Acid Glycosaminoglycans Research Articles

МУКОПОЛІСАХАРИДОЗ ЯК РІДКІСНЕ ГЕНЕТИЧНЕ ЗАХВОРЮВАННЯ В ПЕДІАТРИЧНІЙ ПРАКТИЦІ.

<p>Мукополісахаридози - група метаболічних захворювань сполучної тканини, пов'язаних з порушенням обміну кислих глікозаміногліканів (GAG,<br />мукополісахаридів), викликаних недостатністю лізосомнихферментів обміну глікозаміногліканів. Профілактика мукополісахаридозів - пренатальна діагностика, заснована на безпосередньому визначенні дефіциту ферменту в амніотичних клітинах.<br /><br /></p>

Macroscopic and histological investigation of guanaco footpads (Lama guanicoe, Müller 1776).

The surface of guanaco footpads is characterized by hairless skin with up to 4-mm-thick stratum corneum that protects from abrasion. The horny layer is pliable and elastic, and ensures firm contact with irregular ground. It is padded with a particular structure of the subcutaneous layer, the digital cushion. The flat cushions of each of the two digits are of elongated ovate shape, each about 45-mm long, up to 20-mm wide, and 8-mm thick. The cushions are lined by a 1-2-mm-thick capsule that resembles a tunica albuginea. The capsule consists of coarse collagen fibers, with elastic fibers absent. The cushion capsule and dermis approach each other, and fuse along a line that runs parallel to the longitudinal axes of cushion and digit. Loose connective tissue rich in elastic fibers and acidic glycosaminoglycans separates dermis and cushion capsule lateral to the narrow interconnecting zone. The cushion capsule encloses cloudy yellowish, gelatinous material. Microscopy shows bundles of elastic fibers in abundant mucinous matrix. Tightly gathered elastic bundles adjoin the inner surface of the capsule. Rough cords of elastic fibers branch out from there and traverse to the opposite side. The cushion is pressed flat, and elastic fibers are stretched when bearing weight. With relief of load, elastic fibers contract and reset the cushion's shape. Contractile cells are absent. A resistant capsule and easily malleable mucinous contents establish the functioning as a gel pad. Mucinous connective tissue between elastic fiber bundles contains abundant basophilic matrix. Hyaluronan, chondroitin sulfate, and dermatan sulfate are main matrix constituents. Spindle-shaped or stellate fibroblasts contain vimentin, S100 protein, and neuron specific enolase. Moprhology, staining characteristics and synthesis activities of these cells meet the criteria to be classified as myxoid cells. The connective tissue in guanaco digital cushions represents myxoid tissue.

Полисахариды клеток соединительной ткани стенки двенадцатиперстной кишки эмбрионов человека

These studies are conducted on 36 human embroys and foetus. Four stages are marked out in the development of connective tissue of the duodenum: 1) mesenchymal stage (28-35 the day of the embryo); 2) the stage of loose embryonic connective tissue (35 days - 3.5 months of foetus); 3) the stage of formation of the definitive loose connective tissue (3,5-6,5 months of the fetus); 4) the stage of initial definitive development (6,5 months before birth of the fetus). Each stage is characterized by a specific set of cellular differens, chemical composition of polysaccarides of cells of connective tissue and intercellular substance. On mesenchymal stage of development, the cells and intercellular substance CHIC-positive substances – contain glycogen and proteoglycans that give metachromasia, stained with alcian blue on Shubitch, Hale, but CHIC are negative. At the stage of loose connective tissue in mesenchymal cells, the reduction of glycogen and accumulation of glycosaminoglycans are identified. Glycogen, hyaluronic acid and precursors sulfated groups glycosaminogly-cans are detected in fibroblasts, endothelium of capillaries, in primary blood cells, in macrophages. At the stage of formation of loose connective tissue, there is the accumulation of TIME – amelanotic compounds (proteoglycans) in the cells and in the intercellular substance. Identification of them showed that the precursors of sulfated glycosaminoglycans and chondroitin sulfates (HSC) type C are identified. The intensity of the response to glycogen decreases. In the initial definitive development in the cytoplasm of fibroblasts – there is moderate staining on Hale-positive substances, poor color on Shubich and toluidine blue. In plasmablastics and in B-lymphocytes, the glycogen and glycosaminoglycans types of hyaluronic acid are identified. In the cytoplasm of mast cells, the substances such as hyaluronic acid, HSH type and unfinished synthesis heparina are identified.

NMR characterization of the electrostatic interaction of the basic residues in HDGF and FGF2 during heparin binding

Electrostatic interaction is a major driving force in the binding of proteins to highly acidic glycosaminoglycan, such as heparin. Although NMR backbone chemical shifts have generally been used to identify the heparin-binding site on a protein, however, there is no correlation between the binding free energies and the perturbed backbone chemical shifts for individual residues. The binding event occurs at the end of a side chain of basic residue, and does not require causing significant alterations in the backbone environment at a distance of multiple bonds. We used the H2CN NMR pulse sequence to detect heparin binding through the side-chain resonances Hε–Cε–Nζ of Lys and Hδ–Cδ–Nε of Arg in the two proteins of hepatoma-derived growth factor (HDGF) and basic fibroblast growth factor (FGF2). H2CN titration experiments revealed chemical shift perturbations in the side chains, which were correlated with the free energy changes in various mutants. The residues K19 in HDGF and K125 in FGF2 demonstrated the most significant perturbations, consistent with our previous observation that the two residues are crucial for binding. The result suggests that H2CN NMR provides a precise evaluation for the electrostatic interactions. The discrepancy observed between backbone and side chain chemical shifts is correlated to the solvent accessibility of residues that the K19 and K125 backbones are highly buried with the restricted backbone conformation and are not strongly affected by the events at the end of the side chains.

Influence of Different Growth Factors on Chondrogenic Differentiation of Adipose-Derived Stem Cells in Polyurethane-Fibrin Composites

Introduction Chondrogenic differentiation of adipose-derived stem cells (ASCs) has proven to be feasible. To compensate for laryngeal palsy or cartilage defects after surgery or trauma using tissue engineering, a formable and stable scaffold material is mandatory. Methods ASCs were seeded in fibrin-polyurethane scaffolds and cultured in chondrogenic differentiation medium adding the growth factors TGF-□1, TGF-□3, and BMP-2 for up to 35 days. Results Histological examination showed acid glycosaminoglycans in the extracellular matrix in all groups. Immunofluorescence presented positive staining for collagen II, aggrecan, and SOX-9 in the TGF-□1–, TGF-□3–, and BMP-2-group. With Real-time PCR analyses, chondrogenic differentiation became apparent by the expression of the specific genes COL2A1 (collagen II), AGC 1 (aggrecan), and SOX-9, whereas collagen II expression was low in all groups compared to bone marrow-derived stem cells (BMSC) due to reduced chondrogenic ability. Conclusions These findings demonstrate the general ability of ASCs to differentiate into matrix-producing chondrocytes in fibrin-polyurethane scaffolds. However, further experiments are necessary to enhance this chondrogenic potential of ASCs seeded in fibrin-polyurethane scaffolds in order to produce a suitable regeneration method for treating cartilage defects or an implantable medialization material for vocal cord palsy.

Monotypic gland-cell regions on the body surface of two species of Arion: ultrastructure and lectin-binding properties

Distinct areas of the body surface of Arion (Arion) rufus (Linnaeus, 1758) and A. (A.) vulgaris Moquin-Tandon, 1855 contain only one type of glandular cell. The specific monotypic glandular cells that are characteristic for each of these areas differ with respect to staining properties, the structure of glycans (binding of different lectins) and in their ultrastructure, particularly in the appearance of the endoplasmic reticulum. Four such glandular areas can be defined. (1) The protein gland of the anterior margin of the foot probably produces the proteins responsible for changing the trail mucus produced from other glands to strong glue-mucus. Histochemical reactions point to the presence of neutral mucosubstances, probably mucoproteins. The strongest binding of applied lectins were those specific for N-acetyl-α-d-galactosaminyl residues, specific for β-linked terminal galactose, and specific for galactose β1-3N-acetylgalactosamine. A characteristic feature of the ultrastructure of the gland cells is tightly arranged membranes of the endoplasmic reticulum as typically found in protein secreting cells. (2) The suprapedal gland consists of a flat anterior part (located in the bottom of a funnel-shaped cavity between the ventral surface of the head and the opposite dorsal surface of the anterior foot) and a posterior tubular part on the dorsal side of the foot musculature (opening by an excretory duct into the funnel-shaped cavity). Histochemical reactions indicate the presence of acid glycosaminoglycans of high negative charge density. Binding of lectins with all secretion stages indicate the presence of the terminal sequence Galα-1-3Galβ1-R. As a special feature of the ultrastructure of the gland cells, their endoplasmic reticulum contains densely packed tubules protruding at right angle from its membrane into its lumen. (3) On the ventral surface of the head, a monotypic glandular region extends into the roof of the funnel-shaped recess. Histochemical reactions indicate the presence of neutral mucosubstances. The strongest bindings of the applied lectins with the secretion were specific for N-acetyl-α-d-galactosaminyl residues and for β-linked terminal galactose. (4) Another monotypic glandular region is situated in the ventral surface of the anterior part of the mantle. Histochemical reactions indicate acid mucosubstances with high negative charge density. None of the applied lectins reacted with cells of that region. Each of the first three glandular regions has an extension into the peripodial groove on either side of the foot sole; the ‘peripodial gland’ of authors is therefore a compound structure. The branches of the protein gland extend as far back as the level of the pneumostome, while the branches of the suprapedal gland and of the glandular region of the ventral surface of the head extend further, to the corners of the base of the triangular caudal gland. The trail mucus is produced mainly by the suprapedal gland that extends with its branches into the peripodial groove. Monotypic gland cell regions are possible candidates as sources of mucus of known cellular origin for biochemical analyses.

Cadherin 2 as Human Notochordal Cell Marker and its Expression Pattern in Disk Degeneration

Introduction Cadherins are transmembrane glycoproteins that mediate calcium-dependent cell adhesion. Recent studies suggest that cadherins also have nonadhesive functions. Maturation of human intervertebral disk (IVD) as well as early events of IVD degeneration in a mouse model1 is associated with segregation of nucleus pulposus (NP) cells suggesting that disk degeneration may be associated with cell adhesion molecule activities. From our microarray data analysis and subsequent immunohistochemical assays, we have revealed specific expression of Cdh2 gene and its product, cadherin 2/N-cadherin, in rodent notochordal NP cells, suggesting a potential regulatory role of cadherins in IVD homeostasis. Cadherin 2 belongs to the classic cadherin family. To date, the expression and function of cadherin 2 in IVD and its relationship to disk degeneration remain elusive. We aim to study the expression pattern of cadherin 2 in human IVD using aborted fetus and clinical samples, and to investigate its function in the rodent NP via a protein ablation strategy. Materials and Methods Degenerated lumbar disks (grade 3, Schneiderman's classification) ( n = 5) were obtained from 45 to 58-year-old patients. Scoliotic lumbar disks ( n = 5) from patients were obtained as nondegenerated samples. Lower lumbar spine of the aborted fetus in the second trimester were used as controls. Compartmental origin and degeneration status of the samples was validated by our established multicolor FAST staining method,2 in which the disk sections were sequentially stained with alcian blue, safranin-O, tartrazine, and fast green. Immunohistochemistry for cadherin 2 was performed on paraffin sections with antigen retrieval by hyaluronidase and citrate buffer method and counterstained by hematoxylin to visualize cell nuclei. The percentage of positive cells was calculated and analyzed by nonparametric u test. For protein ablation study, 4-month-old inbred Lewis rats were anesthetized and the tail IVDs were exposed for injection of rabbit anti-cadherin 2 antibody or control IgG ( n = 6 for each) into the NP via 34G hypodermic needle. By 2 weeks and 8 weeks after operation, the disks were harvested for histological examination. Results Human fetal NP cells showed homogeneous cadherin 2 expression. Annulus fibrosus (AF), cartilaginous endplates, and vertebral bodies showed no signal of cadherin 2. However, adult NP showed heterogeneous cadherin 2 expression, where only a subpopulation of the NP cells expressed the protein. Nondegenerated and degenerated NP exhibited different cell distribution with the later tended to contain cell clusters. The frequency of cadherin 2 expressing cells was significantly higher in the degenerated NP (51.9%) than in nondegenerated NP (20.0%). FAST staining assay showed that degenerated NP samples were intensely stained by safranin-O instead of alcian blue, validating a loss of sulfated acidic glycosaminoglycan due to degeneration. Cadherin 2 protein ablation study showed that the vacuolated notochordal cells in the NP partially transformed into elongated or rounded nonvacuolated cells, which are commonly presented in degenerative disks. Conclusion Human fetal NP mainly contains notochordal cells. In this study, we showed that cadherin 2 is expressed homogeneously in fetal NP suggesting cadherin 2 is a marker of notochordal cells. The reduction of cadherin 2 positive NP cells in mature human IVD is consistent with gradual loss of notochordal cells after the first decade of life. Under this notion, our findings imply that a subpopulation (20%) of NP cells retain a phenotype resembling notochordal cells in mature human IVD, although morphologically they are not vacuolated. The higher frequency of cadherin 2 expressing cells in degenerated NP implicates that proliferation of cells of notochordal origin occurs during disk degeneration. Protein ablation study suggests that cadherin 2 has a regulatory function in maintenance of notochordal cells and a loss of its function may initiate disk degeneration. Overall, our study implies a function of cadherin 2 in NP homeostasis. I confirm having declared any potential conflict of interest for all authors listed on this abstract No Disclosure of Interest None declared Yang F, et al. Injury-induced sequential transformation of notochordal nucleus pulposus to chondrogenic and fibrocartilaginous phenotype in the mouse. Journal of Pathology 2009;218(1):113–121 Leung VY, et al. Matrix remodeling during intervertebral disk growth and degeneration detected by multichromatic FAST staining. Journal of Histochemistry and Cytochemistry 2009;57(3):249–256

Cadherin 2 as Human Notochordal Cell Marker and its Expression Pattern in Disk Degeneration

IntroductionCadherins are transmembrane glycoproteins that mediate calcium-dependent cell adhesion. Recent studies suggest that cadherins also have nonadhesive functions. Maturation of human intervertebral disk (IVD) as well as early events of IVD degeneration in a mouse model1 is associated with segregation of nucleus pulposus (NP) cells suggesting that disk degeneration may be associated with cell adhesion molecule activities. From our microarray data analysis and subsequent immunohistochemical assays, we have revealed specific expression of Cdh2 gene and its product, cadherin 2/N-cadherin, in rodent notochordal NP cells, suggesting a potential regulatory role of cadherins in IVD homeostasis. Cadherin 2 belongs to the classic cadherin family. To date, the expression and function of cadherin 2 in IVD and its relationship to disk degeneration remain elusive. We aim to study the expression pattern of cadherin 2 in human IVD using aborted fetus and clinical samples, and to investigate its function in the rodent NP via a protein ablation strategy.Materials and MethodsDegenerated lumbar disks (grade 3, Schneiderman's classification) (n = 5) were obtained from 45 to 58-year-old patients. Scoliotic lumbar disks (n = 5) from patients were obtained as nondegenerated samples. Lower lumbar spine of the aborted fetus in the second trimester were used as controls. Compartmental origin and degeneration status of the samples was validated by our established multicolor FAST staining method,2 in which the disk sections were sequentially stained with alcian blue, safranin-O, tartrazine, and fast green. Immunohistochemistry for cadherin 2 was performed on paraffin sections with antigen retrieval by hyaluronidase and citrate buffer method and counterstained by hematoxylin to visualize cell nuclei. The percentage of positive cells was calculated and analyzed by nonparametric u test. For protein ablation study, 4-month-old inbred Lewis rats were anesthetized and the tail IVDs were exposed for injection of rabbit anti-cadherin 2 antibody or control IgG (n = 6 for each) into the NP via 34G hypodermic needle. By 2 weeks and 8 weeks after operation, the disks were harvested for histological examination.ResultsHuman fetal NP cells showed homogeneous cadherin 2 expression. Annulus fibrosus (AF), cartilaginous endplates, and vertebral bodies showed no signal of cadherin 2. However, adult NP showed heterogeneous cadherin 2 expression, where only a subpopulation of the NP cells expressed the protein. Nondegenerated and degenerated NP exhibited different cell distribution with the later tended to contain cell clusters. The frequency of cadherin 2 expressing cells was significantly higher in the degenerated NP (51.9%) than in nondegenerated NP (20.0%). FAST staining assay showed that degenerated NP samples were intensely stained by safranin-O instead of alcian blue, validating a loss of sulfated acidic glycosaminoglycan due to degeneration. Cadherin 2 protein ablation study showed that the vacuolated notochordal cells in the NP partially transformed into elongated or rounded nonvacuolated cells, which are commonly presented in degenerative disks.ConclusionHuman fetal NP mainly contains notochordal cells. In this study, we showed that cadherin 2 is expressed homogeneously in fetal NP suggesting cadherin 2 is a marker of notochordal cells. The reduction of cadherin 2 positive NP cells in mature human IVD is consistent with gradual loss of notochordal cells after the first decade of life. Under this notion, our findings imply that a subpopulation (20%) of NP cells retain a phenotype resembling notochordal cells in mature human IVD, although morphologically they are not vacuolated. The higher frequency of cadherin 2 expressing cells in degenerated NP implicates that proliferation of cells of notochordal origin occurs during disk degeneration. Protein ablation study suggests that cadherin 2 has a regulatory function in maintenance of notochordal cells and a loss of its function may initiate disk degeneration. Overall, our study implies a function of cadherin 2 in NP homeostasis.I confirm having declared any potential conflict of interest for all authors listed on this abstractNoDisclosure of InterestNone declaredYang F, et al. Injury-induced sequential transformation of notochordal nucleus pulposus to chondrogenic and fibrocartilaginous phenotype in the mouse. Journal of Pathology 2009;218(1):113–121Leung VY, et al. Matrix remodeling during intervertebral disk growth and degeneration detected by multichromatic FAST staining. Journal of Histochemistry and Cytochemistry 2009;57(3):249–256

Influence of different growth factors on chondrogenic differentiation of adipose-derived stem cells in polyurethane-fibrin composites

Chondrogenic differentiation of adipose-derived stem cells (ASCs) has proven to be feasible. To compensate for laryngeal palsy or cartilage defects after surgery or trauma using tissue engineering, a formable and stable scaffold material is mandatory. ASCs were seeded in fibrin-polyurethane scaffolds and cultured in chondrogenic differentiation medium adding the growth factors TGF-b1, TGF-b3, and BMP-2 for up to 35 days. Histological examination showed acid glycosaminoglycans in the extracellular matrix in all groups. Immunofluorescence presented positive staining for collagen II, aggrecan, and SOX-9 in the TGF-b1-, TGF-b3-, and BMP-2-group. With Real-time PCR analyses, chondrogenic differentiation became apparent by the expression of the specific genes COL2A1 (collagen II), AGC 1 (aggrecan), and SOX-9, whereas collagen II expression was low in all groups compared to bone marrow-derived stem cells (BMSC) due to reduced chondrogenic ability. These findings demonstrate the general ability of ASCs to differentiate into matrix-producing chondrocytes in fibrin-polyurethane scaffolds. However, further experiments are necessary to enhance this chondrogenic potential of ASCs seeded in fibrin-polyurethane scaffolds in order to produce a suitable regeneration method for treating cartilage defects or an implantable medialization material for vocal cord palsy.

Thyroid dermopathy localized to areas of injury and responsive to complete decongestive physiotherapy

To the Editor: Thyroid dermopathy is defined by the deposition of acid glycosaminoglycans in the dermis.1 It is the primary cutaneous manifestation of Graves disease, which can also present with opthalmopathy, goiter, or thyroid acropachy.2 Although thyroid dermopathy is most commonly manifested on the legs as pretibial myxedema, other sites of involvement are possible. We report a case of extensive myxedema of the upper and lower extremities that was localized to skin previously traumatized by burns and skin grafting and successfully treated with complete decongestive physiotherapy.

Biological Evaluation of Tissue-Engineered Cartilage Using Thermoresponsive Poly(<i>N</i>-isopropylacrylamide)-Grafted Hyaluronan

In order to contribute to the development of minimally invasive surgery techniques for autologous chondrocyte implantation, a novel self-assembling biomaterial consisting of thermoresponsive poly(N-isopropylacrylamide)-grafted hyaluronan (PNIPAAm-g-HA) has been synthesized as an injectable scaffold for cartilage tissue engineering. The aim of this study was to investigate the efficacy and cytocompatibility of PNIPAAm-g-HA to normal chondrocytes by using reverse transcription-polymerase chain reaction (RT-PCR) analysis and histochemical staining in preliminary in vitro and in vitro experiments. Hematoxylin and eosin staining showed homogeneous distribution of cells in the PNIPAAm-g-HA hydrogel in 3-dimensional in vitro cultivation. Alcian blue staining also indicated that abundant extracellular matrix formation, including acidic glycosaminoglycans, occurred in tissue-engineered cartilage over time in vitro. Cartilage-related gene expression patterns, which were tested in rabbit normal chondrocytes embedded in the hydrogel, were almost maintained for 4 weeks. Transforming growth factor-β1 (TGF-β1) stimulation enhanced the expression of SRY-related HMG box-containing gene 9 (Sox9) and type X collagen genes suggesting promotion of chondrogenic differentiation. Histochemical evaluation showed neocartilage formation following subcutaneous implantation of the chondrocyte-gel mixture in nude mice. Furthermore, TGF-β1 stimulation promoted production and maturation of the extracellular matrix of the in situ tissue engineered hyaline cartilage. These data suggested that PNIPAAm-g-HA could be a promising biomaterial, i.e., a self-assembling and injectable scaffold for cartilage tissue engineering.

Bone matrix glycosaminoglycans and osteoporosis development in early aging OXYS rats

Proteoglycans play a crucial role in bone tissue formation promoting consolidation of collagen fibers and bonds between them and mineral crystals. The composition of extracellular matrix proteoglycans was analyzed in early aging OXYS rats with signs of early osteoporosis versus Wistar rats at the age of 2, 4, 6, and 8 months. It was found that bone mineral density in two month OXYS rats was lower than in age-matched Wistar rats. It increased only till 6 month of age in OXYS rats, and during the whole observation period in Wistar rats. Formation of peak bone mass in Wistar rats was accompanied by change in composition of proteoglycan pools in bone tissue matrix: accumulation of macromolecular keratan sulfate-containing proteoglycans, and decrease of uronic acid and sulfated glycosaminoglycan content. OXYS rats were noted for accumulation of micro- and macromolecular proteoglycans: uronic acids and sulfated glycosaminoglycans. Chondroitin sulfate AC and dermatan sulfate were accumulated in OXYS rat bone tissue with the increase in mineral density difference. Keratin sulfate was completely absent here, in contrast to Wistar rats.

Carboxymethyl‐chitin promotes chondrogenesis by inducing the production of growth factors from immune cells

Many techniques have been tested for their ability to restore cartilage defects, but several problems still remain in the complete healing of injured cartilage. In our previous study, we found that a carboxymethyl-chitin/beta-tricalcium phosphate (CM-chitin/beta-TCP) composite induced cartilage regeneration in the osteochondral defects of rabbits in vivo. We also found that CM-chitin stimulated peritoneal exudate cells (PEC) in mice and induced several kinds of inflammatory cytokines and transforming growth factor beta-1 (TGF-beta1). In this study, we examined whether CM-chitin is responsible for the induction of chondrogenesis via the production of TGF-beta1 in vitro. The murine pluripotent cell line C3H10T1/2 was maintained as a micromass culture in conditioned medium prepared from PEC stimulated with and without CM-chitin. CM-chitin-conditioned medium induced RNA expression of the chondrogenic-factor Sox9 and the matrix proteins aggrecan, Col2a1, and Comp. Their expression levels were decreased in the presence of anti-TGF-beta1 antibody. The micromass tissues cultured in CM-chitin conditioned medium at day 21 were clearly stained by Toluidine blue or Alcian blue (histological staining) and collagen II antibody (immunohistological staining), showing the expression of acidic glycosaminoglycan and type II collagen. Similar results were observed in micromass tissue stimulated with TGF-beta1 as a positive control. However, no chondrogenesis occurred when CM-chitin was added directly to a C3H10T1/2 cell culture. These results indicated that CM-chitin is a potent inducer of chondrogenesis via the induction of TGF-beta1 in immune cells.

Features of the Ocular Harderian Gland in Three Balaenopterid Species Based on Anatomical, Histological and Histochemical Observations

Abstract. The ocular Harderian gland (HG) in three Balaenopterid species (common minke whale Balaenoptera acutorostrata, sei whale B. borealis and Bryde's whale B. edeni) was investigated at macroscopic and microscopic levels. The gland encircled the eyeball similar to a belt form on mainly the corneal side, and was more developed in the rostral and ventral aspects of the eyeball. The multiple secretory ducts of the gland opened into conjunctival fornix and palpebral conjunctiva. The gland also possessed a prominent duct system composed of tubuli which were divided into lobes. Histochemically, the secretory cells of the gland were characterized by the presence of both acid and neutral glycosaminoglycans for Alcian blue (pH 2.5), periodic acid-Schiff, and the absence of lipids for Sudan black B. These characteristics indicated that there are differences from those of HG in some terrestrial mammals, and suggested it may be one of the adaptations for protecting eyes from sea water in aquatic environments.

Liposomal delivery of doxorubicin to hepatocytes in vivo by targeting heparan sulfate

Previous work demonstrated that liposomes, containing an amino acid sequence that binds to hepatic heparan sulfate glycosaminoglycan, show effective targeting to liver hepatocytes. These liposomes were tested to determine whether they can deliver doxorubicin selectively to liver and hepatocytes in vivo. Fluid-phase liposomes contained a lipid-anchored 19-amino acid glycosaminoglycan targeting peptide. Liposomes were loaded with doxorubicin and were non-leaky in the presence of serum. After intravenous administration to mice, organs were harvested and the doxorubicin content extracted and measured by fluorescence intensity and by fluorescence microscopy. The liposomal doxorubicin was recovered almost entirely from liver, with only trace amounts detectable in heart, lung, and kidney. Fluorescence microscopy demonstrated doxorubicin preferentially in hepatocytes, also in non-parenchymal cells of the liver, but not in cells of heart, lung or kidney. The doxorubicin was localized within liver cell nuclei within 5 min after intravenous injection. These studies demonstrated that liposomal doxorubicin can be effectively delivered to hepatocytes by targeting the heparan sulfate glycosaminoglycan of liver tissue. With the composition described here, the doxorubicin was rapidly released from the liposomes without the need for an externally supplied stimulus.

Structural study of the salivary glands of Anocentor nitens (Acari: Ixodidae) during the feeding cycle

The salivary glands of Anocentor nitens (Neumann,1897) occur in pairs and are located in the anterolateral region of the general cavity, with milky white color and approximately equal sizes. They consist of a secretory portion and an excretion duct. In some glandular acini, all the cells had a basophilic appearance they were stained by hematoxylin, whereas others presented cells with different staining affinities. In this work, we describe the variations observed in these glands during the feeding cycle of ticks [after feeding (0 h) and successively at 24, 48, 72, 96, 120, and 144 h]. The cells stained by hematoxylin were shown to be more reactive to Alcian blue, thus demonstrating the presence of acid glycosaminoglycans, whereas those stained using eosin presented weak or no reaction. A strong reaction was found by the use of the periodic acid-Schiff (PAS) technique, thereby suggesting the presence of glycogen and/or glycoconjugates containing hexose, confirmed by using salivary amylase before PAS, with partial destaining of the slides. Continuing presence of residual staining in these cells suggests the presence of glycoconjugates containing hexose. Cells with nuclei of circular outline and few granules (of different sizes) were found in type II acini, 72 h after collection. Type I acini presented wide lumina and walls composed of larger numbers of cells of cubic to cylindrical shape. The pronounced degranulation shown in this study over the course of the feeding cycle was associated with the release of substances for oviposition.

Effect of desmopressin on erythrocyte aggregation

Experiments on rats showed that desmopressin in doses recommended for single injections to humans increased erythrocyte aggregation. A close correlation between erythrocyte aggregation index and blood viscosity, on the one hand, and plasma content of acid glycosaminoglycans on the other was detected.

The Organic−Mineral Interface in Teeth Is Like That in Bone and Dominated by Polysaccharides: Universal Mediators of Normal Calcium Phosphate Biomineralization in Vertebrates?

Solid-state NMR shows that polysaccharides, probably acidic glycosaminoglycans, dominate the mineral−organic interface in tooth material, as they do in bone, suggesting a wide-reaching, perhaps universal, role for them in directing nonpathophysiological vertebrate biomineralization.

Effect of synovectomy on the glycosaminoglycan content in the articular cartilage

Experimental Synovectomy of canine-knee was used for the study of synovial regeneration; histochemical staining with safranin-O and alcian-blue 8 GS, scanning electronmicroscopical studies of cryostat sections with sulfur Stimulation and biochemical analysis of the acid glycosaminoglycan content of cartilage were performed. Following synovectomy the developed "neosynovialis" shows contrary to the situation before a remarkable fibrosis beneath the lining-cells. The acid glycosaminoglycan-content of the cartilage early drops down; 50 days later the GAG-content reaches nearly normal values. At this time not only the histological appearance, but also the nutritive function of neosynovialis seems to be sufficient.

Acid glycosaminoglycans and their chemical modification

The modem state of chemical modification of hyaluronic acid, chondroitin sulfates, and heparin is considered, and the possible application of modified glycosaminoglycans as potential drugs is discussed.