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Biomedical subjects

C W Wu

Publications and source records attributed to C W Wu.

At least 145 records · Page 8Linked to original sources
PubMed1996

A prospective randomised study of laparoscopic v. open cholecystectomy in aged patients with cholecystolithiasis.

Between August 1992 and July 1993, 27 patients aged 70 years of older with cholelithiasis were prospectively randomised into 2 groups. Fifteen patients underwent laparoscopic cholecystectomy and 12 patients underwent open cholecystectomy. Shorter operation time (93.3 +/- 25.3 minutes v. 176.3 +/- 26.1 minutes, P < 0.00001), fewer postoperative analgesic requirements (0.53 +/- 0.52 days v. 2.00 +/- 0.74 days, P < 0.00001), shorter postoperative hospital stay (3.93 +/- 1.71 days v. 7.92 +/- 0.79 days, P < 0.00001) and better cosmesis were found in the laparoscopic cholecystectomy group. The above data suggest that laparoscopic cholecystectomy is the treatment of choice for cholecystolithiasis in elderly patients.

Aged↗
PubMed1995

A movable and regulable inactivation function within the central region of a temperature-sensitive p53 mutant.

p53 is the most frequently mutated gene in human cancer. Naturally occurring mutations of p53 are mainly located within a region containing residues 100-300 and are predominantly of missense type, resulting in loss of the protein's DNA binding activity. Here we show that this type of mutation also represses the p53 N-terminal activation domain. The repression activity is localized in the central region of mutant p53 containing residues 101-318. Interestingly, the central region of a temperature-sensitive mutant p53N247I possesses a movable and regulable inactivation function. It represses other activities present on the same polypeptide chain without strict regard to the configuration of that polypeptide only at the nonpermissive temperature (37 degrees C) and not at the permissive temperature (30 degrees C). Furthermore, this mutant p53 region exhibits no other activity, and its function is independent of endogenous p53 status.

Animals↗
PubMed1995

Cloning and characterization of the endogenous retroviral-tRNA(Glu) multigene family from human genomes of different racial backgrounds.

An 8.3-kb human endogenous retroviral-tRNA(Glu) (HERV-E)-encoding cDNA clone and a 1.5-kb genomic clone were isolated from a Chinese-derived cervical cancer cell line, CC7T, and their sequences determined. The former is a full-length endogenous retroviral cDNA containing corresponding u5-gag-pol-env-u3-r regions. The latter is a partial retroviral DNA segment, covering the gag and pol genes. Analysis of normal human DNA by Southern blot hybridization with three specific HERV-E molecular DNA probes revealed complex restriction-fragment length polymorphisms (RFLP), implying that the human genome contains diverse proviral structures and dispersed integration sites. The complex patterns were virtually identical between DNAs from African-Americans, Asians and Caucasians, with only a few minor variations. The data suggest that these proviral sequences were mostly incorporated into the human genome before racial divergence and, hence, may serve as markers for distinct chromosomal sites.

Amino Acid Sequence↗
PubMed1995

Differential expression of the human metastasis adhesion molecule CD44V in normal and carcinomatous stomach mucosa of Chinese subjects.

BACKGROUND: CD44 is a cell surface adhesion molecule involved in cell-cell and cell-matrix interactions. Tumor cells transfected to overexpress the isoform CD44V readily gain access to lymph nodes and form distant metastases. METHODS: Monoclonal antibodies directed at epitopes common to known CD44 isoforms were used to investigate CD44V expression in 30 normal gastric mucosa tissues, 64 different gastric adenocarcinomas, 20 metastatic adenocarcinoma lymph nodes and 4 established gastric carcinoma cell lines. In addition, CD44V gene expression in six gastric adenocarcinoma tissues and four gastric cancer cell lines were investigated by northern blotting. RESULTS: Immunohistochemistry screening of 30 subjects with normal gastric mucosa did not reveal expression of CD44 variants. Areas of intestinal metaplasia, a precancerous lesion, were stained with antibodies against either V5- or V6-containing isoforms of CD44. Tubular and signet-ring cell types of adenocarcinoma were strongly positive for epitopes encoded by CD44 variants containing exons V5 (41/49 and 10/10, respectively). Some tubular type adenocarcinomas (15/49) also expressed CD44 variants containing the V6 epitope. Tumor differentiation was closely related to CD44 V5 expression (P < 0.001). In addition, 18 of 20 gastric adenocarcinomas metastatic to lymph nodes expressed the V5 epitope of CD44 and 4 of 20 expressed the V6 epitope. Analysis of four established gastric adenocarcinoma cell lines revealed that two had moderate to strong expression of exons V5 and V6 of CD44. An antibody directed against CD44 variants containing exons V8 to V10 strongly stained all gastric adenocarcinoma cell lines. Northern blotting demonstrated that all four tumor cell lines and six gastric carcinoma mucosa tissues expressed CD44V. CONCLUSIONS: Generation of CD44 splice variants may be closely linked with gastric carcinoma tumorigenesis and differentiation. In addition, expression of CD44 variants containing exons V5 and V6 may be used as an indicator of evolving gastric cancer.

Adenocarcinoma↗
PubMed1995

Correlation of expression of CD44 isoforms and E-cadherin with differentiation in human urothelial cell lines and transitional cell carcinoma.

Using immunostaining, immunoblot, reverse-transcriptase polymerase chain reaction and Southern blot, we found that expressions of CD44 isoforms and E-cadherin were very closely linked and were correlated with the differentiation status in human urothelial cell lines and clinical specimens of transitional cell carcinoma. Normal urothelium, well to moderately differentiated cell lines and surgical samples expressed E-cadherin and large CD44 isoforms containing exon v6, which was pivotal in metastasis of rat pancreatic cell line model. Poorly differentiated cell lines and surgical samples, were E-cadherin-negative and expressed primarily standard form CD44, which did not contain exon v6. We concluded that CD44v6 isoforms and E-cadherin were both down-regulated during the carcinogenesis of urothelium. The large exon v6 containing CD44 isoforms were readily detected in normal urothelium, therefore, were not likely linked to cancer metastasis. E-cadherin and CD44v6 may be used as differentiation markers for human urothelial tumors. Immunohistochemical study solely with antibody against epitopes encoded by exon v6 alone is not informative enough as other alternatively spliced exons may change the function of CD44v6 isoforms.

Animals↗
PubMed1995

Cytomegalovirus infection and viral shedding in the genital tract of infertile couples.

The prevalence of cytomegalovirus (CMV) infection and viral shedding in infertile couples in Taiwan and its role in infertility were studied. Two hundred fifty couples were enrolled in this study. Anti-CMV IgG was measured in serum samples from these infertile couples. Viral shedding examined by DNA hybridization was detected in semen from the husband and cervical mucus from the wife. Anti-CMV IgG was detected in 249 (99.6%) of the 250 male serum samples and in 247 (98.9%) of the 250 female serum samples. Viral shedding was detectable in 83 (33.5%) of 248 semen samples and 83 (33.7%) of 246 cervical mucus samples by dot-blot DNA hybridization assay. Semen quality was not apparently affected by the existence of viral shedding. The co-shedding rate in semen and cervical mucus was high (15.9%). It is concluded that the seroprevalence and genital tract viral shedding were relatively high in infertile couples in Taiwan. Viral shedding did not affect the semen quality. Nevertheless, screening of donor semen is recommended.

Adolescent↗
PubMed1995

Complete genomic RNA sequences of cucumber mosaic virus strain NT9 from Taiwan.

The nucleotide sequences of the RNAs 1, 2, and 3 of the cucumber mosaic virus (CMV) Taiwan isolate NT9 were determined and compared at both the nucleotide and amino acid levels with those of CMV strains Fny, Y, O from subgroup I and strain Q from subgroup II. NT9-CMV has an unique feature at the C-terminus of the 3a protein which contains four extra-amino acids. All three RNAs and their encoded proteins, except 2b, of NT9-CMV share more than 90% identity with those of strains in subgroup I, and 72%-85% identity with Q-CMV. The results indicated the conservation of sequences of CMV derived from different geographical locations.

Amino Acid Sequence↗
PubMed1995

Effect of ethanol on the protein secondary structure of the human gastric mucosa, in vitro.

The effect of ethanol on the secondary conformational structure of proteins of the human gastric mucosa was investigated by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) spectroscopy. The IR peak intensity and position of each structural component of gastric mucosa was found to change significantly with the ethanol concentration and length of exposure. The peak intensity due to the beta-sheet and/or beta-turn conformational structure in amide I and II bands of gastric mucosa clearly increased after treatment with ethanol. Moreover, the peak at 1635 cm-1 shifted to 1630 cm-1 after treatment with 40% ethanol for 3 h, or 80% ethanol for 1 h, and a distinct shoulder also appeared at 1643 cm-1. This shift occurred more rapidly and was more pronounced after exposure of mucosa to 80% ethanol, compared with the effect of 40% ethanol, but the alpha-helical structure at the amide I and II bands was not influenced by either concentration of ethanol. Ethanol treatment might also transform the secondary structure of amide III in gastric mucosa from an alpha-helix to a mainly random coil with extensive unfolding. The absorption between 1180 and 980 cm-1, which is assigned to glycoprotein structure, was also reduced after treatment with ethanol. This strongly indicates that ethanol influences the conformation of the lipids and proteins of human gastric mucosa, leading to their deformation.

Ethanol↗
PubMed1995

Morbidity and mortality after radical gastrectomy for patients with carcinoma of the stomach.

BACKGROUND: This study sought to analyze the morbidity and mortality rates after radical gastrectomy for carcinoma, since the operation has been criticized as too morbid for the benefits it may provide. STUDY DESIGN: A prospective study of 474 patients who underwent radical gastrectomy was conducted. RESULTS: The overall morbidity and mortality rates were 20.1 and 3.0 percent, respectively. The morbidity and mortality rates fell significantly from 27.0 to 15.7 percent (p = 0.003) and 5.5 to 1.1 percent (p < 0.001), respectively, after the first 200 cases. By logistic regression analysis, it was found that male gender, combined organ(s) resection, extended lymphadenectomy, respiratory system disease, and tumor location were significantly related to postoperative morbidity. In regard to the extent of lymphadenectomy, relative to R2 resection (n = 102), the odds ratio for morbidity after R3 resection (n = 217) was 2.13, and for R4 resection (n = 155) it was 3.12. Age older than 65 years, total gastrectomy, combined organ(s) resection, and respiratory system disease were factors that negatively affected operative mortality. CONCLUSIONS: These observations suggested that radical gastrectomy can be performed with an acceptable risk of morbidity and mortality in a general hospital.

Age Factors↗
PubMed1994

Lymph node metastasis from carcinoma of the distal one-third of the stomach.

BACKGROUND: A detailed and thorough pathoanatomic study of lymph node (LN) metastases of adenocarcinoma of the distal one-third of the stomach is lacking. METHODS: From December 1987 to March 1992, 190 patients who underwent radical gastrectomy was analyzed. All LN were dissected and labeled according to the Japanese General Rules for the Gastric Cancer Study. RESULTS: A total of 7052 LN with an average of 37.1 per specimen were removed. LN metastases were encountered in 121 patients (63.7%). The most frequent LN metastases were perigastric, above common hepatic artery, along left gastric artery, and hepatoduodenal ligament. The incidence of LN metastasis varied and was highest when tumor was located close to either curvature and extended to duodenum or midbody. The high incidence of LN metastases in the hepatoduodenal ligament was a unique pathologic feature of adenocarcinoma of the distal one-third of the stomach (P = 0.0012). Univariate and multivariate analysis revealed that depth of cancer invasion was the only factor related to LN metastases. CONCLUSIONS: Cancer in the distal one-third of the stomach had a high incidence of LN metastasis to hepatoduodenal ligament nodes. The LN metastasis is correlated with depth of cancer invasion.

Adenocarcinoma↗
PubMed1994

Lymph node metastasis from carcinoma of the distal one-third of the stomach.

BACKGROUND: A detailed and thorough pathoanatomic study of lymph node (LN) metastases of adenocarcinoma of the distal one-third of the stomach is lacking. METHODS: From December 1987 to March 1992, 190 patients who underwent radical gastrectomy was analyzed. All LN were dissected and labeled according to the Japanese General Rules for the Gastric Cancer Study. RESULTS: A total of 7052 LN with average of 37.1 per specimen were removed. LN metastases were encountered in 121 patients (63.7%). The most frequent LN metastases were perigastric, above common hepatic artery, along left gastric artery, and hepatoduodenal ligament. The incidence of LN metastasis varied and was highest when tumor was located close to either curvature and extended to duodenum or midbody. The high incidence of LN metastases in the hepatoduodenal ligament was a unique pathologic feature of lower stomach cancer (P = 0.0012). Univariate and multivariate analysis revealed that depth of cancer invasion was the only factor related to LN metastases. CONCLUSIONS: Cancer in the distal one-third of the stomach had a high incidence of LN metastasis to hepatoduodenal ligament nodes (No. 12). The LN metastasis is correlated with depth of cancer invasion.

Adenocarcinoma↗
PubMed1994

Cervical cytomegalovirus infection in prostitutes and in women attending a sexually transmitted disease clinic.

This study aimed to determine the frequency of, and to define factors associated with, cervical shedding of cytomegalovirus (CMV) in highly sexually active women (licensed prostitutes) and in women attending a sexually transmitted disease (STD) clinic. Cervical specimens obtained from 195 licensed prostitutes and 187 STD patients aged 17-50 years were compared for the presence of cervical CMV with specimens from 70 women of the same ages attending a gynecologic clinic. Cervical CMV was identified by the presence of a CMV-specific immediate-early gene sequence amplified by the polymerase chain reaction. Cervical CMV prevalences of 38.9% and 34.8% were found for licensed prostitutes and STD patients, respectively. These rates were significantly higher than the 24.3% cervical CMV prevalence for women attending the gynecologic clinic. The data suggest that frequent sexual contact with many sexual partners is responsible for the high frequency of cervical CMV observed in licensed prostitutes. The interaction between CMV and urogenital bacterial infections is a plausible explanation for the high cervical CMV prevalence in STD patients.

Adolescent↗
PubMed1994

Humoral immune responses and cytomegalovirus excretion in children with asymptomatic infection.

Forty-two seropositive children aged 3 to 5 years attending a kindergarten were followed up for 1 year in order to examine the relationship between humoral immunity and cytomegalovirus (CMV) excretion status. Anti-CMV antibodies were measured at the beginning and end of the study by enzyme-linked immunosorbent assay, neutralizing antibody test, and immunoblot techniques. Among these children, 32 persistently shed virus in urine, 2 intermittently shed CMV, and 4 experienced reactivation during the study. Virus was never isolated from 4 seropositive children. The level of anti-CMV IgG antibody in seropositive children who remained nonshedders was significantly higher than in children who shed virus during follow-up. On immunoblots, all seropositive nonshedders reacted to a CMV-specific 65 kD antigen, whereas most shedders (80%) did not. These findings suggest that humoral immunity plays a role in controlling persistent CMV infection in children with asymptomatic infection. However, the humoral immunity measured by the neutralizing test and the presence of antibodies against CMV-specific envelope antigens (116 kD/55 kD) apparently play a limited role in modifying persistent excretion and regulating reactivation of latent CMV. Immune evasion by CMV to block these antigens may explain these results.

Antibodies, Viral↗
PubMed1994

No evidence for linkage of long QT syndrome and chromosome 11p15.5 markers in a Chinese family: evidence for genetic heterogeneity.

Recently the defective gene locus in seven Caucasian families with the Romano-Ward form of long QT syndrome (LQT) has been mapped to chromosome 11p. To understand the molecular basis of LQT in Chinese, a three-generation family was investigated. Fourteen family members were studied and five individuals were diagnosed to be affected, according to electrocardiographic criteria. Two genomic DNA probes (c-Ha-ras-3'-HVR and insulin-5'-HVR) and one tetranucleotide repeat polymorphism (THZ) derived from chromosome 11p15.5 loci and previously demonstrated to be closely linked to LQT were used as probes to analyze this family. A lod score of less than -2 was noted for all three polymorphisms. Our data show that there was no evidence of linkage between these three loci and the gene for LQT in this studied family. We believe that this result provides additional evidence for genetic heterogeneity of LQT.

Adolescent↗
PubMed1994

Effect of arginase on splenic killer cell activity in patients with gastric cancer.

Arginase has been detected in high levels in gastric cancer tissues. The effect of arginase on the activities of splenic natural killer (NK) cell, phytohemagglutinin activated killer (PAK) cell, and interleukin-2 activated killer (LAK) cell in patients with gastric cancer (N = 12) was evaluated in vitro. These activities in patients (N = 10) with trauma and benign lesions were used as control. The splenic NK and PAK cell activities in patients with gastric cancer were significantly lower than in the controls (P < 0.05), whereas LAK cell activity did not have significant difference. Arginase inhibited all splenic killer cell activities to a similar degree between patients with gastric cancer and the controls. The inhibition was dose-related. These data suggest that arginase may play a positive role in the spread of gastric cancer cells. However, LAK may be a potential approach of immunoadoptive therapy in the future.

Arginase↗
PubMed1994

Steroid hormone receptors in three human gastric cancer cell lines.

Steroid hormone receptors in three human gastric adenocarcinoma cell lines and their transplanted tumors (except nontumorigenic KATO-III) in nude mice were determined by dextran-coated charcoal assay. Progesterone receptors (PgR) were found in all cell lines, transplanted NUGC-3, and AZ 521 tumors. Estrogen receptors (ER) were found in KATO-III cells, transplanted NUGC-3, and AZ 521 tumors, whereas glucocorticoid receptors (GR) were found only in NUGC-3 tumor and no androgen receptor was found in any cell lines or transplanted tumors. Since NUGC-3 cells had ER, PgR, and GR, it was used for the study of the effects of steroid hormones on growth. The results showed the cell cycle phase distributions and growth rate of transplanted tumors were similar in hormone-treated and nontreated groups. The persistent expression of PgR in gastric cancer cell lines and tumors, and the slight increase of tumor volumes in the progesterone-treated group suggests that progesterone and its receptors may be important in the pathogenesis of gastric cancer, but their biological function remains to be elucidated.

Adenocarcinoma↗