Efficacy of non-invasive mechanical ventilation in the general ward in patients with chronic obstructive pulmonary disease admitted for hypercapnic acute respiratory failure and pH < 7.35: a feasibility pilot study.

AIM: To date non-invasive (NIV) mechanical ventilation use is not recommended in chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF) and pH < 7.30 outside a 'protected environment'. We assessed NIV efficacy and feasibility in improving arterial blood gases (ABG) and in-hospital outcome in patients with ARF and severe respiratory acidosis (RA) admitted to an experienced rural medical ward. METHODS: This paper is a prospective pilot cohort study conducted in the General Medicine Ward of Budrio's District Hospital. Two hundred and seventy-two patients with ARF were admitted to our Department, 112, meeting predefined inclusion criteria (pH < 7.35, PaCO2 > 45 mmHg). Patients were divided according to the severity of acidosis into: group A (pH < 7.26), group B (7.26 ≤ pH < 7.30) and group C (7.30 ≤ pH < 7.35). ABG were assessed at admission, at 2-6 h, 24 h, 48 h and at discharge. RESULTS: Group A included 55 patients (24 men, mean age: 80.8 ± 8.3 years), group B 31 (12 men, mean age: 80.3 ± 9.4 years) and group C 26 (15 men, mean age: 78.6 ± 9.9 years). ABG improved within the first hours in 92/112 (82%) patients, who were all successfully discharged. Eighteen percent (20/112) of the patients died during the hospital stay, no significant difference emerged in mortality rate (MR) within the groups (23%, 16% and 8%, for groups A, B and C, respectively) and between patients with or without pneumonia: 8/29 (27%) versus 12/83 (14%). On multivariable analysis, only age and Glasgow Coma Scale had an impact on the clinical outcome. CONCLUSION: In a non-'highly protected' environment such as an experienced medical ward of a rural hospital, NIV is effective not only in patients with mild, but also with severe forms of RA. MR did not vary according to the level of initial pH.

Possible role of tocopherols in the modulation of host microRNA with potential antiviral activity in patients with hepatitis B virus-related persistent infection: a systematic review.

Hepatitis B virus (HBV) infection represents a serious global health problem and persistent HBV infection is associated with an increased risk of cirrhosis, hepatocellular carcinoma and liver failure. Recently, the study of the role of microRNA (miRNA) in the pathogenesis of HBV has gained considerable interest as well as new treatments against this pathogen have been approved. A few studies have investigated the antiviral activity of vitamin E (VE) in chronic HBV carriers. Herein, we review the possible role of tocopherols in the modulation of host miRNA with potential anti-HBV activity. A systematic research of the scientific literature was performed by searching the MEDLINE, Cochrane Library and EMBASE databases. The keywords used were 'HBV therapy', 'HBV treatment', 'VE antiviral effects', 'tocopherol antiviral activity', 'miRNA antiviral activity' and 'VE microRNA'. Reports describing the role of miRNA in the regulation of HBV life cycle, in vitro and in vivo available studies reporting the effects of VE on miRNA expression profiles and epigenetic networks, and clinical trials reporting the use of VE in patients with HBV-related chronic hepatitis were identified and examined. Based on the clinical results obtained in VE-treated chronic HBV carriers, we provide a reliable hypothesis for the possible role of this vitamin in the modulation of host miRNA profiles perturbed by this viral pathogen and in the regulation of some cellular miRNA with a suggested potential anti-HBV activity. This approach may contribute to the improvement of our understanding of pathogenetic mechanisms involved in HBV infection and increase the possibility of its management and treatment.

Quantum maximum entropy principle for fractional exclusion statistics.

Using the Wigner representation, compatibly with the uncertainty principle, we formulate a quantum maximum entropy principle for the fractional exclusion statistics. By considering anyonic systems satisfying fractional exclusion statistic, all the results available in the literature are generalized in terms of both the kind of statistics and a nonlocal description for excluson gases. Gradient quantum corrections are explicitly given at different levels of degeneracy and classical results are recovered when ℏ→0.

Association between hepatitis B or hepatitis C virus infection and risk of pancreatic adenocarcinoma development: a systematic review and meta-analysis.

BACKGROUND: Pancreatic adenocarcinoma (PAC) is an aggressive cancer with a poor prognosis. To date, PAC causes are still largely unknown. Antigens and replicative sequences of oncogenic hepatitis B (HBV) and hepatitis C (HCV) virus were detected in different extra-hepatic tissues, including pancreas. OBJECTIVE: a systematic review and meta-analysis of epidemiological studies assessing PAC risk in patients with HBV/HCV chronic infections. METHODS: In September 2012, we extracted the articles published in Medline, Embase and the Cochrane Library, using the following search terms: "chronic HBV" and "HCV", "hepatitis", "PAC", "risk factors", "epidemiology". Only case/control (C/C), prospective/retrospective cohort studies (PCS/RCS) written in English were collected. RESULTS: four hospital-based C/C studies and one PCS, in HBV-infected patients and two hospital-based C/C studies and one RCS in HCV-infected subjects met inclusion criteria. In these studies HBsAg positivity enhanced significantly PAC risk (RR = 1.18, 95% CI:1.04-1.33), whereas HBeAg positivity (RR = 1.31, 95% CI:0.85-2.02) as well as HBsAg negative/HBcAb positive/HBsAb positive pattern (RR = 1.12, 95% CI:0.78-1.59) and HBsAg negative/HBcAb positive/HBsAb negative pattern (RR = 1.30, 95% CI:0.93-1.84) did not. Relationship between PAC risk and anti-HCV positivity was not significant, although it reached a borderline value (RR = 1.160, 95% CI:0.99-1.3). CONCLUSIONS: HBV/HCV infection may represent a risk factor for PAC, but the small number of available researches, involving mainly populations of Asian ethnicity and the substantial variation between different geographical areas in seroprevalence of HBV/HCV-antigens/antibodies and genotypes are limiting factors to present meta-analysis.

Photoreceptors for a light biotransducer: a comparative study of the electrical responses of two (type-1) opsins.

The increasing interest in photoactivated proteins as natural replacements for standard inorganic materials in photocells leads to the comparison analysis of bacteriorhodopsin and proteorhodopsin, two widely diffused proteins belonging to the family of type-1 opsins. These proteins share similar behaviors but exhibit relevant differences in the sequential chain of the amino acids constituting their tertiary structure. The use of an impedance network analog to model the protein main features provides a microscopic interpretation of a set of experiments on their photo-conductance properties. In particular, this model links the protein electrical responses to the tertiary structure and to the interactions between neighboring amino acids. The same model is also used to predict the small-signal response in terms of the Nyquist plot. Interestingly, these rhodopsins are found to behave like a wide-gap semiconductor with intrinsic conductivities of the order of 10⁻7 S cm⁻¹.

Acanthosis nigricans in adolescents: a practical approach.

Acanthosis nigricans (AN) is a lesion affecting localized areas of the skin in persons with obesity and/or hyperinsulinemia. Biochemical mechanisms responsible for developing this hyperplastic lesion are unclear, but likely involve local cutaneous growth factors. It is associated with obesity, endocrinopathies (insulin resistance, diabetes mellitus, Cushing disease and acromegaly) and visceral malignancies. Clinicians should recognize AN because it may herald disorders ranging from endocrine disturbances to malignancy. Early recognition of these conditions is essential to identify children who are at highest risk for developing type 2 diabetes and further metabolic abnormalities.

Adolescent health care in Italy: a mini-review.

The purpose of this mini-review is to present the National Health System and services available for adolescents in Italy, and to review the most relevant data on morbidity and mortality in Italian teens. Adolescent medicine in Italy is not a separate speciality, but there are some distinct services for adolescents in paediatric departments or gynaecologic wards, mostly in large cities where university hospitals or hospital of national relevance are located. Primary health care in Italy is provided mainly by general practitioners (GPs) and pediatricians, and on-call physicians (Guardia Medica) for after-hours medical care and services. The number of centres providing care for adolescents in Italy is 4097 (50% of these are in the North of Italy, 20% in the Central regions and 20% in the South and Islands). The population of Italy on January 1st 2011 was approximately 60,477,881 and the number of adolescents, aged 10 to 19 years, was 6,214,000. The most frequent causes of death in adolescents are motor vehicle accidents - more than half of which are related to drug or alcohol use - followed by cancer and suicide. In primary care, adolescents present with a large number of issues, particularly upper respiratory infections, musculoskeletal problems, pain syndromes, obesity, eating disorders, dermatological issues, mood and somatoform disorders, school and mental health problems, and chronic fatigue, many of which require a coordinated, multidisciplinary management approach. The estimated population with a chronic illness is 8%. There are no specific protocols for the transition to adult medicine physicians for patients with chronic diseases or special health needs. In order to improve the quality and quantity of education in adolescent health for paediatricians and GPs, the Study Group of Emilia and Romagna Region for Adolescent Health Care (SGA-ER) is going to organize, beginning in 2012, a two year educational intervention course in adolescent health.

The SGA-ER educational intervention in adolescent health care for Italian physicians: goals, content and instructional design.

Adolescent medicine is a field dedicated to helping young people grow and thrive, in relation to their particular stage of development. In Italy, adolescent medicine is not a distinct speciality, but it is practised in some services for adolescents in paediatric departments. Increasing educational opportunities in adolescent health may help to accelerate the development and dissemination of new and improved therapeutic approaches for serving youth and also attract a larger cadre of physicians. Other pediatric subspecialties, e.g. oncology, rheumatology and adolescent psychiatry, have developed successfully and may represent excellent models for adolescent medicine specialists to emulate. The Adolescent Health Study Group of the Emilia and Romagna Region (SGA-ER) was established in 2010 in an effort to generate strategies and possible solutions to improve the quality and quantity of knowledge in adolescent health care for pediatricians and GPs. Several methods and approaches have been implemented to improve physicians' skills in adolescent health care. The authors report the goals, content and instructional design of an educational course in adolescent medicine. Alliances with other adolescent health groups may provide an additional opportunity for networking, interaction and exchange of ideas amongst professionals.

ASN540SER mutation is associated with a mild form of hypochondroplasia: a 7 years follow-up in an Italian boy.

Skeletal dysplasias (SKD) are genetic disorders that result in the abnormal development of part or all of the skeleton and are commonly associated with short stature. The most common SKDs that typically result in short stature include achondroplasia/hypochondroplasia (HCH) both caused by different mutations in the same gene. HCH diagnosis is based on the clinical appearance during development and conventional X-ray findings. In about 70% of patients, missense mutations in the gene coding for the fibroblast Growth Factor Receptor 3 (FGFR3) affects the amino acid at position 540, mostly resulting in the amino acid exchange N540K.Subjects with HCH, heterozygous for the N540K substitution are significantly more disproportionate than individuals without this mutation. We report the clinical and radiographic features of an Italian family with HCH with an unusual N540S mutation, inside the common mutation hot spot of this condition. This is the first case reported in Italy and the third in the literature. During a 7-years-follow-up, the boy started the puberty at the age of 11.3 years and the growth spurt was observed between 13.7 and 14.9 years (+ 9.1 cm.).During pubertal development the sitting height (SDS) improved from - 1.5 to - 0.6 and the subischial leg length (SDS) progressed from - 2.6 to - 3.3.At the age of 16.7 year the standing height was 157.6 cm ( - 2.4 SDS), testicular volume was 15 ml and bone age 16.5 year. The present study and the other two cases reported in the literature stress the important role of the asn 540 site in the tyrosine kinase I domain in the pathogenesis of HCH and underline the importance that, in patients with HCH who do not have the common N540K mutation, sequence analysis of the tyrosine kinase I domain of FGFR3 should be performed to exclude other changes in that region.

Terahertz generation in nitrides due to transit-time resonance assisted by optical phonon emission.

The conditions for THz radiation generation caused by electron transit-time resonance in momentum and real spaces under optical phonon emission are analyzed for nitride-based materials and their structures. It is shown that such a mechanism provides a unique possibility to realize sub-THz and THz radiation generation at the border between the electro-optical and electronic techniques by using two alternative approaches: (i) amplification of transverse electromagnetic waves in 3D bulk materials and 2D quantum wells, and (ii) longitudinal current-field instabilities in sub-micron and micron n(+)nn(+) diodes. Estimations of frequency regions, output power and efficiency of the generation demonstrate that nitrides are promising materials for THz radiation generation.

Terahertz oscillations in ultra-thin n-In(0.53)Ga(0.47)As ungated channels.

Using a self-consistent Monte Carlo simulator we investigate the spectrum of voltage fluctuations of an n-type InGaAs two-terminal layer of variable thickness W in the range 1-100 nm and variable length L in the range 0.01-10 µm embedded in an external dielectric medium. Calculations are performed at T = 300 K for different dopings and in the presence of an external bias of increasing strength. When the bias is well below the threshold for the Gunn effect the spectrum peaks at the plasma oscillations of the electron gas. For W≥100 nm and carrier concentrations of 10(17)-10(18) cm(-3) the peaks are in good agreement with the standard three-dimensional (3D) expression of the plasma frequency. For W≤10 nm the results exhibit a plasma frequency that depends on the length of the layer, thus implying that the oscillation mode is dispersive. The corresponding frequency covers a wide range of values 0.1-10 THz and is in agreement with the two-dimensional (2D) expression of the plasma frequency obtained for a collisionless regime within the in-plane approximation for the electric field. A region of cross-over between the 2D and 3D behaviours of the plasma frequency is shown for W>10 nm. When the bias is above the threshold for the Gunn effect, we observe the washing out of the plasma peak and the onset of a frequency peak associated with the transit time of the Gunn domain located in the sub-terahertz frequency region.

Nanoscale electrical conductivity of the purple membrane monolayer.

Nanoscale electron transport through the purple membrane monolayer, a two-dimensional crystal lattice of the transmembrane protein bacteriorhodopsin, is studied by conductive atomic force microscopy. We demonstrate that the purple membrane exhibits nonresonant tunneling transport, with two characteristic tunneling regimes depending on the applied voltage (direct and Fowler-Nordheim). Our results show that the purple membrane can carry significant current density at the nanometer scale, several orders of magnitude larger than previously estimated by macroscale measurements.

Neoligamentization process of BTPB used for ACL graft: histological evaluation from 6 months to 10 years.

Following anterior cruciate ligament (ACL) reconstruction with the middle third part patellar tendon, the graft undergoes histological rearrangement due to biomechanical action, which transforms it into a structure similar to the normal ACL. The purpose of our study was to make a qualitative and quantitative histological evaluation, by transmission electron microscopy (TEM), of the neoligamentization process of a bone-patellar tendon-bone (BTPB) graft used as pro-ACL at different follow-up times. We analysed the ultrastructure of collagen fibrils by focusing on their size and distribution with respect to a normal patellar tendon and a normal ACL used as controls. Our results showed that up to 24 months follow-up, progressive ultrastructural changes towards the normal ACL were observed. At longer times after surgery (48 and 120 months) no further changes were evident and the ultrastructure showed a marked reduction in large fibrils, which was typical of the control patellar tendon, and a significant increase in small fibrils. The ultrastructure seemed to combine fibrils from two different morphological units. The BPTB graft used as ACL underwent a transformation process for up to two years. After that period the transformation ceased and for ten years failed to reach the ultrastructural aspect of a normal ACL. However, from an architectural point of view the graft was slowly transformed into a structure similar to ACL with respect to the different mechanical stresses the ligament has to sustain.

Treatment strategies of the borderline ovarian tumors.

The present study was undertaken to establish the role of surgical procedures, histologic type, and stage of the tumor on the survival rate of patients with borderline ovarian tumors in a 5 to 15 years of follow-up. Data reported in the literature have shown the low malignancy of this cancer and that only the stage, but not the pathological diagnosis, is significantly influencing the survival rate of the patients. After 5 years, the survival rate of patients with tumors of stage I to stage II is 98.2% (n=567) and 81.4% (n=46), respectively, with no statistical difference. After 5 years, survival rate between tumors of stage I to stage III is 98.2% (n=567) and 79.1% (n=96), respectively (p< 0.05). The data shows that for borderline ovarian tumors, a minimally invasive surgery is warranted.

Retroillumination versus reflected-light images in the photographic assessment of posterior capsule opacification.

PURPOSE: To investigate the relative merit of retroillumination and of reflected light slit-lamp-derived photographs in the assessment of the opacification of the posterior lens capsule. METHODS: Retroillumination and slit-lamp-derived reflected-light photographs were taken on 23 consecutive eyes with posterior capsule opacification (PCO) in uncomplicated pseudophakia. Subjective grading was performed on both types of photographs to evaluate the extent and density of posterior capsular opacification. Best-corrected visual acuity (BCVA) before and after YAG laser capsulotomy was used to assess the impact of capsular opacification on visual function. RESULTS: After capsulotomy all patients attained a BCVA > or = 46 letters (> or =20/32) with a mean increase of 25 letters, indicating that PCO was the cause of visual impairment in these patients. The relative capacity of retroillumination and of reflected-light photographs to adequately capture the extent and the severity of posterior capsule opacification varied considerably. Reflected-light images, in addition to frequently producing higher severity scores for the opacity than retroillumination photographs, in 4 of 23 eyes (17.4%) proved to be the only technique able to document the presence of PCO. CONCLUSIONS: Our results indicate that, with respect to retroillumination images, reflected-light photography has an increased ability to adequately capture the presence and the severity of PCO and that the use of only retroillumination images may lead to its underestimation. This may be relevant to clinical studies aiming to evaluate incidence and progression of this condition.

Assessment of restrictive cardiomyopathy of amyloid or idiopathic etiology by magnetic resonance imaging.

This study was designed to assess the role of magnetic resonance imaging in the differential diagnosis of amyloid and idiopathic etiology of cardiomyopathy. This technique demonstrated the capability to differentiate the 2 forms, providing high-resolution evaluation of the myocardial wall and detecting the infiltrative pathology by tissue characterization.

Evolution of aortic dissection after surgical repair.

Patients after aortic dissection repair still have long-term unfavorable prognosis and need careful monitoring. The purpose of this study was to analyze the evolution of aortic dissection after surgical repair in correlation to anatomic changes emerging from systematic magnetic resonance imaging (MRI) follow-up. Between January 1992 and June 1998, 70 patients underwent surgery for type A aortic dissection. Fifty-eight patients were discharged from the hospital (17% operative mortality) and were followed by serial MRI for 12 to 90 months after surgery. In all, 436 postoperative MRI examinations were analyzed. In 13 patients (22.5%) no residual intimal flap was identified, whereas 45 patients (77.5%) presented with distal dissection, with a partial thrombosis of the false lumen in 24. The yearly aortic growth rate was maximum in the descending aortic segment (0.37 +/- 0.43 cm) and was significantly higher in the absence of thrombus in the false lumen (0.56 +/- 0.57 cm) (p <0.05). There were 4 sudden deaths, with documented aortic rupture in 2. Sixteen patients underwent reoperation for expanding aortic diameter. In all but 1 patient, a residual dissection was present (in 13 without any thrombosis of the false lumen). Close MRI follow-up in patients after dissection surgical repair can identify the progression of aortic pathology, providing effective prevention of aortic rupture and timely reoperation. Thrombosis of the false lumen appears to be a protective factor against aortic dilation.

Scaling law of resistance fluctuations in stationary random resistor networks

In a random resistor network we consider the simultaneous evolution of two competing random processes consisting in breaking and recovering the elementary resistors with probabilities W(D) and W(R). The condition W(R)>W(D)/(1+W(D)) leads to a stationary state, while in the opposite case, the broken resistor fraction reaches the percolation threshold p(c). We study the resistance noise of this system under stationary conditions by Monte Carlo simulations. The variance of resistance fluctuations is found to follow a scaling law |p-p(c)|(-kappa(0)) with kappa(0) = 5.5. The proposed model relates quantitatively the defectiveness of a disordered media with its electrical and excess-noise characteristics.

Scaling and universality in electrical failure of thin films

We describe the electrical failure of thin films as a percolation in two-dimensional random resistor networks. We show that the resistance evolution follows a scaling relation expressed as R approximately epsilon(-&mgr;) where epsilon = (1-t/tau), tau is the time of electrical failure of the film, and &mgr; is the same critical exponent appearing in the scaling relation between R and the defect concentration. For uniform degradation the value of &mgr; is universal. The validity of this scaling relation in the case of nonuniform degradation is proved by discussing the case in which the failure is due to a filamentary defect growth. The existence of this relation allows predictions of failure times from early time measurements of the resistance.

Role of statins in the management of dyslipidemia after cardiac transplant: randomized controlled trial comparing the efficacy and the safety of atorvastatin with pravastatin.

BACKGROUND: Cardiac transplant patients are at increased risk of dyslipidemia, a known pathogenetic factor in chronic rejection. The aim of this study was to compare the efficacy and the safety of treatment with atorvastatin (AT) and treatment with pravastatin (PV) in a population of dyslipidemic transplant patients. METHODS: Thirty-nine transplant patients were randomized to receive a 4-month cycle of therapy with AT or PV, in a cross-over sequence. We analyzed the effects on their lipid profiles using Student t-test for paired data. RESULTS AND CONCLUSION: Atorvastatin was significantly more effective than PV in reducing total cholesterol (33% vs 21%, p < 0.001), LDL cholesterol (45% vs 30%, p = 0.001), and triglycerides (24% vs 7.7%, p < 0.001), at lower doses and with comparable tolerability and safety.