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Biomedical subjects

L Lustig

Publications and source records attributed to L Lustig.

At least 37 records · Page 2Linked to original sources
PubMed1992

Antilaminin IgG triggers the murine atria phosphoinositide hydrolysis through muscarinic receptor stimulation.

Induction of polyphosphoinositide hydrolysis in cardiac tissue by specific recognition of laminin by antilaminin IgG was assayed. BALB/c mice atria were labelled with the myo-[3H]-inositol precursor and inositol phosphate production was measured in the presence and absence of antilaminin and normal IgG. Antilaminin IgG but not normal IgG specifically increased phosphoinositide (PI) turnover. This increment was blocked by the muscarinic cholinergic antagonist atropine and mimicked by the cholinergic agonist carbachol. The phospholipase C inhibitor diphenylcarbamate (NCDC) also antagonized the stimulatory action of antilaminin IgG on PI turnover. By using an immunofluorescence technique, antilaminin IgG reacted with myocardial cell basement membranes. This antibody fixation was not blocked by atropine. These data suggest that antilaminin IgG specifically recognized myocardial laminin molecules and activated PI turnover through cholinergic stimulation. Even though laminin and cholinergic receptors are different, they probably share common signal transduction systems.

Animals↗
PubMed1991

Testicular lesions and lymphocyte subpopulations in rats immunized with a soluble fraction of testicular homogenate.

A soluble fraction obtained from a testicular homogenate by precipitation with ammonium sulphate (ASPM) was emulsified with Freund's complete adjuvant (CFA) and injected into Wistar rats. At 50 days after the first immunization (total of three injections) the animals had developed moderate and multifocal testicular damage, characterized mainly by sloughing of the seminiferous epithelium. A delayed-type hypersensitivity response and circulating antibodies to ASPM were detected at different times with maximum levels at 50 days. The addition of Bordetella pertussis to the immunization did not increase the severity of the lesion but augmented the cellular and humoral immune response to ASPM. The phenotypic characterization of cells present in the lymph nodes draining from the site of immunization in animals injected with CFA alone (control group) revealed an increase in CD8+ T-cells and a low CD4/CD8 ratio. Conversely, rats immunized with CFA plus ASPM (experimental group) exhibited testicular damage and showed a significant decrease in CD8+ cells with a normal CD4/CD8 ratio. In conclusion, rats immunized with a testicular antigen developed focal aspermatogenic lesions and a concomitant specific immune response as well as lymph-node cell variations focused apparently on the CD8+ T-cell subpopulation.

Ammonium Sulfate↗
PubMed1991

Lymphocyte subsets in the lymph nodes of rats with autoimmune orchitis.

We determined temporal variations of cell subpopulations in the immunization draining lymph nodes during the development of an experimental autoimmune orchitis (EAO) induced in Wistar rats. A phenotypic characterization of T cells and their subsets (CD4+ and CD8+), B, and Ia+ cells was performed by immunofluorescent technique. At the end of the immunization period (30 days), rats injected with testicular homogenate plus adjuvants presented a considerable increase in absolute cell number but normal lymphocyte subset percentages. Testicular damage became evident at 50 days after the first immunization and increased its severity at 80 days: animals that developed EAO presented a lower number of CD8+ cells as compared with undamaged rats. This latter group showed a low CD4/CD8 ratio due to the high proportion of CD8+ cells, which could probably have a suppressor function. At 80 days massive testicular infiltration and decreased absolute cell number in lymph nodes suggest the possible migration of specific lymphocytes to the target organ.

Adjuvants, Immunologic↗
PubMed1990

Antilaminin IgG binds and interacts with cardiac cholinergic receptors.

Antilaminin IgG bound to cholinergic muscarinic receptors of normal mice heart and simulated the biological effect of a cholinergic agonist. Antilaminin IgG interfered with the binding of the radiolabelled muscarinic antagonist, (-)-[3H]quinuclidinyl benzilate, in a noncompetitive fashion. The interaction of antilaminin IgG with the muscarinic cholinergic receptor increased production of cGMP and decreased production of cAMP. Antilaminin IgG also decreased the contractile tension of mouse atria. Both the mechanical and enzymatic effect of antilaminin IgG required the activation of the muscarinic cholinergic system because they were blunted by atropine and mimicked by acetylcholine.

Acetylcholine↗
PubMed1989

Negative inotropic activity of antilaminin IgG: participation of cholinergic mechanisms.

1. Antilaminin IgG decreased the dF/dt of mouse isolated atria and inhibited the mechanical effect of acetylcholine in a non-competitive fashion. 2. Inhibitors of nicotinic and muscarinic cholinoceptors impaired the negative inotropic action of antilaminin IgG in mouse isolated atria. Hemicholinium and tetrodotoxin also reduced the response while the antihistamine, pyrilamine was without effect. 3. These results suggest that antilaminin IgG modulates cholinergic function in mouse isolated atria. Possible mechanisms are discussed.

Acetylcholine↗
PubMed1989

Sequential study of the histopathology and cellular and humoral immune response during the development of an autoimmune orchitis in Wistar rats.

Wistar rats immunized with an homologous testicular homogenate (TH) and complete Freund's adjuvant, followed by i.v. injection of Bordetella pertussis, developed an autoimmune orchitis (EAO). Animals were studied at 7, 16, 30, 50, and 80 days (d) after the first immunization. An important lesion of the testis only appeared at 50 d, increasing in severity and incidence (77%) at 80 d. Lesions were characterized by a prevalent aspermatogenesis with tubular atrophy and mild interstitial mononuclear infiltrates. Delayed-type hypersensitivity response (DTH) against TH was detected early at 7 d and, except for 16 d, it increased with time, reaching a maximum at 80 d. A good temporal relationship between DTH and histopathology was found. Circulating antibodies to TH, detected by ELISA, were only present in 64% of the animals with testis lesion, while no deposits of IgG or C3 in the seminiferous tubules were seen. We describe a sequence of immunological events, concomitant with pathological changes of the testis, during the development of a severe EAO in Wistar rats.

Animals↗
PubMed1989

[Experimental autoimmune orchitis].

Experimental autoimmune orchitis (EAO) has been extensively studied in spite of which its pathogenic mechanisms are still poorly understood. It has been mostly induced in guinea pigs using spermatozoa or a testicular homogenate plus adjuvants. Initially, the aim of our work was to establish if non-spermatic antigens, such as extracellular components of the walls of seminiferous tubules, were able to induce an autoimmune orchitis. For this purpose, we obtained from rat testes: a) a preparation rich in basement membranes of seminiferous tubules (STBM) and b) a soluble fraction of STBM, non-related to collagen (D-STBM), presenting common antigenic determinants with laminin, the main non-collagen glycoprotein of basement membranes. Fifty per cent of rats immunized with STBM, D-STBM or a murine laminin, developed a multifocal and moderate damage of the testes characterized by mild interstitial cell infiltrates, alterations of the basement membranes of seminiferous tubules and Sertoli cells, sloughing of the germinal epithelium and tubular atrophy. Circulating antibodies and a specific cellular immune response were also detected. Moreover, rats passively injected with an heterologous anti-D-STBM serum developed a similar testicular lesion and showed Ig deposits on the basement membranes of seminiferous tubules. In relation to the pathogenic mechanisms of EAO, we studied the variations of T and B cell populations, at the immunization draining lymph nodes, during the development of orchitis. A severe EAO was induced in Wistar rats by immunization with an homologous testes homogenate plus adjuvants.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Feline parvovirus propagates in cat bone marrow cultures and inhibits hematopoietic colony formation in vitro.

Feline parvovirus (FPV) causes leukopenia in naturally infected cats. We investigated the mechanism of hematopoietic depression by this virus in feline bone marrow cultured in vitro. In suspension cultures we demonstrated FPV propagation and replication using DNA molecular hybridization. Viral RNA and DNA were observed by in situ hybridization in about 10% of marrow cells at day 3. Granulocytes and their precursors were virtually absent from infected cultures after six days. Infected cells showed viral capsid protein predominantly in nuclei by immunofluorescence. In clonal assays, FPV most efficiently inhibited hematopoietic colony formation by myeloid progenitor cells (CFU-GM), but erythroid colony formation (BFU-E and CFU-E-derived) was also depressed in the presence of virus. Inhibition of colony formation could be abrogated by physical inactivation of the virus or preincubation with specific neutralizing antibodies. Recombinant human colony stimulating factors GM-CSF and G-CSF supported feline myelopoiesis in progenitor assays, and FPV completely inhibited factor dependent colony formation.

Animals↗
PubMed1988

California's experience with low MS-AFP results.

The California AFP Screening Program was developed to offer pregnant women the opportunity to have their pregnancies screened for open neural tube defects (NTD). Because it is unwise to withhold potentially important clinical information about low MS-AFP results from the screened women and their physicians, follow-up diagnostic evaluations and counseling were offered to women with low MS-AFP results in addition to those with high results or positive family histories of NTD. Between April 7, 1986 and September 30, 1987, over 275,000 women voluntarily participated in the screening program. During the first year of the program 3,939 women were seen for follow-up evaluations due to low MS-AFP results. These evaluations occurred at state-approved AFP follow-up centers where ultrasonographic dating led to reinterpretation of 35% of the results. Of the remaining 2,552 (65%), 1,940 women (76%) had an amniocentesis. Sixteen Down syndrome fetuses were detected for a yield of 1/121 amniocenteses. Additional chromosome abnormalities included trisomies 18 and 13, Ullrich-Turner syndrome, (45,X), Klinefelter syndrome (47,XXY) and triploidy. The total yield of significant chromosome abnormalities was 1/78 amniocenteses.

Adult↗
PubMed1987

Testis lesions and cellular and humoral immune responses induced in rats by immunization with laminin.

Sixty-six percent of rats immunized with laminin isolated from a mouse Engelbreth-Holm-Swarm (EHS) sarcoma developed moderate lesions in the testis characterized by multiple foci of seminiferous tubules with different degrees of sloughing of the germinal epithelium or atrophy intermingled with normal histological areas. Interstitial mononuclear cell infiltrates were seen in the epididymis. By electron microscopy, pathological changes in the basement membranes of the seminiferous tubules, such as splitting and focal thickenings of knob-like projections toward the epithelium, were observed. Moreover, Sertoli cell cytoplasm showed dilated smooth endoplasmic reticulum and large vacuoles. By electron microscopy with the immunoperoxidase technique, staining for in vivo-bound rat IgG was detected along the walls of the seminiferous tubules as a bright linear immunofluorescence and as a dense reaction product on the basal lamina. High titers of circulating antilaminin antibodies were detected by ELISA in all the rats immunized with laminin. As revealed by the skin test, a delayed type hypersensitivity reaction to laminin was observed in these rats.

Animals↗
PubMed1986

Induction of multifocal lesions of the testis by passive transfer of immune cells.

Spleen cells obtained from Wistar rats bearing a multifocal damage of the testis that had been induced by an antiserum against a non-collagenous fraction of basement membranes, were able to transfer similar testicular lesions into normal recipients. Damage was characterized by multiple foci of seminiferous tubules with different degrees of cell sloughing and a mild interstitial mononuclear cell infiltrate. The incidence of testicular damage in the transferred recipients was 83%, while in the control group of rats transferred with spleen cells from donors that had been injected with normal rabbit serum only 4% of the animals presented mild lesions. In order to determine which lymphocyte subpopulations were effective in transferring the disease, rat spleen cells were treated with murine monoclonal antibodies W3/25 and OX8 or with a rabbit anti-rat IgG serum and complement, before the transfer. A multifocal damage of the testes, indistinguishable from that obtained with the untreated spleen cells was transferred in 50% and 25% of the rats injected with spleen cells depleted in B or in T lymphocytes, respectively. The most severe lesions were observed in the rats transferred with cell populations depleted in B cells.

Animals↗
PubMed1985

Multifocal damage of the testis induced in rats by passive transfer of antibodies prepared against non-collagenous fraction of basement membrane.

Multifocal damage of the testis was induced in 70% of the rats injected with an antiserum against a non-collagenous fraction (D-STBM) obtained from a preparation enriched in basement membranes of seminiferous tubules. The damaged areas were characterized by perivascular and peritubular cell infiltrates, changes in the walls of small vessels and seminiferous tubules, and sloughing of the germinal epithelium. By electron microscopy, the most frequent changes observed in basement membrane of the seminiferous tubules were folding, focal thickening, and delamination. By immunofluorescence, discontinuous linear deposits of rabbit IgG were observed along the walls of the seminiferous tubules. In the same localization, faint immunofluorescence showing the presence of rat IgG was also detected. The same pattern was obtained when rabbit and rat IgG eluted from the testes of these rats were layered on sections of normal rat testis. Moreover, by immunoelectron microscopy, discontinuous deposits of rabbit IgG were detected along the basement membranes of the seminiferous tubules. Neither C3 deposits nor changes in the serum CH 50 were observed. By leucocyte migration inhibition reaction (LMIR) a cellular immune response to basement membrane antigens was detected. In the control group, 12% of the rats injected with normal rabbit serum presented mild interstitial cell infiltrates and occasional sloughing of the germinal epithelium. Neither deposits of rat IgG or rabbit IgG nor a cellular immune response were observed.

Animals↗
PubMed1982

Antigens of the basement membranes of the seminiferous tubules induce autoimmunity in Wistar rats.

A preparation enriched in basement membranes from seminiferous tubules was isolated from rat testes (STBM) and injected with complete Freund's adjuvant into Wistar rats. In 60% of animals a mild multifocal orchitis was observed. In damaged areas, perivascular and peritubular mononuclear cell infiltrates and different degrees of cell sloughing of some seminiferous tubules were observed. Electron microscopy revealed focal thickenings and delamination of the basement membrane of the seminiferous tubules as well as vacuolization of Sertoli cell cytoplasm. Using immunofluorescence discontinuous linear deposits of IgG were detected along the seminiferous tubular wall. Moreover, the same pattern of immunofluorescence was observed when the IgG eluted from the testes of the immunized rats was layered on sections of normal rat testis. Circulating antibodies to STBM were detected using passive haemagglutination in approximately 45% of the immunized rats, with titers ranging from 1:20 to 1:80. Leukocyte migration was inhibited when the spleen cells of the immunized rats were incubated with antigens from the basement membrane of seminiferous tubules, whilst a negative reaction was obtained when the soluble fraction of testis homogenate was used.

Animals↗
PubMed1982

Biosynthesis of basement membrane by parietal yolk sac cells.

The biosynthesis of basement membrane (Reichert's membrane) by parietal yolk sac cells of the mouse embryo was studied using immunohistochemistry and autoradiography with the electron microscope. Fab' fragments of characterized antisera to either a mixture of type IV collagen and laminin, or to type IV collagen alone, were conjugated to horseradish peroxidase for the immunohistochemical study; radiolabeled proline, leucine, and glucosamine were utilized either in vivo or in isolated yolk sac membranes in vitro for autoradiography. Whereas neither of the two antisera employed localized in either the Golgi apparatus or in the cytosol, both localized in the rough endoplasmic reticulum (RER) and in the extracellular basement membrane. Furthermore, no evidence of passage of isotopically labeled precursors of basement membrane from the RER to the Golgi apparatus was observed. Consequently, it is concluded that the basement membrane precursors are synthesized in the RER of parietal yolk sac cells and neither traverse the Golgi apparatus nor diffuse across the cytosol of the cell in the process of secretion. By elimination, secretion must be via direct communications between RER and plasma membrane or via small vesicles observed in the cytosol between RER and plasma membrane. These data are not in accord with the concept of the universality of the Golgi apparatus in the biosynthesis of glycoprotein. Parietal yolk sac cells do not use the Golgi apparatus in the biosynthesis of basement membrane, but do use the Golgi apparatus for the biosynthesis of other proteins.

Animals↗
PubMed1979

Isolation and immunological reactivity of soluble fractions from rat seminiferous tubule basement membrane.

A preparation rich in basement membranes isolated from rat testes (STBM) was exposed to pepsin, collagenase, trypsin, and pronase to obtain soluble fractions. The immunological reactivity of these fractions was studied by gel immunodiffusion or by passive hemagglutination tests against an anti-STBM serum. All fractions reacted with the antiserum, but the highest titer was detected when the antiserum was reacted with a fraction that contained only traces of hydroxyproline (fraction 1), whereas low titers were obtained with collagen or collagen fragments isolated from STBM. Antibodies in the anti-STBM serum were mainly directed to the glycoproteins of STBM not related to collagen. Fraction 1, obtained by subsequent collagenase and trypsin digestion of STBM and purification by Sephadex G-200, was a high molecular weight glycoprotein that was free of half-cystine and methionine, had only traces of hydroxyproline, and contained 7.2% neutral sugars, 0.26% sialic acid, and 8.7 residues of glucosamine per 1000 residues of amino acids.

Animals↗
PubMed1978

Experimental orchitis induced in rats by passive transfer of an antiserum to seminiferous tubule basement membrane.

A multifocal damage of the testis was obtained when rats were injected intravenously or under the tunica albuginea of the testis with a rabbit antiseminiferous tubule basement membrane serum. The damage was characterized by foci of perivascular and peritubular infiltrates of mononuclear round cells, infolding, thickening, and rupture of the seminiferous tubular wall and different degrees of injury of the germinal epithelium such as, cell disorganization, cell sloughing, and atrophy. Delamination and thickening of seminiferous tubule basement membrane and vacuolization of the Sertoli cell cytoplasm was often observed by electron microscopy. A linear deposit of rabbit gamma-globulin was detected by immunohistochemical techniques along the basement membranes of the seminiferous tubules and vessels. Testicular damage was not detected in rats injected with normal rabbit serum, used as control. In the kidneys of rats injected intravenously with the immune serum, a deposit of rabbit gamma-globulin was detected along glomerular basement membrane. Focal areas of mononuclear cell infiltrates, hypercellularity of glomeruli and thickening of glomerular capillary walls and Bowman's capsule were also observed.

Animals↗
PubMed1977

Partial chemical and immunological characterization of pepsin-solubilized collagen from the tunica albuginea of rat testis.

A pepsin-solubilized collagen was isolated from the tunica albuginea of rat testis. Intrinsic viscosity, amino acid and carbohydrate composition were similar to data reported for other soluble collagens. An antiserlm to the pepsin-solubilized collagen was obtained and by indirect immunofluorescence an antigen-antibody reaction was observed in the collagen fibers of the tunica albuginea and in the intertubular collagen fibers of rat testis. By serological and immunofluorescence techniques, cross-reactions with other collagens indicates a lack of organ specificity. A strong cross-reaction between this antiserum and basement membranes from different organs of the rat was also found.

Amino Acids↗