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Biomedical subjects

W He

Publications and source records attributed to W He.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Determination on the glycosyl sequence of gypenoside A by TLC-FABMS].

The glycosyl sequence of gypenoside A (A) isolated from Gynostemma pentaphyllum Makino was determinated by TLC-FABMS. The gypenoside A was hydrolysed with cellulase and the hydrolysate showed eight spots on a TLC plate, and the FABMS analysis of these spots indicated they corresponded to gypenoside A, A-Rham, A-Glu, A-Rham-Glu, A-Rham-Glu, A-Glu-Glu, A-Rham-2Glu, A-Rham-2Glu in order. Two chains can be determined to be Rham-Glu, and Glu-Glu, respectively. So the glycosyl sequence of gypenoside A was identical of gypenoside XLIII.

Chromatography, Thin Layer↗
PubMed1997

[IR study on the thermal decomposition of trinuclear and tetranuclear iron benzoate complexes].

The title complexes shown as [Fe3O(C6H5COO)6(H2O)]Cl x 1.5H2O and [Fe4O2 (C6H5COO)7(bipy)2]ClO4 x 3.5H2O were prepared. Their thermal decomposition process was studied qualitatively and quantitatively by means of thermogravimetric analysis and infrared spectroscopic measurement of samples after heating at different temperatures. From the experimental results, the possible thermal decomposition process of the two compounds can be deduced. Additionally, according to the fact that the nu(as) (COO) of the two compounds decreases while the nu(s) (COO) remains unchanged as the heating temperature increases. It can be drawn that the carboxylate coordinative form possible change from bridged to chelate one.

English Abstract↗
PubMed1997

[Application of T1-weighted images by contrast-enhanced frequency-selective presaturation in magnetic resonance imaging].

In this study contrast-enhanced frequency-selective presaturation T1-weighted images and contrast-enhanced spin echo T1-weighted images in 32 cases were detected and analysed comparatively regarding enhancing lesions and the signal intensity of enhancing lesions. The results showed that in the signal intensity of enhancing lesion, the contrast enhanced frequency-selective presaturation T1-weighted images showing high sign were greater than contrast-enhanced spin echo T1-weighted images. The former was better than the later in accurate evaluation of the margin, size and the differential diagnosis of enhancing lesion, especially in the regions containing more fat and bone marrow.

Bone Diseases↗
PubMed1996

Interaction of insulin receptor substrate-2 (IRS-2) with the insulin and insulin-like growth factor I receptors. Evidence for two distinct phosphotyrosine-dependent interaction domains within IRS-2.

Insulin receptor substrate 2 (IRS-2) has recently been shown to be a substrate of the insulin receptor (IR). In this study we utilize the yeast two-hybrid system and assays of in vitro interaction to demonstrate that IRS-2 interacts directly with the IR and the insulin-like growth factor I receptor. We show that, like IRS-1, the region of IRS-2 that contains the putative phosphotyrosine binding and SAIN elements (188-591) is sufficient for receptor interaction and that this interaction is dependent upon the NPX(p)Y (where (p)Y is phosphotyrosine) motifs within the juxtamembrane domains of the receptors. In addition to this amino-terminal NPX(p)Y-binding domain, an additional domain of strong interaction was identified in the central region of IRS-2 and was localized between amino acids 591 and 733. This interaction was found to be dependent upon receptor phosphorylation but was NPX(p)Y-independent. This region does not appear to have either an SH2 or a phosphotyrosine binding domain. Both of the interactions could also be demonstrated in vitro using IRS-2 glutathione S-transferase fusion proteins. We conclude that IRS-2, unlike IRS-1, can interact with tyrosine-phosphorylated receptors such as the IR and insulin-like growth factor I receptor via multiple independent binding motifs. Our findings suggest the existence of a previously unidentified phosphotyrosine-dependent binding domain within the central region of IRS-2.

Animals↗
PubMed1996

Intravenous somatic gene transfer with antisense tissue factor restores blood flow by reducing tumor necrosis factor-induced tissue factor expression and fibrin deposition in mouse meth-A sarcoma.

Fibrin is deposited on the endothelial cell surface in the vasculature of murine methylcholanthrene A-induced sarcomas after injection of tumor necrosis factor (TNF). Capillary endothelial cells of the tumor vascular bed become positive for tissue factor after TNF injection, based on immunocytochemistry and in situ hybridization. Intravascular clot formation was not dependent on tissue factor derived from tumor cells, since in vessels of tumors not expressing tissue factor, TNF also induced fibrin/fibrinogen deposition. However, the time course of fibrin/fibrinogen deposition after TNF differed in tumors expressing no, little, or greater amounts of tissue factor. Fibrin/fibrinogen deposition was more rapid in tumors in which the neoplastic cells expressed tissue factor than in tumors not expressing tissue factor. In the tumors not expressing tissue factor, activation of coagulation was dependent on TNF-induced synthesis of tissue factor by host cells, i.e., endothelium or monocytes/macrophages. Intravenous somatic gene transfer with tissue factor cDNA in the antisense orientation (but not sense or vector alone) reduced intravascular fibrin/fibrinogen deposition and restored blood flow to the tumor, showing that de novo tissue factor expression is central in TNF-induced activation of the coagulation mechanism.

Animals↗
PubMed1996

A phase II study of recombinant human interferon-alpha 2a and zidovudine in patients with AIDS-related Kaposi's sarcoma. AIDS Clinical Trials Group.

To assess safety, antitumor response, and immunological and virological activity of interferon-alpha 2a and zidovudine combination therapy in patients with AIDS-related Kaposi's sarcoma, we conducted an open-label, Phase II, multicenter study. Sixty-three patients with biopsy-proven Kaposi's sarcoma and no previous interferon-alpha therapy received zidovudine 600 mg/day and interferon-alpha 2a 18 x 10(6) U/day. The median duration of follow-up was 49 weeks. Of 62 evaluable patients, 25 (40%; 95% confidence interval, 0.28-0.52) showed a complete (26%) or partial (15%) antitumor response. Eight of 30 patients (27%) with < 100 CD4 cells/mm3 and 17 of 32 patients (53%) with > or = 100 CD4 cells/mm3 had a response. The median time to response was 36 weeks. Of the 25 patients with a response, four developed tumor progression. The median duration of response was 22.4 weeks. Eight patients (13%) developed another AIDS-defining event and 13 (21%) died. The major toxicities included anemia (16%), neutropenia (27%), elevated serum transaminases (16%), weight loss (16%), malaise (14%), fatigue (14%), fever (10%), and headache (6%). Therapy with intermediate-dose interferon-alpha 2a and zidovudine resulted in tumor regression in patients with AIDS-related Kaposi's sarcoma who had a wide range of CD4 cell counts; this therapy was relatively well tolerated.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Rapid-processing procedure for heat polymerization of polymethyl methacrylate in a pressure cooker with automatic controls.

This study introduces a new rapid-processing procedure for curing polymethyl methacrylate denture base resin in an automatically controlled pressure cooker. The cooker filled with water was inflated with 6 kgf/cm2 air pressure and heated to 120 degrees C (248 degrees F) and maintained for 10 minutes. No significant differences were found between the new pressure cooker method and the conventional method for surface hardness and porosity (p > 0.05). The pressure cooker significantly shortened polymerization time, and the polymerization is controlled automatically.

Air Pressure↗
PubMed1996

T and B lymphocytes reacting with the extracellular loop of the beta 2-adrenergic receptor (beta 2AR) are present in the peripheral blood of patients with myasthenia gravis.

Eighteen percent of patients with myasthenia gravis (MG) have serum antibodies against a synthetic peptide corresponding to the second extracellular loop of the human beta 2AR (residues 172-197). In this study we examined T and B cell responses to the peptide, using assays to detect individual cells secreting interferon-gamma (IFN-gamma) and IL-4 or antibodies against the peptide, and by measuring thymidine incorporation in response to the peptide. The peptide from the beta 2AR induced cytokine secretion from blood mononuclear cells in 67% of MG patients, compared with 14-28% of the control groups. Cells secreting antibodies binding to the peptide were present in 54% of MG patients and in 19-28% of controls. The numbers of beta 2AR-reactive cells were higher in MG patients than in controls. Peptide-induced increase in thymidine incorporation in cells was also more frequently demonstrated in patients (26%) compared with controls (about 10%). Activation of cells was dependent on monocytes and on MHC class II DR antigen. Based on the pattern of the cytokine secretion induced, beta 2AR-reactive T cells comprise both T helper type-1 and type-2 subsets. In addition, control peptide-reactive T and B cells were much less frequently demonstrated in the patients, and the number of such cells did not differ between the groups. Our results show that beta 2AR-reactive cells are present in most patients with MG. Such autoreactive antibodies and cells might play a role in the pathogenesis of the disease by influencing the function of skeletal muscle and immune systems.

Adolescent↗
PubMed1996

Laboratory investigation of ecological factors influencing the environmental presence of Burkholderia pseudomallei.

Factors like temperature, pH value, water content in soil, and ultraviolet rays that might have influence on the survival of environmental Burkholderia pseudomallei strains were evaluated. Data showed that the optimal temperature and pH value for B. pseudomallei were 24 C to 32 C and 5 to 8, respectively. Water content in soil of less than 10% brought about the death of the bacteria within 70 days, while water content of more than 40% maintained bacteria life for 726 days. The bacteria were easily killed by ultraviolet rays at 465 mu W/cm2 for 7.75 min while other permanent soil bacteria were killed at 1,860 mu W/cm2 for 31 min. From these results, it could be concluded that proper temperature, enough water in soil, and suitable soil pH might be the three major ecological conditions governing the environmental presence of B. pseudomallei.

Burkholderia pseudomallei↗
PubMed1996

Asymptomatic and late-onset ornithine transcarbamylase (OTC) deficiency in males of a five-generation family, caused by an A208T mutation.

In a large five-generation Polish family, late-onset ornithine transcarbamylase (OTC) deficiency in males segregated with the missense mutation Ala208Thr (A208T), and all heterozygous females were asymptomatic. No other mutations were found in the coding sequences and intron-exon boundaries of the OTC gene. Surprisingly, the mutation originated from the great-grandfather of the index patient who died at age 59 of liver carcinoma. He never had dietary restrictions or hyperammonemic spells throughout life and appears to be the oldest male reported with OTC deficiency. The index patient had a severe OTC deficiency (3% of normal). Eight males died suddenly at ages 4 months to 23 years (average 14 years) after a foudroyant episode triggered by a common infection. The patients remained undiagnosed for 28 years because a metabolic defect was not considered to be the cause of the acute episodes. Recognition of the familial pattern of inheritance was initially unnoticed since the patients were admitted to eight different hospitals. DNA analysis predicted that two 'healthy' boys also had OTC deficiency, which was confirmed by abnormal results of allopurinol challenge tests. Initial suspicion of OTC deficiency in such families is complicated, since symptoms can develop at any age, or even remain absent. This obscures the typical pattern of X-linked inheritance in small families.

Age of Onset↗
PubMed1996

Sequencing, distribution, and inactivation of the dipeptidase A gene (pepDA) from Lactobacillus helveticus CNRZ32.

Previously, the gene for a general dipeptidase (pepDA) was isolated from a gene bank of Lactobacillus helveticus CNRZ32. The pepDA gene consists of a 1,422-bp open reading frame which could encode a polypeptide of 53.5 kDa. No significant identity was found between the deduced amino acid sequence of the pepDA product and the sequence for other polypeptides reported in GenBank. Southern hybridization studies with a pepDA probe indicated that the nucleotide sequence for pepDA is not well conserved among a variety of lactic acid bacteria. Growth studies indicated that a pepDA deletion had no detectable effect on growth rate or acid production by L. helveticus CNRZ32 in milk. Furthermore, no difference in total cellular dipeptidase activity was detected between the mutant and wild-type strains during logarithmic growth in MRS medium.

Amino Acid Sequence↗
PubMed1996

Child malnutrition in China--present status and changing trend.

Halving the malnutrition of under five of years has been set as one of the goals to be achieved by the year of 2000 by Chinese government. So it is important to know the present status of child malnutrition and its trend of changing, in order to predict the possible outcome of the achievement of the goal. According to the Child Survey carried out by the State Statistic Bureau (SSB) in 26 provinces and autonomous regions and 3 municipalities in 1992, the prevalence of malnutrition of under five was: moderate and severe underweight, stunting and wasting were 17.9%, 34.7% and 4.7% respectively. But there are significant differences among urban and rural children and between different provinces. The highest prevalence rate usually occurred in the second year of life of the children, and this may be the result of inadequate weaning food provided to the children. As compared with the data collected in 1987 by SSB in 9 provinces and autonomous regions, an impressive improvement in underweight has occurred within these 5 years. The average declined prevalence was 20.5%. It is specially true for urban children. To stunting, there was also improvement for urban children but not in the rural, resulting and over all increasing of prevalence by 5.9%. To wasting, the prevalence for urban children was low and remained at the same level while there was some what increase in the rural. So, according to these results, with constant economic development and more attempt made in areas and groups at risk, the goal to decrease malnutrition in half in terms of underweight could be reached by the year of 2000.

Body Height↗
PubMed1996

[Mitral valve replacement under beating heart in 137 cases].

To avoid damage of myocardial ischemia, myocardial hypoxia and reperfusion injury, we designed mitral valve replacement in beating heart under extracorporeal circulation with low dose temperature of 31 degrees C to 35 degrees C in 137 cases of rheumatic heart disease, congenital heart disease mitral stenosis and mitral insufficiency, or concurrent aortic insufficiency. The patients were rept in unblocking aorta, unfilling cardiac arrest perfusion, idle pulse and dradycardia of 40-50 times/min, nose temperature of 32 +/- 1 degrees C. Patients with concurrent aortic insufficiency should first undergo replacement of aorta under cold cardiac arrest and then replacement mitral valve under beating heart to reduce the time of cold heart ischemia. Plastic surgery for tricuspid valve was done under beating heart. Good postoperative prognosis was nated: an average arterial pressure of 9.5-10.5 kPa (70 to 80 mmHg), dose of dopamine was obviously reduced. No low cardiac output syndrome, acute renal failure and severe arrythmia were observed in 137 cases, except 4 deaths due to infection and blood coagulation (2.9%). A left cardiac chamber no-level air removal device and aorta perfusioner leading flow device were designed for exsufflation of left pneumatocardia.

Adolescent↗