Comparison of computer-based information support to clinical research in Chinese and Japanese hospitals: a postal survey of clinicians' views

OBJECTIVES

The objectives of this research are to examine the current situation of computer-based information support of clinical research in hospitals and to determine the expectations of clinicians toward clinical research support functions of hospital information systems (HISs) in both China and Japan.

METHODS

172 clinicians from 42 major hospitals in China (2 groups), and 568 clinicians from 79 university hospitals in Japan (2 groups), were surveyed by postal questionnaire during July and August, 1999. The Kruskal-Wallis test was performed to analyze the differences among the groups.

RESULTS

The total response rate was 66.9%. The result shows that 94.8% of the Japanese clinicians, 3.5 times more than those in China, use computers almost every day. High significance was shown for the frequency of non-HIS based information resources used by clinicians between China and Japan (p < 0.001), whereas no significance for the frequency of HIS use by clinicians between the China I and Japan I groups (p = 0.725) was found. 33.3% clinicians in China thought they could obtain 30-50% of the necessary patient data for clinical research from the HIS, about 2 times more than in Japan (p = 0.009).

CONCLUSIONS

Although the degree of computer involvement among clinicians in Japan is much higher than in China, the computer-based hospital information systems have not been developed well for supporting clinical research in both countries. The clinicians expect comprehensive computerized patient records (CPRs) and full use of patient related information in the existing HISs to support their clinical research.

Homology Modeling of Bacillus subtilis Tryptophanyl-tRNA Synthetase

Tryptophanyl-tRNA synthetase (TrpRS) plays a pivotal role in protein synthesis. However, till now no stereostructural data of Bacillus subtilis TrpRS were reported. Here, by using the homology modeling using Bacillus stearothermophilus TrpRS as a template, it is demonstrated that the synthetase has 16alpha helices and 5beta sheets. The only tryptophan Trp(92) is located on the interface of subunits. Also the modeling presents the ligand binding site, active site and the putative binding of tRNA(Trp).

Fibroblast growth factor receptor 2 (FGFR2): genomic sequence and variations

Fibroblast growth factor receptors (FGFRs) play an important role in development and tumorigenesis. Mutations in FGFR2 cause more than five craniosynostosis syndromes. The FGFR2 genomic structure is the largest of the FGFR family. We have refined and extended the genomic organization of the FGFR2 gene by sequencing more than 119 kb of PACs, cosmids, and PCR products and assembling a region of approximately 175 kb. Although the gene structure has been reported to include only 20 exons, we have verified the presence of at least 22 exons, some of which are alternatively spliced. The sizes of six exons differed from those reported previously. Comparison of our sequence and those in the NCBI database detected more than 300 potential single nucleotide polymorphisms (SNPs). However, sequencing regions containing 52 of these potential SNPs verified only 14 in PCR products generated from 16 CEPH alleles. In contrast, direct sequencing of the CEPH DNAs revealed 21 other polymorphisms. Only one SNP was found in the 2,926 bp of coding sequence. Twenty-seven SNPs, two insertion polymorphisms and five microsatellite polymorphisms are contained in approximately 16.6 kb of non-coding sequence. These data yield an average of one polymorphism for approximately 488 bp of non-coding sequence examined. This collection of SNP, insertion, and repeat polymorphisms will aid future association studies between the FGFR2 gene and human disease and will enhance mutation detection.

[Multivariate analysis for prognostic predictors in non-small cell lung cancer]

BACKGROUND

To determine the prognostic predictors for non-small cell lung cancer ( NSCLC) with multivariate analysis.

METHODS

From 1981 to 1994, 158 patients with NSCLC had been treated by surgery alone or combined with radiotherapy and/ or chemotherapy . Their clinical characteristics were collected. All histological slides were reviewed to evaluate the histological type, tumor differentiation and vascular and lymphatic vessel invasion. Oncoprotein overexpressions were measured by immunohistochemistry assay ( ABC) , including Pan-ras, c-myc, c-erb B2, EGFR and p53. PCNA was also measured by ABC. The endpoints for prognosis consisted of survival, local control and distant metastasis. They were calculated by Kaplan-Meier method with Log-rank test determining the difference between subgroups. Cox model was used for multivariate analysis. The prognostic index ( PI) was calculated basing on the results of multivariate analysis, then the high risk group was determined by PI.

RESULTS

The overall actual 5-year survival rate was 44%. The unfavorable predictors were late T and N of TNM stage ( P = 0. 025 and < 0. 001) , lymphatic vessel invasion ( P= 0. 002) and multi-oncoprotein overexpression ( P= 0. 018) . The overall median of PI was 1. 71( 0. 23-3. 75) . The patients were divided into three groups: good prognosis group ( 42 cases, PI ≤ 1. 3) , moderate prognosis group ( 63 cases, 1. 3 < PI ≤ 2. 2) and bad prognosis group ( 53 cases, PI > 2. 2) . There was significant difference in survival rate among the three groups ( P < 0. 001) , 5-year survival rate was 77%, 45% and 21%, respectively.

CONCLUSIONS

The unfavorable predictors are late T, late N, lymphatic vessel invasion and multi-oncoprotein overexpression. PI could be used to determine the high risk group in patients with NSCLC.

[Surgical treatment of central lung cancer by lobar replantation]

BACKGROUND

To explore the feasibility, indication and method of surgical treatment of central-type lung cancer by lobar replantation.

METHODS

A retrospective study on the radical resection of 6 patients with stage III central-type lung cancer of the upper lobe by lobar replantation was made. Two patients underwent double-sleeve right upper and middle lobectomy, firstly. Since the length of resected bronchus or pulmonary artery involved by tumor was too long to perform tension-free anastomosis, we had to transplant the inferior pulmonary vein to the proximal stump of the supperior pulmonary vein, so the lower lobe was preserved. Another four patients underwent radical pneumonectomy, because the tumor had extended through the oblique fissure to the margin of the lower lobe. Subsequently, the lower lobe was isolated from the resected lungs and perfused with heparin solution ( 12 500 U/ 500 ml normal saline) for later replantation. After a radical systematic en-bloc mediastinal lymphadenectomy was performed, the preserved lower lobewas replanted.

RESULTS

Followed up to Dec 2000, 3 patients had been alive for 43, 12 and 8 months separately with a good living quality. One case had tumor recurrence at 19th month and died at 23rd month postoperatively. One case died of tension pneumothorax caused by bronchopleural fistula on the 19th postoperative day. Another case received resection of the replanted lung for pulmonary arteriobroncho-pleural fistula on the 42nd day and died of respiratory failure caused by pulmonary infection on 14th month postoperatively.

CONCLUSIONS

Lobar replantation is an alternative procedure of parenchyma-sparing in patients with stage III central lung cancer of the upper lobe whose cardiopulmonary function is too poor to undergo pneumonectomy.

Seasonal changes of reproductive behavior and fecal steroid concentrations in Père David's deer

From July 1997 to September 1997 and from March 1998 to July 1998, we studied reproductive behaviors of Père David's deer in Dafeng, China. During the field behavioral observations, we collected fresh voided fecal samples from the Père David's stags and hinds periodically and kept those samples under -20 degrees C until laboratory analysis. We analyzed the fecal testosterone, estradiol, and progesterone concentrations in those samples using radioimmunoassay. During this study, we also recorded 17 types of male reproductive behaviors and nine types of female reproductive behaviors. Reproductive behaviors and the fecal steroid concentrations showed overt seasonal fluctuations. There were statistically significant correlations between some male reproductive behaviors, such as anogenital sniffing, urine sniffing, urine spraying, wallowing, bellowing, antler adorning, Antler swags mud, chasing, herding hinds, chin resting, mounting and copulating, with the fecal testosterone concentrations. These results suggested that seasonal reproductive behaviors in stags are strongly associated with circulating testosterone. We also found that some female reproductive behaviors fluctuate corresponding with changes in fecal estrogen concentrations. Although there was no direct evidence to confirm the correlations between female reproductive behaviors and fecal estrogen in our experiment, we could not rule out that reproductive activities of hinds were largely related to ovarian estrogen secretion, and estrogen is necessary for inducing female reproductive behaviors.

Enhancement of bone growth by sustained delivery of recombinant human bone morphogenetic protein-2 in a polymeric matrix

PURPOSE

The purpose of this study was to develop a polymeric sustained delivery system for recombinant human bone morphogenetic protein-2 (BMP-2) and to evaluate local bone growth induced by the sustained release of BMP-2 in an animal model.

METHODS

BMP-2 was incorporated in biodegradable poly(D,L-lactide-co-glycolide) (PLGA) microspheres to obtain different release rates. Two sustained and an immediate release implants were produced by suspending the BMP-2 loaded PLGA microspheres in aqueous sodium carboxymethylcellulose (CMC), lyophilizing, and cutting the dried materials to the size of the animal bone defects. The local in vivo release at the implantation site in rat calvarial defects was determined by gamma scintigraphy using radiolabeled BMP-2. The local bone induction in the critical size of rabbit calvarial defects was evaluated six weeks post implantation.

RESULTS

The immediate release implant showed about 65% initial drug release within 24 h and the remaining BMP-2 quickly exhausted from the implantation site within 7 days. The sustained release implants, showing 45-55% initial release followed by a prolonged release for 21 days, released a greater amount of BMP-2 at the implantation site and maintained higher serum BMP-2 for the longer period of time compared to the immediate release implant. Significant bone growth was observed in all BMP-2 treated defects while the defects without treatment or with BMP-2-free implant showed minimal bone healing. 75-79% of rabbit calvarial defect area was healed with newly induced bone matrix by the sustained release implants in 6 weeks as compared to 45% recovery from the immediate release implant.

CONCLUSION

The sustained delivery of BMP-2 based on the biodegradable PLGA microsphere system resulted in faster and more complete bone healing in the animal model.

DNA methyltransferase 3B mutations linked to the ICF syndrome cause dysregulation of lymphogenesis genes

ICF (immunodeficiency, centromeric region instability and facial anomalies) is a recessive disease caused by mutations in the DNA methyltransferase 3B gene (DNMT3B). Patients have immunodeficiency, chromosome 1 (Chr1) and Chr16 pericentromeric anomalies in mitogen-stimulated lymphocytes, a small decrease in overall genomic 5-methylcytosine levels and much hypomethylation of Chr1 and Chr16 juxtacentromeric heterochromatin. Microarray expression analysis was done on B-cell lymphoblastoid cell lines (LCLs) from ICF patients with diverse DNMT3B mutations and on control LCLs using oligonucleotide arrays for approximately 5600 different genes, 510 of which showed a lymphoid lineage-restricted expression pattern among several different lineages tested. A set of 32 genes had consistent and significant ICF-specific changes in RNA levels. Half of these genes play a role in immune function. ICF-specific increases in immunoglobulin (Ig) heavy constant mu and delta RNA and cell surface IgM and IgD and decreases in Ig(gamma) and Ig(alpha) RNA and surface IgG and IgA indicate inhibition of the later steps of lymphocyte maturation. ICF-specific increases were seen in RNA for RGS1, a B-cell specific inhibitor of G-protein signaling implicated in negative regulation of B-cell migration, and in RNA for the pro-apoptotic protein kinase C eta gene. ICF-associated decreases were observed in RNAs encoding proteins involved in activation, migration or survival of lymphoid cells, namely, transcription factor negative regulator ID3, the enhancer-binding MEF2C, the iron regulatory transferrin receptor, integrin beta7, the stress protein heme oxygenase and the lymphocyte-specific tumor necrosis factor receptor family members 7 and 17. No differences in promoter methylation were seen between ICF and normal LCLs for three ICF upregulated genes and one downregulated gene by a quantitative methylation assay [combined bisulfite restriction analysis (COBRA)]. Our data suggest that DNMT3B mutations in the ICF syndrome cause lymphogenesis-associated gene dysregulation by indirect effects on gene expression that interfere with normal lymphocyte signaling, maturation and migration.

Growth factors stimulate the Na-K-2Cl cotransporter NKCC1 through a novel Cl(-)-dependent mechanism

The Na-K-2Cl cotransporter NKCC1 is an important volume-regulatory transporter that is regulated by cell volume and intracellular Cl(-). This regulation appears to be mediated by phosphorylation of NKCC1, although there is evidence for additional, cytoskeletal regulation via myosin light chain (MLC) kinase. NKCC1 is also activated by growth factors and may contribute to cell hypertrophy, but the mechanism is unknown. In aortic endothelial cells, NKCC1 (measured as bumetanide-sensitive (86)Rb(+) influx) was rapidly stimulated by serum, lysophosphatidic acid, and fibroblast growth factor, with the greatest stimulation by serum. Serum increased bumetanide-sensitive influx significantly more than bumetanide-sensitive efflux (131% vs. 44%), indicating asymmetric stimulation of NKCC1, and produced a 17% increase in cell volume and a 25% increase in Cl(-) content over 15 min. Stimulation by serum and hypertonic shrinkage were additive, and serum did not increase phosphorylation of NKCC1 or MLC, and did not decrease cellular Cl(-) content. When cellular Cl(-) was replaced with methanesulfonate, influx via NKCC1 increased and was no longer stimulated by serum, whereas stimulation by hypertonic shrinkage still occurred. Based on these results, we propose a novel mechanism whereby serum activates NKCC1 by reducing its sensitivity to inhibition by intracellular Cl(-). This resetting of the Cl(-) set point of the transporter enables the cotransporter to produce a hypertrophic volume increase.

Comprehensive-trace level determination of methyltin compounds in aqueous samples by cryogenic purge-and-trap gas chromatography with flame photometric detection

A comprehensive method was developed for the sensitive and fast determination of trace levels of methyltin compounds in aqueous samples. Tin compounds in aqueous solution at pH 5 were converted to the corresponding volatile hydrides: CH3SnH3, (CH3)2SnH2, and (CH3)3SnH, by reaction with potassium borohydride. A CP-4010 purge and trap injector (PTI) was used to purge analyte species from water directly. The volatile derivatives were base-line separated on a capillary column in an Angilent-6890 gas chromatograph by a suitable temperature program and were detected by a flame photometric detector (FPD). The detection limits were 18 ng L-1 for monomethyltin, 12 ng L-1 for dimethyltin, and 3 ng L-1 for trimethyltin, respectively. This method was successfully applied to the determination of methyltin compounds in different aqueous samples.

High-level erythroid-specific gene expression in primary human and murine hematopoietic cells with self-inactivating lentiviral vectors

Use of oncoretroviral vectors in gene therapy for hemoglobinopathies has been impeded by low titer vectors, genetic instability, and poor expression. Fifteen self- inactivating (SIN) lentiviral vectors using 4 erythroid promoters in combination with 4 erythroid enhancers with or without the woodchuck hepatitis virus postregulatory element (WPRE) were generated using the enhanced green fluorescent protein as a reporter gene. Vectors with high erythroid-specific expression in cell lines were tested in primary human CD34(+) cells and in vivo in the murine bone marrow (BM) transplantation model. Vectors containing the ankyrin-1 promoter showed high-level expression and stable proviral transmission. Two vectors containing the ankyrin-1 promoter and 2 erythroid enhancers (HS-40 plus GATA-1 or HS-40 plus 5-aminolevulinate synthase intron 8 [I8] enhancers) and WPRE expressed at levels higher than the HS2/beta-promoter vector in bulk unilineage erythroid cultures and individual erythroid blast-forming units derived from human BM CD34(+) cells. Sca1(+)/lineage(-) Ly5.1 mouse hematopoietic cells, transduced with these 2 ankyrin-1 promoter vectors, were injected into lethally irradiated Ly5.2 recipients. Eleven weeks after transplantation, high-level expression was seen from both vectors in blood (63%-89% of red blood cells) and erythroid cells in BM (70%-86% engraftment), compared with negligible expression in myeloid and lymphoid lineages in blood, BM, spleen, and thymus (0%-4%). The I8/HS-40-containing vector encoding a hybrid human beta/gamma-globin gene led to 43% to 113% human gamma-globin expression/copy of the mouse alpha-globin gene. Thus, modular use of erythroid-specific enhancers/promoters and WPRE in SIN-lentiviral vectors led to identification of high-titer, stably transmitted vectors with high-level erythroid-specific expression for gene therapy of red cell diseases.

Preparation and characterization of a composite PLGA and poly(acryloyl hydroxyethyl starch) microsphere system for protein delivery

PURPOSE

To prepare and characterize a novel composite microsphere system based on poly(D,L-lactide-co-glycolide) (PLGA) and poly(acryloyl hydroxyethyl starch) (acHES) hydrogel for controlled protein delivery.

METHODS

Model proteins, bovine serum albumin, and horseradish peroxidase were encapsulated in the acHES hydrogel, and then the protein-containing acHES hydrogel particles were fabricated in the PLGA matrix by a solvent extraction or evaporation method. The protein-loaded PLGA-acHES composite microspheres were characterized for protein loading efficiency, particle size, and in vitro protein release. Protein stability was examined by size-exclusion chromatography, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and monitoring the enzymatic activity.

RESULTS

Scanning electron microscopy showed discrete PLGA microspheres containing many acHES particles. The composite microspheres were spherical and smooth in size range of 39-93 microm. The drug loading efficiency ranged from 51 to 101%. The composite microspheres showed more favorable in vitro release than conventional PLGA microspheres. The composite microspheres showed 20% less initial with a gradual sustained release compared to high burst (approximately 60%) followed by a very slow release with the conventional PLGA microspheres. The composite microspheres also stabilized encapsulated proteins from the loss of activity during the microsphere preparation and release. Proteins extracted from the composite microspheres showed good stability without protein degradation products and structural integrity changes in the size-exclusion chromatography and SDS-PAGE analyses. Horseradish peroxidase extracted from microspheres retained more than 81% enzymatic activity.

CONCLUSION

The PLGA-acHES composite microsphere system could be useful for the controlled delivery of protein drugs.

Preconcentration of trace amounts of cadmium in aqueous samples on minicolumns packed with Chromosorb series gas chromatographic stationary phases and its determination by electrothermal atomic absorption spectrometry

The adsorption characteristics of five commercially available Chromosorb GC stationary phases towards Cd2+ and their application to the preconcentration and ETAAS determination of Cd2+ in several water samples were studied. The experimental results indicated that although all of the five Chromosorb GC stationary phases studied can retain Cd2+ quantitatively from aqueous solutions at appropriate pH values without adding chelating reagent. Chromosorb 105 displayed the highest adsorption capacity. A highly sensitive, simple methodology for preconcentration and ETAAS determination of trace amounts of cadmium in natural water samples using a Chromosorb 105 packed minicolumn is proposed. Conditions for quantitative and reproducible preconcentration, elution and subsequent ETAAS determination were established. The high retention efficiency (> 95%) for Cd2+ provides a sensitivity enhancement of 100-fold for a 200 mL sample volume with a detection limit of 6.2 ng L(-1) (3 sigma).

[Value of regional intra-arterial induction chemotherapy for locally advanced nasopharyngeal carcinoma]

OBJECTIVE

To define the value of regional intra-arterial induction chemotherapy for locally advanced nasopharyngeal carcinoma (NPC).

METHODS

121 locally advanced NPC(stage III-IV) patients confirmed by pathology were randomly divided into two groups before radiation, and the two groups were given two different methods of chemotherapy: regional intra-arterial chemotherapy (IACT) and systemic chemotherapy (SCT). After radiation the effect of two methods was compared.

RESULTS

The complete response rates were 27.9% in the IACT and 11.7% in the SCT, and 5 years survival rates were 63.9% in the IACT and 45.0% in the SCT respectively. The differences of two groups were significant.

CONCLUSION

IACT is more reasonable than SCT as induction chemotherapy for these locally advanced NPC.

Five unique compounds: xyloketals from mangrove fungus Xylaria sp. from the South China Sea coast

Five unique metabolites, xyloketals A (1), B (2), C (3), D (4), and E (5), and the known 6 were isolated from mangrove fungus Xylaria sp. (no. 2508), obtained from the South China Sea. The structures of these compounds were elucidated by spectroscopic and X-ray diffraction experiments. Xyloketal A is a ketal compound with a C(3) symmetry and xyloketals B-E are its analogues. It was found that xytoketal C slowly rearranged to xytoketal B in DMSO-d(6)() solution at room temperature. Xyloketal A exhibited the activity of inhibiting acetylcholine esterase.

ABL1 promoter methylation can exist independently of BCR-ABL transcription in chronic myeloid leukemia hematopoietic progenitors

Formation of the hybrid BCR-ABL gene is responsible for >95% of chronic myeloid leukemia (CML). The alternative, downstream ABL promoter (Pa), which is usually retained in this chimeric oncogene, was reported to be methylated in many CML patients, but there has been controversy as to whether this methylation is a frequent change in bone marrow (BM) in early chronic phase (CP) or only past this stage. Also, the relevance of Pa promoter methylation to BCR-ABL expression in CML is unclear. We examined methylation of the ABL Pa promoter in uncultured BM samples and in colonies derived from their hematopoietic precursor cells by bisulfite and PCR-based assays (combined bisulfite restriction analysis and methylation-specific PCR). BM from seven CP CML patients at diagnosis had about 20-60% of the copies of the ABL Pa promoter methylated. No Pa methylation was detected in normal BMs or colonies derived from them. In contrast, most colonies from CP CML patients had Pa methylation. Surprisingly, 18-49% of the CML-derived colonies with this methylation reproducibly had no detectable BCR-ABL RNA on nested reverse transcription-PCR. Furthermore, the percentage of BCR-ABL RNA-positive colonies was almost same among the colonies not displaying Pa methylation as among the colonies in which this methylation was found. We conclude that ABL Pa methylation is often an early marker of CML in hematopoietic precursors and in total mononuclear BM cells but that it is not associated with an increased frequency of BCR-ABL RNA-positive cells. This methylation might be emblematic of cancer-associated hypermethylation elsewhere in the genome with the consequent silencing of tumor suppressor genes seen in many malignancies.

Contractile regulation of the Na(+)-K(+)-2Cl(-) cotransporter in vascular smooth muscle

Vasoconstrictors activate the Na(+)-K(+)-2Cl(-) cotransporter NKCC1 in rat aortic smooth muscle, but the mechanism is unknown. Efflux of (86)Rb(+) from rat aorta in response to phenylephrine (PE) was measured in the absence and presence of bumetanide, a specific inhibitor of NKCC1. Removal of extracellular Ca(2+) completely abolished the activation of NKCC1 by PE. This was not due to inhibition of Ca(2+)-dependent K(+) channels since blocking these channels with Ba(2+) in Ca(2+)-replete solution did not prevent activation of NKCC1 by PE. Stimulation of NKCC1 by PE was inhibited 70% by 75 microM ML-9, 97% by 2 microM wortmannin, and 70% by 2 mM 2,3-butanedione monoxime, each of which inhibited isometric force generation in aortic rings. Bumetanide-insensitive Rb(+) efflux, an indication of Ca(2+)-dependent K(+) channel activity, was reduced by ML-9 but not by the other inhibitors. Stretching of aortic rings on tubing to increase lumen diameter to 120% of normal almost completely blocked the stimulation of NKCC1 by PE without inhibiting the stimulation by hypertonic shrinkage. We conclude that activation of the Na(+)-K(+)-2Cl(-) cotransporter by PE is the direct result of smooth muscle contraction through Ca(2+)-dependent activation of myosin light chain kinase. This indicates that the Na(+)-K(+)-2Cl(-) cotransporter is regulated by the contractile state of vascular smooth muscle.

Inhibition of Na,K-ATPase activates PI3 kinase and inhibits apoptosis in LLC-PK1 cells

In the present study we used LLC-PK1 cells, a porcine renal proximal tubular cell line, to investigate whether PI3 kinase activation was involved in the anti-apoptotic effect of ouabain, a specific inhibitor of Na,K-ATPase. Apoptosis was induced by actinomycin D (Act D, 5 microM) and assessed by appearance of hypodiploid nuclei and DNA fragmentation. Ouabain attenuated Act D-induced apoptotic response in a dose-dependent manner. Incubation in a low K(+) medium (0.1 mM) which is another way to decrease Na,K-ATPase activity also had anti-apoptotic effect. Both ouabain and low K(+) medium increased the PI3 kinase activity in p85 immunoprecipitates. Ouabain, as well as incubation in the low K(+) medium, also increased the phosphorylation of Akt. Inhibition of PI3 kinase by either wortmannin or LY294002 reversed the cytoprotective effect of ouabain. These data together indicate that inhibition of Na,K-ATPase activates PI3 kinase in LLC-PK1 cells which could then exert the cytoprotective effect.

[Synchronal ossicular chain reconstruct of chronic suppurative otitis media surgery (389 cases analyze)]

OBJECTIVE

To discuss the best material and operation style of synchronal ossicular chain reconstruct for chronic suppurative otitis media patients.

METHOD

Review and analyze the effect of ossicular chain reconstruct in 389 cases with chronic suppurative otitis media after surgery.

RESULT

The result of hearing improve of macro-tympanum III mould of ossicular chain reconstruct with artificial ossicle was better than other materials and operation types. The outcome of hearing improvement of incudostapedial joint reconstruct was better than the group of macrotympanum III mould of ossicular chain reconstruct with aritificial ossicle.

CONCLUSION

The result of hearing improvement of macro-tympanum III mould of ossicular chain reconstruct with aritificial ossicle was better than other material and operation types. The effect of aritificial ossicle better than self-ossicle in ossicular chain reconstruct surgery.

Phosphatidylinositol 3-kinase signaling controls levels of hypoxia-inducible factor 1

The phosphatidylinositol 3-kinase (PI3K) signaling pathway has inherent oncogenic potential. It is up-regulated in diverse human cancers by either a gain of function in PI3K itself or in its downstream target Akt or by a loss of function in the negative regulator PTEN. However, the complete consequences of this up-regulation are not known. Here we show that insulin and epidermal growth factor or an inactivating mutation in the tumor suppressor PTEN specifically increase the protein levels of hypoxia-inducible factor (HIF) 1alpha but not of HIF-1beta in human cancer cell lines. This specific elevation of HIF-1alpha protein expression requires PI3K signaling. In the prostate carcinoma-derived cell lines PC-3 and DU145, insulin- and epidermal growth factor-induced expression of HIF-1alpha was inhibited by the PI3K-specific inhibitors LY294002 and wortmannin in a dose-dependent manner. HIF-1beta expression was not affected by these inhibitors. Introduction of wild-type PTEN into the PTEN-negative PC-3 cell line specifically inhibited the expression of HIF-1alpha but not that of HIF-1beta. In contrast to the HIF-1alpha protein, the level of HIF-1alpha mRNA was not significantly affected by PI3K signaling. Vascular endothelial growth factor reporter gene activity was induced by insulin in PC-3 cells and was inhibited by the PI3K inhibitor LY294002 and by the coexpression of a HIF-1 dominant negative construct. Vascular endothelial growth factor reporter gene activity was also inhibited by expression of a dominant negative PI3K construct and by the tumor suppressor PTEN.

Epidermal growth factor-induced tumor cell invasion and metastasis initiated by dephosphorylation and downregulation of focal adhesion kinase

Upregulated epidermal growth factor (EGF) receptor (EGFR) expression and EGFR-induced signaling have been correlated with progression to invasion and metastasis in a wide variety of carcinomas, but the mechanism behind this is not well understood. We show here that, in various human carcinoma cells that overexpress EGFR, EGF treatment induced rapid tyrosine dephosphorylation of focal adhesion kinase (FAK) associated with downregulation of its kinase activity. The downregulation of FAK activity was both required and sufficient for EGF-induced refractile morphological changes, detachment of cells from the extracellular matrix, and increased tumor cell motility, invasion, and metastasis. Tumor cells with downregulated FAK activity became less adherent to the extracellular matrix. However, once cells started reattaching, FAK activity was restored by activated integrin signaling. Moreover, this process of readhesion and spreading could not be abrogated by further EGF stimulation. Interruption of transforming growth factor alpha-EGFR autocrine regulation with an EGFR tyrosine kinase inhibitor led to a substantial increase in FAK tyrosine phosphorylation and inhibition of tumor cell invasion in vitro. Consistent with this, FAK tyrosine phosphorylation was reduced in cells from tumors growing in transplanted, athymic, nude mice, which have an intact autocrine regulation of the EGFR. We suggest that the dynamic regulation of FAK activity, initiated by EGF-induced downregulation of FAK leading to cell detachment and increased motility and invasion, followed by integrin-dependent reactivation during readhesion, plays a role in EGF-associated tumor invasion and metastasis.