Polymorphism in the melatonin receptor gene in buffalo populations of the Brazilian Amazon.

Buffalo farming in Brazil is increasing, as is the challenge of identifying molecular markers that will improve productivity. Therefore, the aim of this study was to analyze single nucleotide polymorphisms of the receptor gene for the hormone melatonin in buffaloes from northern Brazil by polymerase chain reactions (PCRs) and restriction fragment length polymorphism assays. The PCR products exhibited a cutting point for HpaI at the 318th position of the gene, indicating a transition substitution (T↔C). This substitution was synonymic, and did not alter the stability of the mRNA structure. Allelic and genotypic frequencies differed between the populations studied, and all of the populations demonstrated endogamy and were in Hardy-Weinberg equilibrium. Therefore, the HpaI restriction marker in the melatonin receptor gene cannot be used for genetic improvement, but is an excellent marker for population genetic studies.

A population-based case-control study of temporal arteritis: evidence for an association between temporal arteritis and degenerative vascular disease?

The first population-based incident case-control study of temporal arteritis (TA) in the US was conducted using the unique data resources of the Rochester Epidemiology Project. During the period 1950-1985, 88 newly diagnosed cases of biopsy-proven TA were identified among residents of Olmsted County, Minnesota. Cases were each matched to four Olmsted County community controls on age, sex and duration of community medical record. Odds ratios (OR) were calculated for marital status, education, Quetelet index, pregnancy, age at menopause, thyroid disease, diabetes, smoking, hypertension, angina, myocardial infarction, peripheral vascular disease, and stroke. Multivariable conditional logistic regression analysis identified statistically significant adjusted OR for smoking (2.3, 95% CI = 1.3-4.1). Elevated ORs which were not statistically significant were noted for angina, myocardial infarction, and peripheral vascular disease. These data suggest that TA and arteriosclerosis may share a common causal pathway. Alternatively, histopathological misclassification of temporal artery biopsies may have resulted in the observed association. Due to the limited power of this population-based study, multicentre collaboration should be encouraged to more precisely define the epidemiology of TA.

Trends in incidence and clinical presentation of temporal arteritis in Olmsted County, Minnesota, 1950-1985.

Ninety-four Olmsted County, Minnesota residents with temporal arteritis (TA) initially diagnosed between 1950 and 1985 (incidence cohort) were identified. The age- and sex-adjusted incidence of TA per 100,000 population age 50 years or older was 17.0 (95% confidence interval [CI] 13.6-20.5), with a marked increase in incidence with age and a threefold greater incidence in women (23.4, 95% CI 18.2-28.7) than in men (7.4, 95% CI 3.7-11.0). The previously described secular increase in TA incidence in Olmsted County women continued from 1970 through 1985, while TA incidence in men declined in this latter time period. Although the frequency of classic clinical manifestations of TA declined over time, the percentage of patients undergoing biopsy who have positive specimens remained relatively constant (women 41%, men 26%). The incidence rate of temporal artery biopsy also increased for women during this period, but declined for men, suggesting that the differing trends in TA incidence by sex may be partially attributable to a detection bias. Future research in TA etiology and epidemiology should focus on possible causal factors linked to the differential TA incidence by sex.

Epidemiology of Reiter's syndrome in Rochester, Minnesota: 1950-1980.

The incidence of Reiter's syndrome in a predominantly white, community-based population is reported. The age-adjusted annual incidence rate for males younger than age 50 was 3.5 per 100,000. No female cases were identified. Over time, a greater proportion of cases have been identified among younger males. In 63% of the patients, either a prolonged or relapsing disease course occurred.