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Biomedical subjects

E A Usenik

Publications and source records attributed to E A Usenik.

17 recordsLinked to original sources
PubMed1989

Delayed phalaris grass toxicosis in sheep and cattle.

A phalaris grass (Phalaris caroliniana) caused neurologic signs and lesions in cattle and sheep. The sheep were hyperexcitable and uncoordinated, with severe muscle twitching, stiff gait, and head nodding. The cattle were thin, nervous, and ataxic. One feature of chronic phalaris toxicosis in these cases was onset of signs weeks or months after removal of the animals from the forage.

Animals↗
PubMed1989

Subcutaneously implanted tissue chambers--a pharmacokinetic study.

The purpose of this study was to characterize the pharmacokinetics of a subcutaneously implanted tissue-chamber model. Thermoplastic tissue chambers were implanted in the paralumbar fossae of six steers. Starting 30 days after implantation, the distribution of intravenously administered antipyrine and phenylbutazone into the tissue chambers was studied. These pharmacokinetic experiments were repeated 10 days later to determine the effect of time after implantation on tissue-chamber distribution. Fifty days after implantation, tissue chambers were drained of transudate, refilled with sterile saline and the rate of influx of endogenous urea, creatinine and albumin was measured. Delayed diffusion of antipyrine and phenylbutazone into tissue chambers was well described using a compartmental model in which tissue-chamber fluid represented the third of three compartments arranged in series. The distribution of antipyrine into tissue chambers was greater than that of phenylbutazone; an observation which is well correlated with the high degree of protein binding of phenylbutazone. There was no effect of time on the penetration of the two agents. Rapid diffusion of urea and creatinine and extremely slow influx of albumin into chambers showed that these chambers formed true interstitial compartments.

Animals↗
PubMed1989

Subcutaneously implanted tissue chambers: a pathophysiological study.

Tissue and fluid changes occurring within tissue chambers were characterised as a function of time after subcutaneous implantation in cattle. Cytological and chemical investigation revealed that the composition of fluid within chambers approached the theoretical composition of true interstitial fluid as time after implantation progressed. Erythrocyte and leucocyte numbers decreased sharply immediately after implantation and had reached stable numbers by 40 days after implantation. At this stage, chamber fluid samples had lower total protein and albumin concentrations, higher K+ and Cl- concentrations and lower pH than corresponding blood samples. Despite an ongoing low-grade chronic inflammatory reaction resulting in fibrous encapsulation of chambers, the vascularity of chamber tissue did not diminish with time after implantation. By 40 days after implantation, the cellular and chemical constituents had stabilised enough to allow use of the model to study drug distribution.

Albumins↗
PubMed1989

Ultrasonographic evaluation of induced testicular lesions in male goats.

To study testicular ultrasonographic features, unilateral testicular artery ligation was performed in 12 bucks to induce predictable ischemic necrosis of the testis. Both scrotal testes then were scanned subsequently on days 1, 3, 5, 7, 15, and 30. On each of the designated days, 2 bucks each were castrated and the excised testes were rescanned outside the scrotum before gross and histologic examinations. In each goat, the testis without the ligated artery served as a control. Gross and histopathologic findings in the testis were compared with ultrasonographic observations. As the study progressed from day 0 to day 15, visually and microscopically, the testis involved in the testicular artery ligation had edema that changed to areas of peripheral necrosis with thickening of the testicular capsule. On day 30, the affected testis had granulation tissue in the areas that previously had been necrotic. Ultrasonographically, the testicular changes were consistent with the gross and histopathologic findings. There were areas of decreased echogenicity that corresponded to the necrotic areas and foci of high echogenicity that corresponded to areas of tubular mineralization. On day 30, the granulation tissue was difficult to differentiate ultrasonographically from normal testicular parenchyma. Between days 3 and 15, hydrocele was seen ultrasonographically in several goats. The excellent association between ultrasonographic findings and gross and histologic changes suggested that testicular ultrasonography might be a valuable diagnostic tool for assessing testicular disease in domestic animals.

Animals↗
PubMed1988

Preputial injuries in beef bulls: 172 cases (1980-1985).

One hundred seventy-two bulls with preputial injuries were treated from 1980 through 1985. Most of the injuries developed during the breeding season (April through August), with a peak during June. The number (111) of bulls represented by 3 beef breeds (Brangus, Brahman, Beefmaster) was greater than the number (61) of the other 9 breeds included in the survey. Preputial prolapse (PP) and posthitis without obvious laceration was diagnosed in 82 of 172 bulls. Preputial laceration, abscessation, stricture with phimosis, and PP with penile hematoma were diagnosed in 46, 22, 15, and 9 bulls, respectively. These abnormalities were treated medically and/or surgically. Questionnaires (n = 145) were mailed, and 83 (57.4%) replies were received. Owners (80/83) of affected bulls responded to questions regarding the future use of their bulls for breeding. Of the bulls with PP and posthitis (n = 34), laceration (n = 17), abscessation (n = 15), stricture with phimosis (n = 8) and PP with penile hematoma (n = 6) and treated medically and/or surgically, 30, 11, 7, 7, and 4 bulls, respectively, (74% overall) were returned to breeding use successfully.

Animals↗
PubMed1987

Preputial hematoma in a stallion.

An 8-year-old Quarter Horse stallion was admitted with a swelling involving the prepuce, dorsal part of the scrotum, and root of the penis. The swelling was first noticed 10 days after breeding, with no evidence that it had resulted from a kick by the mare. The penis was retracted into the prepuce, except for a 10- to 15-cm protrusion of the glans penis. Treatment included warm hydrotherapy, massage, stockinette compression, antidiuretics, antibiotics, penile support, and exercise, without success. At necropsy, a massive preputial hematoma was found extending forward from the root of the penis to 12 cm proximal to the glans penis. The exact origin of the hematoma could not be determined. Most likely, bleeding had originated from the vascular plexus lying subfascially on the surface of the penis outside the intact tunica albuginea or from a branch of the external pudendal artery.

Animals↗
PubMed1987

Monolayer system of cultivating bovine polymorphonuclear leukocytes (PMNL): effect of long-term cultivation on the viability and phagocytic function of the cells.

A monolayer system of cultivating bovine PMNL is described. Poly-L-Lysine (PLL) significantly (P less than 0.01) enhanced the attachment of bovine PMNL to glass. Long-term cultivation up to seven days, in a mixture of calf serum and RPMI 1640, had no effect on the viability of the cells, but cultivation for 3 days or more significantly reduced the ability of the PMNL to phagocytose bacteria.

Animals↗
PubMed1986

Polymorphonuclear leukocyte function in cattle with left displaced abomasum with or without concurrent infections.

Cattle submitted to the University of Minnesota for surgical correction of left displaced abomasum (LDA) were examined for the in vitro phagocytic and bactericidal activities of their polymorphonuclear leukocytes (PMN). The PMN from cattle with LDA with or without concurrent infection had depressed phagocytic function when compared with PMN from healthy animals (controls). Those with concurrent infection had phagocytic activities lower than those in the group of cattle with LDA without any concurrent infection, and the former group was also observed to have depressed intracellular killing. Cattle with LDA complicated by infection were the only group in which phagocytic function was altered during surgical correction of LDA (and recovery). Treatment of PMN from both groups of affected cattle with levamisole in vitro enhanced intracellular killing, but had no effect on phagocytosis.

Abomasum↗
PubMed1984

Effects of selenium-vitamin E injection on bovine polymorphonucleated leukocytes phagocytosis and killing of Staphylococcus aureus.

Phagocytosis and killing of Staphylococcus aureus by polymorphonuclear leukocytes (PMN) from 8 selenium (Se)-deficient dairy cows from Wisconsin was compared with that in 5 Se-vitamin E injected dairy cows from the same herd. There was no significant difference in the ability of the PMN to phagocytize bacteria. However, PMN of Se-vitamin E injected cows killed the phagocytized bacteria significantly (P less than 0.025) better than did PMN from Se-deficient cows. The defect in the killing capability of PMN of Se-deficient cows might be due to reduced dihydronicotinamide adenine dinucleotide phosphate concentration as a result of diminished glutathione peroxidase activity due to Se-deficiency.

Animals↗
PubMed1975

Intestinal obstruction in the horse. Physical signs and blood chemistry.

Physical signs and blood changes were studied in horses with artificially produced obstructions of the duodenum and the small colon and simulated volvulus of the ileum. Horses with obstruction of the duodenum had the most violent physical signs and the shortest survival time. Blood changes were an initial rise in pH followed by acidosis, hyperkalemia and a decrease in HCO3 minus, Na+ and C1 minus. Obstruction of the small colon resulted in mild physical signs. The blood parameters recorded were normal. Simulated volvulus resulted in continuous colic. Blood changes were acidosis and hyperkalemia with a continuous decrease in HCO3 minus and C1 minus levels.

Animals↗