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Biomedical subjects

A Shapira

Publications and source records attributed to A Shapira.

At least 37 records · Page 2Linked to original sources
PubMed1988

Dynamics of bromodeoxyuridine incorporation into DNA of squamous carcinoma cells during mid and late logarithmic growth.

Head and neck squamous carcinoma cell lines, UM-SCC 1, 5, 9, 11B, and 14B, were exposed in vitro to bromodeoxyuridine (BUdR) during logarithmic growth to determine the effects of drug concentration (0.01 to 10 microM) and duration of exposure (3, 7, and 10 days) on cell growth and on incorporation of BUdR into DNA. Concentrations of less than 1.0 microM were not growth inhibitory except with UM-SCC-11B. After 10 days of exposure to 5 microM BUdR, survival fractions for all lines ranged from 2 to 65% of controls. Replacement of thymidine by BUdR in DNA was assessed by gas chromatography/mass spectroscopy. Percentage replacement (% R) was described by the equation % R = 100 (C/t)s/[(C/t)50s + (C/t)s], where C is the concentration of BUdR (microM), t is the time in days, s is a constant, and (C/t)50 is a constant corresponding to % R = 50%. BUdR incorporation reached a time- and concentration-dependent maximum that, after 3 to 7 days of culture in 10 microM BUdR, ranged from 30 to 60% R. Subsequently, % R declined with time even though the cells were fed daily with fresh BUdR-containing medium.

Bromodeoxyuridine↗
PubMed1988

Heterotopic pregnancy.

Three cases of heterotopic pregnancy, i.e. combined intra-uterine and extra-uterine pregnancy are reported. The complexities of diagnosis and management are presented.

Adult↗
PubMed1987

In vitro effects of tamoxifen on UM-SCC head and neck cancer cell lines: correlation with the estrogen and progesterone receptor content.

Eleven squamous-cell carcinoma (SCC) cell lines derived from patients with head and neck cancer were tested together with the MCF-7 breast carcinoma cell line for in vitro growth inhibition by tamoxifen. MCF-7 is known to contain cytosolic receptors for estrogen (ER), progesterone (PgR), androgen (AR) and glucocorticoid. We have previously reported the ER, PgR and AR contents of these 11 head-and-neck SCC cancer lines. Starting from day 3 or 4 after passage, cultures were fed daily with medium containing 5% dextran-charcoal-treated fetal bovine serum (D5) and 0, 1, 2.5, 5, 7.5 or 10 microM tamoxifen. Eight of the 11 SCC lines and MCF-7 showed more than 60% growth inhibition when fed with 5 microM tamoxifen. Of these 8 SCC cell lines, 3 contained both ER and PgR, 4 contained only PgR, and one contained neither receptor. The 3 cell lines that were not inhibited by tamoxifen failed to express either ER or PgR. The action of tamoxifen on the cell lines was further investigated by examining the reversibility and the rate of recovery from tamoxifen-induced growth inhibition in the presence or absence of estrogen. MCF-7 and two ER- and PgR-positive SCC cell lines, UM-SCC-12 and UM-SCC-9, recovered more rapidly when the tamoxifen was replaced with medium containing 17-beta estradiol (E2) than when it was replaced with D5 medium alone. However, of the other tamoxifen-inhibited cell lines studied, each recovered equally well whether the tamoxifen was replaced with D5 medium or with D5 medium containing E2. Furthermore, some cell lines spontaneously resumed growth within 4 to 5 days in the presence of tamoxifen if no new tamoxifen was added to the culture dish. This ability is specific for some cell lines, and further study is required to determine its significance.

Carcinoma, Squamous Cell↗
PubMed1987

Hereditary protein C deficiency during pregnancy.

Hereditary protein C, a primary hypercoagulable state, has not been previously associated with preeclamptic toxemia. A woman with previous preeclamptic toxemia and fetal deaths presented with recurrent deep vein thrombosis during her third pregnancy. Hereditary protein C was diagnosed but full heparinization followed by low-dose heparin failed to prevent preeclamptic toxemia.

Adult↗
PubMed1986

Growth inhibition of laryngeal UM-SCC cell lines by tamoxifen. Comparison with effects on the MCF-7 breast cancer cell line.

Six laryngeal squamous cell carcinoma (SCC) cell lines and the MCF-7 breast cancer line, all of which contain estrogen and progesterone receptors, were tested for in vitro growth inhibition by the antiestrogen tamoxifen citrate. Cell line MCF-7 was more sensitive to growth retardation at 1 mumol/L of tamoxifen citrate, but SCC lines showed higher sensitivity than MCF-7 to cytotoxic effects at higher drug concentrations (7 to 10 mumol/L). A cytostatic level of growth inhibition was produced by 5 mumol/L tamoxifen citrate for both types of cell lines. When tamoxifen and estradiol were added to cultures simultaneously, partial reversal of growth inhibition was observed with MCF-7 but not with UM-SCC-5. All of the cell lines recovered from inhibition when tamoxifen was replaced with 0.1 mumol/L estradiol, but laryngeal SCC lines recovered equally well in estradiol-free medium, whereas MCF-7 recovered only partially in the absence of estradiol. These findings indicate that there are at least two tamoxifen receptor sites--one for which estradiol is a competitor and one for which it is not--and that tamoxifen reversibly blocks growth and may synchronize SCC cells.

Breast Neoplasms↗
PubMed1986

Isolated frog olfactory cilia: a preparation of dendritic membranes from chemosensory neurons.

The recently introduced frog olfactory cilia preparation (Chen and Lancet, 1984; Pace et al., 1985) has been useful for studies of molecular chemosensory mechanisms. Here we describe in detail the properties of this cilia preparation. The "calcium shock" procedure leads to a complete removal of the cilia from the olfactory epithelial surface. Isolated cilia constitute segments of proximal regions with 9 X 2 + 2 microtubular arrangement and a large proportion of membrane vesicles, probably derived from the ciliary distal segments. Polypeptides unique to the olfactory cilia preparation, compared to a control preparation of palate respiratory cilia, are identified by Coomassie brilliant blue staining, silver staining, and radiolabeled lectin overlays, as well as by biosynthetic labeling with 35S-methionine in epithelial explants and protein phosphorylation in isolated cilia. The olfactory cilia preparation contains odorant-sensitive adenylate cyclase, which is absent in control membranes from deciliated epithelium. High activities of tyrosine and serine/threonine protein kinases are also present. The olfactory cilia preparation described should be instrumental in the further elucidation of the biochemistry and molecular biology of vertebrate olfaction.

Adenylyl Cyclases↗
PubMed1985

Total inferior turbinectomy for nasal airway obstruction.

A variety of surgical procedures are performed to open the nasal airway chronically obstructed by hypertrophic inferior turbinates. Because the results are universally unsatisfactory, we suggest bilateral total inferior turbinectomy to patients in whom medical therapy fails. One hundred fifty patients were followed up for one to seven years (mean, 2 1/2 years) and the results of the follow-up were assessed clinically via questionnaire and chart review. Patent nasal airway resulted in 91% of the patients. Eighty percent of the patients reported improvement in nasal breathing, and 14 (27%) of the 51 patients who suffered from nasal drainage preoperatively reported that it had stopped after the operation. Of the 39 patients who had anosmia preoperatively, 46% reported the restoration of their sense of smell. Postoperative complications are minimal, and no patient complained of crusts, dryness, or foul odor.

Adolescent↗
PubMed1983

Myringoplasty in children.

The fact that myringoplasty in children is relatively less satisfactory than in adults, motivated us to perform a retrospective study, gathering material on 53 children aged 4-12 years who underwent 68 operations to determine if any pre-operative or intra-operative parameters might predict the outcome of surgery. Results show that the overall success rate of Type I tympanoplasty was 78%, and that the majority of failures occurred later in the follow-up course. Furthermore, age and technique of operations played the most important roles in the results. The status of the non-operated ear did not influence the surgical outcome. Finally, revision myringoplasty was equally as successful as the primary operations.

Age Factors↗
PubMed1982

Comparison of (2'-5') oligo-adenylate synthetase and interferon blood-levels in mice early after viral infection.

The level of the IFN-induced enzyme (2'-5') oligo A synthetase in the peripheral blood mononuclear cells (PBMC) was determined in mice at different times following virus infection. There was a significant increase (4-7-fold) of the enzyme level within less than 12 h after i.p. injection of either VSV (10(7) pfu) or Sindbis virus (2.10(4) pfu). The elevated level was maintained for about a week and then the activity returned to normal. There was, however, a marked difference in the pattern of serum level of IFN during infection by the two viruses; while in the mice infected by VSV, serum IFN was very high on the first day and declined to an undetectable level by the fourth day, in the mice infected with Sindbis virus, serum IFN was barely detectable at the first day and then increased towards the fourth day of infection. Antiviral antibodies could be detected in the serum only about a week after infection. We conclude that viral infection can result in a rapid elevation of (2'-5') oligo A synthetase in the PBMC, even when serum IFN remains low. Thus, quantitation of the enzyme level can be a useful diagnostic aid in viral infection particularly in the early stages and in cases in which antiviral antibodies and IFN can not be detected.

2',5'-Oligoadenylate Synthetase↗
PubMed1979

The successful use of "high level" PEEP in near fatal Endrin poisoning.

The insecticide Endrin is a highly toxic chlorinated hydrocarbon which can cause severe CNS and respiratory derangement. Death usually follows intoxication within 24 hours. A 19-year-old male developed convulsions and gross pulmonary edema after the ingestion of Endrin. His trachea was intubated and constant positive pressure ventilation with PEEP of up to 28 cm H2O was instituted. The patient survived and recovery appeared to be complete. Severe pulmonary edema is not a common finding in patients who have Endrin poisoning. The use of PEEP above 15 cm H2O is a controversial issue; however, we believe that it contributed significantly to the survival of our patient.

Adult↗
PubMed1978

A hybridization procedure for the isolation of specific RNA segments applied to the analysis of bacteriophage Qbeta RNA.

A method for the isolation of RNA fragments originating from defined regions of bacteriophage Qbeta RNA minus strands is described. Large RNase T1 oligonucleotides were isolated on a preparative scale from Qbeta RNA. The nucleotide sequences (13 to 26 nucleotides) and map positions of these oligonucleotides were known from previous work (Billeter, M. A. (1978) J. Biol. Chem. 253, 8381-8389). After addition of AMP residues (50 in the average) using terminal adenylate transferase, these pure oligonucleotides were hybridized to 32P-labeled Qbeta RNA minus strands synthesized in vitro. Fragments in the size range of 100 to 500 nucleotides were then generated by partial digestion with RNase T1. Fragments hybridized to such oligonucleotides were recovered by chromatography on poly(U)-Sephadex and then resolved according to their size by polyacrylamide gel electrophoresis. The specificity and reproducibility of the method as well as its suitability for the sequence analysis of Qbeta RNA was verified by using in particular a linker oligonucleotide derived from a Qbeta RNA region near the 3' end. The sequence catalogues of the RNase T1 and RNase A oligonucleotides of two fragments isolated in this way, 202 and 310 nucleotides in length, were established and all fragments isolated were shown to contain a sequence complementary to the linker oligonucleotide.

Base Sequence↗