Biomedical subjects

N F Cheville

Publications and source records attributed to N F Cheville.

At least 19 recordsLinked to original sources

PubMed1992

Use of rats to compare atrophic rhinitis vaccines for protection against effects of heat-labile protein toxin produced by Pasteurella multocida serogroup D.

Four bacterin-toxoid and three bacterin commercial vaccines against atrophic rhinitis were tested in rats for their capacity to immunize against the lethal and systemic effects of purified heat-labile protein toxin (D-toxin) produced by Pasteurella multocida serogroup D. Only one bacterin-toxoid vaccine stimulated sufficient immunity to prevent the death of all rats challenged with D-toxin. None of the vaccines prevented weight loss, leukocytosis or increases in serum complement titers in rats challenged with D-toxin. Rats provide an inexpensive animal model for testing the capacity of vaccines to generate antitoxic immunity against the lethal and systemic effects of D-toxin.

Animals↗

PubMed1992

Light microscopic and ultrastructural pathology of seminiferous tubules of rats given multiple doses of Pasteurella multocida group D protein toxin.

Male Holtzman rats were given subcutaneous doses of a purified Pasteurella multocida group D heat-labile toxin on alternate days for up to 22 days. Rats were necropsied at 18 days or 36 days (14 days after last dose of toxin) or when moribund, and testicles were taken for histologic and ultrastructural examination. Other selected tissues, including liver and spleen, were taken for histologic examination. Histologically, testicular and splenic lesions occurred more consistently and at much smaller doses when compared with lesions in other target organs such as liver. Testicular and splenic lesions were present in all rats (6/6) given 0.8 micrograms/kg toxin and were seen in some rats (1/6) given as little as 0.2 micrograms/kg toxin. Only 3/6 rats given 0.8 micrograms/kg toxin had hepatic lesions; no hepatic lesions were seen at doses of 0.2 micrograms/kg. Testicles from toxin-treated rats were smaller and weighed less than controls. Seminiferous tubules were moderately dilated and lined by polygonal sertoli cells. The normal spermatogenic maturation sequence and mature spermatids were absent, and many tubules contained multinucleate spermatocytes. Severely affected tubules were necrotic and mineralized. Ultrastructurally, there was necrosis of adluminal spermatocytes, multinucleate cell formation, and spaces between Sertoli cell plasma membranes. Testicular lesions were similar to those described for vitamin D-deficient rats, vitamin A-deficient rats, vasectomized rats, and rats given intravenous tumor necrosis factor; however, rats given lethal doses of toxin did not have elevated levels of TNF alpha activity.

Animals↗

PubMed1992

Bacterial survival, lymph node changes, and immunologic responses of cattle vaccinated with standard and mutant strains of Brucella abortus.

Forty-eight cattle were used in 4 experiments; 6-week-old calves in experiments 1-3 (n = 24) and 10-month-old heifers in experiment 4 (n = 24). In experiments 1-3, 7 groups of 3 calves each were inoculated SC with 5 strains of Brucella abortus: virulent strain 2308 (2 groups), vaccine strain 19 (2 groups), and mutant strains RB51. 19 delta 31K, and 19 delta SOD. Sera and lymph node tissues were examined at 2-week intervals for evidence of infection. At postinoculation (PI) week 12, 2 calves in each group were given dexamethasone for 5 days. Calves were then euthanatized and lymphoid tissue, spleen, liver, and bone marrow were examined for evidence of B abortus. Calves given strain 2308 had large numbers of bacteria in their lymph nodes, marked granulomatous lymphadenitis in the deep cortex, and loss of lymphoid cells in superficial cortical areas. In addition, they had high serum antibody titers at PI week 16. Calves given strain 19, or genetic mutants derived from strain 19, cleared bacteria from lymph nodes more rapidly, had less lymphoid destruction, and developed antibody titers that did not persist for 16 weeks. The RB51 strain (rough) was cleared most rapidly from lymphoid tissues and induced serum antibody responses only to the core of the lipopolysaccharide molecule. Treatment of calves with dexamethasone did not cause B abortus to reappear in tissues of any calves, nor did serum antibody titers increase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Immunity induced in rats vaccinated with toxoid prepared from heat-labile toxin produced by Pasteurella multocida serogroup D.

Rats were vaccinated with a toxoid (D-toxoid) prepared from purified heat-labile toxin (D-toxin) produced by Pasteurella multocida serogroup D. Vaccination of rats with D-toxoid prevented death and other effects of D-toxin (hepatic necrosis, development of elevated leukocyte counts, lymphopenia, neutrophilia, and elevated complement titers) that occurred in phosphate buffered saline (PBS)-vaccinated control rats.

Animals↗

PubMed1991

Ultrastructural studies of the lung of turkeys (Meleagris gallopavo) inoculated intratracheally with Escherichia coli.

To test the hypothesis that walls of air capillaries are a site for Escherichia coli to pass the air-blood barrier, fimbriated and nonfimbriated strains of E. coli were inoculated intratracheally into 18-day-old turkeys. Venous blood was cultured, and turkeys were necropsied from 0.5 to 8 hours post-inoculation. Lungs were processed for histopathology and electron microscopy. E. coli 078 was identified ultrastructurally using rabbit anti-lipopolysaccharide antibody and protein A-colloidal gold. All birds developed bacteremia; there was no significant difference between groups given fimbriated or nonfimbriated bacteria. Bacteria adhered to the plasma membrane of air capillary epithelial cells and were seen within vacuoles of portions of these cells that lined the fornices of air capillaries. Bacteria were also seen in the basement membrane at the basal surface of air capillary epithelial cells and, rarely, in vacuoles of subjacent endothelial cells. Infected granular and non-granular cells that lined air atria were necrotic 4 hours post-inoculation. Bacteria were within the overlying trilaminar substance and between reticular fibers of the interstitial stroma and pleura at 30 minutes post-infection and thereafter. Thus, the pulmonary air capillaries are a site for entrance of E. coli into the pulmonary blood capillaries, but fimbriae play little or no role in passage across the air-blood barrier.

Air Sacs↗

PubMed1991

Lectin histochemistry of trachea and lung of healthy turkeys (Meleagris gallopavo) and turkeys with pneumonia.

Thirteen lectins were used to characterize lectin-binding specificity of glycoconjugates on sections of formalin-fixed lung and trachea from seven normal turkeys, two turkeys with acute pneumonia, and two turkeys with chronic pneumonia. Neuraminidase was used to digest sialic acid residues. One N-acetylgalactosamine-binding lectin and two N-acetylgalactosamine/galactose-binding lectins stained the apical membrane and cytoplasm of multifocal cells that lined air atria and hyperplastic granular cells. Other lectins in these groups stained ciliated cells of the trachea and bronchi and air capillary epithelial cells. Sialic acid residues were on apical surfaces of ciliated and nonciliated tracheal and bronchial lining cells, air capillary epithelial cells, and vascular endothelial cells. Mannose/glucose-binding lectins stained reticular and elastic fibers in the lamina propria of trachea, primary and secondary bronchi, and the tunica adventitia of arteries and veins. By transmission electron microscopy, colloidal gold-Arachis hypogaea (peanut agglutinin) labeled microvilli on the apical surface of mature granular cells. The L-fucose-binding lectin, in addition to several other lectins, stained nonspecifically in both trachea and lung. These studies show that granular cells that line air atria can be identified with lectins of N-acetylglucosamine and N-acetylgalactosamine/galactose groups, and that apical surfaces of epithelial cells and endothelial cells in the trachea and lung express terminal sialic acid residues.

Acute Disease↗

PubMed1991

Colonization of the pharyngeal tonsil and respiratory tract of the gnotobiotic pig by a toxigenic strain of Pasteurella multocida type D.

Seven-day-old gnotobiotic pigs were inoculated intranasally with Pasteurella multocida and euthanatized 2, 5, 9, and 14 days after inoculation. Tissues from the oropharynx and respiratory tract of pigs were cultured quantitatively and analyzed microscopically. Pigs remained afebrile and alert, except one that died of acute fibrinopurulent pneumonia. Pasteurella multocida was isolated in greatest numbers from the pharyngeal tonsils, but only in low numbers from turbinate, trachea, lung, spleen, and liver. Significant histologic changes were limited to the tonsil. Infected pigs developed mild tonsillitis with lymphocytic hyperplasia, and accumulation of cell debris and bacteria in crypts. Capsular antigens of P. multocida, identified on tissue sections with rabbit anti-capsular polysaccharide antibody and immunocytochemical reagents, were confined to the crypt lumen. Ultrastructurally, bacteria were free within crypt material or within phagosomes of macrophages or neutrophils. In a second experiment, 5-day-old pigs were infected with Streptococcus suis type 2, followed by toxigenic Pasteurella multocida at 7 days of age; one pig died of streptococcal septicemia. Pigs developed a mild tonsillitis, and both bacteria were cultured from the tonsillar crypts for up to 14 days after infection. These studies show that a toxigenic strain of Pasteurella multocida, which is a causative agent of atrophic rhinitis, can colonize the tonsil and respiratory tract of gnotobiotic pigs for up to 14 days. In addition, colonization can occur concurrently with Streptococcus suis type 2.

Animals↗

PubMed1991

Brucella abortus-associated meningitis in aborted bovine fetuses.

Granulomatous meningitis was present in 6/33 bovine fetuses from which Brucella abortus (B. abortus) had been isolated. Meningitis was severe in three fetuses, moderate in one fetus, and mild in the remaining two fetuses. The meningitis was characterized by the infiltration of a mixed population of lymphocytes, plasma cells, and macrophages in the leptomeninges. Vasculitis characterized by the infiltration of lymphocytes and plasma cells in the vascular wall was observed in the vessels of the cerebral cortices of 4/6 fetuses. Gram negative coccobacilli were present in the cytoplasm of the leptomeningeal macrophages and extracellularly. Brucellar antigens labeled by the avidin-biotin-peroxidase complex method were present in massive amounts in leptomeningeal macrophages and in small foci of stained cells in the choroid plexus and ependyma. The findings indicate that B. abortus is one of pathogens capable of inducing meningitis in bovine fetuses.

Abortion, Veterinary↗

PubMed1991

Effect of endocytic and metabolic inhibitors on the internalization and intracellular growth of Brucella abortus in Vero cells.

Uptake, transfer to rough endoplasmic reticulum, and intracellular growth of Brucella abortus were studied in Vero cells treated with endocytic and metabolic inhibitors. Infection of Vero cells was suppressed when inhibitors of energy metabolism (iodoacetate, dinitrophenol), receptor-mediated endocytosis (monodansylcadaverine, amantadine, methylamine), or endosomal acidification (chloroquine, ammonium chloride, monensin) were added to the inoculum. Inhibition was not observed when these drugs were added after the inoculation period. Infection of Vero cells by B abortus was inhibited by dibutyryl-cyclic adenosine monophosphate and Vibrio cholerae enterotoxin, but was stimulated by dibutyryl-cyclic guanosine monophosphate and escherichia coli heat-stable enterotoxin a. Uptake of B abortus by Vero cells was not prevented by colchicine, but was abolished by cytochalasin B. Uptake of heat-killed B abortus and noninvasive E coli was similar to that of viable brucellae. Intracellular growth of B abortus was not affected by cycloheximide. Results indicate that: B abortus may be internalized by a receptor-mediated phagocytic process; transfer of B abortus from phagosomes to rough endoplasmic reticulum may require endosomal acidification; and replication of B abortus within the rough endoplasmic reticulum may not depend on protein synthesis by the host cell.

Amantadine↗

PubMed1991

Lesions and localization of viral antigen in tissues of cattle with experimentally induced or naturally acquired mucosal disease, or with naturally acquired chronic bovine viral diarrhea.

Tissues from cattle that died of experimentally induced mucosal disease (n = 3), naturally acquired mucosal disease (n = 6), or naturally acquired chronic bovine viral diarrhea (n = 4) were examined. Consistent findings were lymphocytic depletion of lymphoid tissues, degeneration of myenteric ganglion cells, and mild adrenalitis. Intracytoplasmic viral antigen was detected in myenteric ganglia and in endocrine glandular cells. Noncytopathic virus was isolated from all cattle, and cytopathic virus was isolated from 12 of 13 cattle.

Animals↗

PubMed1990

Penetration and intracellular growth of Brucella abortus in nonphagocytic cells in vitro.

In pregnant ruminants, Brucella abortus localizes and replicates within the rough endoplasmic reticulum of trophoblastic epithelial cells. In this study, Vero cells were exposed to B. abortus to investigate its internalization and intracellular growth in nonphagocytic cells. A new double-fluorescence staining procedure to discriminate between extracellular and intracellular bacteria was developed. Studies with the double-fluorescence staining procedure and quantitative bacteriologic culture of disrupted host cells showed that various B. abortus strains replicated within Vero cells, including smooth virulent (strains 2308S and 544), smooth attenuated (strain 19), and rough (strains 45/20 and 2308R) strains. Rough brucellae were more adherent and entered a greater number of Vero cells. Intracellular replication occurred in a larger percentage of cells with smooth virulent (2308S and 544) strains than with smooth attenuated (19) or rough (45/20 and 2308R) strains. Differences in adhesiveness and invasiveness were correlated to hydrophobicity of the organism, as measured by hydrocarbon adherence. Ultrastructurally, intracellular smooth (2308S) and rough (45/20) brucellae were consistently found within cisternae of the rough endoplasmic reticulum and nuclear envelope. The results suggest that transfer to the rough endoplasmic reticulum is the limiting step in the infection of nonphagocytic cells by B. abortus.

Animals↗

PubMed1990

Experimental primary postnatal bovine viral diarrhea viral infections in six-month-old calves.

Eight clinically healthy calves were inoculated intranasally, four with either noncytopathic or four with cytopathic bovine viral diarrhea virus, and were necropsied 5 or 12 days post-inoculation. The most frequent gross lesion associated with noncytopathic or cytopathic viral infection was proximal colonic mural edema. Consistent microscopic findings were acute to subacute tracheitis, mild enterocolitis with edema, petechial hemorrhages of mesenteric lymph nodes with mild follicular lymphocytic depletion, and paracortical lymphocytic hyperplasia. At necropsy, cytopathic virus was recovered from 4/4 calves and noncytopathic virus was isolated from 2/4 calves. Neutralizing antibodies to noncytopathic bovine viral diarrhea virus were detected in the two calves from which noncytopathic virus was not recovered. Immunohistochemical analysis of lymphoid tissues demonstrated a small, randomly distributed population of mononuclear cells that contained bovine viral diarrhea viral antigen in 7/8 calves.

Animals↗

PubMed1990

Entry and intracellular localization of Brucella spp. in Vero cells: fluorescence and electron microscopy.

Vero cells were inoculated with the six species of Brucella (B. abortus, B. melitensis, B. suis, B. neotomae, B. canis, and B. ovis) and examined by fluorescence and electron microscopy. All Brucella spp. were internalized by Vero cells. In all cells except those inoculated with B. canis, the numbers of intracellular brucellae increased with time after inoculation. Intracellular brucellae were first seen within phagosomes and phagolysosomes. Subsequent localization within cisternae of the rough endoplasmic reticulum was seen with all species of Brucella, except B. canis, which was restricted to phagolysosomes. Although rough brucellae were more adherent and entered a greater number of Vero cells, intracellular replication occurred in a larger percentage of cells with smooth rather than with rough brucellae. These results suggest that phagocytosed Brucella spp. are transferred 1) to cisternae of the rough endoplasmic reticulum, where unrestricted bacterial replication takes place; or 2) to phagolysosomes in which Brucella spp. fail to replicate. The various strains of Brucella spp. differ in their ability to induce their own transfer to the rough endoplasmic reticulum.

Animals↗

PubMed1989

Serum complement activity and serum enzymes in rats after a subcutaneous injection of toxin prepared from Pasteurella multocida type D.

Toxin produced by Pasteurella multocida type D was investigated for its effect on serum complement and serum biochemistry in rats. Rats were given a sublethal single subcutaneous injection of D toxin equivalent to 0.2 microgram/kg of body weight. Serum obtained 1, 3, 5 and 7 days post-treatment was tested for complement activity, total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). Serum complement titers were significantly elevated (P less than 0.05) at all times after injection of toxin compared to rats injected with diluent and tested at the same intervals. Bilirubin was decreased but both control and D toxin-treated rats had low concentrations of bilirubin in their sera. The other biochemical constituents measured had no consistent pattern that would indicate liver damage in the rats.

Alanine Transaminase↗

PubMed1989

A protein toxin from Pasteurella multocida type D causes acute and chronic hepatic toxicity in rats.

Pasteurella toxin given subcutaneously to rats caused severe liver damage and growth suppression in doses as low as 15.6 ng. Toxin was lethal at and above 31.25 ng. Survival times were dose-dependent, and lesions differed with time of survival after toxin. Rats dead of acute toxicity had focal hepatic necrosis. Liver lesions were associated with diffuse endothelial damage, intravascular trapping of leukocytes, and degeneration of hepatocytes (characterized by glycogen depletion, development of vacuoles, and eosinophilic cytoplasmic inclusions). Endothelial cells, Kupffer cells, and macrophages had evidence of activation, e.g., increased cellular size with increases in Golgi vesicles, granules, and lysosomes. Rats with chronic toxicity (survival greater than 150 hr) had cirrhosis, intestinal villous atrophy, and markedly reduced body weight and fat. These data show that the rat is highly sensitive to toxins of Pasteurella multocida, and that even low doses of toxin cause liver injury and growth suppression.

Animals↗

PubMed1989

Pathogenesis of Brucella abortus infection of the mammary gland and supramammary lymph node of the goat.

Goats, both in late pregnancy and soon after parturition, were inoculated intravenously with Brucella abortus, and mammary glands and supramammary lymph nodes were examined by light and electron microscopy at 2 to 55 days post-inoculation. After 7 days, lymphoplasmacytic, histiocytic interstitial mastitis with a lobular and periductal distribution were detected microscopically. Brucellae, identified in tissues with immunoperoxidase staining and antibody-coated colloidal gold stain, were first seen in macrophages and neutrophils throughout mammary parenchyma, but most commonly in mammary alveoli. In subsequent samples, infected phagocytes progressively increased in number, especially in ductal and alveolar lumina, and adjacent parenchyma. B. abortus was in phagosomes and phagolysosomes in macrophages and neutrophils; degenerate and necrotic phagocytes were often filled with brucellae. Extracellular brucellae were associated with ruptured necrotic infected phagocytes. Supramammary lymph nodes draining infected mammary glands were enlarged. Lymphofollicular hyperplasia, medullary plasmacytosis, and sinus histiocytosis were seen microscopically. Brucellae were seen exclusively in macrophages, which were most often located in subcapsular and cortical sinuses. This study suggests that phagocytic leukocytes 1) transport brucellae into mammary glands; 2) provide a site for intracellular replication in mammary secretions; and 3) transport brucellae from mammary glands to supramammary lymph nodes.

Animals↗

PubMed1989

Effect of nursing on Brucella abortus infection of mammary glands of goats.

Eight 1-year-old, goats were inoculated intravenously with Brucella abortus (B. abortus) on the day of parturition and necropsied at 28 days after inoculation. Four nursed their kids and four did not (milk was not removed from the udders). Tissues and fluids were examined by bacterial isolation, light microscopy, and serologic methods. Nonnursing goats had high titers of brucellae (less than or equal to 10(8) organisms/ml) in milk (brucellae were isolated from four of four udders), had marked enlargement of supramammary lymph nodes, and had lymphoplasmacytic and histiocytic interstitial mastitis. Immunoperoxidase staining revealed that brucellae were primarily in macrophages and neutrophils of the mammary alveolar and ductal lumens and in macrophages of the subcapsular sinuses of the supramammary lymph node. In contrast, nursing goats excreted brucellae intermittently at low concentrations (less than 10(3) organisms/ml) in milk; brucellae were isolated at necropsy from one of four udders; supramammary lymph nodes were not enlarged; and mammary lesions were not seen. Brucellae were detected in more tissues other than the udder, and serum anti-Brucella antibody titers were higher in nonnursing goats than in nursing goats. The present study indicates that the failure to nurse or release milk enhances localization and replication of B. abortus in mammary glands of goats after parturition, and that mammary gland infection may result in increased systemic spread and persistence of brucellae in the host.

Agglutination Tests↗

PubMed1989

Respiratory and pericardial lesions in turkeys infected with avian or mammalian strains of Chlamydia psittaci.

Three groups of turkeys were inoculated with strains of C. psittaci (B577, VS1, TT3) from different restriction endonuclease groups. Turkeys were necropsied at 15 times through post-inoculation day 70. Birds infected with the TT3 strain were lethargic and had decreased body weight. After forced exercise, dyspnea was seen in VS1-infected turkeys. Pericarditis was the most severe lesion in TT3-infected birds. Airsacculitis and bronchopneumonia were the most severe lesions in VS1-infected turkeys. Lateral nasal adenitis was in both VS1- and TT3-infected birds. Only mild peribronchial pneumonia was in B577-infected turkeys. Chlamydial antigen, identified by light microscopy using an immunoperoxidase technique, was seen from post-inoculation days 9 through 50 in the lateral nasal gland and at earlier times in other tissue from VS1- and TT3-infected turkeys. No chlamydial antigen was detected in tissue from B577-infected birds. These studies showed that chlamydial strains from different restriction endonuclease groups are associated with distinct disease syndromes in turkeys.

Air Sacs↗