Randomized comparison of pitavastatin and pravastatin treatment on the reduction of urinary albumin in patients with type 2 diabetic nephropathy.

The effect of pitavastatin and pravastatin treatment on renal function was compared in type 2 diabetic patients with nephropathy in a randomized, controlled, open-label, parallel and multi-centre study. Type 2 diabetic patients with modest renal impairment (serum creatinine level <1.4 mg/dl) accompanied by albuminuria (30-600 mg/g creatinine) were randomly assigned to receive 2 mg of pitavastatin (n = 44) or 10 mg of pravastatin (n = 43) for 12 months. At 12 months, pitavastatin significantly reduced urinary albumin-to-creatinine ratio than pravastatin in subjects with macroalbuminuria (-67.2% vs. +14.5%, p = 0.0040), but not in subjects with microalbuminuria. There was no significant difference in the change in estimated glomerular filtration rate between the two groups. Pitavastatin is more effective than pravastatin for the reduction of albuminuria in type 2 diabetic patients with early stage of diabetic nephropathy.

Biliverdin protects against the deterioration of glucose tolerance in db/db mice.

AIMS/HYPOTHESIS: We have previously shown a negative correlation between serum bilirubin levels and prevalence of type 2 diabetes, suggesting that bilirubin inhibits development of this disease. To confirm this hypothesis, we investigated whether administration of biliverdin, the precursor of bilirubin, protects against the deterioration of glucose tolerance in db/db mice, a rodent model of type 2 diabetes. METHODS: Biliverdin (20 mg/kg daily) was orally administered to 5-week-old db/db mice for 4 weeks. After 4 weeks of treatment, i.p. glucose tolerance and insulin tolerance tests were performed. Insulin content was evaluated by immunostaining and ELISA. Oxidative stress markers (8-hydroxy-2'-deoxyguansosine and dihydroethidium staining) and expression of NADPH oxidase components Pdx1 and Bax were also evaluated in isolated islets. RESULTS: Treatment with biliverdin partially prevented worsening of hyperglycaemia and glucose intolerance in db/db mice. This effect was accompanied by a significant increase in insulin content and Pdx1 expression, and a significant decrease of apoptosis and Bax expression in pancreatic islets from db/db mice. At the same time, levels of oxidative stress markers and NADPH oxidase component production in islets were normalised. Biliverdin had little effect on HOMA of insulin resistance or insulin resistance evaluated by insulin tolerance tests. CONCLUSIONS/INTERPRETATION: Biliverdin may protect against progressive worsening of glucose tolerance in db/db mice, mainly via inhibition of oxidative stress-induced beta cell damage.

Expression of variant luteinizing hormone/chorionic gonadotropin receptors and degradation of chorionic gonadotropin in human chorionic villous macrophages.

Human gonads and non-gonadal organs/tissues express luteinizing hormone/chorionic gonadotropin (LH/CG) receptors. This study aimed to identify the LH/CG receptors and to clarify their function in human placental chorionic villous macrophages. Macrophages as well as syncytiotrophoblasts of human chorionic villous tissues were immunohistochemically positive for LH/CG receptor throughout gestation. By reverse transcription-nested polymerase chain reaction methods, villous macrophages were shown to express a variant type of LH/CG receptor, the sequencing of which revealed a deletion of exon 9. For experiments in vitro, a monocyte-macrophage cell line, THP-1, was transfected with vector alone, wild-type LH/CG receptor, and exon 9-deleted LH/CG receptor after phorbol 12-myristate 13-acetate (PMA) treatment. Non-PMA-treated THP-1 cells transfected with vector alone were also examined. THP-1 cells expressed exon 9-deleted LH/CG receptor after treatment with PMA. After the cells of the four groups were cultured in medium containing intact human CG (hCG), the concentrations of hCG and its beta-core fragment (beta-CF) were measured in the supernatant of the culture medium and in the cell cytosol. Time-dependent hCG uptake was observed in both non-PMA-treated and PMA-treated THP-1 cells, suggesting that the variant receptor is not directly involved in the ingestion of hCG. The degradation of hCG and excretion of beta-CF were progressed in PMA-treated cells but not in the un-treated cells. In the cell cytosol, the ratio of beta-CF and hCG concentrations (beta-CF/hCG) was significantly higher in the PMA-treated cells than in non-PMA-treated cells; however, it did not differ between the PMA-treated cells transfected with exon 9-deleted receptor and those transfected with vector alone. Macrophages may express the variant receptor in order to recognize the intracytoplasmic hCG and transport it to the lysosome. Among the two PMA-treated cells, the ratio was lower in those transfected with wild-type receptor. The expression of the variant receptor may modulate the degradation of hCG but be reduced by expression of the wild-type receptor in its lacking macrophages. Our data suggest a potentially important role for exon 9-deleted LH/CG receptors expressed in human placental villous macrophages in the local metabolism of hCG.

Statin attenuates high glucose-induced and angiotensin II-induced MAP kinase activity through inhibition of NAD(P)H oxidase activity in cultured mesangial cells.

An increased oxidative stress may contribute to the development of diabetic nephropathy. We have recently reported that high glucose level stimulated superoxide production through protein kinase C (PKC)-dependent activation of NAD(P)H oxidase in cultured vascular cells. Here we show that 3-hydroxy-3-methylglutaryl CoA reductase inhibitor (statin) attenuates both high glucose level-induced and angiotensin II (Ang II)-induced activation of p42/44 mitogen-activated kinase (MAP kinase) in cultured human mesangial cells through inhibition of NAD(P)H oxidase activity. The intracellular oxidative stress in cultured mesangial cells was evaluated by electron spin resonance (ESR) measurement. MAP kinase activity was evaluated by western blot analysis using anti phospho-specific MAP kinase antibody and anti-ERK-1 antibody. Exposure of the cells to high glucose level (450 mg/dl) for 72 hrs significantly increased MAP kinase activity as compared to normal glucose level (100 mg/dl). This increase was completely blocked by the treatment of pitavastatin (5x10(-7) M) as well as a NAD(P)H oxidase inhibitor (diphenylene iodonium, 10(-5) M) in parallel with the attenuation of oxidative stress. Ang II-induced activation of MAP kinase was also completely blocked by pitavastatin as well as a diphenylene iodonium in parallel with the attenuation of oxidative stress. In conclusion, pitavastatin attenuated high glucose-induced and Ang II- induced MAP kinase activity in mesangial cells through inhibition of NAD(P)H oxidase. Thus, statins may have a potential as a therapeutic tool for early diabetic nephropathy.

Increased expression of NAD(P)H oxidase subunits, NOX4 and p22phox, in the kidney of streptozotocin-induced diabetic rats and its reversibity by interventive insulin treatment.

AIM/HYPOTHESIS: An increased production of reactive oxygen species (ROS) could contribute to the development of diabetic nephropathy. NAD(P)H oxidase might be an important source of ROS production in kidney as reported in blood vessels. In this study, we show the increased expression of essential subunits of NAD(P)H oxidase, NOX4 and p22phox, in the kidney of diabetic rats. METHODS: The levels of mRNA of both NOX4 and p22phox were evaluated in kidney from streptozotocin-induced diabetic rats and age-matched control rats at 4 and 8 weeks after onset of diabetes by Northern blot analysis. The localization and expression levels of these components and 8-hydroxy-deoxyguanosine (8-OHdG), which is a marker of ROS-induced DNA damage, were also evaluated by immunostaining. RESULTS: The levels of both NOX4 and p22phox mRNA were increased in the kidney of diabetic rats as compared with control rats. Immunostaining analysis showed that the expression levels of NOX4 and p22phox were clearly increased in both distal tubular cells and glomeruli from diabetic rats. Both the localization and the expression levels of these components were in parallel with those of 8-OHdG. Interventive insulin treatment for 2 weeks completely restored the increased levels of these components in the diabetic kidney to control levels in parallel with those of 8-OHdG. CONCLUSIONS/INTERPRETATION: This study provides evidence that NAD(P)H oxidase subunits, NOX4 and p22phox, were increased in the kidney of diabetic rats. Thus, NAD(P)H-dependent overproduction of ROS could cause renal tissue damage in diabetes. This might contribute to the development of diabetic nephropathy.

A possible target of antioxidative therapy for diabetic vascular complications-vascular NAD(P)H oxidase.

A growing body of evidence has shown that oxidative stress may be involved in the development of vascular complications associated with diabetes. However, the molecular mechanism for increased reactive oxygen species (ROS) production in diabetes remains uncertain. Among various possible mechanisms, attention have increasingly been paid to NAD(P)H oxidase as the most important source of ROS production in vascular cells. High glucose level stimulates ROS production through protein kinase C (PKC)-dependent activation of vascular NAD(P)H oxidase. Furthermore, the expression of NAD(P)H oxidase components is increased in micro- and macrovascular tissues of diabetic animals in association with various functional disorders and histochemical abnormalities. These results suggest that vascular NAD(P)H oxidase-driven ROS production may contribute to the onset or development of diabetic micro- or macrovascular complications. In this point of view, the possible new strategy of antioxidative therapy for diabetic vascular complications is discussed in this review.

Hydrosilylation of carbonyl compounds using a PhSeSiMe(3)/Bu(3)SnH/AIBN system.

[reaction: see text] When carbonyl compounds were allowed to react with phenyl trimethylsilyl selenide and tributylstannyl hydride in the presence of a catalytic amount of AIBN as a radical initiator, the hydrosilylation of the carbonyl compounds efficiently proceeded to give the corresponding silyl ethers in moderate to good yields.

Clostridium perfringens enterotoxin binds to the second extracellular loop of claudin-3, a tight junction integral membrane protein.

Claudins (claudin-1 to -18) with four transmembrane domains and two extracellular loops constitute tight junction strands. The peptide toxin Clostridium perfringens enterotoxin (CPE) has been shown to bind to claudin-3 and -4, but not to claudin-1 or -2. We constructed claudin-1/claudin-3 chimeric molecules and found that the second extracellular loop of claudin-3 conferred CPE sensitivity on L fibroblasts. Furthermore, overlay analyses revealed that the second extracellular loop of claudin-3 specifically bound to CPE at the K(a) value of 1.0x10(8) M(-1). We concluded that the second extracellular loop is the site through which claudin-3 interacts with CPE on the cell surface.

Ca(2+)-independent cell-adhesion activity of claudins, a family of integral membrane proteins localized at tight junctions.

In multicellular organisms, various compositionally distinct fluid compartments are established by epithelial and endothelial cellular sheets. For these cells to function as barriers, tight junctions (TJs) are considered to create a primary barrier for the diffusion of solutes through the paracellular pathway [1] [2] [3]. In ultrathin sections viewed under electron microscopy, TJs appear as a series of apparent fusions, involving the outer leaflets of plasma membranes of adjacent cells, to form the so-called kissing points of TJs, where the intercellular space is completely obliterated [4]. Claudins are a family of 16 proteins whose members have been identified as major integral membrane proteins localized exclusively at TJs [5] [6] [7] [8]. It remains unclear, however, whether claudins have the cell-adhesion activity that would explain the unusual intercellular adhesion at TJs. Using mouse L-fibroblast transfectants expressing various amounts of claudin-1, -2 or -3, we found that these claudins possess Ca(2+)-independent cell-adhesion activity. Using ultrathin-section electron microscopy, we observed many kissing points of TJs between adjacent transfectants. Furthermore, the cell-adhesion activity of occludin, another integral membrane protein localized at TJs [9] [10] [11], was negligible when compared with that of claudins. Thus, claudins are responsible for TJ-specific obliteration of the intercellular space.

Clostridium perfringens enterotoxin fragment removes specific claudins from tight junction strands: Evidence for direct involvement of claudins in tight junction barrier.

Claudins, comprising a multigene family, constitute tight junction (TJ) strands. Clostridium perfringens enterotoxin (CPE), a single approximately 35-kD polypeptide, was reported to specifically bind to claudin-3/RVP1 and claudin-4/CPE-R at its COOH-terminal half. We examined the effects of the COOH-terminal half fragment of CPE (C-CPE) on TJs in L transfectants expressing claudin-1 to -4 (C1L to C4L, respectively), and in MDCK I cells expressing claudin-1 and -4. C-CPE bound to claudin-3 and -4 with high affinity, but not to claudin-1 or -2. In the presence of C-CPE, reconstituted TJ strands in C3L cells gradually disintegrated and disappeared from their cell surface. In MDCK I cells incubated with C-CPE, claudin-4 was selectively removed from TJs with its concomitant degradation. At 4 h after incubation with C-CPE, TJ strands were disintegrated, and the number of TJ strands and the complexity of their network were markedly decreased. In good agreement with the time course of these morphological changes, the TJ barrier (TER and paracellular flux) of MDCK I cells was downregulated by C-CPE in a dose-dependent manner. These findings provided evidence for the direct involvement of claudins in the barrier functions of TJs.

[Use of hemostatic clips for endoscopic hemostasis and closure of an esophageal laceration caused by a fish bone].

An 82-year-old woman was admitted to our hospital because of hematemesis. She had had a feeling of a foreign substance in her throat for one week after having eaten fish. On admission she had a fever of 38 degrees C, Hb of 5.8 g/dl, CRP level of 8.8 mg/dl, and bilateral pleural effusions. Endoscopy revealed a deep longitudinal laceration with active bleeding in the esophagus that also caused mediastinitis. Endoscopic hemostasis and closure of the laceration was done with hemostatic clips. The esophageal injury seemed to have been caused by a fish bone. After the treatments described here were carried out, the patient's condition rapidly improved.

[Clinical and pharmacokinetics evaluation of flomoxef in pediatrics].

Flomoxef (FMOX, 6315-S), a new parenteral oxacephem antibiotic was investigated for its clinical efficacy and pharmacokinetics. The results obtained are summarized below. 1. Twenty-eight patients were treated with 39-152 mg/kg per day of FMOX by intravenous administration. Diagnosis of patients were pneumonia in 15 patients, acute upper respiratory tract infection in 5, acute enterocolitis in 3, urinary tract infection in 2 and cholangitis, suppurative lymphadenitis and suspicious sepsis in 1 patient each. Clinical effect was excellent in 7 cases, good in 8, fair in 5, poor in 2 and 6 cases were excluded because therapy periods were too short and other antibiotics were used together. Efficacy rate was 68% and the rate of bacterial disappearance was 83%. 2. Rash was found in 5 cases and thrombocytosis was found in 1 out of 28 cases. However, no severe adverse reaction was encountered. 3. The peak serum level of FMOX was 51.0 micrograms/ml after 20 mg/kg of drip infusion for 30 minutes and the half-life was 17.2 minutes in alpha-phase and 58.2 minutes in beta-phase.

Transdiaphragmatic duodenal duplication in a premature infant.

A case of transdiaphragmatic duodenal duplication in a premature infant is presented. Vertebral abnormalities, which have invariably accompanied this disorder in reported cases so far, were characteristically absent. Therefore, the initial tentative diagnosis was right-sided diaphragmatic hernia. Barium examination was helpful in preoperative diagnosis.

Duplication of the caecum in a neonate simulating intussusception.

A case of caecal duplication in a 36-h-old neonate is described. The patient presented with vomiting and an abdominal mass and the barium enema finding was initially suggestive of intussusception. At laparotomy a duplication cyst completely obstructing the lumen was found. This was considered to have given the radiological picture simulating intussusception.