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Biomedical subjects

Z L Zhang

Publications and source records attributed to Z L Zhang.

At least 37 records · Page 2Linked to original sources
PubMed1999

Influences of chloropazine, nimodipine and their combination on the toxic effects of cadmium in liver and kidney of mice.

The influences of the calmodulin antagonist chlorpromazine (CPZ), and calcium channel blocker nimodipine (NIMO) and their combination on cadmium (Cd) poisoning of mice were studied. A series of biochemical parameters including urinary enzyme activities, blood and urine Cd levels, metallothionein (MT) contents in liver and kidney, hepatic ultrastructure and Ca(2+)-Mg2+ ATPase activity in erythrocyte membrane were determined. Animal models for Cd poisoning were established by peritoneal injection of 1/5 LD50 CdCl2. The experimental groups were protected by administration of CPZ, NIMO and CPZ and NIMO in combination 1 h before the injection of CdCl2. Five days later, samples were collected for analysis. The data showed that CPZ could protect kidney tissue against Cd-induced damage, as the urinary gamma-glutamyl-traspeptidase (gamma-GT) and N-acetyl-beta-D-glucosaminidase (NAG) activities were reduced significantly. There was neither evidence of the protective effect of NIMO on kidney tissue nor an indication of a synergistic effect of CPZ and NIMO. Both CPZ and NIMO showed a considerable protective effect against the decrease in Ca(2+)-Mg2+ ATPase activity, and a synergistic action was observed. Cd content in blood was reduced significantly by CPZ or the combination of CPZ and NIMO, but elevated by NIMO. Both CPZ and NIMO considerably increased MT contents in livers and kidneys and ameliorated damaged to the hepatic ultrastructures caused by Cd. The results indicated that these inhibitors could protect mice against the toxic effects of Cd in liver and kidney tissues, while CPZ was more efficient than NIMO. The combination of CPZ and NIMO exerted a synergistic action. The protective action of these two drugs might be relevant to the function of MT.

Animals↗
PubMed1999

[Integration via Tn10 and expression of Bti cryIVA gene in the chromosome DNA of flourescent Pseudomonas bacterial strains].

cryIVA gene of the Bacillus thuringiensis subsp. israelensis was subcloned into the Tn10 of a suicide transposon plasmid vector and a transposon plasmid pLF97A carrying cryIVA was constructed. By electroporation and transposition, cryIVA gene integrated into chromosome DNA of F.P.DE2. Thus the genetic engineered bacterial strain, F.P.DE202, was constructed. Southern blotting revealed that this integration was happened in different loci of the chromosome. Western blotting demonstrated that cryIVA was expressed in the engineered strain, and that the expressed product possesed the pesticidal ability against the third-instar larva of Bradysia odoriphaga.

Bacillus thuringiensis↗
PubMed1998

[Expression of murine interleukin 12(mIL-12) in insect cells].

Since human IL-12 is species-specific in its functions and elicits little biological responses from mouse lymphocytes, it is necessary to express recombinant murine IL-12 for the usage in studying the effects of this cytokine in various rodent models. Thereby, we can investigate the role of IL-12 in immune response in vivo and evaluate its potential clinical utility. Thus, we firstly constructed two expression vectors, pVL1393-mp40 and pVL1393-mp35. They were used to co-transfect the insect cells(Sf9) separately with linearized polyhedrosis virus genomic DNA. Two kinds of recombinant viruses AcNPV-mp40 and AcNPV-mp35 were visually screened out, and mp40 and mp35 were co-expressed in the insect cells co-infected by AcNPV-mp40 and AcNPV-mp35. The results of real-time Biomolecular Interaction Analysis (BIA) and Northern blot demonstrated that the recombinant mIL-12 was expressed successfully in the insect cells. The molecular weights of recombinant mp40 and mp35 were 40 KDa and 22 KDa on SDS-PAGE under reducing conditions, respectively. The apparent molecular weight of recombinant mIL-12 is 80 KDa under non-reducing conditions of Western blot. Biological activity of the recombinant product was detected in conditional medium using antibody-capture bioassay. The expression level of recombinant mIL-12 was about 10-15 micrograms/10(6) cells, as compared with the calibration curve of mIL-12.

Animals↗
PubMed1997

[The value of the different radiological examining methods in caries diagnosis]

This in vitro study compared the results of clinical examination (abbreviation CE) and the three radiological methods (i.e RVG-radiovisiography) on occlusal and proximal caries diagnosis,using pathological observation as the final standard.The results are:on occlusal caries diagnosis,CE provide the most accordant result to the pathological result.There are statistically significant differences between SR and CE,BW and CE.1st suggests that to occlusal caries diagnosis,CE is still a convenient and efficient way.On proximal caries diagnosis,there are statistically significant differences between SR and CE,BW and CE.BW has the most coincident result with pathological one.

Journal Article↗
PubMed1996

[Study on the distribution and origins of RNA in the metaphase chromosomes of mouse by in situ hybridization at electron microscopic level].

The RNAs in the metaphase chromosomes of mouse are located by use of RNase-gold labelling. The result shows that a lot of RNAs distribute uniformly in the inner and peripheral regions of the chromosome sections. Moreover, the distributions of 18 s rRNA and 5 s rRNA which are studied under the electron microscope by in situ hybridization indicate that 18 s rRNA and 5 s rRNA are two among the several origins of the inner RNAs and peripheral RNAs in mouse metaphase chromosomes.

Animals↗
PubMed1995

[A study of errors of radiography in 10000 intraoral periapical radiographs]

A total of 10000 full-mouth radiographs (10000 periapical radiographs were evaluated for radiographic errors.The result showed that four major types of errors were found in this study,They are cone cutting(5.59%),incorrect vertical angulation(38.84%),incorrect horizontal angulation(37.16%),and incorrect film placement (14.16%).The incidence of radiographic technique errors was 0.096%.Most errors were caused by incorrect vertical angulation and incorrect horizontal angulation(76%).Most errors were found in the cuspid premolar regions(70.6%)

Journal Article↗
PubMed1995

[Radiographic image analysis of root canal in anterior teeth.].

The aim of this study was to determine the number and morphology of anterior dental root canals,and their different types.1200 permanent anterior teeth were examined with radiographs.Each tooth was radiographed with two methods.The results showed there were four types of canals configulation in these teeth,two canals were present in less than one canal,the incidence of two canals was 9.6%.Author indicated that good quality of radiograph get an obvious value in determining both external and internal anatomy of teeth.The radiographs should be taken from two of several different angles.If a radiolucent line was located at mesial to distal of main canal,two canals should be suspected.

English Abstract↗
PubMed1995

[Clinical study on effect of bushen jiangu capsule on postmenopausal osteoporosis].

The therapeutic effect of Kidney Tonifying principle and Bushen Jiangu (BSJG) capsule on postmenopausal osteoporosis (17 cases) was observed and compared with calcium treatment group (17 cases) in double-blind method. The result showed that 3 months after treatment with BSJG capsule, the symptoms of 92.85% patients were improved, and 6 months after treatment, the bone density (BD) of lumbar vertebra of 68.8% patients was significantly higher than that of before treatment, but the BD of control group was lower (P < 0.05). This suggested that BSJG capsule could prevent and improve postmenopausal osteoporosis. The therapeutic mechanisms probably is improving the bone formation and declining the bone absorption.

Bone Density↗
PubMed1994

Lymphocyte subsets in thymus and peripheral lymphoid tissues of aging and diabetic NOD mice.

The nonobese diabetic (NOD) mouse spontaneously develops insulin dependent diabetes mellitus. The disease is associated with a leucocytic infiltration of the pancreatic islets of Langerhans and it is believed that during the development of autoimmune diabetes, the insulin-secreting islet beta-cells are destroyed by autoreactive T lymphocytes. We investigated the alteration of lymphocyte subsets in central and peripheral lymphoid organs of NOD female mice with increasing age beginning before the onset of insulitis and ending well after the onset of diabetes. The spleen, inguinal and pancreatic lymph nodes all increased in cell number, especially after the onset of insulitis (8 weeks), and all decreased after the onset of diabetes. Flow cytometric studies showed a widening of the visible side scatter profile of female NOD lymph node cells which coincided with the initiation of insulitis. Anti-CD4 and anti-CD8 double staining of thymocytes revealed a large increase in the double negative population and a corresponding decrease in the double positive population, but this occurred long after the onset of diabetes. Generally, there was an increase in the CD4:CD8 ratio in the peripheral lymphoid organs during the onset of insulitis which was largely due to an increase in the CD4 T cell population while the ratio decreased after the onset of diabetes. In the spleen this was mostly due to an increase in CD8 T cells. The pancreatic lymph nodes, which theoretically might reflect what is happening in the pancreas, showed an unexpected decrease in overall cell number and a decrease in T-cells (especially CD4 T cells), while B cells were increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1994

[Radiographic investigation of idiopathic osteosclerosis of jaws]

Full-mouth radiographs of 1321 patients were examined for the presence of radiopacitics that could not be attributed to any known sources of bone formation.A total of 75 patients exhibited these foci of idiopathic osteosclerosis.The incidence of disease is 5.7%,including SIO 46.3%,PIO 37.5%,IIO 16.2%.The majority of the opacities were found in the mandible,especially from the mandibular first premolar to first molar region(65%).The lesion was most prevalent in the first three decades of life.

Journal Article↗
PubMed1993

The effect of cyclophosphamide treatment on lymphocyte subsets in the nonobese diabetic mouse: a comparison of various lymphoid organs.

The nonobese diabetic (NOD) mouse is a model for human Type 1 diabetes mellitus. Pancreatic beta-cell destruction in NOD mice is mediated by an autoimmune process which can be accelerated by cyclophosphamide (CP). We studied the phenotype of lymphocytes from central, peripheral and regional lymphoid tissues in prediabetic NOD and C3H mice before and after a single large dose of CP. All lymphoid organs showed a greatly diminished cell number and most alterations appeared early after CP and were transient, but an aggressive insulitis was not seen in NOD mice until 14 d after injection. The pancreatic islets in C3H mice remained intact and were not infiltrated. NOD female mice, which are most prone to spontaneous and CP-induced diabetes, exhibited the most unusual lymphoid kinetics after treatment with CP. Their thymus and spleen showed the least relative drop in total cell number and the most rapid rate of recovery. The thymus of these mice was also found to have an increased proportion of CD3+ thymocytes while CD4/CD8 double positive thymocytes decreased 7 d after CP. At 14 d after CP the number of IL-2R+ thymocytes had surpassed that of normal levels. The most dramatic observation was the rapid recovery and overshoot in the number of pancreatic lymph node cells of female NOD mice which coincided with aggressive insulitis.

Animals↗
PubMed1993

Molecular mechanism of high energy proton radiation--Raman spectroscopic character of microcosmic damage in the space structure of DNA.

High energy proton is an important type of the space radiation. The paper investigates the radiation effect of high energy proton (27.9 MeV) on DNA aqueous solution in the field of the molecular mechanism. The following information about the microcosmic damage to the space structure of DNA was obtained: (i) breakage of a part of interbase hydrogen bonds which maintained double helical structure of DNA; (ii) damage on four bases, in which the damage on adenine ring was the most serious; (iii) obvious change of deoxyribose; (iv) serious damage on backbone phosphate ion (PO2-) and phosphate diester (PO2) and the occurrence of scissions of double-stranded and single-stranded DNAs; (v) obvious decrease in the amount of B-form conformation.

Animals↗
PubMed1993

[Isolation and identification of two new saponins from Bupleurum smithii Wolff].

Two new saikosaponins of oleanane type were isolated from the roots of Bupleurum smithii Wolff, collected in Minhe County, Qinghai, namely saikosaponin k (VIb) and saikosaponin 1 (VIII). Their structures were elucidated on the basis of spectral analysis of UV, IR, 1HNMR, 13CNMR and FAB-MS. Saikosaponin k (VIb) was identified as 3 beta, 16 beta, 23,28-tetrahydroxyoleana-11,13(18)-dien-3-O-beta-D-xylopyranosyl-(1-->2)-beta- D-glucopyranosyl-(1-->3)-beta-D-fucopyranoside, and saikosaponin 1 (VIII) as 3 beta, 16 alpha, 23,28,30-pentahydroxyoleana-11,13(18)-dien-3-O-beta-D- glucopyranosyl-(1-->3)-beta-D-fucopyranoside, respectively.

Drugs, Chinese Herbal↗