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Biomedical subjects

R Baumal

Publications and source records attributed to R Baumal.

At least 163 records · Page 9Linked to original sources
PubMed1971

Synthesis, assembly, and secretion of gamma globulin by mouse myeloma cells. 3. Assembly of the three subclasses of IgG.

The synthesis, assembly, and secretion of the three major subclasses of mouse IgG has been examined in 14 myeloma tumors and two cultured cell lines as well as in the cells from the popliteal lymph nodes of immunized mice. The total amount of IgG synthesized was between 15 and 43% of the cytoplasmic proteins made during a 15 min period. H(2) and H(2)L were the major precursors of IgG(2a) and IgG(1) but, in all of the tumors, HL was also an intermediate. In contrast, HL was a major precursor of IgG(2b). Most of the noncovalent and covalent assembly of IgG occurred after release of the newly synthesized H and L chains from the polyribosomes and assembly was not completed until 10 min or more after the synthesis of the polypeptide chains.

Animals↗
PubMedDate not supplied

The value of immunohistochemical studies using antibody to S100 protein in dermatopathology.

The distribution of S100 protein in normal skin and various tumors involving skin was assessed using rabbit antibody to S100 protein in an immunoperoxidase reaction. In normal skin, S100 protein was detected in the epidermis (melanocytes and Langerhans' cells), dermis (Schwann cells, Pacinian and Meissner's corpuscles, and interdigitating reticulum cells), cells of the sweat gland apparatus, and in chondrocytes. In tumors involving skin, S100 protein was present in nevi, malignant melanomas, histiocytosis X, mixed sweat gland tumors, neural tumors, chondromas, and chondrosarcomas. Detection of S100 protein by immunostaining was useful in understanding the histogenesis of various skin tumors and in assessing the diagnosis and prognosis of a variety of skin lesions encountered in surgical pathology.

Calcium-Binding Proteins↗
PubMedDate not supplied

Sensitivity of multidrug resistant KB-C1 cells to an antibody-dextran-adriamycin conjugate.

Resistance to adriamycin is an important limitation to the use of the drug in cancer therapy. This resistance is often a manifestation of the multidrug resistance phenotype. Studies with multidrug resistant cell lines in vitro may be useful to design approaches for overcoming the drug resistance encountered clinically. We investigated the possibility of overcoming adriamycin resistance in vitro in a multidrug resistant subline (KB-C1) of human epidermal carcinoma (KB-3-1) cells using antibody-mediated drug targeting. Adriamycin was conjugated through a dextran bridge to a monoclonal antibody (mAb), 10B, which bound to KB-3-1 cells with a Ka of 4 x 10(8) M-1. The conjugate retained immunoreactivity with the target cells. Adriamycin (0.2 micrograms/ml) caused a 50% inhibition of DNA synthesis in KB-3-1 cells, but failed to achieve this degree of inhibition in KB-C1 cells at levels as high as 10 micrograms/ml. In contrast, the 10B-dextran-adriamycin conjugate produced 50% inhibition of DNA synthesis in KB-C1 cells at a concentration of 2.5 micrograms/ml. This was significantly more cytotoxic than adriamycin conjugated to control mAb or bovine serum albumin (BSA). Similarly, a 10B-recombinant ricin A (rRA) immunotoxin was more cytotoxic to KB-C1 cells than free rRA. These results indicate that adriamycin resistance in KB-C1 cells in vitro can be partially overcome by specifically targeting adriamycin to the cells using an 10B-dextran-adriamycin conjugate. This approach may be useful in overcoming adriamycin resistance encountered during the course of cancer therapy.

Antibodies, Monoclonal↗
PubMedDate not supplied

Interstitial foam cells in renal biopsies: an aid in differentiating idiopathic membranoproliferative glomerulonephritis (type I) and membranoproliferative glomerulonephritis associated with systemic lupus erythematosus.

A patient with nephrotic syndrome whose renal biopsy showed membranoproliferative glomerulonephritis (MPGN) is described. Clinical and laboratory findings included an erythematous malar flush, proteinuria, casts in the urine and a positive antinuclear factor. Hence, it was not clear whether the MPGN was idiopathic, secondary to early systemic lupus erythematosus (SLE) or mainly a renal form of SLE. Treatment with prednisone and azathioprine was unsuccessful, and no new clinical or serological features of SLE appeared. A second renal biopsy 19 months later showed MPGN and large numbers of interstitial foam cells. The finding of foam cells prompted a review of other renal biopsies which were diagnosed as MPGN type I and diffuse proliferative lupus nephritis (DPLN), including lupus-associated MPGN. Nine of thirty-eight (24%) MPGN type I but none of 22 DPLN biopsies contained interstitial foam cells. Therefore, finding foam cells in a renal biopsy may help in differentiating MPGN type I from lupus-associated MPGN.

Adolescent↗