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Biomedical subjects

L Levine

Publications and source records attributed to L Levine.

At least 37 records · Page 2Linked to original sources
PubMed1998

D1S80 allele frequencies in Hasidic and non-Hasidic New York City Jewish populations.

Allele frequencies were determined for the VNTR locus D1S80 in Hasidic and non-Hasidic Ashkenazi New York City Jewish subpopulations. Samples were amplified via the polymerase chain reaction and underwent genotyping using polyacrylamide gel electrophoresis. In the Hasidic population 14 alleles were observed as opposed to 19 alleles in the non-Hasidic community. Both populations were tested for Hardy-Weinberg equilibrium. The frequency data obtained can be used for comparison to other populations and for allele and genotype frequency estimates in genetic marker profiling of evidentiary specimens.

Alleles↗
PubMed1998

Proteolysis negatively regulates agonist-stimulated arachidonic acid metabolism.

Phenylmethylsulphonyl fluoride, lactacystin (a selective inhibitor of the proteasome) and the peptide aldehydes carbobenzoxyleucylleucylnorvalinal and carbobenzoxyleucylleucylleucinal amplify the production of prostacyclin in rat liver cells incubated for 6 h with the tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and the TPA-type tumour promoters teleocidin and aplysiatoxin. Such stimulation is not dependent upon the simultaneous presence of the inhibitor and TPA. Preincubation of the cells with TPA followed by addition of the inhibitor or preincubation with the inhibitor followed by addition of TPA results in amplified prostacyclin production. Phenylmethylsulphonyl fluoride, lactacystin, and carbobenzoxyleucylleucylnorvaline also enhance prostacyclin production after incubation with interleukin-1beta and transforming growth factor-alpha. The Ca2+ chelator ethyleneglycol-O,O'-bis(2-aminoethyl)-N,N,N',N'-tetraacetic acid inhibits the phenylmethylsulphonyl fluoride-TPA or lactacystin-TPA amplifications. Cells, treated with phenylmethylsulphonyl fluoride, TPA, interleukin-1beta, lactacystin or the peptide aldehydes exhibit increased prostaglandin endoperoxide G/H synthase activity. The increased activities as well as the constitutive prostaglandin endoperoxide G/H synthase activity are inhibited by a selective prostaglandin endoperoxide G/H synthase-2 inhibitor, 1-[2-(4-fluorophenyl)-cyclopenten-1-yl]-4-(methysulphonyl)-b enzene, with an IC50 of approximately 0.5 microM. These results demonstrate that the C-9 rat liver cells express prostaglandin endoperoxide G/H synthase-2 constitutively and express induced prostaglandin endoperoxide G/H synthase-2. Inhibition of proteolytic activity amplifies agonist-stimulated arachidonic acid metabolism in these cells.

Acetylcysteine↗
PubMed1998

Evaluation of clothing systems to determine heat strain.

This article describes the basic evaluation process and test methodology employed when temperature extremes for clothing systems must be considered as part of the U.S. Army's Health Hazard Assessment for material in the development and acquisition process. The goals of the evaluation are to select clothing systems that minimize the hazards of heat strain and to predict the heat strain for persons wearing such clothing. Clothing evaluations begin with biophysical assessments that determine the thermal characteristics (vapor permeability and insulation) for textiles via guarded hot plate tests and for clothing systems via thermal manikin tests. The results from biophysical tests can be used to select the textile and/or clothing with the best thermal characteristics. The data from manikin evaluations also can be used in prediction modeling. Human physiological testing is best done in a controlled laboratory environment, although for realism and user acceptability field trials may also be conducted. Proven test and measurement methods must be employed, and tests must control for confounding variables; subjects serve as their own controls, and test environment and procedures are consistent between trials. The process and test methodology described can be applied to the evaluation of civilian clothing systems as well as to the military systems for which they were developed.

Hot Temperature↗
PubMed1998

No evidence for significant linkage between bipolar affective disorder and chromosome 18 pericentromeric markers in a large series of multiplex extended pedigrees.

Bipolar affective disorder (BP) is a major neuropsychiatric disorder with high heritability and complex inheritance. Previously reported linkage between BP and DNA markers in the pericentromeric region of chromosome 18, with a parent-of-origin effect (linkage was present in pedigrees with paternal transmission and absent in pedigrees with exclusive maternal inheritance), has been a focus of interest in human genetics. We reexamined the evidence in one of the largest samples reported to date (1,013 genotyped individuals in 53 unilineal multiplex pedigrees), using 10 highly polymorphic markers and a range of parametric and nonparametric analyses. There was no evidence for significant linkage between BP and chromosome 18 pericentromeric markers in the sample as a whole, nor was there evidence for significant parent-of-origin effect (pedigrees with paternal transmission were not differentially linked to the implicated chromosomal region). Two-point LOD scores and single-locus sib-pair results gave some support for suggestive linkage, but this was not substantiated by multilocus analysis, and the results were further tempered by multiple test effects. We conclude that there is no compelling evidence for linkage between BP and chromosome 18 pericentromeric markers in this sample.

Adolescent↗
PubMed1998

Can academic radiology departments become more efficient and cost less?

PURPOSE: To determine how successful two large academic radiology departments have been in responding to market-driven pressures to reduce costs and improve productivity by downsizing their technical and support staffs while maintaining or increasing volume. MATERIALS AND METHODS: A longitudinal study was performed in which benchmarking techniques were used to assess the changes in cost and productivity of the two departments for 5 years (fiscal years 1992-1996). Cost per relative value unit and relative value units per full-time equivalent employee were tracked. RESULTS: Substantial cost reduction and productivity enhancement were realized as linear improvements in two key metrics, namely, cost per relative value unit (decline of 19.0% [decline of $7.60 on a base year cost of $40.00] to 28.8% [$12.18 of $42.21]; P < or = .001) and relative value unit per full-time equivalent employee (increase of 46.0% [increase of 759.55 units over a base year productivity of 1,651.45 units] to 55.8% [968.28 of 1,733.97 units]; P < .001), during the 5 years of study. CONCLUSION: Academic radiology departments have proved that they can "do more with less" over a sustained period.

Academic Medical Centers↗
PubMed1997

HLA-DQA1 and polymarker allele frequencies in two New York City Jewish populations.

Allele and genotype frequencies were determined for the HLA-DQA1 and Amplitype Polymarker loci (low density lipoprotein receptor (LDLR), glycophorin A (GYPA), hemoglobin G gammaglobin (HBGG), D7S8, and group-specific component (Gc)) in Hasidic and non-Hasidic Ashkenazi New York City Jewish subpopulations. For all loci tested, except HBGG, the 2 subpopulations meet the assumption of Hardy-Weinberg equilibrium. Comparison of various allele and genotype frequencies for the Hasidic and the non-Hasidic groups showed no significant differences. Comparison of the various allele frequencies in the two subpopulations to another Caucasian group revealed significant differences at the HLA-DQA1 and D7S8 loci in the Hasidic group. These frequency data can be used for comparison to other populations and for frequency estimates in DNA profiling.

Blood Grouping and Crossmatching↗
PubMed1996

Is there an error correcting code in the base sequence in DNA?

Modern methods of encoding information into digital form include error check digits that are functions of the other information digits. When digital information is transmitted, the values of the error check digits can be computed from the information digits to determine whether the information has been received accurately. These error correcting codes make it possible to detect and correct common errors in transmission. The sequence of bases in DNA is also a digital code consisting of four symbols: A, C, G, and T. Does DNA also contain an error correcting code? Such a code would allow repair enzymes to protect the fidelity of nonreplicating DNA and increase the accuracy of replication. If a linear block error correcting code is present in DNA then some bases would be a linear function of the other bases in each set of bases. We developed an efficient procedure to determine whether such an error correcting code is present in the base sequence. We illustrate the use of this procedure by using it to analyze the lac operon and the gene for cytochrome c. These genes do not appear to contain such a simple error correcting code.

Base Sequence↗
PubMed1996

Ryanodine receptor adaptation and Ca2+(-)induced Ca2+ release-dependent Ca2+ oscillations.

A simplified mechanism that mimics "adaptation" of the ryanodine receptor (RyR) has been developed and its significance for Ca2+(-)induced Ca2+ release and Ca2+ oscillations investigated. For parameters that reproduce experimental data for the RyR from cardiac cells, adaptation of the RyR in combination with sarco/endoplasmic reticulum Ca2+ ATPase Ca2+ pumps in the internal stores can give rise to either low [Cai2+] steady states or Ca2+ oscillations coexisting with unphysiologically high [Cai2+] steady states. In this closed-cell-type model rapid, adaptation-dependent Ca2+ oscillations occur only in limited ranges of parameters. In the presence of Ca2+ influx and efflux from outside the cell (open-cell model) Ca2+ oscillations occur for a wide range of physiological parameter values and have a period that is determined by the rate of Ca2+ refilling of the stores. Although the rate of adaptation of the RyR has a role in determining the shape and the period of the Ca2+ spike, it is not essential for their existence. This is in marked contrast with what is observed for the inositol 1,4,5-trisphosphate receptor for which the biphasic activation and inhibition of its activity by Ca2+ are sufficient to produce oscillations. Results for this model are compared with those based on Ca2+(-)induced Ca2+ release alone in the bullfrog sympathetic neuron. This kinetic model should be suitable for analyzing phenomena associated with "Ca2+ sparks," including their merger into Ca2+ waves in cardiac myocytes.

Animals↗
PubMed1996

Prostacyclin production after treatment of rat liver cells with tosyl-L-phenylalanine chloromethyl ketone and 12-O-tetradecanoylphorbol-13-acetate is mediated by a phorbol-ester-stimulated intermediate.

The prostacyclin (PGI2) production in rat liver cells by treatment by N-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and 12-O-tetradecanoylphorbol-13-acetate (TPA) is not dependent upon the simultaneous presence of both ligands. Preincubation of the rat liver cells with TPA followed by addition of TPCK, as well as preincubation of the cells with TPCK followed by addition of TPA, results in PGI2 production. Maximum production is found after a 10 min incubation with TPA or after a 120 min incubation with TPCK. Preincubation with TPA for longer than 10 min or preincubation with TPCK for longer than 2 h results in reduced stimulation of PGI2 production. Dexamethasone does not eliminate the effects of either preincubation or simultaneous addition of TPCK and TPA. EGTA does not affect either preincubation reaction but does completely inhibit PGI2 production after simultaneous addition of the agents. Preincubation of the cells for 30 min with aspirin completely inhibits the TPCK-TPA-stimulated PGI2 synthesis. The PGI2 production following exogenous addition of arachidonic acid to the cells is unaffected by prior treatment of the cells with TPA, TPCK, or TPA plus TPCK. Taken together the data suggest that TPA stimulates the production of an intermediate which activates a Ca(2+)-dependent phospholipase activity. The intermediate is inactivated by a protease which is inhibited by the SH-reactive agent TPCK. The released arachidonic acid is oxygenated by the constitutively expressed cyclooxygenase (prostaglandin H synthase-1).

Animals↗
PubMed1996

Inspiratory resistance effects on exercise breathing pattern relationships to chemoresponsiveness.

This study examined the effects of added inspiratory resistance (R5 5 cm H2O.L-1.S-1) on the relationship between exercise breathing pattern and resting hypercapnic ventilatory responsiveness (HCVR). Twelve men completed an HCVR test and two progressive intensity exercise tasks with minimal (R0) and elevated (R5) resistance. Peak oxygen uptake, and peak power output were not different, but peak VE was decreased with the R5 load. Exercise ventilation (VE was tightly coupled to VCO2 (r = 0.97) as was mean inspiratory flow rate (VT/TI, r = 0.95), but not duty cycle (TI/TTOT, r = 0.39). With imposition of R5, VT/TI was depressed (p < 0.05) at mild (approximately 40% VO2peak) to peak exercise intensities, whereas TI/TTOT was relatively unaffected. At both moderate (approximately 60% peak VO2) and peak exercise intensities, VE was positively correlated (r = 0.62, p < 0.05 and r = 0.82, p < 0.01, respectively) to subjects' HCVR. However, when normalized, VE.VCO2(-1) was significantly correlated to HCVR only at peak exercise ventilation during the R0 load. Analysis of the exercise breathing pattern revealed that at both moderate and peak exercise intensities, VT/TI was positively correlated to HCVR, but TI/TTOT was not. The imposition of R5 decreased the slope of the relationship between exercise VT/TI and HCVR at both moderate and peak exercise intensities, and weakened the positive correlation at the moderate exercise intensity. Our analysis indicates that: 1) the positive correlation between exercise hyperpnea and HCVR is mediated by the mean inspiratory flow rate rather than the duty cycle component of the breathing pattern and, 2) at moderate exercise the relationship between mean inspiratory flow rate and resting HCVR is more sensitive to added inspiratory resistance than minute ventilation per se. These findings suggest that the degree of influence resting HCVR has on exercise hyperpnea is dependent upon the magnitudes of both the ventilatory hyperpnea and mechanical loading placed on the ventilatory system.

Adult↗
PubMed1996

"Things were different then": countertransference issues for younger female therapists working with older female clients.

Older, pre-feminist women have different expectations about marital fulfillment and their role in society than younger women who have grown up with feminist ideals. These differences can emerge within the clinical encounter between a younger female therapist working with an older female client, especially as the latter reviews her life and marital history. This paper discusses the countertransference reactions cross-generational disparities engender in the younger female clinician. The author posits that these need to be examined and addressed in order to build a therapeutic alliance and temper empathic failure on the part of the therapist. The literature on countertransference reactions with the elderly and the role of the life review process is reviewed. The impact of the women's movement and implications for clinical practice are discussed.

Adult↗
PubMed1995

Rhabdoid tumor of the kidney with humoral hypercalcemia and parathyroid hormone-related protein production.

This is a report of a 7-month-old infant with malignant rhabdoid tumor of the kidney (RTK). The patient (pt) demonstrated clinical and biochemical evidence of humoral hypercalcemia of malignancy (HHM). The hypercalcemia responded promptly to calcitonin treatment and tumor removal. Despite aggressive surgery and chemotherapy, the patient expired four months after diagnosis. The primary tumor displayed adenylate cyclase-stimulating activity (ACSA) indicating the production of parathyroid hormone-related protein (PTHrP) by the primary tumor. This is the first report of ACSA documented in a pt with RTK.

Humans↗
PubMed1995

Amplification of arachidonic acid metabolism in rat liver cells (the C-9 cell-line) by tosyl-L-phenylalanine chloromethyl ketone and phenylmethyl-sulfonyl fluoride.

In the presence of the protease inhibitors phenylmethyl-sulfonyl fluoride and N-tosyl-L-phenylalanine chloromethyl ketone, prostacyclin (PGI2) production by rat liver cells treated with epidermal growth factor, platelet-activating factor, 12-0-tetradecanoylphorbol-13-acetate (TPA), and TPA-type tumor promoters (teleocidin and aplysiatoxin) or 1-oleoyl-2-acetylglycerol is amplified. The PGI2 production stimulated by thapsigargin or exogenous arachidonic acid is not amplified. N-Tosyl-L-phenylalanine chloromethyl ketone also amplifies TPA's release of radioactivity from cells isotopically labeled with [3H]arachidonic acid. Indomethacin inhibits the amplification of PGI2 production but no the release of radioactivity. The presence of the protease inhibitors is not required for the amplification of PGI2 production. Prior incubation of the cells with these inhibitors, followed by their removal, still results in amplified PGI2 production by cells subsequently treated with TPA, 1-oleoyl-2-acetylglycerol, or platelet-activating factor but not that stimulated by exogenous arachidonic acid. While phenylmethyl-sulfonyl fluoride's amplification of PGI2 production by cells treated with TPA was blocked by prior incubation with TPA for 20 h, a similar block of amplification in EGF-treated cells was not observed.

Animals↗
PubMed1995

Metabolic and thermal adaptations from endurance training in hot or cold water.

Metabolic and thermal adaptations resulting from endurance training in hot vs. cold water were compared. It was hypothesized that training in hot water would have greater effects on muscle glycogen use and blood lactate accumulation during exercise than training in cold water. Eighteen men exercised at 60% of maximal oxygen uptake while immersed in hot (n = 9) or cold water (n = 9) for 1 h, 5 days/wk, for 8 wk. Training in hot water (35 degrees C) potentiated body temperature increases during exercise, and training in cold water (20 degrees C) blunted body temperature increases during exercise. Before and after training, cardiorespiratory and thermoregulatory responses and muscle glycogen and blood lactate changes were assessed during a 1-h exercise trial in hot water and, on a separate day using the same intensity, in cold water. Oxygen uptake was similar for all trials, averaging 2.0 +/- 0.1 l/min. It was observed that 1) training reduced glycogen use and lactate accumulation during exercise, with no difference between cold and hot water training groups in the magnitude of this effect; 2) lactate accumulation during exercise was the same in hot water as in cold water; and 3) skin temperature decreased more rapidly during cold-water exercise after than before training, with no difference between cold and hot water training groups in the magnitude of this effect. Thus, exercise-induced body temperature increases are not an important stimulus for glycogen-sparing effects and blunted lactate accumulation associated with endurance training.

Adaptation, Physiological↗