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Biomedical subjects

R Schwartz

Publications and source records attributed to R Schwartz.

At least 217 records · Page 12Linked to original sources
PubMed1987

Cognitive impairment and the quality of care in long-term care institutions.

This study sought to determine whether cognitively impaired elderly in long-term care institutions receive a lower quality of care than do the non-impaired. The quality of care for each of 136 elderly in nine units for independent, frail and nursing residents was examined through the tracer method. On the basis of the MSQ test and an assessment by the ward nurse, a composite scale for measuring cognitive impairment was developed. Sixty-one percent of the elderly were found to suffer moderate to severe cognitive impairment. The cognitively impaired patients were found to receive poorer nursing care and staff were unaware of the existence of a greater proportion of their medical problems, compared with the non-impaired. The findings suggest that the lower quality care provided to the cognitively impaired is related to their greater behavioral and social problems such as aggressiveness and apathy. Staff members are apparently less inclined to have contact with patients displaying such problems. Changes of referral policies and training programs for institutional staff on the care of the cognitively impaired elderly are necessary in order to improve care for this group.

Aged↗
PubMed1987

Amniotic fluid erythropoietin correlates with umbilical plasma erythropoietin in normal and abnormal pregnancy.

In the human fetus, elevated plasma erythropoietin levels have been found in high-risk pregnancies at delivery. We examined the relationship of amniotic fluid erythropoietin and umbilical plasma erythropoietin at delivery in 17 normal pregnancies, 41 hypertensive pregnancies, and 37 insulin-treated diabetic pregnancies terminated by elective cesarean section without labor. An additional 27 insulin-treated diabetic patients were studied after undergoing variable durations (86-1184 minutes) of labor. Erythropoietin was analyzed using a highly sensitive and specific radioimmunoassay technique. Fetal plasma erythropoietin concentrations were elevated above the control upper range (50.3 mU/mL) in 59% of the hypertensives and in 38% of the diabetics. The amniotic fluid erythropoietin values were significantly lower than the umbilical plasma erythropoietin values in each study group. Although the umbilical plasma erythropoietin values in the abnormal pregnancy groups differed considerably from the corresponding levels in the controls, the ratio of amniotic fluid erythropoietin to umbilical plasma erythropoietin was approximately the same in controls, hypertensives, and diabetics. Furthermore, the plasma and amniotic fluid levels (In transformed) correlated highly significantly in all three individual groups in absence of labor. In the diabetic labor group, this relationship was nonsignificant. We conclude that in the absence of labor, amniotic fluid erythropoietin reflects fetal plasma erythropoietin. We speculate that amniotic fluid erythropoietin may be an antepartum indicator of fetal hypoxemia.

Amniotic Fluid↗
PubMed1986

Genetic homogeneity of cystic fibrosis.

We studied large Amish/Mennonite/Hutterite kindreds that segregate cystic fibrosis (CF) for linkage between CF and the polymorphic DNA markers pJ3.11 and 7C22 located on chromosome 7. These inbred pedigrees consist of more than 300 members including 30 affected individuals. In these families, linkage between the CF locus and the chromosome 21 marker D21S5 and between CF and the marker at the met oncogene locus on chromosome 7 had been previously indicated. We now report linkage between CF and pJ3.11 (Z = 4.92, theta = 0) and between CF and 7C22 (Z = 3.42, theta = 0). Therefore, CF segregates in these large pedigrees in a manner consistent with data from smaller outbred families with respect to the markers on chromosome 7 closest to CF. These data are consistent with locus homogeneity for the defect causing CF in the populations that have been examined to date.

Chromosomes, Human, Pair 21↗
PubMed1986

Enzymes of purine metabolism in hairy cell leukemia.

Differences in activities of the purine degradative enzymes, adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5'-nucleotidase (5'NT), have been observed among different classes of lymphoid malignancies. Recent studies have shown that hairy cell leukemia (HCL) may respond to treatment with the ADA inhibitor, 2-deoxycoformycin. This study demonstrates that the cells of HCL have significantly lower levels of ADA and 5'NT (P always less than 0.01) when compared to levels in normal B- or T-lymphocytes, but have higher levels of PNP (P less than 0.001 for both comparisons). Recent studies have shown that when treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), cells of B-cell chronic lymphatic leukemia (B-CLL) acquire phenotypic characters of HCL. The authors have therefore also investigated the changes in enzyme pattern of B-CLL after incubation with TPA B-CLL cells are characterized by low levels of ADA, PNP, and 5'-NT, but TPA caused a marked increase in PNP activity (P less than 0.001, t test for paired samples), a pattern similar to HCL. The results from biochemical studies are thus in accordance with the hypothesis that HCL cells are more mature than B-CLL cells. The special enzyme profile of HCL suggests that a PNP inhibitor might also be effective in the treatment of this disease.

5'-Nucleotidase↗
PubMed1986

Anti-tumor properties of lymphocytes activated by the oxidizing mitogens.

Human peripheral blood mononuclear cells when activated with the oxidizing mitogens, neuraminidase/galactose oxidase or sodium periodate, express cytolytic activity for freshly isolated tumor cells and for a variety of cell lines, including NK-resistant solid tumor lines. Normal lymphoid cells are not targets for cytotoxicity and do not inhibit lysis of susceptible targets mediated by the oxidizing mitogen-activated mononuclear cells. The cytotoxic response is rapidly generated and reaches peak levels at 48 hr. The oxidizing mitogens induce expression of IL 2 receptors on peripheral blood mononuclear cells. Combined treatment of cells with IL 2 and the oxidizing mitogens results in a marked enhancement of cytotoxicity. Enhancement is achieved at levels of IL 2 that alone result in minimal generation of cytotoxic cells. Growth of a human renal cancer cell line in nude mice was inhibited when the renal cancer cells were injected together with oxidizing mitogen-activated human mononuclear cells. These studies indicate that oxidizing mitogen-activated cells provide a potentially valuable source of material for the adoptive immunotherapy of tumors.

Adjuvants, Immunologic↗
PubMed1986

HD39 (B3), a B lineage-restricted antigen whose cell surface expression is limited to resting and activated human B lymphocytes.

The B cell-restricted antigen HD39, whose cell surface expression is limited to resting and activated human B lymphocytes, is described in this report. The monoclonal antibody HD39 detects a two-chain glycoprotein with apparent molecular weights of 130,000 and 140,000. During B cell ontogeny, HD39 is first expressed in the cytoplasm of bone marrow derived pre-B cells, then appears on the cell surface of sIgM+ B cells, and finally on the majority of sIgM+ sIgD+ resting B cells. After activation in vitro, the expression of HD39 on the cell surface first increases, and then the antigen is lost as cells begin to differentiate. HD39 is weakly expressed on very few non-T cell ALL and B cell CLL, on approximately 50% of B cell lymphomas, and not on Waldenström's macroglobulinemias and myelomas. In contrast, it is strongly expressed on all hairy cell leukemias. Its limited cell surface expression in B cell ontogeny suggests that HD39 may be important in the events that regulate the activation of the human resting B lymphocytes.

Animals↗
PubMed1986

An immunoenzymatic staining assay (ISA) for the rapid screening of monoclonal antibodies detecting membrane and cytoplasmic antigens.

We report a rapid and very sensitive immunoenzymatic staining assay (ISA) for the determination of the fine specificity of monoclonal antibodies directed against cellular antigens. Reactivity is analysed at the single cell level by light microscopy using alkaline phosphatase-conjugated second and third antibodies on cells bound to Terasaki plates. Reactive cells can be defined by their morphology even in preliminary screening procedures. Only small numbers of cells are necessary for this assay which is comparable to radioimmunoassays in its sensitivity. Plates with fixed cells can be stored at 4 degrees C so that a permanent 'library' of various cell types is always immediately available for use. The test is also suitable for human blood cell phenotyping. Moreover, a simple modification of the procedure by short pretreatment of the cells with the detergent Brij allows the detection of antigens within the cytoplasm. The importance of evaluating the cytoplasmic compartment in order to define antibody specificity and study the distribution of different cytoplasmic and membrane antigens is emphasized.

Antibodies, Monoclonal↗
PubMed1986

Isolation of intercalator-dependent protein-linked DNA strand cleavage activity from cell nuclei and identification as topoisomerase II.

DNA intercalating agents such as 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) have previously been found to induce in mammalian cells the formation of protein-associated DNA single- and double-strand breaks. In the current work, an activity characterized by the production of DNA-protein links associated with DNA strand breaks and by stimulation by m-AMSA was isolated from L1210 cell nuclei and was shown to be due to topoisomerase II. Nuclei were extracted with 0.35 M NaCl, and the extract was fractionated by gel filtration, DNA-cellulose chromatography, and glycerol gradient centrifugation. A rapid filter binding assay was devised to monitor the fractionation procedure on the basis of DNA-protein linking activity. The active DNA-cellulose fraction contained both topoisomerase I and topoisomerase II whereas the glycerol gradient purified material contained only topoisomerase II activity. The properties of the active material were studied at both stages of purification. m-AMSA enhanced the formation of complexes between purified topoisomerase II and SV40 DNA in which the DNA sustained a single- or double-strand cut and the enzyme was covalently linked to the 5' terminus of the DNA. This action was further enhanced by ATP, as well as by nonhydrolyzable ATP analogues. m-AMSA inhibited the topoisomerization and catenation reactions of topoisomerase II, probably because of trapping of the enzyme-DNA complexes. The activity showed a dependence on the type of DNA intercalators used, analogous to what was previously observed in intact cells. m-AMSA had no effect on topoisomerase I.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Heterogeneity of glycoprotein synthesis in human tumor cell lines.

In order to screen human tumor cells for putative cell surface marker molecules, the glycoprotein composition of in vitro cultivated human tumor cell lines of different origin (12 carcinomas, one neuroblastoma, one melanoma and one sarcoma) was analyzed by metabolically labelling the cells with [3H]galactose, [3H]mannose and [3H]fucose and subsequently separating the labelled material by SDS-PAGE. The cell lines expressed their specific glycoprotein patterns. Strongly glycosylated proteins of apparent mol. wt 40-45 kD, 60-62 kD, 80-82 kD and 90-92 kD were shared by nearly all carcinoma cell lines studied. Apart from these glycoprotein clusters, a great diversity was observed between tumor cell lines derived from the same organ. Three bladder carcinoma cell lines had a 112-114 kD glycoprotein in common. Glycoprotein expression of these cell lines remained constant during 1 yr of in vitro culture. Hence, these glycoprotein patterns seem to be useful for monitoring the phenotypic stability of cell lines. A sarcoma cell line was deficient in incorporating fucose and showed strikingly different glycoprotein patterns compared to the other cell lines studied. The metabolic labelling procedure revealed a wide phenotypic heterogeneity of the human carcinoma cell lines concerning glycoprotein synthesis. This method contributes another parameter to map the major glycoprotein species of various types of carcinomas.

Cell Line↗
PubMed1986

Prospective analysis of acute cervical spine injury: a methodology to predict injury.

We developed a prospective study to evaluate the clinician's ability to predict and diagnose cervical spine injury. Of 233 patients evaluated, 24 (10.4%) sustained cervical spine injury confirmed by radiography. The physician was able to predict injury with only 50% accuracy. The incidence of injury was 10.3% (24 of 233). Twenty percent (5 of 24) of cervical spine injuries would have been missed if physicians had used physical examination and mechanism of injury as criteria. Ten elements were identified as being associated statistically with cervical spine injury. Physicians cannot accurately predict the presence of cervical spine injury. Radiographs are ordered for many patients who have no evidence of injury. We used a logistic regression analysis to produce a system for predicting cervical spine injury. This methodology is easily adaptable for use in the emergency department.

Acute Disease↗
PubMed1986

Apparent absorption and retention of Ca, Cu, Mg, Mn, and Zn from a diet containing bran.

To establish conditions for comparisons of mineral bioavailability from plant sources, seven male subjects consumed a constant diet containing bran fiber and phytate. Absorption and retention of Ca, Cu, Mg, Mn, and Zn were measured for 7-day periods through wk 2-7. Intakes of Mg, Mn, and Zn significantly exceeded the RDA; Ca and Cu intakes were only slightly in excess of RDA. All mineral retentions fluctuated from week to week but only Mg and Mn showed a consistent positive trend over time. Phytate excretions showed characteristic individual patterns, but did not appear to change with time. In contrast to previous observations fecal recovery of polyethyleneglycol (PEG) (MW = 4000) was consistently lower than recovery of simultaneously ingested Cr. Only five of the seven subjects returned close to 100% of Cr within 7 days. It was concluded that at least 4 wk were needed for adaptation in investigations involving more than one mineral when the experimental diet is adequate in the nutrients under investigation, that measurements of responses to treatment required 2-3 wk each, and that successive isotopically labeled test meals may overlap if they are spaced at 7-day intervals.

Absorption↗