Interrogating the Functional Correlates of Collateralization in Patients with Intracranial Stenosis Using Multimodal Hemodynamic Imaging.

BACKGROUND AND PURPOSE: The importance of collateralization for maintaining adequate cerebral perfusion is increasingly recognized. However, measuring collateral flow noninvasively has proved elusive. The aim of this study was to assess correlations among baseline perfusion and arterial transit time artifacts, cerebrovascular reactivity, and the presence of collateral vessels on digital subtraction angiography. MATERIALS AND METHODS: The relationship between the presence of collateral vessels on arterial spin-labeling MR imaging and DSA was compared with blood oxygen level-dependent MR imaging measures of hypercapnic cerebrovascular reactivity in patients with symptomatic intracranial stenosis (n = 18). DSA maps were reviewed by a neuroradiologist and assigned the following scores: 1, collaterals to the periphery of the ischemic site; 2, complete irrigation of the ischemic bed via collateral flow; and 3, normal antegrade flow. Arterial spin-labeling maps were scored according to the following: 0, low signal; 1, moderate signal with arterial transit artifacts; 2, high signal with arterial transit artifacts; and 3, normal signal. RESULTS: In regions with normal-to-high signal on arterial spin-labeling, collateral vessel presence on DSA strongly correlated with declines in cerebrovascular reactivity (as measured on blood oxygen level-dependent MR imaging, P < .001), most notably in patients with nonatherosclerotic disease. There was a trend toward increasing cerebrovascular reactivity with increases in the degree of collateralization on DSA (P = .082). CONCLUSIONS: Collateral vessels may have fundamentally different vasoreactivity properties from healthy vessels, a finding that is observed most prominently in nonatherosclerotic disease and, to a lesser extent, in atherosclerotic disease.

Host Range Assessment of Helicotylenchus pseudorobustus (Tylenchida: Hoplolaimidae) on Pasture Species.

The host status of 15 commonly occurring pasture species for Helicotylenchus pseudorobustus was tested in a greenhouse trial. Only tall fescue, with and without Neotyphodium endophyte infection, was a good host (Pf/Pi = final/initial population > 1). Inoculation survival was tested in a second trial, which showed that only 10% of the H. pseudorobustus nematodes survived the first 7 days after inoculation. When the Pf/Pi was adjusted to account for a 10% survival, all of the grass and clover hosts tested had a Pf/Pi > 1. Both trials showed a positive correlation between increased numbers of H. pseudorobustus and free-living nematodes.

Cosmetics in blacks.

Blacks comprise a phenotypically heterogeneous group with respect to skin and hair. They are uniquely multihued with at least 35 different possible shades of pigmentation, and there is considerable variability in hair texture. This accounts for many of the unique skin and hair cosmetic requirements and customs in the black race. These grooming practices may present perplexing problems for the dermatologist when viewed in the context of resultant skin disease; therefore, an awareness and understanding of skin and hair products used by blacks, grooming techniques, and their consequences are essential for clinicians caring for black patients.

Determination of incidence and risk factors for postsclerotherapy telangiectatic matting of the lower extremity: a retrospective analysis.

Telangiectatic matting are vessels less than 0.2 mm in diameter that may appear after sclerotherapy treatment of varicose or telangiectatic leg veins. It is a complication about which very little epidemiologic data have been formally accrued. Therefore, a retrospective analysis was conducted by reviewing the records of 2120 patients in a private practice setting. The overall incidence of telangiectatic matting in our patient population was 16%. To identify risk factors, in-depth comparative analysis of the databases of 160 of the patients who developed telangiectatic matting and a control group of 160 nonmatting patients was performed. Significantly more patients in the matting group were overweight, on hormones during treatment, and had both a family history and a longer duration of spider veins (p less than 0.05). Additionally, the matting group had a significantly higher proportion of people noting onset of their veins after excess hormonal states, relative to before excess hormonal states, than the nonmatting group. Age and excessive standing did not differ significantly between the two groups. The results of this study provide objective, predictive risk factors for the development of telangiectatic matting.