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Biomedical subjects

J Nicolet

Publications and source records attributed to J Nicolet.

At least 181 records · Page 10Linked to original sources
PubMed1981

Cell-mediated and humoral immune response in swine after vaccination and natural infection with Mycoplasma hyopneumoniae.

Litters of pigs were vaccinated with inactivated Mycoplasma hyopneumoniae organisms in Freund's complete adjuvant. The cell-mediated and humoral immune response following vaccination was investigated, and the protective effect of the induced immunity was assayed. The cell-mediated immune response to whole M hyopneumoniae organisms was determined as incorporation of tritiated thymidine, using a microculture system. After vaccination, detectable sensitization of peripheral blood lymphocytes was induced. The inoculations induced considerable antibody titers in the animals. The animals were challenged exposed by natural infection and protective effect of the cell-mediated or humoral response could not be detected.

Animals↗
PubMed1980

Growth medium constituents contaminating mycoplasma preparations and their role in the study of membrane glycoproteins in porcine mycoplasmas.

Several Mycoplasma and Acholeplasma species chosen at random and solubilized with sodium dodecyl sulphate showed a common periodic acid-Schiff positive band with an apparent molecular weight of about 64 000, when examined by polyacrylamide gel electrophoresis. Another more cathodic minor band was detected in M. hyopneumoniae and M. flocculare. The common periodic acid-Schiff positive band appeared when a precipitate of serum constituents of the uninoculated growth medium after incubation was examined. The minor band was identified as a serum glycoprotein contaminating mycoplasmas grown in the presence of swine serum. We draw attention to the compounds as a possible source of error in serological tests or in the lymphocyte stimulation response. After lithium diiodosalicylate solubilization and aqueous phenol extraction, polyacrylamide gel electrophoresis showed a periodic acid-Schiff positive band in membranes from M. hyopneumoniae (molecular weight 75 000) and M. hyorhinis (molecular weight 80 000), suggesting the presence of a membrane glycoprotein. Such a glycoprotein was absent from A. granularum. Since the common periodic acid-Schiff positive band was not extracted by aqueous phenol, this growth medium constituent did not contaminate the preparations of membrane glycoproteins. However, the minor band was present in glycoprotein preparations of M. hyopneumoniae grown in the presence of swine serum.

Acholeplasma↗
PubMed1980

Tween 20 soluble proteins of Mycoplasma hyopneumoniae as antigen for an enzyme linked immunosorbent assay.

The preparation of an antigen of Mycoplasma hyopneumoniae containing selected proteins after treatment with the neutral detergent Tween 20 and purification on Sephadex G25 is described. The antigenic activity and the specificity were determined by means of an enzyme linked immunosorbent assay and compared with that of a whole-cell, SDS-solubilised antigen. The Tween 20 purified antigen showed a comparable activity but a higher specificity.

Animals↗
PubMed1980

Aspergillus nidulans and Aspergillus fumigatus as causal agents of bovine mastitis.

Five cases of bovine udder aspergillosis diagnosed clinically and confirmed by repeated demonstration of fungal hyphae in KOH preparations and isolation of the organism from milk sediments are described. In one case the fungus was identified as Aspergillus nidulans, in the other 4 cases as A. fumigatus. The most pronounced features in altered udders were multiple abscesses with distinctive colonies of fungal hyphae in the centres, embedded in cell detritus, neutrophils and macrophages. These purulent centres were surrounded by varying amounts of granulation tissue. Two cases revealed purulent galactophoritis suggesting an ascending infection through the lactiferous ducts. In one case no changes of the milk ducts were observed. In this case haematogenous infection of the udder cannot be excluded.

Animals↗
PubMed1979

Antibody coated bacteria in urine sediment from cattle infected with Corynebacterium renale.

Using the fluorescent antibody test, the presence of antibody-coated bacteria in 10 out of 17 urine sediment samples from cattle infected with Corynebacterium renale is described. These antibodies were mainly of the immunoglobulin class IgG, and to a lesser extent IgA. This finding is characteristic for infections of the upper urinary tract (pyelonephritis). In seven samples no antibody coating of the bacterial surface was detected. In these cases an infection of the lower urinary tract (cystitis) is suggested.

Animals↗
PubMed1977

Paraplegia due to actinomyces viscosus infection in the cat.

In a 3 year old female domestic cat a suppurative, granulomatous lesion of the tail and sacral area penetrated into the epidural space, causing paraplegia. A viscosus was isolated from the inflammatory tissues. A comparative light and electronmicroscopic study of the bacterial elements and the architecture of the granules (Drusen) show that the latter are in-vivo microcolonies of the agent.

Actinomyces↗
PubMed1977

Histopathological and immunohistological changes in the rabbit lung after experimental exposure to a purified enzyme of Micropolyspora faeni.

Rabbits were exposed intratracheally to enzyme 1, a highly immunogenic esterase isolated from Micropolyspora faeni. A single exposure to active enzyme 1 induced no histologically or immunohistochemically detectable changes in the lungs of experimental animals, while signs of focal interstitial and perivascular inflammatory reactions were evident following a course of three exposures to the enzyme. Interstitial pneumonia with characteristic generalized vasculitis and perivasculitis was produced following seven or nine inoculations. An enzymatically inactive preparation of enzyme 1, even by repeated administration, proved ineffective in eliciting pneumonia. Intracellular antigen within macrophages/histiocytes was demonstrated in the lungs of all experimental animals, including those which had been exposed to inhibited enzyme. Repeated exposure to the enzymatically active preparation resulted in the deposition of immunoglobulin and complement in association with vascular endothelia and in the walls of small- and medium-sized blood vessels; both immunoglobulin and complement could also be demonstrated within macrophages/histiocytes. On the basis of these findings it is concluded that (1) Farmer's lung-like interstitial pneumonia may be produced in rabbits by exposure to a purified, enzymatically active derivative of M. faeni, (2) an important pathogenic principle of the disease may consist in the rapid vascular deposition of immune complexes (type III reaction), and (3) damage by direct enzyme action may prove to contribute significantly in eliciting tissue damage by (an) ancillary mechanism(s) not yet understood.

Animals↗