Mortality risk attributable to atrial fibrillation in middle-aged and elderly people in the Japanese general population: nineteen-year follow-up in NIPPON DATA80.

BACKGROUND: The extent to which atrial fibrillation (AF) contributes to mortality in the Japanese general population has not been clarified. METHODS AND RESULTS: A randomly sampled general population from all over Japan (4,154 men, 5,329 women; age > or =30 years) was enrolled. Single electrocardiogram recordings were taken in the baseline survey. Stroke death, cardiovascular deaths and all-cause deaths during the subsequent 19 years were analyzed by the presence of AF at baseline. Cox's regression analysis was carried out to estimate the hazard ratios (HRs) of each cause of death attributable to AF after adjusting for other risk factors. Prevalence of AF was 0.64% in the study. The observed person-years were 162,980 among persons without AF and 699 among persons with AF. There were 1,919 deaths. Multivariate adjusted HRs for stroke death, cardiovascular death and all-cause death were 2.69, 2.76 and 1.88, respectively (p<0.05). These HRs were 14.7, 9.63 and 4.00 among persons aged 64 years or younger (p<0.05). CONCLUSION: AF affects stroke mortality, cardiovascular mortality and all-cause mortality in the Japanese general population. Careful attention should be paid to persons with AF in order to prevent future cardiovascular events.     

Effects of nateglinide on the elevation of postprandial remnant-like particle triglyceride levels in Japanese patients with type 2 diabetes assessment by meal tolerance test

To elucidate the role of early insulin response in post-prandial hyperlipidemia, we examined triglyceride (TG) and remnant-like particle triglyceride (RLP-TG) levels, using a meal tolerance test (MTT) with or without the administration of nateglinide (NAT). The MTTs were performed 2 d apart in 36 drug-naive patients with type 2 diabetes who had been hospitalized for glycemic control while receiving diet therapy. Before the second MTT, patients were treated with 90 mg NAT. Treatment with NAT was associated with a significant increase in insulin levels in the treated patients 1 h after the test meal, compared to levels in non-treatment. NAT treatment was also associated with a significant decrease in the level of free fatty acids 1 and 2 h after the meal, and with a significant decrease in plasma glucose levels 1, 2, and 4 h after the meal, compared to those in non-treatment. During the first MTT with NAT non-treatment, 13 patients showed serum TG levels of 200 mg/dL or greater when measured 2 h after the meal. In these 13 patients, NAT administration produced a significant decrease in TG levels 1, 2, and 6 h after the meal, as well as a significant reduction in RLP-TG levels 1 and 2 h after the meal. NAT administration was also associated with significant reductions in area under the curve (DeltaAUC) for TG and RLP-TG. These results suggest that, in a clinical setting, the early insulin response is closely associated with both postprandial glucose and postprandial lipid metabolism in Japanese patients with type 2 diabetes.     

CD56 may be a more useful immunohistochemical marker than somatostatin receptor 2A for the diagnosis of phosphaturic mesenchymal tumors

Phosphaturic mesenchymal tumors (PMTs) are the most typical cause of tumor-induced osteomalacia (TIO) associated with mesenchymal neoplasms. Specifically, TIO is attributed to the production of phosphatonins, such as fibroblast growth factor 23 (FGF23), participating in the homeostasis of phosphate. Although immunohistochemistry (IHC) for FGF23 showed characteristic positive staining in PMTs, FGF23 antibodies that can be used for the reliable diagnosis of PMTs are hard to obtain in common pathology laboratories. Somatostatin receptor 2A (SSTR2A) has been previously proposed as an alternatively useful marker for the diagnosis of PMTs. However, SSTR2A is not commonly utilized in pathological laboratories. The CD56 marker is a useful alternative that is comparable to SSTR2A and is similar considering the sensitivity. Even in cases of PMTs originating in the bones, ethylenediaminetetraacetic acid-based decalcification for tissue processing does not seem to affect the IHC of CD56. As CD56 immunopositivity in mesenchymal tumors is limited, it also has some degree of specificity for PMTs. Thus, when PMTs are suspected, the use of CD56 is recommended.     

Melanotic oncocytic metaplasia of the nasopharynx: a case report with a focus on immunohistochemical analyses and literature review

Melanotic oncocytic metaplasia (MOM) of the nasopharynx is an extremely rare lesion, with only 21 cases reported in English literature to date. MOM typically occurs near the Eustachian tube opening in Asian men in their 60 s to 70 s. Here, we present a case of MOM in a 57-year-old Japanese man who is a heavy smoker. The patient did not have complaints; MOM was diagnosed incidentally as 4 flat elevated lesions with brown to black discoloration, ranging from 2 to 3 mm in maximal diameter, were found in the right torus tubarius. On suspecting melanoma, the largest lesion was biopsied. Microscopic examination identified both oncocytic metaplasia and melanin pigmentation of the epithelium in the same gland. Upon immunohistochemical examination, melanocytes displayed reactivity for 3 out of 4 melanocytic markers; immunopositivity for S-100 protein, Melan-A, and MITF and immunonegativity for HMB-45 was observed. Normal melanocytes in the nearby surface respiratory epithelium displayed the same pattern of immunoreactivity. Immunopositivity for S-100 protein and immunonegativity for HMB-45 have been previously reported in MOM. Reduction of stimulation of melanocytes in a longstanding lesion like MOM may explain the immunonegativity for HMB-45. S-100 protein, in conjunction with more specific marker for melanocytes, Melan-A or MITF, could prove the definite presence of melanocytes in this case of MOM. As it has been shown by previous reports that MOM pursues a benign course, it will be sufficient to follow up the patients regularly for the remaining 3 lesions.