Light and electron microscopic studies of nodule structure of alfalfa

1981 ◽  
Vol 27 (1) ◽  
pp. 36-43 ◽  
Author(s):  
J. J. Patel ◽  
A. F. Yang
Keyword(s):  
Light And Electron Microscopy ◽  
Infection Process ◽  
Infection Thread ◽  
Nodule Development ◽  
Electron Microscopic ◽  
Meristematic Region ◽  
Microscopic Studies ◽  
A Site ◽  
Ongoing Infection ◽  
Nodule Tissue

Light and electron microscopy was used to establish the structural organisation of the developing nodule of alfalfa. In these nodules three distinct regions were noted: (1) the base region, site of original infection where the nodule is attached to the root and now composed of degenerating nodule tissue, (2) the central region, or active region composed of nodule cells containing tightly packed bacteroids surrounding a central vacuole, and (3) the meristematic region, a site of new growth, behind which newly formed cells are continually invaded. The ongoing infection process accompanying continued nodule development provided the opportunity to study the release of Rhizobium cells from the infection threads.In the nodules of alfalfa it would appear that the Rhizobium cells are released from infection thread into the nodule tissue in two different ways: (i) release with infection thread membrane and (ii) release in thin-walled vesicular structures. Thus it is concluded that Rhizobium cells are surrounded by the infection thread membrane when they are released from the infection thread into nodule tissue.

A correlated light and electron microscopic study of symbiotic growth and differentiation in Pisum sativum root nodules

1976 ◽  
Vol 54 (18) ◽  
pp. 2163-2186 ◽  
Author(s):  
William Newcomb
Keyword(s):  
Electron Microscopy ◽  
Pisum Sativum ◽  
Rhizobium Leguminosarum ◽  
Root Nodules ◽  
Light And Electron Microscopy ◽  
Infection Thread ◽  
Electron Microscopic ◽  
Cortical Cells ◽  
Garden Pea ◽  
Host Cytoplasm

Plants of the garden pea Pisum sativum cv. Little Marvel were grown in aeroponic culture to facilitate observations and microscopy and were inoculated with Rhizobium leguminosarum, and nodules were sampled at five weekly intervals for light and electron microscopy. The invasion of the cortical cells by the infection thread, the structure of the infection thread, and the release of bacteria from it into the host cytoplasm and the subsequent symbiotic growth and differentiation of the two organisms are described in detail. The fine structure of the nodule is correlated with light microscopic observations and morphogenesis. A restriction in the use of the term 'vesicle' is proposed because of the current multiple and confusing usage of the term. The loss of the nodule meristem and its morphogenetic significance are discussed.

scholarly journals The Vitamin-E-Deficiency Syndrome in Pigs; III. Light- and Electron-Microscopic Studies on Myocardial Vascular Injury

1971 ◽  
Vol 8 (3) ◽  
pp. 239-255 ◽  
Author(s):  
Inger Nafstad
Keyword(s):  
Electron Microscopy ◽  
Vitamin E ◽  
Light And Electron Microscopy ◽  
Deficiency Syndrome ◽  
Endothelial Damage ◽  
Vascular Changes ◽  
Electron Microscopic ◽  
Vitamin E Deficiency ◽  
Small Vessels ◽  
Microscopic Studies

Vascular changes in the myocardium of vitamin-E-deficient pigs were studied by light and electron microscopy. The main changes shown by light microscopy were mural degeneration and multiple microthrombi in small vessels. The thrombotic material gave staining characteristics of platelets and fibrin. With electron microscopy, the main changes were endothelial damage, extravasation of platelets and erythrocytes, and the formation of thrombi composed of platelets and fibrin. The first vascular change occurred in the endothelium; this was succeeded by the formation of thrombi.

Transmission and Scanning Electron Microscopic studies of ocular leprosy in nine-banded armadillos

1989 ◽  
Vol 47 ◽  
pp. 1038-1039
Author(s):  
R. Malaty ◽  
L. Pedroza ◽  
R.W. Beuerman
Keyword(s):  
Light And Electron Microscopy ◽  
Corneal Stroma ◽  
Mycobacterium Leprae ◽  
Lepromatous Leprosy ◽  
Electron Microscopic ◽  
Ocular Complications ◽  
Scanning Electron Microscopic ◽  
Microscopic Studies ◽  
Histopathological Studies ◽  
Preventable Blindness

Leprosy is one of the leading causes of preventable blindness in the world, yet It is largely ignored in blindness prevention programs. To date, little is known about the pathogenesis of ocular leprosy in humans. Histopathological studies have been necessarily 1imited to eyes removed at autopsy or enucleated from patients with advanced lepromatous leprosy. In an attempt to define the pathogenesis of the ocular complications of leprosy, we have studied the eyes of animal models namely, nine-banded armadillos with 1epromatous leprosy and injected Mycobacterium leprae (M. leprae) directly in the corneal stroma of armadillos.Fifty armadillos with experimental or naturally-acquired lepromatous leprosy were studied. Six armadillos were injected in the corneal stroma with 1 ul of an M. leprae suspension and examined two and four months later. Both eyes of each animal were enucleated at autopsy, fixed in paraformaldehyde-glutaraldehyde and processed for light and electron microscopy (EM). For light microscopy, the eyes were embedded in plastic methacrylate and sections stained with a modified acid-fast stain. For EM, tissues were post fixed in 1% OsO4 dehydrated, and embedded in epon.

A comparative study on the gastroduodenal tolerance of different antianaemic preparations

2003 ◽  
Vol 22 (3) ◽  
pp. 137-141 ◽  
Author(s):  
M A Idoate Gastearena ◽  
A G Gil ◽  
A Azqueta ◽  
M P Coronel ◽  
M Gimeno
Keyword(s):  
Protective Effect ◽  
Ferrous Sulphate ◽  
Light And Electron Microscopy ◽  
Mucosal Damage ◽  
Duodenal Mucosa ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Ultrastructural Alteration ◽  
Iron Protein ◽  
Microscopic Studies

The most significant adverse effect of repeated oral administration of iron-containing antianaemic preparations is the gastroduodenal toxicity, attributable to a direct toxic effect of iron on the glandular epithelium. To assess gastroduodenal mucosal damage and the potential protective effect of different antianaemic preparations, a study was carried out to compare the gastroduodenal toxicity caused by three different types of antianaemic drugs in normal and anaemic rats administered at repeated therapeutic doses. Histological damage to the gastroduodenal mucosa was evaluated using light and electron microscopy. In both normal and anaemic rats, pathological changes were less marked in animals treated with ferrimannitol-ovoalbumin (TM/ FMOA) than in those treated with iron protein succinylate or ferrous sulphate. Electron microscopic studies of duodenal mucosa in normal rats treated with iron protein succinylate and ferrous sulphate confirmed a severe ultrastructural alteration, whereas no changes were detected in animals treated with TM/FMOA. In anaemic rats, slight duodenal ultrastructural changes were noted with all three types of treatment. The effectiveness of the preparations in resolving the anaemia was similar in the three groups. It was concluded that TM/FMOA exerts a protective effect against the toxicity normally observed of the iron in other formulations in normal and anaemic rats, which was attributed to the fact that administration of iron bound to a protein core allows for gradual release of iron.

Myocardial Alterations in Cats Kept at 14,110 Feet Elevation for Three Months

1969 ◽  
Vol 27 ◽  
pp. 364-365
Author(s):  
M. B. Bischoff ◽  
W. D. Dean ◽  
T. J. Bucci
Keyword(s):  
Electron Microscopy ◽  
High Altitude ◽  
Ventricular Hypertrophy ◽  
Animal Species ◽  
Cardiac Tissue ◽  
Light And Electron Microscopy ◽  
Myocardial Cells ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Adult Cats

Right ventricular hypertrophy occurs in several animal species when transported from sea level to high altitude. Previous electron microscopic studies in our laboratory have shown enlargement of mitochondria with degeneration of cristae, separation of myofibrils, and increased accumulations of lipid and particulate glycogen in myocardial cells of dogs, rabbits and rats maintained at high altitude for five months. Edematous endothelial cells of the myocardial capillaries were also observed. Our recent work showed that adult cats native to 5,380 feet subjected to 14, 110 feet elevation for 90 days also developed cardiac hypertrophy. The cardiac tissue was examined by light and electron microscopy and the results comprise this communication.

Fixation artifacts in percutaneous needle biopsies of liver

1993 ◽  
Vol 51 ◽  
pp. 20-21
Author(s):  
T.C. Januszewski ◽  
J.M. Harb ◽  
R.A. Komorowski
Keyword(s):  
Electron Microscopy ◽  
Standard Procedure ◽  
Light And Electron Microscopy ◽  
Significant Loss ◽  
Electron Microscopic ◽  
Initial Fixation ◽  
Cacodylate Buffer ◽  
Microscopic Studies ◽  
Block Face ◽  
Liver Biopsies

Percutaneous needle biopsy is a standard procedure for obtaining liver tissues for pathologic studies by light and electron microscopy. Tissues obtained by this procedure usually measure 1mm to 1.5 mm in diameter, and can be placed immediately at the bedside into a standard glutaraldehyde fixative for processing by the electron microscopy laboratory. Although the biopsy thickness is within the penetration range of glutaraldehyde, we have noted a significant loss of preservation in the center of most liver biopsies. The loss is apparent at light and electron microscopic levels. The purpose of this paper is to illustrate the artifact and to discuss the importance of avoiding the artifact when selecting areas of the specimen for electron microscopic studies.Secimens studied were routine liver biopsies submitted to the electron microscopy laboratory after an initial fixation of one hour in 2.5% glutaraldehyde in 0.1M cacodylate buffer. To illustrate the artifact, one-micron thick sections of the entire block face were stained with toluidine blue for light microscopic study (Figure 1).

Light and electron microscopy of virus-associated, intranuclear paracrystals in cultured cells infected with types 2, 4, 6, and 18 human adenoviruses

1969 ◽  
Vol 15 (8) ◽  
pp. 841-845 ◽  
Author(s):  
J. Weber ◽  
S. K. Liao
Keyword(s):  
Phase Contrast ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Human Adenovirus ◽  
Electron Microscopic ◽  
Contrast Microscope ◽  
Microscopic Studies ◽  
Infected Cells ◽  
Relationship Of ◽  
The Relationship

Light and electron microscopic studies of human adenovirus types 2, 4, 6, and 18 infected HEp-2 cells revealed the induction of virus-associated, intranuclear paracrystalline formations. None of these crystalline structures were observed in abortively infected BHK-21 cells by these viruses. By histochemical techniques, the crystals only in Ad. 2 and Ad. 6 infected cells were visualized with the phase-contrast microscope and shown to be protein in nature but devoid of detectable amounts of nucleic acids. The crystals induced by Ad. 2 and Ad. 6 were frequently large, were polygonal in shape, appeared early after infection, and consisted of parallel tubules with a periodicity of 700 Å, whereas those induced by Ad. 4 and Ad. 18 were small, were irregular in shape, appeared later after infection, and consisted of parallel filaments with periodicities of 250 Å and 400 Å, respectively. Neither crystals nor virions were found in uninfected control cells. The relationship of the virus-associated crystals reported in the present study to those observed to date in other adenovirus–host systems was discussed.

scholarly journals Cellular elements in the developing caecum of Japanese quail (Coturnix coturnix japonica): morphological, morphometrical, immunohistochemical and electron-microscopic studies

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aalaa M. AbuAli ◽  
Doaa M. Mokhtar ◽  
Reda A. Ali ◽  
Ekbal T. Wassif ◽  
K. E. H Abdalla
Keyword(s):  
Japanese Quail ◽  
Immune Cells ◽  
Proximal Part ◽  
Goblet Cells ◽  
Intraepithelial Lymphocytes ◽  
Surface Epithelium ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Immunological Surveillance ◽  
A Site

Abstract The present study aims to investigate the histological, histochemical and electron microscopic changes of the caecal proximal part of Japanese quail during both pre- and post-hatching periods starting from the 2nd embryonic day (ED) until four weeks post-hatching. On the 2nd and 3rd ED, the primordia of caeca appeared as bilateral swelling on the wall of the hindgut. On the 7th ED, the lamina propria/submucosa contained the primordia of glands. On the 8th ED, rodlet cells could be observed amongst the epithelial cells. On the 9th ED, the caeca began to divide into three parts with more developed layers. With age, the height and number of villi increased. On the 13th ED, immature microfold cells (M-cells) could be identified between the surface epithelium of the villi. The caecal tonsils (CTs) appeared in the form of aggregations of lymphocytes, macrophages, dendritic cells and different types of leukocytes. Telocytes and crypts of Lieberkuhn were observed at this age. On hatching day, the crypts of Lieberkuhn were well-defined and formed of low columnar epithelium, goblet cells, and enteroendocrine cells. Post-hatching, the lumen was filled with villi that exhibited two forms: (1) tongue-shaped villi with tonsils and (2) finger-shaped ones without tonsils. The villi lining epithelium contained simple columnar cells with microvilli that were dispersed with many goblet cells, in addition to the presence of a high number of intra-epithelial lymphocytes and basophils. Moreover, the submucosa was infiltrated by numerous immune cells. CD3 immunomarker was expressed in intraepithelial lymphocytes, while CD20 immunomarker showed focal positivity in CTs. In conclusion, the caecal immune structures of quails at post-hatching were more developed than those in pre-hatching life. The high frequency of immune cells suggests that this proximal part may be a site for immunological surveillance in the quail caecum. The cellular organisation of the caecum and its relation to the immunity was discussed.

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