Biomedical subjects

J X Liu

Publications and source records attributed to J X Liu.

At least 37 records · Page 2Linked to original sources

PubMed1999

Zinc sulphate solution enema decreases inflammation in experimental colitis in rats.

BACKGROUND: It has been reported that zinc sulphate contributes an anti-inflammatory action in many animal models; however, the impact of zinc in colitis remains unclear. The aim of the present study was to examine the role of zinc sulphate in experimental colitis. METHODS: Colitis was induced by 2,4,6-trinitrobenzenesulphonic acid (TNB) in rats. Beginning at the first day of TNB colitis, the rats were treated with a zinc sulphate enema once daily for 6 days. The rats were examined 8 days later. RESULTS: The TNB induced severe colitis as evidenced by increased mucosal lesion area, mucosal myeloperoxidase (MPO) activity and prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels. Six days after the application of the zinc sulphate enema, the mucosal lesion area, MPO activity, PGE2 and LTB4 levels all decreased significantly. Mucosal superoxide dismutase activity remained unchanged after zinc treatments. CONCLUSIONS: Our data suggest that zinc sulphate enemas have an anti-inflammatory action on experimental colitis.

Animals↗

PubMed1999

Spheres and prolate and oblate ellipsoids from an analytical solution of the spontaneous-curvature fluid-membrane model.

An analytic solution for the Helfrich spontaneous curvature membrane model [H. Naito, M.Okuda, and Ou-Yang Zhong-Can, Phys. Rev. E 48, 2304 (1993); 54, 2816 (1996)], which has the conspicuous feature of representing a circular biconcave shape, is studied. Results show that the solution in fact describes a family of shapes, which can be classified as (i) a flat plane (trivial case), (ii) a sphere, (iii) a prolate ellipsoid, (iv) a capped cylinder, (v) an oblate ellipsoid, (vi) a circular biconcave shape, (vii) a self-intersecting inverted circular biconcave shape, and (viii) a self-intersecting nodoidlike cylinder. Among the closed shapes (ii)-(vii), a circular biconcave shape is the one with a minimum of local curvature energy.

Biophysical Phenomena↗

PubMed1997

Urinary bladder-urethral sphincter dysfunction in mice with targeted disruption of neuronal nitric oxide synthase models idiopathic voiding disorders in humans.

Idiopathic voiding disorders affect up to 10-15% of men and women. We describe bladder abnormalities in mice with targeted deletion of the gene for neuronal nitric oxide synthase which model the clinical disorders. The mice possess hypertrophic dilated bladders and dysfunctional urinary outlets which do not relax in response to electrical field stimulation or L-arginine. The mice also display increased urinary frequency.

Animals↗

PubMed1997

[Effects of tongxinluo capsule on hemodynamics and myocardial oxygen consumption in dogs].

OBJECTIVE: To observe the effects of Tongxinluo (TXL) capsule on hemodynamics and myocardial oxygen consumption in dogs. METHODS: The coronary arterial arterial blood flow, cardiac output, left ventricular pressure, blood pressure, myocardial oxygen consumption of dogs were recorded by the polygraph system before and after intraduodenal administration of TXL. RESULTS: TXL 0.72 g/kg increased obviously the coronary arterial blood flow by 21.56% after administration, and the left ventricular work was increased simultaneously, the difference was significant (P < 0.01) as compared with the control group. CONCLUSIONS: TXL capsule could increase obviously the coronary arterial blood flow, dilate the coronary vessels, improve myocardial blood supply, increase left ventricular work, and result in the enhancement and readjustment of the "pump" function of heart and improvement of the intravascular stasis condition of blood circulation.

Animals↗

PubMed1997

[Effect of yifei kangliu yin on lung cancer metastasis and immune function].

OBJECTIVE: To explore the effect of Yifei Kangliu Yin (YFKLY) on metastasis of lung cancer and immune function. METHODS: (1) Observing remote metastasis of three groups (n = 94) lung cancer patients, measuring the activity of NK cell, and the levels of OKT3, OKT4 of the patients by radioimmunoassay, and doing compared analysis. (2) Observing the effect of YFKLY on C57 mice B16 melanoma, and examining T4, T8 around the foci of cancer metastasis by immunohistochemical method. RESULTS: YFKLY significantly reduced the incidence of remote metastasis in patients and reduced the metastasis foci numbers on C57 mice of B16 melanoma. It was found that NK cell activities, OKT3 and OKT4 in peripheral blood of patients significantly increased, the infiltration of T4 lymphocytes around the foci of cancer metastasis also increased. CONCLUSION: YFKLY had inhibitory effect on the metastasis of cancer cells. It had strengthened the immune functions, aroused the anti-tumor capability.

Adenocarcinoma↗

PubMed1997

[Effect of tongxinluo capsule on experimental myocardial ischemia, arrhythmia and hyperlipidemia].

OBJECTIVE: To study the effects of Tongxinluo capsule (TXLC) on experimental myocardial ischemia and infarction, arrhythmia and hyperlipidemia. METHODS: Using the methods of epicardial mapping and NBT-ink double staining and the ratio of tissue in myocardial infarction in which the anterior coronary artery was ligated in anesthetized dogs, acute myocardial ischemia was induced with pituitrin and hyperlipidemia was induced with feeding high lipid diet in rats, arrhythmia was induced with chloroform in mice. RESULTS: The TXLC reduced significantly the myocardial ischemic limits, degree and the myocardial infarction area, inhibited obviously the ocurrence of arrhythmia and reduced the level of hyperlipidemia. CONCLUSION: The TXLC could improve significantly the myocardial ischemia mycardial infarction and prevent obviously the ocurrence of arrhythmia and hyperlipidemia.

Animals↗

PubMed1997

[Study on therapeutic effect and immunological mechanism of fuzhengfang herbs in mice with Lewis lung cancer].

OBJECTIVE: To observe the therapeutical effect of Fuzhengfang (FZF). METHODS: Therapeutic effect of FZF herbs on mice with Lewis lung cancer was observed, and its regulation on function of red blood cell immune system of the mice was also studied. RESULTS: FZF herbs could inhibit the growth of tumor, and increase the weight of mice with Lewis lung cancer. The quality of life of the mice was improved after treatment with FZF herbs. FZF herbs could increase the activity of red blood cell C3b receptors, reduce the quantity of red blood cell immune complexes, elevate the immune adherent function of red blood cells to tumor cells, raise activity of red blood cell immune adherent enhancing factors in serum, and lower the activity of red blood cell immune adherent inhibitory factors. Chemotherapy could inhibit the growth of tumor, but decrease the weight of mice with Lewis lung cancer. The quality of life of the mice was decreased after chemotherapy. Chemotherapy could reduce the activity of red blood cell C3b receptors, increase the quantity of red blood cell immune complexes, depress the immune adherent function of red blood cells to tumor cells, lower the activity of red blood cell immune adherent enhancing factors in serum, and raise the activity of red blood cell immune adherent inhibitory factors in serum. There was a significant difference between FZF herbs and chemotherapy. CONCLUSION: FZF herbs have a positive therapeutic effect in mice with Lewis lung cancer, and its mechanism might be associated with improving function of red blood cell immune system of mice with Lewis lung cancer.

Animals↗

PubMed1996

Thymocyte apoptosis in response to low-dose radiation.

Thymocyte apoptosis was assessed by counting apoptotic bodies with flow cytometry (FCM) and measuring DNA fragmentation with fluorescence spectrophotometry (FSP). J-shaped dose-response curves were obtained after both whole-body irradiation (WBI) of mice and in vitro irradiation of EL4 cells with doses ranging from 0.025 to 4 Gy X-rays. There was a significant reduction of apoptosis rate to below control level with doses within 0.2 Gy, and a dose-dependent increase in apoptosis with doses above 0.5 Gy. When thymocytes were cultured 24 h after WBI with 75 mGy X-rays in complete RPMI 1640 medium, a reduction in apoptosis was observed in the course of incubation for 72 h, and the presence of Con A in the medium accentuated this reduction in a dose- and time-dependent manner. The implications of these observations and the possible molecular mechanisms for future studies are proposed.

Animals↗

PubMed1996

Effects of furosemide on intracochlear oxygen tension in the guinea pig.

The effects of intravenous furosemide on the perilymphatic oxygen tension of the scala tympani (OT) in the guinea pig and the relationship between changes in OT and changes in auditory cortical-evoked responses were studied, as well as changes in cochlear morphology. Furosemide in dosages of 25 mg/kg and 50 mg/kg caused a sharp decline in OT in addition to elevation of the threshold of auditory cortical-evoked responses. Ischemia of the cochlear stria vascularis was also found but without any damage of hair cells at the light microscopic level. Changes in OT were associated with transient threshold elevations and ischemia of the stria vascularis. Improvements in hearing were directly proportional to the recovery of OT.

Animals↗

PubMed1996

Nitric oxide-dependent penile erection in mice lacking neuronal nitric oxide synthase.

BACKGROUND: Nitric oxide (NO) has been implicated as a mediator of penile erection, because the neuronal isoform of NO synthase (NOS) is localized to the penile innervation and NOS inhibitors selectively block erections. NO can also be formed by two other NOS isoforms derived from distinct genes, inducible NOS (iNOS) and endothelial NOS (eNOS). To clarify the source of NO in penile function, we have examined mice with targeted deletion of the nNOS gene (nNOS- mice). MATERIALS AND METHODS: Mating behavior, electrophysiologically induced penile erection, isolated erectile tissue isometric tension, and eNOS localization by immunohistochemistry and Western blot were performed on nNOS- mice and wild-type controls. RESULTS: Both intact animal penile erections and isolated erectile tissue function are maintained in nNOS mice, in agreement with demonstrated normal sexual behaviors, but is stereospecifically blocked by the NOS inhibitor, L-nitroarginine methyl ester (L-NAME). eNOS is abundantly present in endothelium of penile vasculature and sinusoidal endothelium within the corpora cavemosa, with levels that are significantly higher in nNOS- mice than in wild-type controls. CONCLUSIONS: eNOS mediates NO-dependent penile erection in nNOS- animals and normal penile erection. These data clarify the role of nitric oxide in penile erection and may have implications for therapeutic agents with selective effects on NOS isoforms.

Animals↗

PubMed1996

[Effect of yuxintong capsule on plasma endothelin and serum nitric oxide in acute myocardial ischemia dogs].

Effect of Yuxintong (YXT) capsule on plasma endothelin(ET), serum nitric oxide (NO) and creatine phosphokinase (CPK) activity in experimental acute myocardial ischemia dogs were observed. The results indicated that in acute myocardial ischemia dogs, the serum CPK activity and plasma ET level increased and serum NO level decreased significantly. In comparing with control, YXT not only could reduce significantly the increased plasma ET content and serum CPK activity, but also increase markedly the producing and releasing of NO, P < 0.05-0.001. Therefore, it could protect the myocardia from ischemic damage, the efficacy of YXT was positively dose dependent.

Animals↗

PubMed1996

[Experimental study on inhibitory effect of yifei kangliu decoction on cell proliferation in lung cancer].

In this study, the inhibitory effect of Yifei Kangliu Yin (YFKL) was observed on growth of LAX-83 human lung adenocarcinoma in naked mice. It was found that the YFKL could suppress the tumor growth significantly with a suppression rate of 45.59%. It was also found that positive expression of Ki-67 and cell proliferation significantly decreased, c-myc changed from positive to weak positive and P53 from positive to negative in the YFKL treated group. It suggested that the inhibitory effect of YFKL on proliferation of cancer cells might be realized by way of changing the oncogenetic expression of cancer, so as to influence the cell proliferation directly.

Adenocarcinoma↗

PubMed1995

Nephrotoxicities of aluminium and/or cadmium-metallothionein in rats: creatinine excretion and metabolism of selected essential metals.

The effects of exposure to aluminium (Al) and cadmium (Cd) on urinary creatinine and protein excretion, and the concentrations of calcium, magnesium and copper in kidney and urine were studied in 32 male adult Wistar rats. The animals were divided into 8 groups, groups 1-4 given a calcium-deficient diet (0.01%, i.e. 0.01 g calcium/100 g diet weight) and groups 5-8 a calcium-adequate diet (0.9%) for 6 weeks. Single daily intraperitoneal injections of AlCl3 (10.8 mg Al/kg body weight, per day) were done on 6 consecutive days to groups 3, 4, 7 and 8 during the last week of the experiment. One single intraperitoneal injection of cadmium-metallothionein (Cd-MT, 0.4 mg Cd/kg) was administered 12 hr before the final Al dose to groups 2, 4, 6, and 8 and the rats were sacrificed 47 hr after the Cd-MT injection. The rate of creatinine clearance was significantly lower in rats injected intraperitoneally with either Cd-MT or Al, and the concentrations of magnesium and calcium in urine were lower in rats administered both Al and Cd-MT as compared to those in control groups. Histological examination showed that Al was toxic to the kidney tubule cells of rats, however, an adequate supply of calcium in food protected to some extent the renal tubules from Al toxicity as indicated by a higher creatinine clearance, and there was also less tubule damage as shown by histological examination. The copper concentrations in kidney tissue were lower in groups treated with either Al or Cd-MT.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗

PubMed1995

Reperfusion at reduced flow rates enhances postischemic contractile recovery of perfused heart.

The effects of reperfusion at reduced flow rates on postischemic cardiac contractile function were examined in perfused rat hearts. Isolated hearts were subjected to 35-min ischemia followed by reperfusion at the preischemic flow rate (9.0 ml.g-1.min-1; ordinary flow rate) or at reduced flow rates (0.9-8.1 ml.g-1.min-1). Reperfusion at ordinary flow rate did not generate any left ventricular developed pressure (LVDP), whereas reperfusion at reduced flow rates (0.9-7.2 ml.g-1.min-1) elicited 13-57% of initial contractile force at reperfusion's end; optimal recovery occurred at 3.6 ml.g-1.min-1 (reduced flow rate). Reduced flow rate reperfusion attenuated ischemia-reperfusion-induced increase in left ventricular end-diastolic pressure (LVEDP) and perfusion pressure (PP), alteration in tissue Na+, K+, Ca2+, and Mg2+, release of creatine kinase and ATP metabolites, and development of triphenyltetrazolium chloride-unstained areas. Enhanced postischemic LVDP recovery was inversely related to higher coronary PP at the initial stage (4 min) of reperfusion (r = -0.763). The benefit of reduced flow rate reperfusion could not be attributed to rate of calcium delivery to the heart, formation of oxygen free radicals in myocardium, endothelium-dependent coronary artery dilation, or LVDEP reduction. Enhancement of postischemic LVDP recovery was associated with attenuation of ischemia-reperfusion-induced increases in myocardial sodium and calcium; failure of postischemic LVDP recovery was accompanied by an increase. Reduction in sodium and calcium overload may underlie the beneficial effects of reduced flow rate reperfusion in ischemic-reperfused heart.

Adenosine Triphosphate↗

PubMed1995

[Effects of 24 Chinese medicinal herbs on nucleic acid, protein and cell cycle of human lung adenocarcinoma cell].

Using flow cytometry the authors analysed the effect of 24 Chinese medicinal herbs (CMH) in compound recipe on proliferation index (PI), DNA index, protein index and ratio of various phases in cell cycle of human lung adenocarcinoma cell (SPC-A-1), The PI were more than 20%, in 4 CMH, while 3 CMH such as Gynostemma pentaphyllum, Glehnia littoralis, Panax Ginseng, could strengthen the body resistance. That suggested using CMH of strengthening body resistance not only served as conventional tonice but also as tumor cell inhibitor. Meanwhile the action point of 24 CMH on cell cycle were different. Therefore according to these results a new recombined Chinese recipe would be more effectively used for clinical practice.

Adenocarcinoma↗

PubMed1995

A possible involvement of sodium channel blockade of class-I-type antiarrhythmic agents in postischemic contractile recovery of isolated, perfused hearts.

The present study was undertaken to test the hypothesis that the degree of sodium channel blockade by class-I-type antiarrhythmic agents accounts for enhancement of postischemic contractile recovery of ischemic/reperfused hearts. Electrophysiological studies showed that the class-I-type antiarrhythmic agents quinidine, disopyramide, procainamide, lidocaine, mexiletine, flecainide and pilsicainide suppressed the Vmax value of the rat left ventricular muscle cell, a marker of sodium channel blockade, in a concentration-dependent manner. Isolated rat hearts were subjected to 35 min of ischemia and 60 min of reperfusion. Postischemic contractile recovery, which was never detected in untreated hearts, was enhanced in hearts pretreated with these antiarrhythmic agents during the last 3 min before ischemia at concentrations ranging from 3 to 300 microM. Tissue Na, but not Ca, accumulation was also detected in the ischemic heart, and tissue Na and Ca accumulation was observed in the reperfused heart, which suggests that sodium overload occurs during ischemia, followed by sodium and calcium overload during reperfusion. The degree of postischemic contractile recovery seen in the presence of these antiarrhythmic agents was inversely related to tissue Na or Ca accumulation after reperfusion, which suggests that class-I-type antiarrhythmic agents inhibit sodium overload occurring in ischemic/reperfused myocardial cells. A close relationship between postischemic contractile recovery of the perfused heart and depression in the Vmax value of the ventricular muscle was also observed. These results suggest that the ability class-I-type antiarrhythmic agents to inhibit myocardial sodium channels plays a significant role in the enhancement of postischemic contractile recovery of the ischemic/reperfused heart.

Animals↗

PubMed1994

[Bacteriostasis of rhizoma Coptidis combined with trimethoprim (TMPO)].

The agar-dilution method was adopted to study contrastively the bacteriostasis of Rhizoma Coptidis and TMP, and also of the two drugs in combination. The results indicate that the combination works in good cooperation against Escherichia coli, Bacillus pyocyaneus, Staphylococcus aureus, Shigella flexneri and S. dysenteriae.

Anti-Bacterial Agents↗

PubMed1994

[The CD2, CD4 and CD8 mRNA expression of T lymphocytes in patients with acromegaly and hyperprolactinemia].

The CD2, CD4 and CD8 mRNA expression of human peripheral blood lymphocytes (HPBL) from 49 female patients with acromegaly and hyperprolactinemia and 15 healthy women were studied by dot blotting assay using corresponding CD2, CD4 and CD8 antisense RNA probes. It was found that CD2 mRNA expression increased in women with growth hormone over-expression and the ratio of CD4 and CD8 mRNA declined significantly in the women with prolactin over-expression. These suggested that the mRNA expression of these cluster differentiation antigens in peripheral T lymphocytes was affected by the pituitary hormones. The significance of these findings relevant to the study of the neuroendocrine and immune network was discussed.

Acromegaly↗