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Biomedical subjects

S Wu

Publications and source records attributed to S Wu.

At least 523 records · Page 29Linked to original sources
PubMed1990

[Clinical observation and experimental study of the treatment of aplastic anemia by warming and tonifying the spleen and kidney].

84 cases observed were divided into 4 types according to principles of diagnosis and treatment based on an overall analysis of symptoms and signs, namely: Yang-deficiency of the Spleen and Kidney (62 cases, 73.8%), Yin-deficiency leads to internal heat (6 cases), deficiency of both the Heart and the Spleen (7 cases), and prostration of Qi after loss of blood (9 cases). The patients were treated with the method of warming and tonifying the Spleen and Kidney by using Er-Xian decoction of warming the Kidney. The three other types were also treated with the method after being relieved with the methods of tonifying the Heart and the Spleen, of nourishing Yin to relieve internal heat and cooling blood, and of strengthening Yang to stop chronic hemorrhage respectively so that function of the blood and Qi would promote each other and be improved. The total effective rate was 84.5%, and remission rate was 47.6% among 84 cases, but 91.9% and 50.0% in the type of Yang-deficiency of the Spleen and Kidney alone. Among the effective cases there was a remarkable improvement in the hemogram after treatment (P less than 0.001, less than 0.01), and the long-termed curative effect was also exciting. The mechanism of Er-Xian decoction of warming the Kidney was investigated through the nourishment of the hemopoiesis stem cell. The experiment showed that the decoction could increase CFU-S and GM-CFU in the bone marrow under the lower hemopoietic function of the bone marrow, and increase GM-CFU and CFU-E in the bone marrow of normal rats (P less than 0.001, less than 0.01, less than 0.05). The histological findings showed that there was a reduction in hemorrhage and hyperemia in the bone marrow between the decoction group and the control group, and the recovery of hemopoietic function was better than the latter.

Adolescent↗
PubMed1989

High-sensitivity fluorescence detector fluorescein isothiocyanate derivatives of amino acids separated by capillary zone electrophoresis.

A fluorescence detector has been developed for capillary zone electrophoresis that produces a ten-fold improvement in precision compared with the previous state-of-the-art in fluorescence detection. This instrument, which is based on a sheath-flow cuvette flow chamber and a 0.05-W argon ion laser beam, combines a high numerical aperture collection optic, N.A = 0.65, with a high quantum yield photomultiplier tube, phi approximately = 0.15 at the wavelength of maximum emission. Detection limits (3 sigma) range from the injection of 1.7 . 10(-21) mol (1.3 . 10(-12) M) of fluorescein isothiocyanate (FITC)-labeled arginine, the best case, to 6 . 10(-21) mol (5.6 . 10(-12) M) of FITC-cysteine, the worse case. Signal linearity extends for at least five orders of magnitude from the detection limit to greater than 10(-16) mol (10(-7) M) injected.

Amino Acids↗
PubMed1989

Reversibility of chronic alcohol cardiac depression: 31P magnetic resonance spectroscopy in hamsters.

In order to investigate the reversibility of chronic alcohol cardiac depression, hamsters were fed with 50% ethanol for 3 1/2 months, reaching serum alcohol levels of 0.13 +/- 0.11 g/dl (mean +/- SD). Alcohol was then withdrawn for 2 days. Isolated hearts were perfused according to a modified Langendorff method. Energy metabolites were studied using 31P magnetic resonance spectroscopy of isolated perfused hearts standardized by HPLC analysis of freeze-clamped tissue. Total intracellular calcium [Ca2+]i was measured with atomic absorption spectrophotometry, marking the extracellular space in vivo with K(CoEDTA). In alcohol-treated hamster hearts developed pressure was significantly depressed compared to controls. End-diastolic pressure was significantly increased. Coronary flow was not changed, whereas oxygen consumption and high-energy phosphate levels were significantly depressed. Intracellular pH was significantly decreased. [Ca2+]i was significantly increased. Heart weights were significantly lower. After alcohol withdrawal ventricular function, high-energy phosphate levels, and [Ca2+]i were not significantly different from control. The results indicate that chronic alcohol consumption depresses ventricular function and energy levels and also leads to myocardial acidosis. The increase in intracellular calcium likely causes mitochondrial dysfunction. Withdrawal of alcohol is associated with reversibility of functional and energetic cardiac depression.

Animals↗
PubMed1989

Effects of perfusion pressure on energy and work of isolated rat hearts.

A chemomechanical study of hypertrophied hearts of 6-month-old spontaneously hypertensive rats (SHR) and that of age-matched Wistar-Kyoto (WKY) rats was carried out, analyzing the response of the heart to steady-state changes in coronary perfusion pressure. The ratio of heart (dry)-to-body (wet) weight of WKY rats was 0.37 +/- 0.02 (10(-3] and for SHR was 0.58 +/- 0.03 (10(-3] (p less than 0.01). In the apex-ejecting, isolated, pyruvate-perfused working hearts of WKY rats and SHR, coronary flow was constant when coronary perfusion pressure was set between 140 and 190 cm H2O (range of autoregulation). Coronary flow was perfusion pressure dependent when the coronary perfusion pressure was set below 110 cm H2O for both WKY rats and SHR. Cardiac output, developed pressure, rate of pressure development (dP/dt), and oxygen consumption were constant in the range of autoregulation but decreased in the direction of coronary flow when coronary flow was reduced by a drop in perfusion pressure. Similarly, the phosphorylation potential, phosphocreatine, adenosine triphosphate, and cyclic adenosine monophosphate were constant in the range of autoregulation but decreased directionally with coronary perfusion pressure below 110 cm H2O for both SHR and WKY rats. There was a significantly lower phosphorylation potential in SHR as compared with WKY rats when coronary perfusion pressure was reduced to 80 cm H2O. In the region of autoregulation, coronary flow and oxygen consumption were significantly less in SHR, although developed pressure was significantly greater at both high and low workloads.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Expression of human interferon beta gene controlled by SV40 late promoter in mouse myeloma SP2/0 cells].

The HindII fragment of human interferon beta (IFN-beta) gene was inserted downstream from SV40 late promoter in pSV2-dhfr and cotransfered with pSV2-gpt into the mouse myeloma SP2/0 cells which were hypoxanthine guanine phosphoribosyl transferase (HGPRT) deficient. After the selection in HAT (Hypoxanthine Aminopterine Thymidine) medium containing myciphenolic acid and xanthine, the efficient constitutive expression of IFN-beta could be detected in the supernatant of the survive cells.

Animals↗
PubMed1988

Reversibility of acute alcohol cardiac depression: 31P NMR in hamsters.

Isolated hamster hearts were perfused with 2% ethanol for 30 min and then reequilibrated with control medium. One group of hamsters was pretreated with verapamil. Another group received diltiazem. Myocardial verapamil levels were 9.5 +/- 0.7 mg/g dry wt; diltiazem levels were 22 +/- 7 mg/g dry wt. Energy metabolites were assessed by using 31P NMR standardized with high-pressure liquid chromatography of freeze-clamped tissue. Intracellular calcium was measured by atomic absorption spectrophotometry, marking the extracellular space with K(CoEDTA). After 30 min of perfusion, untreated hamster hearts showed a 74% decrease in developed pressure, a marked increase in end-diastolic pressure, a decrease of ATP from 9.8 to 8.8 mmol, and an increase of Pi from 6.7 to 9.8 mmol, but no change of phosphocreatine (PCr) or intracellular pH (pHi). Verapamil pretreatment partially prevented cardiac depression during alcohol perfusion. Whereas diltiazem had no protective effect. After reequilibration, developed pressure and oxygen consumption significantly exceeded control values. ATP decreased to 8 mmol; pHi, PCr, and Pi showed no significant change. Verapamil-pretreated hearts showed better performance than untreated hearts without change in PCr and Pi, whereas ATP dropped slightly to 8.7 mmol. Thus, functional cardiac depression resulting from acute alcohol exposure is reversible. Increased intracellular calcium levels during alcohol exposure normalized after the removal of alcohol. There was no major change in high-energy phosphates during alcohol exposure or after the removal of alcohol. Verapamil protects the heart from functional depression during alcohol exposure without affecting energy resources.

Adenine Nucleotides↗
PubMed1988

31P and 1H magnetic resonance spectroscopy of acute alcohol cardiac depression in rats.

Cardiac depression in the isolated rat heart perfused with 4% ethanol was correlated with intracellular phosphate energetics and tissue water distributions. Energy metabolites were assessed using 31P magnetic resonance spectroscopy (MRS) and correlated to the mitochondrial redox state using epicardial surface fluorometry. Changes in myocardial water compartmentation were measured by using 1H NMR spectroscopy with an extracellular chemical-shift reagent (DyTTHA) and correlated to results of 2D echocardiography (2DE). During alcohol perfusion there was a significant decrease in developed pressure and in coronary flow. No change was seen in ATP, PCr, pHi, Pi, or NADH. After withdrawal of alcohol from the perfusate cardiac function reverted to control values without a depletion of energy levels. During alcohol perfusion 1H MRS showed a marked redistribution of water from the intra- to the extracellular space, corresponding to a 35% left ventricular wall thinning confirmed by 2DE. The results indicate that acute alcohol cardiac depression is related to a dehydration of myocardial cells, but is not associated with intracellular acidosis or energy depletion.

Acute Disease↗
PubMed1988

Increased left ventricular diastolic stiffness in the early phase of hereditary cardiomyopathy.

Isolated hearts from normal and cardiomyopathic hamsters (160 to 180 days of age) were perfused through the aorta and assessed by echocardiographic and 31P-NMR (nuclear magnetic resonance) techniques. A decreased left ventricular systolic pressure in cardiomyopathic hamsters was associated with diminished cardiac size and left ventricular wall thickness. However, the ratio of inner/outer cross-sectional area and estimated left ventricular volume at any given left ventricular weight was significantly higher, indicating relative left ventricular chamber enlargement in cardiomyopathic hamsters. Left ventricular volumes were increased with an intraventricular balloon. Gradual inflation of the balloon resulted in increments of left ventricular systolic and developed stress that rose to the same values in both groups. At this point, the normalized stress-strain relationship was approximately two times steeper for cardiomyopathic hamsters, while at lower strain values the diastolic stress in cardiomyopathic hamsters was less than in controls, possibly due to cardiac dilatation. Almost the same degree of dilatation was induced in control hearts by the acute addition of 1% alcohol, but it was not followed by increased diastolic stiffness. Examination of hearts by 31P-NMR techniques revealed a decreased phosphocreatine/inorganic phosphate (PCr/Pi) ratio in the cardiomyopathic hamsters that progressed further with balloon inflation and was associated with a relative fall in PCr and adenosine triphosphate (ATP) content. Results suggest increased diastolic stiffness in cardiomyopathic hamsters, which was not seen in acute cardiac depression with alcohol. Diastolic volume overload with increased wall stress is probably the major factor contributing to increased diastolic stiffness early in the cardiomyopathy.

Adenosine Triphosphate↗
PubMed1988

Mechanics and energetics of overstretch: the relationship of altered left ventricular volume to the Frank-Starling mechanism and phosphorylation potential.

Isovolumic perfused rat hearts containing an intraventricular balloon were used to assess the effects of incremental balloon volumes on developed pressure, oxygen consumption, coronary flow, phosphorylation potential obtained by P-31 nuclear magnetic resonance, wall thickness obtained by two-dimensional echocardiography, and diastolic wall stress. Three phases in developed pressure were noted: (1) volumes from 0 to 150 microliter resulted in a continuous increase in developed pressure; (2) with volumes from 150 to 250 microliter, developed pressure remained constant whereas developed (systolic) and diastolic wall stress rose sharply; and (3) with volumes from 250 to 400 microliter, developed pressure fell whereas developed (systolic) and diastolic wall stress continued to rise. The ln [(PCr)/(Pi)] was in synchrony with oxygen consumption at 0 and 50 microliter balloon volumes, and then diverged at volumes greater than 100 microliter. Oxygen consumption increased from 0 to 50 microliter, was constant from 50 to 250 microliter balloon volume, and then declined. The ln [(PCr)/(Pi)] fell precipitously at balloon volumes greater than 100 microliter, most likely limited by oxygen consumption. Coronary flow did not change significantly until 250 microliter or more of water was added to the balloon, and then it started to decline. Volumes greater than 100 microliter result in overstretch of myofibers, as observed by the precipitous decline in ln [(PCr)/(Pi)], and the steep increase in diastolic wall stress. With excessive volume loading, the drop in phosphorylation potential, ln [(PCr)/(Pi)], appears to contribute to the decrease in developed pressure.

Adenosine Triphosphate↗
PubMed1988

The human villous cytotrophoblast: interactions with extracellular matrix proteins, endocrine function, and cytoplasmic differentiation in the absence of syncytium formation.

Human syncytiotrophoblasts are derived from villous cytotrophoblasts by cell fusion. Coincident with this morphologic transformation, trophoblasts acquire specific endocrine functions, including elaboration of chorionic gonadotropin (hCG). We wondered if syncytia formation was a prerequisite for biochemical differentiation or simply was one part of the differentiation program. By growing purified human cytotrophoblasts under serum-free conditions and manipulating the culture surface, we were able to disassociate morphologic from biochemical differentiation. We have shown previously (Endocrinology 1986, 118:1567) that human cytotrophoblasts grown in the presence of fetal calf serum flatten out, aggregate, and form functional syncytiotrophoblasts in vitro over 24-96 hr. Here we demonstrate that when grown in the absence of serum, the cells do not undergo these morphologic changes, but remain as individual spherical cells. If the culture surface was precoated with fibronectin or a variety of collagens, but not albumin, the cells regained their ability to flatten, aggregate, and form syncytia. Attachment to and syncytia formation on fibronectin was blocked by the addition of the R-G-D-S-containing peptide, Gly-Arg-Gly-Asp-Ser-Pro. Attachment to and syncytia formation on type I collagen was blocked by anti-human fibronectin F(ab')2 fragments, while association with type IV collagen was not affected by this antibody, suggesting that fibronectin mediates trophoblast association with type I collagen, but not type IV. Although syncytia formation did not occur when cytotrophoblasts were cultured under serum-free conditions in the absence of ECM proteins, biochemical differentiation was not affected. These cells secreted hCG at the same rate under serum-free conditions whether they were plated on plastic only--which prevented syncytia formation--or fibronectin, laminin or, type IV collagen--which allowed syncytia formation to occur. Furthermore, cytoplasmic differentiation in the absence of syncytia formation was confirmed by performing transmission electron microscopy on cytotrophoblasts grown under serum-free conditions in the presence of 8-bromo-cAMP. We conclude that syncytia formation is not a prerequisite for biochemical differentiation, but simply part of the trophoblast differentiation program.

Cell Adhesion↗
PubMed1987

Influence of heart rate on metabolic and hemodynamic parameters in the Syrian hamster cardiomyopathy.

The effect of varying heart rate in 155- to 170-day-old isolated, perfused cardiomyopathic Syrian hamster hearts was evaluated by 31P nuclear magnetic resonance spectroscopy. At a low paced heart rate of 170 bpm, cardiomyopathic hearts did not differ from normal hearts except for a lower developed left ventricular pressure. As pacing rate was increased progressively to 270/min, cardiomyopathic hearts showed prolongation of contraction, which led to a pronounced rise in diastolic pressure as the interstimulus interval shortened. This was accompanied by a marked decrease in energy-rich phosphorus compounds. By contrast, increasing heart rate in normal hearts did not change left ventricular pressure and caused only a mild reduction in energy-rich phosphorus compounds. Intracellular pH of cardiomyopathic animals paced at 270 bpm was significantly lower than in normal animals. Thus, indices reflecting mitochondrial function of 155- to 170-day-old cardiomyopathic hamsters appear adequate at low heart rate. Increasing the heart rate unmasks latent mitochondrial dysfunction.

Adenosine Triphosphate↗
PubMed1987

Protein analysis of HLA-DR2.3 haplotype.

The human major histocompatibility antigens (HLA-DR, HLA-DQ, and HLA-DP), consisting of alpha and beta chains, show extensive polymorphism. Based on differences of T-cell responses, the serologically defined DR2 specificity has been divided into Dw2, Dw12, and several putative additional "Dw subtype" specificities (AZH, FJO, and MN2, which we shall designate as "DR2.3", and LD-5a). To investigate the relationships of these specificities, DR and DQ molecules were analyzed by two-dimensional gel electrophoresis (2D-PAGE). The 2D-PAGE patterns of the DR molecules are identical among DR2.3 cells. Three DR beta chain polypeptides are expressed on DR2.3 cells. The electrophoretic mobilities of two of these beta chains are different from those of beta chains from the Dw2 and Dw12 cells. The DR molecules of the LD-5a cells show similar 2D-PAGE patterns with those of DR2.3 cells. The 2D-PAGE patterns of DQ molecules are identical among DR2.3 cells. The electrophoretic mobilities of DQ beta chains are different for Dw2, Dw12, LD-5a, and DR2.3 cells. These results indicate that the AZH, FJO, and MN2 cells have identical or very similar DR and DQ molecules and constitute a third, and relatively homogeneous, subgroup ("DR2.3") of the DR2 specificity. In addition, DR2.3 cells have a unique characteristic in that they express three DR beta chains.

Antibodies, Monoclonal↗
PubMed1987

Effects of altered coronary perfusion pressure on function and metabolism of normal and cardiomyopathic hamster hearts.

The effects of a sudden decrease in coronary perfusion pressure from 140 to 0 cmH2O for a 10-second interval were analyzed in normal and cardiomyopathic hamster hearts to determine whether cardiomyopathy would affect the relationship between altered coronary perfusion pressure and left ventricular geometry, wall thickness, myocardial hydrodynamics, and hemodynamics. In normal hamsters, an acute reduction in coronary perfusion pressure resulted in a decrease in left ventricular short axis epicardial cross-sectional area, base to apex length, diastolic wall thickness, myocardial water content and developed pressure. In cardiomyopathic hamsters all results induced by lowering the hydrostatic pressure of the perfusing medium were the same except that diastolic wall thickness failed to decline, indicating a decrease in intramyocardial elasticity in dilated cardiomyopathy. In parallel studies, hearts were freeze clamped at end-diastole and high energy phosphates and energy metabolites analyzed. In both normal and cardiomyopathic hamsters no significant changes were observed in ATP, PCr, or Pi levels at 10 s following the decrease in perfusion pressure. However, during the abrupt decrease in coronary perfusion pressure adenosine increased and cAMP decreased in both groups of animals. The erectile effect of altered coronary perfusion pressure is partially attenuated in the cardiomyopathic hamster in which no change in diastolic wall thickness occurs during an abrupt change in the hydrodynamics of the heart.

Animals↗
PubMed1987

The preventive effect of verapamil on ethanol-induced cardiac depression: phosphorus-31 nuclear magnetic resonance and high-pressure liquid chromatographic studies of hamsters.

Alcoholic depression of left ventricular function was produced in normal hamsters by the administration of increasing concentrations of alcohol in drinking water (up to 50%) for 6 months. The result was assessed by phosphorus-31 nuclear magnetic resonance of isolated perfused hearts and high-pressure liquid chromatography of freeze-clamped tissues. Hemodynamic data and myocardial oxygen consumption were also monitored. Alcoholic hamsters had significantly higher inorganic phosphate and lower ATP levels, while maintaining normal intracellular pH, phosphocreatine, and creatine. Although coronary flow and oxygen consumption were maintained at normal levels, hamsters ingesting 50% ethanol had significantly lower left ventricular developed pressure and dP/dt. Treatment with verapamil during long-term ethanol consumption prevented the development of these metabolic and functional abnormalities. It is hypothesized that alcohol produces membrane abnormalities leading to adverse ion flux, and that these are largely prevented by concurrent administration of verapamil.

Adenosine Triphosphate↗
PubMed1987

Cytogenetic analysis in workers occupationally exposed to nickel carbonyl.

Chromosomal aberration and sister-chromatid exchange (SCE) base-line frequencies and SCE frequencies induced by 10 ng/ml mitomycin C (MMC) were analysed in cultured peripheral lymphocytes of 65 workers occupationally exposed to nickel carbonyl Ni(CO)4. The subjects were divided into 4 groups: (1) control; (2) exposed to nickel carbonyl (= exposed); (3) cigarette smokers; (4) smoking-exposed. The results show that there are no significant differences in chromosomal aberration frequencies, breaks or gaps, between the various groups. However, the SCE base-line frequency of the smoking-exposed group, with an average of 7.7/cell, was significantly higher than that of the control group, with an average of 6.5/cell (P less than 0.01), and also than that of the exposed group with an average of 5.9/cell (P less than 0.01). Similarly, the SCE frequency induced by 10 ng/ml MMC in the smoking-exposed group which averaged 15.5/cell was significantly higher than that of the control group (average of 13.2/cell (P less than 0.05], and also than that of the exposed group with an average of 12.3/cell (P less than 0.01). Under our experimental conditions, it may be that the level of exposure was not high enough to elicit an increase in chromosomal aberrations and SCE frequencies in the non-smoker exposed group. The fact that an increase in SCE frequencies was only found in the smoking-exposed group implies that the two factors, smoking and exposure to nickel carbonyl, are jointly responsible for the result.

Cells, Cultured↗
PubMed1987

The three-dimensional structure of trichosanthin molecule.

A model completed recently of two trichosanthin molecules in an asymmetric unit belonging to the monoclinic system is reported. It can be seen that the molecular structure consists of two domains, one large and one small, and that there are some features in the secondary structure. The dissimilarity between two molecules as well as their interactions in an independent unit correlated in a non-symmetric way has been described, moreover, the binding sites of the heavyatom position in the derivatives are also discussed.

Abortifacient Agents↗