Dystrophin-glycoprotein complex and vinculin-talin-integrin system in human adult cardiac muscle

Costameres were identified, for the first time, in skeletal and cardiac muscle, as regions associated with the sarcolemma, consisting of densely clustered patches of vinculin; they have many characteristics common to the cell-extracellular matrix-type of adherens junctions. Costameres are considered 'proteic machinery' and they appear to comprise two protein complexes, the dystrophin-glycoprotein complex (DGC) and the vinculin-talin-integrin system. In comparison to skeletal muscle, few studies have focused on cardiac muscle regarding these two complexes, and study is generally relative to dystrophin or to cardiac diseases, such as cardiomyopathies. However, insufficient data are available on these proteins in healthy human cardiomyocytes. For this reason, we performed an immunohistochemical study using human cardiac muscle fibers, in order to define the real distribution and the spatial relationship between the proteins in these two complexes. Our data showed a real costameric distribution of DGC and of the vinculin-talin-integrin system; all tested proteins were present in T-tubule and in intercalated disks. Moreover, our data demonstrated that all tested proteins of DGC colocalized with each other, as all tested components of the vinculin-talin-integrin system, and that all tested proteins of DGC colocalized with all tested proteins of the vinculin-talin-integrin system. Finally, all tested proteins of the two complexes were localized in the region of the sarcolemma over the I band, in 100% of our observations. The present study, for the first time, analyzed the majority of proteins of DGC and of the vinculin-talin-integrin system in cardiac muscle fibers, and it confirmed that DGC and the vinculin-talin-integrin system have a role in the transduction of mechanical force to the extracellular matrix. Finally it attributed a key role in the regulation of action potential duration to cardiac myocytes.

Changing spectrum and outcome of 705 fetal congenital heart disease cases: 12 years, experience in a third-level center

INTRODUCTION

Congenital heart diseases are the most common prenatal and postnatal malformations. Nowadays, fetal echocardiography is a widely practiced technique; however, the impact of prenatal diagnosis on prognosis of the newborns affected by congenital heart disease remains uncertain.

OBJECTIVE

To assess the outcome and the changes in the spectrum of prenatally detected congenital heart disease in our tertiary care centre in 12 years of activity (1995-2006).

METHODS AND RESULTS

We detected 705 congenital heart diseases: 32% (223) were associated with extracardiac or chromosomal anomalies or both, and 68% (482) were isolated. Termination of pregnancy was chosen in 81% for associated anomalies and 37% for isolated anomalies (P<0.001). Of these, more than one-third occurred in hypoplasic left heart cases. The general survival rate was 72%; it was significantly lower in the group with associated heart diseases (46 vs. 80%, P<0.001). Over 12 years we noticed a reduction in the number of multimalformed fetuses and of the hypoplasic left heart cases, and a higher number of aortic arch anomalies detected. During the past 6 years of activity the survival rate obtained has significantly increased (55 to 84%, P<0.05), the termination rate has significantly decreased (35 to 14%, P<0.001) and the number of neonatal deaths has significantly decreased (39 to 10%, P<0.001).

CONCLUSION

The survival and the voluntary termination of fetuses with prenatally detected congenital heart diseases are strongly influenced by disease severity and by associated extracardiac or chromosomal anomalies, or both. Over 12 years, the spectrum of fetal congenital heart disease has changed and their outcome has significantly improved.

Thermal effects in static friction: thermolubricity

We present a molecular dynamics analysis of the static friction between two thick slabs. The upper block is formed by N2 molecules and the lower block by Pb atoms. We study the effects of the temperature as well as the effects produced by the structure of the surface of the lower block on the static friction. To put in evidence the temperature effects we will compare the results obtained with the lower block formed by still atoms with those obtained when the atoms are allowed to vibrate (e.g., with phonons). To investigate the importance of the geometry of the surface of the lower block we apply the external force in different directions, with respect to a chosen crystallographic direction of the substrate. We show that the interaction between the lattice dynamics of the two blocks is responsible for the strong dependence of the static friction on the temperature. The lattice dynamics interaction between the two blocks strongly reduces the static friction, with respect to the case of the rigid substrate. This is due to the large momentum transfer between atoms and the N2 molecules which disorders the molecules of the interface layer. A further disorder is introduced by the temperature. We perform calculations at T = 20K which is a temperature below the melting, which for our slab is at 50K . We found that because of the disorder the static friction becomes independent of the direction of the external applied force. The very low value of the static friction seems to indicate that we are in a regime of thermolubricity similar to that observed in dynamical friction.

Bilateral arterial duct 'stenting' in a low-weight neonate with complex congenital heart defect

Bilateral arterial ducts feeding discontinuous pulmonary arteries are a very rare anatomic arrangement in complex heart malformations with pulmonary atresia. In this setting, neonatal ductal closure may result in abrupt pulmonary hypoperfusion and life-threatening systemic hypoxia. In high-risk patients, percutaneous arterial duct stenting might be an engaging and cost-effective alternative to surgery. This paper reports on a critical low-weight neonate with complex heart disease and discontinuous pulmonary arteries dependent on bilateral arterial ducts who underwent successful transcatheter ductal stenting as an alternative to a high-risk surgical palliation.

Aortic coarctation with persistent fifth left aortic arch

A neonate with severe aortic coarctation showed a double lumen transverse aorta (persistent fifth aortic arch) with both channels joining at the isthmus where the obstruction was confirmed by echocardiography and cardiac catheterization. Surgical repair was performed with a pantaloon-shaped patch. Persistent fifth aortic arch does not result in a vascular ring and, per se, is not hemodynamically significant unless associated with other cardiac malformations.

Stenting of the arterial duct in newborns with duct-dependent pulmonary circulation

OBJECTIVE

To evaluate the feasibility and results of stenting of the arterial duct in newborns with duct-dependent pulmonary circulation using low-profile, high-flexibility premounted coronary stents.

DESIGN

Prospective interventional and clinical follow-up study.

SETTING

Tertiary referral centre.

PATIENT POPULATION

Between April 2003 and December 2006, 26 neonates (mean (SD) age 15.2 (19.9) days, mean (SD) weight 3.3 (0.8) kg) underwent attempts at stenting of the arterial duct.

MAIN OUTCOME MEASURES

Procedural success and complication rates. Early and mid-term follow-up results.

RESULTS

The procedure was successfully completed in 24/26 (92.3%) cases. Minor complications occurred in 2/26 (7.7%) cases. No mortality occurred. After stenting, the ductal diameter increased from 1.2 (1.0) mm to 3.1 (0.4) mm (p<0.001) and the percutaneous O(2) saturation increased from 70 (14)% to 86 (10)% (p<0.001), respectively. Over a mid-term follow-up, 2/24 patients (8.3%) needed a systemic-to-pulmonary artery shunt because of inadequate ductal flow and 4/24 patients (16.7%) underwent stent redilatation after 6.0 (4.4) months, but before corrective surgery. Cardiac catheterisation before corrective surgery in 9 patients showed an increase of the Nakata index from 112 (49) mm/mm(2) to 226 (108) mm/mm(2) (p<0.001), without any left-to-right imbalance of the pulmonary artery size. In the subset of 11 patients who improved without needing an additional source of pulmonary blood supply, the stented arterial duct closed uneventfully in 45.5% of cases after 4.0 (2.2) months.

CONCLUSIONS

Stenting of the arterial duct is a feasible, safe and effective palliation in newborns with duct-dependent pulmonary circulation, supporting the spontaneous improvement process or promoting significant and balanced pulmonary artery growth for subsequent corrective surgery.

Percutaneous treatment of ductal origin of the distal pulmonary artery in low-weight newborns

OBJECTIVE

We sought to evaluate the role of percutaneous techniques in the treatment of ductal origin of a distal pulmonary artery (PA) in low-weight infants.

BACKGROUND

Various surgical approaches have been proposed, however, they are highly challenging and risky in neonates.

METHODS

We treated 5 infants weighing < 3 kg with ductal origin of the PA associated with other congenital heart disease. Procedures were performed under general anesthesia and orotracheal intubation.

RESULTS

A total of 7 coronary stents were used. Median procedure and fluoroscopy times were 100 and 8 minutes, respectively. Oxygen saturation increased significantly in all cases (p = 0.026). Both procedural and postprocedural courses were uneventful and the patients were discharged 7-10 days post procedure. During a follow up of 4-12 months, the results remained stable. Two subjects underwent complete corrective surgery 6 months after stent implantation at a weight of 7-9 kg. Ductus arteriosus with the stent inside were completely removed by surgeons who did not report any difficulty. Three subjects await surgery.

CONCLUSION

Percutaneous management of the ductal origin of the pulmonary artery is a safe and efficacious palliative approach.

Symptomatic aorto-pulmonary collaterals early after arterial switch operation

Enlarged bronchial arteries and/or systemic-to-pulmonary collaterals have been frequently demonstrated in association with transposition of the great arteries. They are usually clinically silent, although they might be large enough to cause accelerated pulmonary vascular obstructive disease or symptomatic cardiac volume overload after surgical repair. We report on a low-weight neonate with transposition of the great arteries and intact ventricular septum who showed a stormy postoperative course because of multiple aorto-pulmonary collaterals early after a successful arterial switch operation. Percutaneous coil embolization of these anomalous vessels resulted in sudden weaning from mechanical ventilation and hospital discharge in a few weeks.

Costameric proteins in human skeletal muscle during muscular inactivity

Costameres are regions that are associated with the sarcolemma of skeletal muscle fibres and comprise proteins of the dystrophin-glycoprotein complex and vinculin-talin-integrin system. Costameres play both a mechanical and a signalling role, transmitting force from the contractile apparatus to the extracellular matrix in order to stabilize skeletal muscle fibres during contraction and relaxation. Recently, it was shown that bidirectional signalling occurs between sarcoglycans and integrins, with muscle agrin potentially interacting with both types of protein to enable signal transmission. Although numerous studies have been carried out on skeletal muscle diseases, such as Duchenne muscular dystrophy, recessive autosomal muscular dystrophies and other skeletal myopathies, insufficient data exist on the relationship between costameres and the pathology of the second motor nerve and between costameric proteins and muscle agrin in other conditions in which skeletal muscle atrophy occurs. Previously, we carried out a preliminary study on skeletal muscle from patients with sensitive-motor polyneuropathy, in which we analysed the distribution of sarcoglycans, integrins and agrin by immunostaining only. In the present study, we have examined the skeletal muscle fibres of ten patients with sensitive-motor polyneuropathy. We used immunofluorescence and reverse transcriptase PCR to examine the distribution of vinculin, talin and dystrophin, in addition to that of those proteins previously studied. Our aim was to characterize in greater detail the distribution and expression of costameric proteins and muscle agrin during this disease. In addition, we used transmission electron microscopy to evaluate the structural damage of the muscle fibres. The results showed that immunostaining of alpha 7B-integrin, beta 1D-integrin and muscle agrin appeared to be severely reduced, or almost absent, in the muscle fibres of the diseased patients, whereas staining of alpha 7A-integrin appeared normal, or slightly increased, compared with that in normal skeletal muscle fibres. We also observed a lower level of alpha 7B- and beta 1D-integrin mRNA and a normal, or slightly higher than normal, level of alpha 7A-integrin mRNA in the skeletal muscle fibres of the patients with sensitive-motor polyneuropathy, compared with those in the skeletal muscle of normal patients. Additionally, transmission electron microscopy of transverse sections of skeletal muscle fibres indicated that the normal muscle fibre architecture was disrupted, with no myosin present inside the actin hexagons. Based on our results, we hypothesize that skeletal muscle inactivity, such as that found after denervation, could result in a reorganization of the costameres, with alpha 7B-integrin being replaced by alpha 7A-integrin. In this way, the viability of the skeletal muscle fibre is maintained. It will be interesting to clarify, by future experimentation, the mechanisms that lead to the down-regulation of integrins and agrin in muscular dystrophies.

Hybrid approach in a case of arterial tortuosity syndrome

Arterial tortuosity syndrome is a rare connective tissue disorder characterised by elongation, tortuosity, stenosis and aneurysms of the large and middle-sized arteries. The symptomatology is correlated to the artery affected by the pathology with correlated stenosis. We describe our hybrid surgical procedure in the treatment of a case of kinking of the pulmonary branches with significant gradient and hypertension. Aortic arch and supraaortic vessels presented various deviousness without hemodynamic alterations.

Role of mitochondria and reactive oxygen species in dendritic cell differentiation and functions

Dendritic cells (DC) are potent antigen-presenting cells capable of inducing T and B responses and immune tolerance. We have characterized some aspects of energy metabolism accompanying the differentiation process of human monocytes into DC. Compared to precursor monocytes, DC exhibited a much larger number of mitochondria and consistently (i) a higher endogenous respiratory activity and (ii) a more than sixfold increase in ATP content and an even larger increase in the activity of the mitochondrial marker enzyme citrate synthase. The presence in the culture medium of rotenone, an inhibitor of the respiratory chain Complex I, prevented the increase in mitochondrial number and ATP level, without affecting cell viability. Rotenone inhibited DC differentiation, as revealed by the observation that the expression of CD1a, which is a specific surface marker of DC differentiation, was strongly reduced. Cells cultured in the presence of rotenone displayed a lower content of growth factor-induced, mitochondrially generated, hydrogen peroxide. A similar drop in ROS was observed upon addition of catalase, which caused functional effects similar to those produced by rotenone treatment. These results suggest that ROS play a crucial role in DC differentiation and that mitochondria are an important source of ROS in this process.

Complex multidrug therapy in a patient with pulmonary hypertension before and after orthotopic heart transplantation. A case report

Pulmonary arterial hypertension represents an absolute contraindication for heart transplantation. We report the case of a 30-year-old man with end-stage heart failure due to restrictive cardiomyopathy and pulmonary arterial hypertension. A complex multidrug therapy improved pulmonary haemodynamics to the point that orthotopic heart transplantation could be carried out. At 18-month follow-up after heart transplantation, the patient's cardiac function made a full recovery. Larger prospective studies are warranted to support these results.

Skin blood flowmotion and microvascular reactivity investigation in hypercholesterolemic patients without clinically manifest arterial diseases

Fourier spectral analysis of forearm skin laser Doppler flowmetry (LDF) signal was performed in fifteen hypercholesterolemic patients (HP), without clinically manifest arterial diseases, and in fifteen age-matched healthy control subjects (CS), in order to investigate skin blood flowmotion (SBF). The LDF frequency intervals studied were: 0.01-1.6 Hz total spectrum, as well as 0.01-0.02 Hz (endothelial), 0.02-0.06 Hz (sympathetic), 0.06-0.2 Hz (myogenic), 0.2-0.6 Hz (respiratory) and 0.6-1.6 Hz (cardiac). Skin microvascular reactivity (MVR) to acetylcholine (ACh) and to sodium nitroprusside (SNP) iontophoresis was also investigated. HP showed a lower post-ACh increase in power spectral density (PSD) of the 0.01-0.02 Hz SBF subinterval compared to CS (1.80+/-1.73 PU(2)/Hz vs 3.59+/-1.78 PU(2)/Hz, respectively; p<0.005), while they did not differ in MVR from CS. In eleven HP the 0.01-0.02 Hz SBF subinterval showed a higher post-ACh PSD increase near to the statistical significance after 10 weeks of rosuvastatin therapy (10 mg/day) compared to pretreatment test (3.04+/-2.95 PU(2)/Hz vs 1.91+/-1.94 PU(2)/Hz; p=0.07). The blunted post-ACh increase in PSD of the 0.01-0.02 Hz SBF subinterval in HP suggests a skin endothelial dysfunction in these patients. This SBF abnormality showed a tendency to improve after rosuvastatin therapy in eleven treated patients.

Neonatal patent ductus arteriosus recanalization and stenting in critical Ebstein's anomaly

A critically ill 3-day-old neonate with severe tricuspid valve Ebstein's anomaly, functional pulmonary atresia, and closed ductus arteriosus, unresponsive to prostaglandin infusion, underwent percutaneous ductal recanalization and stenting as an alternative to a surgical shunt. After local prostaglandin infusion through an end-hole catheter, the ductus was passed using a hydrophilic, high-support coronary guidewire. It was then stabilized by coronary stent implantation, after which the arterial oxygen saturation showed a sudden rise. In conclusion, ductus arteriosus recanalization and stenting can be successfully achieved within a few days after spontaneous closure as a cost-effective alternative to a surgical shunt for critical neonatal, duct-dependent Ebstein's anomaly.

Patent ductus arteriosus 'stenting' as a life-saving approach in severe neonatal Ebstein's anomaly

A critical 1-day-old male neonate was referred to cardiac evaluation because of deep cyanosis due to a severe tricuspid valve Ebstein's anomaly with large atrial right-to-left shunt and duct-dependent pulmonary circulation. Ductus arteriosus re-opening by prostaglandin infusion resulted in significant clinical improvement but, after a few hours, it irreversibly closed, and pulmonary vasodilator treatment with inhaled nitric oxide and oral sildenafil did not significantly increase the oxygen saturation. Therefore, it was decided to proceed to ductal recanalization and stenting as an alternative to the surgical shunt. After the procedure, oxygen saturation was raised to over 90%, allowing the baby to be weaned from mechanical ventilation. At 9-month follow-up, he was asymptomatic and showed a systemic saturation over 90% despite complete closure of the stented ductus. In conclusion, ductus arteriosus stenting might be considered to be a reliable and life-saving therapeutic option in severe forms of Ebstein's anomaly as a temporary support to a multidrug vasoactive therapy.

Abnormal regional myocardial deformation properties and increased aortic stiffness in normotensive patients with aortic coarctation despite successful correction: an ABPM, standard echocardiography and strain rate imaging study

The long-term follow-up data subsequent to a successful repair of AoC (aortic coarctation) show that life expectancy remains reduced. Previous standard echocardiographic studies have demonstrated normal or increased systolic cardiac function in patients following successful repair of AoC. SR (strain rate) imaging is a new technique able to detect subclinical myocardial abnormalities. In the present study we investigated whether young patients (without hypertension, as assessed using ambulatory blood pressure monitoring and an exercise test) following successful AoC repair already have abnormal myocardial deformation properties, and the relationship of the deformation properties with aortic stiffness. We studied 166 subjects, 83 AoC non-hypertensive patients (mean age 12+/-4 years) a number of years after successful repair of AoC and 83 age- and sex-matched subjects as controls. Peak systolic SR (1/s) for both regional longitudinal and radial function was assessed. The aortic stiffness index was calculated from the echocardiographically derived thoracic aortic diameters, and the measurement of blood pressure was obtained by cuff sphygmomanometry. The LV (left ventricular) ejection fraction was significantly increased in AoC patients, whereas regional longitudinal SRs were significantly reduced (-1.1+/-0.9 compared with -2+/-0.5, P<0.0001) in patients. The aortic stiffness index was significantly increased in AoC patients (12+/-9, P<0.0001). At multilinear regression analysis, age at repair (P=0.005; coefficient, -0.201; S.E.M., 0.027) and the aortic stiffness index (P=0.0029; coefficient, 0.334; S.E.M., 0.423) predicted longitudinal SR. Despite the presence of a successful repair for AoC, in the absence of hypertension, longitudinal deformation properties were significantly impaired. Moreover, the degree of longitudinal SR impairment was correlated with age at repair and aortic stiffness. Early repair can delay the onset of hypertension in postcoarctectomy patients, but cannot prevent the innate structural and functional abnormalities of the aorta and their deleterious effect on myocardial deformation properties.

Transcatheter closure of congenital ventricular septal defects: results of the European Registry

AIM

To report the experience of 23 tertiary referral European Centres on transcatheter closure of congenital ventricular septal defects (VSD).

METHODS AND RESULTS

Implantation of transcatheter devices was attempted in 430 patients (pts) with congenital VSDs until July 2005. The following anatomic types were present: 119 muscular, 250 perimembranous, 16 multiple, 45 residual post-surgery. Median VSD size was 7 mm (range 3-22), fluoroscopy time 33 min (range 3-146). Devices implanted were Amplatzer muscular or membranous devices in 364, PDA devices in 12, ASD devices in seven, Starflex in seven, and coils in nine patients. Procedure was successful in 410 cases (95%).

COMPLICATIONS

device embolization in five cases (surgery in two, catheter retrieval in three), aortic regurgitation in 14 cases (two of which requiring surgery), tricuspid regurgitation in 27 cases (no surgery was necessary), minor rhythm disturbances in 10 pts, death in one patient, complete heart block (cAVB) in 16 pts [perimembranous 12 of 250 (5%), muscular one of 119 (0.8%), residual post-surgery VSD three of 45 (6.7%)]. CAVB was transient in six patients, requiring permanent pace-makers in 10 cases (3.8%) (six early, four late). In the multivariate analysis, the only variable associated with a risk of the occurrence of complication was age (P=0.012) and weight (P=0.0035). In the univariate analysis, risk factors for the development of cAVB were, device type (P=0.03) and VSD location (P=0.05). After the multivariable Cox proportional hazards analysis, no risk factor was found.

CONCLUSION

Transcatheter closure of congenital VSDs offers encouraging results. COMPLICATIONS are limited; the most relevant one seems to be the device related to cAVB in perimembranous VSD. More experience and long-term follow-up are mandatory to assess safety and effectiveness of this procedure as an alternative to conventional surgery.

Post-ischaemic peak flow and myogenic flowmotion component are independent variables for skin post-ischaemic reactive hyperaemia in healthy subjects

The aim of this study was to clarify whether the post-ischaemic amplification of skin blood flowmotion (SBF) influences the extent of skin post-ischaemic hyperaemia. Forearm skin perfusion was measured by means of laser Doppler flowmetry (LDF) and forearm SBF was examined using Fourier analysis of LDF signal, under basal conditions and following forearm ischaemia in 50 healthy subjects. Power spectral density (PSD) of SBF total spectrum (0.009-1.6 Hz), as well of the frequency intervals (FI) related to endothelial (0.009-0.02 Hz), sympathetic (0.02-0.06 Hz), myogenic (0.06-0.2 Hz), respiratory (0.2-0.6 Hz) and cardiac (0.6-1.6 Hz) activity was measured in PU(2) (LDF perfusion unit)/Hz. Multiple regression analysis evaluated whether post-ischaemic peak-flow, as an indicator of shear stress, or post-ischaemic SBF independently affected the post-peak-flow hyperaemia calculated as corrected area under the LDF curve (C-AUC). Following ischaemia, we observed a statically significant increase in skin perfusion (from basal of 11.7+/-5.8 PU to peak flow of 62.3+/-41.4 PU, p<0.0000005) and in PSD of SBF total spectrum (p<0.01) as well of the different FI considered (p<0.005 for the endothelial and myogenic FI; p<0.05 for the sympathetic, respiratory and cardiac FI) compared to baseline. Multiple regression analysis showed that peak flow and post-ischaemic SBF component of myogenic origin were significant independent variables for the C-AUC (p=0.0000001 and p=0.009, respectively). These findings suggest that not only increased shear stress but also post-ischaemic amplification of myogenic SBF component independently contributes to the more prolonged phase of post-ischaemic skin re-perfusion in healthy subjects.

Transcatheter closure of ruptured sinus of Valsalva aneurysm causing Fontan circulation failure

Congenital sinus of Valsalva aneurysm is a rare cardiac malformation that usually becomes symptomatic as a consequence of intracardiac or extracardiac rupture. It is difficult to suspect in association with complex cardiac defects and its rupture may be misdiagnosed as progressive aortic regurgitation. This case report refers to a patient with tricuspid atresia submitted to Fontan procedure five years previously, in whom a sinus of Valsalva aneurysm rupture into the accessory ventricular chamber caused rapidly progressive heart failure. The malformation was suspected by echocardiography and treated by percutaneous implantation of an Amplatzer duct occluder, with immediate improvement of the patient's clinical and functional status.

Prevalence of stratified epithelium-specific antinuclear antibodies in 138 patients with lichen planus

BACKGROUND

Antibodies to stratified epithelia characterize chronic ulcerative stomatitis, an entity that very closely resembles erosive lichen planus both clinically and histologically. These antibodies are directed against a 70-kd antigen.

OBJECTIVE

Our aim was to verify whether antibodies to stratified epithelia are present in patients with common lichen planus.

PATIENTS AND METHODS

One hundred thirty-eight patients with various forms of lichen planus were studied. Indirect immunofluorescence was performed on both monkey esophagus and HEp2-2000 cells. Immunoblotting was done with cultured keratinocytes used as the source antigen.

RESULTS

Nineteen patients had antibodies to stratified epithelia (in 9 directed against an antigen of 70 kd). Forty-eight patients had circulating antibodies detected by indirect immunofluorescence on both monkey esophagus and HEp2-2000 cells (in 7 directed against an antigen of 70 kd). Indirect immunofluorescence was positive only on HEp2-2000 cells in 21 patients. Indirect immunofluorescence was negative in 50 patients on both HEp2-2000 cells and monkey esophagus. None of the last 71 patients had antibodies directed to an antigen of 70 kd.

LIMITATIONS

This is a serological study; results from direct immunofluorescence studies would be interesting.

CONCLUSION

Antibodies to stratified epithelia directed to an antigen of 70 kd are not exclusive to chronic ulcerative stomatitis, but are also present in some patients with lichen planus.

Skin microcirculatory effect of exogenous calcitonin gene-related peptide (CGRP) evaluated by laser Doppler flowmetry coupled with iontophoresis in healthy subjects

The aim of our study was to evaluate the feasibility of laser Doppler flowmetry (LDF) coupled with iontophoresis in exploring the skin vasodilator activity of exogenous calcitonin gene-related peptide (CGRP) in healthy subjects and to investigate the mechanisms involved in the skin vasodilator activity of this peptide. Forearm skin blood perfusion was measured in conventional perfusion unit (PU; 1 PU=10 mV), using a LDF apparatus (Periflux PF4001, Perimed, Sweden), before and following exogenous CGRP dissolved in distilled water (0.02%) or pure saline iontophoresis. Different iontophoresis protocols were used in a preliminary dose finding study in six subjects. Two pulses (0.1 mA for 30 s each) of anodal CGRP or saline iontophoresis were used in the definitive study in 20 subjects. Power spectral density (PSD) of skin blood flowmotion frequency intervals (FI), related to endothelial (0.009-0.02 Hz), sympathetic (0.02-0.06 Hz), myogenic (0.06-0.2 Hz), respiratory (0.2-0.6 Hz) and heart (0.6-1.6 Hz) activities, was also measured in PU(2)/Hz, by means of spectral analysis of the skin LDF signal registered before and following iontophoresis of CGRP or saline in the definitive study. A significantly higher per cent increase in skin perfusion compared to baseline was observed following CGRP than saline iontophoresis (548+/-369% vs. 326+/-192%, p<0.05), with higher hyperaemic response to pure saline than CGRP iontophoresis in only five subjects. A significant increase (p<0.05) in PSD mean value of the five FI considered, was also observed following CGRP iontophoresis, while saline iontophoresis elicited a significant increase (p<0.05) only in PSD of the FI related to endothelial, respiratory and heart activity. These findings demonstrated that LDF coupled with iontophoresis is a feasible method in evaluating the vasodilator effect of exogenous CGRP in human skin and suggest that this peptide directly or indirectly induces a smooth muscle vascular cells and sympathetic fibres stimulation.

Myocardial infarction in a young athlete with non-obstructive hypertrophic cardiomyopathy and normal coronary arteries

We describe an acute myocardial infarction in a young athlete with non-obstructive hypertrophic cardiomyopathy (HCM) and normal coronary arteries. A 18 year old athlete came to our attention for dispnoea and chest pain during effort. Echocardiography showed non-obstructive HCM, with restrictive physiology. Cardiac catheterization and coronary angiography showed elevated pulmonary artery pressure and normal coronary arteries. He was discharged on sotalol and diuretics. Nine months later, he was resuscitated from a cardiac arrest during mild effort. The ECG revealed a high rate of atrial fibrillation with significant ST-T changes, and echocardiography an akinesia of interventricular septum. Cardiac enzymes were elevated. The coronary angiogram showed normal coronary arteries. This case is important as a reminder that acute myocardial infarction is not only due to coronary artery disease, and that atrial fibrillation may represent a trigger of serious cardiovascular events in patients with HCM.

Sarcoglycan immunoreactivity is lacking in infantile hypertrophic pyloric stenosis. A confocal laser scanning microscopic study

OBJECTIVES

The Dystrophin-Glycoprotein Complex (DGC) is a large multisubunit complex that plays a crucial role in maintaining the structural integrity and physiology of muscle fibers. Dystrophin has been reported to be absent in the pyloric muscle of infantile hypertrophic pyloric stenosis (IHPS) patients. The present study was designed to investigate the other two patterns of DGC (dystroglycan and sarcoglycan complexes) in normal pyloric muscle and their possible modifications in IHPS patients.

METHODS

Ten pyloric muscle biopsies were obtained from babies operated for IHPS and five control pylorus biopsy taken at autopsy from cases without gastrointestinal disease. The DGC sub-complexes (beta-dystroglican and beta, delta- sarcoglycans) were localized immunohistochemically using specific monoclonal antibodies. The results were evaluated using a confocal laser scanning microscope.

RESULTS

Positive immunolocalization of the two DGC sub complexes was demonstrated in the smooth muscle cells (SMCs) of the pyloric region of control patients. Similarly, a positive immune expression of beta-dystroglican was observed in the pyloric SMCs of IHPS patients. On the other hand a negative immunoreaction for sarcoglycans was recorded within the full thickness of the pyloric SMCs of these patients.

CONCLUSIONS

The absence of sarcoglycans within the hypertrophied pyloric muscle may be a predisposing factor in the pathogenesis of IHPS since it could alter the normal physiology of SMCs through the modifications of structural integrity of sarcolemma and signaling between the extracellular and intracellular compartment.

Absent post-ischemic increase of blood flowmotion in the cutaneous microcirculation of healthy chronic cigarette smokers

The aim of the study was to investigate whether chronic cigarette smoke habit is associated with changes of laser Doppler (LD) skin blood flowmotion (SBF). We performed spectral analysis of skin forearm LD signal detected by a LD flowmetry (Periflux PF4, Perimed, Sweden) before and during forearm post-ischemic hyperaemia, in 14 healthy chronic smoker subjects and 14 age and sex matched nonsmoker subjects. Forearm skin ischemia was obtained by a pneumatic cuff, positioned at the right arm and inflated for 3 minutes to 30 mmHg above systolic blood pressure. Power spectral density (PSD) of the SBF total spectrum (0.009-1.6 Hz), as well as 0.009-0.02 Hz , 0.02-0.06 Hz, 0.06-0.2 Hz, 0.2-0.6 Hz and 0.6-1.6 Hz frequency intervals (FI), referred to endothelial, sympathetic, myogenic, respiratory and heart activity, respectively, were measured in LD conventional perfusion units (PU)/Hz. Smokers showed a basal SBF total spectrum PSD mean values not significantly different from nonsmokers (2.14+/-1.58 PU/Hz and 1.93+/-1.35 PU/Hz, respectively). Following ischemia, PSD mean value of SBF total spectrum, as well of five FI considered, significantly increased in nonsmokers (p<0.01), while it did not significantly change in smokers. Smokers and nonsmokers did not differ in basal and post-ischemic skin LD perfusion mean values. The absent post-ischemic increase of the SBF and of its FI related to endothelial and myogenic activity in smokers can be an early sign of skin microcirculatory impairment, suggesting an endothelial and smooth muscle skin microvascular dysfunction associated with the chronic smoking habit.

[Cardiovascular remodelling in patients with sub-clinical hypothyroidism]

Sub-clinical hypothyroidism is defined by elevated serum thyroid-stimulating hormone level in the face of normal free thyroid hormone values. The role of sub-clinical hypothyroidism as independent risk factor for atherosclerosis has been suggested by clinical studies which demonstrated a higher prevalence of peripheral arterial disease, aortic atherosclerosis and coronary artery disease, in patients affected by this pathological condition. This association have been confirmed by the assessment of subclinical atherosclerosis by means of B-mode ultrasonography. Using this method an higher intima-media thickness (IMT) of carotid artery, a close marker of early atherosclerosis changes, have been found in patients with subclinical hypothyroidism compared to control euthyroid subjects. Levothyroxine replacement therapy of sub-clinical hypothyroidism was able to improve both the carotid IMT and atherogenic lipid profile, suggesting that lipid infiltration of the endothelium may represent a mechanism underlying the atherosclerotic process in patients with this pathological condition. Morphologic and functional changes of the myocardial tissue has been also demonstrated in patients with sub-clinical hypothyroidism, using ultrasonic backscatter video densitometry. All these data provide evidence of cardiovascular remodelling in patients with sub-clinical hypothyroidism. Vascular remodelling in sub-clinical hypothyroidism patients could be also studied by means of backscatter analysis of carotid artery, a method which allows the assessment of vascular sclerosis. Our preliminary results using this method suggested that not only atherosclerosis by also sclerosis characterises vascular remodelling in sub-clinical hypothyroidism patients.

Long term effects of bosentan treatment in adult patients with pulmonary arterial hypertension related to congenital heart disease (Eisenmenger physiology): safety, tolerability, clinical, and haemodynamic effect

BACKGROUND

Oral bosentan is an established treatment for pulmonary arterial hypertension (PAH).

OBJECTIVE

To evaluate safety, tolerability, and clinical and haemodynamic effects of bosentan in patients with PAH related to congenital heart disease (CHD).

PATIENTS

22 patients with CHD related PAH (8 men, 14 women, mean (SD) age 38 (10) years) were treated with oral bosentan (62.5 mg x 2/day for the first 4 weeks and then 125 mg x 2/day).

MAIN OUTCOME MEASURES

Clinical status, liver enzymes, World Health Organisation (WHO) functional class, resting oxygen saturations and 6-min walk test (6MWT) were assessed at baseline and at 1, 3, 6, and 12 months. Haemodynamic evaluation with cardiac catheterisation was performed at baseline and at 12 month follow-up.

RESULTS

12 patients had ventricular septal defect, 5 atrioventricular canal, 4 single ventricle, and 1 atrial septal defect. All patients tolerated bosentan well. No major side effects were seen. After a year of treatment, an improvement was seen in WHO functional class (2.5 (0.7) v 3.1 (0.7); p<0.05), oxygen saturation at rest (87 (6%) v 81 (9); p<0.001), heart rate at rest (81 (10) v 87 (14) bpm; p<0.05), distance travelled in the 6MWT (394 (73) v 320 (108) m; p<0.001), oxygen saturation at the end of the 6MWT (71 (14) v 63 (17%); p<0.05), Borg index (5.3 (1.8) v 6.5 (1.3); p<0.001), pulmonary vascular resistances index (14 (9) v 22 (12) WU m(2); p<0.001), systemic vascular resistances index (23 (11) v 27 (10) WU.m(2); p<0.01), pulmonary vascular resistances index/systemic vascular resistances index (0.6 (0.5) v 0.9 (0.6); p<0.05); pulmonary (4.0 (1.3) v 2.8 (0.9) l/min/m2; p<0.001) and systemic cardiac output (4.2 (1.4) v 3.4 (1.1) l/min/m2; p<0.05).

CONCLUSIONS

Bosentan was safe and well tolerated in adults with CHD related PAH during 12 months of treatment. Clinical status, exercise tolerance, and pulmonary haemodynamics improved considerably.

Integrins, muscle agrin and sarcoglycans during muscular inactivity conditions: an immunohistochemical study

Sarcoglycans are transmembrane proteins that seem to be functionally and pathologically as important as dystrophin. Sarcoglycans cluster together to form a complex, which is localized in the cell membrane of skeletal, cardiac, and smooth muscle. It has been proposed that the dystrophin-glycoprotein complex (DGC) links the actin cytoskeleton with the extracellular matrix and the proper maintenance of this connection is thought to be crucial to the mechanical stability of the sarcolemma. The integrins are a family of heterodimeric cell surface receptors which play a crucial role in cell adhesion including cell-matrix and intracellular interactions and therefore are involved in various biological phenomena, including cell migration, and differentiation tissue repair. Sarcoglycans and integrins play a mechanical and signaling role stabilizing the systems during cycles of contraction and relaxation. Several studies suggested the possibility that integrins might play a role in muscle agrin signalling. On these basis, we performed an immunohistochemical analyzing sarcoglycans, integrins and agrin, on human skeletal muscle affected by sensitive-motor polyneuropathy, in order to better define the correlation between these proteins and neurogenic atrophy due to peripheral neuropathy. Our results showed the existence of a cascade mechanism which provoke a loss of regulatory effects of muscle activity on costameres, due to loss of muscle and neural agrin. This cascade mechanism could determine a quantitative modification of transmembrane receptors and loss of alpha7B could be replaced and reinforced by enhanced expression of the alpha7A integrin to restore muscle fiber viability. Second, it is possible that the reduced cycles of contraction and relaxation of muscle fibers, during muscular atrophy, provoke a loss of mechanical stresses transmitted over cell surface receptors that physically couple the cytoskeleton to extracellular matrix. Consequently, these mechanical changes could determine modifications of chemical signals through variations of pathway structural integrins, and alpha7A could replace alpha7B.

Stress stent fracture: Is stent angioplasty really a safe therapeutic option in native aortic coarctation?

An 11-year-old boy was successfully treated by stent implantation for native aortic coarctation. At the 1-year control a severe re-coarctation was found at Doppler analysis and subsequent angiography revealed a transverse stent fracture. A stent-in-stent implantation was performed. Several hypotheses could explain this complication. Interventional cardiologists may pay more attention in following up these patients!

Regulation of dendritic cell migration and adaptive immune response by leukotriene B4 receptors: a role for LTB4 in up-regulation of CCR7 expression and function

Trafficking of dendritic cells (DCs) to peripheral tissues and to secondary lymphoid organs depends on chemokines and lipid mediators. Here, we show that bone marrow-derived DCs (BM-DCs) express functional leukotriene B4 (LTB4) receptors as observed in dose-dependent chemotaxis and calcium mobilization responses. LTB4, at low concentrations, promoted the migration of immature and mature DCs to CCL19 and CCL21, which was associated with a rapid (30-minute) increase of CCR7 expression at the membrane level. At longer incubation times (6 hours), gene array analysis revealed a promoting role of LTB4, showing a significant increase of CCR7 and CCL19 mRNA levels. BM-DCs cultured from BLT1-/- or BLT1/2-/- mice showed a normal phenotype, but in vivo BLT1/2-/-DCs showed dramatic decrease in migration to the draining lymph nodes relative to wild-type (WT) DCs. Consistent with these observations, BLT1/2-/- mice showed a reduced response in a model of 2,4-dinitro-fluorobenzene (DNFB)-induced contact hypersensitivity. Adoptive transfer of 2,4-dinitrobenzene sulfonic acid (DNBS)-pulsed DCs directly implicated the defect in DC migration to lymph node with the defect in contact hypersensitivity. These results provide strong evidence for a role of LTB4 in regulating DC migration and the induction of adaptive immune responses.