HIV-1 is an enveloped retrovirus that acquires its outer membrane as the virion exits the cell. Because of the association of apoptosis with the progression of AIDS, HIV-1-infected T cells or macrophages might be expected to express elevated levels of surface phosphatidylserine (PS), a hallmark of programmed cell death. Virions produced by these cells would also be predicted to have PS on the surface of their envelopes. In this study, data are presented that support this hypothesis and suggest that PS is required for macrophage infection. The PS-specific protein annexin V was used to enrich for virus particles and to inhibit HIV-1 replication in primary macrophages, but not T cells. HIV-1 replication was also significantly inhibited with vesicles consisting of PS, but not phosphatidylcholine. PS is specifically required for HIV-1 infection because viruses pseudotyped with vesicular stomatitis virus G and amphotropic murine leukemia virus envelopes were not inhibited by PS vesicles or annexin V. These data indicate that PS is an important cofactor for HIV-1 infection of macrophages.

Schwann cells within a peripheral nerve respond robustly after a n axonal injury. Recent results have revealed that Schwann cells undergo concurrent proliferation and apoptosis after a chronic nerve injury that is independent of axonal pathology. Although the exact nature of the stimulus that produces this Schwann cell response remains unknown, we postulated that this response may be triggered directly by mechanical stimuli. Thus, we sought to determine how pure Schwann cells responded to a sustained shear stress in the form of laminar fluid flow by evaluating for proliferation, expression of S-100, myelin-associated glycoprotein (MAG), and myelin basic protein (MBP). Immunohistochemistry demonstrated that the Schwann cells were positive for S-100, MAG, and MBP in greater than 99% of the experimental cells. Stimulated cells also revealed an increased rate of proliferation by as much as 100% (p < .001). The mRNA expression of MAG and MBP was down-regulated by 21% (p < .035) and 18% (p < .015), respectively, in experimental cells from RT-PCR assays. Furthermore, Western blot showed a down-regulation in M A G and MBP protein expression by 29% (p < .035) and 35% (p < .02), respectively. This study provides novel information regarding Schwann cell direct response to this physical stimulus that is not secondary to an axonal injury.

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For premenopausal women with invasive breast cancer who undergo BCT, BMI is an independent prognostic factor for LRR. If confirmed, these findings suggest that more aggressive treatment strategies may be warranted for these women.

We present a case of complete deficiency of the Interferon alpha/beta receptor alpha chain (IFNAR1) in a child with fatal systemic hyperinflammation, apparently provoked by live-attenuated viral vaccination. Such pathologic hyperinflammation, fulfilling criteria for haemophagocytic lymphohistiocytosis, is an emerging phenotype accompanying inborn errors of type I interferon immunity.

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