Covered self-expanding transhepatic biliary stents: Clinical pilot study

Purpose: We report our preliminary results with a new type of self-expanding covered stent for treatment of malignant biliary obstruction. Methods: Wallstents, fully covered with high elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 69 mm, were placed transhepatically under fluoroscopic guidance in five patients. The length of the biliary obstruction varied between 30<+>–<+>50 mm. At 1 and 3 months (82<+>–<+>98 days) clinical assessment, serum bilirubin measurement, and ultrasound examination of the biliary tree were performed. Results: Initial uncomplicated deployment of the stents and internal drainage was possible in all patients. Distal stent migration resulted in early biliary reobstruction in one patient. At 3-month follow-up, partial reobstruction, most probably due to sludge formation, was found in another patient. Conclusion: Our initial results indicate that the covered, self-expanding Wallstent endoprosthesis can be reliably and safely deployed transhepatically for malignant biliary obstruction.     

The effects of ropivacaine at clinically relevant doses on myocardial ischemia in pigs

A major risk associated with bupivacaine during myocardial ischemia is ventricular fibrillation. We investigated the influence of ropivacaine on cardiac contractility and the propensity to ventricular fibrillation before and after myocardial ischemia in a placebo-controlled pig study. Anesthetized domestic pigs were administered 1 mg·kg⁻¹ of ropivacaine intravenously over 1 min and then 0.03 mg·kg⁻¹·min⁻¹ as a 30-min infusion, or saline. The following endpoints were measured before and after ropivacaine administration: (1) the ventricular fibrillation threshold (VFT) before and during myocardial ischemia induced by total transient ligation of the anterior interventricular artery and (2) electrophysiological (sinus heart rate, duration of QRS and QT intervals) and hemodynamic (blood pressure, the time derivative of left ventricular pressure [peak LV dP/dt]) parameters. Ropivacaine induced no changes in sinus heart rate, QRS, and or QT before or during ischemia. In contrast, there was a mild increase in the VFT before ischemia, which was drastically and significantly reduced during ischemia. The reduction of peak LV dP/dt during ischemia was further increased by ropivacaine. We also found that the effect of ropivacaine on the VFT was coronary blood flow-dependent, with a markedly decreased threshold in the presence of ischemia. Similar effects have been observed in humans with several other local anesthetics, as well as with class I antiarrhythmic drugs. The results of this study should be taken into account by anesthesiologists when administering ropivacaine to coronary patients.     

Mobile Applications for Control and Self Management of Diabetes: A Systematic Review

Mobile applications (apps) can be very useful software on smartphones for all aspects of people’s lives. Chronic diseases, such as diabetes, can be made manageable with the support of mobile apps. Applications on smartphones can also help people with diabetes to control their fitness and health. A systematic review of free apps in the English language for smartphones in three of the most popular mobile app stores: Google Play (Android), App Store (iOS) and Windows Phone Store, was performed from November to December 2015. The review of freely available mobile apps for self-management of diabetes was conducted based on the criteria for promoting diabetes self-management as defined by Goyal and Cafazzo (monitoring blood glucose level and medication, nutrition, physical exercise and body weight). The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) was followed. Three independent experts in the field of healthcare-related mobile apps were included in the assessment for eligibility and testing phase. We tested and evaluated 65 apps (21 from Google Play Store, 31 from App Store and 13 from Windows Phone Store). Fifty-six of these apps did not meet even minimal requirements or did not work properly. While a wide selection of mobile applications is available for self-management of diabetes, current results show that there are only nine (5 from Google Play Store, 3 from App Store and 1 from Windows Phone Store) out of 65 reviewed mobile apps that can be versatile and useful for successful self-management of diabetes based on selection criteria. The levels of inclusion of features based on selection criteria in selected mobile apps can be very different. The results of the study can be used as a basis to prvide app developers with certain recommendations. There is a need for mobile apps for self-management of diabetes with more features in order to increase the number of long-term users and thus influence better self-management of the disease.     

NiO–Ba0.95Ca0.05Ce0.9Y0.1O3−δ as a Modified Anode Material Fabricated by the Tape Casting Method

The development of new chemically resistant anodes for protonic ceramic fuel cells (PCFCs) is urgently required to avoid the costly deep hydrogen purification method. Ba_0.95Ca_0.05Ce_0.9Y_0.1O_3−δ (5CBCY), which is more chemically resistant than BaCaCe_0.9Y_0.1O_3−δ, was here tested as a component of a composite NiO–5CBCY anode material. A preparation slurry comprising 5CBCY_, NiO, graphite, and an organic medium was tape cast, sintered and subjected to thermal treatment in 10 vol.% H₂ in Ar at 700 °C. Differential thermal analysis, thermogravimetry, quadrupole mass spectrometry, X-ray diffraction analysis, scanning electron microscopy, the AC four-probe method and electrochemical impedance spectroscopy were used for the investigation. The electrical conductivity of the Ni–5CBCY in H₂–Ar at 700 °C was 1.1 S/cm. In the same gas atmosphere but with an additional 5 vol.% CO₂, it was slightly lower, at 0.8 S/cm. The Ni–5CBCY cermet exhibited repeatable electrical conductivity values during Ni-to-NiO oxidation cycles and NiO-to-Ni reduction in the 5CBCY matrix, making it sufficient for preliminary testing in PCFCs.     

Genetic characterization of L-Zagreb mumps vaccine strain

Eleven mumps vaccine strains, all containing live attenuated virus, have been used throughout the world. Although L-Zagreb mumps vaccine has been licensed since 1972, only its partial nucleotide sequence was previously determined (accession numbers , and ). Therefore, we sequenced the entire genome of L-Zagreb vaccine strain (Institute of Immunology Inc., Zagreb, Croatia). In order to investigate the genetic stability of the vaccine, sequences of both L-Zagreb master seed and currently produced vaccine batch were determined and no difference between them was observed. A phylogenetic analysis based on SH gene sequence has shown that L-Zagreb strain does not belong to any of established mumps genotypes and that it is most similar to old, laboratory preserved European strains (1950s-1970s). L-Zagreb nucleotide and deduced protein sequences were compared with other mumps virus sequences obtained from the GenBank. Emphasis was put on functionally important protein regions and known antigenic epitopes. The extensive comparisons of nucleotide and deduced protein sequences between L-Zagreb vaccine strain and other previously determined mumps virus sequences have shown that while the functional regions of HN, V, and L proteins are well conserved among various mumps strains, there can be a substantial amino acid difference in antigenic epitopes of all proteins and in functional regions of F protein. No molecular pattern was identified that can be used as a distinction marker between virulent and attenuated strains.     

Proton MR spectroscopy and diffusion-weighted imaging of intracranial germ cell tumors: Implications for differentiation from other lesions

Introduction

Intracranial germ cell tumors (GCT) are extremely rare brain neoplasms, with imaging characteristics being often non-specific. Considering such imaging limitation in establishing their exact histology, the aim of this paper is to integrate conventional, physiologic and metabolic magnetic resonance imaging (MRI) with histology of these tumors, with the goal of proposing some new insights that could aid in their diagnosis.

Materials and methods

We have retrospectively analyzed preoperative imaging findings in 9 patients with histology proven intracranial germ cell tumors. In all patients conventional magnetic resonance imaging in conjunction with diffusion-weighted imaging (DWI) and proton magnetic resonance spectroscopy (MRS) was performed.

Results

Based on imaging characteristics on conventional sequences germinoma cannot be differentiated from nongerminoma. DWI offered the potential for differentiation of germinomas from non-germinomas since solid part of germinomas demonstrated restricted diffusion with ADC values under 1.0 × 10⁻³ mm²/s, whereas nongerminoma showed elevated diffusion with ADC values above 1.3 × 10⁻³ mm²/s. Short echo MRS demonstrated characteristic spectra in germinomas: increased Cho, decreased NAA and prominent broad lipid resonances.

Conclusion

DWI and MRS imaging findings provide additional information that can facilitate evaluation of intracranial germ cell tumors.     

Imaging in acute stroke

Stroke is a syndrome characterized by a sudden neurological deficit caused by intracranial hemorrhage or ischemia. Computed tomography (CT) maintains a primary role in the evaluation of patients with acute stroke. The optimal magnetic resonance imaging (MRI) protocol in acute stroke includes diffusion-weighted imaging (DWI) to show acute ischemic lesion and MR perfusion study to estimate brain perfusion. Careful selection of patients for a thrombolytic therapy is crucial to improve safety and efficacy.     

Diffusion-tensor MR imaging of the brain in human immunodeficiency virus-positive patients

BACKGROUND AND PURPOSE: There is early evidence that diffusion-tensor imaging (DTI) is useful in demonstrating subtle white matter alterations in different diseases of brain. We hypothesize that DTI in several brain regions in human immunodeficiency virus-positive (HIV+) patients is useful in the early detection of HIV-related brain injury. METHODS: MR imaging and DTI were performed in 60 HIV+ patients and in 30 controls. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC; mm/s(2)) maps were generated and coregistered on T2-weighted images. Regions of interest were placed in the splenium and genu of the callosum, the frontal white matter, and the hippocampus. HIV+ patients were divided into those whose CD4 count were <250 cells/mm(3) or >250 cells/mm(3). According to plasma viral loads, patients were divided into those whose viral loads were <50 copies/mL, 50-100,000 copies/mL, or >100,000 copies/mL. RESULTS: Statistically significant decrease of FA was found in the genu of the corpus callosum in HIV+ patients compared with controls. FA was reduced in the frontal white matter and hippocampi in HIV+ patients compared with controls. Differences, however, were not statistically significant. No statistically significant differences were found between the HIV+ groups for FA of the splenium or between these groups and the controls. ADC values were significantly increased in the genu of HIV+ patients when compared with controls and were also increased in other locations, but without statistical significance. CONCLUSION: As used in this study, DTI was not helpful in identifying patients with early HIV infection.