Apparent bias for P. falciparum parasites carrying the wild-type pfcrt allele in the placenta

Resistance to chloroquine has been linked to polymorphisms within the pfcrt gene of the human malarial parasite Plasmodium falciparum. Here, we have investigated the prevalence of the pfcrt allele associated with chloroquine resistance in the peripheral blood and the placenta of pregnant women diagnosed with a P. falciparum infection. Our molecular epidemiological data show an unequal distribution with a significant under-representation of parasites carrying the mutated pfcrt allele in the placenta, as compared to the peripheral blood. In comparison, no differences were seen with regard to pfmdr1 polymorphisms of these parasites. Our data suggest a selective disadvantage of the polymorphic and a selective advantage of the wild-type pfcrt haplotype in the placenta, supporting the model that the human host provides various microenvironments that favor genetically distinct P. falciparum populations.     

Monobenzone, Superfade, vitiligo and confetti-like depigmentation

Three cases of cutaneous depigmentation after the application of Superfade are presented. Almost total depigmentation occurred on the dorsum of the hands with spread of confetti-like depigmentation to the arms. More distant spread occurred in two cases. Superfade contains 1.5% monobenzyl ether of hydroquinone (monobenzone). This is proposed as the cause of the depigmentation.     

Lateral ankle stabilization using bovine collagen material: xenograft bioprosthesis, model GR

This is a combined research study including use of a reproducible technique for ankle stress x-ray examinations (both preoperatively and postoperatively) and the use of the bovine bioprosthesis tendon implant for stabilization and augmentation of the lateral ankle ligaments. The surgical technique is fully described and the follow-up results indicate that there is long-term ankle stability, and that patient acceptance is very high.     

ECG-synchronized cardiac MR imaging: method and evaluation

An electrocardiographic (ECG) sensing and gating device compatible with a 0.35-tesla (T) magnetic resonance (MR) imager has been developed and used to produce 802 MR images of the heart in 30 patients. The instrument consists of an isolated acquisition module, an electrically floating preamplifier, and a monitor gating module. Two spin-echo images were acquired for each of five, 0.7-cm thick, transaxial sections from the base to the apex of the heart during each ECG-synchronized imaging run. Image quality was assessed in a blind study by two investigators, on a scale from 0 to 3, as diagnostic [2-3] or nondiagnostic [0-1]. There was agreement in 91.4% of their assessments of diagnostic images (68.1% of the images studied). Resolution of heart anatomy on the MR images was adversely affected by prolonged spin-echo time delay, imaging in late diastole, image acquisition at the cardiac apex, irregular triggering, and artifacts. The synchronization of gradient pulses to the ECG at 0.35 T appears safe for patients, permits diagnostic resolution of images, allows image acquisition at distinct points during the cardiac cycle, and enables monitoring of patients during imaging.     

Variable extension of the transitional zone in the medial structure of carotid artery tripod.

BACKGROUND: The goal of our study was to demonstrate the extension of the transitional zone (TZ) between elastic and muscular medial structure in carotid artery tripod. PATIENTS AND METHODS: A histologic study of 56 probes from 8 carotid artery tripods was performed. The probes were obtained from autopsies of 4 adults (mean age: 47.5 years, range 38 to 55 years) and were taken from 7 different topographic sites. RESULTS: At each level of the CCA (at 1 cm and 2 cm proximal to the bifurcation as well as at the bifurcation) we observed an elastic arterial type in 24 (42.8%) probes with 11 to 20 (medium 15.0) elastic fibers per view field (200 x magnification) in the media. In contrast the histologic structure of the ICA and ECA varied as follows: in 8 sections (14.3%) elastic arterial type with 11 to 16 (medium 13.1) elastic fibers, in 11 sections (19.6%) muscular arterial type with 2 to 5 (medium 3.5) elastic fibers and in 9 sections (16.1%) a transitional arterial type with 6 to 8 (medium 6.7) elastic fibers in the media. Atherosclerotic lesions have prevented the assessment of the arterial type in 4 probes (7.1%). The TZ in the medial structure of carotid artery tripods is exclusively localized in the ICA/ECA but not in the CCA. The ICA/ECA presented a TZ with a length up to 0.5 cm (4 probes; 25%), up to 1.5 cm (4 probes; 25%) and longer than 1.5 cm (6 probes; 37.5%). CONCLUSIONS: In this study we confirmed that in the carotid artery tripod, a TZ--an arterial segment with transition from elastic to muscular type--does exist, involving a variable length. Furthermore studies on the impact of the biomechanical properties of the TZ as a potential factor in atherosclerotic disease are justified. In addition, the complex biomechanical behavior of the TZ should be considered prior to interventional procedures.