Biomedical subjects

W Zhang

Publications and source records attributed to W Zhang.

At least 829 records · Page 46Linked to original sources

PubMed1998

[Changes of plasma nitric oxide and endothelin levels in normal pregnant women and pregnancy induced hypertension].

OBJECTIVE: To investigate the relationship of nitric oxide (NO), endothelin-1 (ET-1) levels and pregnancy induced hypertension (PIH). METHODS: 60 patients with PIH, 45 normal pregnant women and 15 normal non-pregnant women were studied. Plasma NO levels were determined. The stable metabolic product NO2-/NO3- of NO was letermined by Griess reaction. Plasms ET-1 levels were measured with radioimmunoassay. RESULTS: The NO2-/NO3- levels of the normal pregnancy group were significantly higher than those of the control group (P < 0.01), particularly in the second trimester of pregnancy. The NO2-/NO3- level of PIH was significantly lower in maternal plasma than that of the last trimester of normal pregnancy (P < 0.01) and nonpregnancy (P < 0.05), and it decreased with the disease development. In severe PIH the umbilical venous blood NO2-/NO3- level was significantly lower than that in the normal term pregnancy group (P < 0.01). The maternal plasma ET-1 level in PIH was significantly higher than that in the normal term pregnancy and control groups (P < 0.01). CONCLUSION: PIH might be related to decreasing synthesis and release of NO, and increasing ET-1 production.

Adult↗

PubMed1998

[Detecting cytokines in patients with preterm premature rupture of membrane].

OBJECTIVE: To study the relationship of maternal blood and amniotic fluid cytokine levels in patients with preterm premature rupture of membrane and chorioamnionitis. METHODS: IL8 and TNF alpha levels of maternal blood and amniotic fluid were determined by 125I radioimmunoassay (RIA) and an enzyme-labeled immunosorbent assay (ELISA). Chorioamnionitis was diagnosed by fetal membrane histology. RESULTS: The maternal serum IL8 levels and amniotic fluid IL8, TNF alpha levels were higher than those of controls (P < 0.05). There was significant relationship between maternal serum and amniotic fluid IL8, TNF alpha with the time of the premature rupture of membanes. The longer the time the higher the maternal serum IL8 and amniotic fluid IL8, TNF alpha; There were 13 patients with chorioamnionitis, and their maternal serum and amniotic fluid IL8, TNF alpha were higher than those of patients with non-chorioamnionitis (P < 0.01-0.05). CONCLUSION: IL8, TNF alpha levels of maternal serum and amniotic fluid are valuable clinical indexes in identification of chorioamnionitis in patients with preterm premature rupture of membranes.

Adult↗

PubMed1998

[Evaluation of thoracic aortic anatomy and function with transesophageal echocardiography].

OBJECTIVE: To evaluate the effects of age, gender, and hypertention on thoracic aortic anatomy and function in Chinese. METHODS: Thoracic aortic diastolic and systolic diameter (Dd and Ds), intimal-medial thickness (IMT), Peterson's and Young's elastic modulus (Ep and Es), and stiffness index (beta) were measured by transesophageal echocardiography in 134 normal subjects and in 42 patients with hypertension. RESULTS: Age was positively correlated with IMT (r = 0.68, P < 0.01), Dd(r = 0.65, P < 0.01), Ds(r = 0.58, P < 0.01), Ep(r = 0.82, P < 0.01), Es(r = 0.71, P < 0.01), beta(r = 0.67, P < 0.01). Men had a greater diameter and IMT than women. In comparison with the control group, the patients with hypertension had significantly increased Dd (20.73 +/- 2.80 mm vs 18.20 +/- 3.03 mm, P < 0.01), Ds (22.17 +/- 2.90 mm vs 19.81 +/- 2.93 mm, P < 0.01), IMT(1.39 +/- 0.66 mm vs 1.17 +/- 0.50 mm, P < 0.05), Ep(1.47 +/- 0.84 vs 0.81 +/- 0.66, P < 0.01), Es(11.91 +/- 8.04 vs 6.49 +/- 3.93, P < 0.01), and beta(3.24 +/- 0.43 vs 2.91 +/- 0.52, P < 0.01). CONCLUSIONS: Aging and hypertension significantly increase aortic diameter, thickness and stiffness. Men have higher aortic diameter and wall thickness than women but similar stiffness.

Adolescent↗

PubMed1998

[Analysis of reasons failed focal debridement in 109 patients with spinal tuberculosis].

OBJECTIVE: To explore reasons failed focal debridement in treating spinal tuberculosis patients and methods to cope with them. METHOD: One hundred nine patients with spinal tuberculosis who failed initial focal debridement from 1987 to 1996 were reviewed. RESULT: The reasons of operational failure were found to be the use of unreasonable regimens and existence of drug resistant strains; inappropriate operational indication, approach and treatment during operation; lesions involving several vertebrae, skipping destruction and complicating with other kinds of extrapulmonary tuberculosis. CONCLUSION: The key to successful treatment of the disease is to choose appropriate operative indication and approach, discard spinal cord pressure and rebuild spinal stability on the basis of reasonable chemotherapy regimen.

Adolescent↗

PubMed1998

[Effects of receptor-mediated endocytosis on macrophage membrane potential, cytosolic pH and lysosomal pH].

The effects of Con A, WGA, Zymosan A on membrane potential, cytosolic pH and lysosomal pH of cultured mouse macrophages were measured with fluorescence method. The results showed all the three kinds of ligands caused macrophage membrane potential hyperpolarization, cytosolic acidification and lysosomal alkalization, but reached their stabilized conditions at different times. The acidification of cytosl might inhibit further endocytosis. Alkalization of lysosomes was a basic factor for exocytosis of lysosomal contents. These receptor-mediated induced changes reflected cellular self-regulation and self-protection.

Animals↗

PubMed1998

[Study on the pathological features of airway inflammation in asthma and chronic bronchitis].

OBJECTIVE: To explore the difference between the pathological features of asthma and chronic bronchitis on airway inflammation, then to provide pathomorphological basis for appropriate diagnosis and treatment of these two different entities. METHOD: To compare the pathological changes of airways from 14 asthmatic and 13 chronic bronchitic patients. RESULT: There were damaging lesions shown on tracheo-bronchial epithelium of asthmatic and chronic bronchitic patients; various inflammatory cells and structural pathological changes occurred in submucosa. The numbers of eosinophilic cells and mast cells in asthmatic group were higher than those of chronic bronchitic group (P < 0.01). Thickness of basement membrane in early stage (P < 0.05) and thickness of smooth muscle were characteristic pathological changes for asthmatic group. Degranulation phenomenon of mast cells was found in asthmatic group. The pathological features of airway mucosa of chronic bronchitic group were different: eosinophilic cells < 1.2/HP and mast cells < 1/HP; no degranulation of mast cells was observed under electronmicroscopy. CONCLUSION: Both asthma and chronic bronchitis (including chronic asthmatic bronchitis) are chronic airway inflammatory illnesses, but obvious pathomorphological difference was found in their airway mucosa. These are two different diseases and the reasons for causing airflow obstruction are also different.

Adult↗

PubMed1998

[The effect of Vit. B12 injection into acupoints in the treatment of verruca plana].

OBJECTIVE: To study the therapeutic effect of combined western and traditional Chinese medicines for the treatment of verruca plana. METHODS: Acupoint injection of Vit. B12 was used to treat 91 patients suffering from verruca plana after unsuccessful therapy of more than 3 methods. RESULTS: Complete cure, 35 cases; significantly improved, 56 patients. The total effective rate was 100%. Compared with the Vit. B12 i.m. injection group and polyinosinic cytidy lic acid i.m. injection group, the difference was highly significant (P < 0.001). The results were also proved by histologic examination. CONCLUSION: The Vit. B12 acupoints injection is a simple and effective method for the treatment of facial verruca plana.

Acupuncture Points↗

PubMed1998

[Fatal complications in traffic accident injury].

OBJECTIVE: To discuss the relative factor, development tendency and prevention of the fatal complications in traffic accident injury. METHOD: We observed injury severity scale (AIS-ISS), clinical response time, and occurrence in traffic accident injury with fatal complications. Ridit mathematical statistics and Q test were used. RESULT: There were high ISS and long clinical response time in traffic accident injury with fatal complications. A significant relation was found between complications and the progress of time after trauma, thereby the clinical course could be divided into phases of cerebral hernia and shock (or acute), transition, infection and multiple organ dysfunction syndrome (MODS). There was higher head AIS in the cerebral hernia. ISS of shock patients was significantly higher than that of the others. Massive infections occurred in the patients with extremity trauma. There was a significant relation between the occurrence of MODS and infection. CONCLUSION: The occurrence of fatal complications is related to the location and severity of injury in traffic accident injury. A regularity is present in the occurrence of fatal complications with time progress.

Abbreviated Injury Scale↗

PubMed1998

[Surgical treatment of aortopulmonary septal defect].

OBJECTIVE: To study the surgical treatment of aortopulmonary septal defect. METHOD: From January 1983 to December 1996, 5 patients with aortopulmonary septal defect (APSD) (2 male and 3 female) aged from 6 to 34 years (mean 17.4 years) underwent surgical treatment. According to Mori's were classification, 5 patients belonged to type I, 2 type II and 1 type III. The diameters of the defect ranged from 1.0 to 3.0 cm. The operations were performed under moderate hypothermic cardiopulmonary bypass. Pulmonary artery incision was performed, in 3 patients while aortic incision in the other 2. All defects were repaired by Dacron patch. RESULT: There were no operative deaths and postoperative complications. During follow-up of 10 months to 12 years, no late complications and deaths were found. CONCLUSION: The operation should be done early as possible whenever the diagnosis is established. The surgical repair should be taken under cardiopulmonary bypass. To chose an incision on the aorta is more reasonable than on the pulmonary artery. The use the dacron patch can prevent stenosis and recanalization after operation.

Adolescent↗

PubMed1998

[Tissue engineering of hyaline cartilage].

OBJECTIVE: To study the new way to repair the defect of the articular cartilage. METHOD: The articular-epiphyseal cartilage complexes from 8 newborn rabbits were enzymatically dissolved, and the chondrocytes were seeded onto the fibrous chitin mesh in a 96-well plate in DMEM medium. RESULT: Cultured for 21 days, the "membrane-like cartilage" was strong enough to be transferred. At the 110th day, the semitransparent cartilage discs were 4.4 mm in diameter and 14.8 mg in weightness. Staining of SatranO showed that engineered "cartilage" was bound of GAGs and the chondrocytes expressed the mRNA of type II collagen by in situ hybridization, which is resemble to that of the normal hyaline cartilage beside the biodegraded fibrous chitin embedded in. The "membrane-like cartilage" cultured for 21 days was grafted into the articular cartilage defects of knee of adult rabbits. Seven of 9 defects healed with new cartilage and the structure was well organized in 16 weeks. CONCLUSION: The biodegradable fibrous chitin is a good "matrix" for cartilage tissue engineering. The engineered "cartilage" is true hyaline cartilage, which is a new "alive cartilage tissue" for the repairment of the defect of articular cartilage.

Animals↗

PubMed1998

[Bilateral ureter within single nipple for cutaneous ureterostomy after radical cystectomy].

OBJECTIVE: To evaluate the effect of bilateral ureter within single nipple for cutaneous ureterostomy after radical cystectomy. METHOD: Bilateral ureter within single nipple for cutaneous ureterostomy was performed on 36 patients after radical cystectomy. RESULT: The nipple was formed well, and urinary drainage was patent. No death or severe complication occurred. The patients have been followed up for 3 months to 3.5 years. Urinary, electrolyte and renal functions were within normal levels. No pyelonephritis or hydronephrosis was observed in IVP, retrograde pyelography and/or sonographic examination of kidneys, no nipple constriction. A right ureter was pulled to the left retroperitoneum and formed a nipple with ureter left on the left abdominal wall. CONCLUSION: This is a simple and safe operation, especially suitable to the old and weak patients.

Adult↗

PubMed1998

[Immunopathologic studies on the effects of immunosuppressant FK 506 on penetrating keratoplasty rejection model in rat].

OBJECTIVES: To study the immunopathologic process of rejection, the effect of certain immune cells and molecules on rejection and elucidate the immunosuppressive mechanism of FK 506. METHODS: By using immunohistochemical techniques, the expression of CD(4)(+) cells, CD(8)(+) cells, macrophages, IL-2 receptor, MHC-II antigen, intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in rejected corneal grafts were studied. RESULTS: Immunohistochemical studies showed diffuse infiltration of CD(4)(+) cells, CD(8)(+) cells and macrophages, and strong expression of IL-2 receptor, MHC-II antigen, ICAM-1 and LFA-1 in rejected corneal grafts, especially in the acute rejection stage. FK 506 can inhibit the expression of these cells and molecules in the grafts. CONCLUSION: Keratoplasty rejection is significantly related to delayed type of hypersensitivity and cytotoxic T cells, and immune adhesion molecules and MHC-II antigen also affect the rejection process.

Animals↗

PubMed1998

[An analysis on therapeutic effects of excimer laser photorefractive keratectomy for high myopia].

OBJECTIVE: To evaluate the therapeutic effects of 193-nm excimer laser photorefractive keratectomy for the correction of high myopia. METHODS: A Keracor 116 excimer laser and a tapered transition zone technique were used to treat high myopia. It was divided into two groups: the first group -6.00 - 9.75 D, 233 eyes; the second group -10.00 - 14.00 D, 55 eyes. The effect of the tapered transition zone on refraction stability was investigated in a 12-month follow-up study. RESULTS: At one year, of these eyes, 79.4% eyes attained visual acuity of 0.5 or better, 31.6% improved to 1.0 or better, 93.8% of the eyes improved or their best corrected visual acuity did not change, whereas 6.2% lost at least one line. Corneal haze was observed to be severe in one month, and diminished considerably at 6 and 12 months. At one year, no haze could be seen in 87.4%. 52.0% were within +/- 1.00 D and 80.9% in +/- 2.00 D. During one year, 14.9% were complicated with glaucoma because of using steroid drops. CONCLUSION: These data show that excimer PRK for treatment of high myopia is an effective and safe refractive surgery. For severe myopia, it is an effective surgery, but predictability is not satisfactory, and long term follow-up is necessary.

Adolescent↗

PubMed1998

[A study on the prevention of selenite cataract with taurine].

OBJECTIVE: To evaluate the prevention of selenite cataract with taurine. METHODS: A prior injection of taurine was given intraperitoneally to Wistar rats 2 days before the selenite challenge and a following daily injection of taurine was needed until the experiment was finished. All of the rats were examined under a split-lamp microscope on selected days. RESULTS: 0.5% taurine showed no effect on lenses, 1%, 2% and 4% taurine could delay the development of nuclear opacity, and 2% and 4% taurine could also delay the development of cortical opacity. CONCLUSIONS: Taurine can prevent the development of selenite cataract. Its effect is dose-dependent.

Animals↗

PubMed1998

[Advances in chromatography and related techniques in China--status report in 1996-1997].

An overview of the use of chromatography and related techniques in China is given in 1996-1997. This review includes five parts, the statistical results of the scientific papers published in 15 domestic and a few foreign periodicals which are closely related to chromatography and presented on 1997 Beijing Conference and Exhibition on Instrumental Analysis and the 11th National Symposium of Chromatography, about chromatographic theory, GC, LC and CE. One hundred thirty seven references are cited.

Animals↗

PubMed1998

[Simultaneous determination of aspartame and amino acids in fermented milk beverages by HPLC].

An RP-HPLC method for the simultaneous determination of aspartame and amino acids in fermented milk beverages were established. Samples were prepared by mixing with methanol at a ratio of 1:1 and centrifuged at 4,000 r/min for 15 min. Ten microL supernatant was moved into a sample tube, dried and derivatized according to PICO-TAG procedure developed by Waters. A Novapak C18 column (3.9 mm x 150 mm) was used instead of PICO TAG column and the gradient elution program was modified correspondingly. Column temperature was maintained at 38 degrees C and the components were detected at 254 nm. Linearity for aspartame at the range in 1-100 mg/L is A = 333 C + 20 with r = 0.9996 where A is the integrated area of chromatographic peak of aspartame and C is the corresponding mass concentration. Repeatability for 8 injections was tested and the RSD of 3.2% was obtained. The recovery of aspartame for 5 samples with the method ranged from 94.2% to 98.7%.

Amino Acids↗

PubMed1998

[Study on the rifampicin polylactic acid microspheres for lung targeting].

In this paper, the effects of different variables on the preparation of polylactic acid microspheres (PLA-MS) were studied. The optimized preparation conditions of rifampicin polylactic acid microspheres (RFP-PLA-MS) were aquired through orthogonal test. The paddle method was used to study the drug release properties of RFP-PLA-MS. Stability of RFP-PLA-MS at different temperatures was also studied. Pharmacokinetic and tissue distribution of RFP-PLA-MS after intravenous administration were carried out in rabbits. The experiments revealed that the RFP-PLA-MS was regular in its morphology with a mean diameter of 9.00 +/- 4.08 microns. The drug loading was 16.0% and encapsulation efficiency was 31.9%. The release properties could be expressed by the following equation: Q = 20.77 + 10.12 T 1/2 (gamma = 0.9892). The RFP-PLA-MS was stable after stored at 4 degrees C and room temperature under desiccated condition for three months. RFP-PLA-MS showed a combination of lung targeting and sustained drug release in experiments on rabbits.

Animals↗

PubMed1998

[Effects of dopexamine on cardiac hemodynamics during myocardial ischemia in rats and in comparison with fenoldopam and procaterol].

The effect of dopexamine hydrochloride(DPX) on cardiac hemodynamics during acute myocardial ischemia (AMI) was studied in rats and compared with those of fenoldopam hydrochloride(FODA) and procaterol hydrochloride (PCT). The results showed that i.v. DPX remarkably attenuated the increases of total peripheral resistance(TPR) and left ventricular end-diastolic pressure and the decreases of + dp/dt max caused by ischemia, while DPX showed no significant effect on mean arterial pressure(MAP). Although FODA was more potent than DPX in attenuating the increase of TPR and the decrease of myocardial contractility caused by ischemia, it significantly decreased MAP. The effects of PCT on all these variables were the smallest among the 3 agents. The results suggest that DPX has a better prospect in the treatment of ischemic heart disease in view of its actions of decreasing TPR, mild increase of myocardial contractility, without MAP decrease and myocardial oxygen consumption increase.

Adrenergic beta-2 Receptor Agonists↗