Search results for "SCOPE"
showing 10 items of 2420 documents
Analysis of synaptic bodies in the Sprague–Dawley rat pineal gland under extreme photoperiods
2007
Synaptic bodies (SBs) are small, prominent organelles in pinealocytes, most probably involved in signal transduction processes. To check the influence of the photoperiod on their shape plasticity and number we chose two extreme lighting conditions, i.e. 20 h of illumination followed by 4 h of darkness (LD 20:4) versus (LD 4:20). Pineal glands were assessed at 0, 4 and 13 h after dark onset. Under both conditions reconstructed SBs were plates or ribbons but never spheres and there were no obvious differences in morphology. Photoperiodic changes in SB profile size and number were investigated: application of the established method for SB quantification based on single section profile counts (…
Strain differences in the ratio of synaptic body types in photoreceptors of the rat retina.
1993
In the retinal outer plexiform layer of seven different rat strains, synaptic bodies (SB) were counted and, according to their morphology, characterized as synaptic ribbons (SR), synaptic spheres (SS) or intermediate structures. It was found that absolute SB numbers showed relatively small variations while SR/SS ratios differed considerably between the strains investigated. These results are discussed with respect to retinal pigmentation and to formation and degradation, respectively, of synaptic ribbons.
Ultrastructural alterations and environmental exposure influence the opiate concentrations in hair of drug addicts
1995
Hair samples were taken at autopsy from the head of 1 male and 1 female subject both known as drug abusers. Some of the strands were bleached by in-vitro cosmetic treatment. The bleached hair as well as the original hair samples were partly exposed to water or soil prior to further investigations and drug monitoring. The exposure times were 4 weeks or 6 months for water and 6 months for soil. The hair fibers were examined by transmission electron microscope (TEM) and by scanning electron microscope (SEM) investigations. The electron microscope studies confirmed that all experimental conditions had produced morphological alterations in the hair fibers. After exposure to water or to soil for …
Transnasal endoscopy for direct visual control of esophageal stent placement without fluoroscopy
2012
Placement of self-expanding metal stents (SEMSs) is a well-established treatment for esophageal stenosis and postoperative anastomotic leaks. Conventional endoscopic procedures for SEMS placement require fluoroscopic guidance, but transnasal endoscopy (TNE) with ultraslim endoscopes may allow precise stent release under direct visual control without the need for fluoroscopy. This prospectively collected data investigated the feasibility and safety of TNE-guided SEMS placement without fluoroscopy. Between March 2009 and February 2011, 20 consecutive patients underwent TNE-guided SEMS placement without fluoroscopy. The technical success rate was 100 % and no fluoroscopy was required during th…
The mechanism of epithelial shedding after ischemic damage to the small intestinal mucosa
1979
The intestinal mucosa of the rat was examined by light and electron microscopy 15, 30, 60 and 120 min after complete ligation of the vessel arcades of the proximal jejunum. The characteristic sign of ischemic damage to the small intestinal mucosa and the reason for epithelial shedding is the appearance of membrane enclosed cytoplasmic blebs which arise at the cell base of the enterocytes and detach the epithelium from the basement membrane. This process begins at the tip of the villi before the enterocytes display signs of irreversible damage and progress to the base of the villi with continuation of the ischemia.
Collagen membranes of dermal and pericardial origin-In vivo evolvement of vascularization over time.
2020
Aim of the study was to compare the evolvement of vascularization over time of collagen membranes (CMs) of dermal and pericardial origin in an in vivo animal study. Twenty-eight mice underwent implantation of three commercially available CM derived from porcine dermis (homogenous structure: CM1 (Control 1) and bilayer structure: CM2 [Control 2]), from porcine pericardium (CM3; Test 1) as well as CM3 sprayed with silica-enhanced nanostructured hydroxyapatite (CM4, Test 2). After 3, 6, 9, and 12 days, intravital fluorescence microscopy was conducted for determination of capillary diameter, density, flow, and length. At Day 12, samples were examined immunohistologically for expression of fibro…
Sub-cellular tumor identification and markerless differentiation in the rat brain in vivo by multiphoton microscopy
2012
Objective/Background Aim of the current study was to localize and differentiate between tumor (glioma) and healthy tissue in rat brains on a cellular level. Near-infrared multiphoton microscopy takes advantage of the simultaneous absorption of two or more photons to analyze various materials such as cell and tissue components via the observation of endogenous fluorophores such as NAD(P)H, FAD, porphyrins, melanin, elastin, and collagen, with a very high resolution, without inducing the problems of photo-bleaching on out-of-focus areas. Methods In vitro and in vivo studies on healthy rat brains as well as C6 glioma cell line allografts have been performed. Near-infrared laser pulses (λ = 690…
Morphology and chronology of ischemic mucosal changes in the small intestine
1983
The morphology and chronology of an absolute ischemia was investigated on the small intestine of man and rat. It could be shown that the morphogenesis of ischemic damage to the intestinal mucosa in man does not differ from that in the rat. However, there are crucial and in therapeutic terms significant differences in the time course of the ischemic damage to the intestinal mucosa. Whereas in the small intestine of the rat, the first appreciable alterations - detachment and disruption of the lining epithelium at the villous tip - are already to be observed after absolute ischemia lasting 15 min, in the human small intestine the same lesions only occur after 4 h. A comparable complete necrosi…
Mid- and Longer-term Follow up of Chimney and/or Periscope Grafts and Risk Factors for Failure
2016
Objective The aim was to report on chimney and periscope grafts (CPGs) and their mid- and longer-term outcomes when they are used to preserve reno-visceral artery (RVA) perfusion in endovascular repair of pararenal (PRAAs) or thoraco-abdominal aortic aneurysm (TAAAs). In addition, factors associated with CPG failure are presented. Limited data exist on the outcomes of CPGs, and mid- and long-term results are generally not reported. Methods This was a prospective study in a cohort of 100 patients with PRAA (69) or TAAA (31). A total of 224 (mean 2.24 per patient) RVAs were preserved with 136 (61%) chimney and 88 (39%) periscope grafts. CPGs were constructed mainly using self expandable stent…
Vessel painting of the microcirculation using fluorescent lipophilic tracers
2005
Flexible approaches to defining microvessel morphometry are useful in the study of both acute and chronic structural changes of the microcirculation. In this report, we examined the utility of the intravascular infusion of lipophilic carbocyanine tracers in the structural assessment of the retina, skin, lung, and colon microcirculation. The microvessel labeling technique, here termed fluorescent vessel painting, involved the intravascular injection of sulfonated lipophilic carbocyanine tracers. The utility of vessel painting in morphometry was assessed using morphometric comparisons with corrosion casting and 2-dimensional and 3-dimensional scanning electron microscopy. The comparisons demo…