Medical marijuana

To evaluate the use of high-resolution magnetic resonance imaging (MRI) for the differentiation of skin tumors in the maxillofacial region, 60 patients (25 female) were examined in a 1.5-T whole-body MR imager with a 2.5-cm surface coil. Plain transverse T1-(TR 500 ms, TE 25 ms), T2-(2200 ms, TE 80 ms), fat-(TR 500 ms, TE 28 ms), and water-suppressed (TR 500 ms, TE 38 ms) SE sequences were used. Following the application of the paramagnetic contrast agent Gd-DTPA, transverse T-weighted and fat suppression sequences were repeated. Before and after contrast administration, tumor signal intensities and percent contrast enhancement were determined by a ROI technique. All tumors were classified by standard histologic technique and evaluated with regard to their response to contrast medium. Quantitative evaluation was performed by three independent radiologists. Additionally, signal- and contrast-to-noise ratios were calculated for each tumor type. All MRI findings were compared with histology. Significant contrast enhancement occurred in most tumors; malignant tumors displayed inhomogeneous enhancement. The optimal pulse sequences for tumor delineation are plain T1-weighted, water-suppressed, and contrast-enhanced fat-suppressed sequences. Tumors could not be specified by signal intensities or percent contrast enhancement, and CNR did not allow for malignant lesions to be differentiated from benign tumors. High-resolution MRI proved to be an adequate method for imaging skin tumors and their inner structure. Tumor typing was not possible by either contrast-administration or modification of sequence parameters. In this regard, further innovations in contrast agent design seem to be necessary.     

Factor XI activation by meizothrombin: stimulation by phospholipid vesicles containing both phosphatidylserine and phosphatidylethanolamine

The activation of factor XI by meizothrombin was investigated using recombinant meizothrombin (R155A meizothrombin) that is resistant to autocatalytic removal of fragment 1. Meizothrombin was capable of activating factor XI at an activation rate similar to that of thrombin. Dextran sulphate and heparin, known cofactors of thrombin-mediated factor XI activation, did not stimulate the activation of factor XI by meizothrombin. However, the activation of factor XI by meizothrombin was markedly enhanced by vesicles containing phosphatidylcholine (PC), phosphatidylserine (PS) and phosphatidylethanolamine (PE), whereas PC/PS or PC/PE vesicles only had a minor effect on the activation. Thrombin-mediated factor XI activation was not influenced by phospholipids. The effect of PC/PS/PE and PC/PS vesicles was studied in a factor XI dependent clot lysis assay. In this assay, factor XI inhibits clot lysis by a feedback loop in the intrinsic pathway via thrombin-mediated factor XI activation. Removal of endogenous phospholipids in plasma by centrifugation resulted in an increased clot lysis, which could be restored to the pre-centrifugation level by the addition of PC/PS/PE vesicles, but not by PC/PS vesicles. When clot lysis was initiated by factor IXa in the presence of a factor XIa blocking antibody, there was no difference in inhibitory effect of PC/PS/PE or PC/PS vesicles. These data suggested that the differences in clot lysis inhibition observed between PC/PS/PE and PC/PS vesicles were caused by factor XI activation by meizothrombin. Meizothrombin-mediated factor XI activation may therefore play an important role in the antifibrinolytic feedback loop in the intrinsic pathway.     

Stereotaxic surgery of temporal lobe epilepsy

Forty patients with temporal epilepsy were operated on with a stereotaxic technique. Eleven patients had a unilateral localization of the epileptic focus, and in 29 bitemporal foci were diagnosed. In evaluating the results of the treatment the dynamics of the epileptic fits, the peculiarities of changes in the mental status, and the degree of social adaptation were taken into consideration. A postoperative improvement was achieved in 73% of the patients with monotemporal lesions, while in those with bitemporal epilepsy and distinct persistent mental disorders the state was improved in 44% of the cases. Indications for the choice of the zone of destruction depending on the clinical peculiarities of the lesion are presented.     

Diskitis caused by Actinobacillus actinomycetemcomitans

A 32-year-old man with acquired immunodeficiency syndrome (AIDS) admitted to the hospital for treatment of visceral leishmaniasis was inadvertently given 10 times the prescribed first dose of sodium stibogluconate ([Sb] 6.5 g instead of 0.65 g). He experienced no immediate major toxicity during the first 48 hours, but a significant rise of pancreatic enzyme activities was observed (amylase at 10 times the upper limit of normal, lipase at 50 times the upper limit of normal) without clinical signs or indications on computed tomography (CT) of pancreatitis. The third day after the overdose, he developed appendicitis, which appeared coincidental; he recovered uneventfully from surgery. Most of the overdose of Sb was eliminated within the first few hours. Pharmacokinetics remained linear; the rapid, long elimination half-lives (2.7 hours and 54 hours, respectively) were similar to those in previously published results. The administration of a chelating agent, dimercaptosuccinic acid (DMSA), 72 hours after the Sb overdose did not modify the pharmacokinetics of the medication.