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Biomedical subjects

C L Chen

Publications and source records attributed to C L Chen.

At least 307 records · Page 17Linked to original sources
PubMed1994

Recovery from propofol anesthesia: a quantitative electroencephalographic analysis.

Four numerical descriptors (median frequency, spectral edge frequency-95%, total power, and delta-ratio) derived from the computer-processed electroencephalogram (Neurometrics Lifescan) were analyzed for their ability to predict imminent arousal from total intravenous anesthesia with propofol. Fifteen patients undergoing minor surgical procedures without intubation were enrolled in the study. Arousal was defined as eye opening in response to verbal stimuli. During emergence from propofol, there were no significant changes among the descriptors except the delta-ratio. Significant change of delta-ratio occurred 210 seconds before patients' arousal and thereafter. An increase of delta-ratio value indicates that patients shifted from anesthetic to arousal state. It is concluded that the degree of delta-ratio change may be used for predicting patients' arousal from propofol anesthesia.

Adult↗
PubMed1994

[Uterus, fallopian tube and ovary within a sliding hernia: a case report].

Sliding hernias of the tube, ovaries and uterus occur occasionally in newborn female infants, but are rare in older women. This report entails a case of a sliding inguinal hernia which contains the organs of the female genital tract in a 56-year-old multipara woman. Under diagnosis of incarcerated inguinal hernia preoperatively, the operative intervention was performed, but it appeared the organs of uterus, ovary and fallopian tube there instead of the intestine. After operation, wound recovery was good. At follow-up six months later, there was no recurrence nor lower abdominal discomfort.

Fallopian Tubes↗
PubMed1994

[The rate and factors of return-to-work in head-injured patients following hospitalization].

Return-to-work is often used as a measure of overall recovery from injury or illness. This study focuses on the labor force population who inhabit in Kaohsiung City, and were hospitalized into Chung Ho Memorial Hospital Kaohsiung Medical College in 1992. The patients were contacted for an interview at least six months post-discharge. In addition to the rate of return-to-work by severity, factors were examined for their influence on return-to-work. Of those 85 eligible individuals, the rate of return-to-work was 81.2%. According to the Glasgow Coma Scale, the head injury severity was classified as mild, moderate and severe. The rate of return-to-work by severity were 86.4%, 78.6%, and 58.3%, respectively. Factors influencing return-to-work were divided into pre-injury, hospitalization, and post-discharge period. According to the study, the three influencing factors that correlated with post-injury employment status were number of productive members in family, length of stay, and physical handicap.

Adolescent↗
PubMed1994

Multiple viral infection as the most common cause of fulminant and subfulminant viral hepatitis in an area endemic for hepatitis B: application and limitations of the polymerase chain reaction.

We tested serum samples from 25 fulminant hepatitis and 7 subfulminant hepatitis patients for hepatitis A, B, C, D and E viral markers and nucleic acids by means of polymerase chain reaction to determine the role of each virus on such catastrophic events in an area endemic for hepatitis B. Of these 32 patients, 14 (44%) were hepatitis B virus carriers with hepatitis D virus superinfection (1 with hepatitis C virus infection), 3 others had coexisting hepatitis B virus and hepatitis C virus infections, 6 had reactivation of underlying chronic hepatitis B, 4 had acute hepatitis B, 2 had acute hepatitis C and 1 had acute hepatitis E. Pathogenesis in the remaining two cases was unclear. Serum hepatitis B virus DNA was detectable in most carriers without superinfection and in one third of those with superinfection detected on polymerase chain reaction (6 of 7 vs. 6 of 16, p < 0.05). Of the polymerase chain reaction-positive samples, only 17% yielded positive results on spot hybridization. Hepatitis B virus DNA was the only marker to indicate coexisting hepatitis B virus infection in one patient positive for hepatitis C virus antibody. Only three of the six hepatitis C virus-infected cases were positive for hepatitis C virus antibody; diagnoses in the remaining three were established by means of detection of hepatitis C virus RNA. Of the hepatitis D virus-infected patients, infection in only half was diagnosed by means of total hepatitis D virus antibody assay. Twelve (86%) were positive for anti-hepatitis D virus IgM and nine (64%) had detectable hepatitis D virus RNA on reverse transcription-polymerase chain reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[Pain control for liver transplants].

Liver is the largest organ and is located in the right upper quadrant of the abdominal cavity. Surgery for liver transplantation is performed through a large skin incision, which gives considerable pain post operatively. We experienced 10 cases of liver transplant, 3 cases used meperidine 0.5 mg/kg intramuscularly, 3 cases used epidural morphine analgesia, and for the remainder 4 cases, we used morphine 2-3 mg intravenously as needed. Liver transplantation is a major surgery. It attracts media for reporting. The hospital administrator realized its importance to the hospital. A 24 hours special nursing team was provided. Addition analgesic medication was given intravenously in a bolus dose of 2-3 mg of morphine. All patients were able to communicate freely with the nursing team. The communication between the patient and nursing team is free. No post-analgesic hypotension or dyspnea were noted. Patients in all three groups were equally satisfied with their analgesic therapy post-operatively. As all patients expect pain after surgery, they were satisfied when the pain was less than what they had anticipated. Blood gases analysis was however better in patients with epidural morphine analgesia.

Adolescent↗
PubMed1994

Thymic carcinoma. Ten years' experience in twenty patients.

Thymic carcinoma is a rare neoplasm with extremely poor prognosis. To evaluate the outcome of treatment in thymic carcinoma, we reviewed a 10-year (1982 to 1992) experience with 20 consecutive patients in Taichung Veterans General Hospital. There were 9 men and 11 women: ages ranged from 34 to 70 years old (mean 51.4 years). None of these patients had concomitant myasthenia gravis. All of the patients received surgical intervention, and the diagnosis was made by pathologic study. Postoperative staging was made according to the modified Masaoka staging system. None of our patients were in stage I. One patient (5%) had stage II disease, 12 (60%) stage III, and 7 (35%) stage IV. The pathologic subtypes of thymic carcinoma included eight squamous cell carcinomas, seven undifferentiated carcinomas, one lymphoepithelioma-like carcinoma, one clear-cell carcinoma, 1 mucoepidermoid carcinoma, and two carcinoid tumors. Curative resection could be done in seven patients (35%). The overall cumulative survival was 45.9% at 3 years and 34.4% at 5 years. The median survival times for patients with complete and incomplete resection were 39.0 months and 14.3 months, respectively (p = 0.1752). The median survival times of patients with postoperative radiotherapy and without postoperative radiotherapy were 39.3 months and 15.0 months, respectively (p = 0.0738). The median survival times of patients with squamous cell carcinoma and undifferentiated carcinoma were 25.4 months and 11.3 months, respectively (p = 0.1464). Our data show that complete resection, postoperative radiotherapy, and squamous cell carcinoma do not indicate a significantly favorable result, even though they result in longer median survival times. Yet a positive trend of favorable outcome in patients who received postoperative radiotherapy is ambiguously shown.

Adult↗
PubMed1993

The carboxyl-terminal domain of the human pregnancy-specific glycoprotein specifies intracellular retention and stability.

The pregnancy-specific glycoproteins (PSGs), which are members of the immunoglobulin superfamily, are the major pregnancy-associated proteins synthesized by the human placenta. Thirty or more PSG members have been identified which are encoded by at least 11 linked genes. The PSG proteins share 85-95% sequence homology in the coding region, but show variability at the carboxyl-terminal (COOH) domains. In the present study, we examined the effects of PSG COOH domains on protein secretion and stability. Using PSGs containing short (11-12 residues) hydrophilic (PSG1e, PSG11s, and PSG16a), short (22 residues) hydrophobic (PSG6r), and long (81 residues) hydrophobic (PSG11w) COOH domains, we showed that most PSG members were secretory proteins except PSG11w which was largely retained in cells. When the PSG11w COOH domain was replaced with a short COOH domain of PSG1e, the resulting PSG-N11w/C1e chimera became secreted into the medium. On the other hand, chimeras that harbored the PSG11w COOH domain, PSG-N1e/C11w and PSG-N16a/C11w, remained in cells, demonstrating that the COOH domain of PSG11w confers intracellular retention. Deletion analysis showed that mutant (PSG11w-C2) that contained the first 21 amino acids of PSG11w COOH domain or mutant (PSG11w-C3) that contained a deletion of hydrophobic residues 372-392 in the PSG11w COOH domain remained largely in cells. In contrast, the PSG11w-C1 mutant which contained the first 12 residues of the PSG11w COOH domain became a secretory protein. Studies of PSG synthesis and processing in the presence of Brefeldin A, a drug that impedes protein transport from endoplasmic reticulum to the Golgi system, showed that PSG11w resided and degraded in the endoplasmic reticulum. The endoplasmic reticulum localization of PSG11w and the cell-associated mutant PSGs was further demonstrated by their sensitivity to endoglycosidase H and indirect immunofluorescence analysis.

Amino Acid Sequence↗
PubMed1993

Purification and properties of selenoprotein W from rat muscle.

Following injection with [75Se]selenite, a low molecular weight 75Se-selenocysteine containing protein was purified from rat muscle. The purification procedure involved ammonium sulfate fractionation, Sephadex G-50 gel filtration, cation exchange chromatography on CM-Sephadex, and reverse phase high pressure liquid chromatography using a C-18 Vydac column. Four forms of the protein were separated by the cation exchange and reverse phase chromatography steps. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of the four proteins revealed masses of 9550 +/- 1, 9596 +/- 1.2, 9858 +/- 1.3, and 9898 +/- 1.1 daltons. Glutamate, glycine, lysine, leucine, and valine are the major amino acids in this protein. About 0.92 g atoms of selenium was found per g mol of protein, and this selenium was present as selenocysteine. Thus, this appears to be a new selenoprotein, and we have named it selenoprotein W.

Amino Acids↗
PubMed1993

Effect of vitamin B12 status on selenium methylation and toxicity in rats: in vivo and in vitro studies.

Animals are known to convert inorganic selenium to less toxic methylated compounds such as dimethylselenide (DMSe) and trimethylselenonium (TMSe). This study investigated the role of vitamin B12, a cofactor of methionine synthetase, in selenium methylation in the rat. Vitamin B12-depleted rats expired 16% of dosed 75Se-selenite as DMSe compared to 45% for control rats and excreted less TMSe in the urine (6.1% of dose) than control (9% of dose) rats. At the same time, higher (p < 0.05) tissue (liver, kidney, muscle) selenium levels and lower (p < 0.05) blood selenium levels were found in vitamin B12-deficient rats. Primary hepatocytes from vitamin B12-deficient rats volatilized 15% of selenite in incubation medium in 5 hr as compared to 49% in hepatocytes from control rats. Hepatocytes from vitamin B12-deficient rats were less resistant to selenite toxicity. In vitro methylation of selenium with liver extract from vitamin B12-deficient rats showed one-third to one-half the rate of volatilization of selenium as compared to control rats. S-adenosylmethionine was required for this reaction. These results show that vitamin B12 deficiency significantly decreases the ability of rats to methylate selenium.

Animals↗
PubMed1993

Adaptive immune responses during murine pregnancy: pregnancy-induced regulation of lymphokine production by activated T lymphocytes.

OBJECTIVE: We hypothesized that the lymphokine production by splenocytes and decidual lymphocytes would be altered because of changes in immunoregulation during pregnancy. STUDY DESIGN: Splenocytes and decidual lymphocytes were isolated from syngeneic and allogeneic pregnant mice at different times of gestation. The lymphocytes (10(7) cells/ml) were stimulated with anti-CD3 antibody, and culture supernatants were assayed for several lymphokines, including interleukin-2, interferon-gamma, interleukin-4, interleukin-6, granulocyte-macrophage colony-stimulating factor, and interleukin-3. Statistical analysis was by analysis of variance or paired t test. RESULTS: Activated splenocytes produced significantly less interleukin-2 and more interleukin-4, interleukin-6, and interleukin-3 as murine pregnancy advanced. Production of interferon-gamma and granulocyte macrophage colony-stimulating factor by activated splenocytes peaked in the first 8 to 14 days of pregnancy. Stimulated decidual lymphocytes produced modest amounts of interleukin-6, granulocyte-macrophage colony-stimulating factor, and interleukin-3 during pregnancy but no interleukin-2, interferon-gamma, or interleukin-4. Similar results were found for both syngeneic and allogeneic matings. CONCLUSIONS: Our findings indicate that splenocyte lymphokine production favors interleukin-4 production over interleukin-2 production. This finding suggests that antibody production would be enhanced and cytotoxic cellular immune responses inhibited during pregnancy. These changes occurred regardless of mating partner, suggesting that the specific antigenic stimulus during normal pregnancy does not regulate lymphokine production. Activated splenocytes and decidual lymphocytes were found to differ in their capacity to produce lymphokines, indicating that the decidua constitutes a distinct and unique immunologic microenvironment.

Animals↗
PubMed1993

Inhibin/activin subunits and activin receptor are co-expressed in Leydig tumor cells.

The expression of genes encoding inhibin/activin subunits and activin receptor was examined in four cultured Leydig tumor cells (MA-10, I-10, R2C, and LC-540). Inhibin alpha-subunit gene was highly expressed in Leydig tumor cell lines except LC-540. Both inhibin beta-A- and beta-B-subunit mRNAs were present in low levels. The 6.5-kb beta-A-subunit mRNA was detected in MA-10, R2C and LC-540 cells, and not in I-10 cells. The expression of the two species of beta-B-subunit mRNA is cell specific. In MA-10 and I-10 cells, 4.4-kb beta-B-subunit mRNA was the predominant species, while in R2C and LC-540 cells both 4.4-kb and 3.3-kb mRNA were present in equal quantities. By contrast, two species (6 and 3 kb) of activin receptor ActRII mRNA were identified in equal intensity in all four Leydig tumor cell lines. Addition of cAMP derivative to MA-10 cells at 0.1 mM for 17 h or 1 mM for 5 h produced a two-fold increase in inhibin alpha-subunit mRNA levels, and small or no significant change in inhibin beta-B-subunit and ActRII mRNAs. However, a 70-80% reduction in inhibin beta-A-subunit mRNA was observed by 1 mM cAMP for 5 h. We concluded that: (1) the inhibin/activin subunit genes and activin receptor gene are co-expressed in Leydig tumor cell lines, and (2) the three inhibin/activin subunit genes are expressed differently, while the activin receptor gene is expressed identically in the four cell lines.

Activin Receptors↗
PubMed1993

A murine model of preterm labor: inflammatory mediators regulate the production of prostaglandin E2 and interleukin-6 by murine decidua.

Inflammatory processes may be important in the initiation and propagation of uterine contractions and preterm labor in human pregnancies. Recently, a murine model of preterm labor has been described. The purpose of our study was to determine whether murine decidua responds to inflammatory mediators, such as lipopolysaccharide (LPS) and the inflammatory cytokines interleukin (IL)-1 beta and tumor necrosis factor (TNF). Allogeneic pregnant mice (C3H/Hen females mated with C57/B6 males) were killed at 12-14 days of pregnancy, decidual tissue was isolated, and explants were placed on the polycarbonate membrane of Costar Transwell inserts. Initial validation studies of this explant system, including biochemical and histologic evaluations, indicated that the decidual tissue remained intact, viable, and responsive to IL-1 beta for at least 5 days in explant culture. Treatment of murine decidual explants with LPS, IL-1 beta, and TNF resulted in significant increases in the production of prostaglandin E2 (PGE2) and IL-6. Thus the regulation of PGE2 and IL-6 production from murine decidua by LPS and inflammatory cytokines is similar to findings previously reported for human decidua. Our findings are consistent with the view that the pathophysiology of infection-induced preterm labor in the mouse may be similar to that in human pregnancy and supports the continued development of murine models of preterm labor.

Animals↗