Nicotine pretreatment alleviates MK-801-induced behavioral and cognitive deficits in mice by regulating Pdlim5/CRTC1 in the PFC.

Increasing evidence shows that smoking-obtained nicotine is indicated to improve cognition and mitigate certain symptoms of schizophrenia. In this study, we investigated whether chronic nicotine treatment alleviated MK-801-induced schizophrenia-like symptoms and cognitive impairment in mice. Mice were injected with MK-801 (0.2 mg/kg, i.p.), and the behavioral deficits were assessed using prepulse inhibition (PPI) and T-maze tests. We showed that MK-801 caused cognitive impairment accompanied by increased expression of PDZ and LIM domain 5 (Pdlim5), an adaptor protein that is critically associated with schizophrenia, in the prefrontal cortex (PFC). Pretreatment with nicotine (0.2 mg · kg-1 · d-1, s.c., for 2 weeks) significantly ameliorated MK-801-induced schizophrenia-like symptoms and cognitive impairment by reversing the increased Pdlim5 expression levels in the PFC. In addition, pretreatment with nicotine prevented the MK-801-induced decrease in CREB-regulated transcription coactivator 1 (CRTC1), a coactivator of CREB that plays an important role in cognition. Furthermore, MK-801 neither induced schizophrenia-like behaviors nor decreased CRTC1 levels in the PFC of Pdlim5-/- mice. Overexpression of Pdlim5 in the PFC through intra-PFC infusion of an adreno-associated virus AAV-Pdlim5 induced significant schizophrenia-like symptoms and cognitive impairment. In conclusion, chronic nicotine treatment alleviates schizophrenia-induced memory deficits in mice by regulating Pdlim5 and CRTC1 expression in the PFC.

Three­dimensional finite element analysis: Anatomical splint fixation for Colles fractures.

With the rapid development of digital research in clinical orthopedics, the efficacy and safety of splint fixation can be better evaluated through biomechanical analysis based on a three-dimensional (3D) finite element model. It is essential to address the current gap in understanding the biomechanical implications of anatomical splint fixation for Colles fractures. By employing advanced 3D finite element analysis, the present study aimed to provide a comprehensive evaluation, offering valuable insights that can contribute to enhancing the effectiveness of anatomical splint fixation in the clinical management of Colles fractures. The 3D finite element models of the forearm and hand were constructed using Mimics 15.0 according to data from computed tomography of a patient with a Colles fracture. After the validity of the model was verified, the corresponding material properties of the models were adjusted to simulate a Colles fracture. Subsequently, the reduction functions, such as radial inclination and ulnar deviation, of the simulated fracture were completed and the mechanical changes of the tissues surrounding the fracture were calculated. Anatomical splints were then placed on the surfaces of the 3D finite element models of Colles fractures at various positions to analyze the changes in the stress cloud diagram, such as for the soft tissue and anatomical splints. In the present study, the constructed 3D finite element models were accurate and valid. The maximum stress of the anatomical splints and soft tissues was 2.346 and 0.106 MPa in pronation, 1.780 and 0.069 MPa in median rotation and 3.045 and 0.057 MPa in supination, respectively. Splint stress reached the highest level in supination and soft tissue stress achieved the highest level in pronation. The peak of splint stress occurred during supination, which contrasts to the peak of soft tissue stress observed in pronation, suggesting splint fixation median rotation can effectively avoid compression of the local soft tissue.

Multiple organs injury and myocardial energy metabolism disorders induced by isoproterenol.

The study sought to assess the detrimental effects of isoproterenol (ISO) on major organs and investigate the potential reversibility of these adverse reactions in mice. Male mice were divided into normal control, 0.2 mg/kg.d and 3.0 mg/kg.d ISO groups, and were subcutaneously administered of the respective doses for 14 consecutive days. Subsequently, a recovery period experiment was conducted, replicating the aforementioned procedure, followed by an additional 2-week recovery period for the mice. Following 14 consecutive days of administration, mice treated with ISO exhibited notable cardiac damage manifested by abnormal ECG patterns, dysregulated energy metabolism, elevated cardiac hypertrophy, and increased heart pathological score. Additionally, the administration of ISO resulted in liver and kidney damage, as evidenced by increased pathological score, serum albumin level, and urea level. Lung damage was also observed, indicated by an increase in lung pathological score. Furthermore, the administration of ISO at a dosage of 3.0 mg/kg.d resulted in a decrease in liver mass index, serum iron content, and an increase in lung mass index. After a 2-week recovery period, mice treated with ISO showed abnormalities in ECG patterns and dysregulated myocardial energy metabolism, accompanied by a decrease in serum iron content. Histopathological examinations revealed continued pathological changes in the heart and lung, as well as significant hemosiderin deposition in the spleen. Furthermore, the group treated with ISO at a dosage of 3.0 mg/kg.d showed an increase in serum AST and TP levels. In summary, the study demonstrates that both 0.2 mg/kg.d and 3.0 mg/kg.d doses of ISO can induce damage to the heart, liver, lung, kidney, and spleen, with the higher dose causing more severe injuries. After a 2-week withdrawal period, the liver, kidney, and thymus injuries caused by 0.2 mg/kg ISO shows signs of recovery, while damage to the heart, lung, and spleen persists. The thymus injury mostly recovers, with minimal kidney pathology, but significant damage to the heart, liver, and lung remains even after the withdrawal period for the 3.0 mg/kg ISO dose.

Early hemodynamics after tibial transverse transport in patients with nonarterial stenosis and arterial stenosis diabetic foot.

BACKGROUND: The diagnosis of peripheral arteriopathy in the diabetic foot is complicated by diabetes and its advanced complications. It has been found that diabetic foot can be categorized into arterial stenosis and non-arterial stenosis, both of which have significant differences in hemodynamic characteristics. AIM: To evaluate the early hemodynamic changes in diabetic foot patients with nonarterial stenosis and arterial stenosis treated by tibial transverse transport (TTT) using high-frequency color Doppler ultrasonography (HFCDU) and a laser Doppler flowmeter. METHODS: Twenty-five patients with Wagner grades 3-5 diabetic foot ulcers were treated with TTT, and the wound healing time and rate were recorded. Patients were grouped according to the results of preoperative lower-extremity ultrasonography. Cases with ≥ 50% stenosis in any of the femoral, popliteal, posterior tibial, anterior tibial, and peroneal arteries of the affected limb were classified as the arterial stenosis group (n = 16); otherwise, they were classified as the nonarterial stenosis group (n = 9). Before and one month after surgery, HFCDU was used to evaluate the degree of lower limb artery lesions and hemodynamic changes in patients. The degree of femoral-popliteal atherosclerotic stenosis, the degree of vascular stenosis and occlusion of the lower-knee outflow tract, and the degree of medial arterial calcification were scored; the three scores were added together to obtain the total score of lower extremity arteriopathy. PeriScanPIM3, a laser Doppler flowmeter system, was used to detect alterations in plantar microcirculation before and 1 mo after surgery. Wound healing and hemodynamic indices were compared between the two groups. RESULTS: The wound healing time of the diabetic foot was significantly shorter in the nonarterial stenosis group than in the arterial stenosis group (47.8 ± 13 vs 85.8 ± 26, P < 0.05), and the wound healing rate of both groups was 100%. The preoperative total lower extremity arteriopathy scores were lower in the nonarterial stenosis group than those in the arterial stenosis group (18.89 ± 8.87 vs 24.63 ± 3.52, P < 0.05). The nonarterial stenosis group showed higher preoperative popliteal artery (POA) blood flow than the arterial stenosis group (204.89 ± 80.76 cc/min vs 76.75 ± 48.49 cc/min, P < 0.05). Compared with the baseline (before surgery), the postoperative POA blood flow of the affected limb in the nonarterial stenosis group decreased one month after surgery (134.11 ± 47.84 cc/min vs 204.89 ± 80.76 cc/min, P < 0.05), while that in the arterial stenosis group increased (98.44 ± 30.73 cc/min vs 61.69 ± 21.70 cc/min, P < 0.05). Although the POA blood flow in the arterial stenosis group was obviously improved one month after surgery, it was still lower than that in the nonarterial stenosis group (98.44 ± 30.73 cc/min vs 134.11 ± 47.84 cc/min, P < 0.05). The nonarterial stenosis group had higher preoperative plantar microcirculation than the arterial stenosis group (56.1 ± 9.2 vs 33.2 ± 7.5, P < 0.05); compared with the baseline, the plantar microcirculation in the arterial stenosis group was significantly improved one month after surgery (51.9 ± 7.2, P < 0.05), while that in the nonarterial stenosis group was reduced (35.9 ± 7.2, P < 0.05). CONCLUSION: Based on preoperative HFCDU findings, diabetic foot patients can be divided into two categories: Those with nonarterial stenosis and those with arterial stenosis, with obvious differences in hemodynamic changes in the early postoperative period between them. In the early stage after TTT, the blood flow volume and velocity and the plantar microcirculation perfusion of the affected limb of the diabetic foot with nonarterial stenosis decreased compared with the baseline, while those of the diabetic foot with arterial stenosis improved significantly compared with the baseline, although both had smoothly healed diabetic foot ulcers.

Tetrafluorophenylene-Containing Vinylbenzyl Ether-Terminated Oligo(2,6-dimethyl-1,4-phenylene ether) with Better Thermal, Dielectric, and Flame-Retardant Properties for Application in High-Frequency Communication.

In an integrated circuit, signal propagation loss is proportional to the frequency, dissipation factor (D f), and square root of dielectric constant (D k). The loss becomes obvious as we move to high-frequency communication. Therefore, a polymer having low D k and D f is critical for copper-clad laminates at higher frequencies. For this purpose, a 4-vinylbenzyl ether phenoxy-2,3,5,6-tetrafluorophenylene-terminated OPE (VT-OPE) resin was synthesized and its properties were compared with the thermoset of commercial OPE-2St resin. The thermoset of VT-OPE shows a higher T g (242 vs 229 °C), a relatively high cross-linking density (1.59 vs 1.41 mmole cm-3), a lower coefficient of thermal expansion (55 vs 76 ppm/°C), better dielectric characteristic at 10 GHz (D k values of 2.58 vs 2.75, D f values of 0.005 vs 0.006), lower water absorption (0.135 vs 0.312 wt %), and better flame retardancy (UL-94 VTM-0 vs VTM-1 with dropping seriously) than the thermoset of OPE-2St. To verify the practicability of VT-OPE for copper-clad laminate, a laboratory process was also performed to prepare a copper-clad laminate, which shows a high peeling strength with copper foil (5.5 lb/in), high thermal reliability with a solder dipping test at 288 °C (>600 s), and the time for delamination of the laminate in thermal mechanical analysis (TMA) at 288 °C is over 60 min.

Efficiency Improvement of Quantum Dot Light-Emitting Diodes via Thermal Damage Suppression with HATCN.

With many advantages including superior color saturation and efficiency, quantum dot light-emitting diodes (QLEDs) are considered a promising candidate for the next-generation displays. Emission uniformity over the entire device area is a critical factor to the overall performance and reliability of QLEDs. In this work, we performed a thorough study on the origin of dark spots commonly observed in operating QLEDs and developed a strategy to eliminate these defects. Using advanced cross section fabrication and imaging techniques, we discovered the occurrence of voids in the organic hole transport layer and directly correlated them to the observed emission nonuniformity. Further investigations revealed that these voids are thermal damages induced during the subsequent thermal deposition of other functional layers and can act as leakage paths in the device. By inserting a thermo-tolerant 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HATCN) interlayer with an optimized thickness, the thermally induced dark spots can be completely suppressed, leading to a current efficiency increase by 18%. We further demonstrated that such a thermal passivation strategy can work universally for various types of organic layers with low thermal stability. Our findings here provide important guidance in enhancing the performances and reliability of QLEDs and also other sandwich-structured devices via the passivation of heat-sensitive layers.

Observation and Suppression of Stacking Interface States in Sandwich-Structured Quantum Dot Light-Emitting Diodes.

Interfacial quality of functional layers plays an important role in the carrier transport of sandwich-structured devices. Although the suppression of interface states is crucial to the overall device performance, our understanding on their formation and annihilation mechanism via direct characterization is still quite limited. Here, we present a thorough study on the interface states present in the electron transport layer (ETL) of blue quantum dot (QD) light-emitting diodes (QLEDs). A ZnO/ZnMgO bilayer ETL is adopted to enhance the electron injection into blue QDs. By probing the ETL band structure with photoelectron spectroscopy, we discover that substantial band bending exists at the ZnO/ZnMgO interface, elucidating the presence of a high density of interface states which hinder electron transport. By inserting a ZnO@ZMO interlayer composed of mixed ZnO and ZnMgO nanoparticles, the band bending and thus the interface states are observed to reduce significantly. We attribute this to the hybrid surface properties of ZnO@ZMO, which can annihilate the surface states of both the ZnO and ZnMgO layers. The introduction of a bridging layer has led to ∼40% enhancement in the power efficiency of blue QLEDs and noticeable performance boosts in green and red QLEDs. The findings here demonstrate a direct observation of interface states via detailed band structure studies and outline a potential pathway for eliminating these states for better performances in sandwich-structured devices.

Validation of Susceptibility Loci for Vitiligo Identified by GWAS in the Chinese Han Population.

Forty-nine susceptible loci have been reported to be significantly associated with vitiligo by genome-wide association studies (GWASs) in European-derived whites. To date, some of these reported susceptibility loci have not yet been validated in the Chinese Han population. The purpose of this study was to examine whether the 16 reported susceptible loci in European-derived whites were associated with vitiligo in the Chinese Han population. Imputation was performed using our previous GWAS dataset by IMPUTE v2.2.2. The 16 imputed top single-nucleotide polymorphisms (SNPs) with suggestive signals, together with the reported SNPs, were genotyped in a total of 2581 patients and 2579 controls by the Sequenom MassARRAY system. PLINK 2.0 software was used to perform association analysis. The dbSNP database, HaploReg, and eQTL data were adopted to annotate the biological function of the SNPs. Finally, four SNPs from three loci were significantly associated with vitiligo, including rs3747517 (P = 1.29 × 10-3, OR = 0.87) in 2q24.2, rs4807000 (P = 7.78 × 10-24, OR = 0.66) and rs6510827 (P = 3.65 × 10-5, OR = 1.19) in 19p13.3, and rs4822024 (P = 6.37 × 10-10, OR = 0.67) in 22q13.2. According to the dbSNP database, rs3747517 is a missense variant of IFIH1, rs4807000 and rs6510827 are located in TICAM1, and rs4822024 is located 6 kb upstream of TEF. Further bioinformatics analysis by HaploReg and eQTL found that rs4807000, rs6510827, and rs4822024 are involved in regulating gene expression. Our study revealed the strong association of 2q24.2 (rs3747517), 19p13.3 (rs4807000, rs6510827), and 22q13.2 (rs4822024) with the risk of vitiligo in the Chinese Han population, which implicates common factors for vitiligo across different ethnicities, and helps expand the understanding of the genetic basis of this disease.

Immunoglobulin kappa and immunoglobulin lambda are required for expression of the anti-apoptotic molecule Bcl-xL in human colorectal cancer tissue.

OBJECTIVE: Aberrant expression of immunoglobulin (Ig) by cancer cells has been documented in a number of malignant tumors but its biological significance is unclear. Cancer cells overexpress anti-apoptotic molecules such as Bcl-xL. The present study aimed to examine the role of expression of Ig light-chain Igk and Iglambda in maintaining the high levels of Bcl-xL in colorectal cancer cells. MATERIAL AND METHODS: Thirty patients with colorectal cancer were recruited to this study. Expression of Igk, Iglambda and Bcl-xL in surgically removed cancer tissue was examined by immunohistochemistry and/or flow cytometry. Using the HT29 cell line as a study platform, RNA interference (RNAi) was employed to knock out the genes of Igk and Iglambda in the cancer cell line; the expression of Bcl-xL in HT29 cells was subsequently analyzed. RESULTS: Human colorectal cancer cells, but not normal colorectal tissue, expressed both Igk and Iglambda in the cytoplasm. High levels of Bcl-xL were detected in cancer cells. Using RNAi to knock out the genes of Igk and/or Iglambda, Bcl-xL expression in HT29 cells was significantly suppressed and the cells became apoptotic. CONCLUSION: The results suggest that expression of Igk and Iglambda is required to stabilize Bcl-xL expression in cancer cells.

LINE-1 family member GCRG123 gene is up-regulated in human gastric signet-ring cell carcinoma.

AIM: To analyze the expression profiles of a human gastric-cancer-related gene, GCRG123, in human gastric signet-ring cell carcinoma tissues, and to perform bioinformatics analysis on GCRG123. METHODS: In situ hybridization was used to explore the GCRG123 expression pattern in paraffin-embedded gastric tissues, including 15 cases of signet-ring cell carcinoma, 15 of intestinal-type adenocarcinoma, and 15 of normal gastric mucosa. Northern blotting was used to analyze the differences in GCRG123 expression between stomach signet-ring cell carcinoma and intestinal-type adenocarcinoma tissues. Online software, including BLAST, Multalin and BLAT, were applied for bioinformatics analysis. National Center for Biotechnology Information (NCBI) and the University of California Santa Cruz (UCSC) databases were used for the analyses. RESULTS: The in situ hybridization signal appeared as blue precipitates restricted to the cytoplasm. Ten out of 15 cases of gastric signet ring cell carcinoma, normal gastric mucosal epithelium and pyloric glands showed high GCRG123 expression. Low GCRG123 expression was observed in gastric intestinal-type adenocarcinoma and normal gastric glands. Northern blotting revealed that GCRG123 was up-regulated in signet-ring cell carcinoma tissue but down-regulated in intestinal-type adenocarcinoma tissue. BLAST and Multalin analyses revealed that the GCRG123 sequence had 92% similarity with the ORF2 sequence of human long interspersed nuclear element retrotransposons (LINE-1, L1). BLAT analysis indicated that GCRG123 mapped to all chromosomes. GCRG123 was found to integrate in the intron-17 and -23 of Rb, 5' flanking region of IL-2 and clotting factor IX genes. CONCLUSION: GCRG123, an active member of the L1 family, was up-regulated in human gastric signet-ring cell carcinoma.

[Expression of S100A6 in primary and metastatic human gastric cancer].

OBJECTIVE: Some members of the S100 gene family have been suggested to be associated with cancer development and metastasis. Our previous cDNA micro-array studies have showed S100A6 expression is elevated in gastric cancer compared with that in paired normal mucosa. To validate our previous results and further investigate the possible role of S100A6 gene in gastric cancer, we carried out this detailed S100A6 expression analysis in more matched gastric cancer samples. METHODS: S100A6 expression was detected in 20 paired fresh surgical samples of gastric tumor tissue and matched non-cancerous mucosa by QRT-PCR. A gastric cancer tissue microarray (TMA) containing 1020 duplicate matched normal mucosa, gastric cancer tissue and metastatic lymph node tissue cores from 208 gastric cancer patients was constructed. S100A6 expression was detected by immunohistochemistry and the correlation between S100A6 expression with clinicopathological factors and survival was analyzed. RESULTS: As quantitated by QRT-PCR, S100A6 transcript level was elevated in 73.7% of the primary cancer lesions with an average 2.25-fold up-regulation than that in matched non-neoplastic mucosa. As displayed by immunohistochemistry, the positive rate of S100A6 in non-neoplastic mucosa, tumor lesions and metastatic lymph nodes was 34.3%, 84.1% and 90.9%, respectively. S100A6 expression level in cancer and metastatic lymph node was significantly higher than their matched non-neoplastic mucosa (P < 0.05). 65.5% of patients showed an increased S100A6 expression in cancer tissue compared with that in matched normal mucosa. S100A6 overexpression was associated with larger tumor size and deeper invasion (P = 0.022 and P = 0.009). No evidence was found for an association between S100A6 expression level and other variables, including tumor grade, nodal metastases, and TNM stage. There was no association between S100A6 expression level and survival. But compared with paired non-neoplastic mucosa, an increased S100A6 expression in tumor lesion predicated a decreasing suvival if compared with a decreased S100A6 expression, though the difference was statistically not significant. CONCLUSION: Elevated expression of S100A6 gene may be an early event in the development and progression of gastric cancer. Further study of this gene may be helpful for understanding the nature of gastric carcinoma.

[Construction of a gastric cancer related gene GCRG213-specific siRNA expression vector and its effect on gastric cancer cells in vitro].

OBJECTIVE: To investigate the effect of gene GCRG213 siRNA transfection into gastric cancer cell line MKN45 cells. METHODS: Two pairs of DNA sequences containing small hairpin structure to GCRG213 were designed and synthesized. The complement form was obtained by annealing and inserted into RNAi expression vector IMG-800. They are IMG-800-1 and IMG-800-2 correspondingly. The recombinant plasmid IMG-800-1, IMG-800-2 and the vector IMG-800 were separately transfected into MKN45 cells conducted by lipofectamine 2000. After G418 selecting, the cells were transfected steadily. Expression of GCRG213 was detected by semi-quantitative RT-PCR and Western Blot. The growth graph of six steady transfected cell cultures was protracted by cell counting. FACS was used to detect the cell cycle, and Annexin V FITC/PI double labeling were used to detect the effects on cell apoptosis in the above-mentioned cells. The clone formation rate in plate and in nude mice was tested to investigate the tumorigenic characteristics of the six steadily transfected cells in vitro and vivo. RESULTS: Through sequencing, two pairs of DNA sequences containing small hairpin structure to GCRG213 were proved to be successfully cloned into siRNA expression vector IMG-800, correspondingly called IMG-800-1 and IMG-800-2. The recombinant plasmid IMG-800-1, IMG-800-2 and vector IMG-800 were transfected separately into MKN45 cells conducted by lipofectamine 2000. After G418 selecting, the cells were transfected steadily. Transfecting the siRNA vector (IMG-800-1, IMG-800-2 ) into the MKN45 cells significantly decreased the expression of GCRG213, at both mRNA and protein levels. The growth graph showed that the growth of IMG-800-1 and IMG-800-2 transfected cells were slower than that of vector transfected cells. The proportion of cells in G2/M and/or S phase decreased in the cells transfected with IMG-800-1 and IMG-800-2 and cell apoptosis increased. The average clone formation rate in vitro decreased in the cells transfected with IMG-800-1 and IMG-800-2, compared with those transfected with vector. In vivo, the time of tumor formation of IMG-800-1 and IMG - 800-2 transducted cells in nude mice was prolonged and the tumor size was smaller. CONCLUSION: GCRG213 SiRNA transfection may induce inhibition of growth and proliferation of tumor cells, promote cell apoptosis, and inhibit the tumorigenicity in vitro and vivo.

Low Dielectric Polyetherimides Derived from Bis[4-(4-(4-aminophenoxy)-2-tert-butylphenoxy)phenyl] Sulfone and 4,4'-Bis[4-(4-aminophenoxy)-2-tert-butylphenoxy]perfluorobiphenyl.

Two diamines, bis[4-(4-(4-aminophenoxy)-2-tert-butylphenoxy)phenyl] sulfone (PSNH2) and 4,4'-bis[4-(4-aminophenoxy)-2-tert-butylphenoxy)perfluorobiphenyl (PFNH2), were prepared from 3-tert-butyl-4-hydroxyanisole using a four-step procedure, including two nucleophilic substitutions, demethylation, and catalytic reduction. On the basis of PSNH2 and PFNH2, two series of low dielectric polyetherimides (PEIs) were prepared. Both series of PEIs exhibit moderate-to-high thermal properties, including a glass transition temperature (T g) > 259 °C (depending on the rigidity of dianhydride), a 5 wt % decomposition temperature (T d5%) > 496 °C, and a coefficient of thermal expansion < 66 ppm/°C. Because of the hydrophobic tert-butyl phenylene oxide structure, both series of PEIs show excellent dielectric properties, with a dielectric constant as low as 2.4-2.7. The structure-property relationship of both series of PEIs is discussed in this work.

Synthesis of a Bisbenzylideneacetone-Containing Benzoxazine and Its Photo- and Thermally Cured Thermoset.

A bis(4-hydroxybenzylidene)acetone/aniline-based benzoxazine (BHBA-a) was prepared from a bisbenzylidene-containing bisphenol, bis(4-hydroxybenzylidene)acetone (BHBA), aniline, and paraformaldehyde through Mannich condensation in a cosolvent of toluene/ethanol (2:1, v/v). The structure of BHBA-a was successfully confirmed by Fourier transform infrared and 1H and 13C NMR spectra. According to the differential scanning calorimetry (DSC) thermogram of BHBA, an immediate exothermic peak after the melting peak was observed, suggesting that BHBA is thermally active. NMR data of thermally treated BHBA confirm that the immediate exothermic peak after melting of BHBA in the DSC thermogram is resulted from the curing of a double bond. UV and 1H NMR spectra of BHBA-a show that the bisbenzylideneacetone moiety underwent dimerization through the [2π + 2π] cycloaddition. Therefore, two procedures were applied to cure BHBA-a. The first one was thermal curing of the double bond of bisbenzylideneacetone and oxazine moieties. The second one was photocuring of the bisbenzylideneacetone moiety, followed by thermal curing of the oxazine moiety. The thermal properties of thermosets were evaluated based on these two procedures. Thermosets of BHBA-a exhibit T g as high as 318 °C for curing procedure 1 and 342 °C for curing procedure 2. These values are much higher than that of a traditional bisphenol/aniline-based benzoxazine thermoset. We conclude that the thermal curing of the double bond of bisbenzylideneacetone and photodimerization of bisbenzylideneacetone contributes to the good thermal properties.

A novel gene, GCRG224, is differentially expressed in human gastric mucosa.

AIM: To clone genes that may predispose us to human gastric cancer and to analyze it's expression in gastric tissues. METHODS: Specimens of paired tumor, paratumor and normal gastric mucosa tissues collected from fifteen patients who suffered from stomach antrum adenocarcinoma were used for analysis. Seven out of the fifteen cases were first studied by fluorescent differential display reverse transcription polymerase chain reaction (DDTR-PCR) analysis. The differentially expressed bands of interest were cloned, analyzed by Northern blot, sequencing and RT-PCR. Through BLAST, the sequencing results were compared with GenBank database for homology analysis. In situ hybridization with DIG-labeled cRNA probes was used to analyze the expression of interesting cDNA bands in paraffin embedded paired normal gastric mucosa and cancer tissues isolated from 30 gastric adenocarcinoma patients. RESULTS: DDRT-PCR showed that one of the interesting cDNA bands, which was named W2, expressed much higher in all seven tested tumor and paratumor samples than in their normal counterparts, it was sub-cloned into a pGEM-T Easy vector. Two subclones were subsequently obtained. One of the subclone, GCRG224, was studied further. The sequencing result showed that GCRG224 consisted of 1 159 base pairs and had one open reading frame (ORF). It located at human chromosome 11q14. No homologue was found in GenBank database with GCRG224-ORF. This nucleotide sequence data were submitted to GenBank with accession No. AF438406. RT-PCR showed that GCRG224 expressed higher in 11/15 gastric cancer tissues than in non-tumor tissues. However, the result of Northern blot analysis showed a higher GCRG224 expression in the non-tumor tissue than in the tumor one. Human multiple tissue Northern blot analysis revealed that GCRG224 also expressed in human normal colon tissue, and peripheral blood leukocyte. In situ hybridization analysis showed that only 5/30 adenocarcinoma, 3/18 dysplasia and 6/18 intestinal metaplasia showed higher GCRG224 expression level than the normal gastric glands. However, GCRG224 was over-expressed predominantly in 26/30 cases of normal mucosal epithelium. CONCLUSION: A novel gene named GCRG224 was identified from human gastric mucosal tissue. It overexpressed in almost all gastric mucosal epithelium but only a small portion of cancer and precancerous leisions. The role of GCRG224 expression in gastric epithelium needs further study.

A gene encoding an apurinic/apyrimidinic endonuclease-like protein is up-regulated in human gastric cancer.

AIM: To identify the gene that may predispose to human gastric cancer and to analyze its expression in gastric cancer and non-tumorous gastric mucosa. METHODS: Cancer, para-tumor, and non-tumor gastric tissues were studied for gene expression profile using fluorescent differential display reverse transcription polymerase chain reaction (DDRT-PCR). The differentially expressed bands of interest were analyzed by cloning, Northern blotting, and sequencing. The sequencing results were compared with the GenBank database for homology and conserved domain analysis. In situ hybridization with DIG-labeled cRNA probes was used to detect the expression of gene in paraffin embedded gastric adenocarcinoma and non-cancerous tissues. RESULTS: A gene expressed higher in tumor and para-tumor tissues than in their non-tumor counterparts of all 7 tested gastric adenocarcinoma patients was identified by means of DDRT-PCR analysis. It was named GCRG213 (gastric cancer related gene 213). Northern blot confirmed the differential expression. GCRG213 (GenBank No. AY053451) consisted of 1094 base pairs with an open reading frame (ORF) which encoded 142 amino acids. The deduced amino acid sequence contained a putative conserved domain, apurinic/apyrimidinic endonuclease (APE). In situ hybridization analysis showed that GCRG213 was expressed higher in gastric cancer tissues than in their corresponding non-tumor ones. Precancerous leisions of gastric adenocarcinoma showed a high GCRG213 expression, too. No difference of the expression patterns was found between the early and advanced gastric cancer. CONCLUSION: A gene named GCRG213 was identified in human gastric adenocarcinoma. It encoded an APE-like protein which was probably a new member of the APE family. GCRG213 was over-expressed not only in gastric cancer, but also in its precancerous leisions. The role of GCRG213 expression in carcinogenesis needs further study.

Colonoscopic screening and follow-up for colorectal cancer in the elderly.

AIM: To improve the prevention and treatment of senile patients with colorectal cancer by evaluating the importance of colonoscopy in clinical screening and follow-up. METHODS: Clinical screening of colonoscopy was performed for 2196 patients aged 60-90 years old according to the protocol,and 1740 of them (79.2%) were followed-up. RESULTS: Colorectal cancer was found in 52 patients, and the detectable rate was 2.4%. Among them, 19 were diagnosed as early colorectal cancer, accounting for 36.5% of the detected colorectal cancer. Among the followed-up patients, early colorectal cancer was found in 9, accounting for 45.0% of the detected colorectal cancer. The resectable rate and 5 years survival rate of colorectal cancer were 97.7% and 80.9% respectively. The incidence of complication was 0.05%, and the successful rate of cecum intubation was 98.9%. CONCLUSION: Colonoscopic screening and follow-up of the elderly for colorectal cancer and pre-cancerous lesion (adenomatoid polyp) can increase the detectable rate of early colorectal cancer and improve its prevention and treatment.

[Clinical analysis of 38 elderly patients with early double primary cancers].

OBJECTIVE: To study the clinical features and proper treatment of 38 elderly patients with early double primary cancers. METHODS: Thirty-eight elderly patients with early double primary cancers treated from January 1980 to March 2003 were retrospectively reviewed for involved organs, treatment and prognosis. RESULTS: Digestive tract was the most frequently involved, followed by urogenital system and lung. Long-term results of endoscopic mucosal resection (EMR), operation and radiotherapy were superior to other methods. The prognosis of gastrointestinal carcinoma was better than that of prostate carcinoma and hematopoietic system. The operation rate decreased with increasing age. The 5-year survival rates of EMR, operation and radiotherapy were 85.7%, 71.1% and 75.0%, respectively. The medium survival time was 120 months in first cancer and 39 months in the second primary cancer. The 5-year survival rates of the first cancer and second primary cancer were 88.6% and 53.8%. CONCLUSION: Yearly follow-up for elderly patients with endoscopy, beta ultrasonic scan and X-ray contribute to finding of early double primary cancers. Operation is the best treatment of early double primary cancers. Endoscopic mucosal resection is especially suitable for old patients with digestive tract and bladder cancer.

[Cloning and tissue expression analysis of up-regulated cDNA fragment in human gastric cancer].

OBJECTIVE: To identify novel human gastric cancer-associated susceptibility gene for early diagnosis and treatment of gastric cancer. METHODS: A primer was designed for 3'-rapid amplification of cDNA end(RACE) and amplified fragments were cloned, then they were analyzed by sequencing. Compared with ESTs in Genbank, the EST fragment represented a novel gene. Combination of Northern blot and virtual Northern and multiple tissues Northern blot, expression of the cDNA in multiple normal and carcinoma tissues were analyzed. RESULTS: One of the important cDNA bands with poly(A) tail was cloned. This band was named W41. Sequence analysis showed that W41 consists of 533 bp. Basic local alignment search tool analysis revealed that W41 has low identity with any genes from GenBank. This sequence data was submitted to GenBank with accession No. AF 325202. Northern blot revealed that W41 presented higher expression in gastric cancer tissue than in normal tissue. Multiple tissue Northern blot revealed that W41 presented higher expression in multiple cancers than in normal tissues. Virtual Northern revealed that the cDNA presented higher expression in tumor series analysis of gene expression libraries than in normal. CONCLUSION: A novel human gastric cancer-associated cDNA fragment was identified.

[Expression of human anti-apoptotic gene survivin and its splice in normal human gastric tissue and gastric cancer].

OBJECTIVE: To analyze the expression of human anti-apoptotic gene survivin (SVV) in normal human gastric tissues and gastric cancer. METHODS: SVV cDNA clone was obtained from human gastric cancer tissues by virtue of RT-PCR, using Dig-marked cRNA probe in situ hybridization to analyze its expression in normal human gastric tissues and gastric cancer. RESULTS: Two SVV cDNA clones, SVV-S4A and SVV-S1B were obtained. The sequence of the former is identical to that of the well-known SVV cDNA; however, in the sequence of the latter, the third exon was missed, i.e., there are only two exons in SVV-S1B. In situ hybridization showed that SVV-S4A is mainly expressed in gastric cancer tissues whereas SVV-S1B is mostly expressed in normal gastric tissues. CONCLUSION: There is difference between SVV-S4A and SVV-S1B in respect to their characteristics of expression in gastric cancer and normal gastric tissues.