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Biomedical subjects

V Bokkenheuser

Publications and source records attributed to V Bokkenheuser.

11 recordsLinked to original sources
PubMed1993

The friendly anaerobes.

Anaerobic bacteria include the most pathogenic of microorganisms. Their primary function, however, is hardly to cause illness. They rarely are involved in epidemics or in clinically significant infections. Some organisms, e.g. lactobacilli, control the normal vaginal ecosystem, and the intestinal anaerobes probably are instrumental in restraining the growth of Clostridium difficile in human carriers. The main role of anaerobes appears to be the provision of catabolic enzymes for organic compounds that cannot be digested by enzymes of eukaryotic origin. They are needed for the catabolism of cholesterol, bile acids, and steroid hormones; they hydrolyze a number of flavonoid glycosides to anticarcinogens; and they detoxify certain carcinogens. Anaerobic enzymes are used industrially in the production of cheese; the conversion of starch to sweeteners; and the transformation of sawdust, wood chips, and waste paper to fuel. Indeed, the anaerobes may well be the gene bank on which future generations of eukaryotic organisms will rely to adapt successfully to an ever-changing world.

Animals↗
PubMed1987

21-Deoxyaldosterone excretion in patients with primary aldosteronism and 21-hydroxylase deficiency.

21-Deoxyaldosterone appears in urine in free and conjugated forms. Total excretion is best determined after acid hydrolysis (pH 1) of urine, followed by extraction, repeated chromatographic purification, and quantitation of the steroid by RIA. 21-Deoxyaldosterone excretion was normal in 70% of patients with essential hypertension (n = 18), while 30% (n = 8) had more or less elevated values. In patients with primary aldosteronism (n = 21) elevated as well as normal values of urinary 21-deoxyaldosterone were found, indicating that in some patients aldosterone may be formed not only from corticosterone but also from the 21-deoxy compound. In patients with 21-hydroxylase deficiency (n = 21) urinary 21-deoxyaldosterone was invariably elevated, whether the patients had the virilizing or salt-losing form of the disease. Although the clinical manifestations of the salt-losing form seem unrelated to the inability to convert 21-deoxyaldosterone to aldosterone, the determination of 21-deoxyaldosterone adds insight into the biosynthesis of aldosterone in primary aldosteronism and 21-hydroxylase deficiency.

Adolescent↗
PubMed1979

Fungal infections of dialysis fistulae.

Bacterial infections of dialysis access fistulae are well known in patients with end-stage renal disease, but fungal infections of these prostheses have not been reported. Two patients who presented with recurrent infections and thromboses of their grafts grew Staphylococcus aureus and Cephalosporium species. This new entity suggests a different approach to the management of clotted grafts in patients with end-stage renal disease. If fungus is isolated from the graft, extirpation of the graft and amphotericin B therapy are suggested. We review here the mycology of Cephalosporium species, in-vitro sensitivity studies, and previous reports of infection with this fungus.

Acremonium↗
PubMed1972

Vibrio fetus infection in man: a serological test.

Antigen preparations derived from a typical human strain of Vibrio fetus were employed in four tests. Of these, the indirect bacterial hemagglutination test proved most sensitive. By this test, antibodies titering 320 to 3,200 were found in five of eight patients with confirmed infections. Two patients without antibodies were on antimetabolites. Antigenic relationship with other compounds, and in particular with Brucella organisms, was not observed. No sero-reactors were found among 184 apparently healthy young men; of 401 unselected hospital patients, four had low sero-titers.

Agglutination↗
PubMed1969

Bacterial 7-dehydroxylation of cholic acid and allocholic acid.

An obligate anaerobic organism capable of dehydroxylating cholic acid to deoxycholic acid and allocholic acid to allodeoxycholic acid was isolated from feces of the rabbit. It was a member of the bacteroides group (Gram-variable, nonsporulating anaerobes). The growth of the organism was inhibited by neomycin, 10-20 micro g/ml. The existence of this organism affords a satisfactory explanation for the development of gallstones in the cholestanol-fed rabbit and for their absence in rabbits simultaneously treated with neomycin.

Animals↗
PubMed1968

Experimental cholelithiasis in the rabbit induced by cholestanol feeding: effect of neomycin treatment on bile composition and gallstone formation.

Fed cholestanol is converted by the rabbit to 5alpha-bile acids which coprecipitate with the normally occurring 5beta-bile acids to form gallstones composed of calcium and sodium glycoallodeoxycholate and glycodeoxycholate. The present study shows that oral administration of large doses of neomycin prevents gallstone formation in the cholestanol-fed rabbit and reduces the elevated concentration of allodeoxycholic acid in bile, with a reciprocal increase in allocholic acid concentration. The reduction in the concentration of allodeoxycholic acid and in the incidence of gallstones is proportional to the dose of neomycin; at a concentration of allodeoxycholic acid below about 20% of total bile acids, gallstone formation does not occur. Neomycin probably exerts its action by modifying the anerobic intestinal flora which dehydroxylate allocholic acid to allodeoxycholic acid; if so, this suggests that both hepatic and bacterial transformations are essential steps in the pathogenesis of cholestanol-induced cholelithiasis. The bile of rabbits on a normal diet contains allodeoxycholic acid (5% of total bile acids). A similar decrease in allodeoxycholic acid concentration and reciprocal increase in allocholic acid concentration is observed when neomycin is administered to rabbits on a normal diet.

Animals↗