Search PubMed⌕ Search

Biomedical subjects

V Perry

Publications and source records attributed to V Perry.

8 recordsLinked to original sources
PubMed1998

The role of the thalamus and basal ganglia in parkinsonian tremor.

The mechanism of parkinsonian tremor may involve a central oscillator, peripheral feedback to the central nervous system (CNS), or both. The thalamus or the globus pallidus is the most likely site for a central oscillator and would be predicted to generate thalamic tremor-related activity characterized, respectively, by calcium spike-associated bursts and by maximal tremor-related activity in the pallidal relay nucleus of thalamus. Thalamic spike trains demonstrate neither of these characteristics. However, cross-correlation, latency, and transfer function analysis indicate that sensory feedback is a critical element in the relationship between thalamic activity and parkinsonian tremor. Therefore, thalamic spike train activity is most consistent with parkinsonian tremor being mediated by peripheral inputs involved in either an unstable reflex loop or sensory modulation of a central oscillator.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1998

Mind games.

Explore the source record for details and available documents.

Animals↗
PubMed1995

The effect of feeding whole cottonseed on the fertility of bulls.

23 bulls were fed whole cotton seed (WCS) for 9 months, which resulted in the ingestion of 7.6 to 19.8 g free gossypol per head daily, or 20.4 to 50.8 mg per kg body weight daily. This level of free gossypol ingestion exceeded that of previous studies of a shorter duration in which gossypol was deemed to have affected bull fertility. There was no significant difference between treated and untreated bulls for total spermatozoal abnormalities, secondary spermatozoal abnormalities, scrotal circumference, scrotal circumference per kg body weight, percentage passing the Society for Theriogenology examination for breeding soundness, and mean breeding soundness examination score. There was a higher proportion of primary spermatozoal abnormalities in untreated than in WCS-fed bulls (P = 0.05). Of the bulls that were prepuberal at the onset of the trial (n = 9), the mean age of onset of puberty was not significantly different in the WCS group than in the untreated group, but it approached significance (P = 0.05). There was no significant difference in the scrotal circumference at the onset of puberty between the two groups. Analysis of the bulls' drinking water showed they could have ingested sufficient minerals in the water to bind with the free gossypol ingested, thereby detoxifying it. This may also explain why the results of previous trials have been so variable.

Animals↗
PubMed1993

In vivo distribution and characterization of two novel mononuclear phagocyte differentiation antigens in mice.

Flow cytometry, immunohistology, and SDS-PAGE Western blot analysis were used to characterize two novel anti-mouse mononuclear phagocyte differentiation antigens defined by monoclonal antibodies. One antibody, Monts-4, recognized an 80-100 kd cell-surface protein expressed on resident macrophages in the peritoneum and stained macrophages in the splenic white pulp and marginal zone, liver, lymph node paracortical regions, Peyers patches, and cortex of the thymus. Monts-4 did not stain blood monocytes or monocyte-derived inflammatory macrophages in the peritoneal cavity. Macrophages that were Monts-4 positive became Monts-4 negative within 24-72 h after culturing in vitro. Monoclonal antibody SK39 recognized a 180 kd cell-surface molecule expressed on inflamed peritoneal monocytes/macrophages and stained macrophages in the splenic red pulp, cortex of the thymus, subcapsule and medullary regions of lymph nodes, and in sites of acute and chronic inflammation. No differences were seen in the expression of these antigens in the immunodeficient SCID versus normal BALB/c mouse. A comparison of the distribution and molecular weights of the Monts-4 and SK39 antigens with other described mononuclear phagocyte-specific antigens, including F4/80 and those defined by the M1/70, ERTR9, MOMA1, MOMA2, and SER4 monoclonal antibodies, shows these to be novel mononuclear phagocyte-specific differentiation antigens.

Animals↗
PubMed1990

Relationships among bovine male and female reproductive traits.

No significant relationship (p greater than 0.05) was found between age at puberty in heifers and the age and scrotal circumference at puberty in related bulls. There was a significant effect (p less than 0.01) of genotype and sire on age at puberty of heifers and a significant effect (p less than 0.05) of genotype on weight at puberty in heifers. There was a significant effect of genotype on age (p less than 0.01) and weight (p less than 0.05) at puberty of bulls. A significant difference (p less than 0.05) in age at puberty of bulls was found between the 2 methods of assessing puberty. It is possible that the assessment of puberty of heifers at 2-month intervals may not have been precise enough to detect such a relationship and/or that the variation in genotypes and ages in this study were too great to establish such a relationship.

Age Factors↗
PubMed1990

Fertility indices for beef bulls.

Young (16- to 30-month-old) beef bulls of 6 different genotypes were assessed for production and reproduction traits at different ages and intervals from single-sire mating. Fertility indices, in the form of multiple regression equations using pregnancy rate as the dependent variable, were derived from these assessments using non-orthogonal analyses of variance and covariance. "Among" and "within" genotype fertility indices showed significant correlations with pregnancy rate. "Within" genotype fertility indices showing significant multiple correlations (p less than 0.01) at 11 (r = 0.75), 8 (r = 0.89), 6 (r = 0.86) and 2 (r = 0.80) months prior to mating. It was found that the most important traits to include in the fertility indices were peripheral LH levels following GnRH stimulation, testicular volume, libido and body weight. In general, the fertility indices showed good correlations with bull reproductive performance and were not significantly affected by bull genotype.

Age Factors↗