Biomedical subjects

Y Zhao

Publications and source records attributed to Y Zhao.

At least 487 records · Page 27Linked to original sources

PubMed1999

A study of the relationship between caries activity and the status of dental caries: application of the Dentocult LB method.

OBJECTIVE: To clarify the relationship between caries activity and the status of caries of primary teeth and the relationship between the quantity of Lactobacillus in the oral cavity and the status of dental caries. METHODS: The status of caries of primary teeth in 164 children ages 3 to 5 was examined. Caries incidence, mean DFT, and Caries Severity Index (CSI) were calculated. Based on the quantity of Lactobacilli in the saliva of preschool children detected with the Dentocult LB method of caries activity, four grades were classified: Grade 0 = 10(3) CFU/mL, Grade I = 10(4) CFU/mL, Grade II = 10(5) CFU/mL, and Grade III = 10(6) CFU/mL. RESULTS: The results showed that 34.15% of the children had caries status beyond Grade I. There were significant differences of caries status, DFT, and CSI among different grades, all of which increased with grades. There was a high correlation between grades and caries incidence, DFT, and CSI in the 164 preschool children. CONCLUSION: As a Caries Activity Test (CAT), detection of Lactobacilli may reveal the status of dental caries and provide valuable information for the prevention and treatment of dental caries.

Chi-Square Distribution↗

PubMed1999

Recombinant Kunitz protease inhibitory domain of the amyloid beta-protein precursor as an anticoagulant in venovenous extracorporeal circulation in rabbits.

Investigations were performed to characterize a recombinant Kunitz protease inhibitory domain of the amyloid beta-protein precursor (rKPI) as anticoagulants. After a single intravenous infusion of wild type rKPI into dogs, its elimination fit a two compartment model with a t1/2alpha and t1/2beta of 5 and 77 min, respectively. Further investigations determined if a variant form of rKPI with 178-fold more potent anti-factor Xa activity (rKPI-DD135, Ki = 0.9 nM) could serve as an anticoagulant in a rabbit model of extracorporeal circulation using a venovenous shunt. A prospective investigation was initiated to compare standard heparin (n = 8) at 400 U/kg with different infusion concentrations of rKPI-DD135. After a single intravenous infusion of 1.89 mg/kg of rKPI-DD135 followed by a constant infusion at 0.003 (n = 3), 0.03 (n = 7), or 0.3 (n = 5) mg/kg/min, the anti-factor Xa activity of the animals' plasma rapidly reaches a steady state for the two lower infusion concentrations of the agent. All infusions of rKPI-DD135 prolong the activated clotting time with less variation than that seen with heparin administration. rKPI-DD135 anticoagulation does not prevent a drop in the platelet counts. Fibrinogen levels decrease only slightly when the circuit is anticoagulated with rKPI-DD135. rKPI-DD135 markedly prolongs the APTT, has little effect on the PT, and reduces plasma prekallikrein and plasminogen activation. The 0.3 mg/kg/min infusion concentration of rKPI-DD135 results in reduced deposition of 111Indium-labeled platelets on the circuit when compared to heparin. Last, after a steady state level is achieved, 60% of the plasma anti-factor Xa activity of rKPI-DD135 is eliminated within 60 min after stopping the infusion. These data show the rKPI-DD135 can provide single agent anticoagulation in a rabbit extracorporeal circuit. Development of short acting factor Xa inhibitors may be useful anticoagulants for cardiopulmonary bypass.

Amyloid beta-Protein Precursor↗

PubMed1999

Somatic embryogenesis of Echinodorus orisis L. and the kinetic changes of the endogenous hormones contents during the embryogenetic process.

Somatic embryogenesis was achieved in young Leaf cuttings of Echinodorus orisis L., an aquatic ornamental plant, in a short period (25 days). Among the cytokinins and their combinations tested, 6-BA (1 mg/L) and Zt (1 mg/L) in MS medium induced the highest efficiency (100%) of somatic embryogenesis, with a maximum of 4.87 embryoids per explant. Roots instead of somatic embryos were formed when NAA (0.5 mg/L) was added to MS medium containing Zt (1 mg/L). Matured embryoids were germinated and rooted in MS medium with IAA (1 mg/L) after 5 days cultivation. Seventy-two percent of the rooted plantlets transplanted survived in the aquarium. The endogenous hormone contents in various stages of somatic embryogenetic process were measured by HPLC. The concentrations of all the hormones tested were about 2 times that of the cuttings from the untreated fresh leaves after 10 days incubation. Meanwhile, the concentration of IAA presents two peaks after 10 and 25 days of cultivation, respectively. The cytokinin (Zt and ZR) peak, about 8 times more than CK, appeared in 15 days cultivation when the heart-shaped embryos formed. The fluctuation of the GA3 concentration was very similar to that of cytokinin. The ABA, however, remains stable at quite high concentration after 10 days of cultivation.

Plant Cells↗

PubMed1999

[Matched case-control study for detecting risk factors of breast cancer in women living in Chengdu].

OBJECTIVE: To detect the risk factors of breast cancer in women living in Chengdu in order to identify high risk population and to conduct proper interventions. METHODS: A matched case-control study was performed in 265 cases with breast cancer who lived in this area. RESULTS: In the univariate analysis, menarche to menopause period > or = 35 years, taking oral contraceptives, history of benign breast diseases, passive smoking, and syrup drinking are the statistically significant risk factors of breast cancer, whereas breast feeding and soybean food consumption are protective factors. Conditional logistic multivariate analysis revealed that history of benign breast diseases and passive smoking are risk factors while soybean food products and breast feeding are protective factors. CONCLUSION: The risk factors of breast cancer in women living in Chengdu are history of benign breast diseases and passive smoking.

Adolescent↗

PubMed1999

Interaction of tumor-infiltrating lymphocyte from oral squamous cell carcinoma with FN enhances its adhesion and cytotoxicity.

OBJECTIVE: To investigate the influence of fibronectin (FN) on cytotoxicity and adhesion of tumor-infiltrating lymphocytes (TIL) from oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: TIL cells were isolated from surgical specimens of 9 patients with OSCC. Specific cytotoxicity for autologous tumor cells were tested by 3H-TdR 4 hours release, and specific TNF-alpha release was detected using enzyme-linked immunosorbent assay. Expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) on TIL cells were analyzed on FACScan following incubation with FITC-conjugated antibody. Cell adhesion ability was evaluated through detection by optical density (OD) values of bound cells and unbound cells. RESULTS: TIL-specific cytotoxic activity for autologous tumor was significantly enhanced, ranging from 17.7% to 67.6% by incubation on FN (P < 0.005). Cell adhesion was increased ranging from 42.5% to 62.7% by coculturing with FN (P < 0.005). The interaction of TIL with FN increased expression of ICAM-1 and LFA-1 on TIL cells as well. But specific TNF-alpha release was not obviously changed by FN (P > 0.5). CONCLUSION: The enhanced TIL activity by FN might be mediated by increased binding of TIL to targets through adhesion strengthening. This culture system would be useful to improve the TIL generation for cancer therapy.

Carcinoma, Squamous Cell↗

PubMed1999

Site-directed mutagenesis analysis of draTG genes and their downstream region from Azospirillum brasilense Yu62.

draT and draG genes are involved in posttranslational regulation of nitrogenase activity of Azospirillum brasilense Yu62. Both genes and their downstream region were mutagenized by Kmr cassette insertions. Analysis of mutations introduced into the draTG region on the A. brasilense Yu62 chromosome showed that mutants affected in draT were incapable of regulating nitrogenase activity in response to ammonium. In contrast, a mutant with an insertion in draG was still capable of ADP-ribosylating dinitrogenase reductase in response to ammonium but was no longer able to recover activity after ammonium depletion. Analysis of mutations introduced into the draTG downstream region (the mutagenized site is about 2 kb downstream from draG) showed that the mutant had higher nitrogenase activity than the wild strain while growing in nitrogen-free medium and medium with 2 mmol/L ammonium. These results reveal that there is no gene required for nitrogen fixation in this mutagenized region, but it is possible that there are genes which play a role in regulating nitrogen fixation. The results of monitoring the expression of transcriptional nifH-lacZ gene fusion in the mutant YZ4 showed that the transcriptional regulation of nif gene in the mutant YZ4 was the same as that in the wild type.

Azospirillum brasilense↗

PubMed1999

[Expression of endothelin-1 and endothelin-1 mRNA in placental villus of pregnancy induced hypertension and the changes of plasma endothelin-1].

OBJECTIVE: To investigate the role of endothelin (ET-1) in the pathogenesis of pregnancy induced hypertension (PIH). METHODS: In 70 cases of PIH the plasma concentration of ET-1 was measured by RIA, and the expressions of ET-1 and its mRNA in placental villus were determined by immunohistochemistry and in situ hybridization respectively. 30 normal pregnant women (NP) served as control group. RESULTS: (1) The Plasma concentration of ET-1 was significantly higher in PIH than that in NP. There was a positive correlation between the plasma ET-1 level and mean arterial pressure in PIH. (2) The expressions of ET-1 and ET-1 mRNA were found in syncytiotrophoblast of placental villus and in the endothelium of fetal vessels. These positive signals were higher in PIH than in NP. CONCLUSION: The injury of endothelium of fetal and placental blood vessels was one of the causes of PIH. The placenta may play an important role in the pathogenesis of PIH.

Adult↗

PubMed1999

[Serum concentration of interleukin-6 in maternal serum and its expression in amniochorionic membranes of preterm premature rupture of membrane].

OBJECTIVE: To investigate the relationship between interleukin-6 (IL-6) and preterm premature rupture of membranes (PPROM). METHODS: Serum IL-6 in 20 cases of normal pregnancy (control group) and 30 cases with PPROM in which 14 had moderate and severe chorioamnionitis (group 1), 16 had no chorioamnionitis (group 2) were measured by enzyme-linked immunosorbent assay (ELISA), and IL-6 protein in fetal membranes were determined by immunohistochemistry technique. RESULTS: The level of serum IL-6 in group 1 (155.17 ng/L) was significantly higher than that in group 2 (79.11 ng/L) and control group (70.15 ng/L) (P < 0.01). Expression of the IL-6 had more positive signs in chorion with chorioamnionitis, especially in infiltrating inflammatory cells. CONCLUSION: IL-6 associated with the onset of preterm labor caused by infection.

Extraembryonic Membranes↗

PubMed1999

[Cerebral metastases in patients with epithelial ovarian carcinoma].

OBJECTIVE: To detect the rate of occurrence, the relevant factors, the diagnosis and treatment of cerebral metastases in patients with epithelial ovarian carcinoma. METHODS: The clinical data were analyzed in 4 cases of cerebral metastases from 132 cases of epithelial ovarian carcinoma after treatment between 1989-1997. RESULTS: The rate of cerebral metastases was 3%. The related factors were advanced stage, and tumor cells differentiation, but no related with the histologic type. More cases of cerebral metastasis were found because of the prolonged survival after cytoreductive surgery and systemic chemotherapy as well as the extraabdominal metastasis. CONCLUSIONS: Computed tomography and magnetic resonance imaging were the important diagnostic methods. Combined treatments including surgery, radiotherapy and chemotherapy can improve the patients status and prolong their lives.

Adenocarcinoma, Mucinous↗

PubMed1999

[Clinical analysis of the absent and/or reverse end diastolic velocity of fetal umbilical artery].

OBJECTIVE: To investigate the relations between absent and/or reverse end diastolic velocity of fetal umbilical artery (AEDV) and maternal and fetal pathological factors and perinatal outcome. METHODS: To analyze the clinical informations of 33 case, with AEDV by pulse doppler ultrasonic examination. RESULTS: (1) There are 9 cases (27.3%) complicated with different kinds of fetal morphologic abnormality, 6 cases of perinatal death. (2) In 6 cases (18.2%) of twins, twin-twin transfusion syndrome (TTTS) occurred in 3 cases. In 6 cases when the body weight differences between the 2 babies were higher than 24.8%, neonatal death occurred in 4 cases. (3) The group with AEDV showed significantly higher incidence of pregnancy induced hypertension, oligoaminos, IUGR, fetal distress and neonatal death than that of normal group. CONCLUSIONS: The appearance of AEDV shows the extreme disfunction of mothermal placental-fetal circulation and may be related to poor outcome.

Blood Flow Velocity↗

PubMed1999

[Study on the expression of calreticulin in hypertrophic scar-derived fibroblasts].

OBJECTIVE: To investigate the expression level and intracellular distribution of calreticulin(CRT) in hypertrophic scar-derived fibroblasts(HSF) and normal skin-derived fibroblasts(NSF). METHODS: Using anti-CRT antibody, CRT was detected in HSF and NSF by immunocytochemistry and ELISA technique. RESULTS: CRT was present in the cytoplasm and nuclei in proliferating HSF or NSF in culture, but HSF possessed significantly higher expression level of CRT than NSF(P < 0.01). When these cells (HSF and NSF) were fused, neither intracellular nor intranuclear staining for CRT was observed. CONCLUSION: In HSF and NSF, the distribution of CRT is widespread. Because of its abundant expression in HSF, we postulate that CRT as a multifunctional protein plays an important role in Ca2+ sequestering, integrin-mediated signalling and cell adhesion.

Adolescent↗

PubMed1999

Combination of intraoperative embolization with surgical resection for treatment of giant cerebral arteriovenous malformation.

OBJECTIVE: To reduce the risk of surgical resection of giant arteriovenous malformation (AVM) (> 6.0 cm) and prevent normal perfusion pressure breakthrough (NPPB) for lowering the postoperative mortality. METHODS: During the operation under barbiturate anesthesia, the proximal end of the feeding arteries were ligated at first, and 0.5 ml isobutyl 12-cyanoacrylate (IBCA) with 0.5 ml 5% glucose was injected into the vessels towards the AVM, then the malformed vessels were resected totally. Postoperative digital subtraction angiography of the four vessels was performed in all patients. RESULTS: 50 patients with giant AVM survived after operation, only 6 (12.0%) had transient neurological dysfunction and 44 (88.0%) recovered after a follow-up of 6-36 months. No patient suffered from normal perfusion pressure breakthrough (NPPB). CONCLUSIONS: The embolization could block the arteriovenous shunts sufficiently to decrease the blood flow away from the normal areas of the brain so as to prevent the incidence of intra- and postoperative rebleeding, especially in NPPB. Therefore, the combination of intraoperative embolization with surgical resection is an effective strategy in the treatment of giant cerebral AVMs, which make it operable for those used to be regarded as inoperable cases.

Adolescent↗

PubMed1999

Repair of stricture of cervical esophagus with platysma myocutaneous flaps.

OBJECTIVE: To observe the effect of repairing stricture of the cervical esophagus with platysma myocutaneous flaps. METHODS: Fifteen patients with stricture of the cervical esophagus were treated by repair with platysma myocutaneous flaps. The causes of stricture included anastomotic stenosis of the cervical esophagus after colon graft transplantation due to esophageal caustic injury (12 patients), anastomotic stenosis after stomach transposition due to resection of the upper esophageal cancer (2), and stricture caused by limited erosive injury of the cervical esophagus (1). The lengths of stricture were about 3.5-4.5 cm. The stricture was incised longitudinally. The platysma myocutaneous flaps about 4 cm-5 cm x 6 cm-7 cm were resected and were transposed to repair the stricture. RESULTS: All flaps survived and no death or serious complications occurred after operation. All patients gained normal functions in swallowing food. CONCLUSION: Repairing stricture of the cervical esophagus with platysma myocutaneous flaps is simple, safe and effective.

Adolescent↗

PubMed1999

The change of insulin-like growth factor-1 in diabetic patients with neuropathy.

OBJECTIVE: To evaluate the possible relationship between insulin-like growth factor-1 (IGF-1) and diabetic neuropathy (DNP). METHODS: Sixty-nine patients with Type 2 non-insulin-dependent diabetes (54 with peripheral neuropathy and 15 without neuropathy) were observed. Normal controls were 34 non-diabetic persons. Diabetic peripheral neuropathy diagnosis was carried out taking into account results of NS, ND, NC and AF. After an overnight fast, blood was taken for IGF-1, glucose, hemoglobin Alc, C-peptide, and insulin. Plasma IGF-1 was measured by radioimmunoassay (RIA) method. RESULTS: The neuropathic group had significantly lower levels for IGF-1 (86.43 ng/ml +/- 45.18 ng/ml) compared to normal controls (119.68 ng/ml +/- 89.42 ng/ml) (P < 0.05), and to diabetic patients without neuropathy (113.75 ng/ml +/- 66.58 ng/ml) (P < 0.05). No significant difference was found between diabetic non-neuropathic group and normal control subjects (P < 0.05). In diabetic subjects there was a positive correlation (gamma = 0.27, P < 0.05) between IGF-1 and beat to variation in heart rate. There were negative correlation between IGF-1 and postprandial blood glucose (gamma = -0.3, P < 0.05), and aspartic acid translocase (gamma = -0.27, P < 0.05). CONCLUSION: In diabetic patients with peripheral neuropathy there are abnormalities of IGF-1 that may contribute to the pathogeneses of diabetic neuropathy.

Aged↗

PubMed1999

[Investigation of serum immunosuppresive acidic protein levels in gynecological tumor].

OBJECTIVE: To study the clinical significance for measureing serum immunosuppresive acidic protein (IAP) levels to diagnoze and follow up survey patients with the gynecological tumor. METHODS: Serum IAP levels were determined by IAP-single radial immunodiffusion test in 235 patients with gynecological tumor, 38 patients had benign ovary tumor, 41 were malignant ovary tumor, 66 hysteromyoma, 34 cervical carcinoma, 16 endometrial carcinoma, 27 received chemotherapy, and 13 had tumor recurrence. The control group consisted of 50 health women. RESULTS: The serum IAP level was (889 +/- 208) mg/L in malignant ovary tumor, and higher than that of the health women and benign ovary tumor, (P < 0.01). In patients with cervical carcinoma and endometrial carcinoma, the IAP level was (741 +/- 213) and (763 +/- 209) mg/L respectively, and higher than that of the health women and benign ovary tumor (P < 0.01). After chemotherapy, the serum IAP level of malignant ovary tumor was decreased. In patients with recurrence of ovary tumor, the IAP levels was increased to compare with the health women (P < 0.01), the incidence of the abnormal value was 100%. CONCLUSION: Detecting IAP level of the gynecological tumor may be an auxiliary index for monitoring gynecological tumor and identifying whether it is benign or malignant.

Adult↗

PubMed1999

[Polymorphisms of apoB gene 3' VNTR alleles and analysis of lipid level in Tibetan population].

OBJECTIVES: To study the distribution and frequency of apoB gene 3' end alleles and try to find if there is any association with the level of plasma lipids. METHODS: PCR and gradient polyacrylamide gel electrophoresis were used to analysize the chromsome DNA and PCR products. RESULTS: Totally 20 alleles were found in the Tibetan group and the distribution of alleles was bimode. The HVE32 and HVE34 were most common, and the frequencies of HVE32 and HVE34 were 0.27 and 0.21 respectively. CONCLUSION: Polymorphism apoB gene resides not only in the variable numbers of the repeat unit, but also in the variation in the oligonucleotide sequence within the repeat units as well as the variation in the arrangement of the repeat units.

Adolescent↗

PubMed1999

[Development of partially sintered alumina block for dental CAD/CAM and mechanical properties testing].

OBJECTIVE: It is a new way to fabricate all ceramic crowns by combining dental CAD/CAM with glass infiltration technology. METHODS: A partially alumina sintered block made of a high purity, fine alumina powder was shaped by isostastic pressure and sintered at 1,400 degrees C. Its mechanical properties were tested and microstructure was observed by SEM. RESULTS: The Vicker's hardness, three-point bending strength, fracture toughness of partially sintered alumina block were 1.65 MPa, 210 MPa, 1.90 MPam1/2 respectively. Micrographs of SEM indicated that partially sintered alumina contained the structure of continuous three-dimensional open pores through the neck growth and surface diffusion of the interparticles. CONCLUSION: The partially sintered alumina block that developed in this way may be used to mill for CAD/CAM and fabricate the shrinkage-free all ceramic crown.

Aluminum Oxide↗

PubMed1999

[Clinical study on effect of xianlong capsule on senile vascular dementia].

OBJECTIVE: To assess the efficacy of Xianlong Capsule (XLC) in treating the senile vascular dementia (VD). METHODS: Forty-six cases of VD were randomly divided into two groups. The XLC group (24 patients) were treated with XLC and the control group (22 patients) were treated with Hydergine. Mini-mental state examination (MMSE), Hamilton depression scale (HDS) marks and clinical symptoms were observed in different groups. RESULTS: XLC could markedly increase MMSE and HDS marks of VD patients. XLC had the effect of improving balance and gait ability of VD patients. CONCLUSION: XLC had certain effect on VD and its effect was better than that of Hydergine.

Aged↗