Scanning Electron Microscopic Findings of the Gliding Surface of the A1 Pulley in Trigger Fingers and Thumbs

2007 ◽  
Vol 32 (4) ◽  
pp. 384-387 ◽  
Author(s):  
M. C. SBERNARDORI ◽  
V. MAZZARELLO ◽  
P. TRANQUILLI-LEALI

The gliding surface of the A1 pulley was studied in 20 cases of primary trigger finger by scanning and transmission electron microscope. In 12 normal specimens, the whole deep surface was covered uniformly by an amorphous extracellular matrix. In the pathological samples, there was the same general surface appearance but, also, areas, varying in shape and dimension where loss of the extracellular matrix had exposed the collagen fibres and a few cells of the middle layer of the pulley. There were also changes typical of “chondroid-metaplasia”. These data were confirmed by transmission electron microscopy. The fragmented areas are probably the result of altered forces of friction between the pulley and the flexor tendon and may be the “gate” through which the forces of friction cause chondroid-metaplasia in the underlying fibrous tissue, a phenomenon recognised to be one step in the pathogenesis of trigger finger.

2007 ◽  
Vol 32 (5) ◽  
pp. 556-559 ◽  
Author(s):  
M. C. SBERNARDORI ◽  
P. BANDIERA

The histopathology of the central parts of 40 A1 pulleys from adult patients with primary trigger fingers was studied using light and transmission electron microscopes and the findings were compared with those in a control series of 10 normal A1 pulleys. The evaluation of the normal A1 pulley revealed a bi-laminar structure. The deepest layer was composed of dense normal connective tissue. The outermost layer was formed by loose connective tissue. In trigger digits, it was possible to identify a tri-laminar structure. The deepest layer was composed of irregular connective tissue, formed by small collagen fibres and abundant extracellular matrix. A considerable amount of chondroid-metaplasia was present in this layer. The middle layer contained dense, normal connective tissue with some fibrocytes. The outermost layer was formed of loose connective tissue. In conclusion, there was an additional layer in the A1 pulley in pathological cases which was not present in normal pulleys.


Author(s):  
S.R. Cole ◽  
L. Hochholzer ◽  
F.B. Johnson ◽  
D.R. Knibbs

Pulmonary alveolar microlithiasis (PAM) is a rare lung disease of unknown etiology characterized by calcified spherules which fill alveolar spaces. Although there are approximately 110 cases of PAM previously reported, only 26 have been confirmed by histologic examination. Increased interstitial fibrous tissue is seen in some cases, and some patients develop shortness of breath. However, many patients remain assymptomatic for years following the diagnosis of PAM.Six cases from the files of the Armed Forces Institute of Pathology and Hartford Hospital were studied. Light, scanning and transmission electron microscopic studies were performed as were chemical, immunocytochemical and energy dispersive x-ray analysis. Analyses suggest that they are composed in part of mucopolysaccharides and Ca3(PO4)2. Our findings indicate that microliths form initially around a cellular nidus by the deposition of calcium and phosphate salts from the extracellular matrix vesicles of surrounding cells similar to the method previously demonstrated 1n the formation of bone and psammoma bodies. PAM is not usually associated with Identifiable systemic disturbances in calcium and phosphorus metabolism.


2019 ◽  
pp. 089270571987394
Author(s):  
Osama Saber ◽  
Mohammed Abu-Abdeen ◽  
A Aljaafari ◽  
Javed Mazher ◽  
Mohamad M Ahmed ◽  
...  

Previous publications showed that graphene sheets polymer nanocomopsites were prepared by incorporating previously prepared graphene into the polymer matrix through two or more successive steps. In this work, graphene sheets were exfoliated from graphite inside the polymer matrix solution for certain period in one step. This approach was easy to perform, low cost, high mass production of graphene and, almost, produces effective results. In this respect, electrolytic solution from poly(vinyl alcohol) (PVA) and salt was prepared and exfoliation process took place inside it for different times. After that, solution was dried to get films of PVA loaded with different concentrations of graphene sheets. Scanning electron microscopic and transmission electron microscopic images of exfoliated graphene sheets were studied. Raman spectroscopy of graphite, graphene nanosheets, and PVA-loaded graphene was studied. The dielectric permittivity, dielectric loss, and alternating current electrical conductivity were studied and had maximum values at 10 min of exfoliation time. Cole–Cole impedance plots show semicircles behavior with lowest radius for samples prepared at 10 min. The elastic modulus was found to have a maximum value at exfoliation time of 30 min.


Author(s):  
R. A. Waugh ◽  
J. R. Sommer

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.


Author(s):  
Henry S. Slayter

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.


Author(s):  
Toichiro Kuwabara

Although scanning electron microscopy has a great potential in biological application, there are certain limitations in visualization of the biological structure. Satisfactory techniques to demonstrate natural surfaces of the tissue and the cell have been reported by several investigators. However, it is commonly found that the surface cell membrane is covered with a minute amount of mucin, secretory substance or tissue fluid as physiological, pathological or artefactual condition. These substances give a false surface appearance, especially when the tissue is fixed with strong fixatives. It seems important to remove these coating substances from the surface of the cell for demonstration of the true structure.


Author(s):  
Masahiro Ono ◽  
Kaoru Aihara ◽  
Gompachi Yajima

The pathogenesis of the arteriosclerosis in the acute myocardial infarction is the matter of the extensive survey with the transmission electron microscopy in experimental and clinical materials. In the previous communication,the authors have clarified that the two types of the coronary vascular changes could exist. The first category is the case in which we had failed to observe no occlusive changes of the coronary vessels which eventually form the myocardial infarction. The next category is the case in which occlusive -thrombotic changes are observed in which the myocardial infarction will be taken placed as the final event. The authors incline to designate the former category as the non-occlusive-non thrombotic lesions. The most important findings in both cases are the “mechanical destruction of the vascular wall and imbibition of the serous component” which are most frequently observed at the proximal portion of the coronary main trunk.


Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.


Author(s):  
C. N. Gordon

Gordon and Kleinschmidt have described a new preparative technique for visualizing DNA by electron microscopy. This procedure, which is a modification of Hall's “mica substrate technique”, consists of the following steps: (a) K+ ions on the cleavage surface of native mica are exchanged for Al3+ ions by ion exchange. (b) The mica, with Al3+ in the exchange sites on the surface, is placed in a dilute aqueous salt solution of DNA for several minutes; during this period DNA becomes adsorbed on the surface. (c) The mica with adsorbed DNA is removed from the DNA solution, rinsed, dried and visualized for transmission electron microscopy by Hall's platinum pre-shadow replica technique.In previous studies of circular DNA by this technique, most of the molecules seen were either broken to linears or extensively tangled; in general, it was not possible to obtain suitably large samples of open extended molecules for contour length measurements.


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