Biomedical subjects

D Wang

Publications and source records attributed to D Wang.

At least 613 records · Page 34Linked to original sources

PubMed1998

[Effects of acute hypoxia on some second messengers in pulmonary and cerebral arterial endothelial and smooth muscle cells].

OBJECTIVE: The alterations of second messengers induced by acute hypoxia were studied. METHODS: The porcine pulmonary and cerebral arterial endothelial cells (PAEC and CAEC) as well as smooth muscle cells (PASMC and CASMC) were cultured, and the hypoxic alteration of [Ca2+]i, inositol phosphates and cyclic nucleotides were measured. RESULTS: During acute hypoxia both [Ca2+]i and cGMP levels increased and IP3, cAMP remained unchanged in PAEC, while in CAEC the intracellular Ca2+ release, the IP3, cAMP and cGMP also increased significantly. A difference in the alteration of cGMP level was observed between PASMC and CASMC. CONCLUSIONS: The heterogeneity of endothelial cells might play a role in the different responses of pulmonary and cerebral vessels to hypoxia.

Animals↗

PubMed1998

[CD4+ T cell activation and IL-5 production in atopic and nonatopic asthmatics].

OBJECTIVE: To understand the reasons and roles of CD4+ T cell activation and IL-5 production in atopic and asthmatic patients. METHOD: Bronchoalveolar lavage(BAL) cells and peripheral blood mononuclear cells (PBMC) from 12 atopic and 10 nonatopic asthmatics, 9 atopic nonasthmatics, and 10 normal controls were cultured with or without house dust mite(HDM), CD4+ T cell activation, and IL-5 production were assessed. RESULT: The percentage of CD4+, CD25+ in unstimulated PBMC cultures were not significantly different in the four groups, but it increased following HDM stimulation in both PBMC and BAL cultures in two atopic groups(P < 0.01). The percentage of CD4+, CD25+ in unstimulated BAL cell culture increased in two asthmatic groups (P < 0.05, P < 0.01). The levels of spontaneous IL-5 released from both BALF cells and PBMC in two asthmatic groups were higher than those in AN and N (P < 0.05, P < 0.01). A significant elevation in IL-5 release following HDM stimulation in PBMC and BALF cells was observed in the both asthmatic and atopic groups; but the value in AA was higher than that in NAA, and it was also higher in BALF cells than in PBMC. CONCLUSION: The allergen stimulation is important reasons for CD4+ T cell activation and IL-5 production in atopics. CD4+ T cell activation and IL-5 production are common feature in atopic and nonatopic asthma, it correlates with both asthmatic and atopic status.

Adult↗

PubMed1998

[Effect of 7 d head down bed rest on cardiopulmonary circulation in human].

Changes of cardiopulmonary circulation in 6 healthy young men during 7 d head down bed rest (-6 degrees HDT) were observed with the XXH-2000 lesser circulation and cardiac function instrument. Decrease of Q-j and Q-j/j-z, increase of hz, hc, and hc/hz were found during the initial 24 h. After 24 h, j-z decreased and Q-j/j-z increased. The results showed that increased pulmonary arterial pressure, increased preload of left and right heart, increased right myocardial contractility and congestion of the lungs appeared during 24 h bed rest, after which right myocardial contractility decreased. It suggests that the lesser circulation and cardiac function testing is a sensitive method for evaluating the cardiopulmonary circulation function during HDT.

Adult↗

PubMed1998

[Study on comprehensive assessment in selection of special work personnel].

A comprehensive assessment method combining fuzzy set theory with traditional approaches is introduced. Method of index assessment and comprehensive assessment along with a fuzzy assessment model are presented. As an example, three fuzzy algorithms are used to assess 6 candidates. Calculated results show that the combination of fuzzy logic and experience of experts is feasible and can deal with unprecise information more effectively as well as the aggregation of fuzzy information and precise data. The new method described in this paper is accurate and the speed of decision-making is much improved as compared with the conventional approaches.

Aerospace Medicine↗

PubMed1998

[Changes in cerebral circulation function during head down bed rest for 7 days].

To further understand the effects and regulation of brain circulation before, during and after short-term -6 degrees head down bed rest (HDT), 6 healthy young men aged 19-21 years, were subjected to HDT for 7 d. Cerebral blood flow velocity in the middle cerebral arteries of both sides was measured with a TC2000TCD instrument in 6 young adults before, during, and after 7d HDT. The results showed that cerebral blood flow velocity in the middle cerebral arteries increased throughout HDT, the increase was obvious in 24 h. They reached the highest value at the 4th hour and the lowest value on the 5 th day, and then, there were a tendency to rise on the 6th day and 7th day. The changes were about the same on both sides.

Adult↗

PubMed1998

[Effect of basic fibroblast growth factor on cultured spiral ganglion cells following glutamate treatment].

OBJECTIVE: To understand the effects of basic fibroblast growth factor (bFGF) on survival and neurogenesis of the cultured spiral ganglion cell (SGC) of mouse after exposed to glutamate, and the effects of hFGF and glutamate on free intracellular calcium ion concentration. METHODS: After exposed to 2 x 10(-2) mol/L glutamate for 2 hours, the medium of SGC was replaced with the media containing 25, 50, 100 micrograms/L bFGF. Medium without bFGF was used as control. RESULTS: Twenty-four hours later, more cells in the control group showed signs of cell death than in bFGF groups. After 14 days, specimens were fixed in 4% paraformaldehyde and stained with toluidine blue. It was shown that the SGC in medium with bFGF exhibited more survival and longer neurites, and the effect was dose dependent (P < 0.01). Application of glutamate to the medium induced an increase to the the free intracellular calcium ion concentration in SGC, but bFGF had no such effect. CONCLUSION: Glutamate excitotoxicity was associated with free intracellular calcium ion concentration elevation in SGC, and bFGF could protect SGC against glutamate neurotoxicity.

Animals↗

PubMed1998

[Living related liver transplantation: a case report].

OBJECTIVE: To study a case of living related liver transplantation. METHOD: The patient was a 10-year-old girl who suffered from congenital diffuse intrahepatic cholangiectasis, recurrent cholangitis and hepatocirrhosis. The donor was the patient's father aged 40. The left lateral lobe of donor's liver was cut and grafted to the patient. Intensive care and treatment as well as follow-up were given after operation. RESULT: For the donor, the operation lasted 400 min, with 410 ml bleeding and 300 g liver removed. The recovery was satisfactory. For the recipient, the operation lasted 652 min, with 1665 ml bleeding, 80 min non-liver stage, 0 min graft hot ischemic stage, and 137 min cold ischemic stage. Immunosuppressive therapy was given using cyclosporin A, azathioprine and adrenocortical hormones. There was an acute rejection 11 days after operation, which was controlled using hormone impulsive therapy. The patient has been surviving 7 months with normal liver function. CONCLUSION: The living related liver transplantation is feasible under modern surgical conditions. It is demonstrated that perfect postoperative management is the key for the successful liver transplantation.

Adult↗

PubMed1998

[Endovascular treatment of intracranial aneurysms with GDC: report of 8 cases].

OBJECTIVE: To assess the usefulness and practical experience in intracranial aneurysm embolization with guglielmi detachable coil (GDC) applied firstly in China. METHOD: Under general anesthesia and systematic anticoagulation, eight cases of intracranial aneurysms were embolized with GDC which was introduced by tracker micro-catheter, combined remodeling technique (RT) if necessary. RESULT: 100% occlusion was achieved in 5 cases, 95% in 2 and 90% in 1, without any complication. Among these cases, 4 failed in the previous attempts of endovascular treatment with mechanical detachable system (MDS), because MDS could not be safely and totally placed inside the aneurysms and Mag 3F/2F micro-catheter could not be navigated into the aneurysms. CONCLUSION: Embolization of intracranial aneurysms with GDC is safe, effective and reliable, and it may offer the cure opportunity to those enearysms which are very dangerous to embolize or can not be embolized with MDS.

Adult↗

PubMed1998

[Animal experiment and clinical application of self-made mechanically detachable coils].

OBJECTIVE: To evaluate the practical and thrombogenetic characteristics of self-made mechanically detachable coils by the animal experiment and primary clinical application. METHOD: The bifurcation type of aneurysm model was established on rabbit and embolized with self-made mechanically detachable coils 2 weeks after surgery. 24 coils were used in 5 experimental aneurysms. Control angiography was performed and the rabbits were sacrificed 2 - 3 weeks after the embolization. The embolized aneurysm samples were examined by pathologist. Ten patients were treated with self-made mechanically detachable coils in primary clinical application. They were divided into aneurysms (7 patients), traumatic carotid-carvenous fistulas (2), dural arterio-venous fistula in carvenous sinus region (1). 146 coils were used totally and all were delivered with mechanical detachable system (MDS Balt co. France). RESULT: Pathologically, the cavities of rabbit aneurysm models were occluded by tungsten coils (2 complete, 3 almost complete). The coils were trapped in granulation tissue which was covered by a thin layer of endothelium on the surface facing the blood flow. In the coils dense packing ones, the aneurysms were completely excluded from the parent circulation by neointimal layers. In the practice procedures, the coils fit MDS (Balt co. France) very well and can be delivered, withdrew and detached smoothly. CONCLUSION: The self-made mechanically detachable coils have practical reliability and evident thrombogenetic effects.

Adult↗

PubMed1998

[Interventional endovascular therapeutic modalities of giant intracranial aneurysm].

OBJECTIVE: To treat 28 cases of intracranial giant aneurysms in the last 7 years and study the therapeutic methods and their effectiveness on this disease. METHOD: The cases of giant aneurysms were divided into several groups. The advantages and disadvantages of the methods were compared. The main modality of endovascular therapy was to use balloon to occlude the parent artery. RESULT: In the 16 cases treated by the proximal balloon occlusion, 13 were cured angiographically with complete obliteration of the aneurysmal sac and in 4 of them the aneurysms disappeared both on CT and MRI. No deterioration after operation was encountered with the exception of 2 deaths. CONCLUSION: Endovascular therapy can cure the intracranial aneurysms which were difficulty treated by direct open operation.

Adolescent↗

PubMed1998

[Primary ileocecal lymphoma: report of 30 cases].

OBJECTIVE: To investigate the best therapeutic method for primary ileocecal non-Hodgkin's lymphoma. METHOD: Clinicopathologic features of 30 patients who had been treated from June 1964 to September 1993 were analyzed retrospectively. RESULT: Twenty-eight patients (93%) underwent resection of their disease. Eleven patients had the resection followed by chemotherapy. Eleven patients had the resection followed by chemotherapy and radiotherapy. All had pathologic evidence. Twenty-nine patients were categorized as B-cell type NHL. One had T-cell lesion. Eleven patients had stage I disease, 11 stage II, 4 stage III, and 4 stage IV. The 5-year survival rate was 36.67%. CONCLUSION: The prognostic factors are stage of the disease and treatment modality. Adequate initial surgery combined with radiotherapy and chemotherapy may provide optimum therapy for patients with primary ileocecal lymphoma.

Adolescent↗

PubMed1998

[Correction of mitral insufficiency with posterior annuloplasty].

OBJECTIVE: To summarize the experience in treating mitral insufficiency (MI), due to secondary annular dilation in the posterior portion of the annulus with mitral valve reconstruction. METHOD: Over the past 10 years, we performed mitral valvuloplasty with posterior annuloplasty in 35 patients, of which 27 patients were associated with congenital abnormalities, 3 patients had mild MI, 24 had moderate MI, and 8 had severe MI. Entire posterior annular plication was performed in 7 patients and partial posterior annular plication in 28. Associated subvalvulopasty was performed in 7 patients and leaflets repair reconstruction in 14. RESULT: There was no postoperative mortality. Complete correction was achieved in 21 patients (60.0%) and partial correction in 11 (31.4%). Mild and moderate insufficiency was found in 3 patients (8.6%) postoperatively. NYHA function class I was gained in 34 patients. One patient developed pulmonary hypertension and died due to right heart failure five years after operation. CONCLUSION: The results indicate that posterior annuloplasty is a safe, effective technique.

Adolescent↗

PubMed1998

[The changes of pancreatic function after cardiopulmonary bypass].

OBJECTIVE: To evaluate the changes of endocrine and exocrine pancreatic function in patients who underwent heart valve replacement under cardiopulmonary bypass (CPB) in order to optimally conside clinical management perioperatively. METHOD: Sixteen patients with heart valve disease were selected. Serum glucose, lactate, insulin, C peptide, amylase and lipase were measured. RESULT: Hyperglycemia and hyperlactacemia were noted after CPB and peaked at 19:00 on the operative day. Their changes were correctly correlated. Serum glucose and lactate returned to the baseline level on the third postoperative day. The average level of serum insulin were normal, but higher on the third postoperative day. However, the level of serum C peptide was higher than the baseline. It doubled the baseline level at 19:00 on the operative day. The average level of serum amylase and lipase was normal, except the higher level of serum lipase on the fourth postoperative day. In our group, 12 patients had normal serum amylase level perioperatively, and 4 increased serum amylase level (25%), among them 2 patients accompanied with hyperlipasimia (16%). There were 8 patients with hyperlipasimia (50%). CONCLUSION: The endocrine and exocrine pancreatic functions were influenced by CPB and did produce pathophysiologic changes.

Adult↗

PubMed1998

[Surgical treatment of spinal dural arteriovenous fistulas].

OBJECTIVE: To discuss the operation modalities of spinal dural arteriovenous fistulae (SDAVFs) and treatment with anticoagulant agents after surgery. METHOD: The medical records, radiographic studies and operations of 23 patients with SDAVFs were reviewed. Laminectomy was performed at the level of the arterialized venous entry into the subarachnoid space in 18 patients with thoracic and lumbar lever AVFs, followed by coagulation, clipping and division of the vein. In 14 of 18 patients, the arteriovenous nidus in the dura was identified and obliterated by coagulation. The draining veins were interrupted at L(5) - S(1) level in 5 patients with sacral AVFs. Anticoagulant treatment was given in 13 patients. RESULT: Outcome was good in 20 patients and 2 of the 20 had transient postoperative neurological deterioration that reversed by anticoagulant agents. No changes were seen in 2 patients except one deteriorated. CONCLUSION: Surgical interruption of arterialized radicular-medullary draining vein of SDAVFs provides lasting occlusion of the fistula, and postoperative anticoagulant therapy can prevent thrombosis of the coronal venous plexus.

Adult↗

PubMed1998

[Analysis of clinicopathologic changes of infection in dead patients after renal transplantation].

OBJECTIVE: To prevent renal transplantation patients from infection. METHOD: Autopsies of 24 patients who had died after renal transplantation were studied. RESULT: The incidence of infection was 66.7% and the lethal infective complications amounted for 50%. The most infectious agents were bacteria, fungi, tuberculosis, virus and actinomyces. CONCLUSION: Pathological features and clinical manifestations of lesions were caused by aforementioned agents. Some management can prevent renal transplantation recipients from infection.

Adolescent↗

PubMed1998

[Corneal topographic analysis after excimer laser photorefractive keratectomy].

OBJECTIVE: To analyze the changes in corneal topography after excimer laser photorefractive keratectomy (PRK). METHODS: The topographic changes of 122 eyes (62 patients) and 96 eyes (49 patients) on which PRK was performed were reviewed after 3 and 6 months of follow-up respectively. RESULTS: The central island pattern had a relationship with the loss of best corrected visual acuity of more than one line in early postoperative period. On subsequent follow-up, the central island pattern tended to become to other patterns (semicircular, keyhole and uniform) and the central corneal power decreased, allowing the visual acuity to improve gradually. The simulated K (Sim K) regression index was a useful indication of the changes in the corneal stroma. Sim K was related to the degree of refractive error. The greater the refractive error, the lower the Sim K. CONCLUSION: Corneal topography is a useful tool in the analysis of corneal changes in PRK.

Corneal Topography↗

PubMed1998

[Synthesis and structure-activity relationships of novel 14 beta-side chain taxol derivatives].

In order to develop new generation of taxol-like anticancer agents with fewer side effects, improved activity, superior pharmacological properties and broad antitumor spectrum, along with structure-activity relationship study, a series of new taxol derivatives are to be synthesized starting from sinenxan A--a biosynthetic taxane. Eight new 14 beta-side chain taxol derivatives with 4-OH and 4-Ac were synthesized in 5 and 6 steps from semisynthetic taxoid intermediate 7, respectively. These included taxol derivatives modified at C-2 position with benzoate, m-Cl benzoate, valerate and phenylacetate. All target compounds together with two other 14 beta-side chain taxol derivatives were tested in a microtubule assembly assay, and in an in vitro cytotoxicity assay (KB, A2780, HCT-8 cell line). All compounds had no effect in the microtubule assembly assay at 10 mumol.L-1. Most of them showed marginal activity in the in vitro cytotoxicity. The structure-activity relationship was different from taxol derivatives. 2-Aliphatic ester displayed similar activity to 2-aromatic ester, which indicated that the aromatic group at C-2 position was not important for cytotoxicity. Comparing among themselves, 4-OH derivatives possessed stronger activity than 4-Ac.

Antineoplastic Agents, Phytogenic↗

PubMed1998

[The use of orthognathic surgery in the treatment of maxillofacial fractures].

35 cases with bony malunion following maxillofacial fractures had been treated successfully by orthognathic surgery technique. Mini-titanium plate had been used in the rigid internal fixation. The article introduced the surgical method and discussed some primary principals which should be paid attention during operation.

Adolescent↗