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Biomedical subjects

T D Bunch

Publications and source records attributed to T D Bunch.

At least 55 records · Page 3Linked to original sources
PubMed1991

In vivo activation of human immunodeficiency virus type 1 long terminal repeat by UV type A (UV-A) light plus psoralen and UV-B light in the skin of transgenic mice.

UV irradiation has been shown to activate the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) in cell culture; however, only limited studies have been described in vivo. UV light has been categorized as UV-A (400 to 315 nm), -B (315 to 280 nm), or -C (less than 280 nm); the longer wavelengths are less harmful but more penetrative. Highly penetrative UV-A radiation constitutes the vast majority of UV sunlight reaching the earth's surface but is normally harmless. UV-B irradiation is more harmful but less prevalent than UV-A. In this report, the HIV-1 LTR-luciferase gene in the skin of transgenic mice was markedly activated when exposed to UV-B irradiation. The LTR in the skin of transgenic mice pretreated topically with a photosensitizing agent (psoralen) was also activated to similar levels when exposed to UV-A light. A 2-h exposure to sunlight activated the LTR in skin treated with psoralen, whereas the LTR in skin not treated with psoralen was activated after 7 h of sunlight exposure. The HIV-1 LTR-beta-galactosidase reporter gene was preferentially activated by UV-B irradiation in a small population of epidermal cells. The transgenic mouse models carrying HIV-1 LTR-luciferase and LTR-beta-galactosidase reporter genes have been used to demonstrate the in vivo UV-induced activation of the LTR and might be used to evaluate other environmental factors or pharmacologic substances that might potentially activate the HIV-1 LTR in vivo.

Animals↗
PubMed1990

Congenital skeletal malformations and cleft palate induced in goats by ingestion of Lupinus, Conium and Nicotiana species.

Three piperidine alkaloid containing plants, Conium maculatum (poison-hemlock), Nicotiana glauca (tree tobacco) and Lupinus formosus (lunara lupine), induced multiple congenital contractures (MCC) and palatoschisis in goat kids when their dams were gavaged with the plant during gestation days 30-60. The skeletal abnormalities included fixed extension or flexure of the carpal, tarsal, and fetlock joints, scoliosis, lordosis, torticollis and rib cage abnormalities. Clinical signs of toxicity included those reported in sheep, cattle and pigs--ataxia, incoordination, muscular weakness, prostration and death. One quinolizidine alkaloid containing plant, Lupinus caudatus (tailcup lupine), on the other hand, which is also known to cause MCC in cows, caused only slight signs of toxicity in pregnant goats and no teratogenic effects in their offspring.

Abnormalities, Multiple↗
PubMed1990

Genetic variability in domesticated and wild sheep based on blood protein characters.

1. The study examined genetic variation, as indicated by eight blood proteins of 539 animals from 11 genotypes (14 flocks) of domesticated sheep and three genotypes of wild sheep. 2. The polymorphic distribution among the animal populations presented a random pattern with wide variation. 3. Genetic variability both between and within populations was larger in domesticated sheep than in their wild relatives. 4. This increased genetic variability observed in domesticated sheep may have resulted from the process of domestication through accelerated genetic drift and promoted gene flow.

Animals↗
PubMed1990

Multiple congenital contractures (MCC) and cleft palate induced in goats by ingestion of piperidine alkaloid-containing plants: reduction in fetal movement as the probable cause.

Fetal movement, observed by ultrasound imaging, was significantly reduced (P less than or equal to 0.001) in pregnant goats gavaged with Conium seed and Nicotiana glauca and temporarily reduced with fresh Conium plant. Conium seed and Nicotiana glauca induced cleft palate and multiple congenital contractures in 100% of the kids born to pregnant goats gavaged with these plants. Multiple congenital contractures included torticollis, scoliosis, lordosis, arthrogryposis, rib cage anomalies, over extension, and flexure and rigidity of the joints. However, in goats gavaged with fresh Conium plant, fetal movement was inhibited for only about 5 hours after each individual dosage and gradually returned to control levels 12 hours after dosing. Fetal malformations in this group were limited from modest to moderate contractures of the front limbs, which resolved by 8-10 weeks post partum. No cleft palates were induced. Fetal movement was not inhibited in goats fed Lupinus caudatus and no cleft palates or multiple congenital contractures were induced in their offspring. The duration of the reduction in fetal movement appears to be an important factor in the severity and permanence of the deformities, particularly with cleft palate, spinal column defects, and severe joint deviation and fixation.

Abnormalities, Drug-Induced↗
PubMed1989

Bot fly larvae (Cephenemyia spp., Oestridae) in mule deer (Odocoileus hemionus) from Utah.

Ninety-nine mule deer (Odocoileus hemionus) from four Utah counties (Cache, Utah, Sanpete and Sevier) were examined for larvae of Cephenemyia spp. in 1985 and 1986. Numbers of first, second and third stage bot fly instars were related to age, sex, year and geographic location of the mule deer. Fawns and adult deer greater than or equal to 5.5 yr had a significantly (P less than or equal to 0.05) higher intensity (means = 37 and means = 68, respectively) of infection than the 1.5- and 2.5-yr-old age groups (means = 19 and means = 26, respectively). Infection by larvae was not significantly different between sexes. Infection was 100% in both years, but the mean intensity was significantly lower in 1986 (P less than 0.05). The decline may be related to differences in soil moisture between the 2 years. In 1985, 82% of the deer examined were infected with all three instars. Seventy-seven percent of all first instar larvae were observed in the trachea, usually in the fold immediately posterior to the epiglottis and corniculate cartilages. This new site of attachment for first instar larvae has not previously been recognized.

Analysis of Variance↗
PubMed1988

The influence of culture and transport on pretransfer development and posttransfer survival of sheep embryos.

Sheep embryos were collected under sterile conditions in Dulbecco's Phosphate Buffered Saline (DPBS) + 10% Fetal Calf Serum (FCS) and cultured in DPBS + 20% FCS at 37 degrees C. They were classified according to their stage of development, from the lowest stage, 13 (less than a morula) to the highest stage, 20 (hatched blastocyst). Morphology was graded from 1 for excellent to 5 for degenerated. All embryos placed in the experiment had a development stage classification of 14 (morula) or higher and morphology classification of 1 to 3. Thirty-four embryos cultured in the laboratory for 24 h (Treatment B) and 32 embryos handled the same way except that they were transported for approximately 12 h (Treatment C) increased an average of 1.8 development classification scores and decreased -0.84 and -0.58 morphology classification scores for the two treatments, respectively. Twelve embryos in Treatment D (the same as Treatment C except that they were cultured in the laboratory for an additional 24 h) progressed 2.2 development classification scores during 48 h culture and did not change (-0.08) in the morphology classification score. The development estimates related to length of culture time but showed no affect of transport. Seventy-five percent of 20 embryos transferred in Treatment C and 42% of 12 embryos in Treatment D survived to parturition, demonstrating that the procedures used to transport and culture them for 24 and 48 h, respectively, maintained embryos capable of post transfer survival. Forty-one percent of the 22 embryos transferred in Treatment A (noncultured) and 20% of 20 embryos in Treatment B survived.

Journal Article↗
PubMed1988

Radio ultrasound observations of the fetotoxic effects in sheep from ingestion of Conium maculatum (poison-hemlock).

Fetal movement in pregnant ewes gavaged with Conium maculatum (poison-hemlock) was reduced significantly, but temporarily. Fetal movement was observed by radio ultrasound at 45, 54 and 60 days of gestation in control ewes and on days 45, 54, and 60 of gestation immediately before and 1 hour following poison-hemlock feeding in treated ewes. Fetal movement was significantly reduced (P less than 0.01) 1 hour after poison-hemlock administration, but returned to normal within 18 hours post treatment. At parturition seven of eleven lambs born to seven treated ewes had varying degrees of front limb abnormalities. Modest to moderate flexure of the carpal joints, some lateral deviation in the front limbs at the pastern joint and kinked tails were observed. These malformations were transient and resolved spontaneously by 8 weeks after lambing.

Animals↗
PubMed1988

Maternal and fetal toxicity of poison hemlock (Conium maculatum) in sheep.

Poison hemlock (Conium maculatum) was toxic to pregnant ewes and their fetuses when fed during gestation days 30 through 60. Maternal effects included trembling, muscular weakness in the neck initially, then progressing to the limbs, ataxia, frequent urination and defecation, and death. Convulsive seizures were not observed. Fetotoxic effects included excessive flexure of the carpal joints with lateral deviation in the front limbs and kinked tails. At term, 7 of 11 lambs had varying degrees of the limb abnormalities, but all lambs appeared clinically normal at 8 weeks after parturition.

Animals↗
PubMed1987

Factors affecting survivability of transferred whole and demi-embryos in a commercial dairy herd.

Sixty Holstein donor cows were superovulated and embryos were collected during a 6-d (27 cows) and a 4-d (33 cows) period approximately 60 d apart. Forty-three donor cows yielded embryos. Ninety-one embryos graded 1 or 2 were split and transferred to 181 recipient Holsteins. Demi-embryos were graded 2, 2-, 3 and 3- prior to transfer. Pregnancy and calving percentages were similar for all demi-embryo grades, averaging 59 and 53% from the two donor groups, respectively. Twin demi-embryo pregnancies averaged 36 and 19% for embryos split at the compacted morula and blastocyst stages, respectively. Twin demi-embryo calvings averaged 30 and 15% for these same groups. Progesterone levels of recipients (of either whole or demi-embryos) of second period donors were measured. Pregnancy rate increased generally with level of progesterone; however, calving percentage was slightly greater for recipients with intermediate levels of progesterone (2-6 ng/ml). Multiparous cow (20) recipients of demi-embryos had 45% pregnancy and 40% calving, while nulliparous heifer (161) recipients averaged 59 and 53% pregnancy and calving, respectively.

Journal Article↗
PubMed1987

Ultrasonographic imaging to monitor fetal and placental developments in ewes fed locoweed (Astragalus lentiginosus).

Ultrasonographic imaging was used to monitor the effects of locoweed (Astragalus lentiginosus) on fetal, placental, and cotyledonary developments in pregnant ewes and proved to be a useful noninvasive method of monitoring the effects of locoweed poisoning on fetal and placental development. Ultrasonographic imaging may be a good research technique to observe the effects of toxicants on fetal movement, fetal heart action, and growth and development of the fetus and placenta. Known effects of locoweed poisoning in pregnant ewes, such as fluid accumulation in the placenta (hydrops allantois, hydrops amnii), altered cotyledonary development, and fetal death were observed with ultrasonographic imaging. A previously unknown effect of locoweed on fetal heart action also was observed. Locoweed decreased fetal heart rates, caused cardiac irregularity, and decreased the strength of heart contractions. All ewes, except No. 3525, fed locoweed aborted. At necropsy, aborted fetuses had hypertrophy of the heart, right ventricular dilatation, rounded at the apex of the heart, and generalized edema.

Animals↗
PubMed1984

Further studies on horn aberrations in Dall's sheep (Ovis dalli dalli) from Yukon Territory, Canada.

The prevalence of horn aberrations in Dall's sheep from the Kluane Lake area of Yukon Territory observed during July 1982 represented 1% of the total population and 7% of rams 6 yr or older. Ewes were not considered in these percentages because they were too difficult to inspect by aerial survey. When these data were combined with other data collected from 1977 through 1981, the prevalence equalled 2.4% of the total population and slightly exceeded 16% in mature rams (greater than or equal to 6 yr). The anomaly followed necrosis of the terminal region of the horn core and the sequestering of portions of the core within the sheath as the sheath continued to grow. Sheath that was produced after the core was anatomically altered resulted in abnormal growth patterns of the horn. Rams with aberrant horns could not maintain homeostatic temperatures within horn cores when horns were experimentally exposed to -80 C for 30 min. Histologic examination of superficial and cornual vascular systems did not reveal any structural alterations that would restrict blood flow within cores of affected horns. Examination of museum specimens consisting of 130 skulls from rams and 81 from ewes collected from Alaska, USA, Yukon Territory, Canada, and Northwest Territories, Canada, established only one ewe and no rams with the horn aberration. The skull was from a ewe and had both horns affected and was collected from the Joe River Drainage, Yukon Territory in 1912.

Animals↗
PubMed1983

Psoroptic scabies in desert bighorn sheep (ovis Canadensis nelsoni) from northwestern Arizona.

Scabies due to infestation by Psoroptes ovis was monitored from 1979 through 1981 in Nelson's desert bighorn sheep in northwestern Arizona. Visual examinations for ear lesions and evaluations of ear scrapings were used to assess the prevalence of mites in sheep that were live-captured or killed during the hunting season. The prevalence of psoroptic scabies in live-captured sheep for the years 1979, 1980, and 1981, was 25%, 25%, and 0%, respectively, and was higher in rams (1979, 65%; 1980, 100%) than in ewes (1979, 11%; 1980, 0%). The severity of ear lesions was also greater in the males. The prevalence in harvested rams was 23%, 44%, and 7%, respectively, for the years 1979-1981. The severity of the ear lesions was highest in 1980. Lesions were confined to the ears. An aerial census of bighorns in the Black Mountains during May of 1981 showed a 38% decrease in total observations from the previous year and a drop in the ewe/lamb ratio from 0.52 in 1980 to 0.29 (P less than or equal to 0.01) in 1981. In the Lake Mead area, there was a population census decline of 33% in 1981 and a non-significant decline in the ewe/lamb ratio from 0.46 to 0.40. The population decline in 1981 and the increased prevalence and severity of psoroptic scabies in the 1980 survey in both areas were believed to be related to the high bighorn population densities in 1980 and the prevailing drought.

Animals↗
PubMed1982

Horn aberrations in Dall's sheep (Ovis dalli) from Yukon Territory, Canada.

Horn aberrations in Dall's sheep from the Kluane Lake area of Yukon Territory were of two basic types. In the more prevalent type, the horn was severed at an annual growth check and the terminal segment of the remaining portion formed a short conical protuberance. The second type had characteristics of the first, but in addition, underwent extreme twisting or torquing during subsequent growth. Sheep with aberrant horns represented 2% of the Kluane Lake population or 14% of harvestable rams (greater than or equal to 6 yr old). Deformed horns, occurring in ewes and rams, were generally observed in animals 6 yr or older. Aberrations followed necrosis of the terminal segment of the horn core: cavitation of the sheath between successive periods of growth or the sequestering of portions of necrotic core within the sheath resulted. All sheep examined (eight) had a normal complement of 54 chromosomes.

Animal Population Groups↗
PubMed1982

Aberrations of the tooth arcade and mandible in Dall's sheep from southwestern Yukon.

Nine Dall's sheep (Ovis dalli dalli) collected in the Ruby Mountains of southwestern Yukon were examined for aberrations of the tooth arcade and mandible. Missing and displaced teeth were common in older sheep (greater than or equal to 6 yr). Necrosis of the mandible was observed in five of eight rams and in one ewe. Corynebacterium pyogenes was cultured from exudates from two rams with enlarged fistulated mandibles. The sequence of events leading to lesions of the tooth arcade and to "lumpy jaw" is postulated to be associated with abnormal wearing of teeth and a disrupted alignment of the tooth arcade, impaction of vegetable matter between teeth and between the gingiva and the root of the tooth, and penetration of the traumatized gingiva membrane and alveolus by oral bacteria which induce a necrotizing infection.

Animal Feed↗
PubMed1981

Survey of chronic sinusitis-induced skull anomalies in desert bighorn sheep.

Bone anomalies were found in 20% of 630 skulls from desert bighorn sheep (Ovis canadensis) representing populations of california bighorn (O canadensis californiana), lower California bighorn (O canadensis cremnobates), Mexican bighorn (O canadensis mexicana), and Nelson bighorn (O canadensis nelsoni) that are native to Arizona, California, Nevada, New Mexico, and Utah. The anomalies were extremely diverse, ranging from osteonecrosis within the matrix of the paranasal sinuses to extensive lysis of the frontal bone, horn core, and sheath. In rams, the necrosis most often occurred in the mid- to posterior region of the cornual sinus and resulted in blistering of the sheath and sometimes a breaking away of the horn. In ewe skulls, the anomalies were generally at the base of the cornual sinus or within the frontal sinus. Osteonecrosis in the ewe skulls had generally invaded the region of the orbit or penetrated the cribriform plate. The skull lesions were most often observed in desert bighorn rams greater than or equal to 5 years old. The age of ewes could not be accurately determined. The skull anomalies were believed to result from pyogenic osteomyelitis.

Animals↗