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The three-dimensional structure of B capsids of the β-herpesvirus human cytomegalovirus (HCMV) was investigated at a resolution of 3.5 nm from electron cryomicrographs by image processing and compared with the structure obtained for the α-herpesvirus herpes simplex virus type 1 (HSV-1). The main architectural features of the HSV-1 and HCMV capsids are similar: theT= 16 icosahedral lattice consists of 162 capsomers, composed of two distinct morphological units, 12 pentamers and 150 hexamers, with triplex structures linking adjacent capsomers at positions of local threefold symmetry. The main differences in the HSV-1 and HCMV capsids are found in the diameter of the capsids (125 and 130 nm, respectively); the hexamer spacing and relative tilt (center-to-center hexon spacing at outer, edge, 17.9 and 15.8 nm, respectively); the morphology of the tips of the hexons (similar in length but 33% thinner in HCMV); and the average diameter of the scaffold (44 and 76 nm, respectively). By analogy with HSV-1, the mass on the HCMV hexon tip is attributed to the smallest capsid protein (HCMV gene UL48/49). The differences in capsid structure are discussed in relation to the ability of the HCMV structure to package a genome some 60% larger than that of HSV-1.

Purpose: To perform a retrospective analysis of chronic limb ischemia and determine whether endovascular surgery can be performed safely and cost effectively on an ambulatory basis.Methods: Among 42 patients undergoing endovascular interventions for lower limb ischemia over a 12-month period ending October 1997, 32 (18 men, mean age 68 years, range 44 to 89) were treated solely by endovascular interventions. These patients were grouped according to time inhospital: 20 (63%) patients had endovascular procedures performed on an ambulatory basis, 7 (22%) were hospitalized for > 24 hours, and 5 (16%) required an overnight stay. The angioplasty procedures, which included placement of 21 stents, were performed in the abdominal aorta (n = 1) and the common iliac (n = 9), external iliac (n = 7), superficial femoral (n = 11), popliteal (n = 5), tibioperoneal (n = 7), and subclavian (n = 1) arteries. Hospital charges were compared for the 3 groups.Results: Other than the presence of coronary artery disease, there were no significant differences in demographics or risk factors among the 3 groups. Angioplasty was technically successful in all patients, and there were no procedural complications. Patients with tissue loss required hospitalization more frequently compared to those with claudication. Significantly more patients who were hospitalized had epidural anesthesia as opposed to local when compared to the ambulatory group, 43% versus 5%, respectively (p = 0.04). Excluding professional fees, mean total hospital cost differed significantly between the ambulatory group and the group of patients with a hospital stay > 24 hours ($8227 versus $40,383, respectively; p = 0.03) and between the 2 hospitalized groups ($9476 for overnight stay versus $40,383 for > 24-hour stay, p = 0.03).Conclusions: Peripheral endovascular interventions can be performed safely on an ambulatory basis resulting in decreased hospital cost. Patients who receive epidural anesthesia, require concomitant open vascular reconstruction, present with tissue loss, or have unstable medical conditions are more likely to require hospitalization.

Accurate ultrastructural localization of the components of centrosomes is an important step toward the determination of their function. We have used an electron microscopy procedure to preserve centrosome-associated antigens which enables their high-resolution localization. The unique part of our procedure is the application of a post-sectioning fixation step which overcomes the poor section contrast and morphological appearance that limits the use of low-temperature processing and Lowicryl embedding. The efficacy of our approach is demonstrated by the efficient labelling of α-tubulin in the well-preserved and contrasted microtubule barrels of the centrides of isolated mammalian centrosomes.

The mechanism of encapsidation of DNA into a bacteriophage head is a most intriguing problem. The portal protein is essential for the assembly of tailed double-stranded DNA (dsDNA) bacteriophages. These turbine-like homo-oligomers consist of 12 or 13 subunits surrounding a central channel. Portal oligomers are located at the vertex of the icosahedral head that binds to the phage tail. It was shown that gp6 portal protein from bacteriophage SPP1 has 13 subunits, prior to their incorporation into the viral procapsid structure. After packaging of the viral DNA inside the phage capsid, additional proteins have been found attached to the portal oligomer: gpl5 and gp 16. A complex of gp6/gpl5/gpl7 forms the connector structure that provides the interface for attachment of the phage tail. We here present the three-dimensional (3D) reconstructions of the gp6 wild-type protein alone and of the gp6/gpl5/gpl6 complex - both at 10Å resolution - based on electron cryo-microscopy using the angular reconstitution single particle methodology.