Biomedical subjects

Z Jin

Publications and source records attributed to Z Jin.

At least 91 records · Page 5Linked to original sources

PubMed1998

[Adaptive response of CHL to hydrogen peroxide induced oxidative stress and the mechanism].

OBJECTIVE: To study peroxidative adaptive response of eukaryocyte and its mechanisms. METHODS: Chinese hamster fibroblast cells (CHL) pretreated with low concentration of hydrogenperoxide (H2O2) were retreated by the following high concentration of H2O2. Cellular viability (MTT method) and DNA strand break (FADU method), as adaptive-acting indicators were selected. Meanwhile, CAT activity and PARP were separately determined on the adaptive response to DNA strand break. RESULTS: There were peroxidative adaptive responses to non-lethal damage of high concentration H2O2 in both cellular viability and DNA strand break levels; but adaptive models (conditions) between the two levels were different. The CAT activity induced by the low level of H2O2 was enhanced and related to peroxidative adaptation to DNA break. Furthermore, PARP blocker, 3-AB, markedly inhibited the adaptive response to DNA-strand break. CONCLUSION: Two models adaptation may be via different inducible adaptive pathways. CAT and PARP participated in the induction of peroxidative adaptation to DNA strand break.

Adaptation, Physiological↗

PubMed1998

[Clinical applications of island and myocutaneous flaps].

OBJECTIVE: This is to introduce the experience in clinical applications of the island and myocutaneous flaps. METHODS: Since 1985 fifteen types of vascularized island and myocutaneous flaps have been applied in 52 cases (21 positions) for the following purposes: repairing traumatic soft tissue defects on the limb, scar contracture, congenital recto-vaginal fistula, reconstructing congenital nasal deformity and rehabilitating function. The non-major artery island flap was used in 47 cases (90.38%) and the retrograde island flap was used in 24 cases (46.15%). The size of the flap ranged from 2.5 cm x 1.5 cm to 15 cm x 12 cm. RESULTS: All the flaps survived with primary healing. Follow-up for 8 months to 11 years showed aesthetically and functionally satisfactory results in all cases. CONCLUSION: These island and myocutaneous flaps have rich blood supply and are highly anti-infective. The operation is easy and the success rate is high.

Adolescent↗

PubMed1998

Cloning and expression of phenylalanine ammonia lyase cDNA in Escherichia coli.

The phenylalanine ammonia lyase (PAL) cDNA was amplified from Petroselinum crispum RNA by using the RT-PCR technique. The amplified 2.2 kb DNA fragment was sequenced and inserted into expression vector pET23b. The resulting plasmid pET23bPAL was then transformed into E. coli JM109DE3. The expressed PAL protein in JM109DE3 (pET23bPAL) accounted for more than 15% of total proteins in the engineering E. coli cells. The activity and specificity of the expressed PAL was identified and tested by using HPLC technique. The results indicated that the PAL activity was good enough for application to enzymatic therapy of phenylketonurea (PKU).

Apiaceae↗

PubMed1998

[Comparison of the effects of inhaled nitric oxide and intravasculare regitine on pulmonary gas exchange in young dogs with oleic-acid acute lung injury].

In order to find an agent which truly improves hypoxemia of some serious pediatric lung diseases, the authors examined the independent effects of nitric oxide inhalation and regitine infusion on blood gases, intrapulmonary shunt and hemodynamics in young dogs with oleic-acid acute lung injury. After nitric oxide inhalation, the results showed moderate increases in PaO2 and SaO2 (P > 0.05) and a significant decrease in Qs/Q tau ratio (P < 0.01). There was a significant decrease of PAP(P < 0.05), while SAP remained unchanged. After regitine infusion, however, there were marked decreases in PaO2 and SaO2 (P < 0.01); meanwhile, Qs/Q tau rose (P < 0.05). These suggest that with the presence of pulmonary pathology nitric oxide inhalation may alleviate the elevated pulmonary pressure without alteration in systemic artery pressure; so it can improve pulmonary ventilation-perfusion distribution and cause favorable changes in blood gases. On the other hand, regitine, as a non-selective vasodilator, reduces pulmonary artery pressure at the cost of significant worsening of blood oxygenation and systemic hypotension; so its routine use in childhood pulmonary diseases should be cautiously considered.

Animals↗

PubMed1998

[The expression of integrin beta 3 in cycling and early pregnant endometrium and its relationship with primary unexplained infertility].

OBJECTIVES: To profile the changes in integrin beta 3 expression in cycling and early pregnant endometrium and its relationship with unexplained infertility. METHOD: Expression of integrin beta 3 on endometrium was detected in 56 normal cycling women during different menstrual phases or early pregnant women, and 9 cases with unexplained infertility during mid-luteal phase by immunohistochemistry technique. RESULTS: Integrin beta 3 was expressed only in the midluteal or pregnant endometrium(after cycle day 19). Compared with normal women, integrin beta 3 failed to express in the midluteal endometrium from women with unexplained infertility. CONCLUSIONS: Our findings suggest integrin beta 3 may play important roles in the process of implantation and decidualization. It might be a new reliable marker of uterine receptivity. Abnormal endometrial integrin beta 3 expression might be the major cause of unexplained infertility.

Adult↗

PubMed1998

[Preoperative localized diagnosis of insulinoma by aterial stimulating and venous sampling methods].

OBJECTIVE: To establish a method for bocative diagnoses of insulinoma, METHOD: Five patients with insulinoma were given locative diagnoses by using ASVS methods which mean injecting calcium stimulatant into pancreatic supplying arteries and then taking blood specimens from henatic vein to gauge the insulin levels. Six samples, each 2 ml, were taken before and 30, 60, 90, 120, 180 seconds after the injection. RESULTS: If the peak of blood-insulin level was twice or higher than the basic level, the tumor was located in the domain. These results were confirmed operatively in all the five cases. CONCLUSION: ASVS is an accurate technique to localize insulinoma.

Adult↗

PubMed1998

[Effects of emodin on the activity of K channel in guinea pig taenia coli smooth muscle cells].

The effects of emodin, cromakalim (KATP channel opener) glybenclamide (KATP channel inhibitor) Ba2+ and TEA on the electrical and contractive activities of the smooth muscle cells in guinea pig taenia coli and the relationship between emodin and four other drugs were studied by using intracellular microelectrode technique and the tension measuring technique. The results are as follows: (1) Emodin enhances the electrical and contractive activities of the smooth muscle cells in guinea pig taenia coli. The effects of emodin depend on its concentration. (2) Emodin can resist the inhibition of cromakalim on the electrical and contractive activities of smooth muscle cells. On the other hand, cromakalim was shown to suppress the effects of emodin. (3) Ba2+, TEA and glybenclamide all can improve the electrical and contractive activities of smooth muscle cells and resist the inhibition of cromakalim. The effects of emodin were found to be similar to that of glybenclamide but different from that of Ba2+ and TEA. The results suggest that the mechanism of action of emodin is to inhibit the activity of KATP channel in the guinea pig taenia coli smooth muscle cells.

Animals↗

PubMed1998

[Studies on characterization of glutamine synthetase from Streptomyces lincolnensis].

Glutamine synthetase from Streptomyces lincolnensis was purified to electrophoretic homogeneity. The effects of pH, temperature and metal ions on the purified enzyme were studied, and the substrate specificity of glutamine synthetase were reported. Under the standard biosynthetic assay system, the substrate saturation curves of glutamine synthetase from Streptomyces lincolnensis for ammonia did not agree with the Michaelis-Menten relationship, with either Mn2+ or Mg2+ as divalent cation, and Hill constants not equal to 1. The K(m) values of GS for Glu and ATP were different with different divalent cation.

Glutamate-Ammonia Ligase↗

PubMed1998

[Purification and properties of alanine dehydrogenase from Streptomyces lincolnensis].

Alanine Dehydrogenase (L-Alanine: NAD+ oxidoreductase, deaminating, EC 1.4.1.1) was purified from Streptomyces lincolnensis through four steps: (NH4)2SO4 precipitation, DEAE-cellulose 52, Affi-Gel Blue and Sepharose 6B. Molecular weight of the enzyme was determined as 170,000 by gel filtration and concentration gradient PAGE. SDS-PAGE showed only one band of 42,500, demonstrating that ADH from Streptomyces lincolnensis was consisted of four identical subunits. The optimal pH for amination was 9.0, for deamination 9.5. The optimal temperature for both amination and deamination was 50 degrees C. The Km valuse for pyruvate, NH4+, NADH, L-Ala and NAD+ were 2.08 x 10(-4) mol/L, 2.00 x 10(-2) mol/L, 2.38 x 10(-5) mol/L, 1.43 x 10(-2) mol/L and 6.67 x 10(-5) mol/L, respectively.

Alanine Dehydrogenase↗

PubMed1998

[An effective method of mutual interference coefficients for correcting spectral interferences in routine ICP-AES for multielement analysis].

An effective method was used to correct spectral interferences in routine ICP-AES for multielement analysis. In this method, all the components in an analysed object were considered to be related to each other, a strict mathematical model was applied and the mutual interference coefficients obtained from the usual artificial samples were replaced by those from natural standard samples which had the some matrix as the samples to be analysed. These mutual interference coefficients were used to correct the analysis data of GSD samples, and the results were mostly more precise than those corrected by the coefficients obtained from artificial samples. The correcting speed of this method is quick enough to satisfy the requirement of real-time correcting of analysis.

English Abstract↗

PubMed1998

[Study on the atomic fluorescence spectrometric determination of trace bismuth in geological samples by hydride generation in slurry].

A method for atomic fluorescence spectrometric determination of trace bismuth in geological samples by hydride generation in slurry was proposed. The effect of various factors, such as acid media, the particle size of sample and the concentration of slurry etc., on hydride generation was investigated. This method is simple and rapid and has been applied to the determination of trace bismuth in GSD standard samples with satisfaction.

English Abstract↗

PubMed1998

[Genetic polymorphism of inter-alpha-trypsin inhibitor in six Chinese populations].

OBJECTIVE: To understand the distribution of allele frequencies of inter-alpha-trypsin inhibitor(ITI) in Chinese populations. METHODS: The polymorphism of this protein in six Chinese populations was investigated using isoelectric focusing followed by immunoblotting technique. RESULTS: Three common alleles, ITI*1, ITI*2, and ITI*3 were observed in four populations, namely Han living in Jilin, Mongol in Hailaer, Tibetan in Lasa, and Bai in Dali respectively. In other two populations, Zhuang in Guangxi and Han in Guangdong, only ITI*1 and ITI*2 were observed. For these populations, the frequency of ITI*1 ranges from 0.5500 to 0.7525; that of ITI*2 from 0.2475 to 0.4322; and that of ITI*3 from 0.0034 to 0.0729. CONCLUSION: This study reveals that there is no parallel relationship between variation of allele frequencies and geographic differences.

Alpha-Globulins↗

PubMed1998

Effects of nicotine administration on elemental concentrations in mouse granulosa cells, maturing oocytes and oviduct epithelium studied by X-ray microanalysis.

A normal maturation of the oocytes is dependent upon, among other things, normally functioning granulosa and corona radiata cells. Analyses performed during human in vitro fertilization programs have revealed that, in smokers, ovarian functions are affected and that smokers have a decreased fertilization rate. Further, animal studies have indicated that nicotine can reach the genital tractus, and that nicotine administration interferes with oocyte maturation, fertilization and early pregnancy. We applied X-ray microanalysis to monitor whether nicotine administration changed the ionic balance of cells in the reproductive tract (granulosa cells, oocytes and oviduct epithelial cells). The animals were given nicotine in the drinking water at a concentration of 108 mumol/l. After 15 days the animals were superovulated, ovaries and oviducts were frozen, and thick cryosections were prepared for energy-dispersive X-ray microanalysis. In the granulosa cells, the concentrations of Na and Cl increased after nicotine treatment, while the K concentrations decreased resulting in an increased Na/K ratio. The treated oocytes had a higher K concentration and a decreased Na/K ratio compared to the controls. In the epithelial cells of the oviduct, the concentrations of Na and K decreased after nicotine treatment without any changes in the Na/K ratio. Thus, heavy nicotine administration to mice causes significant changes in the ionic composition of the granulosa cells, the ovarian oocytes and the oviduct epithelium.

Animals↗

PubMed1997

Developmental changes in the dendritic architecture of salt-sensitive neurons in the nucleus of the solitary tract.

Recent studies have provided evidence that brainstem gustatory neurons undergo substantial dendritic growth during a period of postnatal development that coincides with the maturation of their response to salts, suggesting a relationship (perhaps causal) between the physiology and morphology of developing salt-sensitive neurons. In an initial effort to explore this issue, we used extracellular and intracellular recording and intracellular labeling techniques to examine the structure and function of individual gustatory neurons in the rostral nucleus of the solitary tract (rNST) of young (postnatal day [P] 22-28) and adult rats. We found that P22-28 cells that responded to all three of the salts in our taste array had a greater dendritic length, a greater cell volume, and more dendritic branches than the cells that responded to one salt. As a group, taste-sensitive neurons in P22-28 animals had a higher maximum dendritic branch order and a trend toward more dendritic branch points than gustatory neurons in adult animals. The dendritic arbors of P22-28 taste neurons that responded to all three salts were larger (greater surface area and volume), more extensive in the rostrocaudal axis and exhibited a higher maximum branch order, more branch points and higher swelling density than adult cells that responded to all three salts. These results demonstrate that the morphology of salt-sensitive gustatory neurons in developing animals is closely related to the number of salts that evoke a response. The data also support the postulate that gustatory neurons in the rat brainstem undergo substantial dendritic remodeling between the fourth week of life and adulthood. Dendritic remodeling may play an important role in the maturation of the rNST response to NaCl.

Animals↗

PubMed1997

Comparison of styrene-7,8-oxide adducts formed via reaction with cysteine, N-terminal valine and carboxylic acid residues in human, mouse and rat hemoglobin.

The reactive metabolite of styrene, styrene-7,8-oxide (SO), reacts with a variety of nucleophilic sites in hemoglobin (Hb) to form SO-Hb adducts. Following the in vitro incubation of SO with blood from humans, NMRI mice and Sprague-Dawley rats, the second-order reaction rate constants were determined for the reaction of SO with cysteine (through both the alpha- and beta-carbons of SO), N-terminal valine (through the beta-carbon of SO), and carboxylic acid (presumably through both the alpha- and beta-carbons of SO) residues in Hb. The rate constants for cysteine adducts vary dramatically between species [2.04, 10.7, 133 L (mol Hb)-1 h-1 (alpha binding) for humans, mice and rats, respectively] and [0.078, 2.16, 20.4 L (mol Hb)-1 h-1 (beta binding), respectively]. The considerably higher rate of reaction with cysteine in rat Hb probably reflects the presence of an additional cysteine residue at position beta 125. Although the rate constants for valine adducts (1.82, 0.80, 0.29 L (mol Hb)-1 h-1, respectively) and COOH adducts (3.55, 1.94, 2.37 L (mol Hb)-1 h-1, respectively) are much more consistent, the inter-species differences are statistically significant for the reaction of SO with the N-terminal valine of Hb. Following the i.p. administration of styrene to mice and styrene and SO to rats, the levels of adducts at each of these sites were used in conjunction with the calculated rate constants to predict the integrated blood doses of SO. While the SO doses predicted from cysteine and valine adducts were very similar, that based upon COOH-binding was significantly different, presumably due to the instability of SO-COOH adducts. This research affirms the use of both cysteine and valine adducts, but not carboxylic acid adducts, as biomarkers of exposure to styrene and SO.

Animals↗

PubMed1997

Rac1 mediates collapsin-1-induced growth cone collapse.

Collapsin-1 or semaphorin III(D) inhibits axonal outgrowth by collapsing the lamellipodial and filopodial structures of the neuronal growth cones. Because growth cone collapse is associated with actin depolymerization, we considered whether small GTP-binding proteins of the rho subfamily might participate in collapsin-1 signal transduction. Recombinant rho, rac1, and cdc42 proteins were triturated into embryonic chick (DRG) neurons. Constitutively active rac1 increases the proportion of collapsed growth cones, and dominant negative rac1 inhibits collapsin-1-induced collapse of growth cones and collapsin-1 inhibition of neurite outgrowth. DRG neurons treated with dominant negative rac1 remain sensitive to myelin-induced growth cone collapse. Similar mutants of cdc42 do not alter growth cone structure, neurite elongation, or collapsin-1 sensitivity. Whereas the addition of activated rho has no effect, the inhibition of rho with Clostridium botulinum C3 transferase stimulates the outgrowth of DRG neurites. C3 transferase-treated growth cones exhibit little or no lamellipodial spreading and are minimally responsive to collapsin-1 and myelin. These data demonstrate a prominent role for rho and rac1 in modulating growth cone motility and indicate that rac1 may mediate collapsin-1 action.

ADP Ribose Transferases↗

PubMed1997

Neuroanatomical substrates of late-life minor depression. A quantitative magnetic resonance imaging study.

OBJECTIVE: To examine the neuroanatomical correlates of late-life minor depression using magnetic resonance imaging. DESIGN: Cross-sectional quantitative magnetic resonance imaging study of elderly patients with minor depression and age-matched controls. SETTING: Patients and controls were recruited from the community through advertisements to the Section of Geriatric Psychiatry, University of Pennsylvania, Philadelphia. PARTICIPANTS: Our sample included 18 subjects diagnosed as having minor depression using the modified Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, research criteria and 31 controls without depression. Patients were free of other central nervous system disease and both groups had comparable degrees of medical comorbidity. MAIN OUTCOME MEASURES: All images were acquired on a 1.5-T scanner and absolute and normalized quantitative measures of global and focal brain and cerebrospinal fluid volumes were compared between groups. RESULTS: Prefrontal lobe volume was significantly smaller in the group with minor depression (P = .002) compared with controls after controlling for age, sex, and age by sex interactions. More global measures of brain and cerebrospinal fluid volumes were comparable in both groups. CONCLUSIONS: These data suggest that focal prefrontal atrophy may provide an important neuroanatomical substrate in late-life minor depression.

Aged↗

PubMed1997

Alternative method of subtyping the A subunit of coagulation factor XIII (FXIIIA).

An alternative isoelectric focusing method for the A subunit of coagulation factor XIII (FXIIIA) subtyping is described which employs three different carrier ampholytes, pH 4-6.5, pH 5-6 and pH 5-8 (2:2:1), and sample application at the anode. With this technique ten common subtypes, including a variant, were clearly and reliably identified in Japanese and Chinese population samples.

Electrophoresis, Polyacrylamide Gel↗