Gas Exchanges and Dehydration in Different Intensities of Conditioning in Tifton 85 Bermudagrass: Nutritional Value during Hay Storage.

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.

Frequency of human papillomavirus types 16, 18, 31, and 33 and sites of cervical lesions in gynecological patients from Recife, Brazil.

Human papilloma virus (HPV) is a well-established cause of cervical cancer. While many studies have been performed so far on HPV viral biology, mode of infection and prevention measures, scanty information is available on lesion sites of infected women and the incidence of viral types at specific locations. We looked for a possible relationship between the most common viral types (HPVs 16, 18, 31, 33) found in Recife, PE, Brazil, and lesion sites. We examined 396 HPV-positive women at the Gynecological Unit of the IMIP at Recife; 288 women were positive for HPV 16, 18, 31, or 33, present as a single-virus type or as co-infection. HPV 16 was the most frequent virus type found in the vulva, vagina, uterine cervix-vagina, and uterine cervix. HPV 31 was the second prevalent virus type in vulva, vagina, uterine cervix-vagina, uterine cervix, and mole. HPVs 18 and 33 were present with similar frequencies in the mole-vulva region. Among the co-infections, HPV 16/18 and HPV16/31 were the most frequent in our study group, followed by HPV 16/33.

Degradation of Toluene from Gas Streams by Heterogeneous Fenton Oxidation in a Slurry Bubble Reactor with Activated Carbon-Based Catalysts.

A novel approach for the treatment of volatile organic compounds from gaseous streams was developed. In order to accomplish this, a semi-batch bubble reactor was used, aiming to assess the toluene (selected as model compound) degradation from gaseous streams via heterogeneous Fenton oxidation. Activated carbon-based catalysts-metal-free or iron-impregnated-with different textural and chemical surface properties were used for the first time as catalysts, in order to degrade gaseous toluene using such technology. Complementary characterization techniques, such as nitrogen adsorption at -196 °C, elemental analysis, pH at the point of zero charge (pHPZC), inductively coupled plasma optical emission spectrometry (ICP-OES) and transmission electron microscopy (TEM), were used. The materials' chemical surface properties, particularly the presence of N-surface groups, were herein found to play an important role in toluene adsorption and catalytic performance. The maximum amount of toluene transferred, 6.39 × 10-3 mol, was achieved using melamine-doped activated carbon (N-doped material) that was impregnated with iron (sample herein called ACM-Fe). This iron-based catalyst was found to be quite stable during three reutilization cycles.

Additional activation of the AR gene may be involved in the development of the castration resistance phenotype in prostate cancer.

INTRODUCTION: Several studies have already shown that changes in the AR gene may be associated with a more aggressive disease phenotype and even castration-resistant prostate cancer. Thus, we investigated cytogenetic and molecular alterations linked to AR. MATERIALS AND METHODS: To evaluate AR methylation, we performed a cytogenetic-molecular analysis using fluorescence in situ hybridization that uses specific probes for the AR gene (Xq11.12) and the X chromosome centromere. For AR activity, we performed a qualitative analysis of human androgen receptor activity. To analyze the expression of AR in PC3 and LNCaP cell lines, we used qPCR assays. RESULTS: In the qPCR assay, we found downregulation of AR in the PC3 cell line compared with the LNCaP. We found the presence of X chromosome polysomy in PC-3 and LNCaP cell lines by FISH assay. In the HUMARA-Q assay, we found two X chromosomes/cell and the activity of both AR in the PC-3 cell line. In LNCaP cells, we found two X chromosomes/cell and methylation of only one AR. CONCLUSION: Castration-resistant prostate cancer phenotype represents a significant challenge in the setting of urological management. The X chromosomes and AR-linked alterations may contribute to a better understanding of the disease. However, further studies should be performed in an attempt to elucidate as much as possible the role of AR in the castration-resistant prostate cancer phenotype.

Near-barrier fusion of the 8B + 58Ni proton-halo system.

Fusion cross sections were measured for the exotic proton-halo nucleus 8B incident on a 58Ni target at several energies near the Coulomb barrier. This is the first experiment to report on the fusion of a proton-halo nucleus. The resulting excitation function shows a striking enhancement with respect to expectations for normal projectiles. Evidence is presented that the sum of the fusion and breakup yields saturates the total reaction cross section.

An intranasal administration of Lactococcus lactis strains expressing recombinant interleukin-10 modulates acute allergic airway inflammation in a murine model.

BACKGROUND: Around 300 million people world-wide suffer from asthma, and the prevalence of allergic diseases has increased. Much effort has been used in the study of mechanisms involved in the immune response observed in asthma to intervene for the treatment of this condition. During inflammation in asthma, Th2 cytokines and eosinophils are essential components of the host immune system. Furthermore, for therapeutic interventions against this disease, IL-10 is an important cytokine because it has a central role in the regulation of inflammatory cascades. OBJECTIVE: To evaluate the immunomodulatory effect of Lactococcus lactis strains expressing recombinant IL-10 in a mouse model of ovalbumin (OVA)-induced acute airway inflammation. METHODS: L. lactis expressing recombinant IL-10 in a cytoplasmic (LL-CYT) or secreted form (LL-SEC) and wild-type (LL-WT) were used. IL-10 production by the recombinant strains was evaluated by ELISA. After an intranasal administration of L. lactis producing recombinant IL-10 and the induction of acute allergic airway inflammation in mice, blood samples were collected to detect IgE anti-OVA, and bronchoalveolar lavage (BAL) was harvested for eosinophil count. Additionally, the lungs were collected for the detection of the eosinophil peroxidase (EPO) activity, measurement of cytokines and chemokines and evaluation of pathology. RESULTS: Mice that received LL-CYT and LL-SEC strains showed a significant decrease in eosinophils numbers, EPO activity, anti-OVA IgE and IgG1 levels, IL-4 and CCL3 production and pulmonary inflammation and mucus hypersecretion, compared with the asthmatic group. Only the LL-CYT/OVA group showed reduced levels of IL-5, CCL2, CCL5 and CCL11. CONCLUSION: Treatment with L. lactis producing recombinant IL-10 used in this study (LL-CYT and LL-SEC) modulated experimental airway inflammation in the mouse model independently of Treg cells. Additionally, the LL-CYT strain was more efficient in the suppression of lung inflammation.

Sensitivity to antifungals by Candida spp samples isolated from cases of chronic atrophic candidiasis (CAC).

The treatment of choice for chronic atrophic candidiasis (CAC), also known as denture stomatitis, is topical antifungal therapy. This study aimed to isolate, identify, and assess the antifungal susceptibility of Candida species from mucosal sites in denture wearers with a diagnosis of CAC and determine the prevalence of associated variables. The sample consisted of 44 patients wearing complete or partial dentures who had a clinical diagnosis of CAC. Using sterile cotton swabs, specimens were collected from the oral mucosa of all patients and grown at 30ºC for 48 h in CHROMagar Candida, as a means of isolating and screening the species. The complementary identification of the species was performed using the VITEK 2 automated system (BioMérieux), as well as the determination of their susceptibility to antifungal agents. Data were analyzed using the chi-square test. STATA 13.1 was used for statistical analysis (α = 5%). Of 44 patients with CAC, 33 (75%) had lesions classified as Newton type II. Yeasts were isolated in 38 cases. The most prevalent species was Candida albicans. None of the isolates were resistant to the antifungals tested. Our findings suggest that current indications for antifungal agents are appropriate. Also, antifungal susceptibility testing and proper fungal identification can help dentists to determine the optimal course of treatment for CAC.

HPV31 and HPV33 incidence in cervical samples from women in Recife, Brazil.

Human papillomavirus (HPV) has been extensively studied concerning genomic structure, infection mechanisms, and diversity of types, as well as disease progression stages and development of vaccines. HPV type prevalence can differ in specific populations in different countries, according to ethnicity. This is the first report of an integrated project to evaluate the incidence of HPV types in different regions in Brazil in order to obtain data for vaccine development. Cervical samples were collected from women seen at a public hospital in Pernambuco, Northeast Brazil, for routine evaluation of genital alterations. Selection of the patients was random. There was a strong prevalence of HPV16 and a high incidence of HPV types 31 and 33. These data foster the discussion about the need to evaluate viral prevalence in each geographic region in order to develop targeted vaccine programs.

Papel de la activación adicional del gen RA en el desarrollo del fenotipo resistente a la castración en el cáncer de próstata / Additional activation of the AR gene may be involved in the development of the castration resistance phenotype in prostate cancer

Introducción Diversos estudios han demostrado que los cambios en el gen RA pueden estar asociados a un fenotipo de enfermedad más agresivo e incluso al cáncer de próstata resistente a la castración. Por este motivo, hemos investigado las alteraciones citogénicas y moleculares asociadas al RA.Materiales y métodos Para evaluar la metilación del RA, realizamos un análisis citogenético-molecular mediante hibridación fluorescente in situ que utiliza sondas específicas para el gen del RA (Xq11.12) y el centrómero del cromosoma X. Respecto a la actividad del RA, realizamos un análisis cualitativo de la actividad del receptor de andrógenos humano. Para analizar la expresión del RA en las líneas celulares PC3 y LNCaP, utilizamos ensayos de qPCR.ResultadosEn el ensayo qPCR, encontramos una regulación a la baja del RA en la línea celular PC3 en comparación con la LNCaP. Hallamos la presencia de polisomía del cromosoma X en las líneas celulares PC-3 y LNCaP mediante el ensayo FISH. En el ensayo HUMARA-Q encontramos la presencia de dos cromosomas X/célula y actividad en ambos RA de la línea celular PC-3. En las células LNCaP hallamos la presencia de dos cromosomas X/célula y la metilación de solo un RA.Conclusión El fenotipo del cáncer de próstata resistente a la castración representa un gran desafio en el tratamiento urológico. Estos cromosomas X y las alteraciones ligadas al RA pueden contribuir a una mejor comprensión de la enfermedad; sin embargo, deben realizarse más estudios para arrojar más luz sobre el papel del RA en el fenotipo del cáncer de próstata resistente a la castración (AU)

Introduction Several studies have already shown that changes in the AR gene may be associated with a more aggressive disease phenotype and even castration-resistant prostate cancer. Thus, we investigated cytogenetic and molecular alterations linked to AR.Materials and methods To evaluate AR methylation, we performed a cytogenetic-molecular analysis using fluorescence in situ hybridization that uses specific probes for the AR gene (Xq11.12) and the X chromosome centromere. For AR activity, we performed a qualitative analysis of human androgen receptor activity. To analyze the expression of AR in PC3 and LNCaP cell lines, we used qPCR assays.ResultsIn the qPCR assay, we found downregulation of AR in the PC3 cell line compared with the LNCaP. We found the presence of X chromosome polysomy in PC-3 and LNCaP cell lines by FISH assay. In the HUMARA-Q assay, we found two X chromosomes/cell and the activity of both AR in the PC-3 cell line. In LNCaP cells, we found two X chromosomes/cell and methylation of only one AR.Conclusion Castration-resistant prostate cancer phenotype represents a significant challenge in the setting of urological management. The X chromosomes and AR-linked alterations may contribute to a better understanding of the disease. However, further studies should be performed in an attempt to elucidate as much as possible the role of AR in the castration-resistant prostate cancer phenotype (AU)

Ovarian function after radioiodine therapy in patients with thyroid cancer.

OBJECTIVE: To assess ovarian function in young women treated with radioiodine. METHODS: The study was conducted on 50 women with thyroid carcinoma aged less than 40 years (mean, 29.8 years), with regular menstrual cycles and normal FSH levels prior to radioiodine therapy. FSH determination was repeated 6 and 12 months after radioiodine therapy (mean, 4.24 GBq iodine-131) and menstrual cycles were monitored during this period. RESULTS: Twenty percent of the patients reported amenorrhea during the first year. FSH levels increased after 6 months (from 5.1 +/- 1.8 to 10.6 +/- 2.2 IU/l, p < 0.00 001) and 28 % of the patients showed elevated values, which had returned to normal by the end of the first year. CONCLUSION: Radioiodine causes transitory alterations in ovarian function even in younger women and after a mean activity of 4.2 GBq (115 mCi).

Resource availability and diet in Harpy Eagle breeding territories on the Xingu River, Brazilian Amazon.

In the Tapajos-Xingu interfluve, one of the largest birds of prey, the Harpy Eagle, is under intense anthropogenic pressure due to historical and recent reductions in forest cover. We studied prey availability and use by Harpy Eagle on six breeding territories on the low- and mid-Xingu River, between 2013 and 2015. We evaluated food resource availability using the environmental-surveys database from two methods: terrestrial surveys (RAPELD method) and fauna rescue/flushing before vegetation suppression for the Belo Monte Hydroelectric Complex construction. Harpy Eagle diet was identified by prey remains sampled around six nest trees. Eighteen species of mammals, birds and reptiles comprised the prey items. Most prey species were sloths, primates and porcupines, which have arboreal habits and are found in forested areas, but two species, hoatzin and iguana, are usually associated with riverine habitats. The proportion of prey from each species predated on the nest best studied was different from estimated availability (χ2 = 54.23; df = 16; p < 0.001), however there was a positive correlation (rs = 0.7; p < 0.01) between prey species consumed and abundance available, where the predation was more on species more abundant. Continuous monitoring of the Harpy Eagle diet at these nests could evidence changes in the assemblage of prey species available for Harpy Eagles, due to changes in the seasonal flood pulse of the Xingu River to be caused by the operation of the hydroelectric dam, and changes in habitat features by forest reduction around breeding territories. We believe that it is important to consider the protection of remnants of forested areas in the landscape matrix surrounding the breeding territories to maintain the food resource availability and allow all pairs to successfully reproduce.

Sensitivity to antifungals by Candida spp samples isolated from cases of chronic atrophic candidiasis (CAC) / Sensibilidade a antifúngicos por amostras de Candida spp isoladas de casos de candidíase atrófica crônica (CAC)

Abstract The treatment of choice for chronic atrophic candidiasis (CAC), also known as denture stomatitis, is topical antifungal therapy. This study aimed to isolate, identify, and assess the antifungal susceptibility of Candida species from mucosal sites in denture wearers with a diagnosis of CAC and determine the prevalence of associated variables. The sample consisted of 44 patients wearing complete or partial dentures who had a clinical diagnosis of CAC. Using sterile cotton swabs, specimens were collected from the oral mucosa of all patients and grown at 30ºC for 48 h in CHROMagar Candida, as a means of isolating and screening the species. The complementary identification of the species was performed using the VITEK 2 automated system (BioMérieux), as well as the determination of their susceptibility to antifungal agents. Data were analyzed using the chi-square test. STATA 13.1 was used for statistical analysis (α = 5%). Of 44 patients with CAC, 33 (75%) had lesions classified as Newton type II. Yeasts were isolated in 38 cases. The most prevalent species was Candida albicans. None of the isolates were resistant to the antifungals tested. Our findings suggest that current indications for antifungal agents are appropriate. Also, antifungal susceptibility testing and proper fungal identification can help dentists to determine the optimal course of treatment for CAC.

Resumo O tratamento de escolha para candidíase atrófica crônica (CAC), também conhecida como estomatite protética, é a terapia antifúngica tópica. Este estudo teve como objetivo isolar, identificar e avaliar a susceptibilidade antifúngica de espécies de Candida de locais mucosos em portadores de prótese com diagnóstico de CAC e determinar a prevalência de variáveis associadas. A amostra consistiu em 44 pacientes portadores de próteses completas ou parciais que tiveram um diagnóstico clínico de CAC. Usando swab estéril, foram coletados espécimes da mucosa oral de todos os pacientes e cultivados a 30ºC durante 48 h em CHROMagar Candida, como forma de isolamento e triagem das espécies. A identificação complementar das espécies foi realizada no sistema automatizado VITEK 2 (BioMérieux), bem como a determinação da susceptibilidade delas a agentes antifúngicos. Os dados foram analisados usando o teste do qui-quadrado. O STATA 13.1 foi utilizado para análise estatística (α = 5%). Dos 44 pacientes com CAC, 33 (75%) apresentaram lesões classificadas como Newton tipo II. As leveduras foram isoladas em 38 casos. A espécie mais prevalente foi Candida albicans. Nenhum dos isolados foi resistente aos antifúngicos testados. Nossas descobertas sugerem que as indicações atuais para os agentes antifúngicos são apropriadas. Além disso, testes de susceptibilidade antifúngicos e identificação fúngica adequada podem ajudar os dentistas a determinar o curso ótimo de tratamento para CAC.

Contributions to the knowledge of amphibians and reptiles from Volta Grande do Xingu, northern Brazil.

The region of Volta Grande do Xingu River, in the state of Pará, presents several kinds of land use ranging from extensive cattle farming to agroforestry, and deforestation. Currently, the Belo Monte Hydroelectric Power Plant affects the region. We present a checklist of amphibians and reptiles of the region and discuss information regarding the spatial distribution of the assemblies based on results of Environmental Programmes conducted in the area. We listed 109 amphibian (Anura, Caudata, and Gymnophiona) and 150 reptile (Squamata, Testudines, and Crocodylia) species. The regional species richness is still considered underestimated, considering the taxonomic uncertainty, complexity and cryptic diversity of various species, as observed in other regions of the Amazon biome. Efforts for scientific collection and studies related to integrative taxonomy are needed to elucidate uncertainties and increase levels of knowledge of the local diversity.

What is organ donation and transplantation? Educating through the doubt.

BACKGROUND: Organ transplantation in Brazil is increasing, but one of its current obstacles is the negative response of the population to organ donation. Therefore, to make the process viable, it is essential that people are educated in organ donation and transplantation. The purpose of this research was to evaluate the main doubts on this subject and to clarify these issues by educating the respondents on the basis of their questions. METHODS: Handout questionnaires about organ donation and transplantation were distributed in public schools. The public targets were parents, teachers, and students. The interviewers were trained medical students. RESULTS: In this pilot study with 293 subjects, 97% of respondents had already heard about organ donation; 81% said they would donate their organs, whereas 76% said they would donate the organs of family members and 78% said they believe in the existence of organ trafficking in Brazil. CONCLUSIONS: The high percentage of respondents believing in the existence of an organ trade highlights the urgency in clarifying this topic. To do so, the population must be educated about the ethics of the process of donation, emphasizing the fact that there is no organ trade in Brazil.

Abundance of Harpy and Crested Eagles from a reservoir-impact area in the Low- and Mid-Xingu River.

In the Brazilian Amazon, two monospecific genera, the Harpy Eagle and Crested Eagle have low densities and are classified by IUCN as Near Threatened due to habitat loss, deforestation, habitat degradation and hunting. In this study, we evaluate occurrence of these large raptors using the environmental surveys database from Belo Monte Hydroelectric Power Plant. Integrating the dataset from two methods, we plotted a distribution map along the Xingu River, including records over a 276-km stretch of river. Terrestrial surveys (RAPELD method) were more efficient for detecting large raptors than standardized aquatic surveys, although the latter were complementary in areas without modules. About 53% of the records were obtained during activities of wildlife rescue/flushing, vegetation suppression or in transit. Between 2012 and 2014, four Harpy Eagles were removed from the wild; two shooting victims, one injured by collision with power lines and one hit by a vehicle. Also, seven nests were mapped. The mean distance between Harpy Eagle records was 15 km along the river channel, with a mean of 20 km between nests near the channel, which allowed us to estimate 20 possible pairs using the alluvial forest, riverine forest and forest fragments. Territories of another ten pairs will probably be affected by inundation of the Volta Grande channel, which is far from the main river. The average distance between Crested Eagle records was 16 km along the river channel. The only nest found was 1.3 km away from a Harpy Eagle nest. The remnant forests are under threat of being replaced by cattle pastures, so we recommend that permanently protected riparian vegetation borders (APP) be guaranteed, and that forest fragments within 5 km of the river be conserved to maintain eagle populations.

Production of thyroid-stimulating antibodies in mice by immunization with T-cell epitopes of human thyrotropin receptor.

We examined whether mice, immunized with TSH receptor (TSH-R) peptides, which are known to be T-cell epitopes in patients with Graves' disease, would show thyroid-stimulating antibody (TSAb). We immunized DBA/1J mice with TSH-R peptide amino acids 132-150, 145-163, 158-176, and 172-186 and with a pool of these four peptides. The antibodies produced in these mice were evaluated by measurement of TSAb activity using Chinese hamster ovary cells expressing human TSH-R. Seven of 20 mice showed TSAb activity that could be partially blocked with TSH-R peptides. To assess the role of T-cell epitope-specific T-cells in the production of TSAb, we transferred a T-cell line developed from a TSAb-positive mouse to other syngeneic DBA/1J mice. Two of 4 recipient mice showed TSAb activities. These findings suggest that specific T-cell epitopes of TSH-R play a crucial role in the production of TSAb.

Suppression of development of experimental autoimmune thyroiditis by oral administration of thyroglobulin.

Experimental autoimmune thyroiditis (EAT), which to some extent represents an experimental model of human chronic lymphocytic thyroiditis, is an organ-specific autoimmune disease characterized by autoantibody production to thyroid antigens (Ag) and mononuclear infiltration of the thyroid gland. EAT induced by immunization with human thyroglobulin (hTG) with Freund's adjuvant in CBA/J (H-2K) mice is associated with prominent B and T cell responses. We report that oral administration of hTG effectively reduces the immune responses in EAT in mice in an Ag-specific manner. Both cellular and humoral immune responses are reduced in a dose-dependent manner. Histological evidence of disease is dramatically reduced. Suppression of the immune responses is seen 2 weeks after Ag challenge, with partial inhibition of proliferative and antibody responses. Six weeks after immunization, further inhibition is observed of both T and B cell responses. Hyporesponsiveness of T and B cell reactivity is seen only to hTG; T and B cell responses to other immunogens are not affected, including purified protein derivative and the nonrelated Ag BSA. This model may provide the basis for immunotherapy of autoimmune thyroid diseases in man.

Immunosuppression of thyroiditis.

Immunization of mice with 50 micrograms human thyroglobulin (TG) in complete Freund's adjuvant leads to histological thyroiditis; production of IgG, IgA, and IgM anti-TG antibodies; and in vitro proliferative responses after incubation of lymphocytes with TG. Oral administration of 500 micrograms TG at four intervals before Tg immunization and once afterward causes up to 80% suppression of these responses. The effect is antigen specific and dose dependent. Feeding TG after immunization produces a 40% reduction in responses. We wished to define the mechanism of this antigen-specific oral tolerization. Popliteal lymph nodes (PLN) of orally tolerized animals (T) are reduced in size compared to those in immunized (I) animals not fed TG. PLN and mesenteric lymph nodes (MLN) of I animals produce interleukin-2 (IL-2) and interferon-gamma (IFN gamma) after in vitro incubation with TG, typical of an inflammatory immune response. PLN and MLN of tolerized animals do not proliferate in response to antigen, do not produce IL-2 or IFN gamma, but do not produce the cytokines IL-4 and transforming growth factor-beta (TGF beta). Mixing in vitro of spleen cells from T and I animals causes a reduction in the immune response when incubated with TG, but no reduction in response to purified protein derivative (PPD) (the antigen in complete Freund's adjuvant). When T splenocytes are incubated with TG and PPD together, the response to TG and PPD is suppressed. Partially purified CD8+ cells from tolerized animals produce IL-4 and TGF beta after exposure to human TG and induce suppression, whereas partially purified CD4+ cells produce IL-2 and IFN gamma and do not cause suppression. MLN cells do not proliferate in response to antigen, but do produce inhibitory cytokines. T animals appear to shift the immune response from a Th-1 helper cell subset response to a Th-2 helper cell immunosuppressive response. In this model, oral tolerization produces a dramatic reduction in the immune response. Exposure of MLN to oral TG appears to cause the production of regulatory cells that migrate to spleen and PLN. In vitro studies demonstrate that on exposure to antigen, these regulatory cells produce IL-4 and TGF beta, which suppress all aspects of specific immune responsiveness and nonspecifically suppress other ongoing immune responses (bystander effect). Oral tolerization may include some element of T cell deletion or anergy. This model defines an experimental system with possible relevance to immunosuppression of human autoimmune thyroid disease.

CTLA-4 gene polymorphism associated with Graves' disease in a Caucasian population.

Graves' disease (GD) is an autoimmune thyroid disease. Multiple genetic factors are believed to be involved in its pathogenesis, but the factors are largely unknown, except for sex (female disease preponderance) and the role of human leukocyte antigen (HLA) genes on chromosome 6. To understand the mechanisms underlying the development of GD, a search for non-HLA-linked genes is crucial, and we tested several candidate genes, including the CTLA-4 gene on chromosome 2q33. CTLA-4 molecules may either facilitate or down-regulate the second signal to T-cells, which is provided by the interaction between the two accessory molecules CD28 and B7. One hundred and thirty-three Caucasian patients (26 males) with GD and 85 local controls were included in this study. Polymerase chain reaction was used to amplify DNA containing the (AT)n repeat within the 3'-untranslated region of exon 3 of the CTLA-4 gene. The 5'-forward primer was radiolabeled, and amplified products were resolved on 5-7% sequencing gels. All subjects were previously typed for HLA class II alleles. Twenty-one alleles were observed with sizes ranging from 88-134 basepairs. In the association analysis, the genotype frequencies between GD patients and controls differed significantly (P = 0.012), and the difference was attributable to a higher frequency of the 106-basepair allele among patients (relative risk, 2.82). When the patients were subdivided with respect to sex and HLA, the phenotype frequencies of allele 106 was higher in the female patients with protective HLA specificities (DQA1*0201 positive/DQA1*0501 negative) than in those with susceptible HLA specificities (DQA1*0201 negative/DQA1*0501 positive; 81.8% vs. 45.5%; P = 0.026). The CTLA-4 gene or a closely associated gene (including CD28) confers susceptibility to GD. This association may be more important in female patients with protective HLA specificities, who otherwise would be at low risk of developing the disease.

Graves' disease in severe combined immunodeficient mice.

Graves' disease (GD) is an autoimmune thyroid disorder involving an antibody (TSAb) directed against the TSH receptor (TSHR) producing thyroid stimulation. We have developed an animal model of GD by engrafting peripheral blood mononuclear cells or T cell lines plus autologous thyroid tissue into severe combined immunodeficient (SCID) mice. We xenografted Graves' thyroid tissue from six patients into six groups of SCID mice. Autologous PBMC and T cell lines reactive to recombinant human TSHR extracellular domain and non-TSHR lines were injected ip into the designated groups. In some of the studies, thyroid tissue was irradiated with 2000 rads before xenografting. Irradiation of xenografts induced thyroid tissue damage and release of thyroid antigens and hormones. Mice reconstituted with peripheral blood mononuclear cells or nonspecific T cell lines did not simulate GD. However, we achieved production of TSAb, elevation of serum T3, and TSAb-dependent survival and function of human Graves' thyroid tissue in SCID mice reconstituted with TSHR-specific T cell lines. We reconstituted SCID mice with PBMC and TSHR-specific T cell lines that recognized TSHR peptide 158-176. This may be in vivo evidence of the importance of peptide 158-176 as an immunodominant epitope on the TSHR extracellular domain.