Full-length dystrophin cDNA transfer into skeletal muscle of adult mdx mice by electroporation

We showed that a LacZ expression plasmid (pCAG-lacZ) injection followed by electroporation increased the expression of the LacZ gene in the skeletal muscles of adult mdx mice up to ninefold higher as compared with simple intramuscular DNA injection. When full-length mouse dystrophin plasmid (pCAG-dys) and pCAG-lacZ were co-transfected by electroporation, 56% of dystrophin-positive fibers were stained for beta-galactosidase activity suggesting most of these myofibers are not revertants but transfected ones. Our data indicate that electroporation in vivo could introduce large full-length dystrophin cDNA into skeletal muscle of adult mdx mice.     

Control of oxalate formation from L-hydroxyproline in liver mitochondria

Serine:pyruvate/alanine:glyoxylate aminotransferase (SPT/AGT) is largely located in mitochondria in carnivores, whereas it is entirely found within peroxisomes in herbivores and humans. In rat liver, SPT/AGT is found in both of these organelles, and only the mitochondrial enzyme is markedly induced by glucagon. Although SPT/AGT is a bifunctional enzyme involved in the metabolism of both L-serine and glyoxylate, its contribution to L-serine metabolism is independent of mitochondrial or peroxisomal localization (Xue HH et al., J Biol Chem 274: 16028-16033, 1999). Therefore, the species-specific and food habit-dependent organelle distribution might be required for proper metabolism of glyoxylate at the subcellular site of its formation. Glyoxylate formation from glycolate and that from L-hydroxyproline have been shown to occur in peroxisomes and mitochondria, respectively. The present study found that urinary excretion of oxalate was markedly increased when a large dose of L-hydroxyproline or glycolate was administered to rats. Oxalate formation from L-hydroxyproline but not that from glycolate was significantly reduced when mitochondrial SPT/AGT had been induced by glucagon. The hydroxyproline content of collagen is 10 to 13%, and collagen accounts for about 30% of total animal protein; therefore, these results suggest that an important role of mitochondrial SPT/AGT in carnivores is to convert L-hydroxyproline-derived glyoxylate into glycine in situ, preventing undesirable overflow into the production of oxalate.     

Longterm complete remission of AL-amyloid-related nephrotic syndrome

We describe a 59-year-old man with nephrotic syndrome that was diagnosed as suspected minimal change nephrotic syndrome by the routine examination of renal tissues at first biopsy, because renal histology showed segmental mild mesangial expansion with argyrophilic staining and partial foot process fusion without any deposition. Prednisolone therapy induced complete remission of nephrotic syndrome. Relapse occurred after 4 years of complete remission, and the second renal biopsy revealed amyloid light-chain (AL)-amyloidosis. Re-examination of the first biopsy tissues by Congo red staining confirmed a small amount of amyloid deposition in the mesangial areas although the mesangial areas showed argyrophilic staining, which is atypical for amyloid deposition. This case raises a caution that even when renal histology is not suggestive of amyloidosis and prednisolone therapy is very effective, when a renal histology diagnosis is not confirmed, the clinician should suspect amyloidosis and should, at least, undertake Congo red staining to definitively rule out amyloidosis.     

Comparison of the Nuss procedure for pectus excavatum by age and uncommon complications

BACKGROUND: We summarized our experience of the Nuss procedure for pectus excavatum with comparison by age and uncommon complications. METHODS: Twenty-three patients underwent the Nuss procedure. Their age ranged from 3 to 19 years old. The outcome was compared between two groups divided by age: teenagers (> or = 13 yrs old, n = 5, Group 1) and younger patients (n = 18, Group 2). RESULTS: Cosmetic results were significantly better, and the operating time and postoperative hospital stay in Group 2 were significantly shorter than in Group 1. Complications were more frequently seen in Group 1 than in Group 2. In all three younger patients whose bars were removed after 2 years, the ribs holding the bar were deformed. Uncommon complications occurred in two cases. In one case, pneumothorax occurred due to laceration by a fragment of wire after 12 months, and the fragment fell into the thoracic cavity. In another case, pneumothorax occurred due to injury by the port of a thin thoracoscope. CONCLUSION: The teenaged patients had more complications and poorer cosmetic results. Therefore, this operation should be performed before the teenage years. In younger patients with rapid growth, the bar should be removed less than 2 years to prevent restriction of costal growth.     

Non-high-density lipoprotein cholesterol (non-HDL-C) as a predictor of cardiovascular mortality in patients with end-stage renal disease

BACKGROUND: Patients with end-stage renal disease (ESRD) often show lipid abnormalities that may promote atherosclerosis. Although the standard lipid marker is low-density lipoprotein cholesterol (LDL-C) in official recommendations, the need of fasting blood sampling has prevented routine screening for plasma lipids in hemodialysis patients. METHODS: We therefore evaluated the power of non-high-density lipoprotein cholesterol (non-HDL-C) in predialysis (non-fasting) serum as a predictor of cardiovascular mortality in a cohort of 525 hemodialysis patients. RESULTS: During the mean follow-up of 64 months, 120 deaths, including 44 fatal cardiovascular events, occurred. Patients in the highest tertile of non-HDL-C (137 to 285 mg/dL) had a significantly higher risk for cardiovascular mortality (HR, 3.065; 95% CI, 1.357 to 6.925; P = 0.007) [correction] in a univariate Cox analysis. The association between non-HDL-C and cardiovascular mortality remained significant in multivariate Cox models, which included HDL-C, age, gender, duration of hemodialysis, blood pressure, presence of diabetes mellitus, serum albumin, C-reactive protein, and body mass index. CONCLUSION: Non-HDL-C in predialysis serum was a significant and independent predictor of cardiovascular mortality in hemodialysis patients. Non-HDL-C may be a useful marker for risk assessment in routine practice, although predictive powers of this and the standard fasting LDL-C should be compared in future studies.     

The role of renal sympathetic nervous system in the pathogenesis of ischemic acute renal failure

We investigated the role of renal sympathetic nervous system in the progression of ischemia/reperfusion-induced acute renal failure in rats. Acute renal failure was induced by clamping the left renal artery and vein for 45 min followed by reperfusion, 2 weeks after the contralateral nephrectomy. Renal venous plasma norepinephrine concentrations markedly and significantly increased immediately after reperfusion, thereafter, the increased level declined but remained higher even at 24 h after reperfusion. Renal sympathetic nerve activity was significantly augmented during the renal ischemia. Renal denervation or the administration of pentolinium, a ganglion blocking agent, (5 mg/kg i.v.) at 5 min before ischemia attenuated the ischemia/reperfusion-induced renal dysfunction and histological damage, such as proteinaceous casts in tubuli and tubular necrosis. The elevation of renal venous norepinephrine levels after reperfusion was suppressed by renal denervation or pentolinium treatment. Thus, a surgical or pharmacological blockade of renal sympathetic nerve prevents the progression of ischemia/reperfusion-induced acute renal failure, thereby suggesting that renal sympathetic nervous system plays an important role in the development of the ischemic acute renal failure.     

The analysis of pyridylamino-dextran sulfate oligomers by high-performance liquid chromatography and a novel detection system for sulfated polysaccharides

Dextran sulfate sodium (DSS) is a strong negatively charged heparin-like polysaccharide and has anti-immunodeficiency virus, anti-carcinogenesis, or occasionally tumor-promotion effects. The biological metabolism of DSS, however, remains unclear. In a previous study, we reported a novel method for the separation and quantification of DSS, using fluorometric labeling with 2-aminopyridine and a combination of size-exclusion and reverse phase high-performance liquid chromatography. In the present study, we have applied this method for analyses of in vitro chemical or enzymatic depolymerization of pyridylamino-DSS (PA-DSS). PA-DSS was depolymerized by specific enzymes such as alpha-amylase and alpha-glycosidase, but not by dextranase or heparinase. Unknown enzymes derived from cultured intestinal cells also strongly depolymerized PA-DSS as did alkaline substances. On the other hand, we have established a novel detection system using a post-column reaction. This method utilizes the spectrophotometrically metachromatic reaction of toluidine blue solution with DSS. This novel detection system may be specific and may potentially provide useful information in the analyses of sulfated polysaccharides, which are present in environmental and biological materials.     

Gene expression profile in experimental mesangial proliferative glomerulonephritis

We analyzed gene expression in rat anti-Thy1 antibody-induced glomerulonephritis by using the cDNA microarray method. Ninety-seven genes that differed by more than 1.5-fold intensity in comparison with the controls were selected. Cluster analysis showed that the expression of genes associated with inflammation reached maximum levels at 24 h, while genes involved in the development of fibrosis increased at 7 days after injection. Microarray analysis of animal disease models may be a powerful approach for understanding the gene expression programs that underlie these disorders.