Flow Patterns in Carotid Webs: A Patient-Based Computational Fluid Dynamics Study.

BACKGROUND AND PURPOSE: Carotid webs are increasingly recognized as an important cause of (recurrent) ischemic stroke in patients without other cardiovascular risk factors. Hemodynamic flow patterns induced by these lesions might be associated with thrombus formation. The aim of our study was to evaluate flow patterns of carotid webs using computational fluid dynamics. MATERIALS AND METHODS: Patients with a carotid web in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) were selected for hemodynamic evaluation with computational fluid dynamics models based on lumen segmentations obtained from CT angiography scans. Hemodynamic parameters, including the area of recirculation zone, time-averaged wall shear stress, transverse wall shear stress, and the oscillatory shear index, were assessed and compared with the contralateral carotid bifurcation. RESULTS: In our study, 9 patients were evaluated. Distal to the carotid webs, recirculation zones were significantly larger compared with the contralateral bifurcation (63 versus 43 mm2, P = .02). In the recirculation zones of the carotid webs and the contralateral carotid bifurcation, time-averaged wall shear stress values were comparable (both: median, 0.27 Pa; P = .30), while transverse wall shear stress and oscillatory shear index values were significantly higher in the recirculation zone of carotid webs (median, 0.25 versus 0.21 Pa; P = .02 and 0.39 versus 0.30 Pa; P = .04). At the minimal lumen area, simulations showed a significantly higher time-averaged wall shear stress in the web compared with the contralateral bifurcation (median, 0.58 versus 0.45 Pa; P = .01). CONCLUSIONS: Carotid webs are associated with increased recirculation zones and regional increased wall shear stress metrics that are associated with disturbed flow. These findings suggest that a carotid web might stimulate thrombus formation, which increases the risk of acute ischemic stroke.

Radionuclide therapy of cancer with radiolabeled antibodies.

Radioimmunotherapy (RIT) using radiolabeled monoclonal antibodies (MAbs) directed against tumor-associated antigens has evolved from an appealing concept to one of the standard treatment options for patients with non-Hodgkin's lymphoma (NHL). Inefficient localization of radiolabeled MAbs to nonhematological cancers due to various tumor-related factors, however, limits the therapeutic efficacy of RIT in solid tumors. Still, small volume or minimal residual disease has been recognized as a potentially suitable target for radiolabeled antibodies. Several strategies are being explored aimed at improving the targeting of radiolabeled MAbs to solid tumors thus improving their therapeutic efficacy. In this review, various aspects of the application of radiolabeled MAbs as anti-cancer agents are discussed, and the clinical results of RIT in patients with hematological and various solid cancers (colorectal, ovarian, breast and renal carcinomas) are reviewed.

Radioimmunotherapy of B-cell non-Hodgkin's lymphoma.

In the past decade, several new antibody-based therapies - using either radiolabelled or unlabelled monoclonal antibodies - have become available for the treatment of patients with refractory or recurrent non-Hodgkin's lymphoma (NHL). Unlabelled monoclonal antibodies (mAbs) kill lymphoma cells by activating host immune effector mechanisms, or by inducing apoptosis. These mAbs can also be used to guide radionuclides to the lymphoma. This radioimmunotherapy (RIT) has been studied with various nuclides (131I, 90Y, 67Cu and 186Re) and with various mAbs. In this review the radionuclides, methods of dosing and recent RIT studies in patients with B-cell NHL are reviewed. Most of these studies demonstrate that RIT is an effective new treatment modality for NHL.

Comparison of patients refusing with patients accepting unlinked anonymous HIV testing in an outpatient STD department in The Netherlands.

From 1 February 1993 to 1 February 1994 all new patients, known patients with new problems, and prostitutes attending the Outpatient Department of Sexually Transmitted Diseases (STD) of the University Hospital Rotterdam were asked to participate in unlinked anonymous human immunodeficiency virus (HIV) testing and to answer some questions. Data from the medical records of 300 patients refusing to participate were compared with self-reported data obtained from 2701 people accepting, to verify if the HIV seroprevalence among accepters could be representative for all STD department visitors. Men refusing were more often of foreign origin, had more often had more than one partner during the previous 6 months, more often attended the STD department for the first time, and more often had an STD diagnosed than men accepting. Women refusing were more often of foreign origin, had less often had more than one partner during the previous 6 months, and had more often used drugs intravenously than women accepting. Because most findings associated with refusing are also associated with being infected with HIV, the HIV seroprevalence among refusers is likely to be higher than among accepters. We therefore advise unlinked anonymous HIV testing of all patients visiting an STD department.

Epidemiology of genital chlamydial infections in patients with chlamydial conjunctivitis; a retrospective study.

OBJECTIVE: To determine how often chlamydial conjunctivitis is accompanied by a genital chlamydial infection and if there is a correlation between the dominant hand and the eye first infected. METHODS: We retrospectively studied the records of 65 patients with chlamydial conjunctivitis who were referred to the Outpatient Department of Sexually Transmitted Diseases (STD) of the University Hospital Rotterdam by ophthalmologists of the Eye Hospital Rotterdam. The patients have recently been asked by letter if they were left- or right-handed. RESULTS: Twenty of the 37 men (54%) had a positive chlamydial urethral culture. Seventy per cent of these men had no genital symptoms. Eight of the 37 men (22%) had a non-specific urethritis (NSU). Twenty of the 27 women examined (74%) had a positive chlamydial cervical culture. Sixty per cent of these women had no genital symptoms. Eight women with a genital chlamydial infection also had another genital infection. Five women without a genital chlamydial infection had another genital infection. Two women had no genital infection at all. A correlation between the eye infected and left- or right-handedness of the patient could not be found. CONCLUSIONS: A considerable percentage of the patients with a chlamydial conjunctivitis had a concomitant genital chlamydial infection. The majority of them had no genital symptoms. Since patients with chlamydial conjunctivitis and/or their partners possibly have a concomitant genital chlamydial infection, we recommend referral of both patients and sexual partners to an STD clinic for routine examination and systemic treatment when indicated.