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Biomedical subjects

S Krakowka

Publications and source records attributed to S Krakowka.

At least 19 recordsLinked to original sources
PubMed1992

Chronic active gastritis due to Helicobacter pylori in immunized gnotobiotic piglets.

In gnotobiotic piglets, parenteral vaccination with formalin-killed Helicobacter pylori and oral vaccination with live bacteria induced H. pylori-specific serum immunoglobulins G, M, and A. Vaccination reduced but did not prevent infection by subsequent challenge with viable H. pylori. Oral vaccination with killed bacteria was less effective in inducing serum antibody and had no effect on bacterial colonization. Immunization status influenced the histologic response of piglets to challenge by H. pylori. Lymphoplasmacytic gastritis was more severe in parenterally vaccinated piglets than in the other groups. In addition, neutrophilic infiltrates and neutrophilic gland abscesses in the gastric mucosa were present in 5 of 7 parenterally immunized piglets, none of the orally immunized piglets, and only 1 of 8 infected nonimmune control piglets. Furthermore, there was a positive correlation between immunoglobulin G, M, and A titer at challenge and severity of both neutrophilic and lymphocytic inflammation. These results suggest that although vaccination does not prevent infection by H. pylori, infection of an immune host leads to increased severity and activity of gastritis.

Administration, Oral↗
PubMed1992

Role of Helicobacter felis in chronic canine gastritis.

Five gnotobiotic Beagle dogs were orally inoculated with a pure culture of Helicobacter felis. The remaining two littermates served as contact controls. Thirty days after infection, all animals were euthanatized and specimens were collected for evaluation. In infected dogs, H. felis was recovered from all areas of the stomach. Colonization was heaviest in the fundus and antrum. H. felis was not cultured from any segment of the gastrointestinal tract distal to the duodenum. Two weeks after infection, all five infected dogs had detectable IgM and IgG serum antibody to H. felis, whereas control dogs had no measurable H. felis serum antibody throughout the study. Histopathologic changes in the stomachs of infected dogs included large numbers of lymphoid nodules throughout all regions of the gastric mucosa and were most numerous in the fundus and body. A mild, diffuse lymphocytic infiltrate with small numbers of plasma cells and eosinophils was also present in the subglandular region of all portions of the gastric mucosa. Electron microscopic examination revealed large numbers of spiral-shaped H. felis in gastric mucus adjacent to or superimposed over the areas of inflammation. Occasionally, however, H. felis was observed within the canaliculi of gastric parietal cells. Histopathologic changes in the stomachs of the contact control dogs were limited to focal infiltrates of eosinophils and small aggregates of lymphocytes in the subglandular portions of the gastric mucosa in one animal. Infection with H. felis is a likely cause of naturally occurring lymphofollicular gastritis.

Animals↗
PubMed1979

Influence of adrenal corticosteroids on the susceptibility of cats to feline leukemia virus infection.

The natural resistance of adult specific-pathogen-free cats to feline leukemia virus (FeLV) was abrogated by treatment with various doses of a synthetic corticosteroid, methylprednisolone acetate (MPA), prior to either oral-nasal or i.p. inoculation of FeLV. Persistent viremia was induced in 82% (18 of 22) of MPA-treated cats versus 11% (1 of 9) of age-matched control cats. MPA-treated FeLV-inoculated cats developed prolonged lymphopenia (2 to 8 weeks postinoculation) and a delayed antibody response to the feline oncornavirus-associated cell membrane antigen. The distribution of FeLV group specific antigen in tissues of MPA-treated, FeLV-inoculated cats suggested that corticosteroids enhanced susceptibility to FeLV by impairing early viral containment in the reticuloendothelial and lymphoid tissues.

Animals↗
PubMed1979

Lymphocyte-associated immune responses to canine distemper and measles viruses in distemper-infected gnotobiotic dogs.

Cellular immune responses of peripheral blood lymphocytes to canine distemper virus and measles virus were determined in vaccinated or infected gnotobiotic dogs, using the technique of syncytia inhibition. Cross-reactivity between viruses was detected in both groups of dogs. Peak responses in vaccinated dogs occurred 11 days after vaccination and declined to base-line levels by 3 weeks, whereas responses in infected dogs were present 30 days after inoculation. Fractionation experiments with peripheral blood lymphocytes indicated that synctia inhibition is probably mediated by T lymphocytes.

Animals↗
PubMed1979

Canine distemper virus-associated hypocalcemia.

A retrospective study was done to correlate serum calcium concentrations and parathyroid gland ultrastructure to clinical, immunologic, and pathologic changes experimentally induced in gnotobiotic dogs by canine distemper virus (CDV). Dogs infected with CDV had significantly reduced serum calcium concentrations associated with ultrastructural evidence of parathyroid gland inactivity, degeneration, and viral inclusions. Although CDV-infected dogs exhibited neurologic signs, minimal lesions were present in the central nervous system. It is suggested that viral-induced parathyroid dysfunction may contribute to neutrologic disturbance of CDV infection.

Animals↗
PubMed1979

Effects of prednisolone on the development of immune responses to canine distemper virus in beagle pups.

Effects of oral prednisolone (OP) on the development of immune responses of Beagle pups to canine distemper virus (CDV) were studied. Dogs were treated with OP for 21 days, twice a day for the first 7 days, once a day for the next 7 days, and on alternate days for the last 7 days. Dogs given dosages of OP (1 mg/kg and 10 mg/kg) showed a normal in vivo immunogenic response after CDV vaccination and survived a virulent CDV challenge exposure, whereas non-treated, nonvaccinated dogs became ill or died after challenge exposure. The most marked effect of corticosteroid treatment on the immune system was the graded phytoimmunosuppressive effect upon the lymphocyte blast transformation test.

Administration, Oral↗
PubMed1978

Canine distemper virus-associated encephalitis: modification by passive antibody administration.

Gnotobiotic puppies were intraperitoneally infected with R252-canine distemper virus (CDV), and treated with normal serum (NS) or CDV-specific antibody. Resultant central nervous system (CNS) lesions were evaluated by light and immunofluorescence microscopy. Lesions in NS-treated dogs, if present, consisted of small foci of neuronal degeneration and accompanying microgliosis, restricted to grey matter of the frontal lobe. Dogs receiving anti-CDV antibody, in contrast, had extensive lesions in the brain. Laminar cortical necrosis, gliosis and astrocytic activation of the grey matter of the frontal lobe was the most consistent lesion observed. In addition, foci of cerebellar granule cell layer degeneration and necrosis was seen along with segmental poliomalacia of the spinal cord. In several dogs, eosinophilic intracytoplasmic and intranuclear viral inclusion bodies were observe in neurons. The lesions observed in these dogs are compared to previously reported lesions of CDV infection in dogs.

Animals↗
PubMed1978

Canine distemper virus and multiple sclerosis.

Serum samples from patients with multiple sclerosis (M.S.), patients with subacute sclerosing panencephalitis (S.S.P.E.), and controls were examined for virus-neutralising antibodies against measles virus (M.V.) and 2 strains of canine distemper virus (C.D.V.). M.S. and S.S.P.E. patients had higher M.V. antibody titres than controls. In contrast, no significant differences were observed in mean C.D.V.-neutralising antibody titres between M.S. patients and controls. The results, though obtained from a small number of patients, fail to implicate C.D.V. in the aetiology of M.S.

Animals↗
PubMed1978

Plasmalogenase is elevated in early demyelinating lesions.

Plasmalogenase catalyzes the hydrolysis of ethanolamine plasmalogens to long-chain aldehydes and 2-acyl-sn-glycero-3-phosphoethanolamines. During development, plasmalogenase activity parallels myelination. The enzyme is most concentrated within oligodendroglial cells and is absent from myelin. The normal function of plasmalogenase in white matter may be related to its specificity for plasmalogens that contain most of the thromboxane and prostaglandin precursors. Plasmalogenase activities are elevated in demyelinating CNS tissues including canine white matter with lesions due to distemper virus. Elevated plasmalogenase activity precedes cellular invasion and lysosomal activation as indicated by beta-glucuronidase, acid proteinase and neutral proteinase activities. The elevation of plasmalogenase activity was 4.9-fold greater than normal in an early demyelinating lesion caused by the Snyder-Hill strain of distemper virus. Phospholipases acting on phosphatidyl ethanolamine were not activated in this tissue and have activities much lower than plasmalogenase in control tissues. Plasmalogenase activities are also elevated after intracerebral injections of complement-dependent anti-myelin antibody and after ischemia. Plasmalogenase acting on the oligodendrocyte plasma membrane may be responsible for necrosis of the oligodendrocyte that results in demyelination.

Animals↗
PubMed1978

Influence of transplacentally acquired antibody on neonatal susceptibility to canine distemper virus in gnotobiotic dogs.

In utero acquistion of protective levels of neutralizing antibody to canine distemper virus (CDV) was observed in four litters of colostrum-deprived gnotobiotic and specific-pathogen-free puppies. Pregnant bitches with high antibody titers passively transferred antibody to these pups transplacentally in average titers of 1:7 to 1:16 per litter. Maternally derived antibody protected neonatal pups from otherwise fatal infection with virulent CDV. Protection was associated with a transient lymphopenia and viremia and temporary suppression of lymphocyte responses to phytohemagglutinin-P.

Animals↗
PubMed1978

Syncytia inhibition by immune lymphocytes: in vitro test for immunity to canine distemper.

A simple and rapid (24-h) assay for peripheral blood lymphocyte-associated immunity to canine distemper virus (CDV) is described. The test is based upon leukocyte-associated inhibition of CDV-induced syncytia formation in Vero cells. The technique quantitates the response morphologically, thereby eliminating the requirement for release of radiolabeled compounds. Positive results were determined from specific-pathogen-free and gnotobiotic dogs exposed to CDV via hyperimmunization, vaccination with a modified live virus vaccine, and after virulent virus infection. Preinoculation lymphocytes and lymphocytes from non-immune dogs did not inhibit CDV-induced syncytia formation. Maximum responses were observed 7 to 21 days after initial exposure and declined thereafter. The method can be used to further investigate the role of immune lymphocytes in the recovery from CDV infection.

Animals↗
PubMed1978

Influence of thymectomy on the susceptibility of cats to feline leukemia virus and lymphosarcoma.

Twelve cats were thymectomized at 5 weeks of age. Six of these cats were inoculated at 8 weeks of age and 6 at 4 months of age with the Rickard (R) strain of feline leukemia virus (FeLV), which produces a high incidence of thymic lymphosarcoma. Two groups of age-matched nonthymectomized cats were inoculated with the same FeLV-R stock. Thymectomy prior to FeLV infection had no influence on the induction of viremia or the incidence of lymphosarcoma. In the FeLV-inoculated nonthymectomized cats, lymphosarcoma developed in the thymus. In the thymectomized cats, lymphosarcoma developed in the intestine, mesenteric lymph nodes, and bone marrow, but the malignant lymphoblasts had surface markers characteristic of feline T lymphocytes. It was concluded that the presence of the thymus per se is not required for infection and oncogenesis by FeLV and that feline T lymphocytes may be transformed after peripheralization to other tissues.

Animals↗
PubMed1978

Evaluation of B-lymphocyte levels and functions in gnotobiotic dogs.

Quantitative and qualitative aspects of B-lymphocyte functions in gnotobiotic dogs and conventional dogs were determined. Using 3 different methods to identify B-cells by surface markers and 3 different methods to measure immunoglobulins (eg, serum electorphoresis, immunoelectrophoresis, and radial immunodiffusion), it was determined that gnotobiotic dogs were B-cell deficient. Related studies, however, indicate that the capacity to develop humoral immune responses was unimpaired. It is presumed that lack of immunogenic stimulation within the gnotobiotic isolation units accounts for this observation.

Animals↗
PubMed1978

Thymectomy in preweanling kittens: technique and immunologic consequences.

Thymectomy of 5-week-old kittens was accomplished by left parasternal thoracotomy, ligation of the left internal thoracic artery, and removal of the thymus from the mediastinum by traction and blunt dissection. Thymectomy had no adverse clinical effects, and neither the response of peripheral blood lymphocytes to phytomitogens nor the proportions of circulating lymphocytes bearing T- or B-cell markers differed substantially between thymectomized cats and nonthymectomized control cats. Skin allograft rejection times of the thymectomized cats (3 weeks after operation) were slightly longer than those of littermate nonthymectomized controls. We conclude that removal of the thymus in preweanling kittens does not have important physiologic or immunologic consequences.

Animals↗
PubMed1978

Procedure for processing of central nervous system tissue for immunofluorescence, light, and electron microscopic evaluation.

A rapid and simple procedure has been developed for the simultaneous localization of viral antigen in central nervous system tissues by immunofluorescnece and concomitant correlation with viral induced lesions in the contralateral brain hemisphere. In this study, one-half of the brain was excised from the dog under deep general anesthesia and samples were collected for immunofluorescence by snap freezing in liquid nitrogen. The other half of the brain was perfused under pressure with a buffered glutaraldehyde-paraformaldehyde mixture for subsequent light microscopic and ultrastructural evaluation. The technique was useful in studying central nervous system diseases in large outbred experimental subjects in which economic and other considerations developed for tissue processing in rodents was not feasible.

Animals↗
PubMed1978

Signs of impending parturition in the laboratory bitch.

The most consistent and reliable physical sign of impending parturition in pregnant laboratory beagle bitches was palpable relaxation of pelvic and abdominal musculature. A drop in rectal temperature was of some value but was found to be too variable between individuals to use as the sole criterion. Abrupt changes in attitude or appetite were the chief behavioral changes observed. Since the institution of a standardized record form for all pregnant dogs, 15 consecutive term litters have been successfully derived from pregnant dogs into gnotobiotic life isolation units.

Animals↗