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Min He

Publications and source records attributed to Min He.

At least 37 records · Page 2Linked to original sources
PubMed2005

SpA: web-accessible spectratype analysis: data management, statistical analysis and visualization.

SUMMARY: SpA is a web-accessible system for the management, visualization and statistical analysis of T-cell receptor spectratype data. Users upload data from their spectratype analyzers to SpA, which saves the raw data and user-defined supplementary covariates to a secure database. The statistical engine performs several data analyses and statistical summaries. The visualization engine displays spectratype histograms in a Java applet and in an image file suitable for download. All of these results are also saved to the database and remain accessible to the user. Additional statistical tools specific to the analysis of multiple spectratypes are also available through the SpA interface. AVAILABILITY: The service is freely accessible via the web at http://www.duke.edu/~kepler/spa.html. Additional technical support and specialized statistical analysis and consultation are available by arrangement with the authors and, depending on the service requested, may be subject to fee.

Animals↗
PubMed2005

Statistical analysis of antigen receptor spectratype data.

MOTIVATION: The effectiveness of vertebrate adaptive immunity depends crucially on the establishment and maintenance of extreme diversity in the antigen receptor repertoire. Spectratype analysis is a method used in clinical and basic immunological settings in which antigen receptor length diversity is assessed as a surrogate for functional diversity. The purpose of this paper is to describe the systematic derivation and application of statistical methods for the analysis of spectratype data. RESULTS: The basic probability model used for spectratype analysis is the multinomial model with n, the total number of counts, indeterminate. We derive the appropriate statistics and statistical procedures for testing hypotheses regarding differences in antigen receptor distributions and variable repertoire diversity in different treatment groups. We then apply these methods to spectratype data obtained from several healthy donors to examine the differences between normal CD4+ and CD8+ T cell repertoires, and to data from a thymus transplant patient to examine the development of repertoire diversity following the transplant.

Algorithms↗
PubMed2005

Reagent anions for charge inversion of polypeptide/protein cations in the gas phase.

Various reagent anions capable of converting polypeptide cations to anions via ion/ion reactions have been investigated. The major charge inversion reaction channels include multiple proton transfer and adduct formation. Dianions composed of sulfonate groups as the negative charge carriers show essentially exclusive adduct formation in converting protonated peptides and proteins to anions. Dianions composed of carboxylate groups, on the other hand, show far more charge inversion via multiple proton transfer, with the degree of adduct formation dependent upon both the size of the polypeptide and the spacings between carboxylate groups in the dianion. More highly charged carboxylate-containing anions, such as those derived from carboxylate-terminated polyamidoamine half-generation dendrimers show charge inversion to give anion charges as high in magnitude as -4, with the degree of adduct formation being inversely related to dendrimer generation. All observations can be interpreted on the basis of charge inversion taking place via a long-lived chemical complex. The lifetime of this complex is related to the strengths and numbers of the interactions of the reactants in the complex. Calculations with model systems are fully consistent with sulfonate groups giving rise to more stable complexes. The kinetic stability of the complex can also be affected by the presence of electrostatic repulsion if it is multiply charged. In general, this situation destabilizes the complex and reduces the likelihood for observation of adducts. The findings highlight the characteristics of multiply charged anions that play roles in determining the nature of charge inversion products associated with protonated peptides and proteins.

Algorithms↗
PubMed2005

[Therapeutic effect of far lateral approach on the lesions located ventral to cranial-cervical junction].

OBJECTIVE: To investigate the administration of far-lateral approach in lesions located anterior or anterolateral to brain stem and upper cervical spinal cord. METHODS: Twenty-three patients underwent far lateral approach, including 12 retrocondylar approach, 5 partial transcondylar approach, 3 transfacetal and partial transcondylar approach, 2 transtubercular approach and 1 complete transcondylar approach. RESULTS: Total tumor removal was achieved in 15 patients, subtotal removal in 5 patients, 3 vertibral artery aneurysms were clipped successfully, 3 patients were given occipitalcervical fusion. There was no operative mortality. The most frequent complications were lower cranial nerve deficit, CSF leakage, injury to vertibral artery, and ischemia of brain stem, cerebellum or spinal cord. No patient presented clinical instability of the occipitocervical junction after surgery. CONCLUSIONS: The far-lateral approach is an ideal approach to structures located ventral to cranial-cervicle junction. But some of the surgical steps are technically difficult and carry some degree of risk. The choice of approach depends on the pathological feature and degree of exposure required for effective surgical treatment. Bone removal should be quantified for individual lesion. The approach may be limited to less aggressive steps, while still achieving significant exposure and surgical space.

Adolescent↗
PubMed2005

Targeted biomarker detection via whole protein ion trap tandem mass spectrometry: thymosin beta4 in a human lung cancer cell line.

N-Terminally acetylated thymosin beta4, a species implicated for use as a cancer biomarker, was identified in a human lung cancer cell line using ion trap tandem mass spectrometry at the whole protein level. Ion-ion proton transfer reactions were used for parent ion concentration/manipulation and to simplify interpretation of product ion spectra. Dissociation data for the +6 to +3 charge states are reported. As is usually the case, structural information available from the ion trap collisional activation of the protein is sensitive to parent ion charge state. Each parent ion charge state selected, however, provided sufficient information to make a confident identification. Furthermore, each charge state provided relatively rich fragmentation. Therefore, any of the charge states can be used to detect with high specificity thymosin beta(4) in a complex protein mixture. There are advantages associated with the rapid detection of protein biomarkers at the whole protein level, as opposed to the peptide level following protein digestion, particularly for relatively small protein and polypeptide biomarkers. Having identified and characterized the protein, product ion spectra obtained directly, without recourse to ion-ion proton transfer reactions, can be used for library matching. However, ion-ion proton transfer reactions for parent ion concentration and charge state purification are advantageous in addressing relatively complex mixtures.

Amino Acid Sequence↗
PubMed2005

Proteomic profiling in the sera of workers occupationally exposed to arsenic and lead: identification of potential biomarkers.

Arsenic (As) and lead (Pb) are important inorganic toxicants in the environment. Frequently, humans are exposed to the mixtures of As and Pb, but little is known about the expression of biomarkers resulting from such mixed exposures. In this study, we analyzed serum proteomic profiles in a group of smelter workers with the aim of identifying protein biomarkers of mixed As and Pb exposure. Forty-six male workers co-exposed to As and Pb were studied. Forty-five age-matched male office workers were chosen as controls. Urine As and blood Pb concentrations were determined. Serum proteomic profiles were analyzed by Surface-Enhanced Laser Desorption/Ionization Time-Of-Flight (SELDI-TOF) mass spectrometer on the WCX2 ProteinChip. Using Recursive support vector machine (RSVM) algorithm, a panel of five peptides/proteins (2097 Da, 2953 Da, 3941 Da, 5338 Da, and 5639 Da) was selected based on their collective contribution to the optional separation between higher metal mixture exposure and non-exposure controls. Among these five selected markers, the 3941 Da was down-regulated and the four other proteins were up-regulated. Descriptive statistics confirmed that these five proteins differed significantly between metal exposure and non-exposure. Interestingly, the combined use of the five selected biomarkers could achieve higher discriminative power than single marker. These results demonstrated that proteomic technology, in conjunction with bioinformatics tools, could facilitate the discovery of new and better biomarkers of mixed metal exposure.

Adult↗
PubMed2005

[Prophylactic effect of ambroxol on acute hydrochloric acid aspiration - induced lung injury].

OBJECTIVE: To evaluate the protective effect of ambroxol, a muco-active drug, on acute hydrochloric acid-induced lung injury in rats. METHODS: Thirty pathogen-free SD rats were randomly divided into three groups: group A (n=10) and group B (n=10) were injected normal saline (NS) intraperitoneally (6.7 ml/kg), and group C with ambroxol (50 mg/kg), once a day for 3 consecutive days. Then animals received in tracheal instillation of NS (group A, pH 5.3, 1.2 ml/kg) or hydrochloric acid/NS (group B and C, pH 1.25, 1.2 ml/kg). Five hours after instillation of the injury vehicle, the arterial gas was determined, and the extent of lung injury was assessed by measuring the ratio of wet to dry weight (W/D) and evaluation of pathological change in lung tissue. RESULTS: (1)Partial pressure of oxygen in arterial blood (PaO(2)) was significantly lower in group B than in groups A and C, although pH and partial pressure of carbon dioxide in arterial blood (PaCO(2)) in three groups showed little difference (all P<0.01). (2)The W/D was the highest in group B and the lowest in group A. (3)Severe acute lung injuries were detected in group B by pathological examination, the extent of injury was less in group C than in group B, but more severe than in group A (group A vs. B and B vs. C in mean pathologic score, P<0.01 and P<0.05, respectively). CONCLUSION: Hydrochloric-acid aspiration may induce an acute and diffuse lung injury, with manifestations of hyperpnea, lower PaO(2) and severe pathological changes in lung tissues. Ambroxol may have a protective effect against lung injury induced by hydrochloric acid.

Acute Lung Injury↗
PubMed2005

Application of ulinastatin in severe craniocerebral injuries.

OBJECTIVE: To assess the therapeutic effect of ulinastatin on severe craniocerebral injuries and to explore its mechanism. METHODS: There were 87 cases of severe brain injury in this series and they were either treated by ulinastatin (treatment group, 41 cases) or not (control group, 46 cases) besides routine managements. We estimated C-reactive protein, interleukin-6, superoxide dismutase, and endothelin from plasmas of all the cases on the 1st, 3rd, 5th, and 7th day after injury. RESULTS: C-reactive protein level rose on the 1st and 3rd day after injury in the two groups, but descended in treatment group on the 5th and 7th day and was significantly lower than that in control group (P < 0.01). No significant difference was found for interleukin-6 in two groups during 1-5 days after injury, but on the 7th day, it decreased significantly in treatment group than control one (P < 0.01). Superoxide dismutase was higher in treatment group than control one in 5-7 days after injury (P < 0.01). Endothelin elevated on the 1st day after injury but dropped afterwards in the two groups, in which the level in treatment group was lower than that in control one. The incidence of gastrointestinal hemorrhage was lower in treatment group than control one (P < 0.01). CONCLUSIONS: Ulinastatin has the function of protecting cerebral tissue, reducing the incidence of gastrointestinal hemorrhage, improving hepatic and renal function and prognosis.

Adolescent↗
PubMed2005

[Uvulopalatopharyngoplasty and tongue base coblation treat the 112 cases of severe obstructive sleep apnea -hypopnea syndrome].

OBJECTIVE: To study the effect of the combination of UPPP and tongue base Coblation in treatment of the severe OSAHS. METHOD: One hundred and twelve cases who were diagnosed as severe OSAHS by polysomnography (PSG) were treated surgically by UPPP and tongue base Coblation. RESULT: The follow up period was twelve months. Twenty-four cases were cured, 52 cases have notable effects, 16 cases had effects, 20 cases had no effects. The total ratio of validity was 82.1%. CONCLUSION: The combination of UPPP and tongue base Coblation is a effective method for severe multi-level OSAHS treatment.

Adult↗
PubMed2005

[Effects of extract of Ginkgo biloba on intercellular adhesion molecule-1 and mRNA expression in rats with cerebral injury].

OBJECTIVE: To investigate the effects of Extract of Ginkgo biloba on ICAM-1 and mRNA expression in rats with cerebral injury, and discuss its protective mechanism. METHODS: The acute closed brain injury model was set up in rats according Feeney's method. Seventy-two rats were randomly divided into four groups. The levels of ICAM-1 expression were observed using immunohistochemistry and computerized imaging technique and the expression of mRNA were studied using RT-PCR techniques. RESULTS: ICAM-1 positive cells located in the transitional zone between the necrotic core and normal cortex. ICAM-1 protein and mRNA expression began to show 6 hours after cerebral injury, peaked at 24 hours. As compared with the model group, ICAM-1 and mRNA expression was significantly reduced in the group EGb (P < 0.01). CONCLUSION: EGb can markedly reduce the injury of nerve cell in the transitional zone, alleviate rat cerebral injury, and decrease ICAM-1 and mRNA expression and neutrophils infiltration. The protection may be related with its inhibition on ICAM-1 and mRNA expression.

Animals↗
PubMed2004

Pathogen-induced apoptotic neutrophils express heat shock proteins and elicit activation of human macrophages.

Ingestion of aged or irradiated apoptotic neutrophils actively suppresses stimulation of macrophages (Mphi). Many bacterial pathogens can also provoke apoptosis in neutrophils, but little is known about how such apoptotic cells influence Mphi activation. We found that neutrophils undergoing apoptosis induced by UV irradiation, Escherichia coli, or Staphylococcus aureus could either stimulate or inhibit Mphi activation. In contrast to Mphi that had ingested irradiated apoptotic neutrophils, Mphi that had phagocytosed bacteria-induced apoptotic neutrophils exhibited markedly increased production of the proinflammatory cytokine TNF-alpha, but not the anti-inflammatory cytokine TGF-beta. Moreover, ingestion of bacteria, but not UV-induced apoptotic neutrophils, caused increased expression of FcgammaRI on Mphi, and this effect was not provoked directly by bacteria associated with the apoptotic neutrophils. Instead, we found that a link between pathogen-induced apoptotic neutrophils and up-regulation of the heat shock proteins HSP60 and HSP70, and we also observed that recombinant HSP60 and HSP70 potentiated LPS-stimulated production of TNF-alpha in Mphi. The opposing macrophage responses to neutrophils undergoing apoptosis induced in different ways may represent a novel mechanism that regulates the extent of the immune response to invading microbes in two steps: first by aiding the functions of Mphi at an early stage of infection, and subsequently by deactivating those cells through removal of uninfected apoptotic neutrophils. HSP induction in neutrophils may provide the danger signals required to generate a more effective macrophage response.

Apoptosis↗
PubMed2004

Increasing the negative charge of a macroanion in the gas phase via sequential charge inversion reactions.

Protonated and deprotonated biological molecules in the gas phase play an important role in life sciences research. The structural information accessible from the ions is highly dependent upon their charge states. Therefore, it is desirable to develop means for increasing absolute charge states, particularly for ionization methods, such as MALDI, that yield relatively low charge ions. The work presented here demonstrates the formation of a doubly deprotonated polypeptide or oligonucleotide ion (dianion) from a singly deprotonated analogue via two sequential ion/ion proton-transfer reactions involving charge inversion. The high exoergicity and the large cross section arising from the long-range attractive Coulomb potential of ion/ion reactions make this process plausible. In this example, an overall efficiency of conversion of singly charged ions to doubly charged ions of roughly 8% for polypeptide was noted while lower efficiency (roughly 2%) observed with an oligonucleotide is likely due to a greater degree of neutralization. No other approach to increasing the net negative charge of an anion in the gas phase has as yet been reported.

Amino Acid Sequence↗
PubMed2004

Relationship between microvessel density and telomerase activity in hepatocellular carcinoma.

AIM: To study the relationship between microvessel density (MVD), telomerase activity and biological characteristics in hepatocellular carcinoma (HCC). METHODS: S-P immunohistochemical method and telomeric repeat amplification protocol (TRAP) were respectively used to analyze the MVD and telomerase activity in 58 HCC and adjacent normal tissues. RESULTS: The MVD in HCC with metastasis, lower differentiation or without intact capsule was significantly higher than that in HCC with intact capsule, higher differentiation, or without metastasis. While MVD had no relationship with tumor size, hepatic virus infection and other clinical factors. Telomerase activity was related to differentiation degree, but not to tumor size or histological grade. MVD in HCC with telomerase activity was higher than that in HCC without telomerase activity. CONCLUSION: MVD and telomerase activity may serve as diagnostic criteria of HCC in earlier stage. Meanwhile, there may be a cooperative effect between MVD and telomerase on the growth and metastasis of HCC.

Blood Vessels↗
PubMed2004

Tandem mass spectrometry of half-generation PAMAM dendrimer anions.

Ions derived from negative electrospray ionization of polyamidoamine (PAMAM) dendrimer generation 0.5 were subjected to ion trap tandem mass spectrometry. Ion/ion proton transfer reactions were used to manipulate the charge states of PAMAM precursor ions to form lower charge states from those initially formed by electrospray, as well as to facilitate the interpretation of the product ion mass spectra. Most of the products derived from dendrimer precursor ions could be rationalized by retro-Michael decomposition reactions. The dominant fragmentation channels are highly dependent on the composition of the counter-ions, which in this case are restricted to different numbers of sodium ions and protons, and whether the precursor ion is multiply charged or singly charged. An interpretation is given that is consistent with all of the observations made with the various anions associated with this study. The nature of the structural information that can be obtained via ion trap tandem mass spectrometry of the dendrimers is dependent on the types of precursor ions subjected to study. The tandem mass spectrometry data also provided information about the structure of faulty synthesis products present in the PAMAM dendrimer sample.

Biocompatible Materials↗
PubMed2004

Total equivalent of reactive chemicals in 142 human food items is highly variable within and between major food groups.

Many reactive electrophilic chemicals (e.g., acrylamide and hydrazine) occur in foods, and these could individually or cumulatively contribute to human cancer or other diseases. Glutathione (GSH) reacts with and detoxifies electrophilic compounds and is used physiologically to protect against a broad range of toxic and mutagenic compounds. To elucidate the distribution of reactive chemicals in foods, we added a known amount of GSH to 142 commonly consumed food items and assayed the relative amounts of reactive chemicals in terms of the amount of GSH lost during homogenization and extraction, defined quantitatively in terms of glutathione-reactive units (GRUs). Thirty-four items contained GRUs but no detectable GSH; 53 items contained both GSH and GRUs; 18 items contained no GSH or GRUs; and 37 items contained GSH but no detectable GRUs. Among the food groups, cereals, bread, milk, and milk products had relatively high GRU concentrations and low GSH concentrations; several common beverages also had high GRU concentrations and low GSH concentrations; meats and main course dishes were generally low in GRUs and high in GSH. Fruits and vegetables varied in GRU concentration, but most fresh fruits and vegetables had considerably more GSH than GRUs; exceptions were canned vegetables, which had no GSH or GRUs; fruit drinks, which had moderate levels of GRUs and no GSH; and 3 fruits (blueberries, cherries, and prunes), which had high GRU levels. The results provide a database that can be used with food frequency analyses to evaluate the possible association of health risks with the consumption of foods high in GSH-reactive chemicals.

Alcoholic Beverages↗
PubMed2004

[Analysis on causes of death of childhood leukemia from 1981 to 2000 in the city of Tianjin].

OBJECTIVE: Leukemia is a major cause of death of children in China, which accounts for 50 % of all cancers of children. Data from Tianjin Cancer Hospital was analyzed for mortality of leukemia in children under 20 years from 1981 to 2000 in the city of Tianjin. METHODS: All physicians and medical staff of the hospitals and clinics in the registry area were responsible for filling out the report forms for every new case diagnosed as malignant tumors. Death certificates for malignant tumors have been registered at the local police station and the residential files were checked. All cancer cases with insufficient information were traced to his/her family and relevant persons worked in the clinic. Tianjin Cancer Registry Center periodically conducted an active re-checking program to review all patient records on cancers that was not registered in this period. Tumors diagnosed in this study were coded according to the International Classification of Diseases for Oncology (ICD-O). Mortality rates were calculated by age, sex and date of death. RESULTS: The types of acute lymphoid leukemia, acute myeloid leukemia and chronic myeloid leukemia were the most common types of childhood leukemia in Tianjin, comprised 69.3%, 20.9 % and 8.0%, respectively. The mortality for childhood leukemia decreased slowly during the period of 1981 to 2000 in Tianjin. Mortality and morbidity ratios were 0.51. CONCLUSION: Combined with characteristics of individual forms of childhood leukemia mortality, further epidemiological research is needed to prevent childhood leukemia.

Adolescent↗
PubMed2004

[Effect of compound Salvia injection on blood coagulation in patients with traumatic cerebral infarction].

OBJECTIVE: To investigate the effect of compound Salvia injection (CSI) on blood coagulatory function in patients with traumatic cerebral infarction (TCI). METHODS: Sixty-four patients with TCI were randomly divided into two groups, 32 in each group. The treated group were treated with CSI plus conventional treatment of western medicine, and the control group treated with conventional treatment alone. Changes of symptoms, levels of plasma P-selectin (P-S), von Willebrand's factor (vWf) and D-dimer were observed with ELISA. RESULTS: The treated group was superior to the control group in Glasgow outcome scale (P < 0.01). Before treatment, the levels of plasma P-S, vWf and D-dimer in the TCI patients were higher than those in healthy people. After treatment, all the parameters lowered in both groups, but the effect of lowering was greater in the treated group than that in the control group. CONCLUSION: Blood coagulation disorder exists in patients with TCI, CSI could improve it, and might alleviate the cerebral damage to a certain extent.

Blood Coagulation↗