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Biomedical subjects

C L Chen

Publications and source records attributed to C L Chen.

At least 325 records · Page 18Linked to original sources
PubMed1993

The motility of interposition in patients with esophageal carcinoma after reconstructive esophageal surgery.

This study evaluated the motility of interposition in patients with esophageal carcinoma after different reconstructive operations of the esophagus using an esophageal radionuclide transit test. A modified standard method was used to calculate total mean transit time (MTT), residual fraction (RF), and retrograde index (RI) in the supine position at least 6 months after the reconstructive operations of the esophagus. Eleven patients with esophagogastrostomy (EG), 7 patients with esophagoiliocolostomy (EIC), and 25 normal volunteers with a similar distribution of ages were included in this study for comparison. The values of the scintigraphic parameters in patients with esophageal reconstruction were significantly worse than in normal volunteers (P < 0.05). In addition, the MTT and RF in patients with EG were higher than in patients with EIC (P < 0.05), but no significant difference in RI was demonstrated. In conclusion, the motility of interposition became worse after reconstructive operations, but reconstruction with the colon can preserve better motility than with the stomach.

Colon↗
PubMed1993

Epstein-Barr virus (EBV) gene expression in EBV-positive peripheral T-cell lymphomas.

Epstein-Barr virus (EBV) DNA has been detected in peripheral T-cell lymphomas. In this study, analysis of the EBV termini indicated that the infection was clonal and nonpermissive. Analysis of viral expression detected the processed, spliced mRNAs representing EBNA1, LMP1, LMP2, and BamHI A transcripts in all EBV-positive peripheral T-cell lymphomas. The LMP1 protein was detected by immunofluorescence in a single specimen. In contrast, neither the EBNA2 protein nor the spliced EBNA2 mRNA were detected. These data indicate that EBV-infected T-cell lymphomas are clonal expansions of a single EBV-infected cell with a pattern of gene expression which is distinct from that detected in Burkitt's lymphomas or posttransplant lymphomas but similar to viral expression in nasopharyngeal carcinomas.

Antibodies, Monoclonal↗
PubMed1993

Exercise and glucocorticoid-induced diaphragmatic myopathy.

We tested the hypothesis that a chronically active muscle, such as the rat diaphragm, would be more resistant to glucocorticoid-induced myopathy than a less active locomotor skeletal muscle (plantaris). Furthermore, we sought to determine whether endurance exercise could antagonize the glucocorticoid-induced atrophy in the diaphragm. Rats were assigned to one of seven experimental groups (n = 10 per group) and injected daily over a 10-day period with either a sham solution or prednisolone acetate: group 1: control; sedentary and sham injected; group 2: control; exercise trained and sham injected; group 3; sedentary; prednisolone (0.5 mg.kg-1 x day-1); group 4: sedentary; prednisolone (1.0 mg.kg-1 x day-1); group 5: sedentary; prednisolone (2.0 mg.kg-1 x day-1); group 6: sedentary; prednisolone (5.0 mg.kg-1 x day-1); group 7: exercise trained; prednisolone (5.0 mg.kg-1 x day-1). Slope differences in the dose-response curves suggest that prednisolone-induced muscle atrophy in the plantaris was more severe than that in the diaphragm. Furthermore, high doses of prednisolone resulted in a differential effect on muscle bioenergetic enzyme activities in the plantaris and diaphragm. Prednisolone treatment (> or = 2 mg.kg-1 x day-1) resulted in a significant reduction in phosphofructokinase activity (expressed as microM substrate.min-1 x mg protein-1) and an increase in 3-hydroxyacyl-CoA dehydrogenase activity in the plantaris muscle. In contrast, prednisolone treatment did not influence phosphofructokinase activity (P > 0.05) in the diaphragm but decreased (P < 0.05) relative citrate synthase activity. Finally, 90 min daily of endurance exercise did not antagonize prednisolone-induced myopathy in either the diaphragm or the plantaris.

Adrenal Glands↗
PubMed1993

Detection of Epstein-Barr virus genome in nasopharyngeal carcinoma by in situ DNA hybridization.

To elucidate the possible role of Epstein-Barr virus (EBV) in nasopharyngeal carcinoma (NPC), we investigated the EBV genome in NPC by in situ DNA hybridization using radioisotope- and and biotin-labeled EBV DNA probes. The EBV genome was detected in the tumor cells in all (100%) 60 cases, irrespective of histological type, but not in the lymphocytes. Silver grains, which reflected the copy number of the EBV genome, were more abundant in the nonkeratinizing, spindle cell, and undifferentiated carcinomas than in keratinizing squamous cell carcinoma. In the keratinizing carcinoma, which was poorly differentiated in this series, the EBV genome was usually detected in anaplastic tumor cells, and not in the keratinizing areas. The sensitivity of the radioisotopic technique was superior to that of the biotinylated probe method (100 vs. 81.7%, p < 0.0003). These results suggest that EBV is etiologically related to nasopharyngeal carcinogenesis and that the differentiation of tumor cells in vivo, and probably also in vitro, may become incompatible with EBV replication.

Adolescent↗
PubMed1993

Expression of type II activin receptor genes in the male and female reproductive tissues of the rat.

In addition to the feedback regulation of pituitary FSH secretion, gonadal activins have been shown to modulate physiological functions in the reproductive tissues. These observations suggested that activins and the receptors for these peptides may be coexpressed in gonadal tissues. In this study, we have cloned cDNAs encoding two species of type II activin receptors (ActRII and ActRIIB) from rat testicular mRNA and have shown that the two rat activin receptors share 97% similarity in the nucleotide sequence with those reported in the mouse. Two species [6 and 3 kilobases (kb)] ActRII mRNA were identified in all reproductive tissues of adult male and female rats. The 6-kb ActRII mRNA was the abundant form in most of the reproductive tissues. In placenta, the 6- and 3-kb mRNA were present in equal intensity. Interestingly, the ratio of the expression of two species of ActRII mRNA in rat testis changed with age. The 6-kb mRNA was the predominant form in immature 15- and 20-day-old testis, while the 3-kb mRNA increased with age and became the major form in mature testis. In female rats, however, the 6-kb ActRII mRNA was the abundant species in all of the ovaries examined, including immature, normal cycling, and pregnant rats. One major 2.25-kb species of ActRIIB mRNA was identified in all of the reproductive organs examined. Nucleotide sequence analysis of the isolated ActRIIB cDNA clones revealed that ActRIIB2 was the major isoform found in rat testis. The levels of expression of ActRIIB gene in rat testis or ovary were not changed during development. We conclude that 1) both type II and IIB activin receptor genes are widely expressed in the male and female reproductive tissues; and 2) the expression of 6- and 3-kb ActRII mRNA is tissue dependent as well as age dependent in rat testis.

Activin Receptors↗
PubMed1993

Secretion of immunoreactive beta-endorphin and GnRH by the pig uterus: effects of reproductive status and breed.

Immunoreactive beta-endorphin (ir-BEND) and GnRH (ir-GnRH) have been identified in the pig uterus. The study reported here examined (i) possible biochemical differences between ir-BEND and ir-GnRH present in pig uterine fluids and standard synthetic peptides, and (ii) the secretory profiles of uterine ir-BEND and ir-GnRH during the oestrous cycle and early pregnancy for two breeds of pig, Large White and the highly prolific Chinese Meishan. Reverse phase (RP)-HPLC analysis of concentrated uterine fluids indicated that the majority of ir-BEND eluted with a hydrophobicity similar to that of synthetic BEND 1-31 (BEND) and alpha-N-acetylated BEND 1-31 (Nac-BEND), with a ratio of BEND to Nac-BEND of approximately 1.8:1. The RP-HPLC profiles of ir-GnRH demonstrated a major peak coeluting with synthetic GnRH, along with a minor peak eluting at the void volume. Total content of ir-BEND (pg per uterus) was affected by the interaction of breed with day (P < 0.001), but was independent of reproductive status. In Large White gilts, uterine fluid content of ir-BEND was higher (P < 0.05) on days 10 and 11 than on days 8, 12 and 14; however, in Meishan gilts, ir-BEND decreased from day 8 to days 10 and 11, and remained low on days 12 and 14. Compared to Meishan gilts, Large White gilts had higher ir-BEND concentrations on day 10 (P < 0.01), day 11 (P < 0.0001), day 12 (P < 0.01) and day 14 (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Insulin-like growth factor-I mRNA expression in the interstitial cells of the rat testis.

IGF-I mRNA has been demonstrated in testicular tissue and, more recently, localized specifically to Leydig cells. This study investigated the expression of IGF-I and side-chain cleavage enzyme (SCC) mRNA in two preparations of rat interstitial testicular cells which were separated by buoyant density into Leydig cell-enriched and -depleted fractions. RNA was prepared from interstitial cells obtained from the testes of untreated adult and immature rats and adult rats treated with human chorionic gonadotrophin (hCG) or ethane dimethanesulphonate (EDS; to destroy Leydig cells). IGF-I mRNA was detected in all samples, with five major transcripts ranging from 7.5 to 0.6 kb. Leydig cells (3 beta-hydroxysteroid dehydrogenase-positive and sensitive to EDS) expressed abundant IGF-I and SCC mRNAs, and levels of both were increased following hCG treatment. However, in addition, IGF-I mRNA which was derived from non-Leydig interstitial cells was detected, in the complete absence of SCC message, either in the more buoyant interstitial cells or in both interstitial cell fractions following the destruction of Leydig cells by EDS treatment. IGF-I expression in the Leydig cell-depleted cell fraction was also increased by hCG treatment, and it is therefore suggested that at least part of this non-Leydig interstitial cell IGF-I mRNA originates in Leydig cell precursors. In conclusion, Leydig cells are not the sole origin of IGF-I mRNA in the testis, and the non-Leydig cell expression may be an important component of testicular IGF-I production.

Animals↗
PubMed1993

Hemodynamic responses to surgical stimuli in brain-death organ donors.

Though spinal reflexes have been described in experimental brain-death animals, no documentation has been previously provided for human. The hemodynamic responses to surgical stimuli have been investigated here in eight brain-death organ donors. Baseline systolic blood pressure, diastolic blood pressure, and heart rate in observed patients were 99 +/- 15 mmHg, 61 +/- 13 mmHg, and 105 +/- 22 beats/min respectively. After skin incision, these parameters elevated maximally to 130 +/- 23 mmHg, 74 +/- 17 mmHg, and 119 +/- 18 beats/min (p < 0.05). Either spinal reflex arcs or adrenal medullary stimulation, or both, have been speculated to possibly play the role in these hemodynamic responses. However, the existence of such responses should not invalidate the diagnosis of brain death.

Blood Pressure↗
PubMed1993

The comparative antiarrhythmic and proarrhythmic activity of a 3,7-diheterobicyclo[3.3.1]nonane, BRB-I-28, and lidocaine in the 1-4-day-old infarcted dog heart.

We compared the electrophysiological effects and quantified the antiarrhythmic/proarrhythmic potential of the 3,7-diheterobicyclo[3.3.1]nonane-derivative, BRB-I-28 and lidocaine in 15 consecutive postinfarction dogs. Electrophysiologic studies were performed in anesthetized animals, 1-4 days (mean +/- SE = 2.47 +/- 0.36) after the two-stage ligation of the left anterior descending coronary artery. Inducibility of sustained monomorphic ventricular tachycardia (SMVT) was compared in the pre-drug state, and after i.v. lidocaine (3 and 6 mg/kg) and BRB-I-28 (3 and 6 mg/kg) administration. During the control state, SMVT was inducible in 6/15 dogs (40%). After the administration of lidocaine, the rate of the inducible SMVT slowed (353 +/- 91 to 272 +/- 96 beat/min; p < 0.01), but due to the proarrhythmic action of the drug, SMVT became inducible in 13/15 dogs (87%). Sustained reentry was induced after 3 mg/kg lidocaine in 3 dogs and after 6 mg/kg in 4. The mean aortic blood pressure in these SMVTs was 36 +/- 8 mm Hg. After administration of BRB-I-28 (6 mg/kg) SMVT was not inducible in 2/6 and in 4 the SMVT rate was slowed (380 +/- 104 to 208 +/- 105 beat/min; p < 0.005) before termination in 3. In 2 dogs SMVT was induced after BRB-I-28 was given whereas they were non-inducible in the control state (proarrhythmic effect: 13%). Furthermore the hemodynamic state during the SMVTs was more stable after BRB-I-28 (mean aortic blood pressure = 65 +/- 7 mm Hg; post-BRB-I-28 vs post-lidocaine, p < 0.001). During sinus rhythm, lidocaine caused a transient lowering of the MBP (105 +/- 17 to 84 +/- 18 mm Hg; p < 0.001), whereas, BRB-I-28, induced a consistent but short-lasting pressor response (98 +/- 18 to 120 +/- 29 mm Hg; p < 0.001) after its bolus injection. The low proarrhythmic activity and the lack of a cardiodepressant action makes this new chemical class of antiarrhythmics worthy of further development.

Animals↗
PubMed1993

Sclerosing hemangioma of the lung: a clinicopathologic study.

The clinical and pathological features of 11 cases with sclerosing hemangiomas of the lung seen between 1982, and 1992 were reviewed. There were 1 male and 10 female patients aged 15 to 74 years (mean age, 53 years) at operation. Among the 11, 4 were asymptomatic, with the tumor discovered only on routine chest roentgenograms. All 11 patients had a solitary tumor showing as a well-defined homogeneous round or oval shadow on chest x-rays. Microscopically, 8 of the 11 tumors consisted of a mixture of the four major patterns: hemorrhagic, sclerotic, papillary and solid. Five patients received enucleation; four, wedge resection; one, segmentectomy and one, lobectomy. Since this tumor is usually clinically benign and surgically curative, thoracotomy and complete removal of the tumor by limited resection is recommended.

Adolescent↗
PubMed1993

Bilateral traumatic chylothorax: a complication of fracture-dislocation of the T-spine.

Traumatic chylothorax is a rare complication of fracture-dislocation of the thoracic spine. Not treated adequately, it will be associated with high mortality and morbidity. A review of the English literature shows that bilateral traumatic chylothorax is rarely discussed. A case is presented of fracture-dislocation of the third thoracic vertebra combined with bilateral traumatic chylothorax following a motor vehicle accident. The mechanism of injury is described. The management strategies are, initially, conservative treatment including chest tube drainage, NPO with total parenteral nutrition (TPN), followed by medium-chain triglyceride diet. Without improvement, surgical measures such as mediastinal ligation of the thoracic duct should be considered.

Chylothorax↗
PubMed1993

Role of MR imaging of middle third esophageal carcinoma in determining resectability.

Twenty-one patients with middle third esophageal carcinoma were prospectively evaluated by magnetic resonance imaging (MRI) to determine the resectability of the primary tumor. For 8 of the 21 patients, contrast medium was administered during the procedure. Evidences of aortic or tracheobronchial invasion shown on MRI were compared with surgico-pathologic findings, as well as mediastinal lymphadenopathy. Eleven patients (52%) had proved unresectable tumors (three cases of aortic invasion, five cases of tracheobronchial invasion and three cases of combined aortic and tracheobronchial invasion). In all eleven cases, these features were correctly detected by MRI. Two patients had false-positive findings on MRI. No patient had false-negative results. The sensitivity, specificity and accuracy were 100%, 80%, and 90% for MRI. Unsatisfactory results were obtained in evaluation of regional lymph node metastasis. Only two tumors in eight patients had good enhancement after contrast medium was given. We conclude MRI had a high accuracy in predicting resectability of tumors in patients with esophageal carcinoma.

Aged↗
PubMed1993

[Carcinosarcoma of the esophagus].

Carcinosarcoma of the esophagus is a rare neoplasm of the esophagus, composes both of carcinomatous and sarcomatous elements. From Oct. 1982 to Sept. 1991, there were 516 neoplasms of the esophagus, 2 (0.39%) carcinosarcoma, treated at our hospital. The first patient was a 62-year-old man, pathological stage III (T3N2M0). The second patient was a 68-year-old man, pathological stage I (T1N0M0). The tumors were polypoid and located at the middle portion of the esophagus. They had received subtotal esophagectomy, mediastinal lymph node dissection and cervical esophagogastrostomy, retrosternally. The first patient has still lived disease free for seven years. The second patient died one year after the operation due to intra-abdominal lymphadenopathy, liver metastasis and massive ascites. As epidermoid carcinoma, radical esophagectomy with lymph node dissection is the standard procedure for carcinosarcoma of the esophagus.

Aged↗
PubMed1993

[Biliary ascariasis].

From January 1982 to September 1987, ten diagnosed cases of biliary ascariasis were collected among 8,160 cases who were admitted for biliary tract diseases in our hospital. It represented an incidence of 0.12% in our hospital. In our series, the patients' ages ranged from 33 to 68 years old, with a female predominances. The clinical impression on admission were those of biliary tract stone, infection or pancreatitis. Signs and symptoms of biliary ascariasis were abdominal pain, fever, jaundice, vomiting of round worms and distended gallbladder. Laboratory findings disclosed leukocytosis, mildly elevated alkaline phosphatase, transaminase and bilirubin. There was a relatively high incidence of positive bile culture for bacteria. The reliable diagnostic tools for biliary ascariasis were abdominal real-time ultrasonography and endoscopic retrograde cholangiopancreatography (ERCP). They yielded a diagnostic rate of 40% and 87.5% respectively in our series. The principles of management of biliary ascariasis were conservative treatments including intravenous fluids, nasogastric decompression, antibiotics and antihelmintic agents. Other treatments that were also tried included endoscopic removal of round worms through a T-tube, or nasobiliary drainage. Surgery was considered when there were signs of complications, such as uncontrolled sepsis or suppurative cholangitis. The prognosis of biliary ascariasis was good if patients were diagnosed and treated properly. Regular follow-up with antihelmintic agents is also recommended to avoid reinfection.

Adult↗
PubMed1993

Surgical management of intrathoracic goiter.

Thirty-three consecutive patients of intrathoracic goiters underwent resection at the TCVGH during a nine-year period 1982-1991. The mean age of 21 men and 12 women was 65 years. Six (18 per cent) had undergone prior thyroid surgery. Thirty-one of the 33 patients were euthyroid. Thirty patients underwent transcervical approach for resection; three had cervical incision plus median sternotomy. Pathological examination revealed multinodular goiter in 31 (94 per cent) and follicular carcinoma in two (6 per cent). The mean mass of goiter was 201.25 g and the mean greatest dimension was 10 cm. Thyroidectomy is advisable in all cases of intrathoracic goiter and resection can almost invariably be performed through a transcervical approach.

Adult↗
PubMed1993

Leiomyosarcoma of the gastric cardia: report of a case with unusual clinical manifestation.

In an uncommon presentation of gastric leiomyosarcoma, a rare malignancy of the stomach, a patient aged 63 years was admitted due to progressive exertional dyspnea. Plain film and computed tomography of the chest showed that this patient had a mediastinal neoplasm and the pulmonary function test revealed compromised pulmonary function. Operative findings revealed that this tumor arose in the esophageal-cardiac junction with mediastinal extension; the pathology report was leiomyosarcoma. The patient recovered well and the pulmonary embarrassement was relieved in the succeeding one-year period.

Cardia↗