Natural Attachment Duration of Adult Female Ticks Ixodes Uriae (Acari: Ixodidae) on Free-Living Adult Black-Legged Kittiwakes Rissa Tridactyla

An investigation into the attachment duration of the tick Ixodes uriae on free-living adult black-legged kittiwakes Rissa tridactyla was carried out at a colony in southeast Scotland. Adult kittiwakes (n = 14) were caught and searched for ticks. Newly attached ticks (n = 31) were marked as was the bird before its release. These birds were recaptured at intervals of two to seven days and the presence or absence of the tick was recorded. The median attachment duration was estimated as 7.7 days (SE = 0.38) and estimated times for 5% and 95% of ticks to become detached were 5.22 days (SE = 0.67) and 9.51 days (SE = 0.58) respectively. Information on tick attachment duration is essential for the development of accurate models of tick population dynamics and patterns of disease transmission.     

Alternate pathogenesis of systemic neoplasia in the bivalve mollusc Mytilus.

The proliferative disease systemic neoplasia, also termed hemic neoplasia or disseminated sarcoma, was studied in four Puget Sound, Washington populations of the bay mussel (Mytilus sp.). Using flow cytometric measurement of DAPI-stained cells withdrawn from the hemolymph, DNA content frequency histograms were generated for 73 individuals affected by the disease. The cells manifesting systemic neoplasia were found to exist as either of two separate types, characterized by G0G1 phase nuclear DNA contents of either approximately 4.9 x haploid (pentaploid form) or approximately 3.8 x haploid (tetraploid form). The two disease forms were found to coexist in all four mussel populations sampled, with overall relative prevalences of 66% pentaploid form, 29% tetraploid form, and 5% exhibiting both disease forms simultaneously. These findings represent the first unequivocal demonstration of multiple cell types in a bivalve neoplasia. The two forms appear to represent separate pathogenetic processes rather than sequential stages of a single pathogenesis. Two cell cycling parameters associated with proliferative activity were employed to compare the alternate forms: (i) the percentage of cells assigned to the DNA Synthesis (S) phase of the neoplastic cell cycle, and (ii) the proportion of neoplastic cell mitotic figures in hemocytological preparations. Mean values for both parameters were significantly higher for mussels with the tetraploid form of the disease, suggesting a higher rate of proliferation relative to the pentaploid form. Qualitatively, cells of the tetraploid form contained slightly lower nuclear and cytoplasmic volumes compared to those of the pentaploid form. An observed wide variation in neoplastic cell nuclear size within either disease form may reflect the distribution of cells in the G0G1, S, and G2M phases of the cell cycle. Potential etiologic relationships between the two forms are discussed.     

PGM1 null allele detected in a Caucasian mother-son pair

The presence of a PGM1 null allele in a mother and her son was deduced from their inconsistent phenotypes. Quantitation studies were done to confirm the half-normal enzyme activity. Phenotype analysis of 29 additional genetic markers gave no indication of non-parentage, making non-maternity a very unlikely explanation for the discrepancy.     

Segregation and linkage analyses of dopamine-beta-hydroxylase activity.

Dopamine-beta-hydroxylase (DBH) activity in serum was measured by spectrophotometric methods in 95 persons of a large family (HGAR 2), along with 27 polymorphic markers from blood, urine and saliva. The distribution of DBH activity, after appropriate transformation and age adjustment, showed a significantly better fit to a mixture of two normal distributions than a single normal distribution. Pedigree segregation analyses showed evidence of a possible major gene governing low levels of DBH activity, segregating in this family in a recessive fashion. Linkage analyses between that major locus and the 27 polymorphic markers showed no significant lod scores favoring linkage. The highest lod score obtained was 0.81 with Lp at zero recombination fraction. In addition, published data on DBH activity measured by radiochemical assays on 22 families with 161 members were reanalyzed as a quantitative trait, with appropriate correction for ascertainment bias. The results were similar to that of HGAR 2, corroborating the existence of a major locus for DBH activity.     

Linkage relationships of Lp and Ag serum lipoproteins with 25 polymorphic markers

Summary Linkage relations of Lp and Ag serum lipoproteins with 25 polymorphic marker systems are examined in a large kindred of over 100 persons. The results indicate that Lp and ESD are probably closely linked and so the Lp locus may also be assigned to chromosome 13. No significant linkage is detected between Ag and the other marker systems.This research was supported by: a Public Health Service Research Career Development Award (1-K3-GM-31, 732) and research grant (GM 16697) from the National Institute of General Medical Sciences.     

The Seminole Indians of Oklahoma: Morphology and serology

Two hundred and sixty-three Indians aged six and above were studied in Oklahoma for blood types, hemoglobin types, and physical traits; 53% were Seminoles and the remainder were admixed with Creek or other populations. The results indicate that they resemble the Florida Seminoles in most of their serologic traits. In physical traits they are comparable to the group studied by Krogman two decades ago. Compared with the Florida Seminoles, the Oklahoma sample are slightly taller and heavier, significantly lighter in skin color, and have a lower incidence of sickle cell gene. By both serology and morphology the Oklahoma group are most similar to Florida Seminoles, slightly less similar to other Indian groups, and still less to White and Negro populations. The Oklahoma sample of women showed a non-significantly greater fertility than those of Florida. Some indication of positive assortative mating for skin color was found in both groups.