Risk factors for colonization with extended-spectrum beta-lactamase-producing enterobacteriaceae on admission to rehabilitation centres.

Patients newly admitted to rehabilitation centres are at high risk of colonization with multidrug-resistant bacteria because many of them have experienced prolonged stays in other healthcare settings and have had high exposure to antibiotics. We conducted a prospective study to determine the prevalence of and risk factors for colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) in this population. Subjects were screened by rectal swab for ESBL-PE within 2 days of admission. Swabs were plated on chromagar ESBL plates and the presence of ESBL was verified by a central laboratory. A multilevel mixed effects model was used to identify risk factors for ESBL-PE colonization. Of 2873 patients screened, 748 (26.0%) were positive for ESBL-PE. The variables identified as independently associated with ESBL-PE colonization were: recent stay in an acute-care hospital for over 2 weeks (OR=1.34; 95% CI, 1.12, 1.6), history of colonization with ESBL-PE (OR=2.97; 95% CI, 1.99, 4.43), unconsciousness on admission (OR=2.59; 95% CI, 1.55, 4.34), surgery or invasive procedure in the past year (OR=1.49; 95% CI, 1.2, 1.86) and antibiotic treatment in the past month (OR=1.80; 95% CI, 1.45, 2.22). The predictive accuracy of the model was low (area under the ROC curve 0.656). These results indicate that ESBL-PE colonization is common upon admission to rehabilitation centres. Some risk factors for ESBL-PE colonization are similar to those described previously; however, newly identified factors may be specific to rehabilitation populations. The high prevalence and low ability to stratify by risk factors may guide infection control and empirical treatment strategies in rehabilitation settings.

Amusia for pitch caused by right middle cerebral artery infarct.

A 61-year-old right-handed man with hypertension and dyslipidemia noted that he was singing along to classic rock songs on his car radio, but his voice was off pitch. Six days later, a magnetic resonance imaging scan of his brain revealed a cerebral infarct of the right temporal parietal cortex and insula. Case reports of the precise anatomic correlates of disordered pitch musical processing have been few and fragmentary. The anatomic involvement of our case coincides with the areas of involvement in 3 previously reported cases. Increased awareness of amusia as a rare clinical presentation of stroke should lead to earlier stroke intervention.

Carriage of methicillin-resistant Staphylococcus aureus on admission to European rehabilitation centres--a prospective study.

This study aimed to determine the prevalence of and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) carriage among patients newly admitted to rehabilitation centres. It is a prospective study examining MRSA carriage on admission to seven rehabilitation wards in four countries. Risk factors for MRSA carriage were analysed using univariate and multivariate analyses. A total of 1204 patients were studied. Among them, 105 (8.7%) had a positive admission MRSA screening result. The MRSA carriers were more likely to be male, to have had a recent stay in another long-term-care facility or >2 weeks acute-care hospital stay, history of colonization with MRSA, reduced level of consciousness, peripheral vascular disease and pressure sores. In multivariable logistic regression male gender (odds ratio (OR) 2.2, 95% confidence interval (CI) 1.4-3.6, p 0.001), history of MRSA positivity (OR 6.8, 95% CI 3.8-12.3, p <0.001), peripheral vascular disease (OR 2.5, 95% CI 1.2-5, p 0.013), recent stay in another long-term-care facility (OR 2.1, 95% CI 1.3-3.5, p 0.004), or long (>2 weeks) acute-care hospital stay (OR 1.9, 95% CI 1.2-3, p 0.004), remained significant risk factors for MRSA carriage. MRSA carriage is common on admission to rehabilitation centres but less so, than previously described in long-term-care facilities. Male gender, history of MRSA positivity, previous hospitalization and peripheral vascular disease may predict MRSA carriage, and may serve as indicators for using pre-emptive infection control measures.

Vacuolization of tubules in gadolinium-associated acute renal failure.

While gadolinium was initially thought to be a safe alternative to iodinated contrast agents for patients with chronic renal insufficiency, many reports of gadolinium-associated acute renal failure have now been recorded, particularly in patients with underlying renal insufficiency. In addition, animal models have demonstrated tubule vacuolization with experimental gadolinium administration that is similar to vacuolization seen with other contrast agents. We present a case of a patient with nephrotic-range proteinuria and chronic renal insufficiency, who developed acute renal failure following gadolinium administration undergoing furosemide stimulated diuresis. This case is the first report of pathologic tubule vacuolization in gadolinium-associated nephropathy in a human kidney biopsy. This case suggests a relationship between the pathogenesis of CIN with standard contrast media and CIN with gadolinium. Research is needed to better understand the pathologic findings and pathogenesis of gadolinium-associated nephrotoxicity.

The prevalence and incidence of end-stage renal disease in Native American adults on the Navajo reservation.

Whereas members of the Navajo Nation are at high risk for diabetes mellitus, there are no recent published estimates of the burden of end-stage renal disease (ESRD), an important sequela of diabetes, on the Navajo Nation, a 16 million acre area in Arizona, New Mexico, and Utah with more than 200 000 tribal members. We used data from the US Renal Data System to estimate the prevalence and incidence of ESRD among Native American adults (>/=18 years) living on the Navajo Nation. For comparison, we estimated the prevalence and incidence of ESRD among all adults in the US, all Native American adults in the US, and Native American adults living in Arizona, New Mexico, Utah, and Colorado excluding those living on the Navajo Nation. The age-adjusted prevalence of ESRD in the Native American adults on the Navajo Nation was 0.63%, which was higher than in the US adults (0.19%, P<0.0001) and among the Native American adults in the US (0.36%, P<0.0001), but lower than among the other Native American adults in the Southwest (0.89%, P<0.0001). The age-adjusted incidence of ESRD in the Native American adults on the Navajo Nation was 0.11%, which was also higher than in the US adults (0.045%, P<0.0001) and among the Native American adults in the US (0.073%, P<0.0009), but lower than among the other Native American adults in the Southwest (0.17%, P<0.0003). The reasons behind these disparities merit further study.

Contrast-enhanced MR angiography and perfusion imaging of the hand.

OBJECTIVE: The goal of this investigation was to develop a technique for producing high-resolution gadolinium-enhanced MR images of the hand that show three-dimensional angiographic anatomy and permit measurement of distal soft-tissue perfusion. CONCLUSION: High-resolution MR angiograms of the hand, as well as qualitative perfusion information, can be produced using a rapid sequential gadolinium-enhanced three-dimensional gradient-echo technique.

Development, standardization, and testing of a lexicon for reporting contrast-enhanced breast magnetic resonance imaging studies.

The purpose of this study was to develop, standardize, and test reproducibility of a lexicon for reporting contrast-enhanced breast magnetic resonance imaging (MRI) examinations. To standardize breast MRI lesion description and reporting, seven radiologists with extensive breast MRI experience developed consensus on technical detail, clinical history, and terminology reporting to describe kinetic and architectural features of lesions detected on contrast-enhanced breast MR images. This lexicon adapted American College of Radiology Breast Imaging and Data Reporting System terminology for breast MRI reporting, including recommendations for reporting clinical history, technical parameters for breast MRI, descriptions for general breast composition, morphologic and kinetic characteristics of mass lesions or regions of abnormal enhancement, and overall impression and management recommendations. To test morphology reproducibility, seven radiologists assessed morphology characteristics of 85 contrast-enhanced breast MRI studies. Data from each independent reader were used to compute weighted and unweighted kappa (kappa) statistics for interobserver agreement among readers. The MR lexicon differentiates two lesion types, mass and non-mass-like enhancement based on morphology and geographical distribution, with descriptors of shape, margin, and internal enhancement. Lexicon testing showed substantial agreement for breast density (kappa = 0.63) and moderate agreement for lesion type (kappa = 0.57), mass margins (kappa = 0.55), and mass shape (kappa = 0.42). Agreement was fair for internal enhancement characteristics. Unweighted kappa statistics showed highest agreement for the terms dense in the breast composition category, mass in lesion type, spiculated and smooth in mass margins, irregular in mass shape, and both dark septations and rim enhancement for internal enhancement characteristics within a mass. The newly developed breast MR lexicon demonstrated moderate interobserver agreement. While breast density and lesion type appear reproducible, other terms require further refinement and testing to lead to a uniform standard language and reporting system for breast MRI. J. Magn. Reson. Imaging 2001;13:889-895.

Using AMSA and P-ASA nerve blocks for esthetic restorative dentistry.

Esthetic restorative dentistry procedures represent an increasing segment of the services provided by the general practitioner. One important assessment criterion for a successful anterior esthetic restoration is how well it harmonizes with the lips to create a pleasing smile line. Unfortunately, traditional local anesthetic techniques interfere with this assessment by distorting the lips and face during anesthesia. The anterior, middle superior alveolar block and the palatal approach anterior superior alveolar block injections represent two recently defined techniques to anesthetize maxillary teeth effectively without numbness of the face, lips, or muscles of expression. Although safety and efficacy studies are only beginning to emerge, these injections appear to be useful additions to local anesthetic techniques, especially when anterior esthetic restorative procedures are being performed.

An in vitro study of needle force penetration comparing a standard linear insertion to the new bidirectional rotation insertion technique.

OBJECTIVE: The purpose of this study was to determine the effect of a bidirectional rotation insertion technique on the force necessary to puncture and advance a needle through a tissuelike substance. METHOD AND MATERIALS: Two in vitro penetration test models were constructed using different tissuelike substances of different densities. Each tissuelike substance was tested with 30-gauge, 27-gauge, and 25-gauge needles of two brands commonly used in dentistry. The needles were placed to a standardized depth of 0.5 inch (1.27 cm) at a standardized rate of insertion. A customized dental surveyor allowed controlled forces to be applied. A linear insertion technique and a newly described bidirectional rotation insertion technique were tested. The force of puncture and penetration drag was recorded with an electronic digital scale. A total of 400 needle insertions were performed. RESULTS: A multivariate analysis of technique, material, needle gauge, and needle brand revealed the data to be statistically significant, demonstrating no overlap. The post-hoc analysis of between-subject effects found that the needle insertion technique accounted for the most powerful effect in reducing force penetration. The bidirectional insertion technique had the greatest influence on reducing the force penetration irrespective of material, needle gauge, or needle brand tested in this study. CONCLUSION: The bidirectional rotation insertion technique required two to three times less force than did a standard linear insertion technique. A continuous rotation in a single direction would be expected to produce similar results. Needle gauge and needle design have a smaller effect on reducing force penetration than did the technique used during insertion. The in vitro model used in this study represents a reliable dynamic testing system that can be used for future evaluation of needles.

Histologic response to intraligament injections using a computerized local anesthetic delivery system. A pilot study in mini-swine.

BACKGROUND: Intraligamentary (periodontal ligament) injection has been used to locally control pain with minimal anesthetic dose. The purpose of the present study was to determine the histologic effect of using a computer-controlled local anesthesia delivery system (CCLADS) for the administration of a periodontal ligament injection in the mini-swine model system. METHODS: Thirty-two sites in 3 mini-swine pigs with healthy periodontium were selected. Each site was notched on the mesial-lingual line angle of the tooth to allow a reference for needle placement and provide a histologic marker. An anesthetic cartridge was used with a 30-gauge needle attached to the handpiece of the CCLADS. This provided a controlled flow rate for 2 minutes. The control sites were treated with the same needle in place for 20 seconds. The animals were sacrificed and provided observation periods of 1 hour, 1, 4, 7, 21, and 49 days. Specimens were stained with hematoxylin and eosin and trichrome. RESULTS: Twenty-four hours after injection, limited localized inflammation was present. By 7 days, the ligament appeared within normal limits. Apical migration of the junctional epithelium extended to the apical limit of the notch and was similar in test and control specimens. CONCLUSIONS: Within the limits of this study, the histologic results showed that tissue responses following intraligament injections using a CCLADS demonstrated limited inflammatory responses within the first 24 hours, which abated by 7 days postinjection. Similar migration of the junctional epithelium was seen in test and control specimens and was probably related to tooth injury rather than anesthetic injections. Further investigations are warranted using CCLADS to determine whether clinical benefits will translate in the human model system.

Features of calcaneonavicular coalition on coronal computed tomography.

OBJECTIVE: To determine the findings of calcaneonavicular coalition on coronal CT. DESIGN: We retrospectively reviewed the CT scans of 14 calcaneonavicular coalitions in eight patients. All coalitions were visible on the axial scans, and the diagnosis was confirmed by surgery in five patients. These CT scans were compared with scans of ten normal feet. RESULTS: We identified two features of calcaneonavicular coalition on coronal CT: lateral bridging (an abnormal bony mass lateral to the head of the talus) and rounding of the talus. All eight patients demonstrated at least one of these two findings. CONCLUSION: Although calcaneonavicular coalition is best seen on axial CT scans of the feet, there are two abnormalities, lateral bridging and rounding of the head of the talus, which should suggest the diagnosis on coronal CT scans.