Observations on the fine structure of Oedogonium. VI. The striated component of the compound flagellar "roots" of O. cardiacum

1970 ◽  
Vol 48 (1) ◽  
pp. 189-196 ◽  
Author(s):  
Larry R. Hoffman
Keyword(s):  
Contractile Function ◽  
Flagellar Apparatus ◽  
Flagellar Roots ◽  
Diploid Female ◽  
Haploid Male ◽  
Outer Component ◽  
Cross Striation ◽  
Striated Root ◽  
Male Strain ◽  
Female Strain

The striated, inner component of the compound flagellar "roots" of zoospores and spermatozoids of Oedogonium cardiacum has been studied ultrastructurally after three methods of preparation. The roots constitute an element of the ring-shaped flagellar apparatus, with the roots and basal bodies alternating in equal numbers. Each root consists of two components radially superposed; the outer component is ribbon-like and formed of three parallel microtubular elements, while the inner component is rod-like (tapering at each extremity) and demonstrates a very regular pattern of cross-striation. Although the striated pattern in sectioned roots differed somewhat from the pattern obtained with negatively stained roots, the major periodicity in both instances averaged about 305–325 Å. This contrasts to a periodicity of 150 Å which was reported earlier. The pattern of cross-striation appears the same for roots of both spermatozoids and zoospores when any one method of preparing the material is considered separately. Furthermore, no distinctions were observed in zoospore roots obtained from a haploid male strain, a haploid female strain, and a diploid female strain. The striated root component of Oedogonium may provide mechanical support for the flagellar apparatus, thereby serving as a means for distributing throughout the motile cell the stresses generated by flagellar action. A possible contractile function cannot be excluded.

scholarly journals The centrin-based cytoskeleton of Chlamydomonas reinhardtii: distribution in interphase and mitotic cells.

1988 ◽  
Vol 107 (2) ◽  
pp. 635-641 ◽  
Author(s):  
J L Salisbury ◽  
A T Baron ◽  
M A Sanders
Keyword(s):  
Nuclear Envelope ◽  
Polyclonal Antibodies ◽  
Flagellar Apparatus ◽  
Immunogold Labeling ◽  
Basal Bodies ◽  
Flagellar Roots ◽  
Cell Biol ◽  
Immunofluorescence Studies ◽  
Descending Fibers

Monoclonal and polyclonal antibodies raised against algal centrin, a protein of algal striated flagellar roots, were used to characterize the occurrence and distribution of this protein in interphase and mitotic Chlamydomonas cells. Chlamydomonas centrin, as identified by Western immunoblot procedures, is a low molecular (20,000-Mr) acidic protein. Immunofluorescence and immunogold labeling demonstrates that centrin is a component of the distal fiber. In addition, centrin-based flagellar roots link the flagellar apparatus to the nucleus. Two major descending fibers extend from the basal bodies toward the nucleus; each descending fiber branches several times giving rise to 8-16 fimbria which surround and embrace the nucleus. Immunogold labeling indicates that these fimbria are juxtaposed to the outer nuclear envelope. Earlier studies have demonstrated that the centrin-based linkage between the flagellar apparatus and the nucleus is contractile, both in vitro and in living Chlamydomonas cells (Wright, R. L., J. Salisbury, and J. Jarvik. 1985. J. Cell Biol. 101:1903-1912; Salisbury, J. L., M. A. Sanders, and L. Harpst. 1987. J. Cell Biol. 105:1799-1805). Immunofluorescence studies show dramatic changes in distribution of the centrin-based system during mitosis that include a transient contraction at preprophase; division, separation, and re-extension during prophase; and a second transient contraction at the metaphase/anaphase boundary. These observations suggest a fundamental role for centrin in motile events during mitosis.

scholarly journals Interrelationships between microtubules, a striated fiber, and the gametic mating structure of Chlamydomonas reinhardi.

1978 ◽  
Vol 76 (2) ◽  
pp. 430-438 ◽  
Author(s):  
U W Goodenough ◽  
R L Weiss
Keyword(s):  
Flagellar Apparatus ◽  
Flagellar Roots ◽  
Mating Structure ◽  
Striated Fiber

The microtubule system associated with the Chlamydomonas reinhardi flagellar apparatus is shown to differ from previous descriptions; two of the four flagellar "roots" possess only two microtubules and are associated with a finely striated fiber. In gametic cells this fiber underlies the gametic mating structure and makes contact with it. Functional interpretations are offered.

scholarly journals Genetic effects of acridines onPseudomonas aeruginosa

1969 ◽  
Vol 13 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Vilma Stanisich ◽  
B. W. Holloway
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Vegetative Cell ◽  
Normal Growth ◽  
Fold Increase ◽  
Chromosome Transfer ◽  
Recombinant Formation ◽  
Derivatives Of ◽  
Male Strain ◽  
Female Strain

Mutants ofPseudomonas aeruginosamale strains with altered mating properties have been obtained through treatment with nitrogen half mustards. The response varied with the type of male strain. A mutant of the infectious male PTO 13 was obtained which acts as a female strain and has apparently lost the FP sex factor. A mutant of the non-infectious strain 2 male mates not only with strain 1 females, but shows a thousand-fold increase in its ability to mate with strain 2 males, when it can act as either donor or recipient in conjugation. Derivatives of strain 1 males were obtained which had reduced recombinant forming ability.While acriflavine is ineffective in producing such mutants, and has not been shown to cure male strains of their sex factor inP. aeruginosa, it is very effective in inhibiting infectious transfer of FP from FP+to FP−strains. Furthermore, it markedly inhibits recombinant formation in 1 FP−× 1 FP+crosses, and this latter effect is thought to be due to the inhibition of chromosome transfer by the male parent. In view of the almost complete lack of effect of AF on the normal growth ofP. aeruginosait is likely that the control of chromosome replication during vegetative cell division is different from the occurring during conjugation and that the FP factor is involved in this control during conjugation.

scholarly journals Flagellar root contraction and nuclear movement during flagellar regeneration in Chlamydomonas reinhardtii.

1987 ◽  
Vol 105 (4) ◽  
pp. 1799-1805 ◽  
Author(s):  
J L Salisbury ◽  
M A Sanders ◽  
L Harpst
Keyword(s):  
Flagellar Apparatus ◽  
Central Position ◽  
Free Calcium ◽  
Cell Models ◽  
Nuclear Movement ◽  
Flagellar Roots ◽  
Flagellar Regeneration ◽  
Basal Apparatus ◽  
Ph Shock ◽  
Root Contraction

When Chlamydomonas cells are deflagellated by pH shock or mechanical shear the nucleus rapidly moves toward the flagellar basal apparatus at the anterior end of the cell. During flagellar regeneration the nucleus returns to a more central position within the cell. The nucleus is connected to the flagellar apparatus by a system of fibers, the flagellar roots (rhizoplasts), which undergo a dramatic contraction that coincides with anterior nuclear movement. A corresponding extension of the root system, back to its preshock configuration is observed as the nucleus retracts to a central position. Anterior displacement of the nucleus and flagellar root contraction require free calcium in the medium. Nuclear movement and flagellar root contraction and extension are not sensitive to inhibitors of protein synthesis (cycloheximide), or drugs that influence either microtubules (colchicine) or actin-based microfilaments (cytochalasin D). Detergent-extracted cell models contract and extend their flagellar roots and move their nuclei in response to alterations of free calcium levels in the medium. Cycles of nuclear movement in detergent-extracted models require ATP to potentiate the contractile mechanism for subsequent calcium-induced contraction. Flagellar root contraction and nuclear movement in Chlamydomonas may be causally related to signaling of induction of flagellar precursor genes or to the transport of flagellar precursors or their messages to sites of synthesis or assembly near the basal apparatus of the cell.

Mitochondrial Changes in Choline-Deficient Rat Myocardium

1968 ◽  
Vol 26 ◽  
pp. 112-113
Author(s):  
F. G. Zaki
Keyword(s):  
Muscle Fibers ◽  
Liver Mitochondria ◽  
Ultrastructural Changes ◽  
Choline Deficiency ◽  
Nutritional Disorder ◽  
Low Protein ◽  
Structural Abnormalities ◽  
Cross Striation ◽  
Pericardial Edema ◽  
Myocardial Lesions

Choline-deficiency was induced in Holtzman young rats of both sexes by feeding them a high fat - low protein diet.Preliminary studies of the ultrastructural changes in the myocardium of these animals have been recently reported from this laboratory. Myocardial lesions first appeared in the form of intraventricular mural thrombi, loss of cross striation of muscle fibers and focal necrosis of muscle cells associated with interstitial myocarditis. Prolonged choline-deficiency induced cardiomegaly associated with pericardial edema.During the early phase of this nutritional disorder, heart mitochondria - despite of not showing any swelling similar to that usually encountered in liver mitochondria of the same animal - ware the most ubiquitous site of marked structural abnormalities. Early changes in mitochondria appeared as vacuolation, disorganization, disruption and loss of cristae. Degenerating mitochondria were often seen quite enlarged and their matrix was replaced by whorls of myelin figures resembling lysosomal structures especially where muscle fibers were undergoing necrosis. In some areas, mitochondria appeared to be unusually clumped together where some contained membranelined vacuoles and others enclosed dense bodies and granular inclusions.

Assessment of Myocardial Viability in Persistent Defects on Thallium-201 SPECT after Reinjection Using Gradient-Echo MRI

1996 ◽  
Vol 35 (05) ◽  
pp. 146-152 ◽  
Author(s):  
A. Kögler ◽  
H.-A. Schmitt ◽  
D. Emrich ◽  
H. Kreuzer ◽  
D. L. Munz ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Myocardial Viability ◽  
Cardiac Cycle ◽  
Single Photon ◽  
Contractile Function ◽  
Left Ventricular ◽  
Wall Thickening ◽  
Gradient Echo ◽  
Systolic Wall Thickening

SummaryThis prospective study assessed myocardial viability in 30 patients with coronary heart disease and persistent defects despite reinjection on TI-201 single-photon computed tomography (SPECT). In each patient, three observers graded TI-201 uptake in 7 left ventricular wall segments. Gradient-echo magnetic resonance imaging in the region of the persistent defect generated 12 to 16 short axis views representing a cardiac cycle. A total of 120 segments were analyzed. Mean end-diastolic wall thickness and systolic wall thickening (± SD) was 11.5 ± 2.7 mm and 5.8 ± 3.9 mm in 48 segments with normal TI-201 uptake, 10.1 ± 3.4 mm and 3.7 ± 3.1 mm in 31 with reversible lesions, 11.3 ± 2.8 mm and 3.3 ± 1.9 mm in 10 with mild persistent defects, 9.2 ± 2.9 mm and 3.2 ±2.2 mm in 15 with moderate persistent defects, 5.8 ± 1.7 mm and 1.3 ± 1.4 mm in 16 with severe persistent defects, respectively. Significant differences in mean end-diastolic wall thickness (p <0.0005) and systolic wall thickening (p <0.005) were found only between segments with severe persistent defects and all other groups, but not among the other groups. On follow-up in 11 patients after revascularization, 6 segments with mild-to-moderate persistent defects showed improvement in mean systolic wall thickening that was not seen in 6 other segments with severe persistent defects. These data indicate that most myocardial segments with mild and moderate persistent TI-201 defects after reinjection still contain viable tissue. Segments with severe persistent defects, however, represent predominantly nonviable myocardium without contractile function.

Nerve-sparing radical hysterectomy in patients with infiltrative cervical cancer

2016 ◽  
pp. 46-51
Author(s):  
T. Dermenzhy ◽  
◽  
V. Svintitskiy ◽  
S. Nespryadko ◽  
L. Legerda ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Radical Hysterectomy ◽  
Contractile Function ◽  
Major Elements ◽  
Control Group ◽  
Nerve Sparing ◽  
Group I ◽  
Hypogastric Plexus ◽  
Prognostic Indexes

The objective: to improve an effectiveness of therapy and quality of life of patients with infiltrative cervical cancer using radical hysterectomy accomplished with nerve-sparing methodology. Patients and Methods: Ninety patients with histologically verified infiltrative cervical cancer were cured with radical hysterectomy (RHE) in the Department of Oncogynecology of National Cancer Institute (Kyiv, Ukraine) in 2012-2016. The age of the patients was from 26 to 65 years (an average age of 42.61±1.06). The patients were distributed in 2 groups: group I treated with nerve-sparing radical hysterectomy (NSRHE), 45 patients, the main group; group II treated with radical hysterectomy (RHE III), the control group, 45 patients. The prognostic indexes in the groups were similar. Results. NSRHE that included the dissection of cardinal ligament, separation of dorsal and anterior layers of uterovesical ligament allowed separate uterine branch of inferior hypogastric plexus, preserve an innervation of urinary bladder and prevent the malfunction of its contractile function at postoperative period. Conclusion. The data of the urodynamic study using cystomanometry performed at pre- and early operative periods have shown that surgical treatment of patients with infiltrative cervical cancer with preservation of the major elements of pelvic autonomic plexuses allows significantly decrease the rate of postoperative urogenical malfunctions. Key words: nerve-sparing radical hysterectomy, cervical cancer, cystomanometry.

Justification of technical parameters of an ultrasonic device for improvement of meat salting efficiency

2020 ◽  
pp. 75-77
Author(s):  
Ekaterina Sergeevna Krasnikova ◽  
Natalya Lvovna Morgunova ◽  
Phelix Yakovlevich Rudik ◽  
Aleksandr Vladimirovich Krasnikov ◽  
Nikita Andreevich Semilet
Keyword(s):  
Technological Process ◽  
Muscle Tissue ◽  
Muscle Fibers ◽  
Tissue Structure ◽  
Tissue Microstructure ◽  
Technical Parameters ◽  
Ultrasonic Device ◽  
Lamb Meat ◽  
Local Destruction ◽  
Cross Striation

The results of a study of the effect of wet ultrasonic lamb meat salting on the muscle tissue microstructure are presented, and the technical parameters of the ultrasonic device are justified. It has been established that significant destruction and swelling of muscle fibers, local destruction of the sarcolemma with its pronounced rugosity are observed at ultrasonic salting with a frequency of 35 kHz, the cross-striation is poorly expressed, the tissue structure is disturbed. An ultrasonic salting with a frequency of 26 kHz was accompanied an increase in the number of transverse microcracks and crevices, loosening of muscle fibers, the formation of cavities between them while retention of the tissue structure, which contributes to the appearance of a brine between muscle fibers and accelerates its penetration into the fiber. It allows us to recommend ultrasound at a frequency of 26 kHz for cavitation activation of the brine to intensify the technological process of lamb meat salting.

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