scholarly journals Plasmodium falciparum possesses two GRASP proteins that are differentially targeted to the Golgi complex via a higher- and lower-eukaryote-like mechanism

2008 ◽  
Vol 121 (13) ◽  
pp. 2123-2129 ◽  
Author(s):  
N. S. Struck ◽  
S. Herrmann ◽  
C. Langer ◽  
A. Krueger ◽  
B. J. Foth ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Golgi Complex ◽  
Lower Eukaryote

Organisation in the Structure of the Cytoplasmic Ground Substance

1978 ◽  
Vol 36 (3) ◽  
pp. 627-639
Author(s):  
K.R. Porter
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Random Distribution ◽  
Ground Substance ◽  
The Matrix ◽  
Cell Processes ◽  
Cytoplasmic Ground Substance

Most types of cells are known from their structure and overall form to possess a characteristic organization. In some instances this is evident in the non-random disposition of organelles and such system subunits as cisternae of the endoplasmic reticulum or the Golgi complex. In others it appears in the distribution and orientation of cytoplasmic fibrils. And in yet others the organization finds expression in the non-random distribution and orientation of microtubules, especially as found in highly anisometric cells and cell processes. The impression is unavoidable that in none of these cases is the organization achieved without the involvement of the cytoplasmic ground substance (CGS) or matrix. This impression is based on the fact that a matrix is present and that in all instances these formed structures, whether membranelimited or filamentous, are suspended in it. In some well-known instances, as in arrays of microtubules which make up axonemes and axostyles, the matrix resolves itself into bridges (and spokes) between the microtubules, bridges which are in some cases very regularly disposed and uniform in size (Mcintosh, 1973; Bloodgood and Miller, 1974; Warner and Satir, 1974).

Ultrastructural Aspects of Golgi Complex Function in Parathyroid Cells of Winter Frogs

1973 ◽  
Vol 31 ◽  
pp. 680-681
Author(s):  
William J. Dougherty
Keyword(s):  
Golgi Complex ◽  
Secretory Granules ◽  
Complex Function ◽  
Secretory Activity ◽  
Secretory Proteins ◽  
Perivascular Spaces ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
Ca Ions ◽  
Regulation Of Secretion

The regulation of secretion in exocrine and endocrine cells has long been of interest. Electron microscopic and other studies have demonstrated that secretory proteins synthesized on ribosomes are transported by the rough ER to the Golgi complex where they are concentrated into secretory granules. During active secretion, secretory granules fuse with the cell membrane, liberating and discharging their contents into the perivascular spaces. When secretory activity is suppressed in anterior pituitary cells, undischarged secretory granules may be degraded by lysosomes. In the parathyroid gland, evidence indicates that the level of blood Ca ions regulates both the production and release of parathormone. Thus, when serum Ca is low, synthesis and release of parathormone are both stimulated; when serum Ca is elevated, these processes are inhibited.

Structures Resembling Striated Rootlets in Oocytes

1972 ◽  
Vol 30 ◽  
pp. 124-125
Author(s):  
Valerie V. Ernst
Keyword(s):  
Golgi Complex ◽  
Fibrous Structure ◽  
Oocyte Development ◽  
The Cross

During the earliest stage of oocyte development in the limpet, Acmea scutum, Golgi complexes are small, few and randomly dispersed in the cytoplasm. As growth proceeds, the Golgi complexes increase in size and number and migrate to the periphery of the cell. At this time, fibrous structures resembling striated rootlets occur associated with the Golgi complexes. Only one fibrous structure appears to be associated with a Golgi complex.The fibers are periodically cross banded with an average of 4 dense fibrils and 6 lighter fibrils per period (Fig. 1). The cross fibrils have a center to center spacing of about 7 run which appears to be the same as that of the striated rootlets of the gill cilia in this animal.

Ultrastructural observations on the in vitro cytoadherence of Plasmodium falciparum infected red blood cells

1990 ◽  
Vol 48 (3) ◽  
pp. 914-915
Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Umbilical Vein ◽  
Cell Types ◽  
Amelanotic Melanoma ◽  
Cytoplasmic Process ◽  
Umbilical Vein Endothelial Cells

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).

Demonstration of Secondary Lysosomes in Bovine Megakaryocytes and Platelets Using Acid Phosphatase Cytochemistry with Cerium as a Trapping Agent

1990 ◽  
Vol 63 (01) ◽  
pp. 127-132 ◽  
Author(s):  
Michèle Ménard ◽  
Kenneth M Meyers ◽  
David J Prieur
Keyword(s):  
Acid Phosphatase ◽  
Electron Density ◽  
Golgi Complex ◽  
Initial Report ◽  
Cerium Phosphate ◽  
Virtual Absence ◽  
Phosphatase Cytochemistry ◽  
Secondary Lysosomes ◽  
Trapping Agent

SummaryThe ultrastructure of lysosomes from bovine megakaryocytes (MK) and platelets was characterized using acid phosphatase cytochemistry with beta-glycerophosphate as substrate and cerium as a trapping agent. The technique was easily reproducible; cerium-phosphate precipitates were uniform, readily visualized, and there was a virtual absence of nonspecific reaction product. Acid phosphatase was localized in the trans aspect of the Golgi complex and/or granules of less than 50 nm to 650 nm diameters in MK at all stages of maturation. Forty percent of the MK lysosomes contained inclusions of variable shapes, sizes and electron-density and were classified as secondary lysosomes. Twenty-four percent of the platelet sections contained acid phosphatase-positive granules. Fifty-four percent of these were secondary lysosomes. This is the initial report demonstrating secondary lysosomes in either resting MK or platelets using acid phosphatase cytochemistry. These findings suggest that MK and platelet lysosomes have an intracellular function in resting MK and platelets.

Platelet Hypersensitivity in Acute Malaria (Plasmodium falciparum) Infection in Man

1981 ◽  
Vol 46 (02) ◽  
pp. 547-549 ◽  
Author(s):  
E M Essien ◽  
M I Ebhota
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Infection ◽  
Light Transmission ◽  
Human Platelet ◽  
Platelet Rich Plasma ◽  
Wave Pattern ◽  
Falciparum Infection ◽  
Secondary Wave ◽  
Control Subjects ◽  
The Mean

SummaryDuring acute malaria infection, platelets in human platelet-rich plasma are hypersensitive to the addition of ADP between 1.0 uM and 5.0 uM, or adrenaline 0.11 uM as aggregating agents. The mean maximum aggregation amplitude (as % of light transmission) obtained from 8 subjects in response to added ADP (1.0 uM), 39.8 ± 27 (1SD), was significantly greater than the value in 6 controls (5.2±6.7 (1SD); t = 3, 51 P <0.005). A similar pattern of response was obtained with higher ADP concentrations (2.4,4.5 or 5.0 uM) in 22 patients and 20 control subjects (89.9±14.9% vs 77.8±16.5% (1SD) t = 2.45, P <0.02). Addition of 4.5 uM ADP to patient PRP usually evoked only a single aggregation wave (fused primary and secondary waves) while the typical primary and secondary wave pattern was usually obtained from controls.Mean plasma B-thromboglobulin (BTG) concentration in 7 patients (208.3 ± 15.6 ng/ml) was significantly higher than the value in 6 control subjects (59.2±15.7 ng/ml; t = 13.44, P <0.002).

Durch Vektoren übertragene Erkrankungen

2018 ◽  
Vol 18 (05) ◽  
pp. 332-338
Author(s):  
C. Kleine ◽  
U. Ziegler ◽  
E.-M. Schwienhorst ◽  
A. Stich
Keyword(s):  
Plasmodium Falciparum ◽  
Sich Eine ◽  
Malaria Tropica

ZusammenfassungDer folgende Artikel fokussiert auf Erkrankungen, deren Erreger von Vektoren (Insekten, Spinnentieren) aktiv auf den Menschen übertragen werden. Sie spielen in tropischen und subtropischen Regionen der Erde eine erhebliche Rolle und sind auch im Rahmen der Differenzialdiagnose bei kranken Reiserückkehrern von großer Bedeutung. Am wichtigsten ist die Malaria, insbesondere die lebensbedrohliche Malaria tropica durch Plasmodium falciparum. Jede fieberhafte Erkrankung aus den Tropen erfordert eine zeitnahe Malaria-Diagnostik. Tropische Viruserkrankungen durch Dengue-, West-Nil-, Chikungunya- oder Zika-Viren haben sich in den vergangenen Jahrzehnten massiv ausgebreitet und stellen auch eine zunehmende Bedrohung für den europäischen Raum dar. Andere Vektor-übertragene Erkrankungen sind zwar von großer lokaler Relevanz in endemischen Regionen, aber als importierte Infektionen in Deutschland relativ selten. Bei der Betreuung der Patienten empfiehlt sich eine enge Kooperation mit Tropenmedizinern.

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