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Biomedical subjects

R L Taylor

Publications and source records attributed to R L Taylor.

At least 91 records · Page 5Linked to original sources

Major histocompatibility (B) complex-associated differences in the delayed wattle reaction to staphylococcal antigen.

The influence of the major histocompatibility (B) complex on the delayed wattle reaction (DWR) to Staphylococcus aureus was studied in 109 segregants (B2/B2, B2/B5, and B5/B5) of a fourth generation cross between inbred Regional Poultry Research Laboratory lines 6(1) and 15(1). Chickens were sensitized at 6 weeks of age with S. aureus antigen. One week later, DWR was evaluated by injecting the right wattle with S. aureus antigen. Thickness measurements were taken 4, 24, 48, 72, and 96 hr after injection. A quadratic equation model was used for each bird to calculate maximum wattle thickness, hour of maximum response, and rate of response development and decline. In males, the maximum wattle thickness in response to S. aureus antigen was significantly greater in B2/B5 heterozygotes (1.77 +/- .07 mm) than in either homozygote, B2/B2 (1.36 +/- .13 mm) or B5/B5 (1.39 +/- .08 mm). Heterozygous males reached maximum response sooner and recovered more quickly than homozygous males but these differences were not statistically significant. In females, response developed later than in males but no B complex effect was detected in either rate of development or maximum response.

Animals↗

Operative closure of patent ductus arteriosus in premature infants in the neonatal intensive care unit.

Fifty-two premature infants underwent hemoclip closure of patent ductus arteriosus in the neonatal intensive care unit after a brief trial of fluid restriction and diuretics. Indomethacin was used in only four patients. The median time from diagnosis to operation was 3 days. There were no deaths directly attributable to operation. Nine operative complications developed in nine patients (17 percent). There were no surgical infections. Complications related to prematurity resulted in 20 deaths (38 percent). Patent ductus arteriosus closure in the neonatal intensive care unit prevented the complications of hypothermia, inadvertent extubation, and interruption of vascular access and monitoring. Early operative closure in the neonatal intensive care unit is the treatment of choice in most premature infants with patent ductus arteriosus.

Ductus Arteriosus, Patent↗

Delayed wattle reactions in Eimeria tenella infected chickens.

Wattle reactions to an Eimeria tenella antigen and phytohemagglutinin (PHA) were studied in chickens infected with E. tenella. Two trials were conducted using a total of 224 chickens. Four days after infection with one dose of 10,000 sporulated oocysts, the increase in wattle thickness in response to E. tenella antigen was significantly greater than that of uninfected controls. This significant response persisted through day 10 post infection. Wattle response to PHA 3 days after infection were significantly greater than for uninfected controls. Significant differences in response to PHA were maintained throughout the experiment except on day 6. An increased response to PHA from days 7 to 13 post infection was attributed to the lower parasite burden at that time.

Animals↗

Comparison of the cardiovascular effects of intravenous and intraaortic protamine in the conscious and anesthetized dog.

Controversy exists as to whether intraaortic (IA) administration of protamine sulfate has less adverse effects than the intravenous (IV) route. The effect of protamine on contractility is not well established. Therefore, 9 dogs underwent chronic instrumentation to monitor aortic pressure (AP), left ventricular (LV) pressure, central venous pressure, cardiac index (CI), heart rate, stroke volume index (SVI), systemic vascular resistance index, and LV volume. The end-systolic LV pressure-volume relationship was used as a load-independent measure of contractility. Each dog was administered IV and IA protamine on separate occasions after pretreatment with heparin. Studies were performed with and without anesthesia. In the awake studies, analysis of variance showed greater decreases in mean AP (p less than .03), CI (p less than .05), and SVI (p less than .02) with IA protamine infusion. In the anesthetized animals, there were no significant differences between IA and IV administration of protamine. Protamine did not decrease contractility in any group. We conclude that IA administration of protamine offers no advantage over IV administration in the dog. Protamine does not decrease contractility when given by either route.

Analysis of Variance↗

An investigation of the use of high- and low-preference food as a reinforcer for increased activity of individuals with Prader-Willi syndrome.

The results of this study provide information that might be used to develop an approach to weight loss management for individuals with Prader-Willi syndrome that emphasizes the increase of output. Specifically, our finding that they do have a definite food preference and, subsequently, that they prefer a lesser amount of the high-preference food than a greater amount of low-preference food is contradictory to several non-empirical reports (Holm, 1981; Pipes & Holm, 1981). Further, the use of food as a reinforcer has been considered taboo by those who use more conventional and restrictive management approaches with Prader-Willi syndrome individuals. Our data, however, strongly suggest that a low volume of food can be used as an effective reinforcer for increased activity and exercise.

Adolescent↗

Effect of surgical bursectomy on the ellipsoid, ellipsoid-associated cells, and periellipsoid region of the chicken's spleen.

Surgical bursectomy resulted in cellular depletion of the periellipsoid white pulp, confirming its bursa dependency. Also, in bursectomized birds, the ellipsoid could not be identified, although a small number of abnormal ellipsoid-associated cells (EAC) were observed in the periellipsoid region. The most characteristic finding was the degeneration of the EAC. Degeneration of EAC indicated that the intact bursa was mandatory for normal differentiation of cells of the periellipsoid white pulp into EAC. The promoting effect of the bursa might take place by a bursal hormone. The histological impairment of the EAC was followed by reduced carbon binding and migrating capabilities. Bursectomy resulted in a shift in bacterial phagocytosis in that many cells of the periellipsoid phagocytosed Salmonella. The reduced heterophil infiltration of the ellipsoid in bursectomized birds might be explained by the impaired granular content of the EAC. The impaired migration capability of the EAC might contribute to the low number of germinal centers in bursectomized birds.

Animals↗

Major histocompatibility (B) complex effects on acquired immunity to cecal coccidiosis.

The influence of the major histocompatibility (B) complex on acquired immunity to the avian coccidium Eimeria tenella was studied in 217 F4 segregants (B2B2, B2B5, B5B5) of a cross between inbred lines 6(1) (B2B2) and 15(1) (B5B5) and segregating haplotype combinations of UNH105 (B23B23, B23B24, B24B24), a noninbred line of New Hampshire chickens. Chickens were immunized at 6 weeks of age with 500 oocysts daily for 5 days, then challenged 14 days later with 10 000 oocysts. Responses to infection were evaluated by cecal lesion scores, body weight gain, delayed wattle reaction (DWR), and spleen weight. The F4 segregants of genotypes B2B5 and B5B5 exhibited greater immunity to challenge than B2B2 chickens. B5B5 chickens showed a significantly greater DWR following immunization and larger spleens 6 days after the challenge than either of the other genotypes. However, both B2B5 and B5B5 chickens demonstrated significantly lower lesion scores than B2B2 chickens. There were no significant differences in weight gain among these genotypes. Among 139 line UNH105 segregants, B23B23 hosts had significantly lower lesion scores than B24B24 chickens. No other differences in immune response among line UNH105 genotypes were detected.

Animals↗

Comprehensive toxicology screening in the emergency department: an aid to clinical diagnosis.

An audit of 2,641 toxicology requests from the Georgetown University Hospital Emergency Department from 1981 through 1984 was conducted to assess the contribution of toxicology laboratory results to the clinical evaluation of the intoxicated patient. Positive findings were obtained in 80% of the patients tested. Ethanol was the most common intoxicant, accounting for 48% of all positive results and an average serum concentration of 250 mg/dl. Multiple drug use was documented in 28% of the patients with positive results; some ingested as many as six substances. Women were more likely than men to be polydrug users. A comparison of laboratory findings with diagnosis based on history and examination for 76 patients revealed that the laboratory provided additional information on the nature of the intoxication two-thirds of the time. Our conclusion is that the toxicology laboratory offering a broadly based screening service when properly utilized by the emergency department staff can aid in establishing an accurate diagnosis and provide a guide to therapy in the intoxicated patient.

Adult↗

Type and strength of food preferences of individuals with Prader-Willi syndrome.

The results of these experiments indicate that, contrary to popular belief, individuals with Prader-Willi syndrome demonstrate definite food preferences. These data are consistent with and extend recent findings of Caldwell & Taylor (1983). The general conclusions are that the foods preferred by most individuals with Prader-Willi syndrome are sweet, and that the strength of the food preference is related to the level of cognitive ability (the higher the cognitive level, the stronger the preference). A comparison of the food preferences of an obese, non-Prader-Willi group with similar cognitive deficiencies would be worthy of empirical investigation.

Adolescent↗

High-affinity binding of [3H]acetylcholine to muscarinic cholinergic receptors.

High-affinity binding of [3H]acetylcholine to muscarinic cholinergic sites in rat CNS and peripheral tissues was measured in the presence of cytisin, which occupies nicotinic cholinergic receptors. The muscarinic sites were characterized with regard to binding kinetics, pharmacology, anatomical distribution, and regulation by guanyl nucleotides. These binding sites have characteristics of high-affinity muscarinic cholinergic receptors with a Kd of approximately 30 nM. Most of the muscarinic agonist and antagonist drugs tested have high affinity for the [3H]acetylcholine binding site, but pirenzepine, an antagonist which is selective for M-1 receptors, has relatively low affinity. The ratio of high-affinity [3H]acetylcholine binding sites to total muscarinic binding sites labeled by [3H]quinuclidinyl benzilate varies from 9 to 90% in different tissues, with the highest ratios in the pons, medulla, and heart atrium. In the presence of guanyl nucleotides, [3H] acetylcholine binding is decreased, but the extent of decrease varies from 40 to 90% in different tissues, with the largest decreases being found in the pons, medulla, cerebellum, and heart atrium. The results indicate that [3H]acetylcholine binds to high-affinity M-1 and M-2 muscarinic receptors, and they suggest that most M-2 sites have high affinity for acetylcholine but that only a small fraction of M-1 sites have such high affinity.

Acetylcholine↗

Meckel's diverticulum. II. A novel lymphoepithelial organ in the chicken.

We have studied the lymphoid development and structure of Meckel's diverticulum (MD). The lymphoid accumulation began about 2 weeks of age. Between 2 and 5 weeks of age the longitudinal folds were filled with lymphoid tissue. The intensive germinal center formation occurred between 5 and 7 weeks of age. Germinal center formation was associated with the presence of secretory cells. The absence of the secretory cells in the germinal centers was followed by germinal center inactivity which was indicated by the lack of lymphoblasts and the high number of tingible body macrophages. The lymphoid tissue of MD seemed to be fully developed by 10 weeks of age and remained lymphoid at least until 21 months of age. Meckel's diverticulum produced large numbers of plasma cells which were comparable to those of the gland of Harder. We may regard MD as the third pouch of the intestine and suggest that it may be a novel lymphoepithelial organ in the chicken.

Aging↗

Effect of soluble antigen on the ellipsoid-associated cells of the chicken's spleen.

The ellipsoid-associated cells (EAC) localize on the surface of the ellipsoid. They bind the IV injected horseradish peroxidase (HRP) and bovine serum albumin (BSA), migrate to the red pulp and then enter the systemic circulation. After protein injection, the number of white blood cells increased above the normal level. The highest number of white blood cells occurred between 4 and 6 hr after HRP injection. In this period, the cell enhancement resulted in HRP-positive mononuclear cells which might come from the spleen. This cell population may vary in size and number in the blood and may be identical with the dendritic cell of the chicken. The other type of blood mononuclear cell is histologically identical with the classical monocyte endogenous peroxidase positive type and their number is lower than that of the former. This type of monocytic (MN) cell could be of bone marrow origin.

Animals↗

Friends can be good medicine: an excursion into mental health promotion.

This paper describes Friends Can Be Good Medicine, a multi-media, mental health promotion campaign conducted in 1982 throughout California. The creative design, pilot-test, implementation and results are reviewed. Conceptually, Friends was derived from evidence linking supportive personal relationships with increased physical and mental health. Three major campaign elements were: broadcast media, an array of educational materials, and community activities. Evaluation findings revealed that Friends was most effective when campaign elements reinforced one another. Resulting changes in knowledge, attitudes, and intentions among those reached by Friends were maintained after one year. It is contended that, for better or worse, mass media is part of the health care system.

Attitude↗