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Biomedical subjects

K H Hsu

Publications and source records attributed to K H Hsu.

At least 55 records · Page 3Linked to original sources
PubMed1983

Ventilatory functions of normal children and young adults: Mexican-American, white, and black. III. Sitting height as a predictor.

We studied the ventilatory functions of 1800 normal children ranging in age 7 to 20 years. Boys and girls of black, white, and Mexican-American ethnic groups were represented adequately. The FVC and FEV1 of normal black children were fully 1 SD lower than those of white children with the same standing height. Such racial differences could not be corrected by a scaling factor, because the differences vary with sex and also with height as the children grow. Using sitting height as a predictor greatly reduced the racial differences of ventilatory functions and permitted the application of one set of prediction equations for children of all three groups.

Adolescent↗
PubMed1983

Dimethyl sulfoxide-induced transglutaminase activity in murine-derived Friend erythroleukemia cells.

Friend erythroleukemia cells (FL cells) derived from DBA/2 mice may be induced to differentiate in vitro by addition of dimethyl sulfoxide (DMSO) to the culture medium. Transglutaminase (glutaminyl-peptide gamma-glutamyltransferase, EC 2.3.2.13) (TGase) activity was detected in the lysates of uninduced FL cells and was markedly increased in DMSO-treated cells. DMSO induced TGase activity of differentiating FL cells in a dose-dependent manner over the concentration range 0-280 mM. The increase in TGase activity was observed after 1 day's cultivation of the cells with 280 mM DMSO and continued to 4 days. Another differentiation inducing agent, butyric acid (1.4 mM), was as effective as DMSO in enhancing TGase activity in FL cells. Treatment of controls, a lymphoma cell line and mouse erythrocytes, with DMSO or butyric acid had no effect. These results suggest that the increase in TGase activity in DMSO- or butyric acid-treated FL cells may be related to cell differentiation.

Acyltransferases↗
PubMed1982

Immunosuppressive effect of mouse serum lipoproteins. II. In vivo studies.

Normal mouse serum lipoproteins suppress a number of immunologic functions, such as mitogen stimulation, primary immune response, and allograft rejection in vivo. The effects of one class of lipoproteins, high density lipoprotein (HDL), were investigated after i.v. administration. Maximum suppression of spleen and peripheral blood lymphocyte (PBL) mitogen stimulation occurred when HDL was administered up to 8 hr before testing. Spleen cells remained suppressed 48 hr after injection, while PBL regained most of their activities. Injection of HDL 24 hr after sheep red blood cell (SRBC) immunization was as effective as giving HDL 8 hr before SRBC in suppressing primary immune response to SRBC. Induction of T cell allograft immunity was also suppressed by the injection of HDL.

Animals↗
PubMed1981

Immunosuppressive effect of mouse serum lipoproteins. I. In vitro studies.

Three classes of lipoproteins, very low, low, and high density, were isolated from normal mouse sera and characterized with respect to electrophoretic mobility, content, and composition. All 3 classes of mouse serum lipoproteins migrated into the alpha region at different rates and were composed of more phospholipid and less triglyceride and cholesterol than lipoproteins from man. High density lipoprotein (HDL) was the major lipoprotein, carrying 70% of the serum cholesterol and phospholipid and 85% of the total lipoprotein. Whole mouse serum and all classes of mouse serum lipoproteins inhibited lymphocyte proliferation stimulated by mitogens. No strain specificity was observed. HDL contributed about 73% of the total inhibitory activity. The effect of apoprotein and the lipid portion of very low, low, and high density lipoproteins were also studied.

Animals↗
PubMed1980

Characterization of an auto-rosette inhibitory fraction in mouse serum.

Normal mouse sera inhibited auto-erythrocyte rosette formation by mouse thymus cells. Serum inhibitory factor was associated with high density lipoprotein (HDL) isolated from mouse sera with sequential flotation ultra-centrifugation techniques. Other portions of normal mouse sera, i.e., very low density lipoprotein (VLDL), low density lipoprotein (LDL), lipoprotein-free serum, and delipidated HDL had little or no inhibitory activity. A 20-fold purification with 68% recovery of total serum activity was obtained by this isolation procedure. HDL from the serum of BALB/c, C57BL/6, C3H, and NZB/BIN mice inhibited BALB/c auto-rosettes. Inhibition was observed when lymphocytes were preincubated with HDL and then washed before assaying, but there was no inhibition when erythrocytes were pretreated.

Animals↗
PubMed1979

Ventilatory functions of normal children and young adults--Mexican-American, white, and black. I. Spirometry.

This is a study of the ventilatory functions of 1,805 normal Mexican-American, white, and black students of six public schools in Houston, Texas, with ages ranging from 7 to 20. A roll-seal piston type spirometer was used. The best performed forced vital capacity curve of each student was selected by the computer program from which the following measurements were extracted: FVC, FEV1, FEV1/FVC ratio, PEFR, and MMEF. Each student also had the peak expiratory flow rate measured by the Wright peak flowmeter to establish normal values with this instrument. Significant differences of lung volume and flow rate exist among the three races, and between male and female subjects. Prediction equations and prediction curves for each race and sex are presented. The results of the present study are compared with those of previously published works.

Adolescent↗
PubMed1979

Ventilatory functions of normal children and young adults--Mexican-American, white, and black. II. Wright peak flowmeter.

A study was undertaken to establish the normal values of peak expiratory flow rate using the WPFM in three ethnic groups. This report is based on the testing of 1,805 healthy students 7 to 20 years of age in the Houston public schools. Significant differences of WPFR are noted among the three races, and between boys and girls. Prediction equations and regression lines are presented for each sex/race group. The performance of the WPFM is compared with that of the spirometer.

Adolescent↗
PubMed1979

Sequential appearance of auto-erythrocyte antibody immunoglobulin classes with age.

The autoimmune, short-lived, NZB/BINJ mice were followed for the changes taking place in the number of thymic and splenic nucleated cells from day 1 up to 12 mo of age. The long-lived C57BL/6J mice were monitored in parallel with the NZB mice to see whether similar changes were reflected. Both strains of mice were investigated for the sequential appearance of anti-erythrocyte autoantibody classes by the direct Coombs' agglutination test. IgG1 was the first class of antibody detected on the erythrocytes and was followed by IgG3, IgG2 and IgA, simultaneously. IgM was the last antibody to react with erythrocytes. The C57BL strain had a very small number of mice with low levels of IgG1 antibody on erythrocytes throughout the study.

Aging↗
PubMed1979

Factors contributing to impairment of the mixed lymphocyte reaction in leprosy.

Whereas the mixed lymphocyte reaction was essentially normal in inactive lepromatous leprosy and tuberculoid leprosy, it was severely impaired in active lepromatous leprosy. The impairment was found to be contributed by certain unknown factors in their plasma and subnormal reactivity of their T lymphocytes. The plasma derived from active lepromatous leprosy patients depressed the reaction of normal cells and normal plasma enhanced the reaction of active lepromatous lymphocytes. The cellular factor was studied by using a one-way reaction in which one of the two lymphocyte preparations was inactivated with mitomycin C. The impairment of blastogenesis of active lepromatous lymphocytes was partially reversed by substituting inactivated normal cells for similarly treated leprous cells, and conversely the response of normal allogeneic lymphocytes was depressed by substituting inactivated leprous lymphocytes as the stimulator cells.

Adult↗
PubMed1977

Oxygen transfer and axial dispersion in an aeration tower containing static mixers.

Oxygen transfer from gas to liquid under steady-state cocurrent flow conditions was modeled using the dispersion model, and the oxygen transfer coefficients were estimated from available data for a column with Koch motionless mixers. The dispersion in the column was estimated for several different gas and liquid flow rates using steady-state tracer experiments. The estimated oxygen transfer coefficients were compared with those estimated using complete mixing and plug flow models. The results indicate that the dispersion model is the most appropriate model for estimating the mass transfer coefficient from the available data.

Absorption↗
PubMed1977

Drug resistance among Mycobacterium tuberculosis strains isolated in Taiwan during 1975.

455 strains of Mycobacterium tuberculosis were isolated from patients with history of treatment in Taiwan Provincial Tuberculosis Control Bureau and tested for resistance against various antituberculosis agents including streptomycin (SM), paraaminosalicylic acid (PAS), isoniazid (INH), cycloserine (CS), prothionamide (1321TH), kanamycin (KM), ethambutol (EMB), and rifampicin (RFP). In vitro resistance to SM and INH was more frequently found than others and the resistance to a single drug was more common than multiple resistance.

Antitubercular Agents↗
PubMed1975

The mechanical properties of stratum corneum. I. The effect of water and ambient temperature on the tensile properties of newborn rat stratum corneum.

The tensile properties of the outermost layer of skin of neonatal rats, the stratum corneum, were investigated at a constant strain rate as a function of moisture content and ambient test temperature. The results show that the mechnical behavior of this membrane, whose primary constituent is the fibrous protein keratin, can be significantly altered by variations in both the sorbed water content and ambient temperature. In particular, a brittle to ductile transition was observed at 25 degrees C once the hydration level exceeded 70% relative humidity. Similarly, an identical phenomenon was detected at temperatures beyond 40 degrees C for specimens whose equilibrium moisture concentrations were maintained at 10 g H2 O/100 g dry protein. Differential scanning calrimetry measurements showed the presence of a molecular relaxation process which migrated from 42 degrees C at 40% relative humidity to --18 degrees C at 95% relative humidity. It is postulated that this relaxation process, possibly corresponding to the glass transition of the fibrous protein component of stratum corneum, is primarily responsible for the observed behavior.

Animals↗
PubMed1975

Inhibition of citrate synthase by oleoyl-CoA: a regulatory phenomenon.

Fatty acyl-CoAs are good detergents (dritical micelle concentrations = 3-4 muM) and can inhibit a number of enzymes, including some involved in fatty acid biosynthesis. The regulatory significance of fatty acyl-CoAs as negative effectors has been questioned largely because of the difficulties in distinguishing possible nonspecific detergent effects from more specific regulatory interactions with these enzymes. A new analogue of oleoyl-CoA, oleoyl-(1, N6-etheno)-CoA, is a better detergent (critical micelle concentration = 3.2 muM) than oleoyl-CoA (critical micelle concentration = 4.7 muM). This new analogue is not as good (by an order of magnitude) an inhibitor of citrate synthase [citrate oxaloacetatelyase (pro-3S-CH2-COO-vectoracetyl-CoA); EC 4.1.3.7] nor is it bound as well oleoyl-CoA. Since the only difference between these two compounds is substitution of 1,N6-ethenoadenine for the adenine of CoA, the difference in inhibition and binding implies a specific interaction between the adenine moiety of oleoyl-CoA and citrate synthase. Moreover, since oleoyl-(1,N6-etheno)CoA is a better detergent than oleoyl-CoA, the detergency of oleoyl-CoA is not the sole cause of the fatty acyl-CoA inhibition of citrate synthase. These results support a physiological role for oleoyl-CoA as a negative effector for citrate synthase. An analogous physiological role for fatty acyl-CoA as negative effectors for other enzymes seems reasonable.

Animals↗