Impact of malnutrition on immunity and infection

Malnutrition may be a consequence of energy deficit or micronutrient deficiency. It is considered the most relevant risk factor for illness and death, particularly in developing countries. In this review we described the magnitude of this problem, as well as its direct effect on the immune system and how it results in higher susceptibility to infections. A special emphasis was given to experimental models used to investigate the relationship between undernutrition and immunity. Malnutrition is obviously a challenge that must be addressed to health authorities and the scientific community.

Is the BCG Vaccine Safe for Undernourished Individuals?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nematode burdens and cellular responses in the abomasal mucosa and blood of Florida Native, Rambouillet and crossbreed lambs

This experiment was carried out to compare the worm burden and cellular responses in the abomasal mucosa and blood of Florida Native and Rambouillet lambs and also in animals produced by crosses of these two breeds (generations F1 and F2). Animals were exposed to infection by gastrointestinal nematodes on three different occasions. The first infection was natural, occurring while they were suckling lambs. After weaning, they were kept indoors for 53 days and then were allowed to graze a contaminated pasture for 50 days for a second natural infection. The third infection was an artificial challenge with 6000 Haemonchus contortus infective larvae. The highest mean fecal egg counts (FEC) values were found in Rambouillet lambs followed in decreasing order by F1, F2 and Florida Native lambs. Throughout the trial, most of the high mean packed cell volumes and plasma protein levels were recorded in the F2 lambs; in contrast, most of the low values were found in the Rambouillet lambs. During the natural infection period, the highest percentages of larvae in the fecal cultures of the lambs were Haemonchus. However, high percentages of Trichostrongylus larvae were found particularly in Florida Native lambs. The mean number of blood eosinophils increased after the artificial challenge, reached a peak 21 days after infection and then declined. The highest and lowest blood eosinophil means were recorded in F2 and Florida Native lambs, respectively. The H. contortus burden was significantly higher in Rambouillet and in F1 lambs than in Florida Native and F2 lambs (p < 0.05), while no significant differences were recorded among eosinophil, mast cell and globule leucocyte counts in the abomasal mucosa (p > 0.05). The highest correlation coefficient recorded at the end of this study was between FEC and worm burden (r = 0.7). These two parameters showed a moderate negative correlation with PCV, plasma protein and mast cell counts in the abomasal mucosa. The results obtained in this study indicate that crossbreeding Florida Native and Rambouillet sheep can be a rapid way to combine and improve the characteristics of these two breeds. The parasitological results were promising. however, more studies will be necessary to verify the impact of crossbreeding in other traits. (C) 1999 Elsevier B.V. B.V. All rights reserved.

beta-glucans in promoting health: Prevention against mutation and cancer

The polysaccharides beta-glucans occur as a principal component of the cellular walls. Some microorganisms, such as yeast and mushrooms, and also cereals such as oats and barley, are of economic interest because they contain large amounts of beta-glucans. These substances stimulate the immune system, modulating humoral and cellular immunity, and thereby have beneficial effect in fighting infections (bacterial, viral, fungal and parasitic). beta-Glucans also exhibit hypocholesterolemic and anticoagulant properties. Recently, they have been demonstrated to be anti-cytotoxic, antimutagenic and anti-tumorogenic, making them promising candidate as pharmacological promoters of health. (C) 2008 Elsevier B.V. All rights reserved.

Immunity in plants and animals: common ends through different means using similar tools

A comparative approach is potentially useful for understanding the role of mammal innate immunity role in stimulating adaptive immunity as well as the relationship between these two types of immune strategies. Considerable progress has been made in the elucidation of the co-ordinated events involved in plant perception of infection and their mobilisation of defence responses. Although lacking immunoglobulin molecules, circulating cells, and phagocytic processes, plants successfully use pre-formed physical and chemical innate defences, as well as inducible adaptive immune strategies. In the present paper, we review some shared and divergent immune aspects present in both animals and plants. (C) 2002 Elsevier B.V. All rights reserved.

Cellular and extracellular behavior in the gerbil (Meriones unguiculatus) ventral prostate following different types of castration and the consequences of testosterone replacement

Mongolian gerbils (Meriones unguiculatus) were grouped into two experimental groups: GEx.01 suffered orchiectomy and after 30 days received doses of testosterone cipionate (T), while GEx.02 received weekly and alternated doses of the anti-androgens cyproterone acetate and flutamide for 30 days, and the animals were then euthanized. Structural evaluation reveals a more intense reduction in epithelial height in GEx.02. Smooth muscle cells (SMC) presented a star-shaped aspect after 30 days of hormonal ablation and basal membrane was shown to be more intensely grooved in GEx.01. In both groups, after hormonal replacement, recovery in epithelial height could be noted and the SMC presented its phenotypes, but an increase in RER was seen, characterizing a modulation from its contractile to secreting phenotype. In conclusion, the prostate presented involution capacity after androgen ablation and the ability to reorganize after hormonal replacement, but events resulting from orchiectomy and subsequent T replacement were shown to be more aggressive to the prostate. (c) 2006 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.

Cellular changes in the prostatic stroma of glucocorticoid-treated rats

Glucocorticoid hormones (GCs) have been widely used for the treatment of prostate cancer because of their inhibitory property against tumour growth. However, their mechanism of action in the prostate has received little attention. Excess GCs can lead to peripheral insulin resistance resulting in hyperglycaemia and hyperinsulinaemia. Insulin plays an important role as a cellular stimulant and high levels are related to low levels of androgens. Our objective has been to describe the effects of insulin resistance induced by dexamethasone treatment on the morphology of rat ventral prostate. Mate adult Wistar rats received daily intraperitoneal injections of dexamethasone or saline for five consecutive days after which the rats were killed and the ventral prostate was removed, weighed and prepared for conventional and transmission electron microscopy (TEM). Dexamethasone treatment resulted in atrophy and decreased proliferative activity of prostatic epithelial cells. TEM analysis revealed changes in the epithelium-stroma interface, with some interruptions in the basement membrane. Fibroblasts showed a secretory phenotype with dilated endoplasmic reticulum. Smooth muscle cells exhibited a contractile pattern with 50% atrophy, an irregular membrane and twisted nuclei. Mitochondrial alterations, such as enlarged size and high electron density in the mitochondrial matrix, were also detected in smooth muscle cells. Insulin resistance induced by dexamethasone is thus associated with epithelial atrophy similar to that described for diabetic rats. However, GCs are responsible for morphological changes in the stromal cell population suggesting the activation of fibroblasts and atrophy of the smooth muscle cells.

Long-term inhibition of 5-alpha reductase and aromatase changes the cellular and extracellular compartments in gerbil ventral prostate at different postnatal ages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Maximum entropy, fractal dimension and lacunarity in quantification of cellular rejection in myocardial biopsy of patients submitted to heart transplantation

This paper presents a method for the quantification of cellular rejection in endomyocardial biopsies of patients submitted to heart transplant. The model is based on automatic multilevel thresholding, which employs histogram quantification techniques, histogram slope percentage analysis and the calculation of maximum entropy. The structures were quantified with the aid of the multi-scale fractal dimension and lacunarity for the identification of behavior patterns in myocardial cellular rejection in order to determine the most adequate treatment for each case.

The Role of Immunity and Seasonality in Cholera Epidemics

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Demonstration of antibody and cellular immune response to brain extract in West and Lennox-Gastaut syndromes

Investigamos a resposta imunológica celular e humoral frente a extrato salino de tecido cerebral em 9 pacientes com síndrome de Lennox-Gastaut, 15 pacientes com síndrome de West e 20 crianças normais. A técnica de imunodifusão dupla em gel de agar (Ouchterlony) evidenciou em todos os pacientes, altos níveis de um anticorpo precipitante contra o extrato salino de tecido cerebral. O teste de inibição de migração de leucócitos com o mesmo antígeno mostrou-se positivo na maioria dos pacientes. O possível papel destas respostas autoimmunes na patogenia das sindromes de West e Lennox-Gastaut é discutido.

Histological characterization of cellular types during Scinax fuscovarius oogenesis (Lutz) (Anura, Hylidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of different immunization protocols with P. brasiliensis antigens in Guinea pigs

O objetivo deste trabalho foi desenvolver protocolo eficiente e reprodutível de imunização em cobaias com antígenos de P. brasiliensis, visando a obtenção de modelo experimental para futuros estudos de mecanismos de proteção imunológica. Testaram-se três diferentes antígenos (particulado, solúvel e composto) e seis protocolos nos quais foram avaliadas as influências dos seguintes fatores: presença ou ausência de adjuvante completo de Freund, número de doses imunizantes e intervalo de tempo entre a última dose imunizante e o desafio. A eficiência do protocolo de imunização foi estudada pela avaliação da resposta imune celular e humoral anti-P. brasiliensis, utilizando teste cutâneo e teste de inibição da migração do macrófago, e imunodifusão, respectivamente. Observou-se que: 1. Três doses imunizantes de antígeno induziram melhor resposta do que duas doses; 2. Maior resposta imune foi conseguida com a utilização de adjuvante completo de Freund; 3. Animais desafiados depois de longo tempo (6 semanas) da última dose imunizante mostraram melhor resposta imune anti-P. brasiliensis; 4. Os antígenos solúvel e composto foram igualmente eficientes induzindo maior resposta imune humoral e celular anti-P. brasiliensis enquanto que o antígeno particulado provocou menor reatividade

Effect of Bacillus of Calmette-Guérin, Avridine and Propionlbacterium acnes as immunomodulators on rabies in mice

Avaliou-se a resposta imune celular e humoral de camundongos inoculados com vírus rábico de rua e submetidos aos imunomoduladores Onco-BCG, avridina e Propionibacterium acnes. Os animais submetidos ao tratamento com P.acnes apresentaram um maior percentual de sobrevivência quando comparados aos dos demais tratamentos. Foram observados menores níveis de IFN-g nos animais infectados, sugerindo imunossupressão viral. O teste do Coxim Plantar não foi eficaz para a detecção da resposta de hipersensibilidade retardada na metodologia utilizada, contrariamente ao MIF. A sobrevivência dos animais não apresentou correlação com os níveis de anticorpos soroneutralizantes, concentração de IFN-g e resposta ao MIF.

Immunisation of dogs and guinea pigs against Rhipicephalus sanguineus ticks using gut extract

Tick-bite naive guinea pigs were inoculated three times with Rhipicephalus sanguineus gut or salivary gland extracts and saponin as adjuvant. Dogs were inoculated three times with gut extract only as this fraction induced a more efficient resistance in guinea pigs (lower tick recovery and lower engorged female weights). Freund's adjuvant and saponin were used as adjuvants for the immunisation of dogs. Freund's adjuvant was used to enhance cellular immunity. The highest level of resistance in dogs was induced by the immunisation with gut extract and Freund's adjuvant. Many female ticks from dogs immunised this way engorged fully but died prior to oviposition. Resistant guinea pigs and dogs seemed to trigger different immune mechanisms against R. sanguineus ticks as damage to parasites also differed. A major role for cellular immunity in the resistance of dogs against R. sanguineus ticks is suggested. Resistance mechanisms against R. sanguineus ticks is discussed.