A volumetric method for estimation of breast density on digitized screen-film mammograms

A method is described for the quantitative volumetric analysis of the mammographic density (VBD) from digitized screen-film mammograms. The method is based on initial calibration of the imaging system with a tissue-equivalent plastic device and the subsequent correction for variations in exposure factors and film processing characteristics through images of an aluminum step wedge placed adjacent to the breast during imaging. From information about the compressed breast thickness and technique factors used for taking the mammogram as well as the information from the calibration device, VBD is calculated. First, optical sensitometry is used to convert images to Log relative exposure. Second, the images are corrected for x-ray field inhomogeneity using a spherical section PMMA phantom image. The effectiveness of using the aluminum step wedge in tracking down the variations in exposure factors and film processing was tested by taking test images of the calibration device, aluminum step wedge and known density phantoms at various exposure conditions and also at different times over one year. Results obtained on known density phantoms show that VBD can be estimated to within 5% accuracy from the actual value. A first order thickness correction is employed to correct for inaccuracy in the compression thickness indicator of the mammography units. Clinical studies are ongoing to evaluate whether VBD can be a better indicator for breast cancer risk.     

Evaluation of the VITEK 2 system for rapid direct identification and susceptibility testing of gram-negative bacilli from positive blood cultures

This study explores the possibility of combining the BacT/Alert Microbial Detection System with the VITEK 2 system to achieve rapid bacterial identification and susceptibility testing. Direct inoculation of bacterial suspension to the VITEK 2 ID-GNB card and AST-NO09 card was made by differential centrifugation of blood cultures of organisms with gram-negative enteric bacillus-like morphology. A total of 118 strains were investigated; of these, 97 (82.2%) strains were correctly identified to the species level and 21 (17.8%) strains were not identified; by comparing the results with those of the reference method of API identification systems using a pure culture, it was found that no strain had been misidentified. Among the 21 strains with no identification, 13 (61.9%) strains were nonfermenters. The direct-identification reporting time of VITEK 2 was 3.3 h. Direct testing of susceptibility to 11 antibiotics, i.e., amikacin, cefepime, ceftazidime, ciprofloxacin, gentamicin, imipenem, meropenem, netilmicin, piperacillin, piperacillin-tazobactam, and tobramycin, was also performed by using the broth microdilution (MB) method according to the NCCLS guidelines as a reference. After comparing the MICs of the VITEK 2 system with those obtained by the MB method within +/-twofold dilution, it was determined that the 1,067 organism-antibiotic combinations had an overall correct rate of 97.6% (1,041 combinations). The rates of susceptibility to the 11 antibiotics ranged from 88.7 to 100%, respectively. Only two (0.2%) and four (0.4%) combinations of the susceptibility tests gave very major errors (i.e., reported as sensitive by the VITEK 2 system but shown to be resistant by the MB method) and major errors (i.e., reported as resistant by the VITEK 2 system but shown to be sensitive by the MB method), respectively. The reporting time for the direct testing of susceptibility against the 11 antibiotics for 97 blood culture isolates by the VITEK 2 system ranged from 3.3 to 17.5 h. Compared with conventional methods that require 1 or 2 days, this method can make same-day reporting possible and thus permit better patient management.     

The frequency of thrombotic thrombocytopenic purpura in patients with systemic lupus erythematosus undergoing kidney biopsy

OBJECTIVE: To characterize the frequency of thrombotic thrombocytopenic purpura (TTP) among patients with systemic lupus erythematosus (SLE) undergoing kidney biopsy. METHODS: A retrospective review of all renal biopsies of patients with SLE at Rush-Presbyterian-St. Luke's Medical Center was performed for the years 1989 to 2001. RESULTS: Four cases of clinical and histopathological TTP were identified among the 257 patients with SLE who underwent renal biopsy during the 12 year study period. CONCLUSION: TTP appears to occur at higher than expected frequency among SLE patients undergoing biopsy for unexplained renal failure.     

Diskography outcomes in patients following lumbar diskectomy

The results of lumbar diskography at post-diskectomy and nonoperative disk levels in postoperative patients and patients without prior back surgery were reviewed over 3 years. Other possible predictive factors, including disk degeneration (per the Adam's classification), end-point resistance, gender, and age, also were reviewed. The results revealed that no statistically significant association was noted between the presence of a prior diskectomy and the outcome of diskography. However, disk degeneration classified as ruptured and fissured correlated statistically with positive diskography. Additionally, age between 30 and 39 years and male gender were statistically associated with a positive diskogram. Disk levels displaying a poor end point during diskography injection (not amendable to pressurization) were statistically related to ruptured or fissured disk levels and thus positive diskography. Based on these results, the assumption that disabling low-back pain presenting after lumbar procedure is due to diskogenic disease arising from the surgical level is not supported.     

Protective effect of carbon monoxide inhalation for cold-preserved small intestinal grafts

BACKGROUND: Heme oxygenase (HO)-1 system has been shown to provide protection against oxidative stress through the degradation of heme to biliverdin, free iron, and carbon monoxide (CO). This study investigated cytoprotective efficacy of CO at a low concentration on cold ischemia/reperfusion (I/R) injury of transplanted intestine. METHODS: Lewis rat recipients of syngenic orthotopic small intestinal transplantation with 6 hours UW cold preservation were either kept in room air (air-treated control) or exposed to CO (250 ppm) for 1 hour before and 24 hours after surgery. RESULTS: In air-treated grafts, mRNA levels for interleukin-6, intracellular adhesion molecule-1, cyclooxygenase-2, and inducible nitric oxide synthase promptly increased. Sequential histopathologic analysis of untreated grafts revealed initial rapid epithelial loss, subsequent recruitment of inflammatory infiltrates, and local hemorrhage in the lamina propria, which extended downward to the epithelial crypt and muscle layer with time. CO effectively blocked proinflammatory cascade during I/R injury, inhibited upregulation of inflammatory molecules and ameliorated intestinal tissue injuries. Beneficial effects of CO were associated with improved graft blood flow without inhibiting endogenous HO-1 activity. Recipient animal survival was significantly improved with CO to 100% versus 58% in air-treated controls. CONCLUSIONS: These results indicate a significant role for CO in protecting the intestine from cold I/R injury associating with small intestinal transplantation.     

Expression of soma-restricted proteolipid/DM20 proteins in lymphoid cells

A new family of the myelin proteolipid protein (PLP/DM20) gene products, srPLP/DM20, has been identified recently in thymus and brain. In the central nervous system, srPLP/DM20 products are not localized in the myelin membrane, unlike their classic PLP/DM20 counterparts. In the immune system, the classic PLP/DM20 products appear to be expressed predominantly in thymic cortical epithelium. In this study, we examined the cellular expression of sr-PLP/DM20 proteolipids in lymphoid tissues and cells by immunohistochemistry, FACS analysis and RT-PCR. We found that in contrast to the classic PLP/DM20 products, sr-proteins are mainly expressed in developing thymocytes in thymus and in T- and B-lymphocytes in spleen. These results are of importance in our further understanding, not only the different role of these new PLP gene products in central and peripheral tolerance, but also the function of such products in lymphocyte biology.     

Parity and the risk of Down's syndrome

Interpretation of studies that have examined parity as a risk factor for Down's syndrome has been hindered by inadequate control for maternal age and/or failure to account for the differential use of prenatal diagnosis and pregnancy termination between low-parity and high-parity women. In this case-control study, the authors used exact matching on maternal age-minimize confounding and evaluated the potential impact of differential termination. A total of 898 cases of Down's syndrome and 4,488 controls were identified using Washington State birth certificates from 1984-1998. There was a trend towards increasing risk of Down's syndrome with increasing parity in both younger (age <35 years) and older (age > or =35 years) mothers. Restriction to women with no indication of amniocentesis (for whom differential termination is unlikely) resulted in a blunting of the odds ratios; however, a trend for parity remained. After restriction, odds ratios were as high as 1.65 (95% confidence interval: 1.13, 2.40) in younger women with a parity of three (compared with a parity of zero) and 2.41 (95% confidence interval: 1.41, 4.12) in older women with a parity of four or more. Although the odds ratios for older women were probably biased upwards because of underreporting of amniocentesis on birth certificates, these data support an association between parity and Down's syndrome.     

Clinics in diagnostic imaging (66). Right complete branchial fistula

We report a case of complete branchial fistula in an 18-year-old woman which could be demonstrated by a contrast study. The tract was completely excised and the patient had an uneventful recovery. Branchial fistulae are formed due to the persistence of the embryonic second branchial cleft. Complete fistulae with the internal opening in the region of the tonsillar fossa are not common.     

Heart transplantation. Long-term management related to immunosuppression, complications, and psychosocial adjustments

Commendable long-term care of cardiac transplant recipients begins with excellent discharge preparation. Routine follow-up allows for prompt detection of myriad problems commonly associated with long-term survival after transplantation. Long-term complications, including rejection, infection, hypertension, nephrotoxicity, osteoporosis, malignancy, diabetes, AGA, and psychosocial difficulties present unique challenges. Nursing care from the bedside, outpatient center, and home care has risen to the challenge and now must be active in the development of new strategies to maximize prevention of these many potential complications.     

Ventilation performance using a self-inflating anesthesia bag: effect of operator characteristics

Adequate ventilation is required for successful cardiopulmonary resuscitation (CPR). Operator characteristics that influence ventilation performance are not well defined. This study compared ventilation performance and operator characteristics in 74 medical personnel using a self-inflating anesthesia bag. Ventilation device, operator hand size, ventilation technique, average tidal volume, cumulative minute ventilation, and ventilation pressures were recorded during 3 minutes of ventilation. Ventilation volumes and airway pressures were not correlated with hand size or device type. Techniques that used one hand to squeeze the bag resulted in significantly lower average tidal volume than two-handed techniques, with no significant difference in peak or average airway pressure. There was no difference between emergency department and prehospital personnel in average tidal volume delivered. However, prehospital personnel ventilated at significantly higher airway pressures. Emergency department nurses delivered the greatest average tidal volume (923 cc), while emergency department physicians delivered the least (775 cc). Paramedics recorded the highest airway pressures (average, 53 cm H2O; peak, 72 cm H2O), while respiratory therapists recorded the lowest pressures (average, 34 cm H2O; peak, 54 cm H2O). Ventilation during CPR is a complex, learned skill. Large variation exists among different operators. However, appropriate tidal volumes can be delivered using safe airway pressures. Ongoing assessment and retraining of individuals performing ventilation during CPR are essential.