Observations on the Ultrastructural Appearance of Endocrine Cells of the Small Intestine of the Calf     

G. R. Pearson  E. F. Logan 《Anatomia, histologia, embryologia》1983,12(1):1-6

The endocrine cells of the small intestine of neonatal calves are described, with the aid of transmission and scanning electron microscopy. It is demonstrated that endocrine cells have long microvilli, and are organized into two populations, similar to those of other species.  相似文献   

Cryptococcal pneumonia in a horse   总被引：1，自引：0，他引：1  

E G Pearson  B J Watrous  J A Schmitz  R J Sonn 《Journal of the American Veterinary Medical Association》1983,183(5):577-579

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Effect of genetic selection for milk yield and increased milking frequency on plasma growth hormone and prolactin concentration in Holstein cows     

G W Kazmer  M A Barnes  R M Akers  R E Pearson 《Journal of animal science》1986,63(4):1220-1227

Fifty Holstein cattle, either second to fourth generation daughters of cows randomly bred to non-commercial sires originating in the Virginia Tech dairy herd (estimated mean PDM84 = -455 kg, control animals), or daughters of cows bred to commercially available sires (mean PDM84 = +368 kg, selection animals), were randomly assigned to be milked twice or thrice daily starting at parturition. Serial blood samples were collected via jugular cannulae at 30, 90 and 200 d post-partum (DPP) during both the first and second lactations. Blood samples were collected for 3 h prior to and 4 h following thyrotropin releasing hormone (TRH) administration, and were analyzed for growth hormone (GH) and prolactin (PRL) concentrations. Dry matter intake, body weight and milk yield and fat content were used to calculate net energy balance (NEB) of animals at each DPP sampling period. Mean plasma GH concentrations were greater (P less than .01) in selection vs control animals both before and after TRH administration, and decreased (P less than .01) with advancing lactation (30 greater than 90 greater than 200 DPP). However, NEB was not influenced by genetic merit, implying that observed differences in GH concentrations were not due to that trait. Plasma PRL concentrations were not affected by genetic merit or DPP, but were greater (P less than .01) in the second vs first lactation. Neither PRL or GH concentrations were affected by frequency of milking. The results support the contention that increased plasma GH concentrations are associated with selection for increased milk yield.  相似文献   

CLIOXANIDE, A NEW ANTHELMINTIC ACTIVE AGAINST FASCIOLA HEPATIC A AND HAEMONCHUS CONTORTUS IN SHEEP     

I. G. Pearson  B.V.Sc.  H. V. Whitlock  A.A.I.M.L.T.  C. P. DeGoosh  D.V.M.  K. J. Farrington  M.Sc.  R. C. Jones  B.Sc.  Ph.D. J. A. Haigh 《Australian veterinary journal》1970,46(10):480-484

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Bluetongue in cattle: a serologic survey of slaughter cattle in the United States   总被引：1，自引：0，他引：1  

H E Metcalf  J E Pearson  A L Klingsporn 《American journal of veterinary research》1981,42(6):1057-1061

Serologic tests for bluetongue virus (BTV) were done on 19,758 blood serum samples systematically collected at brucellosis laboratories throughout the United States from Nov 28, 1977 to Feb 20, 1978. Prevalence of BTV antibody varied from 0 to 79% of the samples collected in various states, with a national prevalence of 18.2%. The prevalence was generally low in the northern states and high in the southwestern states. The highest prevalence rates were found in Puerto Rico and the Virgin Islands.  相似文献   

Comparison of bronchodilators in alleviating clinical signs in horses with chronic obstructive pulmonary disease     

E G Pearson  T W Riebold 《Journal of the American Veterinary Medical Association》1989,194(9):1287-1291

A representative of each of 3 types of bronchodilators was given iv to horses with clinical signs of chronic obstructive pulmonary disease. We used atropine (0.01 mg/kg of body weight) as an anticholinergic, isoproterenol HCl as a beta-adrenergic, and aminophylline, the soluble salt of theophylline, as a methylxanthine. Response to these drugs was evaluated by measuring maximal change in intrathoracic pressures (delta Ppl) and observing clinical signs. Atropine caused a significant (P less than 0.01) reduction in delta Ppl, compared with that caused by aminophylline. Atropine caused the delta Ppl to decrease an average of 83 +/- 15% toward normal. Clinical improvement was noticed in 87% of the cases. Maximal changes in pleural pressures were reduced by an average of 21 +/- 14 mm of Hg, with 27% returning completely to normal. Isoproterenol helped 77% of horses clinically, and caused delta Ppl to decrease an average of 68 +/- 31% toward normal. The average reduction in delta Ppl was 16 +/- 10 mm of Hg. Aminophylline helped alleviate clinical signs of 50% of the horses and caused delta Ppl to decrease an average of 41 +/- 36% toward normal. The average reduction in delta Ppl was 10 +/- 11 mm of Hg.  相似文献   

Serum liver enzyme and histopathologic changes in calves with chronic and chronic-delayed Senecio jacobaea toxicosis.     

A M Craig  E G Pearson  C Meyer  J A Schmitz 《American journal of veterinary research》1991,52(12):1969-1978

Progressive changes in serum enzyme activity and liver histologic features were monitored in calves fed tansy ragwort (Senecio jacobaea)-contaminated pellets. The experiments were designed to simulate natural intoxicant ingestion conditions in relationship to the dose and duration of exposure to the toxic plant to correlate early laboratory diagnostic changes with the natural progression of the disease, thereby facilitating early diagnosis and intervention by veterinary clinicians. Eight calves were fed tansy ragwort and 4 additional calves served as controls. In group 1, 4 calves were continuously fed dried tansy ragwort mixed in a pelleted feed at a 5% concentration by dry weight until terminal liver disease developed. Serum liver enzyme (alkaline phosphatase, glutamate dehydrogenase, and gamma-glutamyltransferase) activities were monitored at weekly intervals in these calves and in the 2 controls. In group 2, 4 calves were fed the same contaminated feed for only 60 days, with return to normal feed for the duration of the trial. Two additional calves served as controls. Their liver enzyme activities were monitored every other week in conjunction with percutaneous liver biopsies. All 8 calves fed tansy ragwort-contaminated pellets developed terminal hepatopathy in either a chronic pattern (n = 6) or a chronic-delayed pattern (n = 2), with the onset of a moribund state or sudden death at 11 to 17 weeks and 27 to 51 weeks, respectively. The calves were euthanatized when classic terminal signs of hepatic encephalopathy first became evident. The clinicopathologic patterns of chronic and chronic-delayed toxicoses were typical of over 5,000 cases of field tansy toxicosis diagnosed at the diagnostic laboratory. Serum glutamate dehydrogenase was the first enzyme to increase in most animals, with a short-term increase to peak values followed by a rapid return to normal. This enzyme change was followed by increases in alkaline phosphatase and gamma-glutamyltransferase. Serum enzyme changes preceded development of recognizable histologic lesions. Vacuolar changes in hepatocyte nuclei, biliary hyperplasia, and fibrosis sequentially developed in liver biopsy specimens from each animal, whereas megalocytosis was not a predominant feature until necropsy. On the basis of our findings, we suggest that the optimal tests for diagnosis of pyrrolizidine alkaloid intoxication should consist of liver biopsy and determination of concurrent serum liver-enzyme activities.  相似文献   

Use of a biological extract of Serratia marcescens to decrease doxorubicin-induced myelosuppression in dogs.     

G K Ogilvie  R E Elmslie  M Cecchini  L M Walters  F C Pearson 《American journal of veterinary research》1992,53(10):1787-1790

Fifteen dogs were given doxorubicin, IV, at a dosage of 30 mg/m2 of body surface. A commercially available biological extract of Serratia marcescens (BESM) was administered SC to 9 of these dogs (0.04 mg/kg of body weight every third day, n = 2; 0.08 mg/kg every other day, n = 2; and 0.08 mg/kg daily, n = 5), beginning the day after administration of doxorubicin, in an attempt to find an optimal dosage and schedule of administration of BESM to reduce the duration and severity of chemotherapy-induced myelosuppression. Nine additional dogs were randomized into 3 groups of 3 dogs to receive 1 of the following dosages of BESM SC: 0.08, 0.16, and 0.32 mg/kg. Serum was harvested immediately prior to treatment and at 2, 4, 6, 8, 12, 24, 48, and 72 hours from this latter group of dogs for subsequent analysis of canine granulocyte colony-stimulating factor (G-CSF) by enzyme immunoassay. Increasing the dosage and schedule of administration of BESM reduced the duration and severity of doxorubicin-induced myelosuppression. Neutrophil counts of the group of dogs given BESM daily at a dosage of 0.08 mg/kg and the controls were evaluated statistically. The neutrophil count increased significantly (P < 0.05) above pretreatment values in BESM-treated dogs after day 7. Median neutrophil counts of the BESM-treated dogs were never significantly lower than pretreatment values, whereas the median counts of the dogs treated with doxorubicin alone were significantly below normal for 6 days (days 7-12).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Pathological changes in the small intestine of neonatal calves naturally infected with reo-like virus (rotavirus).     

G R Pearson  M S McNulty  E F Logan 《The Veterinary record》1978,102(21):454-458

Nine calves, of which six had been challenged with an enteropathogenic strain of Escherichia coli, were found to be naturally infected with rotavirus. Rotavirus was recovered from the faeces of six calves and rotavirus antigen was detected in the intestinal mucosa of all calves. Stunting and fusion of villi were seen principally in the proximal and middle small intestine, where rotavirus antigen was detected by immunofluorescence. Typical lesions of enteric colibacillosis were found in the distal ileum of the challenged calves, associated with adhesion of the challenge strain of E coli to the mucosa. All samples were removed from the intestine under general anaesthesia and denudation of villi was not observed. However, following exsanguination and resampling at the same site in the small intestine of one calf, denudation was a constant feature.  相似文献   

Suspected chlorpyrifos toxicosis in a llama, and plasma pseudocholinesterase activity in llamas given chlorpyrifos     

E G Pearson  A M Craig  E D Lassen 《Journal of the American Veterinary Medical Association》1986,189(9):1062-1064

Five days after treatment with chlorpyrifos, a 1.5-year-old male llama was unable to stand, had saliva flowing from its mouth, and had constricted pupils, hyperglycemia, a metabolic acidosis, and a plasma pseudocholinesterase activity of 111 IU/L. Mean (+/- 1 SD) plasma pseudocholinesterase activity of 29 healthy llamas was 233.76 +/- 51.55 IU/L. Five to 8 days after topical application of chlorpyrifos (25 mg/kg of body weight) to 3 healthy llamas, the pseudocholinesterase activity decreased to 38% to 62% of pretreatment (base-line) activity and returned to within 90% of base-line activity by the 36th to 48th day after treatment.  相似文献