Biomedical subjects

C W Wang

Publications and source records attributed to C W Wang.

At least 37 records · Page 2Linked to original sources

PubMed2000

Grip and key pinch strength: norms for 15- to 22-year-old Chinese students.

BACKGROUND: Establishment of norms for hand strength is emerging worldwide and is both important and necessary in public health and hand surgery. The purpose of this study was to establish normative data for hand grip and key pinch strength for 15- to 22-year-old Chinese students. METHODS: The Jamar dynamometer was used to measure grip strength and the Jamar pinch gauge to measure key pinch strength. All subjects were free of disease or injury that might affect hand strength. All complementary factors such as age, sex, height, weight, dominant hand for writing and exercise were recorded. The influences of injury, exercise and living habits on the performance of hand strength were also examined. RESULTS: Out of a total of 2,982 students examined, there were nine men (0.39%) who used the left hand for writing, 143 men (6.27%) who used the left hand during exercise, two women (0.28%) who wrote with the left hand and 26 women (3.70%) who used the left hand during exercise. The mean grip and key pinch strength of the left hand was about 90% that of the right hand. The mean grip and key pinch strength of the women was about 60% that of men. CONCLUSIONS: A strong correlation between the right hand and the left hand in grip and key pinch strength was found. Whether nonanthropometric factors may affect hand strengths was explored as well.

Adolescent↗

PubMed2000

A complex containing both trypsin inhibitor and dehydroascorbate reductase activities isolated from mitochondria of etiolated mung bean (Vigna radiata L. (Wilczek) cv. Tainan no. 5) seedlings.

A complex containing trypsin inhibitor (TI) activity was extracted with 0.1 M TRIS buffer (pH 7.9) from trypsin-treated mitochondria of etiolated mung bean seedlings, and further purified with a Superdex 200 FPLC column. This partially purified complex with an M(r) about 820 kDa exhibited additional dehydroascorbate (DHA) reductase activity with specific activities of 0.21, 1.53 and 1.54 mumol ascorbate formed min-1 mg-1 protein at pH 6.0, 6.5 and 7.0, respectively, when glutathione was added. Much lower DHA reductase activity (0.013 and 0.026 mumol ascorbate formed min-1 mg-1 protein at pH 6.5 and 7.0, respectively) was found when glutathione was omitted. The isolated complex gave positive results when it was tested by TI activity staining after SDS-PAGE, and could be recognized by a polyclonal antibody which was raised against 38 kDa sweet potato Kunitz-type TI, one of the root storage proteins of sweet potato. The possible physiological functions of this complex with both TI and DHA reductase activities were discussed.

Chromatography↗

PubMed1999

Engineered isoprenoid pathway enhances astaxanthin production in Escherichia coli.

The isoprenoid pathway is a versatile biosynthetic network leading to over 23,000 compounds. Similar to other biosynthetic pathways, the production of isoprenoids in microorganisms is controlled by the supply of precursors, among other factors. To engineer a host that has the capability to supply geranylgeranyl diphosphate (GGPP), a common precursor of isoprenoids, we cloned and overexpressed isopentenyl diphosphate (IPP) isomerase (encoded by idi) from Escherichia coli and GGPP synthase (encoded by gps) from the archaebacterium Archaeoglobus fulgidus. The latter was shown to be a multifunctional enzyme converting dimethylallyl diphosphate (DMAPP) to GGPP. These two genes and the gene cluster (crtBIYZW) of the marine bacterium Agrobacterium aurantiacum were introduced into E. coli to produce astaxanthin, an orange pigment and antioxidant. This metabolically engineered strain produces astaxanthin 50 times higher than values reported before. To determine the rate-controlling steps in GGPP production, the IDI-GPS pathway was compared with another construct containing idi, ispA (encoding farnesyl diphosphate (FPP) synthase in E. coli), and crtE (encoding GGPP synthase from Erwinia uredovora). Results show that the conversion from FPP to GGPP is the first bottleneck, followed sequentially by IPP isomerization and FPP synthesis. Removal of these bottlenecks results in an E. coli strain providing sufficient precursors for in vivo synthesis of isoprenoids.

Alkyl and Aryl Transferases↗

PubMed1999

In vitro maturation of human preovulatory oocytes reconstructed by germinal vesicle transfer.

OBJECTIVE: To describe a micromanipulation-electrofusion procedure for transferring germinal vesicles (GVs) between immature human oocytes. DESIGN: Pilot study to assess oocyte maturation after an invasive micromanipulation procedure. SETTING: Research laboratory at a university medical center. PATIENT(S): Immature oocytes were discarded from intracytoplasmic sperm injection (ICSI)-IVF cycles of patients 23-48 years of age. INTERVENTION(S): Initially, GV removal and transfer were performed on the same oocyte; these "self-reconstructed" oocytes were then cultured in vitro for up to 50 hours and examined periodically for maturation as judged by the extrusion of the first polar body. In a second study, GVs from oocytes of "old" patients (>38 years old) were successfully transferred into enucleated immature oocytes of "young" patients (<31 years old). MAIN OUTCOME MEASURE(S): Extrusion of the first polar body was monitored in "reconstructed" and control oocytes; karyotypes also were analyzed at meiosis II. RESULT(S): From 48 oocytes from old patients, 12 GVs were successfully removed, transferred, and fused into previously enucleated oocytes from young patients. After in vitro culture, 7 of these "reconstructed" oocytes matured to meiosis II, a maturation rate not significantly different from that observed in nonmanipulated controls. A normal, second meiotic metaphase chromosome complement was observed in 4 of 5 reconstructed oocytes. CONCLUSION(S): Normal meiosis can occur after the transfer of a GV into an enucleated host oocyte. Germinal vesicle transfer may be a valuable research procedure that generates cell models to characterize the cytoplasmic-nuclear interplay for cell cycle regulation, maturation, and fertilization in the human oocyte; it also may be a potentially attractive alternative to oocyte donation.

Adult↗

PubMed1999

Electrical activation and in vitro development of human oocytes that fail to fertilize after intracytoplasmic sperm injection.

OBJECTIVE: To determine whether electrically stimulated Ca2+ influx can "rescue" fertilization and early embryogenesis in human oocytes that fail to fertilize after intracytoplasmic sperm injection (ICSI). DESIGN: Prospective, randomized trial of a laboratory procedure. SETTING: A research laboratory at a university medical center. PATIENT(S): Discarded oocytes from ICSI-IVF cycles. INTERVENTION(S): Oocytes (n = 104) that showed no evidence of fertilization 16-24 hours after ICSI were assigned to three treatment groups: group 1 (one direct current electrical pulse at 1.36-1.50 kV/cm for 40-60 micros), group 2 (three pulses every 15-20 minutes), or group 3 (treated the same as group 2 but with no electrical stimulation). MAIN OUTCOME MEASURE(S): After stimulation, the oocytes were cultured in vitro for 3-5 days. Oocytes that displayed two pronuclei and a second polar body within 16 hours were considered to have fertilized normally. Fertilization and embryo cleavage rates were compared between groups. RESULT(S): Fertilization occurred in 26 (70%) of 37 and 38 (78%) of 49 group 1 and 2 oocytes, respectively, but in only 5 (27%) of 18 group 3 oocytes. Within 3 days, group 2 embryos routinely developed beyond the two-cell to four-cell stage (61% versus 13% in group 1); 11% of these oocytes developed to the morula or early blastocyst stage. Sex chromosome analyses indicated 10 male and 8 female embryos. CONCLUSION(S): Oocytes that fail to fertilize by 24 hours after ICSI can resume apparently normal fertilization and early embryonic development in response to electrical stimulation. Moreover, the degree of cytoplasmic activation as determined by the number of pulses applied affects fertilization efficiency and early embryonic development.

Adult↗

PubMed1999

Reconstruction of mouse oocytes by germinal vesicle transfer: maturity of host oocyte cytoplasm determines meiosis.

We evaluated the maturational competence of mouse oocytes reconstructed by the transfer and electrofusion of germinal vesicles (GV) into anuclear cytoplasts of GV stage oocytes (both auto- and hetero-transfers), metaphase II stage oocytes or zygotes. Following in-vitro culture, the maturation rates of the reconstructed oocytes to metaphase II did not significantly differ between auto- and hetero-transfers (40/70 versus 95/144 respectively); these rates also did not differ from those of control oocytes (57/97) which were matured in vitro without micromanipulation and electrofusion. In contrast, when a GV was transferred into an enucleated metaphase II oocyte or a zygote, only a few reconstructed oocytes underwent germinal vesicle breakdown (5/30 and 2/21 respectively); moreover, none reached metaphase II stage. Cytogenetic and immunofluorescence analyses were conducted on hetero-GV oocytes that extruded a first polar body. Each oocyte showed two groups of chromosomes, one in the cytoplast and one in the polar body, as well as a bipolar spindle with twenty univalent chromosomes. Our findings suggest that oocytes reconstructed by GV transfer into a cytoplast of the same developmental stage mature normally in vitro through metaphase II. Such oocytes may be a useful research model to elucidate the cytoplasmic and nuclear mechanisms regulating meiosis and the relationships between meiotic errors and age-related changes in the oocyte.

1-Methyl-3-isobutylxanthine↗

PubMed1999

[Ethanol-induced gastric mucosal injury and the protection of taurine against the injury in rats].

40 SD rats were randomly divided into control group, ethanol-induced injury group and taurine protective group for the measurement of the contents of endothelin (ET), nitric oxide synthetase (NOS), somatostatin (SS) and vasoactive intestinal peptide (VIP). The results are as follows. The gastric mucosa was damaged by 75% ethanol, being aggravated with prolonged application time, as shown by a significant increase of the ET content and decreases of the contents of NOS, VIP and SS in the gastric mucosa. In the taurine group, decrease of ET content and increase of the contents of NOS, SS and VIP in the gastric mucosa were observed. Apparently, the changes in ET, NOS, SS and VIP contents of gastric mucosa serve as reliable indices in the pathogenesis by ethanol and protective effect by taurine.

Animals↗

PubMed1997

Effects of depolarization and NMDA antagonists on the role survival of cerebellar granule cells: a pivotal role for protein kinase C isoforms.

Primary cultures of cerebellar granule cells (CGCs) grown in high-K+ (25 mM; K25) medium progressively differentiate in vitro. Differentiation is noticeable after 3-4 days in vitro (DIV) and reach a mature stage after 8 DIV. Longer cultivation of CGCs (>13 DIV) triggers the processes of spontaneous cell death. However, if cultured in normal physiological K concentration (5 mM; K5), a significant proportion of the cells dies by the end of the first week in culture. To address the role of protein kinase C (PKC) in the development of CGCs, we measured the kinase activity as well as the protein level of the kinase isoforms. As the K25 CGC culture proceeded, the PKC activity time-dependently increased by 3.2-fold, reaching a steady state at 8 DIV. Western blot analysis using PKC isoform-specific antibodies revealed an increase in levels of PKC alpha, gamma, mu, lambda, and iota from 2 to 8 DIV. A slight increase or decrease at 4 DIV was observed for PKC epsilon and betaII, respectively, whereas no significant change was observed for betaI. The isoforms of delta, theta, eta, and zeta were not detected. Comparing the 14 DIV cultures with the 10 DIV cultures, the immunoreactivities of PKC iota and epsilon were decreased, those of PKC alpha, betaI, betaII, gamma, and lambda were unchanged, whereas that of PKC mu was still increased. In K5 cultures, the immunoreactivity of each PKC isoform at 2-4 DIV was similar to that observed in K25 cells, although no remarkable differentiation features were observed. Coordinated with the appearance of cell death at 8 DIV in low-K+ cultures, levels of PKC alpha, mu, lambda, and iota, but not the others, were markedly decreased. The NMDA receptor antagonists MK-801 and 2-amino-5-phosphopentanoic acid markedly prevented the age-induced apoptosis of CGCs, and the cells survived >18 DIV under these conditions. The cytoprotective effect of MK-801 was concomitant with the increases in levels of PKC gamma, lambda, iota, and mu at 10 and 14 DIV. In addition, the PKC epsilon level was increased at 14 DIV but decreased at early stages, whereas PKC alpha, betaI, and betaII levels were unchanged, as compared with K25 culture alone. Taken together, induction and up-regulation of PKC isoforms may play an important role in the maintenance of CGC survival by depolarization and MK-801.

2-Amino-5-phosphonovalerate↗

PubMed1997

Bundle branch reentry ventricular tachycardia with two distinct left bundle branch block morphologies.

INTRODUCTION: Bundle branch reentry ventricular tachycardia (VT) is usually amenable to treatment with radiofrequency ablation. Different QRS morphologies during VT are possible when anterograde ventricular activation is over the left bundle branch. Manifestations of this reentrant tachycardia with more than one QRS morphology with anterograde activation via the right bundle have not been reported and would be unusual due to the more discrete anatomy of the right bundle branch. METHODS AND RESULTS: An electrophysiologic study was conducted in a patient with dilated ventricle and diminished ventricular function with VT. Typical characteristics of bundle branch reentry were noted when VT was induced. The study was notable for the presence of a right bundle recording only during macroreentrant beats or VT and the distal location of the recording. Radiofrequency ablation was performed. Postablation stimulation again induced VT, proven to be of the same bundle branch reentry mechanism but of a different QRS morphology. A second ablation was required for complete ablation of this patient's bundle branch reentry VT. CONCLUSION: In bundle branch reentry utilizing the left bundle as the retrograde limb and the right bundle branch as the anterograde limb of the circuit, VT of more than one distinct morphology can be seen. Careful evaluation to assess for the persistence of VT of the same mechanism is necessary to ensure complete ablation of the reentrant circuit. Preexisting right bundle disease and a dilated heart with more dispersed distal right bundle branches may predispose to such a phenomenon.

Adult↗

PubMed1997

Effect of epidermal growth factor on cultured rat hepatocytes poisoned by CCl4.

AIM: To study the effects of epidermal growth factor (EGF) on CCl4-induced primary cultured hepatocytes injury. METHODS: Alanine amino-transferase (AlaAT) and aspartate aminotransferase (AspAT) activities and K+ concentractions were determined by the Auto-biochemistry Assay System. Malondialdehyde (MDA) was determined by thiobarbituric acid method. Radioactivity was determined by liquid scintillometry. Light microscopy and electron microscopy were used. RESULTS: EGF 40 micrograms.L-1 decreased CCl4 (10 mmol.L-1)-induced damages of rat primary cultured hepatocytes by decreasing AlaAT and AspAT leakage and MDA production, and promoted RNA and DNA synthesis, with a high positive correlation between intracellular K+ leakage and DNA syntheses (r = 0.99, P < 0.01). Cytopathological study showed that EGF decreased damage of liver cells. CONCLUSION: EGF maintains the stability of cellular lipid membrane and promotes syntheses of RNA and DNA of hepatocytes, and intracellular K+ transference is a promotor of the message transmission of DNA synthesis.

Alanine Transaminase↗

PubMed1997

Pregnancy after intracytoplasmic injection of immotile sperm. A case report.

BACKGROUND: With the advent of intracytoplasmic sperm injection (ICSI), fertilization and pregnancy have been reported in complete asthenozoospermia. The major problem with the use of immotile sperm for ICSI has been differentiating between live and dead sperm. We successfully selected live sperms with the hypoosmotic swelling test, and a twin pregnancy resulted after intracytoplasmic injection of completely immotile sperm. CASE: A 32-year-old woman and her 36-year-old husband had had primary infertility for four years. Evaluation of the couple showed complete asthenozoospermia of the husband. Ovulation in the wife was successfully stimulated with clomiphene citrate, follicle-stimulating hormone and human menopausal gonadotropin. We selected the viable sperm with the hypoosmotic swelling test. ICSI was then performed. After assisted hatching, we transferred four embryos on the third day after oocyte retrieval. Intrauterine twin pregnancy was confirmed by ultrasonography four weeks later. The healthy infants, free of anomalies, were born on the 36th gestational week. CONCLUSION: The hypoosmotic swelling test is a simple method of selecting immotile and viable sperm for use in ICSI.

Adult↗

PubMed1996

Inability of serum myocyte death markers to predict acute cardiac allograft rejection.

Acute cardiac rejection involves myocyte necrosis. Hence, markers of myocyte death may be useful in diagnosing rejection. Creatine kinase MB, MB isoforms, and troponins I and T were measured in 186 patients undergoing 365 endomyocardial biopsies. No differences were noted with rejection (rejectors vs. nonrejectors: CK=63.8 U/L and 86.6 U/L, P=0.0881; CK MB=2.04 ng/ml and 2.06 ng/ml, P=0.949; troponin T=0.134 ng/ml and 0.0881 ng/ml, P=0.374; troponin I=0.216 ng/ml and 0.707 ng/ml, P=0.357). The time course of troponins T and I levels in rejectors and nonrejectors do not differ with both groups having early elevations. Markers of myocyte death are inadequate predictors of acute rejection in cardiac allografts. The time course of troponins T and I suggests a possible role as prognostic indicators of outcome.

Acute Disease↗

PubMed1996

SK & F 96365 inhibits carbachol-induced phosphoinositide turnover in human neuroblastoma SH-SY5Y and rat cerebellar granule cells.

SK & F 96365, a receptor-mediated Ca2+ entry inhibitor, has been reported to inhibit Ca2+ responses to various agonists without affecting internal Ca2+ release and phosphoinositide turnover. Since muscarinic acetylcholine receptor-mediated phosphoinositide turnover shows a marked dependence on factors affecting cytosolic Ca2+ concentration, the effects of SK & F 96365 on the coupling of muscarinic receptors to the phosphoinositide hydrolysis were examined in human neuroblastoma SH-SY5Y and rat cerebellar granule cells. SK & F 96365 concentration-dependently (3-30 microM) inhibited the inositol phosphate formation elicited by carbachol in both cellular systems. Moreover, SK & F 96365 inhibited the carbachol-induced inositol phosphate formation in the absence of extracellular Ca2+, and similar extent of inhibition was achieved in the presence or absence of extracellular Ca2+. In ligand binding studies, we found that the binding affinities for [3H] N-methyl-scopolamine in both cells were attenuated by SK & F 96365 (3-30 microM), while Bmax values for the ligand were not changed. The competition curves of SK & F 96365 showed a Ki value of 28.4 uM in SH-SY5Y cells. The results indicated that the decrease of carbachol-stimulated phosphoinositide hydrolysis by SK & F 96365 is due to the competitive inhibition of agonist binding to the M3 muscarinic receptors.

Animals↗

PubMed1996

Subtyping of human T-lymphotropic virus type I by amplification of long terminal repeat sequences and restriction fragment length polymorphism analysis in carriers with multiple transfusions.

Five major subtypes of human T-lymphotropic virus type I (HTLV-I) have been proposed: cosmopolitan, Japanese, West African, Central African, and Melanesian. Based on nucleotide variations specific to particular subtypes, it was possible to genotype HTLV-I rapidly by restriction fragment length polymorphism (RFLP) studies following polymerase chain reaction (PCR). In this study, the restriction patterns of two LTR fragments were analyzed using eight restriction endonucleases (AvaI, Eco57I, BsoFI, NdeI, SacI, DraI, MaeII, and MaeIII). Genotyping of HTLV-I was done in nine patients with adult T-cell leukemia or HTLV-I-associated myelopathy/tropical spastic paraparesis, in three prostitutes, and in 19 carriers with multiple transfusion in Taiwan. The subtyping results of RFLP studies using these eight restriction endonucleases were in accordance with those of phylogenetic analysis. A substitution of G by A at nucleotide position 503, which creates the DraI site but suppresses the SacI site, was found not only in the Japanese subtype but also in a minority of the cosmopolitan subtype. A mutation near the position of subtype-specific nucleotide variations might suppress the restriction site and lead to unexpected restriction patterns. Amplification of more than one proviral fragment and RFLP studies with a group of appropriate restriction endonucleases may provide rapid and accurate genotyping of HTLV-I. More carriers are required to evaluate the possibility of mixed infection with different HTLV-I subtypes.

Base Sequence↗

PubMed1996

Comparison of hysterosalpingography and hysteroscopy in female infertility.

STUDY OBJECTIVE: To determine the diagnostic value of hysterosalpingography (HSG) and diagnostic hysteroscopy in infertility evaluations. DESIGN: Comparative 2-year study. SETTING: Outpatient infertility clinic of a tertiary medical center. PATIENTS: Two hundred sixteen women being investigated for infertility. INTERVENTIONS: An HSG was followed by a diagnostic hysteroscopy. MEASUREMENTS AND MAIN RESULTS: The HSGs were interpreted as normal in 79 (36.9%) women and as showing some abnormalities of the uterine cavity in 135 (63.1%). In the former group, 51 patients had a normal uterine cavity, but 28 had abnormal findings on hysteroscopy, a false negative rate of 35.4%. Of 135 women with an abnormal HSG, hysteroscopy found a normal uterine cavity in 21, a false positive rate of 15.6%. The sensitivity of HSG was 80.3% in revealing intrauterine abnormality and its specificity was 70.1%. Although some abnormalities were identified by both methods in 114 women, findings of both procedures were similar in only 88 (77.2%). In 75 (35.0%), the findings of HSG differed from those of hysteroscopy. In only 139 (65%) patients were the findings (normal and abnormal) similar for both methods. CONCLUSIONS: We advocate hysteroscopy in the investigation of female infertility for its accuracy, safety, simplicity, and convenience.

Adolescent↗

PubMed1996

Hysteroscopic extraction of a vaginal foreign body in a child.

A 3.5-year-old girl had a persistent, foul-smelling, blood-tinged vaginal discharge. She was initially treated for recurrent and persistent vulvovaginitis, which resulted in no improvement. Vaginoscopy revealed an intravaginal foreign body, which was removed successfully by hysteroscopy. We believe hysteroscopy is safe, convenient, effective, and easy to perform, even in a child.

Endoscopy↗

PubMed1995

Increased sympathetic nervous system activity in Chinese hypertensive patients with type II diabetes mellitus.

To evaluate the coexistence of sympathetic overactivity and hypertension in type 2 diabetic patients, a population-based study was conducted of newly-diagnosed type 2 diabetic patients recruited from a single community located at northern Taiwan. This study included 2877 (male 1382, female 1495) middle-aged ethnic Chinese adults, aged 45-65 years. Of the 1382 males, 67 had newly-diagnosed type 2 diabetes mellitus, whereas 75 of the 1495 females had type 2 diabetes. The data showed that about 39% of diabetic patients had borderline hypertension (mean blood pressure 141/91 mmHg) whereas the average incidence in non-diabetic subjects was 15.5%. The borderline hypertensive diabetic patients had significantly higher heart rates (mean 78.8 vs. 69.3 beats/min; P < 0.001) than control subjects. However, the cardiac index was similar in both control and diabetic subjects (mean 2.48 vs. 2.53 l/min/m2; P > 0.05). Our data show that sympathetic overactivity and increased incidence of hypertension actually existed in these type 2 diabetic patients of Chinese origin.

Analysis of Variance↗

PubMed1995

Extraumbilical insertion of the operative laparoscope in patients with extensive intraabdominal adhesions.

In 12 patients who had known or suspected intraabdominal adhesions, we evaluated the benefit of using Palmer's point for inserting the Veress needle and primary cannula during laparoscopic adhesiolysis to prevent direct intestinal injury. After inserting the laparoscope through this point, four women were found to have extreme intestinal adhesions around the umbilical area, and intestinal or severe omental injury might occur if the cannulas were inserted directly through the umbilical fossa. The other eight patients had omentum, partial to severe, adherent to the anterior abdominal wall. No complication occurred during insertion of the Veress needle and primary cannula through Palmer's point. Nine patients had successful laparoscopic adhesiolysis and were discharged within 2 days. In the other three women the procedure was converted to laparotomy because of extensive intestinal adhesions (2 patients) and small bowel injury during laparoscopic adhesiolysis (1). Palmer's point can be considered a safe and good alternative site for inserting the Veress needle and primary cannula to lyse dense intestinal and extensive omental adhesions. This technique should provide the surgeon with wider visual angel and surgical field, thus making adhesiolysis much easier to perform.

Abdomen↗