Biomedical subjects

L Wang

Publications and source records attributed to L Wang.

At least 1,135 records · Page 63Linked to original sources

PubMed1999

[The role of mediastinoscopy for the diagnosis of mediastinal tuberculous lymphadenopathy and sarcoidosis].

OBJECTIVE: To find a effective method for diagnosing tuberculous lymphadenopathy and sarcoidosis of mediastinum. METHODS: Mediastinoscopy was conducted in patients who had enlarged mediastinal lymph nodes on chest CT or MRI and were clinically suspected of either tuberculosis or sarcoidosis. Biopsy was done to obtain pathological diagnosis, and make therapeutic program. RESULTS: Of this series of 25 patients, 16 cases were pathologically diagnosed as tuberculous lymphadenopathy, representing 64% (hyperplastic tuberculosis 14 cases; caseous tuberculosis 2 cases); 8 cases were sarcoidosis, representing 32%; one case was difficult to tell tuberculosis from sarcoidosis microscopically, representing 4%. Tuberculosis and sarcoidosis were causes of benign enlargement of mediastinal lymph nodes. They were hard to be differentiated from roentgnologically, sometimes even microscopically; and they might be confused with other malignant diseases, which can also cause the enlargement of mediastinal lymph nodes, such as lymphoma, metastatic malignancies, etc. Thus they were easily resulted in misdiagnosis. Of this series, the initial diagnosis of 21 cases were malignancies, representing 84%, two cases has even undergone chemotherapy at local hospitals. CONCLUSIONS: For patients with enlargement of mediastinal lymph nodes, mediastinoscopy is of great value. It was emphasized to make every effort to obtain definite pathological diagnosis before standard treatment.

Adolescent↗

PubMed1999

[Effect of hypoxia on proliferation and differentiation of the pulmonary vascular pericytes].

OBJECTIVE: To study the effect of hypoxia on proliferation and differentiation of the pulmonary vascular pericytes (PC). METHODS: Cell culture, (3)H-thymidine incorporation ((3)H-TdR), immunocytochemistry and image analysis methods were used. RESULTS: It was found that the (3)H-thymidine incorporation, the expression amounts of proliferating cell nuclear antigen (PCNA) and alpha-smooth muscle actin (alpha-SM-Actin) in direct hypoxia (H) group was 2.16 times (P < 0.01), 1.16 times(P < 0.01) and 1.11 times (P < 0.05) that of normoxia (N) group, in hypoxic endothelial cell conditioned medium (HECCM) group was 1.8 times (P < 0.01), 1.15 times (P < 0.01) and 1.12 times (P < 0.05) that of normoxic endothelial cell conditioned medium (NECCM) group. CONCLUSIONS: It was suggested that hypoxia can stimulate pulmonary artery endothelial cells (PAEC) to secrete some growth factors to enhance PC proliferation and transformation of smooth muscle-like cells.

Actins↗

PubMed1999

[Analysis and prevention of dislocation after total hip replacement].

OBJECTIVE: To analyse and prevent postoperative dislocation after total hip replacement (THR). METHODS: Of 850 cases operated on by THR 15 (1.7%) had postoperative dislocation. Eleven were revision cases while the other 4 were operated on their primary procedures. RESULTS: Postoperative dislocation after THR were found in 15 cases. Eleven cases had posterior dislocation by posterolateral approach after revision of THR. Anterior dislocation occurred in 2 cases who received lateral approach. Another two cases of dislocation were related to the design of prosthesis. Separation of polyethylene liner and metal shell in acetabular prosthesis was noted in the two cases. All the cases but 1 were reduced operatively. The cases with malpositioned prosthesis were revised operatively. Augmentation procedure was carried out to increase the strength of abductor. In one case, relocation of the great trochantor increased the strength of abductor. No redislocation was observed during follow-up. CONCLUSIONS: Postoperative dislocation after THR are due to malpositioning of prosthesis, unbalanced bilateral soft tissues, especially the loosening of abductor. Evaluating carefully the development of the pelvis and the deviation of normal bone markers is important in addition to accurate insertion and installment of the prosthesis intraoperatively. Complete clearance of osteophytes and bone cements around the acetabulumis reqaired apart from the repairment of adjacent soft tissues. Double check of hip stability should be carried out before the closure of incision.

Aged↗

PubMed1999

[Significance of expression of epidermal growth factor receptor, transforming growth factor beta, c-erbB-2 oncogene in myoepithelioma of salivary gland].

OBJECTIVE: To explore the effect of expression of epidermal growth factor receptor (EGFR), transforming growth factor beta (TGF beta), c-erbB-2 oncogene in myoepithelioma and malignant myoepithelioma. METHODS: 20 cases of myoepithelioma and 20 cases of malignant myoepithelioma were examined by immunohistochemical methods. RESULTS: All cases showed overexpression of EGFR and TGF beta, the intensity of expression didn't associate with the benignity and malignity of tumors. The overexpression of c-erbB-2 oncoprotein was seen in 5 cases of myoepithelioma and 13 cases of malignant myoepithelioma, and the cases of malignant myoepithelioma were stained more intense than that of myoepithelioma. CONCLUSION: The synergy of EGFR and TGFR beta had significant relation to the proliferative and differentiation processes of myoepithelial tumor. The activated c-erbB-2 oncogene, that is similar with EGFR in structure, plays an important promoting role in unrestricted progression of malignant myoepithelioma cells.

Biomarkers, Tumor↗

PubMed1999

[Diagnosis and analysis of cyclodialysis by ultrasound biomicroscopy].

OBJECTIVE: To determine the morphologic changes and their clinical significance of cyclodialysis. METHODS: 173 eyes of 173 patients with cyclodialysis were examined by ultrasound biomicroscopy (UBM) for the morphologic changes, and the measurements of relative parameters were analyzed statistically. RESULTS: The cyclodialysis in all the cases was 360 degree. The characteristic manifestations of cyclodialysis found by UBM were as follows: no echoes between sclera and ciliary body, anterior displacement and rotation of ciliary process and displacement of pars plana toward the centre of eyeball. Superciliary effusion could be observed in some cases. In some patients, the ciliary body may be completely disintegrated from the scleral spur, but the disintegration may be quadrantal instead of 360 degree, resulting in a fistula between anterior chamber and superciliary cavity. The anterior chamber depth of the affected eye (2,115 +/- 589) microm was markedly shallower than that of the normal eye (2,736 +/- 441) microm (t = 4.49, P < 0.001). The shallowing of anterior chamber was caused by the anterior displacement and rotation of ciliary processes and the resulting anterior bulging of the iris root. CONCLUSIONS: UBM can be used to make a correct diagnosis of cyclodialysis irrespective of optic media condition, and can provide evidences for treatment.

Adolescent↗

PubMed1999

[Observation of special stain and ultrastructure of lattice, granular and macular corneal dystrophy].

OBJECTIVE: To investigate the histopathological changes of lattice, granular and macular corneal dystrophy. METHODS: Corneal buttons were obtained from penetrating keratoplasty due to severe corneal dystrophy, and their sections and ultrathin sections with several special stains were observed under a light microscope (LM) and electron microscope (EM). RESULTS: In cases with lattice dystrophy, the stromal fusiform deposits seen under LM were confirmed to be amorphous materiel with filaments by EM and stained positively for Masson trichrome, PAS and Congo red. In cases with granular dystrophy, the granular or bread debris deposits found between laminae under LM were extracellular material observed by EM and they were stained positively for Masson trichrome and alcian blue. In cases with macular dystrophy, the stromal spheroid or macular deposits were seen under LM, and there were numerous vacuoles containing fibrils and granules in the cytoplasm of keratocytes and accumulative amorphous material in the stroma under EM; the deposits were positive for colloidal iron and alcian blue stain. CONCLUSION: In corneal lattice dystrophy, there are amyloid deposits; in granular dystrophy, there are extracellular material deposits; and in macular dystrophy, there is mucopolysaccharide accumulation.

Adult↗

PubMed1999

[A study of anterior segment structures in primary infantile glaucoma eyes by ultrasound biomicroscopy].

OBJECTIVE: To investigate anterior segment structures in primary infantile glaucoma (PIG) eyes by ultrasound biomicroscopy (UBM) in vivo. METHODS: UBM high frequency transducer (50 mHz) was used to measure and observe the anterior segment of 38 PIG cases (58 eyes). RESULTS: No matter the severity of the disease or the age at onset, the most significant characteristics of the diseased eyes are relative positional changes between scleral spur and angle apex. In three forth of the eyes, the scleral spur lay in the lateral or posterior-lateral site of the angle apex and in one forth of the eyes the site of the tip of scleral spur was parallel with the iris root insertion. The thickness and length of ciliary processes in the eyes of PIG were greater than that of the normal infantile eyes. The ciliary processes were anteriorly displaced, pulled towards the lens, and part of them got into contact with the iris. CONCLUSIONS: The relative positional changes between scleral spur and angle apex in diseased eyes indicate that the poor development of scleral spur and the iris anterior insertion are the basic pathogenesis in PIG.

Anterior Eye Segment↗

PubMed1999

[Protection against synergistic hepatocarcinogenesis of hepatitis B virus expression and aflatoxin B1 by antioxidant 2(3)-tert-4 -hydroxyanisole (BHA) in HBV large envelope transgenic mice].

OBJECTIVE: To investigate the effects of 2(3)-tert-4-hydroxyanisole (BHA) on protection against synergistic hepatocarcinogenesis of aflatoxin B(1) (AFB(1)) and hepatitis B virus (HBV) expression in HBV large envelope transgenic mice. METHODS: Protective effects of dietary antioxidant BHA on life span was observed in 49 cases of HBV transgenic mice and 48 cases of non-transgenic mice by determinations of enzyme activities and liver MDA, and by direct detection of liver oxidative free radicals (OFR) using electron spin resonance (ESR). RESULTS: In the HBV transgenic mice which exposed to AFB1, the incidence of hepatocellular adenoma was 17% (2/12), but no carcinoma was found in BHA group. In the regular diet group, that was greater with 67% (6/9) of adenoma and 22% (2/9) of carcinoma. BHA could decrease significantly the concentrations of liver MDA and OFR, compared with those with regular diet. The activities of quinone reductase and glutathione S-transferase in liver cytosols increased by 3 - 7 times, as in the controls, in response to BHA. CONCLUSIONS: Addition of BHA to the diet resulted in significantly elevation of phase II enzyme activities in liver. BHA could directly eliminate liver OFR and inhibit growth of hepatocellular altered foci. These actions may effectively put off hepatocellular carcinogenesis in mice.

Aflatoxin B1↗

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

[Roles of bifidobacterium on prevention of experimental colorectal carcinoma and induction of apoptosis].

OBJECTIVE: To explore the effect of bifidobacterium adolescence on prevention from experimental colorectal carcinoma and its antitumor mechanism. METHODS: An animal model of nude mouse tumor transplanted from colorectal carcinoma was set up. Bifidobacteria adolescence were intraperitoneally injected into nude mice in advance. The growth rate, ultrastructure, density of apoptotic cells, rate of bcl-2 and bax oncoprotein expression and its positive cell density in transplanted tumor of nude mice from colorectal carcinoma were investigated by employing transmission microscopy, in situ end labeling technique and immunohistochemical staining. RESULTS: The growth rate of transplanted tumors from colorectal carcinoma in the group with bifidobacterium prevention was slower than that in the control group. Many tumor cells at varied apoptotic stages could be observed in transplantation tumor tissue in the bifidobacterium prevention group and their density of apoptotic cells, rate of bcl-2 and bax oncoprotein expression and its positive cell density were significantly higher in the group with bifidobacterium prevention, as compared with the control group (P < 0.01). But, expression rate of bcl-2 oncoprotein turned contrary to that of bax oncoprotein. CONCLUSION: Bifidobacteria adolescence could markedly prevent from occurrence and development of colorectal carcinoma in vivo and induce apoptosis of tumor.

Animals↗

PubMed1999

[Induction of quinone reductase and glutathion-s-transferase by dimethyl fumarate in rats].

OBJECTIVE: To assess induction of quinone reductase (QR) and glutathion-s-transferases (GSTs) by dimethyl fumarate (DMF) in major viscera of rats. METHODS: Fodder fed to male Wistar rats was supplemented with 2.0% DMF, and blood specimens were collected form the rats 6 h, 24 h, 72 h, 1 week and 2 weeks after feeding, respectively, and then animals were killed. QR and GSTs activities were determined in rats' gland stomach, liver, lung, kidney and heart, and also QR, LDH and GPT activities in their sera were measured with enzyme dynamic methods. RESULTS: Administration of DMF for 24 h, 72 h, 1 week and 2 weeks in rats can significantly increase activities of QR and GSTs in their gland stomach, liver, lung and kidney, as compared with those in controls (P < 0.0001, or P < 0.01), and their serum QR also significantly increased (P < 0.0001, or P < 0.01). But, DMF had no effect on activities of serum GPT and LDH (P > 0.05). CONCLUSION: DMF is a potent induction agent for QR and GSTs in the gland stomach, liver, lung and kidney of rats, which suggests it will hopefully be a protective and antidotic agent against human antioxidant injury.

Animals↗

PubMed1999

[A clinico-pathological study of neuroendocrine tumors in stomach].

OBJECTIVE: To study the pathological classification of gastric neuroendocrine tumors and its clinico-pathological significance. METHODS: Paraffin sections of totally 52 gastric neuroendocrine tumors including 42 carcinoid tumors were studied with immunohistochemical technique, which involved 9 endocrine markers of hormones antibodies and electronic microscopy for investigating the endocrine cells and the contiguous gastric mucosa of the neuroendocrine tumors. RESULTS: The 52 gastric neuroendocrine tumors were divided into three types: Type I, carcinoid, associated with atrophic gastritis, altogether 26 cases. Tumor extension was limited in the mucosa or submucosa, accompanying with hypergastrinemia and G cell hyperplasia. This type is consistently preceded by and associated with generalized proliferation of endocrine cells in the mucosa at fundus. Type II, carcinoid of sporadic type, totally 16 cases, not associating with hypergastrinemia, was more aggressive. Type III, Neuroendocrine carcinomas (10 cases), were highly aggressive tumors. CONCLUSION: A correct identification of different types of gastric endocrine tumors is important and implicit for the treatment and prognosis of neuroendocrine tumors.

Adult↗

PubMed1999

[A clinicopathological study of pancreatoblastoma].

OBJECTIVE: To investigate the clinicopathological, immunohistochemical features and the histogenesis of pancreatoblastoma (PB) in 14 pediatric cases, including 9 male and 5 female patients, their age ranged from 1.5 to 8 years with a mean of 4.4 years. METHODS: Routine pathological, histochemical, and immunohistochemical methods were utilized to analyse the PB specimens. RESULTS: Tumors of 6 patients had metastasized to the liver, spleen and lymph nodes, 8 patients were alive 10 months to 105 months after diagnosis. Histologically, the tumors were composed of dense epithelial elements separated by fibro-stromal tissue, resulting in a nesting or organoid pattern. Immunohistochemically and histochemically, the tumors exhibited acinar, endocrine and ductal differentiation. The positive rates for were: CK 100%, EMA 86%, NSE 79%, CEA 71%, SYN 64%, CgA 43%, alpha1-AT 57%, PAS 100% and mucicarmine 57%. CONCLUSIONS: PB is the most common malignant pancreatic neoplasm of childhood. PB arises from primitive pluripotential cells capable of differentiating into 3 pancreatic cell types: acinar, endocrine and ductal. The prognosis is better than pancreatic carcinoma in adults.

Carcinoembryonic Antigen↗

PubMed1999

[Analysis of the causes of necrosis of retained flap on tibial side after transplantation of the great toe nail flap].

OBJECTIVE: In order to investigate the causes of necrosis of the retained flap after transplantation of the great nail flap, according to the principle of plastic surgery, the following operation was designed. METHODS: A tongue-shaped great toe flap was made with its base on the tibial side of the great toe and the width of the base was 1 cm to 1.5 cm. The flap contained the supporting vessels and nerves and the periosteum was also preserved. RESULTS: From June 1982 to November 1997, the flap was used to repair 267 case, 277 fingers defects. After operation, the retained flap on the tibial side developed necrosis in 13 sides, an incidence of 4.69%, and in 78 sides, there was necrosis on the grafted skin on the donor site, an incidence of 28.7%. Most of the wounds healed after changing dressing, while 37 wounds healed from another skin graft. Of these cases, 178 cases had been followed up for 5 months to 16 years. It was found that the retained tibial tongue-shaped flap showed hyperplasia which extended to the weightbearing area of metatarso-phalangeal of great toe. It showed that the taking off of great toe nail flap according to first dorsal metatarsal artery (FDMA) I, II or III type, the incidence of development of necrosis of retained flap on tibial side showed no significant difference (P > 0.05). CONCLUSION: It was believed that the necrosis of the retained flap was not related to the FDMA classification but had relation with the design, operative technique and presence of infection.

Adolescent↗

PubMed1999

[Effect of puerarin on coronary collateral circulation in dogs with experimental acute myocardial infarction].

OBJECTIVE: To evaluate the effect and mechanism of puerarin on coronary collateral circulation in dogs with experimental acute myocardial infarction. METHOD: Twelve dogs were randomly divided into puerarin (Gegen su, G) group and control(C) group, the acute myocardial infarction model was built in all dogs. Puerarin or saline was administered for 21 days. Coronary angiography was performed before and after ligating coronary artery. The capillaries and distribution vessel density in tissue sections of myocardium were assessed. RESULT: Angiography on hour 2 and day 22 after ligating coronary artery revealed significant augmentation of collateral vessels in G group versus controls. Capillaries and distribution vessel density in ischemic and infarctive zone on day 22 revealed statistically significant augmentation in G group versus controls (P < 0.05 and P < 0.01). CONCLUSION: Puerarin might improve the opening and forming of coronary collateral circulation to ischemic myocardium in dogs and protect ischemic myocardium.

Animals↗

PubMed1999

[Characteristics of pulmonary function changes in cough variant asthma and chronic asthmatic bronchitis].

To understand with greater clearness the characteristics of pulmonary function changes in patients with cough variant asthma (CVA) and patients with chronic asthmatic bronchitis(CAB), 30 cases of CVA and 25 cases of CAB were examined by pulmonary function test and were compared clinically. The results showed the differences in medical history and some clinical manifestations between the two groups were significant (P < 0.05). The expiratory flow parameters (PEF, MMEF, FEV1) of pulmonary function test in CVA were generally normal; these parameters in CAB group, however, were obviously decreased. The airway challenge test uncovered a 100% positive reaction in CVA patients, but only less than 1/4 of the patients with CAB showed positive reaction. Furthermore, the positive concentration of challenge agents (Mch) required for CVA group was 1/4.7 of the ones for CAB group, and the positive Mch concentrations of the two groups seldom crossed each other. It is concluded that some clinical manifestations of CVA and CAB were significantly different, although many similarities between them do exist; the MEFV curve in pulmonary function test and the airway challenge test can be used to differentiate them well.

Adult↗

PubMed1999

[Studies on introducing and cultivating ginseng in Emei Mountain area].

OBJECTIVE: To introduce and cultivate Panax ginseng in Emei Mountainarea of low latitudes. METHODS: Introduce and cultivate ginseng in some fields of different elevations, and determine the contents of ginsenosides in ginseng samples obtained from the different elevations and different growth periods. RESULTS: Ginseng was successfully introduced to Emei Mountain area. Its quality basically approaches the quality of ginseng growing in northeast China. CONCLUSION: It is feasible to introduce and cultivate ginseng in Emei Mountain area with elevations from 1200 m to 1600 m.

Altitude↗

PubMed1999

[Study of the immunological tolerance induced by peripheral intravenous infusion of donor-specific antigens].

In the experiment, donor specific tolerance was induced by DST, DSSL and DSBM through peripheral intravenous transfusion in rat cervical cardiac transplantation model. The results showed there were significant differences in graft survival time between the blank control group and the other groups (P < 0.05). The mean graft survival time days of the DST, DSSL and DSBM groups were 28.9 +/- 13.7, 42.9 +/- 6.6 and 40.3 +/- 11.6 days, respectively. The effect of component infusion was obviously better than that of DST (P < 0.05), but no statistical difference was observed between DSSL and DSBM. CsA gave a noticeable synergistic effect to the induction of immunological tolerance. MLR and CD8+ T cell were remarkably reduced(P < 0.05) in the cases of component transfusion. This study suggested that components transfusion may be of clinical use for donor-specific tolerance inducing.

Animals↗