Histochemical Findings

The main histochemical feature of ML is reflected in the name. Staining of frozen sections with aqueous acetic cresylviolet (Hirsch and Peiffer 1955) results in brown metachromasia of the myelin degradation products instead of the normal purple color of myelin. The method allows differentiation and localization of the alcohol-soluble storage material in ML, although, like most other histochemical tests, it is not completely specific for this lipid. 

The first observers of degenerative diffuse sclerosis, Scholz (1925) and Biel-SCHOWSKY and Henneberg (1928) coined the term prelipoid for these products of myelin disintegration, on the basis of their faint orange stain with Scarlet-red, and considered this substance to be a precursor of neutral fats which stain bright red with the same dye (see fig. 2). 

In addition to its typical brown metachromasia (Diezel 1956, 1957 a, b, 1962 Diezel and Richardson 1957), the lipid in ML stains normally with Sudan black, is weakly PAS positive, CP - and Bial-negative and therefore does not contain neuraminic acid. It can be selectively stained using the trypaflavin-dimethyl-aminobenzaldehyde method (Hollander 1963, 1964 b). 

Studies by Hirsch and Peiffer (1955), Diezel (1955, 1957 b), and Cumings (1955) of tissues from early cases (Scholz 1925 van Bogaert and Scholz 1932 Scholz 1933 van Bogaert and Bertrand 1933 Wicke 1938) where prelipoid material had been described resulted in the unequivocal demonstration of brown metachromasia of myelin breakdown products as well as lipid storage in ganglion 

Metachromatic bodies have been seen in ganglion cells of the retina (Cogan et al. 1958). This material apparently does not originate from myelin sheaths, since the retina does not contain myelinated nerve fibers. 

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Schwaiger, J., F. Bucher, H. Ferling, W. Kalbfus, and R.D. Negele. 1992. A prolonged study on the effects of sublethal concentrations of bis(tri- -butyltin)oxide (TBTO) histopathological and histochemical findings in rainbow trout (Oncorhynchus mykiss). Aquat. Toxicol. 23 31 -48. 

Suda I, Eto K, Tokunaga H, et al. 1989. Different histochemical findings in the brain produced by mercuric chloride and methyl mercury chloride in rats. Neurotoxicology 10(1) 113-125. 

The fetus can synthesize the steroid nucleus (B22, B23, R9, S24), and in this respect the fetal zone of the adrenal cortex in utero is very active. Its production is considerable and owing to a low activity of the enzyme 3/ -HSD (B23, C8, G2, G3, V6), is largely composed of 3 8-hydroxy-A steroids. There is evidence that 3j8-HSD is at least to some extent substrate specific (Bl, V5), and histochemical findings have shown that 3jS-HSD enzymes specific for certain substrates may be present and active in the fetal zone of the adrenal gland (Cl). The level of some of the 3/ -hydroxy-A steroids in fetal blood is higher than that of any other known steroid (cholesterol apart) in human blood at any time. Simmer and co-workers (S20) have indicated that about 75 mg of DHA are produced every 24 hours in late pregnancy and possibly even more 16a-OH-DHA (D9, M16). Certain of the steroids formed, notably DHA, are used by the placenta for estrogen production, but the role of many others remains to be elucidated. 

Two histochemical findings are significant with respect to the alleged role of osteoblasts in bone formation the presence of glycogen vacuoles and alkaline phosphatase. (The properties of the osteoblasts will be further discussed when the mechanism of calcification is considered.) When the osteoblast is completely surrounded by the calcified matrix, it becomes an osteocyte, which is a smaller cell resembling a fibro-... 

Storage of sphingomyelin is also suggested by histochemical findings (Diezel 1957, Seitelberger et al. 1957). 

In heavily infected fish, the cestodes were so closely packed that individuals were (remarkably ) reported as being partially or totally fused together These zones of fusion gave strong histochemical reactions for -SH groups and appeared to be areas of intense metabolic activity. This suggested (750) that, in heavy infections, parasites which fail to find room for attachment on the host mucosa may derive their nutriment from another individual worm. This unusual observation clearly requires confirmation. 

Rahi AH, Hungerford JL, Ahmed AI. Ocular toxicity of desferrioxamine light microscopic histochemical and ultra-structural findings. Br J Ophthalmol 1986 70(5) 373-81. 

Histochemically, mucopolysaccharides outlining the epidermal cells can easily be seen (B28, G9, S23, S25, W19). In addition, Flesch and Esoda (F14) found evidence of a glycoproteolipid in normal stratum corneum and increased amounts in psoriatic scale. They could find no sialic acid in the material, it was resistant to hyaluronidase, and they proposed that a lack of proper breakdown of this material was important in the pathophysiology of the disease. 

A few studies have appeared on various aspects of the composition of muscle lipids in diseased muscle. It has long been known from histochemical studies that in many patients with muscular dystrophy there is a huge increase in adipose tissue between the fibers, but it seems doubtful whether there is an increase in true muscle fat. Pennington et al. (P14) could find no marked abnormality in the fatty acid composition of the infiltrated fat in a case of Duchenne dystrophy when compared with normal adipose tissue. Hughes (H15, H16) has carried out extensive studies on the concentration of various classes of lipids in the various... 

Subsequently, this finding was replicated in rats (Noda and Chikamori, 1976) and birds (Firman and Kuenzel, 1988). Later, microinjection and histochemical studies have confirmed this finding. Russell and coworkers (2003) confirmed and extended the injection studies of Beverly and coworkers (1990) and Monda and coworkers (1997) using injections into the APC. Animals injected with saUne into the APC terminate a threonine-devoid meal within 20 min, but those rats injected with 2 nmol of threonine into the APC continue to eat, as do injected animals given a complete control diet. This study also confirms the 20 min time to meal termination with lAA deficiency (Koehnle et al., 2003, 2004a, b). 

The higher doses of OPC induced neuromuscular block. The recovery of neuromuscular transmission (NMT) is an important mechanism of antidodal action of oximes [8,9]. Smith and Muir [27] stated that this action was not connected to cholinesterase reactivation. This is in agreement with our previous work [7, 11] with microelectrode technique in vivo, as well as with the histochemical and biochemical findings, which showed prcsynaptic and postsynaptic effects of oximes in rat striated muscle after OP intoxication... 

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