Antigenic differences of the scuticociliate Miamiensis avidus from Japan

In Japan and Korea, outbreaks of scuticociliatosis have frequently occurred in Japanese flounder, Paralichthys olivaceus. Morphological observations and small subunit rRNA gene sequences have shown that the causative agent of scuticociliatosis in the flounder is Miamiensis avidus (syn. Philasterides dicentrarchi). In this study, we elucidated the antigenic differences between six Japanese M. avidus isolates as an initial step toward developing an effective vaccine against the disease. Four Japanese flounder isolates (IyoI, Nakajima, JF05To and Mie0301 isolates), one spotted knifejaw, Oplegnathus punctatus, isolate (SK05Kyo), and one ridged-eye flounder, Pleuronichthys cornutus, isolate (RF05To) were subjected to serological analysis. Antisera against IyoI, SK05Kyo, Nakajima and Mie0301 isolates were raised in rabbits and used for immobilization assays and Western blotting. Immobilization assays showed that the six isolates could be divided into three groups, tentatively designated serotype I for IyoI, JF05To, RF05To, SK05Kyo, serotype II for Nakajima and serotype III for Mie0301. Western blotting results supported these three serotypes, with marked similarities in the banding profiles of IyoI, JF05To, RF05To and SK05Kyo isolates, which were distinct from the Nakajima and Mie0301 isolates. Three isolates, IyoI, Nakajima and Mie0301 that were selected as representatives of each serotype, were highly pathogenic to Japanese flounder by experimental infection. Based on these findings, we propose that there are at least three M. avidus serotypes in Japan.

Application of DNA condensation for removal of mercury ions from aqueous solutions

DNA has a unique character that allows it to combine with various chemical substrates at the molecular level, and the DNA binding with chemical pollutants can cause serious damage to the organism. The purpose of this research was to apply the strong bonding character of DNA for the removal of mercury ions. In this research, we used DNA condensation promoted by the action of DNA condensing agents, such as cetyltrimethylammonium bromide and a commercially available combination flocculant made of zeolite, to precipitate out the DNA bound with mercury ion in an aqueous solution. When solutions of mercury at 0.02-100 ppm (parts per million) concentrations at a pH range of 2-11 were treated with double-stranded DNA followed by the condensing agent, more than 95% of the mercury ions could be removed after simple filtration or sedimentation.

Modulation of HIV-1 infectivity and cyclophilin A-dependence by Gag sequence and target cell type

Background

HIV-1 Gag proteins are essential for virion assembly and viral replication in newly infected cells. Gag proteins are also strong determinants of viral infectivity; immune escape mutations in the Gag capsid (CA) protein can markedly reduce viral fitness, and interactions of CA with host proteins such as cyclophilin A (CypA) and TRIM5α can have important effects on viral infectivity. Little information, however, is available concerning the extent that different primary Gag proteins affect HIV-1 replication in different cell types, or the impact on viral replication of differences in the expression by target cells of proteins that interact with CA. To address these questions, we compared the infectivity of recombinant HIV-1 viruses expressing Gag-protease sequences from primary isolates in different target cells in the presence or absence of agents that disrupt cyclophilin A – CA interactions and correlated these results with the viral genotype and the expression of cyclophilin A and TRIM5α by the target cells.

Results

Viral infectivity was governed by the nature of the Gag proteins in a target cell-specific fashion. The treatment of target cells with agents that disrupt CypA-CA interactions often produced biphasic dose-response curves in which viral infectivity first increased and subsequently decreased as a function of the dose used. The extent that treatment of target cells with high-dose CypA inhibitors impaired viral infectivity was dependent on several factors, including the viral genotype, the nature of the target cell, and the extent that treatment with low-dose CypA inhibitors increased viral infectivity. Neither the presence of polymorphisms in the CA CypA-binding loop, the level of expression of CypA, or the level of TRIM5α expression could, alone, explain the differences in the shape of the dose-response curves observed or the extent that high-dose CypA inhibitors reduced viral infectivity.

Conclusion

Multiple interactions between host-cell factors and Gag can strongly affect HIV-1 infectivity, and these vary according to target cell type and the origin of the Gag sequence. Two of the cellular activities involved appear to be modulated in opposite directions by CypA-CA interactions, and Gag sequences determine the intrinsic sensitivity of a given virus to each of these cellular activities.

Cerebral infarction in a patient with congenital complete heart block

Stokes-Adams attacks are fairly common in children with congenital complete heart block, but the occurrence of cerebral infarction is quite unusual. We present the case of a 13-year-old boy with congenital heart block and an embolic stroke involving the cerebral artery. Echocardiography revealed no valvular regurgitation, hypokinetic segments, mural thrombus, or myxoma. Electrocardiographic monitoring demonstrated good response of ventricular rate to exercise and no episodes of atrial or ventricular dysrhythmia. It is assumed that embolism occurred due to bradycardia.

Ruptured cornual pregnancy: case report

Cornual pregnancy is uncommon among ectopic pregnancies. A diagnosis of cornual pregnancy remains challenging, and rupture of a cornual pregnancy causes catastrophic consequence due to massive bleeding. We report a case of a ruptured cornual pregnancy occurring at 12 weeks of gestation. A 34-year-old woman was suspected of having a left cornual pregnancy at 11 weeks of gestation. Transabdominal ultrasound and magnetic resonance imaging revealed an eccentric localization of a gestational sac containing a viable fetus outside the uterine cavity adjacent to the left uterine cornua. The gestational sac was surrounded with a thin myometrial layer. The patient developed a rupture of the left cornual pregnancy with unstable hemodynamics. She underwent emergency laparotomy, which revealed the ruptured left cornual pregnancy with a hemoperitoneum. Cornual resection was performed. The pathological examination confirmed a ruptured cornual pregnancy.

The development of placenta increta following pelvic transcatheter artery embolization for postpartum hemorrhage

OBJECTIVE

Pelvic transcatheter artery embolization (TAE) has been widely used for the management of postpartum hemorrhage (PPH). However, the adverse effects of TAE on the subsequent pregnancy remain poorly understood.

CASE

A 30-year-old woman, gravida 2, para 1, developed PPH due to atonic bleeding and underwent TAE. Thereafter, her menstrual cycle became irregular with less blood volume. Three years later, she became pregnant despite a thin endometrial thickness of 6 mm during the ovulatory period. She delivered a healthy baby at 39 weeks of gestation. No signs of placental separation were obtained, and an attempt at manual extraction of the placenta failed, followed by massive PPH. She underwent emergent TAE. The placenta was not spontaneously delivered even on day 8 postpartum. A supracervical hysterectomy was performed due to a worsening intrauterine infection. Pathological examination revealed findings compatible with placenta increta.

CONCLUSION

A TAE-associated thin endometrium may be attributable to the development of placenta increta. Pregnant women undergoing TAE should be managed carefully because the information about pregnancy outcomes after TAE remains scanty.

Synthetic retinoid CD437 induces mitochondria-mediated apoptosis in hepatocellular carcinoma cells

Retinoids play an important role in the regulation of cell growth and death. Synthetic retinoid CD437 reportedly induces apoptosis in various cancer cell lines. However, the mechanism of inducing apoptosis in hepatocellular carcinoma (HCC) cells by this agent remains to be clarified. In this study, we investigated the signaling pathway by which CD437 induces apoptosis in HCC cell lines. Apoptosis of six human HCC cell lines was induced by treatment with CD437. Caspase-3 and -9 were activated by CD437, suggesting that the apoptosis is mediated by mitochondrial pathways. Consistent with these findings, the treatment with CD437 upregulated Bax protein, downregulated Bcl-2 protein and released cytochrome c into the cytoplasm. Moreover, rhodamine123 staining revealed mitochondrial depolarization in the cells treated with CD437. These data of the present study suggest that CD437 induces apoptosis in HCC cells via mitochondrial pathways.

A role of Wnt/beta-catenin signals in hepatic fate specification of human umbilical cord blood-derived mesenchymal stem cells

Human umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) are expected to be an excellent source of cells for transplantation. In addition, the stem cell plasticity of human UCBMSCs, which can transdifferentiate into hepatocytes, has been reported. However, the mechanisms involved remain to be clarified. To identify the genes and/or signals that are important in specifying the hepatic fate of human UCBMSCs, we analyzed gene expression profiles during the hepatic differentiation of UCBMSCs with human telomerase reverse transcriptase, UCBMSCs immortalized by infection with a retrovirus carrying telomerase reverse transcriptase, but whose differentiation potential remains unchanged. Efficient differentiation was induced by 5-azacytidine (5-aza)/hepatocyte growth factor (HGF)/oncostatin M (OSM)/fibroblast growth factor 2 (FGF2) treatment in terms of function as well as protein expression: 2.5-fold increase in albumin, 4-fold increase in CCAAT enhancer-binding protein alpha, 1.5-fold increase in cytochrome p450 1A1/2, and 8-fold increase in periodic acid-Schiff staining. Consequently, we found that the expression of Wnt/beta-catenin-related genes downregulated, and the translocation of beta-catenin was observed along the cell membrane and in the cytoplasm, although some beta-catenin was still in the nucleus. Downregulation of Wnt/beta-catenin signals in the cells by Fz8-small interference RNA treatment, which was analyzed with a Tcf4 promoter-luciferase assay, resulted in similar hepatic differentiation to that observed with 5-azacytidine/HGF/OSM/FGF2. In addition, the subcellular distribution of beta-catenin was similar to that of cells treated with 5-azacytidine/HGF/OSM/FGF2. In conclusion, the suppression of Wnt/beta-catenin signaling induced the hepatic differentiation of UCBMSCs, suggesting that Wnt/beta-catenin signals play an important role in the hepatic fate specification of human UCBMSCs.

Role of Ca2+ Transporters and Channels in the Cardiac Cell Volume Regulation

Na+/K+ pump is one of key mechanisms to maintain cell volume. When it is inhibited, cells are at risk of swelling. However, in guinea pig ventricular myocytes, the cell area as an index of cell volume was almost constant during 90 min Na+/K+ pump blockade with 40 microM ouabain despite the marked membrane depolarization. In this study, involvements of Ca2+ transporters and channels in the cardiac cell volume regulation were proposed by conducting the computer simulation in parallel with the experimental validation.

Intravenous cyclophosphamide therapy for progressive interstitial pneumonia in patients with polymyositis/dermatomyositis

OBJECTIVES

To study the efficacy and safety of monthly intravenous pulse cyclophosphamide (IVCYC) therapy for progressive interstitial pneumonia in polymyositis/dermatomyositis (PM/DM).

METHODS

Seventeen patients with PM/DM/amyopathic DM (mean age 51.4 +/- 10.4, mean follow-up 32 months) who received IVCYC for progressive interstitial pneumonia between August 1993 and October 2002 were studied. Nine patients had failed to respond to previous treatment with high-dose steroid and/or immunosuppressant. Cyclophosphamide (300-800 mg/m2) was given at least six times every 4 weeks. Oral prednisolone (0.5-1 mg/kg/day) was administered for the first 2 weeks and was gradually tapered. Response to treatment was evaluated based on the degree of exertional dyspnea, pulmonary function test and high-resolution computed tomography (HRCT).

RESULTS

Eleven of 17 patients showed improvement in their dyspnea; six out of seven patients who had required oxygen treatment before IVCYC no longer did so after IVCYC. Eight of 17 patients had >or=10% improvement of vital capacity (VC)% and 9/17 had >or=10 point reduction in their HRCT score. Twelve patients had exhibited at least one result. Two patients with anti-Jo-1 antibodies showed a flare-up of interstitial pneumonia or myositis. After the IVCYC therapy, mean VC% improved by 15% (from 68 to 83%, P = 0.0034). The extent of abnormal lesions in HRCT was reduced from 24 to 13% (P = 0.0055). There was neither death nor severe toxicities observed.

CONCLUSIONS

In this open-label study, IVCYC improved symptoms, pulmonary function tests and HRCT findings in patients with PM/DM. Longitudinal controlled studies are required to further confirm the efficacy of IVCYC.

Modelling Cl- homeostasis and volume regulation of the cardiac cell

We aim at introducing a Cl- homeostasis to the cardiac ventricular cell model (Kyoto model), which includes the sarcomere shortening and the mitochondria oxidative phosphorylation. First, we examined mechanisms underlying the cell volume regulation in a simple model consisting of Na+/K+ pump, Na+-K+-2Cl- cotransporter 1 (NKCC1), cystic fibrosis transmembrane conductance regulator, volume-regulated Cl- channel and background Na+, K+ and Cl- currents. The high intracellular Cl- concentration of approximately 30 mM was achieved by the balance between the secondary active transport via NKCC1 and passive currents. Simulating responses to Na+/K+ pump inhibition revealed the essential role of Na+/K+ pump in maintaining the cellular osmolarity through creating the negative membrane potential, which extrudes Cl- from a cell, confirming the previous model study in the skeletal muscle. In addition, this model well reproduced the experimental data such as the responses to hypotonic shock in the presence or absence of beta-adrenergic stimulation. Finally, the volume regulation via Cl- homeostasis was successfully incorporated to the Kyoto model. The steady state was well established in the comprehensive cell model in respect to both the intracellular ion concentrations and the shape of the action potential, which are all in the physiological range. The source code of the model, which can reproduce every result, is available from http://www.sim-bio.org/.

Sivelestat, a specific neutrophil elastase inhibitor, prevented phorbol myristate acetate-induced acute lung injury in conscious rabbits

The in vivo contribution of neutrophil elastase (NE) in phorbol myristate acetate (PMA)-induced acute lung injury has so far been unclear. This study examined the role of NE in PMA-induced acute lung injury in conscious rabbits, using a specific NE inhibitor, sivelestat sodium hydrate (Sivelestat). A single bolus injection of PMA (40 microg/kg) caused acute lung injury as indicated by an increase in protein concentration and hemorrhage in bronchoalveolar lavage fluid (BALF) 4h after PMA injection. These changes were associated with mild decrease in arterial oxygen pressure and peripheral white blood cell and platelet. When continuously infused starting 1h before and ending 4h post-PMA injection, Sivelestat at 3-30 mg/kg/h that are able to inhibit rabbit NE activity by 60-90%, dose-dependently attenuated both PMA-induced hemorrhagic pneumonitis and the increase in protein concentration in BALF without affecting myeloperoxidase activity in the lung. Histopathological study indicated that sivelestat (30 mg/kg/h) markedly attenuated lung histopathological changes, alveolar hemorrhage and white blood cells migration with evidence of inhibition of NE activity in BALF. These results suggest that NE plays a significant role in PMA-induced acute lung injury and further supports the importance of this enzyme in acute lung injury.