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| 2. |
- Zhou, Xiao-Lei, et al.
(author)
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Definition of candidate low risk APC alleles in a Swedish population.
- 2004
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In: International journal of cancer. Journal international du cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 110:4, s. 550-7
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Journal article (peer-reviewed)abstract
- Many families experience an apparently inherited increased risk of colorectal cancer (CRC) similar to the known syndromes familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). Besides these high-risk syndromes, approximately 10% of all CRC cases come from families with 2 affected 1st-degree relatives, and even 1st-degree relatives to a single case of CRC are at increased risk. Risk subjects from these families frequently show polyps at colonoscopy, which suggests the APC gene as a good candidate susceptibility gene for these attenuated polypotic syndromes. We used the sensitive DHPLC technique to search for possible predisposing germline mutations in the entire APC gene in 91 risk subjects from these high- and low-risk syndromes with unknown predisposing genes. Most exons were also screened for mutations in 96 normal controls and 96 colorectal cancer cases. In our study we probably have identified the most common APC variants in a Swedish population. Among 30 germline variants identified, 1 clearly pathogenic nonsense mutation and 11 putative pathogenic variants (10 missense and one 3' UTR) were found in 20 index patients (22%). Twelve silent as well as 5 intronic variants were considered nonpathogenic. Two of the missense variants found here, E1317Q and D1822V, have previously been related to a difference in risk of colorectal cancer. One variant, 8636C>A, located within the 3' UTR region of the APC gene, was suggested to constitute an additional low risk allele with a similar relative risk as the Jewish I1307K mutation (OR = 1.8; 95% CI, 0.96-3.40). The question of whether all the other variants confer an increased colorectal cancer risk warrants future large association studies.
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| 3. |
- Adell, Gunnar C. E., 1953-, et al.
(author)
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Apoptosis in rectal carcinoma : Prognosis and recurrence after preoperative radiotherapy
- 2001
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In: Cancer. - 0008-543X .- 1097-0142. ; 91:10, s. 1870-1875
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Journal article (peer-reviewed)abstract
- BACKGROUND: Rectal carcinoma is common, with considerable local recurrence and death rates. Preoperative radiotherapy and refined surgical techniques can improve local control. The aim of this study was to investigate the interaction between apoptosis and the outcome of rectal carcinoma, with and without short-term preoperative radiotherapy.METHODS: Specimens were from 162 patients from the Southeast Swedish Health Care region included in the Swedish Rectal Cancer Trial between 1987-1990. New sections from the paraffin blocks of the preoperative biopsies and the surgical specimens were examined for apoptosis using the terminal deoxynucleotidyl transferase mediated digoxigenin nick end labeling (TUNEL) method.RESULTS: The mean percentage of apoptotic cells was 0.3% (0-4%) and 1.1% (0-14.5%) for the preoperative biopsy and the surgical specimen, respectively. The authors analyzed the surgical specimens from nonirradiated patients and divided them into three groups by apoptotic index (AI) as follows: 0%, 0-1%, and > 1%. A high AI was associated with a decreased local recurrence rate compared with an intermediate or a low AI (P = 0.024). There was no significant relation between AI and survival. There was a significant reduction in the local recurrence rate for irradiated patients compared with the nonirradiated in the low (P = 0.015) and intermediate (P = 0.038) AI groups. In the high AI group, there were few recurrences and no significant difference was observed between irradiated and nonirradiated patients. The relative risk of death from rectal carcinoma in Dukes A-C patients was not significantly decreased by radiotherapy, but, in the intermediate AI group, there was a trend (P = 0.08) in favor of the irradiated patients.CONCLUSION: A high AI in rectal carcinoma indicated a decreased local recurrence rate.
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| 4. |
- Adell, Gunnar, 1953-, et al.
(author)
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Decreased tumor cell proliferation as an indicator of the effect of preoperative radiotherapy of rectal cancer
- 2001
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In: International Journal of Radiation Oncology, Biology, Physics. - 0360-3016 .- 1879-355X. ; 50:3, s. 659-663
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Journal article (peer-reviewed)abstract
- BACKGROUND: Rectal cancer is a common malignancy, with significant local recurrence and death rates. Preoperative radiotherapy and refined surgical technique can improve local control rates and disease-free survival.PURPOSE: To investigate the relationship between the tumor growth fraction in rectal cancer measured with Ki-67 and the outcome, with and without short-term preoperative radiotherapy.Method: Ki-67 (MIB-1) immunohistochemistry was used to measure tumor cell proliferation in the preoperative biopsy and the surgical specimen.MATERIALS: Specimens from 152 patients from the Southeast Swedish Health Care region were included in the Swedish rectal cancer trial 1987-1990.RESULTS: Tumors with low proliferation treated with preoperative radiotherapy had a significantly reduced recurrence rate. The influence on death from rectal cancer was shown only in the univariate analysis. Preoperative radiotherapy of tumors with high proliferation did not significantly improve local control and disease-free survival. The interaction between Ki-67 status and the benefit of radiotherapy was significant for the reduced recurrence rate (p = 0.03), with a trend toward improved disease-free survival (p = 0.08). In the surgery-alone group, Ki-67 staining did not significantly correlate with local recurrence or survival rates.CONCLUSION: Many Ki-67 stained tumor cells in the preoperative biopsy predicts an increased treatment failure rate after preoperative radiotherapy of rectal cancer.
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| 5. |
- Andersson, Martin E, et al.
(author)
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Structural and mutational studies of the carboxylate cluster in iron-free ribonucleotide reductase R2.
- 2004
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In: Biochemistry. - 0006-2960. ; 43:24, s. 7966-72
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Journal article (peer-reviewed)abstract
- The R2 protein of ribonucleotide reductase features a di-iron site deeply buried in the protein interior. The apo form of the R2 protein has an unusual clustering of carboxylate side chains at the empty metal-binding site. In a previous study, it was found that the loss of the four positive charge equivalents of the diferrous site in the apo protein appeared to be compensated for by the protonation of two histidine and two carboxylate side chains. We have studied the consequences of removing and introducing charged residues on the local hydrogen-bonding pattern in the region of the carboxylate cluster of Corynebacterium ammoniagenes and Escherichia coli protein R2 using site-directed mutagenesis and X-ray crystallography. The structures of the metal-free forms of wild-type C. ammoniagenes R2 and the mutant E. coli proteins D84N, S114D, E115A, H118A, and E238A have been determined and their hydrogen bonding and protonation states have been structurally assigned as far as possible. Significant alterations to the hydrogen-bonding patterns, protonation states, and hydration is observed for all mutant E. coli apo proteins as compared to wild-type apo R2. Further structural variations are revealed by the wild-type apo C. ammoniagenes R2 structure. The protonation and hydration effects seen in the carboxylate cluster appear to be due to two major factors: conservation of the overall charge of the site and the requirement of electrostatic shielding of clustered carboxylate residues. Very short hydrogen-bonding distances between some protonated carboxylate pairs are indicative of low-barrier hydrogen bonding.
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| 6. |
- Andreyev, HJN, et al.
(author)
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Kirsten ras mutations in patients with colorectal cancer : The 'RASCAL II' study
- 2001
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In: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 85:5, s. 692-696
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Journal article (peer-reviewed)abstract
- Researchers worldwide with information about the Kirsten ras (Ki-ras) tumour genotype and outcome of patients with colorectal cancer were invited to provide that data in a schematized format for inclusion in a collaborative database called RASCAL (The Kirsten ras incolorectal-cancer collaborative group). Our results from 2721 such patients have been presented previously and for the first time in any common cancer, showed conclusively that different gene mutations have different impacts on outcome, even when the mutations occur at the same site on the genome. To explore the effect of Ki-ras mutations at different stages of colorectal cancer, more patients were recruited to the database, which was reanalysed when information on 4268 patients from 42 centres in 21 countries had been entered. After predetermined exclusion criteria were applied, data on 3439 patients were entered into a multivariate analysis. This found that of the 12 possible mutations on codons 12 and 13 of Kirsten ras, only one mutation on codon 12, glycine to valine, found in 8.6% of all patients, had a statistically significant impact on failure-free survival (P=0.004, HR 1.3) and overall survival (P=0.008, HR 1.29). This mutation appeared to have a greater impact on outcome in Dukes' C cancers (failure-free survival, P=0.008, HR 1.5, overall survival P=0.02, HR 1.45) than in Dukes' B tumours (failure-free survival, P=0.46, HR 1.12, overall survival P=0.36, HR 1.15). Ki-ras mutations may occur early in the development of pre-cancerous adenomas in the colon and rectum. However, this collaborative study suggests that not only is the presence of a codon 12 glycine to valine mutation important for cancer progression but also that it may predispose to more aggressive biological behaviour in patients with advanced colorectal cancer. ⌐ 2001 Cancer Research Campaign.
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| 7. |
- Arai, Takeru, et al.
(author)
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Axonal outgrowth in muscle grafts made acellular by chemical extraction
- 2000
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In: Restorative Neurology and Neuroscience. - 0922-6028. ; 17:4, s. 165-174
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Journal article (peer-reviewed)abstract
- Purpose: To compare nerve regeneration in autologous detergent extracted and freeze-thawed muscle grafts and to electrophoretically characterize the grafts. Methods: Autologous acellular muscle grafts were created either by freeze/thawing or by detergent extraction and then used to bridge a 10 mm gap in rat sciatic nerve. The autologous grafts were compared with respect to protein content, using electrophoresis preimplantation, and axonal outgrowth, Schwann cell and macrophage content, using immunocytochemistry (neurofilaments, S-100 protein, ED 1 macrophages) at 5-20 days postimplantation. Results: The extracted muscle grafts were elastic, but the amount of several proteins was reduced and laminin was still present at a position of basal laminae of the muscle fibers. The freeze/thawed grafts were brittle and lacked elasticity, but resulted in minor changes in major proteins. The axons regenerated through both types of grafts (initial delay 6 days and rate 0.7-0.8 mm/day), which shrunk in length by 25 %. There were no apparent differences with respect to Schwann cells and macrophages. Conclusions: The results suggest that detergent extracted mucle tissue, in which some basal lamina proteins remain but cells are removed, could present a new favourable option for nerve grafting.
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| 8. |
- Bai, Xiao, et al.
(author)
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Absorption of formaldehyde (H2CO) in the (A)over-tilde(1)A(2)
- 2004
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In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. - 1386-1425. ; 60:4, s. 821-828
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Journal article (peer-reviewed)abstract
- The electronic A(1)A(2) <-- X(1)A(1) absorption spectra of formaldehyde vapour were studied at temperatures varying from 423 to 770 K with variable pressures from less than 0.1 to 1 MPa. Broadband vibronic and partially rotationally resolved 4(n)(1) rovibronic spectra of formaldehyde showed considerable sensitivity to temperature. The high resolution spectra showed collision-induced broadening as the pressure was increased. The results show that the absorption efficiency of the laser radiation front the third harmonic of Nd:YAG lasers is sensitive to the spectral properties of the laser, such as line position and shape. Promising results were obtained from the comparison between theoretical and measured absorption spectra.
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| 9. |
- Bakhtiar, Shahrzad, et al.
(author)
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Crystallization and preliminary X-ray analysis of an alkaline serine protease from Nesterenkonia sp. Acta
- 2003
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In: Acta Crystallographica. Section D: Biological Crystallography. - 1399-0047. ; 59:3, s. 529-531
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Journal article (peer-reviewed)abstract
- A novel calcium-independent serine protease from an alkaliphilic bacterium, Nesterenkonia sp. AL20, has been purified and crystallized at 296 K using sodium formate as the main precipitant. This enzyme is optimally active at pH 10, exhibits high stability towards autolytic digestion and its stability is not affected by the presence of EDTA or detergents. The triangular prism-shaped crystals diffracted X-rays to beyond 1.5 Å at a synchrotron beamline, with space group R3 and unit-cell parameters a = b = 92.26, c = 137.88 Å. A complete data set has been collected to 1.39 Å resolution. The asymmetric unit is estimated and confirmed by self-rotation function calculation to contain two molecules, giving a crystal volume per protein mass (VM) of 2.68 Å3 Da-1 and a solvent content of 54%.
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