Pharmacological PI3K inhibition in head and neck squamous cell carcinoma: A systematic review.

BACKGROUND: This systematic review aimed to investigate the in vitro and in vivo effects of phosphatidylinositol-3-kinase (PI3K) inhibitors on head and neck squamous cell carcinoma (HNSCC). Considering the role of PI3K and its downstream effectors in cell proliferation, invasion, and survival, it is reasonable to expect that treatment with PI3K inhibitors could control HNSCC onset and progression. Thus, the research question for our review was whether pharmacological inhibition of PI3K affects HNSCC progression. METHODS: In vitro and in vivo studies were selected from six databases. We collected data regarding cell viability, apoptosis, and the regulation of protein expression levels from in vitro studies. For the in vivo studies, we analyzed the reduction in tumor size or gene and protein expression. RESULTS: The included studies showed reduced cell proliferation and apoptosis after treatment with PI3K inhibitors. PI3K inhibitors in combination with other drugs had an enhanced anticancer effects compared to those of single-drug treatments. CONCLUSIONS: The results support the potential of PI3K inhibitors as candidates for clinical trials in HNSCC.

Study of polymorphic variants of the serotonin 2A receptor gene (5-HT2A) and its possible effects on smoking habits of a population from northeastern Brazil.

Previous studies have revealed a genetic component, including genetic polymorphisms in the serotonergic pathway, particularly in the serotonin receptor gene (5-HT2A). The aim of this study was to investigate associations of the T102C (rs6313) and A-1438G (rs6311) polymorphisms with tobacco use in a population from northeastern Brazil. We evaluated these polymorphisms in 135 nonsmokers and 135 smokers using polymerase chain reaction-restricted fragment length polymorphism. The distribution of allele and genotype frequencies and associations of polymorphisms with smoking were assessed with the chi-squared (χ(2)) test, the Fisher exact test, and odds ratio (OR) with a 95% confidence interval (CI). There were no differences in the distribution of genotype and allele frequencies between nonsmokers and smokers for A-1438G (P = 0.80) and T102C (P = 0.35). However, these polymorphisms were significantly associated with habit frequency (A/G: P = 0.02, OR = 6.87, 95%CI = 1.23-38.31, P = 0.04; A/G+G/G: P = 0.04, OR = 3.67, 95%CI = 1.06-12.75, P = 0.07), age of onset (C/C: P = 0.02, OR = 3.26, 95%CI = 1.17-9.07, P = 0.03, and nicotine dependence level (A/G: P = 0.02, OR = 3.28, 95%CI = 1.17-9.18, P = 0.04; A/G+G/G: P = 0.04, OR = 2.81, 95%CI = 1.13-6.99, P = 0.04; T/C: P = 0.03, OR = 3.12, 95%CI = 1.13-8.57, P = 0.04; T/C+C/C: P = 0.02, OR = 3.06, 95%CI = 1.22-7.70, P = 0.02). Therefore, these polymorphisms may not contribute significantly to smoking initiation, they do appear to be associated with habit maintenance.

Avaliação da qualidade de águas purificadas utilizadas em farmácias de manipulação / Assessing the quality of purified water used in compounding pharmacies

The Brazilian Food, Drug and Sanitary Agency (ANVISA) published a Resolution (RDC 67) in 2007, repealing RDC 33 of 2000, which established a legally required monthly analysis of a number of microbiological and physicochemical variables in the purified water used in compounded pharmaceutical preparations, which were not specified in the preceding RDC. In view of the amendment, the aim of this study was to assess the quality of purified water used in compounding pharmacies in the region of Araraquara (SP, Brazil) and review the impact of the most recent regulation (RDC 67 of 2007) on this quality. In the study, 744 samples of purified water were collected from 30 pharmacies in the course of four years (2008 to 2011). The variables recorded were: presence of total coliforms and fecal coliforms/E. coli, pH, color, turbidity, total dissolved solids, fluoride and residual free chlorine. The methods used were pharmacopeial standards for water analysis, published by the Brazilian National Health Foundation (FUNASA) and the American Public Health Association (APHA). Among the samples, 78.90% were in compliance with the required standards. No sample contravened the rules for color and fecal coliforms/E. coli. However, 0.54%, 7.80%, 10.75%, 0.54% and 4.56% of the samples were unacceptable in terms of turbidity, fluorides, pH, free residual chlorine and total coliforms respectively. There was a variation in the number of irregular samples by comparing the years of 2008 and 2009 (20.26% and 26.71%, respectively) and the years of 2010 and 2011 (18.33% and 19.91%, respectively). Four years after the RDC n°. 67 of 2007, manipulation pharmacies are still adjusting to the rules, and it is important that ANVISA and others agencies continue monitoring to ensure the quality of purified water...

A RDC n° 67 de 2007, que revogou a RDC nº 33 de 2000, regulamentou análises mensais que avaliam parâmetros microbiológicos e físico-químicos em águas purificadas utilizadas em preparações magistrais, antes não especificados pela RDC n° 33 de 2000. Diante dessas alterações, o objetivo do trabalho foi avaliar a qualidade de águas utilizadas em farmácias de manipulação em Araraquara e região e verificar o impacto da legislação mais recente (RDC nº 67 de 2007) nessa qualidade. Foram analisadas 744 amostras de água purificada em 30 farmácias no decorrer de quatro anos (2008 a 2011). Os parâmetros avaliados foram: presença de coliformes totais e coliformes termotolerantes/E.coli, pH, cor, turbidez, sólidos totais dissolvidos, fluoreto e cloro residual livre. Os métodos utilizados seguiram padrões de farmacopeias, da FUNASA e da APHA. Dentre as amostras analisadas 78,90% estavam em conformidade com os padrões estabelecidos. Não foram encontradas amostras irregulares quanto aos parâmetros cor e coliformes termotolerantes/E. coli. No entanto, 0,54%, 7,80%, 10,75%, 0,54% e 4,56% das amostras estavam irregulares para turbidez, fluoretos, pH, cloro residual livre e coliformes totais, respectivamente. Foi observada uma variação do número de amostras irregulares ao compararmos os anos de 2008 e 2009 (20,26% e 26,71% respectivamente) com os anos de 2010 e 2011 (18,33% e 19,91% respectivamente). Quatro anos após a RDC n° 67 de 2007, as farmácias de manipulação ainda estão se adequando às normas e é importante que a ANVISA e outros órgãos continuem a fiscalização para garantir a qualidade da água purificada...

Mapa do desenvolvimento da pecuária leiteira no estado de Minas Gerais, Brasil: nova abordagem na pecuária para integração espacial de variáveis produtivas / Map of the development of dairy husbandry in the state of Minas Gerais, Brazil: new approach to livestock for the spatial integration of production variables

Com base nos dados absolutos do Censo Agropecuário 2006, estruturou-se um sistema geográfico de informação e aplicou-se o método de análise multicritério para categorizar e avaliar o desenvolvimento da pecuária leiteira em Minas Gerais, Brasil. As variáveis selecionadas foram representadas espacialmente, classificadas e reclassificadas. Considerando-se seus pesos ponderados, foram combinadas por procedimentos de álgebra de mapas, em que se conformou o mapa com a caracterização do desenvolvimento leiteiro. Dos 853 municípios, 53 foram classificados como altamente desenvolvidos, 55 desenvolvidos, 229 moderadamente desenvolvidos, 500 pouco desenvolvidos e 16 não desenvolvidos. Encontrou-se associação entre o tamanho dos municípios e o desenvolvimento leiteiro; os de maior desenvolvimento tiveram área média de 175.414ha, e os de menor desenvolvimento apresentaram área média de 44.947ha. Esta abordagem para a integração espacial de dados censitários da pecuária possibilita uma nova forma de conhecer a realidade no seu desenvolvimento e promove sua aplicação em outros temas relacionados com a saúde e a produtividade animal...

Based on absolute data collected from the Agricultural census 2006 a Geographic Information System (GIS) and application of a multi-criteria analysis method to categorize and evaluate the development of dairy farming in Minas Gerais, Brazil. The selected variables were represented spatially, classified and reclassified; taking into account that their adjusted weights were combined by map algebra procedures, conforming the map with the characterization of the dairy development. Of the 853 municipalities, 53 were classified as highly developed, 55 developed, 229 moderately developed, 500 low development and 16 non-developed. Associations were found between the size of the municipalities and dairy development. The municipalities with greater development had an average area of 175.414 ha and those with lower development showed an average area of 44.947 ha. This approach with spatial integration of the livestock census data provides a powerful methodology to express the reality in its development and promotes this application in other topics related to animal health and productivity...

The effects of parturition season and suckling mode on the puerperium of Santa Ines ewes and on the weight gain of lambs / Efeitos do período das parições e dos sistemas de amamentação sobre o puerpério de ovelhas Santa Inês e desempenho ponderal de cordeiros

Seventy-seven ewes were randomly divided into groups according to parturition season and suckling mode [Rainy season: continuous (n=14) and controlled (n=13); Dry season: continuous (n=25) and controlled (n=25)]. The controlled suckling mode, in both seasons, resulted in a decrease in variables, intervals between parturition and first estrus (reduction of 27.11 and 11.46 days for rainy and dry season, respectively; P<0.05) and between parturition and estrus of conception (reduction of 12.81 and 13.58 days, for rainy and dry season, respectively; P<0.05). As to the lambs, the weight gain was higher in animals subjected to controlled suckling in relation to continuous, especially when lambing occurred in the rainy season (17.83±0.56 vs. 13.95±0.52kg for Lambs' weight at 90 days old, respectively; P<0.05). Therefore, it was concluded that controlled suckling management is better indicated for the Amazonian region, since it allows the ewes to have a shorter puerperium period and the lambs exhibit higher weight gain.

Foram utilizadas 77 ovelhas, divididas aleatoriamente em grupos de acordo com o período de parição e o manejo de amamentação [chuvoso: contínua (n=14) e controlada (n=13); seco: contínua (n=25) e controlada (n=13)]. O sistema de amamentação controlado, em ambos os períodos, resultou em decréscimo para as variáveis intervalos entre parto e primeiro estro (redução de 27,11 e 11,46 dias para os períodos chuvoso e seco, respectivamente; P<0,05) e entre parto e estro da concepção (redução de 12,81 e 13,58 dia para os períodos chuvoso e seco, respectivamente; P<0,05). Quanto ao desempenho ponderal dos cordeiros, o ganho de peso foi maior para os animais submetidos ao regime de amamentação controlada em relação à contínua, especialmente quando os nascimentos ocorreram no período chuvoso (17,83±0,56 vs. 13,95±0,52kg para o peso dos cordeiros aos 90 dias de idade, respectivamente; P<0,05). Contudo, o manejo de amamentação controlada é indicado para a região amazônica, por permitir menor tempo de puerpério das ovelhas e maior ganho de peso dos cordeiros.

Pulp calcification in traumatized primary teeth: prevalence and associated factors.

AIM: To establish the prevalence of pulp calcifications in 946 patients at the Research and Clinical Center of Dental Trauma in Primary Teeth. STUDY DESIGN: The clinical and radiographic records of l675 traumatized primary teeth were evaluated. Statistical analysis was performed using chi-square and univariate logistic regression. RESULTS: 197 (20.8%) patients showed pulp calcification (PC). A total of 250 (14.9%) calcified teeth were observed In most teeth, PC appeared within the first 12 months following trauma. PC prevalence was higher in cases of repeated trauma (29.6%) than in single trauma (16.4%), p < 0.05, with a 2.14 chance of showing pulp calcification when a child suffered recurrent trauma. Most teeth showing calcified pulp, suffered trauma to the supportive tissue (67.4%), being statistically significant in relation to the trauma to dental tissue (p < 0.05). CONCLUSION: PC is a sequelae in cases of trauma to the primary dentition; teeth that suffered recurrent traumatic injuries show higher risk of presenting.

Ex vivo performance of five methods for root canal length determination in primary anterior teeth.

AIM: To evaluate in a laboratory setting the performance of five methods for the determination of root canal length in primary anterior teeth. METHODOLOGY: Twenty extracted primary incisors, with at least two-thirds of the root, were used. After access cavity preparation, the teeth were embedded in alginate mixed with 0.9% sodium chloride solution. One operator determined root canal length using tactile sense (T), conventional radiography (RAD), tactile sense and conventional radiography (T + RAD), digital radiography (RDIG) and Root ZX electronic apex locator (EAL) methods. Next, the actual length (AL) was visually determined using a K-file from the coronal reference to the apical foramen or apical resorption level. The measurements obtained through each method were compared to the AL using the intraclass correlation coefficient (ICC) with the limits of agreement calculated with Bland and Altman analysis. The measurements were classified as acceptable (+/-1 mm from the AL) or not (>1 mm shorter or longer), and the McNemar test was employed for method comparison. RESULTS: Differences, limits of agreement and ICCs for each method were respectively EAL = -0.29; -1.02 to 0.44; 0.990; T + RAD = 0.17; -2.18 to 2.51; 0.929; RAD = 0.50; -3.41 to 4.41; 0.818; RDIG = 0.95; -3.76 to 5.65; 0.700; and T = -0.48; -5.59 to 4.64; 0.499. The most accurate and acceptable method was the EAL, followed by the T + RAD. : The EAL method performed best for root canal length determination in primary teeth.

Multidisciplinary approach on rehabilitation of primary teeth traumatism repercussion on the permanent successor: 6-year follow-up case report.

Traumatic lesions in primary teeth are frequent in pediatric patients and can cause problems both to the deciduous tooth and permanent successor. The impact strength on deciduous tooth can reach the growing permanent tooth, affecting its morphology, structure and position, or even hampering its proper development. This report describes an aesthetic-functional rehabilitation process in an 8 year 10 month old boy during a multidisciplinary treatment held at the Clinical Center of Dental Trauma in Primary Teeth of the Pediatric Dentistry of Dental College of University of São Paulo, Brazil. The patient presented bilateral posterior cross bite and the permanent left upper central incisor with ectopic eruption and enamel hypoplasy, preceded by avulsion of element 61, occurred when the patient was 1.6 years old. After diagnosis and treatment planning, a quick expansion of jaws was recommended with Hass-type rapid expander and orthodontic leveling with fixed braces. Due to the ectopic eruption, the gingival contour had been altered and hypertrophia was found, compromising aesthetics and avoiding local hygienic procedures. Gingivoplasty was carried out with high-intensity Diode Laser, followed by aesthetic restoration with compound resin. It was concluded that after deciduous teeth traumatism it is important that the patient undergoes clinic and radiographic assistance until the permanent teeth erupt so that an adequate multidisciplinary treatment can be offered to the patient.

The mutagenic potential of Clusia alata (Clusiaceae) extract based on two short-term in vivo assays.

We examined the genotoxic and mutagenic effects of a crude extract of Clusia alata (a potential medicinal plant) on peripheral leukocyte and bone marrow cells of mice, using the comet and chromosome aberration assays. Extracts at doses of 1000, 1500 and 2000 mg/kg were administered by gavage, and a positive control, N-nitroso-N-ethylurea (50 mg/kg) was injected intraperitoneally. Peripheral blood leukocytes were collected 4 and 24 h after the treatments for the comet assay, and bone marrow cells were collected 24 h after the treatments, for the chromosome aberration assay. The comet assay showed that C. alata extract causes an increase in damage to DNA in the peripheral blood leukocytes, but it was significant only with the 2000 mg/kg dose after 24 h; the extract also induced a small but significant increase in the mean number of chromosome aberrations in the bone marrow cells at doses of 1500 and 2000 mg/kg. No evidence of a significant decrease in the mitotic index was observed. Acute consumption of high concentrations of C. alata extract produced some mutagenic effects in bone marrow cells.

Antiinflammatory and chronic toxicity study of the leaves of Ageratum conyzoides L. in rats.

The hydroalcoholic extract (HAE) of Ageratum conyzoides leaves was studied for its antiinflammatory effect on subacute (cotton pellet-induced granuloma) and chronic (formaldehyde-induced arthritis) models of inflammation in rats. The absence or presence of toxicity by prolonged use of HAE was also evaluated through biochemical and hematological analysis of rats blood samples using daily oral doses of 250 or 500 mg/kg body wt., during 90 days. The results showed that the group of rats treated with HAE (250 mg/kg body wt.; p.o.) had a 38.7% (p < 0.05) reduction in cotton-pellet granuloma. The development of chronically induced paw edema was also reduced significantly (p < 0.05) by the plant extract. The toxicity study did not show any treatment-related abnormalities in biochemical and hematological parameters. The biochemical analysis from blood samples drawn from group of rats treated orally with 500 mg/kg body wt. did, however, present 30.2% (p < 0.05) reduction of SGPT activity as compared to the corresponding control group. These results confirm the antiinflammatory properties of A. conyzoides, with no apparent hepatotoxicity.

Capuchin stone tool use in Caatinga dry forest.

Wild capuchin monkeys inhabiting dry forest were found to customarily use tools as part of their extractive foraging techniques. Tools consisted of twigs and sticks, often modified, which were used to probe for insects and, most frequently, of stones of a variety of sizes and shapes used for cracking and digging. The use of tools for digging has been thought to be restricted to humans. These monkeys, living in a harsh dry habitat, survive food limitation and foraging time constraints through their extensive tool use.

Effect of Mycobacterium leprae lipids on BCG- and carrageenan-induced cellular recruitment in mouse pleurisy.

Pathogenic mycobacteria survive inside macrophages and deactivate these cells, using a mechanism that is still poorly understood. Mycobacterial cell wall lipids constitute the first contact with the host cell. Although Mycobaterium leprae and M. bovis BCG share common antigens, they induce opposite inflammatory responses. Apolar M. leprae lipids have been shown to be anti-inflammatory by down-regulating macrophage activation and T-cell functions. We wonder if these lipids would influence cellular migration to BCG or to other inflammatory agent. We investigated the effect of M. leprae, its lipids or delipidated bacteria on acute and chronic BCG- or carrageenan-induced pleurisy. Previous injection of intact or delipidated M. leprae did not alter either the BCG- or carrageenan-induced pleural inflammatory reaction. However, M. leprae lipids enhanced carrageenan-induced acute cellular migration without impairing BCG inflow; moreover, they reduced BCG chronic response. Together these data suggest distinct mechanisms for intracellular deactivation and pleural cell recruitment exerted by mycobacterial structures.

Selective inhibitors of cyclo-oxygenase-2 (COX-2) induce hypoalgesia in a rat paw model of inflammation.

1. It is well-established that inhibitors of cyclo-oxygenase (COX) and hence of prostaglandin (PG) biosynthesis reverse inflammatory hyperalgesia and oedema in both human and animal models of inflammatory pain. 2. Paw oedema and hyperalgesia in rats were induced by injecting carrageenan (250 micro g paw(-1)) into a hindpaw. Both inflammatory responses were followed for 24 h after the injection, measuring hyperalgesia by decreased pain threshold in the paws and oedema by plethysmography. 3. Three selective inhibitors of cyclo-oxygenase-2 (COX-2), celecoxib, rofecoxib and SC 236, given systemically in a range of doses, before the inflammatory stimulus, abolished carrageenan-induced hyperalgesia with little reduction of oedema. These inhibitors also induced hypoalgesia, increasing nociceptive thresholds in the inflamed paw above normal, non-inflamed levels. This hypoalgesia was lost at the higher doses of the selective inhibitors, although hyperalgesia was still prevented. 4. In paws injected with saline only, celecoxib, given at the dose inducing the maximum hypoalgesia after carrageenan, did not alter the nociceptive thresholds. 5. Two non-selective inhibitors of COX-2, indomethacin and piroxicam, abolished hyperalgesia and reduced oedema but did not induce hypoalgesia. 6. Celecoxib given locally into the paw also abolished inflammatory hyperalgesia and induced hypoalgesia without reducing oedema. 7. We conclude that hypoalgesia is expressed only over a critical range of COX-2 inhibition and that concomitant inhibition of COX-1 prevents expression of hypoalgesia, although hyperalgesia is still prevented. 8 Our results suggest a novel anti-nociceptive pathway mediating hypoalgesia, involving COX-2 selectively and having a clear peripheral component. This peripheral component can be further explored for therapeutic purposes.

Genetic variability of avian Escherichia coli strains evaluated by enterobacterial repetitive intergenic consensus and repetitive extragenic palindromic polymerase chain reaction.

In this study, we tested the capability of enterobacterial repetitive intergenic consensus (ERIC) and repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) to detect genetic diversity among Escherichia coli strains isolated from chickens bearing clinical signs of colibacillosis and compared the genotypes so obtained with the O:H serotypes and virulence of those strains. The DNAs from 50 avian E. coli strains and from E. coli ATCC 25922 were used to amplify ERIC and REP sequences. DNA from avian strains produced from 8 to 17 bands by ERIC-PCR and from 6 to 20 bands by REP-PCR; E. coli ATCC produced 11 bands by both methods. ERIC and REP-PCR showed good discriminating power, and the dendograms based on the different patterns revealed extensive genetic diversity among the avian strains. Those strains were allocated into four major clonal clusters, each one with 60% of similarity by ERIC and REP-PCR, and those clusters corresponded to strains with different degrees of pathogenicity. However, 56% of the pathogenic strains (28/50) belonged to two out of three major clonal clusters, and 86% of the nonpathogenic strains tended to group in one cluster and one subgroup. The 32 serotypes detected were distributed in all clusters, and within a serogroup, different DNA fingerprints were observed; however, strains with same serotypes tended to form clusters with similarity coefficients greater than 80%. These results suggest that no specific serotype and genotype is responsible for colibacillosis and that REP and ERIC-PCR are reproducible techniques that can improve the studies needed to clarify the pathways to the pathogenesis of colibacillosis.

Distinct ability to accumulate eosinophils during the inflammatory cellular response to M. bovis BCG in the mouse pleural cavity.

OBJECTIVE AND DESIGN: The host response to Mycobacteria focuses on the development of cell-mediated immunity and granuloma formation. Here, we investigated the onset of cellular responses to mycobacteria in murine pleurisy. MATERIAL: Distinct mouse strains previously described as Bcg susceptible or resistant were inoculated intrathoracically with different doses of live M. bovis BCG. METHODS: At various time intervals, cells harvested from the inflammatory site were identified and ultra-structurally analysed. RESULTS: BCG-induced pleurisy had two peaks of cellular influx at 1 and 15 days after infection. At the first half hour, macrophages were found to be heavily infected. Neutrophil arrival started after 2 h of infection and peaked at 4 h. At this time, neutrophils were found ingesting mycobacteria exclusively with a high infecting dose. BCG was potently more eosinophilotactic in Bcg susceptible mice than in the resistant ones and to other well known eosinophilia inducers: IL-5, PAF-acether or LPS. CONCLUSIONS: Mycobacterial load and mouse susceptibility seem to determine the early granulocyte dynamics in the lesion.

Nitric oxide production by BCG-infected pleural macrophages from C57Bl/6 and DBA-2 mice.

We studied the kinetics of in vivo nitrite production in the inflammatory reaction induced by M. bovis BCG into the pleural space. Pleural macrophages harvested from C57Bl/6 mice after acute BCG infection produced high levels of nitric oxide (NO). Enhanced production was obtained upon stimulation with LPS plus IFN-gamma. In sharp contrast, macrophages from DBA-2 mice produced low levels of NO, as nitrite, at the same time interval (24 h after BCG infection), being completely refractory to further stimulation. After the third day, NO production was similar in both strains. There was a close relationship between nitrite levels in the pleural exudate in vivo and those produced by harvested macrophages in vitro. In this in vivo system, the pattern of NO production by pleural macrophages one day after BCG infection was discrepant and unexpected in the response of C57Bl/6 and DBA-2 mice. However, this early response did not affect the late progressive NO production in both mice strains, that may be responsible to the late control of the mycobacteria growth.

Opposite effects of M. leprae or M. bovis BCG delipidation on cellular accumulation into mouse pleural cavity. Distinct accomplishment of mycobacterial lipids in vivo.

OBJECTIVES AND DESIGN: The effect of mycobacterial lipids on the onset of the early acute inflammatory response in BALB/c mice pleurisy was investigated. MATERIALS AND METHODS: Intact Mycobacterium leprae and Mycobacterium bovis BCG (BCG), their lipids, and delipidated mycobacteria were used to evaluate total leukocytes and cell types migrated to the pleural cavity (8 animals/experimental group). RESULTS: BCG Moreau (x10(-6)/cavity), delipidated BCG and its lipids gradually recruited cells leading to arrival, respectively, of neutrophils (7.8+/-1.9, 4.7+/-0.9, 1.8+/-0.25) followed by mononuclear cells (4.8+/-0.8, 3.7+/-0.7, 2.45+/-0.22) and eosinophils (0.39+/-0.08, 0.32+/-0.11, 0.41+/-0.65). BCG delipidation decreased the number of migrated total leukocytes (ANOVA, and Newman-Keuls-Student-test), whereas M. leprae delipidation accumulated neutrophils (0.85+/-0.01) and eosinophils (1.65+/-0.18). CONCLUSIONS: Intact M. leprae and its lipids did not incite any cell recruitment. Apolar external cell wall lipids from M. leprae and BCG induce different cellular responses. They seem to have a crucial importance at the first contact of mycobacteria with the host cell, modulating the influx of neutrophils/macrophages in the early (4/24 h) onset of the inflammatory reaction.

Opposite cellular accumulation and nitric oxide production in vivo after pleural immunization with M. leprae or M. bovis BCG.

Mycobacteria as intracellular pathogens have evolved mechanisms to survive within macrophages. Our previous data showed that M. leprae (ML), unlike M. bovis BCG, did not induce an inflammatory response in the mice subcutaneous tissue. Further, ML inhibited BCG-induced foot pad oedema and seemed to transform macrophages in epithelioid cells. Since these mycobacteria share common antigens, here we seeked to compare the acute and chronic cellular response evoked by ML and BCG in pleurisy of a mycobacteria-susceptible mice (BALB/c). The total leukocytes, the cell type that migrated to the pleural cavity and macrophage activation assayed by nitric oxide release were determined. Live or dead BCG Moreau recruited the same extent of cells, essentially monocytes and neutrophils, dose-dependently, in both acute and chronic pleurisy. BCG-induced eosinophilia was observed only in the acute response (after 24 h of injection). A significant nitric oxide release by pleural macrophages was triggered by BCG Moreau without previous activation. Nevertheless, ML failed to recruit leukocytes to the pleural space or to lead to nitric oxide production despite the number of bacilli used and the time studied (1, 7 or 14 days after injection). Although these mycobacteria have common antigens that cross-react, these data show a distinct ability of ML or BCG to recruit cells to the pleural space and to activate pleural macrophage for nitric oxide production in vivo.

Down-regulatory effect of Mycobacterium leprae cell wall lipids on phagocytosis, oxidative respiratory burst and tumour cell killing by mouse bone marrow derived macrophages.

The authors have previously demonstrated that lipids from Mycobacterium leprae cell walls inhibit macrophage functions and are endowed with anti-inflammatory properties in vivo. To investigate these observations further, the authors describe here the influence of dead M. leprae or of the lipids extracted from the cell wall of the mycobacterium, enclosed in liposomes, on the phagocytic, oxidative respiratory burst and tumouricidal ability of bone marrow derived macrophages in vitro. Dead M. leprae or its cell wall lipids abrogated the oxidative respiratory burst and phagocytic ability of mouse bone marrow derived macrophages. A dose-dependent inhibitory effect of the bacterial lipid extract on tumour cell killing by lipopolysaccharide (LPS)-activated bone marrow derived macrophages was demonstrated. However, when delipidated M. leprae was added to cultures of bone marrow derived macrophages, immune phagocytosis and superoxide production was up-regulated. Mycobacterium leprae or its lipids did not appear to be toxic to those cells assayed by the MTT (methyl thiazol tetrazolium) test. These data, added to our preceding observations, support the hypothesis that the down-regulatory activity of M. leprae wall lipids on macrophage function might be one of the evasive mechanisms of the bacterium to enable it to perpetuate itself in the host tissues.