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Biomedical subjects

W He

Publications and source records attributed to W He.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Analysis of the T cell receptor Vdelta region gene repertoire in asthmatic subjects].

OBJECTIVE: To explore the role of gammadelta T cells in the asthmatic airway inflammation and identify the forces which induce and maintain the inflammatory process. METHODS: Peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) were obtained from seven asthmatic subjects and seven nonsmoking control subjects. The percentage of gammadelta T cells in PB and BALF were measured by immunofluorescent staining and flow cytometry, the frequency of usage and the clonality of Vdelta subfamilies (Vdelta(1) approximately Vdelta(3)) were assessed by RT-PCR and gene scanning. RESULTS: Higher proportion of gammadelta T cell was detected in the BALF of asthmatic subjects [(7.8 +/- 4.7)%] than that from control subjects [(3.3 +/- 3.0)%] (P < 0.05) and the relative expression level of Vdelta(1) significantly higher in the asthmatic airway [(44 +/- 13)%] than in the control group [(19 +/- 5)%] (P = 0.002). In asthmatic subjects, the monoclonal or oligoclonal expansion of gammadelta T lymphocytes was predominant in BALF, especially Vdelta(1) T lymphocytes. CONCLUSIONS: Antigenic specific gammadelta T cells might play important roles in the inducement and maintenance of airway inflammation.

Adult↗
PubMed2001

[Response of keloid fibroblasts to the effect of tumor necrosis factor-alpha(TNF-alpha)].

OBJECTIVE: To investigate the biologic behavior of keloid fibroblasts and the pathogenesis of keloid. METHODS: Human dermal fibroblasts cultured from normal skin and keloid were treated with tumor necrosis factor-alpha(TNF-alpha) for 48 hours at 10(3) U/ml and 10(4) U/ml. Collagen production by fibroblasts was assessed by 3H-proline in corporation into pepsin-resistant, precipitated extracellular collagenous protein. RESULTS: TNF-alpha caused a concentration-dependent reduction in collagen production in normal dermal fibroblasts. Treatment with TNF-alpha at 10(3) U/ml significantly reduced the collagen synthesis in keloid fibroblasts (P < 0.01). However, the collagen synthesis in keloid fibroblasts did not further decreased after exposure to TNF-alpha at 10(4) U/ml. CONCLUSIONS: Keloid fibroblasts may remain less sensitive to the inhibitory effects of TNF-alpha on collagen synthesis to a certain extent.

Collagen↗
PubMed2001

[The investigation with contrast sensitivity after implantation with UV and UVCY types of intraocular lens].

OBJECTIVE: To research the difference in vision after UV and UVCY two types of intraocular lens implantation (The light 380-790 nm may transmit through the UV lens, and the UVCY lens may partly filter the light < 640 nm including part of the light < 460 nm.). METHODS: MCT 8000 contrast tester was used in the postoperative two months. RESULTS: The contrast sensitivity of the patients with UVCY lenses was superior to that with UV lenses obviously (P < 0.05) under the condition of glare and 3 c/d, 6 c/d space frequency. CONCLUSION: The UVCY lens is more advantageous to improve visual function.

Aged↗
PubMed2001

[Effect of toluene on urease activity of Lou soil].

Urease activity affected by toluene studying results showed as follows: Toluene had little action on Jackbean urease activity, but can remarkably increase soil urease activity in lower toluene concentrations and shorter time, the increasing variation was 1.48-3.96 times than without toluene treatment in seven soil samples tested. The variation was less than 3.98% when sterilized soil samples adsorbed the Jackbean urease. It may be because toluene can kill soil microorganism, release urease within cell and subsequently urease fixed into soil organic-inorganic colloidal. Different soil pH and microbiology can lead to vary differently for urease activity.

Fabaceae↗
PubMed2001

[Analyses on the risk factors of Measles in Anhui province during 1998 and 1999].

OBJECTIVE: To evaluate the measures targeting measles control. METHODS: Measles cases were studied serologically under AFP surveillance system. RESULTS: The incidence was 1.36/100 000 in 1999. The incidence of children under 5 was 3.65/100 000, with 84.00% and 87.49% reduction, as compared with the incidence in 1991 and 1997 before intensified vaccination campaigns in children aged 1 - 6. The indicators of surveillance showed an improvement in 1999 than that in 1998. CONCLUSION: Training for health staff at county, township, vallage levels played an important role in improving the sensibility and timeliness of measles surveillance system. Routine immunization is a key element in curbing measles outbreaks and reducing measles incidence.

Adolescent↗
PubMed2001

[A study of adhesion molecule expression in extraocular muscles of Graves' ophthalmopathy].

OBJECTIVE: To investigate the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) in extraocular muscles (EOM) of the eyes with Graves' ophthalmopathy (GO). METHODS: Seventeen EOM specimens obtained from 16 severe patients with GO and their cryostat sections were observed by double labeling immunohistochemical methods. RESULTS: The expression of ICAM-1 was observed in interstitial and perimysial connective tissue surrounding EOM fibers, mononuclear cells, fibroblasts and vascular endothelial cells. Only were vascular endothelial cells stained for VCAM-1, and ICAM-1 and VCAM-1 immunoreactivities were not detected in EOM cells. CONCLUSIONS: The findings indicate that ICAM-1 and VCAM-1 might be involved in the development of GO, and fibroblasts, vascular endothelial cells and mononuclear cells might play important roles in the autoimmune reaction.

Adult↗
PubMed2001

[Clinicopathological significance of grading on thymic epithelial tumors].

OBJECTIVE: To study the clinicopathologic relevance of a thymic epithelial tumor (TET) grading standard with the WHO classification. METHODS: A grading system for TET was proposed based on the application of WHO histological typing of thymic tumors and analyzed in relation to clinical therapy results and follow-up data of 200 TET cases. RESULTS: In this series, 8 patients (4.0%) belonged to type A, 68 (34.0%) were type AB, 17 (8.5%) were type B1, 39 (19.5%) were type B2, 27 (13.5%) were type B3 and 36 (18.0%) were type C. The remaining 5 cases were rare thymomas. The overall postoperative survival data showed highly significant differences among the histological subtypes (P < 0.001). Type A & type AB thymomas showed excellent prognosis, none of these patients died of tumor; in type B1, only 1 case (5.9%) died at 22 months postoperatively. Types B2, B3 and C thymomas shared the bad, worse and worst prognosis. Ninety-six patients (48.0%) were in stage I, 26 (13.0%) in stage II, 65 (32.5%) in stage III and 13 (6.5%) in stage IV. Clinical stage is also highly significant in predicting survival (P < 0.001). It was found that tumor histology could predict survival expectancies well in stage I and stage II cases. It was also found that type B2, B3 and C thymomas had a statistically significant worse prognosis than type A, AB and B1 thymomas (P < 0.001). According to the histology, clinical data, biological behavior and prognosis, it is proposed that thymomas be divided into 4 grades: grade I, II, III and IV. Follow-up is the best strategy for grade I & II patients after radical surgery. In this series, the 30 patients (15.0%) presenting clinical signs of myasthenia gravis were mostly in type B2 and B3 groups (P < 0.01). CONCLUSIONS: The WHO classification for TET provides good pathological definitions and criteria for diagnosis, which can independently predict the invasiveness and prognosis of TET. TET grading is of use in unifying pathological and clinical findings, in selection of proper therapy and in predicting prognosis.

Adolescent↗
PubMed2001

[Screening the mimic antigen epitopes of triosephosphate isomerase of Schistosoma japonicum Chinese strain (Sjc-Tpi) with random phage peptide library].

OBJECTIVE: To screen the mimic antigen epitopes of the triose phosphate isomerase of Schistosoma japonicum Chinese strain (SjC-TPI) and investigate their immunogenicity. METHODS: The random phage peptide library (PH.D.-12) was screened with the purified antibody(IgG) against SjC-TPI to get the positive phage which contained the mimic antigen epitopes of SjC-TPI, and the immuno-characterization of the mimic antigen epitopes were investigated. RESULTS: Two mimic antigen epitopes (M1, M2) of SjC-TPI were obtained. The immuno-sera of mice (Kunming strain) against the positive phages could recognize both the SjC-TPI and the protein of the positive phages. The DNA sequencing data showed no homology between the sequences of the deduced amino acid of the two mimic antigen peptides and the amino acid of SjC-TPI. CONCLUSION: The two mimic antigen epitopes of SjC-TPI obtained are imitative epitopes of the configuration antigen of SjC-TPI.

Animals↗
PubMed2001

[Protective immunity induced by 23 kDa membrane protein DNA vaccine of Schistosoma japonicum Chinese strain in mice].

OBJECTIVE: To develop 23 kDa membrane protein DNA vaccine of Schistosoma japonicum Chinese strain and test its protective efficacy in infected C57BL/6 mice. METHODS: The full length cDNA encoding SjC23 amplified from pUC19-SjC23 subcloned into pcDNA3.1. 48 female mice were divided into three groups: A, B and C. Group A (control group) was each immunized i.m. with 100 micrograms of pcDNA3.1; group B (SjC23 group) was each immunized i.m. with 100 micrograms of pcDNA3.1-SjC23; group C (SjC23 + IL-12) was each immunized i.m. with a mixture of 100 micrograms of pcDNA3.1-SjC23, 100 micrograms of pcDNA3.1-p35 and 100 micrograms of pcDNA-p40, followed by two boosts of the same DNA once every two weeks. All the mice were challenged with 45 cercariae at week 8, killed and perfused for worms at week 14. The expression of SjC23 and p35, p40 in muscle tissue was determined by immuno-histochemical method. By the culture of spleen cells, the production of IL-2, IL-4, IL-10 and IFN-gamma after the stimulation of rSjC23-HD was determined two weeks before and after challenge. Anti-SjC23 antibodies were tested by Western blotting. RESULTS: SjC23 and p35, p40 were all expressed on the membrane and in the plasma of muscle cells of the infected mice. Significant increase of IL-2 and IFN-gamma in SjC23 and SjC23 + IL-12 groups was observed before and after challenge. Western blotting showed that after the third immunization (before challenge) 8 out of 10 sera from SjC23 group and 9 out of 10 sera from SjC23 + IL-12 group were positive. The worm reduction rate in SjC23 group and SjC23 + IL-12 group was 26.9% and 35.4%, respectively; the number of eggs in liver tissue was reduced by 22.2% and 28.4%, respectively. CONCLUSION: pcDNA3.1-SjC23 DNA vaccine could induce partial protection against Schistosoma japonicum in C57BL/6 mice.

Animals↗
PubMed2001

[Relationship among lymphatic metastasis, pericancerous lymphocytic reaction and dendritic cell infiltration in laryngeal carcinoma cells].

OBJECTIVE: To study the role and the clinical significance of dendritic cell infiltration against tumor cells in patients with laryngeal squamous cell carcinoma. METHODS: Immunohistochemical method using S-100 protein antibody was employed to detect dendritic cells (DC) on paraffin-embedded tissue sections from 23 patients with laryngeal squamous cell carcinomas. The relationships among the density of dendritic cell infiltration in laryngeal carcinomas and cervical lymphatic metastasis, pericancerous lymphocytic reaction and other clinicopathologic parameters were observed. RESULTS: The numbers of dendritic cells infiltrating among laryngeal carcinoma cells in patients with no cervical lymph metastasis was significantly larger than those with cervical lymphatic metastasis (t = 4.889, P < 0.01). Significant increase DC infiltration among laryngeal carcinoma cells was found in the group with intensively positive reaction of pericancerous lymphocyte than in the medium and weakly positive groups. The number of infiltrating dendritic cells in patients who had survived more than 5 years was significantly larger than those survived less than 5 years (t = 4.423, P < 0.01). The numbers of the infiltrating dendritic cells in patients with well-differentiated squamous cell carcinoma and poorly differentiated squamous cells carcinoma were 2.2 +/- 1.07 and 14.6 +/- 7.14 respectively, which were significantly different (q = 4.532, P < 0.05). CONCLUSION: The study showed that DC infiltration among laryngeal squamous carcinoma cells played an important role in the host immune reaction against tumor. It indicated that when the density of infiltrating DC is higher, the patients had less chance of cervical lymph metastasis and may have a longer survival time. There was a coordinative effect between DC infiltration in tumor cells and pericancerous lymphocyte reaction. Thus, the DC infiltration among laryngeal squamous cells could be used as an index of prognosis.

Aged↗
PubMed2001

[Differential expression analysis and cloning of murine thymic aged-related genes].

OBJECTIVE: Differential expression analysis and cloning of murine thymic aged-related genes. METHODS: Different expressions of thymic mRNAs from 1- and 10-month old mice were analyzed via DDRT-PCR and different expression sequence tags (ESTs) were obtained, following by identification with Northern Blotting, DNA sequencing, as well as screening of cDNA library. RESULTS: It was found that there would be a significant difference of gene expression in murine thymuses. Gene expression of some genes were exclusive in thymus from 1 or 10-month old mice, while some expressed different with age. 108 differential display cDNA fragments were recovered, among which 31 were positive for hybridization by Northern blot. After sequenced, 14 ESTs were found to share high homology to known genes, whereas remaining 17 were novel. A murine thymic cDNA library was screened by using one cDNA fragment that expressed with higher level in total RNA of 1-month old murine thymic tissues than 10-month old. Finally, one 1,470 bp fragment was cloned and showed a 99% of homology to murine transketolase. CONCLUSION: Expression of murine thymic genes has displayed a marked difference with age. These genes might be participated in thymic atrophy.

Aging↗
PubMed2000

Modules in the photoreceptor RGS9-1.Gbeta 5L GTPase-accelerating protein complex control effector coupling, GTPase acceleration, protein folding, and stability.

RGS (regulators of G protein signaling) proteins regulate G protein signaling by accelerating GTP hydrolysis, but little is known about regulation of GTPase-accelerating protein (GAP) activities or roles of domains and subunits outside the catalytic cores. RGS9-1 is the GAP required for rapid recovery of light responses in vertebrate photoreceptors and the only mammalian RGS protein with a defined physiological function. It belongs to an RGS subfamily whose members have multiple domains, including G(gamma)-like domains that bind G(beta)(5) proteins. Members of this subfamily play important roles in neuronal signaling. Within the GAP complex organized around the RGS domain of RGS9-1, we have identified a functional role for the G(gamma)-like-G(beta)(5L) complex in regulation of GAP activity by an effector subunit, cGMP phosphodiesterase gamma and in protein folding and stability of RGS9-1. The C-terminal domain of RGS9-1 also plays a major role in conferring effector stimulation. The sequence of the RGS domain determines whether the sign of the effector effect will be positive or negative. These roles were observed in vitro using full-length proteins or fragments for RGS9-1, RGS7, G(beta)(5S), and G(beta)(5L). The dependence of RGS9-1 on G(beta)(5) co-expression for folding, stability, and function has been confirmed in vivo using transgenic Xenopus laevis. These results reveal how multiple domains and regulatory polypeptides work together to fine tune G(talpha) inactivation.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2000

Structures of the contryphan family of cyclic peptides. Role of electrostatic interactions in cis-trans isomerism.

The contryphan family of cyclic peptides, isolated recently from various species of cone shell, has the conserved sequence motif NH(3)(+)-X(1)COD-WX(5)PWC-NH(2), where X(1) is either Gly or absent, O is 4-trans-hydroxyproline, and X(5) is Glu, Asp, or Gln. The solution structures described herein of two new naturally occurring contryphan sequences, contryphan-Sm and des[Gly1]-contryphan-R, are similar to those of contryphan-R, the structure of which has been determined recently [Pallaghy et al. (1999) Biochemistry 38, 11553-11559]. The (1)H NMR chemical shifts of another naturally occurring peptide, contryphan-P, indicate that it also adopts a similar structure. All of these contryphans exist in solution as a mixture of two conformers due to cis-trans isomerization about the Cys2-Hyp3 peptide bond. The lower cis-trans ratio for contryphan-Sm enabled elucidation of the 3D structure of both its major and its minor forms, for which the patterns of (3)J(H)(alpha)(HN) coupling constants are very different. As with contryphan-R, the structure of the major form of contryphan-Sm (cis Cys2-Hyp3 peptide bond) contains an N-terminal chain reversal and a C-terminal type I beta-turn. The minor conformer (trans peptide bond) forms a hairpin structure with sheetlike hydrogen bonds and a type II beta-turn, with the D-Trp4 at the 'Gly position' of the turn. The ratio of conformers arising from cis-trans isomerism around the peptide bond preceding Hyp3 is sensitive to both the amino acid sequence and the solution conditions, varying from 2.7:1 to 17:1 across the five sequences. The sequence and structural determinants of the cis-trans isomerism have been elucidated by comparison of the cis-trans ratios for these peptides with those for contryphan-R and an N-acetylated derivative thereof. The cis-trans ratio is reduced for peptides in which either the charged N-terminal ammonium or the X(5) side-chain carboxylate is neutralized, implying that an electrostatic interaction between these groups stabilizes the cis conformer relative to the trans. These results on the structures and cis-trans equilibrium of different conformers suggest a paradigm of 'locally determined but globally selected' folding for cyclic peptides and constrained protein loops, where the series of stereochemical centers in the loop dictates the favorable conformations and the equilibrium is determined by a small number of side-chain interactions.

Amides↗
PubMed2000

GFP-tagged expression and immunohistochemical studies to determine the subcellular localization of the tubby gene family members.

The tubby gene family consists of four members, TUB, TULP1, TULP2 and TULP3, with unknown function. However, a splice junction mutation within the mouse tub gene leads to retinal and cochlear degeneration, as well as maturity onset obesity and insulin resistance. Mutations within human TULP1 have also been shown to co-segregate in several cases of autosomal recessive retinitis pigmentosa (RP) and TULP1 deficiency in mice leads to retinal degeneration. The primary amino acid sequences of the tubby family members do not predict a likely biochemical function. As a first step in defining their function, we present a detailed characterization of the cellular and subcellular localization of the human (TUB) and mouse (tub) homologous gene products. We report the isolation of TUB splice variants which have different subcellular localizations (nuclear versus cytoplasmic) and which define a nuclear localization signal. In addition, using green fluorescent protein (GFP) tags, we observe a nuclear localization for TULP1, similar to TUB splicing forms TUB 561 and TUB 506. Finally, we report tubby expression in mouse brain by in situ hybridization and by immunohistochemistry with polyclonal antibodies. Protein was found in both the hypothalamic satiety centers and in a variety of other CNS structures including the cortex, cerebellum, olfactory bulb and hippocampus. Both nuclear and cytoplasmic signals were detected with a series of independently generated polyclonal antibodies, consistent with the presence of multiple alternatively spliced isoforms within the CNS.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Aberrant cell cycle progression contributes to the early-stage accelerated carcinogenesis in transgenic epidermis expressing the dominant negative TGFbetaRII.

Mutations in the transforming growth factor beta type II receptor (TGFbetaRII) have been found in various malignant tumors, suggesting that loss of TGFbeta signaling plays a causal role in late-stage cancer development. To test whether loss of TGFbetaRII is involved in early-stage carcinogenesis, we have generated transgenic mice expressing a dominant negative TGFbetaRII (deltabetaRII) in the epidermis. These mice exhibited an increased susceptibility to chemical carcinogenesis protocols at both early and late stages. In the current study, parameters for cell cycle progression and chromosome instability were analysed in deltabetaRII tumors. DeltabetaRII papillomas showed an increased S phase in flow cytometry. Bromodeoxyuridine (BrdU) labeling and mitotic indices in deltabetaRII papillomas also showed a threefold increase compared to papillomas developing in non-transgenic mice. When papillomas further progressed to squamous cell carcinomas (SCC), both control and deltabetaRII SCC showed similar BrdU labeling indices and percentages of S phase cells. However, deltabetaRII SCC cells showed a sixfold increase in the G2/M population. Mitotic indices in deltabetaRII SCC also showed a threefold increase compared to non-transgenic SCC. Consistent with a perturbed cell cycle, deltabetaRII papillomas and SCC showed reduced expression of the TGFbeta target genes p15 (INK4b), p21 (WAF-1) and p27 (Kip1), inhibitors of cyclin-dependent kinases (cdks). However, most deltabetaRII papilloma cells exhibited normal centrosome numbers, and deltabetaRII SCC exhibited a similar extent of centrosome abnormalities compared to control SCC (35-40% cells). Most of deltabetaRII SCC exhibited diploid chromosome profiles. These data indicate that inactivation of TGFbetaRII accelerates skin tumorigenesis at early stages by the acceleration of loss of cell cycle control, but not by increased chromosome instability.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

Identification of a C-terminal cdc25 sequence required for promotion of germinal vesicle breakdown.

Glutathione S-transferase (GST)-cdc25B(31-566) induced germinal vesicle breakdown (GVBD) when microinjected into Xenopus oocytes. Purified, N-terminally truncated forms of cdc25B did not induce GVBD, even though many had phosphatase activity and activated cdc2 in vitro. N-terminally truncated forms of cdc25B inhibited induction of GVBD by longer forms of the enzyme suggesting a direct interaction in vivo. cdc25B(356-556), but not cdc25B(364-529), inhibited GVBD induction by GST-cdc25B(31-566) suggesting that a region of cdc25B near to the C-terminus was responsible for the inhibition. To determine the region of peptide sequence that was inhibitory, cdc25B(356-556) was subjected to proteolysis with endoproteinase lys-C. Following a demonstration that the resulting peptide mixture inhibited GST-cdc25B-dependent GVBD, a series of peptides spanning amino acids at the C-terminus were synthesized. The peptide TRSWAGERSR inhibited GVBD induced by GST-cdc25B. An alanine scan of the peptide revealed residues critical for GVBD inhibition, and site-directed mutagenesis of the corresponding residues in GST-cdc25B(31-566) eliminated its ability to induce GVBD. These results demonstrate that a cdc25B C-terminal domain, involved in dominant-negative inhibition of GVBD-competent cdc25B, is required for induction of GVBD following microinjection into oocytes.

Amino Acid Sequence↗