Alteration of the Intestinal Environment by Lubiprostone Is Associated with Amelioration of Adenine-Induced CKD

The accumulation of uremic toxins is involved in the progression of CKD. Various uremic toxins are derived from gut microbiota, and an imbalance of gut microbiota or dysbiosis is related to renal failure. However, the pathophysiologic mechanisms underlying the relationship between the gut microbiota and renal failure are still obscure. Using an adenine-induced renal failure mouse model, we evaluated the effects of the ClC-2 chloride channel activator lubiprostone (commonly used for the treatment of constipation) on CKD. Oral administration of lubiprostone (500 µg/kg per day) changed the fecal and intestinal properties in mice with renal failure. Additionally, lubiprostone treatment reduced the elevated BUN and protected against tubulointerstitial damage, renal fibrosis, and inflammation. Gut microbiome analysis of 16S rRNA genes in the renal failure mice showed that lubiprostone treatment altered their microbial composition, especially the recovery of the levels of the Lactobacillaceae family and Prevotella genus, which were significantly reduced in the renal failure mice. Furthermore, capillary electrophoresis–mass spectrometry-based metabolome analysis showed that lubiprostone treatment decreased the plasma level of uremic toxins, such as indoxyl sulfate and hippurate, which are derived from gut microbiota, and a more recently discovered uremic toxin, trans-aconitate. These results suggest that lubiprostone ameliorates the progression of CKD and the accumulation of uremic toxins by improving the gut microbiota and intestinal environment.     

Infliximab treatment for refractory Kawasaki disease with coronary artery aneurysm.

Tumor necrosis factor-alpha (TNF-alpha) is considered to be 1 of the factors that induce vasculitis, including coronary artery aneurysm (CA), in Kawasaki disease (KD), because the blood concentration of TNF-alpha is higher in patients with CA compared with those without. Therefore, an anti-TNF-alphaagent (infliximab) was administered to a 1-month-old girl with refractory KD complicated by CA and subsequently, the CA improved and KD was controlled without complications 20 months after the onset.     

Podoplanin expression in the cyst wall correlates with the progression of intraductal papillary mucinous neoplasm

A thickened, enhanced cyst wall on imaging examinations is one of the “worrisome features” described in the consensus guidelines for management of intraductal papillary mucinous neoplasm of the pancreas (IPMN). Podoplanin (PDPN) expression by cancer-associated fibroblasts is known to be an indicator of poor prognosis in some types of cancer. We performed immunohistochemical staining for alpha-smooth muscle actin (α-SMA) in IPMN lesions and determined the pathological wall thickness by measuring the thinnest and thickest α-SMA-positive parts of the wall of the largest cyst in each case, and the mean of these two values was recorded as the wall thickness. The thickness of the pathological wall increased with progression from IPMN with low-grade dysplasia to IPMN with an invasive carcinoma. The pathological wall was thicker in IPMN with main duct involvement, nongastric-type IPMN, and IPMN with mural nodules. We also stained for PDPN and assessed the thickness of cyst wall staining as for α-SMA. The thickness of the PDPN-positive cyst wall varied in a pattern similar to the thickness of the α-SMA-positive pathological cyst wall. PDPN-positive stromal fibroblasts in the invasive component of IPMN-IC were evaluated as a ratio to α-SMA-positive fibroblasts. A high ratio (>50 %) of PDPN-positive stromal fibroblasts was a predictor of poor outcome. PDPN expression in the cyst wall correlates with the progression of IPMN. PDPN may be a significant prognostic marker of IPMN-IC.     

Association of sleep‐disordered breathing with decreased cognitive function among patients with dementia

Sleep is known to be essential for proper cognitive functioning. Sleep disturbance, especially respiratory disturbance during sleep, is a risk factor for the development of dementia. However, it is not known whether hypopnoea during sleep is related to severity of cognitive function in patients already diagnosed with dementia. Considering the high prevalence of sleep problems in aged people, it is important to determine if hypopnoea during sleep contributes to dementia. In addition, it would be desirable to develop a feasible method for objectively evaluating sleep in patients with dementia. For this purpose, a simple sleep recorder that employs single or dual bioparameter recording, which is defined as a type‐4 portable monitor, is suitable. In this study, a type‐4 sleep recorder was used to evaluate respiratory function during sleep in 111 patients with dementia, and data suggesting a possible relationship with cognitive function levels were examined. Multivariate logistic regression was used to investigate the association of severity of dementia with sleep‐disordered breathing, age, diabetes, dyslipidaemia and hypertension. It was found that the respiratory disturbance index was associated with severity of cognitive dysfunction in our subjects. Furthermore, patients younger than 80 years were more susceptible to lower cognitive function associated with sleep‐disordered breathing than patients 80 years old or over, because an increase in the respiratory disturbance index was associated with deteriorated cognitive function only in the former age group. These results suggest that proper treatment of sleep apnea is important for the preservation of cognitive function, especially in patients with early‐stage dementia.     

Immunohistochemistry of γ‐H2AX as a method of early detection of urinary bladder carcinogenicity in mice

Phosphorylated histone H2AX (γ‐H2AX) has been demonstrated as a DNA damage marker both in vitro and in vivo. We previously reported the effects of genotoxic carcinogens in the urinary bladder of rats by immunohistochemical analysis of γ‐H2AX using samples from 28‐day repeated‐dose tests. To evaluate the application of γ‐H2AX as a biomarker of carcinogenicity in the bladder, we examined species differences in γ‐H2AX formation in the urinary bladder of mice. Six‐week‐old male B6C3F₁ mice were treated orally with 12 chemicals for 4 weeks. Immunohistochemical analysis demonstrated that N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine, p‐cresidine and 2‐acetylaminofluorene (2‐AAF), classified as genotoxic bladder carcinogens, induced significant increases in γ‐H2AX levels in the bladder urothelium. In contrast, genotoxic (2‐nitroanisole, glycidol, N‐nitrosodiethylamine and acrylamide) and non‐genotoxic (dimethylarsinic acid and melamine) non‐bladder carcinogens did not upregulate γ‐H2AX. Importantly, 2‐nitroanisole, a potent genotoxic bladder carcinogen in rats, significantly increased the proportion of γ‐H2AX‐positive cells in rats only, reflecting differences in carcinogenicity in the urinary bladder between rats and mice. Significant upregulation of γ‐H2AX was also induced by uracil, a non‐genotoxic bladder carcinogen that may be associated with cell proliferation, as demonstrated by increased Ki67 expression. 2‐AAF caused γ‐H2AX formation mainly in the superficial layer, together with reduced and disorganized expression of uroplakin III, unlike in rats, suggesting the mouse‐specific cytotoxicity of 2‐AAF in umbrella cells. These results suggest γ‐H2AX is a useful biomarker reflecting species differences in carcinogenicity in the urinary bladder.     

No evidence of association between 8q24 and susceptibility to nonsyndromic cleft lip with or without palate in Japanese population

Objective : Recent genome-wide association studies identified susceptibility loci for nonsyndromic cleft lip with or without cleft palate (NSCL±P) on 8q24.21, 10q25.3, 13q31.1, 15q13.3, 17q22, and 18q22 in populations of European origin. The purpose of this study was to determine, using DNA samples, whether 8q24.21 was a susceptibility locus for the development of NSCL±P in Japanese patients. Methods : We used DNA from 167 Japanese NSCL±P patients (45 cleft lip without cleft palate and 122 cleft lip with cleft palate patients) and 190 Japanese unaffected control individuals. We performed an association study using 13 single nucleotide polymorphisms (SNPs) selected on the 8q24.21 locus. Genotyping of each SNP was carried out by direct sequencing of genomic DNA. Additionally, a haplotype block was constructed using the selected SNPs. Results : The 13 selected SNPs were successfully genotyped in 357 individuals. The p values obtained were not low enough to indicate a significant association between the haplotypes and the development of NSCL±P in this population. Conclusions : Our results suggest that the 8q24.21 locus is not associated with susceptibility to NSCL±P in Japanese patients and provide further evidence that ethnicity is a strong factor in determining susceptibility loci, albeit using a limited number of samples. Further studies are needed to identify regions involved in the development of NSCL±P in the Japanese population.     

Finite element analysis to compare stress distribution of connector of lithia disilicate-reinforced glass–ceramic and zirconia-based fixed partial denture

This study used finite element method to analyze the stress distribution in connector of ceramic-based bilayer structures, in simulation of dental crown-like structures with a functional but weak veneer layer bonded onto a strong core layer. The purpose of this study was to evaluate the stress distribution at veneer/core interface of 2 different core materials [Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and lithia disilicate-reinforced glass–ceramic] using three-dimensional finite element analysis. Within the limitations of this study, finite element analysis showed that stress concentrations were located at the veneer/core interface of the connector in Y-TZP core models. The general observation was that compared with Y-TZP, lithia disilicate-reinforced glass–ceramic showed a relatively stable stress value and had a minor effect on the stress concentration susceptibility.