Aging-like Spontaneous Epigenetic Silencing Facilitates Wnt Activation,Stemness, and BrafV600E-Induced Tumorigenesis

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Comparative evaluation of image quality among different detector configurations using area detector computed tomography

The 320-detector row computed tomography (CT) system, i.e., the area detector CT (ADCT), can perform helical scanning with detector configurations of 4-, 16-, 32-, 64-, 80-, 100-, and 160-detector rows for routine CT examinations. This phantom study aimed to compare the quality of images obtained using helical scan mode with different detector configurations. The image quality was measured using modulation transfer function (MTF) and noise power spectrum (NPS). The system performance function (SP), based on the pre-whitening theorem, was calculated as MTF²/NPS, and compared between configurations. Five detector configurations, i.e., 0.5 × 16 mm (16 row), 0.5 × 64 mm (64 row), 0.5 × 80 mm (80 row), 0.5 × 100 mm (100 row), and 0.5 × 160 mm (160 row), were compared using a constant volume CT dose index (CTDI_vol) of 25 mGy, simulating the scan of an adult abdomen, and with a constant effective mAs value. The MTF was measured using the wire method, and the NPS was measured from images of a 20-cm diameter phantom with uniform content. The SP of 80-row configuration was the best, for the constant CTDI_vol, followed by the 64-, 160-, 16-, and 100-row configurations. The decrease in the rate of the 100- and 160-row configurations from the 80-row configuration was approximately 30%. For the constant effective mAs, the SPs of the 100-row and 160-row configurations were significantly lower, compared with the other three detector configurations. The 80- and 64-row configurations were adequate in cases that required dose efficiency rather than scan speed.     

Methodological extensions of meta-analysis with excess relative risk estimates: application to risk of second malignant neoplasms among childhood cancer survivors treated with radiotherapy

Although radiotherapy is recognized as an established risk factor for second malignant neoplasms (SMNs), the dose response of SMNs following radiotherapy has not been well characterized. In our previous meta-analysis of the risks of SMNs occurring among children who have received radiotherapy, the small number of eligible studies precluded a detailed evaluation. Therefore, to increase the number of eligible studies, we developed a method of calculating excess relative risk (ERR) per Gy estimates from studies for which the relative risk estimates for several dose categories were available. Comparing the calculated ERR with that described in several original papers validated the proposed method. This enabled us to increase the number of studies, which we used to conduct a meta-analysis. The overall ERR per Gy estimate of radiotherapy over 26 relevant studies was 0.60 (95%CI: 0.30–1.20), which is smaller than the corresponding estimate for atomic bomb survivors exposed to radiation as young children (1.7; 95% CI: 1.1–2.5). A significant decrease in ERR per Gy with increase in age at exposure (0.85 times per annual increase) was observed in the meta-regression. Heterogeneity was suggested by Cochran''s Q statistic (P < 0.001), which may be partly accounted for by age at exposure.     

Incidence of food residue interfering with postoperative endoscopic examination for gastric pull-up after esophagectomy

Background

In spite of appropriate preparation, food residue that interferes with endoscopic examination is occasionally observed in an operated stomach. The present study aimed to elucidate the incidence of such food residue and determine its risk factors in gastric pull-up after esophagectomy.

Methods

A total of 116 esophagectomized patients underwent the first postoperative endoscopy to survey their gastric pull-up with a median interval of 14 months (range 6–24) after the surgery. Fasting time was 13–16 h before the examination. The amount of food residue was retrospectively classified from Grade 0 (no food residue) to Grade 4 (a large amount of food residue) by two expert endoscopists.

Results

Among the 116 patients, 73 patients were classified as Grade 0, 23 patients as Grade 1, 10 patients as Grade 2, 9 patients as Grade 3, and 1 patient as Grade 4. Food residue (≥Grade 2) that interfered with the examination was observed in 20 patients (17.2 %). There was no significant association between the food residue and patient baseline characteristics.

Conclusion

The food residue interfering with postoperative endoscopic examination was observed in 17.2 % of all surveyed gastric pull-ups.

     

Small follicular lymphoma arising near the ampulla of vater: a distinct subtype of duodenal lymphoma?

A 49-yr-old Japanese woman underwent upper gastrointestinal endoscopy because of nonspecific dyspepsia. Endoscopy revealed a flat elevated lesion about 15 mm in diameter adjacent to the duodenal papilla, the surface of which was uneven and covered with whitish granules. Based on the results of histological examination with immunohistochemistry (positive for CD10, CD20, CD79a, and bcl-2 protein, negative for CD5 and cyclin D1), a diagnosis of grade 1/3 follicular lymphoma was established. Systemic staging examinations suggested the lymphoma was restricted to the mucosa and superficial portion of the submucosa in the duodenal wall. The patient was treated with a combination of CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisolone) and monoclonal anti-CD20 antibody (rituximab), in addition to radiotherapy. After six courses of this combination chemotherapy, complete regression of the lymphoma was observed. Although reports of small duodenal lymphoma (<20 mm or localized to the mucosa or submucosa) are extremely rare, the features of this case are characteristic of small duodenal lymphoma in terms of evolution around the ampulla of Vater, low-grade follicular type, occurrence in a women, occurrence in the fourth decade of life, and favorable outcome, and this type of tumor may need to be distinguished by pathogenesis and clinical behavior from various other gastrointestinal lymphomas.     

Tartrate-resistant acid phosphatase-positive cells in the synovial–cartilage junction and bone marrow during the progression of collagen-induced arthritis in adult rats

We investigated the time-course changes in bone destruction in rats with collagen-induced arthritis (CIA). The synovial–cartilage junction (SCJ) and epiphyseal bone marrow of the femoral posteromedial condyle in CIA rats were evaluated histologically and immunohistologically at 2, 3, 4, 6, and 8 weeks after sensitization. Two weeks after sensitization, tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells formed resorption lacunae on the lateral side of the cortical bone under the SCJ. No resorption lacunae were observed in bone marrow. Three weeks after sensitization, resorption lacunae on the lateral side of the cortical bone expanded, but no bone marrow invasion by pannus was observed. In bone marrow, many TRAP-positive multinuclear cells appeared and formed resorption lacunae in subchondral bone. Four weeks after sensitization, cortical bone was destroyed, and pannus had invaded the bone marrow. After six weeks, trabecular bone and subchondral bone plate were extensively resorbed by TRAP-positive cells. Bone destruction in CIA began with the appearance of TRAP-positive cells on the lateral side of the cortical bone under the SCJ, followed by the TRAP-positive multinuclear cells in bone marrow, which were morphologically unconnected to the SCJ lesions. These histological findings suggested that bone destruction in the early stage of arthritis occurred in two anatomically different regions.     

Chromosomal and microsatellite instability in sporadic gastric cancer

BACKGROUND: Gastric cancer can progress through two pathways of genomic instability: chromosomal (CIN) and microsatellite instability (MSI). It is hypothesized that these two pathways are not always independent and that some tumors show overlap between these two mechanisms. METHODS: A total of 98 sporadic gastric cancers were classified based on their MSI status, using microsatellite assay with BAT26. Evidence for CIN was investigated by identifying loss of heterozygosity (LOH) events on chromosome arms, 5q, 10p, 17p, 17q, and 18q, which are regions harboring tumor suppressor genes that are significant in gastric cancer development. RESULTS: Twelve tumors (12%) showed high-frequency MSI (MSI-H). Overall, 43 of the tumors (44%) had at least one LOH event, with most frequent chromosomal losses observed on 10p and 18q (30%, respectively), followed by 5q (21%), 17p (14%), and 17q (12%). Interestingly, overlap was observed between CIN and MSI pathways. Of 43 cancers with LOH events, four (9%) were also MSI-H. It was also found that 48% of cancers without MSI-H had no LOH events identified, comprising a subgroup of tumors that were not representative of either of these two pathways of genomic instability. CONCLUSION: These results suggest that molecular mechanisms of genomic instability are not necessarily independent and may not be fully defined by either the MSI or CIN pathways in sporadic gastric cancers.     

Two-stage hepatectomy for multiple bilobular liver metastases from colorectal cancer

BACKGROUND/AIMS: To determine an appropriate surgical treatment for patients with multiple liver metastases, we evaluated the efficacy of two-stage hepatectomy in patients with multiple bilobular liver metastases from colorectal carcinoma. METHODOLOGY: Some patients with multiple liver metastases are not candidates for a complete resection by a single hepatectomy, even when downstaged by chemotherapy, after portal embolization. In two-stage hepatectomy, the highest possible number of tumors is resected in a first, noncurative intervention, and the remaining tumors are resected after a period of liver regeneration. Two-stage hepatectomy was performed in 11 patients. RESULTS: Two-stage hepatectomy was feasible in all of the 11 patients. In 3 of them, the first stage was a major resection (more extensive than a lobectomy). This first hepatectomy was uneventful in all patients. The second hepatectomy was also uneventful in nine patients, but in one of the other two, a perihepatic fluid infection occurred, and in the other, postoperative liver failure developed due to a right subphrenic abscess. However, all patients were discharged. The percentage of the expected resection volume at one time, calculated from CT volumetry, was 75.5+/-1.2% and the prognostic score as surgical risk was 56.6+/-4.5. In two-stage hepatectomy cases, the percentage of the resected volume and the prognostic score in the first hepatectomy were 25.4+/-6.4% and 6.7+/-7.3, and in the second, 45.7+/-4.5% and 28.5+/-5.8. During the follow-up procedures, a residual hepatic recurrence was observed in 6 patients, and pulmonary recurrence in 9. The 1- and 3-year survival rates after the first hepatectomy were 90% and 45%, with median survivals of 18 months from the first hepatectomy. CONCLUSIONS: Two-stage hepatectomy is a surgical modality intended for patients with initial unresectable metastases. However, following such surgery, protective treatment against residual liver recurrence and lung metastasis will be a most important issue.