In vitro antifungal activities of voriconazole and reference agents as determined by NCCLS methods: Review of the literature

Voriconazole (Vfend™) is a new triazole that currently is undergoing phase III clinical trials. This review summarizes the published data obtained by NCCLS methods on the in vitro antifungal activity of voriconazole in comparison to itraconazole, amphotericin B, fluconazole, ketoconazole and flucytosine. Voriconazole had fungistatic activity against most yeasts and yeastlike species (minimum inhibitory concentrations [MICs] <2 μg/ml) that was similar or superior to those of fluconazole, amphotericin B, and itraconazole. Against Candida glabrata and C. krusei, voriconazole MIC ranges were 0.03 to 8 and 0.01 to >4 μg/ml, respectively. For four of the six Aspergillus spp. evaluated, voriconazole MICs (< 0.03 to 2 μg/ml) were lower than amphotericin B (0.25 to 4 μg/ml) and similar to itraconazole MICs. Voriconazole fungistatic activity against Fusarium spp. has been variable. Against F. oxysporum and solani, most studies showed MICs ranging from 0.25 to 8 μg/ml. Voriconazole had excellent fungistatic activity against five of the six species of dimorphic fungi evaluated (MIC₉₀s < 1.0 μg/ml). The exception was Sporothrix schenckii (MIC₉₀s and geometric mean MICs ≥ 8 μg/ml). Only amphotericin B had good fungistatic activity against the Zygomycetes species (voriconazole MICs ranged from 2 to >32 μg/ml). Voriconazole showed excellent in vitro activity (MICs < 0.03 to 1.0 μg/ml) against most of the 50 species of dematiaceous fungi tested, but the activity of all the agents was poor against most isolates of Scedosporium prolificans and Phaeoacremonium parasiticum (Phialophora parasitica). Voriconazole had fungicidal activity against most Aspergillus spp., B. dermatitidis, and some dematiaceous fungi. In vitro/in vivo correlations should aid in the interpretation of these results. This revised version was published online in June 2006 with corrections to the Cover Date.     

Energy state, pH, and vasomotor tone during hypoxia in precontracted pulmonary and femoral arteries

To assess effects of smooth muscle energy state and intracellular pH (pH(i)) on pulmonary arterial tone during hypoxia, we measured ATP, phosphocreatine, P(i), and pH(i) by (31)P-NMR spectroscopy and isometric tension in phenylephrine-contracted rings of porcine proximal intrapulmonary arteries. Hypoxia caused early transient contraction followed by relaxation and late sustained contraction. Energy state and pH(i) decreased during relaxation and recovered toward control values during late contraction. Femoral arterial rings had higher energy state and lower pH(i) under baseline conditions and did not exhibit late contraction or recovery of energy state and pH(i) during hypoxia. In pulmonary arteries, glucose-free conditions abolished late hypoxic contraction and recovery of energy state and pH(i), but endothelial denudation abolished only late hypoxic contraction. NaCN had little effect at 0. 1 and 1.0 mM but caused marked vasorelaxation and decreases in energy state and pH(i) at 10 mM. These results suggest that 1) regulation of tone, energy state, and pH(i) differed markedly in pulmonary and femoral arterial smooth muscle, 2) hypoxic relaxation was mediated by decreased energy state or pH(i) due to hypoxic inhibition of oxidative phosphorylation, 3) recovery of energy state and pH(i) in hypoxic pulmonary arteries was due to accelerated glycolysis mediated by mechanisms intrinsic to smooth muscle, and 4) late hypoxic contraction in pulmonary arteries was mediated by endothelial factors that required hypoxic recovery of energy state and pH(i) for transduction in smooth muscle or extracellular glucose for production and release by endothelium.     

Characterization of mucins from cultured normal human tracheobronchial epithelial cells

Early-passage normal human tracheobronchial epithelial (NHTBE) cells grown in air-liquid interface cultures in medium containing retinoids differentiate into a mucociliary epithelium over a 2- to 3-wk period and express increasing mRNA levels of the airway mucin genes MUC5AC and MUC5B as the cultures age; the levels of MUC2 mRNA were very low throughout the study. Using specific antibodies to MUC5AC and MUC5B mucins, we noted a gradual increase in these two mucins in the intracellular and apically secreted pools as a function of time. A low level of MUC2 mucin was detected, which did not change with time. The intracellular and apically secreted mucins isolated from day 14 and day 21 cultures by density gradient centrifugation were similar in density to those previously isolated from human respiratory mucus secretions. The sedimentation rate of the apically secreted mucins indicated that they were highly oligomerized, polydisperse macromolecules similar to those previously documented from in vivo secretions. In contrast, the cell-associated mucins from the cultured NHTBE cells were much smaller, possibly only monomers and dimers. Anion-exchange chromatography detected no differences in charge density between the reduced and carboxymethylated cell-associated and secreted forms of the MUC5AC and MUC5B mucins. The MUC5AC mucin was of similar charge density to its in vivo counterpart; however, MUC5B was more homogeneous than that found in vivo. Finally, evidence is presented for an intracellular NH(2)-terminal cleavage of the MUC5B mucins. These studies indicate that the mucins produced by cultured NHTBE cells are similar to those found in human airways, suggesting that this cell culture model is suited for studies of respiratory mucin biosynthesis, processing, and assembly.     

Modeling of the primary and secondary drying stages of the freeze drying of pharmaceutical products in vials: numerical results obtained from the solution of a dynamic and spatially multi-dimensional lyophilization model for different operational policies

A rigorous unsteady state and spatially multidimensional model is presented and solved to describe the dynamic behavior of the primary and secondary drying stages of the lyophilization of a pharmaceutical product in vials for different operational policies. The results in this work strongly motivate the aggressive control of freeze drying and it is found that heat input control that runs the process close to the melting and scorch temperature constraints yields (i) faster drying times, and (ii) more uniform distributions of temperature and concentration of bound water at the end of the secondary drying stage.     

A Systematic Review of the Level of Evidence in Economic Evaluations of Medical Devices: The Example of Vertebroplasty and Kyphoplasty

Context

Economic evaluations are far less frequently reported for medical devices than for drugs. In addition, little is known about the quality of existing economic evaluations, particularly for innovative devices, such as those used in vertebroplasty and kyphoplasty.

Objective

To assess the level of evidence provided by the available economic evaluations for vertebroplasty and kyphoplasty.

Data Sources

A systematic review of articles in English or French listed in the MEDLINE, PASCAL, COCHRANE and National Health Service Economic Evaluation databases, with limits on publication date (up to the date of the review, March 2014).

Study Selection

We included only economic evaluations of vertebroplasty or kyphoplasty. Editorial and methodological articles were excluded.

Data Extraction

Data were extracted from articles by two authors working independently and using two analysis grids to measure the quality of economic evaluations.

Data Synthesis

Twenty-one studies met our inclusion criteria. All were published between 2008 and 2014. Eighteen (86%) were full economic evaluations. Cost-effectiveness analysis (CEA) was the most frequent type of economic evaluation, and was present in 11 (52%) studies. Only three CEAs complied fully with the British Medical Journal checklist. The quality of the data sources used in the 21 studies was high, but the CEAs conforming to methodological guidelines did not use high-quality data sources for all components of the analysis.

Conclusions

This systematic review shows that the level of evidence in economic evaluations of vertebroplasty and kyphoplasty is low, despite the recent publication of a large number of studies. This finding highlights the challenges to be faced to improve the quality of economic evaluations of medical devices.     

Identification of an elongation factor 1Bγ protein with glutathione transferase activity in both yeast and mycelial morphologies from human pathogenic Blastoschizomyces capitatus

Blastoschizomyces capitatus is an uncommon, opportunistic pathogenic fungus, which causes invasive and disseminated infections. This microorganism is normally present in both environmental and normal human flora. Within a host, B. capitatus is able to grow in both unicellular yeast and multicellular filamentous growth forms. In this study, we obtained in vitro morphological conversion of B. capitatus from yeast-to-mycelial phase to investigate the presence and expression of glutathione transferase (GST) enzymes in both cell forms. A protein with GST activity using the model substrate 1-chloro-2,4-dinitrobenzene was detected in both morphologies and identified by tandem mass spectrometry as a eukaryotic elongation factor 1Bγ (eEF1Bγ) protein, a member of the GST superfamily. No significant difference in GST-specific activity and kinetic constants were observed between mycelial and yeast forms, indicating that eEF1Bγ protein did not show differential expression between the two phases.     

Multicentre prospective validation of use of the Canadian C-Spine Rule by triage nurses in the emergency department

Objectives

The Canadian C-Spine Rule for imaging of the cervical spine was developed for use by physicians. We believe that nurses in the emergency department could use this rule to clinically clear the cervical spine. We prospectively evaluated the accuracy, reliability and acceptability of the Canadian C-Spine Rule when used by nurses.

Methods

We conducted this three-year prospective cohort study in six Canadian emergency departments. The study involved adult trauma patients who were alert and whose condition was stable. We provided two hours of training to 191 triage nurses. The nurses then assessed patients using the Canadian C-Spine Rule, including determination of neck tenderness and range of motion, reapplied immobilization and completed a data form.

Results

Of the 3633 study patients, 42 (1.2%) had clinically important injuries of the cervical spine. The kappa value for interobserver assessments of 498 patients with the Canadian C-Spine Rule was 0.78. We calculated sensitivity of 100.0% (95% confidence interval [CI] 91.0%–100.0%) and specificity of 43.4% (95% CI 42.0%–45.0%) for the Canadian C-Spine Rule as interpreted by the investigators. The nurses classified patients with a sensitivity of 90.2% (95% CI 76.0%–95.0%) and a specificity of 43.9% (95% CI 42.0%–46.0%). Early in the study, nurses failed to identify four cases of injury, despite the presence of clear high-risk factors. None of these patients suffered sequelae, and after retraining there were no further missed cases. We estimated that for 40.7% of patients, the cervical spine could be cleared clinically by nurses. Nurses reported discomfort in applying the Canadian C-Spine Rule in only 4.8% of cases.

Conclusion

Use of the Canadian C-Spine Rule by nurses was accurate, reliable and clinically acceptable. Widespread implementation by nurses throughout Canada and elsewhere would diminish patient discomfort and improve patient flow in overcrowded emergency departments.Each year, Canadian emergency departments treat 1.3 million patients who have suffered blunt trauma from falls or motor vehicle collisions and who are at risk for injury of the cervical spine.¹ Most of these cases involve adults who are alert and in stable condition, and less than 1% involve fracture of the cervical spine.² Most trauma patients who have been transported in ambulances are protected by a backboard, collar and neck supports. Nurses are responsible for initial triage in the emergency department and usually send such patients to high-acuity resuscitation rooms, where they may remain fully immobilized for hours until assessment by a physician and radiography are complete. This prolonged immobilization is often unnecessary and adds considerably to patient discomfort. The delay also adds to the burden of overcrowded Canadian emergency departments in an era when they are under unprecedented pressures.^3–5 These patients occupy valuable space in resuscitation rooms, and repeated efforts to obtain satisfactory radiographs or computed tomography scans of the cervical spine use valuable time on the part of physicians, nurses and technicians.A clinical decision rule is defined as a decision-making tool incorporating three or more variables from the patient’s history, a physical examination or simple tests. Such rules are derived from original research and help clinicians with diagnostic or therapeutic decisions at the bedside. We previously developed a clinical decision rule for evaluation of the cervical spine.^6,7 The Canadian C-Spine Rule comprises simple clinical variables (Figure 1) and was designed to allow clinicians to “clear” immobilization of the cervical spine (i.e., remove neck collar and other devices) without radiography and to decrease immobilization times.⁸ We also validated the accuracy of the rule when used by physicians.⁹ We recently completed an implementation trial at 12 Canadian hospitals to evaluate the impact on patient care and outcomes of the Canadian C-Spine Rule when used by physicians.¹⁰Open in a separate windowFigure 1The Canadian C-Spine Rule to rule out cervical spine injury, adapted for use by nurses. The rule is intended for patients who have experienced trauma, who are alert (score on Glasgow Coma Scale = 15) and whose condition is stable. *The following mechanisms of injury were defined as dangerous: fall from elevation of more than 3 ft (91 cm) or five stairs, axial load to the head (e.g., diving injury), motor vehicle collision at high speed (> 100 km/h), motor vehicle collision involving a rollover or ejection, injury involving a motorized recreational vehicle, bicycle-related injury (rider struck or collision). †Simple rear-end motor vehicle collisions exclude incidents in which the patient was pushed into oncoming traffic or was hit by a bus, large truck or vehicle travelling at high speed, as well as rollovers; all such incidents would be considered high risk. ‡Neck pain with delayed onset is any pain that did not occur immediately following the precipitating incident. Adapted, with permission, from Stiell IG, Wells GA, Vandemheen K, et al. The Canadian Cervical Spine Radiography Rule for alert and stable trauma patients. JAMA 2001;286:1841–8.⁸ Copyright © 2001 American Medical Association. All rights reserved.Nurses in the emergency department usually do not evaluate the cervical spine of trauma patients, and they routinely send all immobilized patients to the emergency department’s resuscitation room. We believe that nurses could safely evaluate alert patients who have arrived by ambulance and whose condition is stable and could “clear” immobilization of the cervical spine of low-risk patients upon arrival at the triage station.¹¹ Patients could then be much more rapidly, comfortably and efficiently managed in other areas of the emergency department. An expanded decision-making role for nurses has the potential to improve the efficiency of trauma care in all Canadian hospitals. Very little research has been done to determine the ability of nurses to clear immobilization of the cervical spine.^12–15 Our objective in this study was to prospectively evaluate the accuracy, reliability and acceptability of the Canadian C-Spine Rule when used by nurses to assess patients’ need for immobilization.     

Epigenetic regulator MLL2 shows altered expression in cancer cell lines and tumors from human breast and colon

Background  

MLL2, an epigenetic regulator in mammalian cells, mediates histone 3 lysine 4 tri-methylation (H3K4me3) through the formation of a multiprotein complex. MLL2 shares a high degree of structural similarity with MLL, which is frequently disrupted in leukemias via chromosomal translocations. However, this structural similarity is not accompanied by functional equivalence. In light of this difference, and previous reports on involvement of epigenetic regulators in malignancies, we investigated MLL2 expression in established cell lines from breast and colon tissues. We then investigated MLL2 in solid tumors of breast and colon by immunohistochemistry, and evaluated potential associations with established clinicopathologic variables.     

Investigations of a prion infectivity assay to evaluate methods of decontamination

Prions are unique infectious agents which have been shown to be transmitted iatrogenically through contaminated surfaces. Surface contamination is a concern on reusable medical devices and various industrial surfaces, but there is currently no standard, accepted model to evaluate surface prion decontamination. In this report, a set of both in vitro and in vivo methods were investigated based on the contamination of surface through artificial exposure to infected brain. An in vitro surface contamination protocol was developed with subsequent biochemical detection of the prion protein (PrPres). In parallel, the in vivo investigations included the contamination of different types of surface materials (stainless steel or plastic wires) with different prion strains (scrapie strain adapted to hamsters 263K or bovine spongiform encephalopathy strain adapted to mouse 6PB1). The in vivo models with various prion strains and brain homogenate dilutions reproducibly transmitted the disease and a relationship was established between the infectivity titre, the transmission rate and the incubation period. Moreover, the in vivo models were studied for their ability to demonstrate the efficacy of heat and chemical-based decontamination methods, with similar results. The in vivo scrapie method described is proposed as a standard to evaluate existing and developing prion decontamination technologies.