Modulation of disseminated intravascular coagulation (DIC) by steroidal and non-steroidal anti-inflammatory drugs

Activation of the coagulation systems by endotoxin and release of vasoactive agents are both essential for the production of microthrombosis. Glucocorticoids prevent activation of factor XII by endotoxinin vivo and decrease production of tissue factor by macrophages. NSAID do not interfere with factor XII activation and increase the severity and risks of microthrombosis by inhibiting synthesis and release of protective prostaglandins. On the other hand, prolonged administration of glucocorticoids results in the reduction of the immune defence and fibrinolysis, increases the α-adrenergic response to endotoxin and sensitizes to endotoxin-induced intravascular coagulation like NSAID.     

Surface activation of factor XII (Hageman factor) — Critical role of high molecular weight kininogen and another potentiator

When factor XII was adsorbed to kaolin it slowly became activated and converted prekallikrein to kallikrein. In the presence of HMW-kininogen the rate of activation of factor XII and consequently that of prekallikrein was markedly enhanced. The enhancing effect of HMW-kininogen was a dose-dependent phenomenon. In order to enhance the activation of factor XII on a surface the HMW-kininogen molecule had to be intact. Cleavage of HMW-kininogen by kallikrein decreased the enhancing effect of HMW-kininogen, there being an inverse relation between the bradykinin-generated and the capacity to enhance factor XII activation. Another potentiator of factor XII activation was isolated from proteins adsorbed to aluminum hydroxide. This potentiator further increased the activation of factor XII, also in a dose-dependent fashion. It was postulated that factor XII is slowly converted into its active form by exposure to negatively charged surfaces; that this process is enhanced by kallikrein and further accelerated by HMW-kininogen and the potentiator; and that these enhancing substances probably act by opening active sites on the factor XII molecule.Supported by a grant from the Ontario Heart Foundation.Supported by the Medical Research Council of Canada.     

Tropomyosin dynamics

Tropomyosin is a two chained α-helical coiled coil protein that binds actin filaments and interacts with various actin binding proteins. Tropomyosin function depends on its ability to move to distinct locations on the surface of actin in response to the binding of different thin filament effectors. Tropomyosin dynamics plays an important role in these fluctuating interactions with actin and is thought to be fundamental to many of its biological activities. For example tropomyosin concerted movement on the surface of actin triggered by Ca²⁺ binding to troponin or myosin head binding to actin has been argued to be key to the cooperative allosteric regulation of muscle contraction. These large-scale motions are affected by tropomyosin internal dynamics and mechanical properties. Tropomyosin internal dynamics corresponding to smaller and more localised structural fluctuations are increasingly recognised to play an important role in its function. A thorough understanding of the coupling between local and global structural fluctuations in tropomyosin is required to understand how time dependent structural fluctuations in tropomyosin contribute to the overall thin filament dynamics and dictate their various biological activities.     

A study of histamine release from human basophils and lung mast cells by products of lymphocyte stimulation

It has been previously reported by Thueson and his co-workers [1] that lymphokine-containing supernatant of cultured human peripheral blood lymphocytes stimulated with Concanavalin-A (Con-A) is capable of releasing histamine from human basophils. Here we confirm such findings, show that such release is additive to that due to immunological stimull (Anti-IgE and antigen) and describe its characteristics and effect in lung tissue. The lymphokine was found to induce a small histamine release from chopped or enzyme-dispersed human lung tissue. As was the case with basophils, the release from lung tissue by this factor, though small, was also found to be additive to that induced by anti-IgE when both agents were added simultaneously. Histamine release from leucocytes by neat supernatant ranged from 9 to 35% and up to 55% when concentrated four-fold. The release resembled that of IgE-mediated reactions in many respects including temperature and calcium dependence, time course and susceptibility to metabolic inhibitors — thus suggesting a non-cytotoxic mechanism. These results show that histamine release by this lymphokine(s) possesses most of the features of an active secretory process. They also suggest that the histamine-releasing factor (HRF) in lymphokine-containing supernatants might be involved in the modulation of type I allergy in humans, apart from its involvement in delayed-type hypersensitivity.     

Modulation of neutrophil Fc and C3b receptors

The effect of the interaction between human neutrophils and aggregated IgG on the expression of the receptors for the Fc portion of IgG (FcR) and for the C3b (C3R) has been investigated. Incubation of neutrophils with the appropriate concentrations of aggregated IgG at 37°C caused the loss of both the FcR and the C3R. This loss (modulation) was energy dependent (i.e., did not take place in cells incubated in the cold) and irreversible in that neutrophils did not reexpress either of the two receptors even upon prolonged incubation in vitro. The mechanisms leading to the modulation of FcR and C3R were different. FcR modulation was independent of the activation of the respiratory burst, since it occurred also in neutrophils from chronic granulomatous disease patients and was not induced by treatment of normal neutrophils with drugs such as phorbol myristate acetate (PMA), known to activate the respiratory burst. The FcR modulation was rather related to the redistribution (“capping”) and endocytosis of the FcR induced by the interaction with aggregated IgG. This possibility was supported by the finding that FcR modulation was blocked by inhibitors of phagocytosis and by the observation that aggregated IgG, tagged with a fluorescent dye, were “capped” and subsequently endocytosed by metabo'lically active cells. Modulation of C3R was dependent upon the activation of the respiratory burst induced by the interaction of aggregated IgG with the neutrophils. This hypothesis was also supported by the finding that the modulation of C3R was induced by treatment of the cells with PMA and did not occur in chronic granulomatous disease neutrophils treated with aggregated IgG or PMA. Furthermore the modulation of C3R was inhibited by the addition of catalase, suggesting that such modulation was consequent to the damaging effect of the oxygen active by-products on the receptor structures. In addition to the C3R modulation described above, another type of C3R loss was observed. This occurred in chronic granulomatous disease (CGD) neutrophils following interaction with the appropriate antigen-antibodycomplement complexes. In these cells, phagocytocis of the complexes caused a concomitant modulation of the C3R that was possibly related to the redistribution and endocytosis of the C3R structures.     

Intrinsic asthma and bacterial histamine release via lectin effect

Bacteria-induced histamine release from basophil leukocytes was observedin vitro in both children with intrinsic asthma (IA) as well as in normal individuals.In vivo the release is suggested to take place only in the lung of IA patients, where a defective pulmonary barrier would permit the bacteria to enter, but not in healthy individuals. The study indicates that two different mechanisms of bacterial histamine release might exist, an IgE-mediated reaction and a non-immunological mechanism consisting of a direct interaction with the basophil cell surface. The non-allergic mechanism might depend on a lectin effect where bacterial surface lectins interact with the basophil cell surface leading to release of histamine. Inhibition studies with carbohydrates suggest a multi-lectin reaction in the bacterial histamine release involving several types of lectins on the bacterial membrane reacting with different carbohydrate moieties on the cell surface of basophil leukocytes.     

The olfactory bulb structure of African giant rat (Cricetomys gambianus,Waterhouse 1840) I: cytoarchitecture

The olfactory system typically consists of two parallel systems: the main olfactory system and the accessory olfactory system. The main olfactory bulb (MOB) acts as the initial processing site for volatile chemical stimuli and receives input from the olfactory receptor cells located in the olfactory epithelium. The African giant rat is reputed to have abilities to detect landmines and tuberculosis samples by sniffing. This study therefore is a preliminary study on the histological and immunohistochemical anatomy of the olfactory bulb of the African giant rat (Cricetomys gambianus, Waterhouse). Nissl and Klüver–Barrera histological staining of the olfactory bulb revealed a cytoarchitecture typical of most mammals with 6 cell layers, and 1–2-layered glomeruli measuring approximately 150 μm each in diameter. Immunohistochemical staining with glial fibrillary acidic protein (GFAP) and 2′,3′-cyclic nucleotide 3-phosphodiesterase (CNPase) revealed cellular conformations relative to most mammals. GFAP immunohistochemistry also revealed cell bodies and processes within the periglomerular area which may potentiate signaling from the olfactory receptor cells, while CNPase largely showed soma and evidence of myelin sheath deposition, confirming myelination at different layers of the bulb. Neurogenesis was examined using the neurogenic markers doublecortin (DCX) and Ki-67. Migration of newly generated cells was observed in all layers of the MOB with DCX and in most layers with Ki-67. The anatomy of the olfactory bulb is described as relatively large in the African giant rat, having a neuroarchitecture similar to most rodents.     

Terpinen-4-ol and alpha-terpineol (tea tree oil components) inhibit the production of IL-1β, IL-6 and IL-10 on human macrophages

Objective

Tea tree oil (TTO) is an essential oil with anti-inflammatory properties, steam distilled from the plant Melaleuca alternifolia. We investigated the immunomodulatory properties of TTO and its components (terpinen-4-ol and alpha-terpineol) using lipopolysaccharide (LPS)-stimulated macrophages.

Methods

The ability of TTO, terpinen-4-ol and alpha-terpineol to modulate the macrophage response to bacterial LPS stimulation was assessed by ELISA for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10 cytokine production and by western blotting for the activation of nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling, which are associated with the expression of pro-inflammatory cytokines. We used a human monocytic cell line (U937) differentiated into macrophages.

Results

LPS induced the production of all cytokines, and TTO and its components significantly reduced the production of IL-1β, IL-6 and IL-10. The production of TNF-α was not affected by either TTO or its major components. The modulation of cytokine production was not mediated by changes in NF-κB or p38 MAPK activation.

Conclusion

TTO, terpinen-4-ol and alpha-terpineol can suppress the production of inflammatory mediators in LPS-stimulated human macrophages; this inhibition was mediated by interfering with the NF-kB, p38 or ERK MAPK pathways.     

Comparison of Chondroitin Sulfate and Hyaluronic Acid Doped Conductive Polypyrrole Films for Adipose Stem Cells

Polypyrrole (PPy) is a conductive polymer that has aroused interest due to its biocompatibility with several cell types and high tailorability as an electroconductive scaffold coating. This study compares the effect of hyaluronic acid (HA) and chondroitin sulfate (CS) doped PPy films on human adipose stem cells (hASCs) under electrical stimulation. The PPy films were synthetized electrochemically. The surface morphology of PPy–HA and PPy–CS was characterized by an atomic force microscope. A pulsed biphasic electric current (BEC) was applied via PPy films non-stimulated samples acting as controls. Viability, attachment, proliferation and osteogenic differentiation of hASCs were evaluated by live/dead staining, DNA content, Alkaline phosphatase activity and mineralization assays. Human ASCs grew as a homogenous cell sheet on PPy–CS surfaces, whereas on PPy–HA cells clustered into small spherical structures. PPy–CS supported hASC proliferation significantly better than PPy–HA at the 7 day time point. Both substrates equally triggered early osteogenic differentiation of hASCs, although mineralization was significantly induced on PPy–CS compared to PPy–HA under BEC. These differences may be due to different surface morphologies originating from the CS and HA dopants. Our results suggest that PPy–CS in particular is a potential osteogenic scaffold coating for bone tissue engineering.     

Clinical and epidemiological survey of acquired immune deficiency syndrome in Europe

The results of a survey on AIDS conducted in Belgium, Denmark, Finland, France, FRG, Italy, the Netherlands, Norway, Sweden, Switzerland and the UK are presented. The definition of AIDS drawn up by the Centers for Disease Control, USA, was used in the survey. On the basis of the number of patients reported annually, it would appear that the disease has reached epidemic proportions in Europe. More than half of the 243 cases documented in the survey were reported during the first nine months of 1983. The most important risk factor in Europe is male homosexuality — among the 223 evaluable AIDS cases, male homosexuals constituted the largest group (58 %). These patients probably contracted the disease through homosexual contacts in the USA, Europe or Haiti. Another new and important risk group has emerged in Europe in addition to male homosexuals — black persons from Central Africa (26 %) and Caucasians who have had intimate contact with natives from Central Africa (3 %). These patients had no known history of homosexuality or drug abuse. The fact that Caucasian patients acquired the disease in this manner suggests that AIDS is not restricted to certain ethnic groups in Central Africa. Drug abuse alone was not identified as a risk factor. The proportion of hemophiliacs and Haitians with AIDS in Europe (2 %) was similar to that found in the USA (4 %). The clinical presentation of the disease in the two most important groups, i.e. male homosexuals and patients from Central Africa, differed slightly. Kaposi's sarcoma was more frequent in the former group (40 %) than in the latter. Furthermore,Pneumocystis carinii was the most frequent agent of opportunistic infections in homosexuals while fungal infections (Cryptococcus neofomans) predominated in the African patients. It is concluded that AIDS has become established in Europe mainly through homosexual contacts and cases imported from Central Africa.     

Annexin A1 in primary tumors promotes melanoma dissemination

Metastatic melanoma is one of the most aggressive forms of skin cancer and has a poor prognosis. We have previously identified Annexin A1 (ANXA1) as a potential murine melanoma-spreading factor that may modulate cell invasion by binding to formyl peptide receptors (FPRs). Here, we report that (1) in a B16Bl6 spontaneous metastasis model, a siRNA-induced decrease in tumoral ANXA1 expression significantly reduced tumoral MMP2 activity and number of lung metastases; (2) in a retrospective study of 61 patients, metastasis-free survival was inversely related to ANXA1 expression levels in primary tumors (HR 3.15 [1.03–9.69], p = 0.045); (3) in human melanoma cell lines, ANXA1 level was positively correlated with in vitro invasion capacity whereas normal melanocytes contained low ANXA1 levels, and (4) the ANXA1 N-terminal peptide ANXA1_2–26 stimulated MMP2 activity after interaction with FPRs and significantly stimulated the in vitro invasion of melanomas by acting on FPRs. These findings identify ANXA1 as a proinvasive protein in melanoma that holds promise as a potential prognostic marker and therapeutic target.     

Effect of substances modifyingγ-aminobutyric acid metabolism on recovery cycles of the interzonal response of the cat motor cortex

The effect of thiosemicarbazide (TSC), depakin and bicuculline on recovery cycles of the interzonal response of the motor cortex was investigated in unanesthetized, curarized cats. Substances modifying the metabolism of γ-aminobutyric acid (GABA) selectively influence the facilitation of this response (with intervals of 20–100 msec between stimuli). After injection of TSC, which lowers the GABA content in the brain, and of bicuculline, which specifically blocks GABA-ergic synapses, facilitation is increased, but after injection of depakin, which increases the GABA concentration, and after intraventricular injection of GABA facilitation is reduced. Caffeine and bemegride increase the amplitude of both conditioning and test responses but have no selective action on facilitation of the test response. Benactyzine and arecoline, substances exciting cholingergic structures, likewise had no selective effect on the recovery cycles. It is suggested that the facilitation described above is the result of interaction between systems of recurrent excitation and inhibition. GABA plays an important role in the regulation of this interaction.     

Linking adiponectin and autophagy in the regulation of breast cancer metastasis

Adipokines within the tumor microenvironment may play important roles in regulating the early steps of breast cancer metastasis. Adiponectin (AdipoQ) is the most abundant adipokine and exists in multiple forms: full-length multimers (fAd) and a cleaved, globular isoform (gAd). While these isoforms are observed as having distinct biological properties, nearly all investigation into AdipoQ in breast cancer has focused on the antitumor roles of fAd, while mostly ignoring gAd. However, evidence from other disease settings suggests that gAd is linked to processes known to promote metastasis. Here, we discuss key areas in which knowledge about AdipoQ in breast cancer is lacking, expressly focusing on data suggesting that gAd is elevated in the microenvironment and may act directly on invasive breast cancer cells to support their initial metastatic progression. We discuss autophagy as a potential mechanism of action for this effect. Overall, given that AdipoQ and AdipoQ receptor agonists have been proposed as therapeutic strategies, it is necessary to better understand the various functions of these regulatory molecules in metastatic breast cancer. Doing so will help ensure the most effective approaches to treating this disease, for which there remain no curative options.     

Effect of hydrocortisone on the stages of immunogenesis

The effect of hydrocortisone was studied on the following stages of immunogenesis: migration of hematopoietic stem cells from the bone marrow; migration of B lymphocyte precursors of antibody-forming cells; cooperative interaction of T and B lymphocytes in the primary immune response to antigenic stimulation by sheep's red cells. Experiments were carried out on F₁(CBA x C57BL) mice. Hydrocortisone, in doses not inhibiting proliferation of hematopoietic cells, had a marked immunodepressive effect which was the resultant of inhibition between different stages of immunogenesis: migration of stem cells and B lymphocytes and cooperation between T and B lymphocytes.     

The Clinical Significance of Posttranslational Modification of Autoantigens

Posttranslational modifications (PTMs) are defined as covalent modifications occurring in a specific protein amino acid in a time- and signal-dependent manner. Under physiological conditions, proteins are posttranslationally modified to carry out a large number of cellular events from cell signaling to DNA replication. However, an absence, deficiency, or excess in PTMs of a given protein can evolve into a target to trigger autoimmunity, since PTMs arise in the periphery and may not occur in the thymus; hence, proteins with PTMs never tolerize developing thymocytes. Consequently, when PTMs arise during cellular responses, such as inflammation, these modified self-antigens can be taken up and processed by the antigen-presenting cells (APCs). Autoreactive T cells, which recognize peptides presented by APCs, can then infiltrate into host tissue where the modified antigen serves to amplify the autoimmune response, eventually leading to autoimmune pathology. Furthermore, a PTM occurring in an amino acid residue can induce changes in the net charge of the protein, leading to conformational modifications in the tertiary and quaternary structure of the protein, especially interaction with human leukocyte antigen (HLA) molecules. Molecular mimicry (MM) was until now the prevailing hypothesis explaining generation of autoimmunity; nevertheless, experimental animal models need inflammation via infection or other immunogens to ensure autoimmunity; MM alone is not sufficient to develop autoimmunity. PTMs could arise as an additive factor to MM, which is required to start an autoimmune response. PTMs have been found to be present in different pathologic conditions such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome, and primary biliary cirrhosis. The aim of the present review is to expose protein posttranslational modifications and the evidence suggesting their role in the generation of autoimmunity.     

Some immunochemical properties of natural antiglobulin factors (homoreactants)

A naturally occurring antiglobulin factor against the Fab-fragment of homologous IgG, contained in the rabbit and human blood serum and γ-globulin preparations, was shown by gelfiltration on Sephadex G-200 to have a molecular weight of about 250,000 daltons. In man this factor does not pass through the placenta in normal pregnancy. Despite differences in the physicochemical and effector properties of 7S IgG and protein with homoreactant activity, the latter has the specific antigenic determinants of IgG. These observations suggest that a complex of IgG with another protein or nonprotein compound possesses homoreactant properties.     

Separation of rosette-forming cells with the aid of an immunosorbent based on sephadex G-25 and G-75

A method of separating rosette-forming cells on columns with an immunosorbent based on Sephadex G-25 and G-75 is described and has been tested. The protein antigen (bovine serum albumin — BSA) is attached by covalent bonds to the surface of the Sephadex granules oxidized by sodium periodate. Cells with receptors on their surface were tested by the rosette method. Up to 88% of the rosette-forming cells were retained on a column packed with BSA-Sephadex granules. Nonspecific retention of the cells was relatively small, about 4%.     

Effect of metabolites of 7,12-dimethylbenz(a)anthracene on the dynamics of its fluorescence in the skin of hairless mice

The effect of two metabolites of 7,12-dimethylbenz(a)anthracene (DMBA)—7-hydroxymethyl-12-methylbenz(a)anthracene and 7,12-dihydroxymethylbenz(a)anthracene—on the dynamics of its fluorescence in the skin of living mice was studied. The first metabolite did not change the dynamics of DMBA fluorescence whereas the second, if applied to the skin in equimolar proportions with DMBA, delayed its fluorescence. A similar effect was obtained with 7,8-benzoflavone—an inhibitor of DMBA metabolism.