Evaluation of genetic consequences of stocking on the southern-margin populations of white-spotted charr.

Coldwater-adapted freshwater fishes, especially their populations along warm-range margins, are most vulnerable to the climate oscillations associated with global warming. Stocking is a major strategy for avoiding the extinction of these species. However, while stocking can reverse the decline of isolated populations, it may also result in a loss of genetic diversity in the native local population due to the introgressive replacement of hatchery genes. To plan an adequate strategy for conserving locally adapted populations, the genetic impacts of stocking on native lineages should be evaluated from small river branches to wide-ranging drainage areas. We investigated the population genetic structure of white-spotted charr (Salvelinus leucomaenis) within its southern range (Lake Biwa basin, Japan). By applying genome-wide SNP analysis to the population's genetic structure, we assessed the extent of genetic introgression resulting from stocking. White-spotted charr in the Lake Biwa watershed constitutes a distinctive genetic group, within which apparent genetic differentiation was observed. The hatchery-reared fish line commonly used for supplementation stocking in the catchment was discernable from the native population, enabling us to analyze genetic introgression across the entire drainage area. Admixed individuals resulting from hatchery introgression were observed in most of the stocked sites that showed relatively high heterozygosity and nucleotide diversity. However, their genetic differentiation was much lower than that of native populations. The supplementation history as well as the road availability contributed substantially to the introgression of hatchery genes. Populations with the native genetic structure remained in the upstream regions of the tested rivers. However, their heterozygosity and nucleotide diversity were low when compared with that of the populations with hatchery supplementation. Our results shed light on the genetic impacts of stocking on isolated native populations and suggest that conventional supplementation methods cannot preserve a unique biodiversity in the distribution margin.

Anadromous red-spotted masu salmon (Oncorhynchus masou ishikawae), a southernmost sea-migration form of salmonid, displays low variation in both age at seaward migration and sea age.

We examined variations in age at seaward migration and sea age for the anadromous form of red-spotted masu salmon (Oncorhynchus masou ishikawae) in two Japanese rivers. The anadromous form of red-spotted masu salmon expressed only two sea migration patterns in the two rivers: (a) the majority of the salmon (95%, n = 81) were of age-0, and age-1 migrants were rare (n = 4); and (b) all the salmon examined (n = 22) made a return migration within a year, with 23% of the salmon exhibiting potamodromy in the river. Owing to low variation in their sea migratory patterns, the anadromous form of red-spotted masu salmon is likely vulnerable to environmental fluctuations.

Iteroparity of stream resident masu salmon Oncorhynchus masou.

The degree of iteroparity in stream-resident forms of masu salmon Oncorhynchus masou was examined using mark-recapture studies in natural streams. In a partially migratory population, at least 10% of resident males survived after maturation and repeatedly matured for up to 5 years. In the landlocked amago salmon subspecies, the post-maturation survival rate was at least 7% and repeat maturation was observed for up to 3 years for both males and females.

Bone formation in a rectal inflammatory polyp.

Heterotopic bone formation (osseous metaplasia) is rarely detected in the gastrointestinal tract. Most of reported cases are associated with malignant lesions. We herein report a case of osseous metaplasia in a rectal inflammatory polyp and a review of the literature on suggested mechanisms for its aetiology. A 39-year-old man visited our hospital with a chief complaint of melena. Total colonoscopy revealed a slightly reddish subpedunculated polyp, about 12 mm in diameter, in the lower rectum. Endoscopic resection was performed. Histologically, several foci of heterotopic bone formation were found. From the review of the literature, all of the polyps described were larger than 10mm in diameter, 55.6% showed inflammatory changes, and 62.5% were detected in the rectum. Osteogenic stimulation was considered to be a result of the inflammatory process. As our inflammatory polyp was located in the rectum, the pathogenesis could be a reactive change stimulated by the repeated local trauma, or be on a peculiar characteristic of the rectal mucosa itself.

Relationship between LDL-C reduction after coronary revascularization and prevention of recurrence of cardiovascular events.

PURPOSE: The purpose of our study was to optimize lipid-lowering therapy in patients undergoing coronary revascularization and to determine whether the percentage change in low-density lipoprotein-cholesterol (LDL-C) level in the 3 months after coronary revascularization could be used as a predictor of the time to recurrence of coronary artery disease (CAD). METHODS: Biochemical values of patients undergoing lipid-lowering therapy after receiving coronary revascularization at the Nippon Medical School Chiba Hokusoh Hospital, Japan, were retrospectively investigated. Recurrence of a cardiovascular event (CVE) was defined by death, myocardial infarction, or angina caused by coronary revascularization more than 3 months after the first event. RESULTS: Of 171 patients under secondary preventive care who had at least one recurrence of a CVE, 75 showed evidence of objective stenotic lesions on coronary angiography. Among these 75 patients, exclusion of those in whom coronary revascularization had not been performed at disease onset, balloon dilatation had been used, serum lipid levels had not been measured, or coronary revascularization had been applied to restenosis left 44 patients suitable for inclusion in the study group. Although the mean value of high density lipoprotein-cholesterol did not change in the 3 months after coronary revascularization, that of (LDL-C) significantly decreased. A significant positive correlation was identified between % decrease in LDL-C and number of days to CVE recurrence. The average LDL-C value (102.8+/-21.7 mg/dL) in the group of patients with no recurrence within 5 years was significantly lower than that (135.3+/-46.1 mg/dL) in the recurrence group (P = 0.0088). The % of patients achieving the LDL-C target level (non-recurrence group vs. recurrence group: 50.0% vs. 16.7%; P = 0.032) and the % decrease in LDL-C (31.0%+/-12.6% vs. 9.6+/-21.0%, P = 0.0012) were significantly greater in the non-recurrence group than in the recurrence group. CONCLUSIONS: From our present study, a decrease in LDL-C 3 months after revascularization surgery reduces the rate of CVE relapse. The % LDL-C decrease could serve as a useful predictor of CVE recurrence, in addition to LDL-C values and achievement of the LDL-C target level.

A retrospective study of immunochemical fecal occult blood testing for colorectal cancer detection.

BACKGROUND: Colonoscopic examination is the common pathway for positive screening tests detecting colorectal lesions. We evaluated a specific, quantitative high-throughput automatic immunochemical fecal occult blood test (Auto iFOBT) method for colorectal cancer (CRC) screening and to determine its concordance with physician assessments informed by complete colonoscopy, the gold-standard technique for evaluation of the colonic mucosa. METHODS: 1200 CRC symptomatic patients were recruited for a retrospective investigation. Colorectal neoplasia were localized by colonoscopy and cancer outcomes were enumerated according to severity. In addition, stool samples were collected and analyzed by Auto iFOBT to derive sensitivity, specificity, and positive predictive value. Qualitative colonoscopy and Auto iFOBT results were correlated, as were cancer severities and quantitative hemoglobin concentrations. RESULTS: Ninety-one patients were found positive for CRC; 50 mucosal, 20 submucosal, and 21 advanced. At standard cutoff, sensitivity was 60%, 90%, and 95%, respectively. Specificity and positive predictive value for all neoplasia and cancers were 89.6% and 86.4%, and 60.9% and 33.7%, respectively. Cancer severities could be approximated roughly according to hemoglobin concentrations. CONCLUSIONS: Specific qualitative 2-day Auto iFOBT is an accurate tool for the detection of colorectal cancer and therefore provides the basis for a large-scale screening program.

Phenobarbital (PB)-induced changes in blood coagulationrelated parameters in pregnant rats, lactating rats and pups.

Effects of repeated administration of phenobarbital (PB) on blood coagulation-related parameters were examined in non-pregnant, pregnant and lactating rats, and also in pups born to PB-treated lactating dams. PB was orally administered at a dose level of 80 mg/kg/day to pregnant (from gestation day (GD) 13), postpartum (from postpartum day (PPD) 7) and non-pregnant rats (from 13 weeks of age) for 7 days. Blood was collected on GD20 or PPD14 to perform blood coagulation examination. Concurrently, the blood coagulation parameters were examined in the pups. Increases in liver weight and/or hepatic cytochrome P450 content were observed in the PB-treated non-pregnant, pregnant and lactating rats. Activated partial thromboplastin time (APTT) was prolonged and anti-thrombin III (ATIII) concentration was increased in the lactating rats, while there were no changes in prothrombin time (PT) or APTT in the non-pregnant and pregnant rats. Moreover, prolongation of PT and APTT and decreases in factors VII and IX activities were observed in their pups. Thus, prolongation of blood coagulation time was confirmed in both dams and their pups following PB-administration to lactating dams. Effects of vitamin K(2) (VK(2)) on PB-induced changes in blood coagulation-related parameters of both dams and their pups were examined by co-administration with PB and VK(2) to lactating dams. PT and APTT were comparable to the control and PB-induced prolongation of blood coagulation time was improved in the pups while APTT was prolonged in dams, suggesting that VK(2) was beneficial to pups but not to dams.

Progression of a sessile serrated adenoma to an early invasive cancer within 8 months.

Recent studies suggest that serrated polyps, including hyperplastic polyps, traditional serrated adenomas, and sessile serrated adenomas, may be morphologically and genetically distinct and linked to microsatellite unstable colorectal cancers, and thus the concept of a hyperplastic polyp-serrate adenoma-carcinoma pathway has been suggested. Furthermore, it has been suggested that transformation from serrated polyps to invasive cancers can be rapid and occurs when the lesions are small; however, direct evidence for this issue is scant. We herein describe a case of a sessile serrated adenoma showing rapid transformation into a submucosal invasive carcinoma with remarkable morphological change in a short period of 8 months. This case is unique and suggestive, as it provided information about the natural history of a sessile serrated adenoma.

Colitis in mice lacking the common cytokine receptor gamma chain is mediated by IL-6-producing CD4+ T cells.

BACKGROUND & AIMS: Mice that have a truncated mutation of the common cytokine receptor gamma chain (CR gamma -/Y) are known to spontaneously develop colitis. To identify the pathologic elements responsible for triggering this localized inflammatory disease, we elucidated and characterized aberrant T cells and their enteropathogenic cytokines in CR gamma -/Y mice with colitis. METHODS: The histologic appearance, cell population, T-cell receptor V beta usage, and cytokine production of lamina propria lymphocytes were assessed. CR gamma -/Y mice were treated with anti-interleukin (IL)-6 receptor monoclonal antibody to evaluate its ability to control colitis, and splenic CD4 + T cells from the same mouse model were adoptively transferred into SCID mice to see if they spurred the appearance of colitis. RESULTS: We found marked thickening of the large intestine, an increase in crypt depth, and infiltration of the colonic lamina propria and submucosa with mononuclear cells in the euthymic CR gamma -/Y mice, but not in the athymic CR gamma -/Y mice, starting at the age of 8 weeks. Colonic CD4 + T cells with high expressions of antiapoptotic Bcl-x and Bcl-2 were found to use selected subsets (V beta 14) of T-cell receptor and to exclusively produce IL-6. Treatment of CR gamma -/Y mice with anti-IL-6 receptor monoclonal antibody prevented the formation of colitis via the induction of apoptosis in IL-6-producing CD4 + T cells. Adoptive transfer of pathologic CD4 + T cells induced colitis in the recipient SCID mice. CONCLUSIONS: Colonic IL-6-producing thymus-derived CD4 + T cells are responsible for the development of colitis in CR gamma -/Y mice.

Therapeutic effects of a new lymphocyte homing reagent FTY720 in interleukin-10 gene-deficient mice with colitis.

BACKGROUND: FTY720 is a novel reagent that possesses potent immunosuppressive activity. The immunosuppression induced by FTY720 is mediated by completely different mechanisms from those of conventional immunosuppressants, that is, by altering the tissue distribution of lymphocytes rather than inhibiting activation. In this study, we examined the efficacy of FTY720 in the treatment of chronic colitis in an interleukin-10 gene-deficient (IL-0-/-) mouse model. METHODS: FTY720 was administered orally for 4 weeks to IL-10-/- mice with clinical signs of colitis. The gross and histologic appearance of the colon and the numbers, phenotype, cytokine production, and apoptosis of lymphocytes were compared with those characteristics in a control group. RESULTS: Single-dose administration of FTY720 resulted in the sequestration of circulating lymphocytes within the secondary lymphoid tissues. Four-week administration resulted in a significant reduction of the CD4+ T lymphocytes subpopulation in the colonic lamina propria and IFN-gamma production of the colonic lymphocytes, accompanied by a significant decrease in the severity of colitis. CONCLUSIONS: Treatment of established colitis in IL-10-/- mice with FTY720 ameliorated the colitis, probably as a result of decreasing the number of lymphocytes in the colonic mucosa and an associated reduction in IFN-gamma production.