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Biomedical subjects

T Wang

Publications and source records attributed to T Wang.

At least 415 records · Page 23Linked to original sources
PubMed1998

Isolation and identification of xylitol dehydrogenase gene from Trichoderma reesei.

A cDNA sub-library from the fungus Trichoderma reesei grown on xylan was constructed in S.cerevisiae recombinant strain H475 harboring a xylose reductase (XR) gene from Pichia stipitis. The xylitol dehydrogenase (XDH) gene was screened from sub-library on a SC selective medium in which xylose was used as a sole carbon source. The length of XDH gene, xdh1, was about 1.3 kb. Southern, Northern and Western blots were carried out, indicating that xdh1 has high affinity with T.reesei and the molecular weight of the xylitol dehydrogenase from T.reesei was about 40 kDa. The strain HX1 harboring both the XR gene from P.stipitis and the XDH gene from T.reesei was able to grow on the xylose medium and converted more than 90% of the xylose into xylitol, ethanol, and other by-products.

Cloning, Molecular↗
PubMed1998

A study of retentive filler and its use in dentistry.

OBJECTIVE: The purpose of this study was to develop a fine compound inorganic filler with special surface microstructure (called retentive filler or RF) and to investigate its use in composite resin and synthetic resin teeth. METHODS: Barium silicate glass and fine silicon dioxide or barium silicate glass were mixed and sintered, then dispersed and classified by sedimentation. The surface microstructure and the particle size distribution of retentive filler were surveyed, and the mechanical properties of the composite resin and the resin tooth material reinforced with RF were tested. RESULTS: Scanning electron microscopy showed that the surface of RF particles is distinguished for its retentive contour microstructure. The particle size of RF is smaller than 3 microns. The mechanical properties of composite resin reinforced with RF are better than that of composites containing normal fillers, and the wear resistance of the resin tooth material containing RF is better than that of normal synthetic resin. CONCLUSIONS: The RF can be successfully prepared by the technological process in this study. Because of the special surface microstructure, RF has a good bonding to the resin matrix. The testing results suggest that it is feasible to improve the mechanical properties, especially the wear resistance of the composite resin and resin teeth, by using retentive filler.

Barium Compounds↗
PubMed1998

Amphotericin B does not increase peritoneal fluid removal.

Intraperitoneal use of amphotericin B (AmB) has been reported to increase ultrafiltration during short peritoneal dwell in rabbits. In this study, we investigated the effect of AmB on peritoneal fluid kinetics in rats. A 4 hour dwell using 25 mL of 2.27% glucose dialysis solution without AmB (control, n = 6), with 1 mg/kg (L-AmB, n = 6) or with 10 mg/kg AmB (H-AmB, n = 6), and with frequent dialysate and blood sampling was done in Sprague-Dawley rats. 131I-albumin was added to the solution as an intraperitoneal (i.p.) volume marker. There was no difference in the drainage volumes measured at 4 hours of the dwell (26.2 +/- 1.1 mL, 26.0 +/- 1.5 mL, and 26.0 +/- 1.1 mL for the control, L-AmB, and H-AmB groups, respectively.) However, the i.p. volumes were higher at 60 minutes, 90 minutes, and 120 minutes of the dwell in the H-AmB group as compared to the other two groups (1 to 1.5 mL higher, all P < 0.05). There were no differences in the peritoneal fluid absorption rate (KE) and the lymphatic flow rate (KEB) between the three groups. The D/D0 for glucose and dialysis-over-plasma concentration ratio (D/P) values for urea, sodium, and total protein, as well as the diffusive mass transport coefficient (KBD) values for these solutes did not differ among the three groups. However, the D/P as well as the KBD values for potassium were significantly higher in the H-AmB and L-AmB groups as compared to the control group, resulting in significantly higher potassium clearances among the two AmB groups as compared to the control group. Our results suggest that i.p. use of AmB did not increase peritoneal fluid removal after 4 hours of dwell in rats. Although the basic membrane permeability may not be altered by AmB, the higher D/P and KBD values as well as the higher clearances for potassium in the AmB groups may suggest a local release of potassium due to the cytotoxic effect of AmB. The contribution of water release from local cells to the increase in i.p. volume in the H-AmB group cannot be ruled out.

Absorption↗
PubMed1998

[Relationship between ventricular arrhythmia and blood lipid in hypertensive patients with left ventricular hypertrophy].

The possible relationship among ventricular arrhythmia(VA), blood lipid(BL) and left ventricular hypertrophy(LVH) were investigated in 92 patients with essential hypertension(EH). The results showed that the incidence of VA and complex VA and ventricular tachycardia(VT) were significantly higher in EH with LVH than those in EH with non-LVH. The incidence of VA and complex VA and VT were highest in hypertensive patients with LVH accompanied with hyperlipemia(HL), and VA seemed closely related to left heart structure and BL. The results suggest that LVH and HL are the two additive risk factors of occurrence of VA in patients with EH.

Adult↗
PubMed1998

[Supraglottic laryngectomy with or without one arytenoid in epiglottic carcinoma. A report of 40 cases].

OBJECTIVE: Supraglottic laryngectomy with or without one arytenoid is a functional laryngectomy suitable for treatment of epiglottic squamous carcinoma. This procedure consists of resection of the thyroid cartilage, epiglottis and the entire preepiglottic space. METHODS: Between 1990 and 1996, supraglottic laryngectomy was used to treat 40 patients with epiglottic carcinoma. The data were collected by a review of patient records and follow-up. The cancers were in stages T1(17), T2(17) and T4(6) according to the 1987 UICC cancer staging criteria. RESULTS: Twelve ipsilateral and one bilateral functional neck dissection were performed simultaneously of which 7 patients had metastasis in lymph nodes. No patient died postoperatively. Only 8(20%) had slight aspiration before the 20th day. All patients had decannulated. Twenty-nine cases received radiotherapy and chemotherapy. A follow-up analysis showed survival rate of 74% at 3 years. CONCLUSION: We propose supraglottic laryngectomy for the surgical treatment of early supraglottic carcinomas, which could acquire almost normal laryngeal function.

Adult↗
PubMed1998

[Neurilemmoma of the larynx with three case reports].

Neurilemmoma of the larynx is rare. We report three cases who were treated in our hospital in recent decade. The tumours mainly involves the aryepiglottic folds, the ventricular folds or extending to the pyriform fossa, uncommon being subglottic. It is believed that the most likely nerve of origin is the superior laryngeal nerve. Surgical approach was median laryngotomy for 2 cases and lateral pharyngotomy for 1 case.

Adolescent↗
PubMed1998

[Leiomyosarcoma of larynx and hypopharynx].

The laryngeal and hypopharyngeal smooth muscle tumors are very rare. One case of hypopharyngeal leiomyosarcoma and two cases of laryngeal smooth muscle tumors were reported: one angioleiomyoma, one leiomyosarcoma and one carcinoleiomyosarcoma. The patients usually present no characteristic symptoms in early stage and the clinical symptoms are similar to squamous cell carcinoma. It is difficult to make a correct diagnosis before operation. Treatment of first choice consists of primary radical resection including a large part of normal tissue. Early lymph node metastasis is rare. Precautary neck dissection is not indicated for subclinic cervical nodal disease. Radiotherapy may be taken as adjuvant or palliative measures.

Aged↗
PubMed1998

Division of C8 nerve root for treatment of spastic cerebral palsy in the upper limbs: a preliminary report.

OBJECTIVE: To investigate the effect of C8 nerve root division on the treatment of spastic cerebral palsy in the upper limbs. METHODS: Two patients were treated with division of the C8 never root. Supraclavicular incision was made to expose the C5-T1 nerve roots. The intraoperative electromyographic recording technique was used to monitor the responses from the flexor digitorum and flexor carpi ulnaris muscle groups simultaneously. The C5-T1 nerve roots were stimulated and the evoked muscle amplitude potentials (EMAP) were recorded from the muscle groups. The EMAP of the muscle groups obtained during electrical stimulation of the C8 nerve root was the largest, which was used as the basis for C8 nerve root division. RESULTS: Division of the C8 nerve root slightly affected the function of the upper limb, and reduced the muscle tone of the flexor wrist and digitorum. CONCLUSION: Division of the C8 nerve root can reduce the muscle tone of the flexor wrist and digitorum in a short time. The long-term effects need to be followed up further.

Adolescent↗
PubMed1998

[The role of mast cells in myocardial fibrosis in SHRsp].

OBJECTIVE: To study the role of mast cells in hypertensive myocardial fibrosis. METHODS: The myocardial collagen and the degree of myocardial fibrosis were assessed using Masson's trichrome staining and image analysis plus toluidine blue as well as proliferating cell nuclear antigen (PCNA) staining and transmission electronic microscopy for SHRsp, aged 34 weeks (S group, n = 6). Besides, age and sex-matched WKY (W group, n = 5) were used as the controls. RESULTS: MC count increased 3.9 folds and PCNA immunostaining positive cells (PCNAP) increased 3.9 fold (both P < 0.0001) in S vs W group. MC were positively correlated with the interstitial collagen volume fraction (ICVF), perivascular collagen area/vascular lumenal cross area (PVCA/VLCA), and PCNAP (r = 0.47, P < 0.05; 0.59, P < 0.001; 0.68, P < 0.001 respectively). Electromicroscopy showed specific piecemeal degranulation of the mast cells, locating between the praliferative interstitial collagen fibers. CONCLUSION: The findings suggested that MCs play a role in certain degree to the myocardial fibrosis present in SHRsp.

Animals↗
PubMed1998

[Correlation of serum markers with fibrosis staging in chronic viral hepatitis].

OBJECTIVE: To assess the correlation between serological fibrosis markers and staging of fibrosis in chronic hepatitis. METHODS: One hundred and fourteen (114) biopsy and 13 autopay liver specimen were reviewed pathohistologically. Serum samples for liver function tests and fibrosis marker assays including serum P-III-P, IV collagen, laminin (LN), hyaluronic acid (HA), h-TIMP-1 were collected simultaneously right before the biopsy or autopsy. HE, sirius red stains as well as staining for reticulum and elastic fiber were done. In besides, IV collagen, laminin, activated stellate cell were assayed by immunohistochemical methods. RESULTS: Among 127 patients, 92 cases of chronic viral hepatitis including early cirrhosis and 18 cases of hepatic cirrhosis were examined pathologically (17 alcoholic liver disease excluded). The overall inflammatory index and fibrotic scoring were noticed to be significantly correlated with each other (r = 0.82, p < 0.01); The markers, such as HA, P-III-P, LN, IV collagen, h-TIMP-1 were positively correlated with the fibrotic staging and scoring (r = 0.610, 0.575, 0.607, 0.641, 0.606 respectively). The higher the marker level, the more serious the fibrotic change. In addition, (18 cases) patients with active cirrhosis (16 cases) showed higher serum marker level than that of the early cirrhosis and the serum markers in the later were higher than that in the non-active cirrhosis. CONCLUSION: Serum fibrosis markers are fairly well correlated with the staging of fibrosis and are considered to be the valuable references for clinical diagnosis. The close correlation between inflammation process and fibrosis suggests that the inflammatory process plays an important role in fibrogenesis.

Biomarkers↗
PubMed1998

[Parapharyngeal space neoplasms and surgical treatment].

This paper reports surgical treated 66 cases of parapharyngeal space neoplasms. They consist of primary 52 and secondary 14 cases, which were 59 benign and 7 malignant tumors. The surgical procedures which have been used are oral approach in 5 cases, the parotid approach in 5 cases, the cervical approach in 47 cases, the cervical approach with mandibular swing in 7 cases and the postaurical C incision approach in 2 cases. The procedures and indications of the cervical approach or (and) its combination with mandibular swing are outlined. It is considered that these two surgical procedures can provide very safe and efficacious approaches to the removal of the primary parapharyngeal space neoplasms encountered.

Adenoma, Pleomorphic↗
PubMed1998

[The study of PCNA expression and AgNORs counting adult-onset laryngeal papilloma].

UNLABELLED: Avidin-Biotin-peroxidase Complex technique (ABC) and silver staining technique were used to study the relationship between proliferative activity and the biological status of adult-onset laryngeal papilloma. The proliferating index of PCNA positive cells was closely related to AgNORs count. The two indices were significantly different among these groups (P < 0.05). CONCLUSION: PCNA expression and AgNORs count are useful in distinguishing between benign and malignant laryngeal neoplasms, monitoring premalignancy and observing tumor biological activity.

Cell Transformation, Neoplastic↗
PubMed1998

[Significance of hypercoagulation index in treatment of allergic purpura by Huoxue Huayu decoction].

OBJECTIVE: To explore the therapeutic mechanism of Huoxue Huayu Decoction (HXHYD) in treating allergic purpura (AP) and the significance of hypercoagulation index (HCI). METHODS: Patients of AP were divided into two groups. On the basis of conventional treatment of western medicine, the HXHYD was given to the treated group additionally, and the cure rate, change of hypercoagulation index of patients were compared with those of the control group treated by western conventional treatment alone. RESULTS: The cure rate of the treated group was 86%, higher than that of control group (48%) significantly. HCI of the treated group was lowered markedly after treatment, as compared with that before treatment, the difference was significant (P < 0.01). CONCLUSIONS: By the comprehensive effect of promoting anticoagulation activity, maintaining the integrity of vascular endothelia and reducing aggregation of platelets, HXHYD could reduce the HCI and improve hypercoagulative state of AP patients, so as to elevate the cure rate significantly.

Adolescent↗
PubMed1998

[Origin of nitric oxide synthase positive nerve fibers at zusanli area in rats].

OBJECTIVE: To find the origin of nitric oxide synthase (NOS) positive nerve fiber at the area around Zusanli point(St. 36). METHODS: The combined method of retrograde transport of horse radish peroxidase and nicotinamide adenosine dinucleotide phosphate diaphorase were adopted. RESULTS: Some peripheral processes of NOS positive neurons were distributed in the Zusanli point from the ganglia of L4 to S1, and some were projected from the lamina IX of L4 to S1 in spinal cord. CONCLUSION: The distributions of NOS positive nerve fibers in the, Zusanli area might be one of the morphological foundations of acupuncture effect of Zusanli point.

Acupuncture Points↗
PubMed1998

[Clinical study on treatment of aplastic anemia mainly with Yishen Shengxue tablet].

OBJECTIVE: To assess the clinical effects of Yishen Shengxue tablet (YSSXT) on aplastic anemia. METHODS: All patients were divided into two groups by simple randomized methods, 106 patients of the treatment group were treated with YSSXT, 36 patients of the control groups were treated with Renshen Guipi Pill (RSGPP). Peripheral blood and bone marrow of the two groups of patients were measured before and after treatment. The toxicity and side effects of YSSXT were also observed. RESULTS: The basical cure rate, remission rate, total effective rate of the treatment and control groups were 23.6%, 36.8%, 82.1% and 11.1%, 22.2%, 58.3% respectively. There was significant difference between the two groups (P < 0.05 and P < 0.001). The effect of treatment group was obviously better than that of control group. Follow up study showed that from onset of the disease to follow up time in the treatment group, the longest one was 18 years 4 months, so the long-term curative effect is promising. During the period of clinical observation, no obvious side effect and toxicity of YSSXT were found. CONCLUSION: YSSXT is an effective and safe drug in treating aplastic anemia. It has a good prospect and application.

Adolescent↗
PubMed1998

[Nonepithelial malignant neoplasms of the larynx and hypopharynx].

OBJECTIVES: Nonepithelial Malignant Neoplasms of the larynx and hypopharynx are rare. Their clinical features, diagnosis and treatment were discussed. METHODS: From 1985 to 1996, 23 cases of nonepithelial malignant neoplasms of the larynx and 3 cases of hypopharynx were diagnosed. There were 21 males and 5 females. Age of the patients ranged from 16 to 65 years. Laryngeal tumours included 11 cases of sarcomas, 1 extramedullary plasmocytoma, 9 lymphomas and 2 malignant melanomas. Hypopharyngeal tumours included 1 leiomyosarcoma and 2 malignant melanomas. Extensive resection was the first treatment for 21 patients. Then, according to their histopathologic features, irradiation or/and chemotherapy were chosen. RESULTS: Follow-up period was from 6 months to 10 years. There were 12 patients survived for 4 to 10 years, including 6 cases of laryngeal sarcomas, 2 supraglottic lymphomas, 2 malignant melanomas of the larynx, 1 malignant melanoma and 1 leiomyosarcoma of the hypopharynx. CONCLUSIONS: Characteristics for these tumours were: 1. usually covered by intact mucosa; 2. laryngeal tumours rarely metastasize to the cervical lymph nodes; 3. difficulties in histopathological diagnosis, and immunohistochemistry is helpful to differentiation and determination.

Adolescent↗
PubMed1998

[Effect of -6 degrees bed-rest on T-lymphocyte proliferation and cytokines production in human].

In this study, the effect of -6 degrees head-down bed-rest on proliferation of T lymphocyte stimulated by phytohemagglutinin, a kind of polyclone T cell activators and cytokines production were observed. The results showed: after 2 d bed-rest, proliferation of T lymphocyte stimulated by phytohemagglutinin decreased significantly; the activity of interleukin-2 trended to decrease; the expression of interleukin-2 receptor tended to increase; the production of interleukin-6 decreased significantly. After 6 d bed-rest, T lymphocyte proliferation restored to normal; the activity of interleukin-2 and expression of interleukin-2 receptor had no change; the production of interleukin-6 decreased significantly. This result demonstrated that -6 degrees bed-rest can decrease T lymphocyte proliferation function, and this decrease may be caused by the reduction of cytokines secretion.

Adult↗