EDS using high (20 keV) and low (5 keV) electron beam accelerating voltages. Changes in the silicon-to-aluminum X-ray line intensity ratio between the two voltages are compared particle-by-particle with the 90th percentile value of the same measurements for a ground glass homogeneous control sample. This provides an index that distinguishes a silica particle that is homogeneously aluminum-contaminated from a clay-coated silica particle. Results The average sample percentages of respirable-sized silica particles alumino-silicate occlusion were: 45% for potteries, 18% for tin mines, and 13% for tungsten mines. The difference between the pottery and the metal mine worksites accounted for one third of an overall chi-square statistic for differences in change in measured silicon fraction between the samples. Conclusion The companion epidemiological study found lower silicosis risk per unit cumulative respirable silica dust exposure for pottery workers compared to metal miners. Using these surface analysis results resolves differences in risk when exposure is normalized to cumulative respirable surface-available silica dust. Am. J. Ind. Med. 48:10,15, 2005. Published 2005 Wiley-Liss, Inc. [source]

Agoraphobia: a review of the diagnostic classificatory position and criteria,,

DEPRESSION AND ANXIETY, Issue 2 2010
Hans-Ulrich Wittchen Ph.D.
Abstract The status of agoraphobia (AG) as an independent diagnostic category is reviewed and preliminary options and recommendations for the fifth edition of The Diagnostic and Statistical Manual (DSM-V) are presented. The review concentrates on epidemiology, psychopathology, neurobiology, vulnerability and risk factors, clinical course and outcome, and correlates and consequences of AG since 1990. Differences and similarities across conventions and criteria of DSM and ICD-10 are considered. Three core questions are addressed. First, what is the evidence for AG as a diagnosis independent of panic disorder? Second, should AG be conceptualized as a subordinate form of panic disorder (PD) as currently stipulated in DSM-IV-TR? Third, is there evidence for modifying or changing the current diagnostic criteria? We come to the conclusion that AG should be conceptualized as an independent disorder with more specific criteria rather than a subordinate, residual form of PD as currently stipulated in DSM-IV-TR. Among other issues, this conclusion was based on psychometric evaluations of the construct, epidemiological investigations which show that AG can exist independently of panic disorder, and the impact of agoraphobic avoidance upon clinical course and outcome. However, evidence from basic and clinic validation studies remains incomplete and partly contradictory. The apparent advantages of a more straightforward, simpler classification without implicit hierarchies and insufficiently supported differential diagnostic considerations, plus the option for improved further research, led to favoring the separate diagnostic criteria for AG as a diagnosis independent of panic disorder. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [source]

Methods for the isolation and identification of Listeria spp. and Listeria monocytogenes: a review

FEMS MICROBIOLOGY REVIEWS, Issue 5 2005
Uta Gasanov
Abstract Listeria monocytogenes is an important food-borne pathogen and is widely tested for in food, environmental and clinical samples. Identification traditionally involved culture methods based on selective enrichment and plating followed by the characterization of Listeria spp. based on colony morphology, sugar fermentation and haemolytic properties. These methods are the gold standard; but they are lengthy and may not be suitable for testing of foods with short shelf lives. As a result more rapid tests were developed based on antibodies (ELISA) or molecular techniques (PCR or DNA hybridization). While these tests possess equal sensitivity, they are rapid and allow testing to be completed within 48 h. More recently, molecular methods were developed that target RNA rather than DNA, such as RT-PCR, real time PCR or nucleic acid based sequence amplification (NASBA). These tests not only provide a measure of cell viability but they can also be used for quantitative analysis. In addition, a variety of tests are available for sub-species characterization, which are particularly useful in epidemiological investigations. Early typing methods differentiated isolates based on phenotypic markers, such as multilocus enzyme electrophoresis, phage typing and serotyping. These phenotypic typing methods are being replaced by molecular tests, which reflect genetic relationships between isolates and are more accurate. These new methods are currently mainly used in research but their considerable potential for routine testing in the future cannot be overlooked. [source]

The use of killer sensitivity patterns for biotyping yeast strains: the state of the art, potentialities and limitations

FEMS YEAST RESEARCH, Issue 6 2007
Pietro Buzzini
Abstract In recent years molecular techniques have been the most useful tools for the unequivocal identification of undetermined strains at the species level. In many instances, however, a further discrimination at the strain level (biotyping) is required, such as during epidemiological investigations, in which the distribution of pathogenic microorganisms is studied, and for patent protection purposes. Although molecular methods are routinely used also for yeast biotyping, several nonmolecular techniques have been proposed. One of these, the determination of the killer sensitivity pattern (KSP) towards a panel of selected killer toxins has proven to be a good auxiliary method. Despite the plethora of studies published, the potential and limitations of the determination of KSPs have never been critically evaluated. In this review the use of this nonmolecular technique as a biotyping tool is discussed and compared with some currently used DNA-based procedures. In addition, methodological, mechanistic and ecological implications are evaluated. [source]

Annotated chromosome maps for renal disease,

HUMAN MUTATION, Issue 3 2009
Amy Jayne McKnight
Abstract A combination of linkage analyses and association studies are currently employed to promote the identification of genetic factors contributing to inherited renal disease. We have standardized and merged complex genetic data from disparate sources, creating unique chromosomal maps to enhance genetic epidemiological investigations. This database and novel renal maps effectively summarize genomic regions of suggested linkage, association, or chromosomal abnormalities implicated in renal disease. Chromosomal regions associated with potential intermediate clinical phenotypes have been integrated, adding support for particular genomic intervals. More than 500 reports from medical databases, published scientific literature, and the World Wide Web were interrogated for relevant renal-related information. Chromosomal regions highlighted for prioritized investigation of renal complications include 3q13,26, 6q22,27, 10p11,15, 16p11,13, and 18q22. Combined genetic and physical maps are effective tools to organize genetic data for complex diseases. These renal chromosome maps provide insights into renal phenotype-genotype relationships and act as a template for future genetic investigations into complex renal diseases. New data from individual researchers and/or future publications can be readily incorporated to this resource via a user-friendly web-form accessed from the website: www.qub.ac.uk/neph-res/CORGI/index.php. Hum Mutat 0, 1,8, 2008. © 2008 Wiley-Liss, Inc. [source]

Adults with intellectual disabilities: prevalence, incidence and remission of aggressive behaviour and related factors

JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 3 2009
S.-A. Cooper
Abstract Introduction Aggressive behaviours can be disabling for adults with intellectual disabilities (ID), with negative consequences for the adult, their family and paid carers. It is surprising how little research has been conducted into the epidemiology of these needs, given the impact they can have. This study investigates point prevalence, 2-year incidence and 2-year remission rates for aggressive behaviour (physically aggressive, destructive and verbally aggressive), and it investigates which factors are independently associated with aggressive behaviour. Methods All adults with ID , within a geographically defined area of Scotland, UK , were recruited to a longitudinal cohort. At baseline, assessments were undertaken of demography, lifestyle, supports, development, problem behaviours, disabilities and physical and mental health. These were repeated for a 2-year period. Results At baseline, the participation rate was 1023 (65.5%). After 2 years, the cohort retention was 651 adults. The point prevalence of Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation (DC-LD) aggressive behaviour was 9.8% (95% confidence interval = 8.0,11.8%), 2-year incidence was 1.8%, and 2-year remission rate from all types of aggressive behaviour meeting DC-LD criteria was 27.7%. The factors independently associated with aggressive behaviours were lower ability, female gender, not living with a family carer, not having Down syndrome, having attention-deficit hyperactivity disorder and having urinary incontinence. Incidence of aggressive behaviour meeting DC-LD criteria in adult life is similar to that for each of psychotic, anxiety and organic disorders. Conclusions Aggressive behaviour is common among adults with ID, but contrary to previous suggestions, more than a quarter remit within the short to medium term. This is important knowledge for professionals as well as the person and her/his family and paid carers. There is much yet to learn about the mechanisms underpinning aetiology and maintenance of aggressive behaviour in this population, and exploratory epidemiological investigations such as this have a role to play in progressing research towards further hypothesis testing and trials to influence clinical practice, service development and policy. [source]

A molecular epidemiological study of sequential oral isolates of Candida albicans from terminally ill patients

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 4 2001
M. J. Wilson
Abstract: The pattern of candidal colonisation was studied in a group of terminally ill patients receiving antifungal treatment for oral candidosis. A total of 43 isolates of C. albicans was collected pre- and post-antifungal treatment from patients up to a maximum period of 4 weeks. Isolates were analysed by electrophoretic karyotyping (EK) and by inter-repeat polymerase chain reaction (IR-PCR). Fifteen electrophoretic karyotypes and 17 IR-PCR profiles were identified. Sequential isolates from 10 patients yielded identical profiles in both EKs and IR-PCR analyses. In the case of four patients, minor differences in the profiles were obtained by either EK or IR-PCR. The findings suggest that antifungal treatment in this patient group fails to eradicate the original C. albicans strain, thereby allowing recolonisation of the oral cavity. The present study has also shown that either EK or IR-PCR is a useful typing approach in such epidemiological investigations. [source]

Tissue distribution of N -acetyltransferase 1 and 2 catalyzing the N -acetylation of 4-aminobiphenyl and O -acetylation of N -hydroxy-4-aminobiphenyl in the congenic rapid and slow acetylator Syrian hamster

MOLECULAR CARCINOGENESIS, Issue 4 2006
David W. Hein
Abstract N -acetyltransferase 1 (NAT1) and 2 (NAT2) enzymes catalyzing both deactivation (N -acetylation) and activation (O -acetylation) of arylamine carcinogens such as 4-aminobiphenyl (ABP) were investigated in a Syrian hamster model congenic at the NAT2 locus. NAT2 catalytic activities (measured with p -aminobenzoic acid) were significantly (P,<,0.001) higher in rapid than slow acetylators in all tissues (except heart and prostate where activity was undetectable in slow acetylators). NAT1 catalytic activities (measured with sulfamethazine) were low but detectable in most tissues tested and did not differ significantly between rapid and slow acetylators. ABP N -acetyltransferase activity was detected in all tissues of rapid acetylators but was below the limit of detection in all tissues of slow acetylators except liver where it was about 15-fold lower than rapid acetylators. ABP N -acetyltransferase activities correlated with NAT2 activities (r2,=,0.871; P,<,0.0001) but not with NAT1 activities (r2,=,0.132; P,>,0.05). Levels of N -hydroxy-ABP O -acetyltransferase activities were significantly (P,<,0.05) higher in rapid than slow acetylator cytosols for many but not all tissues. The N -hydroxy-ABP O -acetyltransferase activities correlated with ABP N -acetyltransferase activities (r2,=,0.695; P,<,0.0001) and NAT2 activities (r2,=,0.521, P,<,0.0001) but not with NAT1 activities (r2,=,0.115; P,>,0.05). The results suggest widespread tissue distribution of both NAT1 and NAT2, which catalyzes both N - and O -acetylation. These conclusions are important for interpretation of molecular epidemiological investigations into the role of N -acetyltransferase polymorphisms in various diseases including cancer. © 2006 Wiley-Liss, Inc. [source]

Potential health effects from non-specific stimulation of the immune function in early age: The example of BCG vaccination

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2008
Marie-Claude Rousseau
There is increasing, but still inconsistent evidence that vaccinations and childhood infections may play a role in the normal maturation of the immune system, and in the development and balance of immune regulatory pathways, both of which might impact health later in life. This review covers the epidemiological evidence regarding the role of Bacillus Calmette,Guérin (BCG) vaccination on the following inflammatory or autoimmune diseases: asthma and allergic diseases, Crohn's disease (CD), insulin-dependent diabetes mellitus (IDDM), and specific cancers. The literature is more comprehensive for asthma and allergic diseases, with 16 studies reporting the absence of an association while seven rather suggest a protective effect of BCG. We found insufficient evidence on CD to conclude at this point. Overall, the evidence for IDDM based on four studies leans towards no association, although some effects were observed in population subsets. Five epidemiological investigations provide evidence on a possible link with cancer incidence or mortality at various sites, with indications of both increased and decreased risks. Given the potential public health implications, it is imperative to acquire a better understanding of how BCG vaccination could influence the development of such chronic health conditions in the population. [source]

Evaluating the usefulness of spa typing, in comparison with pulsed-field gel electrophoresis, for epidemiological typing of methicillin-resistant Staphylococcus aureus in a low-prevalence region in Sweden 2000,2004