Explore the vast range of titles available.

The puzzling linkage between genetic hemochromatosis and histocompatibility loci became even more so when the gene involved, HFE, was identified. Indeed, within the well defined, mainly peptide-binding, MHC class I family of molecules, HFE seems to perform an unusual yet essential function. As yet, our understanding of HFE function in iron homeostasis is only partial; an even more open question is its possible role in the immune system. To advance on both of these avenues, we report the deletion of HFE α 1 and α 2 putative ligand binding domains in vivo. HFE-deficient animals were analyzed for a comprehensive set of metabolic and immune parameters. Faithfully mimicking human hemochromatosis, mice homozygous for this deletion develop iron overload, characterized by a higher plasma iron content and a raised transferrin saturation as well as an elevated hepatic iron load. The primary defect could, indeed, be traced to an augmented duodenal iron absorption. In parallel, measurement of the gut mucosal iron content as well as iron regulatory proteins allows a more informed evaluation of various hypotheses regarding the precise role of HFE in iron homeostasis. Finally, an extensive phenotyping of primary and secondary lymphoid organs including the gut provides no compelling evidence for an obvious immune-linked function for HFE.

Sexual assault is an irrefutable trauma; an insult to the autonomy of the person forced into sexual acts. Sexual assault sequelae range from physical injury and acute traumatic stress, to pregnancy and sexually transmitted infections, including human immunodeficiency virus (HIV). HIV post-exposure prophylaxis (HIV PEP) following sexual assault may decrease the likelihood of HIV transmission. Many patients seeking healthcare post-sexual assault either do not initiate HIV PEP or do not complete the 28-day medication regimen. In this qualitative interpretive description, we interviewed sexual assault patients (N=11) about HIV PEP discussions/reactions, attitudes and understanding related to HIV and PEP, and barriers and facilitators of HIV PEP acceptance and adherence. Participants described a process of losing and reclaiming control throughout post-assault care and follow-up; and how this affected HIV PEP-related decision-making. Most HIV PEP decisions were described as a process of reclaiming control over one outcome while simultaneously losing control of another.

High expression of transferrin receptor (TfR) on the membrane of erythroid cells accounts for the high level of iron required to sustain heme synthesis. Several studies indicate that during erythroid differentiation TfR expression is highly dependent on transcriptional regulation. In this study we characterized the minimal region able to confer transcriptional regulation during erythroid differentiation in Friend leukemia cells (FLC). This region of 120 bp, upstream the transcription start site, contains an overlapping consensus recognition sequence for AP1/CREB/ATF transcription factors and for proteins of the Ets family and a GC rich region. Here, we report that both the Ets and the Ap1/CRE like sites are essential for promoter activity during erythroid differentiation. We showed that Ets-1 binds to the EBS-TfR and its binding activity decreases in FLC induced to differentiate and during normal erythroid differentiation. Consistent with this, FLC constitutively expressing Ets-1 show a decrease in TfR gene expression, globin mRNA and hemoglobin synthesis. We conclude that Ets-1 binding activity is modulated during erythroid maturation and that a deregulated expression of this transcription factor interferes with terminal erythroid differentiation.

Tortuous vasculature is a cause of failure of endovascular treatment of intracranial vascular lesions. We report our experience of direct cervical accesses in patients in whom the arterial femoral route was not attainable. In this retrospective study, 42 direct punctures of the carotid or the vertebral arteries at the neck were performed in 38 patients. The vessel harboring the intracranial lesion was punctured at the neck above the main tortuosity, a sheath was then positioned under fluoroscopic control to allow a stable access to the intracranial circulation. After the procedure, the sheath was removed and hemostasis was gained either by manual compression or by an arterial closure device (4 of 42, 9%). The cervical route allowed access to all intracranial lesions in all 42 procedures. A complication was encountered in six procedures (14%) related to the direct puncture. In 2 of the 42 procedures (4%), a transient vasospasm was encountered. A cervical hematoma formed in 3 of the 42 procedures (7%) after sheath withdrawal (one patient in whom an 8F sheath had been used, required surgical evacuation of a hematoma compressing the upper airways; the other patients did well without surgical evacuation). In the remaining patient (1 of 42 procedures, 2%), a small asymptomatic aneurysm at the puncture site was seen on the follow-up angiogram. Direct cervical arterial approaches to accessing the intracranial circulation is effective in patients in whom the femoral route does not allow the navigation and stabilization of guiding catheters.

The usefulness of the ascorbate dilution method in demonstrating intracardiac shunts and valvular incompetence is known. The ascorbate technique can also be applied to the determination of the transit time of regional vascular beds such as the coronary and the renal systems. Furthermore, the determination of central circulation times may be helpful in the diagnosis of caval obstruction. The method is safe, simple, inexpensive, and reliable.

The KC60 and RbC60 polymer phases exhibit contrasting electronic properties while powder diffraction studies have revealed no definite structural difference. We have performed single crystal X-ray diffraction and diffuse scattering studies of these compounds. It is found that KC60 and RbC60 possess different chain orientations about their axes, which are described by distinct space groups Pmnn and I2/m, respectively. Such a structural difference will be of great importance to a complete understanding of the physical properties.

First single crystal X-ray diffraction studies of polymerized KC60 and RbC60 are presented. While powder diffraction studies showed no definite structural differences, the single crystal diffraction data analysis reveals different relative chain orientations in the two compounds. They are discussed in relation with semi-empirical energy calculations. The structural difference between KC60 and RbC60 may be a key feature for the understanding of their contrasted conducting and magnetic properties.