Classification of chronic glomerulonephritis based on prognostic considerations

Based on the correlation of LM, EM and IF findings of kidney biopsy tissues with the clinical and laboratory findings as well as renal function, classification of primary GN is proposed with special reference to the smouldering and progressive forms of chronic GN. The two forms of chronic GN should be differentiated because their prognoses are different.

Clinical and Pathologic Study of Feline Merkel Cell Carcinoma With Immunohistochemical Characterization of Normal and Neoplastic Merkel Cells

The authors herein describe the morphologic and immunohistochemical features of normal Merkel cells as well as the clinicopathologic findings of Merkel cell carcinoma in cats. Merkel cells were characterized as vacuolated clear cells and were individually located in the epidermal basal layer of all regions examined. Clusters of Merkel cells were often observed adjacent to the sinus hair of the face and carpus. Immunohistochemically, Merkel cells were positive for cytokeratin (CK) 20, CK18, p63, neuron-specific enolase, synaptophysin, and protein gene product 9.5. Merkel cell carcinoma was detected as a solitary cutaneous mass in 3 aged cats (13 to 16 years old). On cytology, large lymphocyte-like cells were observed in all cases. Histologic examinations of surgically resected tumors revealed nests of round cells separated by various amounts of a fibrous stroma. Tumor cells were commonly immunopositive for CK20, CK18, p63, neuron-specific enolase, and synaptophysin, representing the characteristics of normal Merkel cells.

Rapid Recovery of Hypothalamic-Pituitary Axis after Successful Resection of an ACTH-secreting Neuroendocrine Tumor

We describe a 30-year-old man with ectopic adrenocorticotropic hormone (ACTH) syndrome. Before the operation, there was no diurnal variation of ACTH, and ACTH did not respond to CRH or dexamethasone suppression tests. These abnormalities disappeared after the removal of a neuroendocrine tumor in the lung. In addition, plasma ACTH was measureable at as early as postoperative day 3 with ACTH levels increasing thereafter. Furthermore, an insulin tolerance test and inferior petrosal sinus sampling indicated that ACTH was secreted from the pituitary. This case indicates that the hypothalamic-pituitary function can recover within a couple of weeks after curative surgery for ectopic ACTH syndrome.

Functional analysis of mutant FAM20C in Raine syndrome with FGF23-related hypophosphatemia

Raine syndrome is an autosomal recessive disorder characterized by generalized osteosclerosis with periosteal bone formation and a distinctive facial phenotype. Either homozygous or compound heterozygous mutations in family with sequence similarity 20, member C (FAM20C) have been reported to cause this syndrome. Recently, it was reported that fibroblast growth factor 23 (FGF23)-related hypophosphatemia was found in patients with non-lethal Raine syndrome, and Fam20c conditional knockout mice presented Fgf23-related hypophosphatemic rickets. To clarify the mechanism of how FAM20C regulates FGF23, we performed functional analysis of mutant FAM20C proteins reported in Raine syndrome. We analyzed 6 mutant FAM20C proteins (T268M, P328S, R408W, D451N, D478A, and R549W) for their distributions, kinase activities, and effects on dentin matrix protein (DMP1) promoter activity. We also analyzed the effect of Fam20c knockdown on Dmp1 and Fgf23 mRNA levels in UMR-106 cells. As a result, all the mutant FAM20C proteins showed decreased kinase activities compared to wild-type (WT) FAM20C, and most of them also showed impaired secretion. Overexpression of WT FAM20C increased DMP1 promoter activity in Saos-2 cells while mutant FAM20C did not. Fam20c knockdown decreased Dmp1 mRNA and increased Fgf23 mRNA in UMR-106 cells. In conclusion, our results suggest that FAM20C suppresses FGF23 production by enhancing DMP1 expression, and inactivating mutations in FAM20C cause FGF23-related hypophosphatemia by decreasing transcription of DMP1.

Hypophosphatemic osteomalacia and bone sclerosis caused by a novel homozygous mutation of the FAM20C gene in an elderly man with a mild variant of Raine syndrome

BACKGROUND

Hypophosphatemia and increased serum fibroblast growth factor 23 (FGF23) levels have been reported in young brothers with compound heterozygous mutations for the FAM20C gene; however, rickets was not observed in these cases. We report an adult case of Raine syndrome accompanying hypophosphatemic osteomalacia with a homozygous FAM20C mutation (R408W) associated with increased periosteal bone formation in the long bones and an increase in bone mineral density in the femoral neck.

CASE

The patient, a 61-year-old man, was born from a cousin-to-cousin marriage. A short stature and severe dental demineralization were reported at an elementary school age. Hypophosphatemia was noted inadvertently at 27years old, at which time he started to take an active vitamin D metabolite (alphacalcidol) and phosphate. He also manifested ossification of the posterior longitudinal ligament. On bone biopsy performed at the age of 41years, we found severe osteomalacia surrounding osteocytes, which appeared to be an advanced form of periosteocytic hypomineralized lesions compared to those reported in patients with X-linked hypophosphatemic rickets. Laboratory data at 61years of age revealed markedly increased serum intact-FGF23 levels, which were likely to be the cause of hypophosphatemia and the decreased level of 1,25(OH)2D. We recently identified a homozygous FAM20C mutation, which was R408W, in this patient. When expressed in HEK293 cells, the R408W mutant protein exhibited impaired kinase activity and secretion.

DISCUSSION

Our findings suggest that certain homozygous FAM20C mutations can cause FGF23-related hypophosphatemic osteomalacia and indicate the multiple roles of FAM20C in bone.

Randomised clinical trial: prevention of recurrence of peptic ulcers by rabeprazole in patients taking low-dose aspirin

BACKGROUND

Few studies have evaluated the effects of rabeprazole on low-dose aspirin (LDA)-induced gastroduodenal injuries.

AIM

To conduct a randomised, double-blind, triple-dummy, active-controlled, multicentre trial, named the PLANETARIUM study, to assess the efficacy, dose-response relationship and safety of rabeprazole for peptic ulcer recurrence in Japanese patients on long-term LDA therapy.

METHODS

Eligible patients had a history of endoscopically confirmed peptic ulcers and were receiving long-term LDA (81 or 100 mg/day) therapy for cardiovascular or cerebrovascular protection. Subjects were randomly segregated into three groups receiving rabeprazole 10 mg once daily (standard dose in Japan), rabeprazole 5 mg once daily, or teprenone (geranylgeranylacetone; mucosal protective agent commercially available in Japan) 50 mg three times per day as an active control. The primary endpoint was recurrence of peptic ulcers over 24 weeks.

RESULTS

Among 472 randomised subjects, 452 subjects (n = 151, 150, 151, respectively) constituted the full analysis set. The cumulative recurrence rates of peptic ulcers over 24 weeks in the 10- and 5-mg rabeprazole groups were 1.4% and 2.8%, respectively, both of which were significantly lower than that in the teprenone group (21.7%). The cumulative occurrence rate of bleeding ulcers over 24 weeks in the teprenone group was 4.6%, while bleeding ulcers were not observed in the 10- or 5-mg rabeprazole groups. Rabeprazole was well tolerated at both doses.

CONCLUSION

Rabeprazole prevents the recurrence of peptic ulcers with no evidence of a major dose-response effect in subjects on low-dose aspirin therapy.

[Anti-FGF23 antibody therapy for patients with tumor-induced osteomalacia]

Tumor-induced osteomalacia (TIO) is a disease caused by fibroblast growth factor 23 (FGF23) secreted from the causative tumor. This disease is cured by complete surgical removal of the tumor. However, there are several difficult cases in which the responsible tumors cannot be found, are incompletely removed, or relapse after the surgery. Anti-FGF23 antibody is being studied as a novel therapy for FGF23-related hypophosphatemic diseases. The efficacy of anti-FGF23 antibodies were confirmed using a murine model of X-linked hypophosphatemic rickets (XLHR) , which is the most common heritable form of FGF23-related hypophosphatemic disease. In addition, results of phase I study of single injection of humanized anti-FGF23 antibody for adult patients with XLHR were recently published and the safety and effectiveness of this antibody was shown. This antibody therapy may be useful for patients with TIO with similar pathogenesis to that of XLHR.

Functional activities of mutant calcium-sensing receptors determine clinical presentations in patients with autosomal dominant hypocalcemia

OBJECTIVE

Autosomal dominant hypocalcemia (ADH) is a congenital isolated hypoparathyroidism caused by activating mutations in the calcium-sensing receptor (CASR) gene. The clinical features of ADH are heterogeneous; some patients are asymptomatic, and others show severe hypocalcemia with Bartter's syndrome. We therefore recruited 12 patients with ADH to clarify the determinants of their clinical presentation.

DESIGN AND METHODS

We studied two sporadic and 10 familial cases of ADH. Serum concentrations of calcium, intact PTH, and magnesium (Mg(2+)) were measured in each patient. Fractional excretion of Mg (FE(Mg)) was calculated in spot urine samples. A nuclear factor of activated T cells luciferase assay was used to analyze the responsiveness of each mutant CaSR to extracellular Ca(2+).

RESULTS

Genomic analysis revealed five known activating mutations and a novel mutation, E481K, in the CASR. Patients with the A843E, C131W, or F788C mutation showed hypomagnesemia with elevated FE(Mg). Intact PTH in these patients was consistently near the detection limit. In contrast, patients with the P221L, K47N, or E481K mutation exhibited normal Mg(2+) levels. In these patients, intact PTH increased in response to low calcium, and their maximum intact PTH exceeded the lower limit of the reference range. Functional analysis showed an association between the disease severity and the in vitro activity of the mutant CaSR.

CONCLUSIONS

The functional activity of mutant CaSR determines the serum Mg(2+) level, renal Mg(2+) handling, and intact PTH in patients with ADH. The presence of hypomagnesemia with elevated FE(Mg) may indicate the diagnosis of ADH among patients with PTH-deficient hypoparathyroidism.

Postoperative Clostridium difficile infection with PCR ribotype 078 strain identified at necropsy in five Thoroughbred racehorses

Clostridium difficile is an important cause of acute enterocolitis in horses. We describe five cases of C difficile infection occurring postoperatively in Thoroughbred racehorses. Following diarrhoea or colic accompanied by a marked increase in packed cell volume (to ≥60 per cent) and leucopenia (≤4000 cells/μl) within two to four days after surgery in all five horses, four of them died or were euthanased because of colitis or severe diarrhoea. In these four horses, necrotising entero-typhlo-colitis was revealed by postmortem examination, and C difficile was recovered from the contents of the small and/or large intestine. The remaining horse was euthanased because of marked decline in general condition and the presence of a lung abscess, from which C difficile was isolated. The horse had had severe postoperative diarrhoea before the onset of respiratory disorder; laboratory tests for C difficile were not performed on the faeces. All C difficile isolates were toxin-A-positive, toxin-B-positive and actin-specific ADP-ribosyltransferase (CDT)-positive. The isolates were indistinguishable by pulsed field gel electrophoresis analysis, PCR ribotyping, and slpA sequence typing, and the slpA sequences and PCR ribotype patterns were identical to those of known PCR type 078. This case sequence might have been healthcare-associated infection, although there was about a four-month interval between each disease onset.

Randomised clinical trial: rabeprazole improves symptoms in patients with functional dyspepsia in Japan

BACKGROUND

The efficacy of proton pump inhibitors (PPIs) for treating functional dyspepsia (FD) is not well established.

AIM

This study, named the SAMURAI study, aimed to assess the efficacy and dose-response relationship of rabeprazole in Japanese patients with FD in a multicentre, double-blinded, randomised, placebo-controlled trial.

METHODS

Investigated FD was diagnosed using the Rome III criteria. Subjects who did not respond to 1 week of single-blind placebo treatment in a run-in period were randomly assigned to 8 weeks of double-blind treatment with rabeprazole 10 mg, 20 mg, 40 mg or placebo, once daily. Dyspeptic symptoms were assessed by a dyspepsia symptom questionnaire (7-point Likert scale) and symptom diary.

RESULTS

Of 392 subjects entered into the run-in period, 338 were randomly assigned. Although there was no significant difference between placebo and rabeprazole groups in complete symptom relief for four major dyspeptic symptoms, the satisfactory symptom relief of rabeprazole 20 mg was significantly higher than placebo according to the dyspepsia symptom questionnaire (45.3% vs. 28.2%, P = 0.027) and the symptom diary assessment (48.7% vs. 30.0%, P = 0.016). The efficacy was not influenced by syndrome type or Helicobacter pylori status. No statistically significant differences in the incidence of adverse events were seen among treatment groups.

CONCLUSIONS

Rabeprazole 20 mg once daily but not 10 or 40 mg significantly provides satisfactory symptom relief for functional dyspepsia (ClinicalTrials.gov, Number NCT01089543).

[Antagonists of Wnt pathway]

Wnts transduce signals through Wnt/β-catenin pathway (canonical pathway) , in which β-catenin stimulates transcription of target genes, as well as several kinds of non-β-catenin Wnt pathways (alternative pathways) . Wnt/β-catenin pathway is essential for cell proliferation and survival, and its activity is strictly regulated by several antagonists. These antagonists inhibit Wnt signaling either in extracellular fluid, in cytoplasm, or in nucleus. Sclerosteosis and van Buchem disease are rare congenital skeletal diseases caused by inactivating mutations in genes encoding Wnt antagonists. Moreover, it has been reported that knockout mice of Wnt antagonist genes show high bone mass with increased bone formation. Therefore, Wnt antagonists are potential drug targets as bone anabolic agents.

Mandibular reconstruction using a poly(L-lactide) mesh combined with autogenous particulate cancellous bone and marrow: a prospective clinical study

The purpose of this study was to evaluate the stability and viability of mandibular bone regeneration using a poly(L-lactide) (PLLA) mesh and autogenous particulate cancellous bone and marrow (PCBM). Sixty-two procedures were undertaken at eight hospitals (22 malignant tumours, 30 benign tumours, five cysts, two osteomyelitis, two trauma, and one atrophy of the alveolar ridge); the success rate was 84%. The follow-up period was between 9 and 200 months (mean 88.2 months). Consequently, bone regeneration at 6 months postoperation was excellent in 35 cases (57%), good in 17 cases (27%), and poor in 10 cases (16%). In six of the 'poor' cases, the PLLA mesh was removed due to local infection early after surgery. Bone resorption>20% was observed in only one of 46 cases with a follow-up term of >1 year. There were no signs of any other adverse effects except in one case where a section of the tray broke off late in the follow-up period. It is concluded that this method is stable and effective due to favourable morphological and functional recovery and low invasiveness. It may thus be a useful alternative procedure for mandibular reconstruction.

Resolution of clinical symptoms after reopening of an occluded inferior petrosal sinus in a patient with a cavernous sinus dural arteriovenous fistula. A case report

We describe a rare case with a cavernous sinus (CS) dural arteriovenous fistula (DAVF) in which the clinical symptoms disappeared after the patient underwent reopening of an occluded inferior petrosal sinus (IPS). A 66-year-old woman presented with increased intraocular pressure, chemosis, and proptosis on the left side. Angiography demonstrated a left CS DAVF supplied by the dural branches of bilateral internal carotid arteries. The shunt flow was directed to the superior and inferior ophthalmic veins, while the bilateral IPSs were not opacified. Accordingly, a transvenous embolization of the fistula was attempted. Although the microcatheter was navigated to the cavernous sinus through the occluded left IPS, obliteration of the fistula was unsuccessful because of the failure of superselective catheterization at the fistulous point. However, the final image demonstrated the development of an antegrade shunt flow through the left IPS to the internal jugular vein and disappearance of the retrograde reflux to the superior and inferior ophthalmic veins. The patient's clinical symptoms immediately resolved after the operation, and the symptoms have not recurred during a one-year follow-up period. Inappropriate transvenous embolization of CS DAVFs can result in vascular complications arising from the unintentional redistribution of shunt flow. The present case illustrates that the disappearance of retrograde shunt flow to the ophthalmic veins after reopening of the occluded IPS may be sufficient if a superselective approach fails or is anticipated to result only in an incomplete embolization of the fistulous point.

Mutational analysis of patients with FGF23-related hypophosphatemic rickets

OBJECTIVE

X-linked hypophosphatemic rickets (XLHR) caused by mutations in the PHEX gene is considered to be the most frequent cause of fibroblast growth factor 23 (FGF23)-related congenital hypophosphatemic rickets. In previous studies, mutations in the PHEX gene were detected in 60-70% of patients with clinical diagnoses of XLHR. This leads to the question whether current screening methods for mutations in the PHEX gene are inadequate or whether there is a substantial number of patients with other genetic causes of hypophosphatemic rickets. We conducted a genetic analysis of patients with FGF23-related hypophosphatemic rickets to clarify their etiology and evaluate the prevalence of XLHR among this group.

DESIGN AND METHODS

We studied 27 patients with familial and sporadic congenital hypophosphatemic rickets in whom serum FGF23 was above 30 pg/ml using an assay for the full-length protein. Exons and exon-intron junctions of genomic DNA of causative genes for FGF23-related hypophosphatemic rickets were sequenced. PHEX mRNA from peripheral blood was analyzed in some patients.

RESULTS

Direct sequencing of genomic DNA identified 11 novel and four known mutations in the PHEX gene. Additionally, there was a large PHEX gene deletion in one case and abnormal PHEX mRNA splicing in another. In summary, 26 patients (96%) had XLHR and one patient had autosomal recessive hypophosphatemic rickets 2.

CONCLUSIONS

XLHR is by far the most prevalent cause of FGF23-related hypophosphatemic rickets. We propose that analysis of PHEX mRNA from peripheral blood would be appropriate for the first screening step in determining the etiology of FGF23-related hypophosphatemic rickets.

Randomised clinical trial: esomeprazole for the prevention of nonsteroidal anti-inflammatory drug-related peptic ulcers in Japanese patients

BACKGROUND

The use of proton pump inhibitors for prevention of nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal adverse events is well documented. However, data regarding the efficacy and safety of this approach in Japan are scarce.

AIM

To evaluate the efficacy and tolerability of esomeprazole in preventing NSAID-induced peptic ulcers in Japanese at-risk patients.

METHODS

Male and female Japanese adult patients (aged ≥ 20 years) with endoscopically confirmed history of peptic ulcers who required long-term oral NSAID therapy for a chronic inflammatory condition were randomised to 24 weeks' treatment with esomeprazole 20 mg once daily or matching placebo. The primary end point was the Kaplan-Meier estimated proportion of ulcer-free patients.

RESULTS

Overall, 343 patients were randomised to treatment (esomeprazole, n = 175; placebo, n = 168). The Kaplan-Meier estimated ulcer-free rate over the 24-week treatment period was significantly higher (log-rank P < 0.001) in esomeprazole-treated patients (96.0%; 95% CI 92.8, 99.1) than in placebo recipients (64.4%; 95% CI 56.8, 71.9). Esomeprazole was effective at preventing peptic ulcers in both Helicobacter pylori-positive and -negative patients (96.3% vs. 95.5% of patients ulcer-free, respectively); however, in the placebo group, the proportion of ulcer-free patients at 24 weeks was markedly lower among H. pylori-positive than -negative patients (59.7% vs. 69.9%). The NSAID type did not seem to affect the estimated ulcer-free rate with esomeprazole. Treatment with esomeprazole was well tolerated.

CONCLUSION

Esomeprazole 20 mg once daily is effective and safe in preventing ulcer recurrence in Japanese patients with a definite history of peptic ulcers who were taking an NSAID (ClinicalTrials.gov identifier: NCT00542789).