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BACKGROUND: Rectal cancer is a common malignancy with considerable mortality. This review outlines the current status of laparoscopic total mesorectal excision as a treatment option for rectal cancer and emphasizes the need for standardized approaches. METHODS: We searched PubMed for the terms "total mesorectal excision," "rectal cancer," and "laparoscopic surgery" used in the literature between 1993 and 2010. Additional material regarding the latest statistics from the American Cancer Society, reports from the Cochrane Database of Systemic Reviews, and meta-analyses also were searched. RESULTS: Ninety-six articles were selected: (1) 22 randomized controlled trials, (2) 25 nonrandomized comparative studies, (3) 31 case series, (4) 14 reviews, and (5) 1 report from the Cochrane Database of Systemic Reviews; 3 meta-analyses also were reviewed. Exclusion criteria included non-English language articles and case reports. CONCLUSIONS: At present, open resection is still the standard in rectal cancer and the role of laparoscopy is yet to be defined. The benefits of laparoscopic total mesorectal excision have been clearly translated in the surgical management of rectal cancer. Unfortunately, the lack of reports from larger prospective randomized studies have hindered its use so far.

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OBJECTIVE: To investigate the incidence of P53 and K-ras gene mutation in colorectal adenomas and primary colorectal carcinomas. METHODS: There were 25 normal samples, 38 samples of colorectal adenoma, 78 samples of single primary colorectal cancer and 19 samples of multiple primary colorectal carcinomas (7 synchronous colorectal carcinomas and 12 metachronous colorectal carcinomas) collected in this study. With the analysis of clinico-pathologic features for each patient, exon 5-8 of P53 gene and codon 12-13 of K-ras gene of each sample were extended by real-time PCR. Multi-factor correlation analysis was carried out between the clinicopathologic features and the mutation of P53 and K-ras gene in colorectal adenoma and primary colorectal cancer. RESULTS: The P53 gene mutation is 0% (0/25),44.8%(17/38), 43.6% (34/78) and 42.1% (8/19) respectively in normal mucosa tissue, colorectal adenomas, single lesion and multiple lesion of primary colorectal carcinomas, while the proportion of K-ras gene mutation was 0% (0/25), 18.4%(7/38), 39.7% (31/78), 47.4% (9/19) respectively. In our investigation there were obvious statistical differences as to the proportion of mutation of the P53 and K-ras gene between normal mucosa tissue and other three groups respectively (P<0.05), while statistical differences as to the proportion of mutation of K-ras gene were found between colorectal adenomas group and single or multiple colorectal carcinoma group (P<0.05). There was significant statistical difference between P53 and K-ras gene mutation in colorectal adenomas (P<0.05). In addition, there were no statistical differences as to the proportion of mutation of the P53 and K-ras gene between the stage I , II and well-differentiated ones of primary colorectal cancers and the stageIII IV and poorly-differentiated ones. There was no relationship between the age, gender, family history and tumor locations of the patients and the mutation of the P53 and K-ras gene. The stage and grade of differentiation of cancer was not the risky factor of the mutation of the P53 and K-ras gene in primary colorectal cancers. CONCLUSION: The cancers. CONCLUSION: results of this study not only suggest that mutation of P53 suppressor gene and K-ras play a significant role in the procedure of colorectal tumorigenesis, but also indicate that the mutation of P53 gene occurs earlier than K-ras mutation does during tumorigenesis.

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Phase transformations of materials can be studied by in situ synchrotron X-ray diffraction. However, most reported in situ synchrotron XRD studies focus on solid state/gel systems by measuring phase/structure changes during application of pressure or heat. Phase transformations during material synthesis and their applications, especially in wet chemistry processes with different media, have not drawn much attention. Here, using manganese oxides as examples, we report the successful characterization of phase transformations in in situ hydrothermal synthesis conditions by the in situ synchrotron XRD method using a quartz/sapphire capillary tube as the synthesis reactor. The results were used for better design of materials with controlled structures and properties. This method can be generally used for synthesis of manganese oxides as well as for in situ characterization of other material syntheses using hydrothermal, sol-gel, and other methods. In addition, catalytic processes in liquid-solid, gas-solid, and solid-solid systems can also be studied in such an in situ way so that catalytic mechanisms can be better understood and catalyst synthesis and catalytic processes can be optimized.

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A magnetic route has been applied for measurement of the average oxidation state (AOS) of mixed-valent manganese in manganese oxide octahedral molecular sieves (OMS). The method gives AOS measurement results in good agreement with titration methods. A maximum analysis deviation error of +/-7% is obtained from 10 sample measurements. The magnetic method is able to (1) confirm the presence of mixed-valent manganese and (2) evaluate AOS and the spin states of d electrons of both single oxidation state and mixed-valent state Mn in manganese oxides. In addition, the magnetic method may be extended to (1) determine AOS of Mn in manganese oxide OMS with dopant "diamagnetic" ions, such as reducible V5+ (3d0) ions, which is inappropriate for the titration method due to interference of redox reactions between these dopant ions and titration reagents, such as KMnO4, (2) evaluate the dopant "paramagnetic" ions that are present as clusters or in the OMS framework, and (3) determine AOS of other mixed-valent/single oxidation state ion systems, such as Mo3+(3d3)-Mo4+(3d2) systems and Fe3+ in FeCl3.