PubMed Health⌕ Search

Biomedical subjects

C C Tseng

Publications and source records attributed to C C Tseng.

At least 109 records · Page 6Linked to original sources
PubMed1992

Cholinesterase studies with (R) (+)- and (S)(-)-5-(1,3,3-trimethylindolinyl)-N-(1-phenylethyl)carbamate.

A limited number of carbamates have been found useful for treatment of cholinergic symptoms with pyridostigmine and physostigmine being the main focus. In recent years 5-(1,3,3-trimethylindolinyl)N,N-dimethylcarbamate (I) has received considerable attention in the Chinese literature for a similar role. We report on the first synthesis of stereoisomers of an analog of (I). The isomers prepared were (R)(+)-5-(1,3,3-trimethylindolinyl)-N-(1-phenylethyl)carbamate (II) and (S)(-)-5-(1,3,3-trimethylindolinyl)-N-(1-phenylethyl)carbamate (III). The pKa value for each isomer was 6.8. Eel acetylcholinesterase inhibition studies were carried out at 25.0 degrees C over the pH range of 6.0 to 9.0. They reflect the first pH profiles using enantiomorphs of a cholinesterase inhibitor. The inhibition potencies for (II) and (III) over the range examined were similar. At pH 7.60 the ki for II = 7.38 x 10(3) M-1 min-1 (SD = 398) and for (III) the ki = 6.67 x 10(3) M-1 min-1 (SD = 355). In accord with the findings of Wilson and Bergmann20 on physostigmine our results indicate that the protonated form of (II) and (III) is the more potent inhibitor.

Acetylcholinesterase↗
PubMed1992

[Prophylaxis of superficial bladder tumor with the intravesical instillation of bacillus Calmette-Guerin or anti-cancer agents. A retrospective study].

It was retrospectively analyzed whether intravesical instillation of bacillus Calmette-Guerin (BCG) or anti-cancer agents had prophylactic effect or not after removal of superficial bladder tumors. The results over a follow-up period ranging from 6 to 40 months showed 23.8 per cent recurrence in group 1 patients treated with BCG (21 patients), 46.7 per cent recurrence in group 2 treated with anti-cancer agents (45 patients) and 52.3 per cent recurrence in the group 3 (127 patients) which were not received any intravesical drugs. Long-term results among the 3 groups calculated with Kaplan-Meier method demonstrated that the instillation of BCG or of anti-cancer agents was more useful for prophylaxis, compared with the actuarial non-recurrence rates of group 3. The instillation of BCG showed good prophylactic effects especially in recurrent, grade 2 and pTa bladder tumors. The instillation of anti-cancer agents showed to provide prolonged protection from recurrence, but the instillation of BCG did not.

Administration, Intravesical↗
PubMed1992

Locomotor strategies before independent walking: prospective study of 50 mentally retarded children.

To investigate the association between pre-walking locomotor strategies and psychomotor developments in children with mental retardation (MR), 50 children with non-specific MR were included in this study. There were 29 boys and 21 girls, 96% of whom had moderate to severe MR. They were followed from 4-53 months to 25-99 months of age, and their follow-up periods ranged from 10 to 48 months (mean 30 months). According to the pre-walking locomotor strategies, these children were categorized into three groups: the crawling group (n = 34) who used crawling or creeping as their main locomotion pattern before independent walking; the shuffling group (n = 9) who used shuffling prior to independent walking; and the direct-walking group (n = 7) who did not have any other locomotor strategies except rolling. In almost all motor developmental milestones, children in the direct-walking group developed earlier than those in the crawling and shuffling groups. Children in the crawling group had more advanced developments than those in the shuffling group. The difference in the mean ratio developmental quotients of the Bayley Mental Scale among the three groups was not significant. The present study showed that crawling may not be a necessary prerequisite for early ambulation or better cognitive function in MR children.

Child Development↗
PubMed1992

A guide for tooth resection with a used reamer or file.

Tooth resection is an important procedure, frequently encountered in dental treatment. A surgical guide is essential to providing the direction for tooth resection. A used (dulled) endodontic reamer or file can be utilized as directional guide for tooth resection, because it is economical, autoclavable, and safe. The clinical use of this surgical guide is described.

Humans↗
PubMed1992

Hepatectomy accelerates the growth of transplanted liver tumor in mice.

To study the effect of hepatectomy on the growth of liver tumor, Shionogi Carcinoma 42, a mammary tumor, was transplanted into the liver of mice which had undergone 40% hepatectomy. The liver tumor and the number of pulmonary metastases in hepatectomized mice were significantly larger than those in nonhepatectomized mice. Responses to lectins and IL-2, subpopulations, and cytotoxicity to YAC-1 and P815 cells of splenocytes were assessed to evaluate immunological status. At the initial phase after hepatectomy and tumor transplantation into the remaining liver, NK activity transiently increased, and function of B and T cells, especially of helper T cells, decreased, while B-cell function recovered beyond normal levels in a later phase. These results suggest that liver may play an important immunological role and that the immunological modification after hepatectomy may be responsible for the accelerated growth of liver tumor. Accordingly, some adjuvant immunotherapy may be recommended for the prevention of recurrence after hepatectomy for liver tumor.

Alanine Transaminase↗
PubMed1991

Effects of splenectomy on pulmonary metastasis and growth of SC42 carcinoma transplanted into mouse liver.

The carcinoma SC42 was transplanted into the liver of its syngeneic mice DS, and the immunological integrity of the spleen and the effects of splenectomy on the growth and pulmonary metastasis of the liver tumor were assessed. On day 7 after liver tumor transplantation, the natural killer (NK) activity of the splenocytes was significantly elevated; it subsequently decreased at a later stage of the tumor. The response of the splenocytes to PHA and Con-A decreased significantly from the early stage of the tumor. However, the mixed lymphocyte-tumor cell reaction increased significantly from day 14 to day 28. The survival rate of the mice, which had undergone simultaneous splenectomy and liver tumor transplantation, was significantly lower than that of sham-operated control mice. The number of pulmonary metastases in splenectomized mice was significantly greater than in the control mice. There was, however, no difference between the two groups in the weight of the liver tumor. By contrast, splenectomies performed 14 days before or 14 days after tumor transplantation had no significant influence on the survival of the mice. Splenectomies performed on day 0 and on day 3 after tumor transplantation significantly increased the number of pulmonary metastases. Furthermore, the intravenous injection of anti-asialo GM1 antisera on day 0 and day 3 significantly increased the number of pulmonary metastases, but injection of anti-Thy 1.2 antisera had no effect. These results suggest that splenic NK cells may play an important role in the suppression of pulmonary metastasis at early stages of the liver tumor.

Animals↗
PubMed1991

Combining independently effective anticancer agents may not augment the independent antitumor effects: a study using human digestive organ cancer xenograft lines in nude mice.

Five human digestive organ cancer xenograft lines were subcutaneously transplanted in nude mice, and 7 anticancer agents (ACAs) were intravenously administered singly or in combinations at 4 times the standard clinical doses. Cisplatin (P) was effective in 4 lines and 5-fluorouracil (F) was effective in 3 lines. A total of 8 combinations with 2 effective ACAs were assessed in 4 lines and only 1 combination (FP) resulted in an augmented antitumor effect in a single line. A total of 11 combinations with 1 effective ACA plus 1 ineffective ACA were assessed in 2 lines, and only 1 combination (F + carboquone [CQ; Esquinon]) resulted in an augmented effect in a single line. A total of 5 combinations with independently ineffective ACAs were assessed in 1 line, and 1 combination (FP) resulted in augmented antitumor activity. No 2-ACA combinations showed enhanced side effects. Two combinations with 3 effective ACAs were assessed in 2 lines and 1 combination (FP + mitomycin C) resulted in an augmented effect with a greater mortality rate. A total of 12 combinations with both effective plus ineffective ACAs were assessed in 2 lines, and 3 combinations (FP + Adriamycin or FP + CQ or FP + etoposide) resulted in an augmented effect in 1 line with enhanced side effects. These results indicate that the combination of independently effective ACAs does not always cause an augmented antitumor effect, and may sometimes result in augmented side effects. According to this study, the 3-ACA combinations with FP + 1 effective agent appear to be the best regimens for digestive organ cancer.

Animals↗
PubMed1991

In vitro immunomodulating effect of protein-bound polysaccharide, PSK on peripheral blood, regional nodes, and spleen lymphocytes in patients with gastric cancer.

PSK, a protein-bound polysaccharide, has been widely used for cancer immunotherapy in Japan. However, the mechanism of its immunomodulatory effect has not been fully clarified. In the present study the in vitro effect of PSK on the lymphocytes of patients with gastric cancer was studied. Culturing lymphocytes with PSK at 5-100 micrograms/ml increased the level of DNA synthesis, and augmented the cytotoxicities against K562 and KATO-3. Flow-cytometric analysis also showed an increase in the proportion of interleukin-2 (IL-2)-receptor-positive cells after the lymphocytes were cultured with PSK. However the cytotoxicity of cells cultured with PSK was not augmented by the addition of recombinant interferon gamma (rIFN gamma) and rIL-2. Further experiments using fractionated PSK showed that its biological action is present mainly in fractions having molecular masses greater than 10(5) Da. However, these immunomodulations were not seen in all patients. These results suggest that the susceptibility of lymphocytes to PSK may be different in each patients, and that the immunomodulation by PSK may be mediated by mechanisms independent of IFN and IL-2.

Adjuvants, Immunologic↗
PubMed1991

In vivo effects of human recombinant tumor necrosis factor alone and in combination with other biological response modifiers on human digestive organ cancer xenografts transplanted in nude mice.

The present study was designed to evaluate the effect of rTNF alone or in combination with other BRMs on human digestive organ cancers. Six kinds of human digestive organ cancer xenografts (esophageal, stomach, colonic, pancreatic, bile duct, and liver cancers: EC-YO, GC-YN, CC-KK, PC-HN, BDC-SN and Li-7, respectively) were transplanted in nude mice, and rTNF was administered at 10(3), 5 x 10(3), or 10(4)U/head directly into the tumor 3 times a week for 2 weeks. EC-YO was the most sensitive to rTNF, and intratumoral administration of rTNF at 10(3) U/head caused tumor regression. PC-HN, CC-KK and GC-YN were relatively sensitive to rTNF, and their growth was significantly inhibited by rTNF at 5 x 10(3) U/head, however, the tumors regrew after treatment. Li-7 and BDC-SN were resistant to rTNF. The effects of rTNF in combination with recombinant interferon-gamma (rIFN-gamma), recombinant interleukin-2 (rIL-2), or streptococcal preparation OK-432 were assessed in mice transplanted with GC-YN. All combinations of rTNF at 5 x 10(3) U/head and other BRMs were more effective than rTNF alone, and GC-YN tumors were completely regressed after treatment with a combination of rTNF and rIFN-gamma or rTNF and OK-432. However in all cases, the combination of rTNF at 10(3) U/head and any other BRM did not improve the effect. Furthermore, the adverse effects of the combinations were more serious than those of rTNF alone. TNF may still be a useful cytokine, because it can induce the regression of tumors. However, for its clinical application, a method should be developed to reduce its side effects.

Animals↗
PubMed1991

Cocaine-induced respiratory depression in urethane-anesthetized rats: a possible mechanism of cocaine-induced death.

Urethane-anesthetized rats were used to study the mechanism of cocaine-induced death. Continuous recording of the changes in five physiological parameters, including respiratory rate (RR), electroencephalogram (EEG), blood pressure (BP), electrocardiogram (ECG), and body temperature (BT), were conducted after intraperitoneal (IP) administration of a single dose of cocaine HCl (70 mg/kg). In the control group (normothermic with core body temperature 37.7 +/- 0.1 degree C and spontaneously breathing), the death rate was 88% (15/17), and the average time to respiratory arrest was 12.99 +/- 1.40 min (mean +/- SEM). The first set of experiments investigated the contribution of hypothermia to cocaine-induced death. The hypothermic group (core body temperature 33.9 +/- 0.3 degrees C and spontaneously breathing) had a death rate of 81.5% (22/27), and an average time to respiratory arrest of 16.70 +/- 1.24 min, which was significantly (p les than 0.05) prolonged. A substantial decrease in respiratory rate was seen in normothermic group, while all the other measured parameters remained relatively stable until respiratory arrest. Sequential arterial blood gas data in this group showed a decrease in PaO2 from 116.0 +/- 5.7 mmHg to 57.7 +/- 4.6 mmHg, an increase in PaCO2 from 27.7 +/- 2.2 mmHg to 42.7 +/- 3.0 mmHg, and a decrease in pH from 7.467 +/- 0.039 to 7.357 +/- 0.003. To confirm that respiratory depression was an important mechanism of cocaine-induced death in this model, ten normothermic rats underwent mechanical ventilation, and all survived cocaine exposure. This study points to the important role of respiratory depression as a cause of cocaine-induced death.

Anesthesia↗
PubMed1991

Propofol modification of evoked hippocampal dentate inhibition in urethane-anesthetized rats.

To learn more about the site and mode of action of propofol, the authors anesthetized rats with urethane, and implanted a stimulating electrode in the perforant pathway and a recording electrode in the hippocampal dentate gyrus to measure evoked field responses. Catheters were placed in the jugular vein and carotid artery to measure blood pressure, take blood samples for measurement of blood gases, and inject drugs. Rat lungs were ventilated, and increasing doses of propofol or its 10% fat emulsion vehicle were administered. Over a dose range of 2.5-40 mg/kg, propofol had little effect on the field excitatory postsynaptic potential (EPSP) or the field population spike (PS), suggesting no important actions on perforant pathway fibers or intrinsic granule cell excitability. With the use of various paired-pulse stimulation paradigms, it was demonstrated that propofol administration led to a dramatic decrease in granule cell excitability over interpulse intervals of 10-100 ms. The magnitude of this effect clearly was related to dose, and the effect was reversible with discontinuance of drug. The vehicle had marginal effects on granule cell excitability. These were significantly less than those produced by propofol. Transient reductions in blood pressure followed by transient increases to above baseline were observed after administration of propofol at most doses. Increased heart rates accompanied the slight increase in blood pressure. Except at the largest dose of propofol tested, cardiovascular measures had returned to near control levels by 8 min, when the evoked potentials were evaluated. Arterial blood gases showed little change throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Intravenous↗
PubMed1991

Comparative study on various combination chemotherapies against human gastric cancer xenograft lines of well- and poorly-differentiated adenocarcinomas transplanted in nude mice.

Two human gastric cancer xenograft lines (GC-YN and GC-SF) transplanted in nude mice were employed to evaluate and compare the anticancer effect of seven single anticancer agents and their various combinations. Mitomycin C, cisplatin (Briplatin) (CDDP) and 5-fluorouracil (5-FU) were screened out to be effective against GC-YN and only epirubicin (Farmorubicin) (EPIR) was effective against GC-SF. Combinations of two of these 'effective' agents revealed that FP (5-FU + CDDP) is the most effective two-agent combination regimen against both lines, and some of those 'ineffective' single agents showed synergistic effects against both lines when combined with 5-FU. Moreover, three-agent combinations composed of FP and one of the other five agents were also evaluated to select out the most effective regimen. All the combinations showed higher inhibition on the tumor growth of GC-YN than FP regimen, and FP + adriamycin (Adriacin) (ADR) and FP + EPIR were more effective against GC-SF than FP. However, taking toxic effects into consideration, the results suggest that CDDP + 5-FU + EPIR (FPEPIR) may be the regimen most worthy of clinical trial in the chemotherapy against human gastric cancer.

Adenocarcinoma↗
PubMed1991

Low uracil concentration in the liver might be responsible for the decreased antineoplastic activity of fluoropyrimidines in mice with CCl4-induced chronic liver dysfunction.

Some fluoropyrimidines are considered to be metabolized in liver microsomes. The present study was designed to assess the effect of chronic liver dysfunction on the antineoplastic activity of fluoropyrimidines. Chronic liver dysfunction was induced in BALB/c mice by 8 weeks of CCl4 injections. The 5-fluorouracil (5-FU)-sensitive MOPC-104E and 5-FU-resistant Meth-A cells were inoculated subcutaneously into the mice and then various fluoropyrimidines were administered intragastrically. The antitumor activity of the fluoropyrimidines decreased in mice with chronic liver dysfunction, although the concentration of 5-FU in the tumor of normal mice did not differ from that of mice with liver dysfunction. However, the concentration of uracil in the liver was decreased in mice with chronic liver dysfunction. On the other hand, the percent conversion of Tegafur [1-(2-tetrahydrofuryl)-5-FU] to 5-FU in the normal liver did not differ from that in the dysfunctional liver. These results suggest that low uracil concentrations in the liver may result from chronic liver dysfunction and lead to decreased antitumor efficacy of fluoropyrimidines.

Animals↗
PubMed1991

Anticholinesterase activity of potential therapeutic 5-(1,3,3-trimethylindolinyl) carbamates.

Six N-alkyl and N-aryl 5-(1,3,3-trimethylindolinyl) carbamates were synthesized and studied for their structure-activity relationships in inhibiting eel acetylcholinesterase (AChE). The carbamates were 5-(1,3,3-trimethylindolinyl)N,N-dimethylcarbamate (Cui Xing Ning) (I), 5-(1,3,3-trimethylindolinyl)N,N-diethylcarbamate (IV), 5-(1,3,3-trimethylindolinyl)N-ethylcarbamate (III), 5-(1,3,3-trimethylindolinyl)N,N-diethylcarbamate (IV), 5-(1,3,3-trimethylindolinyl)N-heptylcarbamate (V), and 5-(1,3,3-trimethylindolinyl)N-(3-chlorophenyl)carbamate (VI). The inhibition studies were carried out at 25.0 degrees C at pH 7.60. The rank order of the ki values for eel AChE inhibition is II > V > I > III > VI > IV. Compound II has a greater affinity for the enzyme than any irreversible inhibitor cited in the literature (Kd = 7.14 x 10(-8) M). Our findings should aid in the application of these carbamates (1) for counteracting the cholinergic problems associated with various diseases, and (2) for developing potential pretreatment compounds for organophosphate poisoning.

Acetylcholinesterase↗
PubMed1991

The clinical status and histopathological factors affecting natural killer cells of peripheral blood lymphocytes in patients with gastric cancer.

The in vivo function of NK cells is still uncertain, and there are various contradictory reports on NK cells in gastrointestinal cancer. In the present study the activity and proportion of NK cells (Leu 11 + cells) in peripheral blood were assessed in 71 patients with gastric cancer, and analysed with respect to the clinical and histopathological factors, such as the clinical stage, tumor size, degree of invasion, metastasis, histology, etc. There were no differences in the proportions and activities of NK cells between normal volunteers and gastric cancer patients. A low NK cell activity was associated with early gastric cancers (carcinoma in the mucosa or submucosa) less than 2 cm in diameter, large advanced tumors (invasion beyond the muscularis propria) greater than 8 cm in diameter, and metastasis of adjacent regional (perigastric) nodes. Liver metastasis did not affect the NK cell activity, however a high NK activity was found in patients with peritoneal dissemination. The NK activity did not correlate with the proportion of Leu 11 + cells in normal volunteers or in patients with early gastric cancer, however the activity and proportion of NK cells correlated with each other in patients with advanced gastric cancer. These results suggest that the preoperative evaluation of circulating NK cells in gastric cancer patients may be beneficial to assess the extent of nodal metastasis, the degree of tumor invasion, and peritoneal dissemination.

Adult↗
PubMed1991

Periodontal status of patients with Sjögren's syndrome: a cross-sectional study.

Sjögren's Syndrome (SS) is a chronic inflammatory disease characterized by xerostomia. Although it is confirmed that a common observation in SS is increased susceptibility to caries, the degree of influence of SS on periodontal disease has not been well-described. The purpose of this study was to determine the periodontal status of 14 SS female subjects and 14 age-matched females, who did not exhibit SS (controls). The mean age of the SS and control subjects were 52.9 +/- 11.6 and 53.7 +/- 8.9, respectively. The plaque (PI), gingival (GI), bleeding (BI) and calculus (CI) indexes, as well as probing depth (PD) and attachment level (AL), were estimated on 7 index teeth. Data were analyzed by means of the Student t-test. The results indicated that there were no statistically significant differences between the SS and control groups: PI, PD and GI (p greater than 0.05); AL and CI (p greater than 0.1); and BI (p greater than 0.01). Thus, it may be concluded from this study that Sjögren's syndrome has no observable influence upon the indices measured in evaluating periodontal disease.

Adult↗
PubMed1991

Inhibitory effect of stannous fluoride and other commonly used antimicrobial agents on oral bacteria.

The purposes of this investigation were to evaluate and compare the antimicrobial effect of stannous fluoride (SnF2) gel and other commonly used oral antimicrobial agents/products. The antibacterial inhibitory effect of the various agents was evaluated by their effect against oral plaque bacteria including strains of Streptococcus sanguis, Streptococcus sobrinus, Actinomyces viscosus, Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius. A lawn of the specific bacteria to be tested was placed onto blood agar plates. Wells were then punched into the agar and each well was filled with 75 microliters of one of the antimicrobial products or control solutions. A positive control was a 0.12% chlorhexidine solution and a negative control was physiological saline. Agar plates were incubated in an anaerobic chamber at 37 degrees C for 5-7 days. Zones of inhibition in the lawn of bacteria were measured by a boley gauge. Each experiment was performed in duplicate and mean zones of bacterial inhibition were determined. Only 0.4% SnF2 and 0.12% chlorhexidine were consistently more effective in inhibiting oral bacteria when compared with other commercial mouth rinses/agents which had any one of a variety of antimicrobial agents as ingredients (alpha = 0.05). This in vitro study demonstrates that stannous fluoride gel is as effective as chlorhexidine in inhibiting the growth of bacteria often found in dental plaque.

Anti-Bacterial Agents↗