Aromatase activity in breast adipose tissue from women with benign and malignant breast diseases

In order to determine the significance of local oestrogen biosynthesis within the breast, aromatase activity has been measured in adipose tissue from the breasts of women with either benign (n = 36) or malignant breast disease (n = 51). Particulate fractions from all samples possessed aromatase activity, but levels in adipose tissue adjacent to malignant tumours were significantly higher than those in tissue close to benign breast lesions (P less than 0.0001). Elevated aromatase activity in adipose tissue from breast cancer patients may be of importance in view of the central role played by oestrogen in the natural history of breast cancer.     

Standards of care for area mental health services

A provisional set of standards of care was derived from a quality assurance strand of a wider research project, which reported the development of evaluation strategies for area integrated mental health services (AIMHS). In contrast to most published standards, they apply to all facets of care in a comprehensive catchment area mental health service, whether clinical or functional, community or hospital based, urban or rural, or managed by the public, private or voluntary sectors. We review briefly existing sets of standards of mental health services and report the process of development of standards of care, each with sub-sets of performance indicators and examples. While the AIMHS standards and a companion quality assurance manual are still undergoing refinement, they offer a guide for mental health professionals to the provision of services, and a checklist to service-users of services that should be available to them at every stage of care in a mental health system.     

Escherichia coli tryptophan repressor binds multiple sites within the aroH and trp operators

DNase I footprinting and methylation protection studies have been used to analyze the binding of Escherichia coli Trp repressor to the trpR, aroH, and trp operators. The methylation protection assay shows that Trp repressor binds in two successive major grooves of the trpR operator, three successive major grooves of the aroH operator, and four successive major grooves of the trp operator. The simplest model that explains the difference in Trp repressor interaction at the three operators is that the aroH and trp operators are composed of multiple, helically stacked binding sites. When viewed in three dimensions, each site is positioned on a different face of the DNA, and together process up the surface of the DNA helix. Analysis of a deletion derivative of the trp operator supports this model.     

Hemodynamic alterations secondary to an electrical burn in the rat: a pilot study

Rats subjected to a standard electrical burn of 250 volts for 10 seconds receive a severe injury stimulating a pronounced systemic circulatory response. Initial postinjury hyperemia is replaced by a low perfusion state within 24 hours. Our study demonstrates the difficulty in isolating regional microcirculatory alterations under such circumstances. Modification of the burn model or the method of fluid resuscitation may minimize the influence of this dynamic systemic response.     

Inadequate dietary magnesium intake increases atherosclerotic plaque development in rabbits

Epidemiological studies have shown dietary magnesium (Mg) intake and serum Mg levels to be inversely correlated with the development of atherosclerosis. We hypothesized that low levels of Mg would promote atherosclerotic plaque development in rabbits. New Zealand white rabbits (4 months old, n = 22) were fed an atherogenic diet containing 0.12% (−Mg), 0.27% (control), or 0.43% (+Mg) Mg for 8 weeks. Blood samples were obtained at baseline, 2, 4, 6, and 8 weeks and were assayed for total cholesterol, high-density lipoprotein (HDL), non-HDL, triglycerides (TG), C-reactive protein, serum Mg, and erythrocyte Mg. Aortas from −Mg had significantly more plaque, with an intima thickness 42% greater than control and 36% greater than +Mg. Serum cholesterol levels rose over time, and at 8 weeks, −Mg had the highest and +Mg the lowest total and non-HDL cholesterol and TG levels, although these results did not reach significance. Over time, serum Mg levels increased, and erythrocyte Mg levels decreased. C-reactive protein significantly increased in all groups at 4 and 6 weeks but returned to baseline levels by 8 weeks. This study supports the hypothesis that inadequate intake of Mg results in an increase in atherosclerotic plaque development in rabbits.     

Comparison between traditional 2-dimensional cephalometry and a 3-dimensional approach on human dry skulls.

The cephalogram is the standard used by orthodontists to assess skeletal, dental, and soft tissue relationships. This approach, however, is based on 2-dimensional (2D) views used to analyze 3-dimensional (3D) objects. The purpose of this project was to evaluate and compare a 3D imaging system and traditional 2D cephalometry for accuracy in recording the anatomical truth as defined by physical measurements with a calibrated caliper. Thirteen skeletal landmarks were located by both radiographic methods on 9 dry human skulls. Intraclass correlation (0.995), variance (0.054 mm(2)), and standard deviation (SD) (0.237 mm) were averaged over 76 measurements and derived from precision calipers to establish these physical measurements as a reliable gold standard to make comparisons of the 2D and 3D radiographic methods. The results showed great variability of the 2D from the gold standard, with the range varying from -17.68 mm (underestimation of Gn-Zyg R) to +15.52 mm (overestimation of Zyg L-Zyg R). In contrast, the 3D method (Sculptor, Glendora, Calif) indicated a range of the SD from -3.99 (underestimation) mm to +2.96 mm (overestimation). The 3D evaluation was much more precise, within approximately 1 mm of the gold standard. These results indicate that, when the actual distance is measured on a human skull in its true dimensions of 3D space, the Sculptor program, by using a 3D method, is more precise and 4 to 5 times more accurate than the 2D approach. Evaluating distances in 3D space with a 2D image grossly exaggerates the true measure and offers a distorted view of craniofacial growth. There is an inherent problem of representing a linear measure occupying a 3D space with a 2D image.     

Reliability of two-dimensional echocardiography in the assessment of clinically significant abnormal hemidiaphragm motion in pediatric cardiothoracic patients: Comparison with fluoroscopy.

OBJECTIVE: To assess the utility and reliability of echocardiographic assessment of hemidiaphragm motion abnormalities in pediatric cardiothoracic patients. DESIGN: Retrospective observational study, with post hoc blinded assessment of echocardiographic and fluoroscopic results. SETTING: Tertiary care center. PATIENTS: Thirty-six consecutive pediatric cardiothoracic patients with suspected hemidiaphragm paralysis were identified and included in the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The results of both echocardiographic and fluoroscopic studies on all patients were included. In addition, blinded review of study results were performed. The sensitivity and specificity of fluoroscopy in identifying hemidiaphragms that needed plication were 100% and 74%, respectively. The positive predictive value was 55%; negative predictive value was 100%. Comparing reported diagnoses with blinded review of the studies showed poor agreement; reviewers agreed with 89% diagnosed as normal, 44% of paralyzed, and 76% of paradoxical hemidiaphragms. The sensitivity and specificity of echo in identifying hemidiaphragms that needed plication were 100% and 81%, respectively. The positive predictive value and negative predictive value were 66% and 100%. Comparing reported diagnoses with blinded review, reviewers agreed with 97% diagnosed as normal, 81% of paralyzed, and 100% of paradoxical hemidiaphragms. Echocardiography was less accurate in discriminating between paralyzed and paradoxical diaphragm motion. Echocardiography was specific for paradoxical motion, since both patients identified by echocardiography were confirmed by fluoroscopy, but it was not sensitive. In nine patients, echo showed paralyzed motion that was identified by fluoroscopy as paradoxical. CONCLUSIONS: This study supports the use of echocardiography in the assessment of diaphragm function. When the diaphragms are clearly visualized by echo, as they are in the majority of cases, the addition of an additional fluoroscopic study adds no clinical value. The differentiation between paralyzed and paradoxical motion is unreliable by both imaging modalities.