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Biomedical subjects

J Gu

Publications and source records attributed to J Gu.

At least 73 records · Page 4Linked to original sources
PubMed2001

[NO involvement in mediation of spinal neuron sensitization in morphine-withdrawal rats].

The effects of nitric oxide (NO) on the activation of spinal cord neurons were studied using immunocytochemistry, intrathecal injection and antisense oligonucleotides (AS-ONs) techniques in morphine-withdrawal rats. Acute administration of naloxone and chronic administration of morphine changed neither the expression of Fos-LI and NADPH-d positive neurons nor the expression of Fos/NADPH-d double-labeled neurons in the spinal cord of rats. Fos-LI, NADPH-d positive and Fos/NADPH-d double-labeled neurons were increased significantly in number in morphine-withdrawal rats and they were observed in all the laminae of the spinal cord. Intrathecal injection of L-NA, nNOS antisense oligonucleotides significantly inhibited the expression of Fos-LI in the spinal cord and decreased the scores for morphine-withdrawal symptoms in morphine-withdrawal rats, but not in nNOS-S group. The results suggest that NO mediates the spinal neurons sensitization in morphine-withdrawal rats.

Animals↗
PubMed2001

The effects of Lei Gong Teng on reproductive hormones.

The serum reproductive hormone levels were examined with radioimmunoassay in women of child-bearing age before and after treatment with the prescriptions containing Lei Gong Teng ([symbol: see text] Radix Tripterygii Wilfordii). The results showed that Lei Gong Teng could induce amenorrhea, but it was reversible.

Adolescent↗
PubMed2001

[The technical method for noninvasive magnetic stimulation of nerve center and its clinical application].

The increasing use of non-invasive magnetic stimulation technique for nerve center function examination and functional neuromuscular rehabilitation is a new cynosure in biomedical engineering and neuro-electrophysiologic researches. This paper analyzes theoretically the magnetic stimulation of first demonstration extending the technique model to human body, and the magnetic principle of physics. The characteristics of magnetic stimulation can be highlighted by comparing it to conventional electrical stimulation. Also presented are the peripheral multichannel magnetic stimulation to mimic electrical stimulation and the clinical functions toward neuromuscular rehabilitation.

Central Nervous System↗
PubMed2001

[Degradation of the herbicide dicamba under strictly anaerobic conditions].

Degradation of the herbicide dicamba was assayed under methane-producing condition using a coastal wetland soil as an inoculum. Benzene ring 14C labeled dicamba was employed and degradative process proceeds through demethoxylation yielding 3,6-dichlorosalicylic acid as the predominant intermediate. The data showed that the degradation rate of dicamba by the enrichment culture achieved 64%, 91% and 95% after 7, 16 and 27 days of incubation, respectively; only small quantities of CO2(0.74%) and CH4(0.11%) were recovered with insignificant radioactivity. The benzene ring of dicamba was not cleavaged to a significant extent. Future cleaning up of dicamba contaminated environment may require an effective bioremediation techniques.

Anaerobiosis↗
PubMed2001

NO mediated increase of Fos protein and NMDA1A R mRNA expression in rat spinal cord during morphine withdrawal.

AIM: To investigate the effects of nitric oxide (NO) on activation of the rat spinal cord neurons during naloxone-precipitated morphine withdrawal. METHODS: Fos immunocytochemistry, NADPH-d histochemistry, Fos/NADPH-d double-labeling, intrathecal injection, antisense oligonucleotides (AS-ONs) techniques, and RT-PCR were used. RESULTS: Acute administration of naloxone and chronic administration of morphine did not change the expression of Fos protein and NADPH-d positive neurons, and there was no expression of Fos/NADPH-d double-labeled neurons in the spinal cord of rats. Morphine withdrawal increased the expression of Fos protein, NADPH-d positive, and Fos/NADPH-d double-labeled neurons, and they were observed in all the laminae of the rat spinal cord. Intrathecal injection of nNOS antisense oligonucleotides (nNOS-AS) inhibited the increase of Fos protein and NMDA(1A)R mRNA expression in the rat spinal cord during morphine withdrawal and decreased the scores of morphine withdrawal symptoms. The effect of nNOS-AS was greater than that of eNOS-AS. There was no effect in nNOS sense oligonucleotides (nNOS-S) group. CONCLUSION: NO mediated the increase of Fos protein and NMDA1A R mRNA expression in the rat spinal cord during morphine withdrawal.

Animals↗
PubMed2001

Confirmation of susceptibility gene loci on chromosome 1 in northern China Han families with type 2 diabetes.

OBJECTIVE: To confirm previous effort to identify type 2 diabetes susceptibility genes in a Northern Chinese population by conducting a new genome scan with both an increased number of type 2 diabetes families and a new set of microsatellite markers within the previously localized regions. METHODS: A genome scan method was applied. After multiplexed PCR, electrophoreses, genescan and genotyping analysis, we obtained size information for all loci, and then a further study was done by both parametric and non-parametric linkage analysis to investigate the P values and Z values of these loci. RESULTS: We surveyed 34 microsatellite markers which distributed within 5 regions along chromosome 1, and a total of 12,000 genotypes were screened. Evidence of linkage with diabetes was identified for 8 of the 34 loci. All P values of the 8 loci were lower than 0.05, and the highest Z value was 2.17. A very interesting finding is that all 5 markers at the p- terminal 1p36.3-1p36.23 region, spanning a long range of 16.9 cM, were identified to have a low P value of less than 0.05, which suggests that this region may contain multiple susceptibility genes. Regions 4 and 5 also confirmed the previous findings, and we narrowed these two regions to a 2.7 cM and 2.5 cM regions, respectively. CONCLUSIONS: We further confirmed the results gained in the previous genome-wide scan using an increased number of NIDDM families and a new set of microsatellite markers lying within the initially localized regions. The fact that all 5 loci at the p- terminal region displayed a low P value of less than 0.05 suggests that more than 1 susceptibility gene may reside in this region.

Chromosomes, Human, Pair 1↗
PubMed2001

Factor V Leiden mutation in one family of Chinese origin.

OBJECTIVE: To investigate the factor V Leiden mutation associated with activated protein C resistance (APCR) in Chinese. METHODS: Thirty "normal" individuals and twenty patients with thrombotic disease from Chinese Han Nationality were studied with APTT +/- APC, PCR followed by MnLI restriction enzyme analysis, PCR based direct sequence-specific primers (PCR-SSP) and DNA sequence analysis. RESULTS: In one healthy control, the activated protein C (APC) sensitivity ratio (SR) was found to be significantly lower (0.8) than that in other normal control (> 2.0). This individual was identified to be heterozygous for FV Leiden mutation (Arg506-Gln). His grand-uncle, father, brother and son were also identified to be heterozygous for FV Leiden. The APC resistance was found in 3 other cases of thrombotic diseases, but with no FV Leiden mutation. CONCLUSION: This is the first four generations family case of FV Leiden mutation associated with APCR reported within Chinese ethnic population. It is note-worthy that more FV Leiden or whether other gene defects may be associated with APC resistance and acquired APCR causing thrombosis in Chinese population.

Activated Protein C Resistance↗
PubMed2001

[Breast reconstruction with a TRAM flap].

OBJECTIVE: Breast reconstruction with a transverse rectus abdominis myocutaneous (TRAM) flap was performed to enhance the mental and physical well-being of patients. METHODS: The experience with TRAM breast reconstruction in 42 patients was reviewed. The patient selection, flap design and our operative technique were introduced in detail. RESULTS: TRAM breast reconstruction was performed as immediate reconstruction in 25 patients, as delayed reconstruction in 17 cases. 2 cases had partial skin necrosis in the abdominal donor site. 2 had partial necrosis of the TRAM flap. One patient had abdominal hernia. CONCLUSIONS: The additional vascular anastomosis or double-pedicle TRAM flap with intramuscular dissection was the key points to reduce complications. Due to the difficulty of TRAM flap reconstruction, thorough understanding of the technique and surgical accuracy are necessary for both flap safety and aesthetic pleasing results.

Adult↗
PubMed2001

[Posterior semicircular canal occlusion with microwave assisted technique in guinea pigs].

OBJECTIVE: To study the effectiveness of posterior semicircular canal occlusion with microwave assisted technique. METHOD: Posterior semicircular canal occlusion with microwave assisted technique was performed in 20 guinea pigs. Electronystagmography (ENG) and auditory brainstem response (ABR) were recorded preoperatively and postoperatively. Morphological changes were observed under light microscopy. RESULT: Left and right nystagmus returned symmetrical on the 3rd postoperative day. Two ears showed normal symmetrical nystagmus to icc-water stimulation on preoperation and the 30th postoperative day. There were no significant changes of the thresholds of ABR before and after surgery. Histopathological findings revealed that posterior semicircular canal was completely occluded, and that Organ of Corti and crista ampullaris were normal. CONCLUSION: Posterior semicircular occlusion with microwave technique is suggested as an effective and safe treatment for the benign paroxysmal positional vertigo.

Animals↗
PubMed2001

[High level expression of human recombinant albumin gene in the yeast Pichia pastoris].

The yeast Pichia pastoris was transformed by the multi-copy Pichia expression vector that can express secreted human albumin. The high level expression of cell line was selected after screening. The expression of human recombinant albumin in Pichia pastoris induced by different methods were compared. The ratio of secreted human albumin is 80% in total secreted proteins and the expression level reaches as high as is 10 g/L.

Albumins↗
PubMed2001

[Inhibition effect of soybean isoflavones on the oxidative modification of low-density lipoprotein].

In order to investigate the effect of soybean isoflavones(SI) on the oxidative modification to low-density lipoprotein(LDL) and to differentiate the effect of SI and alpha-tocopherol, in vitro and in vivo test were conducted. An in vitro model of LDL oxidative modification induced by copper-ion was established by monitoring the production of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes after SI or alpha-tocopherol was added. The in vivo test was conducted by feeding rats with a high fat diet supplemented with SI and measured the sensitivity of LDL oxidative modification mediated by Cu2+ in vitro. The results revealed that when SI was added into the in vitro LDL oxidation system, the content of TBARS or conjugated dienes in the system was much reduced with a dose-effect relationship, whether lipid oxidation being initiated or not by copper-ion at 37 degrees C. In comparison with SI, only a significant inhibiting effect on lipid oxidation while alpha-tocopherol was added before the initiation of oxidation. High fat diet induced a rising of LDL sensitivity of oxidative stress, and adding SI to the high fat diet could counteract the sensitivity of LDL oxidative modification significantly. It is concluded that SI is a valuable natural antioxidant different from alpha-tocopherol in inhibiting LDL oxidative modification both in vitro and inv vivo.

Animals↗
PubMed2001

[Clinical analysis of 184 eyes with perforating injury].

OBJECTIVE: Try to understand the occurrence and the prognosis of eyes with perforating injury. METHODS: By using retrospective analysis on 184 eyes with perforating injury. RESULTS: Perforating eyes hold 9.5% of total impatient, mostly happened in working place, foreign body is the main cause, the age is mostly from ten to 60, centralize from 20 to 30. the complication includes leucoma, cataract, vitreous hemorrhage etc. After operation, 71 eyes had visual acuity < 0.05. 60.85% of the patients had visual acuity > or = 0.05 and 0.65% of the patients are not cooperative. CONCLUSION: The rate of blindness on eyes with perforating injury is high, it implies that perforating injury could be prevented and treated from the data we collected.

Adolescent↗
PubMed2000

Molecular mechanism of hypoxia-inducible factor 1alpha -p300 interaction. A leucine-rich interface regulated by a single cysteine.

Hypoxia-inducible factor 1alpha (HIF1alpha) plays a pivotal role in embryogenesis, angiogenesis, and tumorigenesis. HIF1alpha-mediated transcription requires the coactivator p300, at least in part, through interaction with the cysteine- and histidine-rich 1 domain of p300. To understand the molecular basis of this interaction, we have developed a random mutagenesis screen in yeast approach for efficient identification of residues that are functionally critical for protein interactions. As a result, four residues (Leu-795, Cys-800, Leu-818, and Leu-822) in the C-terminal activation domain of HIF1alpha have been identified as crucial for HIF1 transactivation in mammalian systems. Moreover, data from residue substitution experiments indicate the stringent necessity of leucine and hydrophobic cysteine for C-terminal activation domain function. Likewise, Leu-344, Leu-345, Cys-388, and Cys-393 in the cysteine- and histidine-rich 1 domain of p300 have also been shown to be essential for the functional interaction. We propose that hypoxia-induced HIF1alpha-p300 interaction relies upon a leucine-rich hydrophobic interface that is regulated by the hydrophilic and hydrophobic sulfhydryls of HIF1alpha Cys-800.

Animals↗
PubMed2000

Comparison of bisoprolol and carvedilol cardioprotection in a rabbit ischemia and reperfusion model.

Carvedilol, a selective alpha(1) and non-selective beta-adrenoceptor antagonist and antioxidant, has been shown to provide significant cardiac protection in animal models of myocardial ischemia. To further explore the mechanisms contributing to the efficacy of carvedilol cardioprotection, the effects of carvedilol on hemodynamic variables, infarct size and myeloperoxidase activity (an index of neutrophil accumulation) were compared with a beta(1) selective adrenoceptor antagonist, bisoprolol. Carvedilol (1 mg/kg) or bisoprolol (1 mg/kg) was given intravenously 5 min before reperfusion. In vehicle-treated rabbits, ischemia (45 min) and reperfusion (240 min) resulted in significant increases in left ventricular end diastolic pressure, large myocardial infarction (64.7+/-2.6% of area-at-risk) and a marked increase in myeloperoxidase activity (64+/-14 U/g protein in area-at-risk). Carvedilol treatment resulted in sustained reduction of the pressure-rate-index and significantly smaller infarcts (30+/-2.9, P<0.01 vs. vehicle) as well as decreased myeloperoxidase activity (26+/-11 U/g protein in area-at-risk, P<0.01 vs. vehicle). Administration of bisoprolol at 1 mg/kg resulted in a pressure-rate-index comparable to that of carvedilol and also decreased infarct size (48.4+/-2.5%, P<0.001 vs. vehicle, P<0.05 vs. carvedilol), although to a significantly lesser extent than that observed with carvedilol. Treatment with bisoprolol failed to reduce myeloperoxidase activity in the ischemic myocardial tissue. In addition, carvedilol, but not bisoprolol, markedly decreased cardiac membrane lipid peroxidation measured by thiobarbituric acid formation. Taken together, this study suggests that the superior cardioprotection of carvedilol over bisoprolol is possibly the result of carvedilol's antioxidant and anti-neutrophil effects, not its hemodynamic properties.

Adrenergic beta-Agonists↗
PubMed2000

Tumor-specific transgene expression from the human telomerase reverse transcriptase promoter enables targeting of the therapeutic effects of the Bax gene to cancers.

Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase, which is highly active in immortalized cells and >85% of human cancers but is quiescent in most normal somatic cells. To test the feasibility of using the hTERT promoter to induce tumor-specific transgene expression in cancer gene therapy, we constructed an adenoviral vector expressing a LacZ reporter gene driven by the hTERT core promoter and evaluated its activity in vitro and in vivo. The hTERT promoter could drive high-level expression of LacZ in tumor cells but not in normal cells and normal mouse tissues. Using a binary adenoviral system that can induce Bax gene expression, we showed that induction of the Bax gene expression via the hTERT promoter elicited tumor-specific apoptosis in vitro, suppressed tumor growth in nude mice, and prevented the toxicity of the Bax gene in vitro and in vivo. Thus, the hTERT promoter is apparently a strong and tumor-selective promoter with potential application in targeted cancer gene therapy.

Adenoviridae↗