Prophylaxis of local vascular graft infection with levofloxacin incorporated into albumin-sealed dacron graft (LVFX-ALB Graft).

An animal model was used to assess the efficacy of levofloxacin (LVFX) incorporated into albumin (ALB)-sealed Dacron (LVFX-ALB) graft for the prevention of vascular graft infections caused by Staphylococcus aureus. Under general anesthetic, an interposition graft was placed into dog carotid artery. On completion of the operation, 0.1 ml of normal saline containing 10(7) colony-forming units (CFU) of a slime-producing S. aureus was inoculated directly onto the graft. After 1 day, the samples were sterilely harvested. The antibacterial activity of LVFX into the LVFX-ALB graft was evaluated by colony counting in bacterial cultures and by the fluorescent antibody method staining bacteria adhesion to the grafts. LVFX-ALB grafts had a lower infection rate than the control grafts (1/4, 10(2) CFU vs 4/4, 1.50 x 10(5)+/-1.38 x 10(5)CFU (mean+/-SE)). In an immunostaining study, LVFX-ALB grafts had small fluorescent areas showing S. aureus adhesion, while fluorescence was observed over the entire surface of the control grafts. Therefore, LVFX-ALB presumably had a bactericidal action and adhesive prevention against inoculated S. aureus. LVFX-ALB may be useful in preventing graft infections during and immediately after vascular reconstruction.     

Regulation of fibronectin expression and splicing in migrating epithelial cells: migrating MDCK cells produce a lesser amount of, but more active, fibronectin

Previously we have demonstrated that in MDCK epithelial cells not only transforming growth factor-beta (TGF-beta) but also hepatocyte growth factor/scatter factor (HGF/SF) regulates fibronectin (FN) splicing by increasing the ratio of EDA-containing FN (EDA+ FN) mRNA to EDA-minus FN (EDA- FN) mRNA (EDA+/EDA- ratio). EDA+ FN is known to be upregulated in tissues where cells actively migrate, such as those during morphogenesis, wound healing, and tumorigenesis. However, a direct association between cell migration and FN splicing at the EDA region has never been investigated. In this work, we have shown by using an in vitro wound migration assay that migrating epithelial cells regulate FN production and splicing differently compared to nonmigrating cells. Wounds were introduced as migration stimuli into the 10-day-old confluent cell sheet, where the EDA+/EDA- ratio and FN mRNA expression levels were stable. In migrating cells at the wound edge, the FN mRNA level decreased by 0.73-fold and the EDA+/EDA- ratio increased by 1.32-fold when compared with nonmigrating cells apart from the wound edge. HGF/SF significantly stimulated cell migration at the wound edge and concomitantly decreased the FN mRNA level by 0.60-fold and increased the EDA+/EDA- ratio by 1.84-fold in migrating cells. In nonmigrating cells apart from the wound edge, FN mRNA expression and splicing were not influenced by either wound stimulation or HGF/SF. EDA+ FN stimulates cell migration more effectively than EDA- FN and thus is considered to be a more active variant of FN. Taken together, migrating MDCK cells appear to regulate FN mRNA expression and splicing to produce a lesser amount of, but more active, FN.     

Marrow stromal cells: implications in health and disease in the nervous system

Chronic degenerative diseases and traumatic injuries are responsible for a decline in neuronal function, which often limit life span. While solid organ transplantation such as liver and kidney has been already applied for thousands of patients, great limitation exists in case of nervous system. Cell transplantation is one of the strategies with potential for treatment of such neural disorders, and many kinds of cells including embryonic stem cells and neural stem cells have been considered as candidates for transplantation therapy. Bone marrow stromal cells (MSCs) have great potential as therapeutic agents, since they are easy to isolate and can be expanded from patients without serious ethical and technical problems. We found a method for the highly efficient and specific induction of functional neurons and Schwann cells from both rat and human MSCs. Induced neurons and Schwann cells were transplanted in animal models of Parkinson's disease, stroke, peripheral nerve injury, and spinal cord injury resulting in the successful integration of transplanted cells and improvement in behavior of transplanted animals. Here we focus on the respective potentials of MSC-derived cells and discuss the possibility of clinical application in neurodegenerative and neurotraumatic diseases.     

Cdk5 phosphorylates and stabilizes p27kip1 contributing to actin organization and cortical neuronal migration

p27(kip1), a cyclin-dependent kinase (CDK) inhibitor (CKI), generally suppresses CDK activity in proliferating cells. Although another role of p27 in cell migration has been recently suggested in vitro, the physiological importance of p27 in cell migration remains elusive, as p27-deficient mice have not shown any obvious migration-defect-related phenotypes. Here, we show that Cdk5, an unconventional neuronal CDK, phosphorylates and stabilizes p27 as an upstream regulator, maintaining the amount of p27 in post-mitotic neurons. In vivo RNA interference (RNAi) experiments showed that reduced amounts of p27 caused inhibition of cortical neuronal migration and decreased the amount of F-actin in the processes of migrating neurons. The Cdk5-p27 pathway activates an actin-binding protein, cofilin, which is also shown to be involved in cortical neuronal migration in vivo. Our findings shed light on a previously unknown new relationship between CDK and CKI in G0-arrested cells that regulates cytoskeletal reorganization and neuronal migration during corticogenesis.     

COSA-1 reveals robust homeostasis and separable licensing and reinforcement steps governing meiotic crossovers

Crossovers (COs) between homologous chromosomes ensure their faithful segregation during meiosis. We identify C.?elegans COSA-1, a cyclin-related protein conserved in metazoa, as a key component required to convert meiotic double-strand breaks (DSBs) into COs. During late meiotic prophase, COSA-1 localizes to foci that correspond to the single CO site on each homolog pair and indicate sites of eventual concentration of other conserved CO proteins. Chromosomes gain and lose competence to load CO proteins during meiotic progression, with competence to load COSA-1 requiring prior licensing. Our data further suggest a self-reinforcing mechanism maintaining CO designation. Modeling of a nonlinear dose-response relationship between IR-induced DSBs and COSA-1 foci reveals efficient conversion of DSBs into COs when DSBs are limiting and a robust capacity to limit cytologically differentiated CO sites when DSBs are in excess. COSA-1 foci serve as a unique live cell readout for investigating CO formation and CO interference.     

Diffuse large B-cell lymphoma presenting with neurolymphomatosis and intravascular lymphoma: a unique autopsy case with diverse neurological symptoms

ABSTRACT: A 78-year-old Japanese male noticed a difficulty in the beginning of standing up, followed by a progressive numbness of extremities with pain, Bell's palsy, dysarthria, and difficulty in swallowing. A clinician had suspected cancer of unknown primary origin, accompanied by the diverse and elusive neurological symptoms, likely presenting as painful mononeuropathy simplex and cranial neuropathy. He developed dysbasia over weeks and died 1 month after the symptom onset. At autopsy, an ill-defined large and soft tumor mass in the right lobe of the liver with direct invasion into the right adrenal gland was observed. The left adrenal gland or right iliopsoas muscle was also involved. Microscopic findings showed a monotonous proliferation of medium-sized to large atypical lymphoid cells, which were diffusely positive for CD20 in immunohistochemistry, consistent with diffuse large B-cell lymphoma (DLBL). Furthermore, the lymphoma cells aggressively infiltrated endoneurial and subperineurial spaces not only in the peripheral nerves and plexuses, but partly in the spinal nerve roots, and intravascular spaces in various tissues. Therefore, systemic lymphoma (DLBL) complicated with neurolymphomatosis (NL) and intravascular lymphoma (IVL) was diagnosed. Very early diagnosis and treatment are necessary for the NL patients with poor prognosis. Virtual slides The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5862472377020448.     

Superoxide scavenging activity of pirfenidone-iron complex

Pirfenidone (PFD) is focused on a new anti-fibrotic drug, which can minimize lung fibrosis etc. We evaluated the superoxide () scavenging activities of PFD and the PFD-iron complex by electron spin resonance (ESR) spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. Firstly, we confirmed that the PFD-iron complex was formed by mixing iron chloride with threefold molar PFD, and the complex was stable in distillated water and ethanol. Secondary, the PFD-iron complex reduced the amount of produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. Thirdly, it also reduced the amount of released from phorbor ester-stimulated human neutrophils. PFD alone showed few such effects. These results suggest the possibility that the scavenging effect of the PFD-iron complex contributes to the anti-fibrotic action of PFD used for treating idiopathic pulmonary fibrosis.     

Applicability of new spin trap agent, 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide, in biological system

Electron spin resonance using spin-trapping is a useful technique for detecting direct reactive oxygen species, such as superoxide (). However, the widely used spin trap 2,2-dimethyl-3,4-dihydro-2H-pyrrole N-oxide (DMPO) has several fundamental limitations in terms of half-life and stability. Recently, the new spin trap 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide (DPhPMPO) was developed by us. We evaluated the biological applicability of DPhPMPO to analyze in both cell-free and cellular systems. DPhPMPO had a larger rate constant for and formed more stable spin adducts for than DMPO in the xanthine/xanthine oxidase (X/XO) system. In the phorbol myristate acetate-activated neutrophil system, the detection potential of DPhPMPO for was significantly higher than that of DMPO (k_DMPO = 13.95 M⁻¹ s⁻¹, k_DPhPMPO = 42.4 M⁻¹ s⁻¹). These results indicated that DPhPMPO is a potentially good candidate for trapping in a biological system.