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Biomedical subjects

Y Zhou

Publications and source records attributed to Y Zhou.

At least 451 records · Page 25Linked to original sources
PubMed1999

Nitric oxide synthase--its distribution and alteration in the intramural ganglia of the urinary bladder in normal and urethra-obstructed guinea pigs.

Nitric oxide (NO) has been proposed to function as an inhibitory neurotransmitter in the lower urinary tract. This study investigates the distribution of NO-containing neurons and its changes following urethral obstruction in the guinea-pig. By using nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry and NO synthase (NOS) immunohistochemistry, the highest frequency of NO-containing neurons was observed in the bladder base. Double labelling studies showed that 70.9% of NADPH-d reactive neurons co-expressed NOS immunoreactivity. Acetylcholinesterase reactivity was present in the majority of the intramural neurons with 54% of them expressed NOS immunoreactivity. NADPH-d reactivity was colocalized with vasoactive intestinal polypeptide, calcitonin gene-related peptide and substance P immunoreactivities in both neurons and fibres. Colocalization study also revealed that NADPH-d reactive neurons formed a distinct cell population from tyrosine hydroxylase positive neurons. At 12 hours after urethral obstruction, NADPH-d reactivity in the intramural ganglion cells was noticeably enhanced and this was sustained till 24 hours whence some intensely stained neurons appeared to undergo degenerative changes. Neuronal degeneration was more drastic at 48 hours so that the number of NADPH-d positive neurons was significantly reduced. The present study suggests that NO is an important neurotransmitter in the urinary bladder and that it may be involved in the relaxation activity in the bladder base during micturition. It is speculated that the increased NADPH-d reactivity in intramural ganglion cells elicited by urethral obstruction may be responsible for the cell death. It is suggested that the resulting cell loss or bladder denervation may account for the urinary dysfunction such as frequency and urgency of micturition in patients with urethral obstruction.

Acetylcholinesterase↗
PubMed1999

Hirudin display on the surface of bacteriophage M13.

Hirudin was fused to the N terminus of M13 minor protein gp3 (197-406) through a linker GGGS by inserting both the hirudin gene and the gp8 signal sequence into the modified phagemid vector pCANTAB 5V to construct pCANTAB 5G8-Hir. The expressed fusion protein was directed by gp8 signal peptide into the periplasm and assembled to the phage particle to form the hirudin-phage. The fusion protein and fusion phage were detected with biotin-thrombin by Western blotting analysis. Antithrombin activity analysis confirmed that the hirudin portion in the fusion protein and fusion phage bear similar native conformation. The successful display of hirudin on the surface of M13 phage laid a sound foundation for the further study on directed evolution of antithrombotic proteins with altered properties.

Antithrombins↗
PubMed1999

Expression of nerve growth factor from Agkistrodon halys Pallas in E. coli and its purification.

The nerve growth factor (NGF) gene of Agkistrodon halys Pallas was cloned into a secretive prokaryotic expression vector pET-22b+ which carried a C-terminal His. Tag sequence. After transforming into E. coli BL21 (DE3), NGF was induced to express at 30 degrees C by IPTG. SDS-PAGE analysis showed an induced expression product band which constituted about 20% of the total bacterial proteins. However, its molecular weight was larger than what was expected. Moreover, the analysis of product solubility revealed that NGF was in the form of inclusion bodies. The inclusion bodies were solubilized in 6 mumol/L guanidine HCl and purified directly by immobilized metal (Ni2+) chelation affinity chromatography. The product was renatured by dilution and air oxidation in the presence of 5 mumol/L CuSO4, and was proved active by examining the survival rate of PC12 cells in a serum-free medium.

Agkistrodon↗
PubMed1999

[Endothelial cell damage induced in vitro by subeschar tissue fluid].

OBJECTIVE: To assess the effect of subeschar tissue fluid (STF) on the function and structure of endothelial cell in vitro. METHODS: Human umbilical vein endothelial cells (HUVEC) were incubated with STF obtained from patients in the early postburn stage. Then the morphological changes in EC were observed, and activity of EC and contents of LDH, 6-keto-PGF1 alpha in media were determined. RESULTS: The activity of LDH and the content of 6-keto-PGF1 alpha were increased gradually after HUVEC incubated with STF, and were higher than that measured after HUVEC incubated with healthy volunteer's sera. Furthermore, activity of HUVEC decreased and they became deformed, showing shrinkage of the cell body with enlargement of intercellular space. In addition, small vacuoles appeared in cytoplasm with karyopyoknosis after 24 h. CONCLUSION: STF can damage endothelial cell and might play an important role in the pathophysiological process of burn injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

PCR assay for the inversion causing severe Hemophilia A and its application.

OBJECTIVE: To develop a new technique based on long distance polymerase chain reaction (LD-PCR) to replace Southern blotting method to detect Factor VIII (FVIII) gene inversion leading to severe Hemophilia A (HA) and carrier. METHODS: Four primers P, Q, A&B were designed and synthesized. P&Q is specific for 5' and 3' flanking regions of F8A1 respectively. A&B is specific for 5' and 3' flanking regions of F8A2/F8A3 respectively. LD-PCR with 3 primers and 3 temprature was set up, optimized and used to detect the inversion. RESULTS: The LD-PCR with primers P, Q, A&B, P, Q&B and P, Q&A can be used to detect the gene inversion and discriminate carrier from wild type. A blind analysis of 53 DNA samples from HA families was carried out by the LD-PCR and Southern blotting respectively. Two sets of the results were completely identical. They were 23 cases of inversion, 27 cases of wild type and 3 cases of carriers. The sensitivity and specificity of LD-PCR are both 100%. Three inversion hemizygotes and 4 female carriers were identified from 5 HA families by the LD-PCR technology. CONCLUSIONS: The LD-PCR with primer P, Q&B or P, Q, A&B can be used to detect the gene inversion and the carrier of inversion. Compared with Southern blotting, this technique is simple, rapid, inexpensive, more sensitive, accurate and non-isotopic.

Chromosome Inversion↗
PubMed1999

Corneal topographic analysis after excimer photorefractive keratectomy.

OBJECTIVE: To evaluate the corneal surface changes and visual quality after excimer photorefractive keratectomy (PRK) for myopia. METHODS: Corneal topographic analysis was performed on 23 patients (38 eyes) with myopia after PRK at the 1-, 3-, 6- month postoperative follow-up visits. RESULTS: The corneal sphericity was changed after excimer PRK. As time went on, the mean surface regularity index (SRI) and the surface asymmetry index (SAI) decreased gradually, and the corneal surface became more smooth; mean simulated keratoscope readings (SimK) showed a gradual restoration. At the 6-month postoperative examination, corneal topography showed four main patterns of ablation: round or oblong (50%), collar-button (23.68%), semicircular (18.42%) and central island (7.9%). Patterns of ablation were correlated with visual acuity. CONCLUSION: The quantitative analysis of corneal topography is essential for evaluating corneal surface changes after PRK and helpful in the surgical design of PRK and in predicting the refractive outcome with greater precision.

Adolescent↗
PubMed1999

[Treatment of mass burns].

OBJECTIVE: Present paper aims at summing up the experience from 42 cases over a four year period(1993-1997) in ten events of mass burn casualties. METHODS: 42 cases were analyzed retrospectively, in whom 15 cases sustained III degree burn over 50% TBSA. Among them 7 cases had III degree burn over 70% and 3 cases with III degree burn over 90%. RESULTS: One case (70% TBSA) died of acute respiratory distress syndrome on third postburn day. Another (III degree 70%) died of acute renal failure on seventh postburn day. The remaining 40 cases were successfully cured. CONCLUSION: Experiences gained in burn care in these ten mass casualties included: sending forward the medical expertise to the site of disaster; airlifting to accelerate transportation, adequate resuscitation in shock stage; early massive excision of eschar and skin grafting; control of burn infection; prevention of Curling ulcer hemorrhage, emphasis on supportive therapy; and the establishment of a skin bank.

Adolescent↗
PubMed1999

[Pathological changes of intracranial arteries in cerebral infarction].

OBJECTIVE: To investigate the cause and severity of intracranial arterial lesions in extensive cerebral infarction (CI). METHODS: 78 consecutive autopsy cases were studied. They included 58 cases of CI and 20 cases of other diseases as control. Medium-sized intracranial arteries and their main branches, small intracerebral arteries, and arterioles were examined with light microscopy. Quantitative analysis was made with computer. RESULTS: CI due to embolism was seen in 33/58 (56.9%) cases, thrombosis in 11/58 (19%), and unknown etiology in 14/58 (24.1%). The mean LA-VA ratios of the medium-sized intracranial arteries and their main branches, small intracerebral arteries and arterioles were lower in the CI patients than in the controls (P < 0.01). Atherosclerotic narrowing of the distal part of M1 segment of both lateral cerebral middle arteries, the basilar arteries and the main branches in the patients with thrombosis was markedly more severe than in those with embolism (P < 0.05, P < 0.01). CONCLUSION: Patients with CI have arterial lesions of different levels but the principal portions of cerebral artery lesions are the medium-sized intracranial arteries and their main branches. Thrombosis and embolism with medium, severe atherosclerotic narrowing of several arteries may play an important role in causing extensive CI in the middle aged and the elderly.

Aged↗
PubMed1999

[Glutamine dipeptide enriched enteral nutrition improving gut permeability in sever burns].

OBJECTIVE: To determine the effect of glutamine dipeptide on gut permeability in severe burns. METHODS: Twenty-four severe burn patients were randomly divided into two groups: control group and GLN group. All patients received enteral nutrition for 12 days after burn. Both groups were isocaloric and isonitrogen. GLN group patients were given nutrition solution enriched with glutamine dipeptide at a dosage at 0.5 g.kg-1.day-1 (equivalent to L-glutamine 0.3 mg.kg-1.day-1). On the day 1 and 12 after burn, the plasma amino acid was measured by a standard amino acid analyzer. On the day 1, 3, 6 and 12, the gut permeability was detected with Lactulose and Manitol assay by HPLC-PED, and then wound healing rate of burn area was determined on the day 30 and hospital stay was recorded. ANOVA was done for data analysis. RESULTS: The plasma GLN concentrations decreased in both groups on day 1, (control group: 361.3 +/- 70.8 microns/L, GLN group: 348.6 +/- 52.5 microns/L, P = 0.624, normal value: 659.5 +/- 35.0 microns/L), and the GLN group showed high plasma GLN concentration on day 12 (566.4 +/- 128.3 microns/L), with significant difference between control group (417.6 +/- 74.8 microns/L, P = 0.002). On day 1, L/M ratio value was the highest in both groups. On day 3, L/M ratio in the GLN group became lower than that of control group, and returned to normal on day 6 and maintained to day 12. There were significant differences of wound healing rate between the two groups and the length of hospital stay on day 30 (CONTROL GROUP: (81 +/- 7)%, GLN group: (89 +/- 7)%, 0.018) (CONTROL GROUP: 68 +/- 27 days, GLN group: 49 +/- 13 days, P = 0.049). CONCLUSION: The glutamine-dipeptide enriched enteral nutrition can improve the plasma GLN level after severe burn, decrease the gut permeability from early stage, ameliorate wound healing rate on day 30, and reduce hospital stay.

Adolescent↗
PubMed1999

[Pre- and post surgical orthodontic treatment of mandibular prognathism].

OBJECTIVE: To analyze the patients we treated in clinic through combined orthodontic-orthognathic surgery, and get some guidance for the future clinical work. METHODS: All 40 skeletal Class III malocclusion patients we analyzed were from joint clinic of our hospital. They aged from 17 to 38. RESULTS: The duration for presurgical orthodontic treatment was 9 months on average (2-25 months), and for postsurgical orthodontic treatment about 7.6 months on average (2-15 months). The duration for whole active treatment was 16 months on average (4-41 months). The objectives of presurgical orthodontic are: Alignment of dental arches, decompensation of anterior and posterior teeth, leveling of arches, and coordination of the width of the upper and lower arches. After presurgical orthodontic treatment, most of the patients could be treated by one piece surgery, which could simplify the surgical procedure and reduce the relapse rate of surgery. During the surgery, we modified the intermaxilary fixation wires. We used rigid rectangular stainless steel wires with Edgewise appliances as the fixation wires instead of conventional canine and molar bands with multiloop wires. The aims of the postsurgical orthodontic treatment are: closing residual spacing, extrusion of posterior teeth for correction of local openbite in premolars region, paralleling of the teeth, and adjustment of occlusion. CONCLUSION: Pre- and post-ssurgical orthodontic treatment is essential to the surgical treatment for mandibular prognathism.

Adolescent↗
PubMed1999

[The comparison of bone densities of mandible and coxofemoral region between senile people with edentulous jaws and those with dentate jaws].

OBJECTIVE: To observe if the senile people with edentulous jaws had lower bone dentilies of mandible and coxofemoral region than those with dentate jaws, and to find the systemic risk factors which were responsible for the tooth loss and the formation of edentulous jaws. METHODS: Two groups of senile people were selected. One group was edentulous and the other was dentate. All of them were examined by dual energy X-ray absorptiometry(DXA). RESULTS: The senile people with edentulous jaws had significantly lower bone densities of mandible(P < 0.001) and they also had lower bone densities of coxofemoral region than the dentate group people. CONCLUSION: It indicated that the decreased of bone densities of mandible and coxofemoral region was one of the systemic risk factors for tooth loss and the formation of edentulous jaws.

Age Factors↗
PubMed1999

[Effect of ginseng injection in treating congestive heart failure and its influence on thyroid hormones].

OBJECTIVE: To observe the effect of Ginseng injection on congestive heart failure (CHF) and its influence on thyroid hormones. METHODS: Fifty-four Patients of CHF were divided into two groups. On the basis of conventional treatment of western medicine, the Ginseng injection was given to the treated group additionally. Blood level of triiodothyronine (T3), thyroxine (T4), reverse triiodothyronine (rT3) and thyroid stimulating hormone (TSH) of all patients were determined before and after treatment by radioimmunoassay. RESULTS: There were significant difference between the treated group and the control group in cure rate and mean course of therapy. The levels of T3 and T4 of all patients were lower than those of the normal control before treatment, and rT3 were higher. Two weeks after treatment, T3 and T4 level in all patients increased significantly and rT3 level significantly decreased(P < 0.05, P < 0.01). CONCLUSION: Ginseng injection has a good effect on patients with CHF. It also has regulatory effect on thyroid hormones.

Adult↗
PubMed1999

[A study on the pathogenicity of acute hepatitis G infection].

OBJECTIVE: To study the infection due to hepatitis G virus (HGV) in liver tissues of patients with acute hepatitis and to investigate its pathogenicity. METHODS: HGV NS5 antigen was detected by using immunohistochemical method in the liver biopsy tissues of patients with acute hepatitis but serologically negative to hepatitis virus antigens from A to E. The clinical and pathological data were also analysed. RESULTS: 37 samples were tested, HGV NS5 antigen was detected in 14 (37.8%). 4 of the 14 were positive for HGV NS5 antigen alone (acute hepatitis G group) and 10 other cases were also positive for HBsAg, hepatitis C virus (HCV) NS3 antigen or EB virus antigen (superinfection group). 7 cases were HBsAg positive alone (acute hepatitis B group) and the remaining 16 cases were negative for all the antigens mentioned above (non-A - G hepatitis group). There was no difference among the 4 groups in the detecting rate of Fas antigen, histological activity index (HAI), serum alanine transferase (ALT) and total bilirubin (TBil). CONCLUSION: It is suggested that HGV appears to play some role in the pathogenesis of acute viral hepatitis and the degree of liver injury in acute hepatitis G may be as severe as that of hepatitis caused by other types of viruses.

Acute Disease↗
PubMed1999

[Immune responses to recombinant expression plasmid encoding hepatitis C virus core antigen].

OBJECTIVE: To study the feasibility of DNA immunization with recombinant expression plasmid containing hepatitis C virus (HCV) core gene against HCV infection. METHODS: The recombinant plasmid containing HCV C gene was constructed and expressed transiently by using lipofectamine in the mouse SP2/0 cells. After appraisal and purification, these plasmid and control DNA were directly injected intramuscularly into BALB/c mice, HCV C specific antibody in the sera was checked with ELISA. Proliferative responses of spleen cells from experimental and control mice were determined by (3)H thymidine incorporation and cytotoxicity T lymphocyte (CTL) activity was measured by standard 4-h (51)Cr release assays. RESULTS: All immunized mice developed anti-HCV core antibodies and this antibody was dose and immune number dependent. Lymphoproliferative responses for HCV core antigen were higher in immunized mice than in control mice (P < 0.05), stimulation indices (SI) were 2.42 - 6.10. CTLs might induce approximately 63.13% lysis of pcDNA HCV C transfected SP2/0 target cells. CONCLUSION: It is suggested that HCV C gene immunization is a promising method of vaccination against HCV infection.

Animals↗
PubMed1999

[Evaluation of pre- and post-operational esophageal manometric findings with achalasia].

OBJECTIVE: To evaluate the manometric feature of pre- and post-operation with achalasia and the result of surgical myotomy through abdominal incision. METHODS: The manometric studies were performed in 23 pre- and 11 post-operational patients, including 11 patients who received both pre- and post-operational studies. 24 hour pH monitoring was performed in 11 after surgical myotomy. RESULTS: Achalasia, a motor disorder of the esophageal body, and hypertension of the resting LES impaired relaxation. The incidence of reflux was 22.2%. CONCLUSIONS: Surgical myotomy through abdominal incision is an effective procedure. It is necessary to avoid LES incompetence or reflux esophagitis.

Adult↗
PubMed1999

[Endogenous protective effects of superoxide dismutases on infectious brain injury in rats].

We studied the alterations of MDA and three forms of SOD activities such as T-SOD, CuZn-SOD, and Mn-SOD in rat cerebral tissues injected by bordetella pertussis (BP) to elucidate protective mechanism of SOD against the infectious brain injury. The results were that water content(WC), Evans blue content(EB), MDA, and Mn-SOD activities in 4 h and 24 h BP-treated groups increased and T-SOD and CuZn-SOD decreased compared to corresponding normal saline(NS)-treated groups, respectively(P < 0.01); MDA increased and had a positive correlation with WC and EB in 4 h BP treated group (r = 0.9650, r = 0.9441, P < 0.01, P < 0.01, respectively); Mn-SOD activities were elevated and had a negative correlation with WC, EB, and MDA (r = -0.8650, r = -0.9021, r = -0.9346, P < 0.01, P < 0.01, P < 0.01, respectively) in 24 h BP-treated group. The results suggest that the increase of component Mn-SOD activities may play an important role in vivo endogenous protective mechanism against delayed infectious brain injury.

Animals↗
PubMed1999

[Use of transcranial Doppler in monitoring cerebral blood flow velocity during peri-operation].

Transcranial Doppler was used to monitor 45 patients' middle cerebral artery blood flow velocity during anesthesia and cardiopulmonary bypass. The result was that the change in middle cerebral artery blood flow velocity was in correspondence with cerebral blood flow. This paper suggests that transcranial Doppler is a simple and practical instrument for monitoring cerebral blood flow.

Adolescent↗