Structural investigations of cross-linked hyaluronan.

Structural properties of several cross-linked hyaluronan derivatives, obtained by scanning electron microscopy, monodimensional NMR microscopy and small angle X-ray scattering of synchrotron radiation, are presented and compared with those observed for non-modified hyaluronic acid, used as a reference material. The experimental results, obtained in different media, showed a consistent picture of the synthesized matrices. In particular, the presence of zones of denser polymeric material observed by electron microscopy resulted in a higher transversal relaxation rate of the bulk water protons as well as in a decrease of the diffusion coefficient obtained by NMR microscopy. Moreover, the presence of polymer junction zones gave rise to the appearance of a well-defined correlation peak in the pattern of intensity of the scattered X-radiation.     

Novel Pancreas Organogenesis Markers Refine the Pancreatic Differentiation Roadmap of Embryonic Stem cells

The generation of pancreatic endocrine and exocrine functional precursors from embryonic stem cells (ESCs) is an intriguing opportunity to address cell therapy challenges. The main goal of cellular regeneration is to derive, in vitro, pancreatic progenitor cells (PPCs) that retain the capacity to differentiate following the in vivo developmental ontogeny. In our work, we aim to refine the pancreatic in vitro cellular transitions, through the identification of the intrinsic factors that mark the pancreas budding process at embryonic stage 10.5 (E10.5), in which pancreas precursor specification predominantly occurs. We identified a cohort of genes (Bex1, Nepn, Pcbd1, Prdxdd1, Rnf160, Slc2a1, and Tff3) that marked the pancreas budding genesis, and above all signaled ESC differentiation transitions during pancreatic lineage commitment. Noticeably, we demonstrated that the expression of Nepn marked a naïve pancreatic cellular state that resembled PPC-like specification. Our data considerably improve the comprehension of pancreatic cellular ontogeny, which could be critical for implementing pluripotent stem cells programming and reprogramming toward pancreatic lineage commitment.     

Humerus osteology,myology, and finite element structure analysis of Cheloniidae

Adaptation of osteology and myology lead to the formation of hydrofoil foreflippers in Cheloniidae (all recent sea turtles except Dermochelys coriacea) which are used mainly for underwater flight. Recent research shows the biomechanical advantages of a complex system of agonistic and antagonistic tension chords that reduce bending stress in bones. Finite element structure analysis (FESA) of a cheloniid humerus is used to provide a better understanding of morphology and microanatomy and to link these with the main flipper function, underwater flight. Dissection of a Caretta caretta gave insights into lines of action, that is, the course that a muscle takes between its origin and insertion, of foreflipper musculature. Lines of action were determined by spanning physical threads on a skeleton of Chelonia mydas. The right humerus of this skeleton was micro-CT scanned. Based on the scans, a finite element (FE) model was built and muscle force vectors were entered. Muscle forces were iteratively approximated until a uniform compressive stress distribution was attained. Two load cases, downstroke and upstroke, were computed. We found that muscle wrappings (m. coracobrachialis magnus and brevis, several extensors, humeral head of m. triceps) are crucial in addition to axial loading to obtain homogenous compressive loading in all bone cross-sections. Detailed knowledge on muscle disposition leads to compressive stress distribution in the FE model which corresponds with the bone microstructure. The FE analysis of the cheloniid humerus shows that bone may be loaded mainly by compression if the bending moments are minimized.     

Approaches to treatments of chronic migraine associated with medication overuse: a comparison between different intensity regimens

Treatment of chronic migraine with medication overuse requires withdrawal from acute medications. However, guidelines and clear indications for different intensity regimens, i.e., day hospital (DH) vs. inpatient treatment, are not available. Patients completed disability, quality of life (QoL) and depression questionnaires; headaches frequency and overused medications category were collected. Mann–Whitney U test and Chi square were used to assess differences between inpatients and DH patients; Bonferroni correction was applied. 194 patients aged 43.9 ± 12 (160 females) were enrolled (100 from DH, 94 inpatients). Inpatients were older, less educated and with lower employment rates. Inpatients had higher MIDAS scores (P = 0.003) and headache frequency (P = 0.002). They had lower QoL for restrictive (P = 0.002) and preventive components; no difference was found for disability, mood state and QoL emotional component. Patients treated during hospitalization had higher disease severity and lower quality of life, but similar disability and mood state than those treated in DH.     

Social behavior impairment in offspring exposed to maternal seizures in utero

Human and animal models have demonstrated that maternal seizures in utero could be deleterious to the development of the offspring. This study focused on the social behavior of offspring exposed to seizures in utero. A pilocarpine model of temporal lobe epilepsy was induced in female Wistar rats that were mated after the first spontaneous seizure. Early after birth, pups from an epileptic mother were reared by a control mother. To evaluate the influence of the adoption process, two other groups were added: rat pups from control mothers cross-fostered with other control mothers, and rat pups reared by their birth mother. Animals exposed to seizures in utero showed impaired social behavior with no signs of anxiety-like behavior. This study demonstrated that epileptic seizures during pregnancy could be harmful to brain development and may increase the risk of developing neurodevelopmental disorders. The mechanisms underlying the abnormalities of social behavior are not well understood, and further studies in this field are warranted.     

Prognosis of patients with spontaneous rupture of hepatocellular carcinoma in cirrhosis

The treatment of cirrhotic patients with spontaneous rupture of hepatocellular carcinoma (HCC) is controversial and largely dependent on general conditions of the patients and compensation of the underlying cirrhosis. We retrospectively reviewed clinical, imaging and surgical records of 24 consecutive cirrhotic patients (17 males, 7 females; age range 52–88 years) with hemoperitoneum from spontaneous rupture of HCC observed from June 2004 to January 2010 at our Institution. When indicated, patients were referred to surgery or trans-arterial embolization (TAE). Advanced decompensated patients were conservatively treated and clinically followed up. Spontaneous rupture of HCC was assessed by aspiration of bloody ascites at paracentesis in all cases. The presence of large blood-clots over HCC and liver surface at US and/or CT was considered a specific sign of ruptured HCC in 14 cases. In two out of four patients who underwent TAE active bleeding from tumor surface could be demonstrated. In 2 cases, the active hemorrhage from the HCC surface could be assessed by contrast-enhanced ultrasonography. Four out of 24 patients underwent surgery. Three out of four of these patients died within 2 weeks, 8 months, and 20 months after operation, respectively. The remaining patient is still alive at 52 months follow-up. Four patients underwent TAE and died at 1, 2, 6 and 10 months after treatment, because of recurrent peritoneal bleeding and/or liver failure. Sixteen patients with ruptured HCC in the advanced Child C cirrhosis were treated conservatively with blood derivative transfusion and with procoagulant drugs. All patients, but one died within 2–18 days. One patient survived the acute hemorrhage from ruptured HCC and died of liver failure after 3 months. We concluded that spontaneous rupture of HCC is usually a fatal event in patients with poor liver function, even after successful TAE. In compensated patients, timely surgical treatment can result in long term and even tumor-free survival of the patient.     

Onabotulinum toxin A for treatment of chronic migraine with medication overuse

Chronic migraine is a common and debilitating headache syndrome. Botulinum neurotoxin (BoNT), a potent toxin produced by the anaerobic bacterium Clostridium botulinum, used largely for treatment of disorders associated with increased muscle tone and hyperidrosis, has been recently used for patients suffering from chronic migraine. In this study, two groups of patients were treated with different dosages of BoNT A to verify the efficacy for chronic migraine. The results confirmed the efficacy of BoNT A when used at the dosage of 150 U. In the second group of patients treated with 100 U, results were not significant. Although these results are preliminary, they led to intense efforts to evaluate the analgesic properties of BoNT A and to assess their clinical applicability.     

Predicting severity of pathological scarring due to burn injuries: a clinical decision making tool using Bayesian networks

It is important for clinicians to understand which are the clinical signs, the patient characteristics and the procedures that are related with the occurrence of hypertrophic burn scars in order to carry out a possible prognostic assessment. Providing clinicians with an easy‐to‐ use tool for predicting the risk of pathological scars. A total of 703 patients with 2440 anatomical burn sites who were admitted to the Department of Plastic and Reconstructive Surgery, Burn Center of the Traumatological Hospital in Torino between January 1994 and May 2006 were included in the analysis. A Bayesian network (BN) model was implemented. The probability of developing a hypertrophic scar was evaluated on a number of scenarios. The error rate of the BN model was assessed internally and it was equal to 24·83%. While classical statistical method as logistic models can infer only which variables are related to the final outcome, the BN approach displays a set of relationships between the final outcome (scar type) and the explanatory covariates (patient's age and gender, burn surface area, full‐thickness burn surface area, burn anatomical area and wound‐healing time; burn treatment options such as advanced dressings, type of surgical approach, number of surgical procedures, type of skin graft, excision and coverage timing). A web‐based interface to handle the BN model was developed on the website www.pubchild.org (burns header). Clinicians who registered at the website could submit their data in order to get from the BN model the predicted probability of observing a pathological scar type.     

Contribution of magnetic resonance cholangiopancreatography to the diagnosis of biliary tract disease

The aim of the study was to assess the role of magnetic resonance cholangiopan-creatography (MRCP) in the diagnosis of biliary tract and pancreatic duct diseases, also in relation to the data reported in the literature. Over the period from Februrary 2002 to July 2004, 252 consecutive patients, with a clinical or instrumental suspicion of biliary disease were submitted to magnetic resonance to investigate the biliary tract. The definitive diagnosis of disease was obtained by surgery and/or endoscopic retrtograde cholangiopancreatography (ERCP) in patients with clinical or diagnostic evidence of disease and by means of follow-up in the remaining cases. MRCP, combined with T2-weighted FSE sequence on the axial plane yielded positive findings in 191/252 patients (75.79%); in 75/191 (39.26%) either ERCP was indispensable (n = 33) or surgery proved necessary (n = 42). MRCP and surgical sample findings proved discordant in 3/42 cases operated on (7.14%); MRCP and ERCP yielded discordant findings in 11/33 cases (33.33%) submitted to ERCP. With the exception of the limitations associated with the difficulty in obtaining dynamic information relating to functional diseases of Oddi's sphincter, for which, moreover, a progressive tecnological updating is underway, MRCP is the diagnostic reference procedure in biliopancreatic disease, reserving a therapeutic role for ERCP.