Polymorphism at the avpr1a locus in male prairie voles correlated with genetic but not social monogamy in field populations.

Integrative studies of genetics, neurobiology and behaviour indicate that polymorphism in specific genes contributes to variation observed in some complex social behaviours. The neuropeptide arginine vasopressin plays an important role in the regulation of a variety of social behaviours, including social attachment of males to females, through its action on the vasopressin 1a receptor (V1aR). In socially monogamous prairie voles (Microtus ochrogaster), polymorphism in the length of microsatellite DNA within the regulatory region of the gene (avpr1a) encoding the V1aR predicts differences among males in neural expression of V1aRs and partner preference under laboratory conditions. However, understanding the extent to which V1aR mediates variation in prairie vole social and reproductive behaviour observed in nature requires investigating the consequences of avpr1a polymorphism and environmental influences under ecologically relevant conditions. We examined the relationship between avpr1a length polymorphism and monogamy among male prairie voles living in 0.1 ha enclosures during a time similar to their natural lifespan. We found no evidence that avpr1a genotype of males predicts variation in social monogamy measured in the field but some indices of social monogamy were affected by population density. Parentage data indicated that a male's avpr1a genotype significantly influenced the number of females with which he sired offspring and the total number of offspring sired. Total brain concentrations of V1aR mRNA were not associated with either male behaviour or avpr1a genotype. These data show that melding ecological field studies with neurogenetics can substantially augment our understanding of the effects of genes and environment on social behaviours.

Bias correction in maximum likelihood logistic regression.

This paper provides an expression for bias of the maximum likelihood logistic regression estimates for use with small sample sizes. This bias correction is based on an expansion of the maximum likelihood equation. Simulation results show these corrections to be highly effective in small samples.

Lectins in diagnostic microbiology: use of wheat germ agglutinin for laboratory identification of Neisseria gonorrhoeae.

A lectin slide agglutination test has been developed for the confirmatory identification of Neisseria gonorrhoeae. With wheat germ lectin as an agglutinin, 164 of 165 clinical isolates of N. gonorrhoeae gave a 3 to 4+ reaction within 6 to 8 min. Four gonococcal isolates, even though negative by the fluoresecent-antibody method, gave strong positive reactions with the wheat germ lectin. Among 23 isolates of Neisseria meningitidis tested, which included representatives of sero-groups A, B, C,D, X, Y, and Z, only one strain in group X gave a false-positive reaction. The nonpathogenic species of Neisseria, as well as Branhamella catarrhalis, all showed negative reactions with the wheat germ agglutinin. The novel method provides a simple, rapid, and inexpensive means for the laboratory diagnosis of gonorrhea and obviates the need for performing second-stage sugar fermentation studies or utilizing the more expensive fluorescent-antibody techniques.

Red cell exchange in the pregnancy complicated by a major hemoglobinopathy.

A new method of partial erythrocyte exchange for pregnancies complicated by a major hemoglobinopathy is described. The Haemonetics 30 Cell Separator allows efficient withdrawal and discard of the patient's erythrocytes. The patient's leukocytes, platelets, and plasma are conserved and returned with washed, compatible donor red cells which contain Hb AA. Three pregnant black women with significant hemoglobinopathies were treated by this modality during their pregnancies. Vaginal term deliveries were accomplished in each case. The method offers advantages in the efficiency of blood quantity displacement, patient comfort, adaptability to the patient with severe anemia, and the use of outpatient facilities. The method is suggested for use whenever a patient with an obstetrically significant hemoglobin variant needs transfusions of erythocytes.