[Hormone replacement therapy of postmenopausal osteoporosis].
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Estradiol↗
Biomedical subjects
S Lin
Publications and source records attributed to S Lin.
[Endothelin and acute renal failure: study on their relation and possible mechanisms].
In order to investigate the role of endothelin in the pathogenesis of ARF, we determined the plasma endothelin (pET) level in different clinical ARF patients and experimental ARF rat models. It was found that pET level was significantly higher in hepatic renal syndrome (n = 9, pET 210.1 +/- 32.0 pg/ml), epidemic hemorrhagic fever (n = 18, 113.3 +/- 14.86 pg/ml), septic shock ARF (n = 8, 121.5 +/- 13.5 pg/ml), gentamicin ARF (n = 7, 55.9 +/- 6.23 pg/ml) patients, and in HgCl2 ARF (n = 8, 31.75 +/- 3.07 pg/ml), glycerine ARF (n = 8, 44.75 +/- 9.8 pg/ml) rats, compared with that of normal persons (n = 9, 33.6 +/- 3.08 pg/ml) or of normal rats (n = 10, 11.4 +/- 0.98 pg/ml). Both in the patients and animal groups, there were a linear relationship between the levels of pET and Scr (r = 0.603 4 and 0.844, P less than 0.01, respectively). Intrarenal infusion ET in dosage of 0.16 micrograms.kg-1/h produced a severe reduction of RPF and GFR in the infused kidney, without significant similar changes on the contralateral kidney. Pretreated with captopril ameliorated the renal hemodynamic changes induced by iv ET (0.67 micrograms.kg-1/h), whereas indomethacin potentiated this effect. It is concluded that both circulating or local generated ET during the ARF play an important role in the pathogenesis of ARF. RAS and PG might involve in its mechanisms.
Acute Kidney Injury↗
Adsorption-desorption isotherm hysteresis of beta-lactoglobulin A with a weakly hydrophobic surface.
Adsorption-desorption isotherms of bovine beta-lactoglobulin A (beta-lact A) on a weakly hydrophobic stationary phase (C1-ether) were measured by frontal analysis. The adsorption isotherms obtained at different pH were found to be dramatically different in shape, column capacity and desorption reversibility. At pH 4.5, an S-shaped adsorption isotherm was observed whereas at pH 6.0 a Langmuir isotherm was found. In addition, the desorption isotherm at pH 6.0 was found to overlap with the adsorption isotherm, and the adsorption-desorption process of beta-lact A under this condition could be characterized by a fully reversible Langmuir model. The desorption isotherm at pH 4.5, however, did not retrace the adsorption isotherm, resulting in hysteresis loops. A higher aggregate (tetramer) of beta-lact A is shown to be in an equilibrium with the beta-lact A protomer (dimer) at pH 4.5 whereas the dimer alone is predominant at pH 6.0. It is further shown that changes in the absorption coefficient between the adsorption and the desorption cycles for the tetramer at pH 4.5 can account for the hysteresis. The results demonstrate that pH can be a sensitive parameter in protein adsorption isotherm behavior and ultimately the behavior of species in preparative-scale chromatography.
Adsorption↗
Presence of an SH2 domain in the actin-binding protein tensin.
The molecular cloning of the complementary DNA coding for a 90-kilodalton fragment of tensin, an actin-binding component of focal contacts and other submembraneous cytoskeletal structures, is reported. The derived amino acid sequence revealed the presence of a Src homology 2 (SH2) domain. This domain is shared by a number of signal transduction proteins including nonreceptor tyrosine kinases such as Abl, Fps, Src, and Src family members, the transforming protein Crk, phospholipase C-gamma 1, PI-3 (phosphatidylinositol) kinase, and guanosine triphosphatase-activating protein (GAP). Like the SH2 domain found in Src, Crk, and Abl, the SH2 domain of tensin bound specifically to a number of phosphotyrosine-containing proteins from v-src-transformed cells. Tensin was also found to be phosphorylated on tyrosine residues. These findings suggest that by possessing both actin-binding and phosphotyrosine-binding activities and being itself a target for tyrosine kinases, tensin may link signal transduction pathways with the cytoskeleton.
Actins↗
Fibroblast and hepatocyte behavior on synthetic polymer surfaces.
Biodegradable poly(phosphoesters) with varying side group chemistry and copolymers of styrene and methyl vinyl ketone (MVK) with varying degrees of hydrophobicity were used to study the growth and behavior of surface-attached fibroblasts and hepatocytes. Mouse 3T3 fibroblasts and chicken embryo fibroblasts attached and proliferated on all of the polymers tested. Fewer cells attached to copolymers of styrene and MVK than to glass or tissue culture polystyrene controls; cell attachment to several poly(phosphoester) surfaces was indistinguishable from controls. The mean speed of fibroblast migration was faster on surfaces where fewer cells attached (59 to 84 microns/h on low attachment surfaces compared with 40 to 46 microns/h on high attachment surfaces). When surface-attached cells were stained with fluorescently labeled phalloidin, only a fraction of the cells on low attachment surfaces were shown to have prominent arrays of actin filament bundles. Chicken hepatocytes also attached to the polymer surfaces. When a suspension containing a large number of cells was placed over the polymer surfaces, approximately 50% of the hepatocytes attached during the first 9 h. Surprisingly, hepatocyte attachment and viability in culture were relatively insensitive to the chemistry of the synthetic polymer substrates. Cell number increased by about a factor of 2 over the first 48 h of culture, then decreased back to approximately 50% of initial cell number over the next several days. Cell morphology did depend on the chemical structure of the substrates.
Actins↗
Pharmacological evaluation of halogenated delta 8-THC analogs.
-(-)-5'-Bromo-delta 8-THC, (-)-5'-trifluoromethyl-delta 8-THC, (-)-5'-iodo-delta 8-THC, (-)-5'-fluoro-delta 8-THC, (-)-11-fluoro-delta 8-THC and (-)-2-iodo-delta 8-THC were synthesized and evaluated in male ICR mice for their effects on sedation, temperature, catalepsy and antinociception following intravenous injection. The analogs were also tested for relative affinities for cannabinoid binding sites derived from rat cortex membranes, using [3H] CP-55,940 as the tritiated ligand. The results showed that the 5'-bromo, 5'-iodo and 5'-trifluoromethyl analogs were 2-40 times more potent than (-)-delta 8-THC in all biological tests, while the 5'-fluoro and 11-fluoro derivatives were less active. With the 2-iodo analog, a 12-fold separation was observed between antinociception and sedation, pointing to the importance of the side chain orientation in determining cannabinoid activity and to the possible involvement of more than one cannabinoid receptor site. The pharmacological data closely paralleled the data obtained from the binding assay.
Analgesics↗
Time-resolved fluorescence of nitrobenzoxadiazole-aminohexanoic acid: effect of intermolecular hydrogen-bonding on non-radiative decay.
The fluorescence kinetics of the nitrobenzoxadiazole (NBD) chromophore were studied at low concentrations in solvents with varying polarity and hydrogen-bonding donor strength. The emission decay was essentially single exponential in all solvents studied. While the absorption and fluorescence solvatochromism is determined largely by the solvent polarity, the S1 state decay kinetics are strongly modulated by the solvent H-bonding capacity. The NBD emission lifetime, generally approximately 7-10 ns in the aprotic solvents, is reduced to 0.933 ns in water. The solvent deuterium isotope effect on the fluorescence decay is substantial in D2O and in methanol-d4, but is insignificant in DMSO-d6. These results are consistent with acceleration of S1----S0 internal conversion through an accepting vibrational mode created by intermolecular hydrogen-bonding of the NBD chromophore to an H atom-donating solvent. This work bears on the practically of using NBD as a fluorophore in assays for estrogen and progesterone receptors.
4-Chloro-7-nitrobenzofurazan↗
Low lumbar burst fractures. Comparison among body cast, Harrington rod, Luque rod, and Steffee plate.
Burst fracture of the low lumbar spine are rare and have not been well delineated in the literature. Thirty-one low lumbar burst fractures (L3-L5) were treated from 1981 through 1989. Average follow-up for 27 of the 31 patients was 46 months. Persistent complaints of back pain seemed to be found more in patients with long instrumentation and fusion and in patients with loss of lordosis. Conservative treatment of low lumbar burst fractures with body cast is a viable option in the neurologically intact patients with minimal height loss and minor angulation. If surgery is chosen, short rigid instrumentation (eg, transpedicular device) is best in accomplishing shorter fusion, maintaining vertebral height, and restoring lumbar lordosis. Harrington distraction rods improve vertebral height but produce loss of lumbar lordosis. Luque rods do not restore vertebral height and are only moderately effective in restoring lumbar lordosis. If patients are neurologically impaired in association with low lumbar burst fractures, posterior decompression by laminotomy or a transpedicular approach is generally effective. Maintaining vertebral height and restoring lumbar lordosis may be important in the prevention of disability from back pain.
Back Pain↗
[Determination and study of inorganic elements in liuwei dihuang decoction by ICP-AES].
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Calcium↗
[Anticancer element selenium in liuwei dihuang decoction].
The contents of selenium in Liuwei Dihuang decoction (six traditional Chinese drugs and their decoction, five decoctions in different compatible ways, a complex decoction of all crude drugs) have been determined by fluorescence spectrophotometric method. The result shows that element selenium is rich in Dihuang. The dissolution ratio of selenium in decoctions of each single crude drug is about 30-40%.
Drug Combinations↗
How best to teach women breast self-examination. A randomized controlled trial.
OBJECTIVE: To compare three methods for teaching breast self-examination. DESIGN: Randomized controlled trial with factorial design. SETTING: A general medicine group practice in a university hospital. PATIENTS: Continuing-care patients from 40 to 68 years of age. Of 456 eligible women, 156 refused participation, 300 were randomly assigned, 269 completed assigned interventions, and 260 completed the post-test 1 year later. INTERVENTIONS: One third of patients received nurse instruction stressing tactile skills (Mammacare group) (Mammatech Corporation, Gainesville, Florida); one third, traditional nurse instruction emphasizing technique (traditional group); and one third, no nurse instruction (control group). Half of each group received physician encouragement. MEASUREMENTS AND MAIN RESULTS: One year later, women in the Mammacare group found more lumps (mean, 57%; 95% CI, 54% to 60%) in manufactured breast models than did those in the traditional (mean, 47%; CI, 44% to 51%) and control (mean, 45%; CI, 42% to 48%) groups. Lump detection specificity was unaffected. Self-reported examination frequency rose in all groups, to 5.1 times per 6 months in the traditional group, 4.2 in the Mammacare group, and 3.9 in the control group. Physician encouragement did not improve sensitivity, specificity, or overall frequency. Women in the Mammacare group used more of seven examination techniques (4.9) than did those in the traditional (3.9) or control (3.2) groups (P less than 0.001). No group increased health care use or reported more overall worry about breast cancer. CONCLUSIONS: Mammacare instruction resulted in more long-term improved lump detection and examination technique use than did traditional instruction or physician encouragement. Breast self-examination instruction should emphasize lump detection skills.
Adult↗
Holography in artificial neural networks.
The dense interconnections that characterize neural networks are most readily implemented using optical signal processing. Optoelectronic 'neurons' fabricated from semiconducting materials can be connected by holographic images recorded in photorefractive crystals. Processes such as learning can be demonstrated using holographic optical neural networks.
Algorithms↗
Covalent labeling of the cocaine-sensitive catecholamine transporter.
Xylamine is an alkylating agent that is a substrate for and specific irreversible inhibitor of the cocaine-sensitive catecholamine transporter that functions in catecholamine reuptake into neurons and PC12 cells. [3H]xylamine prominently labels nine PC12 proteins; the relative xylamine-alkylation of a Mr 54,000 protein was decreased by cocaine and increased in the case of a PC12 variant, B9, which is deficient in catecholamine transport. [3H]xylamine labels no such protein in another transport variant, MPT1. We propose that this Mr 54,000 protein 1) is a component of the catecholamine transporter, 2) is present in B9 cells but in a conformation that reduces transporter activity and makes alkylation by xylamine more likely, and 3) is absent in MPT1 cells. Nerve growth factor treatment restores transporter activity in B9 cells but not in other transporter-deficient variants.
Alkylation↗
The RAD50 gene, a member of the double strand break repair epistasis group, is not required for spontaneous mitotic recombination in yeast.
Mutations in the RAD50 gene of Saccharomyces cerevisiae have been shown to reduce double strand break repair, meiotic recombination, and radiation-inducible mitotic recombination. Several different point mutations (including ochre and amber alleles) have been previously examined for effects on spontaneous mitotic recombination and did not reduce the frequency of recombination. Instead, the rad50 mutations conferred a moderate hyper-rec phenotype. This paper examines a deletion/interruption allele of RAD50 that removes 998 of 1312 amino acids and adds 1.1 kb of foreign DNA. The results clearly indicate that spontaneous mitotic recombination can occur in the absence of RAD50; in fact, the frequency of recombination is elevated over the wild-type cell. One possible interpretation of these observations is that the initiating lesion in spontaneous recombination events in mitosis might not be a double strand break.
Alleles↗
Prevalence of Toxoplasma gondii infection in man and animals in Guangdong, Peoples Republic of China.
Tissue and serum samples from animals and man in Guangdong Province of the Peoples Republic of China were examined for Toxoplasma gondii infection. Tissues from 519 swine, 576 rodents, 84 people, one cat and two dogs were bioassayed in mice. T. gondii was isolated from 13 pools of swine tissues, but not from any other hosts. Serum samples from animals and man were examined at 1:64 dilution in the indirect hemagglutination test. Antibodies to T. gondii were found in 10.4% of 816 pigs, 0.9% of 955 rodents, 0.7% of 3085 people, 4.4% of 90 cattle, 8.3% of 12 rabbits and 2.1% of 47 cats. None were found in 83 buffaloes.
Animals↗
MR imaging of pulmonary parenchyma and emboli by paramagnetic and superparamagnetic contrast agents.
Using experimentally induced pulmonary emboli in an animal model, three intravenously administered contrast agents, Gd-DTPA-albumin microspheres (8-15 microns, 0.2 M particles/mg protein, 39-106 micrograms Gd/mg, 50 mg/ml), Gd-DTPA-liposomes (15-30 microns, 130 micrograms/mg lipid, 6 mg Gd/ml) and superparamagnetic ferrosome, (60 nm, 100 mM iron and 20 mg lipid/ml) were examined for MR imaging. Gd-DTPA entrapped in lung capillaries did not enhance the signal intensity of lung parenchyma, but liposomes (5 ml) served as better Gd-DTPA carriers and increased the parenchymal signal intensity by up to a factor of 2.3. However, neither agent improved delineation of pulmonary emboli. Ferrosome decreased the intensity of lung parenchyma, improving detectability of pulmonary emboli by several factors.
Animals↗
Overconfident prediction of future actions and outcomes by self and others.
In a follow-up study to Dunning, Griffin, Milojkovic, and L. Ross (1990), which had investigated the phenomenon of overconfidence in social prediction, two samples of first-year undergraduates were invited to make predictions about their own future responses (and, in the case of Sample 2, also those of their roommates) over the months ahead. These predictions were accompanied by confidence estimates and were evaluated in the light of actual responses reported later by the subjects in question. The primary finding was that self-predictions, like social predictions, proved to be consistently overconfident. As in Dunning et al., moreover, overconfidence could be traced to two sources. First, expressions of particularly high confidence rarely proved to be warranted; as confidence increased, the gap between accuracy and confidence widened. Second, predictions that went against relevant base rates yielded very low accuracy in the face of relatively unattenuated confidence levels. The implications of these results are discussed, and one potentially important underlying mechanism--the failure to make adequate inferential allowance for the uncertainties of situational construal--is proposed for further research.
Choice Behavior↗
Studies on Cyanidium caldarium Phycobiliprotein Pigment Mutants.
Phycobiliprotein biosynthesis was investigated in four strains of the unicellular rhodophyte, Cyandium caldarium, with different pigment phenotypes. All strains were incapable of synthesizing phycobiliproteins when grown in the dark. Western blotting experiments showed that dark-grown cells of the wild-type and mutant GGB synthesized the alpha and beta subunit polypeptides of allophyocyanin and phycocyanin after exposure to light for 24 hours, whereas cells of mutant IIIC and GGBY did not. Similarly, light promoted the appearance of allophycocyanin and phycocyanin mRNAs in the wild-type and GGB but not in IIIC and GGBY. However, Southern blots of restricted genomic DNA from the wild type, IIIC, GGBY, and GGB, all hybridized with heterologous phycobiliprotein gene probes and revealed that all four strains contained identical Pst, EcoRI, and Dral restriction fragments containing allophycocyanin and phycocyanin genes. Cells of the wild type and GGB incubated in the dark with the heme precursor. delta-aminolevulinate, synthesized allophycocyanin and phycocyanin apoproteins providing strong evidence for the role of a tetrapyrrole in regulation of phycobiliprotein gene expression. However, cells of IIIC and GGBY incubated in the dark with delta-aminolevulinate did not contain detectable quantities of allophycocyanin or phycocyanin apoproteins. The possible role of a tetrapyrrole in phycobiliprotein gene expression and basis for the genetic lesion in mutants IIIC and GGBY is discussed.
Journal Article↗