Evaluation of Corneal Endothelial Damage using Correlated Microscopy Techniques (With 1 color plate)

1976 ◽  
Vol 8 (6) ◽  
pp. 407-413 ◽  
Author(s):  
Gary Wickham ◽  
Perry S. Binder
Author(s):  
R. G. Gerrity ◽  
M. Richardson

Dogs were injected intravenously with E_. coli endotoxin (2 mg/kg), and lung samples were taken at 15 min., 1 hr. and 24 hrs. At 15 min., occlusion of pulmonary capillaries by degranulating platelets and polymorphonuclear leukocytes (PML) was evident (Fig. 1). Capillary endothelium was intact but endothelial damage in small arteries and arterioles, accompanied by intraalveolar hemorrhage, was frequent (Fig. 2). Sloughing of the surfactant layer from alveolar epithelium was evident (Fig. 1). At 1 hr., platelet-PML plugs were no longer seen in capillaries, the endothelium of which was often vacuolated (Fig. 3). Interstitial edema and destruction of alveolar epithelium were seen, and type II cells had discharged their granules into the alveoli (Fig. 4). At 24 hr. phagocytic PML's were frequent in peripheral alveoli, while centrally, alveoli and vessels were packed with fibrin thrombi and PML's (Fig. 5). In similar dogs rendered thrombocytopenic with anti-platelet serum, lung ultrastructure was similar to that of controls, although PML's were more frequently seen in capillaries in the former (Fig. 6).


Author(s):  
C.E. Voegele-Kliewer ◽  
A.D. McMaster ◽  
G.W. Dirks

Materials other than polymers, e.g. ceramic silicates, are currently being investigated for gas separation processes. The permeation characteristics of one such material, Vycor (Corning Glass #1370), have been reported for the separation of hydrogen from hydrogen iodide. This paper will describe the electron microscopy techniques applied to reveal the porous microstructure of a Vycor membrane. The application of these techniques has led to an increased understanding in the relationship between the substructure and the gas transport properties of this material.


Author(s):  
Thomas M. Moore

In the last decade, a variety of characterization techniques based on acoustic phenomena have come into widespread use. Characteristics of matter waves such as their ability to penetrate optically opaque solids and produce image contrast based on acoustic impedance differences have made these techniques attractive to semiconductor and integrated circuit (IC) packaging researchers.These techniques can be divided into two groups. The first group includes techniques primarily applied to IC package inspection which take advantage of the ability of ultrasound to penetrate deeply and nondestructively through optically opaque solids. C-mode Acoustic Microscopy (C-AM) is a recently developed hybrid technique which combines the narrow-band pulse-echo piezotransducers of conventional C-scan recording with the precision scanning and sophisticated signal analysis capabilities normally associated with the high frequency Scanning Acoustic Microscope (SAM). A single piezotransducer is scanned over the sample and both transmits acoustic pulses into the sample and receives acoustic echo signals from the sample.


Author(s):  
M. S. Bischel ◽  
J. M. Schultz

Despite its rapidly growing use in commercial applications, the morphology of LLDPE and its blends has not been thoroughly studied by microscopy techniques. As part of a study to examine the morphology of a LLDPE narrow fraction and its blends with HDPE via SEM, TEM and AFM, an appropriate etchant is required. However, no satisfactory recipes could be found in the literature. Mirabella used n-heptane, a solvent for LLDPE, as an etchant to reveal certain morphological features in the SEM, including faint banding in spherulites. A 1992 paper by Bassett included a TEM micrograph of an axialite of LLDPE, etched in a potassium permanganate solution, but no details were given.Attempts to use n-heptane, at 60°C, as an etchant were unsuccessful: depending upon thickness, samples swelled and increased in diameter by 5-10% or more within 15 minutes. Attempts to use the standard 3.5% potassium permanganate solution for HDPE were also unsuccessful: the LLDPE was severely overetched. Weaker solutions were also too severe.


1996 ◽  
Vol 75 (06) ◽  
pp. 974-975 ◽  
Author(s):  
İbrahim C Haznedaroğlu ◽  
Oktay Özdemir ◽  
Osman Özcebe ◽  
Semra V Dündar ◽  
Şerafettin Kirazli

1967 ◽  
Vol 18 (03/04) ◽  
pp. 592-604 ◽  
Author(s):  
H. R Baumgartner ◽  
J. P Tranzer ◽  
A Studer

SummaryElectron microscopic and histologic examination of rabbit ear vein segments 4 and 30 min after slight endothelial damage have yielded the following findings :1. Platelets do not adhere to damaged endothelial cells.2. If the vessel wall is denuded of the whole endothelial cell, platelets adhere to the intimai basement lamina as do endothelial cells.3. The distance between adherent platelets as well as endothelial cells and intimai basement lamina measures 10 to 20 mµ, whereas the distance between aggregated platelets is 30 to 60 mµ.4. 5-hydroxytryptamine (5-HT) is released from platelets during viscous metamorphosis at least in part as 5-HT organelles.It should be noted that the presence of collagen fibers is not necessary for platelet thrombus formation in vivo.


1970 ◽  
Vol 24 (01/02) ◽  
pp. 010-016 ◽  
Author(s):  
D Green ◽  
H. C Kwaan ◽  
G Ruiz

SummaryCoagulation studies were performed in 52 patients with sickle cell disease during asymptomatic periods and during episodes of crisis and infection. Platelet counts averaged 473,000, 469,000, and 461,000 per mm3 in these 3 groups, and factor VIII concentrations were elevated in all. Fibrinogen was increased to the same extent in both sickle cell and non-sickle cell patients with infection. Fibrinolytic activity, as measured by euglobulin lysis times and zones of lysis on fibrin plates, was markedly reduced during periods of infection in sickle cell patients but not in non-sickle patients. Impairment of fibrinolysis in most patients was not on the basis of overutilization or consumption, since no decrease in the levels of clotting factors or plasminogen was observed. It was suggested that generalized intravascular sickling in these patients may have caused widespread endothelial damage, resulting in decreased production of plasminogen activator.In addition, several sickle cell patients with infection were found to possess elevated levels of an inhibitor directed against urokinase.


1984 ◽  
Vol 51 (01) ◽  
pp. 089-092 ◽  
Author(s):  
M A Boogaerts ◽  
J Van de Broeck ◽  
H Deckmyn ◽  
C Roelant ◽  
J Vermylen ◽  
...  

SummaryThe effect of alfa-tocopherol on the cell-cell interactions at the vessel wall were studied, using an in vitro model of human umbilical vein endothelial cell cultures (HUEC). Immune triggered granulocytes (PMN) will adhere to and damage HUEC and platelets enhance this PMN mediated endothelial injury. When HUEC are cultured in the presence of vitamin E, 51Cr-leakage induced by complement stimulated PMN is significantly decreased and the enhanced cytotoxicity by platelets is completely abolished (p <0.001).The inhibition of PMN induced endothelial injury is directly correlated to a diminished adherence of PMN to vitamin E- cultured HUEC (p <0.001), which may be mediated by an increase of both basal and stimulated endogenous prostacyclin (PGI2) from alfa-tocopherol-treated HUEC (p <0.025). The vitamin E-effect is abolished by incubation of HUEC with the irreversible cyclo-oxygenase inhibitor, acetylsalicylic acid, but the addition of exogenous PGI2 could not reproduce the vitamin E-mediated effects.We conclude that vitamin E exerts a protective effect on immune triggered endothelial damage, partly by increasing the endogenous anti-oxidant potential, partly by modulating intrinsic endothelial prostaglandin production. The failure to reproduce vitamin E-protection by exogenously added PGI2 may suggest additional, not yet elucidated vitamin E-effects on endothelial metabolism.


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