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Biomedical subjects

W X Wang

Publications and source records attributed to W X Wang.

36 records · Page 2Linked to original sources
PubMed1998

"Conventional" antihistamines slow cardiac repolarization in isolated perfused (Langendorff) feline hearts.

We examined the effects of "conventional" antihistamines on cardiac repolarization by using the isolated perfused feline heart model. Representative drugs from the major classes of antihistamines were tested. Each of the antihistamines evaluated in this study elicited a dose-dependent slowing of cardiac repolarization, as indicated by the QT prolongations observed from electrocardiogram (ECG) tracings recorded during these experiments. The concentrations of drugs tested ranged from 1 to 30 microM. Of the drugs analyzed, clemastine and hydroxyzine appeared to be the most potent (relative EC50 values, 5.2 and 6.6 microM, respectively), causing the QT to lengthen by as much as 40-50% at a concentration of 10 microM. Brompheniramine, chlorpheniramine, and diphenhydramine displayed intermediate potencies with respect to QT prolongation (relative EC50 values, 11-13 microM), whereas cyproheptadine, chlorcyclizine, and promethazine were the least potent of the antihistamines tested (relative EC50 values, 16-20 microM). It is concluded that the antihistamines evaluated in this study act directly on the heart to slow cardiac repolarization. These findings could have important clinical relevance for patients taking excessive dosages of conventional antihistamines and those at risk of developing cardiac arrhythmias.

Animals↗
PubMed1995

[Effects of nicorandil on spontaneous beating and action potentials of cultured myocardial cells of neonatal rats].

AIM: To study the anti-arrhythmic mechanism of nicorandil (Nic). METHODS: The myocardial cells of neonatal rats were cultured and effects of Nic on spontaneous beating and action potential of cultured myocardial cells were observed. RESULTS: Nic 32 mumol L-1 and 160 mumol L-1 decreased the spontaneous beating rates of cultured myocardial cells of neonatal rats. Nic 64 mumol L-1 prevented the beating rats induced by CaCl2 1 mmol L-1 and isoproterenol 2 mumol L-1. Nic 32 and 160 mumol L-1 reduced the amplitude, maximal rate of rise, and shortened APD50 and APD90 repolarization. Nic prolonged the spontaneous sinus cycle length. CONCLUSION: The antiarrhythmic mechanism of Nic is related to its direct effects on the myocardial cells.

Action Potentials↗
PubMed1994

[Development of a new fundus image processing system for diagnosis of glaucoma].

For diagnosis of glaucoma, we developed a new fundus image processing system that measures the optic disc structures from the fundus video image and enhances the RNFL. The design and function features are discussed in detail. Clinical application shows that the multifunctional system is accurate in measurements and easy to operate, providing a new approach to the early diagnosis of glaucoma.

Fundus Oculi↗
PubMed1993

Antitumor effect of interleukin 7 in combination with local hyperthermia in mice bearing B16a melanoma cells.

Interleukin (IL)-7 has been evaluated for its influence, alone or in combination with local hyperthermia (LH), on B16a melanoma-bearing mice. Six- to eight-week-old C57BL/6J male mice were inoculated s.c. with 5 x 10(5) tumor cells into the left hind limb. Mice were randomly divided into four groups, and treated s.c. with IL-7 (5 ng) or saline as control, twice a day for three weeks beginning eight days after tumor inoculation. LH, using hot water circulator at 43 +/- 0.2 degrees C for 30 min, was induced to the limb with tumor twice a week for two weeks. Size of the primary tumor was measured every other day for five weeks. Mice were sacrificed five weeks after tumor inoculation. The size of the primary tumor and the number of lung metastases were reduced in mice treated either with IL-7 or LH alone. As a control for IL-7, granulocyte colony stimulating factor (G-CSF) alone had no effect on primary tumor size or number of lung metastases. The greatest antitumor effect was observed in mice treated with IL-7 in combination with LH. Survival was prolonged significantly only in mice treated with IL-7 plus LH compared with that of mice treated with saline. Decreased natural killer (NK) cell activity, number of Thy1.2 cells, and ratio of L3T4+/Lyt2+ cells were associated with tumor growth. These parameters were restored in mice treated with IL-7 plus LH. Increases in levels of IL-1 alpha, IL-6, tumor necrosis factor (TNF alpha) and interferon (IFN gamma) were associated with an increase in the survival of tumor-bearing mice treated with IL-7 and/or LH. These results suggest that changes in T-cell, NK cell and cytokines such as IL-1 alpha, IL-6, TNF-alpha and IFN-gamma in response to IL7 and/or LH might account for prolonged survival of B16a melanoma-bearing mice and that IL-7 might be useful as a potential antitumor agent combined with other therapy in certain malignant solid tumors with metastases.

Animals↗
PubMed1993

Comparative effects of suppressive cytokines on isolated single CD34(3+) stem/progenitor cells from human bone marrow and umbilical cord blood plated with and without serum.

A number of cytokines have been implicated in the suppression of myeloid stem and progenitor cell proliferation. It has been suggested that some of these act directly on the stem/progenitors themselves, based on the effects of these cells, plated in culture at low seeding densities, on highly enriched populations. These studies, however, do not definitively rule out effects on accessory cells. To more rigorously evaluate direct-acting suppressive effects of cytokines, such cytokines were assessed for their effects on colony formation initiated by single bone marrow (BM) or umbilical cord blood (CB) CD34 cells sorted into single wells in the presence of a combination of growth-stimulating cytokines (erythropoietin [Epo], steel factor [SLF], granulocyte-macrophage colony-stimulating factor [GM-CSF], and interleukin-3 [IL-3]) and in the presence or absence of serum. Under these conditions, it was demonstrated that H-ferritin, transforming growth factor-beta 1 (TGF-beta 1), and members of the chemokine family (macrophage inflammatory protein-1 alpha [MIP-1 alpha], MIP-2 beta, platelet factor 4 [PF4], IL-8, and macrophage chemotactic and activating factor [MCAF]) had direct significant suppressive activities on single stem/progenitor cells from adult human BM in the presence or absence of serum. Single sorted CB cells were much less sensitive to inhibition by these cytokines. The reasons for this differential sensitivity are not known. Of possible relevance to this for cytokines, such as H-ferritin and the chemokines that have actions during S-phase of the cell cycle, CB progenitors were in slower cycle at initiation of culture than were BM progenitors.

Antigens, CD↗
PubMed1993

In vivo effects of purified recombinant human macrophage colony-stimulating factor in combination with local hyperthermia on tumor progression in B16a melanoma bearing mice.

Recombinant human (rhu) macrophage colony-stimulating factor (M-CSF) was evaluated, alone or in combination with local hyperthermia (LH), for their antitumor effects in mice inoculated with B16a melanoma cells. Several tumor related parameters and other hematopoietic and immunologic parameters were evaluated 5 weeks after subcutaneous (s.c.) inoculation of tumor cells into the right limbs of C57BL/6J male mice. RhuM-CSF was administered at 20 micrograms/injection, s.c., twice a day for 5 days/week for 2 weeks beginning 6 days after tumor cell inoculation and LH (43 +/- 0.2 degrees C) was given for 30 min twice/week for 2 weeks. Combined therapy prolonged survival of mice and caused significant inhibition of tumor growth, as measured by the volume or size of primary tumor, number and size of lung metastases, and chromatin fragment (CF) formation in tumor bearing mice, while treatment with M-CSF or LH alone had less or no effect. Combined therapy also resulted in increased numbers of splenic T-lymphocytes and the ratio of T-helper/suppressor cells, restoration of natural killer (NK) cell activity, increased numbers of peritoneal macrophages and their erythrophagocytosis capacity, and increased release or production of tumor necrosis factor (TNF)-alpha, but not interleukin (IL)-1 alpha or IL-6. These results add to previous evidence that M-CSF might be a relevant therapeutic agent in combination with other therapies in the treatment of certain malignant diseases.

Animals↗
PubMed1991

Preparation and characterization of monoclonal antibodies against recombinant human tumor necrosis factor alpha.

Tumor necrosis factor (TNF alpha) plays an important role in cytotoxicity and inhibition of tumor cells. Further studies on the structure, function and clinical application of TNF alpha will be useful. Nine clones of hybridoma secreting monoclonal antibodies against recombinant human tumor necrosis factor alpha (rHTNF alpha) were obtained by using cell fusion technology. None of the monoclonal antibodies cross-reacted with rIL-1, rIL-2, rIFN gamma, rIFN alpha and E. coli lysates. Western blot demonstrated that they specifically recognized the rHTNF antigen of M. W. 17000 daltons. Some of the antibodies can also recognize native rHTNF. These antibodies neutralized the cytotoxicity of rHTNF alpha to different extents. They will be utilized as immunoaffinity column to purify rHTNF alpha from recombinant E. coli lysates.

Animals↗
PubMed1990

A comparative experimental study on primary and secondary nerve grafting following inferior alveolar nerve injury.

The damaged inferior alveolar nerve of rabbit was repaired with autogenous ipsilateral greater auricular nerve grafting primarily and secondarily, and electrophysiological, ultrastructural, microvascular and histochemical investigations were performed in this study. The results indicated that the experimental effects of group 1 out of 3 groups (group 1 with immediate grafting, group 2 with grafting after 4 weeks, and group 3 with grafting after 8 weeks) were the best and those of group 2 were second only to group 1 with no obvious difference between these two groups (P greater than 0.05). However, the results of group 3 were not good enough, and there was significant difference from the other two groups (P less than 0.05). Therefore, we were led to conclude that the injury should be repaired at once or within 4 weeks after inferior alveolar nerve was damaged, or within 2 or 3 months thereafter, to improve the function of the injured nerve as greatly as possible.

Animals↗
PubMed1990

[Effects of disodium cromproxate on spontaneous beating and action potentials of cultured myocardial cells of neonatal rats].

Disodium cromproxate (SCP) is an anti-allergic drug. SCP 80, 160, 320 mumol/L markedly increased spontaneous beating rate of cultured myocardial cells, especially SCP 160 mumol/L. SCP 320, 640 mumol/L increased the amplitude, maximal rate of rise and prolonged the duration of the action potentials of the cultured myocardial cells of neonatal rats. The maximal diastolic potential was not affected by SCP.

Action Potentials↗
PubMed1990

[Puerperal thrombophlebitis].

Thirty-eight cases of puerperal thrombophlebitis were reported. The incidence was 0.36% for the 1960s and 0.38% for the 1970s. During 1980s, it was reduced to 0.11%. However, the severity of the disease remained unimproved. Pulmonary and cerebral embolism occurred each in one case. Cesarean section was found to be associated with a 3-19 times increase of risk of developing puerperal thrombophlebitis as compared with vaginal delivery. The pathophysiological changes, diagnostic methods, treatment and prevention are discussed.

Adult↗
PubMed1988

Association of HLA-Bw61 with asthma in the Chinese.

HLA-A and -B typings were detected in 93 asthmatic and 98 normal subjects, all of them of Han nationality, in Shenyang. Antigen frequencies of HLA-A9, A10, Bw61 and Bw62 were found to be much higher than those of normal controls, and -A3 much lower (p less than 0.05). However, after the p-values were corrected, the significant difference was only existing in HLA-Bw61 (pc less than 0.01) with a relative risk of 6.6 (HLA frequencies were 0.2366 and 0.0408 in patient group and control, respectively). Our results indicate a significant association between HLA-Bw61 and the asthmatic patients of Han nationality in Shenyang area, North-east China.

Adolescent↗
PubMedDate not supplied

HNF1 is critical for the liver-specific function of HBV enhancer II.

Hepatitis B virus (HBV) is a hepatotropic virus and its gene expression is highly liver-specific. It has been reported that the function of enhancer II (ENII) and the core and the core promoter (Cp) of HBV has a hepatocyte preference. To understand the effects of liver-specific nuclear factors on ENII, in this report, hepatocyte nuclear factor 1 (HNF1) was investigated for its possible action on ENII function. It was found that HNF1 transactivates ENII/Cp in HeLa cells, and antisense HNF1 suppresses it in HepG2 cells. Deletion analysis revealed that the B element of ENII is the target region responsible for the regulation of HNF1. Sequence alignment suggested the presence of the potential HNF1 binding sites in the B element of ENII. The results of electrophoresis mobility shift assay indicated that the B2 region could specifically bind a GST-HNF1 fusion protein and could compete with binding of HNF1 to the consensus motif in the rat beta-fibrinogen promoter, suggesting that the major binding site of HNF1 is located in the B2 region. Our results demonstrate that HNF1 is one of the important regulatory factors for the liver-specific function of HBV and that it transregulates ENII activity via direct binding to B2.

Animals↗
PubMedDate not supplied

Colonic motility diagnosis based on colonic pressure.

Manometry of the alimentary tract is a valuable and widely used means to evaluate and diagnose the function of the alimentary tract. However, the measurement can be inconvenient due to the invasive method used, and the many factors affecting results. Research on colonic pressure data is even more insufficient. This paper deals with colonic pressure data via an improved method ensuring that pressure data of the whole colon is available. The data is analysed based on the learning vector quantization (LVQ) method. Testing results show that this method distinguishes the normal data and the abnormal data, consistently with the original diagnoses. This method can serve as an assistant diagnosis of colonic motility and contributes to further research on colonic motility based on pressure data.

Adolescent↗