Screening of Alcoholic Yeast Strains for Petite Mutation Frequency and Killer Phenotypes

Seventeen strains of alcoholic yeasts were screened for petite mutation frequency and killer phenotypes with an objective to develop them as industrial strains. The frequency of petite mutations varied with the strain. Though some strains have shown high frequency mutations, a few strains were found to be genetically stable. The killer property was found to vary with the strains. Interestingly, though some strains proved to be sensitive, some strains were found to be killer strains for marker killer strain also. Thus, the study provides the evidence that the killer principle varies with the strain.     

Tracheal Stenosis after Tracheostomy

INTRODUCTIONTracheal stenosis is a late and usually non-life threatening complication of surgical and percutaneous tracheostomies (PDT) as well as delayed endotracheal extubation.METHODSWe undertook a retrospective review of all patients who underwent a surgical tracheostomy over a 10 year period. Patients were included in the study if they had CT or MRI imaging of the tracheostomy site both pre-operatively and six or more weeks post operatively. Patients whose imaging was not available were excluded (n = 3) as were those patients who still had a tracheostomy in situ (n = 8). In total 91 patients were included in the study. In the same period 1170 surgical tracheostomies were performed by the maxillofacial surgeons. The images were analysed by a radiologist and the degree of stenosis reported.RESULTSAll 91 patients underwent a tracheostomy with a window. 83 patients did not demonstrate any stenosis. Looking at the remaining 8 patients with stenosis: 6 patients had stenosis of less than 25%, 1 patient had stenosis between 25-50% and 1 patient had stenosis greater than 50%. Both patients with stenosis greater than 25% had more than one surgical tracheostomy.CONCULSIONWe have shown that the risk of stenosis is 8.8%, lower than often quoted in literature, and when it occurs it is likely to be symptomatic only in severe stenosis. Our main risk of stenosis was repeat surgical tracheostomies which also seems to be linked to a greater degree of stenosis.     

Clinical utility of EUS-guided fine-needle aspiration of mediastinal masses in the absence of known pulmonary malignancy

BACKGROUND: Mediastinal masses represent a diagnostic challenge because of their proximity to numerous critical structures, difficulty of access for tissue sampling, and myriad potential pathologic etiologies. A large, single-center experience with EUS-guided fine-needle aspiration (EUS-FNA) in the diagnosis of non-lung cancer-related mediastinal masses is presented. METHODS: An EUS database was reviewed and all cases of mediastinal mass or lymphadenopathy encountered between 1994 and 1999 were included. Final diagnoses were determined by EUS-FNA cytology and clinical follow-up. RESULTS: Forty-nine patients were identified (27 women, 22 men; mean age 58.1 years, range 30-89 years). A malignant process was diagnosed in 22 cases (45%) and a benign process in 24 (49%). The EUS-FNA specimen was nondiagnostic in 3 cases (6%). An accurate diagnosis was made in 46 of the 49 patients (94%). No complication was noted. CONCLUSIONS: EUS-FNA is a minimally invasive technique that facilitates detection and tissue sampling of mediastinal masses. It is a safe procedure that can be performed with the patient under conscious sedation in an outpatient setting.     

The effect of tranexamic acid on artificial joint materials: a biomechanical study (the bioTRANX study)

Background

Tranexamic acid (TXA) has been successfully used to reduce bleeding in joint replacement. Recently local TXA has been advocated to reduce blood loss in total knee or hip replacement; however, this raised concerns about potential adverse effects of TXA upon the artificial joint replacement.

Materials and methods

In this biomechanical study we compared the effects of TXA and saline upon the following biomechanical properties of artificial joint materials—(1) tensile properties (ultimate strength, stiffness and Young’s modulus), (2) the wear rate using a multi-directional pin-on-plate machine, and (3) the surface topography of pins and plates before and after wear rate testing.

Results

There were no significant differences in tensile strength, wear rates or surface topography of either ultra-high-molecular-weight polyethylene pins or cobalt chromium molybdenum metal plates between specimens soaked in TXA and specimens soaked in saline.

Conclusion

Biomechanical testing shows that there are no biomechanical adverse affects on the properties of common artificial joint materials from using topical TXA.

Level of evidence

V