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Biomedical subjects

A Reichert

Publications and source records attributed to A Reichert.

70 records · Page 4Linked to original sources
PubMed1981

Alkyl-lysophospholipids inhibit the growth of hypernephroid carcinomas in vitro.

Synthetic alkyl-lysophospholipids (ALPs) inhibit the proliferation of human hypernephromas in vitro. Cells of ten different tumors were incubated with 4 ALPs for periods of more than 24h. Eight of ten cell lines showed proliferation rates below 1% of the controls after cultivation. One microgram of ALPs per 10(6) tumor cells was effective, in some experiments a dose response relation was found for even lower concentrations. Equivalent concentrations of cytostatic drugs did not show reproducible higher antitumor effects in vitro. In two of the tested cell lines ALPs did not show any reproducible tumor growth inhibition, whereas at least some of the cytostatic drugs revealed slight cytostatis.

Adenocarcinoma↗
PubMed1981

Enrichment of MLR-activated human suppressor cells by discontinuous density-gradient centrifugation.

6-day allogeneic mixed lymphocyte cultures (MLR) were fractionated on a four-step discontinuous Percoll gradient. The various fractions were added as regulatory cells to freshly established micro-MLRs between the original or third-party cell donors. Unspecific suppressor activity was highly enriched in gradient fraction III (density 1.069--1.062 g/ml), consisting mainly of blast-like cells. Suppressor cells were non-adherent T cells as determined by their spontaneous rosette formation with sheep erythrocytes and their susceptibility to lysis by anti-T-cell globulin plus complement. Mitomycin C treatment diminished their inhibitory capacity. In addition, gradient fraction III was also enriched with alloantigen-activated memory cells. By contrast, unprimed alloreactive cells were recovered from gradient fraction IV (density greater than or equal to 1.070 g/ml), consisting mainly of small, resting lymphocytes.

Adult↗
PubMed1981

Isolation of T lymphocytes in chronic lymphocytic leukaemia by depletion of mouse rosette-forming cells.

Separation of mouse rosette-forming cells (MRFC) was used as a technique to isolate T lymphocytes in patients with chronic lymphocytic leukaemia. The resulting interface fraction (non-MRFC) was highly enriched for sheep rosette-forming T cells (mean value 71.8% SRFC) as compared with unfractionated peripheral blood lymphocytes (mean value 18% SRFC). A higher degree of T-cell purity was achieved by this method than by the sheep rosette sedimentation technique in patients with leucocyte counts greater than 50 X 10(9)/l. Functional tests revealed that depletion of MRFC increased not only phytohaemagglutinin and mixed lymphocyte culture (MLC) reactivity but also the stimulatory capacity in the allogeneic MLC. In contrast, separation of MRFC in normal blood donors gave only a poor degree of separation and was not an effective means to isolate lymphocyte subpopulations.

Animals↗
PubMed1981

Inhibition by alkyl-lysophospholipids of tritiated thymidine uptake in cells of human malignant urologic tumors.

Alkyl-lysophospholipids (ALP) inhibited the uptake of [3H]thymidine by cells from a variety of human urologic tumors in vitro. Cells of prostate carcinomas, a seminoma, various bladder carcinomas and teratocarcinomas showed proliferation rates that were 10% of those of the controls when incubated with some ALP for longer than 24 hours. Concentrations as low as 1 microgram ALP/ml medium (10(6) tumor cells) were effective. Antitumor action increased after incubation for 2-5 days. Morphologic studies showed tumor cell death after incubation periods of this length. Equivalent concentrations of conventional cytostatic drugs used in anticancer chemotherapy protocols did not cause greater inhibition of [3H]thymidine uptake by tumor cells in vitro. Human embryonic fibroblasts were not sensitive to ALP, whereas cytostatic drugs completely inhibited their proliferation at comparable doses.

Cell Division↗
PubMed1981

Growth inhibition of malignant hypernephroma cells by autologous lysophospholipid incubated macrophages obtained by a new method.

In order to obtain pure human macrophages, mononuclear cells from peripheral blood were cultured on teflon membranes and the non-adherent lymphocytes removed. After 24 hours, all remaining adherent cells were detached from the membranes with 100% viability. They showed all the morphological and cytochemical characteristics of human monocytes. Within 10 days of cultivation they differentiated into monolayers of pure macrophages. Untreated macrophages of this origin showed only limited cytostatic effects on autologous hypernephroma cells in vitro. After preincubation with different alkyl-lysophospholipids they revealed a tumor growth inhibition capability of up to 90%.

Adenocarcinoma↗
PubMed1980

Membrne alterations in human glioblastoma.

Plasma membrane-enriched fractions were isolated from human gliomas and brain white matter. These membrane fractions were characterized by electron microscopy and by the distribution of the membrane marker enzymes (Na+K+)-ATPase and 2',3'-cyclic AMP-3'-phosphohydrolase. The comparison of the membranes from tumor and control material by SDS gel electrophoresis reveals an altered tumor membrane. Two proteins of a molecular weight of about 70,000 dalton and 30,000 dalton are found to be more expressed in the tumor membrne.

Adenosine Triphosphatases↗
PubMed1978

Computer-based interpretation of clinical laboratory tests.

A system has been developed for the interpretation of laboratory findings which can aid in medical diagnosis as well as monitoring medical treatment. Tools are provided for defining, updating and verifying rules for the interpretation of laboratory tests in a computer-acceptable form. The present system uses a set of arithmetic logic rules which allows comprehensive evaluation of laboratory data as well as bringing into focus fluctuating and borderline situations and inconclusive data. Application of the system for over a year has shown that it is easy to use by laboratory staff with no knowledge of programming. Moreover, it has forced greater comprehensiveness, objectivity, consistency and speed in the interpretation of laboratory results than is generally achieved by standard practice.

Clinical Laboratory Techniques↗
PubMedDate not supplied

Membrane microstructural templates for enzyme domain formation.

Soluble proteins can spontaneously self-organize into two-dimensional domains at membrane interfaces, given sufficient mobility and specificity to membrane-localized ligands. The authors' recent results studying interfacial domain formation of the membrane-active enzyme, phospholipase A2, indicate that lateral phase separation of heterogeneous membrane mixtures creates anionic templates of specific morphology onto which the enzyme deposits, forming large protein assemblies. Selective removal of membrane components (lysolipid or fatty acid) produces different enzyme interfacial responses and domain morphologies. This leads to the conclusion that complex chemical and physical interactions laterally in the lipid membrane interface as well as between bound protein molecules play a role in organizing protein structures.

Binding Sites↗
PubMedDate not supplied

The N.Y.P.E.N. method: meeting learning needs and satisfying educational requirements.

This article describes how N.Y.P.E.N. (Nurses' Yearly Program for Educational Needs) meets nurses' learning needs and satisfies educational requirements in an 8-hour program that uses a variety of learning methods facilitated by an interdisciplinary group of instructors. Devoting an entire day (away from the nursing units) to learning sessions has proved to be a much more efficient and enjoyable alternative to the often poorly attended programs our department offered in the past. This method can be successfully adapted for any healthcare facility or agency.

Cost-Benefit Analysis↗
PubMedDate not supplied

Lack of correlation between cytotoxicity of agonists and antagonists of platelet activating factor [paf-acether] in neoplastic cells and modulation of [3H]-paf-acether binding to platelets from humans in vitro.

The 3 ether-lipids ET-18-OCH3, SRI 63-154 and paf-acether, the TLP BM 41.440, the ester-linked 2-LPC and CV-3988, were tested for cytostatic/antiproliferative [3H]-thymidine uptake) and cytotoxic (trypan blue dye exclusion, HTCA) activity in 11 neoplastic human cell lines (U 698-M, Nall-1, Su-DHL-4, RPMI 8226, K 562-4, Li-A, HTB-47, HTB-38, CCL218, 85 HG-59, 85 HG-63) and 1 ALL in vitro. 2-LPC and paf-acether showed either no, or only minor, CV-3988 varying activity. There were no significant differences in the activity of ET-18-OCH3, SRI63-154 and BM 41.440, which showed IC50- and LC50-values of less than or equal to 10 micrograms/ml after incubation periods greater than or equal to 48 hours with or during continuous exposure to the cells. The latter three compounds were then tested for interaction with [3H]-paf-acether binding to intact human platelets: ET-18-OCH3 and SRI63-154 reduced [3H]-paf-acether binding in a time-dependent manner. BM 41.440 did not show this interaction. Thus, since the in vitro cytotoxicity of these lipids did not correlate with their modulation of [3H]-paf-acether binding to human platelets, it was concluded that cytotoxicity of ether-lipids is not mediated by specific paf-acether binding sites similar to those present on human platelets. This finding is important for the future design of antineoplastic lipids.

Antineoplastic Agents↗