Ultrastructure Analysis of Tenckhoff Chronic Peritoneal Catheters Used in Continuous Ambulatory Peritoneal Dialysis Patients

1993 ◽  
Vol 13 (2_suppl) ◽  
pp. 33-35 ◽  
Author(s):  
Alberto Giangrande ◽  
Pietro Allaria ◽  
Regina Torpia ◽  
Lucilla Baldassari ◽  
Antonella Gelosia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Structural Defects ◽  
Dialysis Patients ◽  
Catheter Design ◽  
Antibiotic Management ◽  
Clinical Problems ◽  
Scanning Electron

The luminal and external surfaces of 18 curled silicone double-cuff catheters removed from patients who had been on continuous ambulatory peritoneal dialysis (CAPO) for 2-77 months (average 37±21 months) were analyzed by scanning electron microscopy (SEM) and microbiological cultures. Eight catheters (G1) were removed due to recurrent peritonitis or peritonitis refractory to antibiotic management, and the others (G2) due to local or clinical problems. The peritonitis rate was one episode every 24 patient months in G1, and 80 patient-months in G2. All catheter surfaces were covered with proteinlike granular deposits (0.15±0.111cm); 6 catheters were covered by microbial biofilm (0.24±0.161cm). Positive cultures of catheter segments were obtained in 6 cases (4 for G1 and 2 for G2) with a preponderance (33%) of StaphYlococcus aureus among the cultivated bacteria. Structural defects and small linear tears were present on both luminal and external surfaces in 8 catheters. Structural defects were frequent in the catheters removed for recurrent peritonitis. Linear tears appeared more frequently in the catheters used for a longer time. Structural defects of catheter surfaces were also discovered in the newer devices. The structural defects of the catheter appear to facilitate microbial adhesion and colonization and to predispose the patient to recurrence of peritonitis. A better catheter design and an improvement in the production process should therefore be recommended.

Scanning Electron Microscopy of Staphylococcus Epidermidis Adherence to Continuous Ambulatory Peritoneal Dialysis Catheters

1985 ◽  
Vol 43 ◽  
pp. 520-521
Author(s):  
William J. Lamoreaux ◽  
David L. Smalley ◽  
Larry M. Baddour ◽  
Alfred P. Kraus
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Staphylococcus Epidermidis ◽  
Sterile Saline ◽  
Intravascular Devices ◽  
Capd Patient ◽  
Scanning Electron

Infections associated with the use of intravascular devices have been documented and have been reported to be related to duration of catheter usage. Recently, Eaton et al. reported that Staphylococcus epidermidis may attach to silastic catheters used in continuous ambulatory peritoneal dialysis (CAPD) treatment. The following study presents findings using scanning electron microscopy (SEM) of S. epidermidis adherence to silastic catheters in an in vitro model. In addition, sections of polyvinyl chloride (PVC) dialysis bags were also evaluated by SEM.The S. epidermidis strain RP62A which had been obtained in a previous outbreak of coagulase-negative staphylococcal sepsis at local hospitals was used in these experiments. The strain produced surface slime on exposure to glucose, whereas a nonadherent variant RP62A-NA, which was also used in these studies, failed to produce slime. Strains were grown overnight on blood agar plates at 37°C, harvested from the surface and resuspended in sterile saline (0.85%), centrifuged (3,000 rpm for 10 minutes) and then washed twice in 0.1 M phosphate-buffered saline at pH 7.0. Organisms were resuspended at a concentration of ca. 106 CFU/ml in: a) sterile unused dianeal at 4.25% dextrose, b) sterile unused dianeal at 1.5% dextrose, c) sterile used dialysate previously containing 4.25% dextrose taken from a CAPD patient, and d) sterile used dialysate previously containing 1.5% dextrose taken from a CAPD patient.

Scanning Electron Microscopy Studies of Vacuum Evaporated CdCl2 Doped Cadmium Sulphide Films

2000 ◽  
Vol 6 (S2) ◽  
pp. 454-455
Author(s):  
Ram Kishore ◽  
Venkatram Korapati ◽  
W.D. Brown ◽  
H.A. Naseem
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solar Cell ◽  
Thermal Evaporation ◽  
Cell Structure ◽  
Index Of Refraction ◽  
Structural Defects ◽  
Glass Substrates ◽  
Scanning Electron ◽  
Cds Films

CdTe/CdS thin film solar cells are being investigated extensively these days by many workers as an option for low cost photovoltaic applications . In order to achieve high efficiency solar cell it is important that the CdS film should have minimum possible structural defects and reasonably large grain size. The CdS films for CdTe/ CdS solar cell structure are mostly grown on glass substrates by chemical bath deposition (CBD). Although adherent, transparent and conformal films with index of refraction close to single crystal CdS can be grown by CBD, impurity inclusions and micropinholes are a problem there in. Very little work has been carried out to grow CdS films by thermal evaporation in vacuum. In the present work we have grown pure and CdCl2 doped CdS films on glass substrates by thermal evaporation and carried out microstructural investigations of these films using scanning electron microscopy.Corning 7059 glass of 25.4 x 25.4 x 1.2 mm size were used as substrates for the deposition of CdS as well as CdCl2 doped CdS films.

Sclerosing Peritonitis -The Contribution of Chlorhexidine in Alcohol

1985 ◽  
Vol 5 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Brian J. R. Junor ◽  
J. Douglas Briggs ◽  
Margaret A. Forwell ◽  
James W. Dobbie ◽  
Iain Henderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Peritoneal Dialysis ◽  
Peritoneal Cavity ◽  
Inflammatory Reaction ◽  
Fold Increase ◽  
Sclerosing Peritonitis ◽  
Particle Count ◽  
Fibrotic Process ◽  
Scanning Electron

Sclerosing peritonitis now is recognized as an extremely serious complication of peritoneal dialysis. In Glasgow II of 162 patients on CAPD developed sclerosing peritonitis. All 11 came from a group of 54 patients, who used a connecting system that allowed small quantities of the antiseptic spray, chlorhexidine in alcohol, to enter the abdomen. Experiments showed that I ml of this solution added to 2 litres of dialysate produced up to a 20. fold increase in the particle count of the dialysate. Scanning electron microscopy suggested that these particles probably were plastic. In rats intraperitoneal injections of a mixture of antiseptic spray and dialysate produced an inflammatory reaction in the submesothelial tissues, which might represent the early changes of a fibrotic process. To prevent possible longterm complications such as sclerosing peritonitis we should avoid the introduction into the peritoneal cavity of any unnecessary substance and in particular chlorhexidine in alcohol.

On Peculiarities of Defect Formation in 6Н-SiC Bulk Single Crystals Grown by PVT Method

2013 ◽  
Vol 740-742 ◽  
pp. 43-47 ◽  
Author(s):  
Gennadi A. Emelchenko ◽  
Andrey A. Zhokhov ◽  
Ilya I. Tartakovskii ◽  
Andrey A. Maksimov ◽  
Edward A. Steinman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Scattering ◽  
Single Crystals ◽  
Formation Mechanism ◽  
Defect Formation ◽  
Structural Defects ◽  
Bulk Single Crystals ◽  
Scanning Electron

The structural defects in the single 6H-SiC crystals grown by the PVT method have been studied by the scanning electron microscopy, Raman scattering and photoluminescence techniques. The formation mechanism of the defects, micropipes and parasitic polytypes 4H and 15R, observed in the single 6H-SiC crystal has been proposed.

scholarly journals Scanning electron microscopy preparation and analysis of the cell cortex ultrastructure

2020 ◽  
Author(s):  
D. Flormann ◽  
M. Schu ◽  
E. Terriac ◽  
M. Koch ◽  
S. Paschke ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Critical Point ◽  
Structural Defects ◽  
Cell Cortex ◽  
Drying Methods ◽  
Actin Network ◽  
Actin Cortex ◽  
Critical Point Drying ◽  
Scanning Electron

AbstractThe cellular cortex is a 200-nm-thick actin network that lies beneath the cell membrane. It is responsible for the mechanical properties of the cell and is involved in many cellular processes, such as cell migration and interactions with the environment. To develop a clear view of the structure of this meshwork, high resolution imaging is essential, such as electron microscopy. This technique requires complex sample preparation that can lead to artifacts like shrinkage or hole formation. We present a preparation method that reduces artifacts significantly. Here, the final drying step that is typically performed by critical point drying is replaced by hexamethyldisilazane drying. We quantitatively investigated sample integrity after both preparation methods, and show that there are significant advantages of hexamethyldisilazane drying compared to critical point drying. Furthermore, automated analysis of a network is classically performed by thresholding-based software programs, which are sensitive to noise and uneven brightness of images. The here presented analysis that we have developed is based on a vectorial node algorithm. It reproduces all kinds of networks sufficiently to allow derivation of quantitative network-specific parameters, such as mesh hole size. We use this analysis to compare the network structure of cells prepared by these two drying methods, and show that hexamethyldisilazane drying leads to fewer artificial mesh holes compared to critical point drying. We thus present here a significantly improved method to quantitatively investigate the actin cortex of cells, and show that hexamethyldisilazane drying leads to more accurate imaging compared to critical point drying.Insight BoxThe highest resolution for imaging the cellular actin cortex is provided by electron microscopy. Scanning electron microscopy samples require a drying process, usually achieved by critical point drying, which is critical for the sample integrity. We compare the structural defects in the actin cortex of hTert RPE1 cells after critical point drying and a chemical based method, namely hexamethyldisilazane drying. In order to characterize the actin network, we also developed a new vectorial based tracing software. We bring here new tool, both experimental and analytical, which will help to streamline studies of the actin cortex.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

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