Cryo-electron microscopic studies of relaxed striated muscle thick filaments

1990 ◽  
Vol 11 (1) ◽  
pp. 1-11 ◽  
Author(s):  
J. F. Menetret ◽  
R. R. Schröder ◽  
W. Hofmann
Keyword(s):  
Striated Muscle ◽  
Electron Microscopic ◽  
Thick Filaments ◽  
Microscopic Studies

scholarly journals THE RELATIONSHIP BETWEEN MYOFILAMENT PACKING DENSITY AND SARCOMERE LENGTH IN FROG STRIATED MUSCLE

1967 ◽  
Vol 33 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Philip W. Brandt ◽  
Enrique Lopez ◽  
John P. Reuben ◽  
Harry Grundfest
Keyword(s):  
Cross Sections ◽  
Packing Density ◽  
Sarcomere Length ◽  
Striated Muscle ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Semitendinosus Muscle ◽  
Direct Function ◽  
Microscopic Studies

In cross-sections of single fibers from the frog semitendinosus muscle the number of thick myofilaments per unit area (packing density) is a direct function of the sarcomere length. Our data, derived from electron microscopic studies, fit well with other data derived from in vivo, low-angle X-ray diffraction studies of whole semitendinosus muscles. The data are consistent with the assumption that the sarcomere of a fibril maintains a constant volume during changes in sarcomere length. The myofilament lattice, therefore, expands as the sarcomere shortens. Since the distance between adjacent myofilaments is an inverse square root function of sarcomere length, the interaction of the thick and the thin myofilaments during sarcomere shortening may occur over distances which increase 70 A or more. The "expanding-sarcomere, sliding-filament" model of sarcomere shortening is discussed in terms of the current concepts of muscle architecture and contraction.

scholarly journals ELECTRON MICROSCOPIC STUDIES ON THE INDIRECT FLIGHT MUSCLES OF DROSOPHILA MELANOGASTER

1963 ◽  
Vol 17 (2) ◽  
pp. 351-362 ◽  
Author(s):  
S. Ahmad Shafiq
Keyword(s):  
Drosophila Melanogaster ◽  
Epidermal Cells ◽  
Uniform Density ◽  
Electron Microscopic ◽  
Thick Filaments ◽  
Irregular Pattern ◽  
Regular Arrangement ◽  
Microscopic Studies ◽  
Hexagonal Arrangement ◽  
Flight Muscles

The myofibrils in Drosophila have thick and thin types of myofilaments arranged in the hexagonal pattern described for Calliphora by Huxley and Hanson (15). The thick filaments, along most of their length in the A band, seem to be binary in structure, consisting of a dense cortex and a lighter medulla. In the H zone, however, they show more uniform density; lateral projections (bridges) also appear to be absent in this region. The M band has a varying number of granules (probably of glycogen) distributed between the myofilaments. The myofilaments on reaching the Z region appear to change their hexagonal arrangement and become connected to one another by Z filaments. The regular arrangement of the filaments found in most regions of the fibrils is not seen in the terminal sarcomeres of some flight muscles; the two types of filaments appear to be intermingled in an irregular pattern in these parts of the fibrils. The attachment of myofibrils to the cuticle through the epidermal cells is described.

A HISTOCHEMICAL AND ELECTRON MICROSCOPIC STUDY OF SKELETAL MUSCLE IN A CASE OF POMPE'S DISEASE (GLYCOGENOSIS II)

PEDIATRICS ◽  
1966 ◽  
Vol 37 (2) ◽  
pp. 249-259
Author(s):  
Robert Darrell Cardiff
Keyword(s):  
Skeletal Muscle ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Striated Muscle ◽  
Electron Microscopic ◽  
Pompe’S Disease ◽  
Pompe's Disease ◽  
Microscopic Studies ◽  
Alpha Glucosidase ◽  
Glycogenosis Ii

1. A case of Pompe's disease (glycogenosis II) without biochemically or histochemically demonstrable alpha-glucosidase activity is described. 2. Histochemical studies of skeletal muscle suggested that the glycogen is frequently stored as an acid mucopolysaccharide. 3. Electron microscopic studies revealed that the major glycogen deposits in most tissue were within membrane-limited sacs. Striated muscle was an exception because major deposits were frequently extrasaccular. 4. The findings in this case are discussed in relation to current concepts of Pompe's disease. In view of the extrasaccular glycogen deposits in skeletal muscle, it is suggested that an extralysosomal factor plays a significant role in the pathogenesis of Pompe's disease.

scholarly journals THE FINE STRUCTURE OF STRIATED MUSCLE

1956 ◽  
Vol 2 (4) ◽  
pp. 131-142 ◽  
Author(s):  
A. J. Hodge
Keyword(s):  
Skeletal Muscle ◽  
Phase Contrast ◽  
Striated Muscle ◽  
General Structure ◽  
Electron Microscopic ◽  
Strong Contraction ◽  
Other Substances ◽  
Microscopic Studies ◽  
Insect Skeletal Muscle ◽  
Band Material

The available evidence from phase contrast, polarization optical, and electron microscopic studies on vertebrate skeletal muscle, insect skeletal muscle, and dipteran flight muscle is interpreted as favoring the following general structure of striated muscle. A continuous array of filaments (actin) runs through all bands of the sarcomere. These are linked by an axially periodic system of transverse filamentous bridges. Myosin (and probably other substances) are localized in the A bands. The system of transverse bridges compensates the birefringence of actin and is thus responsible for the isotropy of the I band. Myosin is responsible for the birefringence of the A bands. On strong contraction, A band material migrates to the Z bands to form contraction bands. It is not yet certain whether this migration involves myosin or another A band component.

Striated Muscle in the Intestine of Shrimp

1988 ◽  
Vol 46 ◽  
pp. 266-267
Author(s):  
K. C. Liu ◽  
S. F. Tsay ◽  
Y. L. Yu
Keyword(s):  
Striated Muscle ◽  
Penaeus Monodon ◽  
Grass Shrimp ◽  
Circular Muscle ◽  
Electron Microscopic Observation ◽  
Muscularis Mucosa ◽  
Structural Element ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Similar Report

The shrimp, Penaeus monodon, commonly known as grass shrimp by local people. It has been cultured in large quantity and became one of the important aqua- cultural species in recent years. The morphology and histology of penaeid shrimps has been studied by many researchers (1). In our pathological study of the structural aspects of the digestive system, striated muscle was found in the area equivalent to the muscularis mucosa of tunica mucosa and tun.ica muscularis of vertebrates where smooth muscle is the basic structural element. This information is new to us , and to the best of our knowledge, there is no similar report among other Crustacea (2). This report is to present some of our evidence.Shrimps, Penaeus monodon, 50 g. in average body weight, were bought live from the market. Their intestines were disssected out and processed for both light electron microscopic studies. For electron microscopic observation a JEOL 100 CX electron microscope was used at 60 KV. attention was primarily concentrated on the circular muscle of the muscularis mucosa region.

The location of chloride in single striated muscle fibers of the giant barnacle

1968 ◽  
Vol 46 (2) ◽  
pp. 213-219 ◽  
Author(s):  
D. C. Gayton ◽  
J. A. M. Hinke
Keyword(s):  
Membrane Potential ◽  
Striated Muscle ◽  
Total Concentration ◽  
Large Fraction ◽  
Muscle Fibers ◽  
Large Drop ◽  
Fiber Volume ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Striated Muscle Fibers

Chloride-sensitive Ag–AgCl microelectrodes were inserted into single striated muscle fibers of the giant barnacle, Balanus nubilus, to measure the activity of Cl− in the myoplasm, (aCl)i. Chemical analysis was also carried out to determine the total concentration of Cl− in the fiber, [Cl]i. In two sets of experiments, (aCl)i was 28.8 and 22.4 mM while [Cl]i was 75.1 and 66.8 mmoles/kg fiber water respectively. The transmembrane Cl− potential, calculated from the aCl measurements in the myoplasm and the bath, was slightly less than the membrane potential. To locate the large fraction of fiber Cl− that is not free in the myoplasm, Cl− washout studies were done in constant [K]o[Cl]o product Ringer solutions in which [Cl]o was reduced to 50% and 25% of the normal concentration. Fibers which were soaked in these solutions for 30 min showed no change in (aCl)i but a large drop in [Cl]i. From the extent of this drop, it was calculated that these muscle fibers have an extracellular space of about 5% of fiber volume. Electron microscopic studies indicate that this space is comprised of large clefts and smaller tubules which penetrate deeply into the fiber.

scholarly journals Assembly of different isoforms of actin and tropomyosin into the skeletal tropomyosin-enriched microfilaments during differentiation of muscle cells in vitro.

1986 ◽  
Vol 103 (6) ◽  
pp. 2173-2183 ◽  
Author(s):  
J J Lin ◽  
J L Lin
Keyword(s):  
Monoclonal Antibody ◽  
Striated Muscle ◽  
Chicken Embryo Fibroblast ◽  
Muscle Cells ◽  
Electron Microscopic ◽  
Thin Filaments ◽  
Microscopic Studies ◽  
The One ◽  
Muscle Isoforms

We have used a monoclonal antibody (CL2) directed against striated muscle isoforms of tropomyosin to selectively isolate a class of microfilaments (skeletal tropomyosin-enriched microfilaments) from differentiating muscle cells. This class of microfilaments differed from the one (tropomyosin-enriched microfilaments) isolated from the same cells by a monoclonal antibody (LCK16) recognizing all isoforms of muscle and nonmuscle tropomyosin. In myoblasts, the skeletal tropomyosin-enriched microfilaments had a higher content of alpha-actin and phosphorylated isoforms of tropomyosin as compared with the tropomyosin-enriched microfilaments. Moreover, besides muscle isoforms of actin and tropomyosin, significant amounts of nonmuscle isoforms of actin and tropomyosin were found in the skeletal tropomyosin-enriched microfilaments of myoblasts and myotubes. These results suggest that different isoforms of actin and tropomyosin can assemble into the same set of microfilaments, presumably pre-existing microfilaments, to form the skeletal tropomyosin-enriched microfilaments, which will eventually become the thin filaments of myofibrils. Therefore, the skeletal tropomyosin-enriched microfilaments detected here may represent an intermediate class of microfilaments formed during thin filament maturation. Electron microscopic studies of the isolated microfilaments from myoblasts and myotubes showed periodic localization of tropomyosin molecules along the microfilaments. The tropomyosin periodicity in the microfilaments of myoblasts and myotubes was 35 and 37 nm, respectively, whereas the nonmuscle tropomyosin along chicken embryo fibroblast microfilaments had a 34-nm repeat.

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.

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.

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