Sulcus subarachnoid hemorrhage is a common stroke subtype in patients with implanted left ventricular assist devices.

BACKGROUND AND PURPOSE: Stroke is one of the major complications observed in patients with an implanted left ventricular assist device (LVAD). The purpose of this study was to clarify the types and characteristics of acute stroke in patients after LVAD implantation by using brain computed tomography (CT) findings. METHODS: Between 2005 and 2012, 110 consecutive patients who underwent LVAD implantation were reviewed. The most commonly used device was the pulsatile extracorporeal LVAD. Amongst them, 49 patients suffered from acute stroke at least once with a total of 115 stroke events. The clinical categories, lesion sites, laboratory data and CT findings of each acute stroke event were analyzed. RESULTS: Cerebral infarction (35 patients, 72 events), cerebral hemorrhage (25 patients, 31 events) and subarachnoid hemorrhage (SAH) (23 patients, 33 events) were identified. A mean of 2.3 stroke events occurred per person. Of the 72 infarction events, multiple infarctions were observed in 29 events. Of the cerebral hemorrhage events (n = 31), almost all were subcortical lesions (n = 27) and none were observed in the basal ganglia. Of the 23 patients with SAH events (n = 33), SAH localized within a single sulcus, sulcus SAH, was observed in 25 events. CONCLUSIONS: Computed tomography findings of acute stroke after implantation of an LVAD are characteristically multifocal cortical lesions, regardless of brain infarction and hemorrhage. Unexpectedly, sulcus SAH was a common stroke subtype in patients with implanted LVADs. Sulcus SAH should be carefully examined in patients after LVAD implantation, when they complain of non-specific neurological complaints.

Immunohistochemical expression of fibrillin-1 and fibrillin-2 during tooth development.

BACKGROUND AND OBJECTIVE: Oxytalan fibers are categorized as a microfibril assembly without elastin deposition, and are unique components in the periodontal ligament (PDL). However, little is known about their formation during PDL development. To clarify the mechanisms of oxytalan fiber formation in developing PDL, we performed immunohistochemical analysis to detect the direct expression of fibrillin-1 and fibrillin-2, which are major components of microfibrils. MATERIAL AND METHODS: Frozen sections of lower molars from mice at several stages of growth were prepared without chemical fixation and decalcification using the film transfer method. Immunostaining was performed with anti-fibrillin-1 and -2, and anticytokeratin antibodies. RESULTS: Fibrillin-1 was not expressed in the dental follicle during the crown forming stage. At postneonatal day 9, fibrillin-1 expression started with meshwork appearance between the epithelial cells from Hertwig's epithelial root sheath at the root dentin surface. Fibirillin-2 was detected much earlier than fibrillin-1 expression. Fibrillin-2 was expressed with a liner appearance, running parallel to the root axis in PDL, and was partially co-expressed with cytokeratin 14 expression in Hertwig's epithelial root sheath. Furthermore, we detected both fibrillin-1 and fibrillin-2 expression in human PDL. Fibrillin-1 was detected in fibers with a vertically oriented root axis in PDL. Fibrillin-2 was widely expressed in PDL, including around the epithelial cell rests of Malassez. Fibrillin-1 and fibrillin-2 were clearly co-expressed in thick fiber structures in human PDL. CONCLUSION: Our results suggest that both fibrillin-1 and fibrillin-2 expression is required to form thick oxytalan fibers in PDL. Based on the expression patterns for fibrillin-1 and fibrillin-2, they have different functions during tooth root and PDL development. Early expression of fibrillin-2 may regulate dental epithelial cell behavior during root and PDL development.

Risk factors to cause tooth formation anomalies in chemotherapy of paediatric cancers.

This study aimed to investigate the risk factors of tooth formation anomalies in anti-cancer chemotherapies. Long-term survivors treated by conventional chemotherapy (n = 26), conventional chemotherapy with high-dose chemotherapy (HDC) (n = 14), and HDC with total body irradiation (TBI) (n = 6) were analysed for the incidence of tooth agenesis, microdonts, and short-rooted teeth. The tooth agenesis and/or microdonts were found in second premolars and second molars, but not in first molars or central incisors. The ratio of subjects with tooth agenesis and/or microdonts was 66.7% and 18.2% in subjects administered conventional chemotherapy at <4 years and ≥ 4 years of age, respectively, while it was 100% and 25% in subjects administered HDC at <4 years and ≥ 4 years of age. The incidence of tooth formation anomalies did not related with the duration of conventional chemotherapy but increased by HDC. The incidence of tooth formation anomalies did not show significantly differences between the HDC with and without TBI groups, and was higher in busulfan-administered subjects than in subjects given cyclophosphamide. It may be concluded that the high-risk group of tooth agenesis is the subjects with HDC under 4 years of age. However, protocols of conventional chemotherapy are not an important risk factor to cause the tooth formation anomalies.

In vivo transfection of cis element "decoy" against nuclear factor-kappaB binding site prevents myocardial infarction.

The transcriptional factor nuclear factor-kappaB (NFkappaB) plays a pivotal role in the coordinated transactivation of cytokine and adhesion molecule genes that might be involved in myocardial damage after ischemia and reperfusion. Therefore, we hypothesized that synthetic double-stranded DNA with high affinity for NFkappaB could be introduced in vivo as "decoy" cis elements to bind the transcriptional factor and to block the activation of genes mediating myocardial infarction, thus providing effective therapy for myocardial infarction. Treatment before and after infarction by transfection of NFkappaB decoy, but not scrambled decoy, oligodeoxynucleotides before coronary artery occlusion or immediately after reperfusion had a significant inhibitory effect on the area of infarction. Here, we report the first successful in vivo transfer of NFkappaB decoy oligodeoxynucleotides to reduce the extent of myocardial infarction following reperfusion, providing a new therapeutic strategy for myocardial infarction.

Prevention of graft coronary arteriosclerosis by antisense cdk2 kinase oligonucleotide.

Graft coronary arteriosclerosis, which limits the long-term survival of allograft recipients, is characterized by diffuse intimal thickening composed of proliferative smooth muscle cells. We observed that messenger RNA of the cell cycle regulatory enzyme cyclin-dependent kinase (cdk) 2 kinase, which mediates smooth muscle cell proliferation, was elevated in the thickened intima of coronary arteries of murine heterotopic cardiac allografts. We studied the effects of antisense phosphorothioate oligodeoxynucleotide (ODN) against this enzyme using gene transfer mediated by a hemagglutinating virus of Japan (HVJ)-liposome complex intraluminally delivered to inhibit the intimal hyperplasia. At 30 days after transplantation, antisense cdk2 kinase ODN treatment had dramatically inhibited neointimal formation in the allografts. Expression of vascular cell adhesion molecule-1 was also suppressed by antisense cdk2 kinase. However, these effects were not observed in the sense or scrambled ODN-treated allografts. Thus, an intraluminal administration of antisense ODN directed to a specific cell cycle regulatory gene can inhibit neointimal formation after cardiac transplantation.

Hepatocyte growth factor gene therapy of liver cirrhosis in rats.

Liver cirrhosis is the irreversible end result of fibrous scarring and hepatocellular regeneration, characterized by diffuse disorganization of the normal hepatic structure of regenerative nodules and fibrotic tissue. It is associated with prominent morbidity and mortality, and is induced by many factors, including chronic hepatitis virus infections, alcohol drinking and drug abuse. Hepatocyte growth factor (HGF), originally identified and cloned as a potent mitogen for hepatocytes, shows mitogenic, motogenic and morphogenic activities for a wide variety of cells. Moreover, HGF plays an essential part in the development and regeneration of the liver, and shows anti-apoptotic activity in hepatocytes. In a rat model of lethal liver cirrhosis produced by dimethylnitrosamine administrations, repeated transfections of the human HGF gene into skeletal muscles induced a high plasma level of human as well as enodogenous rat HGF, and tyrosine phosphorylation of the c-Met/HGF receptor. Transduction with the HGF gene also suppressed the increase of transforming growth factor-beta1 (TGF-beta1), which plays an essential part in the progression of liver cirrhosis, inhibited fibrogenesis and hepatocyte apoptosis, and produced the complete resolution of fibrosis in the cirrhotic liver, thereby improving the survival rate of rats with this severe illness. Thus, HGF gene therapy may be potentially useful for the treatment of patients with liver cirrhosis, which is otherwise fatal and untreatable by conventional therapy.

Hybrid endovascular stent-grafting technique for patent ductus arteriosus in an adult.

A 51-year-old man was referred to our institution for patent ductus arteriosus (PDA) complicated by left ventricular dysfunction and pulmonary hypertension. Surgical closure of a PDA is usually carried out via a small posterior thoracotomy. However, thoracoscopic procedures are probably not appropriate in adults because of the frequency of calcification and the greater risk of rupture while ligating the ductus. To minimize surgical trauma, we used hybrid endovascular stent grafting combined with revascularization of the left subclavian artery, which enabled us to eliminate shunt flow to the pulmonary artery. At 11-month follow-up, the patient was asymptomatic and showed no complications.

Oxygen-regulated protein-150 prevents calcium homeostasis deregulation and apoptosis induced by oxidized LDL in vascular cells.

Oxidized LDLs (oxLDLs) induce apoptosis, which contributes to the pathogenesis of atherosclerosis. The 150 kDa oxygen-regulated protein (ORP150), an endoplasmic reticulum (ER)-resident chaperone, is upregulated by hypoxia and prevents ischemia-induced cell death. The aim of this work was to investigate whether and how ORP150 can prevent apoptosis induced by oxLDLs in vascular cells. OxLDLs induced ORP150 expression in the ER of human microvascular endothelial cell line (HMEC-1). ORP150 expression was blocked by antioxidants, by the permeant calcium chelator BAPTA-AM, and by inhibitors of the inositol-1,4,5 trisphosphate (IP3) receptors, 2-aminoethyl diphenylborinate (2-APB) and xestospongin C. ORP150 silencing by siRNA-enhanced oxLDL-induced apoptosis, while forced ORP150 expression increased the resistance of cells via an inhibition of the oxLDL-induced calcium rise, and of subsequent calpain activation, cytochrome c release, caspase 3 activation and apoptosis. A similar protective effect was achieved by BAPTA-AM, 2-APB and xestospongin C. Altogether, these data indicate that (i)ORP150 inhibits oxLDL-induced apoptosis by blocking calcium signaling and subsequent apoptosis, (ii)calcium released from ER stores through IP3 channels is involved in the oxLDL-induced calcium rise and apoptosis, and is inhibited by ORP150. Finally, ORP150 is expressed in advanced atherosclerotic lesions, where it may locally participate to reduce the apoptotic effect of oxLDLs and the subsequent risk of plaque rupture.

Stretching modulates oxytalan fibers in human periodontal ligament cells.

MATERIAL AND METHODS: We subjected periodontal ligament fibroblasts to stretching strain to examine the effects on their formation of oxytalan fibers in cell/matrix layers. RESULTS: Stretching increased the levels of fibrillin-1 and fibrillin-2 by 25% relative to the control, but did not affect the gene expression level of either type of fibrillin. Immunofluorescence and immunogold electron microscopy analysis revealed that bundles of oxytalan fibers became thicker under stretching conditions. CONCLUSION: These results suggest that tension strain functionally regulates microfibril assembly in periodontal ligament fibroblasts and thus may contribute to the homeostasis of oxytalan fibers in periodontal ligaments.

Stretching stimulates fibulin-5 expression and controls microfibril bundles in human periodontal ligament cells.

BACKGROUND AND OBJECTIVE: The elastic fiber system comprises oxytalan, elaunin and elastic fibers, differing in their relative microfibril and elastin contents. Human periodontal ligaments contain oxytalan fibers (pure microfibrils). Periodontal ligaments are continuously exposed to various functional forces, such as tooth movement and occlusal loading. We have reported that bundles of microfibrils coalesce in response to mechanical strain in cultured periodontal ligament fibroblasts, as assessed in terms of their positivity for fibrillin-1 (the major component of microfibrils). However, the mechanism of microfibril coalescence is unclear. We hypothesized that the fibrillin-1-binding molecule, fibulin-5, contributes to oxytalan fiber formation under mechanical strain. MATERIAL AND METHODS: We subjected periodontal ligament fibroblasts to stretching in order to examine the effects of fibulin-5 on the formation of oxytalan fibers in cell/matrix layers. We transfected periodontal ligament cells with small interference RNA for fibulin-5, then examined oxytalan fibers using immunofluorescence and electron microscopy. RESULTS: Immunofluorescence showed that fibrillin-1-positive microfibrils coalesced as a result of stretching, compared with cells that were not subjected to stretching. Fibulin-5 colocalized on fibrillin-1-positive microfibrils. Stretching increased fibulin-5 gene expression and protein deposition. Immunofluorescence and immunogold electron microscopy analysis revealed that fibulin-5 suppression inhibited the coalescence of microfibrils under stretching conditions. CONCLUSION: These results suggest that fibulin-5 up-regulated in response to tension strain may control the formation of microfibril bundles in periodontal ligament.

Integrin alphavbeta3 regulates microfibril assembly in human periodontal ligament cells.

Fibrillin-1 is the major structural component of extracellular microfibrils. However, the mechanism by which extracellular fibrillin-1 assembles into microfibrils is not fully understood. Fibrillin-1 contains the Arg-Gly-Asp (RGD) motif, which may allow binding to RGD-recognizing integrins. We hypothesized that integrin alphavbeta3 on the cell surface of human periodontal ligament (PDL) fibroblasts may influence fibrillin-1 assembly into cell/matrix layers. We treated PDL fibroblasts with an integrin alphavbeta3-specific antagonist to examine fibrillin-1 assembly. Western blotting and immunofluorescence analysis showed that treatment with the integrin alphavbeta3 antagonist at 5 muM clearly abolished fibrillin-1 deposition. These results provide for the first time evidence that integrin alphavbeta3 regulates extracellular assembly of fibrillin-1, thereby modulating cell-mediated homeostasis of microfibrils.

Adenovirus-mediated gene expression of the human c-FLIP(L) gene protects pig islets against human CD8(+) cytotoxic T lymphocyte-mediated cytotoxicity.

Cell-mediated immunity, especially of human CD8+ cytotoxic T lymphocytes (CTLs) is believed to have an important role in the long-term survival of pig islet xenografts. Protection against human CD8+ CTL cytotoxicity may reduce the direct damage to pig islets and enable long-term xenograft survival in pig-to-human islet xenotransplantation. We have previously reported that c-FLIP(S/L) genes, which are potent inhibitors of death receptor-mediated proapoptotic signals through binding competition with caspase-8 for recruitment to the Fas-associated via death domain (FADD), markedly suppress human CD8+ CTL-mediated xenocytotoxicity. In addition, the cytoprotective effects of c-FLIP(L) seem to be significantly stronger than those of c-FLIP(S). Accordingly, in the present study, expression of c-FLIP(L) was induced in intact pig islets by adenoviral transduction. Consequently, the cytoprotective capacity of the transgene in pig islets was examined in in vitro and in vivo exposure to human CD8+ CTLs. Cells from untransduced islets or mock islets were sensitive to CD8+ CTL-mediated lysis (59.3% +/- 15.9% and 64.0% +/- 8.9% cytotoxicity, respectively). In contrast, cells from pig islets transduced with the c-FLIP(L) gene were markedly protected from lysis (30.5% +/- 3.5%). Furthermore, prolonged xenograft survival was elicited from pig islets transduced with this molecule as assessed using an islet transplant model using the rat kidney capsule. Thus, these data indicate that intact pig islets can be transduced to express c-FLIP(L) with adenovirus. Pig islets expressing c-FLIP(L) are significantly resistant to human CTL killing and further exhibit beneficial effects to prolong xenograft survival.

In vivo controlling of cellular response to pig islet xenografts by adenovirus-mediated expression of either membrane-bound human FasL or human decoy Fas.

The critical problem with clinical islet transplantation for patients with type 1 diabetes is the severe shortage of human donors. Pig islet xenotransplantation has the potential to provide a virtually unlimited source of donor pancreata. However, our previous studies demonstrated that cell-mediated rejection, especially human CD8(+) cytotoxic T lymphocyte (CTL)-mediated cytotoxicity, remains a major obstacle for long-term islet xenograft survival. Moreover, we have demonstrated that the overexpression of either membrane-bound human FasL (mFasL) or human decoy Fas antigen (decoy Fas) in pig islets not only prevented CTL xenocytotoxicity in vitro, but also prolonged histological survival of pig islet xenografts in vivo. Therefore, the aim of the present study was to determine whether adenoviral transfer of these genes into pig islets ex vivo prior to transplantation had a beneficial effect on posttransplantation glycemic control of diabetic recipients. Isolated pig islets were transfected with adenovirus vector carrying complementary DNA (cDNA) of either mFasL or decoy Fas. The transfected islets were transplanted under the kidney capsule of diabetic recipient rats. Rats transplanted with either mFasL- or decoy Fas-transfected pig islet grafts showed significantly suppressed blood glucose levels from 12 hours to 18 hours posttransplantation compared with control groups transplanted with empty vector-transfected pig islets. Unfortunately, blood glucose levels of these groups were increased, with no significant difference observed at 24 hours posttransplantation. However, transgenic expression of these molecules with clinically tolerable amount of immunosuppressants may be more effective to achieve islet xenograft survival in the future.

Rapamycin induces autophagy in islets: relevance in islet transplantation.

Islet transplantation can provide insulin independence in patients with type 1 diabetes mellitus. However, islet allograft recipients exhibit a gradual decline in insulin independence, and only 10% do not require insulin at 5 years. This decline may reflect drug toxicity to islet beta cells. Rapamycin, a central immunosuppressant in islet transplantation, is a mammalian target of rampamycin inhibitor that induces autophagy. The relative contributions of autophagy in transplanted islets are poorly understood. Therefore, in the present study we sought to evaluate the effects of rapamycin on islet beta cells. Rapamycin treatment of islets resulted in accumulation of membrane-bound light chain 3 (LC3-II) protein, an early marker of autophagy. In addition, rapamycin treatment of isolated islets elicited not only reduction of viability but also downregulation of in vitro potency. To further examine the occurrence of autophagy in rapamycin-treated islets, we used GFP (green fluorescent protein)-LC3 transgenic mice that express a fluorescent autophagosome marker. The GFP-LC3 signals were markedly increased in rapamycin treated islets compared with control islets. In addition, to show improvement by blockade of autophagic signaling, islets were treated with rapamycin in the presence of 3-methyladenine, which inhibits autophagy. Thereafter, both islet viability and islet potency were dramatically improved. The number of GFP-LC3 dots clearly increased after 3-MA treatment. Thus, rapamycin treatment of islets induces autophagy in vitro. This phenomenon may contribute to the progressive graft dysfunction of transplanted islets. Therapeutically targeting this novel signaling may yield significant benefits for long-term islet survival.