Stem cells from umbilical cord blood do have myogenic potential, with and without differentiation induction in vitro

The dystrophin gene, located at Xp21, codifies dystrophin, which is part of a protein complex responsible for the membrane stability of muscle cells. Its absence on muscle causes Duchenne Muscular Dystrophy (DMD), a severe disorder, while a defect of muscle dystrophin causes Becker Muscular Dystrophy (DMB), a milder disease. The replacement of the defective muscle through stem cells transplantation is a possible future treatment for these patients. Our objective was to analyze the potential of CD34+ stem cells from umbilical cord blood to differentiate in muscle cells and express dystrophin, in vitro. Protein expression was analyzed by Immunofluorescence, Western Blotting (WB) and Reverse Transcriptase – Polymerase Chain Reaction (RT-PCR). CD34+ stem cells and myoblasts from a DMD affected patient started to fuse with muscle cells immediately after co-cultures establishment. Differentiation in mature myotubes was observed after 15 days and dystrophin-positive regions were detected through Immunofluorescence analysis. However, WB or RT-PCR analysis did not detect the presence of normal dystrophin in co-cultures of CD34+ and DMD or DMB affected patients' muscle cells. In contrast, some CD34+ stem cells differentiated in dystrophin producers' muscle cells, what was observed by WB, reinforcing that this progenitor cell has the potential to originate muscle dystrophin in vitro, and not just in vivo like reported before.

Prediction of the temperature distribution of partially submersed umbilical cables

The objective of this work is to predict the temperature distribution of partially submersed umbilical cables under different operating and environmental conditions. The commercial code Fluent® was used to simulate the heat transfer and the air fluid flow of part of a vertical umbilical cable near the air-water interface. A free-convective three-dimensional turbulent flow in open-ended vertical annuli was solved. The influence of parameters such as the heat dissipating rate, wind velocity, air temperature and solar radiation was analyzed. The influence of the presence of a radiation shield consisting of a partially submersed cylindrical steel tube was also considered. The air flow and the buoyancydriven convective heat transfer in the annular region between the steel tube and the umbilical cable were calculated using the standard k-ε turbulence model. The radiative heat transfer between the umbilical external surface and the radiation shield was calculated using the Discrete Ordinates model. The results indicate that the influence of a hot environment and intense solar radiation may affect the umbilical cable performance in its dry portion.

Wharton’s jelly absence: a possible cause of stillbirth

The umbilical cord is a structure that provides vascular flow between the fetus and the placenta. It contains two arteries and one vein, which are surrounded and supported by gelatinous tissue known as Wharton’s jelly. There are many umbilical cord abnormalities that are related to the prognosis of fetus survival and birth weight. The authors report a case of umbilical cord constriction due to the localized absence of Wharton’s jelly, which was undiagnosed antenatally and had a fatal outcome. A review of the association between the absence of Wharton’s jelly and an unfavorable pregnancy outcome was undertaken.

Reduced endothelium-dependent relaxation to anandamide in mesenteric arteries from young obese Zucker rats

Impaired vascular function, manifested by an altered ability of the endothelium to release endothelium-derived relaxing factors and endothelium-derived contracting factors, is consistently reported in obesity. Considering that the endothelium plays a major role in the relaxant response to the cannabinoid agonist anandamide, the present study tested the hypothesis that vascular relaxation to anandamide is decreased in obese rats. Mechanisms contributing to decreased anandamide-induced vasodilation were determined. Resistance mesenteric arteries from young obese Zucker rats (OZRs) and their lean counterparts (LZRs) were used. Vascular reactivity was evaluated in a myograph for isometric tension recording. Protein expression and localization were analyzed by Western blotting and immunofluorescence, respectively. Vasorelaxation to anandamide, acetylcholine, and sodium nitroprusside, as well as to CB1, CB2, and TRPV1 agonists was decreased in endothelium-intact mesenteric arteries from OZRs. Incubation with an AMP-dependent protein kinase (AMPK) activator or a fatty acid amide hydrolase inhibitor restored anandamide-induced vascular relaxation in OZRs. CB1 and CB2 receptors protein expression was decreased in arteries from OZRs. Incubation of mesenteric arteries with anandamide evoked endothelial nitric oxide synthase (eNOS), AMPK and acetyl CoA carboxylase phosphorylation in LZRs, whereas it decreased phosphorylation of these proteins in OZRs. In conclusion, obesity decreases anandamide-induced relaxation in resistance arteries. Decreased cannabinoid receptors expression, increased anandamide degradation, decreased AMPK/eNOS activity as well as impairment of the response mediated by TRPV1 activation seem to contribute to reduce responses to cannabinoid agonists in obesity.

Aspetti Ultrasonografici in Corso di Sviluppo Placentare e Adattamento Cardiovascolare nella Cavalla Gravida: ecografia bidimensionale, ecocardiografia ed ecocontrastografia (CEUS)

In corso di gravidanza normale avvengono modificazioni emodinamiche centrali e periferiche volte a garantire le crescenti richieste nutritive dell'unità feto-placentare. L’ecografia con mezzo di contrasto (CEUS-Contrast Enhanced Ultrasonography) a base di microbolle offre una nuova opportunità di monitorare e quantificare la perfusione utero-placentare in condizioni normali e patologiche. L’ecocardiografia è stata ampiamente usata in medicina umana per valutare l’adattamento morfo-funzionale cardiaco materno durante la gravidanza. Gli scopi di questo lavoro prospettico sono stati di applicare, per la prima volta nella specie equina, un mezzo di contrasto di II generazione (Sonovue®), al fine quantificare la perfusione utero-placentare in corso di gravidanza normale, valutandone gli effetti sul benessere materno-fetale e di descrivere le modificazioni nei parametri ecocardiografici morfometrici e funzionali cardiaci, in particolare relativi alla funzione del ventricolo sinistro nel corso di una gravidanza fisiologica. Due fattrici sane di razza Trottatore sono state monitorate ecograficamente in maniera seriale durante l’intero corso della gravidanza, tramite esame bidimensionale, ecocontrastografia dell'unità utero-placentare, flussimetria Doppler delle arterie uterine, ecocardiografia materna in modalità bidimensionale, M-mode, Doppler e Tissue Doppler Imaging. I neonati sono stati clinicamente monitorati e gli invogli fetali esaminati. Il pattern di microperfusione utero-placentare è valutabile quali-quantitativamente tramite la CEUS e dimostra un’aumento del flusso a livello di microvascolarizzazione uterina con l'avanzare della gravidanza; non è stata rilevata la presenza di microbolle a livello di strutture fetali nè effetti dannosi sul benessere materno-fetale. In questo studio sono state osservate delle modificazioni cardiache materne in corso di gravidanza fisiologica, relative all'aumento della FC, del CO ed in particolare all'aumento delle dimensioni dell'atrio sinistro ed a modificazioni nelle onde di velocità di flusso e tissutali di riempimento del ventricolo sinistro.

Asymmetrisches Dimethylarginin als kardiovaskulärer Risikofaktor : Transportmechanismen und Auswirkungen einer Akkumulation

Die vorliegende Dissertation beschäftigt sich mit dem Membrantransporter-vermittelten Export von asymmetrischem Dimethyl-L-Arginin (ADMA) aus der Endothelzelle. Da ADMA-Plasmakonzentrationen mit Erkrankungen wie koronaren Herzkrankheiten, Atherosklerose, Bluthochdruck und Endotheldysfunktion in Verbindung gebracht werden, ist ein effektiver ADMA-Export aus der Zelle heraus unabdingbar. Um den Mechanismus hierfür aufzuklären, wurden die immortalisierte Endothelzelllinie EA.hy926 und weitere primäre Endothelzellen (humane Umbilikalvenenendothelzellen und Endothelzellen der großen und kleinen Herzgefäße) auf die Expression basischer Aminosäuretransporter mittels einer qRT-PCR hin untersucht. Dabei zeigte sich, dass alle getesteten Endothelzellen die Aminosäuretransporter hCAT-1, y+LAT1 und y+LAT2 exprimierten. Basierend auf ADMA-Exportdaten, die mit entsprechenden Transporter-überexprimierenden Xenopus laevis-Oozyten gewonnen wurden, wurde festgestellt, dass alle drei Membrantransporter ADMA exportieren konnten. Der physiologisch wichtige Exportweg für intrazellulär anfallendes ADMA scheint dabei der via y+L zu sein, da es sich hierbei um einen aktiven Exportmechanismus handelt, der im Gegentransport von im humanen Plasma reichlich vorhandenen neutralen Aminosäuren und Natriumionen den nach innen gerichteten Natriumgradienten ausnutzt. Die Wichtigkeit des Membrantransportes für die Kontrolle intrazellulärer ADMA-Konzentrationen wurde in vitro durch Entzug von extrazellulären Austauschsubstraten und einer daraus resultierenden Blockade der Transportfunktion gezeigt. Hierbei wurde innerhalb von zwei Stunden ein 2,5-facher Anstieg der intrazellulären ADMA-Konzentration festgestellt, die bei Präsenz von Austauschsubstrat für die Transporter nicht auftrat. Die Relevanz der y+LATs für den ADMA-Export wurde durch Herunterregulation dieser Proteine mittels siRNA sichtbar: Unter diesen Bedingungen konnte ADMA auch in Anwesenheit von Austauschsubstrat für das System y+L weniger effektiv exportiert werden. Eine wichtige Aufgabe des humanen Endothels ist die Bildung bioaktiven Stickstoffmonoxids, das unter anderem eine Vasodilatation der Gefäße bewirkt. Für diese NO-Synthese wird L-Arginin als Substrat von der endothelialen NO-Synthase benötigt. ADMA stellt einen kompetitiven Inhibitor dar, dessen erhöhtes intrazelluläres Vorkommen möglicherweise hemmend auf die NO-Synthase wirken könnte. Es konnten hier allerdings keine Auswirkungen eines um das 4-fache gestiegenen, intrazellulären ADMA-Spiegels auf die Tätigkeit der endothelialen NO-Synthase festgestellt werden. Möglicherweise bedarf es eines noch weiter zu Gunsten des ADMAs verschobenen, intrazellulären L-Arginin:ADMA-Verhältnisses, um eine Hemmung der NO-Synthase festzustellen. Dies könnte bei einem pathologischen Transporterausfall eintreten, der intrazellulär permanent höhere ADMA-Konzentrationen zur Folge hätte. Des Weiteren hätte ein Anstieg der Arginasetätigkeit und damit einhergehend ein Substratdefizit für die NO-Synthase den gleichen Effekt. Der translationale Ansatz mit humanen peripheren mononukleären Blutzellen von Patienten aus der 2. Medizinischen Klinik zeigte die Tendenz einer Korrelation zwischen dem ADMA-Exportvermögen und der Endothelfunktion und brachte zudem die Erkenntnis eines individuell äußerst variablen ADMA-Exportvermögens zutage.

An angiographic analysis of atherosclerosis progression in below-the-knee arteries after femoropopliteal angioplasty in claudicants

Purpose: To report an angiographic investigation of midterm atherosclerotic disease progression in below-the-knee (BTK) arteries of claudicants. Methods: Angiograms were performed in 58 consecutive claudicants (35 men; mean age 68.3±8.7 years) with endovascular treatment of femoropopliteal arteries in 58 limbs after a mean follow-up of 3.6±1.2 years. Angiograms were reviewed in consensus by 2 experienced readers blinded to clinical data. Progression of atherosclerosis in 4 BTK arterial segments (tibioperoneal trunk, anterior and posterior tibial arteries, and peroneal artery) was assessed according to the Bollinger score. The composite per calf Bollinger score represented the average of the 4 BTK arterial segment scores. The association of the Bollinger score with cardiovascular risk factors and gender was scrutinized. Results: A statistically significant increase in atherosclerotic burden was observed for the mean composite per calf Bollinger score (5.7±8.3 increase, 95% CI 3.5 to 7.9, p<0.0001), as well as for each single arterial segment analyzed. In multivariate linear regression analysis, diabetes mellitus was associated with a more pronounced progression of atherosclerotic burden in crural arteries (β: 5.6, p=0.035, 95% CI 0.398 to 10.806). Conclusion: Progression of infrapopliteal atherosclerotic lesions is common in claudicants during midterm follow-up. Presence of diabetes mellitus was confirmed as a major risk factor for more pronounced atherosclerotic BTK disease progression.

Impact of arterial injury on neointimal hyperplasia after implantation of drug-eluting stents in coronary arteries: an intravascular ultrasound study

Aims: We investigated the impact of arterial injury on neointimal hyperplasia following implantation of drug-eluting stents (DES). Methods and results: A total of 196 patients with 223 segments (sirolimus-eluting stents [SES]: 104, paclitaxel-eluting stents [PES]: 119) underwent intravascular ultrasound eight months after DES implantation. Arterial injury was defined as the balloon-to-artery ratio (BAR). Segments were categorised into two groups: high BAR defined as BAR>1.1 (120 segments), and low BAR defined as BAR ≤1.1 (103 segments). Baseline clinical characteristics were similar for both groups. Although reference vessel diameter was smaller, stent diameter, maximal balloon pressure and balloon diameter were higher in the high BAR compared with the low BAR group. Lumen (7.10±1.91 vs. 6.25±1.69, p=0.001), stent (7.31±1.95 vs. 6.41±1.80, p=0.001), and external elastic membrane (17.1±4.9 vs. 14.8±4.0, p<0.0001) areas (mm2) were higher, but neointimal hyperplasia (0.21±0.36 vs. 0.16±0.48, p=0.42) area (mm2) was similar in the high BAR compared with the low BAR group. Arterial injury as assessed by BAR was not associated with the amount of neointimal hyperplasia (R2=0.003, p=0.40). Conclusions: Arterial injury does not correlate with the amount of neointimal hyperplasia following DES implantation. Conventionally aggressive DES implantation techniques do not adversely affect long-term outcome with respect to restenosis. - See more at: http://www.pcronline.com/eurointervention/30th_issue/79/#sthash.1do4X31G.dpuf

Safety of diagnostic balloon occlusion in normal coronary arteries

Diagnostic coronary balloon occlusion (CBO) is mandatory for collateral function assessment, during angioscopy and optical coherence imaging, and when using certain coronary protection devices against emboli. Thus far, the safety of diagnostic CBO regarding procedural and long-term complications in normal coronary arteries has not been studied. In 316 patients, diagnostic CBO was performed for collateral function measurement in 426 angiographically normal vessels. The angioplasty balloon was inflated for 60 to 120 seconds using inflation pressures of 1 to 3 atm, followed by control angiography during and after CBO. Patients were divided into groups with entirely normal (n = 133) and partially normal (n = 183) vessels. Primary end points were procedural and long-term complications. De novo stenosis development was assessed by quantitative coronary angiography in 35% of the patients. Secondary end points were cardiac events at 5 years of follow-up. Procedural complications occurred in 1 patient (0.2%). In 150 repeat angiographic procedures in 92 patients (follow-up duration 10 +/- 15 months), quantitative coronary angiography revealed no difference in percentage diameter narrowing between baseline and follow-up (4.1% vs 3.9%, p = 0.69). During follow-up periods of 14 and 72 months, respectively, a new stenotic lesion was detected in 1 patient in each group (1.3%). Major cardiac events and percutaneous coronary intervention for stable angina were less frequent in the group with entirely normal than with partially normal vessels (0.8% vs 5.5%, p = 0.02, and 0.8% vs 18%, p <0.0001). In conclusion, low-inflation pressure diagnostic CBO in angiographically normal coronary arteries bears a minimal risk for procedural and long-term complications and can therefore be regarded as a safe procedure.

Reactive oxygen species mediate functional differences in human radial and internal thoracic arteries from smokers

Smoking not only increases the risk that coronary heart disease will develop but also morbidity and mortality in patients with known coronary atherosclerosis and after coronary artery bypass grafting. Excessive generation of reactive oxygen species (ROS) has been implicated as the final common pathway for the development of endothelial dysfunction in various cardiovascular risk factors. This study assessed the influence of smoking on two different human arteries routinely used as coronary artery bypass graft conduits.

Co2-dependent vasomotor reactivity of cerebral arteries in patients with severe traumatic brain injury: time course and effect of augmentation of cardiac output with dobutamine

Failing cerebral blood flow (CBF) autoregulation may contribute to cerebral damage after traumatic brain injury (TBI). The purpose of this study was to describe the time course of CO(2)-dependent vasoreactivity, measured as CBF velocity in response to hyperventilation (vasomotor reactivity [VMR] index). We included 13 patients who had had severe TBI, 8 of whom received norepinephrine (NE) based on clinical indication. In these patients, measurements were also performed after dobutamine administration, with a goal of increasing cardiac output by 30%. Blood flow velocity was measured with transcranial Doppler ultrasound in both hemispheres. All patients except one had an abnormal VMR index in at least one hemisphere within the first 24 h after TBI. In those patients who did not receive catecholamines, mean VMR index recovered within the first 48 to 72 h. In contrast, in patients who received NE within the first 48 h period, VMR index did not recover on the second day. Cardiac output and mean CBF velocity increased significantly during dobutamine administration, but VMR index did not change significantly. In conclusion, CO(2) vasomotor reactivity was abnormal in the first 24 h after TBI in most of the patients, but recovered within 48 h in those patients who did not receive NE, in contrast to those eventually receiving the drug. Addition of dobutamine to NE had variable but overall insignificant effects on CO(2) vasomotor reactivity.

Endovascular Revascularization of Below-the-Knee Arteries: Prospective Short-Term Angiographic and Clinical Follow-up

PURPOSE: To evaluate arterial lesion characteristics and their impact on angiographic and clinical outcomes after endovascular below-the-knee (BTK) revascularization. MATERIALS AND METHODS: Between April 2008 and June 2009, 33 patients (mean age 74.9 years) with 34 limbs and 50 arterial segments (mean lesion length 59.3 mm) undergoing endovascular BTK revascularization agreed to undergo prospective clinical and intraarterial angiographic 6-month follow-up evaluation. Clinical indication for BTK revascularization was critical limb ischemia (CLI) in 18 patients and delayed wound healing without hemodynamic evidence of CLI and intermittent claudication (IC) in 15 patients. RESULTS: Binary restenosis was observed in 40% of treated segments at 6 months. Primary sustained clinical improvement was 82.4% and 55.9% at 3 months and 6 months. Lesion length was independently associated with binary restenosis (hazard ratio [HR] 1.013, 95% confidence interval [CI] 1.000-1.016, P = .05) and lower rates of primary sustained clinical improvement (HR 1.024, 95% CI 1.006-1.042, P = .008). CONCLUSIONS: Endovascular BTK revascularization yields clinical and angiographic benefits both for patients with IC and for patients with CLI. Although arterial lesion length adversely affects angiographic and clinical outcomes after endovascular revascularization, limb salvage rates were substantially higher compared with the comparatively low patency rates after BTK angioplasty.