scholarly journals Observations on the Mycorrhizas of Forest Trees. II. The Rhizosphere of Pinus Radiata D. Don

1967 ◽  
Vol 20 (5) ◽  
pp. 915 ◽  
Author(s):  
RC Foster ◽  
GC Marks
Keyword(s):  
Electron Microscopy ◽  
Clay Minerals ◽  
Pinus Radiata ◽  
Light And Electron Microscopy ◽  
Fungal Species ◽  
Forest Trees ◽  
Large Numbers

Two common mycorrhiza types of Pinus radiata were examined by light and electron microscopy. Large numbers of bacteria and fungal species other than those forming the mycorrhiza as well as diatoms were observed in the mycorrhizosphere. Different morphological types of bacteria were characteristic of different mycorrhizal types, and in some cases the bacteria were associated with lysed regions of the mantle. The distribution of the bacteria within the rhizosphere is discussed in relation to the clay minerals and the carbohydrate and polyphenol metabolisms of the host.

Studies withBrugia pahangi. 14. Intrauterine development of the microfilaria and a comparison with other filarial species

1976 ◽  
Vol 50 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Rosemary Rogers ◽  
D. S. Ellis ◽  
D. A. Denham
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Uterine Wall ◽  
Dense Material ◽  
Intrauterine Development ◽  
Brugia Pahangi ◽  
Electron Dense Material ◽  
Large Numbers ◽  
Egg Shells ◽  
Egg Shell

ABSTRACTThe intrauterine development ofBrugia pahangiembryos was followed from after fertilization to birth, using light and electron microscopy. The origin and development of the sheath of the microfilaria and its Possible role in the nutrition of the developing embryo were particularly investigated. Comparisons were drawn with the intrauterine development of other filarial species. The egg shell of theB. pahangiembryo js distinct from the oolemma and forms the sheath of the microfilaria. It is suggested that the electron dense material released by cells of the uterine wall and passing along the channels between the egg shells of adjacent embryos is nutritive. The death of large numbers of developing embryos in the central uterine Jumen is probably caused by overcrowding as their size rapidly increases, leading to nutritional deficiency.

Studies on the biochemistry and morphology of freshly isolated and maintained rat hair follicles

1989 ◽  
Vol 93 (3) ◽  
pp. 409-418
Author(s):  
M. Philpott ◽  
M.R. Green ◽  
T. Kealey
Keyword(s):  
Electron Microscopy ◽  
Hair Growth ◽  
Adenine Nucleotide ◽  
Light And Electron Microscopy ◽  
Growth Cycle ◽  
Hair Follicles ◽  
Large Numbers ◽  
Thymidine Autoradiography ◽  
Permeable Supports

We have already shown that shearing can be used to yield large numbers of viable intact hair follicles. We now show that these follicles can be viably maintained on permeable supports for 7 days in vitro as determined by their adenine nucleotide contents, rates of [methyl-3H]thymidine and [U-14C]leucine uptake, [methyl-3H]thymidine autoradiography, patterns of keratin synthesis and light and electron microscopy. These studies, however, show that after 7 days maintenance the morphology of maintained follicles shows a closer resemblance to the telogen rather than the anagen follicle. We therefore conclude that the failure of previous attempts at maintaining hair growth in culture is due to hair follicles prematurely entering the resting stage of their hair growth cycle, possibly as a response to isolation.

Distribution, Size and Effective Aperture Area of the Inter-Tracheid Pits in the Radial Wall of Pinus Radiata Tracheids

IAWA Journal ◽  
1989 ◽  
Vol 10 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Lin Jinxing
Keyword(s):  
Electron Microscopy ◽  
Linear Relationship ◽  
Pinus Radiata ◽  
Light And Electron Microscopy ◽  
Radial Wall ◽  
Positive Linear Relationship ◽  
Tracheid Length ◽  
Effective Aperture

The distribution, size and effective aperture area of inter-tracheid pits were studied in a 29-year-old plantation-grown tree of Pinus radiata by means of light and electron microscopy. It was found that the number of pits per tracheid in the first ten years is related more to tracheid length than to the age of the wood. Beyond the tenth year, the number of pits per tracheid is mainly related to the age of the wood, regardless of tracheid length. In addition, there is a positive linear relationship between tracheid diameter and pit diameter, indicating that the larger tracheids contain larger pits. The percentage of the effective aperture area per mrn length of radial tracheid wall is discussed, in relation to the 'percentage of aspirated pits and total area of pit aperture per tracheid.

scholarly journals Ultrastructural Studies in Acute Promyelocytic Leukemia

Blood ◽  
1972 ◽  
Vol 39 (5) ◽  
pp. 628-636 ◽  
Author(s):  
Henry K. Tan ◽  
Bettye Wages ◽  
Harvey R. Gralnick
Keyword(s):  
Electron Microscopy ◽  
Bone Marrow ◽  
Light Microscopy ◽  
Acute Promyelocytic Leukemia ◽  
Disseminated Intravascular Coagulation ◽  
Light And Electron Microscopy ◽  
Promyelocytic Leukemia ◽  
Uniform Size ◽  
Ultrastructural Studies ◽  
Large Numbers

Abstract In this investigation, the cells of eight patients with acute promyelocytic leukemia were followed by light and electron microscopy. Promyelocytes from untreated patients were filled with large, splinter-shaped granules. The granules were lysosomes, with some showing the ultrastructural features of Auer bodies. In cases responsive to chemotherapy, promyelocytes contained only infrequently splinter-shaped lysosomes, while most lysosomes were of more uniform size and shape. The persistence of large numbers of splinter-shaped lysosomes within promyelocytes was associated with episodes of disseminated intravascular coagulation less responsive to heparin treatment. Promyelocytes from patients in remission were similar to promyeloctyes from nonleukemic bone marrow. The ultrastructural differences in lysosome morphology provide a better criterion for distinguishing malignant from normal promyelocytes than previously detectable by light microscopy alone.

A quick, simple method for purifying Leishmania mexicana amastigotes in large numbers

Parasitology ◽  
1981 ◽  
Vol 82 (3) ◽  
pp. 345-355 ◽  
Author(s):  
D. T. Hart ◽  
K. Vickerman ◽  
G. H. Coombs
Keyword(s):  
Electron Microscopy ◽  
Buoyant Density ◽  
Light And Electron Microscopy ◽  
Host Cells ◽  
Leishmania Mexicana ◽  
Cell Debris ◽  
Simple Method ◽  
Large Numbers

SUMMARYA rapid method for the bulk isolation of purified Leishmania mexicana mexicana amastigotes from parasite-induced lesions in experimentally infected mice is described. The procedure includes purification steps based on differences in net cell charge, lysis susceptibility and buoyant density between parasite and host cells. Yields of up to 2 × 1010 untransformed amastigotes with minimal contamination with host cells and cell debris can be obtained. At least 90 % of the purified amastigotes are viable as judged by light and electron microscopy, the staining of their lysosomes with acridine orange, their ability to transform to promastigotes and their infectivity to macrophages in vivo and in vitro.

The Morphology of Vacuolated Cells in the Liver Following Administration of Vitamin A.

1973 ◽  
Vol 31 ◽  
pp. 408-409
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti
Keyword(s):  
Electron Microscopy ◽  
Body Weight ◽  
Vitamin A ◽  
Light And Electron Microscopy ◽  
Liver Cells ◽  
Prominent Feature ◽  
Vascular Space ◽  
Vacuolated Cell ◽  
Vacuolated Cells ◽  
Vacuolated Cytoplasm

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

Control of Autogenous Vein Grafts Prior to Reimplantation, By Electron Microscopy

1972 ◽  
Vol 30 ◽  
pp. 106-107
Author(s):  
John H. L. Watson ◽  
John L. Swedo ◽  
M. Vrandecic
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Physiological Saline ◽  
Experimental Conditions ◽  
Vein Grafts ◽  
Arterial Blood ◽  
Saphenous Veins ◽  
Autogenous Vein ◽  
Control Of Parameters ◽  
Post Implantation

The ambient temperature and the nature of the storage fluids may well have significant effects upon the post-implantation behavior of venus autografts. A first step in the investigation of such effects is reported here. Experimental conditions have been set which approximate actual operating room procedures. Saphenous veins from dogs have been used as models in the experiments. After removal from the dogs the veins were kept for two hours under four different experimental conditions, viz at either 4°C or 23°C in either physiological saline or whole canine arterial blood. At the end of the two hours they were prepared for light and electron microscopy. Since no obvious changes or damage could be seen in the veins by light microscopy, even with the advantage of tissue specific stains, it was essential that the control of parameters for successful grafts be set by electron microscopy.

Ultrastructure of two neoplasms in culture compared with original biopsies

1984 ◽  
Vol 42 ◽  
pp. 50-51
Author(s):  
Joseph M. Harb ◽  
James T. Casper ◽  
Vlcki Piaskowski
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Biopsy Specimen ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Human Tumor ◽  
Soft Agar ◽  
Human Tumor Cells ◽  
Morphological Distinction ◽  
Tumor Types

The application of tissue culture and the newer methodologies of direct cloning and colony formation of human tumor cells in soft agar hold promise as valuable modalities for a variety of diagnostic studies, which include morphological distinction between tumor types by electron microscopy (EM). We present here two cases in which cells in culture expressed distinct morphological features not apparent in the original biopsy specimen. Evaluation of the original biopsies by light and electron microscopy indicated both neoplasms to be undifferentiated sarcomas. Colonies of cells propagated in soft agar displayed features of rhabdomyoblasts in one case, and cultured cells of the second biopsy expressed features of Ewing's sarcoma.

The Effect of Vitamin A on the Intermittent Nitrogen Dioxide Gas Exposure in Hamsters

1976 ◽  
Vol 34 ◽  
pp. 176-177
Author(s):  
J.C.S. Kim ◽  
M.G. Jourden ◽  
E.S. Carlisle
Keyword(s):  
Electron Microscopy ◽  
Vitamin A ◽  
Nitrogen Dioxide ◽  
Chronic Exposure ◽  
Light And Electron Microscopy ◽  
Specific Effect ◽  
Deficient Diet ◽  
Intermittent Exposure ◽  
Hypovitaminosis A ◽  
Gas Exposure

Chronic exposure to nitrogen dioxide in rodents has shown that injury reaches a maximum after 24 hours, and a reparative adaptive phase follows (1). Damage occurring in the terminal bronchioles and proximal portions of the alveolar ducts in rats has been extensively studied by both light and electron microscopy (1).The present study was undertaken to compare the response of lung tissue to intermittent exposure to 10 ppm of nitrogen dioxide gas for 4 hours per week, while the hamsters were on a vitamin A deficient diet. Ultrastructural observations made from lung tissues obtained from non-gas exposed, hypovitaminosis A animals and gas exposed animals fed a regular commercially prepared diet have been compared to elucidate the specific effect of vitamin A on nitrogen dioxide gas exposure. The interaction occurring between vitamin A and nitrogen dioxide gas has not previously been investigated.

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