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Biomedical subjects

Y Yang

Publications and source records attributed to Y Yang.

At least 793 records · Page 44Linked to original sources
PubMed1998

[The influence of different concentrations of hydrofluoric acid on blood calcium level in rats].

OBJECTIVE: To evaluate the effects of different concentration of hydrofluoric acid (HF) on local skin and calcium level of serum. METHODS: SD rats were divided into two groups which were wounded by 20% and 40% percent of HF respectively. Samples of blood and wound tissue were harvested at different postburn time for the analysis of the calcium level of the serum and histological study. RESULTS: It was found that twenty percent of HF was enough to cause a skin damage, and might bring about fatal hypocalcemia after a prolonged contact. High concentration of HF (40%) could cause deep tissue necrosis within a short time, and result in a fatal hypocalcemia within 24 hour even in the case of a small area injury. CONCLUSION: It is important to treat the patient with HF injury as early as possible. Sufficient calcium must be applied guided by laboratory study in order to prevent the fatal hypocalcemia.

Animals↗
PubMed1998

[Effects of mifepristone on proliferation and apoptosis in early chorionic villi].

OBJECTIVE: To study the effects of mifepristone on proliferation and apoptosis in early pregnant chorionic villi. METHODS: Proliferation and apoptosis in early pregnant choionic villi from surgical aspiration and mifepristone induced abortion were studied. Marker for proliferation is proliferating cell nuclear antigen (PCNA) immunohistochemical staining, apoptotic cell death was detected using DNA in situ terminal deoxynucleotidyl transferas-mediated dUTP-biotin nick ending labeling (TUNEL). RESULTS: In early pregnant chorionic villi, proliferating index of cytotrophoblasts was 53.74% +/- 1.34%, not only nuclear but also cytoplasma were PCNA positive staining, syncytiotrophoblasts were negative. There existed apoptotic cell death in trophoblasts, the apoptotic index were 2.52% +/- 0.86% in syncytiotrophoblasts and 0.52% +/- 0.26% in cytotrophblasts, respectively. After 2 days mifepristone treatment, the proliferating index of cytotrophoblasts decreased slightly and PCNA positive cytoplasmic expression disappeared; while apoptotic cell increased significantly, the apoptotic indices were 22.16% +/- 2.26% in syncytiotrophoblasts and 20.12% +/- 1.74% in cytotrophoblasts, respectively. CONCLUSION: Mifepristone may inhibit proliferation and promote apoptosis of trophoblasts in early pregnant chorionic villi.

Abortifacient Agents, Steroidal↗
PubMed1998

[Effects of mifepristone on gene expression of epidermal growth factor in human uterine leiomyoma].

OBJECTIVES: To study the effects of mifepristone on epidermal growth factor gene expression in human uterine leiomyoma. METHODS: 20 patients with leiomyoma were divided into two groups. One was control group who underwent hysterectomy because of leiomyoma, the other was experimental group who underwent hysterectomy after pretreatment with mifepristone 10 mg/daily for 3 months. Epidermal growth factor (EGF) mRNA was semiquantified in samples of leiomyoma and adjacent normal myometrium from patients untreated in different phases of menostrual cycle and from those treated with mifepristone. Semiquantitative reverse transcriptase polymerase chain reaction, using beta-actin as internal standard, was applied to determine levels of EGF mRNA. RESULTS: Leiomyoma untreated with mifepristone had significantly greater amounts of EGF mRNA than adjacent normal myometrium of uterus only in the luteal phase, but not in the follicular phase of cycle. Similarly, leiomyoma untreated with mifepristone also had significantly larger amount of EGF mRNA than treated leiomyoma in the luteal phase of the cycle, whereas, no difference in the follicular phase of the cycle. CONCLUSION: These findings suggested that: (1) EGF mRNA levels in leiomyoma were increased only in the luteal phase, therefore, maybe mainly controlled by progesterone; (2) mifepristone inhibited EGF gene expression in leiomyoma. This may be one of regression mechanism of uterine leiomyoma in response to the antiprogesterone mifepristone.

Epidermal Growth Factor↗
PubMed1998

[Effect of zinc on cadmium-induced fetal damage].

The effect of different zinc level on cadmium (Cd)-induced fetal damage was studied in pregnant rats. Seventy Waster rats were divided into five groups: zinc 30 mg/kg diet, zinc deficiency (3.2 mg/kg), zinc deficiency with Cd 2.0 mg/kg, zinc 30 mg with Cd 2.0 mg and zinc 227 mg with Cd 2.0 mg. The pregnant rats were killed on the 20 th day of gestation. Blood samples were taken and all the fetuses were examined. The result showed that zinc deficiency could induce fetus absorption or malformation, which were increased significantly in zinc dificient plus Cd rats. Fetuses can be protected if high dose of zinc (227 mg/kg) is given. The occurrence of fetus absorption and malformation decreased and survival increased in compared with the nonsupplemented group. The results suggested that fetal malformations can be induced by zinc deficiency, and being worse when Cd is added. Zinc supplementation can offset to some extent the toxic effect of Cd.

Abnormalities, Drug-Induced↗
PubMed1998

[A survey of prostate symptoms in old male population].

To know well the prostate symptoms in old men, the prostate symptom scores of 412 male residents over 60 years of age in Chengdu area (116 in city and 296 in countryside) were investigated by using I-PSS. The results showed that there was a significant difference between the city and countryside in terms of symptoms score(P < 0.05) and quality of life scores (P < 0.05). No significant difference was noted among the three age groups (P > 0.05). However, the mean score and the percentage of high score section in the elder group were higher than those in the younger group. The prevalence of benign prostate hypertrophy (BPH) and the demands on quality of life in city were different from those in countryside, and the prevalence rate of BPH increased with age.

Aged↗
PubMed1998

[Effects of mifepristone on ICE expression and Fas expression in early pregnant chorionic villi].

This study addressed the question whether mifepristone has any effect on apoptosis in early pregnant chorionic villi. Interleukin 1 beta converting enzyme(ICE) expression and Fas expression in early pregnant villi and their changes following mifepristone administration were detected by immunohistochmical method and computer image analysis. During early pregnancy, ICE and Fas were expressed in all component chorionic cells, predominantly syncytiotrophoblasts. ICE stained cytoplasma. Fas stained mainly cytoplasma, and in partial trophoblastic cells, Fas was expressed on membrane and nucleus. In the villi from the pregnant women who received mifepristone for 2 days, expression of Fas increased markely; the ratio of positive nuclear staining cells were significantly raised, but the immunostaining intensity of ICE was slightly increased. These results suggest that mifepristone may terminate early pregnancy via increasing the expression of Fas and promoting apoptosis in the chorionic villi.

Abortifacient Agents, Steroidal↗
PubMed1998

[Immunoprotection in guinea pigs using DNA recombinant plasmid rpDJt and expressed protein P68 in L. interrogans serovar lai].

Immunoprotection against the infection by Leptospira interrogans serogroup Icterohemorrhagiae serovar lai strain 017 was demonstrated in guinea pigs vaccinated with DNA recombinant plasmid rpDJt and expressed protein P68 derived from genomic library of Leptospira strain 017. Thirty days after active immunization, each group received intraperitoneally (1/2 dose) and subcutaneously (1/2 dose) inoculum of L. interrogans serovar lai stain 017; cultures were adjusted to 5 x 10(8) cells/ml. All guinea pigs were observed for 10 days after challenge. Survival (%) of P68 group was 100(7/7); P23 group was 75(3/4); group rpDJt was 77(10/13); group lack recombinant (control) pT7-7 was 25 (3/12), and group with whole-cell inactivated vaccine was 93(13/14). Although the protective antigen in the leptospires has yet to be determined, it is evident that expressed protein P68 conferred a high degree of immunoprotection in guinea pigs.

Animals↗
PubMed1998

[Effect of vasectomy on apoptosis in spermatogenic cells of the male rat].

To explore the effect of vasectomy on apoptosis of spermatogenic cells, we have detected apoptosis in the testis of vasectomized and sham-operated adult rats within a period of 12 postoperative weeks by means of flow cytometry and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuride triphosphate nick-end labeling) method. Flow cytometry found that, in vasectomized rat, the sub-haploid peak was higher and the percentage of cells with sub-haploid was increased. The total number of positive TUNEL cells in the vasectomized group was greater than that in the sham-operated group (P < 0.001). Compared with the same time-phased sham-operated subgroups, the number of apoptotic spermatogonia and primary spermatocytes in the testes of the subgroups 2 weeks, 6 weeks and 10 weeks after vasectomy as well as the number of spermatogonia of the subgroup 12 weeks after vasectomy were significantly higher (P < 0.05). These findings demonstrate that vasectomy could enhance the apoptosis of spermatogenic cells.

Animals↗
PubMed1998

[MMC conditioning regimen (Melphalan, MeCCNU and cyclophosphamide) followed by allogeneic peripheral blood stem cells transplantation for chronic myeloid leukemia].

This paper reports 3 cases of allogeneic peripheral blood stem cell transplantation (Allo-PBSCT) for the patients with chronic myeloid leukemia (CML). The patients received MMC preparative regimen with high dose chemotherapy (Melphalan 170 mg/m2, p.o. on Day-5, MeCCNU 400 mg/m2, p.o. on Day-4, and Cyclophosphomide 60 mg/kg/day, i.v. on Days-3 and -2). The HLA-identical sibling donors received filgrastim (rhG-CSF) for mobilization at a dose of 300 micrograms/day for 6 days. Leukaphereses were done at the 6th day of mobilization. A median of 8000 ml (2 times total blood volume) of blood was processed the collecting: 2.5-4.5 x 10(8)/kg MNC, 12.8-20.0 x 10(6)/kg CD34+ cells (including 4.8-7.5 x 10(6)/kg CD34+CD33-, 8.0-13.0 x 10(6)/kg CD34+CD33+), and 3.5-4.3 x 10(5)/kg CFU-GM. Cyclosporin A and methotrexate were used for GVHD prophylaxis. Hematopoitic function recovered as for 14-20 days to > 0.5 x 10(9)/L of neutrophil count, and for 16-34 days to > 20 x 10(9)/L of platelet count. At day + 100, chromosome analysis of bone marrow cells showed that complete chimera without ph1 positive chromosome in Cases 1 and 3, and a partial chimera with 73% donor karyotype in Case 2. All patients now are in disease free survival. No episode of acute graft versus host disease (GVHD) developed. It was concluded that HLA matched sibling allogeneic PBSCT result in rapid hematopoitic reconstitution and the MMC conditioning regimen is effective both in leukemic cells eradication and in immunosuppression for stem cells engraftment, and the drug related toxicity could be tolerated by patients.

Adult↗
PubMed1998

[Pediatric Haemophilus influenzae type b meninngitis in Hefei city: an epidemiologic study].

OBJECTIVE: To obtain epidemiologic information about Hib meningitis from Hefei. METHODS: Data were collected from 1990 to 1992 by a coordinative group including 13 hospitals. All children with a clinical diagnosis of acute bacterial meningitis were enrolled and specimens were taken for etiologic studies. CSF and blood were tested by standard bacteriologic technique. CSF, blood and concentrated urine were tested directly for detecting antigen by CIE. The data were analysed by epidemiologic methods. RESULTS: Of 60 cases of bacterial meningitis clinically diagnosed, 31 (51.7%) were CIE positive for Hib antigen. Only 3 cases of CSF culture were positive for Hib. The annual incidence of Hib meningitis in Hefei was culculated as 4.81/100,000 children younger than 15 years and 10.66/100,000 children younger than 5 years. The case fatality rate was 9.7%. 21.4% of survivors suffered from neurological or psychological problems. CONCLUSIONS: Using antigen detection combined with bacterial culture, we could make etiologic diagnosis in 90% of the cases. Hib is the most common cause of bacterial meningitis, but the incidence is much lower than in most parts of the world.

Adolescent↗
PubMed1998

[Ischemia and reperfusion reduce the mRNA expression of endogenous basic fibroblast growth factor (bFGF) in rat skeletal muscles].

OBJECTIVE: To explore the expression of bFGF gene in normal and wounded rat skeletal muscles. METHODS: In situ hybridization and quantitative PCR methods were used to evaluate the location of basic fibroblast growth factor (bFGF) mRNA and the amount of bFGF mRNA expression in normal, ischemic or ischemic and reperfused rat skeletal muscles. RESULTS: According to the intensity of the stain in situ hybridization, four main classes of fibers could be identified: strong, moderate, weak and negative stained fibers. bFGF mRNA was found in the cytoplasm in both normal and wounded muscles; however, the signal intensity was much stronger in normal muscles. In the normal muscles, bFGF mRNA was distributed irregularly and sparsely, and 82% of fibers had positive bFGF mRNA staining, and only 52% and 22% of fibers in ischemic or ischemic and reperfused muscles were positive for bFGF mRNA staining in situ hybridization. The results in quantitative PCR study supported the concept of the reduced bFGF mRNA expression in the wounded muscles. CONCLUSIONS: The loss of stored bFGF in wounded skeletal muscles as we showed previously is also caused by its increased damage and reduced secretion.

Animals↗
PubMed1998

[Preventional intervention of myocardial interstitial fibrosis in murine myocardium with acute myocarditis].

OBJECTIVES: To explore that whether intervening the fibrosis of heart interstitium in acute viral myocarditis is practical or not, and offer the experimental basis for clinic to choose the optimum period to intervene myocardial fibrosis. METHODS: Animals were divided into three groups: myocarditis, myocarditis intervened by Losartan, and normal control. The death rate of every group was compared. HE staining and picrosirius red staining and circularly polarized light were used to investigate myocardial collagen expression. Cardiac output was measured by impedance differentiation, and cardiac index was computed to evaluate cardiac function. RESULTS: The death rate of the group with Losartan was 75.0%, and that of the myocarditis group was 41.7%. The cardiac index of the group with the drug was 0.014 +/- 0.001 ml.min-1.cm2, the myocarditis group 0.019 +/- 0.004 ml.min-1.cm2, and the normal control 0.024 +/- 0.002 ml.min-1.cm2. The scanning area of collagen in the group with the drug was 2.06 +/- 0.77 mm, the myocarditis group 4.72 +/- 2.22 mm and the normal control 3.74 +/- 1.50 mm. CONCLUSIONS: Collagen has increased in acute viral myocarditis, but its main role in this time is to repair the necrotic myocardium, and Losartan may block this process and make lesions develop. Therefore, the acute stage is not an practical period for intervening myocardial fibrosis in viral myocarditis.

Animals↗
PubMed1998

[The protective effects of baicalin on pertussis bacilli-induced brain edema in rats].

OBJECTIVE: To evaluate the inhibitory effect of baicalin on iron-dependent lipid peroxidation (IDLPO) and the protective effect on pertussis bacilli-induced brain edema in rats. METHODS: In vitro, the inhibitory effect of baicalin and deferoxamine (DFX) was studied at different concentrations on IDLPO in brain homogenates of Sprague-Dawley rats. In vivo, the protective effect was studied of baicalin and DFX on brain edema induced by injecting purtussis bacilli into the left internal carotid artery in rats. Forty Sprague-Dawley rats were randomly divided into four groups. Group 1 (NS, n = 10), as control; Group 2 (PB, n = 10), pertussis bacilli control; Group 3 (DFX, n = 10), PB + deferoxamine; and Group 4 (BAI, n = 10), PB + baicalin. RESULTS: The baicalin was possessed of an inhibitory effect on IDLPO in rat brain homogenate, moreover, the inhibitory potency of baicalin was approximately 20 times higher than DFX treated alone. In vivo, the increase in the content of water(CW) and Evans blue (EB) was attenuated in groups DFX and BAI (CW: 79.8 +/- 0.7)% and (79.5 +/- 0.6)%; (EB: 11 +/- 7 micrograms/g and 12 +/- 5 micrograms/g) as compared with the group PB (CW: 80.4 +/- 0.9%, EB: 24 +/- 10 micrograms/g). The content of iron was significantly lower than in the left hemispheres (injected side) in the group DFX and the group BAI (79 +/- 9 micrograms/g and 77 +/- 10 micrograms/g) than in the left hemispheres in the group PB(132 +/- 28 micrograms.d-1.g), P < 0.05. The activation of CuZn-SOD (L155 +/- 36 U/mg pr, R177 +/- 75 U/mg pr) was decreased in the group BP compared with the group NS(L 201 +/- 49 U/mg pr, R 249 +/- 49 U/mg pr), P < 0.05. The activation of CuZn-SOD was significantly higher in the left brain tissues in the groups DFX and BAI (222 +/- 49 U/mg pr and 230 +/- 45 U/mg pr, respectively) than in the left brain tissues of the group of PB (P < 0.05). CONCLUSION: The baicalin and DFX have a protective effects on the pertussis bacilli-induced brain edema in rats, and the protective effects are related to the inhibitory effect on IDLPO, chelating Fe2+, and activated CuZn-SOD.

Animals↗
PubMed1998

[Alterations of intracellular free calcium concentration of cerebral neuronal cells in infectious brain injury in rats].

Intracellular free calcium concentration, [Ca2+]i, of cerebral synaptosomes loaded by Fura-2/AM was measured by fluorescent method to clarify alterations of [Ca2+]i in infectious brain injury (IBI) in rats. The results showed that [Ca2+]i, water content (WC), and Evans blue content (EB) in groups injected by Bordetella pertussis suspension (BP) were increased compared to those in groups injected by normal saline (NS) at 0.5 h, 4 h, and 24 h, respectively. Increased [Ca2+]i in BP groups showed time-dependent relationship and the highest level in the 24 h group. There was positive correlation (0.5 h, 4 h) and no correlation (24 h) between [Ca2+]i and WC or EB. It is suggested that [Ca2+]i accumulation of cerebral neuronal cells plays an important role in the pathogenetic mechanism of the acute and delayed IBI induced by BP.

Animals↗
PubMed1998

[Characteristics of radiofrequency current catheter ablation in the treatment of elderly patients with supraventricular tachycardia].

To study the effects and characteristics of radiofrequency current catheter ablation (RFCA) in treatment of elderly patients with supraventricular tachycardia (PSVT), fifty-three elderly patients and fifty non-elderly patients with PSVT were included in this study. RFCA were performed in both groups. The group of elderly patients included 26 patients with atrioventricular nodal reentrant tachycardia and 27 patients with atrioventricular reentrant tachycardia due to 29 atrioventricular accessory pathways (Aps). Twenty-one patients were accompanied with hypertension and coronary heart diseases and 5 sick sinus syndrome cases in the elderly group. All patients in both groups were treated successfully with RFCA. The procedure time of ablation of slow pathway in elderly group was shorter than that of the non-elderly group (P < 0.01). A mild symptom of arterial thrombosis was found in 2 cases of the elderly group after treatment and was cured with aspirin. These results suggest that PFCA is very effective and safe in the treatment of elderly patients with PSVT, especially for patients accompanied with sick sinus syndrome.

Aged↗
PubMed1998

[Multivariate analysis of clinicopathological and immunohistochemical factors in colorectal carcinomas].

OBJECTIVE: To determine the effect of clinicopathological and immunohistochemical factor on the prognosis of colorectal carcinoma. METHODS: The Cox model was used in a series of 68 colorectal carcinomas to study ten prognostic factors. These factors included tumor growth, stromal lymphocyte infiltration and fibrous tissue proliferation, degree of differentiation, Dukes stage, p53 protein, c-erbB-2 protein, P21 protein, PCNA proliferation index and EGFR. RESULTS: Monovariate analysis showed that tumor growth, stromal lymphocyte response, Dukes stage, p53, c-erbB-2 protein and PCNA index influenced prognosis significantly; multivariate analysis revealed 4 significant prognostic factors; P21, c-erbB-2 protein, Dukes stage and PCNA index. The relative risk (RR) for mortality was high in patients having P21 and c-erbB-2 co-expression. The RR of P21 and c-erbB-2 protein positive patients in Dukes A stage was higher than that of P21 and c-erbB-2 protein negative patients in Dukes B stage. CONCLUSIONS: P21, c-erbB-2 protein, PCNA index and Dukes stage were independent predictors of survival. The prognosis of patients with P21 and c-erbB-2 protein co-expression was worse than in patients without this co-expression.

Colorectal Neoplasms↗