Searching for genomic region of high-fat diet-induced type 2 diabetes in mouse chromosome 2 by analysis of congenic strains.

SMXA-5 mice are a high-fat diet-induced type 2 diabetes animal model established from non-diabetic SM/J and A/J mice. By using F2 intercross mice between SMXA-5 and SM/J mice under feeding with a high-fat diet, we previously mapped a major diabetogenic QTL (T2dm2sa) on chromosome 2. We then produced the congenic strain (SM.A-T2dm2sa (R0), 20.8-163.0 Mb) and demonstrated that the A/J allele of T2dm2sa impaired glucose tolerance and increased body weight and body mass index in the congenic strain compared to SM/J mice. We also showed that the combination of T2dm2sa and other diabetogenic loci was needed to develop the high-fat diet-induced type 2 diabetes. In this study, to narrow the potential genomic region containing the gene(s) responsible for T2dm2sa, we constructed R1 and R2 congenic strains. Both R1 (69.6-163.0 Mb) and R2 (20.8-128.2 Mb) congenic mice exhibited increases in body weight and abdominal fat weight and impaired glucose tolerance compared to SM/J mice. The R1 and R2 congenic analyses strongly suggested that the responsible genes existed in the overlapping genomic interval (69.6-128.2 Mb) between R1 and R2. In addition, studies using the newly established R1A congenic strain showed that the narrowed genomic region (69.6-75.4 Mb) affected not only obesity but also glucose tolerance. To search for candidate genes within the R1A genomic region, we performed exome sequencing analysis between SM/J and A/J mice and extracted 4 genes (Itga6, Zak, Gpr155, and Mtx2) with non-synonymous coding SNPs. These four genes might be candidate genes for type 2 diabetes caused by gene-gene interactions. This study indicated that one of the genes responsible for high-fat diet-induced diabetes exists in the 5.8 Mb genomic interval on mouse chromosome 2.

Surgical treatment of clinical N1 non-small cell lung cancer: ongoing controversy over diagnosis and prognosis.

PURPOSE: The preoperative assessment of nodal status in lung cancer is complicated and problematic for physicians and surgeons. Although many patients with clinical N1 (cN1) non-small cell lung cancer (NSCLC) are candidates for surgical treatment, these patients represent a heterogeneous subgroup with unpredictable survival. We conducted this study to evaluate the surgical results of cN1 disease and to attempt to clarify the delicate issues surrounding its diagnosis and prognosis. METHODS: The subjects of this study were 187 consecutive patients with cN1 adenocarcinoma or squamous cell carcinoma of the lung, who underwent complete resection without induction therapy. RESULTS: Only 25% of the adenocarcinomas and 54% of the squamous cell carcinomas were correctly diagnosed as N1 disease preoperatively. Multiple logistic regression analyses revealed that adenocarcinoma (P = 0.0141) was a significant predictor of pN2. Multivariate analyses revealed that nodal metastasis (P < 0.0001), large tumor size (P = 0.0079), and high serum carcinoembryonic antigen value (P = 0.0096) were significantly poor prognostic factors in cN1 patients. CONCLUSIONS: It is difficult to diagnose nodal status in patients with cN1 disease, which requires various surgical procedures, including plasty, possibly with adjuvant therapy in a defined high-risk subgroup.

Suppression of nitrosative and oxidative stress to reduce cardiac allograft vasculopathy.

Oxidant injury occurs when an organ is severed from its native blood supply and then reperfused and continues during subsequent periods of immune attack. Experiments here test the hypothesis that an antioxidant given only in the peri-reperfusion period protects against not only oxidative but also nitrosative stress, leading to reduced vasculopathy long after cardiac allotransplantation. Experiments were performed using a murine heterotopic cardiac transplantation model. An antioxidant, in the form of intraperitoneal high-dose riboflavin, was given to recipients during the initial 3 days after transplantation. Antioxidant-treated mice showed significantly longer graft survival than control mice. At 4 h after transplantation, antioxidant treatment significantly reduced graft lipid peroxidation and oxidized DNA and preserved antioxidant enzyme activity. At day 6 posttransplantation, the redox-sensitive transcription factor nuclear factor-kappaB and inducible nitric oxide synthase were significantly reduced following antioxidant treatment, with concomitant reduction of nitrotyrosine. Despite the limited duration of antioxidant treatment, both acute and chronic rejection were significantly suppressed. In vitro experiments confirmed suppression of nitrosative and oxidative stress and cardiomyocyte damage in antioxidant-treated cardiac allografts. Collectively, antioxidant administration during the initial 3 days after transplantation significantly reduces nitrosative and oxidative stress in cardiac allografts, modulates immune responses, and protects against vasculopathy.

Associations among bronchioloalveolar carcinoma components, positron emission tomographic and computed tomographic findings, and malignant behavior in small lung adenocarcinomas.

OBJECTIVE: The aggressiveness of small adenocarcinomas has not been fully evaluated using integrated positron emission tomography/computed tomography. We investigated malignant aggressiveness according to positron emission tomography/computed tomography, high-resolution computed tomographic findings, and the proportions of pathologically defined bronchioloalveolar carcinomas in cT1N0M0 lung adenocarcinoma. METHODS: Sixty consecutive patients with cT1N0M0 lung adenocarcinomas of 3 cm or less in diameter underwent fluorodeoxyglucose-positron emission tomograph/computed tomography, and high-resolution computed tomography, followed by complete tumor resection. Correlations between the proportion of bronchioloalveolar carcinoma and maximum standardized uptake value on positron emission tomographic scan/computed tomographic scan, ground-glass opacity, and tumor shadow disappearance rate were investigated and the findings were compared with clinicopathologic features. RESULTS: Lymphatic and vascular invasion occurred in 18 (30%) and 13 (22%) patients, respectively, whereas hilar or mediastinal lymph nodes occurred in 8 patients (13%). Maximum standardized uptake value generally seemed the most valuable predictor of lymphatic invasion, vascular invasion, and nodal metastasis compared with ground-glass opacity, tumor shadow disappearance rate, and bronchioloalveolar carcinoma ratios. Although the association was significant between the bronchioloalveolar carcinoma ratio versus maximum standardized uptake value, ground-glass opacity ratio, and tumor shadow disappearance rate (all P < .0001), maximum standardized uptake value (R2 = 0.245) was less correlated with the bronchioloalveolar carcinoma ratio than was the ground-glass opacity ratio (R2 = 0.554) and tumor shadow disappearance rate (R2 = 0.671). CONCLUSIONS: The malignant behavior of small adenocarcinomas with a lower maximum standardized uptake value and a greater proportion of ground-glass opacity, tumor shadow disappearance rate, and bronchioloalveolar carcinoma was less aggressive. Maximum standardized uptake value was a more powerful clinical predictor of biologic tumor performance, independent of pathologic bronchioloalveolar carcinoma proportion. Preoperative assessment of maximum standardized uptake value on positron emission tomographic/computed tomographic findings, in addition to the ground-glass opacity ratio and tumor shadow disappearance rate on high-resolution computed tomographic scans, might be useful to guide treatment strategies for small adenocarcinomas.

Riboflavin-mediated reduction of oxidant injury, rejection, and vasculopathy after cardiac allotransplantation.

BACKGROUND: Riboflavin is a well-known nutritional supplement that has been shown to exhibit antioxidant properties and protect tissue from oxidative damage. We hypothesized that riboflavin given during cardiac ischemia-reperfusion (I/R) might reduce subsequent acute rejection, after allotransplantation, and coronary allograft vasculopathy (CAV). METHODS: A murine heterotopic cardiac transplantation model was used to test whether riboflavin improves I/R injury and acute/chronic rejection. RESULTS: Riboflavin significantly reduced oxidant production and inflammatory mediator production induced by I/R injury, as evidenced by decreased levels of malondialdehyde, myeloperoxidase activity, and tumor necrosis factor alpha. Administration of riboflavin also improved graft survival and suppressed T-cell infiltration and donor-reactive alloantibody formation during the early period after allotransplantation. A murine long-term cardiac allograft model using immunosuppression (preoperative anti-murine CD4 and anti-CD8) was employed to investigate the effect of riboflavin against CAV at 60 days. Riboflavin-treated grafts exhibited a significant decrease in the severity of coronary artery luminal occlusion as compared with saline-treated grafts (17.4+/-1.8% vs. 43.5+/-5.6%, P=0.0012). However, there was no significant effect of riboflavin to reduce donor-reactive alloantibodies in this chronic model. CONCLUSIONS: These data indicate that riboflavin improves early I/R injury and reduces the development of CAV, most likely due to alloantigen-independent effects such as reduced early graft oxidant stress. Riboflavin administered in the setting of cardiac allograft transplantation appears to be a powerful means to reduce early graft lipid peroxidation, leukocytic infiltration, and cytokine production as well as to suppress the late development of cardiac allograft vasculopathy.

Early growth response gene-1 promotes airway allograft rejection.

Chronic airway rejection, characterized by lymphocytic bronchitis, epithelial cell damage, and obliterative bronchiolitis (OB), limits long-term survival after lung transplantation. The transcription factor early growth response gene-1 (Egr-1) induces diverse inflammatory mediators, some involved in OB pathogenesis. An orthotopic mouse tracheal transplant model was used to determine whether Egr-1 promotes development of airway allograft rejection. Significantly higher Egr-1 mRNA levels were seen in allografts (3.2-fold increase vs. isografts, P = 0.012). Allografts revealed thickening of epithelial and subepithelial airway layers (51 +/- 4% luminal encroachment for allografts vs. 20 +/- 3% for isografts, P < 0.0001) marked by significant lymphocytic infiltration. Absence of the Egr-1 gene in donor (but not recipient) tissue resulted in significant reduction in luminal narrowing (34 +/- 4%, P = 0.0001) with corresponding diminution of T cell infiltration. Egr-1 null allografts exhibited a striking reduction in inducible nitric oxide synthase (iNOS) expression. Effector cytokines previously implicated in OB pathogenesis with known Egr-1 promoter motifs (IL-1beta and JE/monocyte chemoattractant protein-1) were reduced in Egr-1 null allografts. These data suggest a paradigm wherein local induction of Egr-1 in tracheal allografts drives expression of inflammatory mediators responsible for lymphocyte recruitment and tissue destruction characteristic of airway rejection.