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Biomedical subjects

R Blau

Publications and source records attributed to R Blau.

9 recordsLinked to original sources
PubMed1999

The effect of estrogen usage on the subsequent hormone receptor status of primary breast cancer.

In order to determine if prior use of exogenous estrogens was related to the estrogen receptor (ER) content of primary breast cancers, a retrospective analysis was performed from 536 patients with invasive breast cancer. The patient's age, menopausal status, oral contraceptive or estrogen replacement therapy usage, and the ER and progesterone receptor (PR) content of the breast cancer were recorded for all patients. Hormone usage in premenopausal and postmenopausal patients was compared to ER and PR levels in primary breast cancers using non-parametric testing. Complete information was available from 508 (193 premenopausal and 315 postmenopausal) patients. Breast cancers were ER positive in 72% of postmenopausal patients and 57% of premenopausal patients. The majority of patients received 'Some' form of hormone therapy (111 of 193 premenopausal patients and 233 of 315 postmenopausal patients). Significantly more estrogen receptors were detected in tumors from patients receiving 'some' estrogen therapy compared to 'never' users. Postmenopausal patients 'never receiving estrogen therapy had a lower rate of ER positive tumors (62%) compared to 'some' users (75%, chi2 = 4.99, p < 0.05). The same relationship was seen for PR ('never' users 44% positive, 'some' users 58% positive, chi2 = 5.19, p < 0.05). We conclude that postmenopausal patients who received 'some' estrogen therapy are more likely to have breast cancers that are estrogen receptor and progesterone receptor positive.

Adult↗
PubMed1999

The risk of premature menopause induced by chemotherapy for early breast cancer.

The objectives of this retrospective case series were to determine the prevalence and timing of menstrual abnormalities in early-stage breast cancer patients undergoing adjuvant methotrexate or anthracycline-based chemotherapy and to more fully assess the possible mechanism of the amenorrhea reported after chemotherapy. One hundred forty-two premenopausal patients undergoing adjuvant chemotherapy were analyzed for patient age, breast cancer stage, type of chemotherapy, and menstrual abnormalities before, during, and after chemotherapy completion. A 24-month minimum follow-up after chemotherapy completion was available for all patients. One hundred nine of 142 patients were evaluable. Sixty-nine patients (46 node negative, 23 node positive) received methotrexate-based chemotherapy, 33 patients (3 node negative, 30 node positive) received anthracycline-based chemotherapy, and 7 patients received both treatments (all node positive). Amenorrhea occurred in about a third of patients during chemotherapy (methotrexate groups 31%, anthracycline group 33%), and a higher proportion were amenorrheic 1 year after chemotherapy was completed (methotrexate group 45%, anthracycline group 46%). Abnormalities were more likely to occur in older premenopausal patients (Chi square = 6.18, p < 0.05), although 28% of patients under age 35 developed persistent abnormal menses. In some amenorrheic patients, follicle-stimulating hormone (FSH) levels were decreased within 6 months of chemotherapy (24.4 IU). The levels tended to be higher after chemotherapy (59.1 IU), suggesting ovarian failure. Menstrual abnormalities and menopause will frequently occur in premenopausal early-stage breast cancer patients, with 30% of all patients amenorrheic 1 year after chemotherapy.

Adult↗
PubMed1995

Rat and human glutamate transporter GLAST1 stable heterologous expression, biochemical and functional characterization.

Human embryonic kidney cell lines (HEK293) which express heterologously and permanently the human and rat GLAST1 (high affinity, Na(+)-dependent, CNS-specific L-glutamate transporter) have been established by the transfer of the two minigenes under the control of the cytomegalovirus promoter by electroporation. The transfected HEKh GLAST1 (human) and HEKrGLAST1 (rat) cell lines strongly express the glutamate uptake system which exhibits all biochemical and electrophysiological properties determined so far in the transiently expressing Xenopus oocyte system except the K+ dependence. These cell lines are a valuable tool for further biochemical, physiological, and pharmacological studies on this uptake system of the most important excitatory neurotransmitter.

Amino Acid Transport System X-AG↗
PubMed1994

Epidemiologic investigation by macrorestriction analysis and by using monoclonal antibodies of nosocomial pneumonia caused by Legionella pneumophila serogroup 10.

A 67-year-old woman was hospitalized with an acute pneumonia of the left lower lobe. Legionella pneumophila serogroup 10 was cultured from two sputum specimens taken on days 18 and 20 and was also detected by direct immunofluorescence assay by using a commercially available species-specific monoclonal antibody as well as serogroup 10-specific monoclonal antibodies. Antigenuria was detected in enzyme-linked immunosorbent assays by using serogroup 10-specific polyclonal and monoclonal antibodies. In the indirect immunofluorescence test rising antibody titers against serogroups 1, 4, 5, 8, 9, 10, 14, and 15 were found in serum, with the highest titers found against serogroups 8, 9, and 10. L. pneumophila serogroups 10 and 6 and a strain that reacted with serogroup 4 and 14 antisera were cultured from both central and peripheral hot water systems of the hospital. Macrorestriction analyses of the genomic DNAs by pulsed-field gel electrophoresis showed that the isolate from the patient was identical to the serogroup 10 strains from the hospital hot water system. In contrast, the genomic DNAs of 16 unrelated L. pneumophila serogroup 10 strains showed 12 different restriction patterns. Monoclonal antibody subtyping revealed only minor differences in L. pneumophila serogroup 10 strains isolated from different sources. In conclusion, macrorestriction analysis is a valuable tool for studying the molecular epidemiology of L. pneumophila serogroup 10.

Aged↗
PubMed1992

Delayed health sequelae of accidental exposure to bromine gas.

The delayed health effects from accidental exposure to bromine vapors in a group of six people were evaluated. During the acute exposure, they had only some respiratory symptoms and skin burns of first to second degree involving small areas. All were treated in one hospital and released within 1-4 d. Six to 8 wk later, some still had health complaints such as cough, shortness of breath, chest tightness, eye irritation, headache, dizziness, fatigue, and memory, sleep, and sexual disturbances, but no objective laboratory or clinical evidence of effects. Mechanisms that might have led to manifestations of such complaints 1-2 mo after the accident are discussed and possible ways to alleviate similar situations are suggested.

Accidents, Traffic↗
PubMed1990

[Late health sequelae of accidental bromine exposure].

Health and environmental assessment of the consequences of accidental contamination of an area in the Negev desert is described and the effects of exposure to bromine vapor in 6 persons evaluated. They were only mildly affected during the acute spillage of the bromine, with some respiratory symptoms and first and second degree skin burns of small exposed areas on the legs. All were treated in hospital and were released within 1-4 days. 6-8 weeks later they demonstrated a complex array of complaints, including cough, shortness of breath, chest tightness, eye irritation, headache, dizziness, fatigue, memory disturbances, sleep and sexual disturbances. These complaints could not be substantiated by objective clinical or laboratory examination. There was thus obvious magnification of the complaints 1-2 months after the accident.

Accidents↗
PubMed1985

Synthesis and processing of human serum apolipoprotein AII in vitro and in Hep G2 cells.

The synthesis and structure of the primary translation product of apo AII in a human liver poly(A+) mRNA primed cell-free system and its cotranslational modification was studied parallel to studies in vivo with Hep G2 cells, a human hepatoma cell line. The primary translation product is a preproprotein containing 100 amino acid residues, which is cleaved by the signal peptidase of endoplasmic reticulum to pro-apo AII with the loss of the N-terminal pre-sequence consisting of 18 amino acid residues. Hep G2 cells contain about equal amounts of the proform of apolipoprotein AII and of mature apo AII. Approximately in the same ratio pro- and mature apo AII are secreted into the medium. Determination of the partial amino-acid sequence by automated Edman degradation of the labelled prepro- and proforms of apo AII led to the segmentation of the N-terminus of the primary translation product, consisting of 23 amino acid residues, into the pre-sequence (18 residues) and the pro-sequence (5 residues) with terminal Arg-Arg-residues at the cleavage site to apo AII. We must therefore correct our previously postulated 17 and 6 residues containing segmentation. So far no information has been obtained in which compartment and at what stage of posttranslational events the dimerization occurs by formation of the single disulfide bond at position Cys6 in the mature apo AII structure, leading to the symmetrical molecule.

Amino Acid Sequence↗