Biomedical subjects

Y Zhou

Publications and source records attributed to Y Zhou.

At least 721 records · Page 40Linked to original sources

PubMed1996

[Rapid detection of Salmonella with MUCAP reagent].

The 4-methylumbelliferyl-caprylate (MUCAP) was applied for the identification of Salmonella, it's specification, sensitity, and availability were reported. 65 strains of standard Salmonella, 48 strains of Salmonella isolated from foods growing on plates of HE, DHL, SS and MaConkey agar have been tested with MUCAP. All of them were identified as MUCAP positive; whereas, among the non-Salmonella tested only Pseudamonas spp., Aeromonas hydrophilia and Plesiomonas shigelloides were shown as positive, but they could be differentiated easily with Salmonella by means of oxidase test. The unspecific reaction of Serratia marcescens could be eliminated by using the plate medium which has been added of 1% sucrose. Both the sensitivity and specificity of the method were up to 97% more, and the operating of the method was very facility and to be done within few minutes.

Hymecromone↗

PubMed1996

Corticotropin-releasing factor and type 1 corticotropin-releasing factor receptor messenger RNAs in rat brain and pituitary during "binge"-pattern cocaine administration and chronic withdrawal.

Endogenous central corticotropin-releasing factor (CRF) may be involved in the neuroendocrine and behavioral responses to cocaine. In the present study, levels of CRF mRNA were measured in the hypothalamus and in several extrahypothalamic brain regions after different regimens of "binge"-pattern cocaine administration. Male Fischer rats were injected with saline or cocaine (15 mg/kg, 1 hr x 3/day) at the beginning of the light cycle, to approximate the manner in which cocaine is often abused by humans, both in terms of temporal pattern and in relation to circadian rhythm. Cocaine administered in this binge regimen produced time-dependent alterations of CRF mRNA levels in the hypothalamus. There was a significant increase in CRF mRNA levels on day 1, which returned to base-line levels on day 2, with elevated plasma corticosterone levels on both days. CRF receptor type 1 and prooplomeianocortin mRNA levels in the anterior lobe of the pituitary were not significantly altered after acute cocaine injections on day 1 or day 2. On day 14 of chronic binge-pattern cocaine administration, decreased hypothalamic CRF mRNA levels and an attenuated elevation in plasma corticosterone levels were found. After 10 days of withdrawal from 14-day binge cocaine, CRF mRNA returned to basal levels. CRF mRNA levels in the amygdala were also significantly increased on day 1 and returned to basal values on day 2. Chronic (14-day) binge cocaine administration did not alter CRF mRNA levels in the amygdala. These results suggest that the attenuated response in the hypothalamic-pituitary-adrenal axis to chronic binge cocaine administration is coupled to the cocaine-induced decreases in CRF gene expression in the hypothalamus and that activation of CRF gene expression in extrahypothalamic regions may have implications for a molecular understanding of the behavioral responses to cocaine.

Adrenocorticotropic Hormone↗

PubMed1996

Percutaneous transluminal balloon pulmonary valvuloplasty using domestic balloon catheter for congenital pulmonary valve stenosis in children.

OBJECTIVE: To estimate the effect of percutaneous balloon pulmonary valvuloplasty (PBPV) using domestic balloon catheter for congenital pulmonary valve stenosis (PVS) in infants and children. PATIENTS AND METHODS: The data of 70 patients aged from 1.5 to 12 years (mean 5.5 +/- 3.4 years) who underwent PBPV using domestic balloon catheter for PVS in our institution were reviewed. Sixty-six patients had dome-shaped valve stenosis, and 4 had displastic valve stenosis. SaO2 reduced in 5 patients and associated open foramen ovale was noted in 23. Predilatation, right ventricular systolic pressure ranged from 60 to 234 mmHg (mean 115.75 +/- 36.15 mmHg). The systolic gradient (delta P) from right ventricle to pulmonary artery was 89.92 +/- 38.25 mmHg. Balloon diameter was selected 120%-142% of pulmonary valve annulus diameter (mean 132%). All patients were followed up for 3 months-4 years by means of clinical examination. ECG, 2D-UCG, and Doppler-UCG. RESULTS: After dilatation, delta P reduced from 89.92 +/- 38.25 to 14.65 +/- 11.40 mmHg (P < 0.001). The rate of decrease in transvalve gradient (delta P) was 83.7%. No patients experienced procedure-related events. Mid-term follow-up showed that no patients had clinical and instrumental complications. Doppler and ECG analyses showed that delta P did not change significantly similar to immediate gradient after PBPV and right ventricular hypertrophy disappeared progressively 6 months after PBPV. CONCLUSIONS: PBPV is a useful, safe and definitive procedure in the treatment of isolated PVS in infants and children. The properties and features of the balloon catheter produced by Shanghai Med-Tech Factory are similar to those of Med-Tech balloon catheter of U.S.A.

Catheterization↗

PubMed1996

Surgical treatment of bone tumors in conjunction with microwave-induced hyperthermia and adjuvant immunotherapy. A preliminary report.

OBJECTIVE: To develop an alternative approach in conjunction with microwave-induced hyperthermia. PATIENTS AND METHODS: Thermotherapy with microwave intracorporeal irradiation was used to treat 73 patients with bone tumors. The series was composed of 58 patients with malignant tumors and 15 with benign tumors: most of tumors occurred about knee joints (53/73 = 72.6%). The surgical procedure included separating the tumor bearing segment from surrounding normal tissues with a safe margin, cooling the normal tissues including the neurovascular bundle and the intraarticular structures with a water circulation system, while heating the tumor with the antenna array of a microwave system and providing an adequate soft-tissue cover for the dead bone. Postoperatively, an immune therapy regimen was carried out regularly. The patients' immunologic functions were monitored by assay of the subpopulation of T cells, IL-2 and sIL-2 R (soluble IL-2 receptor). RESULTS: Follow-up varied from 3 to 38 months (mean 19 months). Excluding 3 patients with malignancy in the vertebrae treated for palliation, 70 were evaluated according to oncological and orthopedic criteria. Five patients had local recurrence and required amputation. The remaining 65 had excellent local control. In 6 of the 55 patients with malignancy of the extremities, lung metastasis occurred one to two years after surgery. The oncological results were similar to those obtained by other limb-saving procedures. Pathological fracture occurred at devitalized bone in 5 patients. In 72.5% of the patients (29 of 40 tumor-free cases followed more than one year), knee joints functioned well, being stable and painless with almost full range of motion. Single photon emission computered tomography (SPECT) for 16 patients revealed revascularization of the devitalized tumor bearing bone segment could accomplish in one year or more. The immune states were improved in various extends after thermotherapy plus immunotherapy in the majority of patients. CONCLUSION: These results show that the use of microwave hyperthermia and adjuvant immunotherapy in conjunction with the surgical treatment of bone tumors can be considered a definitive procedure, which is safe and well-tolerated. The oncological and orthopedic results are encouraging.

Adolescent↗

PubMed1996

[The value of serum CA125 assays in the diagnosis of uterine adenomyosis].

OBJECTIVE: To investigate the value of serum CA125 assays in the diagnosis of uterine adenomyosis. METHODS: Fifty-five consecutive patients with uterine-adenomyosis and twenty with leiomyoma of uterus, diagnosed by surgery and pathology were studied. The blood samples were taken one day before operation. Twenty normal healthy women were served as controls. CA125 levels were determined by radioimmunoassay method. RESULTS: The median (M) CA125 levels (Ql-Qu) for patients with adenomyosis, leiomyoma and normal controls were 102.1 (56.3-182.1)kU/L, 34.6 (33.7-43.8)kU/L and 33.1 (32.7-33.8)kU/L respectively. The differences among the three groups were all significant (P < 0.01). The CA125 positive rates (CA125 > 50kU/L) for the above three groups were 80.0%, 10.0% and 5.0% respectively. Patients with adenomyosis had a higher CA125 positive rate than those with leiomyoma or normal controls (P < 0.001). For patients with adenomyosis the CA125 levels were positively correlated with uterine size (r = 0.33, P < 0.05). The adenomyosis patients treating with sex hormone preparations were found to have lower CA125 levels in comparison with non-users (P < 0.05). The mean CA125 level measured in sixteen patients decreased significantly one week postoperation. CONCLUSIONS: Serum CA125 assay is of great assistance to the diagnosis of uterine adenomyosis as well as to the differential diagnosis between adenomyosis and leiomyoma of uterus.

Adult↗

PubMed1996

[Establishment of human ovarian cancer cisplatin resistant cell line COC1/DDP and its mechanism of resistance].

OBJECTIVE: To establish cisplatin (DDP)-resistant subline of human ovarian cancer and investigate the mechanism responsible for resistance to DDP. METHODS: A DDP-resistant human ovarian adenocarcinoma cell subline (COC1/DDP) was developed by contineous stepwise selection in increasing concentration of DDP from the parent cell line COC1 in vitro. The multiple changes of biological properties in COC1/DDP cell line were determined. RESULTS: COC1/DDP cells were of 6.5-fold resistance to DDP and displayed significant cross-resistant with carplatin and mitomycin C, but still remained sensitive to 5-fluorouracil and adriamycin. As compared to the parent cells, in COC1/DDP cells: the doubling time was reduced by 12.9%. Cellular content of DDP was diminished by more one half and the DNA-interstrand cross-links (ISC) was lower than that of the sensitive cells. Evidence of P-glycoprotein overexpression was not shown in COC1 and COC1/DDP cell lines by means of immunohistochemical method. CONCLUSIONS: The primary factor causing COC1/DDP resistance to DDP is the reduction of intracellular platinum accumulation and DNA ISC formation. The resistance is not considered to be associated with the multidrug resistant and P-glycoprotein.

Adenocarcinoma↗

PubMed1996

Role of copper zinc superoxide dismutase in the short-term treatment of acetic acid-induced colitis in rats.

The present study describe the role of copper zinc superoxide dismutase (CuZnSOD) in the short-term treatment of experimental colitis induced with 8% acetic acid. The colonic mucosa damage index in the group of 10 rats treated intravenously with 30,000 U/kg CuZnSOD was significantly decreased when compared with the control group (10 rats) treated with normal saline (0.4 +/- 0.6 vs 1.5 +/- 0.5 p < 0.01). Assay of SOD in the control group was 0.3 +/- 0.08 and in the SOD treated group, SOD was significantly increased to 0.8 +/- 0.1, glutathione peroxidase was 44.8 +/- 6.3 in the control and 56.4 +/- 9.1 in the treated group (difference not significant). Both myeloperoxidase activity (14.0 +/- 2.5 vs 22.7 +/- 2.5) and lipid peroxidation products (13.8 +/- 2.9 vs 52.9 +/- 9.6) were significantly lower in the colonic mucosa of the SOD treated group in comparison with the control. These results indicate that the anti-inflammatory effects of CuZnSOD were mainly the removal of oxygen free radicals and indirectly the prevention of lipid peroxidation. This study suggests that CuZnSOD may be beneficial in the treatment of patients with ulcerative colitis. However, our experimental data suggest that this treatment will not have strong effects on the control of severe ulcerative colitis.

Acetic Acid↗

PubMed1996

[The influence of electroacupuncture on the mast cells in the acupoints of the stomach meridian].

Giving electroacupuncture at unilateral "Biguan" and "Zusanli" points, we observed the rat subcutaneous mast cells of "Tianshu", "Biguan", "Futu", "Zusanli" and "Xiajuxu" acupoints in bilateral Stamach Meridian. It was found that the numbers of mast cells in all the acupoints studied were higher than that in the non acupoint area. The numbers of mast cell in acupoints were increased under electroacupuncture, while that in non acupoint area was not changed. The results suggested the mast cells play an important role in the functions of the Meridian.

Acupuncture Points↗

PubMed1996

[Influence of cerebral traumatic dementia treated with acupuncture at houxi and shenmen].

Sixty-two cerebral traumatic dementia patients were randomly divided into two groups acupuncture treatment group (Group A, 32 cases) and physical treatment group (Group B, 30 cases). The changes of MMSE scores and auditory P300 were observed before and after the treatment. It were found that the indexes in group A changed significantly (P < 0.05-0.001), and the indexes in group B didn't change significantly (P > 0.1-0.4). The therapeutic effect in group A was better than that in group B(P < 0.001). The results confirmed that the cognitive function of cerebral traumatic dementia patients was increased effectively with acupuncture at Houxi and Shenmen.

Acupuncture Points↗

PubMed1996

[Synergism of three risk factors in hepatocellular carcinogenicity].

To evaluate potential synergistic effects of aflatoxin B1 (AFB1) hepatitis B virus (HBV) and hepatitis C virus (HCV) in the development of human primary hepatocellular carcinoma (PHC), AFB1, HBV-DNA and HCV-RNA in liver tissue sampled from the patients with PHC were detected by high performance liquid chromatography, nested polymerase chain reaction (PCR), and reverse transcription nested PCR. Positive rates of AFB1, HBV-DNA and HCV-RNA were 67.7% (21/31), 88.2% (60/68) and 13.2% (9/68), respectively. Eighteen of the 31 patients were positive for both AFB1 and HBV-DNA, and six of the 68 patients positive for both HBV-DNA and HCV-RNA. Furthermore, AFB1, HBV-DNA and HCV-RNA all were detected in four cases, while all negative in controls. It suggests that all the three factors are directly associated with human hepatic carcinoma, and play a synergistic role on hepatic carcinogenicity.

Adult↗

PubMed1996

[The effect of Gynostemma pentaphyllum mak (GP) on carcinogenesis of the golden hamster cheek pouch induced by DMBA].

The purpose of the study is to examine the effect of GP during carcinogenesis of the golden hamster cheek pouches induced by DMBA. The results indicated that epithelial olysplasia and carcinoma in situ appeared respectively at 3 and 6 weeks. The formation of carcinoma was detected as early as 4 weeks which is earlier than that of former reports. The experiment proves that GP has positive anticarcinogenic function. Long-term observation in those the DMBA has been applied for 3 weeks found that epithelial dysplasia could reverse when GP was given. A compound prescription is better than GP alone.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1996

[Effect of fibronectin on the synthesis of extracellular matrix proteins in periodontal ligament cells].

Immunofluorescence staining method and fluorescence spectrophotometry were used to study the synthesis of extracellular matrix proteins in periodontal ligament cells (PDL cells) when exogenous fibronectin (FN) existed. The results showed that the right amount of exogenous FN (0.044 mumol/l) could increase the amount of type I collagen and type III collagen in PDL cells (P < 0.01), inhibit the synthesis of FN itself (P < 0.01). It suggested that exogenous FN can effect the synthesis of extracellular matrix proteins so as to promote a new connective tissue attachment formation.

Adolescent↗

PubMed1996

[A study on the changes of DCC and MCC genes in colorectal carcinoma and adenoma].

Both deleted in colorectal carcinoma (DCC) and mutated in colorectal carcinomas (MCC) genes are newly found tumour suppresser genes in colorectal carcinomas. In this study mutations of DCC gene and loss of heterozygosity (LOH) of MCC gene were detected with Southern blot and PCR methods respectively. The study consisted of 30 cases of colorectal adenoma (10 with mild, 10 with moderate and 10 with severe dysplasia) and 33 cases of colorectal carcinomas (13 highly, 10 moderately and 10 poorly differentiated, meanwhile 9 in Dukes A, 10 in B and 14 in C stage). Their paired normal colorectal mucosa served as control. The results were as follows: mutation of DCC was not found in any specimen with normal mucosa or with adenoma of mild and moderate dysplaaia, while it was found in one if those with severe dysplasia. Mutation of DCC was, however, found in 7 of the 33 specimens with carcinoma and there was a correlation between the positive rate and the differentiation or staging of the carcinoma. LOH of MCC was not found in normal mucosa, but it was found in 2/10, 3/10 and 4/10 of the adenoma specimens with mild, moderate and severe dysplasia respectively. 18/33 of the carcinoma specimens was found to have LOH of MCC and there was also a correlation between the positive rate and the differentiation or staging of the carcinoma. These results suggest that the frequency of multiple gene changes increase with poor differentiation and increased staging of colorectal carcinoma.

Adenoma↗

PubMed1996

[Anatomy of the endolymphatic sac and its clinical significance].

Using 28 formalin fixed temporal bones and materials of 26 cases of endolymphatic surgery for menieres' disease, the location, vascular distribution and size of the endolyphatic sac (ELS) were investigated. ELS were measured with surgical microscope in all the cadaver specimen with a mean length of 6.9393 +/- 2.0429 mm and mean width of 5.8821 +/-1.6522 mm. All the specimens showed no clear capillary distribution. Only in 24 of the 26 ELS surgeries for Menieres' disease the ELS were found. The mean length was 6.8125 +/- 2.2449 mm, the mean width 5.6666 +/- 1.5084 mm and the vascular distribution was unclear in 29% of the cases. It was found that the ELS usually located at the Donaldson line, and moved downward in the under-developed mastoid with smaller size.

Adult↗

PubMed1996

[Prognosis of laryngeal carcinoma in youth].

The prognosis of 55 cases of laryngeal carcinoma in young people had been studied. The major factors mainly related to prognosis were smoking and misdiagnosis, while the tumour differentiation might be not so important. There was a high recurrence rate of 25.5% in the young patients and low 3- and 5-year survival rates of 47.4% and 34.5% respectively. The mortality of 1-year after surgery was 21.8%. The 3-and 5-year survival rates between total and partial laryngectomy made no difference. The survival rate of patients with positive node was lower. Early diagnosis is most important for young patients. Partial laryngectomy and neck dissection must be performed as far as possible.

Adult↗

PubMed1996

Crystal structure determination of basic phospholipase A2 from venom of Agkistrodon halys pallas by molecular replacement method.

Basic phospholipase A2 (BPLA2) from the venom of Agkistrodon halys pallas has a strong ability to hemolyze erythrocytes. The asymmetrical unit of P2(1)2(1)2(1) crystal of BPLA2 contains two molecules. Self-rotation function was used to study the orientation relationship of these two molecules. Cross-rotation and translation functions were then used to determine the orientations and positions of the two molecules in the unit cell. The model building and preliminary structure refinement were carried out. The result shows that the two molecules in the asymmetrical unit of orthorhombic crystal are related by a non-crystallographic 2-fold symmetry axis.

Agkistrodon↗

PubMed1996

The second space experiment of protein crystallization with domestic facilities.

The second experiment of protein crystallization was performed on domestic re-entry satellite FSW-2 in 1994-07. The results are superior to the ones of the first mission in 1992: 9 of 10 different proteins were crystallized in space, and 70% of the total 48 samples yielded single crystals. Besides hen egg-white lysozyme which grew high-quality crystals on the first mission, an acidic phospholipase A2(aPLA2) from snake venom and hemoglobin from Anser Indicus produced good-quality crystals suitable for X-ray diffraction analyses. The positive effect of microgravity on protein crystal growth is verified again at this time.

Aerospace Medicine↗

PubMed1995

Rotation of subunits during catalysis by Escherichia coli F1-ATPase.

During oxidative and photo-phosphorylation, F0F1-ATP synthases couple the movement of protons down an electrochemical gradient to the synthesis of ATP. One proposed mechanistic feature that has remained speculative is that this coupling process requires the rotation of subunits within F0F1. Guided by a recent, high-resolution structure for bovine F1 [Abrahams, J. P., Leslie, A. G., Lutter, R. & Walker, J. E. (1994) Nature (London) 370, 621-628], we have developed a critical test for rotation of the central gamma subunit relative to the three catalytic beta subunits in soluble F1 from Escherichia coli. In the bovine F1 structure, a specific point of contact between the gamma subunit and one of the three catalytic beta subunits includes positioning of the homolog of E. coli gamma-subunit C87 (gamma C87) close to the beta-subunit 380DELSEED386 sequence. A beta D380C mutation allowed us to induce formation of a specific disulfide bond between beta and gamma C87 in soluble E. coli F1. Formation of the crosslink inactivated beta D380C-F1, and reduction restored full activity. Using a dissociation/reassembly approach with crosslinked beta D380C-F1, we incorporated radiolabeled beta subunits into the two noncrosslinked beta-subunit positions of F1. After reduction of the initial nonradioactive beta-gamma crosslink, only exposure to conditions for catalytic turnover results in similar reactivities of unlabeled and radiolabeled beta subunits with gamma C87 upon reoxidation. The results demonstrate that gamma subunit rotates relative to the beta subunits during catalysis.

Amino Acid Sequence↗