Biomedical subjects

G Zhang

Publications and source records attributed to G Zhang.

At least 145 records · Page 8Linked to original sources

PubMed2001

[Study on homocysteine metabolism related enzymes gene mutations in Chinese patients with ischemic cardiovascular and cerebrovascular diseases].

OBJECTIVE: To explore the significance of gene mutations of cystathionine beta-synthase (CBS844ins68), methionine synthase (MS A2756G) and methylenetetrahydrofolate reductase (MTHFR C677T) in ischemic cardiovascular and cerebrovascular diseases. METHODS: The genotypes of CBS 844ins68, MS A2756G and MTHFR C677T were determined by PCR-based assay in 102 patients with brain infarction, 73 with myocardial infarction and 100 healthy controls. RESULTS: The prevalences of CBS 844ins68 and MS A2756G in the cohort studied were somewhat lower than that in western Caucasian populations. There were no significant differences in the frequencies of CBS 844ins 68, MS A2756G and MTHFR C677T mutations between the patient the and control groups. However, the heterozygous form of CBS 844ins 68 tended to be more prevalent in the controls than in the patients. CONCLUSION: Gene mutations as CBS 844ins 68, MS A2756G and MTHFR C677T may not be independent risk factors for ischemic cardiovascular and cerebrovascular disease in Southern Chinese Han population. The prevalences of CBS 844ins 68 and MS A2756G may vary with different ethnic groups or geographic regions.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed2001

[Indexing system and its quantitative expression for soil quality evaluation in Hainan Island].

Based on the SOTER database and some FAO frameworks, a soil quality indexing system was established, and some evaluation results were presented for some selected GIS photo spot of tropical cropland in Hainan island. With connection to the spatial database, this system could perform the output of evaluation results. The performance and evaluation results were approved by the local expertise. It is suggested that the established models should be modified by the local practice.

China↗

PubMed2001

[Multivariate analysis of the parameters related to prognosis of astrocytoma].

OBJECTIVE: To investigate the clinical and pathological characteristics of astrocytoma and the factors related to pathologic gradings as well as prognosis in astrocytoma. METHODS: 120 cases of the astrocytoma with complete clinical data were selected as the study group, of which 94 cases had follow-up data. 20 cases of normal brain tissue and demyelinating plaques with astrocyte hyperplasia were used as the control group. The expression of Ki-67, VEGF, collagen IV and TRT by immunohistochemical staining and detection of TRTmRNA and telomerase RNA by in situ hybridization were studied. RESULTS: (1) Both astrocytoma and demyelinating lesions showed various positivity for Ki-67. The difference between different gradings of the astrocytoma and non-neoplastic lesions were significant(P < 0.01). Taking 8.5% of Ki-67 expression as threshold, there was significant difference between two survival curves indicating favorable and unfavorable prognosis in the tumor group respectively (P < 0.01). (2) Microvascular changes, such as the density of blood vessels, did not demonstrate any difference between grade I, II astrocytoma and normal tissue, but was significantly increased in grade III and IV astrocytoma and even more in the necrotic area (P < 0.01). The expression of VEGF correlated closely to the density of the blood vessel (P < 0.01). (3) The expression of TRT protein was negative in normal astrocytes but positive in proliferative disease and astrocytoma. The intensity of the positivity was enhanced by the grading of the tumor and correlated with the prognosis (P < 0.01). The expression of hTR, TRTmRNA was less than that of TRT but was well correlated to TRT expression. CONCLUSIONS: Use of the cox-regression model in multivariate analysis shows that there are six parameters closely related to the prognosis of astrocytoma, of which the pathological grade being the most critical factor. Ratio of Ki-67 positivity, age of patient, duration of symptoms are also important factors, while microcystic changes in the tumor and expression of VEGF are independent favorable factors for astrocytoma.

Adult↗

PubMed2001

[Introduction to Go! Poly, a human genome polymorphism database].

Databases play an important role in the study of genetic polymorphism. To meet the need for more studies of human genome polymorphism by Chinese medical and pharmaceutical community, a gene oriented human genome polymorphism database-Go! Poly was constructed. As a generalized polymorphism database, Go! Poly extracted human gene-linked sequence variations of all common types from various public resources including scientific journals and Web resources such as HGBASE (http://hgbase.cgr.ki.se) and dbSNP (http://www.ncbi.nlm.nih.gov/SNP/). The polymorphism data were then categorized into different gene loci, and the reference sequences given by LocusLink were used as positioning reference. To facilitate the use, a friendly web interface and a text based query strategy were implemented. Users can fetch specific polymorphism data in just three steps: find specific gene locus by simple search, display sequence variation information of a specific gene locus select, and view the final result of a specific variation site. Besides, a web-based submission tool is provided for direct submission, which can make the polymorphism information generated by the Chinese scientific community available from this resource.

China↗

PubMed2001

[Effects of radiofrequency catheter ablation in coagulation system].

OBJECTIVE: To investigate the pathogenesis and prophylactic therapy of peripheral vascular embolism after radiofrequency catheter ablation (RFCA). METHOD: 90 patients with supraventricular tachycardia (SVT) were divided into 3 groups. Group A did not use any anticoagulant before RFCA and group B used aspirin (ASA) before RFCA, group C used calcium channel blocker-amlodipine before RFCA. Blood samples were taken at 4 time points, i.e. before and after electrophysiologic examination, immediately after RFCA and 2 days after RFCA. For each blood example, blood levels of platelet alpha-granule membrane glycoprotein-140 (Gmp-140), thromboxane B(2) (TXB(2)), protein C (PC), protein S (PS) were measured. RESULT: In group A, Gmp-140 and TXB(2) of the blood examples taken before electrophysiologic examination were significantly lower than those taken at the three other time points, but there was no significant change of PC and PS as compared with that at the three other time points. Ablation either on the left or right heart did not affect the levels of Gmp-140 and TXB(2); In group B and group C, the levels of Gmp-140 and TXB(2) of the samples were significantly lower than those of the corresponding points in group A. CONCLUSION: It is indicated that platelet aggregability may be introduced by RFCA, but evolution of the anticoagulant system was not caused by RFCA, This may enhance the occurrence of thrombosis. ASA and amlodipine may prevent the occurrence of thrombosis.

Adolescent↗

PubMed2001

[Management of deep facial burn with early postburn debridement and delayed skin grafting].

OBJECTIVE: To explore optimal methods of the management of deep facial burn, so as to prevent the development of facial scar hypertrophy and deformity. METHODS: Partial tangential excision, delayed skin grafting, early relief of the eyelid eschar and immediate skin grafting were carried out in burn patients with deep facial burn during the early postburn stage. RESULTS: The wounds in 12 cases had healed completely within 3 postburn weeks(PBW). Scar hypertrophy and facial deformity were not observed during the follow-up. All the patients could express natural facial expressions. CONCLUSION: Facial deep burn wound could be managed as soon as possible with early partial tangential excision and delayed skin grafting. As a result, facial scar hypertrophy and deformity could be avoided.

Adolescent↗

PubMed2001

[Vitreous surgery for proliferative maculopathy].

OBJECTIVE: To explore the indication of vitrectomy for the treatment of pre-macular proliferative disease, the surgical technique, results and the prevention and treatment of complications. METHODS: Forty-one eyes of 41 cases with different kinds of macular traction or macular pucker, including 12 cases of idiopathic epimacular membrane, 10 cases of macular hole complicated with epimacular membrane and 19 cases of macular pucker after reattachment surgery (no diabetic retinopathy or retinal detachment) were treated with vitreous surgery. The issue of this operation is to find out underlying fissures (an under-bridge) or weakly adherent sites between a membrane and the retina. Using flute-needle, intraocular pick, spade and vitreoretinal forceps, we can separate and peel the proliferative membrane and the posterior cortical vitreous from the retinal surface completely. RESULTS: In 41 cases, epimacular membrane was peeled successfully, and the normal anatomic structure of the macula was restored. Four cases had small amount of hemorrhage in the superficial layer of the retina in and after the operation, and all the other cases did not have any complications, such as retinal tear or detachment. Thirty-eight cases obtained higher visual acuity, and in 3 cases the visual acuity maintained at their pre-operative level. Metamorphopsia was significantly improved, even disappeared. The follow-up period was 3 months to 4 years. CONCLUSIONS: The therapeutic effects of vitreous surgery for treatment of various kinds of proliferative maculopathy are reliable. After the surgery, the visual acuity can be elevated, the symptoms can be ameliorated and the complications can be effectively controlled.

Adult↗

PubMed2001

[Clinical study on the early and short -- term use of antibiotics with broad spectrum in severely burned patients].

OBJECTIVE: To investigate the prevention and treatment effects of early and short -- term use of antibiotics with broad spectrum on postburn severe infection in severely burned patients. METHODS: Thirty -- five burn patients with TBSA from 50% to 95% were enrolled in the study. The patients were divided into early prevention [20 cases, antibiotics were used started from 6 postburn hours (PBH)] and delayed prevention (15 cases, antibiotics were applied after 48 PBH) groups. Plasma levels of LPS, TNFa and IL -- 8 were dynamically monitored with the concomitant observation of clinical signs of postburn sepsis. RESULTS: After major burns, the plasma levels of LPS, TNFalpha and IL -- 8 increased evidently and reached the peak values on 3 similar 5 postburn days (PBD). But the levels of all above factors in the early group were obviously lower than those in the delayed group (P < 0.05 similar 0.01). The incidencies of sepsis and internal organ complications within 2 postburn weeks were much lower in the early group than those in the delayed group (P < 0.05). The subeschar bacterial quantification on 4 similar 7 PBD was evidently lower in the early group than that in the delayed group (P < 0.01). CONCLUSION: Early and short -- term use of antibiotics with broad spectrum in severely burned patients could effectively prevent postburn severe infection and lower down the incidence of internal organ complications.

Adolescent↗

PubMed2001

[Indomethacin induces apoptosis of K562 cells through activation of caspases and elevation of intracellular free calcium].

OBJECTIVE: To investigate the indomethacin (IN) induced apoptosis of K562 cells: (1) the expression, activation and subcellular localization of caspase-3 and -8; (2) the change of intracellular free calcium concentration ([fCa(2+)]i) and its mechanism; and (3) whether the cell apoptosis is cyclooxygenase (cox) dependent or not. METHODS: Changes and subcellular localization of caspase-3 and -8 were observed by laser scanning confocal microscopy (LSCM); expression and activation of caspase-3 and -8 proteins by Western blotting; changes of intracellular [fCa(2+)]i by LSCM coupling with a calcium-fluorescence probe and calcium chelator EGTA blocking test; and cox inhibitor effect by MTT assay. RESULTS: (1) LSCM assay and Western blotting showed that caspase-3 and -8 localized in cytoplasm and nucleus dispersedly and spottedly and were upregulated with the increasing of IN doses. Western blotting also showed the cleavage and activation of caspase-3 and -8 during IN-induced apoptosis. (2) The increase of [fCa(2+)]i in K562 cells was parallel to the increase of IN concentration regardless of the presence or absence of EGTA. But with EGTA treatment, [fCa(2+)]i was much less than that without EGTA treatment. (3) Low dose of IN or other cox inhibitors could not exert cytotoxic effects on K562 cells whereas high dose of IN could. CONCLUSION: (1) The upregulation and activation of caspase-3 and -8 play a fundamental role in apoptosis induced by IN in K562 cells. Both cytoplasm and nucleus are locations where caspase-3 and -8 localized. (2) The increase of [fCa(2+)]i may be critical in the modulation of apoptosis; the extracellular calcium influx is the main source of the elevation of [fCa(2+)]i in K562 cells and can be blocked by the calcium chelator EGTA;the release of calcium from intracellular calcium store is also an important source of the intracellular calcium which can trigger apoptosis without the extracellular calcium influx. (3) Apoptosis of K562 cells induced by IN is cox-independent.

Apoptosis↗

PubMed2001

[Study on the relationship between apoptosis and reactive oxygen species of cancer cell lines induced by anticarcinogens].

OBJECTIVE: To investigate the relationship between apoptosis (AP) and fluorescent intensity of reactive oxygen species (ROS) in cancer cell lines induced by anticancer agents, and the mechanisms of drug sensitivity and resistance. METHOD: K562 cells were treated respectively with each of the Vp16, ADR and DDP, the fluorescent intensity of ROS and AP percentage of K562 cells at different concentration of the drugs treated were assayed by flow cytometry (FCM). RESULT: (1) After treatment with these drugs for 24 hours, the fluorescent intensity of ROS and AP percentage of K562 cells increased obviously as compared with that of control groups. (2) The optimum concentrations of the drugs for ROS production and AP of K562 cells were determined. CONCLUSION: Anticancer agents induced AP of K562 cells, which might be through stimulating ROS production.

Antineoplastic Agents↗

PubMed2001

[Expression of hepatitis B virus antigen in brain tissue from liver cirrhosis patients with hepatitis B and its significance].

OBJECTIVE: To investigate the expression of hepatitis B virus (HBV) antigen in brain tissue from liver cirrhosis patients with hepatitis B and explore its significance. METHODS: HBsAg and HBcAg were detected in the brain tissue from 70 liver cirrhosis dead patients with hepatitis B by S-P immunohistochemical assay, and the relationship between the expression of HBV antigen in brain tissue testing and clinic and pathology was analyzed. RESULTS: 30 patients (42.89%) were positive for HBV antigen. Among them, 24 patients (34.29%) were positive for HBsAg and 18 patients (25.71%) were positive for HBcAg. HBV antigen was mainly found in cytoplasm and distributed in neurons, neurogliocytes and vascular endothelial cells. The positive cells were distributed separately, scatteredly or focally. The expression of HBV antigen was not associated with the serum level of HBV replication but associated with the occurrence of hepatic encephalopathy (HE) and the severity of brain tissue pathologic lesions of HE. CONCLUSIONS: The results indicate that HBV infection develop in brain tissue from liver cirrhosis patients with hepatitis B and HBV may replicate in it. HBV infection in brain tissue may p lay an important role in occurrence and development of HE from liver cirrhosis patients with hepatitis B.

Brain↗

PubMed2001

[Cloning, sequencing of beagle E-selectin genomic DNA and comparison of it with other species].

OBJECTIVE: Selectins are a group of members of Cell Adhesion Molecular family; they play very important roles in inflammation and neovascularization. The aim of this study is to clone, sequence Beagle E-selectin genomic DNA and make homogeneous analyses to compare it with those of other animals. METHODS: Twelve fragments of genomic DNA of Beagle E-selectin were obtained by PCR, and the 12 fragments were cloned in T-vector. At last, the genomic DNA sequences of Beagle E-selectin were obtained through gene sequencing, assembling and base calling, and the gene structure was analyzed. RESULTS: The sequence of Beagle E-selectin genomic DNA that contained the whole open reading box was acgured. The results of homogeneous analyses showed a great extent of E-selectin gene homology among human, porcine and dog. CONCLUSION: The demonstration of a large extent of the gene homology has substantiated in this connection the important roles of E-selectin in transplantation immunity and neoplasm development.

Animals↗

PubMed2001

[MRI manifestation of temporomandibular joints after indirect trauma].

OBJECTIVE: The objective of this study is to investigate the structure changes in temporomandibular joints (TMJs) of goats after indirect trauma. METHODS: The trauma of TMJs of goats achieved under an impact to the right and left mandibular angles with a self-made device. These goats were killed after 2 hours, 7 days, 1 month and 3 months. The TMJs of goats were examined using MRI before killed and checked by histological method, the normal temporomandibular joints were treated as the control. RESULTS: The results of MRI: in the early post-trauma stage, the condylar articular surface was partially lost, and the discs were displaced and ruptured. Further, the hemathrosis of the TMJ and the decreased joint spaces were also observed in the eroded, eburnous surface of the condyle and the deformed disc. In the later stage, the surfaces of condyles were eroded and eburnated, and the discs were deformed. CONCLUSION: The indirect trauma on the TMJs of goats can cause TMJ internal derangement and TMJ osteroarthrosis. MRI cab be used to investigate both hard and soft tissue injuries of the temporomandibular joint, and is appreciated in understanding the pathogenesis of indirect trauma on the TMJ.

Animals↗

PubMed2001

[Phospholipase activities of Candida albicans isolates from oral pre-malignant lesions and oral cancers].

OBJECTIVE: The aim of this study is to compare activities of phospholipase of Candida albicans isolates from oral cavities of two groups of patients, including oral pre-malignant lesions and oral cancers. METHODS: A total of 55 isolates, including oral pre-malignant lesions (21), oral cancers (15), and normal health control (19), were studied using the precipitate zone assay on the egg yolk agar. RESULTS: No significant difference was found in phospholipase activities between these isolates from normal controls and oral pre-malignant lesions, while the activities of phospholipase of isolates from oral cancers were higher than those of the normal controls. CONCLUSION: Candida albicans may play different roles in different manners in these two closely related diseases.

Candida albicans↗

PubMed2001

[The examination of DNA repair capacity in the patients with oral precancerous lesion].

OBJECTIVE: The occurrence of oral precancerous lesion is related with not only carcinogenic environmental factors but also some self-regulating mechanisms. The genetic heredity factors determine individual's DNA repair capacity. The study is attempted to investigate the change of DNA repair capacity of the patients with the precancerous lesion. METHODS: The study is conducted in 16 pairs of oral precancerous lesion and normal controls by using host cell reactivation assay, while some dangerous factors such as smoking, alcohol intaking and family history of cancers are also recorded. RESULTS: The host cell reactivation in the patients with precancerous lesion is lower than that of normal controls (P < 0.05) and is shown to be an independent risk factor in the occurrence of oral precancerous lesion (OR: 3.25 95% CI = 1.01-10.49). CONCLUSION: The host cell reactivation is likely to be a helpful indicator for predict prognosis of cancer for the individuals with highly genetic sensitivity to cancer.

DNA Repair↗

PubMed2001

[A study on the contents of fat and fatty acids in five shellfishes].

The contents of fat and fatty acids in Callista erycina (Linnaeus), Paphia (Paratapes) undulata (Born), Meretrix meretrix (Linnaeus), Chlamys farreri (Jones et Preston) and Patinopecten yessoensis (Jay) were studied. Fat was extracted with Bligh & Dyer (B&D) method. The lipid classes were transesterified with potassium hydroxide in methanol. Fatty acid methyl esters (FAMEs) were assayed with GC-MS and polar capillary column (HP-INNOWax 30 m x 0.25 mm i.d. x 0.25 micron). GC injector temperature was 220 degrees C. The column temperature was programmed from 150 degrees C (1 min) to 200 degrees C at 10 degrees C/min and then from 200 degrees C to 250 degrees C at 2 degrees C/min. FAMEs were identified by MS library, and part by their standards. Total identified fatty acids were over 99% for all samples. Fat contents of them were all over 1% by wet samples. And ratios between omega-3PUFA and omega-6PUFA were above 2 by and large. Patinopecten yessoensis (Jay) contains more fat and the valuable fatty acids, EPA and DHA. It is suitable to use it as the source of EPA and DHA.

Animals↗

PubMed2001

[Detection of bate 2-microglobulin fibronection and interleukin 2 content in patients with nasopharyngeal carcinoma].

OBJECTIVE: To study the clinical significance of detecting of beta 2-microglobulin (beta 2-MG). Fibronection (Fn) and interleukin 2 (IL-2) in patients with nasopharyngeal carcinoma. METHOD: The levels of serum beta 2-MG and IL-2 in 32 patients with nasopharyngeal carcinoma were determined by radioimmunoassay, radial immunodiffusion and ELISA before and after radiotherapy. RESULT: The levels of serum beta 2-MG in patients with nasopharyngeal carcinoma were significantly higher than that in controls (P < 0.05); but serum Fn and IL-2 in patients were significantly lower than that in controls (P < 0.05). The level of serum beta 2-MG decreased in patients after radiotherapy, but the serum Fn and IL-2 increased in patients after radiotherapy. CONCLUSION: Detection of serum beta 2-MG, Fn and IL-2 was useful in clinical diagnosis and prognosis observation of nasopharyngeal carcinoma.

Adult↗

PubMed2001

[Expression of Th1, Th2-typed cytokines and its significance in nasal polyps].

OBJECTIVE: To evaluate the possible role of cytokines in pathophysiology and treatment of nasal polyps. METHOD: The expressions of Th1-typed cytokines IFN-gamma, IL-2, IL-12 and Th2-typed cytokines IL-4, IL-5, IL-8, IL-10, IL-13 were investigated with enzyme-linked immune sorbent assay(ELISA) in 25 patients with nasal polyps. RESULT: There was a significant upregulation of Th2-typed cytokines IL-4, IL-5, IL-8, IL-10, IL-13 in nasal polyps compared with normal nasal mucosa, especially IL-4 and IL-5 (3.9 times and 8.8 times higher than normal mucous respectively) while the expression of Th1-typed cytokines IFN-gamma, IL-2, IL-12 decreased after treated with local glucocorticoid. The levels of Th2-typed cytokines decreased significantly and Th1-typed cytokines had no obvious change. CONCLUSION: The upregulation of Th2-typed cytokines such as IL-4, IL-5, IL-8, IL-10, IL-12 may play an important role in the pathophysiology of nasal polyps and Th2-typed cytokines can be viewed as a target of treatment to nasal polyps.

Adolescent↗