Non-malignant silica-related diseases in a specialized outpatient clinic.

BACKGROUND: Uncontrolled occupational exposure to silica is still frequent in Brazil, with several recent records in the state of Minas Gerais. However, few national studies have addressed silica-related diseases other than silicosis. AIMS: To describe the occurrence of the main non-malignant silica-related diseases: silicosis, tuberculosis (TB), chronic obstructive pulmonary disease (COPD), and autoimmune diseases in a specialized outpatient clinic. METHODS: Case series study of 1525 patients exposed to silica, seen between 1984 and 2021, with descriptive findings of clinical and occupational data from the first medical evaluation. RESULTS: Medians of age and exposure time were 47 and 15 years, respectively, and 97% of patients were male. The prevalence of silicosis was 44%, of which 27% had large opacities. The main occupational sectors were underground gold mining (28%), precious and semi-precious stone work (20%), and artisanal mining (9%). Spirometries were abnormal in 55%, with obstructive disorder being the most common finding. COPD (25%), active TB or sequelae (12%), and connective tissue diseases (6%) were diagnosed in patients with and without silicosis. CONCLUSIONS: The percentage of silicosis appears to be alarming, even considering the biases of selective referrals. The patients were relatively young and already had a functional impact, caused not only by silicosis but by one or more silica-related diseases. COPD, TB, and connective tissue diseases proved to be frequent, leading to the need for specifics protocols to investigate them in individuals exposed to silica. By adopting strategies to combat silicosis, the prevention of other silica-related diseases is concomitantly promoted.

Metal and physico-chemical variations at a hydroelectric reservoir analyzed by Multivariate Analyses and Artificial Neural Networks: environmental management and policy/decision-making tools.

This paper compared and evaluated seasonal variations in physico-chemical parameters and metals at a hydroelectric power station reservoir by applying Multivariate Analyses and Artificial Neural Networks (ANN) statistical techniques. A Factor Analysis was used to reduce the number of variables: the first factor was composed of elements Ca, K, Mg and Na, and the second by Chemical Oxygen Demand. The ANN showed 100% correct classifications in training and validation samples. Physico-chemical analyses showed that water pH values were not statistically different between the dry and rainy seasons, while temperature, conductivity, alkalinity, ammonia and DO were higher in the dry period. TSS, hardness and COD, on the other hand, were higher during the rainy season. The statistical analyses showed that Ca, K, Mg and Na are directly connected to the Chemical Oxygen Demand, which indicates a possibility of their input into the reservoir system by domestic sewage and agricultural run-offs. These statistical applications, thus, are also relevant in cases of environmental management and policy decision-making processes, to identify which factors should be further studied and/or modified to recover degraded or contaminated water bodies.

Effect of chemotherapy with praziquantel on the production of cytokines and morbidity associated with schistosomiasis mansoni.

The objective of the present study was to test the hypothesis that treatment of schistosomiasis mansoni with praziquantel can alter significantly the immune response of patients and generate a reversal of the level of fibrosis. Peripheral blood mononuclear cell (PBMC) samples were collected from, and abdominal ultrasound examinations conducted on, volunteers infected with Schistosoma mansoni and living in an area where the disease is endemic, both prior to and one year after treatment with praziquantel. Subjects were classified into groups according to the level of pathology (i.e., absent, incipient, moderate, or severe fibrosis). PBMCs were stimulated with schistosome soluble egg antigens (SEA), and the levels of production of the cytokines gamma interferon (IFN-gamma), tumor necrosis factor alpha, transforming growth factor beta, and interleukin-4 (IL-4), IL-10, and IL-13 were determined. The chemotherapy was effective in reducing morbidity, particularly for individuals presenting with severe fibrosis. When levels of cytokine production in posttreatment PBMC cultures stimulated by SEA were categorized as low or high, significant differences in the distribution of IL-13 levels between groups presenting with or not presenting with fibrosis were established. Comparison of pre- and posttreatment SEA-induced cytokine levels in individuals who had experienced no change in the grade of fibrosis following chemotherapy revealed that the level of IFN-gamma decreased in subjects with fibrosis whereas that of IL-10 decreased in individuals with and without fibrosis. The data suggest that chemotherapy is effective in reducing the morbidity of the disease and that the level of IL-13 may be a useful indicator of the persistence of fibrosis following treatment.

Cytokine production associated with periportal fibrosis during chronic schistosomiasis mansoni in humans.

Volunteers living in an area where schistosomiasis mansoni is endemic were subjected to ultrasound examination and classified into groups according to the levels of fibrosis diagnosed, namely, absence of indications of fibrosis (group 0), incipient fibrosis (group 1), and moderate/severe fibrosis (group 2). Peripheral blood mononuclear cells (PBMC) collected from the volunteers were stimulated with soluble antigens from adult schistosomes or from schistosome eggs, and the production of the cytokines gamma interferon, tumor necrosis factor alpha, transforming growth factor beta (TGF-beta), interleukin-4 (IL-4), IL-10, and IL-13 was determined. Potential associations of the level of fibrosis with age, sex, intensity of infection, and cytokine production were investigated between the three groups. Univariate analysis identified associations of age (>50), gender (male), and absence of eggs/g of feces with moderate/severe fibrosis and an association of intensity of infection (>100 eggs) with incipient fibrosis. When cytokine production in PBMC cultures stimulated by soluble egg antigens was categorized as low or high, significant differences in the distribution of IL-13 levels were established between groups 0 and 2. No significant differences were detected between the groups in the cytokines produced by PBMC cultures stimulated with soluble antigens from adult schistosomes. When all variables were tested in multivariate analyses, only IL-13 was strongly associated with fibrosis (odds ratio = 5.8; 95% confidence interval [CI] = 1.1 to 30.5). While high levels of TGF-beta appeared to be associated with protection against fibrosis, the strength of the association was low.

[Use of cyclodextrins in the formulation of polyalkylcyanoacrylate nanoparticles charged with different active ingredients]. / Emploi des cyclodextrines dans la formulation de nanoparticules de poly(cyanoacrylate d'alkyle) chargées en divers principes actifs.

Cyclodextrins were used to improve the loading capacity of biodegradable pol(yisobutyl cyanoacrylat)e nanoparticles, which were obtained by anionic polymerization in aqueous medium. We investigated the feasibility of blank nanoparticles in the presence of a series of cyclodextrins (5 mg/ml) and poloxamer 188 (1%). The smaller particles (87 +/- 3 to 103 +/- 6 nm) were obtained in the presence of hydroxypropyl beta- or gamma-cyclodextrin. The nanoparticle loading capacity investigated in the presence of hydroxypropyl beta-cyclodextrin, in the previous conditions, on a series of steroids revealed an increase varying from 5.5 times (megestrol acetate) to 130 times (prednisolone). Differential scanning calorimetry study of the active ingredient (progesterone) in the nanoparticles, revealed an amorphous or molecular state. The in vitro release of the active ingredient occurred very rapidly but reached a plateau depending on the nanoparticle size and the dissolution medium nature. All the active ingredient was released in the presence of esterases. The addition of a preformed hydroxypropyl beta-cyclodextrin/saquinavir inclusion compound to the preparation medium of poly(isobutyl [or] isohexyl cyanoacrylate) nanoparticles, resulted in a 20-fold increase in the encapsulation yield. Presently, poly(isobutyl cyanoacrylate) hydroxypropyl beta-cyclodextrin combined nanoparticles loaded with doxorubicin are in phase II clinical trials.

Apoptosis: a mechanism of immunoregulation during human Schistosomiasis mansoni.

People infected with schistosomes may present with a variety of clinical manifestations ranging from the relatively asymptomatic intestinal (INT) form to the hepatointestinal (HI) or hepatosplenic (HS) forms characterized by hepatomegaly and hepatosplenomegaly with severe portal hypertension, respectively. Flow cytometry analyses were used to evaluate the contribution of apoptosis in specific cell populations from schistosomiasis patients to the development of the different clinical forms of the disease. The results showed that cell death induced by combinations of specific antigen and cytokines corresponds with specific clinical presentations. It was shown that soluble egg antigen (SEA) increased the level of apoptosis only in T cells from INT patients. Stimulation with soluble lung worm antigen preparation (SLAP) did not induce significant differences in the levels of apoptosis in T cells from the patients with the different clinical forms of schistosomiasis. These results suggest for the first time that apoptosis plays an important role in the modulation of the anti-SEA response in INT patients.

Familial resemblance in humoral immune response to defined and crude Schistosoma mansoni antigens in an endemic area in Brazil.

This study addressed whether the humoral immune response to crude and defined Schistosoma mansoni antigens aggregates within families. The sample included 155 siblings from 42 nuclear families in Brazil. Sera examined by ELISA for antibody isotypes reactive to defined schistosome antigens and crude schistosome antigens (soluble adult worm antigen preparation and soluble egg antigen) demonstrated that there was a difference in sibling-pair correlations between defined and crude S. mansoni antigens. In contrast to the finding with crude antigens, egg-positive sibling pairs showed significant familial resemblance for all IgG subclasses and IgE to adult-stage antigens Smp20.8 and Smp50. Only the IgE and IgG4 isotypes showed familial resemblance to the egg-stage antigen, Smp40. Egg-negative sibling pairs showed significant familial resemblance only for IgE and IgG4 to Smp40. That both the IgE and IgG4 response to defined S. mansoni antigens showed familial resemblance is interesting in light of the converging evidence for the role of IgE and IgG4 in human susceptibility and resistance to reinfection.

Clinical forms of human Schistosoma mansoni infection are associated with differential activation of T-cell subsets and costimulatory molecules.

The current study has compared the activation status and the expression of the CD28 molecule on circulating CD4+ and CD8+ lymphocytes from patients with different clinical forms of schistosomiasis. The data show that patients with acute schistosomiasis have an increase on the mean percentage of CD4+ HLA-DR+ cells, whereas chronic asymptomatic patients exhibit an increased mean percentage of CD8+ HLA-DR+ cells. Patients with the hepatosplenic disease showed an increase in both CD4+ HLA-DR+ and CD8+ HLA-DR+ cells. Despite the high levels of CD8+ HLA-DR+ cells in hepatosplenic patients, they presented a decreased ratio of CD8+ CD28+/CD8+ cells. These findings of a different percentage of circulating CD8+ CD28+ cells might explain the different in vitro cellular reactivity of asymptomatic and hepatosplenic patients and the defects in the cytokine secretion patterns reported in individuals with hepatosplenic schistosomiasis.

Human Schistosomiasis mansoni: IL-10 modulates the in vitro granuloma formation.

Granuloma formation and modulation around Schistosoma mansoni eggs that are trapped in host tissues play a pivotal role during schistosomiasis. It has been demonstrated that the granuloma reactions differ in patients with the different clinical forms of the disease. The pathology during murine schistosomiasis has been correlated with a Th2 response while resistance to infection with a Th1 type response. In humans, very little is known about the role of different cytokines on the development of the disease. Here we demonstrate that IL-10 is an important cytokine regulating the in vitro granulomatous reactivity of PBMC from intestinal (INT) patients. This was evidenced by the fact that blockage of this cytokine in the in vitro granuloma assay lead to a significant increase in granuloma size with cells from INT patients but not with individuals in the acute phase or with the hepatosplenic (HS) form of schistosomiasis. These results demonstrate for the first time that, in context with the model, a Th2 cytokine in human schistosomiasis plays an important role in controlling morbidity.

Cytokines as determinants of resistance and pathology in human Schistosoma mansoni infection.

The role of different cytokines in the peripheral blood mononuclear cell (PBMC) proliferative response and in in vitro granuloma formation was evaluated in a cross-sectional study with patients with the different clinical forms and phases of Schistosoma mansoni infection, as well as a group of individuals "naturally" resistant to infection named normal endemic (NE). The blockage of IL-4 and IL-5 using anti-IL-4 and anti-IL-5 antibodies significantly reduced the PBMC proliferative response to soluble egg (SEA) and adult worm (SWAP) antigens in acute (ACT), chronic intestinal (INT) and hepatosplenic (HS) patients. Similar results were obtained in the in vitro granuloma formation. Blockage of IL-10 had no significant effect on either assay using PBMC from ACT or HS. In contrast, the addition of anti-IL-10 antibodies to PBMC cultures from INT patients significantly increased the proliferative response to SEA and SWAP as well as the in vitro granuloma formation. Interestingly, association of anti-IL-4 and anti-IL-10 antibodies did not increase the PBMC proliferative response of these patients, suggesting that IL-10 may act by modulating IL-4 and IL-5 secretion. Addition of recombinant IL-10 decreased the proliferative response to undetectable levels when PBMC from patients with the different clinical forms were used. Analysis of IFN-gamma in the supernatants showed that PBMC from INT patients secreted low levels of IFN-gamma upon antigenic stimulation. In contrast, PBMC from NE secreted high levels of IFN-gamma. These data suggest that IL-10 is an important cytokine in regulating the immune response and possibly controlling morbidity in human schistosomiasis mansoni, and that the production of IFN-gamma may be associated with resistance to infection.

A meta-analysis of mandibular intercanine width in treatment and postretention.

The meta-analysis technique of literature review was applied to a total of 26 previous studies to assess the longitudinal stability of postretention mandibular intercanine width. Weighted averages and standard deviations for the means of 1,233 subjects were compared for linear changes in intercanine transverse dimensions during treatment (T1), immediately after treatment (T2), and after removal of all retention (T3). Net change was defined as the difference between means at T3 and T1. Dimensional changes were also evaluated on the basis of patient pretreatment Angle classification, extraction, and nonextraction treatment modalities of each group. Paired two-tail t-tests were performed between T3 and T1 means on all groups at the a priori level of significance set at a < or = 0.05. Statistically significant differences were observed for the following groups: all patients; nonextraction; extraction; Class I; Class I extraction; Class II extraction; and, Class I Division 1 nonextraction. The findings of this study indicate that regardless of patient diagnostic and treatment modalities, mandibular intercanine width tends to expand during treatment on the order of one to two millimeters, and to contract postretention to approximately the original dimension. While statistically significant differences could be demonstrated within various groups, the magnitudes of the differences were not considered clinically important.

Cytokines as determinants of resistance and pathology in human Schistosoma mansoni infection

The role of diferent cytokines in the peripheral blood mononuclear cell (PBMC) proliferative response and in in vitro granuloma formation was evaluated in a cross-sectional study with patients with the different clinical forms and phases of Schistosoma mansoni infection, as well as a group of individuals "naturally" resistant to infection named normal endemic (NE). The blockage of IL-4 and IL-5 using anti-IL-4 and anti-IL-5 antibodies significantly reduced the PBMC proliferative response to soluble egg (SEA) and adult worm (SWAP) antigens in acute (ACT), chronic intestinal (INT) and hepatosplenic (HS) patients. Similar esults were obtained in the in vitro granuloma formation. Blockage of IL-10 had no significant effect on either assay using PBMC from ACT or HS. In contrast, the addition of anti-IL-10 antibodies to PBMC cultures from INT patients significantly increased the proliferative response to SEA and SWAP as well as the in vitro granuloma formation. Interestingly, association of anti-IL-4 and anti-IL-10 antibodies did not increase the PBMC proliferative response of these patients, suggesting that IL-10 may act by modulating IL-4 and IL-5 secretion. Addition of recombinant IL-10 decreased the proliferative response to undetectable levels when PBMC from patients with the different clinical forms were used. Analysis of IFN-gamma in the supernatants showed that PBMC from INT patients secreted low levels of IFN-gamma upon antigenic stimulation. In contrast, PBMC from NE secreted high levels of IFN-gamma. These data suggest that IL-10 is an important cytokine in regulating the immune response and possibly controlling morbidity in human schistosomiasis mansoni, and that the production of IFN-gamma may be associated with resistance to infection.

Factors affecting high and low human IgE responses to schistosome worm antigens in an area of Brazil endemic for Schistosoma mansoni and hookworm.

We have previously examined the antibody isotype responses to schistosome worm and egg antigens in human populations living in areas of Kenya and the Philippines endemic for Schistosoma mansoni and S. japonicum, respectively. Here, we have analyzed antibody isotype responses to S. mansoni adult worm (AW) antigen and soluble egg antigen (SEA) in more than 500 Brazilian individuals, and found similar relationships with age and sex as in the Kenyan and Filipino populations. Isotype responses to AW antigen broadly increased with age whereas isotype responses to SEA decreased, and a higher proportion of males than females had detectable IgE against AW antigen. Most isotype responses to AW antigen and SEA correlated positively with intensity of infection with S. mansoni except AW antigen-specific IgG2, which correlated negatively. The overall prevalence of infection with S. mansoni in this area was relatively low at only 39.5%; hookworm prevalence was higher at 57.4%. The majority of those infected with S. mansoni were also infected with hookworm (76%). Those individuals with high IgE responses to AW antigen were matched for sex, age, and total IgG to AW antigen as closely as possible with individuals with low levels of AW antigen-specific IgE. The two groups were compared for factors potentially influential in IgE production. No difference was found between the high and low IgE responders for 1) intensity or prevalence of infection with S. mansoni, 2) relative exposure to S. mansoni, 3) number of previous treatments for schistosomiasis, or 4) prevalence of infection with hookworm, but differences were found in other isotype responses to S. mansoni. The high IgE responders had higher IgA and IgG4 against both AW antigen and SEA but lower IgG3 responses to AW antigen than the low IgE responders. The IgE responses to three S. mansoni antigens (paramyosin, Sm22.6, and a 12-kD AW antigen band) were detected in individuals with IgE against AW antigen only.

Cytokine regulation of human immune response to Schistosoma mansoni: analysis of the role of IL-4, IL-5 and IL-10 on peripheral blood mononuclear cell responses.

The role of cytokines on the in vitro proliferative response of peripheral blood mononuclear cells (PBMC) from Schistosoma mansoni infected patients to soluble egg (SEA) and adult worm antigens (SWAP) were evaluated. The results obtained demonstrated that the proliferative response of PBMC from chronic intestinal (INT) patients to SEA and SWAP is increased by the blockage of IL-10 with specific monoclonal antibodies (MAb). The effects of these antibodies were readily reversed by the addition of recombinant IL-10. In contrast, no effect was observed on the PBMC response of acute and hepatosplenic patients (HS) in the presence of anti-IL-10. Anti-IL-4 antibodies decreased the PBMC response of the intestinal (INT) and HS individuals to SEA and SWAP, and the PBMC response of acute patients to SEA but not to SWAP. Addition of anti-IL-5 MAb did not decrease the PBMC response of acute patients to SEA or SWAP. These results suggested that IL-10 has an important role in the modulation of the immune response in chronic asymptomatic patients and that this cytokine may be an important factor in controlling morbidity.

Flow cytometric study of blood leucocytes in clinical forms of human schistosomiasis.

The aim of this study was to examine three distinct groups of schistosomiasis patients and to determine whether cell phenotype profiles could be correlated with the different clinical forms of the disease. The data obtained indicate that Schistosoma mansoni infected patients have a lower percentage of CD3+ T cells than do non-infected individuals. Interestingly, infected patients presented more than twice the mean percentage of circulating activated T cells (CD3+HLA-DR+) when compared to the control group. Examination of T lymphocyte subpopulations showed that patients with the severe hepatosplenic form (HS) of the disease had lower levels of both CD8High+ and CD8Low+ cells when compared to the other groups of patients. All infected individuals had a higher percentage of circulating B cells, with an increase in the CD5+ B cell population that was more evident in the HS group. The data presented here are evidence to support a relationship between the hepatosplenic form of the disease, a decrease on the CD8+ cell population and an elevation on CD5+ B cells.

Esthetic preference of the frontal and profile views of the same smile.

This study has shown that orthodontists and their patients share a common pool of diffuse esthetic values of the same smile. Profile and frontal views of the same smile were not similarly rated for esthetic pleasantness: the profile views were rated higher than the frontal views of the same smile. This finding suggests that orthodontists should consider both frontal and lateral views during evaluation of their patient when planning and assessing orthodontic treatment. More research is needed to determine the generalizability of the finding that orthodontists and patients have similar facial esthetic preferences. Future studies should expand the range of smiles that are evaluated by including both genders, people of different ethnic backgrounds, and people of a variety of ages. Research is also needed to evaluate facial esthetics and smiles in dynamic motion.

Microquantification of proteins with low chromophore content

The advantages of the intrinsic fluorescence of the tryptophan and the absorbance of the methionine residues of the 18 kDa-hsp - a recombinant protein from Mycobacterium leprae - was exploited here to develop a sensitive and low costs method for protein assaying. They presented linearity between 3 and 1000 ìg of protein. The correlations between intrinsic fluorescence or absorbance at 230 nm and protein contents were both superiors to 0.99. These methods can be extended to others proteins with low aromatic residue contents

Searching the internet.

Your first experiences using the Internet search and retrieval programs will be profitable if you understand the environment within which they were designed to work. When used properly, they represent the Internet's directory assistance that will aid you in information discovery.