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Biomedical subjects

S Kochwa

Publications and source records attributed to S Kochwa.

At least 19 recordsLinked to original sources
PubMed1988

Vincristine and prednisone prolong the survival of patients receiving intravenous or oral melphalan for multiple myeloma: Cancer and Leukemia Group B experience.

A total of 589 patients with previously untreated multiple myeloma were randomized to receive daily oral melphalan, pulse-dose intravenous (IV) melphalan, carmustine (BCNU), or lomustine (CCNU). All patients received an initial tapering course of prednisone (Pred). During week 22 (day 154), patients were randomized to receive or not to receive additional therapy with vincristine (VCR) (1 mg/m2) and prednisone (0.6 mg/kg/d for seven days) at 8-week intervals. The influence of VCR/Pred was determined in 302 patients who remained on study beyond 22 weeks after initial therapy. VCR/Pred converted a significant percentage of nonresponders to responders in patients treated with melphalan (55% v 19%, P = .002), but not in patients treated with a nitrosourea (48% v 23%, P = .06). Survival beyond week 22 was significantly longer following the addition of VCR/Pred in patients receiving melphalan (median, 35.3 months v 27.0 months; P = .003) but not in patients receiving BCNU or CCNU (median, 28.1 months v 26.2 months; P = .91). These differences were seen both for oral and IV melphalan. A trend for beneficial effect of VCR/Pred was definitely seen in the good-risk patients (P = .03) but only suggestive for poor-risk patients (P = .12). Following adjustment for VCR/Pred effects, there were no differences in the survival of patients receiving any of the four initial treatments.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Quantitative cerebrospinal fluid IgG measurements as a marker of disease activity in multiple sclerosis.

The value of various parameters of reporting quantitative cerebrospinal fluid (CSF) IgG levels to indicate disease activity in 34 patients with clinically definite multiple sclerosis was examined. IgG alone correlated significantly with increasing degree of disability and increasing number of clinical central nervous system lesions. There was also a trend toward higher mean IgG levels when the course was relapsing and progressive as opposed to progressive or relapsing. For the IgG index, the relationships were the inverse of that noted with IgG alone. IgG-albumin ratio and IgG synthetic rate did not correlate significantly with course, number of CNS lesions, or degree of disability, and there was no statistically significant relationship between any parameter of reporting quantitative CSF IgG and age, duration of disease, history of recent exacerbation, or area of first involvement in the nervous system. We conclude that although newer methods of reporting CSF IgG elevations in multiple sclerosis are more sensitive and some of them, more specific, in confirming a diagnosis than CSF IgG alone, this parameter remains the best marker of disease activity in individual patients.

Humans↗
PubMed1986

Single, sequential, and multiple alkylating agent therapy for multiple myeloma: a CALGB Study.

Four intravenous (IV) alkylating agent regimens were tested in 615 previously untreated patients with multiple myeloma. Patients were randomized to receive melphalan, cyclophosphamide, and carmustine in combination (MCBP), sequentially (Seq-MCBP), or in combination with doxorubicin (MCBPA). The fourth group received IV melphalan (MP) as the only alkylating agent. All groups received a tapering dose of prednisone. Toxicity was similar for all regimens although the nadir of cytopenia was reached more quickly for the regime including melphalan only. Response as measured by reduction in myeloma protein or other parameters were similar for the four treatments. Survival was significantly poorer for the group receiving the alkylating agents in sequence. The survival of high tumor cell load patients who were azotemic was better in the groups treated with IV MP or with the combination of IV MCBP. In view of the simplicity and probable cost savings attached to single-agent treatment, a melphalan/prednisone regimen should be considered as initial therapy for all patients with myeloma.

Adult↗
PubMed1985

Isolation and partial characterization of a fatty acid binding protein in rat liver plasma membranes.

When [14C]oleate-bovine serum albumin complexes were incubated in vitro with rat liver plasma membranes (LPM), specific, saturable binding of oleate to the membranes was observed. Maximal heat-sensitive (i.e., specific) binding was 3.2 nmol/mg of membrane protein. Oleate-agarose affinity chromatography of Triton X-100-solubilized LPM was used to isolate a single 40-kDa protein with high affinity for oleate. On gel filtration, the protein comigrated with various fatty acids but not with [14C]bilirubin, [35S]sulfobromophthalein, [14C]taurocholate, [14C]phosphatidylcholine, or [14C]cholesteryloleate. A rabbit antibody to this membrane fatty acid-binding protein gave a single precipitin line with the antigen but no reactivity with concentrated cytosolic proteins, LPM bilirubin/sulfobromophthalein-binding protein, or rat albumin or other rat plasma proteins. The antibody selectively inhibited heat-sensitive binding of [14C]oleate to LPM. Immunofluorescence studies localized the antigen in liver-cell plasma membranes as well as in other major sites of fatty acid transport. These data are compatible with the hypothesis that this protein may act as a receptor in a hepatocellular uptake mechanism for fatty acids.

Animals↗
PubMed1979

Mechanochemical properties of brain clathrin: interactions with actin and alpha-actinin and polymerization into basketlike structures or filaments.

Two molar urea (pH 7.5) and column chromatography on Sepharose 4B were used to separate clathrin (coat protein) from the membrane of coated vesicles from bovine brain. Lytron (polystyrene) particles were used for study of the interaction of clathrin with contractile proteins. Muscle G-actin, F-actin, and alpha-actinin were bound by clathrin-coated Lytron particles, while no interaction was found when muscle tropomyosin and serum albumin were tested. Clathrin molecules dispersed in a solution of 20 mM Tris-HCl (pH 7.5) were found to be elongated. When the pH was adjusted from 7.5 to 6.5, clathrin molecules associated into basketlike or cage structures similar in size and shape to those observed in enriched preparations of coated vesicles. Below pH 6.0, cages or baskets became amorphous aggregates. Raising the pH from 6.5 to 8.0, addition of 5-10 mM ATP or EDTA, or addition of 200 mM KCl resulted in the dissassembly of baskets and the formation of filamentous arrays of various widths. Because of clathrin's biochemical and biophysical properties, its interaction with contractile proteins, and its presence in the membrane of vesicles of various cell types, we classified clathrin in the group of mechanochemical proteins.

Actinin↗
PubMed1979

Nonuniform distribution of occult blood in feces.

Inhibition of anti-Rh29 by erythrocytic stroma in feces was devised as a specific test for fecal occult blood. The sensitivity of this test was equivalent to that of a standard Hemoccult test, namely, 10(8) erythrocytes/g feces. Comparison of results of this test with results of Hemoccult tests of random stool specimens and of stools following ingestion of autologous blood revealed nonuniform distribution of occult blood in feces. The extent of nonuniformity was determined by testing samples of stool specimens following ingestion of 51Cr-labeled autologous blood. This allowed comparison of Hemoccult, inhibition of anti-Rh, and radioactivity, and showed that the three labels could separate in the feces and that some single small samples of feces could be relatively free of blood while blood was readily demonstrable in other portions. The variability of standard Hemoccult test was somewhat reduced by dispersing the feces in distilled water before performing the test.

Chromium Radioisotopes↗
PubMed1979

Response to therapy in IgG myeloma patients excreting lambda or kappa light chains: CALGB experience.

Sixty-eight previously untreated patients with IgG myeloma who were entered into five protocols of Cancer and Leukemia Group B (CALGB) were studied in order to determine the possible influence of excretion of kappa versus lambda urinary light chains on responses to treatment and survival. All patients in these protocols were included if the serum and urine protein abnormalities were confirmed by one of the two group reference laboratories. Pretreatment characteristics of the two groups of patients did not differ significantly. Of 44 patients with kappa Bence Jones proteinuria, 19 patients (43%) had good responses to treatment, whereas only 3 of 24 patients (13%) with lambda Bence Jones proteinuria had good responses (p = 0.02). Survival for the patients excreting kappa light chains was significantly better than survival for patients excreting lambda chains (median survival 31 versus 12 mo, p = 0.02).

Humans↗
PubMed1979

Improved survival of increased-risk myeloma patients on combined triple-alkylating-agent therapy: a study of the CALGB.

Two hundred fifty-two previously untreated evaluable patients with multiple myeloma were entered into a study testing a regimen of three intravenous alkylating agents, melphalan, cyclophosphamide, and carmustine (BCNU), given in combination (BCMP) against a regimen employing oral melphalan (MP). Both regimens included a tapering course of prednisone. Objective responses based on the Myeloma Task Force criteria were significantly more frequent in the group receiving BCMP. Survival for the entire group of BCMP-treated patients was not significantly better than that for MP-treated patients (p = 0.62). However, when the survival of the poor-risk (high tumor cell load) group of patients treated with BCMP was compared with the survival of the poor-risk (high tumor cell load) group of patients treated with MP, an improvement in survival attributable to BCMP therapy was seen (p = 0.049 and 0.02, respectively). In the good-risk (low and intermediate tumor cell load) group, BCMP treatment resulted in a trend toward poorer survival, but this did not achieve statistical significance (p = 0.080 and 0.23, respectively). These results indicate that optimal therapy in myeloma may be dependent on the extent of disease at the time of first treatment. Additional studies to explore the effects of treatment intensity and duration are needed in order to design improved myeloma treatment based on the patient's extent of disease.

Alkylating Agents↗
PubMed1977

alpha-Actinin and tropomyosin interactions with a hybrid complex of erythrocyte-actin and muscle-myosin.

alpha-Actinin isolated from dog muscle was used to incite antibodies in rabbits, Antibodies, purified by affinity chromatography on CNBr-Sepharose coupled with alpha-actinin and then ferritin-labeled were found to localize on the Z disc of muscle sarcomeres. Molecules of alpha-actinin as an adsorbed monolayer on the surface of polystyrene Lytron particles could bind muscle-actin and tropomyosin from solution. Both the ATPase activity and superprecipitation of an erythrocyte-actin and muscle-myosin hybrid actomyosin complex were altered by alpha-actinin, while tropomyosin diminished these alpha-actinin effects. The binding properties of alpha-actinin are consistent with those of an anchoring protein for microfilaments in nonmuscle cells.

Actinin↗
PubMed1976

Pathogenesis of shigella diarrhea. Serum anticytotoxin antibody response produced by toxigenic and nontoxigenic Shigella dysenteriae 1.

The serum antitoxin response to the cytotoxin contained in preparations of Shigella dysenteriae 1 (Shiga's bacillus) exotoxin was studied in natural and experimental infections of man. Natural infection resulted in the rapid appearance of toxin-neutralizing antibody, which disappeared some time between 9 and 18 mo after infection. Experimental infection of human volunteers provided the opportunity to study immunoglobulin class of the antibody in sera obtained serially from 7 to 50 days after infection. Neutralizing antibody was present only in the IgM fraction isolated by sucrose density gradient ultracentrifugation. This was confirmed by the use of solid-phase immunoaffinity chromatography. Even though the time-course and immunoglobulin class of the antitoxin antibody response was similar to that previously observed for anti-O polysaccharide antibody, the biologically active cytotoxin was shown to be highly susceptible to destruction by proteolytic enzymes. Sera from subjects infected with a virulent invasive chlorate-resistant Shiga mutant thought to be "nontoxigenic" also contained antibody which was similarly restricted to the IgM fraction. Biologically active cytotoxin was recovered when this mutant organism was grown in liquid media with controlled ion concentration. The mutant cytotoxin was heat labile, neutralized by antiwild-type cytotoxin antibody, and was separable by isoelectric focusing into two fractions with pI 7.2 and 6.1 like the wild-type toxin. These studies show that cytotoxin antigen is produced during in vivo infection with Shiga bacilli, resulting in a serum antitoxin antibody response. Without explanation is the restriction of the antibody to the IgM class and lack of evidence for an IgG antibody to the protein cytotoxin. Finally, mutant strain 725, previously designated "nontoxigenic," was shown to produce biologically active cytotoxin in vitro and, in experimentally infected volunteers, to result in a serum IgM antibody similar to that observed during infection with the wild-type strain.

Antibodies, Bacterial↗
PubMed1976

Idiotypic specificities of anti-Rh antibodies.

Idiotypic antibodies were produced in rabbits to Rh antibodies isolated from the serum of an individual with high Rh antibody titer. These antisera after absorption with blood IgG failed to react with immunoglobulins lacking anti-Rh activity. They agglutinated cells coated with the immunizing antibody to high titers. Two other anti-Rh coats out of 22 tested also were agglutinated but to considerably reduced titers indicating a degree of anti-Rh cross specificity. Four other antisera made to red cells coated with different anti-Rh antibodies showed definite but weaker idiotypic specificity. Both the idiotypic and cross-idiotypic antigens of the Rh antibodies were completely blocked when univalent fragments of the Rh antibodies were bound to antigen on the red cell.

Animals↗
PubMed1975

A solid-liquid biphasic model for characterization of properties of muscle and platelet contractile proteins.

Actomyosin, myosin, and actin from different sources are adsorbed, apparently as a monolayer, by polystyrene particles teins for 1 mg of Lytron were about 10-7 liters mol-1, while heterogeneity indices (alpha) varied from 0.70 to 1.0 presumably as a function of spontaneous aggregation in the liquid phase. Adsorption was irreversible. Orientation of absorbed molecules permitted association of bound muscle actin with platelet or muscle myosin. The association constant of the former reaction was 2.78 times 10-6 liters mol-1. Enzymatic properties of adsorbed actomyosin, Mg2+ATPase activity was abolished, but association of myosin with bound actin, or association of actin with bound myosin was accompanied by restoration of Mg2+ATPase activity. Every subunit of F-actin strands, unless F-actin had been fully depolymerized to G-actin, could bind myosin and activate Mg2+ATPase activity. Immunogenic characteristics of muscle myosin were enhanced by Lytron adsorption. Elicited antibodies showed selective specificity for an antigenic determinant located near or at the actin combining site of muscle myosin. Antibodies did not react with actomyosin. Antibodies prevented association of actin with muscle myosin because they inhibited both superprecipitation and development of Mg2+ATPase activity.

Actins↗
PubMed1975

Chemical typing of immunoglobulins and their subtypes.

An analytical method, described herein, is based on differences in the primary structure of immunoglobulins and their subclasses. This method is independent of the supply of specific antisera, is simple and inexpensive to perform, and is fully reproducible. The distribution of subtypes of IgG and IgA resembled published results from immunological studies. Finding of differences in the distribution of subclasses of IgG proteins in patients with light-chain disease or in the absence of M-protein is of special interest.

Autoradiography↗