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For a directly finite exchange ring R which satisfies general comparability, we construct all extreme points of the state space S ( V ( R ),< R >), where V ( R ) denotes the monoid of all isomorphic classes of finitely generated projective R -modules. From this, we further prove that S (( K 0 ( R ),[ R ])) is affinely homeomorphic to M 1 + ( BS ( R )), where BS ( R ) denotes the spectrum of the Boolean algebra B ( R ) of all central idempotents in R , and M + 1 ( BS ( R )) the set of all probability measures on BS ( R ). These generalize the corresponding results on regular rings. Particularly, all of our results hold for exchange rings with all the idempotents central. [ABSTRACT FROM AUTHOR]

Morphological differences were found among specimens of Garra orientalis from Minjiang River, Pearl River, Red River and Hainan Island. To confirm whether the morphological differences among these geographical populations had reached the level of subspecies or species, seventy-two specimens of Garra orientalis were divided into four groups according to the four drainage areas stated above. Ten external morphological characteristics were observed. Thirteen frame characteristics and twenty-three general characteristics were measured and analyzed for multivariate morphometrics. In scatter plots of principal components, the specimens from Hainan Island were relatively concentrated on the scatter plots, but were not completely separated from the other three drainages. The samples from the other three drainages were completely mixed together. These results indicated that the specimens from the different drainages could not be distinguished by morphological comparison and morphometric analysis. Species or subspecies level differentiation of Garra orientalis among geographical populations could instead be studied by molecular biological methods in the future.

Objective: To evaluate the correlation between single nucleotide polymorphisms (SNP) in the promoter of ataxia-telangiectasia mutated (ATM) gene and the susceptibility of nasopharyngeal carcinoma in Cantonese., Methods: A total of 176 NPC Cantonese NPC patients and 202 age-matched healthy controls were enrolled in this study. G/A genotyping of the SNP locus rs189037 in the promoter of ATM gene was performed by PCR and direct sequencing of the PCR products., Results: The genotype frequency of heterozygote G/A was 50% (88/176) and 47.5% (96/202), and that of the homozygote variant A/A was 15.3% (27/176) and 18.3% (37/202) in NPC patients and healthy individuals, respectively. Statistics analysis revealed no evident correlations of the G/A and A/A genotypes to the clinical phenotypes of NPC in either NPC group or healthy control group (OR7equals;1.022, 95%CIequals;0.668-1.564 for G/A+A/A). Analysis after stratification by age and gender found no such correlations either., Conclusion: The genotype frequencies of SNP locus rs189037 in the promoter of ATM gene are similar between NPC patients and healthy subjects, suggesting that rs189037 is not related to the genetic susceptibility of NPC in Cantonese.

Objective: To investigate the role of lung fibroblast activation in radiation-induced lung injury., Methods: Thirty-five male Wistar rats were exposed to a single-dose 30 Gy irradiation of the right hemithorax or sham right lung irradiation. At 1, 7, 14, 28, 56 or 84 days after the irradiation, the rats were sacrificed for examination of alpha-smooth muscle actin (alpha-SMA) expression in the bilateral lung tissues using immunohistochemistry., Results: alpha-SMA expression in fibroblast increased significantly in the out-field and in-field lung tissues within 24 h after irradiation after the irradiation (P<0.001)., Conclusion: Activation of the lung fibroblasts occurred within 24 h after irradiation and found in ont-field and in-field lung tissues, suggesting that radiation-induced lung injury may not have an obvious latency.

Objective: To evaluate the outcomes of patients with unresectable massive primary liver cancer (PLC) receiving three-dimensional conformal radiotherapy (3-DCRT) combined with transcatheter arterial chemoembolization (TACE)., Methods: From January 2001 to December 2004, 84 patients with unresectable massive PLC (tumor size> or =10 cm) received 3-DCRT combined with TACE, including 49 cases in UICC/AJCC T(3) stage and 35 cases in T(4) stages. Lymph node metastasis was found in none of the patients, and portal vein tumor thrombosis (PVTT) was detected in 30 cases. Child-Pugh grade A of liver cirrhosis was present in 64 cases and grade B in 20 cases. The mean value of GTV was 705-/+430 cm(3) (170-2099 cm(3)). Following injections of fluorouracil and hydroxycamptothecine into the target artery of the tumor, the mixture of carboplatin, mitomycin (or pirarubicin) and super-liquefactive iodized oil was injected into the target artery. Gelatin sponge was used to embolize the artery. The procedure was repeated every 1.5-2 months according to the condition of the patients, and each patient received 1-3 such procedures. 3-DCRT was performed in all the patients, who received a total dose of 53.6-/+6.6 Gy (4-6 Gy per fraction at the interval of 48 h), and 3 fractions were given every week., Results: Eight patients died in 3 months after 3-DCRT and were not evaluated. The total response rate (CR+PR) in these patients was 68.9% (51/74). The overall survival rates at 1, 2 and 3 years were 55.4%, 24.7% and 15.4%, respectively. T stage, GTV, PVTT and fraction size had no significant impact on the overall survival. Child-Pugh grade was found to have significant impact on the patients' survival (P=0.035, RR=2.440)., Conclusion: 3-DCRT combined with TACE has definite therapeutic effect on advanced massive PLC, and Child-Pugh grade is an independent prognostic factor in such cases.

Objective: To investigate the relationship between human multidrug resistancel gene (MDR1) polymorphisms and the radiosensitivity of nasopharyngeal carcinoma (NPC)., Methods: Blood samples were collected from 59 NPC patients, who were devided into radiosensitive or radioresistant groups according to their responses to radiation therapy. The genotypes for MDR1 polymorphisms (G2677T in exon 21 and C3435T in exon 26) and their haplotypes were determined by PCR and restriction fragment length polymorphism analysis. The results were further confirmed by sequencing., Results: The 3435CC genotype was associated with a significantly better response to radiotherapy than combined 3435 CT and TT genotype (P=0.026). The 2677GG genotype was also associated with a better response in comparison with combined 2677 GT and TT genotype, but this relation was not statistically significant. Patients with 2677G-3435C haplotype had a significant better response to radiotherapy than those with the other haplotypes (P=0.017)., Conclusion: The MDR1 G2677T and C3435T polymorphisms may help predict the response to radiotherapy in NPC patients.

Background & Objective: It is reported that ATM gene is closely correlated to cellular radiosensitivity in several malignant tumors. Suppression of ATM protein expression leads to cellular radiosensitization. This study was to determine whether this effect also exists in nasopharyngeal carcinoma (NPC) cell line CNE1 by inhibiting the expression of ATM protein through antisense RNA of ATM/PI3K region, which is the most important functional fragment of ATM gene., Methods: The recombinant pDOR-atm expressing antisense RNA of ATM/PI3K segment was constructed with retroviral vector pDOR. CNE1 cells were stably transfected with pDOR-atm by cationic liposome and named CNE1/pDOR-atm. Semi-quantitive RT-PCR was used to detect the level of ATM mRNA. Flow cytometry (FCM) was employed to analyze the percentage of positive cells and mean fluorescence density of protein expressing ATM. Cellular radiosensitivity was evaluated by colony survival assay (CSA) and linear-quadratic model in both CNE1/ pDOR-atm and control cells., Results: The level of ATM mRNA index (RI) was 0.23+/-0.02 in CNE1/pDOR-atm group, and 0.51+/-0.03 in control group (P<0.05). The percentage of positive cells and mean fluorescence density of proteins expressing ATM were 70.8% and 1.81+/-0.12 in CNE1/pDOR-atm group, while 99.3% and 4.51+/-0.18 in control group(P<0.01). The expression of ATM mRNA and protein was inhibited by antisense RNA. The alpha value (one function from linear-quadratic model) of CNE1/pDOR-atm group was 0.40 Gy(-1), while it was 0.36 Gy(-1) in control group. The radiosensitizing ratio of surviving fraction at 2 Gy (SF(2)) was 3.0, indicating that antisense RNA group was more radiosensitive to X-ray than the controls., Conclusion: NPC cell line CNE1 could be radiosensitized by the down-regulation of ATM/PI3K expression.