Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Community Detection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed1992

Validation of a screening questionnaire for the detection of epileptic seizures in epidemiological studies.

A large-scale clinico-epidemiological study of epileptic seizures has been carried out in a highland area in northern Ecuador, South America. This paper describes the design and the two-staged validation procedures undertaken to authenticate the screening questionnaire, which was used to detect epileptic seizures in the community during this project. An initial questionnaire consisting of 20 questions was devised and then validated in a group of healthy subjects and a group of patients with known epileptic seizures. This questionnaire was found to have a sensitivity of 100% and a specificity of 50.8%. A cluster analysis of the responses rates was undertaken and a set of nine questions which presented a specificity of 92% and sensitivity of 98% were chosen to be used during the survey. The validation of this nine-question instrument was then undertaken by direct application to a general population of 72,121 persons. Positive, negative, false positive and false negative rates were derived. The screening instrument was found to have a sensitivity of 79.3%, a specificity of 92.9%, a positive predictive value of 18.3%, a negative predictive value of 99.6% and a Youden's index of 0.79. The methodology of the study and the instruments developed are recommended for future neuro-epidemiological work in epilepsy. The problems of validation are discussed, and previous epidemiological studies of epilepsy reviewed with special emphasis on the handling of questions of validation.

Adolescent↗
PubMed1979

Influenza surveillance by age and target group.

Surveillance for influenza virus infections began in mid-1976, continued through three small influenza A outbreaks (mixed A/Victoria and A/Texas outbreaks in Spring, 1977, and Winter, 1977-1978 and an A/USSR outbreak peaking in March, 1978). Nasopharyngeal specimens were collected for virus isolation from febrile respiratory disease patients coming from four sources: 1) the Sunday walk-in clinic of the Group Health Cooperative of Puget Sound; 2) 200 families under continuous surveillance for respiratory viral infections; 3) patients referred by interested community physicians or self-referred persons in vaccine evaluation studies; and 4) students presenting at the University of Washington health center. Influenza virus isolation rates were as high in children as adults and peaked earlier in adults than in children in all three epidemics. Although referred patients and university students yielded the highest isolation rate, nearly 30%, all four community sources were important in detecting an impending epidemic.

Adolescent↗
PubMed2004

Bruising, coagulation disorder, and physical child abuse.

Child protection is a priority, and the medical community has a responsibility to detect cases of abuse and to intervene using the appropriate measures. Bruises are the most common manifestation of physical abuse, although their interpretation can be extremely challenging for paediatricians as the evidence base is limited. As a history of abuse is a strong risk factor for further non-accidental injury, a correct diagnosis is vital. Clearly, the diagnostic process must determine whether an underlying coagulation disorder exists. It is important to realize, however, that the presence of a coagulation deficit does not necessarily exclude abuse. A growing body of evidence suggests that the practice of estimating bruise age is unreliable; therefore, a key factor in diagnosing abuse is the pattern of bruise distribution, which must be linked to the child's history and stage of development. The paediatrician must also consider the combined probabilities of individual bruises being due to abuse. Our scoring system, which uses a Bayesian approach to evaluate these probabilities and assess bruising patterns, is a potentially useful tool for discriminating between abused and non-abused children. We recommend that paediatricians and haematologists should work together to reach a diagnostic consensus that is acceptable in both the clinic and a court of law.

Adolescent↗
PubMed1999

Appalachian perspective on modifiable risk factors in coronary artery disease: how well are we doing?

BACKGROUND: Despite recognition of modifiable risk factors and available and effective life-style and pharmacologic therapies, many individuals have unrecognized or untreated risk factors for coronary artery disease. METHODS: Using MEDLINE, we searched for relevant review articles and clinical trials related to hypertension, hyperlipidemia, diabetes mellitus, smoking, physical activity, obesity, and psychologic risk factors for coronary artery disease. We carefully reviewed the literature and statistics on modifiable risk factors and identified appropriate physician interventions. RESULTS: A large amount of information is available on coronary artery disease and modifiable risk factors. Much of the data focuses on diagnosis and treatment to goal. CONCLUSIONS: Coronary artery disease remains the number one cause of death in the United States and West Virginia, even though specific guidelines have been established for detection and treatment. The medical community needs to be more aggressive in managing modifiable risk factors.

Appalachian Region↗
PubMed2006

Emticicia oligotrophica gen. nov., sp. nov., a new member of the family 'Flexibacteraceae', phylum Bacteroidetes.

An aquatic bacterium, strain GPTSA100-15T, was isolated on nutritionally poor medium TSBA100 (tryptic soy broth diluted 100 times and solidified with 1.5 % agarose) and characterized using a polyphasic approach. The isolate was unable to grow on commonly used nutritionally rich media such as tryptic soy agar, nutrient agar and Luria-Bertani agar. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate was affiliated with the family 'Flexibacteraceae' in the phylum Bacteroidetes. Phylogenetically, it showed closest similarity (94.0 %) with an uncultured bacterial clone, HP1A92, detected in a sludge microbial community. Among the culturable bacteria, the isolate had highest 16S rRNA gene sequence similarity with Leadbetterella byssophila 4M15T (87.8 %). Sequence similarities with other members of the phylum Bacteroidetes were less than 85 %. The fatty acid profile of the isolate grown on TSBA100 indicated that the major fatty acid was iso-C15:0, which is also present in many members of the family 'Flexibacteraceae'. Cells of strain GPTSA100-15T are Gram-negative, strictly aerobic rods. The DNA G+C content of the isolate is 36.9 mol%. Results of phenotypic, chemotaxonomic and phylogenetic analyses clearly indicate that strain GPTSA100-15T represents a new genus within the family 'Flexibacteraceae'; the name Emticicia gen. nov. is proposed for the genus, with Emticicia oligotrophica sp. nov. as the type species. The type strain of Emticicia oligotrophica is GPTSA100-15T (=MTCC 6937T=DSM 17448T).

Bacterial Typing Techniques↗
PubMed1999

Monoclonal gammopathy of undetermined significance (MGUS)-31 year follow up of a community study.

BACKGROUND: When unselected healthy adults in the community have their serum screened by cellulose acetate or paper electrophoresis, monoclonal gammopathy of undetermined significance (MGUS) may be found in 0.5-1%. AIM: To report upon a 31 year follow up of MGUS in a New Zealand community. METHODS: Serum from 2,192 subjects (82% of the adult population) of a New Zealand town was collected in 1967 and subsequently screened by cellulose acetate electrophoresis. Eleven of the 2,192 (0.5%) were found to have MGUS. Clinical correlation was sought in 1970 and subsequently to elucidate the underlying cause. RESULTS: Seven of the 11 patients have developed a haematological malignancy. Two have been diagnosed as having Waldenstrom's macroglobulinaemia, one malignant lymphoma and acute myelomonocytic leukaemia and four developed myeloma. Myeloma developed at one, nine, 23 and 25 years after the original screening. One myeloma patient and one patient with MGUS are currently alive and well, 31 years after discovery of their gammopathy. CONCLUSIONS: The incidence of MGUS in this community is only half that detected in a comparable study. The association with haematological malignancy in this study (64%) is considerably higher than that found in the Swedish study (6%), possibly because of the longer follow up in New Zealand. MGUS should not only be studied in depth at the time of its discovery, but needs very long term follow up as the underlying disease may not surface until the third decade.

Adult↗
PubMed2007

Unveiling fungal zooflagellates as members of freshwater picoeukaryotes: evidence from a molecular diversity study in a deep meromictic lake.

This study presents an original 18S rRNA PCR survey of the freshwater picoeukaryote community, and was designed to detect unidentified heterotrophic picoflagellates (size range 0.6-5 microm) which are prevalent throughout the year within the heterotrophic flagellate assemblage in Lake Pavin. Four clone libraries were constructed from samples collected in two contrasting zones in the lake. Computerized statistic tools have suggested that sequence retrieval was representative of the in situ picoplankton diversity. The two sampling zones exhibited similar diversity patterns but shared only about 5% of the operational taxonomic units (OTUs). Phylogenetic analysis clustered our sequences into three taxonomic groups: Alveolates (30% of OTUs), Fungi (23%) and Cercozoa (19%). Fungi thus substantially contributed to the detected diversity, as was additionally supported by direct microscopic observations of fungal zoospores and sporangia. A large fraction of the sequences belonged to parasites, including Alveolate sequences affiliated to the genus Perkinsus known as zooparasites, and chytrids that include host-specific parasitic fungi of various freshwater phytoplankton species, primarily diatoms. Phylogenetic analysis revealed five novel clades that probably include typical freshwater environmental sequences. Overall, from the unsuspected fungal diversity unveiled, we think that fungal zooflagellates have been misidentified as phagotrophic nanoflagellates in previous studies. This is in agreement with a recent experimental demonstration that zoospore-producing fungi and parasitic activity may play an important role in aquatic food webs.

Chlorophyll↗
PubMed2005

Pine microsatellite markers allow roots and ectomycorrhizas to be linked to individual trees.

Linking roots and ectomycorrhizas (EcM) to individual host trees in the field is required to test whether individual trees support different ectomycorrhizal communities. Here we describe a method that identifies the source of EcM roots by PCR of polymorphic pine nuclear microsatellite loci using fluorescently labelled primers and high-throughput fragment analysis. ITS-PCR can also be performed on the same EcM DNA extract for fungal identification. The method was tested on five neighbouring Scots pine (Pinus sylvestris var scotica) trees in native woodland. Successful host tree identification from DNA extracts of EcM root tips was achieved for 93% of all root fragments recovered from soil cores. It was estimated that each individual mature pine sampled was colonised by between 15 and 19 EcM fungi. The most abundant fungal species were found on all five trees, and within the constraints of the sampling scheme, no differences between trees in EcM fungal community structure or composition were detected.

DNA Fingerprinting↗
PubMed2003

Surveillance of infectious disease occurrences in the community: an analysis of symptom presentation in the emergency department.

OBJECTIVES: To determine the effectiveness of a simulated emergency department (ED)-based surveillance system to detect infectious disease (ID) occurrences in the community. METHODS: Medical records of patients presenting to an urban ED between January 1, 1999, and December 31, 2000, were retrospectively reviewed for ICD-9 codes related to ID symptomatology. ICD-9 codes, categorized into viral, gastrointestinal, skin, fever, central nervous system (CNS), or pulmonary symptom clusters, were correlated with reportable infectious diseases identified by the local health department (HD). These reportable infectious diseases are designated class A diseases (CADs) by the Ohio Department of Health. Cross-correlation functions (CCFs) tested the temporal relationship between ED symptom presentation and HD identification of CADs. The 95% confidence interval for lack of trend correlation was 0.0 +/- 0.074; thus CCFs > 0.074 were considered significant for trend correlation. Further cross-correlation analysis was performed after chronic and non-community-acquirable infectious diseases were removed from the HD database as a model for bioterrorism surveillance. RESULTS: Fifteen thousand five hundred sixty-nine ED patients and 6,489 HD patients were identified. Six thousand two hundred eight occurrences of true CADs were identified. Only 87 (1.33%) HD cases were processed on weekends. During the study period, increased ED symptom presentation preceded increased HD identification of respective CADs by 24 hours for all symptom clusters combined (CCF = 0.112), gastrointestinal symptoms (CCF = 0.084), pulmonary symptoms (CCF = 0.110), and CNS symptoms (CCF = 0.125). The bioterrorism surveillance model revealed increased ED symptom presentation continued to precede increased HD identification of the respective CADs by 24 hours for all symptom clusters combined (CCF = 0.080), pulmonary symptoms (CCF = 0.100), and CNS symptoms (CCF = 0.120). CONCLUSIONS: Surveillance of ED symptom presentation has the potential to identify clinically important ID occurrences in the community 24 hours prior to HD identification. Lack of weekend HD data collection suggests that the ED is a more appropriate setting for real-time ID surveillance.

Central Nervous System Diseases↗
PubMed1997

In situ microcosms in aquifer bioremediation studies.

The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to emphasize the importance of in situ studies and to describe two different concepts of construction and application of in situ microcosms for studying microbial activity in aquifers. The overall goal is to promote the development and utilization of these valuable and largely unexplored tools.

Biodegradation, Environmental↗
PubMed1999

Diversity and heterogeneity of epibiotic bacterial communities on the marine nematode Eubostrichus dianae.

The diversity of a microbial community covering the surface of a marine nematode was analyzed by performing a 16S ribosomal DNA (rDNA) restriction cutting and sequencing analysis. In two clone libraries constructed by using individual nematodes, 54 and 85 restriction patterns were identified, and only 13 of these patterns were common to both libraries. Sequence analysis indicated that the common patterns belonged to four groups related to sequences of cytophagas, sulfate-reducing bacteria, members of the gamma subclass of the class Proteobacteria, and caulobacters. At least two groups appeared to be permanent members of the community as they were also detected in a 16S rDNA library constructed 3 years previously by using 100 pooled nematode specimens. A surprising outcome was that very dominant filamentous bacteria were apparently not represented in the clone libraries, as quantitative probing showed that none of the common operational taxonomic unit groups displayed the expected overwhelming dominance. Nevertheless, our analysis revealed both an unexpectedly high level of bacterial diversity and heterogeneity in samples representing presumably very similar microenvironments.

Animals↗
PubMed2005

Horizontal gene transfer to endogenous endophytic bacteria from poplar improves phytoremediation of toluene.

Poplar, a plant species frequently used for phytoremediation of groundwater contaminated with organic solvents, was inoculated with the endophyte Burkholderia cepacia VM1468. This strain, whose natural host is yellow lupine, contains the pTOM-Bu61 plasmid coding for constitutively expressed toluene degradation. Noninoculated plants or plants inoculated with the soil bacterium B. cepacia Bu61(pTOM-Bu61) were used as controls. Inoculation of poplar had a positive effect on plant growth in the presence of toluene and reduced the amount of toluene released via evapotranspiration. These effects were more dramatic for VM1468, the endophytic strain, than for Bu61. Remarkably, none of the strains became established at detectable levels in the endophytic community, but there was horizontal gene transfer of pTOM-Bu61 to different members of the endogenous endophytic community, both in the presence and in the absence of toluene. This work is the first report of in planta horizontal gene transfer among plant-associated endophytic bacteria and demonstrates that such transfer could be used to change natural endophytic microbial communities in order to improve the remediation of environmental insults.

Biodegradation, Environmental↗
PubMed2006

Dissemination of fluoroquinolone-resistant Campylobacter spp. within an integrated commercial poultry production system.

While characterizing the intestinal bacterial community of broiler chickens, we detected epsilon-proteobacterial DNA in the ilea of 3-day-old commercial broiler chicks (J. Lu, U. Idris, B. Harmon, C. Hofacre, J. J. Maurer, and M. D. Lee, Appl. Environ. Microbiol. 69:6816-6824, 2003). The sequences exhibited high levels of similarity to Campylobacter jejuni and Campylobacter coli sequences, suggesting that chickens can carry Campylobacter at a very young age. Campylobacter sp. was detected by PCR in all samples collected from the ilea of chicks that were 3 to 49 days old; however, it was detected only in the cecal contents of chickens that were at least 21 days old. In order to determine whether the presence of Campylobacter DNA in young chicks was due to ingestion of the bacteria in food or water, we obtained commercial broiler hatching eggs, which were incubated in a research facility until the chicks hatched. DNA sequencing of the amplicons resulting from Campylobacter-specific 16S PCR performed with the ileal, cecal, and yolk contents of the day-of-hatching chicks revealed that Campylobacter DNA was present before the chicks consumed food or water. The 16S rRNA sequences exhibited 99% similarity to C. jejuni and C. coli sequences and 95 to 98% similarity to sequences of other thermophilic Campylobacter species, such as C. lari and C. upsaliensis. The presence of C. coli DNA was detected by specific PCR in the samples from chicks obtained from a commercial hatchery; however, no Campylobacter was detected by culturing. In order to determine whether the same strains of bacteria were present in multiple levels of the integrator, we cultured Campylobacter sp. from a flock of broiler breeders and their 6-week-old progeny that resided on a commercial broiler farm. The broiler breeders had been given fluoroquinolone antibiotics, and we sought to determine whether the same fluoroquinolone-resistant strain was present in their progeny. The isolates were typed by pulsed-field gel electrophoresis, which confirmed that the parental and progeny flocks contained the same strain of fluoroquinolone-resistant C. coli. These data indicate that resistant C. coli can be present in multiple levels of an integrated poultry system and demonstrated that molecular techniques or more sensitive culture methods may be necessary to detect early colonization by Campylobacter in broiler chicks.

Animal Husbandry↗
PubMed2005

Application of an improved method for the recombinant k 39 enzyme-linked immunosorbent assay to detect visceral leishmaniasis disease and infection in Bangladesh.

Several serology-based immunoassays are used to diagnose visceral leishmaniasis (VL), a chronic protozoan parasitic disease caused by the Leishmania donovani complex. These tests are primarily designed to diagnose the most severe clinical form of VL, known as kala-azar. However, leishmanial infection is frequently asymptomatic and may manifest only as a positive serologic response or positive leishmanin skin test. We modified a previously described enzyme-linked immunosorbent assay (ELISA) that detects patient antibodies reactive with the recombinant Leishmania protein K39 (rK39) to confirm suspected kala-azar and to detect asymptomatic infection in a community study in Bangladesh. With the inclusion of a standard curve on each ELISA plate, the rK39 ELISA was more repeatable (kappa coefficient of agreement=0.970) and more reliable compared to the original method (kappa=0.587, P<0.001). The cutoff point for a positive antibody response was chosen based on the 99th percentile of the ELISA distribution for the negative-control sera. However, we found that sera from all patients with active kala-azar yielded values more than twice the magnitude of this cutoff. Using receiver-operator characteristic curves, we determined a second cutoff value predictive of kala-azar. Using these criteria, the sensitivity and specificity of the modified ELISA for kala-azar were 97.0% and 98.9%, respectively, for sera from our study population. We hypothesize that individuals with antibody levels greater than the 99th percentile of the negative controls but less than the cutoff point for kala-azar have asymptomatic leishmanial infections.

Animals↗
PubMed2006

Novel multiplex PCR assay for detection of the staphylococcal virulence marker Panton-Valentine leukocidin genes and simultaneous discrimination of methicillin-susceptible from -resistant staphylococci.

We developed a new multiplex PCR assay for detection of Panton-Valentine leukocidin virulence genes and simultaneous discrimination of methicillin-susceptible from -resistant staphylococci. This assay is simple, rapid, and accurate and offers the potential for prompt detection of newly emerging community-associated methicillin-resistant Staphylococcus aureus.

Alberta↗
PubMed2004

Early Helicobacter pylori colonisation: the association with growth faltering in The Gambia.

BACKGROUND: Helicobacter pylori is one of the commonest causes of chronic infection of mankind, yet the natural history of acute infection is poorly understood. Some studies suggest that gastric colonisation with H pylori is associated with suboptimal nutrition and growth in childhood. AIMS: To describe the clinical features of early H pylori colonisation and assess its role in the development of infant malnutrition and growth faltering. METHODS: Two consecutive prospective longitudinal cohort studies were conducted at the Medical Research Council Laboratories in a rural community in The Gambia, West Africa. The first birth cohort of 125 infants was followed by a second of 65 children from the same community. H pylori colonisation was detected by sequential 13C urea breath tests, and infant growth was monitored by serial measurements. RESULTS: Children with early H pylori colonisation became significantly lighter, shorter, and thinner than their peers in late infancy. The association was found in both cohorts. No socioeconomic or demographic confounding variables were identified to explain this, and the weight deficit was no longer detectable when the children were aged 5-8 years. CONCLUSIONS: Results suggest that H pylori colonisation in early infancy predisposes to the development of malnutrition and growth faltering, although the effect did not persist into later childhood.

Breath Tests↗
PubMed1996

Choosing the best method for radiological assessment of patellofemoral osteoarthritis.

OBJECTIVE: To assess the reproducibility of different methods of radiological assessment of patellofemoral osteoarthritis (OA) and to determine which is the best view as a research tool in epidemiological studies of knee OA requiring explicit diagnostic criteria to classify the disease in the general population. METHODS: A population based study of 252 unrelated, normal individuals (504 knees) was performed. Lateral and skyline radiographs from each individual were graded for joint space narrowing and osteophytes using a standard atlas. Reproducibility was assessed by two observers on 50 knees. Radiographic features were assessed on their ability to predict knee pain. RESULTS: The skyline views performed better than the lateral views in the assessment of patellofemoral joint OA. The reproducibility for osteophytes was high (kappa > 0.8) and that for joint space narrowing moderate (kappa > 0.6) for both lateral and skyline views. Although the specificity for detecting knee pain was similar in both views, the sensitivity of skyline views in the assessment of knee pain was greater (52.8% versus 30%). The odds ratio for skyline osteophytes as a predictor of knee pain was 7.66 (95% confidence interval (CI) 3.68 to 15.90); that for osteophytes seen on lateral view was 1.83 (95% CI 0.96 to 3.49). Narrowing on both views was a poor predictor of pain. There was frequent disagreement between the lateral and skyline views for detecting osteophytes. CONCLUSION: In a community based study, skyline views performed better than lateral views in terms of reproducibility and for identifying symptomatic patellofemoral joint OA. Skyline radiographs should be the preferred method for examining the patellofemoral joint in such studies.

Female↗
PubMed1977

Toxoplasmosis in the perinatal period.

Although many of the fundamental biological features of toxoplasmosis are today well appreciated, the practical problem of prevention of its most serious consequence--disabling congenital disease, remains unsolved. The reasons vary in different communities, but are concerned with detection of the chief mode of spread, assessment of incidence, delineation of vulnerable antenatal women in latently infected populations, and assessment of the risks of therapeutics. The results of some of the approaches to these problems in Scotland are reported and discussed.

Female↗