Die praktische Bedeutung der Entwicklungshemmungen der Haut

Ohne Zusammenfassung     

Establishing a baseline phase behavior in magnetic resonance imaging to determine normal vs. abnormal iron content in the brain

PURPOSE: To establish a baseline of phase differences between tissues in a number of regions of the human brain as a means of detecting iron abnormalities using magnetic resonance imaging (MRI). MATERIALS AND METHODS: A fully flow-compensated, three-dimensional (3D), high-resolution, gradient-echo (GRE) susceptibility-weighted imaging (SWI) sequence was used to collect magnitude and phase data at 1.5 T. The phase images were high-pass-filtered and processed region by region with hand-drawn areas. The regions evaluated included the motor cortex (MC), putamen (PUT), globus pallidus (GP), caudate nucleus (CN), substantia nigra (SN), and red nucleus (RN). A total of 75 subjects, ranging in age from 55 to 89 years, were analyzed. RESULTS: The phase was found to have a Gaussian-like distribution with a standard deviation (SD) of 0.046 radians on a pixel-by-pixel basis. Most regions of interest (ROIs) contained at least 100 pixels, giving a standard error of the mean (SEM) of 0.0046 radians or less. In the MC, phase differences were found to be roughly 0.273 radians between CSF and gray matter (GM), and 0.083 radians between CSF and white matter (WM). The difference between CSF and the GP was 0.201 radians, and between CSF and the CN (head) it was 0.213 radians. For CSF and the PUT (the lower outer part) the difference was 0.449 radians, and between CSF and the RN (third slice vascularized region) it was 0.353 radians. Finally, the phase difference between CSF and SN was 0.345 radians. CONCLUSION: The Gaussian-like distributions in phase make it possible to predict deviations from normal phase behavior for tissues in the brain. Using phase as an iron marker may be useful for studying absorption of iron in diseases such as Parkinson's, Huntington's, neurodegeneration with brain iron accumulation (NBIA), Alzheimer's, and multiple sclerosis (MS), and other iron-related diseases. The phases quoted here will serve as a baseline for future studies that look for changes in iron content.     

Regional Differences and Tribal Use of American Indian/Alaska Native Cancer Data in the Pacific Northwest

In the Pacific Northwest, cancer is a leading cause of morbidity and mortality for American Indians and Alaska Natives (AI/AN). Misclassification of AI/AN race in state cancer registries causes cancer burden to be underestimated. Furthermore, local-level data are rarely available to individual tribes for use in health assessment and program planning. We corrected race coding in the cancer registries of Idaho, Oregon, and Washington using probabilistic record linkage to a file derived from patient registration records from Indian Health Service and a large urban clinic. We calculated cancer incidence and mortality measures by state, comparing AI/AN to non-Hispanic White (NHW) race. Record linkages identified a high prevalence of misclassified race. Differences in AI/AN cancer patterns were identified across the three state region. Compared to NHW, AI/AN experienced disproportionate late stage rates of some screen-detectable cancers. The correct classification of race is a crucial factor in cancer surveillance and can reveal regional differences even within a relatively small area. The availability of local-level cancer data can help inform tribes in appropriate intervention efforts.     

The medical bookshelf

Books received are listed as space permits, and those of particular interest to our readers are reviewed.     

Improving recognition of psychiatric disorders in a primary care practice

A high percentage of patients who seek care from primary care physicians have a psychiatric disorder, either as the primary illness or secondary to a medical illness or drug use. Drs Thompson and Petersen discuss a number of approaches that physicians can take to better recognize psychiatric disorders, so that they may treat or consult on the less complicated conditions and refer complex or resistant conditions to a psychiatrist.     

Uroporphyrinogen decarboxylase gene mutations in Danish patients with porphyria cutanea tarda

Decreased uroporphyrinogen decarboxylase (UROD) activity is a characteristic feature of the most common of the porphyrias, porphyria cutanea tarda (PCT). A subgroup of the clinically overt PCT cases is associated with mutations in the gene encoding UROD and inherited as an autosomal-dominant trait. In this study, DNAs from 53 Danish PCT patients were subjected to genetic analysis for UROD mutations using denaturing gradient gel electrophoresis. Eleven genetic variations, seven of which are possible disease causing, were identified. All but one of these mutations were previously unknown, lending further support to the assumption that PCT is a heteroallelic disease. Only 11% of the examined patients were previously recognized as familial PCT cases. However, possible disease-related UROD mutations were identified in 24% of the examined patients, indicating that genetic analysis of PCT patients may improve differentiation between familial and sporadic PCT cases.     

Kidney Function in Heart Failure

Objective. The purpose of this investigation was to improve a rankit ordinal model for evaluating and validating dichotomized tests in a prospective Nordic project. Material and methods. The model is based on the assumption that the S‐shaped curve of fractions of positive for increasing concentrations can be de‐convoluted to a histogram and thereby used to calculate the parameters for a ln‐Gaussian distribution. In a Nordic survey, four urine samples with known concentrations of hCG (human chorionic gonadotrophin) and nitrites were distributed to more than 2500 practitioners' offices. Results. The results are presented as parameters (geometric mean and CV) for the components urine‐hCG and urine‐nitrites, together with fractions of positive for clinical critical values (5 and 40?IU/L for hCG), for which fractions should be below 0.01 and above 0.99, respectively, and 7?µmol/L for nitrites. Furthermore, the concentration intervals of varying fractions of positive from 0.01 to 0.99 are estimated as grey zones. The parameters and grey zones for different kits are compared. No urine‐hCG kit fulfilled the low clinical criterion, whereas all fulfilled the high criterion. Seven of the eight nitrites kits had fractions of positive above 0.9 for the company confirmation limit, but varying fractions for the clinically important limit of 7?µmol/L (fractions from 0.06 to 0.83). Conclusions. The present model makes it easy to estimate parameters for the kits, and also to estimate the fractions of measured positives for specified concentrations. It is thus suited for external quality assessment as well as for manufacturers' method validation.