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Biomedical subjects

W S Chen

Publications and source records attributed to W S Chen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Tumor necrosis factor gene polymorphism and septic shock in surgical infection.

OBJECTIVES: To evaluate the relationship of the genotype distribution of the tumor necrosis factor (TNF)-alpha polymorphism with regard to the plasma TNF-alpha concentration and the development of septic shock as well as mortality of infected patients in a surgical intensive care unit (SICU). DESIGN: A total of 112 postoperative critically ill infected patients were prospectively enrolled. SETTING: SICU of a tertiary university-affiliated medical center. PATIENTS: Patients who were consecutively admitted to the SICU because of surgical infection with sepsis. INTERVENTION: Blood sampling. MEASUREMENTS AND MAIN RESULTS: Blood sample was obtained 24 hrs after intensive care unit (ICU) admission or within 2 hrs after the onset of septic shock to determine the plasma TNF-alpha level and to analyze the genotype of the biallelic polymorphism of the TNF-alpha. RESULTS: The allele frequency of the TNF2 in our infected ICU patients was 12%. Forty-two (37.5%) patients admitted fulfilled the criteria of septic shock during their ICU stay. Patients carrying the TNF2 allele were not more likely to develop septic shock, nor did they have a higher mortality rate. In the patients with septic shock, those carrying the TNF2 allele had a significantly higher mortality rate than those with the homozygous TNF1 genotype (92% vs. 62%, p < .05). In those who developed septic shock, the TNF2 allele was significantly associated with higher TNF levels. CONCLUSION: In patients admitted to SICU with surgical infection, the frequency of TNF2 allele was higher than in the general population. SICU patients with TNF2 allele did not show a higher incidence of developing septic shock, nor was there a higher baseline TNF-alpha level after infection. However, once septic shock had developed, the mortality rate was higher in those patients carrying the TNF2 allele.

APACHE↗
PubMed2000

Treatment of painful heels using extracorporeal shock wave.

BACKGROUND AND PURPOSE: Shock wave therapy has been shown to improve many tendinopathies at the tendon-bone junction. The purpose of this study was to investigate the safety and effectiveness of extracorporeal shock wave therapy for the treatment of painful heels. METHODS: Sixty-six patients, including 45 women and 21 men with an average age of 47.70 years (range, 19-75 years), were included in the study. Each patient received 1,000 impulses of shock waves at a 14-kV generator voltage at the affected site under local anesthesia. Twelve patients received a second treatment, and two patients received a third treatment. RESULTS: Of 58 patients with 6 weeks' follow-up, five (9%) were complaint-free, 21 (37%) were significantly better, 27 (47%) were slightly better, and five (9%) were unchanged. Of 41 patients with 12 weeks' follow-up, 11 (27%) were complaint-free, 22 (54%) were significantly better, seven (17%) were slightly better, and one (2%) was unchanged. The results at 12 weeks were much better than those at 6 weeks. The effect of shock waves on painful heels continued between 6 and 12 weeks. Twelve patients who did not respond favorably to the first treatment showed significantly better results after a second treatment. Two patients who had a third treatment also achieved satisfactory results. There were no device-related problems or systemic or local complications. CONCLUSIONS: Extracorporeal shock wave therapy is a new modality that is safe and effective in the treatment of painful heel spurs.

Adolescent↗
PubMed2000

[A new fatty ketone of Radix Polygoni Multiflori Preparata].

OBJECTIVE: Investigating the chemical constituents of Radix Polygoni Multiflori Preparata. METHODS: Compounds were isolated from the CHCl3 extract with column chromatography on silica gel, and identified on the basis of spectral analysis(IR, EI-MS, 1H-NMR, 13C-NMR) and phytochemical properties. RESULTS: Two compounds were isolated and identified as 1,2-dihydroxynonadecone-3(I) and gallic acid(II). CONCLUSION: Compound I is a new compound.

Drugs, Chinese Herbal↗
PubMed2000

[Studies on flavone constituents of Erigeron breviscapus (Vant.) Hand.-Mazz].

OBJECTIVE: To study the chemical constituents of Erigeron breviscapus. METHOD: The constituents were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and physical data. RESULT: Five compounds were isolated and identified as 3, 5, 6, 4'-tetrahydroxy-7-methoxy flavonoid(I); 5, 7, 4'-trihydroxy flavonoid(II); 3, 5, 6, 7, 4'-pentahydroxy flavonoid(III); scutellarein (IV) and 5, 7, 4'-trihydroxy flavanone(V). CONCLUSION: Compounds I, III and V were isolated from this plant for the first time.

Apigenin↗
PubMed2000

[Structural elucidation of a new tetrahydroxystilbene of Radix Polygoni Multiflori Preparata and study on its cardiovascular activity].

AIM: To investigate the cardiovascular active constituents of Radix Polygoni multiflori Preparata. METHODS: Compounds were isolated from the water soluble extract with column chromatography of Sephadex, ODS and HPLC. The compounds were identified on the basis of spectral analysis (IR, EI-MS, FAB-MS, 1HNMR, 13CNMR, 2D-NMR) and phytochemical properties. Its inhibitory effect on the proliferation of bovine vascular smooth muscle cells were bioassayed in vitro. RESULTS: One compound was isolated and identified as: 2,3,5,4'-tetrahydroxystilbene-2-O-(6"-O-alpha-D- glucopyranosyl)-beta-D-glucopyranoside. CONCLUSION: Compound I is a new compound with cardiovascular activity.

Animals↗
PubMed1999

Comparative tyrosine-kinase profiles in colorectal cancers: enhanced arg expression in carcinoma as compared with adenoma and normal mucosa.

There is strong evidence that tyrosine kinases are involved in the regulation of cellular growth and tumor progression. Over-expressions of tyrosine kinases have been documented in a number of neoplasms. To study the roles of tyrosine kinases in colon cancer, we developed a tyrosine-kinase-expression profile for each of the four different stages of colon carcinogenesis, using normal colon mucosa, adenomatous polyps, primary carcinoma and hepatic metastases collected from the same patient. We identified 30 tyrosine kinases expressed in these tissues: they include 10 non-receptor tyrosine kinases (yes, fyn, lyn, brk, abl, arg, jak1, jak3, tyk2 and itk), 17 receptor tyrosine kinases (erbB2, PDGF-Ralpha, PDGF-Rbeta, kit, c-fms, met, ron, FGF-R1, FGF-R2, FGF-R3, FGF-R4, cek5, tie-1, tkt, axl, sky and Ins-R), 2 dual kinases (mek and sek) and one possible novel kinase. Among these kinases, arg kinase appears to be expressed at a higher level in primary carcinoma and metastatic tumor than in adjacent normal mucosa or adenomatous polyp. This result was confirmed by extensive analysis of 50 additional matched sets of normal colon and colon-tumor specimens, using arg-specific primers and RT-PCR reactions. This study identifies a possible role for arg tyrosine kinase in colon carcinogenesis, especially in the transition from adenoma to carcinoma.

Adenoma↗
PubMed1999

The crystal structure of a multifunctional protein: phosphoglucose isomerase/autocrine motility factor/neuroleukin.

Phosphoglucose isomerase (PGI) plays a central role in both the glycolysis and the gluconeogenesis pathways. We present here the complete crystal structure of PGI from Bacillus stearothermophilus at 2.3-A resolution. We show that PGI has cell-motility-stimulating activity on mouse colon cancer cells similar to that of endogenous autocrine motility factor (AMF). PGI can also enhance neurite outgrowth on neuronal progenitor cells similar to that observed for neuroleukin. The results confirm that PGI is neuroleukin and AMF. PGI has an open twisted alpha/beta structural motif consisting of two globular domains and two protruding parts. Based on this substrate-free structure, together with the previously published biological, biochemical, and modeling results, we postulate a possible substrate-binding site that is located within the domains' interface for PGI and AMF. In addition, the structure provides evidence suggesting that the top part of the large domain together with one of the protruding loops might participate in inducing the neurotrophic activity.

Amino Acid Sequence↗
PubMed1999

Risk and patterns of brain metastases in colorectal cancer: 27-year experience.

PURPOSE: In patients with colorectal cancer, brain metastasis is infrequent. This study aims to elucidate the risk, pattern of occurrence, and survival time after different treatment modalities. METHODS: A retrospective review of all patients with colorectal cancer admitted to the Veterans General Hospital-Taipei between 1970 and 1996 from our hospital was performed. Univariate analysis for survival determination was performed. RESULTS: Brain metastases developed subsequent to surgery for colorectal cancer in 53 well-documented patients, at a median of 36 months after surgery. Brain metastases were more commonly seen in rectal cancer and often occurred concurrently with lung metastases. Forty of these patients received active intervention in terms of surgery, chemotherapy, or radiotherapy, with surgical intervention achieving a significantly increased mean survival time (+/- standard deviation) compared with chemotherapy or radiotherapy or both of 86.6 +/-17.35 vs. 2.9 +/- 0.59 months (P < 0.05). CONCLUSION: Increased awareness of the possibility of brain metastases, early diagnosis, and aggressive therapy can provide increased survival time for patients with colorectal cancer with brain metastases.

Adult↗
PubMed1999

Effect of transcutaneous electrical nerve stimulation for pain relief on patients undergoing hemorrhoidectomy: prospective, randomized, controlled trial.

PURPOSE: Posthemorrhoidectomy pain control remains a challenging problem. Transcutaneous electrical nerve stimulation is known to be effective in the treatment of many diseases. Our aim was to investigate the effect of transcutaneous electrical nerve stimulation on pain relief in patients undergoing hemorrhoidectomy. METHODS: Sixty patients with symptomatic hemorrhoids were randomly allocated into two groups, the acupoint group (n = 30) and the nonpoint control group (n = 30). Transcutaneous electrical nerve stimulation was applied to those patients who received hemorrhoidectomy, and patient-controlled analgesia was achieved by injection of morphine through ambulatory infusion pumps. The dependent measures in this study were pain score from 0 (no pain) to 10 (agonizing pain), analgesic doses administrated through patient-controlled analgesia, and postoperative complications. RESULTS: The subjective pain scores evaluated 8, 12, 16, and 24 hours after hemorrhoidectomy in the control group and the acupoint group were 5.9 +/- 0.5 and 4.1 +/- 0.5, 5.7 +/- 0.5 and 3.5 +/- 0.4, 4.1 +/- 0.4 and 2.3 +/- 0.3, and 3.2 +/- 0.4 and 1.9 +/- 0.2, respectively (two-way analysis of variance; P < 0.05). There was a significant difference between treatment groups in morphine use, with 11.6 +/- 2.2 mg in the control group and 6.2 +/- 1.3 mg in the acupoint group (P < 0.05). The acupoint group tended to have less postoperative acute urinary retention (Fisher's exact probability test; P = 0.145) and less need for analgesics than the control group (P = 0.112, Fisher's exact test). CONCLUSION: Transcutaneous electrical nerve stimulation is effective for pain relief in patients receiving hemorrhoidectomy. Its efficacy and safety could assist outpatient pain management after hemorrhoidectomy.

Analgesia, Patient-Controlled↗
PubMed1999

Recalcitrant bicipital radial bursitis.

Three of 12 nonrheumatoid patients with bicipital radial bursitis had recurrent and recalcitrant symptoms and underwent operative treatment. Preoperative computed tomogram showed an anterior distended synovial cyst at the level of the radial tubercle. Magnetic resonance imaging provided a superb demonstration of a bicipital radial bursa which communicated with the elbow joint below the annular ligament. Surgical exploration revealed a valvular mechanism between the distended bursa and the joint cavity. Excision of the distended bursa and closing the capsular defect lead to excellent results. An antecubital cyst resulting from an acute or chronic tear of the anterior capsule at the sacciform recess may communicate with the bicipital radial bursa and become the cause of recurrent and recalcitrant symptoms.

Adult↗
PubMed1999

[Formation of germline chimeras from murine embryonic stem cell lines].

Generation of germline chimeras is the crucial step in ES cell-mediated transgenesis. The prerequisite for germline chimerism is the maintenance of germline differentiating potency of ES cells, whereas production of germline chimeras is the only method to prove whether such potency is maintained. In order to investigate the germline differentiating potency of three newly established ES cell lines (MESPU21, MESPU22 and MESPU29), ES cells were introduced into host embryos from inbred C57BL/6J and outbred KMW or ICR through blastocyst injection or 8-cell stage morula injection. Totally 81 chimeras were obtained; among 42 test-bred ones, 19 were germline transmitters assessed by coat analysis, as is the first report of ES cell-embryo germline chimeras in China. MESPU21 and MESPU22 formed germline chimeras in high frequency and most of those chimeras produced ES cell-derived progeny in high proportion, which proved that both ES cell lines retained good germline differentiating potency and could be used as valuable cellular vehicles to introduce genetic modifications into mouse genome.

Animals↗
PubMed1999

Diagnosis and treatment of cystic lymphangioma of the ascending colon by laparoscopic-assisted surgery: a case report.

Lymphangioma of the colon is a rare disease. Its clinical silence and absence of specific symptoms and signs make it difficult to diagnose preoperatively. We present a case of cystic lymphangioma of the ascending colon associated with constipation in a 72-year-old man and review the pertinent literature. The patient underwent laparoscopic-assisted segmental resection of the colon. The characteristic histologic appearance of cystic lymphangioma provided the definitive diagnosis. The recovery course was uneventful. Two years postoperatively, the patient was symptom-free and without evidence of tumor recurrence.

Aged↗
PubMed1999

[Establishment of two ES cell lines with good germline contribution].

Nine embryonic stem cell lines have been established from mouse strain 129/ter. Three of the nine ES cell lines were karyotypically normal. The nine cell lines showed some difference in the growth rate and the differential competence. Chimeras were made by injecting the ES cells into C57BL/6J blastocysts, and the germline compositions of the chimeras were detected by mating them with albino ICR mice. The results indicated that ES cell line MESPU21 and MESPU22 were both highly germline-competent. Comparing with other ones, these two cell lines both were karyotypically normal and propagated fast. The tissue composition of the teratocarcinomas derived from these cell lines appeared paralle to the results of chimera production. Careful manipulation during the process of ES cell establishment was helpful to obtain good cell lines.

Animals↗
PubMed1998

Apoptosis in mouse embryos: elevated levels in pregastrulae and in the distal anterior region of gastrulae of normal and mutant mice.

The pattern of apoptotic cell death has been surveyed in prestreak and primitive streak embryos of four strains of mice and in three mutants affecting gastrulation. In C57BL/6 embryos, a high level of cell death occurs in the early egg cylinder stage at embryonic day 5 (E5) to E5.5. In all strains, cell death is elevated shortly before gastrulation, but the level varies four- to fivefold among strains. During gastrulation, cell death declines but is relatively more abundant in the distal and distal anterior regions. Early streak embryos cultured in media with reduced levels of growth factors show increased cell death mainly in the distal region. In three mutants with disturbed function of the proximal visceral endoderm and/or primitive streak, cell death is increased, and the regional pattern seen in normal embryos is intensified. The results strongly suggest that the proximal visceral endoderm and primitive streak region are the principal sites of synthesis of growth factors promoting cell survival. We conclude that localized growth factor supply has an important role in regulating the size of the embryo and of embryonic regions.

Animals↗
PubMed1998

Hemodynamic patterns of pharmacologically induced erection: evaluation by color Doppler sonography.

PURPOSE: Penile erection is achieved through hemodynamic mechanisms that can be assessed best with color flow imaging and Doppler waveform analysis. We performed dynamic studies using computer assisted analysis to assess the hemodynamic patterns of pharmacologically induced erection. MATERIALS AND METHODS: A total of 73 color Doppler ultrasound studies was performed in 66 patients with erectile dysfunction. Various blood flow parameters, including peak systolic velocity, end diastolic velocity, mean flow rate, resistive index and artery diameter, were observed continuously and recorded frequently for about 30 minutes after intracorporeal injection of papaverine/phentolamine/prostaglandin E1 mixture. A computerized Doppler waveform analysis of 3 curves or greater was performed for each recording to minimize error. A second injection was administered if the first injection failed to induce a rigid erection. Status of the erection was observed and recorded throughout the study. A computerized graph was generated for each corpus. RESULTS: After intracorporeal injection the time to reach normal or peak velocity varied from 1 to 24 minutes. Among 146 corpus units in 73 color Doppler ultrasound studies we observed the following hemodynamic patterns: I-normal maximal peak systolic velocity (35 cm. per second or greater), sustained; Ia-end diastolic velocity 0 or less with complete erection response (19 units); Ib-end diastolic velocity greater than 0 or incomplete erection response (14 units); II-normal maximal peak systolic velocity (35 cm. per second or greater), transient; IIa-end diastolic velocity 0 or less with complete erection response (21 units); IIb-end diastolic velocity greater than 0 or incomplete erection response (12 units); III-borderline maximal peak systolic velocity (30 to 35 cm. per second); IIIa-end diastolic velocity 0 or less with complete erection response (10 units); IIIb-end diastolic velocity greater than 0 or incomplete erection response (8 units); IV-low maximal peak systolic velocity (less than 30 cm. per second); IVa-end diastolic velocity 0 or less with complete erection response (24 units); and IVb-end diastolic velocity greater than 0 or incomplete erection response (38 units). CONCLUSIONS: Erection is a complex and dynamic process. A new classification of hemodynamic patterns is presented that aids in assessing and interpreting more thoroughly blood flow parameters to stratify more precisely the hemodynamic patterns of erectile dysfunction.

Adult↗
PubMed1998

Gene transfer via pollen-tube pathway for anti-fusarium wilt in watermelon.

In order to obtain transgenic fusarium wilt resistant watermelon plants, squash DNA was introduced into the ovaries of watermelon plants via the pollen-tube pathway. The introduction of foreign genes into ovaries was accomplished using co-transformation with the CaMV35S-GUS as a marker. Transformed watermelon plants contained integrated copies of the GUS activity and the seeds of transformed progeny produced a blue color when stained with 5-bromo-4-chloro-3-indolyl glucuronide, whereas seeds from untransformed control plants did not. Of 200 transformed seedlings, ten were wilt resistant. The presence of the GUS activity in the genome of stable transgenic seedlings was confirmed by Southern blot analysis. Furthermore, the generation of random amplified polymorphic DNA (RAPD) fingerprints using primers with embedded restriction sites showed amplification products unique to these transgenic plants. Primers OPA-1 and OPA-9 gave distinct band patterns of genomic DNA using the polymerase chain reaction.

DNA, Plant↗