Biomedical subjects

Y Xu

Publications and source records attributed to Y Xu.

At least 937 records · Page 52Linked to original sources

PubMed1996

Plasma endothelin and atrial natriuretic peptide in normal and hypertensive pregnancy.

OBJECTIVE: To investigate the possible role of endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) in the pathogenesis of pregnancy-induced hypertension (PIH). MATERIAL AND METHODS: A total of 110 normal pregnant women (in three trimesters, labour or postpartum) and 30 patients with PIH were studied by measuring plasma ET-1 and ANP levels by radioimmunoassay; 23 normal non-pregnant women were selected as controls. RESULTS: Compared with normal non-pregnant women, plasma ET-1 levels were significantly decreased in normal pregnant women during all three trimesters. Plasma ET-1 level was significantly increased in the 2nd stage of labour, compared with that in the 3rd trimester. There were significant positive correlation between plasma ET-1 level and mean arterial pressure in normal non-pregnant women and normal pregnant women in all three trimesters. Compared with matched normal pregnant women, plasma ET-1 and ANP levels were significantly increased, while plasma ANP/ET-1 ratio was significantly decreased in PIH patients. Significant positive correlations existed between plasma ET-1 level and mean arterial pressure or the score index of the severity of PIH. After the treatment with magnesium sulfate infusion, plasma ET-1 and ANP levels were significantly decreased, but plasma ANP/ET-1 ratio was significantly increased in PIH patients. CONCLUSIONS: Augmentation of ET-1 secretion and attenuation of ANP function may be responsible for the development of PIH. ET-1 secretion may be indirectly influenced by magnesium in PIH.

Adult↗

PubMed1996

[The changes of plasma nitric oxide in patients with pregnancy induced hypertension].

OBJECTIVE: To determine whether the antepartum and postpartum plasma nitric oxide (NO) levels were changed in pregnancy induced hypertension (PIH). METHODS: 30 patients with PIH and 30 healthy women in their late pregnancy were studied. The antepartum and postpartum plasma NO2-/NO2- levels, the stable metabolic end products of NO, and cyclic guanosine monophosphate (cGMP) were measured with greiss reagent. RESULTS: (1) The plasma concentration of NO2-/NO2- and cGMP in patients with PIH decreased significantly when compared with that of healthy pregnant women (P < 0.01). (2) The concentration of antepartum plasma NO2-/NO2- was markedly lower than that of postpartum one in PIH patients (P < 0.01). (3) There was a negative correlation between the plasma NO2-/NO3- level and systolic blood pressure in PIH (P < 0.01). (4) A positive correlation was seen between plasma NO2-/NO3- levels and cGMP levels in PIH patients (P < 0.01). CONCLUSION: The decrease of NO synthesis may be one of the important factors responsible for PIH.

Adult↗

PubMed1996

[The relationship between onset of labour and concentration of hyaluronic acid and estradiol to progesterone ratio].

OBJECTIVE: To study the changes of serum hyaluronic acid (HA) level and estradiol (E) to progesterone (P) ratio during pregnancy and their relationship with onset of labour. METHODS: 116 normal pregnant women with different gestation age and different phases in labour and 20 postpartum women were studied with 30 cases of nonpregnant women as control. Concentration of HA, E2 and P were determined by radioimmunoassay. RESULTS: Serum concentration of E2, P and their ratio increased gradually during pregnancy and reached their peaks at the onset of labour. HA concentration was similar to nonpregnant women during first and second trimester, however, significantly increased during labour, and then decreased rapidly to nonpregnant level at 2-3 days postpartum; concentration of HA, E2, P and E2/P increased significantly during labour but unrelated to the gestational age when labour began; serum concentration of HA was negatively correlated with the latent phase (r = -0.344, P < 0.05) but not with the active phase. CONCLUSION: HA, E2, P and E2/P may play an important role in the initiation of labour and may be of value in evaluating cervical ripening and facilitating labour management.

Adult↗

PubMed1996

[The expression of pulmonary surfactant proteins B and surfactant protein C in E. coli].

OBJECTIVE: To express biological active surfactant protein B(SP-B) and surfactant protein C(SP-C) combined with synthetic phospholipids to make an ideal exogenous pulmonary surfactant (PS) for the treatment of respiratory distress syndrome (RDS) in future. METHOD: Prokaryote expression vector pIN-II-ompA2-B-C was established with the cDNA fragments of mature human SP-B and SP-C, then the fusion protein of mature SP-B with SP-C was expressed in E. coli BL21 induced by IPTG. The expression of fusion protein in E. coli was confirmed by Western blot anlaysis. The biological activity of the expressed product was measured by Wilhelmy's surface balance (MTP-2). RESULTS: The fusion protein of SP-B with SP-C could be expressed in E. coli BL21, and their molecular weight (Mr) was 20000 on gel electrophoresis, but the amount was small. According to the measurement of Wilhelmy's surface balance (MTP-2), the minimal surface tension of expressed protein in E. coli BL21 could be reduced to 0.004 N/m2 and the area of hysteresis loop was relatively large. CONCLUSIONS: The results of the investigation will be a basis to obtain SP-B and SP-C with gene engineering technology and to create a new way for producing ideal exogenous PS.

Base Sequence↗

PubMed1996

[Multifactor analysis of predisposing factors of oral candidosis in adults].

To study the prodisposing factors of oral candidosis in adult, analyst statistic package (quantity theories II) were used for the multifactor regressive analysis on 116 cases with oral candidosis and 76 gender and age matched normal controls. Six possible predisposing factors including gender, smoke, job, denture, drug use, systemic and other mucosal disease accompanied were inquired. The results showed that the most active predisposing factors were systemic or other oral mucosa disease accompanied, which include post-operative states, post-radiotherapy states, Sjogren's syndrome; followed by drug use before onset of oral candidosis, especially topic antibiotics; the four other factors (smoke, job, denture and gender) have some effect but do not play any conclusive role on the occurence of oral candidosis.

Adult↗

PubMed1996

Effects of m-nifedipine on dihydropyridine binding sites in hypertrophied left ventricular cell membranes from deoxycorticosterone acetate-salt hypertensive rats.

m-Nifedipine(m-Nif 20 mg.kg-1.d-1 ig) was administered orally to male deoxycorticosterone-acetate-salt(DOCA) hypertensive rats for 9 or 12 wk, the affinity and density of dihydropyridines (DHP) binding sites in the membranes of left ventricle (LV) were investigated. Treatment with m-Nif, whether for prevention (6 wk postoperation) or regression (9 wk postoperation) lowered systolic blood pressure, decreased the weight of left ventricle and the Ca2+ concentration in mitochondria in hypertrophied LV. The density (Bmax) and the total number of DHP binding sites in hypertrophied LV were also markedly decreased (450 +/- 25, 462 +/- 36 fmol.mg-1 vs 836 +/- 47 fmol.mg-1 protein, P < 0.001). There was no difference between groups in constant (KD) values of DHP binding sites. These results indicate that m-Nif prevented and regressed cardiac mass in DOCA hypertensive rats through mechanisms that may be associated with their density of DHP binding sites and control of blood pressure.

Animals↗

PubMed1996

[A prospective study of early detection for primary liver cancer].

In order to evaluate the effectiveness of early detection for primary liver cancer (PLC), a randomized, prospective study was performed in Shanghai from 1992 to 1995. The study population was 35 through 55 years of age, with serum evidence of HBV infection or tory of chronic hepatitis. Seventeen thousand nine hundred and twenty individuals were randomly to allocated screening group and control group. In the screening group, every individual was checked up by serum AFP test and ultrasound every 6 months and in the control group, they were unchecked. After a mean time of 1.2 years, 38 patients with PLC in the screening group were detected while 18 patients with PLC occur in the control group. In patients from the screening group, 76.8% were in subclinical stage, 70.6% of them were treated by surgical resection with 1-, 2-year survival rate of 88.1% and 77.5%, respectively. However, in the control group, none of patients was in subclinical stage, none of the tumors resected, and none of patients survived over 1 year. The lead time was estimated to be 0.45 years. The cost for detecting an early stage PLC patient is RMB 12,600 (US$1,500). The study indicates that screening in the high risk population of PLC can detect patients in early stage, increase the resection rate and the survival rate. Screening program for PLC carried out in high risk populations is thus recommended.

Adult↗

PubMed1996

Antenatal diagnosis and management of Dandy-Walker syndrome.

The Dandy-Walker syndrome (DWS) can be accurately diagnosed in utero by sonographic demonstration of characteristic morphologic changes of the fetus, which includes hydrocephalus, incomplete cerebellar vermis and a posterior fossa cyst. We present a case of Dandy-Walker syndrome diagnosed antenatally. The associated anomalies are reviewed, and the value of antenatal diagnosis is discussed.

Adult↗

PubMed1996

[Transplantation of the remedial free anteromedial thigh flap].

Over one hundred and twenty free anterolateral thigh flaps have been performed since 1988, of which ten were operated as free anteromedial flaps because the nutrient vessels emerged from the medial intermuscular space formed by the sartorius, the rectus femoris and vastus medialis muscles. Clinical study indicated that there were three types of nutrient cutaneous arteries in the space: type 1, the medial branch of the descending branch of the lateral circumflex femoral artery in 6 cases; type 2, the superficial femoris artery in 2 cases; and type 3, the branch of the femoris artery in 2 cases. The name of the flap, the operation technique and the compensative characteristics of the arteries are discussed.

Adolescent↗

PubMed1996

[Side-to-side porto caval shunt with a restricting ring].

Limited side-to-side portalcaval shunt with a limitary ring attached (LPCS-LRA) was used to improve portal perfusion while decompressing the portal system. From December 1988 to December 1994, 154 patients had LPCS-LRA among them ninety-one patients were in 91 Child A, 41 Child B, and 18 Child C. At average 3.2-year follow-up, the hospital mortality was 1.3%, the total mortality was 2.6%, recurrent variceal hemorrhage rate was 1.9%, postoperative encephalomyelopathy rate was 4.1%, and the survival rate at 2, 3, 4, 5, 6 year were 98.3%, 96.6%, 93.7%, 89.2%, 83.3% respectively. The clinical efficacy of LPCS-LRA was satisfactory and the incidence of postoperative encephalomyelopathy was low.

Adult↗

PubMed1996

[Study on relation of kidney-deficiency with hearing damage and serum trace elements in patients with chronic nephropathy].

The hearing and serum trace element of 73 cases of chronic nephropathy were measured. Results showed that the incidence of hearing damage in high frequency was 68.5% with a mean hypoacusis of 35.1 +/- 6.1 dB, while in 55 patients of Kidney Deficiency type, the incidence of hearing damage in high frequency was 83.6%, it was significantly higher than that in patients without Kidney Deficiency. The serum levels of trace elements (iron and zinc) in patients with Kidney Deficiency were lower than that of normal level and in patients without Kidney Deficiency, and the decrease of serum iron was directly proportional to the degree of hearing damage. There were close relationship between the Kidney Deficiency with the hearing damage as well as the serum levels of iron and zinc.

Adult↗

PubMed1996

[Smooth muscle neoplasms of the uterus--a 51 cases study].

To discuss the diagnosis of uterine leiomyosarcoma and leiomyoma of cellular and bizarre type, we reviewed 51 cases and carried out P53 and desmin immunohistochemical staining on 43 cases. We found that in most cases leiomyosarcoma is accompanied by nuclear mitosis, cell atypia and margin infiltration. In a small number of cases, though mitotic figures are scarce, high cell atypia and marked margin infiltration were present. Leiomyoma variants may have high cellular density and bizarre nuclears but have no margin infiltration. Leiomyosarcoma has a high incidence of P53 expression, while no P53 expression was detected in leiomyoma variants. Desmin expression is closely correlated with the differentiation of smooth muscle neoplasms of the uterus. We conclude that nuclear mitotic activity is an important but not independent criteria in the diagnosis of uterine leiomyosarcoma. Cellular atypia and margin infiltration should be considered. P53 and desmin expression can be applied as accessary criteria.

Adult↗

PubMed1996

[Retroviral-mediated transfer of beta-globin gene into human hematopoietic cells].

Transferring beta-globin gene and its enhancer into human hematopoietic cells is the basis for applying beta-thalassemia gene therapy in clinical practice. We isolated ecotropic virus producing clones and amphotropic virus producing clones by using a replication-defective retrovirus vector containing beta-globin gene and its enhancer to transfect ecotropic packaging cell line phi-2 and amphotropic packaging cell line PA317. Then by ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, we obtained high titer amphotropic PA317 producer clones with the highest titer up to 5.9 x 10(6) CFU/ml. Human mononuclear bone marrow cells were infected repeatly with this high titer virus vector under stimulation of hematopoietic growth factors IL-3, IL-6 and SCF, Southern blot hybridization analysis showed that beta-globin gene and its enhancer had been integrated into the genome of human hematopoietic cells.

Enhancer Elements, Genetic↗

PubMed1996

[Expression of retroviral transduced human beta-globin gene in mouse fetal liver cells].

A replication-defective retrovirus vector containing the human beta-globin gene and 36-base-pair HS2 enhancer (N2A beta E36) was constructed and transferred into psi-2 and PA317 packaging cell lines. Titers of amphotropic recombinant retrovirus ranged from 10(3) to 10(4) CFU/ml. Southern blot analysis indicated that intact human beta-globin gene was stably integrated into the genome of the target cells. Northern blot hybridization analysis showed that human beta-globin gene could be expressed in mouse fetal liver cells.

Animals↗

PubMed1996

[Genetic polymorphism of antithrombin III in five Chinese populations].

The genetic polymorphisms of antithrombin III (AT III) in 5 Chinese populations were studied by isoelectric focusing on polyacrylamide gels followed by immunoblotting. The products of two alleles at the antithrombin III locus together with 1 AT III anodic variant and 3 cathode variants were observed. The results revealed that the predominant allele of AT III blood group system in Chinese populations was AT III *1, with frequencies between 0.9773-0.9850. Frequencies of AT III *2 ranged from 0.0091 to 0.0169. These results indicate that the polymorphic information content of AT III blood group system in Chinese populations is limited.

Alleles↗

PubMed1996

[A randomized controlled clinical trial of sulperazon in the treatment of surgical infection].

Randomized controlled clinical study of Sulperazon (Sulbactam/Cefoperazon) was made in the surgical field. 35 cases were treated with Sulperazon and 32 cases with Ceftazidime. In the Sulperazon group (35 patients), the effective rate was 88.6% as compared with 90.6% of the patients in the Ceftazidime group (32 patients) (P > 0.05). The bacterial eradication rate was 86.2% in the Sulperazon group as compared with 88.5% in the Ceftazidime group. No significant difference was noted in both groups. In the Sulperazon group, side effects were not observed except nausea in one case.

Adult↗

PubMed1996

A melanosomal membrane protein is a cell surface target for melanoma therapy.

Differentiation antigens on cancer cells are recognized by the immune system. A prototype set of these autoantigens in melanoma cells are the melanosomal glycoproteins, expressed in both melanomas and normal melanocytes. These are intracellular proteins that can be recognized by both antibodies and T lymphocytes. While one can understand how T cells can respond to intracellular proteins, based on cellular requirements for antigen processing and presentation, it is more difficult to understand how antibody responses to melanosomal proteins could lead to tumor rejection. We demonstrate that gp75 is expressed on the cell surface as well as intracellularly in human and mouse melanomas. The surface expression of gp75 can be augmented by IFN-gamma and during tumor growth in vivo. Surface expression of gp75 on mouse melanoma cells correlates with the ability of a monoclonal antibody (mAb) against gp75 to reject melanomas in syngeneic mice. Antibody-mediated rejection seems to require the Fc portion of the antibody, suggesting a role for Fc receptor-positive effector cells such as natural killer cells. However, although NK1.1(+) cells have been implicated in antibody-induced rejection in vivo, cell surface expression of gp75(+) on melanoma does not lead to susceptibility to antibody-dependent cellular cytotoxicity in vitro. The mAb to gp75 induced tumor rejection in mice carrying both scid and bg/bg traits, showing that neither thymus-dependent T cells nor natural killer cytotoxic activity was required in vivo. Long-term treatment of mice with mAb led to patchy depigmentation in the coat. In summary, an intracellular organellar protein can be expressed at the cell surface and provide an antigenic target for antibody therapy and autoimmunity.

Animals↗

PubMed1996

[Inhibitory effects of m-nifedipine on angiotensin II stimulated proliferation and protein synthesis in cultured rabbit aortic smooth muscle cells].

By using rabbit aortic smooth muscle cells (VSMC) in culture as a model, the effects of m-nifedipine (m-Nif) on the growth of VSMC were observed. The results showed that m-Nif inhibited [3H]-thymidine and [3H]-leucine incorporation into DNA and protein, decreased cell number in a concentration-dependent manner in angiotensin II (ANG II) induced VSMC. At the concentration of 2 mumol.L-1, m-Nif was found to reduce the ANG II (100 nmol.L-1) stimulated [3H]-thymidine, [3H]-leucine incorporation and cell number by 46%, 58% and 53%, respectively. Our results suggest that m-Nif can inhibit ANG II stimulated proliferation and protein synthesis in cultured rabbit aortic VSMC.

Angiotensin II↗