Mutations in COG2 encoding a subunit of the conserved oligomeric golgi complex cause a congenital disorder of glycosylation

The conserved oligomeric Golgi (COG) complex is involved in intra-Golgi retrograde trafficking, and mutations in six of its eight subunits have been reported in congenital disorders of glycosylation (CDG). Here we report a patient showing severe acquired microcephaly, psychomotor retardation, seizures, liver dysfunction, hypocupremia, and hypoceruloplasminemia. Analysis of his serum glycoproteins revealed defects in both sialylation and galactosylation of glycan termini. Trio-based whole-exome sequencing identified two heterozygous mutations in COG2: a de novo frameshift mutation [c.701dup (p.Tyr234*)] and a missense mutation [c.1900T > G (p.Trp634Gly)]. Sequencing of cloned reverse-transcription polymerase chain reaction (RT-PCR) products revealed that both mutations were located on separate alleles, as expected, and that the mutant transcript harboring the frameshift mutation underwent degradation. The c.1900T > G (p.Trp634Gly) mutation is located in a domain highly conserved among vertebrates and was absent from both the public database and our control exomes. Protein expression of COG2, along with COG3 and COG4, was decreased in fibroblasts from the patient. Our data strongly suggest that these compound heterozygous mutations in COG2 are causative of CDG.

Improvement of insulin resistance following transsphenoidal surgery in patients with acromegaly: correlation with serum IGF-I levels

AIM

The aim of this study was to determine the correlation between the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis and glucose intolerance in acromegaly during the early postoperative period.

SUBJECTS AND METHODS

The study included 20 patients with acromegaly caused by GH-secreting pituitary adenoma who received transsphenoidal surgery in our hospital. Glucose tolerance was evaluated with oral glucose tolerance tests (OGTTs) performed during pre- and early postoperative periods (9 [7-18] days after surgery). Homeostasis model assessment of insulin resistance (HOMA-IR) and insulinogenic index (IGI) were calculated, and correlation analyses were performed between these values and the GH-IGF-I axis. Patients were divided according to postoperative changes of the axis, and glucose tolerance was compared between the groups.

RESULTS

In preoperative OGTTs, nine patients had impaired glucose tolerance and two had diabetes mellitus patterns. Postoperatively, significant reduction was observed both in fasting plasma glucose levels (p<0.01) and in HOMA-IR (p<0.01), whereas IGI showed no significant change. HOMA-IR was significantly correlated with serum IGF-I levels both before (r=0.83, p<0.01) and after (r=0.57, p<0.01) surgery, although it was not correlated with serum GH levels. Patients who achieved more than 50% postoperative reduction in serum IGF-I levels showed significant improvement in OGTTs results (p<0.05).

CONCLUSIONS

In patients with acromegaly, serum IGF-I levels, but not GH levels, were significantly correlated with insulin resistance. Early postoperative improvement of glucose tolerance is observed in patients who achieved postoperative reduction in serum IGF-I levels.

Engineered antibody Fc variant with selectively enhanced FcγRIIb binding over both FcγRIIa(R131) and FcγRIIa(H131)

Engaging inhibitory FcγRIIb by Fc region has been recently reported to be an attractive approach for improving the efficacy of antibody therapeutics. However, the previously reported S267E/L328F variant with enhanced binding affinity to FcγRIIb, also enhances binding affinity to FcγRIIa(R131) allotype to a similar degree because FcγRIIb and FcγRIIa(R131) are structurally similar. In this study, we applied comprehensive mutagenesis and structure-guided design based on the crystal structure of the Fc/FcγRIIb complex to identify a novel Fc variant with selectively enhanced FcγRIIb binding over both FcγRIIa(R131) and FcγRIIa(H131). This novel variant has more than 200-fold stronger binding affinity to FcγRIIb than wild-type IgG1, while binding affinity to FcγRIIa(R131) and FcγRIIa(H131) is comparable with or lower than wild-type IgG1. This selectivity was achieved by conformational change of the C(H)2 domain by mutating Pro to Asp at position 238. Fc variant with increased binding to both FcγRIIb and FcγRIIa induced platelet aggregation and activation in an immune complex form in vitro while our novel variant did not. When applied to agonistic anti-CD137 IgG1 antibody, our variant greatly enhanced the agonistic activity. Thus, the selective enhancement of FcγRIIb binding achieved by our Fc variant provides a novel tool for improving the efficacy of antibody therapeutics.

Primary aldosteronism associated with subclinical Cushing syndrome

BACKGROUND

Recently, it has been reported that the incidence of primary aldosteronism (PA) among patients with hypertension is much more frequent than previously reported.

AIM

In the present study, we investigated the frequency and features of PA associated with subclinical Cushing syndrome (SCS).

MATERIAL AND METHODS

Subjects included consecutive patients (no.=39) who were diagnosed as PA and performed adrenal venous sampling between 2003 and 2011 in our institute.

RESULTS

In 39 subjects who were diagnosed as PA, 29 patients were operated and 5 cases (12.8%) showed no suppression in low-dose dexamethasone suppression test. Four cases of them were demonstrated to be associated with SCS, and one was associated with overt Cushing syndrome (CS). Post-operatively, 3 cases received replacement therapy of hydrocortisone, while others did not. Pathological findings indicated the diagnosis of aldosterone-producing adenoma in 4 cases associated with SCS, and of idiopathic hyperaldosteronismin in one case associated with overt CS. In all 5 cases, immunohistochemical analysis demonstrated the immunoreactivities of both 3βHSD and P450c17 in the adrenocortical tumors, the marked cortical atrophy in the zona fasciculata and reticularis, the decreased dehydroepiandrosterone sulfotransferase expression, and suppression of hypothalamo- pituitary-adrenal axis indicating the autonomous secretion of cortisol from the tumor.

CONCLUSIONS

The present study suggests that PA is frequently associated with SCS with prevalence of more than 10%, justifying the routine examinations for SCS in PA cases.

Comprehensive diagnostic ability of endocytoscopy compared with biopsy for colorectal neoplasms: a prospective randomized noninferiority trial

BACKGROUND AND STUDY AIMS

Endocytoscopy enables observation at 450-fold magnification during gastrointestinal endoscopy, allowing on-site "optical biopsy." We compared the accuracies of endocytoscopy and standard biopsy for the diagnosis of colorectal neoplasms.

PATIENTS AND METHODS

We performed a randomized, controlled, open-label trial of patients with colorectal lesions (≥ 5 mm) detected during colonoscopy in a tertiary referral center. We randomly assigned the 203 detected lesions of 170 eligible patients to either the endocytoscopy or standard biopsy group. An on-site endoscopist assessed the histopathology of the endocytoscopy group lesions according to the endocytoscopic findings, whereas a pathologist later assessed standard biopsy group lesions by microscopic examination of the biopsy specimens. We calculated the diagnostic accuracies in both groups with reference to the final histopathology of the resected specimens. The primary endpoint was to determine whether the diagnostic accuracy of endocytoscopy for neoplastic lesions was noninferior to that of standard biopsy (with a predefined noninferiority margin of 10%). Analyses were by intention-to-treat and per-protocol. The study is registered, number UMIN000003923.

RESULTS

Overall, 102 lesions in the endocytoscopy group and 101 in the standard biopsy group were available for primary outcome analysis. There were no complications. The diagnostic accuracy of endocytoscopy for the discrimination of neoplastic lesions was 94.1% (95% confidence interval 87.6% to 97.8%), whereas that of standard biopsy was 96.0% (90.2% to 98.9%), which is within the noninferiority margin (absolute difference -1.9%, -8.6% to +5.0%).

CONCLUSIONS

Endocytoscopy is noninferior to standard biopsy for the discrimination of neoplastic lesions. With its advantage of providing an on-site diagnosis, endocytoscopy could provide a novel alternative to standard biopsy in routine colonoscopy.

Dietary patterns and risk of cardiovascular deaths among middle-aged Japanese: JACC Study

BACKGROUND AND AIMS

Little evidence showed the association between dietary patterns and cardiovascular disease among Japanese. The objective of this study was to examine whether dietary patterns are associated with cardiovascular disease among middle-aged Japanese.

METHODS AND RESULTS

At baseline (1988-1990), 26,598 men and 37,439 women aged 40-79 years enrolled in the Japan Collaborative Cohort (JACC) Study. During the follow-up through 2003, 578 men and 499 women died from stroke, and 272 men and 207 women died from coronary heart disease. We identified three major dietary patterns, 'vegetable', 'animal food' and 'dairy product', by factor analysis for both sexes. The multivariable hazard ratio (HR) and 95% confidence intervals of mortality from total cardiovascular disease in the highest versus lowest quintiles of the vegetable pattern were 0.93 (0.78-1.13), p for trend=0.73 for men and 0.82 (0.67-1.00), p for trend=0.04 for women. The respective HRs of mortality from stroke in the highest versus lowest quintiles of the dairy product pattern were 0.65 (0.49-0.86), p for trend=0.01 for men and 0.70 (0.51-0.97), p for trend=0.02 for women, and those of total cardiovascular disease were 0.89 (0.74-1.08), p for trend=0.23 for men and 0.76 (0.61-0.94), p for trend=0.01 for women. The animal food pattern was not associated with mortality from stroke, coronary heart disease or total cardiovascular disease for either sex.

CONCLUSION

We found that 'vegetable' and 'dairy product' patterns were associated with lower morality from cardiovascular disease, while the 'animal food' pattern was not associated with mortality from cardiovascular disease among Japanese.

Removal characteristics of retinoic acids and 4-oxo-retinoic acids in wastewater by activated sludge treatment

Retinoic acid (RA) receptor (RAR) agonists are potential teratogens to various vertebrates. Their contamination has been detected in municipal wastewater in different countries. This study involved field investigations and laboratory batch treatment experiments to elucidate the removal characteristics by activated sludge treatment of RAs (all-trans RA and 13-cis RA) and 4-oxo-RAs (4-oxo-all-trans RA and 4-oxo-13-cis RA), which were identified as major RAR agonists in municipal wastewater. Results obtained in this study show that currently employed activated sludge treatments can remove RAs, 4-oxo-RAs and overall RAR agonist contamination effectively from municipal wastewater in general, although high RAR agonistic activity might sometimes remain in the effluent. Laboratory experiments revealed that RAs were removed rapidly from the aqueous phase by adsorption to the sludge, after which they were removed further by biological and/or chemical degradation. Aside from adsorption to the sludge, 4-oxo-RAs were also apparently removed by biological and chemical degradation. Biodegradation contributed greatly to the removal. Results of additional experiments indicated that novel non-identifiable RAR agonists can occur through the biodegradation of 4-oxo-RAs by activated sludge and that they can persist for a long period.

Adherence of Enterococcus hirae to the duodenal epithelium of chicks with diarrhoea

A flock of commercial layer chicks in Hokkaido, Japan experienced mortality of 3.53% over the first 7 days of life. Affected chicks were depressed, anorexic and had diarrhoea. The striking pathological feature was dense colonization of epithelial surface of the duodenum by Enterococcus hirae. There was no obvious damage to the enterocytes associated with bacterial adherence. Enterococcus hirae organisms were isolated in large numbers from the small intestines, together with Escherichia coli.

Selection of generic preparations of famotidine orally disintegrating tablets for use in unit-dose packages

Changes in the hardness, dissolution, and the disintegration time of brand name and generic preparations (6 preparations) of famotidine orally disintegrating tablets were investigated. Tablets had been stored in a thermo-hygrostat-controlled environment set to simulate the home conditions of patients up to 8 weeks after unit-dose packaging. Among the tablets in unit-dose packaging prepared immediately after blister packs (BP) were opened, one generic had decreased hardness to less than 2.0 kg after 1 week, 55.1% of its initial hardness value, and a shorter disintegration time of about 1/5 of its initial disintegration time. Generics met the standard for dissolution 8 weeks after unit-dose packaging. The decrease in hardness after unit-dose packaging is presumed to be associated with additives, and particularly the types and amounts of binding agents, but evidence of this association was lacking. The hardness noted in drug interview forms (IFs) and the state of sales of bulk tablet packages must be determined to facilitate the selection of generics that remain hard even after unit-dose packaging.

Elevated BAFF levels in the cerebrospinal fluid of patients with neuro-Behçet's disease: BAFF is correlated with progressive dementia and psychosis

Neuro-Behçet's disease (NBD) is a serious complication of Behçet's disease. Generally, NBD patients with a chronic course are refractory to immunosuppressive treatment, resulting in the deterioration of personality. In this study, levels of B cell-activating factor belonging to the TNF family (BAFF) were measured in the cerebrospinal fluid (CSF) from 18 patients with NBD, 27 patients with epidemic aseptic meningitis (AM), 24 patients with multiple sclerosis (MS) and 34 healthy controls. BAFF levels in patients with NBD were significantly elevated compared with healthy controls, but showed no statistically significant elevation compared with either of the disease controls. In contrast, CSF IL-6 levels were slightly elevated in patients with NBD and significantly elevated in patients with AM and MS compared with healthy controls. Patients with NBD were subdivided into two groups according to their clinical course (eight patients with a slowly progressive course presenting with psychosis and dementia and 10 patients with an acute course including aseptic meningitis, brainstem involvement and myelopathy). BAFF levels were significantly increased in those with a slowly progressive course compared with those with an acute course. CSF BAFF levels did not correlate with serum BAFF levels, CSF cell counts or CSF IL-6 levels in patients with NBD. These data suggested that BAFF was produced within the central nervous system and may be associated with the development of NBD, particularly with a progressive course.

Efficacy of adding sodium alginate to omeprazole in patients with nonerosive reflux disease: a randomized clinical trial

Nonerosive reflux disease (NERD) is the most common form of gastroesophageal reflux disease. Patients with NERD have a lower response rate to proton pump inhibitors (PPIs) than patients with erosive esophagitis when gauged from relief of heartburn. Sodium alginate decreases the acidity of refluxate and protects the esophageal mucosa. However, whether the addition of sodium alginate to PPI therapy can improve NERD symptoms remains unknown. Accordingly, the aim of this study was to evaluate the efficacy of adding sodium alginate to basal PPI therapy for NERD. Patients who had experienced heartburn on at least 2 days per week during the 1-month period before entering the study and had no endoscopic mucosal breaks (grade M or N according to Hoshihara's modification of the Los Angeles classification) were randomized to one of two treatments for 4 weeks: omeprazole (20 mg once daily) plus sodium alginate (30 mL four times a day) (group A) or omeprazole (20 mg once daily) alone (group B). Eighty-seven patients were enrolled, and 76 patients were randomly assigned to group A (n = 36) or group B (n = 40). Complete resolution of heartburn for at least 7 consecutive days by the end of treatment was significantly more common in group A (56.7%) than in group B (25.7%). One patient from group A had mild drug-related diarrhea that was not clinically serious. In conclusion, omeprazole combined with sodium alginate was better than omeprazole alone in Japanese patients with NERD.

The effect of enamel matrix derivative on spreading, proliferation, and differentiation of osteoblasts cultured on zirconia

PURPOSE

This study investigated the effect of enamel matrix derivative (EMD) on spreading, proliferation, and differentiation of osteoblasts cultured on zirconia disks with smooth and rough surfaces.

MATERIALS AND METHODS

EMD was added to the culture medium or coated on zirconia disks that had machined (smooth) or sandblasted (rough) surfaces. The effects of EMD on cell proliferation of MC3T3-E1 osteoblastic cells were examined using a hemocytometer. Osteoblastic differentiation was examined by histologic analysis of alkaline phosphatase (ALP) activity and the degree of mineralization. ALP activity was also measured quantitatively. Scanning electron microscopic analysis was performed to observe cell morphology. Enzyme-linked immunosorbent assay of osteocalcin and reverse-transcriptase polymerase chain reaction of osteocalcin, osteopontin, and type 1 collagen were performed to investigate the expression of osteoblast-related genes.

RESULTS

The addition of EMD to the medium enhanced the spreading, proliferation, and differentiation of osteoblasts cultured on zirconia. However, when it was coated on zirconia, EMD reduced osteoblastic spreading and adhesion in the early stage of culture, although it enhanced proliferation and differentiation of osteoblasts in later stages. A promotive effect of EMD on osteocalcin mRNA expression, mineralization, and ALP activity of osteoblasts cultured on the rough surface was observed.

CONCLUSIONS

EMD may contribute to treatment with zirconia implants via its promotion of osteoblastic proliferation and activity. However, the procedure for application of EMD may be a crucial factor for the outcome of implants.