Pathology

Pathology.—Since hyaluronic acid is the only glycosaminoglycan detected in pulmonary secretions of asthma patients, it may be a specific marker for this particular disease.  

The role of zinc in the metabolism of glycosaminoglycans has been reported for normal and atheromatous rats. In general, zinc deficiency causes a 

Low levels of keratan sulphate in human femoral heads have been suggested to be one of the factors involved in patients suffering from osteoarthrosis. Observed differences in chain length and in the content of keratan sulphate may be related to the degree of malignancy of human chondrosarcomas.  

In two children exhibiting the clinical symptoms of fucosidosis, the diagnosis has been confirmed biochemically by the demonstration of a marked a-L-fuco-sidase deficiency in cultured skin fibroblasts. Examination of the urinary levels of keratan sulphate and chondroitin sulphate of the two patients showed a five- and eight-fold increase over those of normal children of the same age. Since a number of the terminal non-reducing positions of keratan sulphate molecules are occupied by a-L-fucosyl residues, the increased excretion of keratan sulphate in fucosidosis could result from the impaired degradation of keratan sulphate, due to ae-L-fucosidase deficiency. 

The pinocytosis by fibroblasts of )3-D-2-acetamido-2-deoxyhexosidase excreted by cultured fibroblasts from patients with mucolipidosis II disease is not enhanced by neuraminidase-catalysed removal of neuraminic acid residues from the j8-D-2-acetamido-2-deoxyhexosidase.  

Pathology,—The enzyme deficiencies in mucopolysaccharidoses and (he participation of enzymes in excretion and recapture processes in the lysosomes of cultured fibroblasts have been discussed.A comprehensive account of the chemistry, biochemistry, and physiology of proteoglycans in health and disease has appear ed.  

Chondroitin 4-sulphate ig the principal proteoglycan found in the media of cultured B16 mouse melanoma cells. The epiphysial cartilage of four-week-old chickens that had been fed a Mn -deficient diet contained low levels of glycosaminoglycans, owing to a decrease in the D-xylosylation of core proteins and an increase in the degradation of glycosaminoglycans.  

Pathology.—The enzymic deficiencies, corrective factors, and clinical correlations of the mucopolysaccharidoses have been reviewed. The recognition of mucopolysaccharidoses using four screening tests, including a refinement of the albumin turbidity test, and the differentiation of mucopolysaccharidoses by electrophoretic separation of urinary glycosaminoglycans have been reported.  

Srinivasan, B. Radhakrishnamurthy, and G. S. Berenson, Arch. Biochem. Biophys., 

Sakamoto, M. Sakamoto, P. Goldhaber, and M. J. Glimcher, Biochim. Biophys. Acta, 

Taniguchi, T. Miyawaki, N. Moriya, and N. Okuda, Clinica Chim. Acta, 1975,60, 363. 

Tokunaga, T. Futami, E. Wakamatsu, M. Endo, and Z. Yosizawa, Clinica Chim. Acta, 

Pathology.—A useful review of mucopolysaccharidoses, which deals with the defective or missing enzymes, prenatal diagnoses, and enzyme-replacement therapy, has appeared. Other reviews have discussed the ageing of connective tissues and the diagnosis of mucopolysaccharidoses it was pointed out in the latter review that screening tests using cetylpyridinium chloride are unreliable 

260 p Lewis, J. F. Kennedy, and D. N. Raine, in Inborn Errors of Skin, Hair, and Connective Tissue , ed. J. B. Holton and J. T. Ireland, Medical and Technical Publishing Co-Ltd., Lancaster, 1975, p. 229. 

The screening of heterozygotes for Hurler s syndrome is now possible, since the specific activity of the leucocyte-derived a-L-iduronidase in carriers is reduced by roughly 50%. The molecular size of dermatan sulphate excreted in the urine of patients with Hurler s syndrome can be monitored by gel-filtration chromatography on Sephadex G-75. The in vitro correction of the defect in Hurler s fibroblasts with bovine testicular hyaluronidase has produced encouraging results, and such treatment is also effective with Hunter s cells. A sulphated tetrasaccharide, which was obtained on digestion of chondroitin 6-sulphate with testicular hyaluronidase, has been used as the substrate in the determination of 2-acetamido-2-deoxy-D-galactose 6-sulphate sulphatase, an enzyme that is absent in patients with Morquio s disease.  

The reduction (to roughly one-sixth) in the molecular weight of the intracellular heparan sulphate in the fibroblasts of patients with Sanfilippo B or Scheie s syndromes has been attributed to the actions of an ewdb-glycosaminidase and an e c/o-hexuronidase. Immunochemical evidence has been obtained for the presence of a defective 2-acetamido-2-deoxy-a-D-glucosidase in the tissues of patients with Sanfilippo B disease, and that, in addition to arylsulphatase B, other enzymes are present in the corrective factor for Maroteaux-Lamy disease. Arylsulphatases A and B have been separated by chromatography on DEAE-cellulose.  

The keratan sulphate stored in macular dystrophy of the cornea can be dispersed using preparations from rabbit keratocytes or homogenates of porcine corneal stroma. The glycosaminoglycans in the skins of patients with systemic 

The pericellular sulphated glycosaminoglycans of a malignant glioma cell line showed faster turnover than those of normal glial cells.Most of the sulphated glycosaminoglycan was released into the medium rather than being degraded. 

Abnormalities in the distribution of glycosaminoglycans found in kerato-conus cell cultures have been reported. Normal stromal cells incorporate sulphate into sulphated glycosaminoglycans, which are located mainly within the cell layer. In contrast, the keratoconus cells produce most of the newly synthesized material into the growth medium with a much decreased amount within the cell layer. 

A tissue-culture model of the breakdown of cartilage in rheumatoid arthritis has been made on the basis of quantitative aspects of the release of proteoglycans. The findings support the view that a significant component of cartilage breakdown may be mediated by the chondrocytes. 

Compared with normal human articular cartilage, osteoarthritic cartilage shows a significant reduction of dermatan sulphate, chondroitin 6-sulphate, keratan sulphate, and heparan sulphate. The content of glycoprotein also appeared to be reduced. The levels of chondroitin 4-sulphate, keratan sulphate. 

A protein fraction of rat serum prevents the precipitation of lipoprotein by rat heparin and Phosphorylcholine is able to counteract the effect of 

Surgical resection or radiation therapy of DVAs should be avoided Endovascular therapy of DVAs is also not an option 

Another factor contributing to the DVA-related confusion is that many radiologists and clinicians just see abnormal vessels on magnetic resonance imaging (MRI) scans, immediately tell the patient something about a vascular malformation, and refer the patient for neurosurgical extirpation of the lesion. 

To avoid too much irritation, specifically within the group of referring doctors, the term venous angioma should be avoided and DVA should be used. However, if you are reporting about DVA, it is usually necessary to explain what this is. And this is a good reason to read the upcoming chapter. 

Institute of Diagnostic and Interventional Radiology and Neuroradiology, University of Essen, Hufelandstrafie 55, 45122 Essen, Germany 

The pathogenesis of a DVA is still unknown. Saito and Kobayashi et al. (1981) hypothesized that an intrauterine event during formation of the medullary veins or tributaries induces the formation of the collateral venous drainage pathways. This hypothesis is supported by the absence of normal draining veins in the region of the large draining collector vein. 

Phytoalexins also accumulate after exposure to other compounds called elici-tors. Elicitors may originate as a product of the invading pathogen or from exposure to other plants or the activities of humans (Sect. 5.1.3.6). The latter are termed abiotic if they represent elicitors such as detergents, heavy metals, UV light, etc. 

Van der Molen et al. (138) presented evidence that occlusion of the vascular system, which occurs during the wilting of plants, is a direct consequence of ethylene action. They propose that a common signal for the formation of vascular gels 

Patients with Tay-Sachs disease are characterized by the presence of a cherry-red spot in the macular region of the eye. Macrocephaly 

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In statistical terms, a perceptual improvement is therefore obtained if the amplitude distribution in the filtered signal (image) is more concentrated around zero than in the raw data (contrast enhancement). A more concentrated amplitude distribution generally means smaller entropy. Thus, from an operator perception point of view, interesting results should be obtained if the raw data can be filtered to yield low entropy amplitude distributions. However, one should note that the entropy can be minimized by means of a (pathological) filter which always outputs zero or another constant value. Thus, appropriate restrictions must be imposed on the filter construction process. 

As described at the end of section Al.6.1. in nonlinear spectroscopy a polarization is created in the material which depends in a nonlinear way on the strength of the electric field. As we shall now see, the microscopic description of this nonlinear polarization involves multiple interactions of the material with the electric field. The multiple interactions in principle contain infomiation on both the ground electronic state and excited electronic state dynamics, and for a molecule in the presence of solvent, infomiation on the molecule-solvent interactions. Excellent general introductions to nonlinear spectroscopy may be found in [35, 36 and 37]. Raman spectroscopy, described at the end of the previous section, is also a nonlinear spectroscopy, in the sense that it involves more than one interaction of light with the material, but it is a pathological example since the second interaction is tlirough spontaneous emission and therefore not proportional to a driving field... 

Health and Safety Factors. Completely fluorinated alkanes are essentially nontoxic (16). Rats exposed for four hours to 80% perfluorocyclobutane and 20% oxygen showed only slight effects on respiration, but no pathological changes in organs. However, some fluorochemicals, especially functionalized derivatives and fluoroolefins, can be lethal. Monofluoroacetic acid and perfluoroisobutylene [382-21-8] are notoriously toxic (16). 

H. C. Evans, in R. A. Samson,. M. Vlak, and D. Peters, eds.. Fundamental and Applied Aspects ofi Invertebrate Pathology, Proc. 4th International... 

Histamine in the Blood. After its release, histamine diffuses rapidly into the blood stream and surrounding tissues (12). Histamine appears in blood within 2.5 min after its release, peaks at 5 min, and returns to baseline levels by 15 to 30 min. In humans, the diurnal mean of plasma histamine levels is 0.13 ng/g. In urine, elevations of histamine or metaboUtes are more prolonged than plasma elevations. Consequendy, abnormahties are more easily detected by urinary histamine assay. About one-half of the histamine in normal blood is in basophils, one-third in eosinophils, and one-seventh in neutrophils the remainder is distributed among all the other blood components. Increases in blood histamine levels occur in several pathological... 

Allergic Seasonal or Perennial Rhinoconjunctivitis. Histamine can cause all pathologic features of allergic rhinitis (35—37), with the exception of late-phase inflammatory reactions. Pmritus is caused by stimulation of receptors on sensory nerve endings prostaglandins (qv) may also contribute. Sneering, like pmritus, is an H -mediated neural reflex and can also be mediated by eicosanoids. Mucosal edema, which manifests as nasal... 

Two weU-known pathological conditions are the result of an excess or a deficiency of this hormone. The condition in which the body produces an excess of hGH is known as acromegaly or giantism. The condition in which too Httle is produced is dwarfism. 

E. A. Steiohaus, Insect Pathology an Hdvanced Treatise, Vols. 1 and 2, Academic Press, Inc., New York, 1973. 

Increased temperatures should always increase the rates of reactions. Pathological exceptions would probably involve changes in the molecular species involved. 

M. O. Blackstone, Endoscopic Interpretation—Mormal and Pathologic Appearances of the Gastrointestinal Tract, Raven Press, New York, 1984. 

Microscopes are also classified by the type of information they present size, shape, transparency, crystallinity, color, anisotropy, refractive indices and dispersion, elemental analyses, and duorescence, as well as infrared, visible, or ultraviolet absorption frequencies, etc. One or more of these microscopes are used in every area of the physical sciences, ie, biology, chemistry, and physics, and also in their subsciences, mineralogy, histology, cytology, pathology, metallography, etc. 

M. E. Boon, Microwave Cookbook of Pathology the Mrt of Microscopic kisuali yation. Coulomb Press, Leyden, tlie NetEedands, 1988. 

Efficient homeostatic controls of mammalians generally prevent serious toxicity from ingestion of the mineral nutrients. Toxicity may occur under conditions far removed from those of nutritional significance or for individuals suffering from some pathological conditions. Because of very low concentrations in foods, the trace elements are not toxic under normal nutritional conditions. Exceptions are selenium and iron (162). 

O. Akopajan, Some Biological Shifts in the Bodies of Workers in Contact with Molybdenum Dust, Second Scientific Conference of the Institute of Labor of Hygiene and Occupational Diseases on Problems of Labor Hygiene and Occupational Pathology, Erevan, 1963, pp. 103—106. 

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