Search PubMed⌕ Search

Biomedical subjects

C Xu

Publications and source records attributed to C Xu.

At least 217 records · Page 12Linked to original sources
PubMed1997

Effects of zinc gluconate on nephrotoxicity and glutathione metabolism disorder induced by cis-platin in mice.

To examine the effects of zinc gluconate (ZG) on the nephrotoxicity of cis-platin (CDDP), changes in renal function and glutathione metabolism were investigated in mice. Fifty mice were randomly divided into five equal groups: controls, CDDP group and three ZG plus CDDP groups; the dose of ZG was 100 mg, 140 mg and 180 mg/kg respectively. Mice were sacrificed after 48 hours of CDDP (9 mg/kg) treatment; the levels of serum creatinine (Cr) and blood urea nitrogen (BUN) were measured, the glutathione (GSH) and malondialdehyde (MDA) content and the activities of glutathione peroxidase (GHS-PX) and catalase (CAT) in whole blood and renal tissue were assayed. Compared to the control group, there were significant increases in Cr, BUN and MDA, and decreases in the activities of GSH-PX in the CDDP group in whole blood and renal tissue. Preadministration of ZG at the doses of 140 mg/kg and 180 mg/kg significantly increased the concentration of GSH in whole blood, and decreased the levels of Cr and BUN, and the MDA content in whole blood and renal tissue, compared with the CDDP group. We conclude that preadministration of ZG might improve renal function and glutathione metabolism and reduce the nephrotoxicity of cis-platin.

Animals↗
PubMed1997

The effects of dietary soybean versus skim milk protein on plasma and hepatic concentrations of zinc in veal calves.

We assessed the zinc status of veal calves that were fed milk replacers containing either skim milk protein as the sole source of protein or a mixture of skim milk protein and soybean protein. After the milk replacers had been fed for 26 wk, mean body weight gain was 3 kg lower for calves fed the skim milk plus soybean proteins; this decrease was not significant. Inclusion of dietary protein from soybeans versus milk protein alone reduced plasma concentrations of zinc by 43% and reduced hepatic concentrations of zinc by 81%. The impairment of zinc status that was induced by the inclusion of soybean protein was probably caused by its phytate component. The effect of soybean protein on zinc status was rather specific because plasma and hepatic concentrations of copper were unaffected. Despite the high concentration of zinc (142 mg/kg of dry matter) in the milk replacer that contained milk plus soybean proteins, calves displayed a shortage of zinc because their plasma and hepatic concentrations of zinc were significantly reduced.

Animal Nutritional Physiological Phenomena↗
PubMed1997

[Experimental study on the influence of sodium glutamate on embryonal brain development of mouse].

The main component of gourment powder is a typical excitatory amino acid. Its neurotoxic action has been attended extensively. Healthy Kunming strain mice were used in this study. Sodium glutamate was injected into peritoneal cavity from the fourth day of gestation (at dosages of 60, 30 or 10 mg/kg every other day). The embryonal mice were dissected at the eighteenth day of gestation. The brain of embryonal mouse was removed, weighted, and fixed in Carnory's solution. Routine paraffin section was made. HE, Feulgen and Nissl staining methods were used for morphological observation. The ash values of 100 neurons of cerebral cortex of Feulgen and Nissl staining were randomly measured with an automated image analyser. The results showed that there was no morphological change in the experimental and control group. There was no significant differece between experimental groups and control group in the parameters observed (P > 0.05). It was suggested that sodium glutamate was not harmful to embryonal brain development of mouse.

Animals↗
PubMed1997

[The role of insulin resistance in the clustering of cardiovascular risk factors].

The coexistence of multiple cardiovascular risk factors in the same individual is called a clustering of cardiovascular risk factors. Many studies have shown that this phenomenoa is associated with a increased morbility of cardiovascular disease, and insulin resistance may be the common link between the risk factors. This study was designed to link the clustering of cardiovascular risk factors with insulin resistance. Using a new insulin sensitivity index [-log (fasting serum Glu x Ins)] to evaluate the insulin resistance, we investigated the relationship between the insulin sensitivity and cardiovascular risk factors in 106 patients with hypertension or coronary heart disease and 32 normal subjects. The normal group without cardiovascular risk factors was selected as controls. The individual with 2 risk factors were defined as having mild clustering, and those with > or = 3 risk factors as severe clustering. As the number of risk factors increased from 1 to > or = 3, the insulin sensitivity index increased from -1.69 +/- 0.24, -1.95 +/- 0.17 to -2.14 +/- 0.21 respectively. The insulin resistance was positively correlated with serum uric acid in women (P < 0.05), but not in men (P > 0.05). The insulin sensitivity was more decreased in postmenopausal than in pre-menopausal women. The insulin sensitivity index was -2.23 +/- 0.39 vs -1.73 +/- 0.13 (P < 0.05). The insulin resistance is associated with a clustering of risk factors of cardiovascular disease, more cluste-ring, more resistant.

Adult↗
PubMed1997

[Efficacy of dihydroartemisinin in treatment of 37 malaria cases].

Dihydroartemisinin is an efficacious derivative of artemisinin which can be taken orally in treatment of malaria with less side reactions. Thirty-seven cases with malaria were treated with this drug in Beijing and in Ruili City, Yunnan Province. Out of them, 25 cases suffered from falciparum malaria with an average parasitemia of 73,218/microliter and 12 from vivax malaria with an average parasitemia of 4,950/microliter. The dosage was 60 mg daily or 2 mg/kg for paediatric patients for 7 successive days with the first dose doubled. All the patients were clinically cured after treatment. Fever subsided 22-72 hours after the beginning of treatment in falciparum malaria patients with an average fever clearance time of 36.24 +/- 15.30 hours and their parasite clearance time was 24-72 hours with an average parasite clearance time of 44.80 +/- 19.09 hours. One of them had recrudescence 19 days after the disappearance of parasites, hence the recrudescence rate of falciparum malaria was 4.8%. Five early cerebral cases in this series were completely cured after the treatment. All the 12 cases with vivax malaria were also clinically cured after treatment, but 1 case had relapse 35 days after treatment. This patient was completely cured with another course of dihydroartemisinin combined with primaquine. All patients tolerated well the oral administration of dihydroartemisinin and no significant side reactions were seen.

Adolescent↗
PubMed1997

[Effect of monaural cochlear ablation on cell areas of ventral cochlear nucleus neurons in neonatal and adult guinea pigs].

The changes of the cross-sectional areas of anteroventral cochlear nucleus (AVCN) and posteroventral cochlear nucleus (PVCN) were studied in neonatal and adult guinea pigs after monaural cochlear ablation with computer imaging analysis system. The cross-sectional areas of neurons in AVCN and PVCN were not significantly changed after 24 h of monaural cochlear ablation in neonatal guinea pigs. But the cell areas of AVCN neurons of ablated side were respectively reduced by 20.93%, 25.70% and 28.72% compared to non-ablated side in 4 d, 7 d, 60 d after cochlear ablation, the cell areas of PVCN neurons were reduced by 17.58%, 20.30% and 38.55% respectively. The area reduction of AVCN and PVCN neurons of ablated side in 60 d group with monaural cochlear ablation were 51.00% and 32.75% relative to normal control group. Our results showed that cochlear ablation could results in rapid cell area reduction of VCN neurons in guinea pigs. Our investigation implied that it is important to stimulate the auditory nerve early in the patients with hearing loss.

Animals↗
PubMed1997

[Mechanism of protective action of Phyllanthus urinaria L. against injuries of liver cells].

It has been found out that the carbon tetrachloride (CCl4)-induced increase of serum glutamic-pyruvic transaminase (ALT) and elevation of MDA in liver of mice are significantly lowered by Phyllanthus urinaria in vivo, and the coincubation of isolated rat hepatocytes with Phyllanthus urinaria in vitro significantly inhibits CCl4-induced decrease of mobility of membrane of liver cells and increase of intracellular free Ca2+ ([Ca2+]i) concentrations of liver cells. These results suggest that the anti-lipid peroxidation effect and protective action of membrane of Phyllanthus urinaria may be related to its protective action against CCl4-induced liver injuries.

Alanine Transaminase↗
PubMed1997

The mechanism of inhibition of DNA synthesis by HH07A, a derivative of hainanensine.

The synthesis of DNA, RNA and protein in L1210 cells was inhibited by HH07A in a dose-dependent and time-dependent way. HH07A showed much stronger inhibitory effect on [3H]-thymidine incorporation than that on [3H]-uridine or [3H]-tyrosine incorporation. The methods of shift of absorption spectrum, shift of fluorescence emission spectrum and excitation spectrum, and isotope technique were used to investigate the mechanism of action of HH07A on DNA synthesis. The results suggested that the action of HH07A on DNA synthesis was not probably due to direct damage to the DNA template, it might mainly act by interfering with the metabolism of DNA.

Animals↗
PubMed1997

Experimental study on biodynamic response to vibration in human and animals.

In order to study the characteristics of human dynamic response to vibration, 56 subjects were exposed to vibration on X, Y and Z axes. It showed that there were two resonance peaks of most local parts of the human body. The curves of transmissibility are essentially the same in all the subjects. It was found that resonance frequencies of the human body decreased with increase of G levels of vibration. These characteristics were also proved in animals. Using three-level artificial neural network, common reflective relation of the resonance frequency with height and weight of the human body and exciting acceleration were obtained. The above findings might be applicable to studies of vibration ergonomics.

Acceleration↗
PubMed1997

[Somatic mutations of PIG-A gene in Chinese patients with paroxysmal nocturnal hemoglobinuria].

OBJECTIVE: To explore the somatic mutations of PIG-A gene in Chinese patients with paroxysmal nocturnal hemoglobinuria (PNH) and to compare these mutations with those in non-Chinese PNH patients. METHODS: Seven overlapping regions of PIG-A cDNA from granulocytes of 4 PNH patients were amplified by RT-PCR. The mutant segments were identified by HA/SSCP and then cloned and sequenced. RESULTS: In 4 Chinese PNH patients five small PIG-A mutations were found, including four single base substitutions (resulting in 1 consense mutations and 3 missense mutations) and one single base deletion causing a frameshift). These mutations were all different and distributed in different locations of the gene. CONCLUSION: The PIG-A mutations in our patients occurred at random sites and no mutation hot spot was found. Compared with Japanese, British, American and Tai patients, Chinese patients seem to have more single base substitutions and less frameshift. The pattern of mutations in our patients is similar to that in Japanese patients but different from that in other races. These suggest that mutagens might be different in the pathogenesis of PNH in different regions.

Asian People↗
PubMed1997

[The preliminary investigation on proliferative and survival capabilities of normal and abnormal mononuclear cells in bone marrow of patients with paroxysmal nocturnal hemoglobinuria].

OBJECTIVE: To unfold the proliferation and survival behavior of normal and abnormal early hematopoietic cells in paroxysmal nocturnal hemoglobinuria(PNH). METHODS: The bone marrow mononuclear cells (BMMNC) from 6 patients with PNH were separated into two subpopulations using CD59 monoclonal antibody combined with goat-anti-mouse IgG immunomagnetic beads, and then cultured in vitro. RESULTS: The BMMNCs from normal control had better proliferation capacity and stronger potential of suvival than both CD59(+) and CD59(-) BMMNCs from PNH patients. The CD59(+) BMMNCs from PNH patients, which should be expected "normal" in view of the CD59 expression, were surprisingly found to have less capabilities to form CFU-GM and BFU-E in semisolid cultures and less abilities of expansion and survival in liquid cultures than their CD59(-) counterparts. The CD59 expression of CD59(+) BMMNC in PNH patients diminished to some extent after a period of liquid culture while the normal control remained unchanged indicating that some of CD59 antigen on the cells were gradually lost during cultivation. CONCLUSION: In all cases of PNH studied, CD59(-) BMMNCs dominated hemopoiesis, and CD59(+) BMMNCs seems to have less potential to proliferate. The emergence of abnormal CD59(-) cells could not only result from PIG-A gene mutation but might also arise as the consequence of loss of GPI-anchored protein during the course of hematopoietic development and differentiation.

Animals↗
PubMed1997

[IR and UV-vis spectra of nitrogen-doped fullerene].

Nitrogen-doped fullerene derivative's IR and UV-vis spectra are reported. Some of the C60 IR silent modes are activated due to nitrogen atom reducing C60 molecular symmetry. UV-vis spectrum indicates nitrogen is donor.

English Abstract↗
PubMed1997

WIN 35,428 and mazindol are mutually exclusive in binding to the cloned human dopamine transporter.

It has been suggested that cocaine and mazindol bind to separate sites on the dopamine transporter. In the present study, we address this issue by examining the inhibition by mazindol of the binding of [3H]WIN 35,428 ([3H]2beta-carbomethyoxy-3beta-(4-fluorophenyl)-tropane), a phenyltropane analog of cocaine, and the inhibition by WIN 35,428 of [3H]mazindol binding to the cloned human dopamine transporter expressed in C6 glioma cells. The design involved the construction of inhibition curves at six widely different radioligand levels, enabling the distinction between the nonlinear hyperbolic competition (i.e., negative allosteric) model and the competitive (i.e., mutually exclusive binding) model. Nonlinear computer curve-fitting analysis indicated no difference in the goodness of fit between the two models; the negative allosteric model indicated an extremely high allosteric constant of approximately > or = 100, which practically equates to the competitive model. The present results suggest that complex interactions reported between cocaine and mazindol in inhibiting dopamine transport are beyond the level of ligand recognition.

Binding, Competitive↗
PubMed1997

[Dobutamine technetium-99m-MIBI spect in evaluating the effects of coronary interventional management].

OBJECTIVE: To evaluate the effects of coronary interventional management by dobutamine 99mTc-MIBI single photon emission computed tomography (Dobu-ECT). METHODS: Dobu-ECT was performed in pre- and post-interventional management of 32 patients. Dobutamine was administered intravenously at incremental rates from 5 to 40 micrograms x kg-1.min-1 at 3-minute intervals. At the highest infusion rate, 20 mCi 99mTc-MIBI was injected intravenously, and tomographic imaging was performed after one hour. Rest imagings were taken after 24 hours with a second dose of 99mTc-MIBI. RESULTS: In 32 patients accepting interventional treatment, within 3-6 months follow-up, the results of Dobu-ECT showed a total effectiveness rate of treatment was 68.1%. 27 patients of whose Dobu-ECT showed significant reversible defects before procedure, the effectiveness rate was 77.8% (21/26), 6 still had reversible ischemia within the follow-up period, and restenoses of 5 patients were confirmed by angiography. We also compared the effect of percutaneous transluminal coronary angioplasty (PTCA) with intracoronary stenting using Dobu-ECT. The results showed that intracoronary stenting was more beneficial than PTCA (81.3% vs 43.8%, P < 0.05) CONCLUSION: Dobu-ECT can be used to evaluate the effect of interventional management and detect restenosis after procedure.

Adult↗
PubMed1997

[Inhibitory effect of ganciclovir on the HSV1-tk positive subcutaneous tumors transplanted with human ovarian cancer in nude mice].

OBJECTIVE: To investigate the inhibitory effect in vivo of ganciclovir (GCV) on the growth of human ovarian cancer cells (AO) transducted with the thymidine kinase gene of herpes simplex virus I type (HSV1-tk). METHODS: Tumors were induced in nude mice by subcutaneous injection of AO cells and AO cells carried with HSV1-tk gene from China strain (AO/HSV1-tk cells). When the growing tumors were visible, GCV was injected daily into the peritoneum of the nude mice. RESULTS: The average weights of survived AO/HSV1-tkc tumors and AO tumors treated with GCV were 0.087 +/- 0.036 g and 0.661 +/- 0.260 g respectively. Most of the survived AO/HSV1-tkc cells treated with GCV were characterized by hypertrophy and necrosis, but their nuclear chromatins predominantely took the forms of heterchromatins. CONCLUSIONS: GCV could effectively inhibit the growth of HSV1-tk positive human ovarian cancer cells in vivo, but the nuclei of the survival tumor cells appeared to proliferate actively. As the same results of in vitro experiments, this may suggest that HSV1-tk/GCV gene therapeutic system might be combined with S-phase chemotherapy to increase the long-term effect.

Animals↗