Acoustomechanical properties of open TTP titanium middle ear prostheses

OBJECTIVE: The purpose of the study was to identify acoustcomechanical properties of various biostable and biocompatible materials to create a middle ear prosthesis with the following properties: (i) improved handling including a good view of the head of the stapes or footplate and adjustable length, (ii) improved acoustical characteristics that are adequate for ossiculoplastic. The identified material should serve to build CE and FDA approved prostheses for clinical use in patients. METHODS: Test models made of Teflon, polyetheretherketone, polyethylenterephtalate, polysulfone, gold, Al2O3 ceramics, carbon and titanium were investigated for their potential to fulfill the requirements. Acoustical properties were investigated by laser Doppler velocimetry (LDV) in mechanical middle ear models (MMM). Measured data were fed in to a recently created computer model of the middle ear (multibody systems approach, MBS). Using computer-aided design (CAD) measured and computed data allowed creation and fine precision of titanium prostheses (Tübingen Titanium Protheses, TTP). Their handling was tested in temporal bones. Acoustomechanical properties were investigated using the MBS and mechanical middle ear models. MAIN OUTCOME MEASURES: Input impedance, mass, stiffness, and geometry of test models and prostheses were determined. Furthermore, their influence on the intraprosthetic transfer functions and on coupling to either tympanic membrane or stapes was investigated. RESULTS: Final results were FDA- and CE-approved filigreed titanium prostheses with an open head that fulfilled the four requirements detailed above. The prostheses (TTP) were developed in defined lengths of between 1.75 and 3.5 mm (partial) and 3.0 and 6.5 mm (total) as well as in adjustable lengths (TTP-Vario). CONCLUSIONS: The results suggest acoustomechanical advantages of TTPs because they combine a significantly low mass with high stiffness. In contrast to closed prostheses, the open head and filigreed design allow an excellent view of the prosthesis foot during coupling to the head or footplate of stapes, contributing to an improved intraoperative reliability of prosthesis coupling.     

In vitro activity of anidulafungin against selected clinically important mold isolates

In this study, we evaluated the in vitro activity of anidulafungin against selected mold isolates. Anidulafungin showed promising activity against Bipolaris spicifera, Exophiala jeanselmei, Fonsecaea pedrosoi, Madurella mycetomatis, Penicillium marneffei, Phialophora verrucosa, Pseudallescheria boydii, Sporothrix schenckii, and Wangiella dermatitidis.     

Asbestos banned in Argentina

In 1997, Argentina gave priority to asbestos in its National Plan for the Sound Management of Chemicals, and it was the subject of a Technical Task Force on Occupational Cancer. After five years of public hearings in which government, workers, industry advocates, environmentalists, clinicians, scientists, and consumers participated, it was agreed that asbestos exposure is a risk factor for both workers and the general population, and that Argentina should provide to its people the same protections adopted by many developed countries. Pressure from asbestos industry groups initially delayed the inclusion of chrysotile asbestos in the proposed ban, but on January 1, 2003, the mining and import of all forms of asbestos were banned in Argentina.     

Factors related to experiencing respiratory failure in cases of opiate overdose for which care was provided in an open setting. Barcelona, Spain

BACKGROUND: To determine the factors associated with respiratory arrest in opiate overdoses (coma, pupillary miosis, respiratory depression, and response to naloxone) among injecting drug users in the Can Tunis quarter of Barcelona. METHODS: We ran a transversal observational study where all overdoses assisted between March, 2001 and June, 2002. After overdose treatment, data were collected using a standard questionnaire, including: patients' sociodemographic data, opiate and other substances' use prior to overdose, clinical signs and symptoms presented, and medical intervention received, by way of a standardised questionnaire. Logistic regression was used as a tool for analysis. RESULTS: Of 222 opiate overdose cases, 60.8% showed respiratory arrest. Of all risk factors tested, only prior abstinence heroin abstinence for 2 weeks or longer days (OR=1.893; p=0.04), and no previous consumption of benzodiazepines (OR:0.462; p=0.017), proved to have a statistically significant association with suffering a respiratory arrest. Concomitant use of alcohol, cocaine or methadone appeared not associated with suffering respiratory arrest in opiate overdose. CONCLUSIONS: The main risk factor for respiratory arrest in opiate overdoses was a prior abstinence period of more than 2 weeks. Benzodiazepines use was associated with absence of respiratory arrest in overdose cases. Alcohol or methadone use, as well as the use of larger quantities of heroin, was not associated with suffering respiratory arrest in opiate overdoses. A study of other factors, not included in this study, and that could interfere with our results, should be considered for their possible relationship to benzodiazepine use as well as to absence of respiratory arrest in overdose cases.     

Mega-aneurysmal degeneration of a saphenous vein graft following infrainguinal bypass. A case report

True aneurysm formation in infrainguinal autologous vein grafts is rare. The authors report a case of a patient presenting with extensive aneurysmal degeneration of a femoropopliteal bypass vein graft 13 years after the original operation and 8 years after graft revision and thrombolysis for acute occlusion. Over a 2-year period, the vein graft aneurysm expanded from 2.7 to 4.5 cm maximal diameter. He underwent exclusion and partial resection of the vein graft aneurysm with placement of a new femoropopliteal bypass using reversed saphenous vein from the contralateral leg. Histopathologic examination of the aneurysm revealed intimal fibrosis, medial degeneration, and inflammation. This case and review of the literature suggests that true infrainguinal vein graft aneurysms occur infrequently and massive aneurysm degeneration is even more uncommon. Because of the rarity of true infrainguinal vein graft aneurysms, their etiology remains unclear.     

Vascular effects of the Mangifera indica L. extract (Vimang)

The effects of the Mangiferia indica L. (Vimang) extract, and mangiferin (a C-glucosylxanthone of Vimang) on the inducible isoforms of cyclooxygenase (cyclooxygenase-2) and nitric oxide synthase (iNOS) expression and on vasoconstrictor responses were investigated in vascular smooth muscle cells and mesenteric resistance arteries, respectively, from Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Vimang (0.5-0.1 mg/ml) and mangiferin (0.025 mg/ml) inhibited the interleukin-1beta (1 ng/ml)-induced iNOS expression more in SHR than in WKY, and cyclooxygenase-2 expression more in WKY than in SHR. Vimang (0.25-1 mg/ml) reduced noradrenaline (0.1-30 microM)- and U46619 (1 nM-30 microM)- but not KCl (15-70 mM)-induced contractions. Mangiferin (0.05 mg/ml) did not affect noradrenaline-induced contraction. In conclusion, the antiinflammatory action of Vimang would be related with the inhibition of iNOS and cyclooxygenase-2 expression, but not with its effect on vasoconstrictor responses. Alterations in the regulation of both enzymes in hypertension would explain the differences observed in the Vimang effect.