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S Gay

Publications and source records attributed to S Gay.

At least 217 records · Page 12Linked to original sources
PubMed1989

Immunohistologic demonstration of platelet-derived growth factor (PDGF) and sis-oncogene expression in scleroderma.

Although the pathogenesis and mechanisms responsible for excessive connective tissue deposition are not known, it has been thought that specific growth factors may have an effect on scar formation by increasing the fibroblast population and by affecting the amount and types of matrix synthesized. In this regard, we explored the appearance and localization of TGF alpha, TGF beta, PDGF, and sis-onc expression in situ. Sections of skin biopsies from eight scleroderma patients were investigated using specific antibodies to TGF alpha, TGF beta, human PDGF, and sis-onc products for immunohistochemistry. Most significantly, deposition of PDGF was detected in the endothelial lining of small capillaries in association with certain mononuclear cells of the perivascular infiltrates. In particular, strong labeling was observed in the cytoplasm of macrophages. Smooth muscle also appeared to be specifically labeled. Similarly, sis-onc product localized in the same areas. No significant staining was observed with antibodies to TGF alpha. TGF beta was found rather diffusely throughout the dermal connective tissue and was only occasionally observed in capillaries of lesions. We conclude that the PDGF may play an important role in the pathogenesis of scleroderma.

Humans↗
PubMed1989

Immunohistochemical localization of HTLV-I p19- and p24-related antigens in synovial joints of patients with rheumatoid arthritis.

In formalin-fixed, paraffin-embedded synovial tissues from patients with early proliferative rheumatoid arthritis (RA), immunoreactivity could be demonstrated utilizing monoclonal IgG antibodies reactive with the p19 and p24 protein of human T cell leukemia virus (HTLV-I). Additionally, surgical specimens of fresh unfixed synovial tissues from patients with RA also demonstrated immunoreactivity. At the light microscopic level, both HTLV-I antigens were detected in approximately 45% of the rheumatoid synovial tissues by the immunocolloidal gold method with silver enhancement (IGSS) and the avidin-biotin-complex technique (ABC), whereas six of eight of the frozen RA specimens stained positive by immunofluorescence. Patients whose synovial tissues were immunoreactive by immunofluorescence were seronegative to HTLV-I antigens as determined by ELISA and immunoblotting. Conversely, cases with osteoarthritis, juvenile rheumatoid arthritis, psoriatic arthritis, Dupuytren's contracture, and gangrene were shown to be nonreactive by immunohistochemistry. The results indicate that expression of antigens is related to or crossreactive with HTLV-I in synovial tissues from patients with rheumatoid arthritis.

Antibodies, Monoclonal↗
PubMed1988

44-kDal bone phosphoprotein (osteopontin) antigenicity at ectopic sites in newborn rats: kidney and nervous tissues.

Previous immunohistochemical data have shown that the 44-kDal bone phosphoprotein (44K BPP, also called sialoprotein I or oestopontin) recently isolated in our laboratory was synthesized by osteoblasts and osteocytes and was expressed early during differentiation of bone-forming cells. We report here the presence of 44K BPP antigenicity at certain ectopic sites, namely, the proximal-convoluted tubule of the kidney, neurons, sensory and secretory cells in the internal ear. To insure specificity and reproducibility, different immunohistochemical methods were used and affinity-purified antibodies against two separate preparations of pure 44K BPP were tested. In the cells of the proximal-convoluted tubule, 44K BPP immunoreactivity was observed within apical endocytotic vacuoles and within lysosomes. This staining thus correlates with the degradation of the 44K BPP epitope which we previously demonstrated to occur in serum. On the other hand, in the neurons of the acoustic ganglion and the sensory cells of the macula, 44K BPP immunoreactivity was associated with the Golgi apparatus indicating synthesis and secretion by these cells. The finding that the 44K BPP (or a structurally related molecule) is synthesized by neurons and neuroepithelial cells deserves further investigation with respect to a possible embryologic relationship between neuroectodermal cells and the precursors of some bone forming-cells of the skull.

Animals↗
PubMed1988

Autoantibodies to extracellular collagen matrix components in epidermolysis bullosa and other bullous diseases.

In order to determine whether autoantibodies are present in sera from normal individuals and/or patients with selected bullous disorders, a highly sensitive solid-phase radioimmune assay was established using purified native collagen types I-VI, laminin, and fibronectin as substrates. Sixty-four sera were utilized, representing 12 normal controls as well as 4 patients with extensive thermal burns, 18 with autoimmune bullous diseases (11 bullous pemphigoid, 5 pemphigus vulgaris, and 2 epidermolysis bullosa acquisita), and 30 with non-autoimmune mechanobullous diseases [epidermolysis bullosa (EB): 20 simplex, 4 junctional, and 6 dystrophic]. In general, autoantibodies to types I, II and VI collagen and fibronectin were undetectable in any of the patient or control groups. In contrast, autoantibodies to types III and V collagen were noted in 87.5% (28/32) and 90.6% (29/32) of EB sera, respectively, while being only rarely noted in sera from other patient groups. Similarly, autoantibodies to type IV collagen and laminin were detected in 50% (16/32) and 40.6% (13/32) of EB sera, especially from patients with simplex and dystrophic forms of the disease. These data suggest that selected interstitial and basement membrane-associated collagens and laminin may become autoimmunogenic in all three forms of inherited EB in contrast to their relative lack of immunogenicity in at least some of the other intraepidermal and subepidermal blistering disorders. The role, if any, of these autoantibodies in the induction or perpetuation of blistering in EB awaits further studies.

Adult↗
PubMed1988

Collagens support embryo attachment and outgrowth in vitro: effects of the Arg-Gly-Asp sequence.

Collagen types I through VI support attachment and outgrowth of mouse blastocysts in vitro. We found that embryos acquire the ability to attach to collagens type II and VI relatively early in their developmental program. The time at which half of the embryos displayed outgrowth formation and the morphology of outgrowths formed on these two collagen types are similar to those observed for laminin, fibronectin, and hyaluronate. Embryos acquire the ability to outgrow on the other collagen types at a later time in culture. Both "native" and denatured collagens support embryo attachment and outgrowth, indicating that this activity is intrinsic to the primary collagens' structure. A synthetic peptide containing the sequence Arg-Gly-Asp inhibits embryo outgrowth on collagen type II and denatured collagen type IV, whereas a peptide containing the related sequence, Arg-Gly-Glu, has relatively little effect on embryo outgrowth. In contrast, embryo attachment to collagen types I, V, and VI was not inhibited specifically by the Arg-Gly-Asp peptide sequence. Consequently, it appears that embryos use multiple adhesion systems to attach to collagens. Among these are adhesion systems that have a peptide recognition specificity similar to that of fibronectin receptors. These studies indicate that embryo interactions with collagens may be one aspect of the tissue invasion processes that take place during implantation.

Amino Acid Sequence↗
PubMed1988

Collagen content and types in the intestinal strictures of Crohn's disease.

The collagen content and the relative amount of collagen types were quantitated in control intestine as well as in both inflamed and strictured intestine resected from patients with Crohn's disease. The major collagen type in control intestine was type I (68%), followed by types III (20%) and V (12%). In strictured intestine both collagen content and the relative amount of type V collagen were significantly increased compared with control intestine. Histologic studies demonstrated that in strictured specimens there was a striking proliferation of smooth muscle cells of the muscularis mucosae associated with an accumulation of collagen in the submucosa. The thickness of the muscularis propria was also increased. Immunohistochemical studies demonstrated small amounts of type V collagen in the submucosa of control bowel. In contrast, large amounts of type V collagen were seen in the fibrotic, expanded submucosa of strictured bowel, particularly in the areas where smooth muscle cells of the muscularis mucosae had proliferated. Intestinal strictures in Crohn's disease are therefore characterized by an accumulation of collagen, a proliferation of smooth muscle cells, and an increase in type V collagen, a collagen type produced in relatively large amounts by smooth muscle cells. These changes appear to result in both a loss of the normal compliance of the intestine and a thickening of the intestine wall, resulting ultimately in the intestinal obstruction so frequently seen in patients with Crohn's disease.

Amino Acids↗
PubMed1988

Bone marrow derived cells express human T-cell lymphotropic virus type I (HTLV-I)-related antigens in patients with multiple sclerosis.

Mononuclear cells in peripheral blood (PB) and cerebrospinal fluid (CSF) of seven patients and lymph nodes of three patients with clinically definite multiple sclerosis (MS) expressed antigens that reacted with monoclonal antibodies (MoAb) specific for HTLV-I p19 and p24 gag proteins. The labelled cells were visualized with immunoperoxidase staining and indirect immunofluorescence and identified at the ultrastructural level with immunogold technique. The frequency of these cells was low, ranging from 0.1% to less than 0.01% in blood. In CSF it was approximately 10 times lower. Cells reacting with anti-p19 Ab were found in all MS samples, whereas cells reacting with anti-p24 Ab were found in 3 out of 6 blood samples and in 3 out of 7 CSF samples. All lymph nodes (3/3) obtained from MS patients contained cells that reacted with anti-HTLV-I. p19 and p24 Ab. Cells reacting with the same AB were detected in blood of one out of 12 healthy controls. Stained cells were irregular, distinctly larger than lymphocytes, and had abundant cytoplasm, suggesting that they may be monocytes/macrophages. Immunogold particles were located in vacuole-like structures in the cytoplasm. The presence in MS patients of cells that react with HTLV-I Ab indicates that a human retroviral genome is being expressed, and suggests that a virus may be present. Our data support a role for a human retrovirus in multiple sclerosis.

Antibodies, Monoclonal↗
PubMed1988

Autoimmunity to collagen in adult periodontal disease.

Although it has been documented that exogenous antigens of microbial origin are involved in the induction of the local inflammatory responses in human adult periodontitis (AP), endogenous antigens may contribute to the chronicity of this common disease. In this study, we used the enzyme-linked immunospot (ELISPOT) test to enumerate antibody-secreting cells to human collagen Types I-VI by cells isolated from the gingivae and peripheral blood of AP patients. Analyses of dissociated cells from gingivae of 39 AP patients revealed the presence of high numbers of cells that secrete antibodies to Type I collagen, and to a lesser extent, Type III. Although the majority of such cells produced specific antibodies of the IgG class, IgA- and IgM- anti-collagen -secreting cells were also detected. When compared to the total antibody-producing cells, the numbers of cells forming specific antibodies to collagen Type I were surprisingly high. In contrast, anti-collagen antibody-producing cells were rarely detected in the peripheral blood of patients with adult periodontal disease and only low levels of anti-collagen antibodies were present in the serum. The finding of local production of anti-collagen antibodies in AP suggests that autoimmunity may contribute to the pathogenesis of this common disease.

Antibody-Producing Cells↗
PubMed1988

Ultrastructural study of Sjögren's syndrome-like disease in MRL/l mice.

Salivary glands of autoimmune MRL/l mice were examined ultrastructurally and by immunoelectron microscopy to further characterize the Sjögren's syndrome-like disease in these animals. Major salivary glands from 12 female and 7 male MRL/l, two female MRL/n, and one female BALB/c mice were examined by electron microscopy and the glands from 4 female MRL/l mice were subjected to immunoelectron microscopy in order to detect Lyt-1 and Lyt-2 positive lymphoid cells. Mononuclear cell infiltrates were not seen in the salivary gland from the BALB mouse and occurred rarely in glands of MRL/n mice. However, in MRL/l mice, numerous lymphoid cells were present and acinar cells displayed low cytoplasmic density, cytoplasmic vacuolization and cellular lysis. Lymphoid cells were predominantly Lyt-1 positive although some Lyt-2 positive cells were observed. These results suggest that the MRL/l mouse represents a useful model for the study of the pathogenesis of Sjögren's syndrome in man.

Animals↗
PubMed1988

The MRL-lpr/lpr mouse. A model for the study of rheumatoid arthritis.

Autoimmune MRL-lpr/lpr mice develop a spontaneous destructive arthropathy sharing some features with rheumatoid arthritis including synovial cell proliferation, pannus formation, rheumatoid nodule-like lesions and circulating rheumatoid factors. Rheumatoid factors elaborated by MRL-lpr/lpr mice exhibit binding characteristics similar to those found in the sera of patients with rheumatoid arthritis; however, these autoantibodies do not appear to be essential for the induction of arthritis in MRL-lpr/lpr mice. Molecular studies, indicating that VH genes from several VH families are capable of encoding these rheumatoid factors, argue against the existence of unique "autoantibody genes" in the germline of MRL-lpr/lpr mice. Although the mechanisms underlying cartilage injury in MRL-lpr/lpr mice have not been elucidated, available evidence suggests that invading synovial cells play an important role. Delineation of the cellular and molecular mechanisms responsible for articular destruction in MRL-lpr/lpr mice may provide important insights concerning the pathogenesis of rheumatoid arthritis.

Animals↗
PubMed1988

Synovial processes in rheumatoid arthritis.

The clinical feature of rheumatoid arthritis (RA) is characterized by systemic-immunological, local-inflammatory phenomena. But it is the joint destruction which gives RA its dramatic course. Through the years we evaluated joint tissues of app. 14,500 patients with defined RA and besides the conventional inflammatory processes we could prove a mechanism which is responsible for the joint destruction and which is typical for RA. Following an exudative episode, compact, homogeneous cell masses can occur in the synovial membrane which consist of macronuclear, immature, synoviogenous cells. These masses can encroach on the adjacent structures of articular cartilage and subchondral bone which consequently enzymatically will be degraded and destroyed. Since these rapidly growing cell masses are avascular in their aggressive stage, they soon will collapse. The surviving cells "modulate" to fibroblast which start collagen synthesis and thus form the well-known pannus. In the area of the compact, homogeneous cell masses of synovial origin, there are no lymphocytes and plasma cells nor PMN or macrophages. Macrophages only occur after the breakdown of the cell masses and the beginning of pannus formation, this also is the case with lymphocytes and plasma cells. Thus, the immature synoviogenous cell masses are in contrast to the initial synovitis not of inflammatory character. Their cytological and aggressive behavior rather shows oncological analogies. This also corresponds to our proof of the expression of myc and ras to a high degree in the aggressive cell masses in RA.

Arthritis, Rheumatoid↗
PubMed1988

Etiopathogenesis of rheumatoid arthritis-like disease in MRL/1 mice: II. Ultrastructural basis of joint destruction.

MRL/1 mice develop a spontaneous hindlimb arthropathy characterized by proliferation of synovial cells and by dissociation between early destruction of articular tissue and the presence of inflammatory cell infiltration. To characterize the ultrastructural details of the synovial cells of these mice, knee joints from MRL/1, MRL/n, and BALB/c mice were examined by light and electron microscopy. Since the proliferating synovial cells of MRL/1 mice resemble the previously described proliferative synovial cells seen in histopathologic specimens from early rheumatoid arthritis, further study of these cells may provide new insights into the pathogenesis of early joint tissue destruction in human rheumatic disease.

Animals↗
PubMed1987

A comparative immunocytochemical study on the subcellular distributions of 44 kDa bone phosphoprotein and bone gamma-carboxyglutamic acid (Gla)-containing protein in osteoblasts.

Bone gamma-carboxyglutamic acid (Gla)-containing protein (BGP or osteocalcin) and 44 kDa bone phosphoprotein (44K BPP, also called Sialoprotein I or osteopontin) have been localized at the ultrastructural level in osteoblasts from woven bones of newborn rats. Frozen, undecalcified sections of periodate-lysine-paraformaldehyde fixed specimens were incubated with affinity purified, monospecific antibodies against BGP or 44K BPP. The sites of the antigen-antibody reaction were demonstrated by the avidin-biotin-peroxidase complex method using the Hanker-Yates reagent as a peroxidase substrate. In some cases immunostaining could only be achieved after detergent treatment. The immunostained sections were then flat-embedded in Epon 812 and processed for electron microscopy. Strong specific intracellular labeling was obtained with both antibodies, but the patterns of staining differed significantly: BGP antigenicity was mainly located in the endoplasmic reticulum (ER), whereas 44K BPP behaved as a Golgi-specific antigen. In both cases, however, we found no evidence for immunostained secretory vesicles. There was no correlation between the expression of BGP by osteoblasts and the morphological aspect of these cells, their apparent degree of polarization with respect to the bone matrix, or their relation with the mineralized phase.

Animals↗
PubMed1987

Humoral sensitivity to native collagen types I-VI in the arthritis of MRL/l mice.

The presence of immune reactivity to collagen in patients with rheumatoid arthritis as well as recent interest in the type II collagen-induced arthritis model have suggested a role for autoimmunity to collagen as a major disease mechanism. However, data concerning the occurrence of antibodies (AB) against the different types of collagen during a spontaneously occurring, histologically well-defined arthritis have been lacking. Sera from 48 MRL/l mice aged 5 to 25 weeks with spontaneously occurring hindlimb arthritis were obtained. Sera were tested for auto-AB against collagens utilizing highly purified native collage types I-VI. Significant levels of circulating AB against native collagen types I, III, and VI could not be detected in any age group. The greatest elevation of antibodies directed against type II collagen was found in 13- to 15-week-old mice. AB against type IV collagen were detected in slightly elevated levels with a maximum at 9-10 weeks. Most strikingly, AB against type V were markedly elevated after 19 weeks. The occurrence of high levels of AB against type V collagen, largely found in the pericellular matrix of smooth muscle cells, is associated with the late stage of disease characterized by histologically documented vasculitis. The results suggest that AB to collagen occur as a consequence of tissue destruction and that evidence for a pathogenetic role of AB in MRL/l arthritis is lacking.

Animals↗
PubMed1987

Immunohistochemical demonstration of a 44-KD phosphoprotein in developing rat bones.

Polyclonal antibodies against a 44-KD phosphoprotein (44K BPP) from rat bone were raised in rabbits, affinity-purified, and used as probes to study the protein's distribution in various types of developing bones from newborn rats. Three immunostaining procedures were applied utilizing indirect immunofluorescence, avidin-biotin-peroxidase complex, and avidin-gold complex with silver enhancement. All methods gave essentially identical and/or complementary results. Antigenicity for anti-44K BPP was detected in endochondral and membranous bone. In the latter, it was also demonstrated in the osteoid. In the woven bone of lower jaw, immunoreactivity for anti-44K BPP antibodies was found in fibroblast-shaped cells (pre-osteoblasts) that were between the bone trabeculae but not in direct contact with bony extracellular material. In addition to these presumed osteoprogenitor cells, osteoblasts as well as osteocytes were strongly stained; the cytoplasmic staining was associated with the Golgi apparatus. Occasionally immunoreactivity was detected in osteoclasts, but in these cells immunostaining was either diffusely spread in the cytoplasm or present only at sites of bone erosion. These findings support the hypothesis that the 44K BPP is a protein made by osteoblasts and is localized predominantly in bone. Furthermore, the protein appears to be expressed early in histogenesis of the bone-forming cells.

Alkaline Phosphatase↗
PubMed1987

Immunolocalization of Gla proteins (osteocalcin) in rat tooth germs: comparison between indirect immunofluorescence, peroxidase-antiperoxidase, avidin-biotin-peroxidase complex, and avidin-biotin-gold complex with silver enhancement.

Odontoblasts and osteoblasts synthesize gamma-carboxyglutamatic acid (Gla)-containing proteins which are partially deposited in the mineralizing tissues and partially released into the plasma. Using four immunostaining techniques, we have evaluated the question of whether dentin Gla proteins (DGP) are transported to the mineralization front through the odontoblast processes. Undecalcified sections of rat incisors and molar tooth germs were immunostained with affinity-purified antibodies to DGP using the following methods: indirect immunofluorescence; peroxidase-antiperoxidase (PAP); avidin-biotin-peroxidase complex (ABC-peroxidase); and avidin-biotin-gold complex with silver enhancement (ABC-GSS). The results obtained with these four procedures were compared with respect to the developmental appearance of DGP, staining intensity and presence in odontoblastic processes, predentin, dentin, and blood vessels. Qualitatively, similar results were obtained with the four, with respect to the distribution and developmental appearance of DGP, with two exceptions: indirect immunofluorescence never stained DGP within blood vessels, whereas the other methods occasionally did; and because of its sensitivity, only the ABC-GSS method revealed immunostaining for DGP in odontoblastic processes. All methods revealed weak immunostaining in predentin which was considerably enhanced with hyaluronidase treatment; however, hyaluronidase only moderately increased predentin immunostaining with ABC-GSS. Of these four procedures, ABC-GSS is the most sensitive; however, ABC-GSS appears to detect predominantly antigens at the surface of tissue sections. We conclude that DGP is present in odontoblastic processes but in low amounts; the weak staining was due either to rapid transport of DGP through the process or to the fact that this mode of transport is limited.

Animals↗