238 research outputs found
Cloned mouse cells with natural killer function and cloned suppressor T cells express ultrastructural and biochemical features not shared by cloned inducer T cells.
We have examined the morphology, cytochemistry, and biochemistry of mouse leukocyte subsets by analyzing cloned leukocyte populations specialized to perform different immunologic functions. Cloned cells expressing high-affinity plasma membrane receptors for IgE and mediating natural killer (NK) lysis and cloned antigen-specific suppressor T cells contained prominent osmiophilic cytoplasmic granules similar by ultrastructure to those of mouse basophils. Both clones also incorporated 35SO4 into granule-associated sulfated glycosaminoglycans, expressed a characteristic ultrastructural pattern of nonspecific esterase activity, incorporated exogenous [3H]5-hydroxytryptamine, and contained cytoplasmic deposits of particulate glycogen. By contrast, cloned inducer T cells lacked cytoplasmic granules and glycogen, incorporated neither 35SO4 nor [3H]5-hydroxytryptamine, and differed from the other clones in pattern of nonspecific esterase activity. These findings establish that certain cloned cells with NK activity and cloned suppressor T cells express morphologic and biochemical characteristics heretofore associated with basophilic granulocytes. However, these clones differ in surface glycoprotein expression and immunologic function, and the full extent of the similarities and differences among these populations and basophils remains to be determined
Mast cell clones: a model for the analysis of cellular maturation.
Cloned mouse mast cells resemble, by ultrastructure, immature mast cells observed in vivo. These mast cell clones can be grown in the absence of any other cells, facilitating direct investigations of their biochemistry and function. We find that cloned mast cells express plasma membrane receptors (Fc epsilon R) that bind mouse IgE with an equilibrium constant (KA) similar to that of normal mouse peritoneal mast cells. In addition, cloned mast cells do not display detectable la antigens and cannot enhance lg secretion when added to lymphocyte cultures or mediate natural killer lysis. In the presence of 1 mM sodium butyrate, cloned mast cells stop dividing and acquire abundant electron-dense cytoplasmic granules similar to those of mature mast cells. Their histamine content increases concomitant with cytoplasmic granule maturation and may exceed that of untreated mast cells by 50-fold. Unlike peritoneal mast cells, cloned mast cells incorporate 35SO4 into chondroitin sulfates rather than heparin. These findings demonstrate that, unlike fully differentiated mouse peritoneal mast cells, cloned immature mouse mast cells contain no heparin and low levels of histamine. In addition, they establish that high-affinity Fc epsilon R are expressed early in mast cell maturation, well before completion of cytoplasmic granule synthesis and mediator storage
Magnetic-Field-Driven Superconductor-Insulator-Type Transition in Graphite
A magnetic-field-driven transition from metallic- to semiconducting-type
behavior in the basal-plane resistance takes place in highly oriented pyrolytic
graphite at a field kOe applied along the hexagonal c-axis. The
analysis of the data reveals a striking similarity between this transition and
that measured in thin-film superconductors and Si MOSFET's. However, in
contrast to those materials, the transition in graphite is observable at almost
two orders of magnitude higher temperatures.Comment: 4 Figure
Family planning outpatient provider survey; evaluating resident confidence in knowledge of family planning topics and barriers to providing effective care
The Question-
How do residents feel about their knowledge and skills in applying evidence- based care around contraception, miscarriage management and options counseling?https://knowledgeconnection.mainehealth.org/lambrew-retreat-2021/1018/thumbnail.jp
Electron Glass in Ultrathin Granular Al Films at Low Temperatures
Quench-condensed granular Al films, with normal-state sheet resistance close
to 10 k, display strong hysteresis and ultraslow, non-exponential
relaxation in the resistance when temperature is varied below 300 mK. The
hysteresis is nonlinear and can be suppressed by a dc bias voltage. The
relaxation time does not obey the Arrhenius form, indicating the existence of a
broad distribution of low energy barriers. Furthermore, large resistance
fluctuations, having a 1/f-type power spectrum with a low-frequency cut-off,
are observed at low temperatures. With decreasing temperature, the amplitude of
the fluctuation increases and the cut-off frequency decreases. These
observations combine to provide a coherent picture that there exists a new
glassy electron state in ultrathin granular Al films, with a growing
correlation length at low temperatures.Comment: RevTeX 3.1, 4 pages, 4 figures (EPS files) (Minor Additions
Ghrelin
This work was supported by grants from the NIH (DP2DK105570-01 and
2P30DK046200 to MLA, DK21397 to HJG, K01DK098319 to KMH, K01MH091222 to
LH, DK093848 to RJS, R01DK082590 to LS, R01DK097550 to JT, RO1 DK 076037 to
MOT, R01DA024680 and R01MH085298 to JMZ, R01AG019230 and R01AG029740
to RGS) The Wellcome Trust (MK), Science Foundation Ireland (12/YI/B2480 to CWL),
the Alexander von Humboldt Foundation (MHT), the Deutsches Zentrum für Diabetesforschung
(MHT), the Helmholtz Alliance ICEMED e Imaging and Curing
Environmental Metabolic Diseases, through the Initiative and Networking Fund of the
Helmholtz Association (MHT), and the Helmholtz cross-program topic “Metabolic
Dysfunction” (MHT). Allan Geliebter was sponsored by NIH grants R01DK80153;
R01DK074046; R03DK068603; P30DK26687
Radial distribution of dust, stars, gas, and star-formation rate in DustPedia face-on galaxies
Aims. The purpose of this work is the characterization of the radial distribution of dust, stars, gas, and star-formation rate (SFR) in a sub-sample of 18 face-on spiral galaxies extracted from the DustPedia sample.
Methods. This study is performed by exploiting the multi-wavelength DustPedia database, from ultraviolet (UV) to sub-millimeter bands, in addition to molecular (12CO) and atomic (Hi) gas maps and metallicity abundance information available in the literature. We fitted the surface-brightness profiles of the tracers of dust and stars, the mass surface-density profiles of dust, stars, molecular gas, and total gas, and the SFR surface-density profiles with an exponential curve and derived their scale-lengths. We also developed a method to solve for the CO-to-H2 conversion factor (αCO) per galaxy by using dust- and gas-mass profiles.
Results. Although each galaxy has its own peculiar behavior, we identified a common trend of the exponential scale-lengths versus wavelength. On average, the scale-lengths normalized to the B-band 25 mag/arcsec2 radius decrease from UV to 70 μm, from 0.4 to 0.2, and then increase back up to ~0.3 at 500 microns. The main result is that, on average, the dust-mass surface-density scale-length is about 1.8 times the stellar one derived from IRAC data and the 3.6 μm surface brightness, and close to that in the UV. We found a mild dependence of the scale-lengths on the Hubble stage T: the scale-lengths of the Herschel bands and the 3.6 μm scale-length tend to increase from earlier to later types, the scale-length at 70 μm tends to be smaller than that at longer sub-mm wavelength with ratios between longer sub-mm wavelengths and 70 μm that decrease with increasing T. The scale-length ratio of SFR and stars shows a weak increasing trend towards later types. Our αCO determinations are in the range (0.3−9) M⊙ pc-2 (K km s-1)-1, almost invariant by using a fixed dust-to-gas ratio mass (DGR) or a DGR depending on metallicity gradient
Le Forum, Vol. 44 #1
https://digitalcommons.library.umaine.edu/francoamericain_forum/1103/thumbnail.jp
Targeting the androgenic pathway in elderly patients with castration-resistant prostate cancer: A meta-analysis of randomized trials
BACKGROUND:
The novel hormonal drugs have recently entered in the armamentarium of therapies for treatment of metastatic castration-resistant prostate cancer (CRPC). First reports are available for their use in elderly men with CRPC.
METHOD:
A meta-analysis of randomized controlled trials (RCTs) has been performed. PubMed, the Cochrane Library, and American Society of Clinical Oncology (ASCO) University Meeting were searched for data on the use of new hormonal treatment in elderly patients with CRPC.
RESULTS:
Nine studies for a total of 3512 elderly patients were available for meta-analysis. Six studies reported outcomes of patients aged >75 years old while 2 studies reported on patients aged >70 years old. The pooled analysis of the androgen synthesis inhibitors revealed significantly increased overall survival (OS) due to antiandrogen agents compared with placebo or placebo and prednisone (hazard ratio (HR) for death: HR = 0.74, 95% CI: 0.67-0.82; P\u200a<\u200a0.00001). Moreover, the new antiandrogenic therapy significantly improved the progression-free survival (HR = 0.45, 95% CI: 0.31-0.65; P\u200a<\u200a0.0001). The incidence of any grade 653 adverse effect was only moderately higher during with the antiandrogenic therapy as compared to the control arms (response rate = 1.03, 95% CI: 0.88-1.20; P = 0.72).
CONCLUSION:
This study confirmed that agents targeting the androgen axis (i.e., enzalutamide, abiraterone) significantly prolonged OS in elderly men with CRP
Strong Association of 677 C>T Substitution in the MTHFR Gene with Male Infertility - A Study on an Indian Population and a Meta-Analysis
Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme of folate and methionine metabolism, making it crucial for DNA synthesis and methylation. The objective of this study was to analyze MTHFR gene 677C>T polymorphism in infertile male individuals from North India, followed by a meta-analysis on our data and published studies.We undertook genotyping on a total of 837 individuals including well characterized infertile (N = 522) and confirmed fertile (N = 315) individuals. The SNP was typed by direct DNA sequencing. Chi square test was done for statistical analysis. Published studies were searched using appropriate keywords. Source of data collection for meta-analysis included 'Pubmed', 'Ovid' and 'Google Scholar'. Those studies analyzing 677C>T polymorphism in male infertility and presenting all relevant data were included in meta-analysis. The genotype data for infertile subjects and fertile controls was extracted from each study. Chi square test was done to obtain odds ratio (OR) and p-value. Meta-analysis was performed using Comprehensive Meta-analysis software (Version 2). The frequency of mutant (T) allele (p = 0.0025) and genotypes (CT+TT) (p = 0.0187) was significantly higher in infertile individuals in comparison to fertile controls in our case-control study. The overall summary estimate (OR) for allele and genotype meta-analysis were 1.304 (p = 0.000), 1.310 (p = 0.000), respectively, establishing significant association of 677C>T polymorphism with male infertility.677C>T substitution associated strongly with male infertility in Indian population. Allele and genotype meta-analysis also supported its strong correlation with male infertility, thus establishing it as a risk factor
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