Effect of different investments and mold temperatures on titanium mechanical properties

PurposeThe aim of the present study was to evaluate commercially pure titanium (CP Ti) casting quality when a specific to titanium and a conventional phosphate bonded investments were used under different mold temperatures. For this, the evaluated parameters were surface roughness, bending strength, Vickers microhardness, casting quality by radiographies and microstructure of CP Ti.MethodsWax patterns (28 mm × 3 mm × 1 mm) were invested using two phosphate bonded investments: Rematitan Plus (REM), specific to titanium, and Castorit Super C (CAS), a conventional investment, fired and cooled until reaching two mold temperatures: 430 °C (430) and room temperature (RT). Specimens were cast from CP Ti by plasma. After casting, specimens were radiographically examined and submitted to Vickers microhardness, roughness and bending strength evaluation. Microstructure was analyzed in the center and at the surface of specimen.ResultsQualitative analysis of radiographs showed that specimens which were cast using CAS-RT presented more casting porosities while the specimens which were cast with REM-430 did not present any casting porosity. No significant difference was noted among the groups in the surface roughness and Vickers microhardness data, but the bending strength of the specimens cast using CAS was greater than REM groups. The microstructure of the specimens of the different groups was similar, presenting a feather-like aspect.ConclusionCasting porosities found in the specimens cast using conventional investments (CAS) and lower mold temperatures would limit their use, even mechanical properties were similar than in specimens cast using specific to titanium investment (REM) at temperatures recommended by the manufacturer.     

MEF2C deletions and mutations versus duplications: A clinical comparison

5q14.3 deletions including the MEF2C gene have been identified to date using genomic arrays in patients with severe developmental delay or intellectual disability, stereotypic behavior, epilepsy, cerebral malformations and a facial gestalt not really distinctive though characterized by broad and/or high, bulging forehead, upslanting palpebral fissures, flat nasal root and bridge, small, upturned nose, hypotonic small mouth resulting in cupid bow/tented upper lip. MEF2C mutations have been also identified in patients with overlapping phenotype so that it is considered the gene responsible for the 5q14.3 deletion syndrome. To date, one single duplication including MEF2C has been reported in a patient with intellectual disability but its clinical significance remains uncertain also because of the large size of the imbalance. Here we present two further patients with 5q14.3 duplications including MEF2C. Their phenotype indeed suggest the pathogenic effect of the MEF2C duplication although other duplicated genes also brain expressed might contribute to the clinical features. In none of them a clear-cut syndrome can be identified. A comparison between MEF2C deleted/mutated and duplicated patients is also presented.     

Evaluation of Immunogenicity and Efficacy of Anthrax Vaccine Adsorbed for Postexposure Prophylaxis

Antimicrobials administered postexposure can reduce the incidence or progression of anthrax disease, but they do not protect against the disease resulting from the germination of spores that may remain in the body after cessation of the antimicrobial regimen. Such additional protection may be achieved by postexposure vaccination; however, no anthrax vaccine is licensed for postexposure prophylaxis (PEP). In a rabbit PEP study, animals were subjected to lethal challenge with aerosolized Bacillus anthracis spores and then were treated with levofloxacin with or without concomitant intramuscular (i.m.) vaccination with anthrax vaccine adsorbed (AVA) (BioThrax; Emergent BioDefense Operations Lansing LLC, Lansing, MI), administered twice, 1 week apart. A significant increase in survival rates was observed among vaccinated animals compared to those treated with antibiotic alone. In preexposure prophylaxis studies in rabbits and nonhuman primates (NHPs), animals received two i.m. vaccinations 1 month apart and were challenged with aerosolized anthrax spores at day 70. Prechallenge toxin-neutralizing antibody (TNA) titers correlated with animal survival postchallenge and provided the means for deriving an antibody titer associated with a specific probability of survival in animals. In a clinical immunogenicity study, 82% of the subjects met or exceeded the prechallenge TNA value that was associated with a 70% probability of survival in rabbits and 88% probability of survival in NHPs, which was estimated based on the results of animal preexposure prophylaxis studies. The animal data provide initial information on protective antibody levels for anthrax, as well as support previous findings regarding the ability of AVA to provide added protection to B. anthracis-infected animals compared to antimicrobial treatment alone.     

A comprehensive, longitudinal description of the in-hospital and post-discharge clinical, laboratory, and neurohormonal course of patients with heart failure who die or are re-hospitalized within 90?days: analysis from the EVEREST trial

Hospitalization for worsening chronic heart failure results in high post-discharge mortality, morbidity, and cost. However, thorough characterization, soon after discharge of patients with early post-discharge events has not been previously performed. The objectives of this study were to describe the baseline, in-hospital, and post-discharge clinical, laboratory, and neurohormonal profiles of patients hospitalized for worsening heart failure with reduced ejection fraction (EF) who die or are re-admitted for cardiovascular (CV) causes within 90 days of initial hospitalization. Retrospective analysis of 4,133 patients hospitalized for worsening heart failure with EF ≤40% in the Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study with Tolvaptan (EVEREST) trial, which randomized patients to tolvaptan or placebo, both in addition to standard therapy. Clinical and laboratory parameters were obtained within 48?h of admission, during hospitalization, and post-discharge weeks 1, 4, 8, and every 8?weeks thereafter for a median of 9.9?months. Patients with events within 90?days were compared with those with later/no events. All-cause mortality (ACM) and CV re-hospitalization were independently adjudicated. Within 90?days of admission, 395 patients (9.6%) died and 801 patients (19.4%) were re-hospitalized for CV causes. Significant baseline and longitudinal differences were seen between groups with early versus later (>90?days) or no events at 12?months post-randomization. Post-discharge outcomes were similar in the tolvaptan and placebo groups. Patients with early post-discharge events experienced clinically significant worsening in signs and symptoms, laboratory values, and neurohormonal parameters soon after discharge. Identifying these abnormalities may facilitate efforts to reduce post-discharge mortality and re-hospitalization.