Suspended InAs nanowire Josephson junctions assembled via dielectrophoresis.

We present a novel technique for the realization of suspended Josephson junctions based on InAs semiconductor nanowires. The devices are assembled using a technique of drop-casting guided by dielectrophoresis, which allows one to finely align the nanostructures on top of the electrodes. The proposed architecture removes the interaction between the nanowire and the substrate which is known to influence disorder and the orientation of the Rashba vector. The relevance of this approach in view of the implementation of hybrid Josephson junctions based on semiconducting nanowires coupled with high-temperature superconductors is discussed.

(99m)Tc-DTPA scintigraphy assesses the absence of glomerular filtration rate impairment of Aliskiren in high-risk hypertensive subjects. A 12-month follow-up study.

AIM: Glomerular filtration rate (GFR) is commonly calculated using the modification of diet in renal disease (MDRD) and Cockroft-Gault (CG) formulas and recently by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) algorithm and not directly measured, so that the real impact of antihypertensive therapy on GFR could not be well defined. In this study, the effect of Aliskiren on the GFR measured by radionuclide clearance of 99mTc-diethylene triamine penta-acetic acid (DTPA) was investigated. METHODS: In 106 hypertensive subjects (53% men) aged 61.9±12.7 years with uncontrolled blood pressure (BP) receiving at least 2 antihypertensive medications, Aliskiren was added once-daily at a dose of 150-300 mg for 12 months. Clinic BP measurements were taken at every follow-up visit (1st, 6th and 12th month), while 24-hours ambulatory BP and GFR (in mL/min/1.73 m2) were evaluated at baseline and at the end of the follow-up. Analysis of variance for repeated measures of BP, GFR and microalbuminuria was provided. RESULTS: With the use of Aliskiren a significant reduction of BP and microalbuminuria was found (P<0.0001). Only in male population, a significant reduction in GFR calculated with CKD-EPI (82.4±15 vs. 78.6±18.2, P<0.01) and CG (81.6±29.5 vs. 74.2±28.4, P<0.0001) formulas was observed. This impairment of GFR was not found either with MDRD formula (70.5±19.6 vs. 68.3±23.4) or by radionuclide clearance (62.4±18.6 vs. 61.4±20.5). CONCLUSION: This study seems to demonstrate that the efficacy on BP control of Aliskiren is not accompanied by an impairment of GFR. In order to evaluate the effect of Aliskiren on GFR scintigraphy technique or MDRD formula resulted to be the most accurate methods.

Aliskiren improves blood pressure control and prevents cardiac damage in high-risk hypertensive subjects.

AIM: Longitudinal study aimed to evaluate the antihypertensive efficacy, safety and the effect on cardiac damage of Aliskiren, administered to a group of high-risk hypertensive patients with mild impairment of renal function and uncontrolled blood pressure (BP) despite a two-drug antihypertensive treatment. METHODS: One hundred and six patients (56 men and 50 females) aged 61.9±12.7 years, were assigned to receive Aliskiren 150-300 mg once-daily for 12 months. Clinic BP measurements were taken at every follow-up visit (1st, 6th and 12th month), while biochemical tests, estimated glomerular filtration rate (eGFR), 24-hours ambulatory BP measurements (ABMP) and echocardiography were evaluated at baseline and at the end of follow-up. Analysis of variance for repeated measures compared BP, left ventricular mass index (LVMI) and eGFR values changes. RESULTS: A significant reduction (all P<0.0001) of clinic systolic (-28.6 mmHg) and diastolic (-12.8 mmHg) BP values, mean 24h-systolic (-12.3 mmHg) and 24h-diastolic (-6.5 mmHg), day-time systolic (-11.5 mmHg) and diastolic (-6.4 mmHg), night-time systolic (-11.9 mmHg) and diastolic (-7 mmHg) ABPM values and in the use of antihypertensive drugs was observed (3.0±0.9 vs. 2.0±0.7, p=0.01). LVMI was significantly reduced (130.2±36.1 vs. 115.9±33.4 g/m2, P<0.0001); eGFR was steady (75.3±17.3 vs. 73.1±21.5 ml/min/1.73m2, P>0.05). Putative adverse events caused withdrawal of 7 subjects (6 for gastrointestinal disturbances, 1 for alopecia). CONCLUSION: Aliskiren was effective in decreasing both clinical and ABPM values and in reducing LVMI in both genders without any influence on eGFR. The treatment resulted safe, even in combination with ACE-inhibitors and angiotensin II receptor blockers. A significant reduction in the use of concomitant antihypertensive drugs was observed.

Aliskiren improves blood pressure control and prevents cardiac damage in high-risk hypertensive subjects.

Aim: Longitudinal study aimed to evaluate the antihypertensive efficacy, safety and the effect on cardiac damage of Aliskiren, administered to a group of high-risk hypertensive patients with mild impairment of renal function and uncontrolled blood pressure (BP) despite a two-drug antihypertensive treatment. Methods: One hundred and six patients (56 men and 50 females) aged 61.9±12.7 years, were assigned to receive Aliskiren 150-300 mg once-daily for 12 months. Clinic BP measurements were taken at every follow-up visit (1st, 6th and 12th month), while biochemical tests, estimated glomerular filtration rate (eGFR), 24-hours ambulatory BP measurements (ABMP) and echocardiography were evaluated at baseline and at the end of follow-up. Analysis of variance for repeated measures compared BP, left ventricular mass index (LVMI) and eGFR values changes. Results: A significant reduction (all P<0.0001) of clinic systolic (-28.6 mmHg) and diastolic (-12.8 mmHg) BP values, mean 24h-systolic (-12.3 mmHg) and 24h-diastolic (-6.5 mmHg), day-time systolic (-11.5 mmHg) and diastolic (-6.4 mmHg), night-time systolic (-11.9 mmHg) and diastolic (-7 mmHg) ABPM values and in the use of antihypertensive drugs was observed (3.0±0.9 vs. 2.0±0.7, p=0.01). LVMI was significantly reduced (130.2±36.1 vs. 115.9±33.4 g/m2, P<0.0001); eGFR was steady (75.3±17.3 vs. 73.1±21.5 ml/min/1.73m2, P>0.05). Putative adverse events caused withdrawal of 7 subjects (6 for gastrointestinal disturbances, 1 for alopecia). Conclusion: Aliskiren was effective in decreasing both clinical and ABPM values and in reducing LVMI in both genders without any influence on eGFR. The treatment resulted safe, even in combination with ACE-inhibitors and angiotensin II receptor blockers. A significant reduction in the use of concomitant antihypertensive drugs was observed.

Arterial hypertension and thyroid disorders: what is important to know in clinical practice?

This review describes the pathogenic mechanisms of blood pressure (BP) regulation and long-term control in thyroid disorders. Variations from the euthyroid status affect virtually all physiological systems but the effects on the cardiovascular system are particularly pronounced. Thyroid disorders induce several hemodynamic changes leading to elevated BP as a consequence of their interaction with endothelial function, vascular reactivity, renal hemodynamic and renin-angiotensin system. However, in thyroid disorders, the regulation of BP and the development and maintenance of variable forms of arterial hypertension (HT) are different. Hyperthyroidism results in an increased endothelium-dependent responsiveness secondary to the shear stress induced by the hyperdynamic circulation, and contributes to reduce vascular resistance. Conversely, hypothyroidism is accompanied by a marked decrease in sensitivity to sympathetic agonists with an increase of peripheral vascular resistance and arterial stiffness. Furthermore in animal models, hypothyroidism reduces the endothelium-dependent and nitric oxide-dependent vasodilatation. HT due to thyroid disorders is usually reversible with achievement of euthyroidism, but in some cases pharmacological treatment for BP control is required. In hyperthyroidism, ß-blockers are the first-choice treatment to control BP but when they are contraindicated or not tolerated, ACE-inhibitors or calcium-channel blockers (CCB) are recommended. Hypothyroidism is a typical low rennin HT form showing a better antihypertensive response to CCB and diuretics; indeed in hypothyroidism a low-sodium diet seems further to improve BP control. Randomized clinical trials to compare the efficacy on BP control of the antihypertensive treatment in thyroid disorders are needed.

Veralipride-induced acute coronary syndrome unmasking a non-secreting pheochromocytoma.

The administration of veralipride, a centrally acting dopaminergic type 2 (DA2) receptor antagonist, can decrease hot flushes and improve bone density in post-menopausal women (1). Therefore, it entails an alternative to hormone replacement therapy (HRT) in women who have contraindications to estrogen (1). We herein describe the case of a 52-yr-old lady who presented with an acute coronary syndrome shortly after taking veralipride. Based on knowledge that DA2 receptor antagonists trigger catecholamine release (2), a pheochromocytoma was suspected and thereafter diagnosed and excised. Therefore, this is the first case reporting on veralipride unmasking a silent pheochromocytoma.

Extracellular matrix-enriched polymeric scaffolds as a substrate for hepatocyte cultures: in vitro and in vivo studies.

Tissue engineering is a promising approach to developing hepatic tissue suitable for the functional replacement of a failing liver. The aim of the present study was to investigate whether an extracellular cell matrix obtained from fibroblasts-cultured within scaffolds of hyaluronic acid (HYAFF) could influence the proliferation rate and survival of rat hepatocytes both during long-term culture and after in vivo transplantation. Cultures were evaluated by histological and morphological analysis, a proliferation assay and metabolic activity (albumin secretion). Hepatocytes cultured in extracellular matrix-enriched scaffolds exhibited a round cellular morphology and re-established cell-cell contacts, growing into aggregates of several cells along and/or among fibers in the fabric. Hepatocytes were able to secrete albumin up to 14 days in culture. In vivo results demonstrated the biocompatibility of HYAFF-11 implanted in nude mice, in which hepatocytes maintained small well-organised aggregates until the 35th day. In conclusion, the presence of a fibroblast-secreted extracellular matrix improved the biological properties of the hyaluronan scaffold, favoring the survival and morphological integrity of hepatocytes in vitro and in vivo.

Elevated lung cancer risk shortly after smoking cessation: is it due to a reduction of endotoxin exposure?

Several reports indicate that the risk of lung cancer increases slightly for a short period of time after cessation of smoking while the risk of adverse cardiovascular events drops immediately. Recent studies on subjects occupationally exposed to organic dust-containing endotoxin have revealed lower than expected rates of lung cancer. There is experimental evidence that stimulation of the immune system by endotoxin has a protective effect against cancer. Tobacco smoke has been shown to contain high levels of endotoxin. We therefore postulate that cessation of smoking eliminates the protective effect of endotoxin. Any benefit conferred by endotoxin does not, however, justify smoking. As the inverse relationship between exposure to endotoxin and the risk of lung cancer is a strong one, endotoxin-like substances could form the basis of vaccination strategies.

Magnetic resonance imaging volumetric and phosphorus 31 magnetic resonance spectroscopy measurements in schizophrenia.

The purpose of this study was to examine the relationship between phosphorus magnetic resonance spectroscopy (31P MRS) parameters and left prefrontal volumes in both patients with schizophrenia and healthy subjects. 31P MRS parameters and magnetic resonance imaging (MRI) volumetric data were collected in the left prefrontal region in 10 patients with schizophrenia and 10 healthy subjects of comparable age, handedness, sex, educational level, and parental educational level. No correlations were found between any MRS parameter and grey matter volumes in the combined subjects. Phosphomonoester (PME) and grey matter volumes, however, were both correlated negatively with age. PMEs were found to be decreased, and calculated intracellular magnesium ([Mg2+]intra) was found to be increased in the patients with schizophrenia compared with healthy subjects after adjusting for left prefrontal grey and white matter, total brain volume, and age. These findings suggest that cortical grey and white manner volumes are not directly related to PME and [Mg2+]intra abnormalities in schizophrenia patients.

[Spectral analysis and color-coded Doppler study of the changes in aortic regurgitation induced by vasodilators in asymptomatic patients with severe aortic insufficiency]. / Studio Doppler ad analisi spettrale e a codice di colori delle modificazioni del rigurgito aortico indotte da vasodilatatori in pazienti asintomatici affetti da insufficienza aortica grave.

The acute effects of 20 mg of sublingual nifedipine in 12 patients with chronic severe aortic regurgitation were evaluated with M-mode echocardiography, continuous wave and colour Doppler. After nifedipine, heart rate increased from 68 +/- 8 to 82 +/- 11 beats/m' (p less than 0.001); arterial systolic and diastolic pressures decreased from 143 +/- 16 to 129 +/- 9 mmHg (p less than 0.01) and from 61 +/- 11 to 53 +/- 17 mmHg (p less than 0.01) respectively. Left ventricular systolic and diastolic diameters also decreased from 50 +/- 4 to 46 +/- 4 mm (p less than 0.01) and 76 +/- 6 to 72 +/- 6 mm (p less than 0.01) respectively; the slightly increase in fractional shortening which occurred was not significant. The aortic systolic and diastolic velocity integrals decreased from 38 +/- 9 to 34.7 +/- 8 cm (p less than 0.01) and from 203 +/- 41 to 163 +/- 29 cm (p less than 0.001); the diastolic slope of the velocity curve increased a little but significantly: from 334 +/- 70 to 394 +/- 70 cm/sec2 (p less than 0.01). With colour Doppler, protodiastolic jet areas decreased by 19% in the long parasternal view (p less than 0.01), by 28% in the apical view (p less than 0.001), by 26% in the short-axis view (p less than 0.01); the length of the jets in the long parasternal view decreased by 14% (p less than 0.001), but the height did not change significantly. Positive changes from acute nifedipine administration are present in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

[Incidence and significance of ventricular arrhythmia after surgical correction of Fallot's tetralogy]. / Frequenza e significato delle aritmie ventricolari dopo correzione chirurgica della tetralogia di Fallot.

Patients may die suddenly after surgical repair of tetralogy of Fallot. Ventricular arrhythmias (VA) have been considered the possible cause of sudden death in such patients by many Authors. We evaluated the incidence and severity of VA in a group of 65 patients (25 females and 40 males) after surgical repair of tetralogy of Fallot. The age at the time of follow-up varied between 8 and 47 years. We divided our population into 4 groups (A, B, C, D) according to the surgical results (poor and good) and to the age of total correction (less than 12, greater than 12 years). We tested the presence and severity of VA in the different groups of patients and we found a significant difference in the incidence of VA between patients who underwent surgery before and after the age of 12 years (p = 0.0083). The surgical result did not show a significant relation with VA (p = 0.47). Among the patients submitted to surgical repair in the adult age, however, more serious VA are present in those with poor surgical result, and both our cases of sudden death occurred in this kind of patient. We speculate that postoperative ventricular arrhythmias are related to right ventricular function, which in turn appears to be worse in patients who underwent surgical correction at a later age. At last only perspective trials will be able to assess the significance of VA and their relationship with sudden death in this kind of patient.

[Holter evaluation in elderly subjects without cardiovascular disease]. / Valutazione Holter nei soggetti anziani senza malattia cardiovascolare.

In 2001, 22% of the Italian population will be over 60 and the morbidity/mortality rate due to cardiovascular disease is extremely high in this age group. However reports in the literature disagree on the incidence of arrhythmias. The present study assesses the incidence of hyper and hypokinetic arrhythmias in a group of "over-sixties" with no clinical signs of cardiovascular and/or systemic disease. Twenty-four hour Holter monitoring was performed on 103 patients (49 male, 54 female) after clinical examination anamnesis, ECG and chest X-rays had shown a normal picture. There was a wide variation in total heart beats and maximum-minimum cardiac frequency but none of these variables appeared related to age. Total heart beat and minimum cardiac frequency figures were significantly higher among the bedridden (p less than 0.01 and p less than 0.05 respectively). There were no supraventricular arrhythmias in 63% of the patients and only simple forms were encountered in the 38 patients presenting such arrhythmias. Ventricular arrhythmias were absent in 60% of the group, while among the 41 patients presenting these phenomena, as many as 32 presented simple forms, while only 5 were in Lown's class IV and 2 of these due to a single pairing, 1 a single triplet. No significant difference was found in the incidence of supraventricular and ventricular arrhythmias among the 60-69 and 70-79 age groups. There were 3 cases of transitory nocturnal grade I atrioventricular block, but no advanced hypokinetic arrhythmias. The ST-T interval revealed no alterations definitely indicative of ischaemia, despite the presence of alterations in the basal morphology. To sum up, the study revealed a low incidence of supraventricular and ventricular arrhythmias in the elderly population examined and most importantly, the vast majority of those encountered were simple forms.

[Comparison of two-dimensional echocardiography, angiocardioscintigraphy and cineventriculography in the study of left ventricular wall motion in ischemic cardiopathy]. / Confronto tra ecocardiografia bidimensionale, angiocardioscintigrafia e cineventricolografia nello studio della motilità di parete del ventricolo sinistro nella cardiopatia ischemica.

Thirty-two patients with non acute myocardial infarction (inferior in twenty, anterior in ten, anterior and inferior in two) were studied with contrast left ventriculography, two-dimensional echocardiography and radionuclide angiography to assess left ventricular wall motion. We adopted the CASS criteria for the standard left ventriculography, and the Mayo Clinic classification for the echocardiographic study. Radionuclide angiography studies were obtained in left anterior oblique view; the images were evaluated with the use of Walsh-Hadamard transform; the left ventricle was divided in basal and apical septal, apical, posterolateral, posterobasal and two central segments. We tried to correlate the findings of the three techniques both for single segments and larger regions made of contiguous segments. Left ventricular angiography and two-dimensional echocardiography showed a fair concordance for both anterobasal and posterolateral left ventricular wall, whereas for the septal, apical and posterolateral regions contrast and radionuclide angiography had the best correlation. Compared to left ventricular angiography two-dimensional echocardiography shows better sensitivity than radionuclide angiography; the latter is more specific in defining left ventricular wall motion. The two non invasive techniques are therefore helpful in the evaluation of wall motion and their role is complementary.