203 research outputs found

    Use of intraventricular ribbon gauze to reduce particulate emboli during aortic valve replacement

    Get PDF
    BACKGROUND: The incidence of cerebrovascular accidents following aortic valve surgery remains a devastating complication. The aim of this study was to determine the number of potential embolic material arising during aortic valve replacement and to examine the efficacy of using ribbon gauze in the left ventricle during removal of the native valve and decalcification of the aortic annulus. METHODS: Ribbon gauze was inserted into the left ventricular cavity prior to aortic valve excision in an unselected, prospectively studied series of 30 patients undergoing aortic valve replacement. A further 30 lengths of ribbon gauze were soaked in the pericardiotomy blood of the same patients and all were subjected to histological analysis. RESULTS: The median number of tissue fragments from the aortic valve replacement group was significantly higher than in the control group 5 (0–18) versus 0 (0–1) (p = 3.6 Γ— 10(-5)). The size of tissue fragments varied between 0.1 and 9.0 mm with a mean of 0.61 Β± 1.12 mm and a median of 0.2 mm. There was a significantly higher number of tissue fragments associated with patients having surgery for aortic stenosis when compared with patients who had aortic regurgitation with median of 5 (0–18) versus 0 (0–3) (p = 0.8 Γ— 10(-3)). CONCLUSION: Significant capture of particulate debris by the intraventricular ribbon gauze suggests that the technique of left ventricular ribbon gauze insertion during aortic valve excision has merit

    Granulomatous Reactivation during the Course of a Leprosy Infection: Reaction or Relapse

    Get PDF
    Leprosy is a serious infectious disease whose treatment still poses some challenges. Patients are usually treated with a combination of antimicrobial drugs called multidrug therapy. Although this treatment is effective against Mycobacterium leprae, the bacillus that causes leprosy, patients may develop severe inflammatory reactions during treatment. These reactions may be either attributed to an improvement in the immunological reactivity of the patient along with the treatment, or to relapse of the disease due to the proliferation of remaining bacilli. In certain patients these two conditions may be difficult to differentiate. The present study addresses the histopathology picture of and the M. leprae bacilli in sequential biopsies taken from lesions of patients who presented such reactions aiming to improve the differentiation of the two conditions. This is important because these reactions are one of the major causes of the disabilities of the patients with leprosy, and should be treated early and appropriately. Our results show that the histopathology picture alone is not sufficient, and that bacilli's counting is necessary

    No Detectable Fertility Benefit from a Single Additional Mating in Wild Stalk-Eyed Flies

    Get PDF
    Background: Multiple mating by female insects is widespread, and the explanation(s) for repeated mating by females has been the subject of much discussion. Females may profit from mating multiply through direct material benefits that increase their own reproductive output, or indirect genetic benefits that increase offspring fitness. One particular direct benefit that has attracted significant attention is that of fertility assurance, as females often need to mate multiply to achieve high fertility. This hypothesis has never been tested in a wild insect population.Methodology/Principal Findings: Female Malaysian stalk-eyed flies (Teleopsis dalmanni) mate repeatedly during their lifetime, and have been shown to be sperm limited under both laboratory and field conditions. Here we ask whether receiving an additional mating alleviates sperm limitation in wild females. In our experiment one group of females received a single additional mating, while a control group received an interrupted, and therefore unsuccessful, mating. Females that received an additional mating did not lay more fertilised eggs in total, nor did they lay proportionately more fertilised eggs. Female fertility declined significantly through time, demonstrating that females were sperm limited. However, receipt of an additional mating did not significantly alter the rate of this decline.Conclusions/Significance: Our data suggest that the fertility consequences of a single additional mating were small. We discuss this effect (or lack thereof), and suggest that it is likely to be attributed to small ejaculate size, a high proportion of failed copulations, and the presence of X-linked meiotic drive in this species

    EGFR Inhibition in Glioma Cells Modulates Rho Signaling to Inhibit Cell Motility and Invasion and Cooperates with Temozolomide to Reduce Cell Growth

    Get PDF
    Enforced EGFR activation upon gene amplification and/or mutation is a common hallmark of malignant glioma. Small molecule EGFR tyrosine kinase inhibitors, such as erlotinib (Tarceva), have shown some activity in a subset of glioma patients in recent trials, although the reported data on the cellular basis of glioma cell responsiveness to these compounds have been contradictory. Here we have used a panel of human glioma cell lines, including cells with amplified or mutant EGFR, to further characterize the cellular effects of EGFR inhibition with erlotinib. Dose-response and cellular growth assays indicate that erlotinib reduces cell proliferation in all tested cell lines without inducing cytotoxic effects. Flow cytometric analyses confirm that EGFR inhibition does not induce apoptosis in glioma cells, leading to cell cycle arrest in G1. Interestingly, erlotinib also prevents spontaneous multicellular tumour spheroid growth in U87MG cells and cooperates with sub-optimal doses of temozolomide (TMZ) to reduce multicellular tumour spheroid growth. This cooperation appears to be schedule-dependent, since pre-treatment with erlotinib protects against TMZ-induced cytotoxicity whereas concomitant treatment results in a cooperative effect. Cell cycle arrest in erlotinib-treated cells is associated with an inhibition of ERK and Akt signaling, resulting in cyclin D1 downregulation, an increase in p27kip1 levels and pRB hypophosphorylation. Interestingly, EGFR inhibition also perturbs Rho GTPase signaling and cellular morphology, leading to Rho/ROCK-dependent formation of actin stress fibres and the inhibition of glioma cell motility and invasion

    Surgical reconstruction of the left main coronary artery with patch-angioplasty

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Conventional coronary artery bypass grafting (CABG) has been established as the treatment of choice for left main coronary artery (LMCA) stenosis However, the conventional grafting provides a retrograde perfusion to extensive myocardial area and leads prospectively to competitive flow of the non-occluded coronaries thus consuming the grafts. Surgical reconstruction of the LMCA with patch-angioplasty is an alternative method that eliminates these drawbacks.</p> <p>Methods</p> <p>Between February 1997 and July 2007, 37 patients with isolated LMCA stenosis were referred for surgical ostial reconstruction. In 27 patients (73%) surgical angioplasties have been performed. All patients were followed up clinically and with transesophageal echocardiography (TEE) and coronary angiography when required.</p> <p>Results</p> <p>In 10 patients (27%) a LMCA stenosis could not be confirmed. There were no early mortality or perioperative myocardial infarctions. The postoperative course was uneventful in all patients. In 25 patients, TEE demonstrated a wide open main stem flow pattern one to six months after reconstruction of the left main coronary artery with one patch mild aneurysmal dilated.</p> <p>Conclusions</p> <p>The surgical reconstruction with patch-angioplasty is a safe and effective method for the treatment of proximal and middle LMCA stenosis. Almost one third of the study group had no really LMCA stenosis: antegrade flow pattern remained sustained and the arterial grafts have been spared. In the cases of unclear or suspected LMCA stenosis, cardio-CT can be performed to unmask catheter-induced coronary spasm as the underlying reason for isolated LMCA stenosis.</p

    Multiplex PCR technique could be an alternative approach for early detection of leprosy among close contacts - a pilot study from India

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Implementation of Multi drug Therapy (MDT) regimen has resulted in the decline of the total number of leprosy cases in the world. Though the prevalence rate has been declining, the incidence rate remains more or less constant and high in South East Asian countries particularly in India, Nepal, Bangladesh, Pakistan and Srilanka. Leprosy, particularly that of multibacillary type spreads silently before it is clinically detected. An early detection and treatment would help to prevent transmission in the community. Multiplex PCR (M-PCR) technique appears to be promising towards early detection among contacts of leprosy cases.</p> <p>Methods</p> <p>A total of 234 paucibacillary (PB) and 205 multibacillary (MB) leprosy cases were studied in a community of an endemic area of Bankura district of West Bengal (Eastern India). They were assessed by smear examination for acid-fast bacilli (AFB) and M-PCR technique. These patients were treated with Multidrug Therapy (MDT) as prescribed by WHO following detection. A total of 110 MB and 72 PB contacts were studied by performing M-PCR in their nasal swab samples.</p> <p>Results</p> <p>83.4% of MB patients were observed to be positive by smear examination for AFB and 89.2% by M-PCR. While 22.2% of PB patients were found to be positive by smear examination for AFB, 80.3% of these patients were positive by M-PCR. Among leprosy contacts (using M-PCR), 10.9% were found to be positive among MB contacts and 1.3% among PB contacts. Interestingly, two contacts of M-PCR positive MB cases developed leprosy during the period of two years follow up.</p> <p>Conclusion</p> <p>The M-PCR technique appears to be an efficient tool for early detection of leprosy cases in community based contact tracing amongst close associates of PB and MB cases. Early contact tracing using a molecular biology tool can be of great help in curbing the incidence of leprosy further.</p

    The Effect of Plant Inbreeding and Stoichiometry on Interactions with Herbivores in Nature: Echinacea angustifolia and Its Specialist Aphid

    Get PDF
    Fragmentation of once widespread communities may alter interspecific interactions by changing genetic composition of interacting populations as well as their abundances and spatial distributions. In a long-term study of a fragmented population of Echinacea angustifolia, a perennial plant native to the North American prairie, we investigated influences on its interaction with a specialist aphid and tending ants. We grew plant progeny of sib-matings (I), and of random pairings within (W) and between (B) seven remnants in a common field within 8 km of the source remnants. During the fifth growing season, we determined each plant's burden of aphids and ants, as well as its size and foliar elemental composition (C, N, P). We also assayed composition (C, N) of aphids and ants. Early in the season, progeny from genotypic classes B and I were twice as likely to harbor aphids, and in greater abundance, than genotypic class W; aphid loads were inversely related to foliar concentration of P and positively related to leaf N and plant size. At the end of the season, aphid loads were indistinguishable among genotypic classes. Ant abundance tracked aphid abundance throughout the season but showed no direct relationship with plant traits. Through its potential to alter the genotypic composition of remnant populations of Echinacea, fragmentation can increase Echinacea's susceptibility to herbivory by its specialist aphid and, in turn, perturb the abundance and distribution of aphids

    Effectiveness of YouRAction, an Intervention to Promote Adolescent Physical Activity Using Personal and Environmental Feedback: A Cluster RCT

    Get PDF
    Background: In this study the one and six months effects of the computer-tailored YouRAction (targeting individual level determinants) and YouRAction+e (targeting in addition perceived environmental determinants) on compliance with the moderate-to-vigorous physical activity (MVPA) guideline and weight status are examined. In addition the use and appreciation of both interventions are studied. Methods: A three-armed cluster randomized trial was conducted in 2009-2010 with measurements at baseline, one and six months post intervention. School classes were assigned to one of the study arms (YouRaction, YouRAction+e and Generic Information (GI) control group). MVPA was derived from self-reports at baseline, one and six months post intervention. Body Mass Index and waist circumference were measured at baseline and six months post intervention in a random sub-sample of the population. Use of the interventions was measured by webserver logs and appreciation by self-reports. Multilevel regression analyses were conducted to study the effects of the intervention against the GI control group. ANOVA's and chi-square tests were used to describe differences in use and appreciation between study arms. Results: There were no statistically significant intervention effects on compliance with the MVPA guideline, overweight or WC. Access to the full intervention was significantly lower for YouRAction (24.0%) and YouRAction+e (21.7%) compared to the GI (54.4%). Conclusion: This study could not demonstrate that the YouRAction and YouRAction+e interventions were effective in promoting MVPA or improve anthropometric outcomes among adolescents, compared to generic information. Insufficient use and exposure to the intervention content may be an explanation for the lack of effects

    The Non-Catalytic Carboxyl-Terminal Domain of ARFGAP1 Regulates Actin Cytoskeleton Reorganization by Antagonizing the Activation of Rac1

    Get PDF
    The regulation of the actin cytoskeleton and membrane trafficking is coordinated in mammalian cells. One of the regulators of membrane traffic, the small GTP-binding protein ARF1, also activates phosphatidylinositol kinases that in turn affect actin polymerization. ARFGAP1 is a GTPase activating protein (GAP) for ARF1 that is found on Golgi membranes. We present evidence that ARFGAP1 not only serves as a GAP for ARF1, but also can affect the actin cytoskeleton.As cells attach to a culture dish foci of actin appear prior to the cells flattening and spreading. We have observed that overexpression of a truncated ARFGAP1 that lacks catalytic activity for ARF, called GAP273, caused these foci to persist for much longer periods than non-transfected cells. This phenomenon was dependent on the level of GAP273 expression. Furthermore, cell spreading after re-plating or cell migration into a previously scraped area was inhibited in cells transfected with GAP273. Live cell imaging of such cells revealed that actin-rich membrane blebs formed that seldom made protrusions of actin spikes or membrane ruffles, suggesting that GAP273 interfered with the regulation of actin dynamics during cell spreading. The over-expression of constitutively active alleles of ARF6 and Rac1 suppressed the effect of GAP273 on actin. In addition, the activation of Rac1 by serum, but not that of RhoA or ARF6, was inhibited in cells over-expressing GAP273, suggesting that Rac1 is a likely downstream effector of ARFGAP1. The carboxyl terminal 65 residues of ARFGAP1 were sufficient to produce the effects on actin and cell spreading in transfected cells and co-localized with cortical actin foci.ARFGAP1 functions as an inhibitor upstream of Rac1 in regulating actin cytoskeleton. In addition to its GAP catalytic domain and Golgi binding domain, it also has an actin regulation domain in the carboxyl-terminal portion of the protein
    • …
    corecore