Mapping corpus callosum deficits in autism: an index of aberrant cortical connectivity.

BACKGROUND: Volumetric studies have reported reductions in the size of the corpus callosum (CC) in autism, but the callosal regions contributing to this deficit have differed among studies. In this study, a computational method was used to detect and map the spatial pattern of CC abnormalities in male patients with autism. METHODS: Twenty-four boys with autism (aged 10.0 +/- 3.3 years) and 26 control boys (aged 11.0 +/- 2.5 years) underwent a magnetic resonance imaging (MRI) scan at 3 Tesla. Total and regional areas of the CC were determined using traditional morphometric methods. Three-dimensional (3D) surface models of the CC were also created from the MRI scans. Statistical maps were created to visualize morphologic variability of the CC and to localize regions of callosal thinning in autism. RESULTS: Traditional morphometric methods detected a significant reduction in the total callosal area and in the anterior third of the CC in patients with autism; however, 3D maps revealed significant reductions in both the splenium and genu of the CC in patients. CONCLUSIONS: Statistical maps of the CC revealed callosal deficits in autism with greater precision than traditional morphometric methods. These abnormalities suggest aberrant connections between cortical regions, which is consistent with the hypothesis of abnormal cortical connectivity in autism.     

Hair dye use and risk of leukemia and lymphoma.

Data from a population-based case-control study of incident leukemia and non-Hodgkin's lymphoma among adult men in Iowa and Minnesota were used to evaluate risk associated with hair dye use. The relative risk for ever using hair dyes was 1.8 (95% confidence interval [CI] = 1.1-2.7) among leukemia patients, and 2.0 (CI = 1.3-3.0) among cases with non-Hodgkin's lymphoma. There was a suggestion of increased risk with extent of hair dye use. Given the widespread use of hair coloring products, these observations deserve more detailed evaluation in populations where the exposure is relatively common.     

The use of a priori knowledge to quantify short echo in vivo 1h mr spectra

In vivo ¹H MR spectra of the prefrontal cortex acquired with the stimulated echo acquisition mode (STEAM) TE = 20 ms sequence were quantified to determine relative levels of cerebral metabolites. A priori knowledge of spectra from individual metabolites in aqueous solution was incorporated into a frequency domain quantification technique. The accuracy and precision of modeling these metabolites were investigated with simulated spectra of varying signal-to-noise ratios (SNRs) and relative metabolite levels. The efficacy of modeling in vivo data was tested by quantifying 10 repeated measures of two consecutively acquired in vivo spectra (an 8?cm³ volume of interest (VOI) and a 4?cm³ VOI positioned within the 8?cm³ VOI) on the same normal subject. The differences in levels of glutamate (Glu), phosphocreatine plus creatine (PCr+Cr) and choline-containing compounds (Cho₁ between spectra from the 8? and 4?cm³ VOIs corresponded with the expected differences observed in the proportions of gray matter within the VOIs (estimated from ¹H images). Correcting for the T₁ and T₂ relaxation, the estimated concentrations of N-acetylaspartate, PCr+Cr, Cho₁, Glu, and glutamine were consistent with previous in vivo and in vitro reports.     

Applikationsverfahren und dosierungsempfehlungen zur postoperativen analgesie

Systemic application of analgesics is still the most frequently used method of postoperative relief of pain. However, neither intermittent intramuscular nor intermittent intravenous application can provide the patient with a continuous level of analgesia. Lipid-soluble analgesics or those with polar binding that are rapidly metabolized demonstrate an rapid effectiveness. If the analgesia must be administered over a long period, it is due to a low level of lipid solubility, high receptor affinity and low elimination rates. Oral as well as sublingual buccal and rectal applications are characterized by uncertain absorption conditions. There are few investigations on the subcutaneous application of analgesics. After intramuscular administration analgesic levels are achieved within 15 to 60 min, but various conditions may alter the absorption criteria. Intradeltoidal application is preferable to intragluteal injection. Analgesics may be administered intravenously as a bolus, as continuous infusion, or as patient-controlled analgesia. The bolus injection is characterized by a short period of action and the necessity to administer several bolus injections by repeated administration. The continuous infusion of analgesics should begin with the administration of an initial bolus injection. Infusion analgesia should be performed under careful monitoring conditions. The most promising method of pain relief is patient-controlled analgesia (PCA). After an initial bolus injection, the continuous infusion of an analgesic is guaranteed and may be completed by the patient with several bolus injections. PCA requires careful monitoring. We suggest that a special analgesia team to take care of the patient in special analgesia units might be appropriate in the future.