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Biomedical subjects

A Katz

Publications and source records attributed to A Katz.

At least 451 records · Page 25Linked to original sources

Pathogenicity of a highly purified brush border membrane preparation in Heymann nephritis.

The pathogenicity of highly purified brush border membrane (BBM) antigens in Heymann Nephritis was compared to that of a crude renal tubular Fx1A preparation and was found to be equally pathogenic. Both antigen preparations induced formation of autologous antisera. Double immunodiffusion studies demonstrated a reaction of identity between anti-BBM and anti-Fx1A antisera. Both antisera detected the same number of antigenic components when reacted against BBM or Fx1A preparations. When antibody was eluted from the kidneys of rats with Heymann nephritis it reacted in vitro with the renal BBM as shown by indirect immunofluorescence. Eluted antibody also cross reacted with epididymal tubules, but not with other epithelia, showing that the pathogenic antigens have a restricted tissue distribution. Heymann nephritis was readily induced in rats, but could not be induced in dogs, suggesting a species difference in susceptibility to this form of nephritis. Injection of heterologous anti-BBM or anti-Fx1A antisera resulted in rapid localization to the GBM in a granular pattern, suggesting reaction with circulating antigen or in situ immune complex formation with native or planted glomerular components. Rats with aminonucleoside nephrosis showed BBM localization of injected heterologous antisera, demonstrating their specificity in vivo. Our data provide a rationale for using purified BBM antigens for the production of a homogeneous model of Heymann nephritis.

Animals↗

A controlled trial evaluating intensive plasma exchange in renal transplant recipients.

Sixty patients have been entered into a controlled trial evaluating the use of intensive plasma exchange (IPE) in renal transplant recipients. During the first three months post-transplant, patients receive either conventional anti-rejection therapy alone (control group) or conventional anti-rejection therapy and IPE (IPE group) for all rejection episodes. Twenty percent of the grafts in the control group versus 10% in the IPE group have been lost to rejection (p = NS). The actual three month patient and graft survival in the control group (97% and 70%), respectively, is similar to the IPE group (94% and 80%), as is the one year actuarial graft and patient survival in the two groups. No statistically significant benefit of IPE has yet been demonstrated but the trend is encouraging and the complication rate sufficiently low so as to justify continuing the study.

Clinical Trials as Topic↗

C3 deposition in cholesterol-induced atherosclerosis in rabbits: a possible etiologic role for complement in atherogenesis.

Hypercholesterolemia was induced in rabbits by feeding Purina Chow supplemented with cholesterol (5 g/kg body weight/day). The serum cholesterol levels of these rabbits increased progressively and after 3 to 5 months were 4 to 9-fold greater than those of the control animals. Decrease in total hemolytic complement was not apparent during the feeding regimen. Morphologic examination of aortae of these hypercholesterolemic rabbits showed typical atherosclerotic intimal plaques. Immunofluorescent microscopy with fluorescein (F)-labeled anti-rabbit C3 showed deposition of C3 in the intimal and inner medial layers as early as 3 months on high cholesterol diet. C3 deposits were also observed in the renal glomeruli and in the walls of coronary arteries. However, fluorescent studies failed to demonstrate the presence of IgG, IgM, and C4 at these sites. Tissues from control animals fed normal diets were negative for immunoglobulins, C3, and C4. These results suggest that the complement system may be implicated in the pathogenesis of cholesterol-induced atherosclerosis in rabbits.

Animals↗

Celiac disease associated with immune complex glomerulonephritis.

A patient with immune complex glomerulonephritis and celiac disease without dermatitis herpetiformis or other underlying disease associated with glomerulonephritis is presented. Antibodies to wheat proteins were found in serum and withdrawal of gluten from the diet resulted in disappearance of immune complexes from serum and resolution of both renal and intestinal disease, suggesting a dietary source of antigen. Despite extensive immunopathologic studies of the renal biopsy, neither dietary nor endogenous brush border antigens were demonstrated in glomeruli.

Adult↗

Immunologic detection of acoustic neuroma: preliminary report.

In an attempto to provide preoperative histologic identification of internal auditory canal and cerebellopontine angle tumors, and to attempt to detect small tumors and recurrent tumors, immunologic aspects of acoustic neuroma patients and control subjects were studied. Reactions based upon the interaction of patients' fresh lymphocytes in contact with acoustic neuroma antigens were studied by a leukocyte migration inhibition (LMI) assay and a locally developed refinement, the plasma effect assay. These were performed either preoperatively, postoperative, or both, in 17 patients with surgically confirmed acoustic neuromas and in 24 controls subjects. Preoperative tumor patients had a higher likelihood of having elevated LMI and plasma effect assay values than normals. False positive results were rare and the combination of the LMI and plasma effect assay decreased false negative responses to 20%. Meaningful conclusions must await more extensive testing but it has been demonstrated that tumor associated antigens do exist on the membranes of schwannoma cells and that most patients with an acoustic neuroma mount a cell-mediated immune response against these antigens.

Antigens, Neoplasm↗

Multiple myeloma (light chain disease) with rheumatoid-like amyloid arthropathy and mu-heavy chain fragment in the serum.

A 52 year old man presented with multiple myeloma and widespread amyloidosis involving joints, bursae- carpal tunnels, lymph nodes and subcutaneous tissue. Osteolytic bone lesions and pathologic fracture of the neck of the left femur were found. Bone marrow was infiltrated with both plasmacytes and lymphocytes. The majority of plasma cells contained large cytoplasmic vacuoles. Free kappa II type light chains and mu-heavy chain fragment were detected in the serum, and kappa II type Bence Jones protein was found in the urine. The molecular weight of the mu-heavy chain fragment was found to be approximately 50,000 daltons. An immunofluorescence study, using the double labelling technic, showed that the majority of plasmacytes in bone marrow contained both mu and kappa antigenic determinants in the cytoplasm. A review of the 12 previously described patients with mu-heavy chain fragment in the serum showed a variable clinical picture, thus their natural history and therapeutic response are difficult to evaluate at the present time. It seems that mu-heavy chain fragment can be found in a variety of clinical conditions and that mu-heavy chain disease cannot yet be accepted as a separate clinical entity.

Amyloidosis↗

Comparison of RNA synthesis by liver nuclei from rats of various ages.

RNA synthesis was studied in nuclei isolated from male Fischer F344 rats of various ages. Both the initial rate and the extent of RNA synthesis were determined in two distinct media that result in the preferential synthesis of either mRNA or rRNA by hepatocytes. Synthesis of mRNA and rRNA, as determined by [3H]-UMP incorporation into acid-insoluble material, was shown to increase 1.6- to 3-fold from 3- to 6-months. The increase in RNA synthesis during maturation was followed by a 1.6 to 2.7-fold decrease from 6- to 31-months of age depending upon the assay medium and time of incubation. The age-related changes in RNA synthesis by rat liver nuclei were shown not to be due to changes in RNase activity, UTP uptake, or UTP degradation. RNA synthesized by liver nuclei from rats of various ages was characterized by SDS--polyacrylamide gel electrophoresis. Slight age-related differences in the size distribution of RNA isolated from liver nuclei were observed when nuclei from rats of various ages were incubated with [3H]-UTP in either assay medium.

Aging↗

Kinetin Reversal of NaCl Effects.

Leaf discs of Nicotiana rustica L. were floated on NaCl in the presence of kinetin or abscisic acid. On the 5th day (14)CO(2) fixation, [(3)H]leucine incorporation, stomatal conductance, and chlorophyll content were determined. Kinetin either partially or completely reversed the inhibitory effects of NaCl while ABA had no effect.

Journal Article↗

Collection of granulocytes for transfusion. The effect of collection methods on cell enzyme release.

When granulocytes are collected by either discontinuous-flow centrifugation or filtration leukapheresis, lysozyme is released. More lysozyme is released during the filtration procedure than during the centrifugation procedure. A small amount of red cell lysis occurs during the centrifugation but not the filtration procedure. A rise in lactate dehydrogenase levels consonant with the amount of hemolysis is observed. These findings suggest that granulocytes collected by either filtration or discontinuous-flow centrifugation undergo degranulation but not lysis sufficient to cause cytoplasmic enzyme release during the donation.

Blood Transfusion↗

Pregnancy in renal transplant recipients: report of two successful pregnancies in a patient with impaired renal function.

Pregnancy in renal transplant recipients is common and, in spite of several potential problems, overall maternal and fetal outcome has been good in patients with transplants that are functioning well. The presence of renal impairment or hypertension, or both, usually leads to complications, especially in the mother. A patient is described who had a baseline creatinine clearance of about 35 mL/min-1.73 m2 and two successful pregnancies. Renal function deteriorated in the 3rd trimester of the first pregnancy but was reversible; permanent loss of function occurred in the 3rd trimester of the second pregnancy. The potential fetal and maternal risks and details of management of pregnant transplant recipients are reviewed.

Abnormalities, Drug-Induced↗