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Biomedical subjects

W J Li

Publications and source records attributed to W J Li.

At least 19 recordsLinked to original sources
PubMed1998

Chromosomal aberrations induced by 12C6+ heavy ion irradiation in spermatogonia and spermatocytes of mice.

The testes of Kun-Ming strain mice were radiated with different doses of 12C6+ ion or 60Co gamma-ray. Chromosomal aberrations induced in spermatogonia and spermatocytes were analyzed by the air-drying method. The relative biological effectiveness (RBE) of 12C6+ ion was calculated with respect to 60Co gamma-ray for the induction of chromosomal aberrations. The 12C6+ ion and 60Co gamma-ray dose-response relationships for chromosomal aberrations were plotted by linear quadratic models. The results showed that there was an increase in frequency of chromosomal aberrations in all the treated groups compared to controls. The RBE values were 1.67 for aberrations of spermatogonia and 1.66 for aberrations of spermatocytes for a dose of 2.0 Gy. Moreover, a different distribution of the various types of aberrations has been found for 12C6+ ion and 60Co gamma-ray irradiations. The dose-response relationships for 12C6+ ion and 60Co gamma-ray exhibited negative curvature in both spermatogonia and spermatocytes groups: the frequencies of aberrations increased sharply at low doses and exhibited less sharp increases for higher doses, which may be related to an interaction between the chromosomal damage and a block in cell cycle. Our results may provide useful information for the assessment of genetic risks of humans exposed to heavy ions.

Animals↗
PubMed1998

Effects of pre-exposure of mouse testis with low-dose (16)O8+ ions or 60Co gamma-rays on sperm shape abnormalities, lipid peroxidation and superoxide dismutase (SOD) activity induced by subsequent high-dose irradiation.

PURPOSE: To investigate the effects of pre-exposure of mouse testis with low-doses of (16)O8+ ions or 60Co gamma-rays on sperm shape abnormalities, lipid peroxidation and superoxide dismutase (SOD) activity induced by subsequent high-dose irradiation. MATERIALS AND METHODS: Testes of the B6C3F1 hybrid strain mice were pre-irradiated with 0.05 Gy of (16)O8+ ions or 60Co gamma-rays and then after 4 h given a test irradiation with 2 Gy of the same radiation type. SOD activity and thiobarbituric acid reactive substances (TBARS) in the testes were determined by spectrophotometric and TBA methods respectively at 4 h after irradiation. Testis weight, sperm count and sperm morphology were analysed at day 35 after irradiation. RESULTS: Compared with controls, there was a significant increase in SOD activity and a significant decrease in TBARS level of pretreated testes. Testis weight loss, sperm count reduction and sperm abnormalities were significantly lower in the pretreated testes. The bioeffects of a 2 Gy dose of (16)O8+ ions relative to 60Co gamma-rays were 1.84 +/- 0.28 for testis weight, 1.22 +/- 0.25 for sperm count and 1.29 +/- 0.10 for sperm abnormalities. CONCLUSIONS: These data suggest that pre-exposure of testes with a low dose of heavy ions or gamma-rays renders the organ more resistant to subsequent high-dose irradiation. The increase of SOD activity and the decrease of lipid peroxidation levels induced by low-dose ionizing irradiation may be involved in this resistance. The effects with heavy ion irradiation were greater than with gamma-rays.

Animals↗
PubMed1994

The production and preclinical characterization of a chimeric anti-breast-cancer antibody, cBC2.

A chimeric (mouse-human) BC2 antibody (cBC2) was produced which may be used in the diagnosis and treatment of breast cancer. The BC2 variable region genes were amplified by polymerase chain reaction (PCR), using oligonucleotide primers homologous to the framework sequences of mouse VH and V kappa genes. The PCR products were used to create cBC2 expression vectors containing the mouse BC2 VH and V kappa and human constant region (IgG1 and K) genes. Chimeric antibody was produced following transfection of these constructs into Sp2/0 myeloma cells. Binding assays in vitro demonstrated that cBC2 had the same specificity for human milk fat globule membrane (HMFGM) and MUC1+ cells as mBC2, and bound antigen with a similar affinity (cBC2, Ka 5.53 +/- 2.09 x 10(8); mBC2, Ka 1.44 +/- 0.98 x 10(9)). Functionally, only cBC2 (5-25 micrograms ml-1), was able to mediate antibody-dependent cellular cytotoxicity (ADCC) with human effector cells, with 25% maximal specific lysis of MUC1+ cells at an E/T ratio of 100:1. Human complement-mediated lysis was minimal (10-15% specific lysis) with both mBC2 and cBC2. Neither cBC2 nor mBC2 was able to inhibit tumour growth in vivo in the absence of covalently coupled anticancer drugs. However, biodistribution studies demonstrated that both antibodies preferentially targeted MUC1+ tumour cells, with 17% of the injected dose of cBC2, as compared to 27% of mBC2, localized to the MUC1+ tumour at 24 h (less than 6% detected in any other tissue).

3T3 Cells↗
PubMed1994

[Medullipin].

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Animals↗
PubMed1994

[Target therapy by monoclonal antibody against ovarian carcinoma conjugated with liposomes and adriamycin].

Conjugates of monoclonal antibody COC166-9 and adriamycin entrapped in liposome (MLA) were prepared in our laboratory. In vitro growth inhibition of SKOV3 ovarian carcinoma cell line was carried out by MLA and controls. Target therapies by MLA, adriamycin, normal mouse IgG instead of MAb, and control were given for 24 nude mice models with subcutaneous human ovarian carcinoma xenografts and 16 ascitic ovarian carcinoma respectively. MLA group showed the best therapeutic effect than all the other groups which gave a helpful clue to clinical use.

Animals↗
PubMed1994

[Target therapy by monoclonal antibody against ovarian carcinoma conjugated with liposome and adriamycin].

Conjugates of monoclonal antibody (MAb) and adriamycin entrapped in liposome (MLA) were prepared by COC166-9. The MAb against ovarian serous adenocarcinoma was generated in our laboratory. Target therapies were done in nude mice model with subcutaneous tumor xenografts in 24 and ascitic carcinoma in 16 by MLA. The results demonstrated that MLA group presented the best therapeutic effect than all the other groups, which gave a very helpful clue to clinical target therapy of ovarian carcinoma in the future.

Animals↗
PubMed1994

[The induction of specific immunity to human ovarian carcinoma cells by anti-idiotypic antibodies].

Monoclonal anti-idiotypic antibodies, 6B11 and H12, were employed instead of the tumor antigen to induce a specific cellular immunity to ovarian carcinoma cell line SKOV3. 6B11 and 1H12 carring the internal image of ovarian carcinoma antigen. BALB/c mice were immunized with 6B11 or 1H12 and then the mouse foot pad was attacked by the injection of target cell SKOV3 to stimulate a specific delayed-type hypersensitivity (DTH). The results showed that 6B11 induced a severe foot pad swelling (Mean thickness 0.93mm) as seen in the positive control (P > 0.05) induced by ovarian carcinoma antigen; the 1H12 induced swelling was significantly lower than the positive control (P < 0.05). Both 6B11 and 1H12 expressed the effective responses only to SKOV3, but not to the unrelated target cells. Pathological examinations found that there was marked infiltration of inflammatory cells in foot pad of mice primed by 6B11, while by 1H12, only induced a narrow pathological changes. These observations indicated that there would be some essential differences between 6B11 and 1H12 in the behavior of inducing the specific DTH to SKOK3. And as an idiotypic vaccine, 6B11 would be more powerful against ovarian carcinoma.

Animals↗
PubMed1993

[Preparation of monoclonal antibodies against ovarian carcinoma bearing chemical drugs entrapped in liposomes and the cytotoxic tests to carcinoma cells].

Monoclonal antibodies COC166-9 were prepared bearing adriamycin and cis-Platinum entrapped in liposomes respectively as chemoimmunoliposomes MLA and MLP. In vitro growth inhibition of SKOV3 ovarian carcinoma cell lines were tested by MLA and MLP. The results showed that MLA had the same cytotoxic effects as single adriamycin (ADM) in high concentration. However MLA was much stronger than ADM if in low concentration. There was no difference between MLP and single cis-Platinum, of which neither were sensitive to SKOV3 cells.

Antibodies, Monoclonal↗
PubMed1993

[Prevention of fetal growth retardation by low dose aspirin].

A prospective randomized, double-blinded, controlled clinical trial was conducted in 84 pregnant women with high risk of intrauterine growth retardation (IUGR). From the 28th to 30th week of gestation, low dose aspirin 75 mg/day (study group, n = 40) or placebo (control group, n = 44) was given consecutively for 6 to 8 weeks. It was found that the mean value of systolic/diastolic ratio of umbilical artery flow velocity waveforms in the study group was significantly lower than that of the control group after drug use. The occurrences of IUGR and preeclampsia in the study group (7.5% and 10.0% respectively) were remarkably lower than those in the control group (27.3% of both). The adverse effects of low dose aspirin on both mother and fetus were not observed. These results suggest that low dose aspirin administration (75 mg/day) beginning at earlier stage of third trimester may improve the fetal placental circulation, and thus prevent IUGR and/or preeclampsia effectively.

Adolescent↗
PubMed1993

Target therapy of ovarian carcinoma by monoclonal antibodies bearing chemical drugs entrapped in liposomes.

Monoclonal antibody COC166-9 against ovarian carcinoma was conjugated with adriamycin or cisplatinum entraped in liposomes as immunochemical liposomes MLA and MLP respectively. MLA was shown to have the highest effect than adriamycin or other groups on SKOV3 (ovarian cancer cell line) growth inhibition. MLA was also used in target therapy on nude mice bearing human ovarian carcinoma by xenograft of SKOV3 cells. The observations of tumor volumes revealed that this target therapy other than the controls presents a significantly better result which gives a hopeful clue to ovarian carcinoma treatment.

Animals↗
PubMed1993

[Human ovarian epithelial adenocarcinoma with peritoneal metastasis and ascites established in murine models].

By means of SKOV3 subcutaneous xenografts in nude mice, both carcinoma cells and cell suspensions were administrated intraperitoneally to establish a model of metastatic ovarian carcinoma with ascites. The intraperitoneal metastasis and cancer cells in the ascitic fluid were all prove to be adenocarcinoma by microscopic and electromicroscopic examinations. The immunohistochemical and immunocytochemical stainings with monoclonal antibody COC166-9 were the same as SKOV3 cells. The median survival of these nude mice was 68.7 days. This may serve as a good experimental model for testing chemotherapy as well as immunotarget therapy. Similar results obtained by xenografts of OSC2. 40 nude mice were included in this study.

Animals↗
PubMed1992

Changes in serum fibronectin levels at delivery in pregnant women and their fetuses with idiopathic fetal growth retardation.

We determined maternal and neonatal umbilical artery serum concentrations of fibronectin (Fn) in 15 pregnant women with idiopathic IUGR (Intrauterine growth retardation) and 17 normal pregnant women at the time of delivery, by use of a rate nephelometric procedure. The results showed that the maternal serum levels of Fn in pregnant women with idiopathic IUGR were significantly higher than those in normal pregnant women at the time of delivery (P < 0.01), but umbilical artery serum concentrations in the two groups were not significantly different (P > 0.05), suggesting that the significant increase in maternal serum levels of Fn appeared to be related to uteroplacental vascular endothelial cell lesion, formation of microthrombi and deficiency of placental perfusion.

Adult↗
PubMed1992

Tetrodotoxin protects against acute ischemic renal failure in the rat.

Tetrodotoxin has been reported to cause prolonged systemic hypotension without resultant ischemic damage. We tested its ability to protect the kidney during 60 minutes of warm ischemia in uninephrectomized rats. Protection was observed when tetrodotoxin was given intravenously at two microgram./kg. and four microgram./kg. as assessed by serial plasma blood urea nitrogen and creatinine measurements over two weeks. Tetrodotoxin was protective when given immediately before or immediately after the ischemic period. The renal protection of tetrodotoxin was not due to its effects on renal nerves as renal denervation did not protect the kidney from the ischemic damage. The renal protective effects of four microgram. tetrodotoxin/kg. were similar to those of four mg. captopril/kg. but the combination of the two was paradoxically without effect. We tested whether tetrodotoxin and captopril chemically antagonized each other, but in the presence of tetrodotoxin, captopril was still a potent inhibitor of the conversion of angiotensin I to angiotensin II. These results indicate that tetrodotoxin could be useful in elucidating the sequence of events associated with ischemic-reperfusion renal injury and in identifying ways of preserving renal function during renal surgery.

Acute Kidney Injury↗
PubMed1992

[Cervical ripening and drug dilatation for birth control operations].

Cervical ripening in induced labor at second trimester of pregnancy was studied in 81 cases. The method consisted of injecting diazepam gel through Foley's catheter, into the extra-amniotic space, and at the level of cervical internal os. The cervix was found to be softened, the time interval between induction and onset of labor shortened and there was no cervical laceration. A comparison between the experimental and control groups showed significant difference. The use of suppositories for cervical dilatation in 719 cases of induced abortion and 34 cases of insertion and/or removal of IUD was also studied. The results were satisfactory. The mechanism of cervical dilatation and ripening with drug had been investigated at different periods of pregnancy and in non-pregnant women as well.

Abortion, Induced↗
PubMed1991

[Selenium content and glutathione peroxidase in erythrocytes from different populations in areas with high and low mortality of esophageal cancer].

The effects of selenium (Se) concentration and glutathione peroxidase (GSH-Px) activity in the development of esophageal cancer was studied. The results indicated that there were no significant differences in Se level (P greater than 0.2) and GSH-Px activity (P greater than 0.1) in the normal subjects from areas with high and low esophageal cancer mortality. In an area with high esophageal cancer mortality, the Se level and GSH-Px activity of the normal, mild hyperplasia, severe dysplasia and cancer groups decreased gradually. There was a significant difference in the erythrocyte Se concentration of the normal and severe dysplasia groups (P less than 0.03). Erythrocyte Se concentration and GSH-Px activity were significantly lower in the cancer group than in the normal group (P less than 0.001; P less than 0.03). The findings suggest that low erythrocyte Se level and GSH-Px activity were the results of carcinogenesis rather than a cause.

Erythrocytes↗
PubMed1991

[Eighty cases of alveolar hydatid disease treated with albendazole].

Alveolar hydatid disease occurs frequently in Xiji County of Ningxia. 80 cases of the disease were treated orally with albendazole from 1985 to 1988 and the short-term results proved satisfactory. The treatment consisted of two groups. Group I included 72 cases which were orally given 8-10 mg/kg.d of albendazole 2 to 3 times a day after each meal for 30 days and then stop taking the medicine for 10 days as one treatment course. The treatment continued 3-12 months comprising about 24 courses were given with the highest dosage of 412g. Group II included 8 cases who were given 15.6-20 mg/kg.d of the medicine for 14 days (one course) and every two weeks with a 10 days interval. The treatment of group II continued 3-6 months which totalled 19-24 courses with the highest dosage of 270g. All the treated patients tolerate well except that a few of them felt giddy and had diarrhoea which disappeared after the withdrawal of medicine. Through 3-5 years, follow-up observation, it was found that the gener alsymptoms of the treated patients improved and their body weight increased by 2-9.5 kg, some of them could take part in light physical labour. The jaundice index in 80% of them returned to normal. SGPT in 86.4% decreased to within normal range. The enlarged livers in half of the patients decreased by 1-6 cm. 23.7% of the patients were reexamined by B ultrasound scanning which revealed that their enlarged liver reduced in size while the liquifaction area and the shadows of calcification in the livers in 42.5% patients increased obviously.

Adolescent↗