Morphological and quantitative aspects of nodule formation in hemolymph of the blowfly Chrysomya megacephala (Fabricius, 1794)

Insects manifest effective immune responses that include both cellular and humoral components. Morphological and quantitative aspects of cellular and Immoral cooperation during nodule formation in Chrysomya megacephala hemolymph against Saccharomyces cerevisae yeast cells were demonstrated for the first time. The analyses were performed in non-injected larvae (NIL), saline-injected larvae (SIL) and yeast-injected larvae (YIL). The hemolymph of injected groups was collected 0.5, 1, 2, 4, 12, 24, 36, or 48-h post-injection. Morphological aspects of YIL nodulation were investigated using transmission electron microscopy (TEM). Quantitative analyses consisted of total (THC) and differential hemocyte counts (DHC) in all the groups and total yeast count (TYC) in YIL, which were performed in an improved Neubauer chamber. Nodule formation was initiated at approximately 2-h post-injection. Twelve hours after the injection, TEM revealed the presence of an amorphous membrane, at the same time that circulating hemocyte number decreased significantly contrasting the increase of yeast number. Our results showed the ability of C megacephala hemolymph to perform humoral encapsulation when hemocyte population is insufficient to eliminate the microorganisms, warranting consideration in future investigations on the relative roles played by cellular and humoral elements of innate immunity of this calliphorid. (c) 2007 Elsevier B.V. All rights reserved.

Naturally-acquired humoral immune responses against the N- and C-termini of the Plasmodium vivax MSP1 protein in endemic regions of Brazil and Papua New Guinea using a multiplex assay

Background: Progress towards the development of a malaria vaccine against Plasmodium vivax, the most widely distributed human malaria parasite, will require a better understanding of the immune responses that confer clinical protection to patients in regions where malaria is endemic. Methods: Glutathione S-transferase (GST) and GST-fusion proteins representing the N-terminus of the merozoite surface protein 1 of P. vivax, PvMSP1-N, and the C-terminus, PvMSP1-C, were covalently coupled to BioPlex carboxylated beads. Recombinant proteins and coupled beads were used, respectively, in ELISA and Bioplex assays using immune sera of P. vivax patients from Brazil and PNG to determine IgG and subclass responses. Concordances between the two methods in the seropositivity responses were evaluated using the Kappa statistic and the Spearman's rank correlation. Results: The results using this methodology were compared with the classical microtitre enzyme-linked immnosorbent assay ( ELISA), showing that the assay was sensitive, reproducible and had good concordance with ELISA; yet, further research into different statistical analyses seems desirable before claiming conclusive results exclusively based on multiplex assays. As expected, results demonstrated that PvMSP1 was immunogenic in natural infections of patients from different endemic regions of Brazil and Papua New Guinea ( PNG), and that age correlated only with antibodies against the C-terminus part of the molecule. Furthermore, the IgG subclass profiles were different in these endemic regions having IgG3 predominantly recognizing PvMSP1 in Brazil and IgG1 predominantly recognizing PvMSP1 in PNG. Conclusions: This study validates the use of the multiplex assay to measure naturally-acquired IgG antibodies against the merozoite surface protein 1 of P. vivax.

Encapsulation of lemon oil by paste method using beta-cyclodextrin: Encapsulation efficiency and profile of oil volatiles

Microencapsulation of lemon oil was undertaken by kneading with beta-cyclodextrin, at a beta-cyclodextrin to lemon oil ratio of 88:12 (w/w). The resulting paste samples of the complex were vacuum- or spray-dried. Ten selected lemon oil flavor volatiles (alpha-pinene, sabinene, beta-pinene, beta-myrcene, limonene, gamma-terpinene, terpinolene, linalool, neral, and geranial) in the complex were analyzed periodically after 1, 2, 5, 10, 15, 20, and 30 min of kneading time. The results indicated that the levels of these volatiles were not significantly different (P > 0.05) irrespective of mixing time or type of the drying (vacuum- or spray-drying) used. An optimum mixing time was found to be 15 min, at which time the maximum encapsulation of lemon oil (97.7 mg/g of beta-cyclodextrin) was obtained in the complex powder.

Is cell surface calreticulin involved in phagocytosis by insect hemocytes?

The innate immune system of insects consists of humoral and cellular components involved in the recognition of and responses to intruding foreign micro- or macroorganisms. Several molecules have been identified so far that recognize molecular patterns present on microorganisms, such as lipopolysaccharides, peptidoglycans and lipoteichonic acid. These molecules, acting as opsonins, trigger immune responses such as phagocytosis, nodule formation, melanization and encapsulation. Here, we investigated the role of calreticulin (CRT) present on the surface of Pieris rapae hemocytes in phagocytosis. Comparative phagocytosis assays using yeast cells showed that hemocytes from different insects exhibit significant variation in their phagocytosing potential and relative CRT involvement. (C) 2003 Elsevier Science Ltd. All rights reserved.

Effects of high-intensity aerobic interval training vs. moderate exercise on hemodynamic, metabolic and neuro-humoral abnormalities of young normotensive women at high familial risk for hypertension

Exercise training has an important role in the prevention and treatment of hypertension, but its effects on the early metabolic and hemodynamic abnormalities observed in normotensive offspring of hypertensive parents (FH+) have not been studied. We compared high-intensity interval (aerobic interval training, AIT) and moderate-intensity continuous exercise training (CMT) with regard to hemodynamic, metabolic and hormonal variables in FH+ subjects. Forty-four healthy FH+ women (25.0+/-4.4 years) randomized to control (ConFH+) or to a three times per week equal-volume AIT (80-90% of VO(2MAX)) or CMT (50-60% of VO(2MAX)) regimen, and 15 healthy women with normotensive parents (ConFH-; 25.3+/-3.1 years) had their hemodynamic, metabolic and hormonal variables analyzed at baseline and after 16 weeks of follow-up. Ambulatorial blood pressure (ABP), glucose and cholesterol levels were similar among all groups, but the FH+ groups showed higher insulin, insulin sensitivity, carotid-femoral pulse wave velocity (PWV), norepinephrine and endothelin-1 (ET-1) levels and lower nitrite/ nitrate (NOx) levels than ConFH- subjects. AIT and CMT were equally effective in improving ABP (P<0.05), insulin and insulin sensitivity (P<0.001); however, AIT was superior in improving cardiorespiratory fitness (15 vs. 8%; P<0.05), PWV (P<0.01), and BP, norepinephrine, ET-1 and NOx response to exercise (P<0.05). Exercise intensity was an important factor in improving cardiorespiratory fitness and reversing hemodynamic, metabolic and hormonal alterations involved in the pathophysiology of hypertension. These findings may have important implications for the exercise training programs used for the prevention of inherited hypertensive disorder. Hypertension Research (2010) 33, 836-843; doi:10.1038/hr.2010.72; published online 7 May 2010

Humoral responses and immune protection in mice immunized with irradiated T. gondii tachyzoites and challenged with three genetically distinct strains of T. gondii

Toxoplasma gondii is an obligate intracellular parasite that infects a variety of mammals and birds. T. gondii also causes human toxoplasmosis; although toxoplasmosis is generally a benign disease, ocular, congenital or reactivated disease is associated with high numbers of disabled people. Infection occurs orally through the ingestion of meat containing cysts or by the intake of food or water contaminated with oocysts. Although the immune system responds to acute infection and mediates the clearance of tachyzoites, parasite cysts persist for the lifetime of the host in tissues such as the eye, muscle, and CNS. However, T. gondii RH strain tachyzoites irradiated with 255 Gy do not cause residual infection and induce the same immunity as a natural infection. To assess the humoral response in BALB/c and C57BL/6J mice immunized with irradiated tachyzoites either by oral gavage (p.o.) or intraperitoneal (i.p.) injection, we analyzed total and high-affinity IgG and IgA antibodies in the serum. High levels of antigen-specific IgG were detected in the serum of parenterally immunized mice, with lower levels in mice immunized via the oral route. However, most serum antibodies exhibited low affinity for antigen in both mice strain. We also found antigen specific IgA antibodies in the stools of the mice, especially in orally immunized BALB/c mice. Examination of bone marrow and spleen cells demonstrated that both groups of immunized mice clearly produced specific lgG, at levels comparable to chronic infection, suggesting the generation of IgG specific memory. Next, we challenged i.p. or p.o. immunized mice with cysts from ME49. VEG or P strains of T. gondii. Oral immunization resulted in partial protection as compared to challenged naive mice: these findings were more evident in highly pathogenic ME49 strain challenge. Additionally, we found that while mucosal IgA was important for protection against infection, antigen-specific IgG antibodies were involved with protection against disease and disease pathogenesis. Most antigen responsive cells in culture produced specific high-affinity IgG after immunization, diverse of the findings in serum IgG or from cells after infection, which produced low proportion of high-avidity IgG. (C) 2011 Elsevier B.V. All rights reserved.

Histopathology, humoral and cellular immune response in the murine model of Leishmania (Viannia) shawi

Leishmania (Viannia) shawl was recently characterized and few studies concerning modifications in cellular and humoral immune responses in experimental leishmaniasis have been conducted. In this work, immunopathological changes induced by L. shawl in chronically infected BALB/c mice were investigated. Infected BALB/c mice developed increased lesion size associated with strong inflammatory infiltrate diffusely distributed in the dermis, with highly infected macrophages. The humoral immune response was predominantly directed toward the IgG1 isotype. The functional activity of CD4(+) and CD8(+) T cells showed significantly increased TNF-alpha mRNA levels associated with reduced IFN-gamma expression by CD4(+) T cells and the double negative (dn) CD4CD8 cell subset. High IL-4 levels expressed by CD8(+) T cells and dnCD4CD8 and TGF-beta by CD4(+) and CD8(+) T cells were detected, while IL-10 was highly expressed by all three cell subpopulations. Taken together, these results show an evident imbalance between TNF-alpha and IFN-gamma that is unfavorable to amastigote replication control. Furthermore, L. shawi seems to regulate different cell populations to express deactivating cytokines to avoid its own destruction. This study indicates BALB/c mice as a potentially good experimental model for further studies on American cutaneous leishmaniosis caused by L. shawi. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Role of myofibroblasts in tumour encapsulation of hepatocellular carcinoma in haemochromatosis

Background/Aims: Hepatocellular carcinoma is a carcinoma malignancy and a major complication of untreated haemochromatosis. Encapsulation of liver tumours has been associated with a better prognosis and longer disease-free periods following resection, This study investigated the source of the tumour capsule in patients with haemochromatosis and coexisting hepatocellular carcinoma and examined potential factors influencing development. Methods: Five haemochromatosis patients with encapsulated hepatocellular carcinoma were studied. Myofibroblasts were identified using combined immunohistochemistry and in situ hybridisation for a-smooth muscle actin and procollagen alpha (1)(I) mRNA, respectively. Immunohistochemistry was also performed for transforming growth factor (TGF)-beta (1), platelet-derived growth factor (PDGF)-beta receptor and malondialdehyde. Results. Procollagen alpha (1)(I) mRNA co-localised to alpha -smooth muscle actin positive myofibroblasts. The number of myofibroblasts was maximal within the capsule and decreased away from the tumour. TGF-beta (1) protein was expressed in iron-loaded cells in non-tumour liver at the interface of tumour capsule. PDGF-beta receptor expression was observed in mesenchymal cells in the tumour capsule and in portal tracts. Malondialdehyde adducts were observed in the tumour, non-tumour tissue and in the capsule. Conclusions: This study provides evidence that myofibroblasts are the cell type responsible for collagen production within the tumour capsule surrounding hepatocellular carcinoma in haemochromatosis, The production of TGF-beta (1) by iron-loaded hepatic cells at the tumour capsule interface may perpetuate the myofibroblastic phenotype, resulting in, the formation of the tumour capsule.

Evaluation of encapsulation techniques of probiotics for yoghurt

The health benefits provided by probiotic bacteria have led to their increasing use in fermented and other dairy products. However, their viability in these products is low. Encapsulation has been investigated to protect the bacteria in the product's environment and improve their survival. There are two common encapsulation techniques, namely extrusion and emulsion, to encapsulate the probiotics for their use in the fermented and other dairy products. This review evaluates the merits and limitations of these two techniques, and also discusses the supporting materials and special treatments used in encapsulation processes. (C) 2003 Elsevier Science Ltd. All rights reserved.

Reatividade tuberculínica e resposta imunológica celular e humoral "in vitro" em doentes com tuberculose pulmonar

Foi estudada a reatividade tuberculínica e a resposta imunológica celular e humoral "in vitro", em 50 doentes de ambos os sexos, de 20 a 80 anos de idade, com tuberculose pulmonar ativa, internados no Parque Hospitalar do Mandaqui da Secretaria de Estado da Saúde, São Paulo (Brasil), no período de maio a agosto de 1980. Para o estudo da reatividade tuberculínica foi utilizado o PPD, Rt-23, 2 UT, tendo havido 14,0% de não-reatores, 12,0% de reatores fracos e 74,0% de reatores fortes. O estudo da imunidade celular e humoral "in vitro" foi realizado pela quantificação de linfócitos T e B, transformação blástica de linfócitos, liberação do fator inibidor da migração de leucócitos (LIF) e reação de hemaglutinação passiva. Os resultados mostraram a validade do cálculo do número absoluto dos linfócitos T e B. A cultura de linfócitos e a técnica do LIF, foram capazes de detectar a sensibilização dos linfócitos ao PPD, mesmo nos doentes não reatores, e a reação de hemaglutinação passiva revelou a presença de anticorpos específicos na população estudada em títulos superiores aos encontrados em pessoas normais, independentemente da reatividade tuberculínica.

Resposta imune humoral de cães à vacina inativada, de cérebro de camundongos lactentes, utilizada nas campanhas anti-rábicas no Brasil

INTRODUÇÃO: A campanha anti-rábica no Brasil é realizada anualmente utilizando a vacina de cérebro de camundongos lactentes Fuenzalida-Palacios. A resposta imune humoral de cães vacinados durante as campanhas foi analisada objetivando avaliar se os cães apresentavam título protetor (0,5 UI/ml), 12 meses após a vacinação, e quantos deles alcançam esse título 30 dias após o reforço vacinal. MATERIAL E MÉTODO: Foram analisadas 341 amostras de soro de cães domiciliados (259 do Município de São Paulo e 82 do Município de Paulínia), através da Técnica de Inibição de Focos de Fluorescência Rápida. A resposta imune foi avaliada considerando o estado nutricional do animal e o número de vacinações anteriores. RESULTADO: A maioria dos cães não tinha título de 0,5 UI/ml após 12 meses, independentemente do estado nutricional, e a resposta humoral ao reforço vacinal mostrou-se melhor em cães com duas ou mais vacinações prévias. DISCUSSÃO: São discutidos o referencial de 0,5 Ul/ml como título protetor para a espécie canina e a influência do estado nutricional e condição de saúde do animal como responsável pela resposta imune humoral.

Avaliação da resposta humoral à vacina pneumocócica 7-valente em crianças com Aids

OBJETIVO: A doença pneumocócica invasiva é importante causa de morbi-mortalidade em crianças infectadas pelo HIV. O objetivo do estudo foi avaliar quantitativamente a resposta com anticorpos aos sete sorotipos pneumocócicos da vacina em um grupo de crianças infectadas pelo HIV. MÉTODOS: Estudo realizado com 40 crianças infectadas pelo HIV, com idade entre 2 e 9 anos, em seguimento em ambulatório especializado no município de São Paulo, em 2002-2003. A dosagem de anticorpos IgG contra os polissacarídeos da cápsula pneumocócica foi realizada por meio de ensaio imunoenzimático (ELISA). Os anticorpos foram dosados imediatamente antes e um mês após a aplicação da segunda dose da vacina. Utilizaram-se dois critérios para avaliar a resposta à vacina: títulos de anticorpos >1,3 µg/mL na sorologia pós-imunização e aumento >4 vezes nos títulos da sorologia pós em relação à pré-imunização. RESULTADOS: Para o primeiro critério (>1,3 µg/mL), 26 (65%) crianças obtiveram resposta sorológica à vacina, 12 (30%) delas apresentaram títulos de IgG pós-imunização em níveis de pelo menos 1,3 µg/mL para todos os sorotipos. Para o segundo critério (incremento >4 vezes nos títulos para quatro sorotipos ou mais), obteve-se resposta sorológica para 15 (37,5%) crianças. CONCLUSÕES: A resposta à vacina foi considerada satisfatória, com aumento estatisticamente significante dos títulos geométricos médios pós-vacinais em relação aos pré-vacinais para todos os sorotipos estudados.

Suppression of humoral immunity and lymphocyte responsiveness during experimental trypanosoma cruzi infections

C3H/He and C57B1/6 mice were inoculated with 500 Trypanosoma cruzi trypomastigotes (Strain Y). During the acute phase infected mice presented parasitemia and enlargement of lymph nodes and spleens and intracellular parasites were observed in the heart. Examinations of cells derived from spleen and lymph nodes showed increased numbers of IgM and IgG-bearing cells. During the peak of splenomegaly, about day 17 post-infections, splenic lymphocytes showed a marked decrease in responsiveness to T and B-cell mitogens, parasite antigens and plaque forming cells (PFC) to sheep red blood cells (SRBC). Unfractionated or plastic adherent splenic cells from mice, obtained during the acute phase were able to suppress the response to mitogens by lymphocytes from uninfected mice. During the chronic phase. Disappearance of parasitemia and intracellular parasites in the hearts as well as a decrease in spleen size, was observed. These changes preceded the complete recovery of responsiveness to mitogens and T. cruzi antigens by C57B1/6 splenic lymphocytes. However, this recovery was only partial in the C3H/He mice, known to be more sensitive to T. cruzi infection. Partial recovery of humoral immune response also occurred in both strains of mice during the chronic phase.

Depressão humoral específica em pacientes crônicos infectados pelo Trypanosoma cruzi

Realizamos um estudo comparativo entre o xenodiagnóstico e os testes sorológicos para a doença de Chagas. Cento e cincoenta pacientes de algumas áreas endêmicas foram estudados. Quatro deles pareceram revelar um estado particular com um xenodiagnóstico positivo e uma sorologia negativa, esta realizada com quatro diferentes técnicas clássicas (teste de immunofluorescência, ELISA: Enzyme Linked Immunosorbent Assay, teste de fixação do complemento e teste de immuno-eletroforese). O soro de um dos pacientes que apresentou depressão humoral específica mostra elevada quantidade de antígenos circulantes comprovada pela técnica da immuno-eletroforese. Os Autores sugerem o uso de um teste sorológico para detectar a presença de antígenos circulantes de T. cruzi, além da utilização de testes sorológicos clássicos. Isto permitiria o diagnóstico da doença de Chagas em pacientes com uma baixa (ou mesmo inexistente) produção de anticorpos específicos.