Cervical internal carotid artery dissecting hemorrhage: diagnosis using MR

Two men underwent high-resolution magnetic resonance (MR) imaging of the internal carotid artery (ICA) 12 and 16 days after spontaneous dissection of this vessel. One underwent follow-up MR imaging 7 weeks later. T1-weighted images were obtained in both cases, and T2-weighted images were obtained in one patient. In both cases, the MR findings corresponded to the angiographic abnormalities. On both the T1- and T2-weighted images, there was a hyperintense lesion expanding the wall and narrowing the lumen of the ICAs. Follow-up MR imaging showed complete resolution of the mural lesion. Axial images best demonstrated the anatomic and MR signal alterations. The hyperintensity of the lesion on both T1- and T2-weighted images indicated a short T1 and a long T2 as expected in a subacute hematoma. High-resolution MR imaging, therefore, can specifically demonstrate a thrombosed carotid dissection noninvasively at least as early as 12 days. The potential to diagnose carotid dissection in the acute phase using high-field-strength MR imaging and its importance for the prevention of embolic strokes are also discussed.     

Renal artery stenosis: evaluation with intravenous digital subtraction angiography

The ability of diagnostic intravenous digital subtraction angiography (IVDSA) to demonstrate the degree of renal artery stenosis was compared with that of intraarterial angiography in 45 patients with 92 arteries. Stenotic lesions on both IVDSA and intraarterial studies were classified as normal (0% stenosis), minor (less than 50%), low grade (50%-80%), and high grade (80%-99%). There was agreement about the degree of stenosis in 90% of the cases. IVDSA grading was correct in 94% of atheromatous lesions and in 56% of the fibromuscular dysplastic lesions. In the high-grade atheromatous lesions, the degree of stenosis was slightly overestimated on IVDSA studies in 22.5% of the cases. In fibromuscular dysplasia, stenosis was underestimated in 33% of the cases.     

Characteristics and outcome among 14,933 adult cases of in-hospital cardiac arrest: A nationwide study with the emphasis on gender and age

Aim

To investigate characteristics and outcome among patients suffering in-hospital cardiac arrest (IHCA) with the emphasis on gender and age.

Prevalence and Predictors of Video Game Addiction: A Study Based on a National Representative Sample of Gamers

Video gaming has become a popular leisure activity in many parts of the world, and an increasing number of empirical studies examine the small minority that appears to develop problems as a result of excessive gaming. This study investigated prevalence rates and predictors of video game addiction in a sample of gamers, randomly selected from the National Population Registry of Norway (N?=?3389). Results showed there were 1.4 % addicted gamers, 7.3 % problem gamers, 3.9 % engaged gamers, and 87.4 % normal gamers. Gender (being male) and age group (being young) were positively associated with addicted-, problem-, and engaged gamers. Place of birth (Africa, Asia, South- and Middle America) were positively associated with addicted- and problem gamers. Video game addiction was negatively associated with conscientiousness and positively associated with neuroticism. Poor psychosomatic health was positively associated with problem- and engaged gaming. These factors provide insight into the field of video game addiction, and may help to provide guidance as to how individuals that are at risk of becoming addicted gamers can be identified.     

Activation of a suppressor T-cell pathway by interferon.

In addition to antiviral activities, murine fibroblast (type I) interferon (IFN-beta) suppresses immune responses. The mechanism(s) by which IFN-beta suppresses antibody responses by murine spleen cells to sheep erythrocytes in vitro has been investigated. IFN-beta-mediated suppression is partially or completely prevented by catalase, 2-mercaptoethanol, and certain peroxidase substrates (ascorbic acid, potassium iodide, and tyrosine). These same reagents also block suppression by mediators from concanavalin A-activated murine suppressor T cells, soluble immune response suppressor (SIRS)/macrophage-derived suppressor factor (Mphi-SF), and act by inactivating Mphi-SF or preventing formation of Mphi-SF from SIRS. Therefore, these experiments suggested that IFN-beta may act by inducing production of a molecule that has properties of SIRS. Treatment of spleen cells with IFN-beta leads to generation of a population of Lyt2+ suppressor T cells that acts by elaborating a soluble factor. This IFN-beta-induced suppressor T-cell factor (IFN-TsF) has properties in common with SIRS. First, both SIRS and IFN-TsF suppress antibody responses with the same characteristic kinetic pattern; responses initiate normally but prematurely terminate after day 4 of culture. Second, IFN-TsF and SIRS are of comparable size (45,000-55,000 daltons) and are converted to Mphi-SF by low (1 microM) concentrations of H2O2 or by macrophages. Third, Mphi-SF obtained from IFN-TsF or SIRS is inactivated by similar concentrations of reagents such as ascorbic acid, potassium iodide, and 2-mercaptoethanol. These data show that the immunosuppressive properties of IFN-beta are due, at least in part, to its ability to activate suppressor T cells that produce mediators that appear to be analogous to those in the SIRS/Mphi-SF pathway of immunosuppression.