Satellite Tracking of Migration Routes of the Eastern Buzzard (Buteo japonicus) in Japan through Sakhalin.

We satellite-tracked the eastern buzzard (Buteo japonicus) wintering in Japan to delineate both northward and southward migration routes, destinations, and stopover behavior. Twenty-two buzzards were captured and fitted with functional platform transmitter terminals. For these buzzards that departed from the capture sites, we observed a total of 65 northward migrations during 2008-2016 and a total of 55 southward migrations during 2008-2015. In spring, the eastern buzzards migrated eastward along the Seto Inland Sea in the Chugoku region or further inland. In eastern Honshu, they followed two different routes. One was to Hokkaido via the Tsugaru Peninsula from central or northern central Honshu northward along the side of the Sea of Japan in northern Honshu. The other was to Hokkaido via the Shimokita Peninsula, mainly from the Pacific Ocean side of northern Honshu, moving eastward through central Honshu. Of the 17 birds tracked, 10 summered in Sakhalin, three in Hokkaido, three in northern Honshu, and one unknown. In autumn, the buzzards retraced their northward migration routes. Of the 14 birds that were tracked the entire southward migration, 13 (92%) returned to their respective capture sites. One juvenile wintered in an area different from the capture site. Our study contributes to a deeper understanding of the distribution of breeding and wintering grounds and the migration routes of B. japonicus. In addition, the information on migration obtained in this study can contribute toward appropriate environmental impact assessment for wind power facilities in Japan.

Diphtheria in Metro Manila, the Philippines 2006-2017: A Clinical, Molecular, and Spatial Characterization.

BACKGROUND: Diphtheria is a vaccine-preventable disease that persists as a global health problem. An understanding of the pattern of disease is lacking in low- and middle-income countries such as the Philippines. METHODS: We conducted a retrospective review of the clinical, microbiological, and epidemiological features of patients admitted with a clinical diagnosis of diphtheria to an infectious disease referral hospital in Metro Manila, the Philippines, between 2006 and 2017. Cases were mapped and the distribution was compared with population density. Corynebacterium diphtheriae isolates from between 2015 and 2017 were examined by multilocus sequence typing (MLST). RESULTS: We studied 267 patients (range:12-54 cases/year) admitted between 2006 and 2017. The case fatality rate (CFR) was 43.8% (95% confidence interval, 37.8-50.0%). A higher number of cases and CFR was observed among children <10 years. Mortality was associated with a delayed admission to hospital and a lack of diphtheria antitoxin. Between 2015 and 2017 there were 42 laboratory-confirmed cases. We identified 6 multilocus sequence types (STs). ST-302 was the most common (17/34, 48.6%), followed by ST67 (7/34, 20%) and ST458 (5/34, 14%). Case mapping showed a wide distribution of diphtheria patients in Metro Manila. Higher case numbers were found in densely populated areas but with no apparent clustering of ST types. CONCLUSIONS: Our analysis indicates that diphtheria remains endemic in Metro Manila and that the infection is frequently fatal in young children. Improved vaccine coverage and a sustainable supply of diphtheria antitoxin should be prioritized.

Genetic Structure and Diversity of Two Populations of the Eastern Buzzard (Buteo japonicus japonicus and B. j. toyoshimai) in Japan.

The nominotypical subspecies of the Eastern buzzard (Buteo japonicus japonicus; BJJ) is a common raptor inhabiting East Asia and Japan. Another subspecies, B. j. toyoshimai (BJT), inhabits only the Bonin Islands of the Ogasawara Islands, where there are only an estimated 85 breeding pairs. Because of this low population size, this subspecies is classified as endangered (class IB) in Japan. The aims of the present study were to examine genetic differences between BJJ and BJT, determine the genetic structure of the Eastern Buzzard, and assess genetic diversity within each subspecies. We sequenced 1526 bp within the control region of the mtDNA of 10 BJJ individuals during the breeding season in four sites; similarly, we sequenced 23 BJJ individuals during winter in three sites. We detected 24 haplotypes among the 33 individuals. In a similar analysis performed with 12 BJT individuals, three haplotypes were detected. The phylogenetic analysis showed that BJJ and BJT have diverged into distinct clades, supporting the genetic differentiation between the subspecies. Network and mismatch distribution analyses indicated that BJJ may have experienced population expansion. In addition, comparisons with other raptors revealed a high degree of genetic diversity in the BJJ population. In contrast, the genetic diversity of the BJT population is lower than that in other raptors. Our results indicated that it is necessary to protect BJT to prevent the reduction in its genetic diversity.

Alternative lengthening of telomeres frequently occurs in mismatch repair system-deficient gastric carcinoma.

Maintenance of telomeric ends by the telomerase ribonucleoprotein complex or the telomerase-independent alternative lengthening of telomeres is necessary for the immortalization of human cells. The significance of alternative lengthening of telomeres has been suggested in DNA mismatch repair system-deficient cells; however, much remains unknown in human malignancies. In this study, we investigated the telomere maintenance mechanism in gastric carcinoma. In formalin-fixed and paraffin-embedded sections of the high frequency of microsatellite instability (MSI-H) and non-MSI-H gastric carcinomas, there was no difference in telomere length monitored by telomere intensity ratio using telomere-fluorescent in situ hybridization. Immunoreactivity of hTERT, the catalytic subunit of telomerase, was detected in 48% of MSI-H gastric carcinomas. The frequency was significantly lower than that in non-MSI-H gastric carcinomas (86%, P = 0.02). Conversely, the number of the alternative lengthening of telomeres-associated promyelocytic leukemia bodies (APBs) detected by combined promyelocytic leukemia immunofluorescence and telomere-fluorescent in situ hybridization was statistically higher (57%) in the MSI-H gastric carcinomas compared to that in non-MSI-H gastric carcinomas (19%, P = 0.026). The cases with hTERT(+)APBs(-) were more frequent in non-MSI-H gastric carcinomas (76%) than in MSI-H gastric carcinomas (24%), and the cases with hTERT(-)APBs(+) were more frequent in MSI-H gastric carcinomas (33%) than in non-MSI-H gastric carcinomas (10%). These results suggest that alternative lengthening of telomeres-mediated telomere maintenance plays an important role for microsatellite instability-mediated stomach carcinogenesis, as well as the telomerase ribonucleoprotein complex, although the incidence of MSI-H is low. Defects of the mismatch repair system may lead to homeologous recombination of telomeric ends for the telomerase-independent telomere maintenance in gastric carcinomas.

Hypermethylation-modulated downregulation of claudin-7 expression promotes the progression of colorectal carcinoma.

OBJECTIVE: The expression of tight junction-related transmembrane protein claudin-7 (CLDN7) and its regulatory mechanism were investigated in colorectal carcinomas (CRCs). METHODS: Methylation-specific polymerase chain reaction and treatment with the demethylating agent 5-aza-2'-deoxycytidine were conducted to analyze the methylation status at the CLDN7 promoter region in the Colo320 CRC cell line. We used a total of 26 stage 0 CRCs with an adenoma component and 90 invasive CRCs (stage I-IV), as well as their corresponding lymph node metastases, in an immunohistochemical study. RESULTS: In Colo320 (CLDN7-negative) cells, hypermethylation at the CLDN7 promoter was detected and treatment with 5-aza-2'-deoxycytidine restored CLDN7 expression. In CRC tissues, decreased CLDN7 expression was detected in 62% of stage 0 CRCs and 80% of stage I-IV CRCs, compared with their adjacent adenoma lesions and nonneoplastic epithelia, which had a close correlation with the incidence of vessel infiltration and clinicopathologic stage. Hypermethylation at the CLDN7 promoter was detected in 20% of CRCs with low CLDN7 expression. However, CLDN7 expression tended to be re-expressed in their corresponding lymph node metastases. CONCLUSION: These findings suggest that the CLDN7 gene silencing by promoter hypermethylation and the resultant reduction of CLDN7 expression may play an important role in the progression of CRCs.

Prognostic significance of intestinal claudins in high-risk synchronous and metachronous multiple gastric epithelial neoplasias after initial endoscopic submucosal dissection.

Endoscopic submucosal dissection (ESD) is useful in en bloc curative resection and enables patients with early gastric carcinoma (GC) to have a better quality of life. But metachronous recurrence of GC at other sites in the stomach has become a major issue after initial ESD. The purpose of the present paper was to examine gastric (claudin-18) and intestinal claudin (claudin-3 and claudin-4) expression in early GC on immunohistochemistry to clarify the association with clinicopathology, mucin phenotypes, microsatellite instability (MSI) status and the incidence of synchronous and metachronous gastric epithelial neoplasias after initial ESD. According to intestinal claudin expression, a total of 73 early GC were divided into two groups: intestinal claudin-positive (I-CLDN(+)) phenotype (n = 52; 71%); and intestinal claudin-negative (I-CLDN(-)) phenotype (n = 21; 29%). Although no significant association was found with clinicopathology and the MSI status, the I-CLDN(+) early GC correlated with the mucin phenotypes and had a significantly higher incidence of synchronous and metachronous multiple GC and gastric adenomas (P = 0.049). These results indicate that early GC demonstrating I-CLDN(+) phenotype have a high risk of synchronous and metachronous secondary gastric epithelial neoplasias.

Reduced expression of claudin-7 correlates with invasion and metastasis in squamous cell carcinoma of the esophagus.

Claudins are transmembrane proteins that seal tight junctions, bind with peripheral protein zonula occludens (ZO)-1, and are known to play an important role in several normal tissues and cancers. However, the role of claudin-1 and claudin-7 expressions in esophageal squamous cell carcinoma remains to be clarified. In the present study, we confirmed the expressions of claudin-1, claudin-7, and ZO-1 in the prickle cell layer of the normal human esophageal squamous epithelium. The expressions of claudin-1 and claudin-7 at the invasive front of the esophageal squamous cell carcinoma were analyzed immunohistochemically to clarify their role in tumor progression. Reduced expression of claudin-7 at the invasive front of the esophageal cancer was significantly associated with the depth of invasion (P = .004), stage (P = .038), lymphatic vessel invasion (P = .001), and lymph node metastasis (P = .014). In contrast, significant association was not detected between claudin-1 expression and clinicopathologic factors except for histologic differentiation of the tumor (P = .0029). Comparison of claudin-7 expression at the invasive front of the primary tumor and its corresponding metastatic lymph nodes revealed significant reduction in claudin-7 expression in the metastatic lymph nodes (P = .007). These results suggest that the reduced expression of claudin-7 at the invasive front of esophageal squamous cell carcinoma may lead to tumor progression and subsequent metastatic events. Thus, claudin-7 can be a novel marker for the prediction of lymph node metastasis.