Ultrastructure of tracheid cell walls in radiata pine (Pinus radiata) mild compression wood

1999 ◽  
Vol 77 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Adya P Singh ◽  
Lloyd A Donaldson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fluorescence Microscopy ◽  
Pinus Radiata ◽  
Cell Walls ◽  
Laser Scanning ◽  
Compression Wood ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Transmission Electron

The structure of tracheid cell walls in mild compression wood of Pinus radiata D. Don was examined by confocal laser scanning fluorescence microscopy (CLSM) and transmission electron microscopy (TEM). Fluorescence microscopy using lignin autofluorescence revealed cell to cell variations in lignification of the cell corner middle lamella (CCML) and outer S2 (S2L) regions supporting observations made at higher resolution with TEM. The mild compression wood sample examined lacked the characteristic intercellular spaces of most grades of compression wood and thus represents the least severe grade of compression wood. TEM observations revealed evidence for radial striations in the S2 region probably representing regions of alternating high and low lignin concentration, which may be the precursor to the helical cavities found in severe compression wood. These radial striations typically showed a sinuous and branched structure, extending partly into the S2L region, where the orientation of lignin lamellae was predominantly tangential following the arrangement of the cellulose microfibrils. At high magnification lignin occurred in a patchy distribution overlaying the typical lamellate arrangement associated with normal wood. Significant variability in the lignification of the CCML region was also observed sometimes giving a patchy or granular appearance. The lignification of the CCML and the S2L regions was generally comparable, while S1 and S2 layers were less lignified. A residual S3 layer was sometimes present in the form of a very thin layer slightly more lignified than the adjacent S2 layer.Key words: compression wood, Pinus radiata D. Don, ultrastructure, confocal laser scanning microscopy, transmission electron microscopy, lignin distribution.

Micromorphological Characteristics of Compression Wood Degradation in Waterlogged Archaeological Pine Wood

Holzforschung ◽  
1999 ◽  
Vol 53 (4) ◽  
pp. 381-385 ◽  
Author(s):  
Yoon Soo Kim ◽  
Adya P. Singh
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Laser Scanning ◽  
Compression Wood ◽  
Outer Part ◽  
Middle Lamella ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Wood Degradation ◽  
Transmission Electron

Summary The degradation characteristics of waterlogged archaeological compression wood excavated in South Korea were examined by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Degradation of Pinus compression wood occurred mainly in the inner part of the S2 layer. In contrast, the outer part of the S2 layer remained relatively intact. CLSM and TEM showed the erosion type of bacterial attack to be dominant in the secondary cell walls of both severe and mild compression wood. However, in some cases the middle lamella was also degraded, which suggests that other forms of microbial attacks, such as bacterial tunnelling, were also present. Bacterial erosion in the severe compression wood was mainly confined to the inner part of the S2 layer whereas in the mild compression wood it also extended into the outer part of the S2 and the S1 layer. The extent of erosion correlated to the differences in the amount and distribution of lignin, particularly in the outer S2 layer between the severe and mild compression wood cells. These features are compared with the degradation of normal Pinus wood.

Microtubule targeted therapeutics loaded polymeric assembled nanospheres for potentiation of antineoplastic activity

2016 ◽  
Vol 186 ◽  
pp. 45-59 ◽  
Author(s):  
Radhika Poojari ◽  
Rohit Srivastava ◽  
Dulal Panda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Laser Scanning ◽  
Present Approach ◽  
Laser Scanning Microscopy ◽  
Microtubule Assembly ◽  
Confocal Laser ◽  
Cancer Cell Proliferation ◽  
Transmission Electron ◽  
Hepatocarcinoma Cells

Polymeric nanoassemblies represent an attractive strategy for efficient cellular internalization of microtubule targeted anticancer drugs. Using dynamic light scattering, zeta potential, transmission electron microscopy and scanning electron microscopy, the physical properties and surface morphology of microtubule-binding PEGylated PLGA assembled nanospheres (100–200 nm) were analyzed. The present approach leads to strong internalization as observed by confocal laser scanning microscopy and transmission electron microscopy in hepatocarcinoma cells. The effect of these nanoassemblies on microtubules and mitosis were explored using immunofluorescence microscopy. The effects of these nanoassemblies on cancer cell proliferation and cell death revealed their antitumor enhancing effects. Perturbation of the microtubule assembly, mitosis and nuclear modulations potentiated the antineoplastic effects delivered via nanospheres in hepatocarcinoma cells. The extensive biomolecular and physical characterizations of the synthesized nanoassemblies will help to design potent therapeutic materials and the present approach can be applied to deliver microtubule-targeted drugs for liver cancer therapy.

scholarly journals Ultrastructure and Functional Morphology of the Appendages in the Reef-Building Sedentary Polychaete Sabellaria Alveolata (Annelida, Sedentaria, Sabellida)

2020 ◽  
Author(s):  
Christian Meyer ◽  
Thomas André ◽  
Günter Purschke
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Blood Vessels ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Entire Body ◽  
Receptor Cells ◽  
Body Regions ◽  
Transmission Electron

Abstract Background: The sedentary polychaete Sabellaria alveolata, the sandcastle or honeycomb worm, possesses four different kinds of appendages besides the parapodia: opercular papillae, tentacular filaments, palps, and branchiae. It exhibits a highly specialized anterior end, the operculum, formed by the prostomium, peristomium, and two anterior segments. Besides the median organ, the operculum comprises opercular papillae, tentacular filaments, and palps. Paired branchiae are present from the second thoracic chaetiger onwards on the posteriorly following segments except for the last ones. Only the palps have been studied thus far by transmission electron microscopy in late larvae of a different species. In order to bridge the data gap, we investigated the appendages of S. alveolata by applying light microscopy, confocal laser scanning microscopy, scanning, and transmission electron microscopy. Results: In S. alveolata the entire body is covered by a thin cuticle characterized by the absence of layers of parallel collagen fibers with no differentiation between the various body regions including the branchiae. The opercular papillae bear numerous tufts of receptor cells and lack motile cilia. The tentacular filaments show a distinctive ciliation pattern; their most conspicuous morphological feature is their cell-free cartilaginous endoskeletal structure enclosed by ECM. Besides musculature the filaments include a single coelomic cavity but blood vessels are absent. The palps are ciliated with two coelomic cavities and a single blind-ending blood vessel. Besides external ciliation and receptor cells, the coelomate branchiae are highly vascularized and equipped with numerous blood spaces extending deep into the basal regions of the epidermal cells (diffusion distances: 150–400nm). Conclusions: All appendages, including the branchiae, bear receptor cells and, as such, are sensory. The opercular papillae resemble typical parapodial cirri. In contrast, the tentacular filaments have a double function: sensing, collecting and transporting particles. A similarity to branchiae can be excluded. The palps are typical grooved palps similar to another sabellariid studied. A revised classification of polychaete branchiae is suggested; thereby, the branchiae of S. alveolata belong to the most common type comprising coelom, musculature, and blood vessels. The results indicate that diffusion distances between blood and environment have been underestimated in many cases.

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