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Biomedical subjects

C C Tseng

Publications and source records attributed to C C Tseng.

At least 163 records · Page 9Linked to original sources
PubMed1978

[Study on the rapid, secondary-growth mutants of Staphylococcus epidermidis (author's transl)].

According to colony type, growth rate and development of secondary growth on the proteose-peptone No. 3 mannitol salt agar (PMS) and the nutrient agar (NA) media, Staphylococcus epidermidis may be classified into three groups. Group I includes strains which develop smooth colonies on both media. Group II consists of those which show rapid propagation of entire clones and develop secondary growth on the PMS medium, but grow only smooth colonies on the NA medium, and which may be called reversible mutants. Group III includes thoes which show secondary growth on both PMS and NA as well as other media, which may be called irreversible mutants. One percent proteose-peptone No. 3 and 5--7% NaCl are the essential ingredients for the induction of mutation, and mannitol can enhance it. Except the high sensitivity of the reversible mutants of human origin, the three groups of chicken origin showed similar drug susceptibility to biosynthesis inhibitors of protein and cell wall. On the HI medium, chloramphenicol inhibited secondary growth of irreversible mutants at 25.0 microgram/ml minimal antimutagenesis concentration (MAC), whereas streptomycin, penicillin, erythromycin and oxytetracycline did not at all. The irreversible mutants had higher resistance to biosynthesis inhibitors of DNA or RNA, e.g. mitomycin C (MMC), novobiocin (NOV) and rifampicin (RIF), than the other two groups. On the HI medium, MMC at the MAC of 0.16 microgram/ml, NA at 25.0 microgram/ml and NOV at 2.5 microgram/ml inhibited the secondary growth of irreversible mutants, but RIF did not. To the irreversible mutants, the MIC and MAC of NA on the PMS medium were both higher than those on the HI medium. The MACs of MMC and NOV on the PMS medium were also higher than those on the HI medium, but their geometric mean MIC remained almost unchanged on both media. Because the MACs of MMC (0.31 microgram/ml) and NA (100.0 microgram/ml) to the reversible mutants on the PMS medium were much similar to those of the irreversible mutants, it suggests that both groups had the similar mutation mechanism.

Anti-Bacterial Agents↗
PubMed1975

Extracellular deoxyribonuclease activity of Pseudomonas aeruginosa.

Pseudomonas aeruginosa cultured on deoxyribonucleic acid (DNA) media containing Nissan's heart extract or chicken heart extract could produce extracellular deoxyribonuclease, while on other DNA media with heart extracts from cow, pig and mouse could not. Variation in the kind of peptones in the DNA media did not make significant difference in this activity, although some peptones caused cloudiness of the media. P. aeruginosa did not need cation activators of chloride compounds to produce extracellular deoxyribonuclease. On the modified Eiken's DNA medium, gram negative bacilli other than P. aeruginosa and Serratia marcescens, i.e. Klebsiella, Salmonella, Shigella, Escherichia coli and Alcaligenes did not produce deoxyribonuclease. The production of extracellular deoxyribonuclease activity on the modified Eiken's DNA medium can be used as a supporting test for biochemical identification of P. aeruginosa.

Culture Media↗
PubMedDate not supplied

Cocaine toxicity and the calcium channel blockers nifedipine and nimodipine in rats.

Two dihydropyridine type calcium channel blockers (CCBs) were studied for any protective or therapeutic effect upon cocaine-induced toxicity and death in rats. To test for the protective effects, rats were pretreated with vehicle (control), nifedipine or nimodipine, intraperitoneally (IP) 30 minutes prior to an LD85 of cocaine, or intravenously (IV) 10 minutes prior to cocaine administration. Animals receiving IP control vehicle developed seizures in 5.6 +/- 1.0 minutes and respiratory arrest in 9.8 +/- 1.4 minutes. Animals pretreated IP with nifedipine or nimodipine developed seizures and respiratory arrest significantly sooner than the controls, although the overall incidences of seizures and respiratory arrest were not significantly different. Pretreatment with IV CCBs resulted in similar findings. To test the therapeutic effect of CCBs given following cocaine overdose, rats were administered cocaine IP and then treated with IV nifedipine or nimodipine once seizures occurred. In these animals, there was no significant difference in the incidence or time to respiratory arrest compared to vehicle controls. This study demonstrates that neither pretreatment nor posttreatment with the CCBs nifedipine or nimodipine reduces cocaine toxicity in this rodent model.

Animals↗
PubMedDate not supplied

Bacteremia after endoscopic band ligation of esophageal varices.

In a 6-month period, 17 consecutive unselected patients undergoing emergency or elective endoscopic variceal band ligation were evaluated prospectively for clinical and bacteriological signs of bacteremia after each treatment session. None had signs of sepsis, fever, or chills; however, in one patient, a coagulase-negative Staphylococcus epidermidis was cultured from peripheral blood at 5 but not 30 min after the procedure. These data indicate that, in contrast to sclerotherapy, endoscopic variceal ligation rarely induces bacteremia.

Adult↗
PubMedDate not supplied

Clinical and upper gastroendoscopic features of patients with dengue virus infection.

Clinical observation was made on 238 dengue fever cases during an epidemic in Taiwan from September to November 1988. Dengue virus infection type 1 was responsible for all cases. The majority of patients had acute onset of fever with abdominal pain, diarrhoea, and vomiting. Gastrointestinal haemorrhage with manifestation of haematemesis and/or melena was observed in 28 (11.8%) of our patients. The clinical gastrointestinal features in patients with a peptic ulcer history were not different from those in patients without it. There was no significant difference in incidence of gastrointestinal manifestations between premedication and non-premedication patients. Sixty-six non-premedication patients in our series were examined by gastroduodenoscopy. Haemorrhagic gastritis was the most common finding in 27 (40.9%) patients. The incidence of gastric and/or duodenal ulcerations was higher in patients with a peptic ulcer history compared with those without it (P less than 0.01). However, the incidence of upper gastrointestinal bleeding was similar between these two groups (19.2% vs 9.8%). Thrombocytopenia in patients with gastrointestinal haemorrhage was more prominent than in those without it (P less than 0.005). This implied that thrombocytopenia might be one of the predisposing factors for gastrointestinal haemorrhage.

Adult↗
PubMedDate not supplied

The small subunit ribosomal RNA gene sequence of Pleistophora anguillarum and the use of PCR primers for diagnostic detection of the parasite.

Using the polymerase chain reaction (PCR) and two primers for conserved regions of the small subunit ribosomal RNA (SSU-rRNA) of Microsporidia, a DNA segment about 1,195 base pairs long was amplified from a DNA template prepared from purified spores of the microsporidian species Pleistophora anguillarum. These spores had been isolated from adult eels (Anguilla japonica) with "Beko Disease." A comparison of sequence data from other microsporidian species showed P. anguillarum SSU-rRNA to be most similar to Vavraia oncoperae. When juvenile eels were artificially infected with P. anguillarum, enzyme-linked immunosorbent assay could detect a positive infection only 12 days post-infection. However, when suitable PCR primers were used, a DNA fragment of about 0.8 kb was detected from these juvenile eels after only 3 days post infection. No PCR product was obtained with templates prepared from clinically healthy control animals.

Anguilla↗
PubMedDate not supplied

Adult-onset minimal change disease among Taiwanese: clinical features, therapeutic response, and prognosis.

There are some racial differences in the prevalence and prognosis of idiopathic nephrotic syndrome; however, reports about minimal change disease (MCD) in Chinese were rare. We retrospectively analyzed 123 Chinese adults with idiopathic nephrotic syndrome, who received percutaneous renal biopsy in our institution within the last 10 years. In total, 46 patients (37.4%) were compatible with the pathological diagnosis of MCD. The male to female ratio was 1.2:1. The mean age of onset was 30.9 years, and 80% of the patients with MCD were less than 40 years. The mean daily proteinuria was 10.2 g, and serum albumin was 1.8 mg/dl. Azotemia occurred in 16 (35%) of 46 cases; hypertension, 13%; and microscopic hematuria, 13%. High selectivity index for proteinuria (SI <0.1) was noted in 12 (39%) of 31 cases; and high IgE level was found in 83.7% of the study subjects, although only one case had allergic history. Complete remission in 36 MCD patients treated with corticosteroid was achieved by 42% (15/36), 80% (29/36), and 94% (34/36) within 4, 8, and 12 weeks, respectively. The time interval to remission was similar between the younger group (<40 years old, 1.7 months) and older group (>40 years old, 1.6 months). Nineteen (56%) of 34 cases with steroid response did not relapse, and the other cases (44%) had a mean relapse rate of 1.5 times per patient within a period of 45 months. The age of onset in MCD cases was not significantly correlated with steroid-responsive rate, and the time interval to remission. However, a tendency existed between the onset in the young age and the sequentially relapsing rate (p = 0.06). Two cases with primary steroid resistance and 5 cases with frequent relapse or steroid dependence responded well to intravenous pulse therapy of cyclophosphamide, except one refractory case. No thrombotic episode was ever noted in our group. Regarding infectious complications, primary peritonitis occurred in one, pneumonia in one, and cellulitis in 6 cases during active nephrotic stage. Two mortality cases, one with E. coli-related necrotizing fasciitis and one from pneumonia, were noted. In brief, compared with children, adult patients with MCD had lesser high selectivity index for proteinuria, the same steroid-responsive rate (94%), but slower response, and significantly lesser relapsing rate. The intravenous pulse therapy of cyclophosphamide may be an alternative regimen for adult patients with steroid resistance or dependency. In addition, the Asian adult-onset MCD had younger age, male predominance, and lesser relapsing rate in comparison to those of the Western population.

Adolescent↗
PubMedDate not supplied

Blood pressure and left ventricular hypertrophy in patients on different peritoneal dialysis regimens.

OBJECTIVE: To examine the relation between the results of ambulatory 24-hour blood pressure monitoring (ABPM) and left ventricular mass index (LVMI), then to find the independent determinant for left ventricular hypertrophy (LVH) in peritoneal dialysis (PD) patients. Finally, to evaluate the differences in the clinical and cardiovascular characteristics between patients on continuous ambulatory PD (CAPD) and continuous cyclic PD (CCPD). DESIGN: An open, nonrandomized, cross-sectional study. SETTING: Divisions of nephrology and cardiology in a medical center. PATIENTS: Thirty-two uremic patients on maintenance PD therapy (22 patients on CAPD, and 10 on CCPD) without anatomical heart disease or history of receiving long-term hemodialysis. INTERVENTIONS: Home blood pressure (BP) and office BP were measured using the Korotkoff sound technique by sphygmomanometer. ABPM was employed for continuous measurement of BP. Echocardiography was performed for measurement of cardiac parameters and calculation of LVMI. MAIN OUTCOME MEASURES: Multivariate logistic regression analysis was performed for independent determinant of LVH in PD patients. The differences in clinical and cardiovascular characteristics between CAPD and CCPD patients were compared. RESULTS: Simple regression analysis showed positive correlations between LVMI and the duration of hypertension, ambulatory nighttime BP/BP load/BP load > 30%, serum phosphate, calcium-phosphate product, ultrafiltration (UF) volume, and percentage of UF volume during the nighttime. A negative correlation was noted between LVMI and dipping. In multiple regression analysis, the duration of hypertension was the only variable linked to LVMI. In multivariate logistic regression analysis, only ambulatory nighttime systolic BP load > 30% had an independent association with LVH. There were correlations between office/home BP and ambulatory 24-hour BP. In addition, CCPD patients had higher LVMI, UF volume during the nighttime, and percentage of UF volume during the nighttime than those of CAPD patients. CONCLUSIONS: In this study, ambulatory nighttime systolic BP load > 30% had an independent association with LVH. Office and home BP measurements were correlated with ABPM in PD patients. The result that CCPD patients had a higher LVMI than CAPD patients may be due to a relative volume overload during the daytime in CCPD patients.

Adult↗
PubMedDate not supplied

Antitumor activity of 5'-deoxy-5-fluorouridine in human digestive organ cancer xenografts and pyrimidine nucleoside phosphorylase activity in normal and neoplastic tissues from human digestive organs.

5'-Deoxy-5-fluorouridine (5'-DFUR) is believed to be metabolized to 5-fluorouracil (5-FU) by pyrimidine nucleoside phosphorylase (PyNPase). PyNPase activity is reported to be higher in neoplastic tissues than in normal tissues, and this has been proposed as an explanation for the selective cytotoxicity of 5'-DFUR against tumors. In the present study, PyNPase activity was measured in 95 neoplastic and normal specimens from human digestive organ tissues. In specimens from the esophagus, stomach, intestine and pancreas, PyNPase activity was higher in neoplastic tissues than in normal tissues. However, PyNPase activity in non-malignant liver tissues, especially cirrhotic liver tissues, was much higher than in the normal tissues of the other digestive organs. PyNPase activity in non-malignant liver tissues was a high as in primary liver tumors, and PyNPase activity in metastatic liver tumors was lower than in primary tumors and non-malignant cirrhotic tissues. The in vivo antitumor activities of oral 5'-DFUR and intravenous 5-FU were also assessed in 6 human digestive organ cancer xenograft lines transplanted subcutaneously in nude mice, and the relationship between the in vivo antitumor effects of 5'-DFUR and PyNPase activity in the tumors was assessed. However, there was no statistically significant correlation between them. Although the in vivo antitumor effect of intravenous 5-FU correlated significantly with the in vitro sensitivity of the tumors to 5-FU (assessed by DNA synthesis inhibition assay), the in vivo effects of 5'-DFUR did not correlate with the in vitro sensitivity to 5-FU. It is suggested that: (a) the liver may be the major site for metabolizing 5'-DFUR to 5-FU, and (b) measuring PyNPase activity in the tumor may not be a useful indicator for chemotherapy with 5'-DFUR.

Adenocarcinoma↗
PubMedDate not supplied

The role of additional chemotherapy with oral UFT in intravenous combination chemotherapy with cisplatin and 5-fluorouracil for human gastric cancer xenograft lines of well- and poorly- differentiated adenocarcinomas transplanted in nude mice.

In order to assess the role of maintenance chemotherapy with the oral anticancer agent UFT, a mixture of uracil and futraful, in the intensive intravenous chemotherapy for gastric cancer, nude mice transplanted with human gastric cancer xenografts were treated with intravenous 5-fluorouracil (5-FU) and cisplatin (CDDP), alone or in combination, with or without the oral anticancer agent UFT. UFT was given at its maximal clinical dose of 10 mg/kg of body weight daily for 2 weeks, while 5-FU and/or CDDP was intravenously administered at the dose of 20 mg/kg and 1.8 mg/kg of body weight respectively once a week, alone or in combination, for two weeks. The results revealed that 5-FU or CDDP alone were ineffective for both GC-YN, a well differentiated adenocarcinoma line, and GC-SF, a poorly differentiated adenocarcinoma line; however, UFT was effective for GC-SF. In combinations, only the three-agent combination 5-FU + CDDP + UFT (FPU) was effective for GC-YN; however, all the two-agent combinations and FPU were effective for GC-SF. FPU significantly suppressed the growth of GC-YN much more than all the other treatment groups. In contrast, although all combinations as well as UFT alone were effective for GC-SF, there was no significant difference among these effective groups. Moreover, no side effects were noted in combined use of UFT. This study suggests that oral UFT as a maintenance treatment may be beneficial in the combination chemotherapy for human gastric cancer.

Adenocarcinoma↗
PubMedDate not supplied

Relationships for recombinant interleukin-2-stimulated mixed lymphocyte tumor extract reaction between peripheral blood lymphocytes and regional node lymphocytes in gastric cancer patients.

To investigate the relationship between "systemic" antitumor immunity and "local" antitumor immunity with respect to the histopathological stage of gastric cancer, interleukin-2 stimulated mixed lymphocyte tumor extract reactions (ILS-MLTR) of peripheral blood lymphocytes (PBL) and regional node lymphocytes (RNL) were evaluated in 59 gastric cancer patients. ILS-MLTRs of both PBL and RNL decreased with the advance of cancer stage, but ILS-MLTRs of PBL were always lower than those of RNL. Positive correlations in MLTR between PBL and RNL were found in patients with depth of invasion to muscularis propria and serosa and peritoneal dissemination. Inverse correlations between PBL and RNL were noted in patients with stage IV and distant nodal involvement. These results suggest that variations in the anticancer immunities might be effectively managed by an immunotherapy which is designed according to the responsiveness in the immune parameter ILS-MLTR.

Cells, Cultured↗
PubMedDate not supplied

Splenectomy abolishes antitumor effect of immunotherapy with streptococcal preparation, OK-432, on mouse liver tumors.

In the present study, we investigated the therapeutic effects of oral and subcutaneous administration of OK-432 prior to or following the transplantation of murine liver tumors. In addition, the effect of splenectomy on the antitumor activity of OK-432 was investigated. Mice which received OK-432 orally prior to tumor transplantation exhibited significantly lower tumor weight and significantly improved survival, when compared to the control mice. Prior subcutaneous injection of OK-432 did not show any antitumor activity. On the other hand, both oral and subcutaneous administration of OK-432, subsequent to tumor transplantation, led to a significant improvement of survival and a decrease in the number of lung metastases, although tumor weight was not affected. The anti-tumor effect of OK-432 required the presence of the spleen, since the survival of the mice with liver tumors was not improved by OK-432 if splenectomy and tumor transplantation were performed simultaneously. These results suggest that immunotherapy with OK-432 may beneficial in the treatment of liver tumors and that these effects are dependent on the presence of the spleen.

Animals↗