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Biomedical subjects

Wei He

Publications and source records attributed to Wei He.

At least 91 records · Page 5Linked to original sources
PubMed2005

Trends in hospitalization and mortality for subarachnoid hemorrhage and unruptured aneurysms in the United States.

OBJECTIVE: During the past decade, endovascular obliteration of intracranial aneurysms and new treatments for vasospasm and cerebral ischemia have been introduced. To analyze the effectiveness of these new strategies, we evaluated changes in morbidity and mortality rates in patients at least 18 years of age who were hospitalized for ruptured and unruptured intracranial aneurysms during the past 16 years. METHODS: National estimates of hospitalization for subarachnoid hemorrhage (SAH) and unruptured intracranial aneurysms and associated in-hospital outcomes and mortality were obtained from National Hospital Discharge Survey data. All the variables pertaining to hospitalization were compared for three distinct time periods: 1986-1990, 1991-1995, and 1996-2001. RESULTS: There were 94,692, 104,746, and 133,269 admissions for SAH during the periods 1986-1990, 1991-1995, and 1996-2001, respectively. Mortality rates for hospitalizations related to SAH demonstrated no significant change in mortality during the periods 1986-1990, 1991-1995, and 1996-2001 (27.6%, 24.6%, and 26.3%, respectively. Procedures performed for SAH from 1996 to 2001 included surgical clipping (28%), endovascular/wrapping (2%), and no procedure (70%). The number of admissions for unruptured intracranial aneurysms was 23,481 from 1986 to 1990, 28,017 from 1991 to 1995, and 51,904 from 1996 to 2001. There was an overall trend (P = 0.07) toward reduced in-hospital mortality during the three periods: 5.9%, 6.3%, and 1.4% for 1986-1990, 1991-1995, and 1996-2001, respectively. CONCLUSION: The mortality rate for unruptured intracranial aneurysms demonstrates a significant trend of reduction during the past 16 years. The mortality rate for SAH demonstrates limited change during the same period; it is presumed that this is attributable to the multitude of factors that influence outcome.

Adolescent↗
PubMed2005

Construction of a novel kind of expression plasmid by homologous recombination in Saccharomyces cerevisiae.

Based on a previously used plasmid pHC11, a new plasmid pHC11R was constructed. Cutting plasmid pHC11R with proper restriction enzymes, the resulting larger DNA fragment pHC11R' was co-transformed with a PCR amplified expression cassette of human IFNalpha2b into yeast. By means of the homologous sequences at both ends of two DNA fragments, a novel expression plasmid pHC11R-IFNalpha2b was formed via homologous recombination in the yeast. Compared with pHC11-IFNalpha2b, the expression plasmid pHC11R-IFNalpha2b was smaller in size and in absence of antibiotic resistant gene. The stability and copy number of pHC11R-IFNalpha2b were greatly increased and the expression level of heterologous protein was improved. As the derivatives of pHC11R, a series of recombination expression vectors pHRs containing different combination of expression elements were developed. This led to a rapid and powerful method for cloning and expressing of different genes in yeast.

Escherichia coli↗
PubMed2005

Investigation of elemental content distribution in femoral head slice with osteoporosis by SRXRF microprobe.

A synchrotron radiation X-ray fluorescence microprobe analysis technique was used to scan a slice of the femoral head from its periphery to its center, via cartilage, compact, and spongy zones in order to determine the distribution and the way inorganic substances are lost in bone tissue. The sample preparation and experimental apparatus are described in detail. The quantitative computerized tomography of elemental distribution, such as Ca, P, K, Fe, Zn, Sr, and Pb in bone slice tissue, including cartilage, substantial compact, and substantial spongy, is investigated. Combined with the correlation among P, K, Zn, Sr, and Ca, the route of loss of minerals and the physiological functions of some metal elements in bone are also discussed.

Adult↗
PubMed2005

[Effect of change of plasma K+ and pH value induced by exercise on muscle fatigue and surface EMG].

OBJECTIVE: This study was undertaken to explore the relationship between plasma K+, H+ and muscle fatigue as well as electromyogram changes. METHODS: Fourteen male students enrolled as the subjects of this study performed two exercise tests of different intensity (200 W; 120 W) on a cycle ergometer till being fatigued. The plasma K+, pH value and electromyography (EMG) of active and inactive muscles during 10 s isometric contraction fixed load were measured before exercise and at 0, 5, 10, 20 minutes after exercise. RESULTS: Both plasma K+ and mean power frequency (MPF) of the active muscles changed significantly (P<0.01) after exercise, but recovered in 20 minutes and were highly negatively correlated. Plasma pH at 20 minutes after 200 W exercise was significantly lower than that at rest (P<0.01), but did not change after 120 W exercise, and no correlation was found between pH and EMG. Integral electromyography (IEMG) of inactive muscles at 20 minutes after 120 W exercise was significantly lower than that at rest (P<0.05). CONCLUSION: The results showed that high extra cellular K+ concentration for exercise is one of the main factors inducing fatigue and MPF decrease of the active muscles as well as IEMG decrease of the inactive muscle, but H+ is not a main factor for fatigue and it has no direct effect on EMG.

Adult↗
PubMed2005

[Ultrasound-mediated gene delivery].

Recently there have been increasing interests in ultrasound-mediated gene delivery techniques. This paper reviews the general concept of sonoporation, the effect of contrast agents, and the in vitro and in vivo applications of such techniques. Factors which contribute to the efficiency of gene delivery were also discussed. The technology is promising and has great potential in targeted drug delivery and gene delivery applications.

DNA↗
PubMed2005

[Construction of a large human scFv library against SARS virus].

AIM: To construct a large human scFv library against SARS virus by using in vivo recombination. METHODS: Total RNA was isolated from the lymphocytes of 6 patients recovered from SARS. mRNA was isolated and reverse transcribed into cDNA. The V(H) and V(L) fragments were amplified from the cDNA and then assembled into scFv genes. The scFv genes were amplified and ligated into phagemid pDAN5. The primary library was constructed by transforming the recombinant phagemid into E.coli TG1. The secondary library was generated by in vivo recombination in E.coli BS1365 following the infection of BS1365 by primary library phages. RESULTS: A primary library of 3x10(9) and a second library of 3x10(11) were constructed. CONCLUSION: A large human scFv library against SARS virus with good diversity was constructed, which may be used for screening antibodies to SARS virus antigens.

Antibodies, Viral↗
PubMed2005

[Judd-Ofelt spectral theory].

In this article, the development and application of Judd-Ofelt spectral theory(J-O theory) was reviewed briefly. J-O theory was used to analyze the absorption and emission spectra of rare earth ions in solids, and compute their transition probabilities, line strengths, energy lifetimes, emission cross sections, and so on. When J-mixing was considered in J-O theory, the theoretical and experimental results were more consistent. The spectra of Pr3+ can be analyzed relatively accurately with modified J-O theory. The spectral properties of anisotropic crystal can be analyzed from the unpolarized-light transmission spectrum of a quadratic sample without special-orientation processing. The overlapped absorption bands can be treated as one band approximatively. The J-O parameters can also be calculated with fluorescence lifetimes.

Algorithms↗
PubMed2005

[The effect of macrophage colony stimulating factor on laryngeal cancer Hep-2 cell line].

OBJECTIVE: To investigate the possible role of M-CSF and its receptor in the laryngeal carcinoma Hep-2 cell line. METHOD: Cell proliferation was assayed by MTT analysis and [3H] thymidine incorporation, after Hep-2 cell line culturing with M-CSF and M-CSFR. M-CSF concentration of surpernatant measured by a ELISA technique. Immunohistochemistry was performed on Hep-2 cell line and laryngeal carcinoma tissue. RESULT: The concentration of M-CSF increased after cell culturing. M-CSF can reduced the Hep-2 cell count. The action can be blocked by Anti-M-CSFR. CONCLUSION: Our observations support the hypothesis that M-CSF may inhibit the growth and differentiation in Hep-2 cell line.

Carcinoma, Squamous Cell↗
PubMed2005

[Expression and significance of cyclin D1 in human adenoid cystic carcinoma].

OBJECTIVE: To observe the expression of cyclin D1 in human adnoid cystic carcinoma and its correlation with clinical characters. METHODS: The expression of cycline D1 was evaluated with immunohistochemical method in forty-one cases of human adnoid cystic carcinoma, 15 cases of PA and 12 cases of normal salivary gland tissue. RESULTS: The expression of cyclin D1 in normal tissue was negative, significantly different from PA and ACC (P < 0.05). The expression level of PA was significantly lower than ACC (P < 0.05). High expression of cyclin D1 was correlated with clinical stage and histological classification (P < 0.05), but not with sex, age, tumor site, recurrence, metastasis. CONCLUSION: High expression of cyclin D1 promotes the formation and development of ACC.

Carcinoma↗
PubMed2005

[Lactase and its gene regulation in BALB/c mice at different ages].

OBJECTIVE: In order to clarify the trend of change in lactase and its gene regulation pattern, the authors determined the lactase activities and mRNA levels in BALB/c mice at different ages. METHODS: The lactase activities and mRNA levels of the 3-, 5-, 7-, 9- week old mice were determined by the modified method of Dahlqvist and in situ hybridization respectively. RESULTS: The 3 wk old mice had the highest lactase activities, to the contrary, the 9 wk old mice had the lowest lactase activities. Meanwhile, the lactase mRNA levels displayed no diversities. CONCLUSION: The mice had higher lactase activities before weaning, but significantly very low activities after weaning. These findings indicate that BALB/c mice have the same adult-type hypolactasia as human. No statistically significant difference in lactase mRNA levels between the 4 age-groups implies that lactase gene is regulated at the translational and/or post-translational levels, but not at the transcriptional level.

Age Factors↗
PubMed2005

[Calcium antagonistic effect of Xanthotoxol on isolated guinea pig atria].

OBJECTIVE: To study the mechanism of depressant effect of xanthotoxol (XT) on contractility in the isolated guinea pig atria. METHODS: The contractile force of the isolated left atria was determined by tension recording method. RESULTS: In the experiments on contractility of the left atria XT and Verapamil (Ver) significantly depressed the positive staircase phenomena, which was reversed by Ver but not by XT. However, the post-rest potentiation of myocardial contraction in the left atria was only markedly decreased by XT but not by Ver. Furthermore, XT not only attenuated the positive inotropic action, but also delayed the following toxicity response induced by ouabain in the isolated left atria. CONCLUSION: XT blocked not only the voltage dependent calcium channel, but also the receptor operated calcium channel in the isolated guinea pig atria.

Animals↗
PubMed2005

[Effect of Panax notoginseng saponins on intercellular adhesion molecule-1 expression and neutrophil infiltration in cerebral infarction tissue of rats].

OBJECTIVE: To investigate the effect of Panax notoginseng saponins (Pns) on the expression of intercellular adhesion molecule-1 (ICAM-1) and brain neutrophil infiltration induced by transient focal cerberal ischemia and reperfusion in rats. METHODS: Focal cerebral ischemia-reperfusion model in rats (male) were made by transient occlusion of the middle cerebral artery (MCA) for 2 h followed by 24 h reperfusion. Pns 25 and 50 mg/kg were administered ip at 2 h after reperfusion. At 24 h after reperfusion, neutrophil infiltration and the expression of intercellular adhesion molecule-1 (ICAM-1) were measured with myeloperoxidase (MPO) activity, and immunohistochemistry, respectively. RESULTS: After ischemia reperfusion, the expression of ICAM-1 and MPO activity in the ischemic hemisphere cortex of MCA area and caudate putamen were markedly increased. Treatment with 50 mg/kg Pns inhibited neutrophil infiltration and the expression of ICAM-1. CONCLUSION: Pns inhibited neutrophil infiltration and the expression of ICAM-1 following focal cerebral ischemia-reperfusion in rats, attenuated the ischemic brain inflammation.

Animals↗
PubMed2005

[Research on extracting process for Fengshitongbi capsules].

OBJECTIVE: The optimal extraction technology of Fengshitongbi capsule was investigated in this study. METHODS: Orthogonal tests were employed for optimum of extraction technology, the determination of the contents of Chlorogenic acid and Sinomenine were gained by HPLC and TLC-scanning respectively. RESULTS: Six volume of water,extracting 3 times with half an hour each time, and seven volume of 70% ethanol, extracting two times with one and a half hour each time were considered the optimum extraction technology of Flos Lonicerae and Caulis Sinomenii as well as Rhizoma Smilacis Glabrae respectively. CONCLUSION: The considerable extraction rate of active components in the drugs is achieved by applying the selected technology.

Capsules↗
PubMed2005

Thrombolysis for ischemic stroke in the United States: data from National Hospital Discharge Survey 1999-2001.

OBJECTIVE: Although some data regarding the use of thrombolysis are available from community-based studies, national estimates of the use of thrombolysis for ischemic stroke are not available. We performed this study to determine the frequency of thrombolysis for ischemic stroke in the United States and associated in-hospital outcomes. METHODS: National estimates of thrombolysis, associated in-hospital outcomes, and mortality were obtained from National Hospital Discharge Survey data from 1999 to 2001. Patient numbers and frequency distributions were calculated for a nationally representative sample of patients hospitalized with a primary diagnosis of ischemic stroke. Thrombolysis was further stratified into thrombolysis with (intra-arterial) or without (intravenous) cerebral angiography. RESULTS: There were 1,796,513 admissions for ischemic stroke between 1999 and 2001. Of these admitted patients, 1,314 (0.07%) underwent intra-arterial thrombolysis and 11,283 (0.6%) underwent intravenous thrombolysis. The days of hospitalization (mean +/- standard deviation) were significantly higher for patients admitted with ischemic stroke treated with intra-arterial thrombolysis (10.7 +/- 4.8) or intravenous thrombolysis (7.1 +/- 3.6) compared with non-thrombolytic admissions (5.4 +/- 5.7). We observed a trend toward a higher frequency of use of intravenous and intra-arterial thrombolysis and hospitals with greater number of beds (P < 0.01). The mortality rates for hospitalizations were not significantly different for admissions with ischemic stroke treated with intra-arterial or intravenous thrombolysis compared with other ischemic strokes. The rates of discharge to home after hospitalizations were significantly lower for patients treated with intravenous thrombolysis (19.8%) compared with those not treated with thrombolysis (53.1%). CONCLUSION: The present study provides national estimates of patients undergoing thrombolysis for ischemic stroke. Further efforts need to be made to increase the proportion of patients with ischemic stroke who receive thrombolysis in the United States.

Aged↗
PubMed2005

Distinct pattern of human Vdelta1 gammadelta T cells recognizing MICA.

Gammadelta T cells represent one unique recognition pattern, the limited recognition, which distinguishes from the specific recognition for alphabeta T cells and pattern recognition for macrophages. Vdelta1 gammadelta T cell is the major subset of human gammadelta T cells, which predominates in mucosal tissue including the intestinal epithelia. Presently, a few antigens that human Vdelta1TCR can recognize have been identified. Among them, MHC class I chain-related molecules A (MICA) have been studied most intensively. Besides Vdelta1TCR, MICA is also the ligand of NKG2D, a C-type lectin-like activating immunoreceptor. In human, only Vdelta1 cells can simultaneously express both types of receptors of MICA while NK cells, alphabetaT cells and other subsets of gammadelta T cells likewise express NKG2D. Although the precise mechanisms are still enigmatic, this distinct pattern of Vdelta1 cells recognizing MICA predicts unique biological significance of Vdelta1 cells in immune defense. Recent years, some progresses have been made in this issue. In this review we summarize the related reports and put forward some novel views based on our group's studies.

Animals↗
PubMed2005

[Cloning and preparation of cDNA probe from BAlb/c mice].

OBJECTIVE: Lactase gene Lac isolated from BALB/c mice was sequenced, in order to clarify the characteristics of its encoding product and prepare the cDNA probe for further researches on Latose Intolerance by in situ experiment. METHODS: A total RNA was isolated by Trizol kit from the small intestine of 4wk old BALB/c mice, then its cDNA was obtained by RT-PCR, etc. After sequencing, the cDNA sequence was submitted to NCBI GenBank. Then a prediction of the characteristics of its deduced protein was made by bioinformatics. The The cDNA coding preparation of the cDNA probe was carried out by the method of random primer. RESULTS: The cDNA coding sequence was possessed of 912 bp, encoding 303 amino acids residues. In the secondary structure of its deduced product, there existed a motif of glycosyl-hydro-F1-1 located between the amino acid residues 121-129, and there was a transmembrane helicers at the C-terminal. CONCLUSION: The Lac gene thus obtained is lactase gene authentically; its deduced protein product is lactase.

Animals↗
PubMed2005

Unraveling the mystery of gammadelta T cell recognizing lipid A.

Traditionally, the materials which are regarded as antigens recognized by gammadelta T lymphocytes are protein and carbohydrate, not nucleic acid or lipid. Recently, it has been demonstrated that gammadelta T cells can recognize lipid A and directly induce immune responses that involve CD1 (cluster of differentiation type 1) family and Toll like receptors (TLRs). This is a review about the interacting-mechanism, immunological effect and clinical application of them.

Animals↗