Biomedical subjects

W Chen

Publications and source records attributed to W Chen.

At least 631 records · Page 35Linked to original sources

PubMed1998

[Level of NCF and TNF-alpha in the BALF of ILD patients and their clinical significance].

OBJECTIVE: To investigate the relationship between the level of the neutrophil chemotactic factor(NCF), tumor necrosis factor-alpha(TNF-alpha) in patients with interstitial lung disease(ILD) and the activity of ILD. METHOD: The NCF activities in the BALF and in the serum from 11 patients with sarcoidosis, 7 with idiopathic pulmonary fibrosis (IPF) and 8 normal subjects were determined using the membrane filter and radio-immunoassay. The level of TNF-alpha was also detected. RESULT: In the 7 IPF patients, the level of NCF and TNF-alpha (203 +/- 44 cells/10 HP, 11.7 +/- 2.9 ng/L) in the BALF was higher than that in 8 control patients (83 +/- 45 cells/10 HP, 6.5 +/- 1.4 ng/L, P < 0.01). The level of NCF and TNF-alpha in the BALF from 11 patients with sarcoidosis (186 +/- 50 cells/10 HP, 12 +/- 3 ng/L) was highet than those in 8 control patients (P < 0.01). The level of NCF and TNF-alpha in the BALF from patients with IPF was positive correlated with the percentage of neutrophil (NCF: r = 0.89, P < 0.01; TNF-alpha: r = 0.86, P < 0.05). The level of NCF and TNF-alpha in the BALF of patients with sarcoidosis was positive correlated with the percentage of lymphocyte (NCF: r = 0.78, P < 0.01; TNF-alpha: r = 0.73, P < 0.01. CONCLUSION: The level of NCF and TNF-alpha in the BALF from patients with IPF and sarcoidosis can act as the marker of the activity of alveolitis of IPF and sarcoidosis.

Adult↗

PubMed1998

[Diagnosis and treatment of tuberculosis of bone marrow].

OBJECTIVE: To explore appropriate diagnosis and treatment of tuberculosis of bone marrow. METHOD: Clinical and pathologic data of 11 cases with tuberculosis of bone marrow out of 2,410 cases underwent biopsy from 1990 to 1997 were retrospectively analyzed. RESULT: High fever, weariness, emaciation and anaemia were found in 11 cases, abdominal distension and abdominal pain in 4, ascites in 3, liver and spleen enlargement in 5. All the cases had no local osteoarticular abnormalities. Negative sputum smear acid-fast staining results were found in 11 cases, abnormal liver function in 9, increased erythrocyte sedimentation rate (30-168 mm/1 h) in 6 detected. Chest radiographs showed hematogenous disseminated pulmonary tuberculosis in 4 cases, no tuberculous lesion in 7. Tuberculous granulomas were found in 11 cases, caseous necrosis in 6, and positive granulomatous tissue acid-fast staining results in 3. Ten out of 11 cases accompanied tuberculous lesions in other parts of body except bone marrow. Eight cases recovered after combined antituberculosis chemotherapy, and other 3 died. CONCLUSION: Tuberculosis of bone marrow is the bone marrow involvement of hematogenous disseminated tuberculosis with nonspecific manifestations. Possibility of hematogenous disseminated tuberculosis should be considered in patients with long-term high fever, and in addition to common pulmonary abnormalities, the bone marrow biopsy should also be taken into consideration. Moreover, combined antituberculosis chemotherapy should be given immediately after the diagnosis of the disease.

Adult↗

PubMed1998

[Study on the replacement of the portal vein of pig with autogeneous-peritoneal tube].

OBJECTIVE: To investigate the possibility of applying autogeneous peritoneal tube in the portal vein reconstruction. METHODS: Twenty-seven small healthy domestic pigs were used. A section of portal vein about 2.5-3.0 cm long was resected and replaced by autogenous peritoneum tube (APT), autogenous vein and decron artificial blood vessel respectively. Patency and pathological changes of the APT grafts were investigated after the replacement. RESULTS: Twenty-four animals survived the operation. In the early stage of replacement, the APTs were dilated slightly, the cannual patency rate (CPR) was 12/13(92.3%). 3 months later, the fibrous hypertrophy and thickness were observed. The CPR was 8/10(80%). 2 more months later, the CPR was 4/6(66.7%), which was quite similar to that reconstructed by autogeneous vein. All three pigs which were replaced by decron blood vessel were dead within three to five hours after operation because of portal thrombi found by autopsy. After 12 weeks of replacement, scanning electron microscopy revealed that APT grafts were covered with a layer of endothelial-like cells. Endothelial cells and mesothelial cells were seen under transmitted electronic microscopy. CONCLUSIONS: The long-term patency of the APTs were slightly lower than that of the autogenous vein, peritoneum might be a perspective self-material for portal vein reconstruction and worth further studying.

Animals↗

PubMed1998

[The expression study of human stem cell factor (hSCF) in E. coli].

OBJECTIVE: To improve the expression level of recombinant human stem cell factor (rhSCF). METHODS: With PCR techniques and synthesized oligonucleotide as primers, the number of nucleotides between the SD sequence and the starting codon ATG of human stem cell factor cDNA was altered, and the preferable codons of E. coli in the N-terminal amino acid sequence were selected. RESULTS: SDS-PAGE electrophoresis indicated that the ratio of expressed rhSCF to total E. coli proteins increased from 12% to 40% by thermal inducing. With DNA sequencing, the reading frame of the gene was proved to be correct. The sequence of 17 N-terminal amino acids of purified recombinant hSCF has been proved to be identical to the natural hSCF, except the first amino acid-Met. CONCLUSIONS: These studies suggest that the 5'-flanking region of hSCF cDNA plays an important role in its gene expression.

Amino Acid Sequence↗

PubMed1998

[Effect of tetrandrine on the collagen contents of lungs in rats with chronic hypoxia].

OBJECTIVE: To investigate the effect of tetrandrine (Tet) on the collagen contents of lung tissues in rats with chronic hypoxic pulmonary hypertension. METHOD: Using colorimetric method after oxidized by chloramine T to determine hydroxyproline contents of lung tissues and extrapulmonary arteries, using Masson method, image pattern analysis technique and gray scale scanning to observe the changes of collagen distribution in extrapulmonary arteries and lung tissues in rats with hypoxia and the effect of treatment with Tet. RESULT: Tet could remarkably reduce the mean pulmonary arterial pressure and pulmonary vascular resistance in rats with hypoxic pulmonary hypertension and could inhibit the increase of collagen contents in lung tissues and extrapulmonary arterial wall. CONCLUSION: Tet may be used as one of the main drugs in the treatment of chronic hypoxic pulmonary hypertension due to its action of reducing mPAP and collagen contents.

Alkaloids↗

PubMed1998

[Inhibition of potassium channel by chronic hypoxia on pulmonary artery smooth muscle cells in rats].

OBJECTIVE: To explore the possible effect of potassium channel in chronic hypoxic pulmonary hypertension. METHOD: Male Wistar rats were placed in the identical normobaric or hypoxic environmental chamber. In one chamber, rats were maintained in 10% +/- 0.5% O2(by displacement with N2) for 3 weeks, whereas in the other, rats were maintained in air. The single smooth muscle cell was isolated from pulmonary artery (phi 200-700 microns) of Wistar rats with acute enzymatic digestion method. Using patch-clamp technique, we recorded the outward K+ currents in pulmonary artery smooth muscle cells and identified a Ca2+.ATP activated K+ channel (K+Ca-ATP) and a delayed rectifier K+ channel among the outward K+ currents. We compared the activities of Ca2+.ATP activated K+ channel (K+Ca-ATP) or delayed rectifier K+ channel in smooth muscle cells isolated from pulmonary artery of chronic hypoxic and normoxic rats. RESULT: The activities of Ca2+.ATP activated K+ channel (K+Ca-ATP) and delayed rectifier K+ channel in chronic hypoxic group are much lower than that in normal group (T test, P < 0.01). Cromakalim (10 mmol) caused a marked enhancement of activity of the reduced K+Ca-ATP but not the delayed rectifier K+ channel in rats of hypoxic group. CONCLUSION: The persistent decrease of potassium channel activity may contribute to setting the development of chronic hypoxic pulmonary hypertension. Cromakalim, one of potassium channel openers, can decrease the pulmonary hypertension induced by chronic hypoxia and may be a new effective drug for treatment of hypoxic pulmonary hypertension.

Animals↗

PubMed1998

[Effect of water extract of Poria on cytosolic free calcium concentration in brain nerve cells of neonatal rats].

OBJECTIVE: To investigate the effect of Poria cocos, a Chinese medicinal herb, on cytosolic free calcium concentration ([Ca2+]i) in brain nerve cells of neonatal rats. METHODS: Double-wave-length fluorospectrophotometer and laser confocal scanning microscope were used to measure the [Ca2+]i in neurons. RESULTS: The water extract of poria (31-250 mg/L) induced a dose-dependent increase in [Ca2+]i, but poria at the range of 500 mg/L did not cause [Ca2+]i to increase. It was also shown that the water extract of poria significantly inhibited the increment of [Ca2+]i induced by 500 mumol/L glutamate. The similar results were observed from the experiments in primarily cultured hippcampal neurons of neonatial rats by using laser confocal scanning microscope. CONCLUSIONS: The water extract of Poria cocos has the effect of bidirectional regulation on cytosolic free calcium in brain nerve cells.

Animals↗

PubMed1998

[Radioimmunological image in tumor bearing nude mice with monoclonal antibody against human laryngeal carcinoma].

OBJECTIVE: To investigate the specific autoradiographic diagnosis of laryngeal carcinoma and its metastasis. METHODS: Three strains of the mixed monoclonal antibodies against human laryngeal carcinoma (McAbLC9, 11, 12) labelled with 131I were injected(intraperitoneally) into the nude mice bearing squamous cell carcinoma. The tumor autoradiography was done by single photo-emission computed tomography (ECT). The percent injected dose/g of tumor were measured, and the radioactivity ratio of tumor to non-tumor tissues(T/NT) were calculated. RESULTS: The 131I-McAbLC 9, 11, 12 can accumulate in the area of the laryngeal carcinoma within limited time, and demonstrate a satisfactory tumor imaging at 96 h. In experimental groups: The %ID/g of tumor tissues (mean +/- s, n = 6) was 18.8 +/- 0.61; The %ID/g of tumor tissues in the control group was 4.46 +/- 0.82 (mean +/- s, n = 6) at 96 h. The difference was statistically significant (P < 0.01, t = 34.97). CONCLUSION: The results suggest that 131I McAbLC9, 11, 12 is specific and sensitive in recognising human laryngeal carcinoma cell, and the area and size of tumor can be easily detected by ECT. It is feasible for localization of tumor and its metastasis.

Animals↗

PubMed1998

[The determination of melatonin in health-caring medicine for specific purposes by high performance liquid chromatography-mass spectrometry].

A rapid and precise method for the determination of melatonin in health-caring medicine for specific purposes, based on high performance liquid chromatography-mass spectrometry, has been developed. The compound was identified using DAD UV spectrum and mass spectrum. Hypersil ODS column, 100 mm x 2.1 mm i.d., and mobile phase of methanol-water (70:30, V/V) were used for the assays. The quantitation was performed with external standard, and detection at 275 nm. The calibration curve of melatonin was linear in the range of 5-50 mg/L and the detection limit was ca. 0.2 ng.

Chromatography, High Pressure Liquid↗

PubMed1998

Temporal and spatial features of slow positive potential related to visual selective response during head-down-tilt.

The temporal and spatial features of visual ERP changes during 2 hour HDT (-10 degrees) were compared with that during HUT (+20 degrees) in 15 normal subjects. The stimuli consisted of two color LED flashes appeared randomly in left (LVF) or right (RVF) visual field with the same probability. The subjects were asked to make switch response to target signals (T) differentially: switching to left for T in LVF and to right for T in RVF, and making no response to non-target signals (N). Five sets of tests were made during HUT and HDT. ERPs were obtained from 9 locations on the scalp. Mean amplitude of the ERPs in the period 0.30-0.55 s were taken as the amplitude of slow positive potential (P400). The results obtained were: (1) The mean amplitude of P400 decreased during HDT which was more significant at the 2nd, 3rd and 5th set of tests; (2) spatially, the reduction of mean P400 amplitude during HDT was more significant for signals from RVF and were more significant at posterior and central brain regions than those from frontal locations. These data provide further evidence showing that the higher brain function was affected by the simulated weightlessness and that this effect was not only transient but also with interesting spatial characteristics.

Adult↗

PubMed1998

[Changes of brain potentials related to selective mental arithmetic during simulated weightlessness].

To study the effect of simulated weightlessness on brain function state, the brain event-related potentials (ERPs) during a selective mental arithmetic task were compared between head down tilt (HDT) and head up tilt (HUT) in 15 normal subjects. The results were: target (T) flash signals induced significant slow positive potentials and they decreased significantly in amplitude especially during HDT as compared with that during HUT. The data provide new evidence indicating that the ability of brain response declined during simulated weightlessness.

Adult↗

PubMed1998

[Clinical observation and anatomical analysis of middle turbinate and ethmoidal internal wall moved to external side after microsurgery].

OBJECTIVE: To assess the effect of middle turbinate (MT) and ethmoidal internal wall(EIW) moved externally after microsurgery. METHODS: Twenty-four cases (45 sides) were followed-up endoscopically for (16.3 +/- 9.3) months. Thirteen cases (24 sides) were observed by CT scans. Three cadaver heads were measured for anatomical analysis. RESULTS: Forty-one (91%) of 45 sides obtained better olfactory function after operation. Twenty-two (91%) of 24 sides were found to have better CT changes in sinus ventilation as compared with preoperative CT scans. The gap between the MT and EIW to the orbital wall was (12.0 +/- 1.0) mm, while that between the ethmoidal bulla and processus uncinatus was only (2.3 +/- 0.6) mm as revealed in the autopsy. CONCLUSION: MT and EIW moderately moved suitably to externally had no bad effect on sinus ventilation, and it improved olfaction.

Adolescent↗

PubMed1998

[Expression of nitric oxide synthase in squamous cell carcinoma of tongue and its prognosis].

OBJECTIVE: To study the expression of nitric oxide synthase (NOS) in squamous cell carcinoma of tongue and its prognosis. METHODS: The NOSI, NOSII and NOSIII of 55 cases of squamous cell carcinoma of tongue were detected by immunohistochemistry. RESULTS: The expressive rates of NOSI, NOSII and NOSIII were 30.9%, 40.0% and 38.2% respectively. There were significant differences between the patients with and without neck nodal metastasis, and between the patients survival more than 5 years and less than 5 years (P < 0.01), There were differences between G1, G2 and G3 and the clinical stages in NOSII (P < 0.05). CONCLUSION: The expression of the NOSI, NOSII and NOSIII in squamous cell carcinoma of tongue is raleted to its prognosis and the NOSII plays a more important role in growth, differentiation, metastatic capability and prognosis of the tumor.

Adult↗

PubMed1998

[90Y glass microspheres intraradiopraxis of advanced hepatic carcinoma].

OBJECTIVE: To evaluate intraradiopraxis with (90)Y glass microspheres for advanced hepatic carcinoma. METHOD: 28 patients were divided into two group: A treated by (90)Y and hepatic artery embolism and chemotherapy (HAEC) (n = 13), and B by (90)Y and hepatic artery embolism (HAE) (n = 15), and 15 cases (group C) only treated by HACE simultaneously were used as controls. The average age, course, and diameter of tumor were similar in all groups (P > 0.05). RESULT: The effective rate of the group A and B was 61.5% and 66.6% respectively, and that of the group C was only 33.3% (P < 0.001). The average survival time of the group A and B was 9.86 and 11.9 months respectively, and that of the group C was only 4.5 months (P < 0.001). CONCLUSION: The intraradiopraxis with (90)Y glass microsphere would be a valuable method for patients with hypo-leukocyte count, insensitive to chemotherapy or resistant to chemotherapy.

Adult↗

PubMed1998

[Apoptosis and expression of PCNA in superficial transitional cell bladder cancer as related to recurrence].

OBJECTIVE: To determine the expression of apoptosis and PCNA in superficial transitional cell bladder cancer and to evaluate its significance as a recurrence marker. METHOD: 87 cases of superficial transitional cell bladder cancer were analysed for the expression of apoptosis and PCNA by using the 3-end labeling method of DNA and immunohistochemical staining in tissue sections. The apoptotic indexes and PCNA indexes were respectively the percentages of apoptotic cells or PCNA positive cells among tumor cells. RESULT: The end labeling method allowed a precise evaluation of the expression of apoptosis. Apoptosis occurred in 89.6% of superficial transitional cell bladder cancer. In 17 patients who suffered from tumor recurrence, the ratio of apoptosis indexes to PCNA indexes was significantly higher than that in those without recurrence (P < 0.01). CONCLUSION: The ratio of apoptosis indexes to PCNA indexes was believed to be related to tumor recurrence and might be of value in the assessment of recurrence of superficial transitional cell bladder cancer.

Adult↗

PubMed1998

[Preoperative staging of esophageal carcinoma: comparison of endoesophageal ultrasonography, computerized tomography and conventional clinical staging].

OBJECTIVE: To evaluate the value of different methods in preoperative staging of esophageal carcinoma. METHOD: Thirty-six patients undergoing resection of esophageal carcinoma were examined with endoesophageal ultrasonography (EU) before operation. Eight of 36 patients could not be evaluated because of severe esophageal stenosis. Computerized tomography (CT) was performed in 21 patients. Comparison was made between stagings based on EU, CT as well as the conventional clinical staging system, respectively with surgical-pathological staging after resection. RESULT: The accuracy of conventional clinical staging for esophageal cancer was only 36%. The accuracy of CT in T, N and pTNM staging was 38.1%, 57.1% and 47.6% respectively. For EU, the figures were 77.8%, 72.2% and 72.2%, and were improved to be 85.7%, 78.6% and 83.1% when untraversable patients were excluded. CONCLUSION: While conventional clinical staging system lacks accuracy in evaluating esophageal carcinoma, CT makes only moderate improvement. Based on direct morphological examination of lesions, EU is highly accurate in preoperative staging of esophageal carcinoma, especially in evaluating the extent of luminal wall invasion and regional lymph node involvement. Therefore, EU is of critical value in the therapeutic selection for esophageal carcinoma.

Endosonography↗

PubMed1998

[The surgical treatment of tetralogy of fallot in 136 adults].

OBJECTIVE: To summarize the experience of surgical treatment of tetralogy of Fallot (TOF) in adults. METHOD: From April 1975 to December 1997, 136 adult patients underwent total corrective repair of tetralogy of Fallot. The patient age ranged from 14 to 52 years old. The ventricular septal defects were closed with Dacron patch in 112 patients, with pericardial patch in 24 patients. A right ventricular outflow patch was required to eliminate right ventricular outflow tract obstruction in 126 patients. RESULT: Five patients died during hospitalization, with a hospital mortality of 3.68%. Four early postoperative deaths were due to severe low cardiac output syndrome. CONCLUSION: In view of current improved and standardized techniques, we conclude that the total corrective repair of TOF may have an excellent result in adult patients.

Adolescent↗

PubMed1998

[Observation of anterior chamber angle with ultrasonic biomicroscopy after posterior chamber implantation of intraocular lens].

OBJECTIVE: To observe the changes of anterior chamber angle after extracapsular cataract extraction (ECCE) with posterior chamber implantation of intraocular lens (IOL) and discuss the associated factors. METHODS: The changes of anterior chamber angle in 31 cases (41 eyes) with senile cataract were observed with ultrasonic biomicroscopy after ECCE and posterior chamber implantation of IOL. RESULTS: (1) There were 6 eyes with peripheral anterior synechia of the iris, 12 eyes with abnormal pupillary configuration, which were related to the position of IOL haptics. (2) The IOL haptics fixed out of the capsular bag were not all fixed at the ciliary grooves. (3) After postoperative 3 months, the residual cortex of the lens still existed. Too much residual cortex in the eye caused postoperative peripheral iris bombe and narrowing of chamber angle. CONCLUSION: The changes of anterior chamber angle after posterior chamber implantation of IOL are related to the position of IOL haptics and much residual cortex must be avoided.

Adult↗