Ultrastructure

2 Diverse terms have been used to describe the zones in basement membranes, including basal lamina and lamina rara. The terminology used here follows the recommendation of the International Anatomical Nomenclature Committee (Laurie and Leblond, 1985). 

The lamina densa is a well-delineated, highly stained zone whose presence is the sine qua non of a basement membrane. Many investigators use the term basement membrane to refer to this sheet-like structure, particularly where the presence of unique basement membrane components, such as collagen IV and laminin, can be established with specific antibodies. At higher magnification, the lamina densa can be seen to be a three-dimensional network of 3- to 8-nm cords (Fig. 2). In addition, in such preparations one can usually see tubule-like structures (basotubules) as well as small parallel rods known as double pegs (Inoue et al., 1983 Laurie et al., 1984). 

The reticular layer of basement membrane in a tissue such as the skin contains a variety of matrix structures. Strands of basement membrane may project down to type I collagen fibers. Anchoring fibers, banded fibers composed of type VII collagen, extend into the basement mem- 

Those components common to all basement membrane and believed to be integral to it rather than adventitiously associated with it are listed in 

Heparan sulfate proteoglycans Low density (Mr, 500-650K) 3-4 heparan sulfate chains Filtration 

The cellulose microfibrils are aligned fairly parallel in a helical pattern within each layer in the cell wall and oriented at different microfibril angles in the 

In addition to the fibrillar morphology of the fibre cell wall, the fibres are characterized by capillaries, voids, and interstices providing the cellulose fibres a highly porous character. The pore size ranged from 5 up to 30 nm and the pore volume fraction attained 1-3% for cotton and wood pulp. However, the total pore volume and pore size distribution are very sensitive to pretreatments. Mercerization leads to a decrease in pore diameter and an enhancement of micropore surface, while enzyme treatments enlarge the existing pores [4]. 

Acid hydrolysis enhances the pore system by removing amorphous cellulose from the surface and revealing the macrofibrillar structure of cellulose fibres [5]. Drying results in an irreversible reduction of the pore volume as a result of the pores collapse arising from the capillary forces, a mechanism called hornification. 

Due to the pore and void system, the surface area of cellulose fibres exceeds by far the geometrical outer surface of the fibre. The inner surface area is considered a key parameter w ith regard to accessibility and adsorption behaviour of lignocellulosic material in their native form as well as in a modified form. 

The abundance of OH functionalities brings to cellulose a high reactivity and opens the way to a multitude of modification chemical reactions calling on the OH chemistry. Moreover, cellulose has the particularity of being a porous material, the extent of which is boosted after water expansion, and this property plays an important role in the adsorption process. 

In primates, including man, the Clara cell has the features of a serous secretory cell that produces a protein-rich secretion. 

Volume density of cell components (nucleus, smooth ER, glycogen, smooth ER/glycogen, mitochondria, TEM Plopper et al (1983), Mariassy and Plopper (1984) 

In the rabbit, mitochondria in the Clara cells appear of two types (Hook et al. 1990) One form is normal with prominent cristae and the other form is larger, generally rounded, and contains a few indistinct cristae. An apparent continuity between the large and small forms suggests that the different forms must be closely related. 

In mice and rats, but not humans, the smooth endoplasmic reticulum of the Clara cell tends to present as a meshwork of branching tubules and/or vesicles. It is believed to be involved in the detoxification of drugs. Evidence demonstrating that the Clara cell is the primary site of cytochrome P-450 monooxygenase activity within the lung derives from four different approaches  

Agranular endoplasmic reticulum showing vesicular dilatation 

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Knoll G and Plattner H 1989 Ultrastructural analysis of biological membrane fusion and a tentative correlation with biochemical and biophysical aspects Electron Microscopy of Subcellular Dynamics ed H Plattner (London CRC) pp 95-117... 

D. Eengel and G. Wegener, in Wood, Ultrastructure, Reactions, DeGmyter, Berlin, 1983, Chapt. 5. 

J. D. Mackenzie, in L. L. Hench and D. R. Ulrich, eds.. Ultrastructure Processing of Ceramics, Glasses and Composites,]ohxi Wiley Sons, Inc., New York, 1984. 

Nowadays the one of the leading cause of death in industrial country is Heart Failure (HF). Under the pathological conditions (e.g., Ischemic Heart Disease (IHD)) the changes in the enzymes activity and ultrastructure of tissue were obtained. The behavior of trace elements may reflect the activity of different types of enzymes. Pathological changes affects only small area of tissue, hence the amount of samples is strictly limited. Thereby, nondestructive multielemental method SRXRF allow to perfonu the analysis of mass samples in a few milligrams, to save the samples, to investigate the elemental distribution on the sample area. 

As research reveals the ultrastructural organization of the cell in ever greater detail, more and more of the so-called soluble enzyme systems are found to be physically united into functional complexes. Thus, in many (perhaps all) metabolic pathways, the consecutively acting enzymes are associated into stable multienzyme complexes that are sometimes referred to as metabolons, a word meaning units of metabolism. ... 

Strum, J. (1969). Photophores of Porichthys notatus ultrastructure of innervation. Anat. Rec. 164 433-461. 

Hench LL, Ulrich DR (eds) (1984) Ultrastructure processing of ceramics, glasses and composites, Wiley-Interscience, New York... 

Pickett-Heaps, J.D. (1967). The effects of colchicine on the ultrastructure of dividing plant cells, xylem wall differentiation and distribution of cytoplasmic micrombules. Dev. Biol. 15, 206-236. 

Eisenberg, B.R. (1983). Quantitative ultrastructure of mammalian skeletal muscle. In Handbook of Physiology, Section 10, Skeletal Muscle (Peachey, L.D., Adrian, R.H., Geiger, S.R., eds.) American Physiological Society, Bethesda, MD. 

Although clinical examination provides important clues to diagnosis of congenital myopathies, ultrastructural and histochemical examination of muscle biopsies provides the key to definitive identification. Most of the congenital myopathies... 

Muscle biopsy is usually undertaken to confirm the provisional clinical diagnosis. Because the skin lesions normally precede those in muscle, biopsies of muscle taken early may show little abnormality. Inflammatory foci may be scanty or absent and muscle fiber diameters may be normal. However typical biopsies show discrete foci of inflammatory cells, with a predominance of B-lymphocytes (see Figure 18). These cells are situated in perimysial connective tissue rather than in the en-domysium and are often also perivascular in location. Muscle fiber necrosis occurs in JDM but muscle fibers do not appear to be the primary target of the disordered immune process. Rather, it is the micro vasculature of the muscle which appears to degenerate first and muscle necrosis is preceded by capillary necrosis, detectable at the ultrastructural level. 

Muscle biopsy with full histochemical and ultrastructural investigation is necessary for the confirmation of a diagnosis of IBM. The inclusions which are the hallmark of this disorder are to be found in three locations (a) basophilic granular inclusions are found at the periphery of vacuoles within the cytoplasm of muscle fibers (b) eosinophilic hyaline inclusions are also found in the cytoplasm but are not associated with vacuoles and (c) intranuclear inclusions consisting of aggregates of filamentous microtubules are found in a variable percentage of muscle nuclei. Inclusions of the first two types are visible at light microscope level, whereas the third type is detectable at the electron microscope level only. Ultrastructural... 

Biopsy findings show disseminated muscle fiber atrophy which is confined to type 2 fibers, in many instances with type 2B (glycolytic) fibers most affected (Figure 23). Muscle necrosis is not seen, though at ultrastructural level focal myofibrillar disruption and myofilament loss may be evident. The muscle atrophy seems to be due to decreased protein synthesis, and at high doses, to increased catabolism. The reason for the selective effect on phasic, glycolytic fibers is not clear since, although steroids interfere with carbohydrate metabolism and oxidative capacity, there seems to be no overall effect on ATP levels. Nevertheless it has been... 

Fujikawa, S. Miura, K. (1986). Plasma membrane ultrastructural changes caused by mechanical stress in the formation of extracellular ice as a primary cause of slow freezing injury in fhiit-bodies of basidiomycetes (Lyophyllum ulmarium [Fr.J KOhner). Cryobiol. 23,371-382. 

Ultrastructural properties of human enamel apatite. In Lazzari, E., ed.. Handbook of Experimental Aspects of Oral Biochemistry, Florida, CRC Press 159-179. 

Changes in constructive metabolism and ultrastructural organization of Bacillus cereus cells under the action of a specific autoregulatory factor. Microbiology, Vol.48, No.2, (February 1979), pp.240-244, ISSN 1350-0872... 

Munns, R., Greenway, H., Stelter, T.L. Kuo, J. (1983). Turgor pressure, volumetric elastic modulus, osmotic volume and ultrastructure of Chlorella emersoni grown at high and low external NaCl. Journal of Experimental Botany, 34,144-55. 

Among resurrection plants two seemingly very different kinds of response occur at the ultrastructural level. In many desiccation tolerant seeds, pollens, mosses and vascular plants, dehydration brings about rather... 

These extensive alterations in cell structure and the biochemical machinery are indicative of entry into an ametabolic condition. In this condition damage from free radicals is potentially decreased, certainly the loss of chlorophyll and chloroplast structure removes a major source of free radical generation. About 50% of the extremely desiccation tolerant monocots exhibit extensive loss of chlorophyll and ultrastructural organisation when desiccated. Dicots, ferns and bryophytes retain most of their chlorophyll and exhibit small changes in structure when dry (see Gaff,... 

Even a moderate quantity of salt reaching the leaves has a drastic effect on photosynthesis and leaf ultrastructure, much more than could be accounted for by the average tissue concentration (Flowers etal., 1985). Salt may accumulate in the apoplast (because it is not taken up fast enough by the cells of the leaf), and this would result in severe localised water deficit (Oertli, 1968). Differences in apoplast/protoplast balance are thought to be responsible for varietal differences in tissue salt load which can be accommodated (tissue tolerance Yeo Flowers, 1986). The xylem concentration of Na" is very much lower to young leaves than to older leaves (Yeo et al., 1985). This is advantageous in salt resistance because it means that at least some leaves are protected from salt, which otherwise causes premature leaf death (Yeo Flowers, 1984 Fig. 2). 

Urry D.W., Whai is elastin what is not, Ultrastructural Pathology, 4, 227, 1983. 

In a histometric, immunohistochemical and ultrastructural study, TCA peeling in concentrations of 10,20 and 30% were compared with dermabrasion in nine dark-skinned patients (Fitzpatrick s IV and V) with photodamage [24]. Both procedures induced increasing amounts of types I and III collagen. However,... 

El-Domyati MB, Attia SK, Saleh FY, Ahmad HM, Uitto JJ (2004) Trichloroacetic acid peeling versus dermabrasion a histometric, immunohistochemi-cal, and ultrastructural comparison. Dermatol Surg 30 197-188... 

Ditre CM, Griffin TD, Murphy GF, Sueki H, Telegan B, Johnson WC, Yu RJ, Van Scott EJ (1996) Effects of alpha-hydroxy acids on photoaged skin a pilot clinical, histologic, and ultrastructural study. J Am Acad Dermatol 34(2 Pt 1) 187-195... 

Strmac, M. and Braunbeck, T. (1999). Effects of triphenyltin acetate on survival, hatching success, and liver ultrastructure of early life stages of zebrafish (Danio rerio). Ecotoxicology and Environmental 44, 25-39. 

G. C., Resorption rate, route of elimination, and ultrastructure of the implant site of polylactic acid in the abdominal wall of the rat, J. Biomed. Mater. Res., 7, 155, 1973. 

A method of assessing the toxicity of implants has been proposed based on the effects on cell ultrastructure in organ cultures, on cell surface characteristics, and cell population doubling times. The effects have been correlated with hemorrhage, fibrosis, and necrosis, respectively (103). Poly-e-caprolactone was stated to give minimal tissue reaction and could not be scored in these tests. 

Wollenberg A. Kraft S. Hanau D. Bieber T Immuno-morphological and ultrastructural characterization of Langerhans cells and a novel, inflammatory dendritic epidermal cell population in lesional skin of atopic eczema. J Invest Dermatol 1996 106 446-453. 

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