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Biomedical subjects

J F Brown

Publications and source records attributed to J F Brown.

At least 91 records · Page 5Linked to original sources
PubMed1981

Development of immunity to porcine rotavirus in piglets protected from disease by bovine colostrum.

Bovine colostrum with rotavirus-neutralizing activity was fed for 10 days to two groups of piglets, one of which was inoculated intranasally with a rotavirus of porcine origin. A third group, which did not receive colostrum, was also inoculated with the virus, and these piglets developed diarrhea, excreted rotavirus in the feces, and died 6 days after infection. In contrast, the infected piglets fed with bovine colostrum remained healthy, although they developed antibody to rotavirus. Twenty-seven days after the primary inoculation, piglets in the colostrum-fed groups were inoculated intranasally with virus. Those in the previously unexposed group became clinically ill and excreted rotavirus, whereas those which had experienced a previous subclinical infection (the colostrum-fed, virus-inoculated group) remained healthy. It was concluded that bovine colostrum protected piglets from the clinical effects of a porcine rotavirus and that these animals developed an immunity which prevented subsequent disease.

Animals↗
PubMed1978

Gastrointestinal microecology of BALB/c nude mice.

The aerobic, facultative, and anaerobic microorganisms cultivable from the stomachs, ilea, ceca, and colons of BALB/c athymic (nu/nu) mice (normal and wasting), thymus-implanted normal nude mice, and their heterozygous (nu/+) littermates were investigated. Ninety-one species representing 23 genera of bacteria and yeasts were isolated from the 27 mice. The wasting nude mice showed significantly lower numbers of lactobacilli in their stomach microbiota than did mice from the other three groups. The littermate animals appeared unique among the four groups in having corynebacteria as a major constituent of their stomach and ileal flora. The normal nude mice appeared to have a more diverse anaerobic stomach flora than their heterozygous littermates. These minor differences are discussed with respect to possible immunological, physiological, and environmental factors as their cause. Because the gastrointestinal microfloras of the mice from the four groups were not radically divergent from each other, it was concluded that loss of T-cell function does not dramatically alter the makeup of the cultivable gastrointestinal microflora in these mice.

Aerobiosis↗
PubMed1977

Transparent plastic incubator for the anaerobic glove box.

An incubator designed for use inside an anaerobic glove box is described. The incubator is made of transparent plastic material, has sliding plastic doors, and can be made in various sizes from readily available materials.

Journal Article↗
PubMed1977

Pulmonary and rhinocerebral mucormycosis. Successful outcome with amphotericin B and griseofulvin therapy.

An ominous prognosis is associated with combined pulmonary and rhinocerebral mucormycosis (phycomycosis). We report the case of a diabetic patient with ketoacidosis who had extensive pulmonary and rhinocerebral mucormycosis that responded satisfactorily to amphotericin B and griseofulvin therapy. The affected lung is completely atelectatic and has remained so for 12 months without evidence of necrosis or abscess formation.

Adult↗
PubMed1976

The interaction of macromolecular solutions with macromolecular monolayers adsorbed on a hydrophobic surface.

In order to elucidate the general patterns of intermacromolecular surface interactions that may be involved in hemocompatibility phenomena, monolayers of representative macromolecules on an octadecylsilylated glass surface were exposed to solutions of other macromolecules, and the changes in interfacial composition were characterized by zeta potential-pH titration curves, as measured by alternating flow streaming current analysis and, in some cases, by radiotracer labeling. Experiments with poly(vinylpyrrolidone) (PVP), a blood-compatible linear polymer; bovine serum albumin (BSA), a representative serum protein; whole human serum (HS), a complex mixture of proteins; and erythrocyte surface glycoprotein (GP), an extended-chain macromolecular amphiphile, showed the following: 1) Penetration of the original monolayer occurred within 24 hr in 9 of the 12 possible cases; it did not occur for BSA or HS monolayers exposed to PVP, and probably not for PVP exposed to GP. 2) In all cases, penetration was accompanied by no more than partial displacement of the original monolayer, thereby generating a mixed monolayer. Each of the six possible binary mixed monolayers could be obtained by at least one of the two possible mixing sequences. 3) In the three binary systems containing BSA, the formation of the mixed monolayer could be related to increased adsorption in the two-component system. 4) The two components of the mixed monolayers were not equally distributed across their thicknesses: thus, the outer surfaces of the PVP-BSA and (at neutral pH) the PVP-HS mixed monolayers contained only PVP; that of the BSA-HS mixtures only HS. In the PVP-HS, and probably the GP-BSA and GP-HS mixed monolayers, the composition of the outer surface appeared pH-dependent. The resultant zeta potential versus pH profiles in the latter two cases resembled those of intact blood cells. The results suggest that neither the compact monolayers of globular proteins nor the diffuse monolayers of randomly coiled water-soluble polymers can, by their prior adsorption on a synthetic surface, prevent the subsequent adsorption of other globular macromolecules. It is possible that the randomly coiled polymers may impede the adhesion of platelets to the substrate since the results indicate that the adsorption of such polymers causes a displacement of the shear plane.

Adsorption↗
PubMed1976

Polymer membrane sensors for continuous intravascular monitoring of blood pH.

A new type of pH sensor suitable for chronic intra-vascular implantation by virtue of its small size, flexibility, and ruggedness was constructed and evaluated. The pH-sensitive element was a thin film of an elastromeric polymer made ion permselective to proteons by adding a lipophilic, specific H+-ion carrier. This was coated onto small diameter silver wires to form sensors. In preliminary trials in anesthetized dogs, the sensors permitted continuous, accurate in vivo blood pH measurement with rapid response (less than 0.1 s).

Blood↗
PubMedDate not supplied

PCB metabolism, persistence, and health effects after occupational exposure: implications for risk assessment.

Analysis of the kinetics and congener selectivities for PCB metabolism in occupationally exposed workers shows that the lipid PCB concentrations required for the induction of P4502B cytochromes must be > 20 mg/kg; for inducing P4501A and the associated toxic effects, > 600 mg/kg. The observed kinetic behavior indicates that the reported statistical associations between serum PCB levels and certain disease states in the general population (lipid PCBs generally 0-2 mg/kg) probably arise from correlations with the factors that control steady-state xenobiotic levels in human serum (notably, P450 activity and serum lipids) rather than from novel toxic activities of the PCBs.

Body Burden↗