Competition between glycoprotein hormones and horseradish peroxidase for mannose-specific binding sites in cells of endocrine organs

Mannose-specific binding sites for horseradish peroxidase (HRP) were studied in paraformaldehyde-fixed, frozen sections of endocrine organs by a cytochemical method reported previously. In the testis, HRP was bound to interstitial cells, probably macrophages, and to sites extending along the surface of spermatozoa in the seminiferous tubules. In the epididymis, cells in the connective tissue, probably fibroblasts or macrophages, showed the specific reaction. In the ovaries, the reaction for lectin-bound HRP was observed in connective tissue cells of the theca externa, and in the mucosa of the uterus, binding of HRP occurred to many fibroblasts. The glycoprotein was also bound to cells in the connective tissue of the thyroid, probably mast cells, as well as to endothelial cells in the adrenal medulla and cortex. In all cases, the binding reaction required Ca2+ and was suppressed by mannose or mannan. Partially purified and highly purified preparations of glycoprotein hormones [ovine follicle-stimulating hormone, ovine luteinizing hormone, bovine thyroid-stimulating hormone, and human chorionic gonadotropin] as well as bovine thyroglobulin and yeast invertase competed with the binding of HRP to all the cells mentioned thus showing that the hormones were bound to the same sites as HRP. When 1 microM HRP was present in the incubation medium, the addition of 15-25 microM of highly purified hormones almost suppressed the reaction for lectin-bound HRP and competitive effects could be observed at even lower concentrations of the hormones.     

Cross-Protection Studies with Three Serotypes of Pasteurella haemolytica in the Goat Model

Cross-protection studies employing three serotypes of Pasteurella haemolytica (Ph) were performed in goats, with challenge exposure by transthoracic injection. Indirect hemagglutination (IHA) serum titers showed that the herd had been naturally infected with Ph biovar A, serovar 2 (PhA2) prior to the study. Sixty-four weanling male Spanish goats were randomly allotted to 16 groups. Fifteen goats were given two transthoracic injections into the lungs 21 days apart with live Pasteurella haemolytica biovar A, serovar 1 (PhA1) in agar beads. Fifteen goats were given two transthoracic injections into the lungs 21 days apart with live PhA2 in agar beads. Sixteen goats were given two transthoracic injections into the lungs 21 days apart with live P. haemolytica biovar A, serovar 6 (PhA6) in agar beads. Eighteen control (CON) goats were given two transthoracic injections into the lungs 21 days apart with agar beads alone. Fourteen days after the second injection, goats were challenge-exposed to either live PhA1, PhA2, or PhA6 by transthoracic injection into the lung, and 4 days later, all goats were euthanatized and necropsied. Serum antibody to P. haemolytica antigens was measured throughout the experiment. Mean volumes of consolidated lung tissue for the CON goats challenged with PhA1, PhA2, and PhA6 were 28.29 cm³, 8.36 cm³, and 16.29 cm³, respectively. Mean volumes of consolidated lung tissue for the PhA1-immunized goats challenged with PhA1, PhA2, and PhA6 were 4.38 cm³, 0.25 cm³, and 1.90 cm³, respectively. Mean volumes of consolidated lung tissue for the PhA2-immunized goats challenged with PhA1, PhA2, and PhA6 were 9.68 cm³, 0.05 cm³, and 3.39 cm³, respectively. Mean volumes of consolidated lung tissue for the PhA6-immunized goats challenged with PhA1, PhA2, and PhA6 were 14.05 cm³, 1.27 cm³, and 4.53 cm³, respectively. These data demonstrate protection in immunized goats challenged with the homologous serotype of P. haemolytica. PhA1-immunized animals were protected against serotype 2 challenge as well as against serotype 6 challenge. PhA2-immunized animals were not protected against serotype 1 challenge, but were protected against transthoracic PhA6 challenge. PhA6-immunized animals were not protected against serotype 1 challenge, but were protected against transthoracic PhA2 challenge. There appears to be some cross-protection among the P. haemolytica serotypes, and this fact should be taken into consideration when developing vaccines against this organism. Received: 13 June 1997 / Accepted: 6 October 1997     

Pasteurella haemolytica Ultraviolet-Irradiated Vaccine by Parenteral and Aerosol Routes Compared in the Goat Model

Positive control 1 (PC1) (n = 9) goats were injected transthoracically into the left lung with live Pasteurella haemolytica biovar A, serovar 1 (PhA1) in polyacrylate (PA) beads on days 0 and 21. Positive control 2 (PC2) (n = 6) goats were nebulized with live PhA1 and PA beads on days 0 and 21. Negative control (NC) goats (n = 6) were each injected transthoracically into the left lung with PA beads alone on days 0 and 21. Four groups (n = 6) were administered PA beads mixed with ultraviolet (UV) killed PhA1 on days 0 and 21. The treatment doses of bacteria for these groups were principal group 1 (PR1) injected into the left lung (7.7 × 10¹⁰ cfu); PR2, 7.7 × 10¹⁰ UV-killed PhA1 injected subcutaneously (SC); PR3, 7.7 × 10¹⁰ UV-killed PhA1 injected SC only on day 21; PR4, nebulized with PA beads mixed with 5.6 × 10¹⁰ cfu of UV-killed PhA1; and PR5, nebulized with PA beads mixed with 5 × 10⁸ cfu of UV-killed PhA1. All goats were challenged transthoracically in the right lung with 1 × 10⁸ cfu of live PhA1 on day 42 and necropsied on day 46. The sizes of consolidated lung lesions at the challenge site were used as a measure of immunity. The data show that the introduction of live PhA1 into the lungs of goats, either by injection or aerosolization, offers excellent protection against a subsequent homologous challenge. The data also demonstrate that two transthoracic injections (21 days apart) of UV-killed PhA1 (PR1), and subcutaneous injection of UV-killed PhA1(PR2) also offer excellent protection against a subsequent homologous live PhA1 challenge. One SC injection of UV-killed PhA1 (PR3) appears to offer only partial protection against a subsequent homologous live PhA1 challenge. Inhalation of UV-killed PhA1 mixed with PA beads (PR4 and PR5) induced no protection in goats against a subsequent live PhA1 transthoracic challenge. Received: 3 February 1998 / Accepted: 18 March 1998     

Effects of insulin on cellular growth and proliferation

Insulin stimulates the growth and proliferation of a variety of cells in culture. The growth-stimulatory effects of insulin are observed in G_o/G_l arrested cells limited for serum growth factors or essential nutrients, and in cells growing in hormone-supplemented serum-free media. Some, but not all, of the effects of insulin on growth require superphysiological concentrations of insulin. The action of insulin on growth is synergistic with the action of other hormones and growth factors, including FGF, PDGF, PGF_2α and vasopressin. This observation, as well as other observations regarding the temporal sequence of action of growth factors, suggests that different growth factors act on different intracellular biochemical events. Several hypotheses have been proposed to explain the effect of insulin on cellular proliferation, including regulation of essential metabolic processes and interaction of insulin with receptors for insulin-like growth factors. Evidence supporting these various hypotheses is reviewed. In addition to the growth-stimulatory effect of insulin observed in cell culture, a number of clinical examples suggest that insulin is an important growth-regulating hormone during fetal development.     

A monoclonal antibody directed to terminal residue of {beta}-galactofuranose of a glycolipid antigen isolated from Paracoccidioides brasiliensis: cross-reactivity with Leishmania major and Trypanosoma cruzi

A mouse monoclonal antibody, MEST-1, was produced against Band1 glycolipid antigen of Paracoccidioides brasiliensis. The glycanstructure of Band 1 antigen was recently elucidated and themonosaccharides sequence was defined as: Galfß1     

Staining patterns for the anti-horseradish peroxidase antibody reaction in proplasma cells developing in the medulla of rat popliteal lymph nodes during the secondary response

The development of plasma cells from lymphocytes was studied in the medulla of popliteal lymph nodes of rats during the secondary response to horseradish peroxidase (HRP). Changes in the microscopic appearance of proplasma cells were compared with changes in the intensity of the anti-HRP antibody reaction in these cells. Early proplasma cells, appearing 2 to 3 days after the injection of HRP into the footpads, were relatively small cells similar in size to lymphocytes. Their small nuclei were eccentrically located due to the one-sided enlargement of the pyroninophilic cytoplasm. The reaction for the anti HRP antibody in these cells was weak or negative. Other proplasma cells located in the same medullary cord regions showed a more intense antibody reaction. This change was correlated, in many cases, with an enlargement of the nucleus, giving the cells a blast-like appearance. Three to 6 days after the reinjection of the antigen, the medullary cords contained many mature plasma cells characterized by an intense antibody reaction. The mature plasma cells were always accompanied by proplasma cells, the latter varying in microscopic appearance (stage of development) asd staining intensities (antibody contents). The staining intensities and the microscopic appearance of proplasma cells, and the proportion of proplasma cells to plasma cells, varied in different medullary cord regions of the same lymph nodes. The staining patterns, together with the microscopic appearance of the cells, seemed to show whether antibody formation was inhibited or stimulated.