Biomedical subjects
Publications and source records attributed to R D Smith.
Many periparturient events affect breeding performance in dairy cows. These events include disorders, high early lactation milk yield, other cow factors, and calf factors. The effects range in severity from "annoying" to "devastating."
Acute renal failure following retrograde pyelography is a rare occurrence. The mechanisms reported have focused upon urinary tract obstruction either at an intrarenal or ureteric level. This report describes the first biopsy-proven case of acute tubular necrosis complicating retrograde pyelography. We propose the etiology to be direct tubular toxicity resulting from pyelolymphatic reflux of contrast.
Cure of amebic liver abscess is associated with resistance to recurrent invasive amebiasis and the development of a humoral and cell-mediated immune response. We determined whether human immune sera contain blocking antibody for the 170-kilodalton (kDa) galactose or N-acetylgalactosamine (Gal/GalNAc)-binding lectin of Entamoeba histolytica. By Western blot (immunoblot) of whole amebae subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, all eight immune sera studied here prominently recognized a 170-kDa amebic protein. Western blot of the purified Gal/GalNAc lectin with pooled human immune sera (PHIS) confirmed that the 170-kDa band was the adherence lectin. Immunoprecipitation of [35S]methionine-metabolically-labeled amebae with the antilectin monoclonal antibody H8-5 and with PHIS demonstrated that the 170-kDa lectin was the major antigen recognized by PHIS. The in vitro adherence of E. histolytica trophozoites to CHO cells at 4 degrees C was inhibited by prior exposure of amebae to greater than or equal to 1.0% PHIS. The humoral response to the Gal/GalNAc-binding lectin of the parasite may contribute to the development of protective immunity against invasive amebiasis.
Entamoeba histolytica adheres to human colonic mucus, colonic epithelial cells, and other target cells via a galactose (Gal) or N-acetyl-D-galactosamine (GalNAc) inhibitable surface lectin. Blockade of this adherence lectin with Gal or GalNAc in vitro prevents amebic killing of target cells. We have identified and purified the adherence lectin by two methods: affinity columns derivatized with galactose monomers or galactose terminal glycoproteins, and affinity columns and immunoblots prepared with monoclonal antibodies that inhibit amebic adherence. By both methods the adherence lectin was identified as a 170-kD secreted and membrane-bound amebic protein. The surface location of the lectin was confirmed by indirect immunofluorescence. Purified lectin competitively inhibited amebic adherence to target cells by binding to receptors on the target Chinese hamster ovary cells in a Gal-inhibitable manner.
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Two cases of Ewing sarcoma were karyotyped by using a fluorodeoxyuridine synchronisation procedure on short term cultures of fresh tumour material. This procedure enables rapid cytogenetic analysis of such material. Both showed relatively simple karyotypes, 48,XX, +2, +7,t(11;22)(q24;q12), ?dup(12)(q21----q24) and 47,XX,i(1q),t(11;22)(q24;q12). These results further support this translocation between chromosomes 11 and 22 as a specific marker for Ewing sarcoma. Cytogenetic studies in such cases are an important adjunct to histological studies and in some cases may contribute to the resolution of the diagnosis.
The relationship between breeding performance and postpartum milk yield was evaluated using data collected in a prospective field project from 33 New York Holstein herds. Herds selected were enrolled in the New York Dairy Herd Improvement Cooperative program and received monthly or biweekly herd health visits from the New York State College of Veterinary Medicine. Factors other than milk yield (e.g., postpartum reproductive disorders, inseminator, housing) that influence breeding performance were controlled in multiple regression analyses. Milk yield had a slight linear antagonistic relationship with conception at first service, services per conception, and days open but not with interval from parturition to first service, interval between first and second services, or interval between second and third services. Services per conception and days open increased by .009 and .6, respectively, for each 100-kg increase in cumulative milk yield during the first 60 d of lactation. Postpartum reproductive disorders, service method (artificial vs. natural), inseminator (farmer vs. technician), and calving interval of the previous lactation had more important relationships than milk yield with measures of breeding performance.
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Three isolates of Anaplasma marginale--Virginia (VAM), Illinois (IAM), and Florida (FAM)--were compared for infectivity for Dermacentor andersoni. The isolates were selected, in part, because of a tail-like appendage that has been demonstrated in the VAM and IAM, but not in the FAM. Ticks were exposed to the isolates as nymphs either naturally by feeding on a calf with anaplasmosis or artificially by percutaneous inoculation with infected bovine erythrocytes. They were examined for infectivity after molting to the adult stage by determining their capability to transmit the disease to susceptible calves and by demonstrating colonies in tick gut sections. Only those ticks exposed to the VAM proved to be infected with A marginale; ticks naturally exposed and those artificially infected with this isolate transmitted the disease to susceptible calves. Colonies of A marginale were observed only in gut tissues of ticks naturally infected with VAM. The IAM (appendage present) and FAM (appendage absent) could not be found in ticks exposed by either method, indicating that factors other than the presence of inclusion appendages may be involved in infection of ticks by A marginale.
Data concerning the activities of faculty and various characteristics of academic departments of pathology were obtained from questionnaires returned by 94 chairmen and 1571 faculty members. Data concerning manpower that was the subject of a previous report indicated that the projected supply of MD pathologists for faculty positions was significantly less than the anticipated demand. This article describes the characteristics of academic departments, particularly the activities of faculty that have bearing on the training and expectations of pathologists who are seeking faculty positions.
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The systemic administration of the anticancer drug bleomycin is associated with the development of lung damage and fibrosis. Intratracheal (i.t.) instillation of bleomycin has often been employed in animal models of this lesion to more rapidly elicit lung damage. However, various drugs and chemicals are known to induce lung damage and fibrosis when given i.t. The results presented here demonstrate that, in addition to bleomycin, the i.t. instillation of dactinomycin, mitomycin c, doxorubicin, and cyclophosphamide resulted in increased lung levels of hydroxyproline, an indicator of fibrosis. In contrast, increases were not seen following i.t. doses of 5-fluorouracil or vincristine, and 1,3-bis(2-chloroethyl)-1-nitrosourea(BCNU) actually decreased lung hydroxyproline content. These findings suggest that i.t. treatments with bleomycin may produce lung damage more representative of anticancer drugs in general than the specific lesion which is produced when bleomycin is administered systemically. The mechanisms underlying i.t. drug-induced increases in lung hydroxyproline are not known, but may be related to the ability of cell-cycle-nonspecific anticancer drugs to directly damage alveolar epithelial cells.
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Escherichia coli isolated from children with diarrhea were tested for enterotoxin production and for hybridization with gene probes for heat-labile (LT) and heat-stable (ST-H and ST-P) enterotoxin. Fecal specimens were also examined directly for genes coding for enterotoxins. E. coli that hybridized with the cloned enterotoxin gene probes was identified by colony hybridization from 46 children, by enterotoxin production from 38 children, and by specimen hybridization from 37 of 304 children examined. Eighty-six percent (473 of 550) of E. coli that hybridized with the cloned DNA probes produced enterotoxins. Four E. coli that hybridized with the LT and 73 E. coli that hybridized with the ST-H probes were nonenterotoxigenic. These isolates were subsequently shown not to hybridize with other constructions of the same probes and did not hybridize with synthetic single-stranded oligonucleotides directed against the LT or ST genes.
Celiprolol HCl is a new cardioselective beta adrenoceptor antagonist with both mild propranolol-sensitive partial agonist activity and propranolol-insensitive cardiostimulatory properties. The purpose of the present investigation was to assess the significance of this unique pharmacological profile in a study of the effects of celiprolol in anesthetized dogs with depressed myocardial function. Dogs were acutely instrumented to directly monitor myocardial contractile force (CF), arterial pressure (AP), heart rate (HR), and ECG limb lead II. Mecamylamine 1 mg/kg i.v., and verapamil, 0.5 mg/kg i.v., reduced CF (80 +/- 6 g), HR (76 +/- 4 beats/min), and AP (59 +/- 8 mm Hg). Celiprolol (3 mg/kg i.v.) did not produce any further decrement in myocardial function. There were no appreciable ECG changes. These data suggest that celiprolol may be the drug of choice in patients receiving verapamil, since it should not further compromise myocardial function.
Adherence by axenic Entamoeba histolytica trophozoites to mammalian cells is mediated by an N-acetylgalactosamine (GalNAc)-inhibitable adhesin on the surface of the parasite. We isolated 35 hybridoma cell lines producing antibodies to E. histolytica as indicated by ELISA with sonicated amebic protein or by immunofluorescence assay with fixed whole trophozoites. Tissue culture supernatants were further screened for subcloning by the ability to bind to Chinese hamster ovary (CHO) cells which were first exposed to a partially purified soluble preparation of the amebic GalNAc-inhibitable lectin. Eight tissue culture supernatants were positive in this assay. Antibodies from four subcloned cell lines (D3-14, H8-5, I12-2, and I1-21) inhibited amebic adherence to CHO cells (P less than 0.01). Of the original 35 tissue culture supernatants, 3 also inhibited amebic adherence (P less than 0.01; F1, F14, and J10); monoclonal antibodies in these supernatants did not bind to lectin-exposed CHO cells. Three purified monoclonal antibodies (H8-5, I12-2, and I1-21) inhibited amebic adherence at greater than or equal to 2 micrograms/10(4) amebae (P less than 0.05). None of these inhibitory monoclonal antibodies immunoprecipitated with a soluble amebic protein preparation following sodium dodecyl sulfate-polyacrylamide gel electrophoresis under denaturing conditions. Monoclonal antibodies which inhibit in vitro adherence by E. histolytica will be useful in purification of the GalNAc-inhibitable lectin.