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Biomedical subjects

J Alroy

Publications and source records attributed to J Alroy.

At least 109 records · Page 6Linked to original sources

Histochemical similarities between human and animal globoid cells in Krabbe's disease: a lectin study.

Lectin-histochemical studies were performed on paraffin-embedded brain tissue sections to identify the specific sugar residues of undegraded "stored" substances in the cytoplasm of globoid cells from patients with globoid cell leukodystrophy. We studied brain tissues from six human patients with galactosylceramide lipidosis (i.e., Krabbe's disease) and compared them to brain tissues from animals with a similar enzyme deficiency including seven Twitcher mice, three dogs and two cats. The globoid cells in all 18 cases studied stained with succinylated-wheat germ agglutinin (S-WGA), but did not stain with Dilichos biflorus agglutinin, soybean agglutinin or Ulex europaeus agglutinin-I. Bandeirea simplicifolia agglutinin-I stained the globoid cells in Twitcher mice, dogs and cats but not those in humans. Concanavalia ensiformis agglutinin, wheat germ agglutinin and Ricinus communis agglutinin-I all stained each of the globoid cells in the mouse, dog and cat tissues, but only in some of the human cases. Peanut agglutinin, however, variably stained globoid cells in the mouse and dog cases but not at all in the human and cat cases. These results demonstrate a common terminal carbohydrate residue N-acetyl glucosamine, which binds S-WGA in the undegraded material stored within the globoid cells in galactoceramide lipidosis. These cells also contained various other stored molecules with sugar residues whose nature is determined by species or individually.

Animals↗

Cell surface carbohydrates in proliferative epidermal lesions. II. Masking of peanut agglutinin (PNA) binding sites in solar keratoses, Bowen's disease, and squamous cell carcinoma by neuraminic acid.

Seventy-six skin biopsies of proliferative lesions were studied by using 4 different lectins and an avidin-biotin-peroxidase complex. In solar keratosis, Bowen's disease and squamous cell carcinoma, malignant-appearing keratinocytes exhibited loss of membrane staining with Concanavalia ensiformis agglutinin (Con A), but revealed cytoplasmic staining. When incubated with peanut agglutinin (PNA), the malignant keratinocytes did not stain. However, the PNA binding sites were not absent, but masked by sialic acid. Following cleavage of the sialic acid with neuraminidase, free PNA binding sites could be demonstrated in the plasma membranes. In contrast, the keratinocytes in keratoacanthomas showed membrane staining with Con A and also contained free PNA binding sites. These histochemical findings confirm and extend our earlier observations regarding cell surface carbohydrates in premalignant and malignant epidermal lesions.

ABO Blood-Group System↗

A neuraminidase from Trypanosoma cruzi removes sialic acid from the surface of mammalian myocardial and endothelial cells.

Trypanosoma cruzi causes Chagasic heart disease, a major public health problem in Latin America. The mechanism of interaction of this protozooan parasite with host cells is poorly understood. We recently found that the infective trypomastigote form a T. cruzi exhibits neuraminidase activity and can desialylate mammalian erythrocytes. However, it is not known if T. cruzi can also modify the surfaces of cardiovascular cells that are directly involved in the most important clinical manifestations of this disease. Accordingly, this study determined whether T. cruzi can remove sialic acid from cultured rat myocardial or human vascular endothelial cells. Sialic acid was labeled metabolically with the precursor 3H-N-acetyl-D-mannosamine. Soluble neuraminidase, isolated from intact T. cruzi trypomastigotes, caused significant release of labeled material from myocardial cells (e.g., 2,174 +/- 27 dpm/h vs. spontaneous release of 306 +/- 30 dpm/h, n = 4, P less than 0.001). Chromatographic analysis showed that the bulk of the radioactivity released by T. cruzi neuraminidase was sialic acid. Intact T. cruzi trypomastigotes also released sialic acid from metabolically labeled myocardial cells in a concentration-dependent manner. In contrast, a noninfective form of T. cruzi, the amastigote, did not desialylate these cells. Galactose oxidase labeling demonstrated newly desialylated glycoproteins on the surface of myocardial cells treated with T. cruzi neuraminidase. Desialylation of myocardial cells was confirmed histochemically by the appearance of binding sites for peanut agglutinin, a lectin that binds to complex oligosaccharide moieties after removal of the terminal sialyl residue. T. cruzi neuraminidase also removed sialic acid from adult human saphenous vein endothelial cells, as determined by both histochemical and metabolic labeling studies. Thus, infective forms of T. cruzi can chemically modify the surfaces of myocardial and vascular endothelial cells by desialylation. This alteration may play a role in the initial interaction of this parasite with these important target cells of the host cardiovascular system.

Adult↗

Lectin histochemistry of glycolipid storage diseases on frozen and paraffin-embedded tissue sections.

Lectin histochemical studies were performed on frozen and paraffin-embedded brain tissue sections from six cases of galactosylceramide lipidosis (i.e., globoid cell leukodystrophy, or Krabbe's disease) in Twitcher mice and one case of canine infantile GM1-gangliosidosis. The globoid cells in Krabbe's disease stained with Ricinus communis agglutinin-I (RCA-I), peanut agglutinin (PNA), and Bandeirea simplicifolia agglutinin-I (BS-I) in frozen sections. However, paraffin sections and frozen sections pretreated with chloroform-methanol or xylene, from the same animals, stained with Concanavlia ensiformis agglutinin (ConA), wheat germ agglutinin (WGA), and succinylated-WGA (S-WGA), in addition to staining with RCA-I, PNA, and BS-I. The affected neurons of canine infantile GM1-gangliosidosis stained only with RCA-I in frozen sections. In paraffin sections, however, these cells were negative with RCA-I but positive with BS-I, ConA, Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA) and Ulex europaeus agglutinin (UEA-I) in paraffin sections. These results indicate that in paraffin processing of glycolipid storage disease tissue, some lectin receptors are lost and others are unmasked. The retained receptors can be stained with specific lectins and could serve as markers to characterize and differentiate among the various glycolipid storage diseases.

Animals↗

Multiple phenotypes of prostatic glandular cells in castrated dogs after individual or combined treatment with androgen and estrogen. Morphometric, ultrastructural, and cytochemical distinctions.

To demonstrate a potential for multidirectional differentiation in mature prostatic epithelium, 17 beta-estradiol 17-cyclopentylpropionate (ECP) and 5 alpha-androstane-3 alpha, 17 beta-diol dipropionate (3 alpha-diol DP) were administered individually and in combination to castrated dogs. Quantitative ultrastructural and cytochemical methods were used to distinguish phenotypes of glandular cells in the various hormonal environments. Castration-induced glandular cell regression was accompanied by an increased nuclear to cytoplasmic ratio; by enhanced keratin positivity, expressed as dispersed immunolabeled tonofilaments; and by an absence of peanut agglutinin (PNA) binding sites on luminal membranes. Administration of ECP resulted in squamous metaplasia as well as hypertrophy of the glandular epithelium. The hypertrophied estrogen-modified glandular (EMG) cells were characterized by a new population of small (0.29 micron in diameter) secretory granules, bundles of tonofilaments, and PNA-positive luminal membranes. Treatment of castrated dogs with 3 alpha-diol DP produced a greater epithelial hypertrophy than ECP. These cells were characterized by larger (0.49 micron in diameter) secretory granules, dispersed tonofilaments, and no detectable PNA receptors. Joint administration of ECP and 3 alpha-diol DP caused a florid response including squamous metaplasia and hypertrophy of the glandular epithelium which was associated with the emergence of a novel phenotype in androgen-estrogen modified glandular (A-EMG) cells. In A-EMG cells, secretory granules were similar in size to those found in 3 alpha-diol DP-dominated epithelium whereas tonofilaments often appeared in bundles and luminal membranes were PNA positive, i.e., features found in EMG cells. Our results indicate that atrophic canine prostatic glandular cells possess pluripotentiality of response to sex hormones.

Androgens↗

Localization of lectin binding sites in human, cat, and rabbit corneas.

Paraffin sections of human, cat, and rabbit corneas were stained with nine lectins, using an avidin-biotin-complex procedure to study glycoconjugates of the epithelium, keratocytes, and stromal matrix. Wheat germ agglutinin (WGA) stained plasma membranes of all epithelial cell layers of cat and human and superficial and wing cells of rabbit. Plasma membranes of superficial and wing cells of cat epithelium also stained with peanut agglutinin (PNA) and Ricinus communis agglutinin I (RCA-I). Human and cat keratocytes stained with WGA and RCA-I. Stromal matrices of all three species were stained with concanavalin A and lentil agglutinin. In neuraminidase-treated sections, the entire epithelium and keratocytes of all three species stained with PNA. Corneal sections from the three species did not stain with Bandeiraea simplicifolia I, Bandeiraea simplicifolia II, Ulex europeus I, and Soybean agglutinin. These data suggest the presence of oligosaccharides with: N-acetylglucosamine/sialic acid residues in cell membranes of corneal epithelium of all species studied and in the keratocytes of human and cat; terminal beta-galactose residues in cat and human keratocytes, beta-galactose-galactosamine chains in cat epithelial cell membranes; and sialic acid-beta-galactose-galactosamine chains in epithelial cell membranes and keratocytes of all three species.

Animals↗

Alterations in stromal glycoconjugates in macular corneal dystrophy.

Nine biotinylated lectins were used as histochemical probes to localize the carbohydrates residues of glycoconjugates in normal corneas and in corneas with macular and granular dystrophy. The lectin binding patterns of normal corneas and of corneas with granular dystrophy were indistinguishable from one another, but were distinctly different from those found in corneas with macular dystrophy. Concanavalin A reacted weakly with normal corneal stromal matrix, but stained stromal matrix of corneas with macular dystrophy intensely. Furthermore, unlike the normal corneal matrix, stromal matrix of corneas with macular dystrophy reacted positively with wheat germ agglutinin (WGA), Ricinus communis agglutinin I (RCA-I), Ulex europeus I, Dolichos biflorus, Bandeiraea simplicifolia I, Bandeiraea simplicifolia II, and soybean and peanut lectins. This study demonstrates specific alterations in glycoconjugates which occur in the corneal matrix of patients with macular dystrophy, namely the presence of oligosaccharides with terminal alpha-fucose, beta-galactose, N-acetylglucosamine and N-acetylgalactosamine residues, and oligosaccharide chains with a beta-galactose-N-acetylgalactosamine sequence.

Adult↗

Isolation of T-lymphotropic retrovirus related to HTLV-III/LAV from wild-caught African green monkeys.

Present evidence suggests that the acquired immune deficiency syndrome (AIDS) emerged in Central Africa as a new disease in recent decades. This disease has recently approached epidemic proportions in many parts of the world. The etiologic agent of AIDS is believed to be the virus HTLV-III/LAV, which has been proposed as having originated from a recent simian-human transmission in Africa. This report describes the isolation of a designated STLV-IIIAGM retrovirus closely related to HTLV-III/LAV from seven healthy wild-caught African Green monkeys (Cercopithecus aethiops) that showed the presence of antibodies designated STLV-IIIAGM. In vitro growth characteristics, ultrastructural morphology, and major proteins of 160,000 kilodaltons (kD), 120 kD, 55 kD, and 24 kD are similar to and cross-reactive with the analogous antigens of HTLV-III/LAV. The use of these serologic markers in the detection of STLV-IIIAGM-infected monkeys may be important in assuring the continued safety of a variety of biologic reagents that are derived from these primate species. The existence of a retrovirus closely related to HTLV-III/LAV that naturally infects an African nonhuman primate in the apparent absence of disease may provide a unique model for the study of human AIDS and the development of an effective vaccine.

Animals↗

Neurovisceral and skeletal GM1-gangliosidosis in dogs with beta-galactosidase deficiency.

Beta-galactosidase-deficient siblings in two litters of English springer spaniel puppies showed a progressive neurological impairment, dwarfism, orbital hypertelorism, and dysostosis multiplex. An excess of GM1-ganglioside was found in the brain. Three abnormal oligosaccharides were present in samples of urine, brain, liver, and cartilage. Light microscopy of selected tissue specimens revealed cytoplasmic vacuoles in neurons, circulating blood cells, macrophages, and chondrocytes. Ultrastructural studies demonstrated that these membrane-bound vacuoles were of two types--one containing lamellated membranes and the other, finely granular material. These clinical and pathological findings are similar to those observed in human patients affected by the infantile form of GM1-gangliosidosis.

Animals↗

Human and canine fucosidosis: a comparative lectin histochemistry study.

Selected formalin-fixed, paraffin-embedded tissues of human and canine fucosidosis were stained with nine different lectins. Neurons, splenic sinusoidal cells, hepatic Kupffer cells, tissue macrophages, and capillary endothelium from human patients with fucosidosis stained intensely with Ulex europaeus agglutinin-I (UEA-I), but the same cells were unstained in tissues from canine fucosidosis. Since UEA-I specifically binds to terminal fucose residues, and fucose-rich undegraded metabolites are stored in affected cells of both human and canine fucosidosis, the variable lectin staining pattern demonstrates an unexpected species-specific histochemical variability. This finding highlights the fact that although both species have decreased fucosidase activity, the precursor substrates, undegraded stored metabolites, and particular cells affected by this enzyme deficiency are different.

Animals↗

Identification of chitin as a structural component of Giardia cysts.

The intestinal parasite Giardia lamblia is a significant cause of diarrheal disease, which is perpetuated by the infective cyst form of the parasite. Although a rational approach to the control of giardiasis would be to inhibit cyst formation, nothing is known of the chemical composition of the cyst wall or of its biosynthesis. In these studies, we have shown that chitin is a major structural component of G. lamblia and G. muris cyst walls. This conclusion is based on the finding that chitinase specifically destroys the cyst wall, as revealed by electron microscopy. The presence of chitin was also shown directly by lectin binding studies. Of 12 lectins with diverse carbohydrate recognition specificity, only the N-acetylglucosamine-specific lectins wheat germ agglutinin, succinylated wheat germ agglutinin, and tomato lectin bound to cyst walls, as shown by fluorescence microscopy and cytochemistry. Wheat germ agglutinin binding was completely abolished by treatment of the cysts with purified chitinase. This effect was specific since it could be prevented by incubating the enzyme with chitin before treatment of the cysts. Treatment of cysts with N-acetyl-beta-glucosaminidase partially inhibited wheat germ agglutinin binding, whereas other glycosidases and proteases had no effect. These findings indicate that chitin is a major structural component of Giardia cyst walls and raise the possibility that inhibitors of chitin synthesis may be of use in preventing encystation and thus controlling spread of the disease.

Acetylglucosamine↗

Swainsonine toxicosis mimics lectin histochemistry of mannosidosis.

Cells affected by locoweed (Astragalus lentiginosus) and Swainsona galegifolia toxicosis or mannosidosis exhibit similarities in their catabolism of N-linked glycoproteins and accumulation of cytoplasmic vacuoles. We used nine different biotinylated lectins as histochemical markers for specific sugars and avidin-biotin-peroxidase complex as a visualant to study the cells affected with these conditions. Since locoweed and Swainsona spp block mannosidase activity, we expected a similar lectin staining pattern in cells under these conditions as that seen in mannosidosis. Concanavalia ensiformis agglutinin, wheat germ agglutinin and succinyl wheat germ agglutinin stained the undegraded glycoproteins and oligosaccharides stored in the lysosomes of affected cells in all three conditions. Bandeirea simplicifolia-I, Dolichos biflorus agglutinin, peanut agglutinin, Ricinus communis agglutinin-I, soybean agglutinin and Ulex europaeus agglutinin-I did not stain any of these cells. These results indicate that in all three conditions there is an accumulation of undegraded oligosaccharides that contain alpha-mannosyl and beta-N-acetyl glucosamine residues which are revealed by lectin staining in the vacuoles of all affected cells.

Alkaloids↗

Distribution of carbohydrate residues in normal skin.

Sections of biopsies of normal skin obtained from 11 individuals were incubated with 8 lectins using an avidin-biotin complex (ABC). All sections when incubated with the appropriate lectin showed the presence of the following carbohydrate residues: L-fucose, beta-(1-4)-D-GlcNAc)2 (N-acetylglucosamine), acetylneuraminic acid, Gal-beta-(1-3)-GalNAc (N-acetyl-galactosamine), beta-D-galactose, alpha-D-glucose, and alpha-D-mannose. In addition, sections of individuals with blood group A showed alpha-D-GalNAc and sections of individuals with blood group B showed alpha-D-galactose. In the stratum (str.) basale, carbohydrates were present in small quantities, but as the cells matured and moved upward, the incorporation of carbohydrates into the cell membranes increased considerably. In the str. granulosum, lectin reactivity was absent in many sections, probably due to masking by phospholipids. The dark cells in the eccrine glands showed reactivity with all lectins except in the one nonsecretor with blood group A1, whose dark cells showed no L-fucose and alpha-D-GalNAc. The endothelial cells of the blood vessels showed lectin reactivity except when incubated with concanavalin A. The sebaceous glands showed both cytoplasmic and membrane staining when incubated with various lectins.

Acetylgalactosamine↗

Cell surface carbohydrates in psoriasis. Defective cytoplasmic transport by glycoconjugates carrying fucose residues suggested by lectin staining.

Eleven biopsy specimens of normal skin and twenty-four biopsy specimens of psoriatic lesions were examined histochemically by using several lectins (Ulex europaeus, UEA-1; Dolichos biflorus, DBA; Bandeirea simplicifolia, BS-I; Concanvalia ensiformis, Con A; Triticum vulgaris, WGA; Ricinus communis, RCA; Arachis hypogoea, PNA) in order to evaluate the presence and distribution of various carbohydrates in normal and psoriatic keratinocytes. The findings revealed that keratinocytes from psoriatic lesions are distinguished by a different composition of carbohydrate residues incorporated in their plasma membranes. In particular, the intracellular transport of alpha-L-fucose, alpha-D-mannose, and alpha-D-glucose to the plasma cell membrane is impeded, whereas their synthesis in the cytoplasm of the psoriatic keratinocytes is largely unaltered. In addition, due to the lack of terminal alpha-L-fucose, the alpha-D-N-acetyl-galactosamine and alpha-D-galactose residues cannot be transferred to the plasma membranes and, therefore, the antigens for blood groups A and B remain incomplete in psoriatic epidermis. On the basis of these findings and in comparison with previous findings of our group on hyperproliferative, malignant keratinocytes, it is concluded that particularly the disordered cytoplasmic transport of alpha-L-fucose-carrying glycoconjugates may represent a specific defect in psoriasis, possibly linked with the pathogenesis of this disease.

Acetylgalactosamine↗

Nephrogenic adenoma and embryonic kidney tubules share PNA receptor sites.

Nephrogenic adenoma a rare bladder, ureter, or urethral lesion, is of disputed pathogenesis, metaplastic and congenital etiologies both being implicated in its development. Since light and electron microscopy have been unable to fully resolve the lesion's pathogenesis, the authors used biotinylated lectins as probes and avidin-biotin peroxidase complex (ABC) as a visualant to study cases of nephrogenic adenomas and compared their lectin binding patterns with those of normal transitional epithelium, human embryonic kidneys, and cases of cystitis cystica and glandularis and squamous metaplasia of the bladder in an effort to clarify this issue. Only the epithelial lining of the luminal surface and tubuli in nephrogenic adenoma and tubules in embryonic kidney exhibited free PNA receptor sites. The striking staining similarities between the epithelial components of nephrogenic adenomas and mesonephric and metanephric tubules complement previous findings concerning the origin of nephrogenic adenoma.

Adenoma↗

Cell-surface carbohydrates in proliferative epidermal lesions. Distribution of A, B, and H blood group antigens in benign and malignant lesions.

The distribution of A, B, and H blood group antigens was studied by means of peroxidase-antiperoxidase technique in normal skin and in lesions of carcinomas in situ (solar keratoses, Bowen's disease), squamous cell carcinoma, keratoacanthomas, and verrucae. In normal skin, the epidermis of persons of blood group O showed H antigens throughout the epidermis; of blood group A, H and A antigens; and of blood group B, H and B antigens. In lesions of solar keratoses, there were no antigens of blood groups in the irregular downward proliferations. In five of 11 cases of Bowen's disease, there were no antigens of blood groups in the epidermis. In eight out of 10 cases of squamous cell carcinoma, no antigens of blood groups were found in the islands of the neoplastic process, but in two cases they were present in a patchy distribution. In the benign lesions examined, the antigens of A, B, and H blood groups were always present, although in verrucae the staining was confined to the upper layers of the epidermis only.

ABO Blood-Group System↗

Identification of glycoprotein storage diseases by lectins: a new diagnostic method.

The specific diagnosis of glycoprotein storage diseases is made by demonstrating a deficiency in enzyme activity or an elevation of undegraded oligosaccharides in cells or body fluids. Prospective sampling and expensive specialized biochemistry, which is also time consuming, are required for such studies. We used lectin reagents on paraffin-embedded tissue sections to identify the specific sugars in undegraded stored substances. We studied 22 cases of glycoprotein storage diseases and differentiated histochemically between alpha- and beta-mannosidosis, fucosidosis, and sialisidosis. Cells affected with alpha-mannosidosis stained with Concanavalia ensiformis (Con A), Triticum vulgaris (WGA), and succinyl-WGA (S-WGA), while beta-mannosidosis cells did not stain with any of the lectins used. In fucosidosis the affected cells stained with Ulex europeus-I (UEA-I), while sialisidosis-affected cells stained with WGA, and in three cases with Arachis hypogea (PNA). This study indicates that lectin histochemistry provides a reliable specific diagnostic pattern for some glycoprotein storage diseases using a simple and inexpensive method.

Adult↗