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Biomedical subjects

H R Wilson

Publications and source records attributed to H R Wilson.

At least 181 records · Page 10Linked to original sources
PubMed1976

Novel heterocyclic nitrofurfural hydrazones. In vivo antirypanosomal activity.

Hydrazine derivatives of several pyrazolo[1,5-alpha]pyrimidines (A), pyrazolo[1,5-alpha]-1,3,5-triazines (B), s-triazolo[1,5-alpha]pyrimidines (C), and imidazo[1,2-alpha]pyrimidines (D) were synthesized and condensed with 5-nitrofurfural in order to obtain the corresponding nitrofurfural hydrazones of each heterocycle (1d-14d). Each compound was screened for in vitro activity against Trypanosoma cruzi. The compounds were then tested in vivo against experimental infections of T. cruzi in laboratory (C3H/He strain) mice. An interesting structure-activity relationship was uncovered, revealing that 5-methyl-7-(5-nitrofurfurylidenehydrazino)pyrazolo[1,5-alpha]pyrimidine (2d) greatly increased the mean survival time (IMST) of mice with terminal infections. Subtle alterations in the structure of 2d, such as the substitution of a 5-hydrogen for the 5-methyl group (1d) or the substitution of the 3-hydrogen by the water-soluble 3-sulfonic acid (3d) or 3-sodium sulfonate (4d), resulted in a drastic loss of in vivo and in vitro activity.

Animals↗
PubMed1976

Influence of high temperature stress of 16-day embryos on subsequent hatchability.

Two experiments were conducted to determine the effect of acute heat stress on late-stage chicken embryos. Embryos were incubated at a normal control temperature (37.5 degrees C.) for 16 days and were then subjected to 40.6, 43.3, 46.1 or 48.9 degrees C. for various periods of time in another incubator of the same type. At the end of the stress period all embryos were placed back into the control incubator for the remainder of the incubation period. Exposure of embryos for 24 hours to a temperature of 40.6 degrees C, caused no major detrimental effects on hatchability. Exposure for 6 hours to the temperature of 43.3 degrees C, caused a decrease in hatchability with a severe decline in hatchability occurring after 9 hours of exposure. Exposure to 46.1 degrees C. for 3 hours or 48.9 degrees C for 1 hour killed all embryos. Chicks which hatched following a severe heat stress had a high incidence of clubbed, wiry down and exhibited an unsteady gait.

Animals↗
PubMed1975

Lead toxicity of bobwhite quail.

Five experiments were conducted involving both juvenile and adult Bobwhite quail (Colinus virginianus) to study the toxicity of lead acetate, lead shot, powdered lead and antimony. Performance of juvenile birds receiving up to 1,500 p.p.m. of lead as lead acetate was not significantly influenced during the six-week experimental period. Feeding 3,000 p.p.m. lead as lead acetate was not significantly influenced during the six-week experimental period. Feeding 3,000 p.p.m. lead as lead acetate was associated with a significant depression of body weight and an increase in mortality. Feeding growing quail up to 2,000 p.p.m. lead from either lead acetate or powdered lead, 3 or 6% antimony (as % of shot dosage or 5 lead shot per week caused no significant effects upon either body weight or mortality. No significant trends were noted in body weight, feed intake, semen quality or organ weight of adult quail that received up to 1,500 p.p.m. lead from lead acetate. Dosing adult Bobwhite quail cocks with 10 or more lead shot per week caused a significant increase in nortality, and more than 90% of those dosed with 30 shot per week died by the end of four weeks.

Aging↗
PubMed1975

Synthesis and antitrichomonal activity of certain pyrazolo (1,5-a) pyrimidines.

Several bridgehead nitrogen heterocycles were synthesized to be screened as antimicrobial agents, modeled after nalidixic acid. The activity of these new compounds, all derivatives of 3-nitro-4,6-disubstituted pyrazolo (1,5-a)pyrimidin-7-ones (3,7,8, and 9), however, was found to be highly specific for Trichomonas foetus and completely lacking in activity against bacteria, fungi, and parasites other than Trichomonas. Of the nine componds synthesized, including the intermediate 4,6-disubstituted pyrazolo (1,5-a) pyrimidin-7-ones (2-6) and the 6-substituted or unsubstituted pyrazolo (1,5-a) pyrimidin-7-ones (1 and 4), only 6-carbethoxy-4-ethyl-3-nitropyrazolo(1,5-a)pyrimidin-7-one (7) was found to be a potent antitrichomal agent, being comparable or perhaps better than metronidazole. From a tentative structure-activity relationship study, it was apparent that the combination of the 3-mitro, 4-ethyl, and 6-carbethoxy groups imparted specific activity, wheras other substitutions imparted little or no antitrichomonal activity.

Animals↗
PubMed1975

Characteristics of White Leghorn chickens selected for heat tolerance.

A series of studies was conducted to identify and delineate factors associated with responses of chickens to high ambient temperatures. Two populations of birds were used which had been selected divergently for tolerance to stress at 40.6 degrees C. and 75% R.H. and at 5 weeks of age. After four generations of selection for survival time the lines had separated by 28 minutes: 58 vs. 86 minutes for the low and high, respectively. Egg production, hatchability, Haugh units and specific gravity did not differ between lines. Egg weight was greater in the low line. The body temperature of chicks at 30 minutes of heat stress was correlated (r = -0.454; P less than 0.05) to survival time. Body weight was correlated (r = -0.325) with resistance to heat stress while loss of body weight during heat stress was correlated (r = +0.478) with resistance. There was no apparent difference between lines in respect to resistance of 16-day old embryos to heat stress.

Animals↗
PubMed1975

Relationship of heat tolerance and oxygen consumption in chickens.

Chicks from lines genetically selected for high or low heat tolerance were compared to lines selected for high or low oxygen consumption. Oxygen consumption, survival time, respiration rate, lung capacity and body weight were determined. Selection for high oxygen consumption ahd high heat tolerance resulted in birds with similar characteristics. The high line birds for both heat tolerance and oxygen consumption had greater oxygen consumption, survival time and lung capacity but lower body weight.

Animals↗
PubMed1975

The temperature required to initiate blastoderm development of bobwhite quail eggs.

Three experiments were conducted to determine the temperature required to initiate blastoderm development of Bobwhite quail eggs. In the first two experiments, groups of eggs were incubated for eight days at the following temperatures: 24.4 degrees C., 25.6 degrees C., 26.7 degrees C., 27.8 degrees C. and 28.9 degrees C. At the end of the incubation period, the diameter of the blastoderm was measured with a vernier caliper. In the third experiment, the same procedure was used except that a group of eggs which had not been incubated were used as controls. Results from the first and third experiment showed significant increases in blastoderm size of eggs incubated above 24.4 degrees C. In the second experiment there was a numerical increase in the blastoderm size when eggs were incubated above 24.4 degrees C., and significant increases in the size of blastoderms of eggs incubated above 25.6 degrees C. On the basis of the results of theses experiments, it was concluded that the temperature required to initiate blastoderm development of Bobwhite quail eggs was between 24.4 degrees C. and 25.6 degrees C.

Animals↗
PubMed1975

Reduction of aflatoxin effects of quail.

A natural occuring outbreak of aflatoxicosis was observed in Bobwhite quail chicks while on a brooding experiment. A slight reduction in effects was noted for birds which received Tylan in the water from 0-3 days and Terramycin from 0-35 days of age. No symptoms of aflatoxicosis were observed in birds which received a product (FloxAid) containing two antibiotics and eight vitamins from 0-14 days. It is postulated that the primary mode of protection was via the water soluble vitamin D content of the product with possibly some protection from vitamins A, E and K.

Aflatoxins↗
PubMed1975

Debeaking method for Bobwhite quail.

Four experiments were conducted to determine the suitability of various debeaking procedures for Bobwhite quail at hatching or at one week of age. Two experiments were conducted using a "precision" type debeaking method with the following treatments: control; debeaked at hatching with debeaker guide plate holes of 2.38 or 2.78 mm; debeaked at seven days of age using guide plate holes of 2.38, 2.78 or 3.18 mm. Two experiments tested a "touch-burn" method at hatching with the following treatments: control; burned 1/4 distance to nares; and burned 1/2 distance to nares. The "precision" type methods at hatching or seven days of aged reduced mortality from cannibalism; however, these methods were found to be relatively slow and difficult, and the birds lacked uniformity in beak and body size at five weeks of age. Burning 1/2 distance to nares was too severe, causing a reduction in body weight and poor feed efficiency. Burning 1/4 distanct to nares gave the most favorable results: growth and feed efficiency as good or better than controls, uniform birds and decreased cannibalism.

Animals↗