Domestication and geographic origin of Oryza sativa in China: insights from multilocus analysis of nucleotide variation of O. sativa and O. rufipogon.

Previous studies have indicated that China is one of the domestication centres of Asian cultivated rice (Oryza sativa), and common wild rice (O. rufipogon) is the progenitor of O. sativa. However, the number of domestication times and the geographic origin of Asian cultivated rice in China are still under debate. In this study, 100 accessions of Asian cultivated rice and 111 accessions of common wild rice in China were selected to examine the relationship between O. sativa and O. rufipogon and thereby infer the domestication and evolution of O. sativa in China through sequence analyses of six gene regions, trnC-ycf6 in chloroplast genomes, cox3 in mitochondrial genomes and ITS, Ehd1, Waxy, Hd1 in nuclear genomes. The results indicated that the two subspecies of O. sativa (indica and japonica) were domesticated independently from different populations of O. rufipogon with gene flow occurring later from japonica to indica; Southern China was the genetic diversity centre of O. rufipogon, and the Pearl River basin near the Tropic of Cancer was the domestication centre of O. sativa in China.

The regimen of gemcitabine and cisplatin combined with radio frequency hyperthermia for advanced non-small cell lung cancer: a phase II study.

PURPOSE: This phase II randomised trial was designed to evaluate the therapeutic efficacy and feasibility of radio frequency regional hyperthermia in combination with chemotherapy for patients with advanced non-small lung cancer (NSCLC). METHODS: Eighty patients with pathologically proven advanced NSCLC, were enrolled and divided into two groups. Group A patients were treated by radio frequency regional hyperthermia in combination with the regimen of gemcitabine and cisplatin (GP). Group B patients were treated with the GP regimen alone. RESULTS: In group A, one patient achieved a complete response (CR), 18 achieved a partial response (PR), 18 achieved a stable disease and three experienced a progression of the disease. Thirty-three patients had a positive Clinical Benefit Response (CBR). In group B, no patient achieved CR, 17 achieved PR, 19 achieved a stable disease and four experienced a progression of the disease. Nineteen patients had a positive CBR. Significant differences between the two groups were observed for the CBR (P < 0.05), but not for RR. Major toxicities included bone marrow depression, nausea, vomiting, without significant differences between the two groups (P > 0.05). CONCLUSIONS: Radio-frequency regional hyperthermia in combination with chemotherapy (GP) is a safe, well tolerated, and effective therapeutic modality for patients with advanced NSCLC. The addition of hyperthermia improved quality of life.

Rapid quantitation of lamivudine-resistant mutants in lamivudine treated and untreated patients with chronic hepatitis B virus infection.

BACKGROUND: Long-term lamivudine treatment induces emergence of lamivudine-resistant hepatitis B virus (HBV) in a significant number of patients with chronic HBV infection. Rapid and quantitative methods to determine the percentage of lamivudine-resistant mutants in total HBV are important during lamivudine therapy. METHODS: We established a quantitative real-time PCR method with selective primers and TaqMan probe to detect the percentage of lamivudine-resistant mutants in total HBV without the need of external DNA standards. This percentage was calculated as the PCR efficiency raised to the differences between threshold cycle number (DeltaCt) of mutant and control reactions. Clones of the HBV polymerase gene containing the different YMDD variants were diluted in series and tested. Serum samples from 145 lamivudine-treated and 98 untreated patients with chronic hepatitis B virus infection were analyzed using this method and compared with DNA sequencing. RESULTS: As little as 0.1% mutant plasmids in 10(6)-10(9) copies/ml of wild-type plasmids were detected. Among the 145 patients treated with lamivudine, 42 of them had mutants with percentages of 5-100%. In six discordant results between real-time PCR and DNA sequencing, real-time PCR detected mutants with percentages of 5-20%, which were concordant with subclone sequencing. Five of 98 lamividine-untreated patients had mutants of 10-20% in wild-type virus populations. Compared to DNA sequencing, real-time PCR was fast and cost-effective. CONCLUSION: This real-time PCR is a rapid, sensitive and cost-effective method for relative quantitation of YMDD mutants of HBV.

Detection of YMDD mutants using universal template real-time PCR.

AIM: To establish a rapid and accurate method for the detection of lamivudine-resistant mutations in hepatitis B virus and monitor of lamivudine resistance during lamivudine treatment in patients with chronic hepatitis B virus infection. METHODS: We established a real-time PCR method using a universal template and TaqMan probe to detect YMDD mutants. Variants of YVDD and YIDD were tested by individual reactions (reaction V and reaction I) and total hepatitis B viruses were detected in another reaction for control (reaction C). Results were determined by deltaCt < 3.5 (deltaCt = Ct of reaction V or I - Ct of reaction C). Clones of the HBV polymerase gene containing different YMDD mutations were tested. Serum samples from 163 lamivudine-treated patients with chronic hepatitis B virus infection were detected using this method and the results were confirmed by DNA sequencing. RESULTS: As many as 1000 copies per milliliter of wide-type plasmid were detected and nonspecific priming was excluded. In the 163 samples from patients treated with lamivudine, lamivudine-resistant mutations were detected in 51 samples. CONCLUSION: This universal real-time PCR is a rapid and accurate method for quantification of YMDD mutants of HBV virus in lamivudine-treated patients and can be used to monitor lamivudine-resistant mutations before and during lamivudine therapy.

MLH1 polymorphisms and cancer risk: a meta-analysis based on 33 case-control studies.

OBJECTIVE: Cumulative evidence suggests that MLH1, the key component in the mismatch pathway, plays an important role in human cancers. Two potential functional polymorphisms (-93G>A and I219V) of MLH1 have been implicated in cancer risk. The aim of this meta-analysis was to summarize the evidence for associations. METHODS: Eligible studies were identified by searching the electronic literature PubMed, ScienceDirect and Embase databases for relevant reports and bibliographies. Studies were included if of case-control design investigating MLH1 polymorphisms (-93G>A and I219V) and cancer risk with sufficient raw data for analysis. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to evaluate the strength of associations. RESULTS: Our meta-analysis from 33 published case-control studies showed the variant A allele of -93G>A polymorphism to be associated with increased risk in all genetic models (AA vs. GG: OR = 1.22, 95% CI: 1.03-1.44), especially among non-Asians (AA vs. GG: OR = 1.28, 95% CI: 1.04-1.58). For the I219V polymorphism, however, there was no main effect associated with overall cancer risk in any genetic model. CONCLUSIONS: The meta-analysis suggested that the MLH1 -93G>A polymorphism may be a biomarker of cancer susceptibility. Large sample association studies and assessment of gene-to-gene as well as gene-to-environment interactions are required to confirm these findings.

The effect of endostatin and gemcitabine combined with HIFU on the animal xenograft model of human pancreatic cancer.

OBJECTIVE: To investigate the influence of the recombinant human endostatin and gemcitabine combined with HIFU on the mouse xenograft model of pancreatic cancer. METHODS: Use human pancreatic cancer cell line PANC-1 to set up the mouse xenograft model, then randomized into four arms. Each arm was treated with gemcitabine, endostatin, gemcitabine combined with endostatin and normal saline respectively. Observe the volume of the tumor, the serum VEGF level and MVD in the tumor tissue among the different arms. All mice were treated with HIFU, then pathological examination was done. RESULTS: The tumor volume, serum VEGF level and MVD in the combined-therapy arm are all lower than the monotherapy arms and the control arm. The coagulation necrosis occurred in tumors after HIFU treatment. CONCLUSION: Endostatin and gemcitabine has better effect than gemcitabine or endostatin monotherapy on the animal xenograft model of human pancreatic cancer. HIFU combined with chemotherapy and/or targeted therapy may enhance the effect for pancreatic cancer.

[Immunomodulatory effects of spleenic cells added by sIL-15Ralpha on the regulation of melanoma cell growth].

AIM: To study the immunomodulatory effects of spleenic cells added by souble IL-15Ralpha on the regulation of melanoma cell growth. METHODS: The spleenic cells of mice were prepared for culture for 48 hours by adding or not adding soluble IL-15Ralpha (sIL-15Ralpha). Then the adherent cells and non- adherent cells were separated. FACS was used to detect the expression of CD4, CD8, B220, CD11c and CD1a; as mentioned above, the four groups (non-adherent cells of spleenic cells, adherent cells of spleenic cells, non-adherent cells of spleenic cells added by sIL-15Ralpha, adherent cells of spleenic cells added by sIL-15Ralpha) were mixed with melanoma cells separately, then injected intraperitoneally into the cells to mice to observe the tumor volume of the mice, control group was only injected intraperitoneally into melanoma cells. RESULTS: The melanoma growth rate of mice with adherent cells added by sIL-15Ralpha was significantly less than that of the other groups. FACS showed the molecules of this group were possibly dendritic cells. CONCLUSION: sIL-15Ralpha added by spleenic cells can make an immunomodulatory effets possibly mainly by the effects of dendritic cells and inhibit the growth of tumor cells.

Sequential treatment with lamivudine and interferon-alpha monotherapies in hepatitis B e antigen-negative Chinese patients and its suppression of lamivudine-resistant mutations.

OBJECTIVES: To assess the efficacy of sequential treatment with lamivudine and interferon-alpha monotherapies in Chinese patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B. METHODS: One hundred and sixty-two patients with HBeAg-negative chronic hepatitis B were included in this study. Ninety-eight were treated with lamivudine alone (100 mg per day) for 48 weeks (group B). Sixty-four were treated with lamivudine alone (100 mg per day) for 20 weeks, then combined with interferon-alpha-2b (5 million units three times per week) for 4 weeks and then treated for another 24 weeks with interferon-alpha-2b alone (5 million units three times per week) (group A). All patients were followed for an additional 24 weeks. RESULTS: After 48 weeks of treatment, the percentage of patients with normalization of alanine aminotransferase (ALT) levels or hepatitis B virus (HBV) DNA levels below 1000 copies/mL was not significantly different between the lamivudine monotherapy group (55.10% and 55.10%, respectively) and the sequential treatment group (59.36% and 56.25%, respectively). The percentage of patients with normalized ALT levels was significantly higher in group A (53%) than in group B (36%) at week 72 (P<0.05). The percentage of patients with lamivudine-resistant mutations was significantly higher with lamivudine monotherapy (22.45%) than with sequential therapy (P<0.05). CONCLUSIONS: Sequential treatment of chronic hepatitis B with lamivudine and interferon-alpha monotherapies is as effective as lamivudine-alone treatment in Chinese patients. However, sequential treatment can significantly suppress the emergence of lamivudine-resistant mutations.