Transient elevation of serum bile acids during acute pancreatitis

Summary An increase of serum bile acids was detected in patients with biliary acute pancreatitis who could be investigated during the first 24 hours after the onset of the acute phenomena. Serum bile acids levels, as well as α-amylase activity, however rapidly decreased and were found within normal limits after 48–72 h, while the increased serum γ-glutamyltransferase activity persisted for at least 7 days. Changes affecting serum bile acids in patients with acute pancreatitis unassociated to biliary disease or in patients with acute biliary disease unaccompanied by a pancreatic reaction were less important. Mechanisms leading to these changes and their possible pathogenic relevance are briefly discussed.     

NAD(P)H oxidase 4 mediates transforming growth factor-beta1-induced differentiation of cardiac fibroblasts into myofibroblasts

Human cardiac fibroblasts are the main source of cardiac fibrosis associated with cardiac hypertrophy and heart failure. Transforming growth factor-beta1 (TGF-beta1) irreversibly converts fibroblasts into pathological myofibroblasts, which express smooth muscle alpha-actin (SM alpha-actin) de novo and produce extracellular matrix. We hypothesized that TGF-beta1-stimulated conversion of fibroblasts to myofibroblasts requires reactive oxygen species derived from NAD(P)H oxidases (Nox). We found that TGF-beta1 potently upregulates the contractile marker SM alpha-actin mRNA (7.5+/-0.8-fold versus control). To determine whether Nox enzymes are involved, we first performed quantitative real time polymerase chain reaction and found that Nox5 and Nox4 are abundantly expressed in cardiac fibroblasts, whereas Nox1 and Nox2 are barely detectable. On stimulation with TGF-beta1, Nox4 mRNA is dramatically upregulated by 16.2+/-0.8-fold (n=3, P<0.005), whereas Nox5 is downregulated. Small interference RNA against Nox4 downregulates Nox4 mRNA by 80+/-5%, inhibits NADPH-driven superoxide production in response to TGF-beta1 by 65+/-7%, and reduces TGF-beta1-induced expression of SM alpha-actin by 95+/-2% (n=6, P<0.05). Because activation of small mothers against decapentaplegic (Smads) 2/3 is critical for myofibroblast conversion in response to TGF-beta1, we also determined whether Nox4 affects Smad 2/3 phosphorylation. Depletion of Nox4 but not Nox5 inhibits baseline and TGF-beta1 stimulation of Smad 2/3 phosphorylation by 75+/-5% and 68+/-3%, respectively (n=7, P<0.0001). We conclude that Nox 4 mediates TGF-beta1-induced conversion of fibroblasts to myofibroblasts by regulating Smad 2/3 activation. Thus, Nox4 may play a critical role in the pathological activation of cardiac fibroblasts in cardiac fibrosis associated with human heart failure.     

Successful epilepsy surgery in frontal lobe epilepsy with startle seizures: a SEEG studyFrontal epilepsy with startle seizures

Pre‐surgical assessment and surgical management of frontal epilepsy with normal MRI is often challenging. We present a case of a 33‐year‐old, right‐handed, educated male. During childhood, his seizures presented with mandibular myoclonus and no particular trigger. As a young adult, he developed seizures with a startle component, triggered by unexpected noises. During his ictal episodes, he felt fear and grimaced with sudden head flexion and tonic axial posturing. Similar seizures also occurred without startle. Neuropsychological assessment showed executive dysfunction and verbal memory deficit. The cerebral MRI was normal. Electro‐clinical reasoning, investigations performed, the results obtained and follow‐up are discussed in detail. [Published with video sequence]     

Optimization of multimodal spectral imaging for assessment of resection margins during Mohs micrographic surgery for basal cell carcinoma

Multimodal spectral imaging (MSI) based on auto-fluorescence imaging and Raman micro-spectroscopy was used to detect basal cell carcinoma (BCC) in tissue specimens excised during Mohs micrographic surgery. In this study, the MSI algorithm was optimized to maximize the diagnosis accuracy while minimizing the number of Raman spectra: the segmentation of the auto-fluorescence images was optimized according to the type of BCC, sampling points for Raman spectroscopy were generated based on auto-fluorescence intensity variance and segment area, additional Raman spectra were acquired when performance of the segmentation algorithm was sub-optimal. The results indicate that accurate diagnosis can be achieved with a sampling density of ~2,000 Raman spectra/cm², based on sampling points generated by the MSI algorithms. The key benefit of MSI is that diagnosis of BCC is obtained based on intrinsic chemical contrast of the tissue, within time scales similar to frozen-section histopathology, but without requiring laborious sample preparation and subjective interpretation of stained frozen-sections.OCIS codes: (170.0170) Medical optics and biotechnology, (170.5660) Raman spectroscopy, (170.4580) Optical diagnostics for medicine, (170.1870) Dermatology     

Graphene nanoplatelets-sericin surface-modified Gum alloy for improved biological response

In this study a “Gum Metal” titanium-based alloy, Ti-31.7Nb-6.21Zr-1.4Fe-0.16O, was synthesized by melting and characterized in order to evaluate its potential for biomedical applications. The results showed that the newly developed alloy presents a very high strength, high plasticity and a low Young''s modulus relative to titanium alloys currently used in medicine. For further bone implant applications, the newly synthesized alloy was surface modified with graphene nanoplatelets (GNP), sericin (SS) and graphene nanoplatelets/sericine (GNP–SS) composite films via Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The characterization of each specimen was monitored by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle (CA) measurements, and Fourier Transform Infrared Spectroscopy (FTIR). The materials'' surface analyses suggested the successful coating of GNP, SS and GNP–SS onto the alloy surface. Additionally, the activities of pre-osteoblasts such as cell adhesion, cytoskeleton organization, cell proliferation and differentiation potentials exhibited on these substrates were investigated. Results showed that the GNP–SS-coated substrate significantly enhanced the growth and osteogenic differentiation of MC3T3-E1 cells when compared to bare and GNP-coated alloy. Collectively, the results show that GNP–SS surface-modified Gum alloy can modulate the bioactivity of the pre-osteoblasts holding promise for improved biological response in vivo.

GNP–SS functionalized Gum alloy exhibits superior bioactivity in inducing in vitro osteogenesis.     

A comparative study of non-invasive methods for fibrosis assessment in chronic HCV infection

Background and Aims

To compare several non-invasive methods of fibrosis assessment in chronic hepatitis C virus (HCV) infection (platelet count, the APRI score, the Forns score, the Lok score, FIB-4, Transient Elastography [TE]), versus percutaneous liver biopsy (LB).

Methods

Our study included 150 patients with chronic HCV infection in which LB, liver stiffness measurement (LSM) by means of TE and biological tests needed for calculating the scores (according to the classic formulas) were performed in the same session.

Results

The best test for predicting significant fibrosis (F = 2 Metavir) was LSM with AUROC-0.773, followed by APRI (AUROC-0.763), Forns (AUROC-0.744), platelet count (AUROC-0.732), Lok (AUROC-0.701) and FIB-4 (AUROC-0.669), but the differences were not statistically significant (P > 0.05). For excluding cirrhosis, all the tests had excellent NPV (>97%). The best test for predicting cirrhosis was LSM (AUROC-0.979), significantly better than platelet count (AUROC- 0.899, P = 0.022) and than FIB-4 (AUROC-0.839, P = 0.042), otherwise the differences were not statistically significant (P > 0.05). All of the non-invasive tests were statistically significantly correlated (P < 0.0001) to the severity of fibrosis: APRI r=0.570; Forns r=0.540; Lok r=0.4843; FIB-4 r=0.4171; platelet count r=-0.4842.

Conclusions

LSM by means of TE seems to be more sensitive than APRI, Forns, Lok and FIB-4 scores and than platelet count for the prediction of significant fibrosis, but the differences are not statistically significant. The APRI score and Forns scores correctly identified most (71%) of the patients having, or not having, significant fibrosis. LSM was the best method for predicting cirrhosis, but all the evaluated tests had excellent predictive value (AUROCs 0.839-0.979).     

Variceal upper digestive bleeding--an ever new complication in liver cirrhosis

Variceal bleeding in liver cirrhosis is a medical emergency with a high mortality. The therapeutic options in patients with portal hypertension are: treatment of acute bleeding from varices, prevention of the first bleeding episode and prevention of rebleeding. Treatment of acute bleeding from varices includes: blood volume restitution, use of antibiotics for preventing bacterial infections, vasoactive drug therapy (terlipressin, somatostatin, vapreotide, octreotide), endoscopic band ligation for acute esophageal bleeding and endoscopic therapy with tissue adhesive (cyanoacrylate) for acute gastric variceal bleeding. Endoscopic treatments are best used in association with pharmacological therapy. In primary prophylaxis non-selective beta- blocker therapy and endoscopic band ligation are useful. Beta blockers, band ligation or both should be used for prevention of recurrent bleeding. In patients who fail endoscopic and pharmacological treatment for prevention of rebleeding TIPS and transplantation should be considered.