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Biomedical subjects

R Bayer

Publications and source records attributed to R Bayer.

At least 55 records · Page 3Linked to original sources
PubMed1994

Hepatitis B virus surface antigen binds to apolipoprotein H.

We have previously demonstrated that a plasma membrane-enriched fraction isolated from human liver is capable of binding recombinant hepatitis B surface antigen (rHBsAg) (P. Pontisso, M. A. Petit, M. Bankowski, and M. E. Peeples, J. Virol. 63:1981-1988, 1989). In this study we have separated the plasma membrane proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and used a ligand-blotting technique to identify a 46-kDa rHBsAg-binding protein. This protein could be removed from the membranes with a weakly acidic buffer, implying that it is peripherally bound. Examination of human serum revealed that the 46-kDa binding protein is a serum protein. Isolation of plasma lipoproteins revealed that the binding protein is in part associated with chylomicrons and high-density lipoproteins, both of which are targeted to the hepatocyte during the normal course of lipid metabolism. The binding protein was identified as apolipoprotein H (apo H), also known as beta 2-glycoprotein I, on the basis of copurification of the rHBsAg-binding activity with the apo H protein and the ability of cDNA-expressed apo H to bind rHBsAg. Serum-derived HBsAg also binds to apo H, indicating that binding is not unique to rHBsAg. Binding is saturable, requires only the small S protein of rHBsAg, and is inhibited by excess rHBsAg, antibodies to HBsAg, and antibodies to apo H. The binding activity of apo H is destroyed upon reduction, indicating that 1 or more of its 22 disulfide bonds are required for interaction with rHBsAg. The possibility that an interaction between hepatitis B virus particles and lipoprotein particles may facilitate entry of the virus into hepatocytes is discussed.

Apolipoproteins↗
PubMed1993

Malignant cystic epithelial-stromal tumor of the prostate.

A huge cystic tumor in the pelvis of a 62-year old man, cytologically by fine needle aspiration biopsy, was composed of malignant spindle cells and transitional as well as glandular epithelial cells. Histochemical, immunostaining, and ultrastructural studies of the aspirated specimens and on the radically resected tumor indicated that the neoplastic cells are of prostatic fibroleiomyomatous stromal and epithelial origin. The lesion did not extend to the urothelium of the urinary bladder. This tumor resembles the rare cystadenoleiomyofibroma of the prostate, yet the cytologic abnormalities suggest a malignant potential. Long-term follow-up and recognition of additional cases are necessary to define the biologic behavior of this neoplasm.

Adenocarcinoma↗
PubMed1993

AIDS and the limits of control: public health orders, quarantine, and recalcitrant behavior.

We undertook a survey to document the extent to which public health powers have been used to warn or restrict individuals infected with human immunodeficiency virus (HIV) whose behavior poses a risk of transmission to others. In the period from 1981 through 1990, 24 state health departments either had no mechanism for receiving reports about individuals whose behavior posed a risk of HIV transmission or took no action if they had received such reports. In states that had developed programs for dealing with such individuals, the most common response was the use of cease and desist orders. As of 1992, 10 instances of quarantine had been reported, almost all of which involved relatively brief periods of isolation. Whatever justification exists for using public health authority to confront individuals whose behavior poses a risk of HIV transmission to others, it is clear that the central focus of HIV prevention efforts must remain education, counseling, voluntary testing and partner notification, drug abuse treatment, and needle exchange programs.

Behavior↗
PubMed1993

The dual epidemics of tuberculosis and AIDS: ethical and policy issues in screening and treatment.

As the recent increase in cases of tuberculosis is addressed, there is a danger that the need for increased protection of the public health will create a climate in which the rights of individuals with tuberculosis and human immunodeficiency virus (HIV) infection may be disregarded. This paper considers ethical and policy issues in the control of tuberculosis. The authors conclude that mandatory HIV testing is not critical to effective tuberculosis control, and that although individuals infected with HIV are at increased risk for developing tuberculosis, exclusionary employment practices are not justified. Because failure to complete the course of tuberculosis treatment increases the prospect that drug-resistant strains will develop, it is crucial to require all those who commence treatment to complete their therapy. To ensure the completion of treatment, special attention must be paid to the needs of the homeless, drug users, and those with psychiatric impairments. In addition, all tuberculosis patients should begin their posthospital care under direct observation. Patients who fail to complete treatment despite efforts to encourage and facilitate their cooperation should be subject to confinement after a hearing with full due process protections.

AIDS Serodiagnosis↗
PubMed1992

HIV prevention and the two faces of partner notification.

In the cases of medical patients with sexually transmitted diseases (particularly those with the human immunodeficiency virus), two distinct approaches exist to notifying sexual and/or needle-sharing partners of possible risk. Each approach has its own history (including unique practical problems of implementation) and provokes its own ethical dilemmas. The first approach--the moral "duty to warn"--arose out of clinical situations in which a physician knew the identity of a person deemed to be at risk. The second approach--that of contact tracing--emerged from sexually transmitted disease control programs in which the clinician typically did not know the identity of those who might have been exposed. Confusion between the two approaches has led many to mistake processes that are fundamentally voluntary as mandatory and those that respect confidentiality as invasive of privacy. In the context of the AIDS epidemic and the vicissitudes of the two approaches, we describe the complex problems of partner notification and underscore the ethical and political contexts within which policy decisions have been made.

Confidentiality↗
PubMed1991

Granulocyte-macrophage colony stimulating factor for the treatment of drug induced agranulocytosis.

Drug induced agranulocytosis is an uncommon but potentially fatal complication. In some cases, it may be associated with hypoplasia and depletion of granulocytic precursors in the marrow, leading to prolonged neutropenia. We report on the use of granulocytic-macrophage colony stimulating factor (GM-CSF) in two such cases, at a dose of 10 micrograms per kilogram per day subcutaneously. The absolute neutrophil count rose above 500/mm3 in 3 days in both cases. We believe that GM-CSF expedited the recovery of granulocyte counts in our patients and warrants further study in the management of drug induced neutropenia.

Agranulocytosis↗