scholarly journals Fine structure ot the protonema in the moss Ceratodon purpureus and its response to a cytokinin

2015 ◽  
Vol 47 (1–2) ◽  
pp. 143-152
Author(s):  
Krystyna Idzikowska ◽  
Alicja Szweykowska
Keyword(s):  
Fine Structure ◽  
Metabolic Activity ◽  
Structural Changes ◽  
Ceratodon Purpureus ◽  
Apical Cells ◽  
Cytokinin Treatment

Fine structure of the protonema is described, with a special attention to its differentiation depending on the position of cells in the protanemal filament, as well as in response to a cytokinin treatment. Complexes of micro-filaments with osmiophilic globules represented structures of particular interest. They appeared temporarily, almost exclusively in apical cells. The cytokinin treatment resulted in the apical cells in an increased number of cytokinetic figures and in structural changes indicating increased metabolic activity. In the intercalary cells, changes in response to the cytokinin were much smaller and mostly concerned an augmented development of the thylakoid system in chloroplasts. After a prolonged (5 days) treatment, degeneration symptoms developed in all cells, particularly in nuclei and chloroplasts, whereas the structure of mitochondria was relatively stable. The results are compared with the observations concerning the cytokinin-induced gametophore buds and with the data of biochemical and physiological investigations of the protonema.

Fibroblasts During Hypertrophic Scar Formation and Resolution

1973 ◽  
Vol 31 ◽  
pp. 428-429
Author(s):  
C. W. Kischer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Proliferation ◽  
Fine Structure ◽  
Metabolic Activity ◽  
Hypertrophic Scar ◽  
Normal Skin ◽  
Ground Substance ◽  
Hypertrophic Scars ◽  
Scanning Electron

The morphology of the fibroblasts changes markedly as the healing period from burn wounds progresses, through development of the hypertrophic scar, to resolution of the scar by a self-limiting process of maturation or therapeutic resolution. In addition, hypertrophic scars contain an increased cell proliferation largely made up of fibroblasts. This tremendous population of fibroblasts seems congruous with the abundance of collagen and ground substance. The fine structure of these cells should reflect some aspects of the metabolic activity necessary for production of the scar, and might presage the stage of maturation.A comparison of the fine structure of the fibroblasts from normal skin, different scar types, and granulation tissue has been made by transmission (TEM) and scanning electron microscopy (SEM).

scholarly journals FINE STRUCTURAL CHANGES IN PROPLASTIDS DURING PHOTODESTRUCTION OF PIGMENTS

1964 ◽  
Vol 22 (2) ◽  
pp. 443-451 ◽  
Author(s):  
Shimon Klein ◽  
Lawrence Bogorad
Keyword(s):  
Fine Structure ◽  
Levulinic Acid ◽  
Structural Changes ◽  
Prolamellar Body ◽  
Membrane Structures ◽  
Lamellar Structures ◽  
Amino Levulinic Acid ◽  
Stroma Lamellae ◽  
Green Pigments ◽  
Bean Leaves

Etiolated bean leaves supplied δ-amino-levulinic acid in the dark synthesize large amounts of protochlorophyllide which is not converted to chlorophyllide upon illumination of the leaves. The fine structure of the proplastids is not affected by the treatment. When leaves containing "inactive" protochlorophyllide are exposed to light of 700 ft-c for 3 hours, they lose practically all their green pigments. During this period large stacks of closed membrane structures are built up in the region of the prolamellar body. These lamellar structures remain even when no or only traces of pigment are left in the leaves. In untreated control leaves the pigment content remained constant during similar illumination and the structural changes in the plastids consisted of a rearrangement of the vesicles from the prolamellar bodies into strands dispersed through the stroma; lamellae and grana formation occurred later.

Conversaziones 1974

1975 ◽  
Vol 29 (2) ◽  
pp. 163-171
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cell Walls ◽  
Structural Changes ◽  
Vascular Tissue ◽  
Root Systems ◽  
Plant Roots ◽  
Tracer Studies ◽  
Water Move ◽  
Intact Root

CONVERSAZIONES were held this year on 9 May and 27 June. At the first conversazione twenty-seven exhibits and two films were shown. The fine structure of plant roots in relation to transport of nutrient ions and water was demonstrated by Dr D. T. Clarkson of the A.R.C. Letcombe Laboratory, Wantage and Dr A. W. Robards of the Department of Biology, University of York. Two major pathways by which nutrients and water move radially across the cortex towards the central vascular tissue have been distinguished by the use of tracer studies of adsorption by different zones of intact root systems, microautoradiography and electron microscopy. Movement can be apoplastic through cell walls, or symplastic between cells joined by plasmodesmata. As the root ages, structural changes in the endodermis reduce movement in the former pathway but the symplast is not interrupted by the elaboration of endodermal walls because plasmodesmatal connexions remain intact. These observations help explain the contrasting extent to which different ions and water reach the shoot from young and mature parts of root systems.

Abstract P043: Correlation Between Blood Pressure And Left Ventricular Metabolism In HIV Individuals With And Without Cocaine Use As Assessed By FDG-PET/CT

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Abhijit Bhattaru ◽  
Rina Ghorpade ◽  
Chaitanya Rojulpote ◽  
Paco E Bravo ◽  
Shivaraj Patil ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Metabolic Activity ◽  
Fdg Pet ◽  
Structural Changes ◽  
Left Ventricular ◽  
Myocardial Uptake ◽  
Hiv Patients ◽  
Cocaine Use ◽  
Pet Ct ◽  
Fdg Pet Ct

Objectives: Elevated blood pressure from cocaine can increase left ventricular (LV) metabolic activity, leading to structural changes such as hypertrophy. We aimed to assess the association between blood pressure and LV myocardial uptake of FDG, hypothesizing that HIV individuals with raised blood pressure will have higher FDG uptake. Methods: University of Pennsylvania enrolled patients with HIV on antiretroviral therapy with viral load <200 copy/ml. Cocaine usage in moderate to high amounts (cocaine disease score≥5) was subsequently documented. Full body PET scans were acquired 120 minutes post-injection of 18F-FDG(15 mCi) with low-dose CT scans for attenuation correction. Patients with imaging artifacts were excluded from the analysis. Regions of interest were drawn on axial slices using computer software (OsirixMD, v9.0.02) around LV myocardium. Average standard uptake value means (aSUVmean) were calculated for each patient. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were obtained prior to imaging; mean arterial pressure (MAP) was subsequently calculated. Linear regressions and Mann-Whitney U tests were employed for statistical analysis. Results: aSUVmean was higher in HIV patients with cocaine use (U(Ncocaine = 11, Nno cocaine=11) = 93, p=0.0336). In patients with cocaine use, there was a positive correlation between blood pressure and aSUVmean (SBP: r=0.70, p=0.0164; DBP: r=0.69, p=0.0185; MAP: r=0.72, p=0.0120). No significant correlations were found in HIV patients without cocaine use (SBP: r=0.03, p=0.9239; DBP: r=-0.50, p=0.1153; MAP: r=-0.32, p=0.3345). Conclusions: LV myocardial metabolism was more strongly positively correlated with blood pressure in HIV patients using cocaine compared to HIV patients without cocaine. These data suggest FDG-PET/CT can be used to monitor LV metabolic activity and allow for timely assessment of structural changes caused by cocaine use and hypertension.

Temperature Effects on Formation and Fine Structure of Brassica napus Leaf Waxes

1976 ◽  
Vol 24 (3) ◽  
pp. 309 ◽  
Author(s):  
DJ Armstrong ◽  
MI Whitecross
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Brassica Napus ◽  
Growth Temperature ◽  
Temperature Effects ◽  
Structural Changes ◽  
Leaf Waxes ◽  
Surface Waxes ◽  
Biochemical Level

Incorporation of 1-14C-palmitic acid, a precursor of leaf waxes, into leaf strips of Brassica napus was examined by thin section autoradiography and electron microscopy. Label was found to be associated with mitochrondria, Golgi vesicles and endoplasmic reticulum of epidermal cells, and also with the outer epidermal wall across which cuticular lipids are expected to migrate. Variations in growth temperatures produced structural changes in surface waxes as previously reported but no specific correlation could be found between changes in surface fine structure and variations in subcellular morphology. It is concluded that variations in wax fine structure, as influenced by growth temperature, resulted from effects at the biochemical level.

scholarly journals THE ULTRASTRUCTURE OF THE VITELLINE BODY IN THE OOCYTE OF THE SPIDER TEGENARIA PARIETINA

1957 ◽  
Vol 3 (6) ◽  
pp. 977-984 ◽  
Author(s):  
Jean André ◽  
Charles Rouiller
Keyword(s):  
Fine Structure ◽  
Metabolic Activity ◽  
Central Zone ◽  
Mature Oocyte ◽  
Gradual Transition ◽  
Retinal Rods ◽  
Regular Arrangement

The vitelline body in the mature oocyte of the spider Tegenaria parietina is composed of 4 different zones. 1. The central zone contains granular areas, vesicles, and a few lamellae. 2. The lamellar zone consists of numerous concentric lamellae. These sheets, 45 A in thickness, are stacked in groups. The fine structure and the regular arrangement recall those of myelin sheets, retinal rods, and chloroplasts. Between the stacks of lamellae, finely granular masses and various vesicles are to be found. 3. The "zone of transition" consists of a finely granular substance accumulated in abundant masses. This substance is composed of very closely packed granules about 50 to 60 A in diameter. Very often, near the lamellae, the granules show alignment giving a gradual transition from grains to lamellae. 4. The vesicular zone contains ergastoplasm, dense particles, mitochondria, and Golgi material. It is suggested that the peculiar ultrastructure of these cytoplasmic components may be related to an intense metabolic activity.

The Effect of Light and Darkness on the Fine Structure of the Retinal Clubs of Dendrocoelum Lacteum

1962 ◽  
Vol s3-103 (64) ◽  
pp. 543-548
Author(s):  
P. RÖHLICH ◽  
L. J. TÖRÖK
Keyword(s):  
Fine Structure ◽  
Structural Changes ◽  
Marginal Zone ◽  
Original Structure ◽  
Photosensitive Substance ◽  
Effect Of Light

The number and size of the vacuoles in the retinal clubs of the eye of Dendrocoelum lacteum increase considerably in animals kept in darkness. As a consequence, the volume of the whole retinal club enlarges, the microvilli forming its marginal zone becoming shorter and thicker. When exposed to light, the retinal clubs regain their original structure; the number and size of the vacuoles diminish and the zone of the microvilli widens. These structural changes are interpreted as due to a photosensitive substance which is produced in the axial cytoplasm of the club, stored in vacuoles and disintegrated by light in the zone of the microvilli.

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