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Biomedical subjects

G F Hoffsis

Publications and source records attributed to G F Hoffsis.

At least 37 records · Page 2Linked to original sources
PubMed1990

Urinary indices of renal function in sheep with induced aminoglycoside nephrotoxicosis.

Aminoglycoside nephrotoxicosis (AGNT) was induced in ewes by daily SC administration of gentamicin. Changes in urinary indices of renal function during the development of AGNT are reported. Measurements from timed, volume-measured urine samples were made on days 0, 7, and 8 and included creatinine clearance, total excretion (TE) rates of electrolytes (Na, K, Cl, P) and urine volume. Measurements from free-catch urine samples (without volume measurement) were made daily and included fractional excretion (FE) rate of electrolytes, urine osmolality, and urine-to-serum osmolality and urine-to-serum creatinine ratios. With the onset of AGNT, FE rates of Na, K, Cl, and P- increased many fold above baseline values (200x, 4 to 5x, 6 to 9x, and 70 to 95x, respectively, on days 7 and 8), indicating decreased tubular reabsorption or increased tubular secretion. The increased FE rates were not representative of increases in total electrolyte excretion rates. The total excretion of Na (TENa) was mildly increased, TEK was decreased, TECl was unchanged, and TEP was significantly increased on days 7 and 8. Abnormal urinalysis results, glucosuria, and increased FEP preceded appreciable increase in serum creatinine concentration. Other abnormal urinary indices of renal function coincided with or followed the increase in serum creatinine concentration. Urinary indices may help characterize renal function associated with the disease state, but did not provide early indication of AGNT.

Acute Kidney Injury↗
PubMed1990

Caudal epidural analgesia induced by xylazine administration in cows.

Xylazine (0.05 mg/kg of body weight diluted to a 5-ml volume, using 0.9% NaCl) or 5 ml of 0.9% NaCl was administered epidurally into the first caudal intervertebral space (Co1-Co2) in 8 cows (mean +/- SD body weight, 583 +/- 150 kg). Cows were observed for responses to deep needle pricking of the caudal dermatomes (S3 to Co), sedation, and ataxia. Heart rate, respiratory rate, body temperature, rate of ruminal contractions, coccygeal arterial blood pressure, pHa, blood gas tension (PaO2, PaCO2), base excess, total solids concentration, and PCV were determined before and after xylazine administration. Epidurally administered xylazine induced sedation and selective (S3 to Co) analgesia for at least 2 hours. Mild ataxia of hind limbs was observed in 6 cows, but all cows remained standing. Heart rate, respiratory rate, rate of ruminal contractions, arterial blood pressure, PaO2, PCV, and total solids concentration were significantly (P less than 0.05) decreased, and PaCO2, base excess, and bicarbonate concentration were significantly (P less than 0.05) increased after xylazine administration. Epidurally administered 0.9% NaCl did not alter sensory perception to needle pricking and did not affect any of the physiologic variables determined. Although epidural administration of xylazine induced analgesia and sedation in healthy cows, it should be avoided for epidural analgesia in cattle with heart disease, lung disease, and/or gastrointestinal disease because of its potent cardiopulmonary and ruminal depressant effects.

Analgesia, Epidural↗
PubMed1989

Atresia coli in calves: 26 cases (1977-1987).

Atresia coli was identified in 26 calves. In calves with abdominal distension, progressive depression, and the absence of feces since birth, atresia coli should be suspected. Surgery was performed on 24 calves, involving decompression of the distended large intestine followed by colonic anastomosis. Nine calves were subsequently discharged; 3 of those calves reached breeding age. As an adult, 1 of the calves produced 5 offspring unaffected by atresia coli. Early postoperative mortality was associated with hypothermia, peritonitis, and ischemic necrosis of the large intestine. Calves with visible signs of peritonitis at surgery had a poor prognosis. Four calves had motility disturbances of the colon after surgery. These were characteristic of a functional obstruction and were unresponsive to treatment. Surgery was most successful in calves that were bright, alert, and ambulatory.

Anastomosis, Surgical↗
PubMed1989

Jejunal mucosal lactase activity from birth to 3 weeks in conventionally raised calves.

The descending portion of the duodenum of 6 Holstein calves less than 24 hours old was cannulated. Sequential biopsy specimens of the proximal jejunal mucosa were obtained every other day for 3 weeks. Lactase activity in the mucosal specimens was determined and was highest at day 1, but decreased with age. Mean lactase activity was significantly (P less than 0.05) higher for days 1, 3, 5, and 7, compared with days 19 and 21.

Aging↗
PubMed1989

Comparison of three intestinal cannulas used to obtain repeated biopsy of the jejunal mucosa in the newborn calf.

This project was designed to develop a standardized cannulation technique which would allow repeated jejunal mucosal biopsy. Three intestinal cannulas of various designs were evaluated in a total of 25 neonatal calves. Cannula A, a T-design made of acrylic plastic, was implanted into the jejunum (2) or duodenum (7). Cannula A did not allow proper directional passage of the biopsy instrument. Peritonitis was diagnosed at necropsy in 4 calves. Cannula B, a modification of A with an angled port to facilitate the directional passage of the biopsy instrument, also proved unsatisfactory. This cannula required a larger enterotomy for placement and resulted in the death of 1 calf. Cannula C was made of tygon tubing with a proxplast mesh flange which was sutured to the serosal surface of the intestine. No intestinal leakage was observed in 14 calves fitted with this cannula. This cannula was the least expensive and allowed the biopsy instrument to be easily directed. Surgical implantation of this cannula (C) in the descending duodenum proved to be an excellent method to obtain successive mucosal biopsies of the jejunum in the neonatal calf.

Animals↗
PubMed1988

Prognostic value of anion gap calculation in cattle with abomasal volvulus: 58 cases (1980-1985).

Values for anion gap, serum chloride, and base excess were tabulated for 58 dairy cows with abomasal volvulus. Test values for survivors (n = 40) and nonsurvivors (n = 18) were compared. Surviving cattle were released for production or salvage. Nonsurviving cows died or were euthanatized. Accuracy of preoperative anion gap, serum chloride, and base excess values in predicting outcome was evaluated by calculating the sensitivity, specificity, predictive value, and negative predictive value of these at assigned cutoff values. Anion gaps greater than or equal to 30 mEq/L were indicative of a poor prognosis. At this value, the sensitivity (0.889), specificity (0.925), predictive value (0.842), negative predictive value (0.949), and efficiency (0.914) were higher than when serum chloride concentration less than or equal to 84 mEq/L or base excess value less than or equal to 0 were used to denote poor prognosis. We concluded that preoperative anion gap calculation could reliably predict the outcome of cows with abomasal volvulus and was more accurate than either serum chloride concentration or base excess value.

Abomasum↗
PubMed1986

Evidence of paratuberculosis in Ohio's white-tailed deer, as determined by an enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) was developed and used to detect antibodies to Mycobacterium paratuberculosis in serum samples obtained in December of 1983 from 954 hunter-killed white-tailed deer (Odocoileus virginianus) in 13 Ohio counties. Positive or negative status was determined by calculating a signal-to-noise ratio, a ratio between the optical density of the test serum and negative reference sera; a ratio of greater than or equal to 3.0 was considered positive. Twenty-four samples (2.5%) were found to be assay positive, using this method. A statistically significant difference among age groups was found, with those less than or equal to 6 months of age having a lower proportion of positives. Differences by sex were not observed. To determine the validity of the ELISA in deer, serum samples from 46 fallow (Dama dama) and axis deer (Axis axis) harvested from a known infected population were tested by ELISA and agar-gel immunodiffusion. The agar-gel immunodiffusion test showed evidence of exposure of the deer to M paratuberculosis or a related antigen. The ELISA closely approximated the prevalence of paratuberculosis infection as previously determined by fecal culture in this population. As a result of these tests, it was concluded that free-ranging Ohio deer have been infected with M paratuberculosis or exposed to a closely related antigen.

Animals↗
PubMed1985

Characterization of Mycobacterium paratuberculosis antigenic proteins.

The characterization of a purified antigen from Mycobacterium paratuberculosis, recently made commercially available for use in serodiagnosis by enzyme-linked immunosorbent assay (ELISA), of paratuberculosis in cattle was described. This assay had 89% specificity and 83% sensitivity for M paratuberculosis infection. The protein/polypeptide composition of the purified antigen was compared with that of a crude protoplasmic extract of strain 18 M paratuberculosis used in the agar-gel immunodiffusion test and ELISA and with that of sonicated strain 19698 M paratuberculosis organisms grown on Dorset-Henley synthetic liquid medium. The sonicated M paratuberculosis contained 27 major proteins/polypeptides; the crude protoplasmic extract, 18; and the purified antigen contained 14 proteins/polypeptides, using sodium dodecyl-sulfate polyacrylamide-gel electrophoresis analysis. The serologic reactivity of these proteins/polypeptides were defined, using the enzyme-linked immuno-electrotransfer blot technique. The sonicated M paratuberculosis contained 20 serologically reactive proteins/polypeptides (34,000 to 84,000 daltons); the crude protoplasmic extract contained 3 (37,000 to 45,000 daltons); and the purified extract contained a diffuse polypeptide band (34,000 to 38,000 daltons). Identification by enzyme-linked immuno-electrotransfer blot technique of M paratuberculosis antigens reactive in the ELISA will allow us to further study these antigens in the ELISA to improve sensitivity and specificity of the diagnostic test.

Animals↗
PubMed1984

Abomasal emptying defect in Suffolk sheep.

Twelve Suffolk sheep were examined because of an abomasal emptying problem. Anorexia and weight loss were evident in 11 of the sheep. Ventral abdominal distention was observed in 5 sheep. Laboratory analyses failed to show the hypochloremic, hypokalemic metabolic alkalosis commonly found in cattle with a similar problem. Rumen chloride concentrations in 3 sheep indicated reflux of abomasal contents into the rumen.

Abomasum↗
PubMed1978

Echocardiographic diagnosis of endocarditis in a bull.

A 2-year-old Charolais bull was examined because of lameness that developed after infection of a tail laceration. A systolic murmur was auscultated during the routine physical examination. A diagnosis of endocarditis and polyarthritis secondary to septicemia from the tail lesion was made. The diagnosis was supported by echocardiography and blood cultures, which yielded Corynebacterium pyogenes. The clinical diagnosis was confirmed at necropsy.

Animals↗
PubMed1977

Atresia coli in a twin calf.

Atresia coli was diagnosed in a newborn calf. The calf was an identical twin, as evidenced by identical blood type and identical electrophoretic patterns for hemoglobin, transferrin, and amylase. The other calf was clinically normal. The calves resulted from embryo transfer and represented cleavage of a single embryo in the recipient animal. These findings indicate atresia coli in this calf was probably not hereditary.

Animals↗
PubMed1977

Total intravenous feeding of calves.

Total intravenous feeding was accomplished for 5 clinically normal calves and for 1 calf with atresia coli. During the trials, which lasted 8 to 14 days (mean of 12 days), calves were not permitted to ingest any food or water. Body weight and state of hydration remained essentially constant. Plasma protein content decreased, but there were only minor changes in other physiologic measures. Calves were clinically normal at the conclusion of the trials.

Animals↗