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Biomedical subjects

Z B Zhang

Publications and source records attributed to Z B Zhang.

At least 19 recordsLinked to original sources
PubMed2003

S-Nitrosoglutathione-induced mouse thymocyte apoptosis studied by fluorescence near-field scanning optical microscopy.

This study is an attempt to deeply understand the mechanisms ensuring self-tolerance of T cells via clonal deletion of thymocytes and exploring T lymophocyte homeostasis by observing the apoptosis of single mouse thymocyte induced by S-nitrosoglutathione (GSNO, a nitric oxide donor) using fluorescence near-field scanning optical microscopy (NSOM) in illumination mode. The GSNO-induced thymocytes were stained with propidium iodide containing 0.01% Triton X-100 and excited with light of 488 nm and the emitting fluorescence at 525 nm. According to the NSOM fluorescence image and the simultaneously obtained topography image, the feature of mouse thymocyte apoptosis was characterized by scattering pattern of the fluorescence spots with the size 0.2-2.1 micro m at the full width at half-maximum of fluorescence intensity 78-80 kHz in the GSNO-treated thymocyte nucleus. Whereas there is no fluorescence from the untreated thymocyte. The intensity of the fluorescence from the dexamethasone-treated thymocyte was much stronger than that from GSNO-induced thymocytes. Furthermore, the fluorescence distribution in the latter were concentrated in the nucleus. Those results also demonstrate the advantages of NSOM such as high spatial resolution and the topography of biology samples.

Animals↗
PubMed2001

Acceleration of atherogenesis by COX-1-dependent prostanoid formation in low density lipoprotein receptor knockout mice.

The cyclooxygenase (COX) product, prostacyclin (PGI(2)), inhibits platelet activation and vascular smooth-muscle cell migration and proliferation. Biochemically selective inhibition of COX-2 reduces PGI(2) biosynthesis substantially in humans. Because deletion of the PGI(2) receptor accelerates atherogenesis in the fat-fed low density lipoprotein receptor knockout mouse, we wished to determine whether selective inhibition of COX-2 would accelerate atherogenesis in this model. To address this hypothesis, we used dosing with nimesulide, which inhibited COX-2 ex vivo, depressed urinary 2,3 dinor 6-keto PGF(1alpha) by approximately 60% but had no effect on thromboxane formation by platelets, which only express COX-1. By contrast, the isoform nonspecific inhibitor, indomethacin, suppressed platelet function and thromboxane formation ex vivo and in vivo, coincident with effects on PGI(2) biosynthesis indistinguishable from nimesulide. Indomethacin reduced the extent of atherosclerosis by 55 +/- 4%, whereas nimesulide failed to increase the rate of atherogenesis. Despite their divergent effects on atherogenesis, both drugs depressed two indices of systemic inflammation, soluble intracellular adhesion molecule-1, and monocyte chemoattractant protein-1 to a similar but incomplete degree. Neither drug altered serum lipids and the marked increase in vascular expression of COX-2 during atherogenesis. Accelerated progression of atherosclerosis is unlikely during chronic intake of specific COX-2 inhibitors. Furthermore, evidence that COX-1-derived prostanoids contribute to atherogenesis suggests that controlled evaluation of the effects of nonsteroidal anti-inflammatory drugs and/or aspirin on plaque progression in humans is timely.

6-Ketoprostaglandin F1 alpha↗
PubMed2000

Comparison of genetically engineered microbial and plant phytase for young broilers.

This study was conducted to compare the efficacy of genetically engineered microbial (Natuphos) and plant (Phytaseed) phytase for enhancing the utilization of phytate P in corn-soybean meal-based diets fed to young broilers and to evaluate the safety of Phytaseed phytase. Three levels of each of the two sources of phytase (250, 500, and 2,500 U/kg of diet) were added to a corn-soybean meal basal diet containing 0.46% total P, 0.21% nonphytate P, and 0.92% Ca. There were eight cages per treatment (eight birds per cage for Weeks 2 to 3 and seven birds for Weeks 4 to 5), except for the basal diet without added phytase that had 16 cages. Cage BW and feed consumption were recorded weekly. During Week 5, cage excreta samples were collected for determination of apparent retention coefficients of DM, Ca, and P. At the end of Week 5, all birds were killed, and the left and right toes were removed for determination of toe ash weight and percentage. Forty birds (one per cage from the diet without added phytase and diets with 500 or 2,500 U phytase/kg from both sources) were randomly selected for gross necropsy and histologic evaluation of liver, kidney, and bone tissues. Addition of both sources of phytase resulted in similar increases (P < 0.05) of BW gain; feed intake; gain:feed; apparent retention of DM, P and Ca; and toe measurements. Phosphorus excretion decreased as phytase addition increased. No significant abnormalities were seen in any of the 40 broilers necropsied. Further, the fit of a nonlinear function revealed that most measurements reached a plateau at 2,500 U/kg. Based on performance, bone characteristics, and retention of P, Ca, and DM of young broilers, the efficacy of Phytaseed phytase was similar to that of Natuphos phytase for enhancing the utilization of phytate P in corn-soybean meal-based diets. General necropsy and histologic examination of liver, kidney, and tibial tissues revealed no adverse effects of phytase source or level.

6-Phytase↗
PubMed2000

Comparison of phytase from genetically engineered Aspergillus and canola in weanling pig diets.

Ninety-six crossbred pigs with an average weight of 9.0 kg were used in a 5-wk trial to compare the efficacy of genetically engineered Aspergillus ficuum phytase, expressed in Aspergillus niger (Natuphos) or in canola seed (Phytaseed), for enhancing the utilization of phytate P in corn-soybean meal-based diets fed to young pigs and to evaluate the safety of Phytaseed phytase. Three levels of the two sources of phytase (250, 500, or 2,500 U/kg of diet) were added to a corn-soybean meal basal diet containing .35% total P, .09% available P, and .50% Ca. There were six pens per treatment (one barrow and one gilt/pen), except that the diet without added phytase was fed to 12 pens of pigs. Pen feed consumption and BW were recorded weekly. During wk 5, pen fecal samples were collected for determination of apparent digestibilities of DM, Ca, and P. At the end of wk 5, all barrows were killed, and the 10th rib on both sides was removed for determination of shear force and energy. Thirty pigs (six from the diet without added phytase and the diets with 500 and 2,500 U/kg phytase from both sources) were randomly selected for gross necropsy and histologic evaluation of liver, kidney, and bone tissues. Both sources of phytase were equally effective in increasing (P < .05) daily gain, gain:feed, apparent digestibilities of DM, P, and Ca, and 10th rib measurements. Fecal P excretion was reduced with phytase addition. Feed intake was increased by phytase levels during wk 4 to 5. No significant abnormalities were seen in any of the 30 pigs necropsied. The fit of a nonlinear function revealed that most measurements were reaching a plateau at 2,500 U/kg phytase. In summary, based on performance, bone measurements, and digestibilities of P, Ca, and DM of young pigs, the efficiency of Phytaseed was similar to that of Natuphos for enhancing the utilization of phytate P in corn-soybean meal-based diets. General necropsy and histologic examination of tissues indicated no toxic effect of phytase.

6-Phytase↗
PubMed2000

Blood level of B and CD4+ lymphocytes measured before induction of an experimental tumor in rats predicts tumor progression and survival.

After an initial series of experiments indicated that early responses of B lymphocytes were important in controlling tumor metastases in two rat models of cancer (N. Quan et al., Cancer Res., 59: 1080-1089, 1999), the present study assessed whether differences in the number of B lymphocytes that are normally present in different individual rats before any tumor development could predict tumor growth, metastases, and length of survival when tumor challenge subsequently occurred. Repeated baseline measures of several circulating lymphocyte subtypes (i.e., natural killer, B, CD4+, CD8+ lymphocytes) were made in individual inbred WAG rats before any introduction of tumor cells, and stable baselines for these subtypes were found. Animals were then injected with 2 x 10(6) CC531 tumor cells (a syngeneic tumor) into the leg, and the size of the resulting primary tumor measured. Primary tumors were surgically removed 6-7 weeks after tumor-cell injection, and animals then followed until death from metastases. In two experiments, the size of the primary tumor as well as the length of time that animals survived correlated with the pretumor percentage of certain lymphocyte subtypes in peripheral blood before tumor-cell injection. Baseline percentage of B lymphocytes was significantly negatively correlated with the size of the primary tumor and was positively correlated with the duration of survival. Baseline percentage of CD4+ lymphocytes showed the opposite relationship, being positively correlated with tumor size and negatively correlated with survival time, although these correlations were lower than those for B lymphocytes. Percent B lymphocytes in circulation also declined during tumor development. In summary, a high percentage of endogenous peripheral blood B lymphocytes predicted growth of smaller primary tumors and longer survival after experimental tumor induction in a rat model, further suggesting that B lymphocytes are involved in protection against development of certain tumors.

Adenocarcinoma↗
PubMed2000

[Background analysis of chromosome controling genetic of water use efficiency of Triticum].

Water use efficiency (WUE) of flag leaf of different genetic material was measured by LCA-3 model photosynthesis apparatus. The results show as follows: The order of flag leaf WUE of different chromosome set is AA > BB > DD > RR. Among twenty Chinese Spring ditelosomic, the flag leaf WUE of A ditelosomic set is the highest, the high WUE genes locate on 1AL, 2AL, 2AS and 7AS chromosome arm. Among seven wheat-S. Cereals addition lines, the high WUE gene locates on 4R chromosome, the flag leaf WUE of 5R chromosome is the lowest. In the end of this paper, the research advance of stress resistance gene location on the fourth chromosome set of Triticum was discussed.

Chromosome Mapping↗
PubMed2000

[The development of a original multifunctional peritoneal biopsy needle].

A multifunctional peritoneal biopsy needle is introduced in this paper, which can be used for peritoneal biopsy, brush biopsy and routine, biochemical and cytological examination. The clinical applications show that it could raise markedly the diagnosis rate of ascites, and especially it has important clinic diagnosis value for tuberculous and cancer ascites, and primary peritonitis complicated by hepatocirrhosis. It is simple, safe and practical to operate this needle.

Ascites↗
PubMed1999

[Gas chromatographic and gas chromatography-mass spectrometric analyses of aromatic hydrocarbons in oils and rock extracts simultaneously by using bench-top gas chromatograph-mass spectrometer].

This article reports a successful example that an injected sample is simultaneously introduced into two fused silica capillary columns and detected separately by a flame ionization detector (FID) and an HP 5973 mass selective detector (MSD) both installed on an HP 6890 Gas Chromatograph. This GC and GC/MS analyses of aromatic hydrocarbons in oils and rock extracts were carried out by using this method and good results were achieved. This method is of great value in organic geochemistry research because it is efficient and economical.

English Abstract↗
PubMed1998

Effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride on heart function, lactate dehydrogenase and its isoenzymes in rats with cardiac hypertrophy.

AIM: To investigate the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on cardiac systolic and diastolic function, lactate dehydrogenase (LDH) activity, and LDH isoenzymes in rats with cardiac hypertrophy. METHODS: The cardiac hypertrophy of rats was induced by partly occluding abdominal aorta. The rats were given i.g. DDPH for 8 wk 4 wk after operation, and isolated working heart was made. RESULTS: Eight wk later, in model group, left ventricle systolic pressure (LVSP), LV + dp/dtmax, -dp/dtmax and aorta pressure (AP) decreased by 20.2%, 20.0%, 41.4%, and 13.6%, respectively. Left ventricle ending diastolic pressure (LVEDP) increased by 173.9%. The hemodynamic study showed that flowing liquid of aorta (AF) and coronary (CF) and cardiac output (CO) decreased by 49.4%, 41.2%, and 48.9%, respectively. After the rats were given i.g. DDPH, the all above-mentioned parameters recovered to different degrees. Under condition of cardiac hypertrophy, LDH isoenzymes and subunits changed significantly. Isoenzymes LDH3, LDH4, and LDH5, especially LDH5 increased, LDH1 decreased, subunit M in hypertrophied heart increased 1.69 times than that in normal heart. DDPH could decrease subunit M and increase subunit H. CONCLUSION: DDPH can increase cardiac function, coronary flow and reverse changes of LDH isoenzymes in rats with cardiac hypertrophy.

Animals↗
PubMed1995

Oxidatively modified very low density lipoprotein enhances monocyte adhesion to endothelial cells.

Very los density lipoprotein (VLDL) was incubated with CuCl2(10 mumol/L) at room temperature for 24 hours. The thiobarbituric acid reactive substance (TBARS) was much higher and the electrophoretic mobility was much faster in VLDL after incubation with CuCl2 than that in VLDL without incubation with CuCl2. It demonstrated that VLDL was oxidatively modified by Cu2+. Endothelial cells were pretreated with normal VLDL (N-VLDL) and oxidatively modified VLDL (O-VLDL) and then the adhesion of monocyte to endothelial cells was assayed. We observed that O-VLDL at all the concentrations used enhanced monocyte adhesion to endothelial cells significantly. The results suggest that oxidative modification of VLDL may play a role in the early stage of atherogenesis by increasing monocyte adhesion to endothelial cells.

Cell Adhesion↗
PubMed1995

Experimental and clinical studies on the reduction of erythrocyte sorbitol-glucose ratios by ascorbic acid in diabetes mellitus.

In order to confirm the effect of ascorbic acid (AA) on human erythrocyte sorbitol accumulation and explore its mechanism of action, the effects of ascorbic acid in vitro on the sorbitol (S) and glucose (EG) content of human erythrocytes and in particular on the S/EG ratio as a marker of aldose reductase (AR) activity were carefully observed. The results showed that both the accumulation of erythrocyte sorbitol and the S/EG ratio were strongly reduced by the addition of AA. The sorbitol content in the erythrocyte and the S/EG ratio were reduced by a maximum of 87.3% and 83.4% and 93.8% and 63.9% when the medium's AA concentration was at its peak with 5.6 mmol/l and 28 mmol/l glucose in the medium, respectively. The contents of erythrocyte glucose measured coincidentally revealed a positive correlation with the ascorbic acid concentration in the medium during incubation in 5.6 mmol/l glucose while at a higher glucose level (28 mmol/l) in the medium the correlation became negative. These results suggested that the polyol pathway could be inhibited effectively by AA through its direct action on AR. The results of a double-blind cross-over trial using AA tablets or inositol tablets in eight diabetic patients showed that the supplementation of 1000 mg AA/day for 2 weeks resulted in reductions of 12.2% and 21.8% in erythrocyte sorbitol and red cell sorbitol/plasma glucose (S/PG) ratio, respectively (P < 0.05), whereas the fasting plasma glucose levels measured coincidentally revealed no changes (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[Reduction of erythrocyte sorbitol by ascorbic acid in patients with diabetes mellitus].

The content of erythrocyte sorbitol could be reduced by ascorbic acid (AA). To confirm the effect of AA on human erythrocyte sorbitol accumulation and explore its mechanism of the action, we studied in vitro the effects of ascorbic acid on the contents of both sorbitol and glucose in human erythrocytes. The effect of AA on the ratio of sorbitol to glucose in erythrocyte (S/EG) which was referred to as a marker of aldose reductase (AR) activity was observed. Both the accumulation of erythrocyte sorbitol and S/EG were reduced by the addition of ascorbic acid (AA) during in vitro incubations. The sorbitol content in the erythrocyte and S/EG were reduced by a maximum of 87.3%, 83.4% and 93.8%, 63.9% when the medium's AA concentration was at its peak in the 5.6 mmol/L and 28 mmol/L glucose concentration of medium respectively. These suggested that the activity of polyol pathway could be inhibited effectively by AA which might directly act on the activity of AR. The results of a double-blind cross-over trial using AA tablets or inert inositol tablets in 8 diabetic patients showed that the supplementation of 1,000 mg AA/day continued for 2 weeks resulted in reductions of 12.2% and 21.8% in both erythrocyte sorbitol and red cell sorbitol: plasma glucose (S/PG) ratio, respectively (P < 0.05). The fasting plasma glucose levels measured coincidently revealed no changes (P > 0.05). This suggests that the supplementation of moderate AA (1,000 mg/day) might provide a simple, safe and effective means of preventing and ameliorating chronic complications of diabetes.

Adolescent↗
PubMed1991

[A preliminary study on substance P and vasoactive intestinal polypeptide contents in intestinal mucosa of chronic diarrhea with splenic weakness].

By means of radioimmunoassay, the mucosal substance P (SP) and vasoactive intestinal polypeptide (VIP) concentration in distal ileum, transverse colon and sigmoid colon in 30 patients of chronic diarrhea with splenic weakness was determined and compared with that in 28 patients of chronic diarrhea without splenic weakness and in 15 controls without chronic diarrhea. In patients of chronic diarrhea with splenic weakness, the SP contents in the mucosa of distal ileum (120.95 +/- 90.70 pg/mg wet weight) was significantly increased compared with that in controls without diarrhea (47.86 +/- 35.49 pg/mg wet weight) and in chronic diarrhea without splenic weakness (52.50 +/- 42.49 pg/mg wet weight), P less than 0.01 and 0.01 less than P less than 0.05 respectively. The VIP contents of sigmoid mucosa in patients of chronic diarrhea with splenic weakness (510.63 +/- 265.22 pg/mg wet weight) was markedly increased in comparison of that in controls without chronic diarrhea (308.67 +/- 204.49 pg/mg wet weight), 0.01 less than P less than 0.05, and was not significantly augmented compared with that in chronic diarrhea without splenic weakness (398.97 +/- 240.80 pg/mg wet weight), but the tendency of increase was present. Our results suggested that the increased SP and VIP in patients of chronic diarrhea with splenic weakness might be closely related to the symptom of chronic diarrhea. According to the general function of VIP, the authors predicted that VIP might play a more important role in the pathogenetic action of chronic diarrhea with splenic weakness.

Adult↗
PubMed1990

Marfan syndrome in China: a collective review of 564 cases among 98 families.

This is a collective review of 564 patients with Marfan syndrome among 98 pedigrees reported from 18 provinces and cities in China over a 37-year period from 1951 to 1987. A positive family history of Marfan syndrome was found in 74.3% of the patients: the mode of inheritance was dominant in 73.8% and recessive in 0.5%. Sporadic cases occurred in 25.7%. A screening of 29,067 children found five children with Marfan syndrome, giving a prevalence of 17.2 per 100,000 of the population, a gene frequency of 8.61 per 100,000 genes, and a penetrance of 71.69%. Pleiotropy was clear in these cases: arachnodactyly in 77%, ectopia lentis in 86.8%, and dilated aortic root in 80.1%. Chromosome examination showed no regular aberrations except in a family of five in whom a giant-satellited chromosome 14 was found in three afflicted members but not in the two unaffected relatives. The high prevalence of aortic root dilation in Marfan syndrome makes echocardiography the most useful and practical means of diagnosis. Close follow-up and regular echocardiographic evaluation are indicated not only in patients with Marfan syndrome but also in their families, for both diagnostic and therapeutic purposes.

Adolescent↗
PubMed1990

Studies on gastrin in duodenal ulcer.

By immunocytochemical method and radioimmunoassay, the gastrin secreting cells (G cells) and gastrin concentration in antral mucosa, gastric juice and serum in 20 patients with duodenal ulcer (DU) were studied. The number of G cells and gastrin concentration in antral mucosa showed no significant difference as compared with normal control. The number of G cells in patients with DU and antral atrophy was much higher than those with antral atrophy but with DU. It indicated that G cells were increased in number in DU, and the gastrin concentration in gastric juice (271.11 +/- 255.25 pg/ml) was much higher than in sera (74.71 +/- 43.07 pg/ml). G cells were distributed in different parts of pyloric glands, showing that gastrin in gastric juice should come directly from G cells. The disturbance of feedback mechanism in regulating gastric acidity might be an important role in hypersecretion of gastric acid in DU. The increase of gastrin concentration in gastric juice might be closely related to hyperplasia of parietal cells.

Adult↗