Ultrastructural studies on plastids of generative and vegetative cells in Liliaceae

1986 ◽  
Vol 72 (6) ◽  
pp. 840-844 ◽  
Author(s):  
M. -B. Schröder
Keyword(s):  
Vegetative Cells ◽  
Ultrastructural Studies

Ultrastructure of Cercarial Tails

1974 ◽  
Vol 32 ◽  
pp. 180-181
Author(s):  
Richard S. Demaree ◽  
Donald M. Wootton
Keyword(s):  
Schistosoma Japonicum ◽  
Intermediate Hosts ◽  
Suitable Host ◽  
Ultrastructural Studies ◽  
Tail Structure

Cercariae (juvenile trematodes with tails) emerge from mollusk intermediate hosts and swim toward definitive hosts or encystment objects. The locomotor power is furnished by the tail. Upon reaching a suitable host or encystment object, the tail is cast off and the cercariae penetrate and/or encyst. Ultrastructural studies of cercariae are sparse. There is even lessUltrastructural studies of cercariae are sparse. There is even less information about the tail structure; and body-to-tail morphology has been documented only for Acanthatrium oregonense and Schistosoma japonicum.

Scanning and Transmission Electron Microscopy of Endomentrium in Women Wearing TCu-380-A IUD 's

1977 ◽  
Vol 35 ◽  
pp. 666-667
Author(s):  
A. Gonzalez Angulo ◽  
R. Berlioz ◽  
R. Aznar
Keyword(s):  
Copper Wire ◽  
Uterine Cavity ◽  
Morphological Evidence ◽  
Secretory Phase ◽  
Ultrastructural Studies ◽  
Proliferative Phase ◽  
Contraceptive Devices ◽  
Transmission Electron ◽  
Intrauterine Contraceptive ◽  
Myelin Figure

Recent ultrastructural studies on endometrial tissues from women wearing copper, wire intrauterine devices have disclosed morphological evidence of impaired glycogen degradation and secretion resulting in interference with the viability of blastocysts. Reduced microapocrine secretion observed with the scanning electron microscope supports this (1). In addition, organelle modifications have been observed in the epithelial cells of these women. The changes are seen in biopsies taken in the proliferative phase of the cycle and consist of mitochondrial vacuolation and myelin figure formation. These modifications disappear in the secretory phase and therefore have been regarded as reversible (2).The aim of the present studies was to investigate surface epithelial changes as well as organelle modifications in relation to the site of contact with an IUD that releases greater amounts of copper. Endometrial tissue was obtained from the uterine cavity of four young women wearing TCu-380-A intrauterine contraceptive devices for 4-6 weeks.

The Cellular Origin in Atheromatous Lesion

1970 ◽  
Vol 28 ◽  
pp. 202-203
Author(s):  
T. M. Murad ◽  
H. A. I. Newman ◽  
K. F. Kern
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Rabbit Aorta ◽  
Mixed Population ◽  
The Other ◽  
Cellular Origin ◽  
Ultrastructural Studies ◽  
Atherosclerotic Lesions ◽  
Show Evidence ◽  
Early Lesion

The origin of lipid containing cells in atheromatous lesion has been disputed. Geer in his study on atheromatous lesions of rabbit aorta, suggested that the early lesion is composed mainly of lipid-laden macrophages and the later lesion has a mixed population of macrophages and smooth muscle cells. Parker on the other hand, was able to show evidence that the rabbit lesion is primarily composed of lipid-laden cells of smooth muscle origin. The above studies and many others were done on an intact lesion without any attempt of cellular isolation previous to their ultrastructural studies. Cell isolation procedures have been established for atherosclerotic lesions through collagenase and elastase digestion Therefore this procedure can be utilized to identify the cells involved in rabbit atheroma.

Adrenocorticotropin Production by a Mammary Carcinoma

1977 ◽  
Vol 35 ◽  
pp. 462-463
Author(s):  
K.S. McCarty ◽  
N.R. Wallace ◽  
W. Litaker ◽  
S. Wells ◽  
G. Eisenbarth
Keyword(s):  
Adrenocorticotropic Hormone ◽  
Small Cell ◽  
Hormone Production ◽  
Carcinoma Of The Breast ◽  
Ectopic Acth ◽  
Ultrastructural Studies ◽  
Subcutaneous Metastases ◽  
Ectopic Acth Production ◽  
The Right ◽  
Pituitary Carcinomas

The production of adrenocorticotropic hormone by non-pituitary carcinomas has been documented in several tumors, most frequently small cell carcinoma of the lung, islet cell carcinomas of the pancreas, thymomas and carcinoids. Electron microscopy of these tumors reveals typical membrane-limited "neurosecretory" granules. Confirmation of the granules as adrenocorticotropin (ACTH) requires the use of OsO4 as a primary fixative to give the characteristic cored granule appearance in conjunction with immunohistochemical demonstration of the hormone peptide. Because of the rarity of ectopic ACTH production by mammary carcinomas and the absence of appropriate ultrastructural studies in the two examples of such ectopic hormone production in the literature of which we are aware (1,2), we present biochemical and ultrastructural data from a carcinoma of the breast with apparent ACTH production.The patient had her primary tumor in the right breast in 1969. The tumor recurred as visceral and subcutaneous metastases in 1976 and again in 1977.

Electron microscopy of endocardial cell populations

1978 ◽  
Vol 36 (2) ◽  
pp. 486-487
Author(s):  
T. G. Sarphie ◽  
C. R. Comer ◽  
D. J. Allen
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Cellular Transformation ◽  
Cell Populations ◽  
Cell Surfaces ◽  
Kb Cells ◽  
Dna Viruses ◽  
Cell Cycles ◽  
Ultrastructural Studies ◽  
Endocardial Cell

Previous ultrastructural studies have characterized surface morphology during norma cell cycles in an attempt to associate specific changes with specific metabolic processes occurring within the cell. It is now known that during the synthetic ("S") stage of the cycle, when DNA and other nuclear components are synthesized, a cel undergoes a doubling in volume that is accompanied by an increase in surface area whereby its plasma membrane is elaborated into a variety of processes originally referred to as microvilli. In addition, changes in the normal distribution of glycoproteins and polysaccharides derived from cell surfaces have been reported as depreciating after cellular transformation by RNA or DNA viruses and have been associated with the state of growth, irregardless of the rate of proliferation. More specifically, examination of the surface carbohydrate content of synchronous KB cells were shown to be markedly reduced as the cell population approached division Comparison of hamster kidney fibroblasts inhibited by vinblastin sulfate while in metaphase with those not in metaphase demonstrated an appreciable decrease in surface carbohydrate in the former.

Ultrastructural observations of human monocytes infected with HIV-1

1991 ◽  
Vol 49 ◽  
pp. 108-109
Author(s):  
James K. Koehler ◽  
Steven G. Reed ◽  
Joao S. Silva
Keyword(s):  
Gradient Centrifugation ◽  
Virus Production ◽  
Human Monocyte ◽  
Red Cross ◽  
Human Monocytes ◽  
Blood Monocytes ◽  
Hiv Replication ◽  
Electron Microscopic ◽  
Ultrastructural Studies ◽  
Hiv 1

As part of a larger study involving the co-infection of human monocyte cultures with HIV and protozoan parasites, electron microscopic observations were made on the course of HIV replication and infection in these cells. Although several ultrastructural studies of the cytopathology associated with HIV infection have appeared, few studies have shown the details of virus production in “normal,” human monocytes/macrophages, one of the natural targets of the virus, and suspected of being a locus of quiescent virus during its long latent period. In this report, we detail some of the interactions of developing virons with the membranes and organelles of the monocyte host.Peripheral blood monocytes were prepared from buffy coats (Portland Red Cross) by Percoll gradient centrifugation, followed by adherence to cover slips. 90-95% pure monocytes were cultured in RPMI with 5% non-activated human AB serum for four days and infected with 100 TCID50/ml of HIV-1 for four hours, washed and incubated in fresh medium for 14 days.

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