Three-dimensional finite-element model of the human temporomandibular joint disc during prolonged clenching

In the temporomandibular joint (TMJ), overloading induced by prolonged clenching appears to be important in the cascade of events leading to disc displacement. In this study, the effect of disc displacement on joint stresses during prolonged clenching was studied. For this purpose, finite-element models of the TMJ, with and without disc displacement, were used. Muscle forces were used as a loading condition for stress analysis during a time-period of 10 min. The TMJ disc and connective tissue were characterized as a linear viscoelastic material. In the asymptomatic model, large stresses were found in the central and lateral part of the disc through clenching. In the retrodiscal tissue, stress relaxation occurred during the first 2 min of clenching. In the symptomatic model, large stresses were observed in the posterior part of the disc and in the retrodiscal tissue, and the stress level was kept constant through clenching. This indicates that during prolonged clenching the disc functions well in the asymptomatic joint, meanwhile the retrodiscal tissue in the symptomatic joint is subject to excessive stress. As this structure is less suitable for bearing large stresses, tissue damage may occur. In addition, storage of excessive strain energy might lead to breakage of the tissue.     

Three presenile patients in which neuropsychological and neuroimaging examinations suggest possible progression to dementia with Lewy bodies

We report three presenile patients who were initially suspected of having Alzheimer's disease (AD) or being in the prodromal stage of AD, regardless of visuoperceptual dysfunctions in daily living, because they lacked the core features and prodromal non‐motor symptoms of dementia with Lewy bodies. Subsequently, progression to dementia with Lewy bodies was suspected based on neuropsychological and neuroimaging findings; additionally, one of the three patients suffered from visual hallucinations. Neuropsychological examinations such as subjective contours, cube copying and block design in the Wechsler Adult Intelligence Scale‐III revealed visuoperceptual dysfunction in all three patients even when other cognitive functions were rather preserved. Brain magnetic resonance imaging revealed no significant brain atrophy, including in the parieto‐occipital area and the hippocampus, while brain ¹⁸F‐fluorodeoxyglucose positron emission tomography demonstrated right dominant metabolic reductions in the occipital lobe, including the primary visual cortex, in all three patients. We suggest the possibility of progression to dementia with Lewy bodies, but not AD or posterior cortical atrophy. Regardless of the presence of core features and prodromal non‐motor symptoms, this progression is suggested when there are difficulties only in higher‐level visual processing such as subjective contours and block design in the Wechsler Adult Intelligence Scale‐III, no significant atrophy of the parieto‐occipital area and hippocampus on brain magnetic resonance imaging, and hypometabolism in the occipital lobe including the primary visual cortex on brain ¹⁸F‐fluorodeoxyglucose positron emission tomography.     

An intra-abdominal desmoid tumor difficult to distinguish from a gastrointestinal stromal tumor: report of two cases

Desmoid tumors are benign fibroblastic neoplasms with no metastatic potential, but a propensity for local recurrence even after complete surgical resection. These lesions can develop at any site in the body, and commonly occur in the intra-abdominal area. Intra-abdominal desmoid tumors usually occur at the mesentery or retroperitoneum, and may morphologically mimic gastrointestinal stromal tumors (GISTs). Distinguishing between these tumors is important, because the therapies differ substantially, but is often difficult even with the use of CD117 staining. We herein report the cases of two patients with sporadic intra-abdominal desmoid tumors that were differentiated from GIST by immunohistological examination using beta-catenin and CD34. Desmoid tumors specifically express nuclear beta-catenin, and show no expression of CD34. We recommend staining for beta-catenin and CD34 when an intra-abdominal desmoid tumor is suspected.     

Prevalence and risk factor analysis of nephrosclerosis and ischemic nephropathy in the Japanese general population

Background

Nephrosclerosis/ischemic nephropathy (NS/IN) ranks third among renal diseases requiring dialysis in Japan. Although it is an important renal disease in terms of frequency, its prevalence, new incidence, and risk factors are not fully elucidated.

Methods

We analyzed the prevalence, incidence, concurrent diseases, and risk factors of NS/IN by using data from specific health checkups of Kumamoto citizens between 2008 and 2010.

Results

Although the prevalence of NS/IN was 1?2 % in people in their 40s, it increased sharply with age, reaching 17.6 % in people aged 70–74 years. The incidence of new NS/IN was 0.4?0.5 % per year. In multivariate logistic regression analysis, factors such as age, male gender, body mass index (BMI), hyperuricemia, hypertension, and dyslipidemia correlated with NS/IN. When risk factors associated with NS/IN progress were evaluated by multivariate logistic regression analysis, four factors—male gender, hypertension, BMI, and current smoking—significantly correlated.

Conclusion

The analysis of Kumamoto citizens aged 40–74 years receiving specific health checkups showed that in addition to hypertension and age that were considered important, male gender and obesity are also risk factors for NS/IS independent from hypertension.     

Functional analysis of a novel G87V TNFRSF1A mutation in patients with TNF receptor-associated periodic syndrome

Tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is an autoinflammatory disease that is caused by heterozygous mutations in the TNFRSF1A gene. Although more than 150 TNFRSF1A mutations have been reported to be associated with TRAPS phenotypes only a few, such as p.Thr79Met (T79M) and cysteine mutations, have been functionally analyzed. We identified two TRAPS patients in one family harboring a novel p.Gly87Val (G87V) mutation in addition to a p.Thr90Ile (T90I) mutation in TNFRSF1A. In this study, we examined the functional features of this novel G87V mutation. In-vitro analyses using mutant TNF receptor 1 (TNF-R1)-over-expressing cells demonstrated that this mutation alters the expression and function of TNF-R1 similar to that with the previously identified pathogenic T79M mutation. Specifically, cell surface expression of the mutant TNF-R1 in transfected cells was inhibited with both G87V and T79M mutations, whereas the T90I mutation did not affect this. Moreover, peripheral blood mononuclear cells (PBMCs) from TRAPS patients harboring the G87V and T90I mutations showed increased mitochondrial reactive oxygen species (ROS). Furthermore, the effect of various Toll-like receptor (TLR) ligands on inflammatory responses was explored, revealing that PBMCs from TRAPS patients are hyper-responsive to TLR-2 and TLR-4 ligands and that interleukin (IL)-8 and granulocyte–macrophage colony-stimulating factor (GM-CSF) are likely to be involved in the pathogenesis of TRAPS. These findings suggest that the newly identified G87V mutation is one of the causative mutations of TRAPS. Our findings based on unique TRAPS-associated mutations provide novel insight for clearer understanding of inflammatory responses, which would be basic findings of developing a new therapeutic and prophylactic approach to TRAPS.     

The superior approach with the stomach roll-up technique improves intraoperative outcomes and facilitates learning laparoscopic distal pancreatectomy: a comparative study between the superior and inferior approach

Surgery Today - We introduced a superior approach and a unique technique to retract the stomach, called the “stomach roll-up technique”, to standardize laparoscopic distal...     

Correction to: Cost-effectiveness of mass screening for dipstick hematuria in Japan

Clinical and Experimental Nephrology -     

Epidemiology of CKD in Japan

Concept of chronic kidney disease (CKD) is widely accepted, since it is a risk factor for end-stage renal disease (ESRD) and cardiovascular disease. In Japan, the prevalence of ESRD is increasing and is currently more than 2,000 per million populations. More than 40% of incident ESRD is due to diabetes mellitus. The prevalence of a low glomerular filtration rate (GFR < 60 mL/min/1.73 m2) is estimated to be 10% of the adult population. Studies based on several community-based screening programs suggest that Japan has a higher prevalence of CKD than any other countries. Early detection through urine test for proteinuria and measurement of serum creatinine is strongly recommended. Goal of treatment of CKD is to decrease the incidence of ESRD and cardiovascular disease.