Morphology and morphometry of the human early foetal brain: A three-dimensional analysis.

Morphometric analyses in the early foetal phase (9-13 postconceptional week) are critical for evaluating normal brain growth. In this study, we assessed sequential morphological and morphometric changes in the foetal brain during this period using high-resolution T1-weighted magnetic resonance imaging (MRI) scans from 21 samples preserved at Kyoto University. MRI sectional views (coronal, mid-sagittal, and horizontal sections) and 3D reconstructions of the whole brain revealed sequential changes in its external morphology and internal structures. The cerebrum's gross external view, lateral ventricle and choroid plexus, cerebral wall, basal ganglia and thalamus, and corpus callosum were assessed. The development of the cerebral cortex, white matter microstructure, and basal ganglia can be well-characterized using MRI scans. The insula became apparent and deeply impressed as brain growth progressed. A thick, densely packed cellular ventricular/subventricular zone and ganglionic eminence became apparent at high signal intensity. We detected the emergence of important landmarks which may be candidates in the subdivision processes during the early foetal period; the corpus callosum was first detected in the sample with crown-rump length (CRL) 62 mm. A primary sulcus on the medial part of the cortex (cingulate sulcus) was observed in the sample with CRL 114 mm. In the cerebellum, the hemispheres, posterolateral fissure, union of the cerebellar halves, and definition of the vermis were observed in the sample with CRL 43.5 mm, alongside the appearance of a primary fissure in the sample with CRL 56 mm and the prepyramidal fissure in the sample with CRL 75 mm. The volumetric, linear, and angle measurements revealed the comprehensive and regional development, growth, and differentiation of brain structures during the early foetal phase. The early foetal period was neither morphologically nor morphometrically uniform. The cerebral proportion (length/height) and the angle of cerebrum to the standard line at the lateral view of the cerebrum, which may reflect the growth and C-shape formation of the cerebrum, may be a candidate for subdividing the early foetal period. Future precise analyses must establish a staging system for the brain during the early foetal period. This study provides insights into brain structure, allowing for a correlation with functional maturation and facilitating the early detection of brain damage and abnormal development.

Circulating angiopoietin-like protein 2 levels and mortality risk in patients receiving maintenance hemodialysis: a prospective cohort study.

BACKGROUND: Patients undergoing hemodialysis treatment have a poor prognosis, as many develop premature aging. Systemic inflammatory conditions often underlie premature aging phenotypes in uremic patients. We investigated whether angiopoietin-like protein 2 (ANGPTL 2), a factor that accelerates the progression of aging-related and noninfectious inflammatory diseases, was associated with increased mortality risk in hemodialysis patients. METHODS: We conducted a multicenter prospective cohort study of 412 patients receiving maintenance hemodialysis and evaluated the relationship between circulating ANGPTL2 levels and the risk for all-cause mortality. Circulating ANGPTL2 levels were log-transformed to correct for skewed distribution and analyzed as a continuous variable. RESULTS: Of 412 patients, 395 were included for statistical analysis. Time-to-event data analysis showed high circulating ANGPTL2 levels were associated with an increased risk for all-cause mortality after adjustment for age, sex, hemodialysis vintage, nutritional status, metabolic parameters and circulating high-sensitivity C-reactive protein levels {hazard ratio [HR] 2.04 [95% confidence interval (CI) 1.10-3.77]}. High circulating ANGPTL2 levels were also strongly associated with an increased mortality risk, particularly in patients with a relatively benign prognostic profile [HR 3.06 (95% CI 1.86-5.03)]. Furthermore, the relationship between circulating ANGPTL2 levels and mortality risk was particularly strong in patients showing few aging-related phenotypes, such as younger patients [HR 7.99 (95% CI 3.55-18.01)], patients with a short hemodialysis vintage [HR 3.99 (95% CI 2.85-5.58)] and nondiabetic patients [HR 5.15 (95% CI 3.19-8.32)]. CONCLUSION: We conclude that circulating ANGPTL2 levels are positively associated with mortality risk in patients receiving maintenance hemodialysis and that ANGPTL2 could be a unique marker for the progression of premature aging and subsequent mortality risk in uremic patients, except those with significant aging-related phenotypes.

Effects of cardiac output on the onset of rocuronium-induced neuromuscular block in elderly patients.

PURPOSE: The aim of this study was to elucidate the relationship between the onset of rocuronium-induced neuromuscular block and arterial pressure-based cardiac output (CO) in elderly patients. METHODS: Forty elderly patients aged 65-83 years were enrolled in this study. After induction of anesthesia, contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation were acceleromyographically evaluated and 1 mg/kg rocuronium was administered following CO measurement. The correlation between onset of rocuronium action and CO was analyzed. RESULTS: The mean [SD] CO reduced after induction of anesthesia from 5.1 [1.8] L/min to 3.8 [1.1] L/min. The onset time of rocuronium-induced neuromuscular block was 110.3 [23.9] s (range 60-165). There was a statistically significant inverse correlation between the onset time of rocuronium and CO [onset time (s) = - 13.2·CO + 159.7, R2 = 0.376]. CONCLUSIONS: In the elderly, CO influences the onset of action of rocuronium.

Verruciform Xanthoma with Equivocal Exfoliative Cytological Diagnosis.

Verruciform xanthoma (VX), a papillary or wart-like lesion of the mucosa, is histopathologically characterized by papillary projection of the epithelium and an aggregation of foam cells in the lamina propria. Here, we describe a case of VX in the posterior mandibular gingiva, initially suspected to be a benign lesion based on clinical findings and cytology prior to an excisional biopsy. The patient was a 62-year-old man who had visited a local dentist approximately 1 year earlier, presenting with a white lesion in the left posterior mandibular gingiva that resisted removal by scraping. The lesion was left untreated as there were no subjective symptoms. Thereafter, the surface of the lesion roughened and the patient was referred to our department for a comprehensive examination. A circumscribed, granular mass, 15-mm in diameter, with a red and white surface was observed in the left posterior mandibular buccal gingiva. Exfoliative cytology was performed. The diagnosis was a class III lesion. Excisional biopsy was performed under local anesthesia. Histopathological examination led to a diagnosis of VX. At 1 year postoperatively, the patient is making satisfactory progress without recurrence. Verruciform xanthoma is difficult to diagnose preoperatively, and is commonly resected under a clinical diagnosis of papilloma or benign tumor. A benign lesion was also initially suspected in the present case and cytological analysis performed to confirm absence of malignancy. The lesion could not be diagnosed as VX preoperatively. Verruciform xanthoma can be over-diagnosed based solely on cytological examination because it often involves cellular atypia reflecting its characteristic extension of rete pegs and keratinization of surface cells, indicating the need for care in arriving at a definitive diagnosis.

Low-density lipoprotein apheresis for proteinuria in lupus nephritis with intraglomerular foam cells containing cholesterol crystals.

A 28-year-old woman with systemic lupus erythematosus was referred to our hospital due to nephrotic-level proteinuria despite approximately 1 year of treatment with 50 to 60 mg/d of prednisolone and 100 to 150 mg/d of cyclosporine with methylprednisolone pulse therapy. Kidney biopsy showed diffuse global lupus nephritis (World Health Organization class 4-G A/C) with many intraglomerular foam cells containing cholesterol crystals. Surprisingly, proteinuria diminished after only 5 low-density lipoprotein (LDL) cholesterol apheresis sessions. This case demonstrated the potential of LDL apheresis to exhibit a remarkable effect on not only focal segmental glomerulosclerosis, but also other types of nephritis, particularly nephritis with intraglomerular foam cells.

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.

Amyloid A amyloidosis in a Japanese patient with familial Mediterranean fever associated with homozygosity for the pyrin variant M694I/M694I.

Familial Mediterranean fever (FMF) is an autoinflammatory disease common in eastern Mediterranean populations. The most severe complication is the development of secondary amyloid A (AA) amyloidosis. A 51-year-old Japanese male who had been suffering from periodic fever since in his twenties was referred to our hospital for proteinuria. Histological findings from renal biopsy revealed the deposition of AA amyloid fibrils, suggesting that renal dysfunction was due to AA amyloidosis. Gene analysis of the patient and his mother showed that both were homozygous for the M694I mutation in the MEFV gene. His mother was also a carrier of the SAA1.3 allele, which is not only a univariate predictor of survival but also a risk factor for the association of AA amyloidosis with rheumatoid arthritis in Japanese patients, and the SAA1-13T allele in the 13T/C polymorphism on the 5'-flanking region of the SAA1 gene. The patient was also a carrier of the SAA-13T allele. Colchicine resulted in not only an amelioration of the acute febrile attacks of FMF inflammation, but also an improvement in kidney dysfunction due to AA amyloidosis.

The antifibrotic effect of a serine protease inhibitor in the kidney.

Interstitial fibrosis is a final common pathway for the progression of chronic kidney diseases. Activated fibroblasts have an extremely important role in the progression of renal fibrosis, and transforming growth factor (TGF)-ß1 is a major activator of fibroblasts. Since previous reports have indicated that serine protease inhibitors have a potential to inhibit TGF-ß1 signaling in vitro, we hypothesized that a synthetic serine protease inhibitor, camostat mesilate (CM), could slow the progression of renal fibrosis. TGF-ß1 markedly increased the phosphorylation of TGF-ß type I receptor, ERK 1/2, and Smad2/3 and the levels of profibrotic markers, such as α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), and plasminogen activator inhibitor-1, in renal fibroblasts (NRK-49F cells), and they were all significantly reduced by CM. In protocol 1, 8-wk-old male Sprague-Dawley rats were subjected to unilateral ureteral obstruction (UUO) and were concurrently treated with a slow-release pellet of CM or vehicle for 14 days. Protocol 2 was similar to protocol 1 except that CM was administered 7 days after UUO. CM substantially improved renal fibrosis as determined by sirius red staining, collagen expression, and hydroxyproline levels. The phosphorylation of ERK1/2 and Smad2/3 and the levels of α-SMA, CTGF, promatrix metalloproteinase-2, and matrix metalloproteinase-2 were substantially increased by UUO, and they were all significantly attenuated by CM. These antifibrotic effects of CM were also observed in protocol 2. Our present results suggest the possibility that CM might represent a new class of therapeutic drugs for the treatment of renal fibrosis through the suppression of TGF-ß1 signaling.

Down-regulated Th17 cells in a patient with familial Mediterranean fever associated with amyloid A amyloidosis in the treatment of canakinumab.

Autoinflammatory diseases are innate immune-mediated inflammatory disorders, unlike autoimmune diseases, which are characterised by abnormalities in adoptive immunity, although autoimmune and autoinflammatory diseases have certain similar clinical features. Familial Mediterranean fever (FMF), the most common monogenic autoinflammatory disease, is associated with mutations in the MEFV gene that encodes pyrin, which results in inflammasome activation and uncontrolled production of interleukin (IL)-1ß. Regular use of colchicine, the primary drug for FMF treatment, prevents febrile attacks and reduces the long-term risk of subsequent complications of amyloid A (AA) amyloidosis. However, a minority of FMF patients develop colchicine resistance, and anti-IL-1ß treatment with canakinumab, which is a genetically modified human IgG subclass type 1 (IgG1) monoclonal antibody specific for human IL-1ß, was beneficial in inhibiting inflammation in such patients. Here, we present a patient with FMF associated with AA amyloidosis, who was treated with canakinumab and demonstrated down-regulated Th17 cells and activated Th17 cells (from 21.4% to 12.8%, and from 1.45% to 0.83%, respectively) in peripheral blood, as shown by immunophenotyping via multicolour flow cytometry and by disease activity and improved laboratory inflammatory surrogate markers-C-reactive protein (CRP) and serum AA protein (SAA). CRP had values within normal limits, but SAA did not (Spearman's rank correlation coefficient; ρ = 0.133). We report that SAA and IL-1ß may differentiate Th17 cells from CD4+-naïve T cells, and we discuss interactions between autoinflammation and autoimmunity as a model based on this case, through modes of action with IL-1ß and SAA. This report is the first demonstrating that an IL-1ß antagonist may reduce Th17 cells in FMF as a therapeutic option.

In vivo contribution of serine proteases to the proteolytic activation of γENaC in aldosterone-infused rats.

Aldosterone plays an important role in the regulation of blood pressure by modulating the activity of the epithelial sodium channel (ENaC) that consists of α-, ß-, and γ-subunits. Aldosterone induces a molecular weight shift of γENaC from 85 to 70 kDa that is necessary for the channel activation. In vitro experiments demonstrated that a dual cleavage mechanism is responsible for this shift. It has been postulated that furin executes the primary cleavage in the Golgi and that the second cleavage is provided by other serine proteases such as prostasin or plasmin at the plasma membrane. However, the in vivo contribution of serine proteases to this cleavage remains unclear. To address this issue, we administered the synthetic serine protease inhibitor camostat mesilate (CM) to aldosterone-infused rats. CM decreased the abundance of the 70-kDa form of ENaC and led to a new 75-kDa form with a concomitant increase in the urinary Na-to-K ratio. Because CM inhibits the protease activity of serine proteases such as prostasin and plasmin, but not furin, our findings strongly indicate that CM inhibited the second cleavage of γENaC and subsequently suppressed ENaC activity. The results of our current studies also suggest the possibility that the synthetic serine protease inhibitor CM might represent a new strategy for the treatment of salt-sensitive hypertension in humans.

Effect of a serine protease inhibitor on the progression of chronic renal failure.

The number of the chronic renal failure (CRF) patients is increasing explosively. Hypertension, proteinuria, inflammation, fibrosis, and oxidative stress are intertwined in a complicated manner that leads to the progression of CRF. However, the therapeutic strategies to delay its progression are limited. Since serine proteases are involved in many processes that contribute to these risk factors, we investigated the effects of a synthetic serine protease inhibitor, camostat mesilate (CM), on the progression of CRF in 5/6 nephrectomized (Nx) rats. Eighteen male Sprague-Dawley rats were divided into three groups: a sham-operated group (n = 6), a vehicle-treated Nx group (n = 6), and a CM-treated Nx group (n = 6). Following the 9-wk study period, both proteinuria and serum creatinine levels were substantially increased in the vehicle-treated Nx group, and treatment with CM significantly reduced proteinuria and serum creatinine levels. The levels of podocyte-associated proteins in glomeruli, such as nephrin and synaptopodin, were markedly decreased by 5/6 nephrectomy, and this was significantly ameliorated by CM. CM also suppressed the levels of inflammatory and fibrotic marker mRNAs including transforming growth factor-ß1, TNF-α, collagen types I, III, and IV, and reduced glomerulosclerosis, glomerular hypertrophy, and interstitial fibrosis in histological studies. Furthermore, CM decreased the expression of NADPH oxidase component mRNAs, as well as reactive oxygen species generation and advanced oxidative protein product levels. Our present results strongly suggest the possibility that CM could be a useful therapeutic agent against the progression of CRF.

Heat shock protein 90 as a molecular target for therapy in oral squamous cell carcinoma: Inhibitory effects of 17­DMAG and ganetespib on tumor cells.

Heat shock protein 90 (HSP90) expression is upregulated in numerous types of cancer. However, its role as a candidate for molecular targeted therapy in oral squamous cell carcinoma (OSCC) cells is poorly understood. In the present study, a common upstream search was performed using molecular network analysis software for proteins with expression abnormalities that were found in a proteomic analysis of six OSCC cell lines. HSP90 was identified as a target protein. In clinical samples, high frequencies of HSP90­high expression were detected via immunohistochemistry (26/58; 45%). Furthermore, the HSP90 expression status was associated with cervical lymph node metastasis (P=0.015). Furthermore, the potential of HSP90 as a candidate for molecular targeted therapy in OSCC cells was investigated using the HSP90 inhibitors 17­dimethylaminoethylamino­17­demethoxygeldanamycin (17­DMAG) and ganetespib. KON cells, which strongly express HSP90, were treated with the HSP90 inhibitors. The numbers of living cells in the 17­DMAG and ganetespib­treated groups were lower than those in the non­treated group. The cells treated with the inhibitors demonstrated reduced cell viability and migration, and this was associated with markedly decreased levels of the HSP90 target proteins EGFR, phospho­EGFR, phospho­MEK and phospho­MAPK in the treated groups compared with the non­treated group. To the best of our knowledge, this was the first study to investigate the effects of 17­DMAG and ganetespib on OSCC cells. The present results indicated the potential of HSP90 as a useful candidate for molecular targeted therapy in OSCC. However, additional studies with larger sample sizes are required to confirm these findings.

Integrin-linked kinase pathway in heterogeneous pulmonary sarcomatoid carcinoma.

Pulmonary sarcomatoid carcinoma (PSC) is classified as poorly differentiated, and non-small cell lung carcinomas that contained a component of sarcoma or sarcoma-like differentiation are rare. The underlying carcinogenetic mechanism governing PSC remains unclear. The current study investigated the underlying carcinogenetic mechanism of PSC based on the hypothesis that it involves the epithelial-mesenchymal transition (EMT) process. Mutation analysis of PSCs, including carcinosarcoma, pleomorphic carcinoma and epithelial carcinoma specimens, was performed using targeted deep sequencing, whole transcriptome analysis and digital spatial profiling (DSP). PSCs exhibit a distinct mutation profile, with TP53, SYNE1 and APC mutations. Therefore, clustering of the gene expression profiles allowed the PSCs to be distinguished from the epithelial carcinomas. Increased gene expression of fibronectin in PSC was an important contributor to differential profiles. Pathway analysis revealed enhanced activity of the integrin-linked kinase (ILK) signaling pathway in the PSCs. DSP analysis using 56 antibodies of marker proteins confirmed significantly higher expression of fibronectin in PSCs. Intratumor heterogeneity of fibronectin expression was observed in sarcoma components. In conclusion, epithelial-mesenchymal transition process mediated by ILK signaling may be associated with carcinogenetic mechanisms of PSC. Overexpression of fibronectin mediated by ILK signaling appears to serve a role in the EMT involved in the PSC transformation process.

Expression of cell adhesion molecule 1 in human and murine endometrial glandular cells and its increase during the proliferative phase by estrogen and cell density.

AIMS: Cell adhesion molecule 1 (CADM1) mediates interepithelial adhesion and is upregulated in crowded epithelial monolayers. This study aimed to examine CADM1 expression in the human endometrium of proliferative and secretory phases, and its transcriptional regulation in terms of estrogen stimuli and higher cellularity. MAIN METHODS: CADM1 immunohistochemistry was conducted on endometrial tissues from women in their 40s and adult mice subcutaneously injected with estradiol following ovariectomy. Dual-luciferase reporter assays were conducted using human endometrial HEC-50B and HEC-1B cells and reporter plasmids harboring the human CADM1 3.4-kb promoter and its deleted and mutated forms. Cells were transfected with estrogen receptor α cDNA and reporter plasmids, and treated with estradiol before luciferase activity measurement. KEY FINDINGS: Immunohistochemistry revealed that CADM1 was clearly expressed on the lateral membranes of the simple columnar glandular cells in the proliferative phase, but not in the secretory phase, from both women and the mouse model. The glandular cell density increased two-fold in the proliferative phase. Reporter assays identified three Sp1-binding sites as estradiol-responsive elements in the proximal region (from -223 to -84) of the transcription start site (+1) in HEC-50B cells. When the cell culture was started at eight-fold higher cell density, the CADM1 3.4-kb promoter was transactivated at a two-fold higher level in HEC-50B cells. This cell density effect was not detected for the CADM1 2.3-kb or 1.6-kb promoter. SIGNIFICANCE: Two (proximal and distal) promoter regions are suggested to function additively to transactivate CADM1 in endometrial glandular cells that crowd in the proliferative phase.

α-Fetoprotein-Producing Endometrial Carcinoma Is Associated With Fetal Gut-Like and/or Hepatoid Morphology, Lymphovascular Infiltration, TP53 Abnormalities, and Poor Prognosis: Five Cases and Literature Review.

The clinicopathological, immunohistochemical, and molecular characteristics of α-fetoprotein (AFP)-producing endometrial carcinoma (AFP+ EC) are poorly understood. From 284 cases of endometrial carcinoma in our pathology archive, we identified five cases (1.8%) of AFP+ EC with fetal gut-like (4/5) and/or hepatoid (2/5) morphology. All cases exhibited lymphovascular infiltration. In addition, 24 cases of endometrial carcinoma with elevated serum AFP levels were retrieved from the literature. The patient age ranged from 44 to 86 years (median: 63). Of 26 cases whose FIGO (International Federation of Gynecology and Obstetrics) stage and follow-up information was available (mean follow-up 24 months), 15 were stage I or II and 11 were stage III or IV. Even in stage I or II disease, death or relapse occurred in more than half of the patients (8/15). Detailed analysis of our five cases revealed that, on immunohistochemistry, AFP+ EC was positive for SALL4 (4/5), AFP (3/5), and HNF1ß (4/5) in >50% of neoplastic cells and negative for estrogen and progesterone receptors (5/5), PAX8 (4/5), and napsin A (5/5). Four cases exhibited aberrant p53 immunohistochemistry and were confirmed to harbor TP53 mutations by direct sequencing. No mutation was found in POLE, CTNNB1, or KRAS. In conclusion, AFP+ EC merits recognition as a distinct subtype of endometrial carcinoma, which occurs in 1.8% of endometrial carcinoma cases, are associated with TP53 abnormalities, exhibit lymphovascular infiltration, and can show distant metastasis even when treated in early stage.

Regulation of adrenal aldosterone production by serine protease prostasin.

A serine protease prostasin has been demonstrated to have a pivotal role in the activation of the epithelial sodium channel. Systemic administration of adenovirus carrying human prostasin gene in rats resulted in an increase in plasma prostasin and aldosterone levels. However, the mechanism by which the elevation of prostasin levels in the systemic circulation stimulated the plasma aldosterone levels remains unknown. Therefore, we examined if prostasin increases the aldosterone synthesis in a human adrenocortical cell line (H295R cells). Luciferase assay using CYP11B2 promoter revealed that prostasin significantly increased the transcriptional activity of CYP11B2. Prostasin significantly increased both CYP11B2 mRNA expression and aldosterone production in a dose-dependent manner. Surprisingly, treatment with camostat mesilate, a potent prostasin inhibitor, had no effect on the aldosterone synthesis by prostasin and also a protease-dead mutant of prostasin significantly stimulated the aldosterone production. A T-type/L-type calcium channel blocker and a protein kinase C (PKC) inhibitor significantly reduced the aldosterone synthesis by prostasin. Our findings suggest a stimulatory effect of prostasin on the aldosterone synthesis by adrenal gland through the nonproteolytic action and indicate a new role of prostasin in the systemic circulation.

Amyloid A amyloidosis in a patient with Caplan's syndrome, with special reference to genetic predisposition.

Secondary amyloid A (AA) amyloidosis, which is a disorder of protein conformation and metabolism, is an important serious complication of inflammatory diseases, especially rheumatoid arthritis (RA). AA amyloidosis develops when AA fibrils, which are derived from the acute-phase reactant, serum amyloid AA (SAA) protein, in the circulation, are deposited in organs and cause systemic organ dysfunction. Caplan's syndrome, or rheumatoid pneumoconiosis, is a rare type of lung disease in which individuals suffering from RA develop lung nodules that are associated with occupational exposure to silica and coal dust. Confirmation of diagnosing as Caplan's syndrome requires the patient's occupational history, imaging studies, and serology. A 72-year-old male, working as a tunnel construction worker for 38 years, with RA who had both chronic cardiac and renal dysfunction was referred to our hospital. He received a diagnosis of pneumoconiosis about 20 years ago, after which he was also diagnosed with RA. So far we performed medical English literature searches on the combination of Caplan's syndrome with AA amyloidosis; there were no articles in relation to such association. Although RA is one of the most common underlying diseases that occur with AA amyloidosis, our report here is the first description of a case of Caplan's syndrome associated with AA amyloidosis. In this report, we provide details about this rare disease occurring with AA amyloidosis and discuss on the possible pathogenesis of AA amyloidosis from a genetic point of aetiological view.

Camostat mesilate inhibits prostasin activity and reduces blood pressure and renal injury in salt-sensitive hypertension.

Prostasin, a glycosylphosphatidylinositol-anchored serine protease, regulates epithelial sodium channel (ENaC) activity. Sodium reabsorption through ENaC in distal nephron segments is a rate-limiting step in transepithelial sodium transport. Recently, proteolytic cleavage of ENaC subunits by prostasin has been shown to activate ENaC. Therefore, we hypothesized that serine protease inhibitors could inhibit ENaC activity in the kidney, leading to a decrease in blood pressure. We investigated the effects of camostat mesilate, a synthetic serine protease inhibitor, and FOY-251, an active metabolite of camostat mesilate, on sodium transport in the mouse cortical collecting duct cell line (M-1 cells) and on blood pressure in Dahl salt-sensitive rats. Treatment with camostat mesilate or FOY-251 decreased equivalent current (Ieq) in M-1 cells in a dose-dependent manner and inhibited the protease activity of prostasin in vitro. Silencing of the prostasin gene also reduced equivalent current in M-1 cells. The expression level of prostasin protein was not changed by application of camostat mesilate or FOY-251 to M-1 cells. Oral administration of camostat mesilate to Dahl salt-sensitive rats fed a high-salt diet resulted in a significant decrease in blood pressure with elevation of the urinary Na/K ratio, decrease in serum creatinine, reduction in urinary protein excretion, and improvement of renal injury markers such as collagen 1, collagen 3, transforming growth factor-beta1, and nephrin. These findings suggest that camostat mesilate can decrease ENaC activity in M-1 cells probably through the inhibition of prostasin activity, and that camostat mesilate can have beneficial effects on both hypertension and kidney injury in Dahl salt-sensitive rats. Camostat mesilate might represent a new class of antihypertensive drugs with renoprotective effects in patients with salt-sensitive hypertension.