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Biomedical subjects

Y H Hu

Publications and source records attributed to Y H Hu.

At least 19 recordsLinked to original sources
PubMed2006

Lipoprotein lipase gene S447X polymorphism modulates the relation between central obesity and serum lipids, a twin study.

OBJECTIVE: To investigate the impact of lipoprotein lipase (LPL) gene S447X polymorphism on the relation between central obesity and lipid levels. DESIGN: A total of 961 adult twin pairs were included from the program of Chinese Twin Registry, between 2001 and 2002. Central obesity was defined as waist circumference > or =90 cm for male and > or =80 cm for female. Two statistical methods were performed to test the modification effect of S447X polymorphism of LPL gene on the relation between central obesity and lipid levels: one was Generalized Estimating Equation (GEE) models for all twin pairs and the other was co-twin matched case-control analysis in 82 central obesity discordant monozygotic twin pairs. RESULTS: In GEE models for all twins, central obesity was significantly associated with serum lipids except for high-density lipoprotein (HDL), while X447 allele had favorable effects on the levels of triglyceride (TG), HDL and TG to HDL ratio (TG/HDL). The interactions of S447X polymorphism and central obesity were statistically significant for TG/HDL and HDL. In central obesity discordant monozygotic twin pairs, central obesity was significantly related with 26.2% increase of TG and 27.2% increase of TG/HDL in S/S447 genotype, while in 447X allele carrier, central obesity was significantly related with 13.7% increase of HDL. CONCLUSION: These results suggest that LPL gene S447X polymorphism modifies the relation between central obesity and serum lipids, which also stresses the importance of reducing waist circumference to improve serum lipids for people with central obesity, especially those with S/S447 genotype.

Adult↗
PubMed2005

Increased plasma concentration of nitric oxide in type 2 diabetes but not in nondiabetic individuals with insulin resistance.

OBJECTIVE: Insulin resistance (IR) is a key element in the pathogenesis of type 2 diabetes. The results of recent experiments on insulin-mediated vasodilatation have suggested that vascular insensitivity is a component of IR. However, it is still controversial that patients with type 2 diabetes have a decreased ability of insulin to increase endothelial nitric oxide (NO) release. METHOD: Plasma concentration of NO was examined in 26 patients with type 2 diabetes and 78 nondiabetic volunteers during an insulin suppression test. The test measured the efficacy of insulin in promoting disposal of the infused glucose load, in which the steady state plasma glucose (SSPG) during the 150-180 min of the test was used as an index of IR. Plasma NO levels were assayed by measurement of the stable end products of their metabolism. Comparison of plasma NO levels between groups were performed by Mann-Whitney test and relationships between SSPG and different variables were analyzed by partial correlations. RESULTS: Our results showed that the plasma NO levels were significantly higher in the diabetic group. When the nondiabetic subjects were analyzed according to their SSPG levels, there was no difference of plasma NO levels between those with SSPG>160 mg/dl and those with SSPG<160 mg/dl. There were also no difference of NO levels between those with a family history of type 2 diabetes and those without. In the nondiabetic group, SSPG correlated with BMI, fasting insulin, triglyceride and HDL-cholesterol, but neither with plasma NO levels nor fasting plasma glucose. CONCLUSION: Our data suggests that the impairment of NO activity in patients with type 2 diabetes is due to an impaired effect rather than its production. This altered NO signaling pathway is not an early event in insulin resistant individuals. Any such changes will not be apparent until type 2 diabetes with overt hyperglycemia develops.

Blood Pressure↗
PubMed2005

Effects of Si-Jun-Zi decoction polysaccharides on cell migration and gene expression in wounded rat intestinal epithelial cells.

Si-Jun-Zi decoction (SJZD), a traditional Chinese herbal prescription, has been used clinically for treating patients with disorders of the digestive system. Previous studies indicated that the polysaccharides of SJZD (SJZPS) are the active components contributing towards its pharmacological effects in improving gastrointestinal function and immunity. However, the protective and restitutive effects on intestinal epithelial cells remain unknown. In the present study, SJZPS were first extracted and chemically characterized. Then their stimulatory and restitutive effects on intestinal epithelial cells (IEC-6 cells) were elicited by different in vitro models including migration of wounded IEC-6 cells and cell proliferation. Results indicated that SJZPS not only protects the cells against the harmful impairment of indomethacin but also enhances re-epithelialization of a wounded monolayer at an optimal dose of 100 mug/ml at 24 h incubation. To elucidate the modulatory effect of SJZPS on wounded IEC-6 cells at the molecular level, an oligonucleotide microarray was employed to study differential gene expression of SJZPS-treated IEC-6 cells and the candidate genes were validated by RT-PCR. There was increased expression of genes coding for ion channels and transporters, which are critical to cell migration and restoration of wounded intestinal cells, suggesting a possible mechanism for re-epithelialization. In conclusion, our data show for the first time that SJZPS can enhance intestinal restitution and protect against indomethacin-induced damage of intestinal epithelial cells. These findings provide new insight into the mechanism of action of a traditional Chinese herbal prescription, SJZD, in intestinal wound restitution.

Animals↗
PubMed2005

Incidental primary hyperparathyroidism in a hypercalcaemic woman with tuberculous peritonitis.

We report on a 51-year-old woman with initial hypercalcaemia and unknown ascites. In spite of unyielding laparoscopy, laparotomy showed findings compatible with tuberculous peritonitis (TBP). Unexpectedly, a series of examinations eventually revealed the concurrence of hyperparathyroidism due to a parathyroid adenoma. Anti-tuberculous regimen was given and was uneventful. However, hypercalcaemia was not decreased but sustained at a high level even after anti-tuberculous therapy for 3 months. Parathyroidectomy was performed with subsequent normalisation of hypercalcaemia. The aetiology of hypercalcaemia in a patient with an explored disease able to cause this electrolyte abnormality such as TBP may be a coexistent occult parathyroid adenoma.

Adenoma↗
PubMed2004

Heritabilities and genetic correlations of laying performance in Muscovy ducks selected in Taiwan.

1. Genetic parameters in the base population of a closed experimental strain of Muscovy ducks, selected for body weight at 10 weeks of age, were estimated from data in 8 successive generations, for the following traits: age at first egg (AGE1EGG), total number of eggs laid at 40 and 52 weeks of age (NEGG40 and NEGG52), number of eggs laid during 15 and 22 weeks in the first laying cycle (NEGG15W and NEGG22W), and their Box-Cox transformed data. 2. The method of multi-trait restricted maximum likelihood with an animal model was used to estimate genetic parameters. Only the results obtained with non-transformed data are shown. 3. Heritability estimates for laying performance showed moderate values, increasing little with age: 0.20+/-0.03 (AGE1EGG), 0.23+/-0.03 (NEGG40), 0.27+/-0.03 (NEGG52), 0.20+/-0.03 (NEGG15W), and 0.22+/-0.03 (NEGG22W). 4. Genetic correlations between laying traits were high. Genetic correlation between AGE1EGG and egg number was negative, it was positive between total numbers of eggs at 40 and 52 weeks and egg numbers in the first laying cycle. 5. Body weight at 10 weeks of age exhibited positive genetic correlations (0.46+/-0.06) with age at first egg and negative with egg production traits (-0.28+/-0.06 to -0.41+/-0.06). 6. The cumulated predicted genetic gains, after 7 generations of selection, expressed per genetic standard deviation unit (sigma(g)) were 0.06 sigma(g), 0.07 sigma(g), 0.17 sigma(g), 0.23 sigma(g), and 0.25 sigma(g) for AGE1EGG, NEGG40, NEGG52, NEGG15W, and NEGG22W, respectively. 7. Selecting Muscovy ducks to improve laying in Taiwanese climatic conditions would be possible using the number of eggs laid up to 52 weeks of age as the selection criterion. Because unintended selection effects for laying traits were present, the selection experiment for body weight at 10 weeks of age was not antagonistic with laying traits.

Animals↗
PubMed2001

Important prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after radiotherapy.

PURPOSE: To evaluate the long-term outcome and prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after initial radiotherapy (RT). METHODS AND MATERIALS: From January 1985 to December 1986, 100 patients (71 males, 29 females) with a diagnosis of nasopharyngeal carcinoma were found on computed tomography (CT) to have skull base erosion. The mean age was 41 years (range 16-66). Ninety-six patients had World Health Organization type III undifferentiated carcinoma, and 4 had type I. The metastatic workup, including chest radiography, liver ultrasound scanning, and liver function test was negative. All patients underwent external beam RT (EBRT) alone to 66-80 Gy during 6-8 weeks. A daily fraction size of 2 Gy was delivered using 60Co or a linear accelerator. No patient received chemotherapy. All patients were followed at regular intervals after irradiation. The median follow-up was 22.3 months (range 2-174). Survival of the cohort was computed by the Kaplan-Meier method. The potential prognostic factors of survival were examined. Multivariate analyses were performed using the Cox regression model. RESULTS: The 1, 2, 5, and 10-year overall survival rate for the cohort was 79%, 41%, 27%, and 13%, respectively. However, the subgroup of patients with both anterior cranial nerve (I-VIII) and posterior cranial nerve (IX-XII) involvement had a 5-year survival of only 7.7%. A difference in the time course of local recurrence and distant metastasis was observed. Both local recurrence and distant metastasis often occurred within the first 2 years after RT. However, local relapse continued to occur after 5 years. In contrast, no additional distant metastases were found after 5 years. The causes of death included local recurrence (n = 59), distant metastasis (n = 21), both local recurrence and distant metastasis (n = 1), and unrelated causes (n = 5). After multivariate analysis, complete recovery of cranial nerve involvement, cranial nerve palsy, and headache after irradiation were found to be independent prognostic factors in this cohort. CONCLUSIONS: We present one of the longest follow-ups of patients with nasopharyngeal carcinoma invading the skull base. Our results demonstrate the importance of cranial nerve involvement, recovery of headache, and cranial nerve palsy. These factors should be carefully evaluated from the history, physical examination, and imaging studies. A subgroup of patients with skull base involvement had long-term survival after RT alone. The findings of this study are important as a yardstick against which more aggressive strategies, such as combined radiochemotherapy and altered fractionation RT can be compared.

Adolescent↗
PubMed2001

Conditionally expressed G alpha 15 couples to endogenous receptors in GH3 cells.

The mammalian G proteins G15 and G16 couple a wide variety of receptors to phospholipase C (PLC) in co-transfected systems, and it has been suggested that they can be used as tools in agonist-screening systems. Using the reversed tetracycline-controlled transactivation system we generated rat pituitary GH3 cell clones that expressed Galphal5 and Galpha16 conditionally to study the coupling of endogenous receptors to both G proteins. In cells expressing moderate levels of Galpha15, activation of various endogenous receptors increased inositol phosphate production, whereas conditional expression of Galpha16 had no significant effect on agonist-dependent PLC activity. Activation of PLC through Galpha15 in response to carbachol did not increase cytosolic [Ca2+] ([Ca2+]i) but stimulated protein kinase C. While carbachol decreased the secretory activity in non-induced GH3 cells, it increased secretion in cells expressing Galpha15. Our data demonstrate that Galpha15 has a higher functional promiscuity than Galpha16 when studied in a system that preserves physiological G protein and receptor levels. In addition, Galpha15-mediated coupling of a receptor to PLC can change the cellular response to receptor agonists, indicating that downstream cellular functions can be used to detect receptor activation in screening systems employing a promiscuous G protein.

Animals↗
PubMed2001

[Study on the optimal conditions in simultaneous reaction and separation for L-malic acid production].

Based on the principle of coupling reaction and separation process, free cells containing fumarase were used for producing L-malic acid. The calcium fumarate was used as substrate to produce calcium malate directly. This new method was more advantageous than the traditional immobilized cells conversion system in aspects such as simple equipment and operation, high conversion efficiency and the yield of product. The results showed that at reaction temperature 40 degrees C, pH7.0-7.5, reaction time 20-28 h, the conversion efficiency was up to 99.9% and about 3.2 kg calcium fumarate was converted to calcium malate per liter enzyme suspension. Also, L-malic acid produced in free fumarase system satisfied USP criterion, the residual fumaric acid was less than 0.1% and the cost was approximately to that of DL-malic acid produced by chemical synthesis.

Biotransformation↗
PubMed2000

[Graft of AAA bone combined with autologous red bone marrow for treatment of bone defects].

To evaluate the effect of autolyzed antigen-extracted allogenic bone ("AAA" bone) graft combined with autogenic red bone marrow on bone defects, 58 cases with benign bone tumor(66 long bones) were treated with curettage operation, and the post-curettage bone defects were filled with the complex of "AAA" bone combined with autogenic red bone marrow. Forty two cases(49 bones) were followed up by taking X-ray radiography every 2 months in a period of 1-3 years. The result showed that 49 bones all got bony healing within 9 months(6 months in average). It is suggested that "AAA" bone combined with autogenic red bone marrow may be an ideal material for bone defect repairing.

Adolescent↗
PubMed1999

Discovery of a regulatory motif that controls the exposure of specific upstream cyclin-dependent kinase sites that determine both conformation and growth suppressing activity of pRb.

The conformation and activity of pRb, the product of the retinoblastoma susceptibility gene, is dependent on the phosphorylation status of one or more of its 16 potential cyclin-dependent kinase (cdk) sites. However, it is not clear whether the phosphorylation status of one or more of these sites contributes to the determination of the various conformations and activity of pRb. Moreover, whether and how the conformation of pRb may regulate the phosphorylation of the cdk sites is also unclear. In the process of analyzing the function and regulation of pRb, we uncovered the existence of an unusual structural motif, m89 (amino acids 880-900), the mutation of which confers upon pRb a hypophosphorylated conformation. Mutation of this structural domain activates, rather than inactivates, the growth suppressor function of pRb. In order to understand the effect of the mutation of m89 on the phosphorylation of cdk sites, we identified all the cdk sites (Thr-356, Ser-807/Ser-811, and Thr821) the phosphorylation of which drastically modify the conformation of pRb. Mutation of each of these four sites alone or in combinations results in the different conformations of pRb, the migration pattern of which, on SDS-polyacrylamide gel electrophoresis, resembles various in vivo hypophosphorylated forms. Each of these hypophosphorylated forms of pRb has enhanced growth suppressing activity relative to the wild type. Our data revealed that the m89 structural motif controls the exposure of the cdk sites Ser-807/Ser-811 in vitro and in vivo. Moreover, the m89 mutant has enhanced growth suppressing activity, similar to a mutant with alanine substitutions at Ser-807/Ser-811. Our recent finding, that the m89 region is part of a structural domain, p5, conserved antigenically and functionally between pRb and p53, suggests that the evolutionarily conserved p5 domain may play a role in the coordinated regulation of the activity of these two tumor suppressors, under certain growth conditions.

Amino Acid Sequence↗
PubMed1999

Heritabilities and genetic correlations of body weights and feather length in growing Muscovy selected in Taiwan.

1. Heritabilities and genetic correlations in the base population of a closed strain of Muscovy duck, moderately selected for body weight at 10 weeks of age, have been estimated from the data of 9 successive generations for the following traits: male and female body weight at 10 and 18 weeks of age (BW10m, BW18m, BW10f, BW18f) and length of the 8th primary feather at 10 weeks of age (F110m, F110f). 2. Multivariate REML with an animal model was used, pooling data from the 9 generations (3283 and 3289 male and female offspring respectively). The same trait expressed in male and female was considered as 2 different traits. 3. The 8th primary feather was longer in females than in males by 6% to 22% at 10 weeks of age. Body weight was heavier in males than in females by 42% to 58% at 10 weeks of age and by 57% to 75% at 18 weeks of age. 3. The heritability estimates for body weight traits showed moderate values, being a little higher for females than for males at the same age, increasing with age from h2=0.24 at BW10m to h2=0.43 at BW18f. 4. The heritability estimates for feather length showed that a greater response would be obtained in selection for male feather length (h2=0.37) than for female length (h2=0.14). Both have high genetic correlations with body weight so they could be indirectly improved. 5. Heritabilities of the difference in body weights between males and females at 10 weeks (h2=0.07) and 18 weeks of age (h2=0.10) were small, as well as for feather length (h2=0.10). It would probably be difficult to modify sexual dimorphism in body weight through selection. 6. Genetic correlations between BW10m, BW18m and BW10f, BW18f were respectively r(g)=0.77 and r(g)=0.80. They were larger for body weight at the same ages between males and females, r(g)=0.90 (r(g)=0.88 between F110m and F110f). Body weight in males and females at the same age should be better considered as 2 different traits in a selection programme. 7. The cumulated predicted genetic gains expressed per unity of the genetic standard deviation (sigma(g)) over the 8 generations of selection were 1.3 sigma(g) and 1.4 sigma(g) respectively for the BW10m and BW10f. The predicted correlated responses were 1.2 sigma(g) for body weights at 18 weeks of age, 0.9 sigma(g) and 0.7 sigma(g) for F110f and F110m respectively.

Animals↗
PubMed1999

[Changes in the content and activity of HSC70/HSP68, proteinases and phosphatases during liver regeneration].

This article reports changes in acid and alkaline phosphatases (ACP and AKP), constitutive heat shock protein 70/induced heat shock protein 68 (HSC70/HSP68) and acid and neutral proteinases during liver regeneration (0-144 h) after 2/3 hepatectomy (partial hepatectomy, PH). Both ACP and AKP had two active peaks at 4 and 48 h, 16 and 96 h, respectively, which were followed by significant decrease. The content of HSC70/HSP68 also showed two peaks (16 and 96 h), of which the content after the second peak decreased more obviously than after the first peak. Moreover a 90 kD neutral proteinase was induced at the time from 2 to 6 h and a 27 kD acid proteinase was induced at 36 h. The results suggest that the ACP and the 90 kD neutral proteinase may participate in activating hepatocytes from G0-phase into G1-phase, and AKP and HSC70/HSP68 may play a role mainly in DNA synthesis, cellular metabolism and proliferation. Furthermore 27 kD acid proteinase may be involved in re-differentiation of hepatocytes and reconstruction of liver tissue.

Acid Phosphatase↗
PubMed1999

[Effects of tea polyphenols on microcirculation and antioxidation in aircrew].

OBJECTIVE: To study the effects of tea polyphenols (TP) on bulbi conjunctiva microcirculation (BCM) and antioxidation in aircrew and find out the proper antioxidant for the health protection of aircrew. METHOD: Fourty healthy aircrew were divided into TP group (TP 600 mg/d.po) and control group (placebo) randomly. The effects of TP on microcirculation and antioxidation in aircrew were tested after 20 days. RESULT: Red blood cell (RBC) superoxide dismutase (SOD) activity and GSH-PX (Whole blood glutathione peroxidase)/MDA (serum malondialdehyde) ratio in TP group were significantly higher than those in control (P<0.01), and serum MDA level was significantly decreased after TP administration (P<0.05). The numbers of capillaries and blood flow in micrangium were significantly increased, RBC aggregation, ischemia area and A (arteriole)/V (venule) ratio were remarkably decreased in TP group (P<0.01). The total integral value of microcirculation in TP group was significantly reduced in comparison with that in the control group. CONCLUSION: TP can significantly increase the antioxidative ability of aircrew, decrease the BCM disturbance and improve the microcirculatory function.

Adult↗
PubMed1997

Defective platelet activation in G alpha(q)-deficient mice.

Platelets are small disc-shaped cell fragments which undergo a rapid transformation when they encounter vascular damage. They become more spherical and extrude pseudopodia, their fibrinogen receptors are activated, causing them to aggregate, they release their granule contents, and eventually form a plug which is responsible for primary haemostasis. Activation of platelets is also implicated in the pathogenesis of unstable angina, myocardial infarction and stroke. Here we show that platelets from mice deficient in the alpha-subunit of the heterotrimeric guanine-nucleotide-binding protein Gq are unresponsive to a variety of physiological platelet activators. As a result, G alpha(q)-deficient mice have increased bleeding times and are protected from collagen and adrenaline-induced thromboembolism. We conclude that G alpha(q) is essential for the signalling processes used by different platelet activators and that it cannot be replaced by G alpha(i) or the beta gamma subunits of the heterotrimeric G proteins. G alpha(q) may thus be a new target for drugs designed to block the activation of platelets.

Animals↗
PubMed1997

Association of body mass index, physical activity, and reproductive histories with breast cancer: a case-control study in Gifu, Japan.

To further clarify risk factors for breast cancer in Japanese women, a self-administered questionnaire was completed by 157 cases with histologically confirmed breast cancer from 1989 to 1993 and by 369 age and residential area matched controls in Gifu, Japan. Conditional logistic regression model was used to assess the relations. Multivariate analyses showed that breast cancer risk decreased with body mass index for premenopausal women (RR = 0.45; 95 % CI = 0.22-0.92 for BMI > or = 23 vs. < 21 (kg/m2)), but the risk increased with body mass index for postmenopausal women (RR = 1.98; 95 % CI = 0.86-4.55 for BMI > or = 24 vs. < 21.5 (kg/m2)). The risk increased with a small number of births in pre- and post-menopausal women (1.83; 1.11-2.99 and 6.06; 2.40-15.3 for 1-2 births and nulliparity, respectively, vs. > or = 3 births). Ex- or current smoking increased the risk of breast cancer (2.31; 1.19-4.49). Reduced risk of premenopausal breast cancer was associated with high energy expenditure in physical activity during teenage, although the trend was not statistically significant.

Adult↗
PubMed1997

A patient-adaptable ECG beat classifier using a mixture of experts approach.

We present a "mixture-of-experts" (MOE) approach to develop customized electrocardiogram (ECG) beat classifier in an effort to further improve the performance of ECG processing and to offer individualized health care. A small customized classifier is developed based on brief, patient-specific ECG data. It is then combined with a global classifier, which is tuned to a large ECG database of many patients, to form a MOE classifier structure. Tested with MIT/BIH arrhythmia database, we observe significant performance enhancement using this approach.

Adaptation, Physiological↗
PubMed1997

Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance. The Da Qing IGT and Diabetes Study.

OBJECTIVE: Individuals with impaired glucose tolerance (IGT) have a high risk of developing NIDDM. The purpose of this study was to determine whether diet and exercise interventions in those with IGT may delay the development of NIDDM, i.e., reduce the incidence of NIDDM, and thereby reduce the overall incidence of diabetic complications, such as cardiovascular, renal, and retinal disease, and the excess mortality attributable to these complications. RESEARCH DESIGN AND METHODS: In 1986, 110,660 men and women from 33 health care clinics in the city of Da Qing, China, were screened for IGT and NIDDM. Of these individuals, 577 were classified (using World Health Organization criteria) as having IGT. Subjects were randomized by clinic into a clinical trial, either to a control group or to one of three active treatment groups: diet only, exercise only, or diet plus exercise. Follow-up evaluation examinations were conducted at 2-year intervals over a 6-year period to identify subjects who developed NIDDM. Cox's proportional hazard analysis was used to determine if the incidence of NIDDM varied by treatment assignment. RESULTS: The cumulative incidence of diabetes at 6 years was 67.7% (95% CI, 59.8-75.2) in the control group compared with 43.8% (95% CI, 35.5-52.3) in the diet group, 41.1% (95% CI, 33.4-49.4) in the exercise group, and 46.0% (95% CI, 37.3-54.7) in the diet-plus-exercise group (P < 0.05). When analyzed by clinic, each of the active intervention groups differed significantly from the control clinics (P < 0.05). The relative decrease in rate of development of diabetes in the active treatment groups was similar when subjects were stratified as lean or overweight (BMI < or > or = 25 kg/m2). In a proportional hazards analysis adjusted for differences in baseline BMI and fasting glucose, the diet, exercise, and diet-plus-exercise interventions were associated with 31% (P < 0.03), 46% (P < 0.0005), and 42% (P < 0.005) reductions in risk of developing diabetes, respectively. CONCLUSIONS: Diet and/or exercise interventions led to a significant decrease in the incidence of diabetes over a 6-year period among those with IGT.

Adult↗