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Biomedical subjects

K Wang

Publications and source records attributed to K Wang.

At least 145 records · Page 8Linked to original sources
PubMed2001

[Analysis of loss of heterozygosity on 19p in primary gastric cancer].

OBJECTIVE: To investigate the loss of heterozygosity (LOH) frequency of microsatellite loci in primary gastric cancer samples and locate the deleted regions on 19p in which might exist human gastric cancer related genes. METHODS: The LOH of microsatellite loci on chromosome 19p was analyzed using PCR-SSLP-silver stain method in 43 primary gastric cancers and their paired normal tissues. RESULTS: In 43 primary gastric tumors, LOH was detected on the site for D19S424(29.63%), D19S216(11.53%), D19S406 (33.33%), D19S413(8.57%), D19S221(13.15%), D19S226(8.00%), D19S411(6.45%), D19S883(6.89%), and D19S886(10.71%), microsatellite instability (MSI) was found at the same time at locus D19S886 (17.85%). CONCLUSION: The most common LOH occurrence at D19S406 and D19S424 might imply the existence of the potential genes related to the tumorigenesis of gastric cancer in these loci.

Chromosome Mapping↗
PubMed2001

[A study on the epidemiological characteristics of obesity in Chinese Adults].

OBJECTIVE: To elucidate the epidemiological characteristics of obesity in Chinese adults and to provide scientific basis for public health policy-making, as well as for prevention and control of obesity among Chinese. METHODS: Using the data from diabetes mellitus, epidemiological studies carried out in 11 provinces/autonomous regions/municipalities of China from July 1995 to June 1997, including 42 751 subjects aged 20 - 74 years who had lived in the communities for no less than 5 years. Diagnostic criteria was based on the recommendation from WHO. Epidemiological characteristics of overweight and obesity were analysed. RESULTS: The prevalence rate of overweight and obesity among Chinese adults were 21.51% and 2.92% respectively. The age-standardized prevalence rates of overweight and obesity standardized by Chinese population aged 20 - 74 years were 18.28% and 2.48% respectively in 1990, when standardized by the standard population of world in 1992, the prevalence rates were 18.61% and 2.49% respectively. The prevalence of overweight and obesity in female (21.71% and 3.73% respectively) were significantly higher in male (21.25% and 2.11% respectively), the prevalence rates of obesity in male and in female increased with the increase of age, with the lowest prevalence in 20 year old group (1.23% and 0.96% respectively), the highest were 60 year old group (3.30% and 6.91% respectively). Among 11 provinces, the highest prevalence rates of overweight and obesity were in Beijing (34.75% and 5.14% respectively) of males, and in Shandong (34.56% and 9.36% respectively) of females. The prevalence rates of obesity were significantly higher in northern part of the country (2.64% in males and 4.85% in females) then in the south (1.36% in males and 2.15% in females), as well as significantly higher in urban (2.65% in male and 4.21% in female) than in rural (0.88% in male and 2.80% in female). CONCLUSION: Overweight and obesity had become prevalent in Chinese adults, more seen in the north than in the south, more in females than in males, and in older age than in younger, suggesting an earlier research and practice of prevention and control for overweight and obesity need to be implemented in China.

Adult↗
PubMed2001

[Assessment of quality of life in patients with diabetes mellitus and impaired glucose tolerance].

OBJECTIVES: To understand the quality of life (QOL) in patients with diabetes mellitus and impaired glucose tolerance, and investigate factors affecting their QOL. METHODS: Using the SF-36 instrument to assess QOL among 108 patients with diabetes mellitus, 109 patients with impaired glucose tolerance and 116 normal glucose tolerance subjects. RESULTS: In subjects with diabetes mellitus, the proportion of general perceived health assessed to be excellent or good was 12.04%; as compared with the same-age people, the proportion assessed to be good or fairly good was 62.04%. In subjects with impaired glucose tolerance, the two proportions was 13.76% and 69.72% respectively. The total score attained excellent or good level was 72.23% and 83.49% respectively in patients with diabetes mellitus and impaired glucose tolerance. The mean score of multi-item dimensions assessment (ranged from 58.33 to 87.38) decreased in diabetes mellitus; the lowest score being emotional role functioning and the highest mean score being physical functioning. Compared with normal glucose tolerance subjects, the mean score of physical functioning, physical role functioning, general health perception, vitality and the total score in diabetes mellitus was significantly decreased; and compared with in impaired glucose tolerance patients, the mean score of vitality, mental health and the total score was significantly decreased in diabetes mellitus. The result of correlation analysis demonstrated that age, occupational, duration of disease, number of symptoms and complications, level of fasting blood glucose and 2-hour past oral blood glucose affected the QOL of diabetes mellitus patients. CONCLUSIONS: The results suggested that to enhance the QOL in patients with diabetes mellitus, control of plasma glucose, pay attention to psychological treatment and measures related to diabetes mellitus with different characteristics must be early adopted.

Adult↗
PubMed2001

[Principle demonstration of nutrient delivery system in a space vegetable planting prototype facility].

Objective. To develop a nutrient delivery system for space vegetable planting prototype facility to be used in future space station, and to preliminarily testify its feasibility through ground-based demonstration experiments. Method. A nutrient delivery system in a space vegetable planting prototype facility was designed and fabricated, and ground based demonstration experiments of plant cultivation were conducted. Result. Nutrient could be steadily delivered to plant cultivation matrixes through capillary action, water content of planting matrixes could be controlled automatically and maintained constant, and the planted material lettuce showed basically normal morphology and color. Conclusion. The nutrient delivery system in a space vegetable planting prototype facility could basically meet the requirements for plant nutrient delivery under space microgravity environmental condition.

Capillary Action↗
PubMed2001

[The effect of frozen storage for amniotic membrane ultrastructure].

OBJECTIVE: To observe the effect of frozen storage for amniotic membrane ultrastructure, and provide the experimental evidence for clinical use. METHODS: The amniotic membranes of fresh-obtained and -80 degrees C frozen storage 30 d, 60 d, 90 d and 180 d were examined with transmission electron microscope, and the ultrastructural changes were observed. RESULTS: The epithelium in the fresh-obtained amniotic membrane was observed as intact structure, abundant organelles in cytoplasm and intercellular contact with desmosome. A great quantity of collagen micro-fibrils were found in the stroma, and the light and shade striation were observed in the collagen micro-fibrils of fresh-obtained amniotic membrane. The epithelium degenerated and died gradually as the increase of frozen storage time. At the frozen storage of 90 days, the epithelial chromatin dissolved, organelles degenerated and mitochondrion vacuolated. At the frozen storage of 30 days and 60 days, the pattern of collagen micro-fibrils in stoma was similar to that in fresh-obtained amniotic membrane; At the frozen storage of 90 days, some of collagen micro-fibrils in stoma showed intumescence. At the frozen storage of 180 days, the number of collagen micro-fibrils in stoma decreased, and some of them showed intumescence and dissolvent. CONCLUSION: Frozen storage can result in amniotic membrane epithelium death and collagen micro-fibrils intumescence and dissolvent.

Adult↗
PubMed2001

[Histopathological observation of acute facial nerve impairment in rabbits].

OBJECTIVE: To investigate histopathological changes of acute facial nerve impairment. METHODS: Ligation of facial nerve outside stylomastoid foramen with 3-0 silk, observation of histopathological changes of facial nerve on the 1st day, 3rd day and 5th day after ligation. RESULTS: The facial nerve showed all kinds and various degrees of histopathological changes, from swelling to degeneration, in myeline and axon respectively. CONCLUSION: All kinds and various degrees of pathological changes have been observed in myeline and axon after the ligation of facial nerve in rabbits. This study demonstrates that such injuries to the facial nerve become increasingly serious as the ligation lasts day after day.

Animals↗
PubMed2001

[Observation of facial nerve evoked potentials in rabbits].

OBJECTIVE: To investigate the possibility of recording the Antidromic Nerve Evoked Potentials (ANEP) from rabbit's scalp. METHODS: With electrical stimulation of peripheral segment of facial nerve outside the stylomastoid foramen in rabbits, recordings were made on scalp using low-impedance silver disc electrode. RESULTS: At the vertex, clear ANEPs composed of two waves, wave P1 and P0, were recorded in all experimental animals. CONCLUSION: The study shows that ANEPs can be recorded on rabbits' scalp. The ANEPs have two waves, P1 and P0. The sources of the responses are from facial nerve and its muscle respectively.

Animals↗
PubMed2001

The roles of bcl-2 gene family in the pulmonary artery remodeling of hypoxia pulmonary hypertension in rats.

OBJECTIVE: To investigate the roles of apoptosis in the pulmonary artery remodeling of pulmonary hypertension secondary to hypoxia and illustrate the relative genes expression. METHODS: Thirty rats were divided into hypoxia group (10% O2, 8 h/d) and normal control group. On the 15th day of hypoxia, pulmonary artery pressure and right ventricular hypertrophy index were measured and pulmonary artery vessels were studied by light microscope. Then terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique was used to detect nucleosomal DNA fragmentation of apoptotic cells. In situ hybridization and RT-PCR were used to detect the expression level of bcl-2 and bax. RESULTS: The pulmonary artery pressure and right ventricular hypertrophy index of hypoxia group were increased significantly, the pulmonary artery wall of hypoxic group become incrassate than control group. Apoptotic cells can be found in lung with hypoxia or without hypoxia. Compared with control group, apoptotic index of hypoxic group decreased significantly. Through the methods of in situ hybridization and RT-PCR, we found the expression of bcl-2 increased whereas bax decreased significantly in the hypoxic group. CONCLUSION: The alternation in bcl-2 and bax expression induced by hypoxia play an important role in the pulmonary artery remodeling which is the main pathologic change of pulmonary hypertension secondary to hypoxia.

Animals↗
PubMed2001

The tree shrew apolipoprotein C-I cDNA: sequence and its expression.

A rabbit anti-serum to tree shrew apolipoprotein C-I (apo C-I) was used to screen an expression cDNA library constructed by us from tree shrew (TS) liver tissue. Two apo C-I cDNA clones were obtained. The longer one consists of 380 nucleotides, including 21 bp and 95 bp at the 5' and 3' end of the non-translated regions respectively, and a 264-bp fragment in an open reading frame encoding 88 amino acids prepropeptide which contains 26 amino acids of signal peptide and a mature protein (62 amino acids). Comparing the amino-acid sequence deduced from this cDNA with those of the published mammalian apo C-Is reveals that it shared some structural similarity with rat, mouse and dog apo C-I, but it had 5 more amino acids than that of human and baboon. The expression of apo C-I mRNA in 8 different tissues were also assayed with Northern blot. The results demonstrated that liver had the highest expression, intestine had much less expression and no expression in other tissues, which is much different from human and other species. This study has laid down a good foundation for further studying on the function and the stucture of tree shrew apo C-I gene.

Amino Acid Sequence↗
PubMed2001

[Determination of sulfamethoxazole in compound sulfamethoxazole tablet by first derivative ratio spectrometry].

The first derivative ratio spectrometry is used for the determination of sulfamethoxazole in compound sulfamethoxazole tablet. According to the first derivative ratio spectrum of sulfamethoxazole, peak-zero method is applied for the determination at 251 nm. There is a good linear correlation between the first derivative ratio spectrum value and concentration (1-15 micrograms.mL-1) for the method that can eliminate the disturbance of trimethoprim, and no difference while comparing the method with pharmacopoeia method (P > 0.05).

Spectrophotometry, Ultraviolet↗
PubMed2001

[Regulation on the immunological effect of mogrosides in mice].

OBJECTIVE: To investigate the cellular immunological effect of mogrosides in mice. METHODS: Mogrosides was administered to normal or CTX-induced immunosuppressive mice, and their macrophage function and T lymphocyte proliferation were detected. RESULTS: Mogrosides could promote phagocytosis and T lymphocyte proliferation significantly in the CTX-induced immunosuppressive mice, but not in the normal mice. CONCLUSION: The results suggested that mogrosides had certain up-regulation on cellular immunity in the CTX-induced immunosuppressive mice.

Animals↗
PubMed2001

[Application of 18FDG-PET in the diagnosis of lung cancer].

OBJECTIVE: To evaluate the ability of 18FDG-PET in the identification of pulmonary mass and preoperative mediastinal lymph node staging of lung cancer. METHODS: Thirty-four patients with pulmonary neoplasm were evaluated with 18FDG-PET and CT scan respectively. PET data were analyzed semiquantitatively by calculating standardized uptake value (SUV) and also by a visual method. PET and CT results were compared with pathological results. RESULTS: When the visual method was used, the sensitivity and accuracy for detection of malignant mass of 18FDG-PET were 93% and 85% respectively, whereas those of CT were 63% and 53% (P < 0.05) respectively. The accuracy of preoperative mediastinal lymph node staging was 100% by PET and 78% by CT (P < 0.05). Semiquantitative method also provided an accuracy of 74% for detection of malignant mass. CONCLUSIONS: Compared with CT, 18FDG-PET was more accurate to discriminate the property of tumor and mediastinal lymph node stage status of lung cancer.

Adult↗
PubMed2000

Modular motif, structural folds and affinity profiles of the PEVK segment of human fetal skeletal muscle titin.

The extension of the PEVK segment of the giant elastic protein titin is a key event in the elastic response of striated muscle to passive stretch. PEVK behaves mechanically as an entropic spring and is thought to be a random coil. cDNA sequencing of human fetal skeletal PEVK reveals a modular motif with tandem repeats of modules averaging 28 residues and with superrepeats of seven modules. Conformational studies of bacterially expressed 53-kDa fragment (TP1) by circular dichroism suggest that this soluble protein contains substantial polyproline II (PPII) type left-handed helices. Urea and thermal titrations cause gradual and reversible decrease in PPII content. The absence of sharp melting in urea and thermal titrations suggests that there is no long range cooperativity among the PPII helices. Studies with solid phase and surface plasmon resonance assays indicate that TP1 interacts with actin and some but not all cloned nebulin fragments with high affinity. Interestingly, Ca(2+)/calmodulin and Ca(2+)/S100 abolish nebulin/PEVK interaction. We suggest that in aqueous solution, PEVK is an open and flexible chain of relatively stable structural folds of the polyproline II type. PEVK region of titin may be involved in interfilament association with thin filaments in a calcium/calmodulin-sensitive manner. This adhesion may modulate titin extensibility and elasticity.

Actins↗
PubMed2000

Importance of the free sulfhydryl groups of lecithin-cholesterol acyltransferase for its sensitivity to oxidative inactivation.

Lecithin-cholesterol acyltransferase (LCAT) of human plasma is known to be highly susceptible to oxidative inactivation, although the mechanism of this inactivation is unknown. We tested the hypothesis that the high sensitivity of the enzyme is due to the derivatization of its two free SH groups flanking the active site pocket. Modification of the SH groups with a reversible inhibitor protected the enzyme against oxidative inactivation. Mutagenesis of either of the cysteines to glycine increased the resistance of the enzyme, which retained 46% of activity in presence of 150 microM Cu(2+), compared to only 27% of the activity retained by the wild type enzyme (WT). Replacement of both the cysteines with glycines resulted in retention of over 65% activity. Cysteine replacement similarly protected the enzyme from inactivation by the oxidized substrate. Chicken LCAT, which has only one cysteine (Cys(26)), was more resistant than the human enzyme. Introduction of an additional cysteine corresponding to the second cysteine in human LCAT (N184C) resulted in increased susceptibility of chicken enzyme (87% loss of activity in presence of 150 microM Cu(2+), compared to 55% loss in WT). Substitution of the lone cysteine with glycine (C26G) resulted in a more resistant enzyme, which lost <40% activity under the same conditions. These results show that the primary targets of the oxidizing agents or the products of oxidation are the SH groups of the enzyme, whose derivatization leads to steric inhibition of the activity.

Animals↗
PubMed2000

Long-term follow-up after coronary stenting and intravascular red laser therapy.

A high restenosis rate remains a limiting factor for coronary angioplasty and stenting. Recently, use of intravascular red light therapy (IRLT) has been shown to be effective in different animal models and in humans in reducing the restenosis rate. Sixty-eight patients were treated with IRLT in conjunction with coronary stenting procedures. Mean age was 64 +/- 9 years. Treated lesions were type A (11), type B (42), and type C (18) with a mean lesion length of 16.5 +/- 2.4 mm. Reference vessel diameter and minimal lumen diameter (MLD) before therapy were 2.90 +/- 0.15 and 1.12 +/- 0.36 mm, respectively. After stenting and laser irradiation, MLD was 2.76 +/- 0.39 mm. No procedural complications or in-hospital adverse events occurred. All patients were followed up as depicted in the protocol. Sixty-one patients underwent angiographic restudy, which revealed restenosis in 9 patients (14.7%). Observed restenosis rate by artery size was > 3 mm (n = 21, 0%), 2.5 to 3.0 mm (n = 28, 14.2%), and <2.5 mm (n = 12, 41.6%). We conclude that IRLT is safe and feasible and reduces the expected restenosis rate in patients after coronary stenting in arteries of >2.5 mm.

Aged↗
PubMed2000

Helicobacter pylori-selective antibacterials based on inhibition of pyrimidine biosynthesis.

We report the discovery of a class of pyrazole-based compounds that are potent inhibitors of the dihydroorotate dehydrogenase of Helicobacter pylori but that do not inhibit the cognate enzymes from Gram-positive bacteria or humans. In culture these compounds inhibit the growth of H. pylori selectively, showing no effect on other Gram-negative or Gram-positive bacteria or human cell lines. These compounds represent the first examples of H. pylori-specific antibacterial agents. Cellular activity within this structural class appears to be due to dihydroorotate dehydrogenase inhibition. Minor structural changes that abrogate in vitro inhibition of the enzyme likewise eliminate cellular activity. Furthermore, the minimum inhibitory concentrations of these compounds increase upon addition of orotate to the culture medium in a concentration-dependent manner, consistent with dihydroorotate dehydrogenase inhibition as the mechanism of cellular inhibition. The data presented here suggest that targeted inhibition of de novo pyrimidine biosynthesis may be a valuable mechanism for the development of antimicrobial agents selective for H. pylori.

Amino Acid Sequence↗
PubMed2000

Sequencing and expression analysis of the serine protease gene cluster located in chromosome 19q13 region.

The human kallikrein gene cluster, located in the chromosome band 19q13, contains several tissue-specific serine protease genes including the prostate-specific KLK2, KLK3 and prostase genes. To further characterize the gene cluster, we have mapped, sequenced, and analyzed the genomic sequence from the region. The results of EST database searches and GENSCAN gene prediction analysis reveal 13 serine protease genes and several pseudogenes in the region. Expression analysis by RT-PCR indicates that most of these protease genes are expressed only in a subset of the 35 different normal tissues that have been examined. Several protease genes expressed in skin show higher expression levels in psoriatic lesion samples than in non-lesional skin samples from the same patient. This suggests that the imbalance of a complex protease cascade in skin may contribute to the pathology of disease. The proteases, excluding the kallikrein genes, share approximately 40% of their sequences suggesting that the serine protease gene cluster on chromosome 19q13 arose from ancient gene duplications.

Amino Acid Sequence↗