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Gang Wang

Publications and source records attributed to Gang Wang.

At least 145 records · Page 8Linked to original sources
PubMed2004

Functional segregation of plural regions representing cardinal contours in cat primary visual cortex.

Our previous data based on an imaging study suggested that, in cat area 17, the representations of cardinal orientations overlap less than the representation of their nearby angles. The purpose of this study was to further investigate the underlying single-cell properties. Optical imaging was performed first to map the cortical regions corresponding to the four principal contours, the two cardinals and the two obliques. The cortical region activated by a principal orientation but not by the +10 degrees or -10 degrees neighbouring angles, namely the area with optically relative independent orientation selectivity (RIOS), was mapped together with the regions that overlapped with the +10 degrees and/or -10 degrees neighbouring angles (non-RIOS). Electrode penetrations were targeted to the RIOS and non-RIOS regions in each of the four orientations. A comparison between the RIOS and the non-RIOS regions documented a significantly higher percentage of cells with the orientation preference of the cardinal orientations in the cardinal RIOS region than that seen in the other regions. Additionally, the difference in the tuning width of cells between the RIOS and non-RIOS in the cardinal region was significantly larger than the difference between the RIOS and non-RIOS in the oblique region. The cells in the cardinal RIOS region were tuned more sharply and the cells in cardinal non-RIOS region more broadly than the oblique RIOS and/or the non-RIOS region, which showed no significant difference. These data strongly suggest the existence of functional segregation in the region corresponding to the cardinal contours.

Animals↗
PubMed2004

Monitoring of T lymphocyte subset during ATG induction therapy in hand allograft with report of 3 cases.

OBJECTIVE: To investigate the significance of T lymphocyte subset determination during antithymocyte globulin (ATG) induction therapy in reducing the total drug dose, incidence of complications and cost of treatment in hand allograft. METHODS: The changes in peripheral blood T lymphocyte subsets (CD3+, CD4+, CD8+, and CD28) were determined by flow cytometry in 3 cases of hand allograft who received ATG treatment. RESULTS: Flow cytometry showed that the percentages of CD3+, CD4+, and CD8+ T lymphocytes, along with the ratio of CD4/CD8, decreased significantly during ATG induction therapy, and the results were consistent in the 3 cases. Long-term continuous changes of peripheral blood lymphocytes were observed after antithymocyte globulin induction therapy. CONCLUSION: The understanding of the immunological state of the patient with hand allograft after ATG induction therapy by monitoring T lymphocyte subsets may allow adjustment of the total dose of the drugs administered and help prevent the occurrence of complications.

Adult↗
PubMed2004

[Expression changes of tau protein and microtubule-associated proteins in testis intersitium of rats].

OBJECTIVE: To examine the expression of the tau protein and microtubule-associated proteins in the testis interstitium of aged and young rats. METHODS: Sprague-Dawley male rats were divided into a young group(6 months, n = 10) and an aged group(28 months, n = 10). The two steps immunohistochemistry method with the antibody against tau protein and MAP alpha was performed on the testis tissues of the rats. RESULTS: The results showed that the immunoreactive cells of tau protein of the testis interstilial of the aged rats obviously increased(P < 0.001) than those of the young, while the immunoreactive cells of the microtubule-associated proteins decreased(P < 0.01) in the aged. CONCLUSION: The changes in the expression of the tau protein and microtubule-associated proteins may be related to the aging process of the testis.

Aging↗
PubMed2004

[Influence of different mechanical environments on repair of cartilage defect with rabbit marrow mesenchymal stem cells].

OBJECTIVE: To study the influence of different mechanical environments on repair cartilage defect with marrow mesenchymal stem cells as seed cells. METHODS: The rabbit marrow mesenchymal stem cells were isolated and cultured. The cartilage defects were repaired by autologous tissue engineered cartilage with the marrow mesenchymal stem cells as seed cells. Fifteen rabbits with cartilage defect were divided into 3 groups: dislocation group with cell-free scaffold (control group), dislocation group with cartilaginous construct and normal mechanical environment group with cartilaginous construct. The repaired tissue was harvested and examined 6 weeks postoperatively. RESULTS: The repair tissue in normal mechanical environment group with cartilaginous construct showed cartilage-like tissue in superficial layer and subchondral bone tissue in deep layer 6 weeks postoperatively. The defect was filled with bone tissue in dislocation group with cartilaginous construct 6 weeks postoperatively. The surrounding normal cartilage tissue showed vascular invasion from subchondral area and the concomitant thinning of the normal cartilage layer. The cartilaginous construct left in the femoral trochlea groove formed hyaline cartilage-like tissue. The defect was repaired by fibrous tissue in control group. CONCLUSION: The repaired tissue by tissue engineered cartilage with marrow mesenchymal stem cells as seed cells showed the best result in normal mechanical environment group, which indicates that it will be essential for the formation and maintenance of tissue engineered cartilage to keep the normal mechanical stress stimulus.

Animals↗
PubMed2004

[Effects of mifepristone on the proliferation, apoptosis, and cis-platinum (DDP) sensitivity of chemo-resistant human ovarian cancer cells].

BACKGROUND & OBJECTIVE: Mifepristone is an effective progesterone receptor antagonist. It was reported that mifepristone can inhibit the growth of ovarian carcinoma cells either in vitro or in vivo, but the exact mechanism is unknown. The effect of mifepristone on the growth, apoptosis and cis-platinum (DDP)-sensitivity of chemo-resistant ovarian carcinoma cell lines have scarcely been reported. The purpose of this study was to investigate the effect and its mechanism of mifepristone on the proliferation, apoptosis and DDP sensitivity of DDP-resistant human ovarian carcinoma cells, and to give experimental basis for treating refractory ovarian carcinoma with mifepristone. METHODS: DDP-resistant human ovarian carcinoma cell line SK-OV-3 cells were cultured in vitro, and the MTT assay was used to examine the antiproliferative effect of mifepristone with or without DDP on SK-OV-3 cells. The cooperative effects between mifepristone and DDP in inhibiting the growth of SK-OV-3 cells were analyzed. TdT mediated dUTP nick end labeling (TUNEL) and flow cytometry (FCM) were used to examine the effects of mifepristone with or without DDP on the apoptosis and cell cycle of SK-OV-3 cells. RESULTS: Mifepristone produced concentration-dependent antiproliferative effect on SK-OV-3 cells at all experimental concentrations.Enhanced antiproliferative effects were found when SK-OV-3 cells were cultured with mifepristone at 0.625, 1.25, 2.5, 5, 10, and 20 microg/ml combined with 1.25 microg/ml or 2.5 microg/ml DDP (q >1.15). Only additive effects were found when the cells were cultured with mifepristone and 0.625 microg/ml or 5.0 microg/ml DDP (0.85< q< 1.15). Mifepristone induced concentration-dependent apoptosis in SK-OV-3 cells and arrested cells in the G(0)/G(1)-phase of cell cycle. The apoptosis rate were 14.52%, 36.14%, and 53.22%,respectively,when the cells were cultured with mifepristone at 1.25, 2.50, and 5.00 microg/ml. The percentage of G(0)/G(1)-phase cells was increased with the concentration of mifepristone. Synergic effect between mifepristone (at 1.25, 2.5, and 5 microg/ml) and 2.5 microg/ml DDP was found in inducing SK-OV-3 cells apoptosis (q >1.15) and G0/G1-phase stasis. CONCLUSION: Mifepristone can inhibit the growth of chemo-resistant human ovarian carcinoma cells,and enhance its DDP sensitivity. This may be associated with the synergic effect between mifepristone and DDP in inducing apoptosis and G(0)/G(1)-phase stasis.

Apoptosis↗
PubMed2004

[Expression of human Fab antibody against keratin in E.coli and its renaturation].

AIM: To express Fd fragment and L chain of human anti-keratin Fab in E.coli BL21(DE3) respectively and obtain human anti-keratin Fab by renaturation in-vitro. METHODS: Genes of L chain and Fd fragment of anti-keratin antibody from the plasmids p3MH/ Fab were subcloned into vector pET32a respectively. The recombinant plasmids pETL and pETFd were transformed into E.coli BL21(DE3) and induced to express with IPTG. Fd fragment and L chain inclusion bodies were solubilized and combined in equal molar ratio in the refolding solution. The renatured Fab was characterized by SDS-PAGE, Western blot and ELISA. RESULTS: Fd fragment and L chain of human anti-keratin Fab were efficiently expressed. ELISA and Western blot showed that the renatured Fab could bind with human keratin. CONCLUSION: The successfully prepared anti-keratin Fab with binding activity to human keratin laid a solid foundation for its further application.

Escherichia coli↗
PubMed2004

[Systematic assessment on randomized controlled trials for treatment of stable angina pectoris by compound salvia pellet].

OBJECTIVE: To assess the therapeutic effect and safety of compound salvia pellet (CSP) in treating stable angina pectoris (SAP). METHODS: Literatures regarding randomized clinical trials of CSP versus nitrate ester preparation in treating SAP, without any language limitation, were reviewed. Jadad scale was used to assess the methodological quality of the inclusive trials, and Cochrane systematic evaluation was applied for it. RESULTS: Seventeen randomized trials conformed to the inclusion criteria were reviewed, all in Chinese language. The combined results of the two comparing groups on therapeutic effect in symptom of angina and electrocardiogram (ECG) showed that the relative risk (RR) was 1.12 (1.06, 1.19) and the 95% credibility interval (CI) was 1.42 (1.20, 1.57). CONCLUSION: Based on the Cochrane systematic review, CSP showed the therapeutic effect in treating SAP on relieving angina and improving ECG better than that of nitrate ester preparation, and with less adverse reaction and good tolerance. However the conclusion cannot be reached yet due to the low methodological quality of the trials collecting and lacking in some important final markers and relevant criteria for quality of life, more rationally designed and strictly executed randomized trials with large samples are necessary.

Angina Pectoris↗
PubMed2004

[Imbalanced T cell-specific transcription factors T-bet and GATA-3 contributes to type 2 T helper cell polarization in asthmatic patients].

OBJECTIVE: To identify the T helper cell predominant differentiation in asthmatic patients and to explore the modulation of T cell-specific transcription factors T-bet/GATA-3. METHODS: Thirty-two asthmatic patients were enrolled, among whom 18 were atopic defined by positive antigen skin test and 12 were children. Lymphocytes were isolated from peripheral blood and incubated with PHA (100 microg/ml) at 37 degrees C for 48 hours. INF-gamma and IL-4 concentrations in the supernatant were detected by ELISA. The T-bet and GATA-3 mRNA expression levels in lymphocytes were assayed by reverse transcription-polymerase chain reaction (RT-PCR) while the ratio of CCR3+ and CCR5+ cells in lymphocytes was counted by flow cytometry (FCM) after direct immunofluorescence staining. RESULTS: IL-4 concentration in the lymphocyte supernatant of the asthmatic group was (118 +/- 25) microg/L, which was significantly elevated compared to that of the healthy control group (75 +/- 12) microg/L (P < 0.01). When subgroups of asthmatic patients were compared, the results showed that atopic subjects had a higher IL-4 level than non-atopic subjects [(126 +/- 23) microg/L vs (107 +/- 26) microg/L, P < 0.01], but no significant difference was demonstrated between adults and children [(118 +/- 25) micro g/L vs (121 +/- 25) microg/L, P > 0.05]. Significantly lower concentration of INF-gamma in the asthmatic group was detected as compared to the control [(651 +/- 85) microg/L vs (1 179 +/- 332) microg/L, P < 0.001]. The concentration of INF-gamma was higher in atopic subjects than in non-atopic subjects [(618 +/- 89) micro g/L vs (680 +/- 83) microg/L, P < 0.01], but no difference was found between adults and children. The percentage of CCR3+ cells in lymphocytes was (9.4 +/- 5.8)% in the asthmatic group and (4.9 +/- 2.3)% in the control (P < 0.05), while the percentages of CCR5+ cells was (6 +/- 7)% and (13 +/- 7)%, respectively (P < 0.05). RT-PCR revealed that T-bet mRNA expression levels were as follows: 0.13 +/- 0.03 in the asthmatic group and 0.18 +/- 0.04 in the control (P < 0.01); 0.120 +/- 0.030 in atopic subjects and 0.140 +/- 0.010 in the non-atopic subjects (P < 0.05); 0.120 +/- 0.020 in children and 0.130 +/- 0.020 in adults (P > 0.05). The levels of GATA-3 mRNA expression were 0.43 +/- 0.07 in asthma and 0.29 +/- 0.09 in the control (P < 0.01), however, no differences were found between atopic and non-atopic, children and adults (0.50 +/- 0.12 vs 0.40 +/- 0.10, 0.44 +/- 0.09 vs 0.43 +/- 0.07, respectively, P > 0.05). A positive correlation was found between concentration of INF-gamma and T-bet mRNA level (r=0.663, P < 0.01), while no correlation with GATA-3 mRNA expression was found. The concentration of IL-4 was negatively correlated with T-bet mRNA level (r=-0.250, P < 0.05) and positively with GATA-3 mRNA level (r=0.72, P < 0.01). It was interesting that a closer relationship existed between the ratio of T-bet to GATA-3 and the ratio of INF-gamma to IL-4 (r=0.873, P < 0.01). CONCLUSIONS: In asthma there is a tendency of Th2 polarization with over-production of Th2-like cytokines in which T-bet deficiency may be a key factor. T-bet might direct T cells to Th1 differentiation while GATA-3 orientated Th2 maturation. Considering the fact that committed Th2 cells underwent re-differentiation induced by T-bet, this novel Th1-specific transcription factor is a fascinating target gene for modifying to restore the Th1 and Th2 balance.

Adolescent↗
PubMed2004

Clinical analysis of craniocerebral trauma complicated with thoracoabdominal injuries in 2165 cases.

OBJECTIVE: To explore the optimal treatment for craniocerebral trauma complicated with thoraco-abdominal injuries. METHODS: A total of 2165 cases of craniocerebral trauma complicated with thoraco-abdominal injuries admitted to our hospital between July 1993 and June 2003 were retrospectively studied. Among them, 382 cases sustained severe craniocerebral trauma (in which 167 were complicated with shock), 733 thoracic injuries, 645 abdominal injuries and 787 thoraco-abdominal injuries. On admittance, 294 cases had developed shock. With the prime goal of saving life, respiratory and circulatory systems and encephalothilipsis were especially treated and monitored. Priority in management was directed to severe or open injures rather than to moderate or closed injures. For cases with cerebral hernia due to intracranial hematoma and severe shock due to blood loss, cerebral hernia and shock were treated concurrently. RESULTS: After treatment, 2024 (93.49%) cases survived and the other 141 (6.51%) died. Among patients who had severe craniocerebral injury with shock and those without, 78 (46.71%) and 53 (24.56%) died, respectively. For patients who had underwent craniocerebral and thoraco-abdominal operations concurrently and those who had not, the death rates were 58.49%-65.96% and 28.57% respectively, indicating a significant difference (P<0.05). CONCLUSIONS: Treatment for hematoma hernia, shock and disturbed respiration is the key in the management of multiple trauma of craniocerebral, thoracic or abdominal injuries, especially when two or three conditions occurred simultaneously. Unless it is necessary, operations at two different parts at the same time is not recommended. It is preferred to start two concurrent operations at different time.

Adult↗
PubMed2004

[Using AR model to analyze injured nerve with needle EMG signal].

The two main factors to affect the style of the recruitment are temporal recruitment and spatial recruitment. This study sought a new way to analyze the recruitment with the modern spectrum method. The abnormal spatial recruitment and temporal recruitment of varied injury degrees of intramuscular neuron were compared through the AR model. At last, AR coefficients were extracted and passed through BP artificial neuron network to classify different NEMG signals and good result was gained.

Action Potentials↗
PubMed2004

[Construction and screening of the human phage antibody library from a patient with melanoma].

AIM: To construct and screen the human phage antibody library from a patient with melanoma. METHODS: Total RNA was extracted from the peripheral blood mononuclear cells (PBMCs) of a patient with melanoma who has survived for twenty years. The heavy chain Fd fragments and kappa light chains were amplified by RT-PCR. The amplified products were cloned into phagemid vector to construct Fab antibody library. The library was panned with two kinds of melanoma cells for 4 rounds. RESULTS: Antibody library contained 1.2 x 10(8) different clones. Specific phage antibodies against one of the two melanoma cells were obtained after 4 rounds of panning. CONCLUSION: Specific human phage antibodies against melanoma cells were obtained.

Antibodies, Neoplasm↗
PubMed2004

Effects of glycine and methylprednisolone on hemorrhagic shock in rats.

BACKGROUND: Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP can protect against organ injury and death caused by hemorrhagic shock, and to elucidate the underlying mechanisms of these protective effects in rats. METHOD: To establish a shock model, Wistar rats were bled to maintain mean arterial pressure at 30-50 mmHg for 1 hour and subsequently resuscitated with the shed blood and normal saline. Just prior to resuscitation, the rats were randomly assigned to four groups: sham group (operation performed without inducing shock), shock group, shock + glycine group (glycine injected at the beginning of resuscitation) and shock + MP group (MP injected at the beginning of resuscitation). RESULTS: (1) Seventy-two hours after resuscitation, the survival rate of rats from the shock group had decreased to 20%, while the survival rates of rats from the shock + glycine and shock + MP groups were 77.8% and 80%, respectively. The difference was significant (P <0.05). (2) Eighteen hours after resuscitation, pathological alterations in the organs of the rats were apparent. In rats from the shock group, edema, interstitial leukocyte infiltration, and cellular degeneration occurred in the liver, lungs, kidneys, and heart. Glycine and MP reduced these pathological changes significantly. (3) Eighteen hours after resuscitation, the levels of creatine phosphokinase, transaminases, and creatine were elevated significantly in rats from the shock group, indicating injury to the heart, liver, and kidneys, while these levels were elevated only slightly in the shock + glycine and shock + MP groups. The differences were significant (P <0.01). (4) There were significant increases in intracellular calcium and production of tumor necrosis factor (TNF-alpha) by isolated Kupffer cells stimulated by endotoxin after hemorrhagic shock. These changes were completely prevented by glycine and MP (P <0.01). CONCLUSION: Glycine and MP reduce organ injury and mortality caused by hemorrhagic shock by preventing increase of intracellular calcium levels in Kupffer cell, suppressing Kupffer cell activation, decreasing the production of TNF-alpha by Kupffer cells, and blocking systemic inflammatory responses.

Animals↗
PubMed2004

[Expression of androgen receptor and heat shock protein 90alpha in the testicular biopsy specimens of infertile patients with spermatogenic arrest].

OBJECTIVE: To explore the association of spermatogenic arrest with the expression of AR and HSP90alpha. METHODS: The two-step immunohistochemical method was used to examine the expression of AR and HSP90alpha in the testicular biopsy specimens of 57 infertile men with spermatogenic arrest, compared with those taken from 15 normal healthy men. RESULTS: AR was expressed in the nuclei of the spermatogonia, spermatocytes and round spermatids of the normal testicular biopsy, but the intensity of the AR expression showed difference in each type of cells. Furthermore, the high expression of AR in spermatogonia and spermatids was on the margin of the cytoplasm, and perinuclear (forming a ring-like structure) were very distinctive in the spermatogenic arrest testicular biopsy specimens. HSP90alpha was expressed in spermatogonia, spermatocytes, Sertoli cells, Leydig cells and myoid cells in the normal testicular tissues, but highly expressed in the testicular tissues with spermatogenic arrest. The immunostaining intensity of HSP90alpha showed significant difference (P < 0.05) between the two kinds of testicular tissues. CONCLUSION: The results indicate that the abnormal expression sites of AR may make the androgen receptor unable to mediate androgen into the nucleus, which may down-regulate the gene transcription activity of spermatogenic cells. It is possible that the high expression of HSP90alpha may lead to a dramatic decrease in AR stability and an increase in AR abiquitirylation.

Adult↗
PubMed2004

[Construction and expression of eukaryotic expression vector for intact IgG against human keratin].

AIM: To construct an eukaryotic expression vector containing the gene of anti-keratin antibody and express it in CHO(dhfr(-)) cells. METHODS: Both the V(L) and V(H) genes of an anti-keratin Fab from a phage display library were amplified by PCR. Using PCR product as the template, the V(kappa) and V(H) genes with the leader sequences (named L(kappa) and L(H) respectively) were amplified by overlapping PCR. After digested with endonuclease Xba I/BamH I and Xho I/Hind III, L(kappa) and L(H) genes were inserted into pWD digested with Xba I/BamH I and Xho I/Hind III, respectively to construct pWDkappaH. After PCR and sequencing, the expression plasmid pWDkappaH was transfected into CHO (dhfr(-)) cells. The culture supernatant of the transfected cells was collected and assayed for IgG activity. RESULTS: The eukaryotic expression vector pWDkappaH was constructed successfully and expressed in CHO(dhfr(-)) cells. The expression of intact IgG against keratin was identified by ELISA and RT-PCR. CONCLUSION: The successful expression of intact IgG against keratin lays the foundation for its clinical application.

Animals↗
PubMed2004

[Studies of somatic embryogenesis and genetic transformation by Agrobacterium- mediated in soybean].

Somatic embryogenesis was induced and the regenerated plants were obtained by higher concentrations of auxins with immature cotyledon of 55 genotypes in soybean. Bivalent insect resistant genes were transformed into immature cotyledon of soybean which have high frequency of somatic embryogenesis via Agrobacterium-mediated. The results showed that 14 genotypes possessed high frequency of somatic embryogenesis (more than 40%) among soybean genotypes from Northeast area. 2147 immature cotyledons of 5 different soybean genotypes cultured in Northeast area were inoculated with LBA4404 (including pGBI121S4ABC plasmid). 17 plantlets were obtained under Kanamicy selection. 12 plantlets showed positive reaction in PCTR and PCR-Southern detection. These analyses confirmed the presence of introduced Bt gene in soybean.

Cotyledon↗
PubMed2004

[Research progress on system of transgene in soybean].

This review introduced the recent research progress on transgenic methods and system of receptor in soybean. The major obstacles of genetic transformation in soybean and possible approach for solving the problem were also discussed. Cotyledon node via Agrobacterium tumefaciens-mediated and immature cotyledon via particle bombardment were thought to be the efficient systems of genetic transformation. Three problems existed in genetic transformation of soybean. The first one was that the system of tissue culture needs to be further improved. The second was that efficiency of genetic transformation was still low and difficult to be repeated. The last one was that restricted genotypes of soybean have been transformed successfully as a receptor. The path of solving these problems need to set a new and high efficient system for tissue culture in soybean. Also the number of target gene to be transformed will be increased from single gene to several genes at same time.

Agrobacterium tumefaciens↗