In vitro effects of wound-dressings on key wound healing properties of dermal fibroblasts

Healing of complex wounds requires dressings that must, at least, not hinder and should ideally promote the activity of key healing cells, in particular fibroblasts. This in vitro study assessed the effects of three wound-dressings (a pure Ca2+ alginate: Algostéril®, a Ca2+ alginate + carboxymethylcellulose: Biatain alginate® and a polyacrylate impregnated with lipido-colloid matrix: UrgoClean®) on dermal fibroblast activity. The results showed the pure calcium alginate to be non-cytotoxic, whereas the other wound-dressings showed moderate to strong cytotoxicity. The two alginates stimulated fibroblast migration and proliferation, whereas the polyacrylate altered migration and had no effect on proliferation. The pure Ca2+ alginate significantly increased the TGF-β-induced fibroblast activation, which is essential to healing. This activation was confirmed by a significant increase in Vascular endothelial growth factor (VEGF) secretion and a higher collagen production. The other dressings reduced these fibroblast activities. The pure Ca2+ alginate was also able to counteract the inhibitory effect of NK cell supernatants on fibroblast migration. These in vitro results demonstrate that tested wound-dressings are not equivalent for fibroblast activation. Only Algostéril was found to promote all the fibroblast activities tested, which could contribute to its healing efficacy demonstrated in the clinic.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research priorities for ultra-rare inherited bleeding disorders

BACKGROUND

Ultra-rare inherited bleeding disorders (BDs) present important challenges for generating a strong evidence foundation for optimal diagnosis and management. Without disorder-appropriate treatment, affected individuals potentially face life-threatening bleeding, delayed diagnosis, suboptimal management of invasive procedures, psychosocial distress, pain, and decreased quality-of-life.

RESEARCH DESIGN AND METHODS

The National Hemophilia Foundation (NHF) and the American Thrombosis and Hemostasis Network identified the priorities of people with inherited BDs and their caregivers, through extensive inclusive community consultations, to inform a blueprint for future decades of research. Multidisciplinary expert Working Group (WG) 3 distilled highly feasible transformative ultra-rare inherited BD research opportunities from the community-identified priorities.

RESULTS

WG3 identified three focus areas with the potential to advance the needs of all people with ultra-rare inherited BDs and scored the feasibility, impact, and risk of priority initiatives, including 13 in systems biology and mechanistic science; 2 in clinical research, data collection, and research infrastructure; and 5 in the regulatory process for novel therapeutics and required data collection.

CONCLUSIONS

Centralization and expansion of expertise and resources, flexible innovative research and regulatory approaches, and inclusion of all people with ultra-rare inherited BDs and their health care professionals will be essential to capitalize on the opportunities outlined herein.

Totum-854 reduction of blood pressure is associated with tissue remodeling in aorta and heart of SHR rat

Introduction and purpose

Arterial Hypertension (AHT) is a major cause of premature death worldwide. We have developed Totum-854 (T-854), a polyphenol-rich botanical composition to reduce the risk of developing AHT. We assessed the acute and chronic effects on blood pressure in spontaneous hypertensive rats (SHR).

Method

Acute protocol: 12-week-old SHR rats received randomly in a cross-over design, a dose of vehicle (VEH, 1% Tween 20), Captopril (50mg/kg) and T-854 (1250mg/kg) per os with at least 48h-wash-out interval between two gavages. Arterial pressure was recorded during 24h post-gavage, thanks to a radio-telemetry device (HD-S10, DSI) directly into the abdominal aorta. Baseline arterial pressure was measured before oral gavage during 90 min.

Chronic study

18-week-old SHR rats received vehicle (VEH, 1% Tween 20) or T-854 (1000mg/kg) per os once a day for 8 weeks. Arterial pressure was recorded before the oral gavage for 90 min once a week with a radio-telemetry device (HD-S10, DSI). Delta (Δ) SBP and ΔDBP were calculated by subtracting baseline blood pressure (before the start of oral gavage) to measured blood pressure every week. At the end of supplementation, rats were euthanized, and aorta and heart were sampled. Aorta was embedded in paraffin and Masson's trichrome staining was performed in slides obtained by a microtome. Media thickness was measured with ImageJ. For the heart, mRNA was extracted using Trizol and cardiac hypertrophy/fibrosis gene expression was evaluated by RT-qPCR.

Results

Acute supplementation with T-854 exhibited an intermediate profile between VEH and Captopril response for change in SBP and DBP curves. SBP and DBP were reduced in comparison to VEH with 24h-AUC decreased by 93.6±67.8 mmHg h and 70.8±54.6 mmHg h for captopril and T-854, respectively.

When T-854 was administered chronically during 8 weeks, ΔSBP and ΔDBP evolution were significantly different in comparison to VEH group (p<0.05). These curves were maintained under vehicle curves from the 2nd week of supplementation and until the end of the study. After 8 weeks of T-854 supplementation, tissue analysis showed a decrease of 10% on the aorta media thickness in T-854 supplemented rats (p<0.05). Cardiac MMP-2 gene expression was also lower in T-854 group compared to VEH (p=0.059).

Conclusion

T-854 24h-post-gavage acute effect on blood pressure in hypertensive SHR rats suggests a rapid effect, with a decrease in blood pressure few hours after oral administration. Moreover, chronic T-854 supplementation prevents AHT development in SHR. In conclusion, T-854 appears as an efficient strategy to prevent HTA suggesting also a protective role of T-854 on vascular and heart structure and function.

Funding Acknowledgement

Type of funding sources: None.

Totum-070 prevents diet-induced hypercholesterolemia in western diet fed mice and inhibits cholesterol uptake in human enterocyte caco2 cell line

Introduction

It is well known that hypercholesterolemia is an important modifiable risk factor in the development of cardiovascular diseases. Lowering blood cholesterol level reduces the incidence of atherosclerotic disease. Totum-070 (T070) is a clinical stage polyphenol-rich active substance composed by the association of 5 plant extracts.

Purpose

We assessed the hypothesis that administration of T070 prevents hypercholesterolemia in western diet fed mice and explored the potential mechanisms involved in vitro in human enterocytes.

Methods

C57BL/6 mice were fed either a normal diet (ND) or western diet (WD) for 6 weeks and received either vehicle or T070 (1mg/kg or 3mg/kg) daily by gavage (n=14 mice per group). Food intake, body weight and plasma lipid were monitored along study duration. Liver and feces lipid content were quantified at the end of the study. For in vitro studies, human Caco2 cells were differentiated in transwells for 21 days. To perform cholesterol uptake assay, [1,2-3H(N)]-cholesterol was incubated in apical medium for 1 hour in presence or not of T070 prior to quantification of radioactivity in the cells.

Results

In mice, supplementation with T070 had no effect on food intake during the study. At the end of the in vivo study, body weight in WD-fed mice was increased to 28.3±0.8 g compared to the ND group (24.5±0.4 g, p<0.001). Interestingly, a significant (p<0.01) 29% reduction in body weight gain was observed in the T070 3mg/kg group compared to the WD group at the end of the study. Compared to WD group, total-cholesterol in mice supplemented by T070 was reduced in a dose dependent manner (298±8 mg/dl WD vs 276±9 mg/dl T070 1mg/kg, p=0.19, and 265±8 mg/dl T070 3mg/kg, p<0.05). Furthermore, hepatic steatosis induced by the WD was reduced by 73% (p<0.001) in the T070 3mg/kg group. Hepatic and intestinal gene expression were drastically altered by WD feeding compared to ND, while supplementation with T070 tended to restore normal expression levels for many genes implicated in lipid and lipoprotein metabolism. A significant increase in fecal cholesterol excretion was observed in mice supplemented with T070 3 mg/g compared to the mice fed with WD alone (442.3±151.7 nmol/day WD + T070 3mg/g vs 75.4±5.9 nmol/day WD, p<0.05). Studies in human enterocytes demonstrated that 1 g/l T070 reduced cholesterol uptake by 35% (p<0.001), suggesting that T070 inhibits intestinal cholesterol absorption.

Conclusion

Our results show the beneficial effect of supplementation with Totum-070 to prevent induction of hypercholesterolemia in a nutritional mouse model. Investigation of mechanisms of action in enterocytes demonstrate the role of Totum-070 to inhibit intestinal cholesterol absorption. These results highlight the interest of using Totum-070 for the management of hypercholesterolemia.

Funding Acknowledgement

Type of funding sources: None.

Disease Burden in Patients with Glanzmann's Thrombasthenia: Perspectives from the Glanzmann's Thrombasthenia Patient/Caregiver Questionnaire

Purpose

Glanzmann’s thrombasthenia (GT) is a rare bleeding disorder caused by a mutation in the αIIbβ3 integrin essential for optimal platelet function and hemostasis. The aim of this study was to identify the burden of GT on patients and caregivers through better understanding of the management and psychosocial impact of this disorder.

Patients and Methods

Participants for this online survey were recruited using a rare disease specialty recruiter from Comprehensive Health Education Services. Data were collected from January 31 through March 12, 2019. The questionnaire was designed to collect information regarding demographics, diagnosis, treatment, and psychosocial impact.

Results

Of the 45 respondents (24 patients and 21 caregivers), the majority were female (58%), white (64%), and employed full-time (53%) and had no family history of GT (64%). Many patients reported significant bruising at birth (76%), and the mean age at diagnosis was 2.6 years. About half of the patients experienced 1 bleed per day, and 13% had over 500 bleeds of any severity per year. Most bleeds were skin bruising or mouth bleeds, but patients also reported joint/muscle and gastrointestinal bleeds. Most patients reported receiving a platelet transfusion (82%), and some had developed platelet refractoriness (38%) or antibodies (32%). Common treatments were antifibrinolytics (82%) and recombinant activated factor VII (rFVIIa) (42%), likely due to the presence of antibodies. Many (58%) patients experienced issues with excessive bleeding at school; 38% reported missing school as a result. Female patients struggled to find a gynecologist with knowledge of the management of GT. Most patients were satisfied with the support they receive from their current partner (65%) and their friends (76%).

Conclusion

Most patients with GT are diagnosed early. Patients experience considerable psychosocial impact. Patient and physician education concerning treatment alternatives and the support of the GT community are critical.

Psychosocial Impact and Disease Management in Patients with Congenital Factor VII Deficiency

Purpose

Congenital factor VII (FVII) deficiency is a rare bleeding disorder of variable phenotype with predominantly mucocutaneous bleeding. The aim of this study was to identify the burden of FVII deficiency on patients and caregivers through a better understanding of the management and psychosocial impact of this disease.

Materials and Methods

A rare disease specialty recruiter from Comprehensive Health Education Services recruited participants for this online survey, which was conducted from January 31 to March 12, 2019. A moderator-assisted questionnaire was used to collect data on demographics, diagnosis, treatment, and psychosocial impact.

Results

Of the 45 respondents (25 patients and 20 caregivers), the majority were female (56%). Respondents reported a wide variety of initial bleeding symptoms, including bruising (58%), epistaxis (56%), and menorrhagia (36% of females). Because symptoms varied between individuals and were not always severe, diagnosis was often delayed. Mean time to obtain a diagnosis was 6.5 years and mean age at first diagnosis was 12.9 years. One-quarter (24%) of the respondents reported more than 100 bleeds of any severity over the previous year. When treating bleeds, 44% of patients reported using antifibrinolytics, and 42% reported using recombinant activated factor VII. Almost 31% of respondents reported missing schooldays as children, and 16% reported losing or resigning from a job in adulthood as a direct result of their disease. Notably, 29% of caregivers and 10% of their partners had also experienced issues with employment. Forty percent of respondents reported not participating in contact sports during childhood, and 22% continued to avoid contact sports in adulthood.

Conclusion

Overall, FVII deficiency has a substantial psychosocial impact, but most patients are satisfied with their disease management and are optimistic about their future. Patients desire additional educational, social, and financial support.

Phenotypical variability in congenital FVII deficiency follows the ISTH-SSC severity classification guidelines: a review with illustrative examples from the clinic

Background

One of the most common rare inherited bleeding disorders, congenital factor VII (FVII) deficiency typically has a milder bleeding phenotype than other rare bleeding disorders. Categorizing severity in terms of factor activity associated with hemophilia (severe <1%, moderate 1%–5%, mild 6%–40%) has led to the observation that bleeding phenotype does not follow closely with FVII activity. Over the past decade, large-scale global registries have investigated bleeding phenotype more thoroughly. The International Society on Thrombosis and Haemostasis has reclassified FVII deficiency as follows: severe, FVII <10%, risk of spontaneous major bleeding; moderate, FVII 10%–20%, risk of mild spontaneous or triggered bleeding; mild, FVII 20%–50%, mostly asymptomatic disease.

Case reports

Eleven illustrative cases of congenital FVII deficiency adapted from clinical practice are described to demonstrate the variability in presentation and in relation to FVII activity levels. Severe FVII deficiency usually presents at a young age and carries the risk of intracranial hemorrhage, hemarthrosis, and other major bleeds. Moderate FVII deficiency tends to present later, often in adolescence and particularly in girls as they reach menarche. Milder disease may not be apparent until found incidentally on preoperative testing, during pregnancy/childbirth, or following unexplained bleeding when faced with hemostatic challenges.

Conclusion

It is important for health care professionals to be aware of the new definitions of severity and typical presentations of congenital FVII deficiency. Failure to appreciate the risks of major bleeding, including intracerebral hemorrhage in those with FVII activity <10%, may put particularly young children at risk.

Impact of mild to severe hemophilia on education and work by US men, women, and caregivers of children with hemophilia B: The Bridging Hemophilia B Experiences, Results and Opportunities into Solutions (B-HERO-S) study

The psychosocial impact of hemophilia on work was recently investigated in the Hemophilia Experiences, Results and Opportunities (HERO) study. The findings revealed that hemophilia had an impact for adults with moderate/severe hemophilia and caregivers of children with hemophilia. HERO did not specifically evaluate impact on education in adults/children with mild/moderate hemophilia or the impact on employment of spouses/partners of caregivers of affected children. The Bridging Hemophilia B Experiences, Results and Opportunities into Solutions (B-HERO-S) study evaluated the impact of hemophilia on the lives of adult men/women with mild-severe hemophilia B and caregivers of boys/girls with hemophilia B and their spouses/partners. Many adults with hemophilia B (94%) reported that hemophilia had a negative effect on their ability to complete a formal education, often attributed to the inability to attend or concentrate in school as a result of hemophilia-related bleeding or pain. Most adults with hemophilia B (95%) and caregivers/partners (89%/84%) indicated that hemophilia had a negative impact on employment. Most adults with hemophilia were employed (81%), with construction/manufacturing (35%) as the most frequently reported industry; many worked in jobs requiring manual labor (39%). Of those unemployed, 62% never worked, and those who stopped working reported that they left the workforce due to financial issues (59%), including insurance coverage/co-pays, or hemophilia-related issues (55%). Nearly one-third of caregivers voluntarily left the workforce to care for children with hemophilia. These results suggest a need to focus more effort on career counseling for adults with hemophilia B and caregivers of affected children, especially around mild/moderate hemophilia, as this population may not be as well informed regarding potential impact in school and the workplace.

Impact of mild to severe hemophilia on engagement in recreational activities by US men, women, and children with hemophilia B: The Bridging Hemophilia B Experiences, Results and Opportunities into Solutions (B-HERO-S) study

The psychosocial impact of hemophilia on activities was recently investigated in the Hemophilia Experiences, Results and Opportunities (HERO) study (675 people with hemophilia and 561 caregivers of children with hemophilia in 10 countries). The impact of hemophilia B may not be accurately reflected in the HERO results, as ~75% of respondents described issues affecting males with hemophilia A. To address the needs of this population, the Bridging Hemophilia B Experiences, Results and Opportunities Into Solutions (B-HERO-S) was developed as a pilot study in the United States in collaboration with the hemophilia community. The analysis reported here assessed engagement in recreational activities and changes to treatment regimens around activities as reported by 299 adults with hemophilia B and 150 caregivers of children with hemophilia B. Nearly all adults with hemophilia B (98%) experienced a negative impact on their participation in recreational activities due to hemophilia-related issues, and most caregivers (90%) reported that hemophilia B had a negative impact on their child's engagement in recreational activities. One of the main reasons identified for discontinuing past activities was the risk of bruising or bleeding (adults/children with hemophilia B, 49%/41%). In particular, adults with hemophilia B reported a history of activity-related bleeding, and most adults decreased their participation in high-risk activities as they aged. Substantial percentages of adults and children with hemophilia B (including mild/moderate severity) altered their treatment regimens to accommodate planned activities. These findings may help inform guidelines for individualizing treatment regimens around participation in recreational activities based on hemophilia severity, baseline factor level, and activity risk and intensity.

Unmet needs in the transition to adulthood: 18- to 30-year-old people with hemophilia

Young adults with hemophilia face unique challenges during the transition to adulthood, including issues associated with switching from pediatric to adult hematology care, building mature interpersonal relationships, and establishing an independent career with an assurance of medical insurance coverage. A greater understanding of these challenges is essential for developing effective strategies to address the specific needs of this population. These challenges may be differentiated from those of older adults with hemophilia in large part because of more extensive childhood prophylaxis and safer factor products, resulting in fewer joint problems and lower rates of HIV and HCV infections. This analysis of the changing nature and unmet needs of today's young adults entering into adult hemophilia treatment centers, as well as potential strategies for optimally addressing these needs, was developed following roundtable discussions between patients, caregivers, hematologists, and other health care professionals participating in comprehensive care. Challenges identified among young adults with hemophilia include psychosocial issues related to maturity, personal responsibility, and increased independence, as well as concerns regarding when and with whom to share information about one's hemophilia, limited awareness of educational and financial resources, and a low perceived value of regular hematology care. The initiatives proposed herein highlight important opportunities for health care professionals at pediatric and adult hemophilia treatment centers, as well as national organizations, community groups, and career counselors, to address key unmet needs of this patient population.

Functional connectivity of human chewing: an fcMRI study

Mastication is one of the most important orofacial functions. The neurobiological mechanisms of masticatory control have been investigated in animal models, but less so in humans. This project used functional connectivity magnetic resonance imaging (fcMRI) to assess the positive temporal correlations among activated brain areas during a gum-chewing task. Twenty-nine healthy young-adults underwent an fcMRI scanning protocol while they chewed gum. Seed-based fcMRI analyses were performed with the motor cortex and cerebellum as regions of interest. Both left and right motor cortices were reciprocally functionally connected and functionally connected with the post-central gyrus, cerebellum, cingulate cortex, and precuneus. The cerebellar seeds showed functional connections with the contralateral cerebellar hemispheres, bilateral sensorimotor cortices, left superior temporal gyrus, and left cingulate cortex. These results are the first to identify functional central networks engaged during mastication.

Abstract S6-3: Neurocognitive impact in adjuvant chemotherapy for breast cancer linked to fatigue: A Prospective functional MRI study

Background: Our previous research showed evidence of compromised cognitive function prior to adjuvant chemotherapy for breast cancer, with fatigue as a contributory factor. Fatigue is a common symptom reported by women treated for breast cancer, yet its association with neurocognitive function has not been systematically examined. In this prospective study, we examined possible alterations in neurocognitive responses, namely, working memory, from pre- to post- adjuvant treatment during functional magnetic resonance imaging (fMRI) and further investigated whether early fatigue might be linked to cognitive alterations over time.

Methods: Women treated with either adjuvant chemotherapy (anthracyline-based combination regimen, n=29) or radiotherapy (n = 37) for localized breast cancer (Stages 0-IIIa) and age-matched healthy controls (n = 32) were enrolled. Participants performed a verbal working memory task (VWMT) with varying levels of demand for cognitive control during fMRI scanning and provided self-reports of fatigue (FACT-F) at two time points coincident with pre- and one-month post chemotherapy assessments. Imaging data were analyzed with general linear models using SPM5; comparative statistics were used to determine group differences, and correlational analyses addressed relationships of fatigue and neurocognitive measures.

Findings: The chemotherapy group reported significantly greater severity of fatigue (p &lt; .05) and performed less accurately on the VWMT both pre- and one-month post-treatment than the other groups. Greater fatigue was correlated with poorer performance on the VWMT at both time points across groups, with stronger correlation post-treatment (r = −.22, p = .03). A 2 time-point (pre- vs. post-treatment) × 2 group (chemotherapy vs. controls) × 2 demand-level contrasts (high minus low vs. medium minus low) analytic model showed a significant group × time interaction (p &lt; .05), mainly due to lower pre-treatment activation in an area of the prefrontal cortex supporting working memory, the anatomical left inferior frontal gyrus (LiFG), at higher task demand in the chemotherapy group. The radiotherapy group scored between the other two groups with intermediate activation of those contrasts. Of interest, lower pre-treatment activation in the LiFG in the high-low demand contrast predicted severity of fatigue across all participants at the post-treatment assessment (r = −.27, p &lt; .01), linking early compromise in neurocognitive performance with greater fatigue over time.

Discussion: Neurocognitive alterations during a working memory task and greater fatigue were evident before any adjuvant chemotherapy for breast cancer. Notably, functional alterations in working memory processes were evident with fMRI before adjuvant chemotherapy and predicted severity of post-treatment fatigue. Importantly, across all participants, greater fatigue over time was correlated with reduced cognitive performance. Taken together, these findings indicate that pre-treatment neurocognitive compromise and fatigue are key contributors to the cognitive impact often attributed solely to chemotherapy. Early therapeutic interventions targeting fatigue may improve cognitive function and reduce the distress of “chemo brain” throughout the course of adjuvant treatment.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S6-3.

An increase in the redox state during reperfusion contributes to the cardioprotective effect of GIK solution

This study aimed at determining whether glucose-insulin-potassium (GIK) solutions modify the NADH/NAD(+) ratio during postischemic reperfusion and whether their cardioprotective effect can be attributed to this change in part through reduction of the mitochondrial reactive oxygen species (ROS) production. The hearts of 72 rats were perfused with a buffer containing glucose (5.5 mM) and hexanoate (0.5 mM). They were maintained in normoxia for 30 min and then subjected to low-flow ischemia (0.5% of the preischemic coronary flow for 20 min) followed by reperfusion (45 min). From the beginning of ischemia, the perfusate was subjected to various changes: enrichment with GIK solution, enrichment with lactate (2 mM), enrichment with pyruvate (2 mM), enrichment with pyruvate (2 mM) plus ethanol (2 mM), or no change for the control group. Left ventricular developed pressure, heart rate, coronary flow, and oxygen consumption were monitored throughout. The lactate/pyruvate ratio of the coronary effluent, known to reflect the cytosolic NADH/NAD(+) ratio and the fructose-6-phosphate/dihydroxyacetone-phosphate (F6P/DHAP) ratio of the reperfused myocardium, were evaluated. Mitochondrial ROS production was also estimated. The GIK solution improved the recovery of mechanical function during reperfusion. This was associated with an enhanced cytosolic NADH/NAD(+) ratio and reduced mitochondrial ROS production. The cardioprotection was also observed when the hearts were perfused with fluids known to increase the cytosolic NADH/NAD(+) ratio (lactate, pyruvate plus ethanol) compared with the other fluids (control and pyruvate groups). The hearts with a high mechanical recovery also displayed a low F6P/DHAP ratio, suggesting that an accelerated glycolysis rate may be responsible for increased cytosolic NADH production. In conclusion, the cardioprotection induced by GIK solutions could occur through an increase in the cytosolic NADH/NAD(+) ratio, leading to a decrease in mitochondrial ROS production.

The OptIPuter microscopy demonstrator: enabling science through a transatlantic lightpath

The OptIPuter microscopy demonstrator project has been designed to enable concurrent and remote usage of world-class electron microscopes located in Oxford and San Diego. The project has constructed a network consisting of microscopes and computational and data resources that are all connected by a dedicated network infrastructure using the UK Lightpath and US Starlight systems. Key science drivers include examples from both materials and biological science. The resulting system is now a permanent link between the Oxford and San Diego microscopy centres. This will form the basis of further projects between the sites and expansion of the types of systems that can be remotely controlled, including optical, as well as electron, microscopy. Other improvements will include the updating of the Microsoft cluster software to the high performance computing (HPC) server 2008, which includes the HPC basic profile implementation that will enable the development of interoperable clients.

Rapid reduction of liver steatosis in omega3-depleted rats injected with a novel lipid emulsion

The bolus intravenous administration of a novel medium-chain triglyceride: fish oil emulsion (MCT:FO) to normal subjects was recently found to increase within 60 min the amount of long-chain polyunsaturated omega3 fatty acids ( omega3) in platelet and leukocyte phospholipids and, hence, was proposed as a tool to prevent such pathological events as cardiac arrhythmia in selected patients who have to undergo urgent anesthesia and/or surgery. This study investigates whether other cells located outside the vascular bed may also benefit from this procedure for replenishing phospholipids with omega3. For such a purpose, the MCT:FO emulsion (1.0 ml) was injected into normal or omega3-depleted rats examined, one hour later, for the content and fatty acid pattern of liver triglycerides and phospholipids. Control experiments included the administration of saline or a medium-chain triglyceride:olive oil emulsion. The results reveal that the bolus intravenous injection of MCT:FO to the omega3-depleted rats resulted in the enrichment of liver phospholipids in omega3 and a marked reduction in hepatic steatosis. In conclusion, it is proposed that such a procedure may indeed allow a rapid supply of omega3 not only to circulating and vascular endothelial cells but also to extravascular cells, with a resulting correction of the biochemical and biophysical defects linked to a deficiency in these fatty acids.

Cardioprotective effect of spontaneous activity

In the perspective of giving a better understanding of the cardioprotective effects attributable to the tandem low caloric intake and training, Lou/C rats would be an interesting model since these animals exhibit spontaneously these two characteristics for months, without any dietary manipulations or stressor stimuli. No information was so far available on their cardiac function. Therefore, the aim of this pilot study was (i) to document cardiac function before and after ischemia in this strain, and (ii) to investigate whether spontaneous wheel-running activity can improve the ability of cardiac muscle to recover its function after an ischemic period. Cardiac mechanical and metabolic functions were measured in isolated Langendorff hearts from Wistar sedentary, Lou/C sedentary, and Lou/C wheel-running male rats submitted to a 20-min low-flow ischemia and 20-min reperfusion. In Lou/C sedentary rats, rate-pressure product, an index of cardiac work, was decreased before ischemia as compared to Wistar sedentary animals (- 24 %, p < 0.05). After ischemia, cardiac mechanical function recovery did not significantly differ between these two groups. Nevertheless, flux of non-oxidative glycolysis was lower before and after ischemia in Lou/C sedentary animals than in Wistar sedentary rats. In Lou/C rats, during normoxic perfusion, wheel-running activity significantly decreased heart rate (- 15 %), oxygen consumption (- 2.2 %) and cardiac efficiency (- 37 %), whereas coronary flow and flux of non-oxidative glycolysis were significantly increased (+ 15 % and + 263 %, respectively). After ischemia, recovery of cardiac mechanical function and cardiac efficiency were improved in Lou/C wheel-running rats versus Lou/C sedentary animals (p < 0.05). In conclusion, the impact of ischemia-reperfusion is similar between Lou/C- and Wistar sedentary rats. Spontaneous wheel-running activity decreases cardiac efficiency before ischemia and confers a protection against ischemia- and reperfusion-induced injury in isolated Lou/C rat hearts.

Accelerated clearance of plasma triglycerides and free fatty acids in omega3-depleted rats

The present study aims mainly at exploring the effects of a severe depletion in polyunsaturated long-chain omega3 fatty acids upon the fate of circulating lipids. The plasma concentration and fatty acid pattern of triglycerides, diglycerides, free fatty acids, and phospholipids were measured in omega3-depleted and control rats injected intravenously one hour before sacrifice with either saline, a control medium-chain triglyceride:olive oil emulsion or a medium-chain triglyceride:fish oil emulsion recently found to rapidly increase the phospholipid content of C20:5omega3 and C22:6omega3 in different cell types. The estimated fractional removal rate of the injected triglycerides and the clearance of free fatty acids from circulation were both higher in omega3-depleted rats than in control animals. The injection of the lipid emulsions apparently inhibited intracellular lipolysis, this being least pronounced in omega3-depleted rats. The increased clearance of circulating triglycerides and unesterified fatty acids in omega3-depleted rats may favor the cellular accumulation of lipids. In turn, such an accumulation and the lesser regulatory inhibition of tissular lipolysis may match the increased clearance of circulating unesterified fatty acids and, hence, account for the lack of any significant difference in plasma unesterified fatty acid concentration between these and control animals.

Visual cortex activation in kinesthetic guidance of reaching

The purpose of this research was to determine the cortical circuit involved in encoding and controlling kinesthetically guided reaching movements. We used (15)O-butanol positron emission tomography in ten blindfolded able-bodied volunteers in a factorial experiment in which arm (left/right) used to encode target location and to reach back to the remembered location and hemispace of target location (left/right side of midsagittal plane) varied systematically. During encoding of a target the experimenter guided the hand to touch the index fingertip to an external target and then returned the hand to the start location. After a short delay the subject voluntarily moved the same hand back to the remembered target location. SPM99 analysis of the PET data contrasting left versus right hand reaching showed increased (P < 0.05, corrected) neural activity in the sensorimotor cortex, premotor cortex and posterior parietal lobule (PPL) contralateral to the moving hand. Additional neural activation was observed in prefrontal cortex and visual association areas of occipital and parietal lobes contralateral and ipsilateral to the reaching hand. There was no statistically significant effect of target location in left versus right hemispace nor was there an interaction of hand and hemispace effects. Structural equation modeling showed that parietal lobe visual association areas contributed to kinesthetic processing by both hands but occipital lobe visual areas contributed only during dominant hand kinesthetic processing. This visual processing may also involve visualization of kinesthetically guided target location and use of the same network employed to guide reaches to visual targets when reaching to kinesthetic targets. The present work clearly demonstrates a network for kinesthetic processing that includes higher visual processing areas in the PPL for both upper limbs and processing in occipital lobe visual areas for the dominant limb.

Acute in vivo administration of a fish oil-containing emulsion improves post-ischemic cardiac function in n-3-depleted rats

A novel i.v. lipid preparation (MCT:FO) containing 80% medium chain-triacylglycerols and 20% fish oil was recently developed to rapidly replenish cell membrane phospholipids with omega 3 (n-3) polyunsaturated fatty acids (PUFA). In regard of this property, we investigated the effect of a single i.v. administration of MCT:FO on the recovery of cardiac function after ischemia in control and n-3-depleted rats. Results were compared with those obtained either with a control preparation, where FO was replaced by triolein (MCT:OO), or with saline. Saline (1 ml) or lipid preparation (also 1 ml) was injected as a bolus via the left saphenous vein. After 60 min the heart was removed and perfused for 20 min in normoxic conditions according to Langendorff. Thereafter, the heart was subjected to a 20 min zero-flow normothermic ischemia, followed by 40 min reperfusion. Cardiac mechanical and metabolic functions were monitored. In control rats, the previous administration of a lipid preparation (MCT:FO or MCT:OO) versus saline improved cardiac function during aerobic reperfusion post-ischemia. N-3-depleted rats showed decreased basal cardiac function and impaired recovery following ischemia. However, the bolus injection of MCT:FO opposed the deleterious effect of long-term n-3-deficiency and, in this respect, was superior to MCT:OO over the first 20 min of reperfusion. This novel approach to rapidly correct n-3 PUFA-deficiency might be clinically relevant and offer interesting perspectives in the management of acute ischemic accidents.

High dietary sucrose triggers hyperinsulinemia, increases myocardial β-oxidation, reduces glycolytic flux and delays post-ischemic contractile recovery

Although the causal relationship between insulin resistance (IR) and hypertension is not fully resolved, the importance of IR in cardiovascular dysfunction is recognized. As IR may follow excess sucrose or fructose diet, the aim of this study was to test whether dietary starch substitution with sucrose results in myocardial dysfunction in energy substrate utilization and contractility during normoxic and post-ischemic conditions. Forty-eight male Wistar rats were randomly allocated to three diets, differing only in their starch to sucrose (S) ratio (13, 2 and 0 for the Low S, Middle S and High S groups, respectively), for 3 weeks. Developed pressure and rate x pressure product (RPP) were determined in Langendorff mode-perfused hearts. After 30 min stabilization, hearts were subjected to 25 min of total normothermic global ischemia, followed by 45-min reperfusion. Oxygen consumption, beta-oxidation rate (using 1-13C hexanoate and Isotopic Ratio Mass Spectrometry of CO2 produced in the coronary effluent) and flux of non-oxidative glycolysis were also evaluated. Although fasting plasma glucose levels were not affected by increased dietary sucrose, high sucrose intake resulted in increased plasma insulin levels, without significant rise in plasma triglyceride and free fatty acid concentrations. Sucrose-rich diet reduced pre-ischemic baseline measures of heart rate, RPP and non-oxidative glycolysis. During reperfusion, post-ischemic recovery of RPP was impaired in the Middle S and High S groups, as compared to Low S, mainly due to delayed recovery of developed pressure, which by 45 min of reperfusion eventually resumed levels matching Low S. At the start of reperfusion, delayed post-ischemic recovery of contractile function was accompanied by: (i) reduced lactate production; (ii) decreased lactate to pyruvate ratio; (iii) increased beta-oxidation; and (iv) depressed metabolic efficiency. In conclusion, sucrose rich-diet increased plasma insulin levels, in intact rat, and increased cardiac beta-oxidation and coronary flow-rate, but reduced glycolytic flux and contractility during normoxic baseline function of isolated perfused hearts. Sucrose rich-diet impaired early post-ischemic recovery of isolated heart cardiac mechanical function and further augmented cardiac beta-oxidation but reduced glycolytic and lactate flux.

Effect of exogenous adenosine and monensin on glycolytic flux in isolated perfused normoxic rat hearts: role of pyruvate kinase

We studied the effect of exogenous adenosine in isolated perfused normoxic rat hearts on glycolytic flux through pyruvate kinase (PK). We compared its effect with that of myxothiazol, an inhibitor of mitochondrial ATP production. Moreover, we tested whether an increase of membrane ionic flux with monensin is linked to a stimulation of glycolytic flux through PK. After a 20-min stabilization period adenosine, myxothiazol or monensin were administrated to the perfusate continuously at various concentrations during 10 min. The contraction was monitored and the lactate production in coronary effluents evaluated. The amount of adenine nucleotides and phosphoenolpyruvate was measured in the frozen hearts. Myxothiazol induced a decrease of the left ventricular developed pressure (LVDP : -40%) together with a stimulation of glycolytic flux secondary to PK activation. In contrast, adenosine primarily reduced heart rate (HR: -30%) with only marginal effects on LVDP. This was associated with an inhibition of glycolysis at the level of PK. The Na+ ionophore monensin affected HR (+14%) and LVDP (+25%). This effect was associated with a stimulation of glycolysis secondary to the stimulation of PK. These results provide new information of action of adenosine in the heart and support the concept of a direct coupling between glycolysis and process regulating sarcolemmal ionic fluxes.

Multiport-readout frame-transfer 5 megapixel CCD imaging system for TEM applications

A multiport-readout, frame-transfer charge-coupled device (CCD) digital imaging system has been successfully developed and tested for intermediate-high-voltage electron microscopy (IVEM) applications up to 400 keV. The system employs a back-thinned CCD with 2560 x 1960 pixels and a pixel size of 24 microm x 24 microm. In the current implementation, four of the eight on-chip readout ports are used in parallel each operating at a pixel rate of 1- or 2-MHz so that the entire CCD array can be read out in as short as 0.6 s. The frame-transfer readout functions as an electronic shutter which permits the rapid transfer of charges in the active pixels to four masked buffers where the charges are readout and digitized while the active area of the CCD is integrating the next frame. With a thin film-based phosphor screen and a high-performance lens relay, the system has a conversion factor of 2.1 digital units per incident electron at 400 keV, and a modulation transfer function value of 14% at the Nyquist frequency.

3D spiral cardiac/respiratory ordered fMRI data acquisition at 3 Tesla

Three-dimensional (3D), multi-shot functional magnetic resonance imaging (fMRI) data acquisitions are desirable because of higher resolution and reduced susceptibility artifacts, due to shorter readouts and thinner slices. However, 3D multi-shot techniques are more susceptible to physiological noise, which can increase inter-image variance and lead to inaccurate assessment of activation. This work presents a 3D spiral fMRI data acquisition method at 3 T in which the acquisition of views was ordered to match the phase of either the respiratory or the cardiac cycle. For the acquisition timing parameters used in this work, cardiac ordering was found to reduce inter-image variance by 19%. Cardiac ordered data acquisitions showed the same reduction in variance as sequentially ordered data with cardiac contributions estimated and removed using an externally acquired reference prior to reconstruction. Respiratory ordering showed no reduction in fluctuation noise due to poor alignment of views to the respiratory phase.

Mapping of a gene for long QT syndrome to chromosome 4q25-27

Long QT syndrome (LQTS) is a heterogeneous inherited disorder causing syncope and sudden death from ventricular arrhythmias. A first locus for this disorder was mapped to chromosome 11p15.5. However, locus heterogeneity has been demonstrated in several families, and two other loci have recently been located on chromosomes 7q35-36 and 3p21-24. We used linkage analysis to map the locus in a 65-member family in which LQTS was associated with more marked sinus bradycardia than usual, leading to sinus node dysfunction. Linkage to chromosome 11p15.5, 7q35-36, or 3p21-24 was excluded. Positive linkage was obtained for markers located on chromosome 4q25-27. A maximal LOD score of 7.05 was found for marker D4S402. The identification of a fourth locus for LQTS confirms its genetic heterogeneity. Locus 4q25-27 is associated with a peculiar phenotype within the LQTS entity.

Primary Epstein-Barr virus infection with clonal T-cell lymphoproliferation

A case of fatal Epstein-Barr virus infection in a previously healthy girl who was first found to have severe infectious mononucleosis with spontaneous recovery is reported. Because an abnormal immune response to the virus persisted, the disease relapsed, manifesting in cutaneous and pulmonary lesions associated with hemophagocytic syndrome responsible for death. Pathologic findings were characterized by polymorphous atypical lymphoid infiltrate, prominent necrosis, and histiocytic hyperplasia. Lymphoid cells displayed CD8 phenotype and clonal T-cell receptor gene rearrangement. Viral genome was detected in lesions by Southern blot and located in nuclei of lymphoid cells by in situ hybridization. Pathologic findings suggested fatal infectious mononucleosis; however, phenotype and genotype favored a malignant diagnosis. Clonality was demonstrated to have arisen during primary infection. Virologic examination indicated that Epstein-Barr virus was a causative agent. Such a process belongs to the recently recognized spectrum of Epstein-Barr virus-related T-cell lymphoproliferative disorders that might overlap fatal infectious mononucleosis in patients who are especially vulnerable to the virus.