Correction to: Association of initial prednisolone dose with remission,relapse, and infectious complications in adult‑onset minimal change disease

Clinical and Experimental Nephrology - In the original publication, the author has found few errors. The corrections are given below.     

Involvement of intestinal permeability in the oral absorption of clarithromycin and telithromycin

The involvement of intestinal permeability in the oral absorption of clarithromycin (CAM), a macrolide antibiotic, and telithromycin (TEL), a ketolide antibiotic, in the presence of efflux transporters was examined. In order independently to examine the intestinal and hepatic availability, CAM and TEL (10 mg/kg) were administered orally, intraportally and intravenously to rats. The intestinal and hepatic availability was calculated from the area under the plasma concentration–time curve (AUC) after administration of CAM and TEL via different routes. The intestinal availabilities of CAM and TEL were lower than their hepatic availabilities. The intestinal availability after oral administration of CAM and TEL increased by 1.3‐ and 1.6‐fold, respectively, after concomitant oral administration of verapamil as a P‐glycoprotein (P‐gp) inhibitor. Further, an in vitro transport experiment was performed using Caco‐2 cell monolayers as a model of intestinal epithelial cells. The apical‐to‐basolateral transport of CAM and TEL through the Caco‐2 cell monolayers was lower than their basolateral‐to‐apical transport. Verapamil and bromosulfophthalein as a multidrug resistance‐associated proteins (MRPs) inhibitor significantly increased the apical‐to‐basolateral transport of CAM and TEL. Thus, the results suggest that oral absorption of CAM and TEL is dependent on intestinal permeability that may be limited by P‐gp and MRPs on the intestinal epithelial cells. Copyright © 2014 John Wiley & Sons, Ltd.     

Association of crossing capillaries in the finger nailfold with diabetic retinopathy in type 2 diabetes mellitus

Aims/IntroductionCrossing capillaries in the finger nailfold might potentially be a novel diabetic retinopathy (DR) biomarker that could be assessed non‐invasively in the clinical setting. However, the association between crossing capillaries and DR is controversial. This study aimed to investigate the association between the percentage of crossing capillaries in the finger nailfold and DR in patients with type 2 diabetes mellitus.Materials and MethodsThis cross‐sectional study enrolled 108 type 2 diabetes mellitus patients (aged 40–75 years) who visited the outpatient diabetic clinic at Osaka University Hospital, Osaka, Japan, between May and October 2019. Capillary morphology was assessed using nailfold capillaroscopy based on the simple capillaroscopic definitions of the European League Against Rheumatism Study Group. Details of DR and other laboratory data were obtained from medical records. The association between the tertile of the percentage of the crossing capillary and DR was analyzed using multivariable logistic regression.ResultsAfter adjusting for age, sex, diabetes duration, glycated hemoglobin, systolic blood pressure, body mass index, and use of renin–angiotensin system inhibitor and antihyperlipidemic medication, the percentage of crossing capillaries was significantly associated with DR (multivariable‐adjusted odds ratios for increasing tertiles of the percentage of crossing capillary: 1 [reference], 2.05 [95% confidence interval 0.53–7.94], and 4.33 [95% confidence interval 1.16–16.21]; P‐trend = 0.028).ConclusionsA higher percentage of crossing capillaries in the nailfold was associated with a higher risk of DR, independent of traditional risk and inhibiting factors, in patients with type 2 diabetes mellitus.     

Genome-wide RNA interference screen identifies previously undescribed regulators of polyglutamine aggregation

Protein misfolding and the formation of aggregates are increasingly recognized components of the pathology of human genetic disease and hallmarks of many neurodegenerative disorders. As exemplified by polyglutamine diseases, the propensity for protein misfolding is associated with the length of polyglutamine expansions and age-dependent changes in protein-folding homeostasis, suggesting a critical role for a protein homeostatic buffer. To identify the complement of protein factors that protects cells against the formation of protein aggregates, we tested transgenic Caenorhabditis elegans strains expressing polyglutamine expansion yellow fluorescent protein fusion proteins at the threshold length associated with the age-dependent appearance of protein aggregation. We used genome-wide RNA interference to identify genes that, when suppressed, resulted in the premature appearance of protein aggregates. Our screen identified 186 genes corresponding to five principal classes of polyglutamine regulators: genes involved in RNA metabolism, protein synthesis, protein folding, and protein degradation; and those involved in protein trafficking. We propose that each of these classes represents a molecular machine collectively comprising the protein homeostatic buffer that responds to the expression of damaged proteins to prevent their misfolding and aggregation.     

Skeletal muscle glucose transporter gene expression is not affected by injecting growth-hormone-secreting cells in young rats

Summary To elucidate the diabetogenic effect of growth hormone on glucose metabolism the regulation of glucose transporter (GLUT) gene expression was examined in rat skeletal muscles. Female Wistar-Furth rats were implanted subcutaneously with growth-hormone-producing pituitary tumour (GH₃) cells. Animals were killed 4 or 9 weeks after GH₃ cell injection. Although body weight, serum growth hormone and insulin-like growth factor I levels were remarkably elevated during the 4–9 week period, serum blood glucose levels were within normal range. Muscles were obtained from the quadriceps muscle, diaphragm and heart, respectively. Northern blot analysis and Western blot analysis were performed using specific cDNA probes and antibodies. During the 4–9 week period, the levels of muscle GLUT 1 and 4 mRNA (corrected by β-actin mRNA level) in each muscle from the rats injected with tumour cells were not significantly different from those of control rats. Chronic elevation of growth hormone in these rats did not cause any change in GLUT1 and 4 expression compared to the controls during the euglycaemic period. These results provide the first evidence that chronic growth hormone elevation itself does not affect a key gene of in vivo glucose metabolism.     

Characterization of a mutation in a family with saposin B deficiency: a glycosylation site defect.

Saposins are small, heat-stable glycoproteins required for the hydrolysis of sphingolipids by specific lysosomal hydrolases. Saposins A, B, C, and D are derived by proteolytic processing from a single precursor protein named prosaposin. Saposin B, previously known as SAP-1 and sulfatide activator, stimulates the hydrolysis of a wide variety of substrates including cerebroside sulfate, GM1 ganglioside, and globotriaosylceramide by arylsulfatase A, acid beta-galactosidase, and alpha-galactosidase, respectively. Human saposin B deficiency, transmitted as an autosomal recessive trait, results in tissue accumulation of cerebroside sulfate and a clinical picture resembling metachromatic leukodystrophy (activator-deficient metachromatic leukodystrophy). We have examined transformed lymphoblasts from the initially reported saposin B-deficient patient and found normal amounts of saposins A, C, and D. After preparing first-strand cDNA from lymphoblast total RNA, we used the polymerase chain reaction to amplify the prosaposin cDNA. The patient's mRNA differed from the normal sequence by only one C----T transition in the 23rd codon of saposin B, resulting in a threonine to isoleucine amino acid substitution. An affected male sibling has the same mutation as the proband and their heterozygous mother carries both the normal and mutant sequences, providing additional evidence that this base change is the disease-causing mutation. This base change results in the replacement of a polar amino acid (threonine) with a nonpolar amino acid (isoleucine) and, more importantly, eliminates the glycosylation signal in this activator protein. One explanation for the deficiency of saposin B in this disease is that the mutation may increase the degradation of saposin B by exposing a potential proteolytic cleavage site (arginine) two amino acids to the amino-terminal side of the glycosylation site when the carbohydrate side chain is absent.