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Biomedical subjects

S Yu

Publications and source records attributed to S Yu.

At least 235 records · Page 13Linked to original sources
PubMed1998

Plasma aldosterone concentration of cats.

Aldosterone concentrations in the plasma of specific-pathogen-free, domestic, short-hair cats given sodium replete diets were measured by a radio-immunoassay. Plasma samples assayed were taken from male and female cats of 8, 12, 17, 20, 26, 29, 40 and > 52 weeks of age, from adult non-pregnant queens, and from queens in the ninth weeks of pregnancy and in the second and fifth week of lactation. Plasma aldosterone concentration was also measured in samples taken four times over a 24 h period (06:00-06:30, 11:00-11:30, 17:00-17:30 and 23:00-23:30) in a group of seven adult male cats. neither age nor sex had a significant effect on the plasma aldosterone concentration. Also, queens had similar aldosterone concentrations in plasma whether they were non-pregnant, pregnant, or lactating. No circadian rhythm was observed in plasma aldosterone concentrations in adult male cats. The plasma aldosterone concentrations of 148 cats (87 males and 61 females, ranging in ages from 8 to > 52 weeks) had a positive skew distribution with a median of 161 pmol l-1. The upper value for plasma aldosterone concentration in healthy domestic cats as defined by the 95 percentile was 700 pmol l-1.

Aging↗
PubMed1998

Rpe65 is necessary for production of 11-cis-vitamin A in the retinal visual cycle.

Mutation of RPE65 can cause severe blindness from birth or early childhood, and RPE65 protein is associated with retinal pigment epithelium (RPE) vitamin A metabolism. Here, we show that Rpe65-deficient mice exhibit changes in retinal physiology and biochemistry. Outer segment discs of rod photoreceptors in Rpe65-/- mice are disorganized compared with those of Rpe65+/+ and Rpe65+/- mice. Rod function, as measured by electroretinography, is abolished in Rpe65-/- mice, although cone function remains. Rpe65-/- mice lack rhodopsin, but not opsin apoprotein. Furthermore, all-trans-retinyl esters over-accumulate in the RPE of Rpe65-/- mice, whereas 11-cis-retinyl esters are absent. Disruption of the RPE-based metabolism of all-trans-retinyl esters to 11-cis-retinal thus appears to underlie the Rpe65-/- phenotype, although cone pigment regeneration may be dependent on a separate pathway.

Animals↗
PubMed1998

Financing changes of schistosomiasis control programmes in China 1980-1995: a case study in Songzi county.

To assess the financing changes of schistosomiasis control programmes in China and estimate the impact of these changes on patients' treatment-seeking behaviour and control of schistosomiasis, a survey was conducted in five schistosomiasis-endemic areas of the lake regions, Hubei province, in 1996. This paper reports financing changes and their impact on the incidence and prevalence of schistosomiasis from one of the five areas as a case study. By examining the surveillance and financial data from 1980 to 1995, and through focus group discussions we found that the schistosomiasis control programmes in People's Republic of China have gone through dramatic financing changes from 1980 to 1995, when the transitions of China's social, economic, and political systems happened. The proportions of funding to schistosomiasis control programmes from high level governmental agencies, county budgets, and services revenue changed from 60%, 23%, and 17%, respectively, in 1980-1987 to 0.7%, 22.3%, and 72% in 1995. The percentages of expenditure of schistosomiasis control activities, salaries and bonuses, and other activities unrelated to schistosomiasis control, were 53.5%, 14.4, and 17.2% in 1980. These percentages changed to 7.7%, 33.3%, and 53.3%, respectively, in 1995. The preponderant role of the state in organizing, financing, and delivery of the services was replaced with the new system which is more influenced by the market economy. The incidence and the prevalence of schistosomiasis in the study area have increased year by year from 1980 to 1990, although there has been a tendency to decrease after 1991 but not to the low pre1980 levels. The collapse of the community-based medical system in rural areas and the dramatic financing changes of schistosomiasis control programmes have created major difficulties for schistosomiasis control in China.

China↗
PubMed1998

Interleukin-12 enhances contact hypersensitivity by modulating the in vivo cytokine pattern in mice.

It has been proven that interleukin-12 (IL-12) can modify Th1 and Th2 cell-mediated immune diseases by altering the development and cytokine production of the cells. In this study, we investigated the in vivo immunomodulatory effect of recombinant murine IL-12 on contact hypersensitivity, a Th1 cell-mediated disease. For this purpose, Balb/C mice were sensitized with 3% 4-ethyoxymethylene-2-phenyl-oxazol-5-one (OXAZ), and recombinant mouse IL-12 was given simultaneously during the induction phase. Contact allergy was then elicited by ear challenge with 1% OXAZ. We examined the mouse ear swelling response, in vivo cytokine gene expression in the skin and local lymph nodes, and in vitro cytokine production by the spleen lymphocytes. It was found that in vivo IL-12 treatment during the induction phase significantly enhanced the ear swelling response to OXAZ in sensitized mice. Moreover, remarkable mononuclear cell infiltration and edema and higher expression of Th1 cytokine mRNAs (IL-2 and interferon-gamma) in the skin lesion and local lymph nodes were observed in contact allergic mice with IL-12 treatment compared with contact allergic mice without IL-12 treatment. The expression of Th2 cytokine mRNA (IL-4) in the skin lesion and local lymph nodes, however, was largely downregulated, with no change in IL-5 mRNA in IL-12-treated contact allergic mice. We found, unexpectedly, that, similar to the effects on phytohemagglutinin (PHA) stimulated in vitro IL-2 and IFN-gamma production, PHA-induced in vitro IL-4 production was enhanced in the spleen lymphocytes from IL-12-treated contact allergic mice. Our results indicate that exogenous IL-12 enhanced contact hypersensitivity probably because of the in vivo promoting and suppressing effects of IL-12 on Th1 and Th2 gene expression, respectively.

Animals↗
PubMed1998

Expression of interleukin-18 in murine contact hypersensitivity.

In this study, we made a mouse model for contact hypersensitivity (CH) using oxazolone as a contact allergen and examined the expression of interleukin-18 (IL-18) in the diseased skin sites at both mRNA and protein levels. In the kinetic study by semiquantitative RT-PCR, IL-18 mRNA was constitutively produced in normal murine skin but increased significantly at 12 h and peaked at 24 h in the ear skin of CH mice. A positive correlation was confirmed between the IL-18 mRNA signal and CH, as measured by mouse ear swelling response. Histologically, in situ hybridization showed that the IL-18 mRNA signal was weakly observed in the dermis but not the epidermis of normal skin, whereas the IL-18 mRNA signal was found intensively in the dermis, particularly in inflammatory cell areas. Using IL-18-specific antibody immunostaining, it was further found that IL-18 protein production had a histologic location similar to that of IL-18 mRNA in both normal and CH mice. The present study suggests that IL-18 may be implicated in the pathogenesis of murine CH.

Animals↗
PubMed1998

Depressive disorders among the Chinese elderly in a suburban community.

A community survey of depression among the Chinese > or = 65 years in age was performed in a suburban setting. One hundred and eighty-seven individuals comprised the survey group. Among them, 65 (34.8%) were scored > or = 11 on the Chinese version of the Geriatric Depression Scale. Compared with nondepressed individuals, those with depressive disorders were more likely to be older and with poor family support. Forward stepwise logistic regression analysis identified only age as significantly correlating with geriatric depression scores.

Age Factors↗
PubMed1998

Analysis of the exochelin locus in Mycobacterium smegmatis: biosynthesis genes have homology with genes of the peptide synthetase family.

Mycobacteria secrete the siderophore exochelin when grown under iron-limiting conditions. In order to understand iron uptake mechanisms in mycobacteria, we have taken a genetic approach to identify those genes involved in exochelin biosynthesis and transport in Mycobacterium smegmatis. Of the 6,000 chemically mutagenized clones of M. smegmatis mc2155 screened on agar plates containing chrome azural S, 19 mutants that had lost the ability to produce or secrete exochelin were identified. Thirteen of these mutants were complemented by a single M. smegmatis cosmid. Sequence analysis of this cosmid revealed nine open reading frames, three of which are homologous to genes encoding transporter proteins, which are likely involved in exochelin transport. Complementation and Tn10 mutagenesis analysis identified two new genes, fxbB and fxbC, which are required for exochelin biosynthesis. The fxbB and fxbC genes encode large proteins of 257 and 497 kDa, respectively, which are highly homologous to peptide synthetases, indicating that exochelin biosynthesis occurs by a nonribosomal mechanism.

Amino Acid Sequence↗
PubMed1998

Correlations between scores on Chinese versions of long and short forms of the Geriatric Depression Scale among elderly Chinese.

A total of 187 elderly Chinese from the community were interviewed with the Chinese versions of the Geriatric Depression Scale-the long form and the short form. The scores on a proposed new version of the short form were also calculated. Cronbach alpha for the Geriatric Depression Scale-long form was .86. The correlations were significant between scores on the long and short forms (r = .94, p < .05) and between these on the long and new short forms (r = .91, p < .05). Cronbach coefficient alpha for the short form was .77 and for the new short form .81. Results of our study indicated that responding by these elderly persons on both short forms is acceptably internally consistent in comparison with those on the original Geriatric Depression Scale.

Aged↗
PubMed1998

[Relationship between body surface zinc loss and dietary zinc intake in children].

OBJECTIVE: To study the effects of body surface loss of zinc on the determination of dietary supply of zinc. METHODS: Body surface loss of zinc was determined in 24 preschool children with normal zinc nutrition (Group A) and zinc malnutrition (Group B). RESULTS: Body surface loss of zinc was 0.25 and 0.23 mg daily in Groups A and B with dietary zinc intake of 5.45 and 5.03 mg, respectively, and 0.29 and 0.25 mg daily with dietary zinc intake of 7.20 and 6.73 mg, respectively. The body surface loss of zinc accounted for five percent of the total. CONCLUSION: Considering the loss of zinc from body surface, it is suggested that dietary zinc supply be increased by 21 percent. When children is in good status of zinc nutrition, body surface loss of zinc correlates proportionally with their dietary zinc intake.

Child↗
PubMed1998

The effects of radix Salviae miltiorrhizae on lipid accumulation of peroxidized low density lipoprotein in mouse peritoneal macrophages--lipid analysis and morphological studies.

Mouse peritoneal macrophages were incubated in DMEM with pox-LDL and Rradix Salviae Miltiorrhizae (RSM) to investigate the effects of RSM on the internalization of peroxidized low density lipoprotein (pox-LDL) by using lipid analysis and electron microscopy. Lipid peroxide (LPO) concentrations were increased slightly in the medium after incubation of macrophages with normal LDL (n-LDL), while decreased significantly in the media after incubation of macrophages with pox-LDL. In the three groups with pox-LDL, it could be found that there was a dose-dependent decrease of concentrations of LPO and total cholesterol (TCH) in the two RSM groups, and the decrease in the two RSM groups was much greater than in the group without RSM. RSM accelerated a more decrease of LPO than cholesterol contents in the media containing pox-LDL. The ultrastructural studies also showed that RSM induced the accumulation of lipid droplets in the cytoplasm of mouse peritoneal macrophages. The results suggested that RSM could accelerate the phagocytosis and degradation of pox-LDL by macrophages.

Animals↗
PubMed1998

[The second phase clinical observation of anti-radiation effect by superoxide dismutase].

Multiple center randomized controlled double blind clinical trait was conducted to evaluate the anti-radiotherapy effect by SOD (produced by Hunan Biochemical Work) in 159 patients. Injection of 4000U SOD immediately after receiving radiotherapy significantly reduced the occurrence rate of skin, oral mucosal, pelvic visceral and systematic adverse reaction, only the reduction of leukopenia did not reach the statistical significant level. No adverse effect of SOD injection was observed. The results suggest that SOD is a safe and effective agent to attenuate the radiotherapy reactions.

Adolescent↗
PubMed1998

[Changes of blood lipids and apolipoproteins in patients with silent myocardial ischemia].

Serum lipid profiles and apolipoproteins were measured in 148 patients with silent myocardial ischemia (SMI) and 30 healthy control subjects comparable in age. The serum lipid profiles and apolipoproteins were abnormal in all types of SMI which were more significant in type II and III. The extent of ST segment depression in ECG were positively correlated with serum TG, TC, LDL, B100, B100/A1, Lp(a); and negatively correlated with A1, HDL1, HDL2, HDL-C/TC. Multiple-factor stepwise regression analysis revealed that the increased concentration of serum TG, LDL, and B100/A1 ratio and decrease of HDL2-C are independent risk factors in SMI.

Aged↗
PubMed1998

[Clinical significance of heart rate variability: analysis of silent myocardial ischemia].

To study the potential role of dynamic electrocardiogram(DEG) in silent myocardial ischemia (SMI) patients, we measured the extension of ischemia and heart rate variation-time-domain analysis in 148 patients with SMI and 30 healthy controls by DEG and followed up all patients for 1.5 years. The results were that the extension of myocardial ischemia (the extension of ST segment depression, episodes of SMI attack, and the total ischemia time), the incidence rate of ventricular premature heat increased gradually and the difference of heart rate. Heart rate variant hinder(HRVI), and SDNN decreased gradually in SMI I, III, II types. And the extension of ischemia had positive correlation with the lowest heart rate and the incidence rate of ventricular premature beat, while negative correlation with HRVI and SDNN, indicating that the impairment of cardial autonomic nerves is associated with the extension of ischemia. Also, we found that 23 patients out of 148 patients with SMI died and the levels of HRVI and SDNN of the patients who died were lower than that of the survivals. We conclude that the heart rate variability can serve as a prognosis index of SMI.

Aged↗
PubMed1998

[Detection of microcystins in source and tap water from a lake].

The microcystins in source and tap water collected from seven waterworks around a lake in summer, 1996 were detected by enzyme-linked immunosorbent assay (ELISA). Microcystins were determined in the source water from all the seven waterworks, and the concentrations ranged from 280 to 35,300 ng/L. Low concentrations of microcystins were also detected in the tap water of three waterworks. The results suggest that microcystins in source water could not be removed completely by conventional adding bleaching powder treatment.

Bacterial Toxins↗
PubMed1998

[Serum concentration of insulin-like growth factor-I in cord blood].

OBJECTIVE: To evaluate the role of insulin-like growth factor-I (IGF-I) in fetal growth and placental growth. METHODS: Cord blood IGF-I was determined by radioimmunoassay (RIA) after serum samples were extracted with acid-ethanol. Linear correlation between variables was tested by calculating pearson's correlation coefficient. student's test was used to compare mean values between groups. RESULTS: In 102 tested samples, the concentration of cord blood serum IGF-I was correlated with the gestational age, the birth weight of neonates and placental weight (r = 0.32, P < 0.001, r = 0.68, P < 0.001, r = 0.75, P < 0.001). The mean serum level of IGF-I in the small-for-gestational-age (SGA) neonates was significantly lower than that in average-for gestational-age (AGA) (t = 4.77, P < 0.001), But the serum concentration of IGF-I in the Large-for-gestational-aga (LGA) neonates was significantly higher than that of AGA neonates (t = 7.97, P < 0.001). CONCLUSION: Those results suggested that IGF-I is an important regulator for fetal and placental growth and development. It has the key role for macrosomia and IUGR forming.

Adult↗