Ultrastructure of Persisting Mitotic Nucleoli of Mung Beans

1975 ◽  
Vol 33 ◽  
pp. 308-309
Author(s):  
J. P. Braselton
Keyword(s):  
Methylene Blue ◽  
Light Microscopy ◽  
Mung Bean ◽  
Higher Plants ◽  
The Other ◽  
Equatorial Plate ◽  
Cell Divisions ◽  
Primary Roots

Although nucleoli are generally believed to disperse during mitotic prophase, various groups of algae, fungi, and protozoans regularly possess persisting, in some cases “autonomous,” nucleoli during mitosis. Persisting nucleoli also occur in some higher plants and animals, but there have been only a few ultrastructural observations of such nucleoli. This study was initiated to better characterize cell divisions of a plant in which nucleoli regularly persist during mitosis.Aceto-carmine squash preparations for staining nucleoli for light microscopy reveal that mung bean primary roots possess mitotic divisions in which over 90% of the metaphases exhibit nucleoli. One micrometer sections of plastic embedded tissue stained with aqueous methylene blue for light microscopy also show nucleoli at metaphase (Fig. 1). Light microscopic observations show that some metaphase nucleoli are roughly spherical and occur on or near the equatorial plate; some are elongated perpendicularly to the plane of the equatorial plate and extend toward one or the other, or both, pole(s); while others appear spherical and occur at either pole.

Comparative strengths and weaknesses of peroxidase and colloidal gold in pre- and post-embedding immunolabeling techniques

1987 ◽  
Vol 45 ◽  
pp. 1002-1005
Author(s):  
D. R. Abrahamson ◽  
P. L. St.John ◽  
E. W. Perry
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Light Microscopy ◽  
Colloidal Gold ◽  
Light Microscope ◽  
Ultrastructural Localization ◽  
The Other ◽  
Quantitative Studies ◽  
Dense Suspension ◽  
Antigen Localization

Antibodies coupled to tracers for electron microscopy have been instrumental in the ultrastructural localization of antigens within cells and tissues. Among the most popular tracers are horseradish peroxidase (HRP), an enzyme that yields an osmiophilic reaction product, and colloidal gold, an electron dense suspension of particles. Some advantages of IgG-HRP conjugates are that they are readily synthesized, relatively small, and the immunolabeling obtained in a given experiment can be evaluated in the light microscope. In contrast, colloidal gold conjugates are available in different size ranges and multiple labeling as well as quantitative studies can therefore be undertaken through particle counting. On the other hand, gold conjugates are generally larger than those of HRP but usually can not be visualized with light microscopy. Concern has been raised, however, that HRP reaction product, which is exquisitely sensitive when generated properly, may in some cases distribute to sites distant from the original binding of the conjugate and therefore result in spurious antigen localization.

scholarly journals Exploiting the Binocular Head in Polarized Light Microscopy

1994 ◽  
Vol 2 (4) ◽  
pp. 16-16
Author(s):  
Walter C. McCrone
Keyword(s):  
Light Microscopy ◽  
Polarized Light ◽  
Polarized Light Microscopy ◽  
The Other ◽  
Monocular Viewing ◽  
Area Of Interest

Having been brought up on monocular microscopes I find the omnipresent binocular systems a luxury. To support this viewpoint I'd like to suggest some benefits you may not have considered.Because I'm used to monocular viewing I sometimes use two different oculars, say 10X and 25X, in order to scan quickly to find an area of interest and then to examine the detail with higher magnification. Occasionally I use both oculars simultaneously and “concentrate” on either image to the exclusion of the other. A better way is to set the interocular distance at the extreme setting most different from your own interocular distance. By moving your head about a centimeter either way you can use either ocular.

scholarly journals Glomerulonephritis in schistosomiasis with mesangial IgM deposits

1981 ◽  
Vol 76 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Ageu Godoy Magalhães Filho ◽  
Antônio Victoriano Barbosa ◽  
Teresa Cristina Ferreira
Keyword(s):  
Cell Proliferation ◽  
Light Microscopy ◽  
Immunofluorescence Microscopy ◽  
The Other ◽  
Proliferative Glomerulonephritis ◽  
Mesangial Proliferative Glomerulonephritis ◽  
Normal Pattern ◽  
Glomerular Lesions ◽  
Capillary Walls ◽  
Igm Deposits

Twenty one cases of hepatoesplenic schistosomiasis patients without clinical and laboratory evidence of renal disease, were studied by surgical biopsies using light microscopy and immunofluorescence. The cases were classified histologically as: normal pattern (6 cases); minimal changes (6 cases); and mesangial proliferative glomerulonephritis (9 cases). By the immunofluorescence microscopy using anti IgM, IgG, IgA and C3, the predominant finding in all biopsies, except the normal cases, was granular deposits of IgM in the mesangium along with C3. On the other hand, IgG was present in all cases including normal biopsies along the capillary walls. However IgG was also present in the mesangium only in cases with glomerular lesions. This finding may well be similar to that recently described as IgM mesangial nephropathy. According to our cases a mesangial proliferative glomerulonephritis, characterized by segmental cell proliferation and deposition of IgM in the mesangium, is probably the entity found in the early stages of mansonic schistosomiasis.

Method for the Quantification of Alginate in Microcapsules

1993 ◽  
Vol 2 (5) ◽  
pp. 429-436 ◽  
Author(s):  
Jean-Pierre Hallé ◽  
Danielle Landry ◽  
Alain Fournier ◽  
Michèle Beaudry ◽  
Francois A. Leblond
Keyword(s):  
Methylene Blue ◽  
Alkaline Medium ◽  
High Sensitivity ◽  
Sodium Concentration ◽  
The Other ◽  
Sensitive Assay ◽  
Reliable Measurement ◽  
Alginate Concentration ◽  
Other Substances ◽  
Alginate Content

Alginate is a key reagent in the preparation of microcapsules for cell transplantation. To address the question of the intracapsular alginate concentration, a sensitive assay has been developed to quantify the alginate content of microcapsules. The method is based on the metachromatic change induced by alginate binding to the dye, 1,9-dimethyl methylene blue (DMMB). The assay has a high sensitivity and precision. It covers a wide concentration range enabling the measurement of alginate in dilute supernatants as well as in microcapsules. For the latter, the membrane is initially dissolved by incubating the microcapsules in an alkaline medium. The effect of potentially interfering substances (poly-l-lysine (PLL), citrate, chloride, sodium) and of pH has been studied. Poly-l-lysine interfered with the assay at pH 6.5 but not at pH 13. Interference by sodium augmented with increasing sodium concentration and reached a plateau at 200 mM. This problem was overcome by routinely adjusting all samples to 500 mM sodium. The other substances tested had a negligible effect on the assay. The reliable measurement of alginate with this new assay will allow the optimization of the intracapsular alginate concentration.

scholarly journals VARIATIONS IN THE STRUCTURE OF MITOCHONDRIA

1956 ◽  
Vol 2 (4) ◽  
pp. 305-312 ◽  
Author(s):  
E. W. Dempsey
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Internal Structure ◽  
Outer Wall ◽  
The Other ◽  
Metabolic Processes ◽  
Intracellular Membranes ◽  
Janus Green ◽  
Definition Of ◽  
Shape Complexity

A characteristic internal structure, consisting of a double-layered outer wall enclosing a matrix-filled space through which pass double-layered membranous folds, would appear to comprise as satisfactory a definition of mitochondria for electron microscopy as their intravital affinity for Janus green affords for light microscopy. Relying for identification upon this characteristic internal structure, mitochondria appear to be pleomorphic structures which vary in size, shape, complexity, and density. They are labile also in that their number may increase or decrease under controlled conditions. The possibility therefore exists that these organelles are constantly being formed and destroyed, perhaps by their participation in metabolic processes. The problem of the origin of mitochondria is in an unsatisfactory state. New organelles unquestionably are formed in particular physiological states. The possibility that new bodies are produced by fission of ones already present does not seem adequate. On the other hand, the possible fabrication of new mitochondria out of intracellular membranes, although an attractive hypothesis, has not been adequately substantiated.

An in vitro Evaluation of Artificial Caries-like Lesions on Restored Overdenture Abutments

1988 ◽  
Vol 67 (3) ◽  
pp. 582-584 ◽  
Author(s):  
P.P. Kambhu ◽  
R.L. Ettinger ◽  
J.S. Wefel
Keyword(s):  
Light Microscopy ◽  
Polarized Light ◽  
Polarized Light Microscopy ◽  
The Other ◽  
Type Ii ◽  
Restorative Materials ◽  
Abutment Teeth ◽  
The Mean ◽  
Materials Used

An acidified dialyzed gelatin gel system was used to determine the caries resistance of a variety of restorative materials used to obturate the canal orifice of overdenture abutment teeth. The restorative materials used were Tytin, Tytin + Copalite, P30 + Scotchbond, Fuji Ionomer-Type II, and Miracle Mix. Polarized light microscopy and microradiography were used to examine the caries-like lesions adjacent to the restorations. The lesions formed in the Fuji Ionomer-Type II and Miracle Mix groups appeared arrested at the wall adjacent to the restoration, and did not penetrate apically down the wall as did those associated with the other restorative materials. The mean depths of lesions adjacent to Fuji Ionomer-Type II and Miracle Mix restorations were significantly less than those of Tytin, Tytin + Copalite, or P30 + Scotchbond.

Creativity Thinks on the Significances of Geobiology about the Coal Series

2014 ◽  
Vol 1065-1069 ◽  
pp. 114-118
Author(s):  
Shuo Fu Tian ◽  
Chao Jin Lu ◽  
Yuan Wang
Keyword(s):  
Green Algae ◽  
Higher Plants ◽  
The Other ◽  
Coal Bed ◽  
Geologic History ◽  
Blue Green Algae ◽  
Living Things ◽  
Coal Petrology ◽  
The Relationship ◽  
Lower Plants

It is the components, living things evolution processes, development environments, distribution layers and the earliest time for coal series formation that are investigated and studied in detail based on the author’s graduation thesis, the “Geobiology” , the “China coal petrology” and the other’s some references in this paper. And it is considered that mainly two types of the Coal Series might be distinguish in the geologic history in China, respectively consisted of the lower organisms (especially the lower plants, blue-green algae) and higher organisms (especially the higher plants, pteridophyta, gymnosperms, Anthophyta). Meanwhile, the conclusions can be drawn that the development of the organisms is not only controlled by the environments, on the other hand, the environments and their sediments are also affected by the ecologies of the organisms. So the coal bed or coal series can be used as the marks of the environment explanation, perhaps having some Significances of Geobiology. In additional, the relationship with an unconformity or disconformity is discussed here, too.

Problems associated with ageing squid from their statoliths: towards a more structured approach

1994 ◽  
Vol 6 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Marek R. Lipinski ◽  
M. Deon Durholtz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Regression Analysis ◽  
Light Microscopy ◽  
The Other ◽  
Etching Solution ◽  
Significant Difference ◽  
Structured Approach ◽  
Fish Otoliths ◽  
Scanning Electron

It appears that squid statoliths cannot yet be regarded as accurate an ageing tool as fish otoliths. Statoliths from the same pair, prepared differently for viewing and counting increments, were compared. Increment counts do not imply age in days, because this was not validated. One statolith from each pair was examined by light microscopy (LM) after preparation following a new method. The other was viewed by Scanning Electron microscopy (SEM) with a modified etching solution. Shape of each statolith was similar when compared by multiple regression analysis (11 variables, n=53). There was a weak but significant difference between sexes (statoliths of females were slightly larger). All other differences were insignificant. Microscopic observation and increment counts of increments were successfully carried out for 37 pairs of statoliths. Significant differences between two independent counts were found for the LM method, but no significant differences were found between two independent SEM counts. Counts were significantly different when interpreted by both LM and SEM, probably because of poor resolution in the LM readings and over-resolution (growth layers prominent and numerous) in those read by SEM. Recommendations are made on how ageing studies, based on statoliths, should be structured and the results evaluated.

Pollen morphology of Sabinaria magnifica (Cryosophileae, Coryphoideae, Arecaceae)

Phytotaxa ◽  
2015 ◽  
Vol 207 (1) ◽  
pp. 135 ◽  
Author(s):  
Giovanni Raul Bogota ◽  
Carina Hoorn ◽  
Wim Star ◽  
Rob Langelaan ◽  
Hannah Banks ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
The Other ◽  
Transmission Electron ◽  
Palm Species ◽  
Scanning Electron

Sabinaria magnifica is so far the only known species in the recently discovered tropical palm genus Sabinaria (Arecaceae). Here we present a complete description of the pollen morphology of this palm species based on light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We also made SEM-based comparisons of Sabinaria with other genera within the tribe Cryosophileae. Pollen grains of Sabinaria magnifica resemble the other genera in the heteropolar, slightly asymmetric monads, and the monosulcate and tectate exine with perforate surface. Nevertheless, there are some clear differences with Thrinax, Chelyocarpus and Cryosophila in terms of aperture and exine. S. magnifica differs from its closest relative, Itaya amicorum, in the exine structure. This study shows that a combination of microscope techniques is essential for the identification of different genera within the Cryosophileae and may also be a necessary when working with other palynologically less distinct palm genera. 

Inhibition of δ-Aminolevulinic Acid Synthesis by Glyphosate

Weed Science ◽  
1981 ◽  
Vol 29 (5) ◽  
pp. 571-577 ◽  
Author(s):  
Lynn M. Kitchen ◽  
William W. Witt ◽  
Charles E. Rieck
Keyword(s):  
Carbon Dioxide ◽  
Zea Mays ◽  
Aminolevulinic Acid ◽  
Higher Plants ◽  
Acid Synthesis ◽  
The Other ◽  
Porphyrin Ring ◽  
Fresh Weight ◽  
Ring Compounds ◽  
Site Of Action

The effect of glyphosate [N-(phosphonomethyl) glycine] on barley (Hordeum vulgareL.) and corn (Zea maysL.) shoot δ-aminolevulinic acid (ALA) production was examined by monitoring ALA content in the tissue and measuring incorporation of14C precursors into ALA and chlorophylla. Barley shoot ALA content was significantly decreased by 1 mM glyphosate after 9, 11, and 15 h of illumination. ALA production by treated barley shoots was 30 nmoles•g fresh weight-1•h-1at each interval tested, compared with 75 to 120 nmoles•g fresh weight-1•h-1for the control. In corn shoots, ALA content was reduced 32, 45, and 58% by 0.1, 1.0, and 10.0 mM glyphosate, respectively, after 12 h illumination. Incorporation studies with14C-glutamate,14C-α-ketoglutarate, and14C-glycine into ALA showed a 77, 92, and 91% inhibition, respectively, in barley shoots treated with 1 mM glyphosate. Incorporation of14C-ALA into chlorophyllawas not affected by 1 mM glyphosate. Thus, the site of action of glyphosate may involve two enzyme pathways:one controlling the conversion of α-ketoglutarate to ALA, and the other controlling the condensation of glycine with succinyl CoA to form ALA and carbon dioxide. Inhibition of ALA synthesis blocks synthesis of chlorophyll, as well as all other porphyrin ring compounds found in higher plants. Thus, inhibition of ALA synthesis may be an integral component of the herbicidal mode of action of glyphosate.

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