Postnatal development of the geniculocortical projection in the cat: Electrophysiological and morphological studies

1983 ◽  
Vol 51 (1) ◽  
Author(s):  
N. Kato ◽  
S. Kawaguchi ◽  
T. Yamamoto ◽  
A. Samejima ◽  
H. Miyata
Keyword(s):  
Postnatal Development ◽  
Morphological Studies ◽  
Geniculocortical Projection

Morphological studies on the fetal and postnatal development of rat Leydig cells

1985 ◽  
Vol 110 (1_Suppla) ◽  
pp. S98-S99 ◽  
Author(s):  
S. G. HAIDER ◽  
D. PASSIA ◽  
W. HILSCHER
Keyword(s):  
Postnatal Development ◽  
Leydig Cells ◽  
Morphological Studies

scholarly journals Features of the expression of Fox-1 in rat’s thyroid after prenatal dexamethasone action

2021 ◽  
Vol 25 (3 (99)) ◽  
pp. 124-131
Author(s):  
O. Fedosieieva
Keyword(s):  
Thyroid Gland ◽  
Postnatal Development ◽  
Morphological Changes ◽  
Large Diameter ◽  
The Body ◽  
Synthetic Activity ◽  
Compensatory Mechanism ◽  
Morphological Studies ◽  
Thyroid Glands ◽  
Experimental Group

The purpose of the work was to establish the features of Fox-1 expression and distribution in the parenchyma of the thyroid gland of rats in the postnatal period of ontogeny in the norm and after intrauterine action of dexamethasone.Material and methods: thyroid gland of rats (162 animals) of the Wistar line at the age from 1 to 14 days of postnatal development. Experimentally, the animals were injected intrauterinely with a solution of dexamethasone at a dose of 0.05 ml at a dilution of 1:40 on the 18th day of the dated pregnancy. The material was examined using a set of methods of morphological studies (production of histological serial sections, survey microscopy, morphometry, immunohistochemistry and statistical processing).Results of the research. In the thyroid glands of neonatal prenatal dexamethasone, the parenchyma was well developed and consisted of hollow colloid-type follicles and single colloid-type microfollicles, and a bright cytoplasmic reaction with Fox-1 antibodies was observed throughout the organ parenchyma. In the thyroid glands of animals of the 3rd day of life, morphological changes occurred in all groups of the experiment. In animals of the experimental group, hollow follicles of colloidal type of small, medium and large diameter were chaotically visualized throughout the body, and large follicles of irregular shape with immunohistochemical weak or negative reaction with Fox-1 antibodies in thyrocytes and lumen without colloidal evidence, which detected a decrease in the specific synthetic activity in these thyrocytes. On day 7 in the experimental group in the flattened thyrocytes of overstretched follicles, the expression of Fox-1 was present only in the apical part. On days 11-14 of postnatal development in the thyroid glands of rats experimentally prenatally exposed to dexamethasone in the wall of large follicles with flattened epithelium began extrafollicular proliferation of thyrocytes on the background of visualization in the lumen of these follicles desquamated cells. Intensive perinuclear and cytoplasmic Fox-1 positive reaction was present in extrafollicular proliferating thyrocytes.Conclusions. 1. The detected changes in the first day of life in the thyroid gland of rats indicated that prenatal administration of dexamethasone affects the intensification of differentiation not only structural and functional units - follicles, but also a specific synthetic intracellular apparatus of thyrocytes, judging by the intensification of Fox-1. Thus, immature pre-mRNA is converted into mature mRNA, from which thyroid proteins, in particular thyroglobulin, are translated. By the time of birth, this process in the experimental group reaches a significant development, covering the entire parenchyma of the gland. 2. In rats prenatally receiving dexamethasone, the period of lactation was characterized by intense structural changes in the thyroid gland, in particular intracellularly in thyrocytes of monolayer flattened epithelium, the expression of Fox-1 antibodies was sharply reduced, which was then replaced by a bright cytoplasmic reaction in proliferative clusters and follicles of colloidal type of secretion, which is an adaptive-compensatory mechanism of intracellular enhancement of proliferation of synthesizing organelles in response to the restructuring of a significant number of existing follicles by hypofunctional type, aimed at maintaining normal levels of thyroid function.

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

Chromic Acid Etching of Polyethylene

1973 ◽  
Vol 31 ◽  
pp. 72-73
Author(s):  
J. D. Muzzy ◽  
R. D. Hester ◽  
J. L. Hubbard
Keyword(s):  
Chromic Acid ◽  
Low Cost ◽  
Acid Etching ◽  
Crystalline Morphology ◽  
Bulk Specimen ◽  
Morphological Studies ◽  
Perfect Form ◽  
Molecular Length ◽  
Lamellar Texture ◽  
Cost Studies

Polyethylene is one of the most important plastics produced today because of its good physical properties, ease of fabrication and low cost. Studies to improve the properties of polyethylene are leading to an understanding of its crystalline morphology. Polyethylene crystallized by evaporation from dilute solutions consists of thin crystals called lamellae. The polyethylene molecules are parallel to the thickness of the lamellae and are folded since the thickness of the lamellae is much less than the molecular length. This lamellar texture persists in less perfect form in polyethylene crystallized from the melt.Morphological studies of melt crystallized polyethylene have been limited due to the difficulty of isolating the microstructure from the bulk specimen without destroying or deforming it.

Biological and Morphological Studies on Low-Leukemia-Strain Mice with Hodgkin's-Like Neoplasia Induced by Serial Cell-Free Transmission of Leukemic Organs of SJL/J Strain Mice

1968 ◽  
Vol 26 ◽  
pp. 210-211
Author(s):  
S. Fujinaga ◽  
K. Maruyama ◽  
C.W. Williams ◽  
K. Sekhri ◽  
L. Dmochowski
Keyword(s):  
Tissue Culture ◽  
Type A ◽  
Reticulum Cell ◽  
Type B ◽  
Viral Origin ◽  
Serial Transfer ◽  
Strain Mouse ◽  
Morphological Studies ◽  
Cell Neoplasm ◽  
Free Material

Yumoto and Dmochowski (Cancer Res.27, 2098 (1967)) reported the presence of mature and immature type C leukemia virus particles in leukemic organs and tissues such as lymph nodes, spleen, thymus, liver, and kidneys of SJL/J strain mice with Hodgki's-like disease or reticulum cell neoplasm (type B). In an attempt to ascertain the possibility that this neoplasia may be of viral origin, experiments with induction and transmission of this neoplasm were carried out using cell-free extracts of leukemic organs from an SJL/J strain mouse with spontaneous disease.It has been possible to induce the disease in low-leukemia BALB/c and C3HZB strain mice and serially transfer the neoplasia by cell-free extracts of leukemic organs of these mice. Histological examination revealed the neoplasia to be of either reticulum cell-type A or type B. Serial transfer is now in its fifth passage. In addition leukemic spleen from another SJL/J strain mouse with spontaneous reticulum cell neoplasm (type A) was set up in tissue culture and is now in its 141st serial passage in vitro. Preliminary results indicate that cell-free material of 39th tissue culture passage can reproduce neoplasia in BALB/c mice.

Morphological studies of linear (AB)n multiblock copolymers and their blends

1992 ◽  
Vol 50 (1) ◽  
pp. 384-385
Author(s):  
Richard J. Spontak ◽  
Steven D. Smith ◽  
Arman Ashraf
Keyword(s):  
Electron Microscopy ◽  
Microphase Separation ◽  
Multiblock Copolymers ◽  
First Order ◽  
Morphological Studies ◽  
Transmission Electron ◽  
First Order Phase Transition ◽  
Covalently Bonded ◽  
Total Molecular Weight ◽  
First Order Phase

Block copolymers are composed of sequences of dissimilar chemical moieties covalently bonded together. If the block lengths of each component are sufficiently long and the blocks are thermodynamically incompatible, these materials are capable of undergoing microphase separation, a weak first-order phase transition which results in the formation of an ordered microstructural network. Most efforts designed to elucidate the phase and configurational behavior in these copolymers have focused on the simple AB and ABA designs. Few studies have thus far targeted the perfectly-alternating multiblock (AB)n architecture. In this work, two series of neat (AB)n copolymers have been synthesized from styrene and isoprene monomers at a composition of 50 wt% polystyrene (PS). In Set I, the total molecular weight is held constant while the number of AB block pairs (n) is increased from one to four (which results in shorter blocks). Set II consists of materials in which the block lengths are held constant and n is varied again from one to four (which results in longer chains). Transmission electron microscopy (TEM) has been employed here to investigate the morphologies and phase behavior of these materials and their blends.

Mast cell-nerve fiber interaction: Ultrastructural studies

1990 ◽  
Vol 48 (3) ◽  
pp. 428-429
Author(s):  
E.Y. Chi ◽  
M.L. Su ◽  
Y.T. Tien ◽  
W.R. Henderson
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Substance P ◽  
Nerve Fiber ◽  
Sensory Nerves ◽  
Ultrastructural Studies ◽  
Morphological Studies ◽  
Granulocyte Infiltration ◽  
Intracutaneous Injection ◽  
Recent Attention

Recent attention has been directed to the interaction of the nerve and immune systems. The neuropeptide substance P, a tachykinnin which is a neurotransmitter in the central and peripheral nervous systems produces tissue swelling, augemntation of intersitial fibrin deposition and leukocyte infiltration after intracutaneous injection. There is a direct correlation reported between the extent of mast cell degranulation at the sites of injection and the tissue swelling or granulocyte infiltration. It has previously been demonstrated that antidromic electrical stimulation of sensory nerves induces degranulation of cutaneous mast cells, cutaneous vasodilation and augmented vascular permeability. Morphological studies have documented a close anatiomical association between mast cells and nonmyelinated nerves, that contain substance P and other neuropeptides. However, the presence of mast cells within nerve fasicles has not been previously examined ultrastructurally. In this study, we examined ultrastructurally the distribution of mast cells in the nerve fiber bundles located in the muscular connective tissue of rat tongues (n=20).

Sign in / Sign up

Export Citation Format

Share Document