The Challenges of Waste Toward the 21st Century

The problems of waste disposal have become major issues in Japan. Japan must deal directly with these issues. In early 1970s, “KOGAI” or environmental pollution already loomed as major problems. A number of technical innovations and systems were proposed to recycle various waste products. Based on those experiences, current situation of urban refuse, waste plastics, scrapped tires and scrapped automobiles in Japan and their challenges toward 21st century are discussed.

A Japanese Survey of Perioperative Antibiotic Prophylaxis in Cataract Surgery

PURPOSE

The objective of this study was to identify trends in the use of perioperative antibiotic prophylaxis in cataract surgery in Japan.

DESIGN

This was a national survey by mail or interview.

METHODS

The use of perioperative antibiotic prophylaxis in cataract surgery was evaluated by conducting a survey in 6 regions within Japan from October 1, 2011, to March 1, 2012.

RESULTS

Responses were received from 285 (75%) of the 387 surgeons who were surveyed. The results revealed that 89% (255/285) administered ophthalmic antibiotic ointment. Forty-seven percent (133/285) used antibiotics in forms other than ophthalmic ointments within 6 hours after surgery, 7% (19/285) used eyedrops, 24% (67/285) used antibiotics via an irrigation bottle, 1% (2/285) used intracameral injections, and 24% (69/285) used subconjunctival injections.

CONCLUSIONS

Although poor intraocular penetration of ophthalmic ointments has been reported, ophthalmic ointments are widely used. The fact that antibiotics should ideally be administered within 6 hours after surgery is not widely recognized. However, intracameral injection, which achieves much higher antibiotic concentration in the anterior chamber than other methods, is a technique that should be widely acknowledged.

Pharmacotherapeutic determinants for QTc interval prolongation in Japanese patients with mood disorder

An increased incidence of sudden death has been observed among patients treated with antidepressants. A prolonged QTc interval is a known prognostic factor for fatal arrhythmia, and several studies have shown that the use of antidepressants can cause a prolonged QTc interval. However, few studies, especially in Japan, have compared the effects of multiple drugs on QTc interval or examined dose relationships in a clinical setting.We compared the effects of antidepressants on QT interval, corrected to QTc by Bazett's formula, in 729 Japanese patients who were diagnosed with mood disorder.Using stepwise multiple linear regression analysis, we found that the use of tricyclic antidepressants (P<0.01) and concomitant use of antipsychotics (P<0.05), as well as advanced age and being female (known factors for prolonged QTc interval; both P<0.01), significantly prolonged the QTc interval. Analysis of individual antidepressants also revealed that the use of clomipramine (P<0.01) and amitriptyline (P<0.05) significantly prolonged the QTc interval.Our results reveal that tricyclic antidepressants, especially clomipramine and amitriptyline, confer a risk of prolonged QTc interval in a dose-dependent manner. The selective serotonin reuptake inhibitors investigated (fluvoxamine, paroxetine, sertraline) were not indicated as risk factors for QTc prolongation.

Rapid clearance of supplemented tetrahydrobiopterin is driven by high-capacity transporters in the kidney

Tetrahydrobiopterin (BH(4)) is an essential cofactor of aromatic amino acid hydroxylases and NO synthase. Supplementation of BH(4) potentially targets cardiovascular dysfunction as well as inherited BH(4) deficiencies and BH(4)-responsive phenylketonuria. However, the high cost/effect ratio of the recommended daily dose of BH(4) supplementation acts against further popularization of this therapy. The aim of this study was to attenuate urinary excretion with the intention of improving efficacy of BH(4) supplementation. The rapid excretion of BH(4) in the urine was confirmed to be the major route of supplemented BH(4) loss. In addition to glomerular filtration into the urine, a dominant rapid exclusion by renal secretion was observed in rats (T((1/2))=16 min) when the plasma BH(4) was higher than about 1 nmol/mL (more than 10 times higher than normal), due to BH(4) supplementation. The rapidity of the process was slowed by prior administration of cyclosporin A, a representative anti-excretory drug, and the excretion decelerated to a moderate rate (T((1/2))=53 min). By the combined administration of BH(4) plus cyclosporin A, the blood BH(4) levels were dramatically elevated. It was hypothesized that the drug interfered with kidney excretion of BH(4) rather than by attenuating organ tissue distribution by inhibiting biopterin uptake from the plasma. Consistent with this hypothesis, biopterin levels after BH(4) administration were elevated in major organs in the presence of anti-excretory drugs without notable change in their BH(4) fraction which was consistently 95% or higher regardless of combined administration with the drugs. Targeting these putative transporters would be a promising approach for improving the efficiency of BH(4) supplementation therapy.

Tetrahydrobiopterin in intestinal lumen: its absorption and secretion in the small intestine and the elimination in the large intestine

In treating hereditary deficiency of tetrahydrobiopterin (BH(4)), supplementation with BH(4) might be the ultimate choice of therapy. Oral administration of BH(4) has been believed to be inefficient owing to poor absorption of BH(4) in the intestine. In this study, we found a considerable amount of BH(4) as well as its oxidized pterins in the ingredients of intestinal lumen of mice when they were served food that did not contain significant amounts of biopterin. Ligation of the biliary duct led to significant decrease in luminal biopterin. Supplementation of BH(4) either by intraperitoneal administration of sepiapterin or of 6RBH(4) ((6R)-L-erythro-5,6,7,8-tetrahydrobiopterin) increased the BH(4) content in the intestinal lumen with a slight delay after the rise of blood BH(4). In these mice, biopterin appeared in the large intestine, caecum and colon, 2 h after the administration. The appearance of BH(4) in the large intestine was accompanied by a large amount of pterin (2-amino-4-hydroxypteridine). The amounts of biopterin + pterin that appeared in the large intestine after intraperitoneal administration of BH(4) were not greater than those found after oral administration at the same dose. When the mice were treated with a large dose of antibiotics prior to the BH(4) administration, the amount of biopterin increased in the caecum but the amount of pterin decreased greatly. These results suggested that a large proportion of BH(4) administered moved to the large intestine, where most biopterin was decomposed presumably by enteric bacteria. Nonetheless, most of the orally administered biopterin was taken up by the small intestine and the amount of biopterin reaching the large intestine was almost the same as that which appeared after direct injection of 6RBH(4) into the peritoneal cavity.

Knocking out ubiquitin proteasome system function in vivo and in vitro with genetically encodable tandem ubiquitin

At present, the 26S proteasome-specific inhibitor is not available. We constructed polyubiquitin derivatives that contained a tandem repeat of ubiquitins and were insensitive to ubiquitin hydrolases. When these artificial polyubiquitins (tUbs, tandem ubiquitins) were overproduced in the wild-type yeast strain, growth was strongly inhibited, probably because of inhibition of the 26S proteasome. We also found that several substrates of the ubiquitin-proteasome pathway were stabilized by expressing tUbs in vivo. tUbs containing four units or more of the ubiquitin monomer were found to form a complex with the 26S proteasome. We showed that tUb bound to the 26S proteasome inhibited the in vitro degradation of polyubiquitinylated Sic1 by the 26S proteasome. When tUB6 (six-mer) messenger RNA was injected into Xenopus embryos, cell division was inhibited, suggesting that tUb can be used as a versatile inhibitor of the 26S proteasome.

Development of a rapid method to generate multiple oncolytic HSV vectors and their in vivo evaluation using syngeneic mouse tumor models

Replication-conditional herpes simplex virus (HSV)-based vectors have great potential in the treatment of various types of cancers including brain tumors. HSV mutants lacking the U(L)39 gene and both copies of the gamma(1)34.5 gene (e.g. MGH1, G207) have been demonstrated to possess oncolytic effects as well as potent anticancer vaccination effects without compromising safety. Such mutants thus provide optimal templates to produce novel oncolytic HSV vectors for cancer gene therapy applications. In order to accomplish quick and efficient construction of oncolytic HSV vectors, a novel BAC-based method designated as 'HSVQuik system' was developed. This system sequentially utilizes two different site-specific recombination systems to introduce virtually any transgene cassettes of interest into the deleted U(L)39 locus (Flp-FRT in Escherichia coli) and to release the vector genome sequence from the procaryotic plasmid backbone (Cre-loxP in Vero cells). Taking advantage of the HSVQuik system, we constructed three oncolytic HSV vectors that express mouse IL4, CD40 ligand and 6CK, respectively. In vivo therapeutic experiments using two luciferase-labeled syngeneic mouse brain tumor models revealed that expression of these immunomodulators significantly enhanced antitumor efficacy of oncolytic HSV. The HSVQuik system, together with luciferase-labeled tumor models, should expedite the process of generating and evaluating oncolytic HSV vectors for cancer gene therapy applications.

Imaging immediate-early and strict-late promoter activity during oncolytic herpes simplex virus type 1 infection and replication in tumors

An increasing number of oncolytic viruses have been developed and studied for cancer therapy. In response to needs for non-invasive monitoring and imaging of oncolytic virotherapy, several different approaches, including a positron emission tomography-based method, a method using secreted marker peptides, and optical imaging-based methods, have been reported. Among these modalities, we utilized the luciferase-based bioluminescent assay/imaging systems to determine the kinetics and dynamics of a productive viral infection. The replication cycle of herpes simplex virus type 1 (HSV-1) is punctuated by a temporal cascade of three classes of viral genes: immediate-early (IE), early (E) and late (L) genes. U(L)39- and gamma(1)34.5-deleted, replication-conditional HSV-1 mutants that express firefly luciferase under the control of the IE4/5 or strict-late gC promoters were generated. These oncolytic viruses were examined in cultured cells and a mouse tumor model. IE promoter- and strict-late promoter-mediated luciferase expression was confirmed to indicate viral infection and replication, respectively. Incorporation of a strict-late promoter-driven luciferase cassette into oncolytic HSV-1 vectors would be useful for assessing tumor oncolysis in preclinical tumor treatment studies.

Preparation of ubiquitinated substrates by the PY motif-insertion method for monitoring 26S proteasome activity

For analysis of the mechanism of the 26S proteasome-mediated protein degradation in vitro, the preparation of well-defined substrate, the ubiquitinated proteins, of the 26S proteasome is inevitable. However, no method has been available to ubiquitinate a given protein. Here, we propose a relatively simple method for preparation of the ubiquitinated substrates using HECT-type ubiquitin ligase Rsp5, termed the PY motif-insertion method. The principle of this method is that the PY motif, known as the Rsp5-binding motif, is inserted into protein to be ubiquitinated by Rsp5. In this communication, we describe that Sic1 was successfully ubiquitinated by the PY motif-insertion method and demonstrate that Sic1 thus ubiquitinated was degraded by the purified yeast 26S proteasome.

Infectious delivery of the 132 kb CDKN2A/CDKN2B genomic DNA region results in correctly spliced gene expression and growth suppression in glioma cells

The expression of genes from genomic loci can be relatively complex, utilizing exonic, intronic and flanking sequences to regulate tissue and developmental specificity. Infectious bacterial artificial chromosomes (iBACs) have been shown to deliver and express large genomic loci (up to 135 kb) into primary cells for functional analyses. The delivery of large genomic DNA inserts allows the expression of complex loci and of multiple splice variants. Herein, we demonstrate for the first time that an iBAC will deliver and correctly express in human glioma cells the entire CDKN2A/CDKN2B genomic region, which encodes for at least three important cell-cycle regulatory proteins (p16(INK4a), p14(ARF) and p15(INK4b)). Two of these proteins are expressed from overlapping genes, utilizing alternative splicing and promoter usage. The delivered locus expresses each gene at physiological levels and cellular responses (apoptosis versus growth arrest) occur dependent on cellular p53 status, as expected. The work further demonstrates the potential of the iBAC system for the delivery of genomic loci whose expression is mediated by complex splicing and promoter usage both for gene therapy applications and functional genomics studies.

Chestnut bur-shaped aggregates of chrysotile particles enable inoculation of Escherichia coli cells with plasmid DNA

In the present study, Escherichia coli cells exhibited antibiotic resistance after transformation with exogenous plasmid DNA adsorbed onto chrysotile particles during agar-exposure. We previously demonstrated penetration of E. coli by chrysotile particles during agar-exposure. To further investigate the mechanism by which transformation of E. coli is achieved through the use of chrysotile fibers, the interaction between E. coli cells and chrysotile was examined during agar-exposure. Dispersion of chrysotile particles within the chrysotile solution was analyzed by flow cytometry. A suspension containing E. coli cells expressing blue fluorescence protein and chrysotile particles was exposed to agar using stirring apparatus, which allowed a constant vertical reaction force to be applied to the surface of the gel. Fluorescence microscopy was then used to illustrate the adsorption of fluorescein isothiocyanate-conjugated DNA oligomers to chrysotile. Larger aggregates were observed when increasing concentrations of chrysotile were added to the solution. With prolonged exposure, during which surface moisture diffused into the agar gel, greater concentrations of chrysotile were observed on the agar surface. In addition, chrysotile aggregates exceeding 50 microm developed on the agar surface. They were shaped like a chestnut bur. The chrysotile aggregates penetrated the cell membranes of adherent E. coli cells during agar-exposure due to sliding friction forces generated at the interface of the agar and the stirring stick. E. coli cells thus acquired plasmid DNA and antibiotic resistance, since the plasmid DNA had been adsorbed onto the chrysotile particles. The inoculation of plasmid DNA into E. coli cells demonstrates the usefulness of chrysotile for E. coli transformation.

Histological evidence of redox system breakdown caused by superoxide dismutase 1 (SOD1) aggregation is common to SOD1-mutated motor neurons in humans and animal models

Living cells produce reactive oxygen species (ROSs). To protect themselves from these ROSs, the cells have developed both an antioxidant system containing superoxide dismutase 1 (SOD1) and a redox system including peroxiredoxin2 (Prx2, thioredoxin peroxidase) and glutathione peroxidase1 (GPx1): SOD1 converts superoxide radicals into hydrogen peroxide (H2O2), and H2O2 is then converted into harmless water (H2O) and oxygen (O2) by Prx2 and GPx1 that directly regulate the redox system. To clarify the biological significance of the interaction of the redox system (Prx2/GPx1) with SOD1 in SOD1-mutated motor neurons in vivo, we produced an affinity-purified rabbit antibody against Prx2 and investigated the immunohistochemical localization of Prx2 and GPx1 in neuronal Lewy body-like hyaline inclusions (LBHIs) in the spinal cords of familial amyotrophic lateral sclerosis (FALS) patients with a two-base pair deletion at codon 126 and an Ala-->Val substitution at codon 4 in the SOD1 gene, as well as in transgenic rats expressing human SOD1 with H46R and G93A mutations. The LBHIs in motor neurons from the SOD1-mutated FALS patients and transgenic rats showed identical immunoreactivities for Prx2 and GPx1: the reaction product deposits with the antibodies against Prx2 and GPx1 were localized in the LBHIs. In addition, the localizations of the immunoreactivities for SOD1 and Prx2/GPx1 were similar in the inclusions: the co-aggregation of Prx2/GPx1 with SOD1 in neuronal LBHIs in mutant SOD1-related FALS patients and transgenic rats was evident. Based on the fact that Prx2/GPx1 directly regulates the redox system, such co-aggregation of Prx2/GPx1 with SOD1 in neuronal LBHIs may lead to the breakdown of the redox system itself, thereby amplifying the mutant SOD1-mediated toxicity in mutant SOD1-linked FALS patients and transgenic rats expressing human mutant SOD1.