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X T Li

Publications and source records attributed to X T Li.

At least 37 records · Page 2Linked to original sources
PubMed1996

Effects of tetrandrine on cytosolic free calcium in cultured rat myocardial cells.

AIM: To study the effects of tetrandrine (Tet) on myocardium. METHODS: Using Fura 2-AM and AR-CM-MIC cation measurement system, cytosolic free calcium ([Ca2+]i) was examined in cultured rat single myocardial cells. RESULTS: The resting [Ca2+]i was 90 +/- 12 nmol.L-1 in the presence of Ca2+ 1.3 mmol.L-1 in Hanks' solution. Tet 1-100 mumol.L-1 had no effect on the resting [Ca2+]i, but 10-100 mumol.L-1 depressed the [Ca2+]i elevation when extracellular Ca2+ was 5 mmol.L-1. Tet 1-100 mumol.L-1 inhibited KC1 (30 and 60 mmol.L-1) induced [Ca2+]i elevation in a concentration-dependent manner, the IC50 value was 8.8 mumol.L-1 (95% confidence limits: 3.3-23.7 mumol.L-1) and 6.9 mumol.L-1 (95% confidence limits: 2.8-17.4 mumol.L-1), respectively. Norepinephrine (NE) 10 mumol.L-1 caused a rapid increase in [Ca2+]i in the presence or absence of extracellular Ca2+, Tet 30-100 mumol.L-1 only decreased the former. Tet 10-100 mumol.L-1 also decreased ouabain (Oua)-induced elevation in [Ca2+]i. CONCLUSION: Tet had inhibitory effects on Ca2+ transmembrane movement, but it is not a selective calcium channel blocker in rat myocardial cells.

Alkaloids↗
PubMed1995

[Effects of tetrahydroprotoberberines on cytosolic free calcium in cultured rat single myocardial cells].

Effect of tetrahydroberberine (THB), l-tetrahydropalmatine (THP) and l-stepholidine (SPD) were supposed to be related to the blocking of calcium influx. In this paper, using Fura-2/AM and AR-CM-MIC cation measurement system, the effects of THB, THP and SPD on cytosolic free calcium ([Ca2+]i) in cultured rat single myocardial cells were examined and compared with verapamil (Ver). THB, THP and SPD (10-100 mumol.L-1) were found to increase resting [Ca2+]i gently, which was not depressed by tetrodotoxin. THB, THP and SPD (1-100 mumol.L-1) were also shown to inhibit the KCl-induced [Ca2+]i elevation, the IC50 values of THB and SPD were 50.9 (95% confidence limits: 18.5-140) mumol.L-1 and 23.5 (95% confidence limits 7.6-73.4) mumol.L-1, respectively. THB, THP and SPD 30 mumol.L-1 were also shown to inhibit the elevation of [Ca2+]i induced by high extracellular calcium and norepinephrine; but the inhibitory effects of these drugs were weaker than those of Ver. The three compounds showed no significant effect on ouabain induced [Ca2+]i increase. These results suggest that the inhibitory effects of THB, THP and SPD on [Ca2+]i in myocite by blocking voltage-dependent calcium channels were similar but inferior to Ver.

Animals↗
PubMed1994

[Prophylactic effects of zhuling and BCG on postoperative recurrence of bladder cancer].

The prophylactic effects of Chinese herbal medicine Zhuling (Grifola umbellata pilat) and BCG on bladder cancer after TURBT and partial cystectomy were evaluated. 146 patients with bladder cancer were divided into 3 groups, Zhuling, BCG, and control group. Follow-up for 48-124 months (average 70.8 months) showed that the tumor recurrence rate was 33.3%, 34.3% and 65.1%, respectively. Compared to the control group, the recurrence rate of Zhuling group and BCG group was significantly decreased (P < 0.01). The effect of Zhuling was similar to that intravesical BCG. Zhuling was cheaper and convenient in usage, and no side effects.

Administration, Intravesical↗
PubMed1994

[Double J stent for pelvis-ureter junction stricture].

Twenty-one patients (27 ureters) with pelvis-ureter junction stricture were treated by persistent dilatation with indwelling double J stent in the ureter. The double J stents were inserted by means of retrograde cystoscopic approach. The duration of stents left in the ureters was 3 approximately 12 months. Follow-up for 5 approximately 36 months after removed the double J stents showed the extinction of the symptoms, remission of the hydropyonephrosis and improvement of the renal function. The excretion urography and retrograde pyelography showed improvement of stricture in 25 ureters. We suggest that persistent dilatation with double J stent be used as first choice for treatment of pelvis-ureter junction stricture.

Adolescent↗
PubMed1994

[Squamous cell carcinoma of urinary epithelia: report of 15 cases].

From May 1983 to 1992, 15 patients with urinary epithelial squamous cell carcinoma in renal pelvis (7) and in bladder (8) were treated. Eleven of them were complicated by urinary tract stone. Of the 15 patients, 8 were misdiagnosed as having simple urinary stone and 1 renal tuberculosis. It is suggested that active treatment for urinary stones be used to prevent the occurrence of squamous cell carcinoma and that possibility of concomitant epithelial tumor in patients with long-term and large urinary stones be considered.

Aged↗
PubMed1990

[Anticancer spectrum of pingyangmycin in vitro].

Pingyangmycin (PYM), produced by Streptomyces pingyangensis n. sp., was found to be identical to bleomycin A5. In the present study, a comparative observation was carried out in 10 human cancer cell lines. As determined by a colony-forming assay, the dose-response curves obtained from cells exposed to PYM for 1 h were of one type only: biphasic exponential. The sensitivities of these cells derived from different types of tumors, however, varied with a broad range of ID50 values (0.03-0.82 microgram/ml). A hepatoma cell line (BEL-7402) and three lines derived from squamous carcinomas of the esophagus (Eca109 and CaEs17) or the nasopharynx (CNE) were relatively sensitive (ID50 less than 0.20 microgram/ml) to PYM which is known to have clinical activity against these diseases. Two gastric adenocarcinoma cell lines (MGc80-3 and BGC-823) and a pulmonary adenocarcinoma cell line (SPC-A-1) appeared to be less sensitive to the drug, with ID50 values of 0.21-0.47 microgram/ml. PYM was 7-fold more effective against LTEP-78 cells derived from pulmonary squamous carcinoma as opposed to SPC-A-1 cells, resulting in a low ID50 value of 0.04 microgram/ml. However, PYM as a single agent has not yet received full evaluation in relation to this type of lung cancer. In contrast with other cell lines of squamous cancer origin, HeLa and CC-801 cells derived from uterine cervix carcinomas which have been evaluated as highly responsive to PYM had the highest ID50 values (greater than 0.70 microgram/ml).

Adenocarcinoma↗
PubMed1989

[Chemosensitivity of MGc 80-3 human gastric adenocarcinoma cells and its clinical significance].

The survival curves of MGc80-3 cells exposed for 24 hr to various concentrations of 10 anticancer drugs were obtained by means of colony-forming assay. Comparison of drug doses required to reduce cell survival by 90% (ID90) with the clinically achievable peak plasma drug concentration (PPC) showed that MMC, ADM, and 5-Fu had strong cytotoxicity (PPC/ID90 = 18-36), whilst the other drugs were less effective (PPC/ID90 less than or equal to 11). The fact that MMC, ADM, and 5-Fu are most effective in the treatment of gastric cancer suggests that the cell line MGc 80-3 may still retain its original drug sensitivity which is consistent with that noted in clinical gastric cancer. This cell line could be useful in screening for new compounds with activity against this disease.

Adenocarcinoma, Mucinous↗
PubMed1989

[Clinical evaluation of renal autotransplantation in renal vascular hypertension].

From 1976 to 1984, 22 cases of renal vascular hypertension were treated with renal autotransplantation. 20 cases have been followed up for 3-11 years, 17 cases of them over 5 years. The results showed that 14 cases were cured, 5 cases relieved, 1 cases ineffective. 19 cases of these patients suffered from large arteritis, 3 cases from atherosclerosis. The clinical efficacy of the former was better than the later. Our results suggest that the clinical efficacy has nothing to do with the course of disease. For bilateral renal arteriostenosis, as long as the extent of contralateral arteriostenosis do not exceed by 50%, good result can be achieved by means of renal autotransplantation for more severe side arteriostenosis.

Adolescent↗
PubMed1986

[Comparison of in vitro assays for the cytotoxic effect of anticancer drugs].

The cytotoxic effects of three anticancer drugs, methotrexate (MTX), 5-fluorouracil (5-Fu) and oridonin (Rub A), were investigated using a human gastric adenocarcinoma cell line (MGc80-3) and a human esophageal cancer cell line (CaEs-17) by means of colony-forming assay, dye exclusion test, measurement of incorporation of 3H-thymidine into DNA and examination of mitotic index. MGc80-3 cells, exposed for 24 hr to increasing concentrations of MTX (0-1.6 micrograms/ml), 5-Fu (0-12 micrograms/ml) or Rub A (0-25 micrograms/ml), showed different types of dose-survival curves determined by colony-forming assay. It suggests that these drugs have different models of action. The killing effect of MTX and 5-Fu was obviously underestimated by dye exclusion; the cell numbers were reduced to about 30% and 60% of control, while the colony formation showed approximately 2.5 and 3.5-log kill. When CaEs-17 cells exposed for 6 hr to varying concentrations of Rub A (0-15 micrograms/ml), the reduction in cell number (15 micrograms/ml, T/C = 18.0%) was always less than that (15 micrograms/ml, T/C = 3.8%) in colony formation. Under the same condition, the mitotic index, however, increased with increasing dosage first, and then the T/C values, at higher concentrations (5-15 micrograms/ml), reached approximately 200%. Although the drug significantly inhibited the incorporation of 3H-thymidine, the pattern of the dose-response curve differed from the dose-survival curve. These findings in cytobiochemistry and morphology may contribute to explain the cytotoxicity of an anticancer drug, but failed in correlation with the data obtained by colony-forming assay which seems to be the most reliable method for determining drug-induced cell lethality.

Adenocarcinoma↗
PubMed1985

Identification of anthracycline analogues with enhanced cytotoxicity and lack of cross-resistance to adriamycin using a series of mammalian cell lines in vitro.

Clinical resistance to adriamycin (ADR) develops readily, and cardiotoxicity is a major dose-limiting side effect. A range of anthracycline derivatives have been synthesized recently, and a number reported to exhibit significantly reduced cardiotoxicity in experimental animals. Using NIL 8 Syrian hamster overy cells and two continuous human tumour cell lines derived from colon carcinomas we have screened a series of 11 anthracycline analogues, determining their in vitro cytotoxic effects by colony-forming assays. Five agents proved significantly more cytotoxic than ADR: dihydroxyanthraquinone (DHAQ), mitoxantrone (DHAD), 4-demethoxydaunorubicin (4-DNR), 4'-0-tetrahydropyranyl-adriamycin (THP-ADR), and 4'-deoxyadriamycin (4-ADR). We have also established in vitro a subline of the L5178Y murine lymphoma resistant to ADR and have used this model to identify derivatives with potential value for overcoming ADR resistance. We have observed three patterns of response: (i) complete cross-resistance with 4'-epiadriamycin and daunorubicin; (ii) slight cross-resistance with 4-DNR, THP-ADR, 7-con-O-methyl-nogarol and aclacinomycin A; and (iii) complete absence of cross-resistance with 4-ADR, 4'-O-methyladriamycin, DHAQ, DHAD, and methylhydroxyellipticinium. These straightforward preclinical screens thus identify three drugs which may merit clinical evaluation, since they not only show an increased level of cytotoxicity in vitro to ADR at equivalent concentrations but also overcome resistance to ADR in this murine model system.

Animals↗