Amígdalas y adenoides: defensa ante agentes patógenos y su implicancia estomatológica / Tonsils and adenoids: defend to pathogenic agents and their stomatological involvement

La función de las amígdalas siempre ha sido discutida, desde afirmar que no tenían funcionalidad, hasta la actualidad que se plantea un papel inmunológico, con actividad linfocitaria de defensa, debido a la localización de linfocitos en el tejido de las amígdalas. Este artículo de actualización pretende describir desde la embriología, histología, fisiología, patología y estomatología, el rol que desempeñan las mismas en su papel inmunológico ante la acción de agentes patógenos. Se destaca la acción conjunta de las amígdalas palatinas, amígdalas faríngeas o adenoides, amígdalas peritubarias, amígdalas linguales y todo el resto de tejido linfático que conforman el anillo linfático faríngeo o anillo de Waldeyer, ya que cumplen un rol determinante en la defensa del organismo (AU)

The function of the tonsils has always been debated, from stating that they had no functionality, to the present day that an immunological role is proposed, with lymphocyte defense activity, due to the location of lymphocytes in the tissue of the tonsils. This update article aims to describe from embryology, histology, physiology, pathology and stomatology, the role they play in their immunological role against the action of pathogens. The joint action of the palatine tonsils, pharyngeal or adenoid tonsils, peritubal tonsils, lingual tonsils and all the rest of the lymphatic tissue that make up the pharyngeal lymphatic ring or Waldeyer's ring is highlighted, since they play a decisive role in the defense of the organism (AU)

Índice neutrófilo-linfocito como factor pronóstico de COVID-19 / Neutrophil to lymphocyte ratio as a prognostic marker in COVID-19

En diciembre de 2019 un nuevo coronavirus se identificó como causa de un brote de neumonía y distrés respiratorio en Wuhan, China. En marzo de 2020 fue declarado pandemia. Resulta importante conocer predictores de mala evolución para optimizar estrategias de cuidados. El índice neutrófilo-linfocito (INL) constituye un novedoso marcador pronóstico en enfermedades cardiovasculares, oncológicas e infecciosas. Este trabajo analiza su valor pronóstico en COVID-19. Se evaluó una cohorte retrospectiva de 131 pacientes con COVID-19 confirmado, entre marzo y mayo de 2020. Se analizaron las características basales de la población, la asociación del INL ≥ 3 con COVID-19 grave y la tasa de mortalidad de la enfermedad. La mediana de edad fue de 52 años, 54% fueron hombres. En 21 pacientes se encontraron criterios de gravedad, 9 de ellos requirieron ventilación mecánica. Presentó INL ≥ 3 el 81% (18/21) de los pacientes graves y el 33% (36/110) de los pacientes leves (OR = 8.74. IC del 95%: 2.74-27.86; p < 0.001). La edad y la hipertensión se asociaron con enfermedad grave. La mortalidad observada en la cohorte fue del 7% (9). En 7 de los 9 pacientes fallecidos se observó un INL ≥ 3 (p = 0.03). El INL, en conjunto con otros predictores, podría usarse como un marcador pronóstico temprano dada la alta accesibilidad y el bajo costo de la prueba.

In December 2019, a new coronavirus was identified as the cause of an outbreak of pneumonia and respiratory distress in Wuhan, China. It was declared pandemic in March 2020. It is important to know predictors of poor outcomes in order to optimize the strategies of care in newly diagnosed patients. The neutrophil to lymphocyte ratio (NLR) constitutes a novel prognostic marker for oncologic, cardiovascular and infectious diseases. We aimed to assess its prognostic value in COVID-19. We evaluated a retrospective cohort of 131 patients with COVID-19 from March to May 2020. We analyzed the association of an NLR ≥ 3 with severe COVID-19, baseline characteristics of the population and the mortality rate. The median age was 52 years, and 54% were men. 21 patients presented criteria of severe disease, 9 of them required mechanical ventilation. NLR ≥ 3 was found in 81% (18/21) of severe patients and in 33% (36/110) of mild patients (OR = 8.74. 95% CI 2.74-27.86; p < 0.001). Age and hypertension were associated with severe disease. A mortality rate of 7% (9) was obtained. Seven of the 9 patients who died presented NLR ≥ 3, with a significant association between mortality and NLR ≥ 3 (p = 0.03). NLR could be used in conjunction with other predictors, as an early prognostic marker in COVID-19 given its accessibility and low cost.

Evaluation of thymic lymphocyte loss of broiler using Digital Analysis of the Lymphoid Depletion System (ADDL) / Avaliação de perda de linfócitos do timo em frangos usando análise digital do sistema de depleção linfóide (ADDL)

The thymus is a lymphoid organ and usually evaluated for the degree of lymphocyte loss with subjective histological techniques. This study aimed to adapt and to apply of the digital analysis of the lymphoid depletion system (ADDL) in the thymus in order to obtain a more accurate analysis. Glucocorticoid was used to induce immunosuppression in 55 broilers at 21 days of age; other 15 broilers were the control group. After euthanasia of the broilers, postmortem examination was made. Both thymic chains were collected and six lobes were selected for histological examination of the degree of lymphocyte depletion (scores 1 to 5) and for submission to all stages of processing by the ADDL system. The artificial constructed neural networks (ANN) obtained 94.03% of correct classifications. In conclusion, it was possible to adopt objective criteria to evaluate thymic lymphoid depletion with the ADDL system.(AU)

O timo é um órgão linfóide, que é normalmente avaliado para o grau de perda de linfócitos a partir de técnicas histológicas subjetivas. Este trabalho teve como objetivo a adaptação e aplicação do sistema de análise digital de depleção linfóide (ADDL) para o timo, a fim de tornar sua análise mais acurada. Glicocorticóides foram utilizados a fim de induzir imunossupressão em 55 aves de 21 dias de idade. Outras 15 aves formaram o grupo controle. Posteriormente, para cada um dos aves, realizou-se a eutanásia e necropsia. Ambas as cadeias do timo foram coletadas e foram selecionadas seis lóbulos para processamento histológico, análise quanto ao grau de depleção linfocitária (escores de 1-5) e submissão a todas as fases do processamento pelo sistema ADDL. Observou-se que a rede neural artificial (RNA) construída obteve 94,03% de classificações corretas. Em conclusão, foi possível adotar critérios objetivos para avaliar a depleção linfóide tímica utilizando o sistema ADDL.(AU)

Lympho-proliferative responses to various Fasciola hepatica worm's antigens: an in vitro study

Fascioliasis is an important zoonotic disease with approximately 2-4 million people infected worldwide and a further 180 million at risk of infection. F. hepatica can survive within the bile ducts for many years through its ability to suppress the host immunity with Fasciola cathepsin L1 cysteine protease and Glutathione S transferase playing an important role. The aim of the present study is to investigate the in vitro lympho-proliferative responses of hepatic hilar lymphocytes [HLN] of infected sheep in response to different F. hepatica antigens. The suppressive effects of Fasciola excretory/secretory [ES] and tegument [TEG] and their fractions were also investigated. Our results showed that both ES and TEG had significant suppressive effects on lymphoproliferation, up to 74% and 92%, respectively. When these antigens were fractionated, fraction 3 [MW of >10000-30000] of both ES [64%] and TEG [59%] in addition to fraction 4 [MW of

Vascular endothelial growth factor-A enhances indoleamine 2,3-dioxygenase expression by dendritic cells and subsequently impacts lymphocyte proliferation

Dendritic cells (DCs) are antigen (Ag)-presenting cells that activate and stimulate effective immune responses by T cells, but can also act as negative regulators of these responses and thus play important roles in immune regulation. Pro-angiogenic vascular endothelial growth factor (VEGF) has been shown to cause defective DC differentiation and maturation. Previous studies have demonstrated that the addition of VEGF to DC cultures renders these cells weak stimulators of Ag-specific T cells due to the inhibitory effects mediated by VEGF receptor 1 (VEGFR1) and/or VEGFR2 signalling. As the enzyme indoleamine 2,3-dioxygenase (IDO) is recognised as an important negative regulator of immune responses, this study aimed to investigate whether VEGF affects the expression of IDO by DCs and whether VEGF-matured DCs acquire a suppressor phenotype. Our results are the first to demonstrate that VEGF increases the expression and activity of IDO in DCs, which has a suppressive effect on Ag-specific and mitogen-stimulated lymphocyte proliferation. These mechanisms have broad implications for the study of immunological responses and tolerance under conditions as diverse as cancer, graft rejection and autoimmunity.

Developmental changes in cell proliferation and apoptosis in the normal duck bursa of Fabricius

The aim of this work was to investigate developmental changes in cell proliferation and apoptosis in normal duck bursa of Fabricius using flow cytometry and immunohistochemistry. Studies were carried out on Tianfu ducks on days 24 and 27 of embryogenesis (E24 and E27) along with days 20, 70, and 200 of postnatal development (P20, P70, and P200). Results showed that the percentage of G0/G1 bursa cells significantly increased between E24 and P200 while the percentage of cells in the S phase or G2 + M phase as well as the proliferating index obviously decreased during the same period. Proliferation cell nuclear antigen was detected in lymphocyte and interfollicular epithelium. The proliferative lymphocyte density tended to decrease from E24 to P200. Apoptotic bodies in macrophages, free apoptotic bodies, or nuclei with condensed chromatin in lymphocytes in follicles were identified by transferase-mediated dUTP nick-end labeling. Both flow cytometry and microscopic analysis reveal that the proportion of apoptotic cells and apoptotic lymphocyte density increased from E24 to P20, fell on P70, then rose again on P200. Our foundings demonstrate that cell proliferation decreases and apoptosis increases with age. These changes may account for duck bursa development and involution.

¿Es la hipertensión sensible a sal una enfermedad inflamatoria?: Papel de los linfocitos y macrófagos / Is salt sensitive hypertension an inflammatory disease?: Role of lymphocytes and macrophages

La hipertensión arterial sistémica es un problema de salud pública. Esta entidad afecta al 43% de la población mexicana y es considerada una de los principales factores de riesgo para el desarrollo de eventos vasculares cerebrales, insuficiencia cardiaca e insuficiencia renal. La prevalencia de hipertensión arterial sistémica se ha incrementado durante las últimas décadas debido a la adopción de una dieta alta en sal. Existe evidencia de que la hipertensión sensible a sal se acompaña de alteraciones estructurales renales como dilatación tubular, fibrosis intersticial en parches, expresión de osteopontina e infiltrado túbulo intersticial de linfocitos y macrófagos, que impiden una excreción urinaria de sodio adecuada y en consecuencia, favorecen el desarrollo de HAS. De forma experimental se ha demostrado que estas alteraciones estructurales tienen una naturaleza inflamatoria y que la administración de medicamentos inmunosupresores disminuye la lesión tisular y mejoran el control de la presión arterial. En conjunto, los conocimientos derivados de los estudios de hipertensión sensible a sal pueden derivar en el desarrollo de nuevos fármacos destinados a mejorar el pronóstico asociado a la hipertensión arterial sistémica.

High blood pressure is a public health problem. This entity affects 43% of the mexican population and is considered a major risk factor for development of stroke, cardiac failure and chronic kidney disease. Hypertension prevalence has increased over the last decades, mainly because of high salt diet. There is evidence showing that salt-sensitive hypertension develops structural changes as tubular dilation, patchy interstitial fibrosis, osteopontin expression and lymphocytic/macrophage tubulointerstitial infiltrate that blunts urinary sodium excretion and therefore promotes HBP. It has been shown that this structural damage has an inflammatory origin and that immunosuppresant drugs down-regulates tissular injury and improves blood pressure control. In summary, this salt-sentitive hypertension data can be used in development of new and potent blood pressure drugs.

A comparative study of apoptosis in reticular and erosive oral lichen planus

The oral lichen planus (OLP) is a chronic inflammatory disease, probably autoimmune, with different clinical forms. The most common types are the reticular and the erosive ones. Apoptosis participates in the destruction of basal keratinocytes, but its role in the perpetuation of the subepithelial lymphocytic infiltrates was not yet investigated. To evaluate the involvement of apoptosis in the epithelium and in subepithelial lymphocytic infiltrates, 15 samples of reticular and erosive OLP and 10 samples of healthy oral mucosa were collected and processed histologically. Apoptosis was quantified in the epithelium and in inflammatory cell infiltrates. TUNEL reaction was used to measure apoptosis in the infiltrates. Erosive OLP showed more intense epithelial apoptosis than reticular OLP and controls. In contrast, apoptosis in the inflammatory cell infiltrates was more frequent in reticular than in erosive OLP. Lymphocytes were the predominant cells within the inflammatory cell infiltrates and were more frequent in erosive OLP than in reticular type. These results suggest that different apoptotic levels are involved in the erosive/reticular switch in OLP, determining different clinical presentations. In conclusion, decreased apoptosis in inflammatory infiltrates may contribute to the persistence of T lymphocytes, worsening the attack to the epithelium in erosive OLP.

O líquen plano oral (LPO) é uma doença crônica inflamatória, provavelmente auto-imune, com diferentes formas clínicas. Os tipos mais comuns são o reticular e o erosivo. A apoptose participa da destruição dos ceratinócitos basais, no entanto o seu papel na perpetuação do infiltrado linfocitário subepitelial ainda não foi investigado. Para avaliar o envolvimento da apoptose no epitélio e no infiltrado linfocitário subepitelial, quinze amostras de LPO reticular, quinze de LPO erosivo e dez amostras de mucosa oral saudável foram coletadas e processadas histologicamente. A apoptose foi quantificada no epitélio e nas células do infiltrado inflamatório. A reação de TUNEL foi usada para mensurar a apoptose no infiltrado. A intensidade da apoptose no epitélio mostrou ser maior no LPO erosivo que no LPO reticular e estes foram maiores que no controle. Em contraste, a apoptose nas células do infiltrado inflamatório foi mais freqüente no LPO reticular que no LPO erosivo. Os linfócitos foram as células predominantes dentro do infiltrado inflamatório e foram mais freqüentes no tipo erosivo de LPO que no tipo reticular. Estes resultados sugerem que diferentes níveis de apoptose estão envolvidos no tipo erosivo e reticular de LPO, determinando as diferenças nas apresentações clínicas. Em conclusão, a diminuição da apoptose no infiltrado inflamatório pode contribuir para a persistência dos linfócitos T, piorando o ataque ao epitélio no LPO erosivo.

Cognitive awareness of carbohydrate intake does not alter exercise-induced lymphocyte apoptosis

OBJECTIVE: The purpose of this investigation was to determine whether cognitive awareness of carbohydrate beverage consumption affects exercise-induced lymphocyte apoptosis, independent of actual carbohydrate intake. INTRODUCTION: Carbohydrate supplementation during aerobic exercise generally protects against the immunosuppressive effects of exercise. It is not currently known whether carbohydrate consumption or simply the knowledge of carbohydrate consumption also has that effect. METHODS: Endurance trained male and female (N = 10) athletes were randomly assigned to one of two groups based on either a correct or incorrect cognitive awareness of carbohydrate intake. In the incorrect group, the subjects were informed that they were receiving the carbohydrate beverage but actually received the placebo beverage. Participants completed a 60-min ride on a cycle ergometer at 80 percent VO2peak under carbohydrate and placebo supplemented conditions. Venous blood samples were collected at rest and immediately after exercise and were used to determine the plasma glucose concentration, lymphocyte count, and extent of lymphocyte apoptosis. Cognitive awareness, either correct or incorrect, did not have an effect on any of the measured variables. RESULTS: Carbohydrate supplementation during exercise did not have an effect on lymphocyte count or apoptotic index. Independent of drink type, exercise resulted in significant lymphocytosis and lymphocyte apoptosis (apoptotic index at rest = 6.3 ± 3 percent and apoptotic index following exercise = 11.6 ± 3 percent, P<0.01). CONCLUSION: Neither carbohydrate nor placebo supplementation altered the typical lymphocyte apoptotic response following exercise. While carbohydrate supplementation generally has an immune-boosting effect during exercise, it appears that this influence does not extend to the mechanisms that govern exercise-induced lymphocyte cell death.

Regulação cruzada entre peroxidases e indolamina 2.3 dioxigenase no controle da metabolização do triptofano / Peroxidases and indoleamine 2.3 dioxygenase crosstalk modulating tryptophan metabolization

Triptofano (TRP) é metabolizado por duas vias, a via serotonérgica e a via das quinureninas. Na via serotonérgica, TRP é metabolizado a serotonina (5-HT) e, em algumas células, à melatonina (MLT) que pode ser oxidada à N1-acetil-N2-formil-5- metoxiquinuramina (AFMK) e N1-acetil-5-metoxiquinuramina (AMK) por ação de peroxidases. Na via das quinureninas o TRP é diretamente metabolizado à N formilquinurenina (NFK) e em seguida a quinurenina (QUIN). A enzima indolamina 2, 3 dioxigenase (IDO) é uma das responsáveis por esta reação. Dada a importância da IDO na tolerância imunológica e pelo fato desta enzima ser induzível nos propusemos a avaliar a existência de uma regulação cruzada entre esta enzima e a via serotonérgica. Avaliando a interferência de AMK sobre a ação de IDO e a interferência de QUIN sobre a formação de AFMK por peroxidases, observamos uma possível interação entre as vias. AMK é um inibidor competitivo clássico de IDO e o Ki encontrado foi de 0,98 mM. QUIN é um inibidor acompetitivo linear simples da formação de AFMK e o Ki encontrado foi de 0,1 mM. A inibição da formação de AFMK também ocorre para a peroxidase humana (mieloperoxidase, MPO). Além de representarem uma regulação cruzada utilizada in vivo, as inibições encontradas podem ser relevantes para a proposta de novos inibidores de IDO e MPO na terapia imunomodulatória. Dado o nosso interesse pelas enzimas IDO e MPO, avaliamos ainda a localização intracelular destas enzimas em células de peritônio de camundongo, tanto residente como ativada com concanavalina A (Con A). O estímulo com Con A representa uma ativação de linfócitos T mediado por interferon gama (IFN-γ) e foi usado como modelo experimental para avaliar condições de localização em células ativadas. Por imunocitoquímica verificamos que IDO e MPO localizam-se próxima à membrana plasmática sendo que uma leve dispersão apenas de MPO foi observada em células ativadas com Con A. A localização intracelular das duas enzimas é no...

Tryptophan (TRP) is metabolized by two mains pathways, the serotoninergic pathway and the kynurenine pathway. In the serotoninergic pathway, TRP is metabolized to serotonin (5-HT) and, in some cells, to melatonin (MLT). The later can even be oxidized to acetyl-N1-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5 -methoxykynuramine (AMK) by peroxidases. In the kynurenine pathway, TRP is metabolized to N-formylkynurenine (NFK) and to kynurenine (KYN). Indoleamine 2, 3 dioxygenase (IDO) is one of those responsible for this reaction. Since IDO is importat in immune tolerance and the fact that this enzyme is inducible by cytokines we proposed whether there is a cross regulation between this enzyme and the serotoninergic pathway. A possible interaction between MLT and TRP oxidation pathways was shown by the AMK influence on IDO activity and QUIN interference on AFMK formation by peroxidases. AMK was shown to be an IDO classical competitive inhibitor with a Ki of 0.98 mM. QUIN was a peroxidase (horseradish peroxidase, HRP) classical uncompetitive inhibitor and Ki was found to be 0,1 mM. AFMK formation inhibition was also found in human peroxidase (myeloperoxidase, MPO). Beyond the in vivo crosstalk, new IDO and MPO inhibitors in immunomodulatory therapy would be proposed by the compounds shown in this study. Given our interest in IDO and MPO, we also evaluated their intracellular localization in both resident and concanavalin A (Con A) activated mice peritoneum cells. Con A stimulation is a IFN-γ mediated T lymphocytes activation and was our experimental model to evaluate activated cells. In light microscopy we observed IDO and MPO localization near the membrane and MPO only had a dispersed localization in Con A activated cells. Cytoplasm, nucleus and vesicles were the intracellular localization of both enzymes. Interestingly, we found MPO in isolated cells and in cell clusters of two or more cells. MPO was founded on macrophages, B1 cells and cell clusters by...

Evaluation of annexin V and Calcein-AM as markers of mononuclear cell apoptosis during human immunodeficiency virus infection

Evaluation of apoptosis by flow cytometry is generally accomplished by methods that use annexin V-FITC as vital dye, which access phosphatidylserine exposed on the external membrane at the beginning of this process. In addition, the concomitant use of propidium iodide makes possible to verify the characteristic nuclear alterations in the late stages of apoptosis, as a consequence of the increase in membrane permeability. On the other hand, the use of calcein-AM in association with ethidium homodimer (EthD-1) allows the evaluation of cell apoptosis through detection of esterase activity and cellular membrane physical and chemical alterations. The aim of this study was to compare the sensibility of calcein-AM and EthD-1 with annexin V-FITC and propidium iodide for early apoptosis evaluation in peripheral blood mononuclear cell culture, obtained from HIV-infected patients. Apoptosis and cellular viability were detected and quantified by flow cytometry after 24 and 48 hours incubation times. Our results showed that calcein-AM/EthD-1 was more sensitive for apoptotic cell quantification in both incubation times than annexin V-FITC/propidium iodide (mean of 46.95 percent ± 3.56, p < 0.0001, for 24 hours and mean of 37.67 percent ± 2.47, p < 0.0014 for 48 hours), besides allowing to clearly define viable, apoptotic and dead cell populations.

Apoptosis de linfocitos asociada a enfermedades infecciosas / [Lymphocyte apoptosis associated to infections]

During infections, the presence of lymphocyte apoptosis both in peripheral blood and in lymphatic organs has been described. This kind of programmed cell death can be either induced by host control mechanisms aimed at eliminating infected lymphocytes and/or retaining immune system homeostasis, or by the pathogen in order to complete its life cycle, spreading the infection and/or suppressing the immune response. Thus, apoptosis has advantages and disadvantages for the host depending on the pathogen life cycle and/or the specificity of the lymphocyte population affected. Identification of the mechanisms involved in autoreactive or pathogen-specific lymphocyte apoptosis could lead to strategies designed to interfere immunologically or pharmacologically in favor of the host.

Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon

The mercury rejected in the water system, from mining operations and lixiviation of soils after deforestation, is considered to be the main contributors to the contamination of the ecosystem in the Amazon Basin. The objectives of the present study were to examine cytogenetic functions in peripheral lymphocytes within a population living on the banks of the Tapajós River with respect to methylmercury (MeHg) contamination, using hair mercury as a biological indicator of exposure. Our investigation shows a clear relation between methylmercury contamination and cytogenetic damage in lymphocytes at levels well below 50 micrograms/gram, the level at which initial clinical signs and symptoms of mercury poisoning occur. The first apparent biological effect with increasing MeHg hair level was the impairment of lymphocyte proliferation measured as mitotic index (MI). The relation between mercury concentration in hair and MI suggests that this parameter, an indicator of changes in lymphocytes and their ability to respond to culture conditions, may be an early marker of cytotoxicity and genotoxicity in humans and should be taken into account in the preliminary evaluation of the risks to populations exposed in vivo. This is the first report showing clear cytotoxic effects of long-term exposure to MeHg. Although the results strongly suggest that, under the conditions examined here, MeHg is both a spindle poison and a clastogen, the biological significance of these observations are as yet unknown. A long-term follow-up of these subjects should be undertaken.

Early pregnancy decidua as a source of TGFB

Several studies have shown that decidual tissue produces soluble factors which can regulate a variety of immunosuppressive activities, but the cell type and the molecule responsible is not clearly defined. This study was performed in order to assess 1] whether active Transforming Growth Factor Beta [TGF beta] was present in decidual supernatants produced by explants, cell suspensions and endometrial granulated lymphocytes [eGL] [CD56+CD16-CD3-], and 2] define whether eGL acts as a major decidual suppressor cell for production of TGF beta in early pregnancy decidua. TGF beta assay was applied using TGF beta -sensitive CCL-64 mink lung epithelial cell line [Mv/Lu]. The supernatants from 10 human specimens of early pregnancy decidua were used in the assay in their native state, after acidification and after treatment with anti-TGF beta. The present study showed that decidual supernatants contain both TGF beta activity in which eGL CD56-positive cells have an important role in production of this suppressor factor. Studies of TGF beta activity in pathological pregnancy may be worthwhile to elucidate whether this molecule is critical for survival of the fetoplacental unit

Partial purification and characterization of a novel murine factor that augments the expression of class I MHC antigens on tumor cells

A soluble factor which augments the expression of major histocompatibility complex class I (MHC I) antigens on a number of murine tumor cell lines, has been isolated from the culture supernatants of mixed lymphocyte reaction of spleen cells derived from C57B1/6, Balb/c and Swiss mice. The factor, termed MHC-augmenting factor (MHC-AF) has been partially purified by Sephadex G-100 column chromatography and reverse phase HPLC. MHC-AF activity is associated with an 18 kDa molecule. MHC-AF activity was resistant to pH 2.0 treatment and partially purified MHC-AF preparations did not have any activity in L929 cell/vesicular stomatitis virus (VSV) interferon bioassay system. Antibodies to IFN-gamma did not block the activity of MHC-AF. These results indicate that a MHC-AF distinct from IFN-gamma, is produced by mouse spleen cells undergoing a mixed lymphocyte reaction.

A role for lymphocytes and cytokines on the eosinophil migration induced by LPS

In the present work we review the existing evidence for a LPS-induced cytokine-mediated eosinophil accumulation in a model of acute inflammation. Intrathoracic administration of LPS into rodents (mice, rats and guinea pigs) induces a significant increase in the number of eosinophils recovered from the pleural fluid 24 hr later. This phenomenon is preceded by a neutrophil influx and accompanied by lymphocyte and monocyte accumulation. The eosinophil accumulation induced by LPS is not affected by inhibitors of cyclo or lipoxygenase nor by PAF antagonists but can be blocked by dexamethasone or the protein synthesis inhibitors cycloheximide. Transfer of cell-free pleural wash from LPS injected rats (LPS-PW) to naive recipient animals induces a selective eosinophil accumulation within 24 hr. The eosinophilotactic activity present on the LPS-PW has a molecular weight ranging between 10 and 50 kDa and its effect is abolished by trypsin digestion of the plural wash indicating the proteic nature of this activity. The production of the eosinophilotactic activity depends on the interaction between macrophages and T-lymphacytes and its effect can not be blocked by anti-IL-5 monoclonal antibodies. Accumulated evidence suggest that the eosinophil accumulation induced by LPS is a consequence of a eosinophilotactic cytokine produced through macrophage and T-cell interactions in the site of a LPS-induced inflammatory reaction.

Lesiones anatomo e histopatologicas compatibles con neumoni enzootica porcina a nivel de matadero de Santa Cruz / Anatomic and histologic lesions consistent with endozootic pig neumonia in Santa Cruz

Se determino lesiones anatomo e histopatologicas compactibles con neumonia enzootica porcina (NEP) en cerdos faenados en los mataderos de Santa Cruz de la Sierra, en los meses de agosto y Septiembre de 1995. El muestreo se realizo dos veces por semana; de todos los animales faenados en el dia, se procedio al examen macroscopico de los pulmones en el momento de la evisceracion y se tomaron muestras a los que presentaban lesiones macroscopicas compatibles con NEP; estas fueron procesadas y se utilizo la tecnica de histopatologia de rutina. Los resultados obtenidos se sometieron a un analisis estadistico de comparacion de proporciones mediante la prueba de Chi Cuadrado. De 1000 pulmones inspeccionados 237 (23,7 por ciento) resultaron con lesiones macroscopicas

Alteraçöes metabólicas e funcionais em células e órgäos do sistema imunológico de ratos induzidas pela administraçäo intragástrica do óleo de peixe / Metabolic and functional changes in cells and organs of immune system of rats due to the fish oil administrated by gavage

O consumo de cápsulas de óleo de peixe (OP) por humanos visa a atenuaçäo dos sintomas e prevençäo de várias patologias. As alteraçöes metabólicas e funcionais em células e órgäos do sistema imunológico causadas pelo OP pela administraçäo intragástrica (AIG) foram avaliadas. Ratos recém-desmamados (50-70 g) foram submetidos a AIG diária com óleo de peixe, óleo de soja ou manteiga de cacau (0,4 por cento do peso), por 28 dias. Os dados da AIG do OP foram também comparados com os da dieta enriquecida com OP. Foram avaliados: aumento de permeabilidade vascular (reaçäo anafilática), funcionalidade de macrófagos (produçäo de 'H IND. 2O IND. 2', 'O IND. 2' e fagocitose), proliferaçäo de linfócitos, a atividade máxima das enzimas: hexoquinase, glicose-6-fosfato desidrogenase, citrato sintase (metabolismo de glicose), catalase, glutationa peroxidase e superóxido dismutase (antioxidantes) no baço, linfonodo mesentérico e timo. A concentraçäo de TBARs nos mesmos órgäos e no plasma e a capacidade antioxidante do plasma foram também determinadas

Possible modulatory role of non-activated lymphocytes on insulin secretion

In order to study the probable physiological role of non-activated lymphocytes on islet B-cells, we incubated and perfused rat pancreatic islets in the presence of low (2.8 mM) and high (l6.7 mM) glucose concentrations after pre-exposure for 60 min to rat lymphocytes or to substances secreted by lymphocytes. Insulin secretion and 86Rb+, 45Ca2+ and [3H]-phosphoinositide metabolite fluxes were lower compared to controls when islets were pre-exposed to lymphocytes but were not different when islets were pre-exposed to substances secreted by lymphocytes. These alterations in isotope flux suggest that, when lymphocytes and islets are in contact, closure of potassium channels and a paradoxical effect of glucose load on insulin release occur in the presence of low glucose concentrations. The alterations observed are probably due to a swift and direct action of lymphocyte secretion perhaps induced by a direct contact of islet cells.

Radio-adaptive response in human lymphocytes in vitro.

An attempt has been made to investigate the adaptive response to ionizing radiation in the human lymphocytes in vitro using cytochalasin-B blocked micronucleated binucleate cells (mn-BNCs) as a cytogenetic end point. Whole blood samples drawn from healthy donors, of either sex were irradiated in vitro at a dose of 1 cGy (adaptive or conditioning dose) Cobalt-60 gamma radiation (dose rate 1.12 cGy/min) at about 26 hr after mitogenic stimulation. After 31 hr of their initiation, groups of cultures were subsequently exposed to a challenging dose of 100 cGy gamma radiation (dose rate 82 cGy/min.). Eight males in the age group ranging from 25 to 55 years and eight females (age group 25 to 29 years), have been analysed during this study. Analysis of data revealed 40.6% reduction in the frequency of mn-BNCs among the males with a range from 25.7% to 54.7%. In case of females, also the per cent reduction varied from 26.3% to 49.0%, with a mean value of 33.7%. Pooling the data from males and females gave an overall reduction of 37.1% in the frequency of radiation induced mn-BNCs due to pre-exposure to 1 cGy radiation.