Development and Determination of Hairs and Bristles in the Milkweed Bug, Oncopeltus Fasciatus (Lygaeidae, Hemiptera)

1966 ◽  
Vol 1 (4) ◽  
pp. 475-498 ◽  
Author(s):  
P. A. LAWRENCE
Keyword(s):  
Oncopeltus Fasciatus ◽  
Cytoplasmic Process ◽  
Dense Population ◽  
Electron Microscopic ◽  
German Word ◽  
Cell Divisions ◽  
Microscopic Studies ◽  
Mother Cells ◽  
Proliferative Cell

The term ‘organule’ is proposed as an English equivalent for the German word ‘Kleinorgan’. The different organules on the third sternite of Oncopeltus are described: larvae possess innervated bristles and special sensilla termed ‘chemosensilla’, whereas the adult develops, in addition, a dense population of non-innervated hairs. The hairs, bristles and ‘chemosensilla’ each develop from mother cells which undergo a particular series of differentiative divisions. The course of events is described for each type of organule. Electron-microscopic studies of the fine structure of the outgrowing hairs are described. As in the outgrowth of a scale, longitudinal arrays of microtubules and bundles of fibres are found in the first cytoplasmic process of the trichogen cell. Experiments show that bristle determination occurs between the onset of the moult and the proliferative cell divisions in the epidermis. The period of hair determination is found to occur later than that of the bristles and to be later than the proliferative cell divisions in the last larval stage. A discussion of the results includes a review of the knowledge of differentiative divisions concerned in the formation of organules in other groups of insects, and a consideration of Wigglesworth's theory of bristle determination.

The Estimation of Long-Range Internal Stress Fields by Spectral-Acoustic Method

2014 ◽  
Vol 1013 ◽  
pp. 121-126 ◽  
Author(s):  
Aleksandr Smirnov ◽  
Nikolai Ababkov ◽  
Aleksandra Glinka
Keyword(s):  
Conceptual Model ◽  
Physical And Mechanical Properties ◽  
Acoustic Method ◽  
Electron Microscopic ◽  
Limiting State ◽  
Acoustic Characteristics ◽  
Complex Criterion ◽  
Microscopic Studies ◽  
Hazardous Production

A conceptual model consisting of diagrams, text and terminology dictionary, made in a formalized way and representations of functions, each of which reflects the real state of the long-running metal at all stages of the life cycle. Based on the developed conceptual model, analysis of the results of electron microscopic studies measuring the acoustic characteristics and determination of physical and mechanical properties of the complex criterion limiting state long working metal technical devices hazardous production facilities.

Electron Microscopic Studies of Base Sequence in DNA

1974 ◽  
Vol 32 ◽  
pp. 300-301
Author(s):  
Michael Beer
Keyword(s):  
Base Sequence ◽  
Staining Reaction ◽  
Extended Form ◽  
Electron Microscopic ◽  
Microscopic Studies

I shall review the work on the electron microscopic determination of base sequence in DNA restricting myself to the approach in which one kind of base is selectively marked. The requirements for success are 1. Appropriate staining reaction: stain must be detectable yet sufficiently compact to allow resolution of adjaconts. Reactions must be sufficiently selective and sufficiently gentle to preserve the.polynucleotide chain. 2. Deposition of polynucleotide chains in untangled and sufficiently extended form. 3. Means for accurately enumerating unmarked bases between the marked ones.

Morphology, ecology and distribution of the diatom (Bacillariophyceae) species Simonsenia delognei (Grunow) Lange-Bertalot

2014 ◽  
Vol 43 (4) ◽  
Author(s):  
Andrzej Witkowski ◽  
Joanna Żelazna-Wieczorek ◽  
Cüneyt Solak ◽  
Maxim Kulikovskiy
Keyword(s):  
Seasonal Distribution ◽  
Taxonomic Identification ◽  
Diatom Species ◽  
Electron Microscopic ◽  
Central Poland ◽  
Morphological Studies ◽  
Nw Turkey ◽  
Microscopic Studies ◽  
First Time

AbstractSimonsenia delognei is a diatom species which is relatively rarely recorded, but apparently widespread in Europe and other continents. This taxon has recently been discovered for the first time in springs of Central Poland, where it was found to occur abundantly. Somewhat later this species has also been identified and photographed in samples from the Eagean Region in Turkey. Light and electron microscopic studies were carried out on S. delognei populations from the Quaternary spring located near Łódź (Central Poland) and from the Porsuk and Felent Rivers and a spring in the Türkmen Mountains in Kütahya and Havuzdere Stream in Yalova (NW Turkey). Morphological studies were accompanied by environmental measurements and determination of changes in the seasonal distribution of S. delognei in a key area, i.e. the Porzeczkowe spring in Central Poland, which are included in the present study. Identification of S. delognei under a light microscope is difficult and hence an electron microscope is required for accurate taxonomic identification.

Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

1978 ◽  
Vol 36 (2) ◽  
pp. 46-47
Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder
Keyword(s):  
Mammary Gland ◽  
Protein Denaturation ◽  
Chemical Constituents ◽  
Freeze Substitution ◽  
Electron Microscopic Examination ◽  
Mouse Mammary Gland ◽  
Electron Microscopic ◽  
Preparation Methods ◽  
Microscopic Studies ◽  
Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

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.

Early Development of Drug-Induced Hepatic Necrosis

1971 ◽  
Vol 29 ◽  
pp. 576-577
Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser
Keyword(s):  
Early Development ◽  
Hepatic Necrosis ◽  
Screening Tests ◽  
Dense Matrix ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Drug Induced ◽  
Hepatocellular Damage ◽  
Sprague Dawley Rats ◽  
Microscopic Studies

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.

Electron Microscopic identification of Pre-B Lymphocytes in the Bone Marrow of a Patient with Chronic Myelocytic Leukemic in Blast Crisis

1982 ◽  
Vol 40 ◽  
pp. 346-347
Author(s):  
T. Mullin ◽  
G. Yee ◽  
M. Aheam ◽  
J. Trujillo
Keyword(s):  
Blast Crisis ◽  
Immunoglobulin M ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Transformation Theory ◽  
Electron Microscopic ◽  
Chemotherapeutic Sensitivity ◽  
Microscopic Studies ◽  
Hematopoietic Precursor ◽  
Lymphoblastic Transformation ◽  
B Lineage

There have been numerous reports in the current literature suggesting that hematopoietic precursor cells in some human chronic myelocytic leukemias (CML) undergo lymphoblastic transformation at the time of the acute blast crisis (BC) stage. The primary evidence offered in support of this transformation theory--lymphoblastic appearing morphology, increased terminal deoxynucleotidyl transferase (TdT) activity, and chemotherapeutic sensitivity to vincristine and prednisone--has been indirect, however, since these features may occur in nonlymphoid cells. More direct support for the Pre-B lineage of these cells has recently been provided by immunofluorescent light microscopic studies demonstrating the presence of intracytoplasmic immunoglobulin M (IgM) in these CML-BC cells.

Origin of Hepatic Nuclear Inclusion Bodies

1973 ◽  
Vol 31 ◽  
pp. 426-427
Author(s):  
F. G. Zaki ◽  
J. A. Greenlee ◽  
C. H. Keysser
Keyword(s):  
Inclusion Bodies ◽  
Storage Disease ◽  
Glycogen Storage ◽  
Nutritional Deficiencies ◽  
Nuclear Inclusion ◽  
Electron Microscopic ◽  
Human Liver Cells ◽  
Microscopic Studies ◽  
Per Se ◽  
Experimental Liver

Nuclear inclusion bodies seen in human liver cells may appear in light microscopy as deposits of fat or glycogen resulting from various diseases such as diabetes, hepatitis, cholestasis or glycogen storage disease. These deposits have been also encountered in experimental liver injury and in our animals subjected to nutritional deficiencies, drug intoxication and hepatocarcinogens. Sometimes these deposits fail to demonstrate the presence of fat or glycogen and show PAS negative reaction. Such deposits are considered as viral products.Electron microscopic studies of these nuclei revealed that such inclusion bodies were not products of the nucleus per se but were mere segments of endoplasmic reticulum trapped inside invaginating nuclei (Fig. 1-3).

Novel methods for demonstrating osseointegration of hydroxylapatite-coated titanium hip prostheses

1991 ◽  
Vol 49 ◽  
pp. 34-35 ◽  
Author(s):  
P. Frayssinet ◽  
J. Hanker ◽  
D. Hardy ◽  
B. Giammara
Keyword(s):  
Hip Prosthesis ◽  
Ethanol Concentration ◽  
Bone Matrix ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Hip Prostheses ◽  
Cellular Inclusions ◽  
Microscopic Studies ◽  
Diamond Saw ◽  
Plasma Sprayed

Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed methods allowing light and electron microscopic studies as well as microanalysis of the interface between bone and a metal biomaterial coated by plasma-sprayed hydroxylapatite(HA) ceramic.An HA-coated titanium hip prosthesis (Corail, Landos, France), which had been implanted for two years, was removed after death (unrelated to the orthopaedic problem). After fixation it was dehydrated in solutions of increasing ethanol concentration prior to embedment in polymethylmethacrylate(PMMA). Transverse femur sections were obtained with a diamond saw and the sections then carefully ground to a thickness of 200 microns. Plastic-embedded sections were stained for calcium with a silver methenamine modification of the von Kossa method for calcium staining and coated by carbon. They have been examined by back-scatter SEM on an ISI-SS60 operated at 25 KV. EDAX has been done on cellular inclusions and extracellular bone matrix.

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