Histochemical study of Hurler's disease by the use of peroxidase-labelled lectins

Avaliação lectino-histoquímica de fígado e linfonodo mesentérico de búfalos mantidos em pastagens de Brachiaria spp

Resumo: Animais que se alimentam em pastos de Brachiaria spp. comumente apresentam macrófagos espumosos isolados ou agrupados no fígado, além de cristais no interior de ductos biliares. A patogênese da formação e a natureza do material armazenado nestas células, contudo, ainda não são completamente conhecidas. Através da avaliação lectino-histoquímica, saponinas esteroidais (metabólitos glicosilados secundários) têm sido identificadas nos cristais e no citoplasma das células espumosas, e provavelmente são responsáveis por danificar o fígado e levar ao acúmulo de filoeritrina. Por meio deste trabalho, objetivou-se padronizar e caracterizar a utilização da lectino-histoquímica na detecção de metabólitos glicosilados nos tecidos de búfalos mantidos em diferentes pastos de Brachiaria spp. no Brasil. Fragmentos de fígado e linfonodo mesentérico de 40 animais foram analisados: 10 búfalos mantidos em pastagem predominante de B. decumbens por aproximadamente 12 meses; 10 búfalos mantidos em pastagem predominante de B. brizantha por aproximadamente 18 meses; 10 búfalos mantidos em pastagem de B. brizantha por aproximadamente quatro anos; e, como controle negativo, 10 búfalos mantidos em pastagem livre de Brachiaria spp. desde o nascimento. Quatorze lectinas foram testadas (Con-A, SBA, WGA, DBA, UEA, RCA, PNA, GSL-I, PSA, LCA, PHA-E, PHA-L, SJA e SWGA), em um total de 1120 fragmentos avaliados. Estudos anteriores demonstraram que a lectina PNA possui marcada reatividade para macrófagos espumosos de bovinos e ovinos. No presente estudo, a lectina SWGA apresentou acentuada reatividade e alta especificidade para macrófagos espumosos; WGA, GSL, PHA-E e PHA-L mostraram moderada a acentuada reatividade, mas baixa especificidade aos macrófagos espumosos; as outras lectinas não apresentaram reatividade ou especificidade relevantes. Além disso, não houve diferença relevante de marcação entre os fragmentos coletados de animais que se alimentaram de B. decumbens por 12 meses e B. brizantha por 18 meses. Porém, a diminuição da presença e marcação lectino-histoquímica dos macrófagos espumosos nos tecidos dos búfalos que ingeriram Brachiaria brizantha durante mais tempo indica que os animais podem passar por um processo de adaptação de acordo com o tempo de ingestão da planta. A avaliação lectino-histoquímica pode ser utilizada para caracterizar o material armazenado em macrófagos espumosos presentes no fígado e linfonodo mesentérico de búfalos que se alimentam em pastagens de Brachiaria spp. e ajuda na compreensão da patogênese de formação destas células.

Lectin Histochemistry of Foam Cells in Tissues of Cattle Grazing Brachiaria spp

Brachiaria decumbens and B. brizantha (signal grass), which occupy millions of acres in Brazil, are an important source of fodder for ruminants. Sporadic outbreaks of photosensitization in ruminants grazing on signal grass have been reported. Intoxicated animals showed the presence of foamy cells in the liver, spleen, intestinal submucosa and lymph nodes. These foamy cells are macrophages. They are very difficult to distinguish with haematoxylin and eosin stain, especially in the case of isolated cells. The purpose of the present study was to detect specific carbohydrate residues of storage material in the foamy cells in tissues of cattle exposed to Brachiaria spp. The characterization of glycoconjugates provides clues to the pathogenesis of these cells. Besides, the lectin peanut agglutinin was found to be an excellent marker to differentiate and quantify the foam cells, and could be used as a specific marker.

Capillary electrophoresis with laser-induced fluorescence detection for laboratory diagnosis of galactosemia

Galactosemia, a metabolic disorder associated with the intolerance to dietary galactose due to an inherited enzymatic deficiency, is indicated by heightened levels of galactose in urine (galactosuria). In this report, capillary electrophoresis (CE) with laser-induced fluorescence detection was evaluated for its ability to screen urinary carbohydrates, particularly galactose. Neonatal urine samples with normal and abnormal levels of galactose were analyzed with galactose concentrations quantitated relative to urinary creatinine concentrations to account for variable urinary dilution. Analysis of nine samples by CE in a single-blind manner defined four as negative (normal) and five as positive for galactosuria with galactose levels as high as 146.8 +/- 5.9 mM. Galactosuria was correlated with clinical galactosemia diagnoses for four of the positive samples, while the remaining positive was associated with a patient diagnosed with Hurler's syndrome.

Clinical and clinicopathologic characteristics of ovine GM-1 gangliosidosis

Ovine GM-1 gangliosidosis is an inherited lysosomal storage disease. Nine lambs affected with the disease were studied to characterize clinical signs and to determine if there were any pathognomonic clinicopathologic abnormalities. Evaluation included physical, ophthalmic, and neurologic examinations, complete blood counts, serum enzyme and electrolyte analyses, urinalyses, cerebrospinal fluid analyses, blood gas analyses, roentgenograms, electromyograms, and electrocardiograms. Two affected lambs had clinicopathologic tests performed before and after the onset of clinical signs. The only consistent abnormalities recognized were nonspecific signs referable to the central nervous system; predominantly ataxia, conscious proprioceptive deficit most severe in the hind limbs, blindness, and recumbency. Lambs continued to eat and drink, though at diminished levels and with loss of body condition. It was concluded that there are no pathognomonic clinicopathologic abnormalities associated with ovine GM-1 gangliosidosis, and antemortem diagnosis requires enzyme assay of leukocytes or cultured fibroblasts, or lectin histochemistry of tissues obtained by biopsy. Lysosomal storage diseases should be considered among the differential diagnoses in young animals presenting with early neonatal death or with nonspecific neurological signs, in concert with an absence of diagnostic clinicopathologic findings.

Quantitative analysis of activated Kupffer cells in viral hepatitis: application of computer image analysis for lectin histochemistry

Lectin histochemistry revealed that Kupffer cells in the normal liver bound lectins such as Concanavalin A (Con A), Ricinus communis agglutinin (RCA) and Wheat germ agglutinin (WGA), but did not bind Peanut agglutinin (PNA), Dolichos fibflorus agglutinin (DBA), Ulex europaeus agglutinin I (UEA-I) or Soybean agglutinin (SBA). Kupffer cells in viral liver diseases, however, bound the PNA lectin and the binding was specific to Kupffer cells in liver parenchyma. Computer image analysis was performed using light micrographs of sections stained with immunoperoxidase and diaminobenzidine (DAB). The dark brown area of reaction products was detected by analyzing each color component (red, green and blue) in the picture and was expressed as the percent area in the parenchyma. Quantitative analysis revealed the percent area occupied by Kupffer cells positive for the PNA lectin was as follows: acute hepatitis, 2.83 +/- 0.74; chronic persistent hepatitis, 2.51 +/- 0.88; chronic aggressive hepatitis, activity moderate and severe, 4.71 +/- 2.23 and 3.45 +/- 1.84; and liver cirrhosis, 1.96 +/- 0.99. The percent area of Kupffer cells was significantly higher in CAH2A than that in chronic persistent hepatitis or in liver cirrhosis. These results suggest that the PNA lectin could be used as a marker for activated Kupffer cells and that activated Kupffer cells were increased in volume in chronic aggressive hepatitis.

Lectin histochemistry of foamy cells in non-nervous tissues of feline sphingomyelinosis

Foamy cells in non-nervous tissues from a female Siamese cat with sphingomyelinosis were examined by lectin histochemistry. Many foamy cells, so-called Niemann-Pick cells, were found in the non-nervous tissues, such as liver, spleen, lung, kidney, adrenal gland, lymph node and tonsil. These cells were positive for Concanavalia ensiformis agglutinin, Ricinus communis agglutinin-I and wheat germ agglutinin. Storage materials in the foamy cells were different from those in affected cells of the nervous tissues. This study suggests that lectin histochemistry might be helpful in the diagnosis of sphingomyelinosis.

Application of lectin histochemistry and carbohydrate analysis to the characterization of lysosomal storage diseases

In lysosomal storage diseases that involve a defect in the catabolism of glycoconjugates, lectin histochemistry adds a new dimension to the characterization of stored carbohydrates as it identifies sugar residues in situ in the affected cells and, thus, determines which cell types are affected by storage. It may be combined with chemical and biochemical analysis by h.p.l.c. The present review summarizes recent results for a variety of storage diseases and presents new data for GM1-gangliosidosis.