Evaluation of Thermoreversible Gelation Polymer for Regeneration of Focal Liver Injury

Liver injuries are often associated with complications including infection of the dead space, bleeding, leakage of bile and so on. We have recently developed a thermoreversible gelation polymer (TGP) which provides a good healing environment for wounds and possibly reduces complications. The purpose of this study was to evaluate whether adequate regeneration occurred with a liver defect by using TGP. The sol-gel transition of TGP is reversibly controlled by temperature; TGP is soluble below a lower critical solution temperature (LCST) of 22 degrees C, and becomes solid above the LCST. Soluble TGP can reach anywhere, and gelation of TGP occurs at the wound surface by body temperature to fill the wound/cavity. A section of median part of the left lobe comprising 3% (2 x 2 cm wide and 1 cm deep) of the liver was resected, and the Beagle dogs were assigned to three groups: 'resection alone group', 'resection + fibrin glue (FG) group' and 'resection + TGP group'. The resection alone group and the resection + FG group showed severe fibrosis at week 12, and a scarring was clearly visible. The resection + TGP group showed almost complete healing by week 4, with no adhesion and recession of the wound; the resection site was completely filled with TGP, liver-like capsule organoids emerged to cover the wound and neovascularization was observed within the organoids. Furthermore, the resected liver regenerated completely by week 12, TGP was replaced by hepatocytes, and the presence of hepatic lobules confirmed structural reorganization. The number of RCA-1-positive macrophages accumulating around the wound was significantly reduced in the resection + TGP group compared to the other two groups. In the early stage of liver resection and regeneration, TGP seemed to suppress the accumulation of macrophages and stellate cells. In the late stage, when massive inflammatory cell accumulation had subsided, TGP was degraded, that may contribute to avoid unnecessary inhibition of the liver regeneration process. Collectively, TGP may induce efficient regeneration by reducing the fibrosis and enhancing proliferation, even with a minor liver defect. Because TGP has good biocompatibility, it may become useful as an ideal biomaterial for the treatment of liver injuries.

Competitive plasma protein adsorption onto fluorinated polyimide surfaces

A series of fluorinated polyimides cured at different temperatures was prepared, and plasma protein adsorption and platelet adhesion onto the polyimide films were evaluated in vitro using scanning electron microscopy, a micro-bicinchoninic acid protein assay, and a gold-colloid-labeled immunoassay. In particular, we focused on competitive plasma protein adsorption onto polyimide film because elucidation of the competitive adsorption mechanism is needed for a good understanding of in vivo biocompatibility of polyimide. Interestingly, the trend of IgG adsorption onto the polyimide surface measured in human plasma was completely contrary to that observed with IgG dissolved in PBS, and the adsorption increased with an increase in the curing temperature. We propose that the human plasma F(c) region in IgG might selectively adsorb onto polyimide film cured at high temperatures because of competitive plasma protein adsorption to the surface.

Repair of false para-anastomotic aortic aneurysms using an endovascular stent graft technique in a patient with severe pulmonary disease: report of a case

Conventional surgery for para-anastomotic aortic aneurysms is technically challenging, and is associated with high morbidity and mortality. This report describes the case of a patient with severe pulmonary diseases in whom false para-anastomotic aortic aneurysms were successfully repaired using an endovascular stent graft technique.

Highly repetitive DNA families restricted to germ cells in a Japanese hagfish (Eptatretus burgeri): a hierarchical and mosaic structure in eliminated chromosomes

It is known that in eight hagfishes chromosome elimination occurs during early embryogenesis. The eliminated chromosomes are mostly C-band positive, so that none of the somatic cells have any C-band-positive chromatin. Recently, some highly repetitive DNA sequences have been reported as eliminated elements in these hagfishes based on molecular biological methods. However, no germline-restricted repetitive DNA have been directly isolated from the Japanese hagfish Eptatretus burgeri, from which approximately 21% of the total DNA is eliminated from presumptive somatic cells. Through electrophoretic investigation after digestion with restriction endonucleases, two DNA families that are restricted to germline DNA were isolated. Molecular cloning and sequence analysis revealed that these families are composed of closely related sequences of 64 and 57bp in length, respectively. Southern blot hybridization revealed that the two DNA families are restricted to germline DNA and were thus named EEEb1 and EEEb2, respectively. Moreover, these eliminated elements were highly and tandemly repeated, and it is predicted that they might amplify by saltatory replication and have evolved in a concerted manner. By densitometric scanning, EEEb1 and EEEb2 were found to amount to make up approximately 18.5 and 0.024% of the total germline genomic DNA, accounting for 88.6% of the total eliminated DNA. A fluorescence in situ hybridization experiment demonstrated that EEEb1 is located on all C-band-positive chromosomes that are limited to germ cells, suggesting that EEEb1 is the primary component of eliminated DNA of E. burgeri.

Relationship between obsessive-compulsive disorder and chaos

Pharmacological treatment using serotonin reuptake inhibitors is often useful for patients with obsessive-compulsive disorder (OCD). Brain imaging studies indicated that hyperactivity of the striatum observed in OCD patients is normalized after successful pharmacological treatment. But, so far, there is no available model, which can explain both of these phenomena. This report proposes a hypothesis that serotonin reuptake inhibitors can induce chaos in the activity of striatal neurons and this chaotic behavior is essential to improve OCD symptoms and normalize the hyperactivity in the striatum. Moreover, it can be explained also by this model that there exists a subtype of patients for whom pharmacological treatment is not useful. As a method, simulation using the Hodgkin-Huxley equations and the chaotic neural network, which can reproduce the chaotic behavior in the real neuron, are used.

Biocompatibility of fluorinated polyimide

Contact between blood and biomaterial triggers a complex series of events including protein adsorption, leukocyte adhesion and activation, and complement activation. In this article, a series of fluorinated polyimides cured at a different temperatures was prepared, and the biocompatibility of the membranes was evaluated using in vitro protein adsorption, neutrophil adhesion, and complement activation experiments under static conditions. We found that protein adsorption, neutrophil adhesion, and complement activation for the polyimides significantly depends on the curing temperature and decreases with an increase in the temperature and that the polyimide has a good biocompatibility compared with poly(styrene) and polydimethylsiloxane. We concluded that the rearrangement of molecules such as CF(3), sulfone, and ketone at the outermost surface occurs because of curing, which induces an increase in the hydrophobicity and that the cured polyimide suppresses protein adsorption, neutrophil adhesion, and complement activation because of its high hydrophobicity and low surface free energy.

Gas transfer and blood compatibility of asymmetric polyimide hollow fiber

We have fabricated an asymmetric polyimide hollow fiber for use as a membrane oxygenator. A dry/wet phase inversion process has been applied to a spinning process to prepare the hollow fiber. The fiber structure consisted of a complete defect-free skin layer and a porous substructure characterized by the presence of an open-cell structure and macrovoids. The outer diameter was 480 microm with a wall thickness of 50 microm. Transfer rates of O2 and CO2 in the asymmetric polyimide fiber were 2.3 x 10(-5) and 1.1 x 10(-4) (cm3 (STP)/(cm2 s cmHg)), respectively, which were four times higher than those measured in the polydimethylsiloxane (PDMS) fiber of the presently-available membrane oxygenator. The (QO2/QN2) selectivity of the polyimide fiber was 4.9, indicating that the surface skin layer is essentially defect-free. The blood compatibility of the polyimide hollow fiber has been evaluated in vitro and in vivo. The polyimide had an excellent blood compatibility when compared with PDMS.

Clinical characteristics of non-immune-mediated, idiopathic type 1 (type 1B) diabetes mellitus in Japanese children and adolescents

To clarify the characteristics of idiopathic type 1 (type 1B) diabetes mellitus (DM), we compared the clinical features of immune-mediated type 1 (type 1A) DM and type 1B DM in 85 Japanese children and adolescents with DM. The prevalence of type 1B DM was 16.5%. The patients with type 1B DM were significantly younger at diagnosis and had a higher frequency of preceding viral infection before onset, compared to those with type 1A DM. They displayed more severe metabolic decompensation with a higher frequency of ketoacidosis at diagnosis than patients with type 1A DM. They had strong, HLA-defined genetic susceptibility, similar to that in type 1A DM. Some patients with type 1B DM exhibited a remarkably abrupt onset and rapid loss of beta-cell capacity. From these findings, it is considered that type 1B DM differs from type 1A DM with respect to age at onset and the trigger event, such as viral infection, leading to rapid destruction of beta-cells without autoimmunity in the etiology of the disease.

Connective tissue growth factor as a major angiogenic agent that is induced by hypoxia in a human breast cancer cell line

Connective tissue growth factor (CTGF) is known to be a potent angiogenic factor. Here, we present the evidence that the hypoxic induction of angiogenesis by human breast cancer cells (MDA-231) can be ascribed at least in part to CTGF. Our results indicate that (i) CTGF is abundantly present in MDA-231 cells in vitro and in vivo, (ii) its secretion is up-regulated by hypoxia, and (iii) its gene expression is enhanced in MDA-231 cells cultured under hypoxic conditions. These data suggest CTGF may stimulate angiogenesis by paracrine mechanisms, thereby contributing to the invasion of breast cancer cells. This is the first evidence that human cancer cells differentially express CTGF protein and mRNA under the control of hypoxic conditions.

Protective effect of histidine on para-nonylphenol-enhanced hydroxyl free radical generation induced by 1-methyl-4-phenylpyridinium ion (MPP+) in rat striatum

The present study examined the antioxidant effect of histidine, a singlet oxygen ((1)O(2)) scavenger, on para-nonylphenol (an environmental estrogen-like chemical)-enhanced hydroxyl radical (.OH) generation induced by 1-methyl-4-phenylpyridinium ion (MPP+) in extracellular fluid of rat striatum. Rats were anesthetized, and sodium salicylate in Ringer's solution (0.5 nmol/microl/min) was infused through a microdialysis probe to detect the generation of.OH as reflected by the non-enzymatic formation of 2,3-dihydroxybenzoic acid (DHBA) in the striatum. Introduction of para-nonylphenol (10 microM) significantly enhanced MPP+ -induced.OH generation. Histidine (25 mM) decreased the para-nonylphenol-enhanced.OH formation. Although the level of MPP+ -induced.OH formation trapped as DHBA after para-nonylphenol treatment increased, para-nonylphenol failed to increase either the level of dopamine and DHBA formation in the reserpinized animals. These results indicate that para-nonylphenol and MPP+ -enhanced.OH generation was based on 1O(2) production, and histidine may have a preventive effect on para-nonylphenol and MPP+ -induced.OH generation in rat striatum.

Machado-Joseph disease with retinal degeneration and dementia

OBJECTIVES

To clarify the phenotypic varieties in Machado-Joseph disease (MJD).

MATERIALS AND METHODS

We studied a 64-year-old man with ataxia, retinal degeneration and dementia neurologically, ophthalmologically and genetically.

RESULTS

The patient noted dysesthesia of his hands at age 57 and later had memory disturbance. He had gait disturbance and needed a wheelchair at age 64. His total IQ was 61 on the WAIS-R. He had loss of central vision, ophthalmoplegia, hearing impairment, dysarthria, truncal and limb ataxia, sensory disturbance, and mild weakness of the extremities. Electrophysiologically he was suspected to have polyneuropathy. Brain MRI showed marked atrophy of the cerebellum and pons with mild cerebral atrophy. Ophthalmologic evaluation revealed multiple chorioretinal atrophy. Expanded CAG repeat numbers in MJD1 were 64.

CONCLUSION

These findings indicate that the clinical features of MJD might cover a wider spectrum than previously expected, though it is possible that these complications, namely retinal degeneration and dementia, were incidental findings in this patient.

Antisense oligodeoxynucleotide targeted to Midkine, a heparin-binding growth factor, suppresses tumorigenicity of mouse rectal carcinoma cells

Midkine (MK), a heparin-binding growth factor, is overexpressed in a wide range of human carcinomas and is believed to contribute to tumorigenesis and tumor progression. To develop an antitumor reagent, we designed a phosphorothioate antisense oligodeoxynucleotide molecule based on the secondary structure of MK mRNA. The antisense MK at the dosage of 5 microM suppressed MK production by CMT-93 mouse rectal carcinoma cells after cationic liposome-mediated transfection, to 13% of that in control cultures. The growth of CMT-93 cells and their colony formation in soft agar were inhibited by the addition of the antisense MK, whereas the control reagent, the sense MK, showed no effects. On s.c. injection into nude mice, CMT-93 cells transfected with the antisense MK formed tumors much smaller than those by control cells. Finally, untreated CMT-93 cells were inoculated to nude mice, and 7 days later the antisense MK (50 microM) with atelocollagen was directly injected into the preformed tumor region to evaluate the curative effect; the injection was repeated at the interval of 2 weeks. During the period of 10-41 days after initiation of therapy, the rate of increase of tumor volume treated with the antisense MK was found to be about 4.2-fold lower than that seen after treatment with the sense MK. On this occasion, proliferation of tumor cells as estimated by 5-bromodeoxyuridine incorporation was strongly inhibited, whereas angiogenesis was less affected. These findings strongly suggested the usefulness of MK antisense oligodeoxynucleotide as a new reagent for cancer therapy.

Matrix metalloproteinase-2 and -9 in bile as a marker of liver metastasis in colorectal cancer

Matrix metallproteinases (MMP)-2 and -9 are associated with cancer invasion and metastasis. MMP-2 and MMP-9 activities have never been assayed in bile. In the present study we investigated whether MMP-2 and -9 activities in the bile could be a marker for evaluation of liver metastasis in colorectal cancer. Fifty-three patients underwent colorectal resection for histologically verified adenocarcinoma. Twenty-six patients had colorectal cancer without liver metastasis and 27 patients had metastatic liver tumor. Six patients were studied as carcinoma-free control. MMP-2 and MMP-9 activities were assayed in bile using gelatin zymography and quantitated. Active MMP-2 activity of colorectal cancer with liver metastasis group (24.1 +/- 2.5 pixel count) was significantly higher than that of colorectal cancer without liver metastasis group (11.4 +/- 1.3 pixel count) (P < 0.001) or of control group (6.4 +/- 1.0 pixel count) (P < 0.001). Active MMP-9 was not detected in bile. ProMMP-9 activity of colorectal cancer with liver metastasis group (530.3 +/- 127.5 pixel count) was significantly higher than that of colorectal cancer without liver metastasis group (213.9 +/- 33.2 pixel count) (P = 0.008). This is the first report showing that the levels of active MMP-2 and proMMP-9 in bile were significantly higher in liver metastasis of colorectal cancer than in metastasis-free colorectal cancer. The results suggest that activities of active MMP-2 and proMMP-9 in the bile may be useful markers for predicting liver metastasis in colorectal cancer.

A case of an ascending aortic aneurysm due to mesoaortitis complicated with idiopathic thrombocytopenic purpura

An 80-year-old man was referred to our hospital for the surgical treatment of an ascending aortic aneurysm. The diagnosis of idiopathic thombocytonenic purpura was also made by hematological studies which included the examination of the aspirated bone marrow. Preoperative chest computed tomography showed an ascending aortic aneurysm with a maximum diameter of 80 mm. Echocardiography demonstrated mild aortic regurgitation. The platelet count increased by intravenous administration of immunoglobulin. A prosthetic graft replacement of the ascending aorta and aortic valve repair were carried out with the aid of cardiopulmonary bypass, selective cerebral perfusion and hypothermic circulatory arrest. No difficulty was encountered in hemostasis and the postoperative course was uneventful. Histological examination of the aneurysmal wall showed chronic mesoaortitis with patchy destruction of musculo-elastic medial tissue and adventitial focal lymphocytic infiltrates that were similar to syphilitic mesoaortitis, although serological treponemal tests were all negative. Perioperative administration of gamma-globulin is useful to minimize the hemorrhagic complication in a patient undergoing cardiovascular surgery with idiopathic thrombocytopenic purpura.

Observation of compressional Alfvén modes during neutral-beam heating on the national spherical torus experiment

Neutral-beam-driven compressional Alfvén eigenmodes at frequencies below the ion cyclotron frequency have been observed and identified for the first time in the National Spherical Torus Experiment. The modes are observed as a broad spectrum of nearly equally spaced peaks in the frequency range from approximately 0.2omega(ci) to approximately 1.2omega(ci). The frequency has a scaling with toroidal field and plasma density consistent with Alfvén waves. The modes have been observed with high bandwidth magnetic pickup coils and with a reflectometer.

Cell-type-specific trans-activation of herpes simplex virus thymidine kinase promoter by the human T-cell leukemia virus type I Tax protein

The human T-cell leukemia virus type I Tax protein (HTLV-I Tax) is known as a trans-activating factor for a variety of genes, including those of cytokines. Here, we show that Tax is capable of activating the herpes simplex virus thymidine kinase (HSV-TK) promoter in certain mammalian cell lines. In murine NIH 3T3 fibroblasts and human HeLa cells, trans-activation by Tax was remarkably strong, whereas in human chondrocytic HCS-2/8 and monkey kidney Cos-7 cells, the responsiveness of the TK promoter to Tax was poor. Deletion analysis revealed that one of the two previously described Sp1 sites is required for the Tax responsiveness, whereas the CTF binding site is not. The results suggest possible interactions between the oncogenic Tax protein and the viral TK in coinfected cells in vivo. Care should be taken in the context of HTLV-I research, as the HSV-TK promoter has been widely used in molecular biology and gene therapeutics.

Technical advance: an automated device for cryofixation of specimens of electron microscopy using liquid helium

Metal-contact rapid freezing using liquid helium is theoretically the best method for preserving the fine structure of living cells with high temporal resolution in preparation of tissue samples for electron microscopy. However, this method is not commonly used, because of its technical difficulty and low reproducibility. We have designed and constructed an automatic device which allows simple, rapid and reproducible preparation of high-quality electron microscopic specimens by the non-specialist. We assessed the quality of cryofixation in samples prepared using this device by examining the preservation of cellular ultrastructure in relation to distance from the freezing block, and found that the region within 10 microm of the metal-contact plane was fixed with the highest quality. We applied this device, in combination with freeze-substitution methods and immunocytochemical techniques, to two phenomena involving rapid movement of subcellular components: (1) active movement of subcellular structures in the papillar cells of stigma and (2) light-induced rapid subcellular translocation of phytochrome A. Considering the importance of understanding subcellular processes of living cells for molecular and cell biology, this device will be a useful tool for diverse biological applications in the near future.

Protective effect of tamoxifen on 1-methyl-4-phenylpyridine-induced hydroxyl radical generation in the rat striatum

We examined whether tamoxifen could suppress 1-methyl-4-phenylpyridine (MPP(+))-induced hydroxyl radical generation in the extracellular fluid of rat striatum, using in vivo microdialysis system. MPP(+) (5 mM) enhanced generation of hydroxyl radicals with concomitant increased efflux of dopamine. Tamoxifen (1--100 microM) dose-dependently suppressed the hydroxyl radical formation induced by MPP(+). Tamoxifen (100 microM) significantly attenuated dopamine efflux induced by MPP(+). The result in the present study is the first demonstration showing the protective effect of tamoxifen on hydroxyl radical generation induced by MPP(+) by suppressing dopamine efflux.

Novel mode of processing and secretion of connective tissue growth factor/ecogenin (CTGF/Hcs24) in chondrocytic HCS-2/8 cells

The synthesis, processing, and secretion of human connective tissue growth factor (CTGF/Hcs24) in a human chondrocytic cell line, HCS-2/8, were analyzed immunochemically. By metabolic pulse-labeling, chasing, and subsequent immunoprecipitation analyses, active synthesis of CTGF was observed not only in growing HCS-2/8 cells, but also in confluent cells. However, secretion and processing of CTGF were found to be regulated differentially, depending upon the growth status. During phases of growth, HCS-2/8 cells released CTGF molecules immediately without sequestering them within the cell layer. In contrast, after the cells reached confluence, the secretion slowed, resulting in an accumulation of CTGF in the cells or extracellular matrices (ECMs). Also, in confluent cell layers, a 10 kDa protein that was reactive to an anti-CTGF serum was observed. This CTGF-related small protein was not detected immediately after labeling, but gradually appeared within 6 h after chase, which suggests its entity as a processed subfragment of CTGF. Surprisingly, the 10 kDa protein was stable even 48 h after synthesis, and was not released by ECM digestion, suggesting an intracellular maintenance and function. Taken together, the behavior of CTGF in HCS-2/8 cells is remarkably different from that reported in fibroblasts, which may represent unique roles for CTGF in the growth and differentiation of chondrocytes.

Left ventricular epicardial outflow tract tachycardia: a new distinct subgroup of outflow tract tachycardia

The present study investigated the incidence and ECG characteristics of ventricular tachycardias (VTs) originating from the left ventricular (LV) epicardium. Thirty-one consecutive patients with VT or premature ventricular contraction originating from the outflow tract (OT-VT) underwent catheter ablation. Twenty-one OT-VTs were ablated from the endocardium in the right ventricular (RV) OT and 3 were ablated from the endocardium in the LVOT. In the remaining 7 patients, 4 (13%) OT-VTs were LV epicardial in origin, and 1 of these was ablated from the left sinus of Valsalva. The ECG characteristics of OT-VT of epicardial origin included prominent tall R-waves in the inferior leads, an R-wave in V1 and an S-wave in V2, precordial R-wave transition in V2-4, a deep QS-wave in aVL, and no S-wave in V6. In addition, there was an atypical left bundle branch block morphology with an inferior axis. These findings were observed during pacing from several sites in the LV epicardium. Furthermore, pacing from the left sinus of Valsalva caused a relatively tall R in V1, deep S-wave in V2 and a tall R-wave with a shallow S-wave in V3, as well as tall R-waves in the inferior leads, which represented intermediate characteristics between RV endocardial OT-VT and LV endocardial OT-VT. In conclusion, OT-VT originating from the LV epicardium is not uncommon and has characteristic ECG findings. Some of them can be ablated from the left sinus of Valsalva.

Regulatory mechanism of human connective tissue growth factor (CTGF/Hcs24) gene expression in a human chondrocytic cell line, HCS-2/8

CTGF/Hcs24 is a multi-functional growth factor that potentiates either the growth or differentiation of mesenchymal cells, according to the biological conditions. Among various functional aspects of CTGF/Hcs24, it is especially notable that CTGF/Hcs24 may promote endochondral ossification in growth cartilage through all stages, and it is highly expressed in a human chondrosarcoma-derived chondrocytic cell line (HCS-2/8). In this study, to clarify the regulatory mechanism of CTGF/Hcs24 gene expression in chondrocytes, we analyzed the transcriptional activity of the CTGF/Hcs24 promoter and the effect of the CTGF/Hcs24 3'-untranslated region (3'-UTR) on gene expression in HCS-2/8 by means of an established DNA transfection and luciferase reporter gene assay system. As a result, the luciferase activity of the CTGF/Hcs24 promoter was found to be remarkably high in HCS-2/8. The 3'-UTR of the CTGF/Hcs24 gene strongly repressed the luciferase activity in HCS-2/8, when it was linked to the downstream of the luciferase reporter gene, suggesting its functionality also in chondrocytic cells. Deletion analysis of the CTGF/Hcs24 promoter clarified a major segment responsible for the enhanced CTGF/Hcs24 promoter activity in HCS-2/8. The TGF-beta response element in the DNA segment was active in HCS-2/8, and point mutations in the element moderately decreased the highly maintained promoter activity with total loss of TGF-beta responsiveness. These results indicate that the strong expression of the CTGF/Hcs24 gene in HCS-2/8 was mainly caused by high transcriptional activity of the CTGF/Hcs24 promoter, and that the TGF-beta response element is one of the critical elements that support the high transcription activity.