Biomedical subjects

M Wang

Publications and source records attributed to M Wang.

At least 559 records · Page 31Linked to original sources

PubMed1998

[Clinical and experimental study on using Cassia angustifolia extract as enema after abdominal operation].

OBJECTIVE: To investigate the curative effect and mechanism of using Cassia angustifolia extract (CAE) in treating gastrointestinal tract dysfunction after abdominal operations. METHODS: Enema administration of CAE (Clyster method) was used. RESULTS: The result of 130 patients was very effective in reducing the rate of gastrointestinal decompression, accelerating the restitution of borborygmi and the time of exhaustion. Animal experiment showed the CAE function is very obvious in enhancing the bowel movement of rats (P < 0.05). It can enhance peristalsis and contraction amplitude of vibration in the isolated ileum of rats (P < 0.05). It can push on the charcoal powder in intestinal tract of mice obviously (P < 0.05). CONCLUSION: CAE could regulate disordered function of gastrointestinal tract after abdominal operations.

Abdomen, Acute↗

PubMed1998

Cloning and characterization of a metal responsive element-containing fragment from the Wilson disease gene locus by junction trapping.

All mammalian metallothionein genes studied to date have several metal responsive elements (MRE) with consensus sequences of TGCRCNC (R, purine) in their regulatory region. MRE-like sequences were also found in many other metal-related genes. To see whether there is also such a sequence at the genetic locus (13q14.3) of Wilson disease, which is a genetic disorder of copper metabolism, junction-trapping method based on the MRE sequence was used. A fragment containing MRE and MRE-like sequences from YAC 27D8 at the WND locus was successfully cloned and mapped back to the YAC by PCR. Presence of such a sequence in the copper transporter gene at the WD locus might imply that it has a possible interesting role in the regulation of WD gene expression.

Adenosine Triphosphatases↗

PubMed1998

[The histopathological analysis of root fractures of molars with vital pulp].

OBJECTIVE: To analyze the causes of root fractures by examining fractured roots histologically. METHODS: Fractured roots were sectioned for microscopic analysis in conventional histological ways. RESULTS: 1. Among 18 roots cut transversely were 14 flat roots with 2 canals, 2. most of the fractures passed along incremental line in dentine, 3. of the longitudinally sectioned roots, areas of marked resorption were visible on the dentine within the fractures of apical third, and 4. repairs of both soft and hard tissues were observed in the fracture spaces. CONCLUSION: The fractures of roots were associated with morphology of roots and incremental lines in dentine. The repair and cure of fractured roots were not impossible.

Humans↗

PubMed1998

[Treatment of portal hypertension by using pericardial vascular disconnection and mesocaval side-to-side shunting].

OBJECTIVE: To prevent post-operative bleeding, to maintain the blood supply to the liver from the portal vein and to reduce the incidence of hepatic encephalopathy. METHOD: The blood vessel was cut around the cardial opening and the venae cavae was anastomosed in 37 patients with portal hypertension. RESULT: The success rate of surgery was 100%. The free portal pressure (FPP) was 3.16 +/- 0.581 kPa, which was lower than the FPP (3.91 +/- 0.642 kPa) before operation (P < 0.01). Follow-up for 5 to 22 months showed that liver function recovered from III to I in 5 patients, and from III to II in 7. Ascites disappeared in all and varix improved in 82.9% patients. CONCLUSION: Cutting flow combined with fraction flow can effectively maintain the blood supply to the liver in treating portal hypertension.

Adolescent↗

PubMed1998

[Expression of nm23 in gastrointestinal smooth muscle tumors and its relation to cell proliferative activity].

OBJECTIVE: To determine the relationship between nm23 expression and benign or malignant degree, metastasis, prognosis and cell proliferative activity of gastrointestinal smooth muscle tumors (GISMT). METHOD: 86 cases of GISMT were studied, and nm23 was detected by the immunohistochemical staining S-P method. The cell proliferative activity was evaluated by the silver colloid method for argyrophilic nucleolar organizer regions proteins (AgNORs) and by the immunohistochemical staining S-P method for proliferating cell nuclear antigen (PCNA). RESULT: The expression of nm23 declined significantly according to the following order: leiomyomas, low malignant leiomyosarcomas, high malignant leiomyosarcomas (P < 0.01). The expression of nm23 was associated with the tumors with or without contiguous organ invasion or distant metastasis, the size of tumors, the tumors with or without center necrosis (P < 0.01 or P < 0.05). The five-year survival rate was significantly higher in patients with nm23 positive expression than that with nm23 negative expression (P < 0.05). The expression of AgNORs and PCNA with nm23 negative cases was obviously higher than that with nm23 positive cases (P < 0.01). CONCLUSION: nm23 is a valuable indicator for the biological characteristics of GISMT. nm23 expression and cell proliferative activity can supply a deficiency each other in distinguishing malignant from benign tumors, judging the malignant degree, and predicting the prognosis of the patients with GISMT.

Adolescent↗

PubMed1998

[Unreamed interlocking intra medullary nailing in treating tibial and fibular fractures].

OBJECTIVE: To report the experience in the use of unreamed interlocking intramedullary nails. METHOD: From 1995 to 1997, 54 tibial and fibular fractures were treated with unreamed interlocking intramedullary nails they included open fractures (9 cases) and close fractures (45). RESULT: All fractures healed within 6 months and showed good knee and ankle joint functions. Slight postoperation infection was found in one of the open fractures. Incomplete injury of peroneal nerve was noted in 1 case. CONCLUSION: Unreamed interlocking intramedullary nail can be used to treat diaphyseal fractures effectively. It can protect the soft tissue envelope around the fracture and prerent local blood supply from further damaginge.

Adolescent↗

PubMed1998

[Maisonneuve fracture of the fibula: clinical and experimental study].

OBJECTIVE: To study the traumatic mechanism and clinical treatment of Maisonneuve fracture. METHOD: 19 of 25 patients (6 - 60 months, average 16.8 months) were followed up. 11 patients were operated on and 8 were treated conservatively. Of the 25 patients, 8 had MRI. Osteotomy and serial section of the interosseous membrane (IOM) on fresh cadaveric specimens were doc carried out to observe the diastasis on stress mortise view. RESULT: Functional rehabilitation of the ankle joint: in 11 operative cases, 8 showed good results and 3 fair. In 8 conservative cases, 3 showed good results, 2 fair and 2 poor. MRI: IOM was ruptured in a range 3 - 8 cm proximal to the tibial plafond in the 8 cases. No IOM rupture was found at the high fibular fracture level. Fresh cadaveric experiment: fixation of the medial side alone can not control the syndesmotic diastasis on the artificial Maisonneuve fracture model made on cadaveric specimen. CONCLUSION: The injury level of the IOM during Maisonneuve fracture may not be consistent with the high fibular fracture. The limited external rotation of the fibula during injury by the superior tibio-fibular syndesmosis comprise to the high level fibular fracture. ORIF with syndesmotic fixation is recommended for the treatment.

Adult↗

PubMed1998

[Metabolic transformation of (-)-clausenamide in rat liver microsomes].

The metabolic transformation of (-)-clausenamide, isolated from the leaves of Clausena lansium (Lour.) Skeels, was studied in vitro with phenobarbital-induced rat liver microsomal incubate containing the NADPH-generating system. The constitution of the incubation system was optimized and a RP-HPLC-DAD method was developed for the on-line analysis of (-)-clausenamide and its metabolites. The major metabolites were isolated and purified by silica gel column chromatography, preparative TLC and HPLC and their structures were determined as 6-OH clausenamide (CM1) and 5-OH clausenamide (CM2) by 1HNMR and MS.

Animals↗

PubMed1998

[The development of an intelligent four-channel aggregometer].

The paper introduces the hardware and software design of the instrument. We use 89C52 single-chip computer as the microprocessor to control the amplifier, AD and DA conversion chip to realize the sampling, data process, printout and supervision. The final result is printed out in form of data and aggregation curve from PP40 plotter.

Artificial Intelligence↗

PubMed1998

[Study of portable synchronous ECG recorder and its long-distance communication system].

This paper presents a convenient long-distance ECG communication system. It is made up of portable ECG recorder, hospital work station and public telephone network. This paper also introduces a kind of modulation and demodulation method in sound coupling communication-pulse edge modulation and demodulation. This system has rational structure, convenient operation and strong management power. A Philips 80C552 used as CPU in the recoder which is portable, cheap and reliable.

Electrocardiography, Ambulatory↗

PubMed1998

[Fibrinolytic properties and thrombolytic effect of a novel fibrinolytic enzyme from Streptomyces sp. Y405].

A novel protease (designated as SW-1) purified from the fermentation broth of Streptomyces sp. strain Y405 showed fibrinolytic activity. In vitro, on plasminogen-free fibrin plate which had been heated at 85 degrees C for 30 minutes to eliminate plasminogen, SW-1 showed the same fibrinolytic activity as the mixture of SW-1 and plasminogen. Without adding plasminogen into the fibrin clot tube SW-1 showed the same effect as with plasminogen (P > 0.05). The results might indicate that SW-1 is a fibrinolytic enzyme which degrades fibrin directly, but not a plasminogen activator which degrades fibrin by activating plasminogen. SW-1 was found also to degrade fibrinogen. In vivo, the thrombolytic effect of SW-1 (4000 u.kg-1) on venous thrombus in rat was most remarkable versus that of control(P < 0.001), but was not divergent versus that of urokinase at the some dose(P > 0.05). SW-1 was shown to enhance plasminogen and plasmin activity but did not show significant effect on endogenous t-PA or alpha 2-PI. SW-1 also caused decrease of fibrinogen level in plasma, indicating that it degrades the fibrin in thrombus and at the same time degrades the circulating fibrinogen to certain extent. The changes of these biochemical data demonstrated the thrombolytic properties of SW-1 in vivo.

Animals↗

PubMed1998

[Problems and solutions in the use of RAPD to the identification of the Chinese drugs "xi-xin" (Herba asari) and its substitutes].

The use of random amplified polymorphic DNAs (RAPD) on the identification of crude drugs has a few special problems, e.g., the influence of the degree of degradation of DNA templates on the amplified products, the reliability of results by one or two primers and the application range of RAPD, etc., so the problems were discussed through researches on Herba Asari. In this experiment, the DNA of twenty-one samples from different locations and collected at different time were extracted. The suitable concentrations of DNA templates and the suitable primers were selected. After this, the DNA of these samples were amplified by RAPD. The results showed that the concentration and the degree of degradation of DNA templates, and the different sources of crude drugs affected the result of RAPD assay. Some suggestions were made to solve these problems, such as the selection of DNA templates concentration, the screening of suitable primers, and the use of contrast groups and cluster analysis. Furthermore, the application range of RAPD to the identification of crude drugs was discussed. All of these will provide the guide to the use of RAPD for the identification of crude drugs.

Asarum↗

PubMed1998

[Synthesis and antiinflammatory activity of 2-(E)-benzylidene-5-(N-substituted aminomethyl) cyclopentanones].

Nineteen kinds of 2-(E)-benzylidene-5-(N-substituted aminomethyl) cyclopentanones were synthesized via Mannich reaction or amine exchange reaction and identified spectrometrically. One compound exhibited significant antiinflammatory activity, showing obvious inhibitory effect on xylene-induced mice ear swelling, carrageenin-induced rats paw edema and increased capillary permeability induced with acetic acid in mice. Its ED50 values in these inflammatory models were calculated to be 67.8 mg.kg-1, 25.3 mg.kg-1 and 41.8 mg.kg-1 respectively, nearly equal to those of ibuprofen and aspirin.

Animals↗

PubMed1998

[Accumulation and effluxion of chloroquine in chloroquine-sensitive and chloroquine-resistant Plasmodium berghei].

AIM: To explore whether the difference in the amount of chloroquine (CQ) accumulated in CQ-resistant (CR) and in CQ-sensitive (CS) P. berghei is involved in the infected erythrocytes (RBC) or in the parasites. METHODS: The concentration of CQ in infected RBC and parasites following ig administration of CQ to CS and CR infected mice was determined by HPLC method (extra standard). RESULTS: 3 h after 4.06 mg/kg and 400 mg/kg administration, the accumulation of CQ in both infected RBC was similar, but in CR was 54.0% and 42.1% less than in CS (P < 0.001) respectively. The CQ accumulation in CS 3 h and 7 h after ig administration of CQ 400 mg/kg was similar (0.780 +/- 0.128 nmol/protein and 0.760 +/- 0.180 nmol/mg protein), while in CR the CQ-accumulation was higher at 7 h than that at 3 h after CQ administration (0.452 +/- 0.079 nmol/mg protein and 0.559 +/- 0.124 nmol/mg protein P < 0.02). CONCLUSION: The low CQ accumulation in CR is attributable to the parasite rather than to the infected RBC, and CR was not found to excrete CQ more rapidly than CS.

Animals↗

PubMed1998

[Application of improved western blot method in diagnosis of cysticercosis].

AIM: To evaluate the diagnostic value of four specific antigens from cDNA of Cysticercus cellulosae. cC1, cC2, and cP1 and cH1 (28 kDa, 18 kDa, 14 kDa and 34 kDa), mixing in equal proportions for the diagnosis of cysticercosis. METHODS: Taking the FP (fusion proteins) as antigen to make IWB (improved Western blot) analysis basing on the detection of antibody responses against FP, and making ELISA/IHA-crude antigen(CA) analysis. They were evaluated comparatively while using 107 infected sera of cysticercosis cases, 40 infected sera of clonorchiasis cases, 24 infected sera of echinococcosis cases and 34 sera of healthy persons. The FP are encoded by cDNAs of beta-galactosidase-specific antigens of Cysticercus cellulosae isolated from the cDNA library. RESULTS: 94(87.9%) sera from 107 cysticercosis cases recognized FP in IWB and could not cross-react with the sera of echinococcosis cases, clonorchiasis cases and healthy persons, the specific rates were 100%, whereas ELISA, IHA using CA were 84.1% and 74.8%, respectively and could cross-react with the sera of echinococcosis cases, the false positive rates were 2.5% and 12.5% respectively; CA-ELISA/IHA could cross-react with the sera of clonorchiasis patients, the false positive rates were 8.3% and 16.7%, respectively; and they could also cross-react with the sera of healthy persons, the false positive rates were 8.8% and 11.8%, respectively. CONCLUSION: The recombinant FP used in the immunodiagnosis of cysticercosis is specific and sensitive.

Animals↗

PubMed1998

[Studies on the basis of molecular biology of the phase change of influenza A(H3N2) viruses].

The analysis of nucleotide sequences on HA1 domain of 35 strains of influenza A(H3N2) virus showed that their HA1 genes all were 984 nucleotides in length coding for a HA1 protein with 328 amino acids and there was not any occurrence of insertion or deletion of nucleotides on HA1 genes among them. The appearance of "O" phase strain of influenza A (H3N2) virus was closely related with substitution at 226 position of amino acid on HA1 protein molecule and the three-dimensional structural change of HA protein. The results in this paper indicated that the positions with multiple changes on HA1 protein molecule located at the top of HA protein, especially at antigenic determinant B site or receptor binding site. These further demonstrated that the substitution of amino acid on HA1 protein molecule was caused mainly by suppress of herd immunity. This study also showed that the position of the cysteine and proline residues on the HA1 protein molecule were conservative and that the glycosylation sites located at N and C terminals, especially at N terminal of the HA1 protein The significance of such a distribute delta of glycosylation sites in the evolution of viral genes and epidemiology still remain unknown.

Amino Acid Sequence↗

PubMed1998

[Seroepidemiologic survey for A/PR/8/34 (H1N1) virus from Chinese residents].

A total of 414 serum specimens were collected from the residents with ages of < or = 20 year old in eight different parts of China for detecting antibody to A/PR/8/34(H1N1) influenza virus with HI test. Of them, 24 had antibody with HI titers > or = 20 to A/PR/8/34(H1N1) virus. These 24 specimens were tested with the same method using A/swine/Iowa/15/30 (H1N1), A/Guangxi/10/94(H1N1) and A/Beijing/53/97(H1N1) viruses. The results showed that except 5 of them had antibody with HI titers 20-40 to A/Beijing/53/97(H1N1) virus, the rest had antibodies with titers < 20 to the viruses for checking test. Therefore, the antibody to A/PR/8/34(H1N1) virus in the tested sera was not caused by cross reaction of antibodies against another H1N1 viruses. The results in this paper also further demonstrated that the A/PR/8/34(H1N1) like virus was circulating in residents in China.

Adolescent↗

PubMed1998

[A quantitative measurement of retinal nerve fiber layer thickness by optical coherence tomography in normal Chinese people].

PURPOSE: To measure retinal nerve fiber layer(RNFL) thickness in normal Chinese people for the use of early diagnosis in glaucomatous patients. METHODS: Optical Coherence Tomography(OCT) was used in 111 eyes of 77 Subjects to create cylindrical cross sections of the RNFL around the optic nerve head with scan diameter of 3.46 mm. The differences in RNFL thickness were analyzed with age, sex, either eye. RESULTS: We found a decrease in RNFL thickness with aging especially in the superior quadrant(P < 0.05), but there weren't significant difference between right and left eyes, neither the sex(P > 0.05). The Mean RNFL thickness of different ages(mean +/- s) was as following: the superior quadrant 128.00 +/- 10.31-149.00 +/- 13.17, the inferior quadrant 132.95 +/- 9.54-142.33 +/- 10.60, the overall mean RNFL thickness 109.00 +/- 4.72-114.28 +/- 7.98 microns. CONCLUSION: The preliminary study showed that neither sex nor either eye were associated with significant differences in RNFL thickness. It is necessary to define the normative value by age group on a larger scale.

Adolescent↗