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PubMed2006

Direct characterization of Blastocystis from faeces by PCR and evidence of zoonotic potential.

In vitro propagation followed by PCR, and a PCR-based method capable of the direct detection of Blastocystis in faeces were utilized to detect Blastocystis from various hosts in Australia, including primates and their handlers from the Perth Zoo. In addition, Blastocystis isolates from dogs and humans living in a localized endemic community in Thailand were also characterized genetically. PCR-based detection directly from faeces was shown to be more sensitive compared with in vitro culture for the detection of Blastocystis. Moreover, phylogenetic analysis of Blastocystis isolates amplified utilizing in vitro techniques prior to PCR revealed that this method favoured the preferential amplification of Blastocystis subtype 5 over subtype 1. This study is the first to provide molecular-based evidence supporting the zoonotic potential of Blastocystis in dogs, possums and primates in a natural setting.

Animals↗
PubMed2004

Distribution-abundance relationship for passerines breeding in Tunisian oases: test of the sampling hypothesis.

The positive relationship between local abundance and distribution of species is a widely recognized pattern in community ecology. However, it has been suggested that this relationship can simply be an artefact of sampling because locally rare species are less detectable then locally abundant ones, and hence their distribution can easily be underestimated. Here, we use count data to investigate the relationship between distribution and abundance of passerines breeding in a sample of oases from southern Tunisia, and we provide a test of the sampling artefact hypothesis. In particular, we checked for a difference in detection probability between localized and widespread species, and we tested if increasing the sampling effort affects the significance of the relationship. A significant positive relationship between the average local abundance of passerine species and the proportion of occupied oases was found. The use of a capture-recapture approach allowed us to estimate and to compare the detection probabilities of localized and widespread species subsets. We found that localized species were locally less detectable than widespread species, which is consistent with the main assumption of the sampling artefact hypothesis. However, increasing the detection probability of species by conducting more counts did not affect the significance of the relationship, which did not give support to the sampling artefact hypothesis. Our work implies that sampling contributed to the distribution-abundance relationship we found, but that it is unlikely that such a relationship could entirely be explained by an artefact of sampling. It also underlines the insight that can be gained by using probabilistic approaches of estimating species number and detection probability when attempting to disentangle sampling from ecological effects in community ecology studies.

Animals↗
PubMed1993

Breast-feeding and the risk of life-threatening rotavirus diarrhea: prevention or postponement?

PURPOSE: To assess the relationship between breast-feeding and the risk of life-threatening rotavirus diarrhea among Bangladeshi infants and children younger than 24 months of age. DESIGN: Case-control study. SETTING: A rural Bangladesh community. PARTICIPANTS: One hundred two cases with clinically severe rotavirus diarrhea detected in a treatment center-based surveillance system during 1985 and 1986, and 2587 controls selected in three surveys of the same community during the same calendar interval. OUTCOMES: Cases and controls were compared for the frequency of antecedent breast-feeding patterns. RESULTS: Compared with other feeding modes, exclusive breast-feeding of infants was associated with significant protection against severe rotavirus diarrhea (relative risk (RR) = 0.10; 95% confidence interval [CI] = 0.03, 0.34). However, during the second year of life, the risk of this outcome was higher in breast-fed than in non-breast-fed children (RR = 2.85; 95% CI = 0.37, 21.71), and no overall protection was associated with breast-feeding during the first 2 years of life (RR = 2.61; 95% CI = 0.62, 11.02). CONCLUSIONS: Although exclusive breast-feeding appeared to protect infants against severe rotavirus diarrhea, breast-feeding per se conferred no overall protection during the first 2 years of life, suggesting that breast-feeding temporarily postponed rather than prevented this outcome. While not detracting from efforts to promote breast-feeding to alleviate the burden of diarrhea due to nonrotaviral enteropathogens, our findings cast doubt on whether such efforts will impact on the problem of severe rotavirus diarrhea.

Bangladesh↗
PubMedDate not supplied

Detection of respiratory syncytial virus nucleic acid in archival postmortem tissue from infants.

Archival lung tissue from 99 cases of sudden infant death syndrome (SIDS) and from 58 matched comparison cases with known causes of death was studied. Sections were examined by in situ hybridization (ISH) using a cocktail of three synthetic oligonucleotides with sequences chosen from the published sequence of the nucleoprotein gene of respiratory syncytial virus (RS virus). The oligonucleotides were end-labelled with dinitrophenyl (DNP) or digoxigenin (DIG) and hybrids were detected immunocytochemically. RS virus nucleic acid was detected in 24 cases of SIDS (24%) and in 11 (19%) of the comparison group. Specificity was confirmed using a DIG-labeled cloned probe covering the whole of the nucleoprotein gene sequence. With one exception, the same results were obtained. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to confirm the specificity of these results. When matched for age and month and year of death, 76 SIDS cases and 38 controls could be compared. Twenty-one SIDS cases (27.6%) and seven comparison cases (18.4%) contained detectable RS virus sequences by ISH, with a higher detection rate in winter in both groups. The differences were not significant and reflected the seasonal pattern of RS virus infection in the community rather than a causal relationship of RS virus with SIDS. Detection of RS viral mRNA through the summer months suggests that persistence is possible.

Autopsy↗
PubMed2004

Assessing structural and functional plankton responses to carbendazim toxicity.

A model ecosystem experiment was conducted to investigate the ability of an in situ Daphnia magna feeding bioassay to assess impairment of ecosystem function. Animals were deployed in model ecosystems dosed with different concentrations of the fungicide carbendazim, and effects on the postexposure feeding rate of D. magna were compared with effects on zooplankton species richness (ecosystem structure) and development of phytoplankton biomass (ecosystem function). In the medium-dosed systems (21 microg/L), a structural change was observed within the zooplankton community, but no indirect effects on phytoplankton development were detected. It appears that at this treatment level, functional redundancy was sufficient to prevent functional impairment despite species loss. The feeding assay did not show any response at this concentration. In the high-dosed systems (221 microg/L), structural changes in the zooplankton community were accompanied by increased development of phytoplankton biomass. The feeding bioassay also showed a significant response at this concentration. At the high treatment level, species loss resulted in functional impairment, indicating that at this level, functional redundancy could not compensate for loss of individuals. The D. magna feeding bioassay matched well with the functional response (i.e., the indirect effects on phytoplankton) in the dosed systems but not with the more subtle effects on zooplankton community structure. These results lend positive support to the use of in situ feeding bioassays in combination with structural indices, such as species richness, to assess the effects of stress on ecosystem functioning in a direct way.

Animals↗
PubMedDate not supplied

Cytology screening program in an urban and rural community in India. Review of a ten-year experience.

An approach to the detection and management of early cervical cancer and its precursors utilizing basic and inexpensive equipment and a team of workers comprising physicians, cytotechnicians and social workers in an urban and rural community in India is described. In the ten-year period from 1970 to 1979, a total of 26,217 patients had Papanicolaou smears taken; 104 patients had histologically proven carcinoma in situ or microinvasive cancer of the cervix in which the clinical findings at the time of cell study did not indicate malignancy. The policy of management based on judicial conservatism and essential radicalism gave good survival rates and minimum morbidity.

Carcinoma in Situ↗
PubMed1996

The effect of nonresponse on prevalence estimates for a referent population: insights from a population-based cohort study. Atherosclerosis Risk in Communities (ARIC) Study Investigators.

Characterization of nonrespondents, with the aim of detecting nonresponse bias, is a crucial component of prospective studies. This study was undertaken to investigate the demographic and health characteristics of nonrespondents to a population-based cohort study of cardiovascular disease, to determine whether early-stage nonrespondents differ from late-stage nonrespondents, and to estimate the bias in prevalence estimates for the source population. Sixty-seven percent of eligible subjects completed all phases of the cohort recruitment. Compared to respondents, nonrespondents were less likely to be married, less likely to be employed, and less likely to be well educated. Nonrespondents tended to describe their general health in less favorable terms and were more likely to be smokers. Their reported disease profile, however, was not dissimilar to that of respondents. For several demographic and health characteristics, including marital status, education, and smoking, early-stage nonrespondents differed from respondents more than did late-stage nonrespondents. For example, 42% of early nonrespondents were smokers compared to 37% of late nonrespondents and 22% of respondents. Overall, the bias in prevalence estimates related to nonresponse was small (< 5%) for most of the measured characteristics. Although nonresponse to health surveys is associated with typical attributes, early nonrespondents differ from respondents more than do late-stage nonrespondents. With few exceptions, however, a 33% nonresponse rate did not appear to introduce substantial bias into prevalence estimates for the source community.

Age Distribution↗
PubMed1988

Applied cancer prevention and the primary caregiver. A challenge to the community.

The cure rate for cancer can be increased from the current 51% to 75% by the year 2000. Two important actions that will make this goal possible are the prevention of cancers that are caused by known carcinogens and the earlier detection of cancer in asymptomatic individuals. Current knowledge about the cause of cancer makes it prudent for persons to change their lifestyles (primary prevention). Tobacco products are the number one culprit in cancer cause and it is estimated that 30% of all cancer deaths in the United States would not occur if tobacco use had been avoided. The sound principles of cancer prevention and early detection need to be applied by primary care physicians and community cancer centers working together. Caution must be advised when recommending a variety of diets and medicines that, as yet, have no proven value in cancer prevention. Cancer control research is needed to expand cancer control applications in a cost effective and acceptable manner.

Attitude of Health Personnel↗
PubMed2006

West Nile virus infection among pregnant women in a northern Colorado community, 2003 to 2004.

OBJECTIVE: Since West Nile virus (WNV) was first detected in New York in 1999, it has spread across North America and become a major public health concern. In 2002, the first documented case of intrauterine WNV infection was reported, involving an infant with severe brain abnormalities. To determine the frequencies of WNV infections during pregnancy and of intrauterine WNV infections, we measured WNV-specific antibodies in cord blood from infant deliveries after a community-wide epidemic of WNV disease. METHODS: Five hundred sixty-six pregnant women who presented to Poudre Valley Hospital (Fort Collins, CO) for delivery between September 2003 and May 2004 provided demographic and health history data through self-administered questionnaires and hospital admission records. Umbilical cord blood was collected from 549 infants and screened for WNV-specific IgM and IgG antibodies with enzyme-linked immunosorbent assays, with confirmation by plaque-reduction neutralization tests. Newborn growth parameters, Apgar scores, and hearing test results were recorded. RESULTS: Four percent (95% confidence interval: 2.4-5.7%) of cord blood samples tested positive for WNV-specific IgG antibodies. No cord blood samples were positive for WNV-specific IgM antibodies. There were no significant differences between infants of seropositive and seronegative mothers with respect to any of the growth parameters or outcomes measured. CONCLUSIONS: Intrauterine WNV infections seemed to be infrequent. In our study, WNV infection during pregnancy did not seem to affect adversely infant health at birth. Larger prospective studies are necessary to measure more completely the effects of maternal WNV infection on pregnancy and infant health outcomes.

Antibodies, Viral↗
PubMed2003

Impact of a cancer screening program on breast cancer stage at diagnosis in a medically underserved urban community.

BACKGROUND: Our previous report showed that the disparity in breast carcinoma survival between black and white women because of advanced stage of disease at presentation in poor black women is related to their low socioeconomic status and lack of health insurance. This observation led to establishment of a community-oriented free cancer screening service. STUDY DESIGN: To evaluate the impact of screening on breast cancer stage at diagnosis, analysis of data from the Harlem Hospital Tumor Registry between 1995 and 2000 was performed and compared with our 1964-1986 report. RESULTS: Twenty-three percent of cancers (324 of 1,405) diagnosed between 1995 and 2000 were breast carcinoma. Data confirm that lack of insurance remains a major problem among poor black women. We observed a marked fall, from 49% in our earlier report to 21% in this study, in late-stage (III and IV) disease at presentation. This fall is associated with significant (p < 0.001) improvement in early detection of breast cancer, with 41% of cancers in stages 0 and I in this data compared with 6% in the previous study. Of note, 53% of women with breast carcinoma had breast-conserving surgery and 45% had modified radical mastectomy in this study; 71% had radical or modified radical mastectomy in the earlier report. CONCLUSIONS: This study confirms the importance of a free cancer screening program in the improvement of early-stage breast cancer detection, treatment, and survival in a poor urban community.

Adenocarcinoma↗
PubMed2003

Automatic particle detection through efficient Hough transforms.

Manual selection of single particles in images acquired using cryo-electron microscopy (cryoEM) will become a significant bottleneck when a very large number of images are required to achieve three-dimensional reconstructions at near atomic resolution. Investigation of fast, accurate approaches for automatic particle detection has become one of the current challenges in the cryoEM community. At the same time, the investigation is hampered by the fact that few benchmark particles or image datasets exist in the community. The unavailability of such data makes it difficult to evaluate newly developed algorithms and to leverage expertise from other disciplines. The paper presents our recent contribution to this effort. It also describes our newly developed computational framework for particle detection, through the application of edge detection and a sequence of ordered Hough transforms. Experimental results using keyhole limpet hemocyanin (KLH) as a model particle are very promising. In addition, it introduces a newly established web site, designed to support the investigation of automatic particle detection by providing an annotated image dataset of KLH available to the general scientific community.

Algorithms↗
PubMed2005

Enzyme immunoassay of Cryptosporidium-specific immunoglobulin G antibodies to assess longitudinal infection trends in six communities in British Columbia, Canada.

A newly developed enzyme-linked immunosorbent assay (ELISA) that detects immunoglobulin G antibodies to the 27-kDa Cryptosporidium parvum sporozoite surface antigen was used to test 4,097 sera collected from pregnant women in 6 communities in British Columbia, Canada, between January 1996, and December 1997. Waterborne outbreaks of cryptosporidiosis occurred in two of the study communities during the period of follow-up, and ELISA seropositivity was high in all six communities during the study period (77% positive to 92% positive). In the community with the largest outbreak, levels of antibody to the 27-kDa antigen increased rapidly and then decayed to background levels within 3-4 months of the peak of the epidemic curve. Trends in serologic reactivity were complex in all communities, and increased antibody levels not related temporally to known waterborne outbreaks were also observed. Serological assays may provide more accurate information regarding community levels of Cryptosporidium infection.

Adolescent↗
PubMed2006

Detection of activity among uncultured Actinobacteria in a drinking water reservoir.

The abundance, identity and activity of uncultured Bacteria and Actinobacteria present in a drinking water reservoir (North Pine Dam, Brisbane, Australia) were determined using a combination of fluorescence in situ hybridization (FISH) alone or with catalysed reporter deposition (CARD-FISH) with microautoradiography. The CARD-FISH technique was modified relative to previous described procedures and performed directly on gelatine cover slips in order to allow simultaneous combination with microautoradiography. Almost twofold higher numbers of microorganisms could be identified as either Bacteria or Actinobacteria using the CARD-FISH technique as compared with the traditional FISH technique. A combination of FISH or CARD-FISH with microautoradiography showed generally higher activity among the Actinobacteria than among all Bacteria. Another important observation was that many cells within the FISH-negative populations of both Actinobacteria and Bacteria were actively assimilating thymidine. Thus, great care should be taken when extrapolating the active fraction of a prokaryotic community to be equivalent to the FISH-detectable population in such environments. Bacterial groups within Actinobacteria produce the odours geosmin and 2-methylisoborneol, which lower the quality of surface water when used for drinking. The results indicate that combined microautoradiography and CARD-FISH may serve as an effective tool when studying identity and activity of microorganisms within freshwater environments.

Actinobacteria↗
PubMed1997

Biodiversity within hot spring microbial mat communities: molecular monitoring of enrichment cultures.

We have begun to examine the basis for incongruence between hot spring microbial mat populations detected by cultivation or by 16S rRNA methods. We used denaturing gradient gel electrophoresis (DGGE) to monitor enrichments and isolates plated therefrom. At near extincting inoculum dilutions we observed Chloroflexus-like and cyanobacterial populations whose 16S rRNA sequences have been detected in the 'New Pit' Spring Chloroflexus mat and the Octopus Spring cyanobacterial mat. Cyanobacterial populations enriched from 44 to 54 degrees C and 56 to 63 degrees C samples at near habitat temperatures were similar to those previously detected in mat samples of comparable temperatures. However, a lower temperature enrichment from the higher temperature sample selected for the populations found in the lower temperature sample. Three Thermus populations detected by both DGGE and isolation exemplify even more how enrichment may bias our view of community structure. The most abundant population was adapted to the habitat temperature (50 degrees C), while populations adapted to 65 degrees C and 70 degrees C were 10(2)- and 10(4)-fold less abundant, respectively. However, enrichment at 70 degrees C favored the least abundant strain. Inoculum dilution and incubation at the habitat temperature favored the more numerically relevant populations. We enriched many other aerobic chemoorganotrophic populations at various inoculum dilutions and substrate concentrations, most of whose 16S rRNA sequences have not been detected in mats. A common feature of numerically relevant cyanobacterial, Chloroflexus-like and aerobic chemorganotrophic populations, is that they grow poorly and resist cultivation on solidified medium, suggesting plating bias, and that the medium composition and incubation conditions may not reflect the natural microenvironments these populations inhabit.

Bacteria, Aerobic↗
PubMed1999

Prostate cancer risk assessment program. A model for the early detection of prostate cancer.

Prostate cancer is the most common form of cancer (except skin cancer) in men. Several factors have been associated with an increased risk for prostate cancer, including age, ethnicity, family history, lifestyle, and environmental exposures. Recognition of the importance of the interaction of these factors in prostate cancer has led to an interest in their evaluation as a model both for studying genetic susceptibility patterns and for studying and providing educational tools and preventive interventions. One such model has been developed at Fox Chase Cancer Center. Critical to the implementation of the model has been the establishment of the Prostate Cancer Risk Registry (PCRR) and Prostate Cancer Risk Assessment Program (PRAP). Together, they serve as a unique resource for investigating the interaction between environmental factors and genetic susceptibility patterns; exploring the early, premalignant biological markers of prostate cancer; and prospectively assessing the quality of life (QOL) of men at risk. In addition, PRAP facilitates the evaluation of models for prostate cancer risk counseling and screening in the community. This paper describes this model for early detection and risk reduction, along with preliminary data from its first two study aims. The program is particularly relevant in view of the wealth of genetic information emerging from the Human Genome Project.

Humans↗
PubMed2001

Culturability as an indicator of succession in microbial communities.

Successional theory predicts that opportunistic species with high investment of energy in reproduction and wide niche width will be replaced by equilibrium species with relatively higher investment of energy in maintenance and narrower niche width as communities develop. Since the ability to rapidly grow into a detectable colony on nonselective agar medium could be considered as characteristic of opportunistic types of bacteria, the percentage of culturable cells may be an indicator of successional state in microbial communities. The ratios of culturable cells (colony forming units on R2A agar) to total cells (acridine orange direct microscopic counts) and culturable cells to active cells (reduction of 5-cyano-2,3-ditolyl tetrazolium chloride) were measured over time in two types of laboratory microcosms (the rhizosphere of hydroponically grown wheat and aerobic, continuously stirred tank reactors containing plant biomass) to determine the effectiveness of culturabilty as an index of successional state. The culturable cell:total cell ratio in the rhizosphere decreased from approximately 0.25 to less than 0.05 during the first 30-50 days of plant growth, and from 0.65 to 0.14 during the first 7 days of operation of the bioreactor. The culturable cell:active cell ratio followed similar trends, but the values were consistently greater than the culturable cell:total cell ratio, and even exceeded I in early samples. Follow-up studies used a cultivation-independent method, terminal restriction fragment length polymorphisms (TRFLP) from whole community DNA, to assess community structure. The number of TRFLP peaks increased with time, while the number of culturable types did not, indicating that the general decrease in culturability is associated with a shift in community structure. The ratio of respired to assimilated C-14-labeled amino acids increased with the age of rhizosphere communities, supporting the hypothesis that a shift in resource allocation from growth to maintenance occurs with time. Results from this work indicate that the percentage of culturable cells may be a useful method for assessing the successional state of microbial communities.

Amino Acids↗
PubMedDate not supplied

The Peckham experiment: a pioneering exploration of wellness.

The Peckham Experiment, under the direction of Williamson and Pearse, was an attempt to study health rather than disease. This study was conducted through the mechanism of the Pioneer Health Centre which provided recreational opportunities and annual physical examinations to a large membership of apparently healthy individuals. In many ways, both the wellness movement and the family practice movement were foreshadowed by their family-centered approach and their finding that most of the apparently well individuals actually suffered from some detectable disorder.

Community Health Centers↗
PubMed2000

Adverse drug reactions in elderly patients: alternative approaches to postmarket surveillance.

In the last three years, the Food and Drug Administration has withdrawn seven prescription drugs from the market, and it has required intensified warnings for a number of others, all due to the discovery of previously unforeseen side effects associated with their use. Adverse drug reactions are a leading cause of death in the United States. For a variety of physiological and socio-medical reasons, the elderly are particularly susceptible to adverse drug reactions. Because the pre-approval process cannot expose all potential risks associated with a drug, the authors assert that policymakers should consider implementing a more extensive, and more integrated, post-approval surveillance and testing system. They conclude that the recent cluster of drug withdrawals due to safety problems raises legitimate questions about the rigor and effectiveness of the post-approval monitoring system for new drugs, and these questions extend beyond the obvious difficulties associated with the collection and analysis of risk data. Traditionally viewed as a regulatory problem for the FDA, the problem of adverse drug reactions implicates patient welfare and the provision of medical care more broadly, and a purely regulatory mind set unnecessarily constrains thinking about possible approaches to improving drug safety. Possible solutions to the problem ought to contemplate more formalized involvement of the medical community, pharmacists, and patients. This Article introduces a proposed systems approach to detecting and preventing adverse drug reactions, and discusses several other incremental reforms to existing systems that may help the medical community to improve the overall safety of prescription drug therapy for the elderly, and ultimately for all patients.

Adverse Drug Reaction Reporting Systems↗