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Fernandes Silva L, Vangipurapu J, Kuulasmaa T, Laakso M. An intronic variant in the GCKR gene is associated with multiple lipids. Sci Rep 2019; 9:10240. [PMID: 31308433 PMCID: PMC6629684 DOI: 10.1038/s41598-019-46750-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 07/02/2019] [Indexed: 12/25/2022] Open
Abstract
Previous studies have shown that an intronic variant rs780094 of the GCKR gene (glucokinase regulatory protein) is significantly associated with several metabolites, but the associations of this genetic variant with different lipids is largely unknown. Therefore, we applied metabolomics approach to measure metabolites in a large Finnish population sample (METSIM study) to investigate their associations with rs780094 of GCKR. We measured metabolites by mass spectrometry from 5,181 participants. P < 5.8 × 10-5 was considered as statistically significant given 857 metabolites included in statistical analyses. We found novel negative associations of the T allele of GCKR rs780094 with serine and threonine, and positive associations with two metabolites of tryptophan, indolelactate and N-acetyltryptophan. Additionally, we found novel significant positive associations of this genetic variant with 12 glycerolipids and 19 glycerophospholipids. Significant negative associations were found for three glycerophospholipids (all plasmalogen-cholines), and two sphingolipids. Significant novel associations were also found with gamma-glutamylthreonine, taurocholenate sulfate, and retinol. Our study adds new information about the pleiotropy of the GCKR gene, and shows the associations of the T allele of GCKR rs780094 with lipids.
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López Rodríguez M, Fernandes Silva L, Vangipurapu J, Modi S, Kuusisto J, Kaikkonen MU, Laakso M. Functional Variant in the GCKR Gene Affects Lactate Levels Differentially in the Fasting State and During Hyperglycemia. Sci Rep 2018; 8:15989. [PMID: 30375486 PMCID: PMC6207693 DOI: 10.1038/s41598-018-34501-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 10/06/2018] [Indexed: 12/31/2022] Open
Abstract
The rs780094 single nucleotide polymorphism (SNP; C/T) of glucokinase regulatory protein gene (GCKR) is a regulatory genetic variant that has been associated with lactate levels in the fasting state. However, the association of this locus with lactate during hyperglycemia, and the mechanisms underlying these associations remain unknown. We investigated the association of rs780094 with lactate levels in a frequently sampled oral glucose tolerance test in humans and evaluated the effect of increasing GCKR expression on lactate production in liver cells. The C allele of rs780094 was associated with lower lactate levels in fasting but increased lactate level during hyperglycemia independently of insulin levels. Increased expression of GKRP induced higher lactate level in HepG2 cells and in human primary hepatocytes (HPH) upon glucose stimulation by increasing the amount of GCK. Glucagon induced the expression of GCKR in HepG2 and HPH cells. Our results suggest that the association of rs780094 with lactate levels may involve differential GCKR expression between the carriers of the C and T alleles.
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Silva LF, Carvalho-Reis ENR, Bonardi JP, de Lima VN, Momesso GAC, Garcia-Junior IR, Faverani LP. Comparison between piezoelectric surgery and conventional saw in sagittal split osteotomies: a systematic review. Int J Oral Maxillofac Surg 2017; 46:1000-1006. [PMID: 28433212 DOI: 10.1016/j.ijom.2017.03.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 03/09/2017] [Accepted: 03/21/2017] [Indexed: 11/27/2022]
Abstract
A systematic review of the advantages and disadvantages of piezoelectric surgery in comparison with conventional saws for sagittal split osteotomy (SSO) was performed. Relevant studies published in the last 10 years were identified through a search of the PubMed/MEDLINE, Science Direct, and Embase databases and assessed against predetermined eligibility criteria. The initial search resulted in 1736 articles. After applying the inclusion and exclusion criteria, 12 articles remained. A total of 799 patients with an average age of 27.5 years underwent SSO performed using a saw or ultrasonic device. Results showed that it took longer to perform the osteotomies using an ultrasonic device than using a conventional saw. At ≥6 months of follow-up, neurosensory disturbance was seen in 4.7% of patients who underwent piezoelectric surgery versus 61.6% of patients who underwent surgery in which a conventional saw was used. It was found that the use of piezoelectric surgery in SSO leads to the best outcome regarding neurosensory disturbance when compared to conventional saws (P=0.04) at ≥6 months of follow-up. Further studies are required for the evaluation of the other clinical parameters assessed.
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Yoshizaki K, Fuziwara CS, Brito JM, Santos TMN, Kimura ET, Correia AT, Amato-Lourenco LF, Vasconcellos P, Silva LF, Brentani MM, Mauad T, Saldiva PHN, Macchione M. The effects of urban particulate matter on the nasal epithelium by gender: An experimental study in mice. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 213:359-369. [PMID: 26942683 DOI: 10.1016/j.envpol.2016.02.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 02/11/2016] [Accepted: 02/11/2016] [Indexed: 06/05/2023]
Abstract
Nose is the first portion of the respiratory system into contact with air pollution particles, including organic compounds that could act as endocrine releasers. The objective was to identify and quantify estrogenic receptor-β (ERβ), aryl hydrocarbon receptor (AhR), the cytochrome P450 enzymes CYP1A1, 1A2, 1B1, and mucus profile in the nasal epithelium of mice. BALB/c mice male (n = 32) and female (n = 82) in proestrus, estrus and diestrus were divided into two groups: 1) exposed to ambient air; 2) concentrated ambient particles (CAPs) to achieve an accumulated dose (concentration vs. time product) of 600 μg/m(3), the time of the exposure was controlled to ensure the same concentration for all groups (5 days per week for 40-51 days). RT-PCR (Erβ-1, Erβ-2, Ahr, Cyp1a1, Cyp1a2, Cyp1b1), immunohistochemistry and morphometry (ERβ, AhR) were used to analyze. The mucus profiles were examined using acid (Alcian Blue) and neutral (periodic acid Schiff's) stains. Exposed females had significantly lower levels of Erβ-2 mRNA than exposed males (p = 0.036). Cyp1b1 mRNA in diestrus females was significantly lower in the CAP-exposed group compared with the ambient air group (p ≤ 0.05). ERβ expression in the epithelium and submucosa nucleus was lower in estrus exposed to CAPs compared with ambient air. CAPs increases AhR in the epithelium (p = 0.044) and submucosa (p = 0.001) nucleus of female when compared with male mice. Exposure to CAPs, also led to relatively increased acidic content in the mucus of males (p = 0.048), but decreased acidic content in that of females (p = 0.04). This study revealed sex-dependent responses to air pollution in the nasal epithelium that may partially explain the predisposition of females to airway respiratory diseases.
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Machado FH, Mattedi AP, Dupas FA, Silva LF, Vergara FE. Estimating the opportunity costs of environmental conservation in the Feijão River watershed (São Carlos-SP, Brazil). BRAZ J BIOL 2016; 76:28-35. [PMID: 26909620 DOI: 10.1590/1519-6984.08614] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 10/22/2014] [Indexed: 11/22/2022] Open
Abstract
The objective of this study was to infer the opportunity cost of land use of the Feijão River watershed (São Carlos-SP, Brazil), in order to estimate the financial resources necessary to compensate landowners willing to convert their production areas into areas of environmental preservation. Net values were estimated by calculating the Annual Value and the Net Present Value of each activity. The area used for agricultural production was estimated using the Land Cover Map of the watershed. The study involved four production areas: forestry, livestock, sugarcane and orange, accounting for 66% of the watershed area of 22,300 hectares. Considering a scenario of total consent from landowners, the 2011 net annual values were estimated at R$ 13.4 million: R$ 2.2 million (eucalyptus), R$ 1.9 million (livestock), R$ 1.1 million (sugarcane) and R$ 8.2 million (orange). This amount would be used as payment for ecosystem services.
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Barbosa BC, Fagundes R, Silva LF, Tofoli JFV, Santos AM, Imai BYP, Gomes GG, Hermidorff MM, Ribeiro SP. Evidences that human disturbance simplify the ant fauna associated a Stachytarpheta glabra Cham. (Verbenaceae) compromising the benefits of ant-plant mutualism. BRAZ J BIOL 2015; 75:58-68. [PMID: 25945621 DOI: 10.1590/1519-6984.07213] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 09/30/2013] [Indexed: 11/21/2022] Open
Abstract
Interaction among species, like ants and plants through extrafloral nectaries (EFNs), are important components of ecological communities' evolution. However, the effect of human disturbance on such specific interactions and its ecological consequences is poorly understood. This study evaluated the outcomes of mutualism between ants and the EFN-bearing plant Stachytarpheta glabra under anthropogenic disturbance. We compared the arthropod fauna composition between two groups of twenty plant individuals, one in an area disturbed by human activities and one in a preserved area. We also check the plant investment in herbivory defense and the consequential leaf damage by herbivore. Our results indicate that such disturbances cause simplification of the associated fauna and lack of proper ant mutualist. This led to four times more herbivory on plants of disturbed areas, despite the equal amount of EFN and ant visitors and low abundance of herbivores. The high pressure of herbivory may difficult the re-establishment of S. glabra, an important pioneer species in ferruginous fields, therefore it may affect resilience of this fragile ecological community.
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Machado FH, Silva LF, Dupas FA, Mattedi AP, Vergara FE. Economic assessment of urban watersheds: developing mechanisms for environmental protection of the Feijão river, São Carlos--SP, Brazil. BRAZ J BIOL 2015; 74:677-84. [PMID: 25296217 DOI: 10.1590/bjb.2014.0073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 11/17/2013] [Indexed: 11/21/2022] Open
Abstract
In order to determine the willingness of the population of São Carlos (a city in the state of São Paulo, Brazil) to pay for the environmental protection (WTP) of the Feijão River's watershed, the Contingent Valuation Method (CVM), as well as the bidding-games technique, were used. In October 2010, 280 questionnaires were applied to a probabilistic sample of the population. A multivariate logistic regression model was built, creating five scenarios adjusted to the age and probability to pay according to the significant variables found. Concerning the WTP, 56% of the interviewees showed willingness to pay a monthly amount using the water bill as a vehicle for this. The WTP average was 1.94 US Dollar (USD), with a standard deviation of 1.91 USD. The total annual amount for the scenario that considers the whole population over 18 years old was of USD 3,930,616.80. The main argument for the negative WTP was that the interviewees could not afford it (14%).
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Koyama RV, Silva LF, Henriques VB, Tran C, Yoshikawa GT. Pure red cell aplasia associated with systemic lupus erythematosus. ACTA REUMATOLOGICA PORTUGUESA 2014; 39:265-268. [PMID: 25326408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Pure red cell aplasia is a rare condition described in patients with autoimmune diseases such as systemic lupus erythematosus. Bone marrow examination of a 52-year-old female showed selective severe hypoplasia, scarce hematopoietic reserves, and no abnormality in other cell lineages, which are findings compatible with red cell aplasia. This condition has not responded to corticosteroids, cytotoxic drugs or intravenous immunoglobulin. After therapy with high doses of glucocorticoids, cyclophosphamide, and immunoglobulin failed, she was treated with human recombinant erythropoietin, monthly pulses of methylprednisolone, and cyclophosphamide, simultaneously. Data on treatment with erythropoietin for pure red cell aplasia associated with systemic lupus erythematosus is limited, but it appears to be reasonable to try in refractory cases.
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Medeiros AMA, Barbosa JEL, Medeiros PR, Rocha RM, Silva LF. Salinity and freshwater discharge determine rotifer distribution at the Mossoró River Estuary (Semiarid Region of Brazil). BRAZ J BIOL 2011; 70:551-7. [PMID: 20730341 DOI: 10.1590/s1519-69842010000300011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 09/25/2009] [Indexed: 11/21/2022] Open
Abstract
The present study aimed at evaluating differences in rotifer distribution in three estuarine zones in an inverse estuary located in the Semiarid Region of Brazil. Zones were chosen based on their proximity to the ocean and river border as a means of reflecting a horizontal salinity gradient. High freshwater discharge during the rainy season was the major determinant of rotifer composition. On the other hand, due to higher salinity values during the dry season, very low values of species richness and abundance were observed in all zones. Therefore, the study highlights the constraints of salinity and the positive influence of seasonality and river proximity on rotifer species in a semiarid estuarine environment.
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Cavalcanti MGS, Araújo HRC, Paiva MHS, Silva GM, Barbosa CCGS, Silva LF, Brayner FA, Alves LC. Ultrastructural and cytochemical aspects of Schistosoma mansoni cercaria. Micron 2008; 40:394-400. [PMID: 19081261 DOI: 10.1016/j.micron.2008.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 09/18/2008] [Accepted: 09/19/2008] [Indexed: 10/21/2022]
Abstract
An alternative to identify the critical processes necessary to the parasite establishment of the host is to focus on the evolutionary stage responsible for the primary invasion, i.e. the infection structure. The objective of this study was to ultrastructurally characterize Schistosoma mansoni cercariae, using cytochemical techniques. In order to identify basic proteins, techniques such as ethanolic phosphotungstic acid (EPTA) and ammoniacal silver staining were used. Calcium sites location was achieved using the Hepler technique and to evidence anionic groups, we used cationic ferritin particles and enzyme treatment with trypsin Vibrio cholerae, chondroitinase and neuraminidase. The EPTA technique highlighted the presence of basic tegument proteins, nucleus and nucleolus from subtegumental cells, inclusion bodies and preacetabular glands. After using ammoniacal silver, we observed a strong staining in all infective larvae, particularly in the nuclei of muscle cells, circular muscle tissue and preacetabular glands. Calcium site locations were shown to be uniform, thereby limiting the inner spaces of the larvae, especially muscle cells. Samples treated with cationized ferritin particles presented strong staining at the cuticular level. Neuraminidase treatment did not alter the stained shape of such particles on the trematode surface. However, trypsin or chondroitinase treatment resulted in absence of staining on the larval surface. This information on the biochemical composition of the infecting S. mansoni larvae provides data for a better understanding of the biology of this parasite and background on the intriguing parasite-host relationship.
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Silva LF, Brayner FAS, Santos ACO, Lanfredi RM, Peixoto CA. Identification and location of albumin-like antigens in third-stage larva of W. bancrofti, in adult forms of Litomosoides chagasfilhoi and in the free-living nematode Caenorhabditis elegans. Micron 2006; 37:666-74. [PMID: 16516479 DOI: 10.1016/j.micron.2006.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 01/18/2006] [Accepted: 01/19/2006] [Indexed: 11/23/2022]
Abstract
Antigens resembling those of host proteins have been identified on the surface of several filarial parasites, such as immunoglobulins and serum albumins. The origin of albumin-like antigens on filarial parasites remains unclear. Several authors suggested that they have been adsorbed, or that they were metabolic waste products from nutritional utilization of human albumin, or perhaps a contamination with human products. This study searched for human albumin-like antigens by Western blot and ultrastructural analyses on filarial parasites, third stage of W. bancrofti and adult females of Litomosoides chagasfilhoi, and on the free-living Caenorhabditis elegans nematode. Our results showed approximately 67kDa proteins recognized by anti-human albumin antibodies on extracts and excretory-secretory (ES) products of the third-stage W. bancrofti. Similar albumin-like proteins were also detected on the filarial parasite L. chagasfilhoi and on C. elegans extracts. The immunocytochemistry analysis showed human albumin-like antigens on similar tissues of these nematodes. These results provide evidence that these proteins have antigenic similarity and similar distribution in nematodes tissues. Our observations suggest that albumin-like antigens presented on filarial parasites are not acquired from the host, but rather are shared antigenic determinants found even in the third-stage larvae recovered from the invertebrate host.
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Silva LF, Alves LC, Santos SS, Cavalcanti MGS, Peixoto CA. Cytochemical characterization of the third-stage larva of Wuchereria bancrofti (Nematoda: Filarioidea). Parasitol Res 2006; 99:14-20. [PMID: 16450133 DOI: 10.1007/s00436-005-0054-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Accepted: 09/28/2005] [Indexed: 11/27/2022]
Abstract
In the present paper, we report the results we obtained using several cytochemical techniques to analyze the infective larva of Wuchereria bancrofti. An imidazole osmium tetroxide solution was used to visualize unsaturated fatty acids. A highly contrasted material forming a continuous structure was observed on the larval surface and over the epicuticle. A strong reaction was observed on the esophagus and also on the inner secreted material. Carbohydrates containing vic-glycol groups were not observed on the cuticle of the third-stage larva of W. bancrofti submitted to the Thiéry technique. Using a panel of eight gold-labeled lectins, we found that the cuticle exhibited slight labeling with all lectins used, indicating residues of N-acetyl-D: -glucosamine, N-acetyl-galactosamine, D: -galactose, D: -manose, and L: -fucose. Surface anionic sites were visualized by using cationized ferritin particles. Treatment with trypsin partially inhibited the reaction, whereas the treatment with chondroitinase ABC, a specific enzyme for glycosaminoglycans, completely abolished the labeling with cationic particles.
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Alves LC, Brayner FAS, Silva LF, Peixoto CA. The ultrastructure of infective larvae (L3) of Wuchereria bancrofti after treatment with diethylcarbamazine. Micron 2005; 36:67-72. [PMID: 15582480 DOI: 10.1016/j.micron.2004.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2004] [Revised: 04/28/2004] [Accepted: 05/07/2004] [Indexed: 11/24/2022]
Abstract
Although the large use of diethylcarbamazine (DEC), as the major anti-filaricide drug, its mechanism of action remains a matter of controversy. Several authors defend the hypothesis that DEC has no direct effect on nematodes. This study demonstrated that infective larvae (L3) of Wuchereria bancrofti treated in vitro with DEC presented several behaviour and morphological changes. The first alteration produced by treatment for 2 h with 3, 5, 10 microg/ml of DEC was the reduction of motility. Larvae treated with 5, 10 microg/ml DEC showed severely affected organelles, formation of several vacuoles, mainly in neurocytes and in the muscle cells, and dissolution of cytoplasm. Some larvae showed extreme cellular disorganization with abundance of large and dense mitochondria and numerous large vacuoles containing residual organelles. Lamellar bodies, probably related to an assembly of hipodermal membranes, were also observed in some damaged larvae. Thus, undoubtedly in vitro treatment with concentrations of DEC similar to therapeutic conditions, which are 1-5 microg/ml (Hawking, 1979), had a direct effect on infective larvae of W. bancrofti by causing, primarily neuromuscular alterations with subsequent damage to organelles.
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Silva LF, Taciro MK, Michelin Ramos ME, Carter JM, Pradella JGC, Gomez JGC. Poly-3-hydroxybutyrate (P3HB) production by bacteria from xylose, glucose and sugarcane bagasse hydrolysate. J Ind Microbiol Biotechnol 2004; 31:245-54. [PMID: 15221664 DOI: 10.1007/s10295-004-0136-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Accepted: 03/31/2004] [Indexed: 10/26/2022]
Abstract
Fifty-five bacterial strains isolated from soil were screened for efficient poly-3-hydroxybutyrate (P3HB) biosynthesis from xylose. Three strains were also evaluated for the utilization of bagasse hydrolysate after different detoxification steps. The results showed that activated charcoal treatment is pivotal to the production of a hydrolysate easy to assimilate. Burkholderia cepacia IPT 048 and B. sacchari IPT 101 were selected for bioreactor studies, in which higher polymer contents and yields from the carbon source were observed with bagasse hydrolysate, compared with the use of analytical grade carbon sources. Polymer contents and yields, respectively, reached 62% and 0.39 g g(-1) with strain IPT 101 and 53% and 0.29 g g(-1) with strain IPT 048. A higher polymer content and yield from the carbon source was observed under P limitation, compared with N limitation, for strain IPT 101. IPT 048 showed similar performances in the presence of either growth-limiting nutrient. In high-cell-density cultures using xylose plus glucose under P limitation, both strains reached about 60 g l(-1) dry biomass, containing 60% P3HB. Polymer productivity and yield from this carbon source reached 0.47 g l(-1) h(-1) and 0.22 g g(-1), respectively.
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Alves LC, Brayner FA, Silva LF, Pimentel RC, Rocha A, Peixoto CA. Immunocytochemical localization of antigens recognised by tropical pulmonary eosinophilia and individuals with intestinal helminths antisera in microfilaria of Wuchereria bancrofti. JOURNAL OF SUBMICROSCOPIC CYTOLOGY AND PATHOLOGY 2002; 34:211-6. [PMID: 12117283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Ultrathin sections of microfilaria of W. bancrofti embedded in the hydrophilic resin L.R. White were incubated with sera from patients with a typical picture of filarial tropical pulmonary eosinophilia (TPE) and sera from patients of a non-endemic region for filariasis regarding intestinal helminths. Both groups had a similar pattern of labelling, except that the labelling intensity was higher with the sera of patients with filarial TPE. The present study indicates relevant epitopes recognised by sera from TPE-patients and also individuals with intestinal helminths in all tissues of microfilaria of W. bancrofti, instead of being localised in a specific nematode region. These findings suggest that sera from people from an area not endemic for filaria, harbouring intestinal helminths, also share antifilarial antibodies that recognise antigens of microfilaria of W. bancrofti.
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Brämer CO, Silva LF, Gomez JGC, Priefert H, Steinbüchel A. Identification of the 2-methylcitrate pathway involved in the catabolism of propionate in the polyhydroxyalkanoate-producing strain Burkholderia sacchari IPT101(T) and analysis of a mutant accumulating a copolyester with higher 3-hydroxyvalerate content. Appl Environ Microbiol 2002; 68:271-9. [PMID: 11772636 PMCID: PMC126583 DOI: 10.1128/aem.68.1.271-279.2002] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia sacchari IPT101(T) induced the formation of 2-methylcitrate synthase and 2-methylisocitrate lyase when it was cultivated in the presence of propionic acid. The prp locus of B. sacchari IPT101(T) is required for utilization of propionic acid as a sole carbon source and is relevant for incorporation of 3-hydroxyvalerate (3HV) into copolyesters, and it was cloned and sequenced. Five genes (prpR, prpB, prpC, acnM, and ORF5) exhibited identity to genes located in the prp loci of other gram-negative bacteria. prpC encodes a 2-methylcitrate synthase with a calculated molecular mass of 42,691 Da. prpB encodes a 2-methylisocitrate lyase. The levels of PrpC and PrpB activity were much lower in propionate-negative mutant IPT189 obtained from IPT101(T) and were heterologously expressed in Escherichia coli. The acnM gene (ORF4) and ORF5, which are required for conversion of 2-methylcitric acid to 2-methylisocitric acid in Ralstonia eutropha HF39, are also located in the prp locus. The translational product of ORF1 (prpR) had a calculated molecular mass of 70,598 Da and is a putative regulator of the prp cluster. Three additional open reading frames (ORF6, ORF7, and ORF8) whose functions are not known were located adjacent to ORF5 in the prp locus of B. sacchari, and these open reading frames have not been found in any other prp operon yet. In summary, the organization of the prp genes of B. sacchari is similar but not identical to the organization of these genes in other bacteria investigated recently. In addition, this study provided a rationale for the previously shown increased molar contents of 3HV in copolyesters accumulated by a B. sacchari mutant since it was revealed in this study that the mutant is defective in prpC.
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Alves LC, Brayner FA, Silva LF, Miranda J, Rocha A, Peixoto CA. Immunocytochemical localization of antigens recognized by asymptomatic microfilaremic patient's antisera in microfilariae of Wuchereria bancrofti. Parasitol Res 2001; 87:1050-5. [PMID: 11763438 DOI: 10.1007/s004360100455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Ultrathin sections of microfilariae of Wuchereria bancrofti embedded in hydrophilic resin were incubated with sera from patients, using antisera from asymptomatic microfilaremic patients with different microfilarial densities [1-100 microfilariae (mf)/ml, 101-500 mf/ml, > 1,000 mf/ml]. All groups studied showed reactivity against relevant epitopes in all tissues of microfilariae of W. bancrofti, instead of being localized in a specific nematode region, although the number of colloidal per square micron was inversely proportional to the microfilaremia. Such results confirm data obtained by other authors and indicate a possible role for the humoral response in the mechanism for the destruction of circulating microfilariae.
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Peixoto CA, Silva LF, Teixeira KM, Rocha A. Ultrastructural characterization of intracellular bacteria of Wuchereria bancrofti. Trans R Soc Trop Med Hyg 2001; 95:566-8. [PMID: 11706674 DOI: 10.1016/s0035-9203(01)90042-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Ultrastructural observations on the structure and distribution of endosymbiotic bacteria within the tissues of Wuchereria bancrofti are described. In female worms the organisms were observed in the lateral cords of the hypodermis, oocytes, developing eggs and in intrauterine microfilariae. Organisms were also detected in blood microfilariae and in the intestine of third-stage larvae. Bacteria were not observed in male worms.
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Badauê-Passos D, Ventura RR, Silva LF, Olivares EL, Ramalho MJ, Antunes Rodrigues J, Reis LC. Effect of losartan on sodium appetite of hypothyroid rats subjected to water and sodium depletion and water, sodium and food deprivation. Exp Physiol 2001; 86:621-8. [PMID: 11571491 DOI: 10.1113/eph8602189] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The involvement of angiotensin AT1 receptors in sodium appetite was studied in hypothyroid rats treated with the angiotensin II antagonist losartan. Losartan was administered chronically by the oral route or acutely by the subcutaneous route after water and sodium depletion or water, sodium and food deprivation. Three days after addition of losartan to the food at the dose of 1.0 mg x g(-1), the rats significantly reduced (P < 0.02) their spontaneous intake of 1.8% NaCl. Increasing the dose of losartan to 2.0 and 4.0 mg x g(-1) did not reduce NaCl intake; in contrast, the intensity of the sodium appetite gradually returned to previous levels. The simultaneous administration of captopril, an angiotensin converting enzyme inhibitor, and losartan significantly increased (P < 0.05) NaCl intake and after captopril removal NaCl intake returned to the levels observed with losartan treatment alone. The administration of losartan 4 days after the beginning of captopril treatment significantly reduced (P < 0.0001) NaCl intake. Following acute administration of losartan, water- and sodium-depleted rats significantly reduced their NaCl and water intake (P < 0.001). The administration of losartan also induced a significant reduction in NaCl and water intake in water, NaCl and food-deprived rats (P < 0.0001 and P < 0.001, respectively). The present results show that chronic treatment with oral losartan inhibited spontaneous sodium appetite in hypothyroid rats. Continuation of treatment rendered rats resistant to the blockade of AT1 receptors. Water and sodium depletion and water, NaCl and food deprivation induced sodium appetite, which in the short term depends on cerebral angiotensinergic activity mediated by the activation of AT1 receptors.
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Molander GA, Quirmbach MS, Silva LF, Spencer KC, Balsells J. Toward the total synthesis of variecolin. Org Lett 2001; 3:2257-60. [PMID: 11463290 DOI: 10.1021/ol015763l] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] An annulative approach toward the total synthesis of the sesterterpenoid variecolin (1) is presented. Synthesis of the key hemiketal, containing the core ABC ring skeleton, has been achieved on a model system by an expeditious route utilizing samarium(II) iodide. Furthermore, enantioselective syntheses of component fragments for the total synthesis have been developed.
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Costa-Filho A, Werneck CC, Nasciutti LE, Masuda H, Atella GC, Silva LF. Sulfated glycosaminoglycans from ovary of Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2001; 31:31-40. [PMID: 11102832 DOI: 10.1016/s0965-1748(00)00101-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We have characterized sulfated glycosaminoglycans from ovaries of the blood-sucking insect Rhodnius prolixus, and determined parameters of their synthesis and distribution within this organ by biochemical and histochemical procedures. The major sulfated glycosaminoglycan is heparan sulfate while chondroitin 4-sulfate is a minor component. These glycosaminoglycans are concentrated in the ovarian tissue and are not found inside the oocytes. Besides this, we detected the presence of a sulfated compound distinguished from sulfated glycosaminoglycans and possibly derived from sulfated proteins. Conversely to the compartmental location of sulfated glycosaminoglycans, the unidentified sulfated compound is located in the ovarian tissue as well as inside the oocytes. Based on these and other findings, the possible roles of ovarian sulfated glycosaminoglycans on the process of oogenesis in these insects are discussed.
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Silva LF, Lemme EM. [Nutcracker esophagus: clinical evaluation of 97 patients]. ARQUIVOS DE GASTROENTEROLOGIA 2000; 37:217-23. [PMID: 11460602 DOI: 10.1590/s0004-28032000000400006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nutcracker esophagus is a manometric abnormality classified as a primary esophageal motor disorder, characterized by high pressure peristaltic waves in distal esophagus and related to non-cardiac chest pain. Further studies observed nutcracker esophagus in dysphagic patients and recently in gastroesophageal reflux disease. However, there is controversy about the meaning of this motor disorder and there are few clinical studies involving a great number of patients. A retrospective study involving 97 patients with manometric criteria of nutcracker esophagus according a control group was undertaken. Most of the patients were female (63.9%), mean age 54.3 years. The chief complaint was chest pain, followed by dysphagia and heartburn. Clinical findings, as a whole were chest pain (53.6%), dysphagia (52.6%), heartburn (52.6%), regurgitation (21.6%), otorhinolaryngologic symptoms (15.4%), dyspepsia (15.4%) and odynophagia (4.1%). The majority of patients had multiple symptoms, however in 28% just a single one was observed. Endoscopic examination observed erosive esophagitis in 8% of the patients, while signs of esophageal motor disorders were showed by esophagogram in 16.4%. Esophageal pH recordings indicated abnormal gastroesophageal reflux in 41.2% of the cases reported. We concluded that there are other symptoms in nutcracker esophagus patients besides chest pain and dysphagia and the use of esophageal pH recordings is helpful to establish its association with acid reflux and guide the appropriate therapy.
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Silva LF, Gomez JG, Oliveira MS, Torres BB. Propionic acid metabolism and poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P3HB-co-3HV) production by Burkholderia sp. J Biotechnol 2000; 76:165-74. [PMID: 10656331 DOI: 10.1016/s0168-1656(99)00184-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Mutants of Burkholderia sp. that are unable to grow on propionic acid (prp) but still accumulate P3HB-co-3HV from carbohydrate and propionic acid were studied. In shaken flask tests, yields of 3HV from propionic acid (Y(3HV/Prop)) increased from 0.10 g g(-1) in the wild type to c.a. 0.35 g g(-1) in mutants affected in alpha-oxidation pathway or to 0.80 g g(-1) in mutants not affected in that pathway. In bioreactor tests, mutant IPT 189 showed Y(3HV/Prop) = 1.20 g g(-1), a yield very close to the theoretical maximum of 1.35 g g(-1). Accumulation of 3HV units from unrelated carbon sources was undetectable in these mutants indicating that 3HV units are produced directly from propionic acid. Thus, the industrial use of those mutants to produce the copolymer from sucrose and propionic acid could significantly reduce the production costs. The results strongly suggest the existence of at least two pathways that are involved in the oxidation of propionic acid in Burkholderia sp. Their rates would be modulated by the availability of propionic acid.
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Silva LF, Panfilio CB, Hernández-Fustes J, Hernández-Cossio O, Hernández-Fustes OJ. [Miller-Fisher syndrome and cavernous angioma]. Rev Neurol 1999; 28:1057-9. [PMID: 10390773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
INTRODUCTION The Miller-Fisher syndrome is considered a variant of acute inflammatory demyelinating polyradiculoneuropathy, generally is a benign disorder. CLINICAL CASE We describe a patient who has had, acutely, ataxia, areflexia and ophthalmoplegia. It has been electrophysiologically diagnosed as Miller-Fisher syndrome. The symptoms appeared after an infectious disease, namely sinusitis. The evoked potential studies suggested lesions at the brain stem and we found a cavernous angioma at MRI. CONCLUSION We prepared a review of the literature published so far, showing that there is still much controversy about the physiopathology of this syndrome and the importance of the immunologic diagnoses.
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Teixeira CF, Yasaka WJ, Silva LF, Oshiro TT, Oga S. Inhibitory effects of beryllium chloride on rat liver microsomal enzymes. Toxicology 1990; 61:293-301. [PMID: 2109906 DOI: 10.1016/0300-483x(90)90179-k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A single i.v. dose (0.1 mmol Be2+/kg) of beryllium chloride prolonged the duration of pentobarbital-induced sleep and zoxazolamine-induced paralysis, in rats. The effects are correlated with changes of the pharmacokinetic parameters and with the in vitro inhibition of both aliphatic and aromatic hydroxylation of pentobarbital and zoxazolamine. In vitro N-demethylation of meperidine and aminopyrine was partially inhibited while O-demethylation of quinidine was unaffected by liver microsomes of rats pretreated with beryllium salt. The findings give clues that beryllium chloride inhibits some forms of cytochrome P-450, especially those responsible for hydroxylation of substrates, like pentobarbital and zoxazolamine.
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