Urinary tract infections: new insights into a common problem

This review discusses recent advances in the understanding of how the common pathogen, uropathogenic Escherichia coli, interacts with the host to lead to infection.     

Correlation between clinical diagnosis and arthroscopic findings of the shoulder

Objective: To assess the accuracy of clinical examination by non-specialist orthopaedic surgeons of patients presenting to a diagnostic and treatment centre (DTC) for arthroscopic shoulder surgery. Methods: A retrospective review of notes of 130 consecutive shoulder arthroscopies performed at a DTC over a 10 month period. Preoperative clinical diagnosis was compared with operative arthroscopic findings. Additional information from preoperative imaging was compared with clinical examination and arthroscopic findings. Preoperative clinical examinations and consent were undertaken by clinical fellows, (SpR level) and non-upper limb consultant orthopaedic surgeons. Consultants specialising in upper limb surgery performed the operations. Results: Six main groups were identified on the basis of clinical examination: impingement 76 cases (58%), instability 22 cases (17%), frozen shoulder 11 cases (8%), rotator cuff tear four cases (3%), non-specific pain eight cases (6%), and normal clinical examination nine cases (7%). Impingement and instability diagnosed clinically strongly correlated with the arthroscopic findings. Clinical diagnosis of frozen shoulder and rotator cuff tears had a weaker correlation with the arthroscopic findings. Of the nine cases of normal clinical examination, abnormality was found at arthroscopy in all cases. Conclusion: There have been very few studies comparing clinical examination of the shoulder with arthroscopic findings. This study emphasises the importance of good clinical examination skills in diagnosing common shoulder abnormalities. The addition of imaging, particularly ultrasound and magnetic resonance imaging further increases the likelihood of an accurate diagnosis. Shoulder examination should be taught with as much emphasis at both undergraduate and postgraduate level as other orthopaedic clinical examinations.     

Surgical skill is predicted by the ability to detect errors

BACKGROUND: Objective analysis methods of surgical performance are now available so comparison between surgeons is available. One such method is by direct observation using the Objective Structured Assessment of Technical Skills (OSATS), but this is a time-consuming process; therefore, a simple screening tool for the ability to detect errors (previously validated) was analyzed and considered as a predictor of qualitative performance. METHODS: Thirty-eight volunteer surgeons were recruited to the skills laboratory to undertake 3 exercises. Two were bench-top surgical tasks that were scored using the global rating of the OSATS technique. The third task was the ability to detect simple errors in 22 synthetic models of common surgical procedures, some of which contained purposefully made errors. P<.05 was deemed to be statistically significant. RESULTS: The scores (interquartile ranges in parentheses) for the 3 sections were excision of sebaceous cyst=21 (19,24), closure of small bowel enterotomy=23 (21,27), and identification of errors=31 (27,34). Three scorers blinded to the operative models exhibited an interobserver reliability of .9 and .91 for the video tasks, respectively. Spearman's rank correlations between the error examination and performance on the 2 tasks were both statistically significant at .69 (cystectomy) and .54 (enterotomy). CONCLUSIONS: The ability to detect simple surgical errors is a predictor of technical skill and performance of bench tasks. What must be answered is whether the use of such models and principles can shorten the qualitative surgical learning curve.     

Intradermally focused infrared laser pulses: thermal effects at defined tissue depths

BACKGROUND AND OBJECTIVES: To produce controlled, spatially confined thermal effects in dermis. STUDY DESIGNS/MATERIALS AND METHODS: A 1 W, 1,500 nm fiber-coupled diode laser was focused with a high numerical aperture (NA) objective to achieve a tight optical focus within the upper dermis of skin held in contact with a glass window. The delivery optics was moved using a computer-controlled translator to generate an array of individual exposure spots. Fresh human facial skin samples were exposed to a range of pulse energies at specific focal depths, and to a range of focal depths at constant pulse energy. Cellular damage was evaluated in frozen sections using nitro-blue tetrazolium chloride (NBTC), a lactate dehydrogenase (LDH) activity stain. Loss of birefringence due to thermal denaturation of collagen was evaluated using cross-polarized light microscopy. The extent of focal thermal injury was compared with a model for photon migration (Monte Carlo Simulation), heat diffusion, and protein denaturation (Arrhenius model). RESULTS: Arrays of confined, microscopic intradermal foci of thermal injury were created. At high NA, epidermal damage was avoided without active cooling. Foci of thermal injury were typically 50-150 microm in diameter, elliptical, and at controllable depths from 0 to 550 microm. Both LDH inactivation and extracellular matrix denaturation were achieved. CONCLUSION: Spatially confined foci of thermal effects can be achieved by focusing a low-power infrared laser into skin. Size, depth, and density of microscopic, thermal damage foci may be arbitrarily controlled while sparing surrounding tissue. This may offer a new approach for nonablative laser therapy of dermal disorders.