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11.
Colonic perforation after corticosteroid and surgical treatment of intervertebral disk disease in a dog Perforation of the distal segment of the descending colon, after corticosteroid and neurosurgical treatment for an intervertebral disk herniation, resulted in the death of a 3-year-old, male, Lhasa Apso. Initially, the dog was paraparetic in the hindlimbs, but became paraplegic after 4 days of conservative treatment. Corticosteroids were administered before referral and during decompressive hemilaminectomy. Six days after surgery, the dog had improved neurologically, but was depressed, anorectic, and vomiting. Abdominocentesis revealed septic peritonitis. The dog died shortly after a perforation in the descending colon was surgically corrected.  相似文献   
12.
Congenital aortic stenosis usually affects the subvalvular region, and occurs mainly in Newfoundland, Golden Retriever, German Shepherd, and Boxer dogs. The disorder is inherited as a dominant trait with variable penetrance in Newfoundland dogs.

The prevalence of subaortic stenosis-like heart murmurs in Golden Retriever dogs appears to be very much greater than previously suspected.

Most cases of aortic stenosis represent mild lesions, are detected as incidental findings, and result in no loss of longevity or quality of life. Moderate or severe stenosis may result in exertional weakness, syncope, or sudden death. Signs of congestive heart failure are rare unless mitral valve insufficiency is present.

Generally, electrocardiography and radiography are unrevealing in this disorder. Doppler echocardiography may be the best diagnostic tool to detect even mild cases of aortic stenosis.

At present, therapy is limited due to the technical expertise and expense required. The prognosis depends on the severity of the lesion.

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13.
Much attention is focused today on predicting how plants will respond to anticipated changes in atmospheric composition and climate, and in particular to increases in CO(2) concentration. Here we review the long-term global fluctuations in atmospheric CO(2) concentration as a framework for understanding how current trends in atmospheric CO(2) concentration fit into a selective, evolutionary context. We then focus on an integrated approach for understanding how gas exchange metabolism responds to current environmental conditions, how it previously responded to glacial-interglacial conditions, and how it may respond to future changes in atmospheric CO(2) concentration.  相似文献   
14.
The distribution of gross lesions of Mycobacterium bovis was examined in 94 tuberculous feral ferrets (Mustela furo) collected from 1992 to 1995 from areas of Otago endemic for bovine tuberculosis. Overall, 56.4% of tuberculous ferrets had single-site lesions, 24.5% had multiple infections and 19.1% had generalised infections. The mesenteric lymph node was the most common site of infection (34.5% of all lesions), with the retropharyngeal (17%) and the prescapular lymph nodes (16.4%) also frequently infected. Only 2.9% of lesions involved the respiratory tract. Of single-site lesions, 60.4% were in the mesenteric lymph node. The high proportion of lesions in the alimentary tract suggests that the ingestion of infectious material, possibly carrion or prey, is an important source of infection. Peripheral lymph nodes contributed to 24.5% of all infections, suggesting that within species transmission by social contact such as fighting and mating also occurs. Open and respiratory lesions were found in 11.7% of tuberculous ferrets, which suggests that ferrets are potentially infectious and therefore may be involved in the transmission of bovine tuberculosis to domestic stock and other mammals. The distribution of gross M. bovis lesions in ferrets is compared to those observed in possums (Trichosurus vulpecula) and badgers (Meles meles).  相似文献   
15.
The open society     
Opel JR 《Science (New York, N.Y.)》1984,225(4660):378-380
The open society, unlike the closed society, requires constant citizen thought and action to ensure that it will continue to survive and prosper. Today in the United States we should give particular attention to three immediate problems. We should reinvigorate our national economic health and international competitiveness, particularly by reducing our unprecedented budget deficits and reforming our tax system. We must strengthen our scientific and engineering vitality, particularly in graduate engineering education and in secondary school instruction in science and mathematics. And we should work with our allies in the free industrialized world to keep our international open society as open as possible, encouraging a flow of people and information and ideas across national boundaries while instituting sensible and efficient safeguards against leakage of critical military technology to the Soviet Union.  相似文献   
16.
Silicified anthoecia (fertile le'mmas and paleas) of grasses (Berriochloa communis, Berriochloa primaeva, and Berriohldoa cf. nova) were found in, the oral cavity and rib cage articulated skeletons of Teleoceras major buried in late Clarendonian volcanic ash in. Nebraska The plant fossils, thought to be food residues, help clarify, the enigmatic paleobiological role, of Teleocears, which had hippotamus-like porportions but very high-crowned teeth. Telecoceras was probably amphbious, but siliceous grasses formed a significant portion of its diet.  相似文献   
17.
Thirty isolates of Haemophilus pleuropneumoniae from clinical and slautherhouse cases of porcine Haemophilus pleuropneumonia in Saskatchewan as well as six isolates from British Columbia and Ontario were subjected to cultural, biochemical, serological and antibiotic sensitivity tests. All strains were Gram-negative pleomorphic rods or coccobacilli which grew only in the presence of V factor and all produced porphyrin from delta-aminolaevulinic acid. Biochemically, the organism was positive for urease, O-nitrophenyl-β-D-galactopyranosidase and the fermentation of sucrose, mannitol, dextrose, lactose and xylose, but was usually negative for indole. Most strains of H. pleuropneumoniae were sensitive to chloramphenicol, furamazone, carbenicillin and ampicillin, but only about 50% were sensitive to tetracycline. Serotype 5 was more common than serotype 1 or the untyped strains among Saskatchewan isolates. In addition, serotype 3 was identified from British Columbia.

Retrospective epidemiological studies showed that Haemophilus pleuropneumonia occurred and recurred on farms in the Saskatoon and adjoining districts, serviced by the diagnostic laboratories of the Western College of Veterinary Medicine and that the disease was more common among three month old pigs during the fall-winter season.

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18.
19.
Feeding currents of free-swimming calanoid copepods, observed through an expanded krypton laser beam and a back-focus dark-field optical system, show that these planktonic animals generate a double shear field to help in detecting food. The interrelation between flow field, perception of food items, and body orientation explains why these animals are generally negatively buoyant.  相似文献   
20.
Pleural effusions from 23 dogs and 25 cats hospitalized between November 1986 and April 1987 at the Veterinary Hospital of the University of Pennsylvania (VHUP) were classified as chylous (chylomicrons present) or nonchylous (chylomicrons absent) by the presence or absence, respectively, of a chylomicron band on lipoprotein electrophoresis gels of the effusions. Triglyceride concentrations, cholesterol concentrations, and cholesterol/triglyceride (C/T) ratios were compared between the chylous and nonchylous groups in each species. Cholesterol concentrations were not significantly different between chylous and nonchylous effusions in both dogs and cats. Cholesterol/triglyceride ratios of less than 1 were present in all dogs and cats with chylous effusions; however, 12% of dogs with nonchylous effusions and 50% of cats with nonchylous effusions also had a C/T ratio less than 1. Triglyceride concentrations accurately classified all effusions as chylous or nonchylous in both dogs and cats. Pleural effusions with triglyceride concentrations greater than l00 mg/dl were chylous in all cases, whereas, effusions with triglyceride concentrations less than l00 mg/dl were nonchylous in all cases.  相似文献   
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