58 research outputs found
Coronary angioscopy
Coronary angioscopy will not replace angiography as the gold standard for imaging atherosclerotic coronary arteries. However, there may well be a clinical niche for a technology that gives accurate information regarding a specific lesion, if that information can be used to improve the acute or chronic outcome of an interventional procedure. Our experience demonstrates that angioscopy indeed provides this information. Using angioscopy, we now have access to information regarding arterial wall disease that heretofore has been available only at necropsy. In addition, whereas angiography has provided only a 2-dimensional, gray-scale image of the coronary vessels, angioscopy offers a full-color, 3-dimensional perspective of the intracoronary surface morphology. These important lesion-specific details, not reliably available from angiography alone, may ultimately be used to improve patient outcome and to assess risk
ProNGF Induces p75-Mediated Death of Oligodendrocytes following Spinal Cord Injury
AbstractThe neurotrophin receptor p75 is induced by various injuries to the nervous system, but its role after injury has remained unclear. Here, we report that p75 is required for the death of oligodendrocytes following spinal cord injury, and its action is mediated mainly by proNGF. Oligodendrocytes undergoing apoptosis expressed p75, and the absence of p75 resulted in a decrease in the number of apoptotic oligodendrocytes and increased survival of oligodendrocytes. ProNGF is likely responsible for activating p75 in vivo, since the proNGF from the injured spinal cord induced apoptosis among p75+/+, but not among p75−/−, oligodendrocytes in culture, and its action was blocked by proNGF-specific antibody. Together, these data suggest that the role of proNGF is to eliminate damaged cells by activating the apoptotic machinery of p75 after injury
Genetic and functional analyses point to FAN1 as the source of multiple Huntington Disease modifier effects
A recent genome-wide association study of Huntington’s disease (HD) implicated genes involved in DNA
maintenance processes as modifiers of onset, including multiple genome-wide significant signals in a chr15
region containing the DNA repair gene FAN1. Here, we have carried out detailed genetic, molecular and
cellular investigation of the modifiers at this locus. We find that missense changes within or near the DNA
binding domain (p.Arg507His and p.Arg377Trp) reduce FAN1's DNA binding activity and its capacity to rescue
mitomycin C-induced cytotoxicity, accounting for two infrequent onset-hastening modifier signals. We also
identified a third onset-hastening modifier signal whose mechanism of action remains uncertain but does not
involve an amino acid change in FAN1. We present additional evidence that a frequent onset-delaying modifier
signal does not alter FAN1 coding sequence but is associated with increased FAN1 mRNA expression in the
cerebral cortex. Consistent with these findings and other cellular overexpression/suppression studies, knock
out of FAN1 increased CAG repeat expansion in HD induced pluripotent stem cells. Together, these studies
support the process of somatic CAG repeat expansion as a therapeutic target in HD, and clearly indicate that
multiple genetic variations act by different means through FAN1 to influence HD onset in a manner that is
largely additive, except in the rare circumstance that two onset-hastening alleles are present. Thus, an
individual’s particular combination of FAN1 haplotypes may influence their suitability for HD clinical trials,
particularly if the therapeutic agent aims to reduce CAG repeat instability
Effect of holes and vortices on beam quality
The effect of a vortex on the invariant quality factors of a light beam is studied. It is shown that a vortex degrades beam quality. The beam intensity at the eye of the vortex necessarily vanishes, creating a hole in the intensity distribution. The degradation in the beam quality is shown to be due partly to the vortex phase and partly to the hole. The results are illustrated graphically. An important inequality to be obeyed by the beam-quality parameters is exhibited
Directional coronary atherectomy in heart transplant recipients
Cardiac allograft vasculopathy is one of the most common obstacles to the long-term survival of heart transplant recipients. Percutaneous transluminal angioplasty has been used as a palliative treatment for discrete lesions caused by this disease, but it is often complicated by restenosis. This report describes two cases in which directional coronary atherectomy was used to treat the discrete lesions and explores the possible advantages of this intervention in lieu of the traditional approach. Our results suggest that directional coronary atherectomy is a feasible alternative to conventional balloon angioplasty
Hemangiopericytoma of the pancreas: Report of a case and review of the literature
Hemangiopericytoma is an uncommon vascular tumor with variable malignant potential. The origin, structure and function of pericytes remains controversial. Intra-abdominal hemangiopericytomas are highly aggressive soft tissue tumors with a great propensity for malignant transformation. We report on a case of hemangiopericytoma of the pancreas in a 53-year-old female presenting with abdominal pain. Ultrasonography and CT scan revealed a cystic tumor of the head of the pancreas. The patient underwent successful pancreaticoduodenal resection and is alive with no signs of recurrence 25 months following surgery. Ultrastructural studies are necessary to differentiate hemangiopericytomas from other sarcomas. Malignancy may be ascertained only in the presence of metastases or local recurrence. Routine surveillance is advocated
Partial congenital defect of the left pericardium: Angiographic diagnosis and treatment by thoracoscopic pericardiectomy: Case report
Congenital defects of the pericardium are extremely rare and frequently difficult to diagnose. We present a diagnosis of partial congenital defect of the left pericardium based on a characteristic chest X-ray and left ventriculogram. Additionally, we report findings of a diastolic, migratory coronary stenosis on coronary arteriography which, to date, has not been reported. Confirmation of the diagnosis by mediastinoscopy was followed by thoracoscopic pericardiectomy
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