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Biomedical subjects

Z Jin

Publications and source records attributed to Z Jin.

At least 73 records · Page 4Linked to original sources
PubMed1999

The neuroprotective effects of intrathecal administration of the selective N-type calcium channel blocker ziconotide in a rat model of spinal ischemia.

PURPOSE: Spinal cord ischemia and resulting paraplegia represent a major complication associated with surgical repair of the thoracoabdominal aorta. Although the mechanism of spinal neuronal degeneration during ischemia is unclear, it may involve excessive calcium influx via N-type voltage-sensitive calcium channels (VSCCs). The neuroprotective capacity of intrathecal (IT) administration of the selective N-type VSCC blocker ziconotide, previously shown to be potently analgesic, was studied. METHODS: In a rat aortic occlusion model, spinal cord ischemia was induced for 8, 9, or 10 minutes by occluding the descending thoracic aorta. Ziconotide was administered IT as (1) a continuous infusion of 300 or 600 ng/kg/h initiated 24 hours before ischemia and continuing an additional 24 hours or (2) a 0.3 microgram bolus injected 45 minutes before the induction of ischemia. Animals were allowed to live for 24 hours, and recovery of motor function was evaluated during this period. Spinal cords were processed using a silver impregnation technique and microtubule-associated protein type II (MAP2) immunohistochemistry. RESULTS: Continuous IT infusion of ziconotide provided significant protection against 8- and 9-minute occlusions, but not 10-minute occlusions, as indicated by recovery of motor function, degree of spinal neuronal degeneration, and loss of MAP2 immunoreactivity. Acute IT pretreatment with ziconotide provided transient protection during the initial 4 hours of reperfusion; however, this protective effect was no longer present at 24 hours. CONCLUSION: These data implicate N-type VSCC activation in spinal neuronal degeneration caused by transient spinal ischemia, because selective blockade of this channel by continuous IT infusion of ziconotide was protective against injurious intervals of spinal ischemia. Based on these findings, ziconotide may provide both neuroprotection and preemptive analgesia for aortic aneurysm surgery.

Analysis of Variance↗
PubMed1999

Comparison of acute effects on right ventricular haemodynamics of surgical versus interventional closure of atrial septal defects.

OBJECTIVES: We compared the acute effects on right ventricular haemodynamics of surgical versus transcatheter closure of medium-sized atrial septal defects. METHODS: We studied 47 consecutive patients with a defect in the oval fossa and a ratio of pulmonary to systemic flows between 1.5: 1 and 2: 1. They were divided into two groups according to whether the defects were closed by surgery, performed in 23 patients, or by interventional catheterization, achieved in 24 patients. By means of transthoracic cross-sectional echocardiography, we measured right ventricular end-diastolic and endsystolic volumes and calculated ejection fractions. These calculations were performed before, and between 1 and 7 days after closure of the defect. RESULTS: Before closure of the defect, all patients had an enlarged right ventricle with normal function. After closure by either method, there was no difference in the rate of normalization of end-diastolic volume, but endsystolic volume remained enlarged. Thus, the calculated ejection fraction was lower than before closure. CONCLUSIONS: There was no difference in right ventricular volumes or function early after closure of atrial septal defects, irrespective of whether this was achieved surgically or via transcatheter closure.

Adolescent↗
PubMed1999

c-Rel is crucial for lymphocyte proliferation but dispensable for T cell effector function.

The TCR signals are essential for T cell activation and proliferation, primarily through the induction of cytokine and cytokine receptors. Several transcription factor families, including NF-kappaB/Rel, have been implicated in the regulation of cytokine gene expression in T cells in response to antigen, cytokine and mitogenic stimulation. In this study, we show that the mice with a null mutation in the lymphoid-specific c-Rel gene have normal development of lymphoid tissues and T cell compartment. However, T cells derived from the c-Rel knockout mice have several functional abnormalities. The c-Rel-deficient T lymphocytes fail to respond to activation and proliferation signals mediated by the TCR and mitogens in vitro. This is attributed to an impaired production of cytokines IL-2, IL-3 and granulocyte macrophage colony stimulating factor. In addition, the induction of IL-2R alpha chain is impaired in the c-Rel(-/-) T cells. The poor expression of cytokines and IL-2R alpha chain correlates with a reduced nuclear translocation of NF-kappaB components in c-Rel(-/-) T cells. Since activation is prerequisite for differentiation into effector cells, c-Rel(-/-) T cells failed to differentiate into cytotoxic T cells or Th cells without rescuing cytokines. However, upon supplement with exogenous IL-2, the c-Rel(-/-) cytotoxic T lymphocytes are able to execute cytotoxicity and the c-Rel(-/-) Th cells are capable of providing help to normal B cells. These data suggest that c-Rel is important for inducible cytokine and cytokine receptor expression, and a key regulator of early activation and proliferation in T cells.

Animals↗
PubMed1999

[Effect of the herpes simplex virus I-thymidine kinase gene-ganciclovir system on the transplant of human ovarian cancer on the omentum of nude mice].

OBJECTIVE: To investigate the therapeutic effect of the herpes simplex virus I-thymidine kinase gene (HSV1-tk)/ganciclovir (GCV) system on human ovarian cancer. METHODS: The nude mice tumors were formed by injection of human ovarian cancer cell line AO and AO/HSV1-tkc (AO cells carried with HSV1-tk gene which was constructed in China) subcutaneously, and then were transplanted to the omentum of nude mice. The filter-passing culture fluid of VPC/HSV1-tkc was injected daily into the peritoneum of the nude mice in the group of in vivo. Finally, all of the three groups of nude mice (control, in vivo, ex vivo) accepted the treatment of GCV. RESULTS: The inhibitory rate of the RV/HSV1-tkc/GCV to AO tumors were 46.8%, and, only could the residual microscopic tumors be seen in most of the nude mice omentum transplanted with AO/HSV1-tkc tumor after GCV treatment. CONCLUSIONS: GCV could more effectively inhibit the growth of the human ovarian tumors carried with HSV1-tk gene which was transplanted onto the nude mice omentum than which transplanted subcutaneously; The application of the HSV1-tk/GCV system would be very promising in the gene therapy of ovarian cancer.

Animals↗
PubMed1999

[The diagnostic value of 13C-urea breath test in Helicobacter pylori colonization density and the severity of gastritis].

OBJECTIVE: To evaluate the diagnostic value of (13)C-urea breath test (UBT) in Helicobacter pylori (Hp) colonization density and the severity of gastritis. METHODS: The diagnostic accuracy of UBT in the diagnosis of Hp infection with reference to histology (HE and Warthin-Starry stain) was analyzed and the UBT results (DOB values) among the groups of gastritis with different degrees of severity were compared. RESULTS: By using UBT, 96 of 103 patients with Hp -positive histology were detected (sensitivity, 93.2%), the specificity was 89.1%. DOB value in the Hp colonization dense group was significantly higher than in the other groups (low and moderately dense) (P < 0.05). A significant but weak, correlation was found between the DOB values and the colonization density either with (rs = 0.599 0, P < 0.000 1) or without (r(s) = 0.245 7, P = 0.015 8) inclusion of histologically negative patients. In Hp positive patients, DOB values neither in the groups of active gastritis (0 - 3 grade) nor in the groups of chronic gastritis (1 - 3 grade) had no significant difference. There was no correlation between DOB values and severity of inflammatory infiltration. CONCLUSION: (13)C-UBT has high sensitivity and specificity in the detection of Hp infection. There is significant but weak, correlation between DOB values and the colonization density of Hp. DOB values could not reflect the density of neutrophil and lymphocyte infiltration.

Adolescent↗
PubMed1999

[Influence of intravenous-immunoglobulin on T lymphocyte subsets, NK cell and some cytokines in mice with experimental viral myocarditis].

This study sought to gain an insight into the immunological pathogenesis of viral myocarditis and the mechanism of therapeutic action of intravenous-immunoglobulin (IVIG) on the disease, BALB/c mice were randomized into four groups: normal control group; "myocarditis model group", inoculated intraperitoneally with CVB3; "IVIG protection group", injected intraperitoneally with CVB3 and IVIG; and "IVIG treatment groups", injected intraperitoneally with CVB3 and IVIG. The amount of T cell in different T cell subsets and the activities of NK cell, IL-1 and IL-2 were assayed using spleen specimen while peripheral blood was used to measure TNF activity. The results showed: that in comparison with normal control, all spleen T cell subsets decreased in amount in myocarditis model group, so did its NK cell activity while its IL-1, IL-2 and TNF activities increased significantly. When compared with myocarditis model group, however, both IVIG protection group and IVIG treatment group showed significant elevation of NK cell activity and T cell subsets but reduced IL-1, IL-2 and TNF activities with no remarkable change in T cell subsets. The results of suggest that the immunological injury mediated by T cells plays a critical role in the pathogenesis of viral myocarditis. The protective and therapeutic effects of IVIG on the murine CVB3 myocarditis and the related immunological evidence of its actions may indicate the prospect that IVIG will become a potent and safe treatment for viral myocarditis in human.

Animals↗
PubMed1999

[Surgical reconstruction of laryngeal and tracheal stenosis].

OBJECTIVE: Reconstruction of laryngotracheal stenosis. METHOD: According to the pathologic condition of the larynx and trachea, various surgical procedures were designed for the treatment of laryngotracheal stenosis. These techniques included endoscopic management, laser therapy and laryngotrachoetomy with autogenous tissue and stent. RESULT: Among 36 patients, 32 were decannulated. The success rate was 88.8%. CONCLUSION: In order to improve the curation effects of laryngjotrachal stenosis, the choice of surgical procedure must be individualized to the pathologic condition of larynx and trachea, as well as the experience of the surgeon. Learning previous successful experience is also very important for a good result.

Adolescent↗
PubMed1999

Study on GMA-DNA adducts.

OBJECTIVE: DNA modification fixed as mutations in the cells may be an essential factor in the initiation step of chemical carcinogenesis. In order to explore the mechanism of gene mutation and cell transformation induced by glycidyl methacrylate (GMA), the current test studied the characteristics of GMA-DNA adducts formation in vitro. METHODS: In vitro test, dAMP, dCMP, dGMP, dTMP and calf thymus DNA were allowed to react with GMA (Glycidyl Methacrylate). After the reaction, the mixtures were detected by UV and subjected to reversed-phase HPLC on ultrasphere ODS reversed-phase column, the reaction products were eluted with a linear gradients of methanol (solvent A) and 10 mmol/L ammonium formate, pH 5.0 (solvent B). The synthesized adducts were then characterized by UV spectroscopy in acid (pH 1.0), neutral (pH 7.2), alkaline (pH 11.0) and by mass spectroscopy. RESULTS: The results showed that GMA could bind with dAMP, dCMP, dGMP and calf thymus DNA by covalent bond, and the binding sites were specific (N6 of adenine, N3 of cytosine). Meanwhile, a main GMA-DNA adduct in the reaction of GMA with calf thymus DNA was confirmed as N3-methacrylate-2-hydroxypropyl-dCMP. CONCLUSIONS: GMA can react with DNA and/or deoxynucleotide monophosphate and generate some adducts such as N6-methacrylate-2-hydroxypropyl-dAMP and N3-methacrylate-2-hydroxypropyl-dCMP, ets. Formation of GMA-DNA adducts is an important molecular event in gene mutation and cell transformation induced by GMA.

Animals↗
PubMed1998

Natural infection of a homozygous delta24 CCR5 red-capped mangabey with an R2b-tropic simian immunodeficiency virus.

A homozygous 24-bp deletion (Delta24) was found in the CC chemokine receptor 5 (CCR5) of 11 out of 15 red-capped mangabeys (RCMs), Cercocebus torquatus torquatus, both in Africa and in an American zoo. The CCR5 Delta24 defect encompassed eight amino acids in frame in the fourth transmembrane region. Unexpectedly, RCM-009, one of 11 homozygotes (Delta24CCR5/ Delta24CCR5), was found to be naturally infected with a divergent simian immunodeficiency virus (SIV) strain, which was not R5-tropic, but used CCR2b (R2b) as its major coreceptor. SIVrcmGab1 was the only R2b-tropic SIV among other divergent SIVs tested. Cells transfected with the Delta24 CCR5 did not support entry of R5-tropic SIVmac, SIVcpz, SIVmne, HIV-2, or HIV-1, and were also inactive in signal transduction mediated by beta-chemokines. At 86.6%, the Delta24 allelic frequency was significantly higher than that of the 32-bp deletion found in humans. The Delta24 frequency was 4.1% in 34 sooty mangabeys (SMs), a geographically isolated subspecies that was naturally infected with R5-tropic SIV. Finding identical deletions in two mangabey subspecies separated for 10,000 years or more dates the Delta24 CCR5 deletion as ancient. However, the source of the selective pressure for the high rate of CCR5 deletion in RCMs remains to be determined. The high allelic frequency of the Delta24 CCR5 in RCMs, in comparison to that of SMs, suggests that R2b-tropism may have been acquired by SIVrcm, as an adaptation to CCR5 genetic defects appeared in its host.

Amino Acid Sequence↗
PubMed1998

[Genetic polymorphisms of TH01 and VWA loci in Tibetans in China].

OBJECTIVE: To understand the genetic relationship between Han population and Tibetan population, the genetic polymorphisms of two STR loci, TH01 and VWA were studied in the Tibetans in China. METHODS: EDTA-blood specimens were collected from 89 healthy unrelated Tibetan individuals in Lasa. DNA was extracted using Chelex method. The DNA samples were amplified by PCR technique, and the PAGE horizontal electrophoresis were used to typing the PCR products. RESULTS: There were five alleles at TH01 locus in Tibetan population. The alleles frequencies were TH01*6:0.097, TH01*7:0.227, TH01*8:0.091, TH01*9:0.481 and TH01*9.3:0.104. A total of 12 genotypes were observed in 77 individuals for TH01. For VWA locus there were seven alleles and the allele frequencies were VWA *14:0.101, VWA*15:0.034, VWA*16:0.208, VWA*17:0.303, VWA*18:0.208, VWA*19:0.129 and VWA*20:0.017. A total of 20 genotypes for VWA were observed in 89 individuals. The results of test for Hardy-Weinberg equilibrium showed that the genotype distributions observed at both STR loci were correspondent with those expected(chi-square =7.421 df =8 P>0.05 for TH01; chi-square =19.61 df =14 P>0.05 for VWA). CONCLUSION: There is no significant difference between Han and Tibetan populations in allele frequencies at TH01 and VWA loci. The results of analysis using genetic distance and phylogenetic tree indicate that Tibetan population is identical with Han population at TH01 and VWA loci .

Asian People↗
PubMed1998

Late-onset minor and major depression: early evidence for common neuroanatomical substrates detected by using MRI.

The purpose of our study was to examine the neuroanatomical correlates of late-onset minor and major depression and to compare them with similar measures obtained from nondepressed controls. Our study groups were comprised of 18 patients with late-onset minor depression, 35 patients diagnosed with late-onset major depression, and 30 nondepressed controls. All subjects were scanned by using a 1. 5-tesla MRI scanner. Absolute whole brain volume and normalized measures of prefrontal and temporal lobe volumes were obtained and used for comparison among groups. Our findings indicate that patients with minor depression present with specific neuroanatomical abnormalities that are comparable with the major depression group but significantly different from the controls. Normalized prefrontal lobe volumes show a significant linear trend with severity of depression, with volumes decreasing with illness severity. Whole brain volumes did not differ significantly among groups. These findings have broad implications for the biology of late-life depression and suggest that there may be common neurobiological substrates that underlie all clinically significant forms of late-onset mood disturbances.

Aged↗
PubMed1998

[Genetic polymorphism at D20S161 locus in Chinese populations].

OBJECTIVE: To understand the genetic relationship between different populations in China and to obtain the preliminary data on the genetic poly- morphisms of D20S161 in seven populations in China. METHODS: EDTA-blood specimens were collected from 753 healthy unrelated individuals in seven Chinese populations, including Chengdu(Han), Guangzhou(Han),Jilin(Han),Lasa (Tibetans),Dali(Bai), Nanning(Zhuang) and Hailaer(Menggu),respectively. DNA was extracted with Chelex method. The DNA samples were amplified by PCR technique, and the PAGE horizontal electrophoresis was used for typing the PCR products. RESULTS: Seven alleles at D20S161 locus were observed in six populations,while six alleles at D20S161 were observed in one population in Dali(Bai). The numbers of genotypes observed were 25, 19,21,19,16,20 and 22 for Chengdu(Han), Guangzhou(Han), Jilin(Han), Lasa(Tibetans), Dali(Bai), Nanning(Zhuang)and Hailaer(Menggu), respectively. The allele frequencies were D20S161*16:0.0220-0.0657, D20S161*17:0.1429-0.2947,D20S161*18: 0.3237-0.4835. D20S161*19:0. 0909-0.1850,D20S161*20:0.1263-0.1786,D20S161* 21: 0.0421-0.1010, D20S161*22:0-0.0250.A total of 26 genotypes were observed in 753 individuals. The heterozygosity was between 65.31% 80.41% for the seven populations. The results of test for Hardy-Weinberg equilibrium showed that the genotype distributions observed were correspondent with the expected. CONCLUSION: There are seven alleles in Chinese populations, of which D20S161*18 is most frequently observed. No significant difference in the distribution of allele frequencies at D20S161 (X2=57.9342,P>0.01) was noted among the seven Chinese populations. D20S161 may be a very useful genetic marker for both paternity test and personal identification of casework in forensic medicine and for the purpose of population genetics.

Base Sequence↗
PubMed1998

[Genetic polymorphism of FXIII B subunit in seven Chinese populations].

OBJECTIVE: To understand the distribution of allele frequencies of blood factor XIIIB subunit(FXIIIB) in Chinese populations and evaluate the genetic polymorphism of FXIIIB for the purposes of population genetics and forensic haemogenetics. METHODS: The genetic polymorphism of FXIIIB subunit in seven Chinese populations was investigated. Isoelectrofocusing technique on polyoacrylamid gels followed by immunoblotting was used to determine the phenotype of individuals in each population sample. RESULTS: There were three common alleles in all the seven Chinese populations. The frequency of FXIIIB*3 was the highest, that of FXIIIB*2 was the lowest, and the one of FXXIIIB*1 was at the middle. All of them reached to the polymorphism's level. A rare variant allele was also found in some Chinese populations. Comparison of the constituents of FXIIIB phenotypes in the seven populations showed that there was no significant difference (P>0.05). The distribution of the allele frequencies in these populations reflected most likely the mode of the distribution in all Chinese populations. The phylogenetic tree and genetic distance, based on the allele frequencies of FXIIIB differentiated the populations in the world into the main ethnic groups as what other authors reported. CONCLUSION: FXIIIB is a useful genetic marker for population genetics and forensic haemogenetics.

China↗
PubMed1998

[Genetic polymorphisms of FABP2 and F13A1 loci in Han population].

OBJECTIVE: To find more STR loci usable in forensic medicine and understand the distribution of the genetic polymorphisms of two STR loci FABP2 and F13A1 in the Han population in Chengdu. METHODS: EDTA-blood specimens were collected from 115 healthy unrelated Han individuals in Chengdu, DNA was extracted using Chelex method. The DNA samples were amplified by PCR technique, and the PAGE horizontal electrophoresis was used for typing of the PCR products. RESULTS: The allele frequencies were FABP2*1:0.513,FABP2*2:0.096, FABP2*3:0.330, FABP2*4:0.052, FABP2*5:0.009, and 10 genotypes were observed in 115 individuals for FABP2; while for F13A1, the allele frequencies were F13A1*1:0.128, F13A1*2: 0.053, F13A1*3:0.288, F13A1*4:0.527, F13A1*5:0.004 and 10 genotypes were observed in 113 individuals. The result of test for Hardy-Weinberg equilibrium showed that the genotype distribution observed at FABP2 locus was correspondent with the expected. CONCLUSION: FABP2 may be a useful marker for paternity test or personal indentification of biological stain. On the other hand, more studies need to be done to understand the polymorphism at F13A1 locus in Chinese population because a deviation from Hardy-Weinberg equilibrium has been observed in this Han population.

Carrier Proteins↗
PubMed1998

c-Rel is essential for B lymphocyte survival and cell cycle progression.

c-Rel is a lymphoid-specific member of the NF-kappaB/Rel family of transcriptional factors. To investigate the role of c-Rel in B lymphocyte function, we generated a c-Rel(-/-) mouse via a gene targeting approach. Although early lymphocyte development is normal in c-Rel(-/-) mice, there are significantly fewer B cells displaying a memory (IgM/IgD-) phenotype. Upon immunization, c-Rel(-/-) mice generate fewer B cells with a germinal center (PNAhi) phenotype. In vitro, c-Rel(-/-) B cells proliferate poorly upon ligation of their surface IgM or CD40 receptors or when stimulated with either lipopolysaccharide (LPS) or T cell help. Early molecular events that precede proliferation, such as increases in RNA synthesis as well as IL-2 receptor alpha chain expression, are greatly diminished in c-Rel(-/-) B cells. Furthermore, c-Rel(-/-) B cells are impaired in the ability to receive survival signals generated by anti-IgM or LPS. In contrast, CD40-mediated cell survival is normal in c-Rel(-/-) B cells, suggesting the involvement of a survival-signaling pathway that is independent of c-Rel. When c-Rel (-/-) B cells are co-stimulated with either anti-IgM and CD40 or LPS and CD40, they are rendered capable of progressing through the cell cycle. Finally, co-culture experiments suggest that the defects observed in c-Rel(-/-) B cells are intrinsic to the cell and can not be rescued through either cell-cell contact or addition of soluble factors. Thus, c-Rel is requisite for differentiation to the germinal center and memory B cells in vivo and is required for the transduction of survival and cell cycle progression signals mediated by anti-IgM and LPS in vitro. Furthermore, while c-Rel is involved in CD40-induced proliferation, it is apparently dispensable for the survival signals transduced by CD40.

Animals↗
PubMed1998

Semaphorins A and E act as antagonists of neuropilin-1 and agonists of neuropilin-2 receptors.

Neuropilin-1 (NP-1) has been identified as a necessary component of a semaphorin D (SemD) receptor that repulses dorsal root ganglion (DRG) axons during development. SemA and SemE are related to SemD and bind to NP-1, but do not repulse DRG axons. By expressing NP-1 in retinal neurons and NP-2 in DRG neurons, we demonstrate that neuropilins are sufficient to determine the functional specificity of semaphorin responsiveness. SemA and SemE block SemD binding to NP-1 and abolish SemD repulsion in axons expressing NP-1. SemA and SemE seem to have a newly discovered protein antagonist capacity at NP-1 receptors, whereas they act as agonists at receptors containing NP-2.

Animals↗
PubMed1998

Tetramethylpyrazine, a Chinese drug, blocks coronary vasoconstriction by endothelin-1 and decreases plasma endothelin-1 levels in experimental animals.

The purpose of this study was to investigate effects of tetramethylpyrazine (TMP), a Chinese plant-derived medicine, on coronary vasoconstriction and related electrocardiographic and histologic changes caused by endothelin-1 (ET-1), and on plasma ET-1 levels. ET-1 (75 pmol) was administered into the left coronary artery (LCA) in anesthetized closed-chest dogs with and without prior infusion of TMP (80 mg/kg). Coronary arterial diameter (CAD) was determined by coronary arteriography (CAG). Blood pressure and electrocardiogram (ECG) were monitored continuously. Histologic damage in tissues was ascertained microscopically. Plasma ET-1 and 6-keto-PGF1 levels were determined by RIA 90 min after i.v. injection of TMP (25 mg/kg; n = 5) in rabbits. Intracoronary injection of ET-1 resulted in a significant vasoconstriction of the entire vascular bed of the LCA, with a decrease in CAD of 35.9 +/- 5.7% (n = 5; p < 0.01) and ischemic changes on ECG and in tissues of endocardium, myocardium, coronary endothelial cells, and capillary vessels. Pretreatment with TMP produced a significant increase in CAD by 38.5 +/- 7.8% (n = 5; p < 0.01) and greatly suppressed the vasoconstriction produced by ET-1. The myocardial tissue damage estimated from the ratio of ischemic area for the entire area after ET-1 injection (35.6%) was completely abolished by TMP (0.6%). In addition, TMP injection induced a significant decrease in plasma ET-1 levels and an increase in 6-keto-PGF1 levels in rabbits. The Chinese medicine TMP could be a useful therapeutic agent in ischemic heart disease by suppressing coronary vasoconstriction and ischemic changes in the tissues produced by ET-1.

6-Ketoprostaglandin F1 alpha↗