Epidemiological field studies of animal populations.
Numerous survey designs have been developed for epidemiological field studies of human populations, most of which are also applicable to field studies of animal poulations. Each design has its own advantages and disadvantages. The final design selected for a particular study depends upon such factors as the overall purpose of the study, the geographic dimensions of the study area, the diseases incidence or prevalence and species to be studied as well as the planned use for the data. Population dynamics including the distribution and density of the species to be studied are factors that should also be considered in the initial design of a study. A surveillance system, using mailed questionnaire data and a subsequent survey using direct interviews of validate the data in a statewide study of swine birth defects are used to illustrate some of the techniques that can be applied to domestic animal populations in a fairly large geographic area. The type of data collected, its use and its limitations are also considered. (+info)
Enzymes and reproduction in natural populations of Drosophila euronotus.
Populations of Drosophila euronotus, one from southern Louisiana )3 samples), and one from Missouri (2 samples), were classified for allele frequencies at alkaline phosphatase (APH) and acid phosphatase (ACPH) loci. The two populations differed consistently in allele frequencies at both loci. The APH locus is on the inversion-free X chromosome; the chromosomal locus of the autosomal ACPH is unknown, and could involve inversion polymorphism. Wild females from Missouri and Louisiana populations heterozygous at the APH locus carried more sperm at capture than did the corresponding homozygotes. This heterotic association was significant for the combined samples, and whether it was the result of heterosis at the enzyme locus studied, or due to geographically widespread close linkage with other heterotic loci, it should help to maintain heterozygosity at the APH locus. In a Louisiana collection which included large numbers of sperm-free females, simultaneous homozygosity at both enzyme loci was significantly associated with lack of sperm. It is suggested that the latter association is the result of young heterozygous females achieving sexual maturity earlier than do the double homozygotes. The average effective sperm load for 225 wild females was only 29.4, suggesting the necessity for frequent repeat-mating in nature to maintain female fertility. A comparison of the sex-linked APH genotypes of wild females with those of their daughters indicated that among 295 wild-inseminated females from five populations, 35% had mated more than once, and of this 35%, six females had mated at least three times. Because of ascertainment difficulties, it is clear that the true frequency of multiple-mating in nature must have been much higher than the observed 35%. Laboratory studies indicate that multiple-mating in this species does not involve sperm displacement, possibly due to the small number of sperms transmitted per mating, and the fact that the sperm receptacles are only partially filled by a given mating. (+info)
Changes in newspaper coverage of cardiovascular health issues in conjunction with a community-based intervention.
Numerous community-based prevention projects, with significant media components, have been conducted over the past decade. Multiple evaluation strategies have been used to document the effectiveness of these interventions, including intermediate measures of community impact such as assessment of media coverage. As part of the evaluation of a community-based intervention (the Bootheel Heart Health Project), dissemination of information on cardiovascular disease (CVD) was measured through a media content analysis of newspapers. Data were analyzed from 23 newspapers in six rural counties in southeastern Missouri for the period October 1988 through August 1993. An increase was observed in CVD-related coverage in the pre-intervention period (mean articles per month = 31.5) compared with the post-intervention period (mean articles per month = 50.7) (F = 10.2; P = 0.003). In supporting data from a separate randomized risk factor survey of 1510 residents in the same area, respondents reported hearing of heart health coalitions primarily through local newspapers. The current study documents increasing print media coverage of cardiovascular health issues in a high-risk, rural area and shows that media content analysis can be a useful evaluation tool in community-based interventions. (+info)
Transfusion-transmitted malaria--Missouri and Pennsylvania, 1996-1998.
Malaria is a rare but potentially serious complication of blood transfusion. During 1958-1998, 103 cases of transfusion-transmitted malaria in the United States were reported to CDC. This report summarizes the investigation of three cases that occurred during 1996-1998 in Missouri and Pennsylvania and illustrates the key features of transfusion-transmitted malaria and the importance of donor screening. (+info)
Known mutations of apoB account for only a small minority of hypobetalipoproteinemia.
Low LDL cholesterol and apoB levels in plasma cosegregate with mutations of apoB in some kindreds with familial hypobetalipoproteinemia. Approximately 35 apoB mutations, many specifying apoB truncations, have been described. Based on the centile nomenclature where the full-length nature apoB consisting of 4536 amino acids is designated as apoB-100, only those truncations of apoB >25% of normal length are detectable in plasma. Previously, we reported on five unrelated kindreds with familial hypobetalipoproteinemia in whom although no apoB truncations were detectable in plasma, low apoB levels were nevertheless linked to the apoB gene. In one of those kindreds, we reported a donor splice site mutation in intron 5 (specifying apoB- 4). We now describe a nonsense mutation in exon 10 (apoB-9) in two of the other unrelated families. Both the apoB-4 and apoB-9 mutations have been reported by others in unrelated families. Recurrent mutations of apoB-40 and apoB-55 also have been reported, suggesting that recurrent mutations of apoB may account for an appreciable proportion of familial hypobetalipoproteinemia kindreds. To test this hypothesis, we searched for four apoB mutations whose products are not detected in plasma including the apoB-4, apoB-9, and two other previously reported mutations in exons 21 and 25. We studied three groups with plasma cholesterols <130 mg/dl in whom no apoB truncations were detected in plasma: a) 28 FHBL probands from St. Louis, b) 151 individual St. Louisians, and c) 28 individual Sicilians. One subject from the 28 kindreds and two subjects among 151 hypobeta individuals from St. Louis harbored the exon 10 mutation. None of the other mutations were detected. Thus, among hypobeta lipoproteinemic subjects without any detectable apoB truncations in plasma, <5% had an apoB truncation-producing mutation. As only about 0.5% of hypobeta lipoproteinemic subjects have plasma-detectable apoB truncations, our data suggest that the known apoB truncations account for only a small proportion of hypocholesterolemia. (+info)
Key informant surveys as a tool to implement and evaluate physical activity interventions in the community.
Key informant surveys are important tools for planning and evaluating community health programs. A survey was conducted to gather views on policies toward physical activity from four sets of key informants: physicians, church leaders, business leaders and civic leaders. Surveys were mailed to 797 key informants who were selected from 12 southeastern Missouri counties. For comparison, data from a telephone survey of 2106 persons in the general population were also analyzed. The majority (> 85%) in all four key informant groups were very supportive of required physical education in schools, but less supportive (< 69%) of government funding for places where community members can exercise. Physicians perceived community members as having somewhat greater access to places to exercise relative to the other key informant groups. Comparisons of the key informant surveys to the population survey indicated similar levels of support for physical activity policy. The information from this survey has been useful in identifying support for physical activity policy and gaining access to potential influences for community change. Since key informant research in the area of physical activity policy and cardiovascular disease prevention is sparse, there is a need for future studies. (+info)
Residential radon exposure and risk of lung cancer in Missouri.
OBJECTIVES: This study investigated residential radon exposure and lung cancer risk, using both standard radon dosimetry and a new radon monitoring technology that, evidence suggests, is a better measure of cumulative radon exposure. METHODS: Missouri women (aged 30 to 84 years) newly diagnosed with primary lung cancer during the period January 1, 1993, to January 31, 1994, were invited to participate in this population-based case-control study. Both indoor air radon detectors and CR-39 alpha-particle detectors (surface monitors) were used. RESULTS: When surface monitors were used, a significant trend in lung cancer odds ratios was observed for 20-year time-weighted-average radon concentrations. CONCLUSIONS: When surface monitors were used, but not when standard radon dosimetry was used, a significant lung cancer risk was found for radon concentrations at and above the action level for mitigation of houses currently used in the United States (148 Bqm-3). The risk was below the action level used in Canada (750 Bqm-3) and many European countries (200-400 Bqm-3). (+info)
Heat-related illnesses and deaths--Missouri, 1998, and United States, 1979-1996.
Although heat-related illness and death are readily preventable, exposure to extremely high temperatures caused an annual average of 381 deaths in the United States during 1979-1996. Basic behavioral and environmental precautions are essential to preventing adverse health outcomes associated with sustained periods of hot weather (daytime heat index of > or = 105 F [> or = 40.6 C] and a nighttime minimum temperature of 80 F [26.7 C] persisting for at least 48 hours). This report describes four heat-related deaths that occurred in Missouri during 1998, summarizes heat-related deaths in the United States during 1979-1996, describes risk factors associated with heat-related illness and death, especially in susceptible populations (young and elderly, chronically ill, and disabled persons), and recommends preventive measures. (+info)