Search PubMed⌕ Search

Biomedical subjects

R H Whitlock

Publications and source records attributed to R H Whitlock.

At least 73 records · Page 4Linked to original sources
PubMed1986

Endotoxin-induced changes in the hemostatic system in neonatal calves: the effect of antiserum to a mutant Escherichia coli (J-5).

Changes in the hemostatic system were studied in 22 neonatal calves given a small dosage of Escherichia coli endotoxin (0.5 microgram/kg) by slow (5-hour) IV infusion. The effect of pretreatment with an antiserum to mutant of E coli O111:B4 (J-5) was evaluated. The platelet count, plasma fibrinogen concentration, prothrombin time, and activated partial thromboplastin time changed significantly from base line during and after endotoxin infusions in all calves. The mean platelet count was significantly decreased from 1 through 24 hours after endotoxin infusion was started. Mean plasma fibrinogen was decreased 2 through 12 hours after endotoxin infusion was started. The mean prothrombin time and activated partial thromboplastin time were significantly greater than base line at 3 to 6 hours and 3 to 12 hours, respectively, after endotoxin infusion was started. Serum concentration of fibrinolytic degradation products remained less than 10 micrograms/ml. Bovine J-5 antiserum did not prevent the endotoxin-induced changes in the hemostatic system of these neonatal calves.

Animals↗
PubMed1986

Endotoxin-induced changes in plasma concentrations of thromboxane and prostacyclin in neonatal calves given antiserum to a mutant Escherichia coli (J-5).

Plasma concentrations of the stable hydrolysis products of thromboxane (Tx) A2, TxB2, and prostacyclin (6-keto-prostaglandin F1 alpha; PGF1 alpha) were evaluated in 22 neonatal calves given endotoxin (0.5 microgram/kg) by slow IV infusion over a 5-hour period. The effect of pretreatment with bovine antiserum to a mutant of Escherichia coli O111:B4 (J-5) on plasma concentrations of these eicosanoids was determined. Plasma concentrations of TxB2 and 6-keto-PGF1 alpha were increased in response to endotoxin infusion. The mean plasma concentrations of TxB2 peaked 1 hour after endotoxin infusion began and was significantly increased from base line through 8 hours. Mean plasma 6-keto-PGF1 alpha concentration increased more slowly and was increased from base line only at 2 hours after endotoxin infusion began. Administration of bovine J-5 antiserum had no significant effect on endotoxin-induced thromboxane and prostacyclin production.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Endotoxemia in neonatal calves given antiserum to a mutant Escherichia coli (J-5).

Endotoxemia was characterized in neonatal calves given a small amount of colostrum and smooth Escherichia coli endotoxin by small-dosage (0.5 microgram/kg of body weight), slow (5-hour) IV infusion to mimic natural conditions. Responses were compared among 22 calves freely allotted to groups treated with saline solution (group I), preimmunization plasma (PP, group II), or antiserum to the rough mutant of E coli O111:B4 (J-5, group III) before endotoxin was infused. Bovine J-5 antiserum was produced by immunization of 4 cattle with J-5 boiled cell bacterin. The antiserum titers of immunoglobulin (Ig) M, IgG1, and IgG2 to the J-5 boiled cells, as determined by enzyme-linked immunosorbent assay, were 240, 7,680, and 960, respectively. The PP had enzyme-linked immunosorbent assay titers to J-5 of 240, 480, and 60 of IgM, IgG1, and IgG2, respectively. Endotoxemia in the 3 groups was characterized by significant (P less than 0.05) time-related changes in rectal temperature, heart rate, respiratory rate, capillary refill time, oral mucous membranes, nose moistness, scleral injection, attitude, PCV, total plasma protein concentration, WBC count and differential, plasma glucose, and lactate concentrations. The only significant treatment effects on clinical or laboratory values were higher mean total plasma protein concentrations in groups II and III 10 to 30 hours after endotoxin infusion was started than that in group I and increasing mean most-severe attitude abnormality score in groups I, III, and II (P less than 0.05). The administration of bovine J-5 antiserum to neonatal calves resulted in significantly higher serum IgG1 and IgG2 titers to J-5 boiled cells (P less than 0.05), and cross-reactive IgG2 to the challenge endotoxin (P less than 0.01) than did treatment with PP or saline solution; however, this antiserum did not mitigate the effects of sublethal endotoxemia. There was a significant negative correlation between IgG2 to J-5 at base line and the mean attitude abnormality score at 4.5 hours after infusion was started (P less than 0.05).

Animals↗
PubMed1985

Salmonella shed by horses with colic.

Salmonella was isolated from 13 of 100 colicky horses admitted to a referral hospital. Seven horses were shedding the microorganism at or soon after hospital admission. A unique serotype was introduced into the hospital by a horse not shedding Salmonella at admission. It was concluded that 8 horses were infected before admission. Whether the remaining 5 horses were infected before or after admission could not be determined. Salmonella senftenberg was the most commonly isolated serotype from colicky horses and from horses with salmonellosis that were not colicky on hospital admission during the survey period. This organism was rarely isolated at the hospital before initiation of this survey.

Animals↗
PubMed1985

Comparison of rectal mucosal cultures and fecal cultures in detecting Salmonella infection in horses and cattle.

Bacteriologic cultures of 65 rectal mucosal samples and 335 fecal samples from 53 horses and 5 cattle shedding Salmonella were performed. Salmonella spp were isolated from 34 (52%) rectal mucosal samples, 21 (32%) concurrent fecal samples, and 150 (45%) total fecal samples. The use of rectal mucosal samples when compared with concurrently obtained fecal samples significantly (P less than 0.025) improved the ability to isolate Salmonella spp. Concurrent bacteriologic culture of rectal mucosal samples and fecal samples resulted in 39 (60%) isolations. Compared with a series of fecal samples, Salmonella was isolated significantly more often when rectal mucosa and feces were cultured concurrently. Salmonella was isolated from rectal mucosal samples when it was not isolated from feces.

Animals↗
PubMed1984

Perforated abomasal ulcers in adult dairy cows.

Case records of adult dairy cattle with abomasal ulcers admitted to the University of Pennsylvania from 1968 through 1980 were evaluated. Of 6,385 adult dairy cattle admitted during that period, 69 had abomasal ulcers of clinical importance. Of 43 ulcers that had perforated, 17 were associated with local peritonitis and 22 were associated with diffuse peritonitis; 4 had perforated so recently that peritonitis had not had time to develop. Perforated ulcers were found in 40 cows that had recently calved (32 cows with ulcers that had perforated within 4 weeks after calving) and often had concurrent disease(s) (39 cows with at least one other disease). Ten cows with local peritonitis survived, whereas only 2 of the cows with diffuse peritonitis survived.

Abomasum↗
PubMed1984

Toxic hepatopathy in neonatal foals.

Six foals of three different breeds, born to healthy mares, appeared normal at birth, and died at two to five days of age with icterus, ataxia, head pressing, and terminal hepatic coma. Their livers were less than one-half normal weight. Most of the liver was dark red-brown and slightly rubbery. Histologically, these areas were characterized by severe bile ductule proliferation, mild portal tract fibrosis, and massive hepatocellular necrosis and lobular collapse. A small proportion of the liver, usually on the peripheral part of the lobes, was grossly light brown and slightly raised. Histologically, these areas had mild to severe bile stasis in canaliculi. In the thin marginal zone between the severely affected and mildly affected liver, there was mild bile ductule proliferation and periportal fatty change and necrosis. Alzheimer's type II cells, characteristic of hepatoencephalopathy, were numerous in the brains of all foals. Within two hours after birth, all the foals had been given an oral proprietary nutritional paste, the ingredients of which included a viable Aspergillus sp and an iron compound. Similar lesions were produced in an experimental foal.

Animals↗
PubMed1984

Renal clearance and fractional excretion of electrolytes over a 24-hour period in horses.

Four consecutive 6-hour urine collections were obtained from 10 healthy adult horses given free access to a complete pelleted ration and water. Samples of blood were collected from the jugular vein at the start of the test period and then every 6 hours for 4 consecutive samples. Mean renal clearance of creatinine (CCr) varied significantly during the four, 6-hour collections, ranging from 1.474 in period II to 2.702 ml/min/kg of body weight during period III (P less than 0.05). The CCr in period III was significantly different from the 24-hour mean value of 1.877 ml/min/kg (P less than 0.05). The mean 6-hour clearances of potassium (CK), chloride (CCl), and calcium (CCa) also varied significantly during the 4 collections (P less than 0.05). The 24-hour mean CK and CCl were different from the mean during period III (P less than 0.05). There was significant correlation between mean 24-hour CCr and CK (P less than 0.01); CCr and CCl (P less than 0.05); CNa and CK (P less than 0.01); CNa and CCl (P less than 0.01); and CK and CCl (P less than 0.001). The 95% confidence interval for 6-hour mean values of fractional excretion of Na (FENa) was 0.032% to 0.522%; FEK was 23.345% to 48.074%; FECl was 0.588% to 1.861%; and FECa was -0.158% to 6.723%. Although FENa, FECl, and FECa were highly variable within and between individual horses, mean values for periods I to IV did not differ significantly over time or from 24-hour mean values. The FEK varied less throughout the 24-hour test period. Mean urine volume, urine concentrations of Cr and K, urine osmolality, urine-to-plasma osmolality, urine-to-plasma urea nitrogen, and plasma urea nitrogen varied significantly through time periods I to IV (P less than 0.05); however, means for time periods I to IV were not different from 24-hour means.

Animals↗
PubMed1984

Radiographic, macroscopic, and microscopic changes in growth plates of calves raised on hard flooring.

The effect of flooring on the development of physeal and metaphyseal lesions of the limbs was studied in 1- to 5-month-old dairy calves. Calves were allotted to 2 groups. Group I was housed on a clay floor throughout the study and group II was housed on metal slats until weaned and then on concrete. Radiographs of the right thoracic limb of the animals were made 7 times during the experimental period and of the right thoracic and pelvic limbs at necropsy. Selected sections of the physeal regions of the distal part of the radius, metacarpus, metatarsus, and rib were examined microscopically. The physes of the limbs in the 2 groups had eosinophilic streaks and patches which originated in the germinal zone and were associated with blood vessels. These foci varied from small streaks parallel to the chondrocyte columns to multiple horizontal branching patches in which cleft formation and necrosis interrupted the physis, resulting in osseous bridging. Remnants of necrotic cartilage or cartilage containing hypertrophied chondrocytes were located in the metaphysis adjacent to the areas of physeal disruption. Multiple undulations of the physes with variations in thickness and orientation of the chondrocyte columns occurred in the physes of all limbs examined. These areas did not interrupt the physis and were not associated with metaphyseal lesions. The ribs in both groups had focal areas of failure of endochondral ossification characterized by elongation of the hypertrophied zone, accumulation of fibrin and hemorrhage in the zone of provisional calcification, and retention of cartilage within the metaphysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Toxic hepatic failure in newborn foals.

Eight foals, 2 to 5 days of age, with similar clinical signs and laboratory and pathologic findings, died from hepatic failure. The predominant clinical signs were depression and icterus. Abnormally high values were found for plasma ammonia content, aromatic-to-branch-chain amino acid ratio, total serum bilirubin content, gamma glutamyl transferase activity, alkaline phosphatase activity, and PCV; partial thromboplastin time and prothrombin time were prolonged. Some foals had high sorbitol dehydrogenase activity. These laboratory findings were suggestive of subacute hepatic disease and failure. Predominant pathologic findings were limited to the liver and brain. The livers were less than half the expected size for 2- to 5-day-old foals, had prominent bile ductule proliferation, hepatic cell necrosis, and mild periportal fibrosis. These findings suggested both prenatal and postnatal diseases caused by exposure to a hepatoxin. The predominant lesion in the brain was the presence of Alzheimer type II astrocytes, which are characteristic of hepatoencephalopathy. Although the periportal fibrosis was suggestive of in utero exposure to a toxin, epidemiologic information suggested that the hepatic failure more likely resulted from oral inoculation of a microorganism culture product at birth. The same disease was reproduced in 2 newborn foals by feeding this product.

Animals↗
PubMed1983

Bleeding abomasal ulcers in adult dairy cattle.

Case records of abomasal ulcers in adult dairy cattle admitted to the University of Pennsylvania during a 12-year period were reviewed. The only records retrieved were those for cases in which the clinical signs were directly associated with gastrointestinal bleeding. Of 6,385 adult cows admitted during the study period, 69 had clinical ulceration. Twenty-four were bleeding ulcers: 12 nontumor-associated bleeding ulcers and 12 lymphosarcoma-associated bleeding ulcers. Nontumor-associated bleeding ulcers were commonly found in young cows (7 cows less than or equal to 4 years old) that often had concurrent postparturient disease conditions. Lymphosarcoma-associated bleeding ulcers were found more commonly in older cows (10 cows greater than or equal to 6 years old) during all stages of lactation, often without concurrent diseases (8 cows).

Abomasum↗
PubMed1983

Fecal leukocytes and epithelial cells in horses with diarrhea.

Fecal samples from 74 horses with diarrhea were examined microscopically for leukocytes and epithelial cells. The diarrhea was categorized as either acute (less than two weeks) or chronic, Salmonella positive or negative, and mild or severe (based on the fecal consistency). A large number of fecal leukocytes was strongly suggestive of salmonellosis; however, approximately 1/3 of the horses with Salmonella-negative diarrhea also shed fecal leukocytes. Fecal leukocytes were more common in horses with acute and/or severe diarrhea regardless of cause. Numbers of fecal colonic mucosal epithelial cells were increased in severe diarrhea, and their presence in horses with chronic diarrhea was correlated with salmonellosis. The study supports the concept that fecal leukocytes and epithelial cells occur in increased numbers in equine salmonellosis but also occur in other types of diarrhea.

Animals↗
PubMed1981

Indications of unilateral bovine nephrectomy: a report of four cases.

Unilateral nephrectomy was done on 4 cows with renal disease. The history and clinical signs varied and were not pathognomonic for disease of the urinary system. Serum creatinine and BUN concentrations were normal in each cow prior to nephrectomy, in spite of advanced renal disease. Results of urinalysis were abnormal in 3 cows. Cystoscopic examination aided in the diagnosis, by revealing unilateral hematuria in 1 cow. Palpation per rectum revealed a large abdominal mass adjacent to the kidney in 2 cows. Exploratory celiotomy was necessary in 3 cows to determine the exact nature of their disease. Nephrectomy was easily performed; however, ligature security was critical. A biopsy of the remaining kidney at the time of nephrectomy aided in determining medical therapy and prognosis. Three cows recovered from the effects of the disease and became productive members of the herd. One cow was euthanatized because of end-stage renal disease in the remaining kidney.

Animals↗
PubMed1981

Brainstem auditory evoked response in the diagnosis of inner ear injury in the horse.

Brainstem auditory evoked response (BAER) testing was done to evaluate inner ear/VIIIth cranial nerve (CN8) function in the horse. The BAER test consisted of stimulating the auditory system with clicks and recording far-field responses of the brainstem auditory components via cutaneous electrodes and a signal averaging system. The normal response was shown to be a series of waves occurring within the first 10 msec after the stimulus click. Functional loss of the auditory receptor organ (cochlea) or CN8 results in loss of the entire response on the side of the injury. Because of the anatomic relationships of the peripheral auditory and vestibular systems, trauma to one will injure the other. Therefore, auditory testing (BAER tests) may be used to advantage in the diagnosis of peripheral vestibular disease. The BAER test was used in a horse that had signs suggestive of vestibular dysfunction or a brain lesion. The test helped to demonstrate a unilateral inner ear/CN8 lesion and to discount the probability of a more central lesion.

Animals↗