Biomedical subjects

X Chen

Publications and source records attributed to X Chen.

At least 793 records · Page 44Linked to original sources

PubMed1999

[The clinical analysis and review of literature of pulmonary carcinosarcoma and blastoma].

OBJECTIVE: To explore the clinical characteristics, diagnosis, treatment of pulmonary carcinosarcoma and blastoma. METHODS: Summarizing retrospectively 15 cases of pulmonary carcinosarcoma and 2 cases of pulmonary blastoma from January 1979 to November 1998, and reviewing literature to analyse their histologic, clinical feature, diagnosis and treatment. RESULTS: Pulmonary carcinosarcoma and blastoma both were found to be rare malignant tumors, and both epithelial and mesenchymal elements can be seen under the microscopy with different characteristic features. It was hard to be diagnosed before operation. The main symptoms of pulmonary carcinosarcoma were cough, expectoration, sometimes bloody phlegm. X-ray showed that peripheral type were most common, and 2-5 cm in size, well-distributed in density, some showed central or eccentric cavities whose wall was irregular. The margin of the focuses were clear, leafy, the distensive lymph nodes of hilum or mediastium could also be seen. Bronchoscopic examination revealed the bronchial cavity was obstructed by mass or became stricted. Local biopsy can found squamous, adenocarcinoma or large cell carcinoma, respectively. Malignant cell can also be found in sputum. So it was easy to be confused with lung cancer. 14 cases of the carcinosarcoma were treated surgically and diagnosed, 1 case was diagnosed by lymph node biopsy. The symptoms of pulmonary blastoma were fever and hemoptysis. X-ray or CT scan showed an isolated mass in the lung, with uneven density. Malignant cells in pleural effusion were found in one case and can not be diagnosed definetely but by pulmonary puncture. The another case was diagnosed by surgical operation. 15 cases of this group were followed up, in which 4 cases are still alive (including 1 case of pulmonary blastoma), the 1-year survival of carcinosarcoma is 30% (3/10), 2-year survival 20% (2/10), in which 1 case survived more than 6 years. Another pulmonary blastoma case only survived 3 months. CONCLUSIONS: These 2 kinds of malignant tumor are often easy to be misdiagnosed, and prognosis is very poor. Surgical resection is the main method of diagnosis and treatment.

Adult↗

PubMed1999

[A study of clinicopathology and lectin immunohistochemistry in unicystic ameloblastoma].

OBJECTIVE: To investigate clinicopathological characteristics of unicystic ameloblastoma and histological markers for differential diagnosis with odontogenic cyst. METHODS: HE staining and histopathological observation, and lectin UEA-1, BSA-1 immunohistochemistry staining. RESULTS: 40 cases of unicystic ameloblastoma were divided histologically into 3 groups. In odontogenic cysts, most of epithelial lining showed positive binding with UEA-1 and BSA-1, whereas negative reactions were obtained for these two lectins in the epithelial components of unicystic ameloblastoma and solid or multicystic ameloblastoma, except for limited UEA-1 or BSA-1 binding to markedly keratinized tumor cells in several cases of ameloblastomas. CONCLUSION: The unicystic ameloblastoma is a distinct entity which has characteristic clinicopathology. The lectin staining for UEA-1 and BSA-1 is a useful histological aid to differential diagnosis between unicystic ameloblastoma and odontogenic cyst.

Adolescent↗

PubMed1999

[Evaluation of dental diseases and clinical therapy of children in 1990, 1995].

OBJECTIVE: To study changes in patterns of children's dental diseases and their dental care improvements. METHODS: The survey was conducted on the basis of selection of 1,066 and 1,016 medical records of January, April, July and October of 1990 and 1995, respectively, from the complete hospital file. RESULTS: There was a distinct increase in pain and swelling as chief complaint, in regular check and in occlusal discrepancies, all with a significant difference of P < 0.01. No significant difference was found in caries and dental injury in both years. However in either of the two years caries remained the major dental disease. In dental treatment a significant difference (P < 0.01) indicated an increase in interception orthodontics and preventive treatment and a decrease in pulpal treatment. There was no remarkable differences in decay filling and extraction of teeth. CONCLUSION: The survey signified changes in patterns of children's dental diseases and evident improvement in children's dental therapy.

Child↗

PubMed1999

[Effect of tripterine on concentration of free calcium and hydrogen in vascular smooth muscle cells].

OBJECTIVE: To investigate the effects of tripterine on concentration of free calcium (Ca2+) and hydrogen (H+) in vascular smooth muscle cells (VSMC). METHODS: By using fluorescence staining method, changes of the free calcium and hydrogen in single VSMC were studied with laser confocal scanning analyzer after different concentrations of fetal calf serum (FCS), tripterine and FCS plus tripterine were added into the culture pools respectively. RESULTS: The concentration of intracellular Ca2+ increased rapidly, sequentially and significantly after addition of 30% FCS (P < 0.05), 0.3 mg/L tripterine plus 30% FCS had inhibition effect on the concentration of the intracellular Ca2+, 20% FCS reduced the concentration of intracellular H+ significantly (P < 0.05), and 0.2 mg/L tripterine caused a significant increasing concentration of H+ (P < 0.05). CONCLUSION: Tripterine has an antagonistic action on the increasing concentration of intracellular Ca2+ induced by FCS, the inhibitory effect of tripterine on the Ca2+ channel of VSMC membrane may be responsible for this new mechanism.

Animals↗

PubMed1999

[Effect of regulation of kidney-yin and kidney-yang on hypothalamus-pituitary-adrenal-thymus axis in monosodium L-glutamate rats].

OBJECTIVE: To study the interrelationship between hypothalamus-pituitary-adrenal-thymus (HPAT) axis and Kidney-Yang and Kidney-Yin in arcuate nucleus destroyed rats. METHODS: Monosodium glutamate (MSG) 4 mg/g body weight was given subcutaneously to neonatal rats at 2, 4, 6, 8 and 10th day after born to destroy the ARC, and Zuogui pill or Yougui pill (5 g/kg daily) was given respectively by gastrogavage when the model rats entered adulthood. RESULTS: Immunohistochemical staining showed that in the model group the number of corticotropin-releasing hormone (CRH) positive neurons in hypothalamic paraventricular nucleus and anterior pituitary adrenotrophin (ACTH) positive secretory cells, which stained deeply, were more than those in the control group, the adrenal fasciculate zone disturbed with increased cells and obviously dilated sinusoid. The thymus atrophied with lymphocyte proliferation apparently lower, blood corticosterone, ACTH content and hypothalamic CRF level higher in the model than those in the control. Zuogui pill could improve above-mentioned pathophysiologic changes effectively but Yougui pill could not. CONCLUSION: Process of pathophysiology of HPA axis hyperfunction accompanied cell-mediated immunodeficiency may belong to the category of Kidney-Yin Deficiency Syndrome.

Animals↗

PubMed1999

[Changes of serum elastase, alpha 1-antitrypsin, procollagen III peptide and malonaldehyde in smokers with and without chronic obstructive pulmonary diseases].

OBJECTIVE: Serum elastase, alpha(1)-antitrypsin (alpha(1)-AT), procollagen III peptide (PIIIP) and malonaldehyde (MDA) were studied in smokers with and without chronic obstructive pulmonary disease (COPD) to explore the roles of these factors in COPD induced by smoking. METHODS: A design of 154-pair case-control study was used. alpha(1)-AT, MDA and PIIIP were determined with colorimetric method, fluo-spectrophotometric method and radio-immunological assay, respectively, in non-smoker control and smokers with and without COPD. RESULTS: Serum PIIIP content was increased in smokers and alpha(1)-AT decreased significantly in patients with COPD. CONCLUSION: Decreased alpha(1)-AT may be a susceptible factor in the development of COPD caused by smoking.

Adult↗

PubMed1999

[A study on the pathogenicity of acute hepatitis G infection].

OBJECTIVE: To study the infection due to hepatitis G virus (HGV) in liver tissues of patients with acute hepatitis and to investigate its pathogenicity. METHODS: HGV NS5 antigen was detected by using immunohistochemical method in the liver biopsy tissues of patients with acute hepatitis but serologically negative to hepatitis virus antigens from A to E. The clinical and pathological data were also analysed. RESULTS: 37 samples were tested, HGV NS5 antigen was detected in 14 (37.8%). 4 of the 14 were positive for HGV NS5 antigen alone (acute hepatitis G group) and 10 other cases were also positive for HBsAg, hepatitis C virus (HCV) NS3 antigen or EB virus antigen (superinfection group). 7 cases were HBsAg positive alone (acute hepatitis B group) and the remaining 16 cases were negative for all the antigens mentioned above (non-A - G hepatitis group). There was no difference among the 4 groups in the detecting rate of Fas antigen, histological activity index (HAI), serum alanine transferase (ALT) and total bilirubin (TBil). CONCLUSION: It is suggested that HGV appears to play some role in the pathogenesis of acute viral hepatitis and the degree of liver injury in acute hepatitis G may be as severe as that of hepatitis caused by other types of viruses.

Acute Disease↗

PubMed1999

[Effect of plasminogen activator inhibitor 1 gene transfer into mesangial cells on Extracellular matrix accumulation].

OBJECTIVE: To observe the influence of plasminogen activator inhibitor 1 (PAI-1) overexpression on extracellular matrix (ECM) accumulation of rat mesangial cells. METHODS: PAI-1/GFP green fluorescent protein fusion gene eukaryotic expression vector pCMX-PAI-1-GFP was constructed and delivered into cultured rat mesangial cells by liposome. PAI-1/GFP expression was observed by fluorescent microscope. FN, LN and Type IV collagen levels were measured by Northern blot analysis and ELISA method. RESULTS: Northern blot analysis, SDS-PAGE analysis and Western blot analysis demonstrated that PAI-1/GFP gene can be transcripted and translated in rat mesangial cells. PAI-1/GFP gene can express a specific protein. The recombinant PAI-1/GFP had significant inhibition activity on urokinase-type plasminogen activator and displayed autonomous fluorescence. The PA activity of cell supernatants decreased markedly in gene transfer group. FN, LN and Type IV collagen levels were higher than in a control group. CONCLUSION: Over-expression of PAI-1 gene leads to mesangial ECM accumulation. The changes of PA/PAI-1 activity in supernatants of cultured rat mesangial cells might be the key factor in ECM accumulation regulation.

Animals↗

PubMed1999

[Methodology of DNA fingerprinting and its application in identification of M. tuberculosis].

OBJECTIVE: To explore methodology of DNA fingerprinting technique and its application in identification of strains of M. tuberculosis. METHODS: This research was based on different copy numbers and location of chromosome DNA IS6110 in M. tuberculosis genome. After DNA of M. tuberculosis were cut by endonuclease PvuII, the products were transferred to nylon membrane, then detected and hybridized by enhanced chemiluminescent (ECL) labeling techniques. RESULTS: Fifty clinical isolates from different TB patients had unidentical DNA fingerprinting patterns. DNA fingerprinting patterns showed a great difference from sputum and pus specimens of the same patient. H(37) R(v) ofloxacin resistant and sensitive strains had an identical DNA fingerprinting pattern. CONCLUSIONS: Identification of M. tuberculosis strains is feasible by DNA fingerprinting technique.

DNA Fingerprinting↗

PubMed1999

[The proper opportunity of surgery for rectal cancer after preoperative adjuvant chemotherapy].

OBJECTIVE: To discuss the proper opportunity of surgery for rectal cancer after preoperative intra-arterial chemotherapy. METHODS: Preoperative chemotherapy was performed on 27 rectal cancer cases at Dukes stage B and C. The therapy comprised of arterial infusion of 5-fluorouracil 600 mg/m(2), mitomycin 15 mg/m(2) and epirubicin 30 mg/m(2) for one course. Miles' or Dixon's operation was carried out 7 to 10 days later. The effects of chemotherapy were evaluated. Dynamic changes of proliferating cell nuclear antigen (PCNA) expression were studied by immunohistochemistry on paraffin-embedded sections. RESULTS: Hematochezia was remitted in 19 cases. Histologically, the effects of chemotherapy were considered as slight, moderate and marked in 9, 15 and 3 cases, respectively. Side effects were slight and recovered in 4 days. There was a high expression of PCNA in rectal cancer. On the 7th to the 10th day, proliferating index was significantly higher than that of before chemotherapy (46.48 +/- 10.62)%, P < 0.05. CONCLUSIONS: Preoperative adjuvant chemotherapy plays a role in the treatment of resectable rectal cancer. It is suggested that radical surgery should be carried out 5 to 6 days after intra-arterial chemotherapy.

Adult↗

PubMed1999

[Timing changes of apoptosis and proliferating cells nuclear antigen after intra-arterial infusion chemotherapy for rectal cancer].

OBJECTIVE: To investigate the timing changes of apoptosis (APO) and PCNA after intra-arterial infusion chemotherapy for rectal cancer. METHODS: Twelve patients were subjected to percutaneous arterial femoralis catheterization by Seldinger's technique and infusion of anti-cancer drugs: 5-fluorouracil (5-Fu) 600 mg/m(2), mitomycin (MMC) C5 mg/m(2) and epirubicin (EDR) 35 mg/m(2). The biopsy of rectal tumor tissues was done before chemotherapy, and 24, 48, 72 hours and 7-10 days after chemotherapy. Apoptotic cells were examined by terminal-deoxynucleotidyl-transferase (TdT)-mediated dUTP-fluorescein and labeling. The expression of proliferating cells nuclear antigen (PCNA) was detected by immunohistologic staining. RESULTS: The apoptosis index (AI) of rectal cancer cells before chemotherapy, and 24, 48, 72 hours, and 7-10 days after chemotherapy was 6.84 per thousand, 19.53 per thousand, 13.15 per thousand, 11.85 per thousand and 11.86 per thousand respectively. The PCNA index (PI) was 45.56%, 40.68%, 39. 87%, 51.28% and 63.75% before and 24, 48, 72 hours, and 7-10 days after chemotherapy. CONCLUSIONS: Intra-arterial infusion chemotherapy not only induced apoptosis effectively, but also inhibited temporarily tumor cells proliferation in patients. The curative surgical treatment should be performed as soon as possible after chemotherapy.

Adult↗

PubMed1999

[Surgical treatment of ventricular septal defect in infants: report of 230 cases].

OBJECTIVE: To review the experience of surgical treatment of ventricular septal defect (VSD) in infants. METHODS: 230 infants with VSD of less than 3 years old underwent surgical repair from Feb. 1990 to Dec. 1997. Their ages ranged from 3 to 36 months. Their weight was 3.2 to 15.5 kg. The number of patients with perimembranous VSD was 192, and that of subpulmonary VSD 36. Two patients had multiple VSDs. 150 patients (65.2%) had moderate or severe pulmonary hypertension before operation. RESULTS: Thirteen patients died during hospitalization period, with a hospital mortality of 5.65%. The main causes of death were pulmonary hypertensive crisis and arrhythmia. The leading complications were pulmonary infections, arrhythmia and pulmonary hypertensive crisis. CONCLUSIONS: Surgical treatment of VSD in infancy may have a satisfactory outcome, it standardized surgical techniques and the improved perioperative management are used.

Cardiac Surgical Procedures↗

PubMed1999

[Effect of dietary arginine supplementation on wound healing and the relationship between dose and response in burn rats].

OBJECTIVE: To examine the dose-effect of dietary L-arginine supplementation on burn wound healing. METHODS: The effect of dietary L-arginine supplementation was studied in rats with deep thickness burn (10% TBSA). The time for epithelization of burn wound was determined. Photography of burn wound was taken for measuring percentage of burn wound healing area. Biopsies of burn wound were taken for measuring the content of hydroxyproline, the ratio between type I and type III collagen, and dermal cell cycle. RESULTS: Supplemental dietary L-arginine after burn in rats shortened the time for epithelization of burn wound, increased the content of hydroxyproline, decreased the ratio between type I and type III collagen, elevated the DNA content of dermis. Supplemental dietary L-arginine in the dose of 200 mg x kg(-1) x d(-1) was more effective than any other, 50 mg x kg(-1) x d(-1) and 800 mg kg(-1) x d(-1) showed no beneficial effect on the healing of burn wound. CONCLUSIONS: Suitable L-arginine supplementation can enhance burn wound healing in rats.

Animals↗

PubMed1999

[Fisher discriminant analysis for carcinogenic potency of aromatic amines].

OBJECTIVE: To study the relationship between carcinogenicity and their structure and physicochemical parameters of aromatic amines. METHODS: Fisher discriminant analysis for carcinogenicity of aromatic amines in two different batches was conducted with estimation of parameters of physicochemical using central atom and functional groups in combination with structural parameters of polycyclic aromatic hydrocarbons (PAHs). RESULTS: The discriminant efficacy approximated to that of the two in a series of equations (I and III) established by Yuta, but inferior to the optimal equation II. CONCLUSION: The selected physicochemical parameters can be applied to QSAR study on carcinogenicity of most aromatic amines, with better results in Fisher discriminant analysis.

Amines↗

PubMed1999

[Effects of methylmercury on embryonic cell behavior and expression of related gene].

OBJECTIVE: To explore the mechanism of embryonic developmental toxicity of methyl mercury at cellular and gene levels. METHODS: Effects of methylmercury on embryonic cell behavior and gene expression in rats were observed with in vitro (0, 0.05, 0.10, 0.20, 0.40, 0.80 and 1.60 mg/L of methylmercury) and in vivo (0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg/L of methylmercury) rat models, in situ hybridization and TdT-induced dUTP nick end labeling techniques. RESULTS: Methylmercury could pass through yolk-sac placenta quickly, and inhibit placenta development and blood vessel differentiation there at higher concentration. There was a dose-response relationship between concentration of methylmercury and its embryonic developmental toxicity. Its developmental toxicity mainly characterized as patent neural tube and anomalous flexion. Methylmercury could induce excessive apoptosis of embryonic cells, inhibit apparently the synthesis of cellular DNA and RNA and damage its cellular ultrastructure. It also could induce significantly the expression of heat shock protein 70 mRNA and inhibit the expression of fibronectin and p16 mRNA. There was relationship between heat shock protein 70 mRNA, Ca(2+), apoptosis and teratogenesis. CONCLUSION: Disturbance of embryonic cell behavior and related gene expression played important roles in developmental toxicity caused by methylmercury.

Animals↗

PubMed1999

[Studies on immunization strategies for hepatitis B in different endemic areas of China].

OBJECTIVE: To compare the cost-benefit of immunization with hepatitis B (HB) vaccine in different endemic areas of HB and to explore the optimal strategy for it. METHODS: Cost-benefit analysis and comprehensive weighted score analysis (CWSA) were used to screen the optimal immunization strategy for low, medium and heavy endemic areas of HB. RESULTS: Significant economic benefit was obtained in Long-An County, Guangxi Zhuang Autonomous Region, Shanghai and Jinan, Shandong Province from HB immunization programs for infants. The greatest benefit cost ratio (BCR) was provided by the low-dose immunization strategy, which was 49.91, 54.53 and 37.68, respectively for heavy, medium and low endemic areas of HB. The maximal net benefit could be obtained by the high-dose immunization strategy with better immune protective efficacy. CWSA showed that the low-dose immunization strategy was the optimal one for HB immunization. CONCLUSION: It is suggested that the low-dose immunization strategy be implemented in undeveloped areas to obtain a greater BCR, and the high-dose one be implemented in more developed areas to obtain more net benefit and lower prevalence of hepatitis B surface antigen carriage.

China↗

PubMed1999

[Effects of homocysteine on cardiovascular development in early chicken embryo].

OBJECTIVE: To study the relationship between homocysteine (HCY) and cardiovascular development in the early embryo and to determine whether folic acid and cobalamine (Vit B(12)) can reduce the developmental toxicity of HCY to cardiovascular system. METHODS: Incubation test for chicken embryo, electron microscopy, methylgreen-pyronine stain, in situ fragment end labeling, and intervention trial with folic acid and vitamin B(12) were used in the study. RESULTS: Treatment of 0 - 16.0 micromol of HCY/per embryo could disturb their heart development and differentiation of blood vessels at fetal ages of two and four days, in a dose-response pattern, with 24.1% and 25.0% of heart defect and 60.7% of inhibition of blood vessels of yolk sac in 8.0 micromol of HCY, respectively. A dose of more than four micromol/per embryo could damage the structure of myocardial cells and organelle, and inhibit the synthesis of cellular DNA and RNA. It was the first time to find that 8.0 micromol of HCY could induce excessive apoptosis of myocardial cells (2.7%), significantly higher than that in the normal control group. Folic acid could antagonize the cardiovascular toxicity caused by HCY, stronger than what Vit B(12) could do. CONCLUSION: HCY was a new risk factor which could damage cardiovascular development, and folic acid could effectively antagonize its developmental toxicity. Cellular apoptosis might relate to cardiovascular defect.

Animals↗

PubMed1999

[Effects of EB virus LMP on the differentiation and growth of human nasopharyngeal carcinoma cell line CNE1].

OBJECTIVE: To study the effects of EBV-LMP gene on differentiation and growth of human nasopharyngeal carcinoma (NPC) cell. METHODS: With NPC cell line (CNE1) as target, electroporation was used to transfect EBV-LMP gene and the vector into CNE1 cells. The proliferation changes of transfectants were measured in vitro by proliferation experiment. FCM method and transplantation in nude mice were used. RESULTS: LMP promoted the growth ability of NPC CNE1 cells in vitro. The average A ratio (3.98 +/- 0.11) in the treatment group was higher than in the control group (2.36 +/- 0.05) and also in the negative control group (2.75 +/- 0.07, P < 0.01). Clone forming test (25.2%, 378/1 500) in the treatment group was higher than in the control groups (11.2%, 168/1 500) and negative control groups (13.4%, 201/1 500). When FCM method was used, the keratin positive rate (82.7%) in the treatment group was markedly decreased as compared with the control (92.5%) and negative control groups (95.7%, P < 0. 05). Latent period (26.6 +/- 7.7) days and internal double time (2.51 +/- 0.18) days of transplant tumor of the treatment group were markedly shortened, tumor take rate (5/6) was increased, cells of the transplant tumor in the treatment group showed an image of small size, great allotype, and a trend of low differentiation. CONCLUSION: The EBV-LMP can promote the growth and inhibit the differentiation of NPC CNE1 cells. EBV-LMP may play an important role in the development of NPC and in studying its mechanism.

Animals↗