Acoustic analysis of gradient-coil noise in MR imaging

A survey was conducted of acoustic noise levels in magnetic resonance (MR) imaging systems. Static magnetic flux and radio-frequency pulses did not affect the function of shielded sound-pressure detection equipment. Noise levels were measured at bore isocenter during a variety of imaging sequences in six MR imaging systems with magnetic fields of 0.35-1.5 T. Measured noise ranged from 82 to 93 dB on the A-weighted scale and from 84 to 103 dB on the linear scale. Noise levels increased during sequences employing thinner section thickness and shorter repetition and echo times and were independent of field strength. Gradient-coil noise in MR imaging is an annoyance but is well within safety guidelines.     

Antegrade internal ureteral stenting: a technical refinement

A pliable, easy to place, double pigtail, internal ureteral stent made of elastomeric polyurethane is described. The tapered distal pigtail end minimizes bladder irritation and the combination of a pusher and absorbable suture enables optimal placement of the proximal pigtail end in the renal pelvis. Ten stents used in eight patients remained functional without bladder irritation for a mean period of 8 months (range, 2-14 months).     

Pulmonary nodules studied by computed tomography

The authors analyzed 177 pulmonary nodules using thin-section computed tomography (CT), calculating the representative CT number (RCT#) from a computer printout. None of the 96 malignant nodules had an RCT# greater than 151 H. Of the 81 benign nodules, 14 were shown to be calcified by conventional radiography and had an RCT# ranging from 763 and 1,023 H. Thirty had an RCT# greater than 200 H; this included 24 which showed no calcification on conventional tomograms. The remaining 37 benign nodules had an RCT# less than 200 H; 6 of them were hamartomas, including 2 which were diagnosed as such due to their fat content.     

In-vitro antimicrobial activity of marine actinobacteria against multidrug resistance Staphylococcus aureus

Objective

To investigate the antibacterial activity of marine actinobacteria against multidrug resistance Staphylococcus aureus (MDRSA).

Methods

Fifty one actinobacterial strains were isolated from salt pans soil, costal area in Kothapattanam, Ongole, Andhra Pradesh. Primary screening was done using cross-streak method against MDRSA. The bioactive compounds are extracted from efficient actinobacteria using solvent extraction. The antimicrobial activity of crude and solvent extracts was performed using Kirby-Bauer method. MIC for ethyl acetate extract was determined by modified agar well diffusion method. The potent actinobacteria are identified using Nonomura key, Shirling and Gottlieb 1966 with Bergey''s manual of determinative bacteriology.

Results

Among the fifty one isolates screened for antibacterial activity, SRB25 were found efficient against MDRSA. The ethyl acetate extracts showed high inhibition against test organism. MIC test was performed with the ethyl acetate extract against MDRSA and found to be 1 000 µg/mL. The isolated actinobacteria are identified as Streptomyces sp with the help of Nonomura key.

Conclusions

The current investigation reveals that the marine actinobacteria from salt pan environment can be able to produce new drug molecules against drug resistant microorganisms.