scholarly journals AN ELECTRON MICROSCOPE ANALYSIS OF NERVES INFECTED WITH THE B VIRUS

1949 ◽  
Vol 90 (4) ◽  
pp. 291-296 ◽  
Author(s):  
E. De Robertis
Keyword(s):  
Electron Microscope ◽  
Gastrocnemius Muscle ◽  
Phosphotungstic Acid ◽  
Proximal Part ◽  
Spherical Particles ◽  
B Virus ◽  
Large Particles ◽  
Electron Microscope Analysis ◽  
Sciatic Nerves ◽  
The Right

Rabbits were infected with B virus in the right gastrocnemius muscle and both sciatic nerves were fixed and analyzed under the electron microscope, after periods varying between 26 and 144 hours. Starting at 72 hours, a few neurotubules of the right sciatic show the presence of spherical particles, ranging between 300 and 600 Å. The number and size of the particles increase with time and appear to reach a maximum at 144 hours when the paralysis starts. At this moment also the proximal part of the left sciatic nerve shows the presence of dense particles. The relation of the particles with the periodic structure of the neurotubules was studied both in preparations stained in phosphotungstic acid and those shadowed with chromium. The small and medium sized particles are located within the edges of the neurotubules, and the large particles appear to be attached to the neurotubules. The possible significance of the dense particles is discussed.

A Device for Magnification Measurement

1972 ◽  
Vol 30 ◽  
pp. 622-623
Author(s):  
J.A. Eades ◽  
A. van Dun
Keyword(s):  
Electron Microscope ◽  
Small Displacement ◽  
Private Communication ◽  
Piezoelectric Crystal ◽  
Double Exposure ◽  
Standard Methods ◽  
Elegant Method ◽  
The Right ◽  
Piezo Electric

The measurement of magnification in the electron microscope is always troublesome especially when a goniometer stage is in use, since there can be wide variations from calibrated values. One elegant method (L.M.Brown, private communication) of avoiding the difficulties of standard methods would be to fit a device which displaces the specimen a small but known distance and recording the displacement by a double exposure. Such a device would obviate the need for changing the specimen and guarantee that the magnification was measured under precisely the conditions used.Such a small displacement could be produced by any suitable transducer mounted in one of the specimen translation mechanisms. In the present case a piezoelectric crystal was used. Modern synthetic piezo electric ceramics readily give reproducible displacements in the right range for quite modest voltages (for example: Joyce and Wilson, 1969).

Incorporation of Cholesterol into Peripheral Nerve Myelin

1972 ◽  
Vol 30 ◽  
pp. 334-335
Author(s):  
Frank A. Rawlins
Keyword(s):  
Electron Microscope ◽  
Sciatic Nerve ◽  
Electron Microscope Autoradiography ◽  
Myelin Sheaths ◽  
Microscope Autoradiography ◽  
Grain Distribution ◽  
Sciatic Nerves ◽  
Autoradiographic Analysis ◽  
Old Mice ◽  
Short Times

Several speculations exist as to the site of incorporation of preformed molecules into myelin. The possibility that an autoradiographic analysis of cholesterol-1,2-H3 incorporation at very short times after injection might shed some light in the solution of that problem led to the present experiment.Cholesterol-1,2-H3 was injected intraperitoneally into 24 tenday old mice. The animals were then sacrificed at 10,20,30,40,60,90,120 and 180 min after the injection and the sciatic nerves were processed for electron microscope autoradiography. To analyze the grain distribution in the autoradiograms of cross and longitudinal sections from each sciatic nerve myelin sheaths were subdivided into three compartments named: outer 1/3, middle 1/3 and inner 1/3 compartments.It was found that twenty min. after the injection of cholesterol -1.2-H3 (Figs. 1 and 2), 55% of the total number of grains (t.n.g) found in myelin were within the outer 1/3 compartment, 9% were within the middle 1/3 and 36% within the inner 1/3 compartment

Residual Gas Reactions in the Electron Microscope: I. Qualitative Observations on the Water Gas Reaction

1968 ◽  
Vol 26 ◽  
pp. 292-293
Author(s):  
Richard E. Hartman ◽  
Roberta S. Hartman ◽  
Peter L. Ramos
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Gas Phase ◽  
Absolute Temperature ◽  
Residual Gas ◽  
Gas Reactions ◽  
Image Position ◽  
The Right ◽  
Water Gas ◽  
Thinning Rate

The action of water and the electron beam on organic specimens in the electron microscope results in the removal of oxidizable material (primarily hydrogen and carbon) by reactions similar to the water gas reaction .which has the form:The energy required to force the reaction to the right is supplied by the interaction of the electron beam with the specimen.The mass of water striking the specimen is given by:where u = gH2O/cm2 sec, PH2O = partial pressure of water in Torr, & T = absolute temperature of the gas phase. If it is assumed that mass is removed from the specimen by a reaction approximated by (1) and that the specimen is uniformly thinned by the reaction, then the thinning rate in A/ min iswhere x = thickness of the specimen in A, t = time in minutes, & E = efficiency (the fraction of the water striking the specimen which reacts with it).

scholarly journals Focused Genetic Recombination of Bacteriophage T4 Initiated by Double-Strand Breaks

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 543-556
Author(s):  
Victor Shcherbakov ◽  
Igor Granovsky ◽  
Lidiya Plugina ◽  
Tamara Shcherbakova ◽  
Svetlana Sizova ◽  
...  
Keyword(s):  
Genetic Recombination ◽  
Bacteriophage T4 ◽  
Proximal Part ◽  
Coupling Model ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
The Right ◽  
Frequency Distance

Abstract A model system for studying double-strand-break (DSB)-induced genetic recombination in vivo based on the ets1 segCΔ strain of bacteriophage T4 was developed. The ets1, a 66-bp DNA fragment of phage T2L containing the cleavage site for the T4 SegC site-specific endonuclease, was inserted into the proximal part of the T4 rIIB gene. Under segC+ conditions, the ets1 behaves as a recombination hotspot. Crosses of the ets1 against rII markers located to the left and to the right of ets1 gave similar results, thus demonstrating the equal and symmetrical initiation of recombination by either part of the broken chromosome. Frequency/distance relationships were studied in a series of two- and three-factor crosses with other rIIB and rIIA mutants (all segC+) separated from ets1 by 12-2100 bp. The observed relationships were readily interpretable in terms of the modified splice/patch coupling model. The advantages of this localized or focused recombination over that distributed along the chromosome, as a model for studying the recombination-replication pathway in T4 in vivo, are discussed.

Brodie’s Abscess of the Proximal Humerus Metaphysis: A Case Report

2021 ◽  
Vol 11 (9) ◽  
Author(s):  
Nilesh Vishwakarma ◽  
Shaival Chauhan ◽  
Shrey S Binyala ◽  
Sanjeev K Singh
Keyword(s):  
Case Report ◽  
Shoulder Joint ◽  
Proximal Part ◽  
Focal Lesion ◽  
Posterior View ◽  
Brodie’S Abscess ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Pyogenic Osteomyelitis ◽  
Metaphyseal Region

Introduction:Primary subacute pyogenic osteomyelitis, or Brodie’s abscess was initially documented by Sir Benjamin Brodie in 1832. We present a case report with a 6-months follow-up period, demonstrating the successful diagnosis and surgical treatment of a focal lesion of the proximal metaphysis of the right humerus in a 21-years-old female. The pathology of hematologic osteomyelitis and its role in the development of a subacute abscess along with a review of literature and an in detail description of the pathogenesis of Brodie’s abscess is discussed and submitted. Case Report:A 21- years -old healthy female with a history of fall sustaining injury to the right shoulder one 1 year back followed by which she presented to the outpatient clinic with a swelling over her right shoulder. The patient was managed conservatively with analgesics and was relieved of pain over a course of one 1 week of medications, the patient now presents with pain and swelling in the right shoulder joint on and off since the episode of fall one 1 year back, which had increased over a period of past one 1 week. A week before the most recent presentation she started experiencing some discomfort and pain in her right shoulder. No recent trauma was reported. A mild swelling appeared over the proximal part of the humerus. There were no constitutional symptoms of fever or any illness reported. On examination, there was noted a painful restriction of ROM at the right shoulder joint with no rotator cuff injury. Laboratory investigations were suggestive of raised inflammatory markers. Radiograph of the right shoulder taken in the true antero-posterior view with the shoulder in the neutral rotation was suggestive of an oval lucency with surrounding sclerosis in the proximal metaphyseal region of the humerus. Magnetic resonance imaging MRI of the right shoulder joint showed features consistent with Brodie’s abscess in the proximal metaphyseal region of the humerus. Surgical debridement of the abscess w

scholarly journals Clinical and morphological study of calf enlargement following S-1 radiculopathy

1992 ◽  
Vol 50 (3) ◽  
pp. 383-386 ◽  
Author(s):  
Osvaldo J. M. Nascimento ◽  
Marcos R. G. de Freitas ◽  
Myrian D. Hahn ◽  
Abelardo Q. C. Araújo
Keyword(s):  
Gastrocnemius Muscle ◽  
Rare Condition ◽  
Satisfactory Explanation ◽  
Lower Back ◽  
Left Buttock ◽  
Left Calf ◽  
One Year ◽  
The Right ◽  
Gastrocnemius Muscles

Calf enlargement following sciatica is a rare condition. It is reported the case of a 28-year-old woman who complained of repeated episodes of lower back pain radiating into the left buttock and foot. One year after the beginning of her symptoms, she noticed enlargement of her left calf. X-ray studies disclosed L5-S1 disk degeneration. EMG showed muscle denervation with normal motor conduction velocity. Open biopsies of the gastrocnemius muscles were performed. The left gastrocnemius muscle showed hypertrophic type 2 fibers in comparison with the right gastrocnemius. Electron microscopy showed mildly increased number of mitochondria in these fibers. A satisfactory explanation for denervation hypertrophy has yet to be provided.

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