Echocardiographic evaluation of deformity and enlargement of the canine mitral valve annulus associated with myxomatous degenerative mitral valve disease.

INTRODUCTION/OBJECTIVES: Quantitative evaluation of the morphology of the mitral valve annulus (MVA) in dogs with myxomatous mitral valve disease (MMVD) may improve the techniques of mitral valve plasty. This study aimed to compare the MVA morphology on echocardiography in normal dogs and dogs with MMVD and to compare the echocardiographic and intraoperative measurements of the MVA in dogs with MMVD. ANIMALS, MATERIALS AND METHODS: The study population comprised 59 healthy dogs (control group) and 371 dogs with MMVD (MMVD group). The anterior-posterior diameter and transversal diameter (TD) of the MVA and the aortic annulus diameter were measured by echocardiography to calculate the mitral valve flattening ratio, mitral annulus area (MAA), mitral annulus circumference (MAC), contraction ratio of the MAA and aortic annulus area. In the MMVD group, the mitral annulus diameter (MAD) was macroscopically measured during mitral valve plasty. Areas and lengths were divided by the body surface area (BSA) and √BSA, respectively, for comparative analyses. RESULTS: The systolic and diastolic anterior-posterior diameter/√BSA, transversal diameter/√BSA, MAA/BSA converted to a natural logarithm (Ln(MAA/BSA)), and MAC/√BSA was significantly higher in the MMVD group than the control group, whereas flattening ratio values and contraction ratio of the MAA was significantly lower. Neither the aortic annulus diameter /√BSA nor the Ln(aortic annulus area/BSA) significantly differed between groups. In the MMVD group, diastolic MAC/√BSA and MAA/BSA correlated significantly with the MAD/√BSA. CONCLUSIONS: The MVA is larger and rounder in dogs with MMVD than controls. Two-dimensional echocardiographic measures of MAA and MAC correlate well with intraoperative measures of MAD.

High-Brightness Continuous-Wave Electron Beams from Superconducting Radio-Frequency Photoemission Gun.

Continuous-wave photoinjectors operating at high accelerating gradients promise to revolutionize many areas of science and applications. They can establish the basis for a new generation of monochromatic x-ray free electron lasers, high-brightness hadron beams, or a new generation of microchip production. In this Letter we report on the record-performing superconducting rf electron gun with CsK_{2}Sb photocathode. The gun is generating high charge electron bunches (up to 10 nC/bunch) and low transverse emittances, while operating for months with a single photocathode. This achievement opens a new era in generating high-power beams with a very high average brightness.

Cockroach allergen serine proteinases: Isolation, sequencing and signalling via proteinase-activated receptor-2.

BACKGROUND: Allergy to the German cockroach (Blattella germanica) is a significant asthma risk factor for inner-city communities. Cockroach, like other allergens, contains trypsin-like enzyme activity that contributes to allergenicity and airway inflammation by activating proteinase-activated receptors (PARs). To date, the enzymes responsible for the proteolytic activity of German cockroach allergen have not been characterized. OBJECTIVES: We aimed to identify, isolate and characterize the trypsin-like proteinases in German cockroach allergen extracts used for clinical skin tests. For each enzyme, we sought to determine (1) its substrate and inhibitor enzyme kinetics (Km and IC50), (2) its amino acid sequence and (3) its ability to activate calcium signalling and/or ERK1/2 phosphorylation via PAR2. METHODS: Using a trypsin-specific activity-based probe, we detected three distinct enzymes that were isolated using ion-exchange chromatography. Each enzyme was sequenced by mass spectometery (deconvoluted with an expressed sequence tag library), evaluated kinetically for its substrate/inhibitor profile and assessed for its ability to activate PAR2 signalling. FINDINGS: Each of the three serine proteinase activity-based probe-labelled enzymes isolated was biochemically distinct, with different enzyme kinetic profiles and primary amino acid sequences. The three enzymes showed a 57%-71% sequence identity with a proteinase previously cloned from the American cockroach (Per a 10). Each enzyme was found to activate both Ca++ and MAPK signalling via PAR2. CONCLUSIONS AND RELEVANCE: We have identified three different serine proteinases from the German cockroach that may, via PAR2 activation, play different roles for allergen sensitization in vivo and may represent attractive therapeutic targets for asthma.

Synaptic dysfunction, memory deficits and hippocampal atrophy due to ablation of mitochondrial fission in adult forebrain neurons.

Well-balanced mitochondrial fission and fusion processes are essential for nervous system development. Loss of function of the main mitochondrial fission mediator, dynamin-related protein 1 (Drp1), is lethal early during embryonic development or around birth, but the role of mitochondrial fission in adult neurons remains unclear. Here we show that inducible Drp1 ablation in neurons of the adult mouse forebrain results in progressive, neuronal subtype-specific alterations of mitochondrial morphology in the hippocampus that are marginally responsive to antioxidant treatment. Furthermore, DRP1 loss affects synaptic transmission and memory function. Although these changes culminate in hippocampal atrophy, they are not sufficient to cause neuronal cell death within 10 weeks of genetic Drp1 ablation. Collectively, our in vivo observations clarify the role of mitochondrial fission in neurons, demonstrating that Drp1 ablation in adult forebrain neurons compromises critical neuronal functions without causing overt neurodegeneration.

Effects of escitalopram on plasma concentrations of aripiprazole and its active metabolite, dehydroaripiprazole, in Japanese patients.

INTRODUCTION: The effects of escitalopram (10 mg/d) coadministration on plasma concentrations of aripiprazole and its active metabolite, dehydroaripiprazole, were studied in 13 Japanese psychiatric patients and compared with those of paroxetine (10 mg/d) coadministration. METHODS: The patients had received 6-24 mg/d of aripiprazole for at least 2 weeks. Patients were randomly allocated to one of 2 treatment sequences: paroxetine-escitalopram (n=6) or escitalopram-paroxetine (n=7). Each sequence consisted of two 2-week phases. Plasma concentrations of aripiprazole and dehydroaripiprazole were measured using liquid chromatography with mass spectrometric detection. RESULTS: Plasma concentrations of aripiprazole and the sum of aripiprazole and dehydroaripiprazole during paroxetine coadministration were 1.7-fold (95% confidence intervals [CI], 1.3-2.1, p<0.001) and 1.5-fold (95% CI 1.2-1.9, p<0.01) higher than those values before the coadministration. These values were not influenced by escitalopram coadministration (1.3-fold, 95% CI 1.1-1.5 and 1.3-fold, 95% CI 1.0-1.5). Plasma dehydroaripiprazole concentrations remained constant during the study. CONCLUSION: The present study suggests that low doses of escitalopram can be safely coadministered with aripiprazole, at least from a pharmacokinetic point of view.

Biased signalling and proteinase-activated receptors (PARs): targeting inflammatory disease.

Although it has been known since the 1960s that trypsin and chymotrypsin can mimic hormone action in tissues, it took until the 1990s to discover that serine proteinases can regulate cells by cleaving and activating a unique four-member family of GPCRs known as proteinase-activated receptors (PARs). PAR activation involves the proteolytic exposure of its N-terminal receptor sequence that folds back to function as a 'tethered' receptor-activating ligand (TL). A key N-terminal arginine in each of PARs 1 to 4 has been singled out as a target for cleavage by thrombin (PARs 1, 3 and 4), trypsin (PARs 2 and 4) or other proteases to unmask the TL that activates signalling via Gq , Gi or G12 /13 . Similarly, synthetic receptor-activating peptides, corresponding to the exposed 'TL sequences' (e.g. SFLLRN-, for PAR1 or SLIGRL- for PAR2) can, like proteinase activation, also drive signalling via Gq , Gi and G12 /13 , without requiring receptor cleavage. Recent data show, however, that distinct proteinase-revealed 'non-canonical' PAR tethered-ligand sequences and PAR-activating agonist and antagonist peptide analogues can induce 'biased' PAR signalling, for example, via G12 /13 -MAPKinase instead of Gq -calcium. This overview summarizes implications of this 'biased' signalling by PAR agonists and antagonists for the recognized roles the PARs play in inflammatory settings.

A predictive factor of insufficient liver regeneration after preoperative portal vein embolization.

BACKGROUND: Preoperative portal vein embolization (PVE) is performed to enhance the future remnant liver function (FRLF) and volume (FRLV). However, the volume of the nonembolized liver does not increase enough in some patients, which results in an insufficient FRLF. The aim of this study was to evaluate the predictors of insufficient FRLF after PVE for extended hepatectomy. METHODS: This retrospective study included 172 patients (107 patients with cholangiocarcinoma, 40 patients with metastatic liver cancer and 25 patients with hepatocellular carcinoma) who underwent PVE before extended hepatectomy. The total liver function was evaluated by measuring the indocyanine green plasma clearance rate (KICG). Computed tomography volumetry was conducted to evaluate the total liver volume and FRLV. The KICG of the future remnant liver (remK) was calculated using the following formula: KICG × FRLV/total liver volume. The safety margin for hepatectomy was set at remK after PVE (post-PVE remK) ≥ 0.05. RESULTS: One hundred and twenty-three patients with a post-PVE remK level of >0.05 underwent hepatectomy without postoperative liver failure [sufficient liver regeneration (SLR) group], and 9 patients with a post-PVE remK level of <0.05 did not due to insufficient FRLF [insufficient liver regeneration (ILR) group]. In the SLR group, the KICG values did not change after PVE (median, 0.144-0.146, p = 0.523); however, the %FRLV and remK increased significantly (35.0-44.3%, p < 0.001 and 0.0488-0.0610, p < 0001, respectively). In contrast, in the ILR group, the KICG values decreased significantly (0.128-0.108, p = 0.021) and the %FRLV increased marginally (27.4-32.6%, p = 0.051). As a result, the remK did not increase significantly (0.0351-0.0365, p = 0.213). A receiver operating characteristic curve demonstrated an remK value of 0.04 obtained before PVE (pre-PVE remK) to be the optimal cutoff point for defective liver regeneration. The univariate and multivariate analyses revealed that a pre-PVE remK value of <0.04 was a factor for ILR. It was also correlated with postoperative liver failure in the analysis of the patients who underwent hepatectomy. CONCLUSIONS: The patients in the ILR group did not achieve SLR after PVE due to a significant decrease in the KICG and an insufficient increase in %FRLV. A pre-PVE remK value of <0.04 is a useful predictor of insufficient regeneration of the nonembolized liver, even after PVE.

Perivascular adipose tissue-derived relaxing factors: release by peptide agonists via proteinase-activated receptor-2 (PAR2) and non-PAR2 mechanisms.

BACKGROUND AND PURPOSE: We hypothesized that proteinase-activated receptor-2 (PAR2)-mediated vasorelaxation in murine aorta tissue can be due in part to the release of adipocyte-derived relaxing factors (ADRFs). EXPERIMENTAL APPROACH: Aortic rings from obese TallyHo and C57Bl6 intact or PAR2-null mice either without or with perivascular adipose tissue (PVAT) were contracted with phenylephrine and relaxation responses to PAR2-selective activating peptides (PAR2-APs: SLIGRL-NH(2) and 2-furoyl-LIGRLO-NH(2) ), trypsin and to PAR2-inactive peptides (LRGILS-NH(2) , 2-furoyl-OLRGIL-NH(2) and LSIGRL-NH(2) ) were measured. Relaxation was monitored in the absence or presence of inhibitors that either alone or in combination were previously shown to inhibit ADRF-mediated responses: L-NAME (NOS), indomethacin (COX), ODQ (guanylate cyclase), catalase (H(2) O(2) ) and the K(+) channel-targeted reagents, apamin, charybdotoxin, 4-aminopyridine and glibenclamide. KEY RESULTS: Endothelium-intact PVAT-free preparations did not respond to PAR2-inactive peptides (LRGILS-NH(2) , LSIGRL-NH(2) , 2-furoyl-OLRGIL-NH(2) ), whereas active PAR2-APs (SLIGRL-NH(2) ; 2-furoyl-LIGRLO-NH(2) ) caused an L-NAME-inhibited relaxation. However, in PVAT-containing preparations treated with L-NAME/ODQ/indomethacin together, both PAR2-APs and trypsin caused relaxant responses in PAR2-intact, but not PAR2-null-derived tissues. The PAR2-induced PVAT-dependent relaxation (SLIGRL-NH(2) ) persisted in the presence of apamin plus charybdotoxin, 4-aminopyridine and glibenclamide, but was blocked by catalase, implicating a role for H(2) O(2) . Surprisingly, the PAR2-inactive peptides, LRGILS-NH(2) and 2-furoyl-OLRGIL-NH(2) (but not LSIGRL-NH(2) ), caused relaxation in PVAT-containing preparations from both PAR2-null and PAR2-intact (C57Bl, TallyHo) mice. The LRGILS-NH(2) -induced relaxation was distinct from the PAR2 response, being blocked by 4-aminopyridine, but not catalase. CONCLUSIONS: Distinct ADRFs that may modulate vascular tone in pathophysiological settings can be released from murine PVAT by both PAR2-dependent and PAR2-independent mechanisms.

Successful renal transplantation for a patient with pyoderma gangrenosum.

Pyoderma gangrenosum (PG), a rare skin disease of unknown etiology, forms intractable skin ulcers at surgical or traumatic sites. This case is a 40-year-old woman with PG who experienced end-stage renal disease due to type 1 diabetes mellitus. Arteriovenous fistula (AVF) creation and peritoneal dialysis introduction were considered to be difficult, because this patient had a history of developing intractable aseptic ulcers at surgical sites. Therefore, she continued hemodialysis via a temporary catheter. With frequent catheter exchange, there was stenosis of both the femoral veins and the internal jugular vein. Therefore, a hemodialysis catheter that could be used for the long term was inserted into the left jugular vein as a final site. To prevent the patient not being able to continue hemodialysis, we performed a kidney transplantation to save her life. We performed a blood type-compatible, living donor kidney transplantation after confirming the absence of active skin lesions. The 69-year-old donor was her mother. Induction immunotherapy started with tacrolimus, mycophenolate mofetil, steroids, and basiliximab. Intravenous pulses of methylprednisolone were performed to prevent ulceration of the surgical site on days 0-2 (500 mg/d). The postoperative course was excellent. After the operation, ulceration of the surgical site was never observed. The serum creatinine value was 0.87 mg/dL at 6 months. To our knowledge, renal transplantations for a patient with PG has not been previously reported.

A potent and selective p38 inhibitor protects against bone damage in murine collagen-induced arthritis: a comparison with neutralization of mouse TNFalpha.

BACKGROUND AND PURPOSE: The p38 kinase regulates the release of proinflammatory cytokines including tumour-necrosis factor-alpha (TNFalpha) and is regarded as a potential therapeutic target in rheumatoid arthritis (RA). Using the novel p38 inhibitor Org 48762-0, we investigated the therapeutic potential of p38 inhibition and compared this to anti-mouse (m)TNFalpha antibody treatment in murine collagen-induced arthritis (CIA). EXPERIMENTAL APPROACH: Pharmacological profiles of Org 48762-0 were characterized in kinase assays, cellular assays and in lipopolysaccharide (LPS)-induced inflammation in mice. The effects of Org 48762-0 and of mTNFalpha-neutralization on established arthritis were examined in murine CIA. KEY RESULTS: Org 48762-0 potently inhibited p38alpha kinase with a high degree of kinase selectivity. In cellular assays, Org 48762-0 reduced LPS-induced TNFalpha release. Oral administration of Org 48762-0 in mice showed drug-like pharmacokinetic properties and inhibited LPS-induced cytokine production. These pharmacological characteristics of Org 48762-0 prompted a comparison of therapeutic efficacy with mTNFalpha-neutralization in CIA. Org 48762-0 and anti-mTNFalpha antibody treatment equally inhibited development of arthritis when evaluated macroscopically. Radiological analyses revealed protection against bone damage for both treatments, although statistical difference was reached with Org 48762-0 treatment only. Further, micro-computed tomographical and histopathological analyses confirmed the protective effects of Org 48762-0 on joint damage. CONCLUSIONS AND IMPLICATIONS: Pharmacological targeting of p38 kinase provided good protection against joint tissue damage in CIA. In our experiments, neutralization of mTNFalpha produced less prominent suppression of bone damage. Our data suggest a therapeutic potential for selective and potent p38 inhibitors in RA.

Genetic and epigenetic alterations in myelodysplastic syndrome.

Myelodysplastic syndrome (MDS) is a clonal disorder characterized by dyshematopoiesis and high susceptibility to acute myeloid leukemia (AML). As patients with MDS have widely variable prognosis, we need to stratify them according to chromosomal abnormalities, genetic alterations, and epigenetic deregulations associated with progression to AML in order to treat these patients appropriately. Recently, evidence has been accumulating on the molecular mechanism underlying self-renewal of stem cells. Specifically, we have been focusing on Polycomb-group (PcG) genes, which play an important role in supporting self-renewal. There is emerging evidence indicating that the PcG complexes are indispensable for sustaining stem cell activity and cancer stem cells. We have reported that the expression of BMI1, a member of PcG, in hematopoietic stem cells or progenitor cells predicts the prognosis of patients with MDS and progression to acute leukemia. And recent genome-wide analyses showed that major transcriptional regulators governing development are under the regulation of PcG complexes. Thus PcG not only provides a molecular marker for monitoring disease progression of MDS, but also provides a clue for elucidating a molecular mechanism underlying the disease progression, which may help in the development of a new therapeutic strategy against MDS. Herein, we describe cytogenetic, genetic and molecular aberrations in MDS, focusing on epigenetic alterations through PcG.