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Biomedical subjects

M Neumann

Publications and source records attributed to M Neumann.

At least 145 records · Page 8Linked to original sources
PubMed1995

Changes in the polyunsaturated fatty acids of breast milk from mothers of full-term infants over 30 wk of lactation.

The fatty acid composition of breast milk from 23 breast-feeding women was serially assessed by capillary gas chromatography from the 6th to the 30th wk of lactation. The proportions of total n-3 and n-6 fatty acids were unchanged with time, although some significant differences were noted for individual polyunsaturated fatty acids (PUFAs). Of the n-3 PUFAs, only docosahexaenoic acid (DHA, 22:6n-3) concentrations changed, decreasing between 6 and 16 wk from 0.26 +/- 0.13% to 0.21 +/- 0.13% of total fatty acids but remaining at this proportion until 30 wk. Of the n-6 PUFAs, 18:3, 20:3, 20:4, and 22:5 all showed reductions with time. Compared with concentrations observed in a 1981 study, linoleic acid was higher (14% compared with 11% of total fatty acids), whereas the concentration of DHA was lower (0.21% compared with 0.32% of total fatty acids), possibly reflecting a general change in the diets of Australian women.

Adult↗
PubMed1995

Restriction of human immunodeficiency virus type 1 production in a human astrocytoma cell line is associated with a cellular block in Rev function.

Chronically human immunodeficiency virus type 1 (HIV-1) strain IIIB-infected human TH4-7-5 astrocytoma cells show low-level virus production. Cocultivation of TH4-7-5 cells with myelomonocytic cells led to active virus production in these target cells after a lag period, indicating cell-determined restriction of virus replication in the glial cells. HIV-1 transcript patterns of TH4-7-5 cells contained only a small proportion of Rev-dependent mRNA species, mimicking a Rev-negative phenotype despite the presence of rev mRNAs and protein. Sequencing of the single provirus integrated in TH4-7-5 cells demonstrated that the rev gene and the Rev-responsive element are intact. These results suggested inhibited function of the Rev-regulatory unit in these astrocytoma cells. Transfection of TH4-7-5 cells with a Rev expression plasmid resulted in weak or no induction of proviral p24gag antigen levels compared with the dramatic increase observed in Rev-permissive HeLa cells. Immunofluorescence analysis of TH4-7-5 cells transfected with a rev-expressing plasmid revealed prominent cytoplasmic and nuclear-nucleolar localization of Rev, in contrast to the predominant nuclear-nucleolar localization pattern of Rev in HeLa cells. We conclude that restriction of virus production in TH4-7-5 cells is at least partially due to a block in Rev-dependent posttranscriptional regulation of HIV expression.

Amino Acid Sequence↗
PubMed1994

rel Is rapidly tyrosine-phosphorylated following granulocyte-colony stimulating factor treatment of human neutrophils.

Stimulation of neutrophils with granulocyte-colony stimulating factor (G-CSF) results in an enhanced respiratory burst, prolonged survival, and increased tumor cell killing. The effects of G-CSF are mediated by binding to specific, high affinity receptors. G-CSF receptors lack intrinsic tyrosine kinase activity, but activation of the receptor results in the rapid induction of tyrosine kinase activity. Antiphosphotyrosine immunoblots of whole cell lysates prepared from neutrophils show that the G-CSF rapidly induces prominent tyrosine phosphorylation of a protein of a relative molecular mass of 80 kDa. Using monospecific antibodies, the 80-kDa tyrosine-phosphorylated protein has been shown to be p80c-rel, a proto-oncogene belonging to a family of transcriptional regulators which include NF-kB. The induction of tyrosine phosphorylation of p80c-rel was unique to G-CSF in that granulocyte-macrophage colony stimulating factor which also stimulates neutrophils and induces tyrosine phosphorylation does not result in tyrosine phosphorylation of p80c-rel. The consequences of p80c-rel tyrosine phosphorylation are not yet known; however, tyrosine-phosphorylated p80c-rel is capable of binding to DNA, and G-CSF stimulation results in an increase in the amount of p80c-rel which binds to DNA. These results demonstrate that one of the first biochemical events which occurs in neutrophils following G-CSF stimulation, activation of a tyrosine kinase, leads directly to the tyrosine phosphorylation of p80c-rel. Thus, the tyrosine kinase activated by G-CSF appears to directly transduce a signal to a protein which functions as a transcriptional regulator.

Adult↗
PubMed1994

[Sexual relations between therapist and patient].

The delicate problem of sexual relations between therapist (physician or psychotherapist) and patient is described. Despite strict prohibitions, violation of medical ethics by therapists has long been known to occur. Research shows that the phenomenon is not at all rare. The steps taken to minimize the frequency of such ethical violations and to punish offenders is reviewed. Special emphasis is put on the tendency, quite common in Israel, to a conspiracy of silence and mutual covering-up and protection by professionals, preventing patients' complaints from being properly considered. Some measures recommended to combat such harmful and dangerous violations of professional ethics are discussed.

Ethics, Medical↗
PubMed1994

A double-blind trial of carbamazepine in negative symptom schizophrenia.

Twenty-eight residual schizophrenics hospitalized in a chronic institution with a 9 to 30 year history of disease, with predominantly negative symptoms were given carbamazepine. Carbamazepine was administered in a double-blind trial and therapeutic effects were measured by the Scale for the Assessment of Negative Symptoms (SANS). Patients were also assessed for positive symptoms using the Brief Psychiatric Rating Scale (BPRS), for depression using the Hamilton Depression Scale, for extrapyramidal symptoms by the Simpson and Angus scale, to rule out these symptoms as sources of secondary negative symptoms. The study continued for 7 weeks with therapeutic carbamazepine levels achieved during the last 5 weeks. There was no significant positive effect of carbamazepine on negative symptoms.

Adult↗
PubMed1994

Platelet aggregation inhibiting and anticoagulant effects of oligoamines, XXIII: Influence of the oligoamine RE 1492 on the deformability of red blood cells.

The influence of the oligoamine RE 1492 on the deformability of Red Blood Cells (RBCs) was measured with the micropipette aspiration technique and the capillary rigidometer. The maximal cell flow resistance (MCFR) and the apparent elastic membrane shear modulus mu were increased by 45% at RE 1492 concentrations > 10 mumol/L. There was a decrease of the surface/volume ratio of 6% at RE 1492 concentrations of 25 mumol/L. The qualitative analysis of the polypeptide pattern of membranes and extracted membranes of human RBCs suggests that the reduction of deformability is due to an increased affinity of skeletal proteins to the cytosolic part of the membrane. RE 1492 caused a decrease of osmotic hemolysis by 80% at concentrations of 8 mumol/L.

Anticoagulants↗
PubMed1994

Drug-induced changes in the expression of MDR-associated genes: investigations on cultured cell lines and chemotherapeutically treated leukemias.

The induced expression of multiple drug resistance (MDR)-associated genes as a direct response of tumor cells to antineoplastic drugs could be an important factor influencing the success of cancer chemotherapy. We investigated the effects of such compounds on mdr1/P-glycoprotein (P-gp) gene expression and drug sensitivities in the T-lymphoblastoid human cell line CCRF-CEM and MDR sublines. Thereby, we observed that actinomycin D or adriamycin administered at sublethal concentrations induced increases of mdr1 mRNA levels and resistance within 72 h. Furthermore, on leukemia cell samples collected before and after chemotherapy we checked by a complementary DNA polymerase chain reaction (cDNA-PCR) approach for similar alterations in the relative expression levels of the MDR-associated genes (a) mdr1/P-gp (b) mrp (MDR related protein), and (c) the topoisomerase II isoforms alpha and beta. We found a concomitant increase in mdr1 and mrp gene expression combined with a decreased expression of topoisomerase II alpha in the course of the second relapse of an acute lymphoblastic leukemia (ALL). This points to the emergence of at least three different MDR mechanisms in this type of leukemia unresponsive to chemotherapy. A chronic myeloid leukemia (CML) in blast crisis, however, showed combined increases in mdr1 (about 20-fold) and mrp (about four fold) gene expression after intense but unsuccessful chemotherapy over a 6-month period. Our results indicate the occurrence of induced resistance in vitro and in vivo and suggest a contribution of the newly identified ATP-binding cassette (ABC) transporter MRP in MDR.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

The branching angles in computer-generated optimized models of arterial trees.

The structure of a complex arterial tree model is generated on the computer using the newly developed method of "constrained constructive optimization." The model tree is grown step by step, at each stage of development fulfilling invariant boundary conditions for pressures and flows. The development of structure is governed by adopting minimum volume inside the vessels as target function. The resulting model tree is analyzed regarding the relations between branching angles and segment radii. Results show good agreement with morphometric measurements on corrosion casts of human coronary arteries reported in the literature.

Animals↗
PubMed1994

Splicing variability in HIV type 1 revealed by quantitative RNA polymerase chain reaction.

A quantitative RNA-polymerase chain reaction (PCR) method able to detect the majority of mRNAs produced by human immunodeficiency virus type 1 (HIV-1) was developed and used to study expression of different HIV-1 clones in human cells. Amplified mRNAs were compared to known cDNA standards. This comparison permitted the optimization of PCR conditions and eliminated the generation of artifactual PCR bands. The use of RNA and cDNA standards demonstrated that the RNA amplification is linear within the tested range and suggested that it can be used to quantitate individual mRNAs. The results demonstrate the overall conservation of splicing in different HIV-1 clones. Although, in general, splicing was conserved, extensive qualitative and quantitative variability was observed in different HIV-1 clones. This variability is likely one determinant of the biological characteristics of the different HIV-1 clones, and demonstrates a great plasticity of the HIV-1 genome. The described RNA-PCR methodology was used for the study of HIV-1 expression in unstimulated peripheral blood mononuclear cells (PBMCs) of infected individuals. In general, the same mRNAs were identified in HIV-infected cultured cell lines and in unstimulated PBMCs. Analysis of a variant band found after amplification of PBMC RNA from an HIV-infected individual revealed a new splice site for the generation of Rev/Nef-encoding mRNAs. The availability of a sensitive, rapid, and essentially quantitative method to examine the major HIV-1 mRNAs will facilitate the detailed analysis of HIV-1 expression in human cells.

Base Sequence↗
PubMed1994

Solution-oriented therapy techniques for women's health nurses.

This article introduces nurses to Solution-Oriented Therapy techniques. Because these techniques focus on outcomes and lend themselves to brief contacts, they are well suited to the amount of time a nurse may have with a patient. These techniques are easy to use and emphasize positive regard and actions the patient can take for herself and her family.

Female↗
PubMed1994

Functional and conserved domains of the Drosophila transcription factor encoded by the segmentation gene knirps.

The Drosophila gap gene knirps (kni) is required for abdominal segmentation. It encodes a steroid/thyroid orphan receptor-type transcription factor which is distributed in a broad band of nuclei in the posterior region of the blastoderm. To identify essential domains of the kni protein (KNI), we cloned and sequenced the DNA encompassing the coding region of nine kni mutant alleles of different strength and kni-homologous genes of related insect species. We also examined in vitro-modified versions of KNI in various assay systems both in vitro and in tissue culture. The results show that KNI contains several functional domains which are arranged in a modular fashion. The N-terminal 185-amino-acid region which includes the DNA-binding domain and a functional nuclear location signal fails to provide kni activity to the embryo. However, a truncated KNI protein that contains additional 47 amino acids exerts rather strong kni activity which is functionally defined by a weak kni mutant phenotype of the embryo. The additional 47-amino-acid stretch includes a transcriptional repressor domain which acts in the context of a heterologous DNA-binding domain of the yeast transcriptional activator GAL4. The different domains of KNI as defined by functional studies are conserved during insect evolution.

Amino Acid Sequence↗
PubMed1994

Peripheral blood lymphocyte subsets and survival in small-cell lung cancer.

Measurement of lymphocyte subsets in peripheral blood is likely to reflect immune response of patients and therefore may be linked to survival in small-cell lung cancer (SCLC). Forty patients with SCLC (14 with limited and 26 with extensive disease at study entry) were included and followed for up to 23 months. Peripheral blood lymphocytes were determined by flow cytometry and levels for total-, T-, B-, helper-, suppressor-, activated T-cells and natural killer cells established and the T-helper-suppressor ratio (H-S ratio) calculated. Quartiles of lymphocyte subset cell counts at the start of follow-up and for the change over follow-up were investigated. Cox regression models indicated that H-S ratio was a significant predictor (p = 0.02) of survival. The risk ratio, after adjustment for competing risk factors, sex, age and stage of disease, was found to be 0.66 (95 percent confidence intervals, 0.46 to 0.95) and predicted that for each quartile of greater H-S ratio, the risk of death decreased by 34 percent. For change in cell counts over follow-up, total lymphocytes (p = 0.02) demonstrated a significant association with survival. Although our observation is limited by the fact that 13 patients were unavailable for follow-up, we conclude that H-S ratio can serve as an easily accessible marker of immune function and possible prognostic value in SCLC.

Carcinoma, Small Cell↗
PubMed1994

[Viral hepatitis infection and response to the hepatitis B vaccine in hemodialyzed patients].

Data from 219 hemodyalized patients receiving attention in our Hospital and other private centers in our city are shown. Mean age was 46.9 (range: 14-85), and 132 were male; mean time under dialysis was 20 months, and subjects received an average of 5 transfusions per patient year. Serological reactivity to HBs Ag, Anti HBs and IgG anti HBc by ELISA were investigated in all of them, and anti HCV by second generation enzimo-immunoassay (EIA II) in 73 HBe Ag/anti HBe system were determined in HBs Ag positive patients and those reactive to anti HCV (EIA II) were confirmed by LIA (immunoblotting of synthetic peptides LIA-TEK Organos Teknica). Recombinant anti HBV vaccine 40 mcg at 0-1 and six month were received by 81 cases without HBV markers in their sera and a protective response was considered when anti HBs titration of 10 mU/ml or more were obtained two months later. Prevalence for anti HBc and anti HBs were 38.8% respectively and that for HBs Ag was 21% with 78% of them reactive for HBs Ag. True reactivity for anti HCV (confirmed by LIA) was present in 35.6%, but it was 9.7% in our Hospital and 54.8% in private units (p < 0.0002). Anti HBs titration was done in 69/81 patients who received anti HBV vaccine, and a protective response in 49% were obtained; the other 12 patients underwent acute hepatitis B during the vaccination period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗