RESUMO
Moyna of Purba Medinipur district is widely known as an aquaculture hub of West Bengal, India. Though very good production is achievable from this fish culture system, management practices are inappropriate, which could create the sustainability problem of this culture system. The present study was thus undertaken for the estimation of plankton population, water quality, carbon footprint and carbon sequestration of this intensive aquaculture practices. Information on spawn to fry, fry to fingerlings and grow-out culture were collected through the structured questionnaire from the fish farmers. The plankton density, primary productivity, carbon footprint and carbon sequestration were analyzed using standard procedures. The phytoplankton, zooplankton and primary productivity were maximum at the stocking period and minimum during the middle of culture period. The lowest feed conversion ratio (FCR) was noticed with the minimum amount of feed applied in the pond. The CO2-e emission ranged from 0.56 to 4.89 kg CO2-e/kg fish (av. 2.13) for the production levels of 5.0 to 10.7 t/ha/yr. The pond water developed salinity and ammonium-N increased from 0.01 to 0.50 mg/l. The ponds with high feed loading (28 to 32 t/ha/yr) had the highest average sediment accumulation rate (11.0 ± 3.0 cm/yr) and carbon sequestration (704 ± 30 g C/m2/yr).
Assuntos
Pegada de Carbono , Sequestro de Carbono , Animais , Dióxido de Carbono , Aquicultura , Índia , PlânctonRESUMO
Our objective was to evaluate the performance of HIV testing algorithms based on WHO recommendations, using data from specimens collected at six HIV testing and counseling sites in sub-Saharan Africa (Conakry, Guinea; Kitgum and Arua, Uganda; Homa Bay, Kenya; Douala, Cameroon; Baraka, Democratic Republic of Congo). A total of 2,780 samples, including 1,306 HIV-positive samples, were included in the analysis. HIV testing algorithms were designed using Determine as a first test. Second and third rapid diagnostic tests (RDTs) were selected based on site-specific performance, adhering where possible to the WHO-recommended minimum requirements of ≥99% sensitivity and specificity. The threshold for specificity was reduced to 98% or 96% if necessary. We also simulated algorithms consisting of one RDT followed by a simple confirmatory assay. The positive predictive values (PPV) of the simulated algorithms ranged from 75.8% to 100% using strategies recommended for high-prevalence settings, 98.7% to 100% using strategies recommended for low-prevalence settings, and 98.1% to 100% using a rapid test followed by a simple confirmatory assay. Although we were able to design algorithms that met the recommended PPV of ≥99% in five of six sites using the applicable high-prevalence strategy, options were often very limited due to suboptimal performance of individual RDTs and to shared falsely reactive results. These results underscore the impact of the sequence of HIV tests and of shared false-reactivity data on algorithm performance. Where it is not possible to identify tests that meet WHO-recommended specifications, the low-prevalence strategy may be more suitable.
Assuntos
Algoritmos , Testes Diagnósticos de Rotina/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Infecções por HIV/diagnóstico , Programas de Rastreamento/métodos , África Subsaariana , Guias como Assunto , Humanos , Sensibilidade e Especificidade , Organização Mundial da SaúdeRESUMO
The present study determines the fat depot-specific expression of leptin and TNF-α and its association with biochemical parameters in postmenopausal women. A total of 108 postmenopausal women were recruited prospectively; 54 were with metabolic syndrome (cases) and 54 were without metabolic syndrome (controls). Leptin and TNF-α mRNA expression in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were done by Real Time-RT PCR. In cases, the mean (±SD) serum estrogen was significantly lower (41.33±24.90 vs. 23.95±14.45, p<0.001) while leptin (12.85±4.51 vs. 10.34±3.89, p=0.002) and TNF-α (13.81±7.13 vs. 8.00±4.38, p<0.001) were significantly higher as compared to controls. Further, the mean relative VAT mRNA expression of both leptin (0.33±0.29 vs. 0.05±0.09, p<0.001) and TNF-α (0.32±0.31 vs. 0.13±0.09, p<0.001) and expression of SAT leptin (4.91±4.01 vs. 0.50±0.92, p<0.001) also lowered significantly in cases as compared to controls. Further, the relative VAT expression of both leptin (r=-0.32, p<0.001) and TNF-α (r=-0.23, p<0.01) showed significant and negative correlation with glucose; expression of SAT leptin showed significant and positive correlation with HDL (r=0.20, p<0.05) and serum estrogen (r=0.30, p<0.01) while negative correlation with glucose (r=-0.26, p<0.01) and serum TNF-α (r=-0.29, p<0.01); and expression of SAT TNF-α showed significant and positive correlation with insulin (r=0.21, p<0.05) and HOMA (r=0.20, p<0.05). In conclusion, the VAT and SAT leptin mRNA expressions may have a modulatory role in metabolic syndrome.
Assuntos
Resistência à Insulina/fisiologia , Leptina/genética , Síndrome Metabólica/metabolismo , Pós-Menopausa , Gordura Subcutânea/metabolismo , Fator de Necrose Tumoral alfa/genética , Idoso , Glicemia/análise , Estrogênios/sangue , Feminino , Expressão Gênica , Humanos , Índia , Insulina/sangue , Gordura Intra-Abdominal/química , Gordura Intra-Abdominal/metabolismo , Leptina/sangue , Pessoa de Meia-Idade , RNA Mensageiro/análise , Gordura Subcutânea/química , Fator de Necrose Tumoral alfa/sangueRESUMO
Asthma is a complex genetic disease, which arises from the interaction of multiple genes and environmental stimuli. These influences are important to asthma pathogenesis. These can be mechanically explained by the Epigenetic phenomenon, which consists of the chromatin and its modifications, as well as a covalent modification of cytosines residing at the dinucleotide sequence CG in DNA by methylation. This reaction is catalyzed by a family of DNA methyltransferase enzyme (DNMTs). DNMT1 is one of them which maintained the methylation status during replication and also critical for the development, differentiation and regulation of Th1 and Th2 cells. Therefore we studied the DNMT1 mRNA expression profiling as well as CpG methylation status in promoter region. For these studies we developed asthma mouse model, and used Flow cytometer, qRT(2)-PCR, Methylation specific PCR, bisulfate conversion and BiQ analyzer. We found that DNMT1 expression level was low in all the tissues (lung, trachea and BALF cells) of asthmatic in comparison to normal mice. This was due to the methylation of regulatory sites of DNMT1 promoter region at cytosine residue. As the incidence of asthma is increasing globally and in world, this study assumes greater significance in designing and developing therapeutic means.
Assuntos
Asma/genética , DNA (Citosina-5-)-Metiltransferases/genética , Epigênese Genética , Regulação da Expressão Gênica , Animais , Asma/imunologia , Asma/patologia , Sequência de Bases , Hiper-Reatividade Brônquica/genética , Hiper-Reatividade Brônquica/imunologia , Hiper-Reatividade Brônquica/patologia , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Ilhas de CpG , Citocinas/biossíntese , Citocinas/genética , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/química , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , Modelos Animais de Doenças , Feminino , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Camundongos , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/metabolismoRESUMO
Maternal hypothyroidism affects postnatal lung structure. High prevalence of hypothyroxinemia (low T4, normal T3) in iodine-deficient pregnant women and associated risk for neuropsychological development along with high infant/neonatal mortality ascribed to respiratory distress prompted us to study the effects of maternal hypothyroxinemia on postnatal lung development. Female Sprague Dawley rats were given a low-iodine diet (LID) with 1% KClO(4) in drinking water for 10 days, to minimize thyroid hormone differences. Half of these rats were continued on iodine-deficient diet; ID (LID with 0.005% KClO(4)) for 3 mo, whereas the rest were switched to an iodine-sufficient diet; IS [LID + potassium iodide (10 µg iodine/20 g of diet + normal drinking water)]. Pups born to ID mothers were compared with age-matched pups from IS mothers at postnatal days 8 (P8) and 16 (P16) (n = 6-8/group). ID pups had normal circulating T3 but significantly low T4 levels (P < 0.05) and concomitantly approximately sixfold higher thyroid hormone receptor-ß mRNA in alveolar epithelium. Lung histology revealed larger and irregularly shaped alveoli in ID pups relative to controls. Lung function was assessed at P16 using a double-chambered plethysmograph and observed reduced tidal volume, peak inspiratory and expiratory flow, and dynamic lung compliance in ID pups compared with IS pups. Significant lowering of surfactant protein (SP)-B and SP-C mRNA and protein found in ID pups at P16. ID pups had 16-fold lower matrix metalloproteinase-9 mRNA levels in their alveolar epithelium. In addition, mRNA levels of thyroid transcription factor-1 and SP-D were significantly higher (3-fold) compared with IS pups. At P16, significantly lower levels of SP-B and SP-C found in ID pups may be responsible for immature lung development and reduced lung compliance. Our data suggest that maternal hypothyroxinemia may result in the development of immature lungs that, through respiratory distress, could contribute to the observed high infant mortality in ID neonates.
Assuntos
Hipotireoidismo/metabolismo , Iodo/deficiência , Pulmão/crescimento & desenvolvimento , Complicações na Gravidez/metabolismo , Mucosa Respiratória/metabolismo , Glândula Tireoide/metabolismo , Tiroxina/deficiência , Animais , Feminino , Humanos , Hipotireoidismo/etiologia , Hipotireoidismo/fisiopatologia , Lactente , Pulmão/patologia , Pulmão/fisiopatologia , Complacência Pulmonar , Proteínas Nucleares/biossíntese , Peptídeos/metabolismo , Pletismografia , Gravidez , Complicações na Gravidez/etiologia , Complicações na Gravidez/fisiopatologia , Alvéolos Pulmonares/crescimento & desenvolvimento , Alvéolos Pulmonares/patologia , Alvéolos Pulmonares/fisiopatologia , Proteína B Associada a Surfactante Pulmonar/biossíntese , Proteína D Associada a Surfactante Pulmonar/biossíntese , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Mucosa Respiratória/patologia , Glândula Tireoide/fisiopatologia , Receptores beta dos Hormônios Tireóideos/biossíntese , Fator Nuclear 1 de Tireoide , Fatores de Transcrição/biossínteseRESUMO
Glutathione S transferase (GST) gene polymorphism examined among north Indians and correlated with hydroquinone (HQ) genotoxicity to help in clinical prediction of susceptibility of HQ toxicity. Lymphocytes of individuals with/without GSTM1, GSTT1, and GSTP1 (ile/ile or val/val) were exposed to HQ (20, 40, or 80 microM) and examined chromosomal aberrations (CA) or cytokinesis-block micronucleus assays. Among north Indians the frequencies of GSTM1 (null), GSTT1 (null), and both null were found to be 41.1, 21.9, and 12.7%, whereas frequencies of GSTP1 with (ile/ile) or (ile/val), or (val/val) were 52, 42.1, or 5.9%, respectively. Individuals with null GSTM1, GSTT1, and GSTP1 (val/val) showed inhibition of mitotic index (MI) and significant (p < 0.01) induction of CA as compared to individuals with GSTM1, GSTT1, and GSTP1 (ile/ile). Micronucleus formation was found to be significant (p < 0.05 or 0.01) in both the genotypes. Results indicate that GSTM1, GSTT1 (null), and GSTP1 (val/val) are sensitive to HQ genotoxicity.
Assuntos
Glutationa S-Transferase pi/genética , Glutationa Transferase/genética , Hidroquinonas/toxicidade , Mutagênicos/toxicidade , Polimorfismo de Fragmento de Restrição , Adolescente , Adulto , Células Cultivadas , DNA/genética , Feminino , Predisposição Genética para Doença/genética , Humanos , Índia , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Linfócitos/ultraestrutura , Masculino , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Pessoa de Meia-Idade , Índice Mitótico , Reação em Cadeia da Polimerase , Adulto JovemRESUMO
Asthma, a multifactorial, chronic inflammatory disease encompasses multiple complex pathways releasing number of mediators by activated mast cells, eosinophils and T lymphocytes, leading to its severity. Presently available medications are associated with certain limitations, and hence, it is imperative to search for anti-inflammatory drug preferably targeting signaling cascades involved in inflammation thereby suppressing inflammatory mediators without any side effect. Curcumin, an anti-inflammatory molecule with potent anti-asthmatic potential has been found to suppress asthmatic features by inhibiting airway inflammation and bronchoconstriction if administered through nasal route. The present study provides new insight towards anti-asthmatic potential of intranasal curcumin at lower doses (2.5 and 5.0 mg/kg) in Balb/c mice sensitized and challenged with ovalbumin (OVA) which is effective in inhibiting airway inflammation. These investigations suggest that intranasal curcumin (2.5 and 5.0 mg/kg) regulates airway inflammation and airway obstruction mainly by modulating cytokine levels (IL-4, 5, IFN-Æ´ and TNF-α) and sPLA2 activity thereby inhibiting PGD2 release and COX-2 expression. Further, the suppression of p38 MAPK, ERK 42/44 and JNK54/56 activation elucidate the mechanism behind the inhibitory role of intranasal curcumin in asthma progression. Thus, curcumin could be better alternative for the development of nasal formulations and inhalers in near future.
Assuntos
Obstrução das Vias Respiratórias/tratamento farmacológico , Asma/tratamento farmacológico , Curcumina/uso terapêutico , Administração Intranasal , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , MAP Quinase Quinase 4/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Prostaglandina D2/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimer's disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition.
Assuntos
Ácidos Docosa-Hexaenoicos/análise , Ácido Eicosapentaenoico/análise , Ácidos Graxos/análise , Peixes/classificação , Peixes/metabolismo , Análise de Alimentos , Animais , Índia , Especificidade da EspécieRESUMO
The micronutrients (vitamins and minerals) are required in small amounts but are essential for health, development, and growth. Micronutrient deficiencies, which affect over two billion people around the globe, are the leading cause of many ailments including mental retardation, preventable blindness, and death during childbirth. Fish is an important dietary source of micronutrients and plays important role in human nutrition. In the present investigation, micronutrient composition of 35 food fishes (includes both finfishes and shellfishes) was investigated from varying aquatic habitats. Macrominerals (Na, K, Ca, Mg) and trace elements (Fe, Cu, Zn, Mn, Se) were determined by either atomic absorption spectroscopy (AAS) or inductively coupled plasma mass spectrometry (ICP-MS)/atomic emission spectrometry (ICP-AES). Phosphorus content was determined either spectrophotometrically or by ICP-AES. Fat-soluble vitamins (A, D, E, K) were analyzed by high-performance liquid chromatography (HPLC). The analysis showed that, in general, the marine fishes were rich in sodium and potassium; small indigenous fishes (SIFs) in calcium, iron, and manganese; coldwater fishes in selenium; and the brackishwater fishes in phosphorous. The marine fishes Sardinella longiceps and Epinephelus spp. and the SIFs were rich in all fat-soluble vitamins. All these recommendations were made according to the potential contribution (daily value %) of the species to the recommended daily allowance (RDA). Information on the micronutrients generated would enhance the utility of fish in both community and clinical nutrition.
Assuntos
Produtos Pesqueiros/análise , Análise de Alimentos , Metais/análise , Valor Nutritivo , Oligoelementos/análise , Animais , Humanos , ÍndiaRESUMO
Bat spleen and mesenteric lymph node cell cultures treated with varying doses of LPS showed significant blastogenic and DNA synthetic responses between 72-96h. Peak responses were not different when the cell culture medium was supplemented either with autologous serum or heterologous serum indicating the absence of any significant suppressor factor in autologous bat serum. In contrast, blastogenesis and DNA synthesis peaks appeared early, at 48h, in lymphocytes depleted of suppressor T cells by pretreatment with cyclophosphamide. Direct antibody producing cells against SRBC were studied in normal spleen and mesenteric lymph node cell cultures. The peak PFC response was lacking even at 120h while CY pretreated bat lymphocytes, showed peak PFC responses at 96h. Thus the delayed immune response in bats seems to be a function of suppressor T cells but serum suppressor factor(s) possibly exerts no significant effect. The function of suppressor cells in bats in relation to their role as carriers of several dreaded bacteria and viruses is discussed.
Assuntos
Quirópteros/imunologia , Ativação Linfocitária/efeitos dos fármacos , Fatores Supressores Imunológicos/análise , Animais , Formação de Anticorpos , Soro Antilinfocitário/farmacologia , Células Cultivadas , Ciclofosfamida/farmacologia , Cabras/sangue , Cinética , Lipopolissacarídeos/farmacologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologiaRESUMO
In vitro activation of lymphocytes from the bat, Pteropus giganteus with Con A has been analysed in terms of blastogenesis, DNA synthesis and the effector function, the cytotoxic response. We have observed that lymphocytes of P. giganteus are capable of responding to Con A stimulus and the peak of blastogenesis, DNA synthesis and cytotoxic response have been found at 120 hours with the optimal dose of 10 micrograms X ml-1 Con A; it seems the process of activation in the bat's lymphocytes is delayed compared to this in mice. Significance of this delay in the process of activation of immune response in the bat has been discussed.
Assuntos
Quirópteros/imunologia , Concanavalina A , Hipersensibilidade Tardia , Ativação Linfocitária , Animais , Sobrevivência Celular , Células Cultivadas , Citotoxicidade Imunológica , Replicação do DNA , Linfócitos/citologia , Linfócitos/imunologiaRESUMO
To determine the effects of changes in maternal cigarette use during pregnancy on birthweight, a sample of Caucasian births free of major malformations (n = 9,943) was examined. Births were stratified by level of maternal smoking in the first trimester and subdivided according to whether the mother continued at the same level, reduced, or quit by the second trimester. Birthweights were adjusted statistically for extraneous variables. As expected, second and third trimester cigarette use was associated with birthweight, but so too was cigarette use during the first trimester, and the effect of quitting varied significantly with the level of first trimester smoking. Among moderate and light smokers, who comprise the majority of smokers, quitting before the second trimester is associated with heavier infants. However, infants of heavy smokers who quit by the second trimester did not weigh significantly more than infants of mothers who continued to smoke heavily throughout pregnancy, and weighed significantly less than infants of nonsmokers or other smokers who quit. Thus, quitting by the end of the first trimester may not completely negate the effect of heavy first trimester smoking, and the adaptive value of qutting is unequal among different levels of first trimester smoking. Further research on prenatal growth should take cigarette smoking in all trimesters into account. © 1994 Wiley-Liss, Inc.
RESUMO
Fermented silkworm pupae (SWP) silage or untreated fresh SWP pastes were incorporated in carp feed formulations replacing fishmeal. The feed formulations were isonitrogenous (30.2-30.9% protein) and isocaloric (ME = 2905-2935 kcal/kg). Feeding under a polyculture system consisting of 30% each of catla (Catla catla), mrigal (Cirrhinus mrigala) and rohu (Labeo rohita) with 10% silver carps (Hypophthalmychthys molitrix) was carried out in ponds to evaluate the nutritive quality of SWP silage. Survival rate, feed conversion ratio and specific growth rate, respectively, were 84.2%, 2.10 and 2.39 for fermented SWP silage, 65.8%, 2.98 and 2.26 for untreated SWP and 67.5%, 3.16 and 2.20 for fishmeal indicating clearly that the fermented SWP silage was nutritionally superior to untreated SWP or fishmeal. The dietary influence on the proximate composition of whole fish was marginal.
Assuntos
Bombyx , Carpas/crescimento & desenvolvimento , Suplementos Nutricionais , Pupa , Silagem , Animais , Bombyx/crescimento & desenvolvimento , Fermentação , Especificidade da EspécieRESUMO
The effect of the water soluble fraction of the ethanol extract of Nyctanthes arbor-tristis (NAT) on tumor necrosis factor-alpha (TNF-alpha) level in plasma of arthritic and soluble protein A (SpA)-treated Balb/c mice has been studied. Oral administration of this fraction in arthritic mice showed a consistent depletion of TNF-alpha from the host plasma. A similar depletion of TNF-alpha in the plasma of SpA-treated mice has been observed. The extract also reduces plasma interferon-gamma level but the plasma IgM and IgG levels are not affected. The implications of these observations are discussed in the light of management of TNF-alpha in clinical disorders.
Assuntos
Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Administração Oral , Animais , Artrite Experimental/sangue , Artrite Experimental/tratamento farmacológico , Proteínas Sanguíneas/metabolismo , Modelos Animais de Doenças , Eletroforese em Gel de Poliacrilamida , Etanol/química , Immunoblotting , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Interferon gama/sangue , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Plantas Medicinais/metabolismo , Proteína Estafilocócica A/toxicidadeAssuntos
Salicilatos/intoxicação , Acidose/induzido quimicamente , Idoso , Intoxicação Alcoólica/diagnóstico , Alcalose/induzido quimicamente , Alcalose Respiratória/induzido quimicamente , Arritmias Cardíacas/induzido quimicamente , Coma/induzido quimicamente , Cetoacidose Diabética/diagnóstico , Diagnóstico Diferencial , Encefalite por Arbovirus/diagnóstico , Humanos , Masculino , Infarto do Miocárdio/diagnóstico , Intoxicação/diagnóstico , Salicilatos/sangue , Neoplasias Gástricas/diagnóstico , SudoreseRESUMO
The Fc binding property of soluble protein A (SpA) from Staphylococcus aureus has been utilized to form IgG-SpA complexes which enabled an increase or decrease of IgG from the host depending on the dose of SpA administered. When 5 micrograms SpA was administered the IgG-SpA complexes were rapidly catabolized and, hence, low plasma IgG levels were observed. In contrast 25 micrograms SpA resulted in a significant increase in the IgG level in the host plasma. Based on these observations, the present investigation attempted to study the effect of IgG depletion/increase on the primary and secondary B-cell response to sheep erythrocyte (SRBC) antigen in Balb/c mice. Introduction of 5, 10 and 25 micrograms SpA at the time of the primary antigenic challenge inhibited both the primary IgM and the secondary IgM and IgG responses in a dose-dependent manner. Administration of 5 and 10 micrograms SpA at the time of the secondary antigenic challenge enabled the host to maintain the otherwise depressed secondary IgM response equivalent to the normal primary response. In contrast, 25 micrograms SpA at the time of the secondary antigenic challenge inhibited both the IgM and IgG PFC responses. These results extend our understanding of the mechanism of switch in immunoglobulin class expression during antigen driven maturation of the B-cell response.
Assuntos
Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Proteína Estafilocócica A , Animais , Eritrócitos/imunologia , Imunoglobulina G/análise , Imunoglobulina M/análise , Camundongos , Camundongos Endogâmicos BALB C , Proteína Estafilocócica A/metabolismoRESUMO
The immunosuppressive potential of aflatoxin B1 (AFB1), the carcinogenic metabolite of Aspergillus flavus, was evaluated in growing rats. The weanling rats were subchronically exposed to 60, 300 and 600 micrograms AFB1/kg body weight for four weeks on alternate days by oral feeding. Various parameters of cell mediated immunity (CMI) and humoral immunity were assessed in control and treated animals. CMI was evaluated by measuring delayed type of hypersensitivity (DTH) response and humoral by plaque forming cell (PFC) assay. The lymphoproliferative response assay for T- and B-cells was also performed. It was observed that AFB1 selectively suppressed cell mediated immunity in growing rats. AFB1 suppressed CMI at the 300 and 600 micrograms dose levels only as measured by DTH response assay. It is concluded that continuous low level exposure of aflatoxin to growing host may enhance its susceptibility to infection and tumorigenesis.
Assuntos
Aflatoxina B1/toxicidade , Formação de Anticorpos/efeitos dos fármacos , Tolerância Imunológica/imunologia , Imunidade Celular/efeitos dos fármacos , Animais , Hipersensibilidade Tardia , Ativação Linfocitária/efeitos dos fármacos , Masculino , RatosRESUMO
Gestational exposure to 10 and 100 mg/kg body weight (m.b.w.) hexachlorocyclohexane throughout the gestation period was done to Swiss albino mice. HCH (alpha, beta and gamma isomers) residue analysis in pups showed a higher contamination in the lymphoid organs (Spleen, Thymus and Kidney) than liver in dose dependent manner. Immune functions of the offsprings of these dams along with the offsprings of vehicle treated or untreated control dams were assessed using selected parameters of both the cellular and humoral immune responses. The delayed hypersensitivity (DTH) response to sheep erythrocytes (SRBC) was significantly higher (p less than 0.01) in pups of the dams exposed to 10 mg/kg b.w. HCH and significantly impaired in pups of the dams exposed to 100 mg/kg m.b.w. HCH as compared to controls. Mitogenic responsiveness of the spleen cells in response to Concanavalin A (Con A) and Lipopolysaccharide (LPS) was almost two fold and eight fold higher respectively and antibody response to SRBC, as measured by plaque forming cells (PFC) assay was two fold higher (p less than 0.001) in pups exposed to 10 mg/kg HCH. However, 100 mg/kg m.b.w. HCH did not affect either mitogenic response or PFC response of the pups. The results, therefore, suggest that lower dose of HCH is capable of modulating the development and function of developing immune system possibly by modulating the functional organization of the T-cell populations.