Phagocytosis and nitric oxide production by peritoneal adherent cells in response to Candida albicans in aging: a collaboration to elucidate the pathogenesis of denture stomatitis

Abstract Elderly denture wearers are commonly affected by Candida-associated denture stomatitis (DS), an inflammatory process of the oral mucosa strongly associated with Candida spp and other microorganisms, as well as local and systemic factors. The impaired immune response against pathogens is among the inherent host factors that have been also associated with the pathogenesis of DS. Mononuclear phagocytes respond to the pathogens through phagocytosis followed by the production of several substances inside the phagosomes, among them are the reactive nitrogen species (RNS). A failure in these mechanisms may contribute to the DS development. Objective The aim of this study was to investigate the influence of aging on the internalization and the production of nitric oxide (NO) by peritoneal adherent cells (PAC), in response to Candida albicans (C. albicans). Material and methods PAC obtained from young and aged mice were challenged with dead or viable C. albicans by using predetermined proportions (cells:yeast) for 30 and 120 minutes. Phagocytosis was analyzed by acridine orange dye, and NO production by the Griess reaction. Results C. albicans phagocytosis by PAC from aged mice was similar to that of young mice, although the cells from older mice cells present more internalized fungi compared with matched control. In addition, a tendency towards impaired NO production by peritoneal mononuclear phagocytes from aged mice was observed. Conclusions PAC from aged mice may capture and store many fungi, which in turn may mean that these cells are effectively unable to eliminate fungi, probably due to impaired NO production. Therefore, considering the important role of C. albicans overgrowth in the pathogenesis of DS and the aspects observed in this study, aging may favor the onset and severity of local candidosis such as DS and its systemic forms.

Induction of inflammatory cell accumulation using human mast cell tryptases.

The aim of this study was to investigate the effects of human tryptases on inflammatory cell accumulation in vivo. Various concentrations of purified lung or skin tryptases were injected into the peritoneum of BALB/c mouse. At 6 hours or 16 hours following injection, cells from the peritoneal lavage were collected and stained with modified Wright's stain. Differential cell counts were performed and results were expressed as absolute numbers of each cell type per mouse peritoneum. The results showed a dose-dependent infiltration of neutrophils with a maximal increase of up to 32 fold or 43 fold in numbers at 16 hours following an injection of skin and lung tryptases, respectively. Skin tryptase was able to attract more eosinophils than lung tryptase. Significant increases in lymphocyte and macrophage numbers were also observed. In conclusion, both skin and lung tryptases are able to induce nucleated cell accumulation in the peritoneum of mice with similar specificity and potency.

Heterogeneous response of adipose tissue to cancer cachexia

Cancer cachexia causes disruption of lipid metabolism. Since it has been well established that the various adipose tissue depots demonstrate different responses to stimuli, we assessed the effect of cachexia on some biochemical and morphological parameters of adipocytes obtained from the mesenteric (MES), retroperitoneal (RPAT), and epididymal (EAT) adipose tissues of rats bearing Walker 256 carcinosarcoma, compared with controls. Relative weight and total fat content of tissues did not differ between tumor-bearing rats and controls, but fatty acid composition was modified by cachexia. Adipocyte dimensions were increased in MES and RPAT from tumor-bearing rats, but not in EAT, in relation to control. Ultrastructural alterations were observed in the adipocytes of tumor-bearing rat RPAT (membrane projections) and EAT (nuclear bodies)

Organogenesis and tissue regeneration of fallopian tube: a desired metaplastic transformation of mesodermal stem cells in live animal models (dogs).

The capacity of stem cells of peritonium of mesodermal origin to undergo metaplastic transformation and form different tissues developed from mesoderm germ layer is exploited with ulterior motive to use it in the management of human diseases. The excised fallopian tube was replaced with a tube on a stent constructed from autogenous peritoneum from a suitable donor site. The effect of the surroundings environment of the new tissue system to which the peritoneum stem cells are now exposed was studied for 3, 6 and 12 months period in live animal models. The gross and histological studies revealed development of all the component of the wall of the fallopian tube. The lumen of the constructed peritoneal tube was well preserved in its whole length including the anastomotic sites. The scientific rationale of the working hypothesis on which the work is based, is discussed.

Monócitos e mastócitos peritoneais na doença inflamatória do cólon, em ratos / Peritoneal monocytes and mast cells in the inflammatory colon disease in rats

Com o objetivo de conhecer o comportamento dos monócitos e mastócitos em peritônio livre na vigência de doença inflamatória do cólon, células que sabe-se participam ativamente do processo inflamatório, colite ulcerativa é induzida em ratos com ácido acético à 10 por cento. Utilizaram-se 20 animais Wistar, 10 para controle e 10 para indução de colite. Os macrófagos são marcados com azul de Tripan e células são capturadas do peritônio livre após 5 dias de evolução. Observou-se que o número de monócitos/macrófagos era 3 vezes maior no líquido peritoneal obtido dos animais com doença inflamatória do que nos seus controles e o número dos mastócitos 2 vezes maior (p<0,001). Estes achados permitem admitir que o peritônio participa ativamente do processo inflamatório

Formation of neoureter from peritoneum in live animal model (dog).

Regeneration of ureter in vivo is possible from peritoneal stem cells as both are derivative of embryonal germ layer mesoderm. The peritoneal stem cells are engaged in repair of loss due to normal wear and tear by differentiation and proliferation. With pluripotent nature, they have a capacity to undergo metaplastic transformation to various mesodermal tissues. The intrinsic cell factor along with regional tissue organisers coupled with functional need of the region, a desired metaplastic transformation to ureteric wall components is possible.

Contribuiçäo do exame citopatológico do peritônio no diagnóstico da carcinomatose peritoneal / Contribution of the cytopathological study of the peritoneal membrane in the diagnosis of peritoneal membrane in the diagnosis of peritoneal carcinomatosis

Os autores avaliam o papel da citologia exofoliativa do peritônio às cegas, uma nova técnica, no diagnóstico da carcinomatose peritoneal. Para tanto, Estudaram 146 pacientes com ascite de diversas etiologias, nos quais analisaram o exame citopatológico convencional do líquido da ascite. Quando os dois métodos foram comparados, em 100 dos casos, observou-se ter a citologia exfoliativa maior sensibilidade, com igual especificidade.PropSem, assim, sua utilizaçäo na investigaçäo das ascites de origem näo esclarecida, já que, além da maior sensibilidade, é um método tecnicamente de fácil realizaçäo, näo oneroso e que näo aumenta a morbidade da paracentese

Capacidad fagocítica de las células del exudado peritoneal de ratones inmunizados con una preparación ribosomal de Salmonella Typhi Ty2 / Phagocytic capacity of exudate peritoneal cells from mice immunized with Salmonella typhi Ty2 ribosomal fraction

Se comparó la capacidad fagocítica de células ael exudado peritoneal (CEP) de ratones CFW inmunizados con una preparación ribosomal de Salmonella typhi Ty2, con la de ratones protegidos con una vacuna de bacterias inactivadas por calor, ambas en relación con lo obtenido en animales testigo, no inmunizados. Los ribosomas se administraron subcutáneamente en una dosis inicial de 100 µg de ARN y se dio un refuerzo igual a los 14 días, ambos con adyuvantes incompleto de Freund (AIF). Los ratones inmunizados con vacuna de células muertas, recibieron una sola dosis subcutánea con 16***6 bacterias en AIF. Al cabo de 7, 11, 14, 18, 22, 25, y 31 días se indujeron y extrajeron las CEP de los animales de cada grupo e individualmente se cultivaron in vitro junto con S. Typhi Ty2 virulento no opsonizado en relación células-bacterias 1:200. La sobrevida de las bacterias fagocitadas se determinó a las 24 horas de cultivo: las CEP se romperon y por cuenta viable se enumeraron las bacterias no digeridas. Los resultados indican que las CEP de los inmunizados eliminan bacterias con mayor eficiencia que las de testigos. También se demostró que la eficiencia bactericida fue significativamente mayor (P máxima de 0.005) para las CEP de los ratones tratados con la fracción ribosomal que las CEP de los animales vacunados con bacterias intactas no viables. Fiebre tifoidea; vacuna ribosomal; inmunidad a Salmonella; Salmonella typi; fagocitosis por células peritoneales

Participation of mannose receptors on the surface of stimulated macrophages in the phagocytosis of glutaraldehyde-fixed Candida albicans, in vitro

We have evaluated the participation of mannose receptors on the surface of stimulated macrophages in the phagocytosis of Candida albicans in vitro. A dose-dependent 8.6 to 88.3% reduction of phagocytosis was observed in the presence of 0.5 to 5.0 mg/ml of the mannose-rich glycoprotein invertase (either native or denatured) in the incubation medium. Macrophages plated onto substrates coated with poly-L-lysine-mannan also showed a 99% reduction of phagocytic activity toward Candida albicans, but phagocytosis of IgG-coated erytrocytes was not inhibited under the same conditions. These results indicate that mannose receptors are involved in one of the initial steps of phagocytosis of Candida albicans by macrophages

Superoxide-independent hydrogen peroxide release by activated macrophages

The present data show that freshly explanted BCG-activated mouse peritoneal macrophages release large quantities of hydrogen peroxide upon initial contact with a foreign substratum, without the requirement for other membrane stimuli such as phorbol diesters. The hydrogen peroxide detected under these conditions does not originate from extracellularly released superoxide, since 2 x 10**5 BCG-activated macrophages spontaneously released 1.6 nmol hydrogen peroxide but only 0.2 nmol superoxide. Thus, more than 90% of the hydrogen peroxide detected was not derived from extracellular superoxide dismutation. The dissociation between hydrogen peroxide and superoxide release was further demonstrated in cytochalasin B- or lidocaine-treated cells or in the absence of glucose. Under these conditions, hydrogen peroxide release was markedly inhibited while superoxide release was unaffected. These observations provide evidence that another metabolic pathway is involved in the generation and release of hydrogen peroxide during adherence and spreading of freshly explanted activated macrophages onto a substratum

Mycobacterium lepraemurium in Cultured Mouse Peritoneal Macrophage: A Preliminary Report

Efforts have been made to accomplish a long term in vitro cultivation of mouse peritoneal macrophage as a host cell for growth of Mycobacterium lepraemurium. Following the inoculation with live or heat-killed Myco. lepraemuriuum of cultured macrophages either on a cover-slip in Leighton tube or in a small petri dish, microscopic observations of acid-fast (AF) stained slide preparation, and total counts of AF bacilli that were released by ultrasonic treatment from the macrophages in small petri dish have been followed in order to present microscopic and quantitative evidence of the actual multiplication of Myco. lepraemurium in cultured mouse peritoneal macrophage. The results are summarized and conclusions are as follows; 1. Successful long term in vitro cultivation of mouse peritoneal macrophage has been accomplished. The growth medium for tissue culture consisted of NCTC 109;50% heat-inactivated calf serum; 40% and beef embryo extract (diluted 1 : 5); 10% and the medium was renewed every 3 to 4 days. The incubation temperature was 37 degrees C; before and at 30 degrees C; after the inoculation with Myco. lepramurium. The CO2 content inside the CO2 humidity incubator for the cultivation of macrophage was kept at 5%. 2. In cultures of macrophage inoculated with live Myco. lepraemurium, clear features of increases in the number of AF bacilli inside individual cell, of elongation of bacill and of increased solidity in AF staining were observed. However, these features were absent in cultlires of macrophage inoculated with heat-killed Myco. lepraemurium. 3. The ultrasonic treatment of macrophage inoculated with 1ive Myco. lepraemurium, and the quantitative assessment of total number of AF bacilli through the course of 6 to 8 weeks after inoculation has provided partial but substantial evidence of actual multiplication of Myco. lepraemurium in cultured macrophages.