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1.
Eur J Prosthodont Restor Dent ; 32(1): 56-64, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-37721553

RESUMO

INTRODUCTION: The association of the periodontium with the fixed prosthesis is the basis of prosthetic rehabilitation. This prospective case series aimed to evaluate periodontal health through the relation between periodontal/peri-implant disease progression and the use of fixed partial dentures (FPDs). METHODS: Probing depth (PD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI) on either teeth or implants were evaluated at up to 25-year follow-up and compared with the baseline. Statistical analysis was performed using the Kaplan-Meier test (p⟨0.05). RESULTS: The prospective evaluation showed that the patients maintained adequate periodontal health. Failure (severe periodontal stages) occurred in 12.5% of patients. The survival rate for 107 teeth/implants was 80.48%. The comparisons for clinical parameters revealed no statistically significant difference (p⟩ 0.05). At T1, the measurements for anterior and posterior regions, respectively, were PD =2.7mm and 3.1mm; CAL= 3.3mm and 3.6mm; GI=0.5 (both regions); and PI=0.79 and 0.62. Periodontal/peri-implant disease progression did not relate to the use of prostheses. CONCLUSIONS: Patients with more frequent follow-up appointments and lower GI and PI showed periodontal health for longer periods. Patients with different oral hygiene levels present different periodontal disease progression. Periodic hygiene control and motivation are vital factors for extensive oral rehabilitation success.


Assuntos
Implantes Dentários , Peri-Implantite , Doenças Periodontais , Humanos , Implantes Dentários/efeitos adversos , Doenças Periodontais/induzido quimicamente , Prótese Parcial Fixa , Seguimentos
2.
Med Oral Patol Oral Cir Bucal ; 28(1): e56-e64, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36243993

RESUMO

BACKGROUND: Point-of-care-ultrasound can be applied to preview a difficult airway, detect the presence of fluid collection, and soft-tissue edema, and guide the drainage location, although is rarely used. The purpose of this study is to validate a protocol for the assessment of these clinical features on patients with severe odontogenic infections. MATERIAL AND METHODS: This was a single-group prospective cohort study (n=20) including patients with the diagnosis of deep-neck propagation of odontogenic infection. A transcervical linear high-frequency probe transducer (13-6 MHz) was used to scan the structures of the upper airway and the infectious collections. The drainage was guided by ultrasound and the patients were daily evaluated, according to the protocol. The data were extracted and the airway volume, midline deviation, and other important data such as length of hospital stay, dysphagia, voice alteration, raised floor of the mouth, dyspnea, and neck swelling were registered. RESULTS: The ultrasound examination was correlated with multiple clinical findings, such as dyslalia (p=0,069), dysphagia (p=0,028), dyspnea (p=0,001), among others. This protocol has an advantage as it can be used at bedside evaluation, allowing the assessment of severe and unstable patients, and predicting the increase of the hospitalization time (p=0,019). CONCLUSIONS: This protocol is reliable for the assessment of the upper airway, even in an emergency, predicting not only the severity of the clinical features but aids in the determination of the length of the hospitalization time.


Assuntos
Odontologia , Infecções , Testes Imediatos , Ultrassonografia , Humanos , Transtornos de Deglutição , Dispneia , Hospitalização , Pescoço/diagnóstico por imagem , Estudos Prospectivos , Controle de Infecções Dentárias , Testes Imediatos/normas , Ultrassonografia/normas , Boca/diagnóstico por imagem , Odontologia/métodos , Infecções/diagnóstico por imagem
3.
Med Oral Patol Oral Cir Bucal ; 27(6): e518-e524, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36173726

RESUMO

BACKGROUND: The latest trend in surgery is to look for minimally invasive procedures, with fewer complications and a shorter recovery time. This study aims to compare the minimally- invasive envelope flap, with smaller incision and fewer dissection and the conventional envelope flap, with a 20mm incision, on impacted mandibular third molar surgery, focusing on the hypothesis that there were no differences in postoperative outcomes. MATERIAL AND METHODS: A double-blind randomized clinical trial was designed to compare both incisions, focused on determining the approach with minor postoperative side-effects and minor impact on quality-of-life. A total of 60 patients were enrolled for the study if their presented impacted mandibular third molar and was 18-years-old or more. Both groups were evaluated from time elapsed on the surgery, maximum mouth opening, swelling and quality of life assessment. RESULTS: The flap choice influenced facial swelling (p=0,03), pain on the first three days (p=0,037), interference with oral hygiene (p=0,019) and discomfort on speech (p=0,07). Chewing, swallowing, trismus, pain after seven days, postoperative complications and other quality-of-life arrangements were no different between groups. CONCLUSIONS: The minimally- invasive envelope flap could lead to a less painful experience for the patient, with fewer impact on the oral hygiene and speech discomfort.


Assuntos
Dente Serotino , Dente Impactado , Humanos , Adolescente , Dente Serotino/cirurgia , Qualidade de Vida , Extração Dentária/efeitos adversos , Extração Dentária/métodos , Mandíbula/cirurgia , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Dente Impactado/cirurgia , Dente Impactado/complicações , Trismo , Edema , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle
4.
Int J Dent Hyg ; 15(1): 23-29, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26053214

RESUMO

OBJECTIVE: To investigate the influence of educational activity in the school environment based on prescriptive and subjective oral health indicators. METHODS: Cross-sectional, comparative study involving students between 9 and 12 years of age, from schools that have educational activities and those that do not, designated schools A and B. The oral health indicators used were the Simplified Oral Hygiene Index (OHI-S) and the Community Periodontal Index (CPITN). Knowledge and attitudes with regard to oral health were evaluated using a structured questionnaire. RESULTS: A total of 289 schoolchildren took part, 50.5% from school A and 49.5% from school B, in the town of Montes Claros, in the Brazilian state of Minas Gerais. In school A, the schoolchildren's OHI-S was satisfactory for 9.6%, normal for 78.8% and deficient for 11.6%, while in school B, the respective percentages were 3.5%, 17.5% and 79% (chi-squared, P < 0.001). The students in school A showed better CPITN results, namely lack of bleeding for 61.6%, the presence of bleeding for 29.5% and presence of tartar for 8.9%, while in school B, the respective results were 25.2%, 45.5% and 29.4% (chi-squared, P < 0.001). Students in school A achieved more correct answers in questions that evaluated knowledge of oral health. The account of daily use of dental floss in school A was 21.7% and in B, 3.6% (chi-squared, P < 0.001). CONCLUSION: It is believed that educational activity in the school environment had a positive effect on oral health conditions, the consolidation of knowledge and incorporation of oral hygiene habits.


Assuntos
Saúde Bucal/educação , Serviços de Saúde Escolar , Estudantes/estatística & dados numéricos , Criança , Feminino , Humanos , Masculino , Índice de Higiene Oral , Índice Periodontal , Avaliação de Programas e Projetos de Saúde , Serviços de Saúde Escolar/organização & administração
5.
Int J Obes (Lond) ; 40(11): 1627-1634, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27531045

RESUMO

BACKGROUND/OBJECTIVES: Maternal obesity increases risk for childhood obesity, but molecular mechanisms are not well understood. We hypothesized that primary umbilical vein endothelial cells (HUVEC) from infants of overweight and obese mothers would harbor transcriptional patterns reflecting offspring obesity risk. SUBJECTS/METHODS: In this observational cohort study, we recruited 13 lean (pre-pregnancy body mass index (BMI) <25.0 kg m-2) and 24 overweight-obese ('ov-ob', BMI⩾25.0 kg m-2) women. We isolated primary HUVEC, and analyzed both gene expression (Primeview, Affymetrix) and cord blood levels of hormones and adipokines. RESULTS: A total of 142 transcripts were differentially expressed in HUVEC from infants of overweight-obese mothers (false discovery rate, FDR<0.05). Pathway analysis revealed that genes involved in mitochondrial and lipid metabolism were negatively correlated with maternal BMI (FDR<0.05). To test whether these transcriptomic patterns were associated with distinct nutrient exposures in the setting of maternal obesity, we analyzed the cord blood lipidome and noted significant increases in the levels of total free fatty acids (lean: 95.5±37.1 µg ml-1, ov-ob: 124.1±46.0 µg ml-1, P=0.049), palmitate (lean: 34.5±12.7 µg ml-1, ov-ob: 46.3±18.4 µg ml-1, P=0.03) and stearate (lean: 20.8±8.2 µg ml-1, ov-ob: 29.7±17.2 µg ml-1, P=0.04), in infants of overweight-obese mothers. CONCLUSIONS: Prenatal exposure to maternal obesity alters HUVEC expression of genes involved in mitochondrial and lipid metabolism, potentially reflecting developmentally programmed differences in oxidative and lipid metabolism.


Assuntos
Células Endoteliais da Veia Umbilical Humana/metabolismo , Metabolismo dos Lipídeos/genética , Mães , Obesidade/genética , Complicações na Gravidez/genética , Cordão Umbilical/citologia , Adulto , Estudos de Coortes , Feminino , Desenvolvimento Fetal , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Lactente , Inflamação/fisiopatologia , Fenômenos Fisiológicos da Nutrição Materna/fisiologia , Mitocôndrias/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Obesidade/prevenção & controle , Gravidez , Complicações na Gravidez/metabolismo , Complicações na Gravidez/patologia , Efeitos Tardios da Exposição Pré-Natal
6.
Clin Genet ; 78(3): 267-74, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20236118

RESUMO

Eleven affected members of a large German-American family segregating recessively inherited, congenital, non-syndromic sensorineural hearing loss (SNHL) were found to be homozygous for the common 35delG mutation of GJB2, the gene encoding the gap junction protein Connexin 26. Surprisingly, four additional family members with bilateral profound SNHL carried only a single 35delG mutation. Previously, we demonstrated reduced expression of both GJB2 and GJB6 mRNA from the allele carried in trans with that bearing the 35delG mutation in these four persons. Using array comparative genome hybridization (array CGH), we have now identified on this allele a deletion of 131.4 kb whose proximal breakpoint lies more than 100 kb upstream of the transcriptional start sites of GJB2 and GJB6. This deletion, del(chr13:19,837,344-19,968,698), segregates as a completely penetrant DFNB1 allele in this family. It is not present in 528 persons with SNHL and monoallelic mutation of GJB2 or GJB6, and we have not identified any other candidate pathogenic copy number variation by arrayCGH in a subset of 10 such persons. Characterization of distant GJB2/GJB6 cis-regulatory regions evidenced by this allele may be required to find the 'missing' DFNB1 mutations that are believed to exist.


Assuntos
Conexinas/genética , Regulação da Expressão Gênica , Sequências Reguladoras de Ácido Nucleico/genética , Deleção de Sequência , Alelos , Sequência de Bases , Deleção Cromossômica , Cromossomos Humanos Par 13/genética , Hibridização Genômica Comparativa , Conexina 26 , Conexina 30 , Saúde da Família , Feminino , Testes Genéticos , Genótipo , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/genética , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Penetrância , Homologia de Sequência do Ácido Nucleico
7.
Sci Rep ; 9(1): 17926, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784616

RESUMO

Dengue is an important arboviral infection, causing a broad range symptom that varies from life-threatening mild illness to severe clinical manifestations. Recent studies reported the impairment of the central nervous system (CNS) after dengue infection, a characteristic previously considered as atypical and underreported. However, little is known about the neuropathology associated to dengue. Since animal models are important tools for helping to understand the dengue pathogenesis, including neurological damages, the aim of this work was to investigate the effects of intracerebral inoculation of a neuroadapted dengue serotype 2 virus (DENV2) in immunocompetent BALB/c mice, mimicking some aspects of the viral encephalitis. Mice presented neurological morbidity after the 7th day post infection. At the same time, histopathological analysis revealed that DENV2 led to damages in the CNS, such as hemorrhage, reactive gliosis, hyperplastic and hypertrophied microglia, astrocyte proliferation, Purkinje neurons retraction and cellular infiltration around vessels in the pia mater and in neuropil. Viral tropism and replication were detected in resident cells of the brain and cerebellum, such as neurons, astrocyte, microglia and oligodendrocytes. Results suggest that this classical mice model might be useful for analyzing the neurotropic effect of DENV with similarities to what occurs in human.


Assuntos
Encéfalo/virologia , Vírus da Dengue/patogenicidade , Dengue/patologia , Encefalite por Arbovirus/patologia , Gliose/patologia , Replicação Viral , Animais , Encéfalo/patologia , Células Cultivadas , Dengue/virologia , Vírus da Dengue/fisiologia , Encefalite por Arbovirus/virologia , Gliose/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microglia/patologia , Microglia/virologia , Células de Purkinje/patologia , Células de Purkinje/virologia
8.
Braz J Biol ; 66(1B): 211-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16710515

RESUMO

We report the occurrence of cyanobacterial blooms and the presence of cyanotoxins in water samples from the Armando Ribeiro Gonçalves reservoir (06 degrees 08 S and 37 degrees 07 W), located in the state of Rio Grande do Norte, in the semiarid region of northeastern Brazil. The cyanobacterial species were identified and quantified during the rainy and dry seasons in the year 2000. Cyanotoxins such as microcystins, saxitoxins and cylindrospermopsins were analyzed and quantified using HPLC and ELISA methods. The mixed toxic blooms of Cylindrospermopsis raciborskii, Microcystis spp (M. panniformis, M. protocystis, M. novacekii) and Aphanizomenon spp (Aphanizomenon gracile, A. cf. manguinii, A. cf. issastschenkoi) were persistent and represented 90-100% of the total phytoplankton species. Toxic cyanobacterial blooms from the Armando Ribeiro Gonçalves reservoir were analyzed and found to have three phases in relation to the annual cycle. During the rainy season, an intense toxic bloom of Cylindrospermopsis raciborskii was recorded along with saxitoxins (3.14 microg.L(-1)). During the transition period, between the rainy and dry seasons, different species of Microscytis occurred and microcystin as high as 8.8 microg.L(-1) was recorded. In the dry season, co-dominance of Cylindrospermopsis raciborskii, Microcystis spp and Aphanizomenon spp occurred and the concentrations of saxitoxin remained very low. Our results indicate the presence of microcystins (8.8 microg.L(-1)) and saxitoxins (3.14 microg.L(-1)) into the crude water, with increasing concentrations from the second fortnight of April to late May 2000. The occurrence of toxic blooms in this reservoir points to a permanent risk of cyanotoxins in supply waters, indicating the need for the implementation of bloom control measures to improve the water quality. Exposure of the local population to cyanotoxins through their potential accumulation in fish muscle must also be considered.


Assuntos
Aphanizomenon/isolamento & purificação , Toxinas Bacterianas/análise , Cylindrospermopsis/isolamento & purificação , Microcystis/isolamento & purificação , Microbiologia da Água , Aphanizomenon/metabolismo , Toxinas Bacterianas/biossíntese , Brasil , Cromatografia Líquida de Alta Pressão , Cylindrospermopsis/metabolismo , Monitoramento Ambiental/métodos , Ensaio de Imunoadsorção Enzimática , Microcystis/metabolismo , Densidade Demográfica , Estações do Ano
9.
Virology ; 489: 95-107, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26748331

RESUMO

The lack of an immunocompetent animal model for dengue mimicking the disease in humans is a limitation for advances in this field. Inoculation by intracerebral route of neuroadapted dengue strains in mice is normally lethal and provides a straightforward readout parameter for vaccine testing. However, systemic effects of infection and the immune response elicited in this model remain poorly described. In the present work, BALB/c mice infected by the intracerebral route with neuroadapted DENV2 exhibited several evidences of systemic involvement. DENV-inoculated mice presented virus infective particles in the brain followed by viremia, especially in late stages of infection. Infection induced cellular and humoral responses, with presence of activated T cells in spleen and blood, lymphocyte infiltration and tissue damages in brain and liver, and an increase in serum levels of some pro-inflammatory cytokines. Data highlighted an interplay between the central nervous system commitment and peripheral effects under this experimental condition.


Assuntos
Cérebro/virologia , Vírus da Dengue/fisiologia , Dengue/virologia , Animais , Cérebro/patologia , Dengue/patologia , Vírus da Dengue/patogenicidade , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Virulência
10.
J Clin Virol ; 32(4): 305-12, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15780810

RESUMO

The dengue virus (DV) causes one of the most important arthropod-borne human viral diseases throughout the tropical and subtropical countries. However, the morbidity and mortality of DV infections could be reduced with an early hospitalization care and a rapid risk identification of developing the dengue haemorrhagic fever (DHF). The nonstructural glycoprotein 1 (NS1) has been pointed as a reagent for immune-assay diagnostic test optimization. To evaluate this potential, recombinant DV2-NS1 proteins (rNS1) were produced from Escherichia coli (NS1EC) and insect cells (NS1IC) expression. The tests were performed by analysis of a human serum panel reacted against different rNS1 forms. The results demonstrated high correspondence between the DV positive sera and the assay results using native or refolded forms of either NS1IC or NS1EC. Also, the IgG and IgM anti-rNS1 level profiles showed distinct distribution, depending on protein form and disease status. However, the IgM anti-rNS1 reactions did not show sensibility to detect the DV in primary infections. The data obtained from the paired serum samples reactivity comparison suggested a heterogeneous human immune response and absence of correspondence between the IgG and IgM profile levels. Moreover, a patient with negative reference test could be detected by specific IgG anti-rNS1 assays presented here. Therefore, these results sustain the usefulness of dengue nonstructural proteins, in particular the NS1, in diagnostic tests as a complementary reagent.


Assuntos
Anticorpos Antivirais/sangue , Dengue/diagnóstico , Proteínas não Estruturais Virais/imunologia , Animais , Linhagem Celular , Dengue/sangue , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Técnicas Imunoenzimáticas , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Insetos , Proteínas Recombinantes/biossíntese , Proteínas não Estruturais Virais/biossíntese , Proteínas não Estruturais Virais/genética
11.
Transplant Proc ; 37(5): 2293-6, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15964402

RESUMO

Bone Marrow Transplant (BMT) is a lifesaving procedure for several diseases. Histocompatibility between host and donor is crucial for the success of this therapy. Since human leukocyte antigen (HLA) genes are the most polymorphic in humans, a foreknowledge of their frequencies and a vast register of volunteer donors are important for patients who need an unrelated donor. This research evaluated data from 3500 HLA-typed donors using PCR-SSP (One Lambda ABDRX kits, low/medium resolution). The allele and haplotype frequencies were calculated from the donor HLA typings. Among the total sample we observed that the allelic groups HLA-A*02, -B*35, and -DRB1*11 had frequencies of 0.228, 0.112, and 0.125, respectively. The haplotype HLA-A*01-B*08-DRB1*03 was the most frequent (0.024). We also compared our results with another study conducted in a Northeastern Brazilian population. The identification of the most common allelic groups and haplotypes is of great interest, not only to know the HLA composition of the population but also to search for the best HLA match for a transplant. However, the search for the perfect match depends on the eventual registration of every specific donor in the national registers for bone marrow donation.


Assuntos
Transplante de Medula Óssea/imunologia , Antígenos HLA/genética , Antígenos HLA/imunologia , Haplótipos , Doadores Vivos , Brasil , Antígenos HLA-B/genética , Antígenos HLA-B/imunologia , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Cadeias HLA-DRB1 , Teste de Histocompatibilidade , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples
12.
AIDS Res Hum Retroviruses ; 11(9): 1143-5, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8554914

RESUMO

PIP: Findings are reported from a study conducted to fully sequence the gp120 gene from a Brazilian HIV-1 isolate containing the GWGR motif and compare it to the Brazilian B and F sequences already described. Genomic DNA isolated from six patients in an ongoing HIV cohort study was screened for the presence of the viral V3 loop GWGR motif. Sequence analysis revealed that BZ(GWGR)1 is closely related to the North American MN prototype strain, with 80.1% amino acid identity and 89.1% nucleic acid similarity, and with 6 deletions and 11 insertions. Large differences were, however, observed when the V1 and V2 regions of MN and BZ(GWGR)1 were compared. Tree analysis based upon amino acid sequences and the four Brazilian isolates introduced in the analysis indicate that BZ(GWGR)1 belongs to the HIV-1 B subtypes. Several features of BZ(GWGR)1 suggest that some biological advantage may be derived from the differences between that variant and the American/European prototype strain.^ieng


Assuntos
Variação Genética , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/virologia , HIV-1/genética , Filogenia , Sequência de Aminoácidos , Sequência de Bases , Brasil/epidemiologia , Primers do DNA/genética , DNA Viral/genética , Infecções por HIV/epidemiologia , HIV-1/classificação , HIV-1/isolamento & purificação , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
13.
Biophys Chem ; 87(2-3): 111-20, 2000 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-11099174

RESUMO

The thermal stability of the lipase from Chromobacterium viscosum was assessed by deactivation (loss of activity), fluorescence, circular dichroism (CD) and static light scattering (SLS) measurements. Lipase fluorescence emission is dominated by the tryptophyl contribution. An increase in the tyrosyl contribution from 2 to 16% was only observed upon prolonged incubation at 60 degrees C. The effect of temperature on the tryptophyl quantum yield was studied and two activation energies were calculated. Tryptophan residues in the native structure have an activation energy of 1.9 kcal mol(-1) for temperature-dependent non-radiative deactivation of the excited state. A structural change occurs at approximately 66.7 degrees C and the activation energy increases to 10.2 kcal mol(-1). This structural change is not characterized by tryptophan exposure on the surface of the protein. The deactivation and the evolution of structural changes with time after lipase incubation at 60 degrees C were assessed by fluorescence, CD and SLS measurements. CD spectra show that both secondary and tertiary structures remain native-like after incubation at 60 degrees C in spite of the fluorescence changes observed (red-shift from 330 to 336 nm on the trytophyl emission). SLS measurements together with the CD data show that deactivation may be due to protein association between native molecules. Deactivation and the decrease on the fraction of non-associated native lipase evaluated by changes in fluorescence intensity with time, show apparent first order kinetics. According to the rate constants, fluorescence changes precede deactivation pointing to an underestimation of the deactivation. Reactivation upon dilution during the activity assay and substrate-induced reactivation due to lipase interfacial adsorption are possible causes for this underestimation.


Assuntos
Chromobacterium/enzimologia , Lipase/química , Fenômenos Químicos , Físico-Química , Dicroísmo Circular , Estabilidade Enzimática , Luz , Lipase/metabolismo , Modelos Moleculares , Conformação Proteica , Espalhamento de Radiação , Espectrometria de Fluorescência , Triptofano/química
14.
Toxicon ; 42(3): 289-95, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14559080

RESUMO

Blooms of cyanobacteria in water bodies cause serious environmental problems and the occurrence of toxic strains are also related with the human health. Aquatic animals could bioaccumulate microcystins (cyanobacteria hepatotoxins) and so, beyond water, the ingestion of contaminated food represents a human health risk. Recently, WHO recommended a maximum concentration of microcystins (MCYSTs) in drinking water and established the tolerable daily intake (TDI) for consumption of cyanobacteria products contends MCYSTs (0.04 microg(-1) kg(-1) day(-1)). Sepetiba Bay is located in the municipal districts of Rio de Janeiro, Mangaratiba and Itaguai; being an important place of fishing activity. Due to the industrial development in the area, this bay is submitted to different environmental impacts, increasing the organic and industrial pollution. A strain of the nanoplanktonic cyanobacteria Synechocystis aquatilis f. aquatilis that produce MCYSTs was already isolated. In this study, we verified MCYSTs presence in muscle tissue of fish and crustaceans, which were harvested monthly in Sepetiba Bay during 11 months, in order to evaluate the potential risk of their ingestion. MCYSTs were analyzed by immunoassay techniques using the ELISA Microcystin Plate Kit (ENVIROLOGIX INC) and the concentration were expressed as microcystin-LR equivalent. The analyses of seston samples, water, muscle tissues showed the presence of this cyanotoxin in all samples and it was verified that 19% of the animals' samples were above the limit recommended by WHO for human consumption. The maximum value found was of 103.3 microg kg(-1) (TDI 0.52 microg kg(-1) day(-1)) and the minimum, was 0.25 microg kg(-1) in crabs muscle tissue (TDI of 0.001 microg kg(-1) day(-1)). Such data demonstrate that, although in low concentrations, there is already a contamination of fish and crustaceans from Sepetiba Bay. We highlight that the recommended limit refers to healthy adult.


Assuntos
Toxinas Bacterianas/farmacocinética , Crustáceos/metabolismo , Cianobactérias/isolamento & purificação , Peixes/metabolismo , Peptídeos Cíclicos/farmacocinética , Animais , Toxinas Bacterianas/análise , Brasil , Toxinas Marinhas/análise , Toxinas Marinhas/farmacocinética , Microcistinas , Peptídeos Cíclicos/análise , Fitoplâncton/microbiologia , Distribuição Tecidual , Água/química , Microbiologia da Água , Poluentes da Água/farmacocinética
15.
Photochem Photobiol ; 72(4): 444-50, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11045712

RESUMO

The spectroscopic properties of alpha-chymotrypsin (alpha-Chym), L-tryptophan (Trp) and N-acetyl-L-tryptophan (NAT) solubilized in hydrated reverse micelles of sodium bis(2-ethylhexyl) sulfosuccinate in iso-octane were followed by fluorescence as a function of the amount of intramicellar water and initial pH. The lack of pH dependence observed for Trp in these systems, as opposed to what occurs in bulk water, and the similarities found for the protein in both media foresee different locations of these probes. In reverse micelles, fluorescence quenching studies using acrylamide emphasize the existence of structural alterations within the protein when its global charge changes from positive (pH = 7) to negative (pH = 10). The ensemble of the data points to an interfacial location of the zwitterionic Trp, an intermediate region of less tightly bound water for the location of the anionic Trp and NAT and an almost bulk water environment for alpha-Chym.


Assuntos
Quimotripsina/química , Ácido Dioctil Sulfossuccínico/química , Tensoativos/química , Triptofano/análogos & derivados , Triptofano/química , Animais , Bovinos , Quimotripsina/metabolismo , Micelas , Espectrometria de Fluorescência/métodos , Água/química , Água/metabolismo
16.
Pharmacol Biochem Behav ; 32(4): 885-90, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2798537

RESUMO

Sustained levels of proline comparable to those of human type II hyperprolinemia were achieved in blood and brain of rats subcutaneous proline administration twice a day from the 6th till the 28th day of life. Control rats were treated with saline in the same volumes. Behavioral studies using aversive and nonaversive tasks were performed one week or one month after treatment. Proline treatment did not affect rats' performance in the inhibitory avoidance task, but reduced significantly habituation in the open field. Our results seem to indicate that early postnatal administration of proline to rats affects habituation to a novel environment. If this happens to be so the present tendency to consider hyperprolinemia as a benign condition should be revised.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Habituação Psicofisiológica/efeitos dos fármacos , Prolina/farmacologia , Fatores Etários , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/anatomia & histologia , Química Encefálica , Feminino , Masculino , Tamanho do Órgão/efeitos dos fármacos , Prolina/sangue , Prolina/farmacocinética , Ratos , Ratos Endogâmicos , Distribuição Tecidual
17.
J Biochem Biophys Methods ; 34(1): 45-59, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9089383

RESUMO

This work describes a methodology to monitor protein unfolding by using the well known changes in tyrosine absorbance with the ionization of the side chain phenol group. It can be applied to proteins that are functionally active at pH values higher than 9.0 where the current UV differential spectroscopy technique can not be used. The simplicity and facility of the proposed methodology (only two absorbance measurements have to be acquired) can make it very useful namely for technological applications. Thermal unfolding of cutinase and alpha-chymotrypsin were followed using this methodology and the thermodynamic stability data were obtained assuming a two-state mechanism. The transition from the folded to the unfolded state was further confirmed by fluorescence maxima for both proteins proving the validity of the methodology based on UV measurements.


Assuntos
Proteínas/química , Espectrofotometria Ultravioleta/métodos , Animais , Hidrolases de Éster Carboxílico/química , Bovinos , Quimotripsina/química , Fusarium/enzimologia , Concentração de Íons de Hidrogênio , Desnaturação Proteica , Dobramento de Proteína , Proteínas Recombinantes/química , Termodinâmica
18.
J Photochem Photobiol B ; 29(1): 23-31, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7472800

RESUMO

Photophysical properties of a non-steroidal anti-inflammatory drug, Naproxen (6-methoxy alpha-methyl-2-naphthalene acetic acid sodium salt), were investigated in solvents of different polarity, hydrogen donor ability and also in cyclodextrins. The results indicate that in all cases the emitting state is the 1L(b) singlet. In alcoholic solvents, an intermolecular hydrogen bond is responsible for the observed photophysical behaviour of the probe whereas in non-protic solvents (polar and weakly polar) an intramolecular hydrogen bond type is postulated to rationalize the data found. In water, the non-radiative rate constant has a value similar to those found in aqueous solutions of alpha- and beta-cyclodextrins where the probe form complexes. The behaviour in water is explained by a water-structure enforced hydrophobic effect. The spectroscopic results are interpreted on the basis of a multiple-parameter model that considers specific solute-solvent interactions. These were also observed in the ground state and detected by Fourier transform infrared spectroscopy. Molecular mechanics (MM) and molecular orbital (AM1) calculations also support the existence of two conformations (rotamers) in Naproxen with non-equivalent intramolecular hydrogen bond-like formation.


Assuntos
Anti-Inflamatórios não Esteroides/química , Naproxeno/química , Ciclodextrinas/química , Hidrogênio , Ligação de Hidrogênio , Modelos Químicos , Estrutura Molecular , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier
19.
J Submicrosc Cytol Pathol ; 36(2): 121-30, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15554498

RESUMO

The difficulty in studying dengue virus (DENV) infection in humans and in developing a virus vaccine is the absence of a suitable animal model which develops the full spectra of the Dengue haemorrhagic fever (DHF) and Dengue shock syndrome (DSS). Despite the fact that viruses have been found in various animal tissues, we isolated DENV from tissues of adult BALB/c mice, inoculated with DENV serotype 2 (DENV-2) obtained from human serum. Viruses were ultrastructurally identified and immunolocalized by immunofluorescence techniques in C6/36 mosquito cell cultures, inoculated with tissues (liver, lung, kidney and cerebellum) macerate supernatant from mice, 48 h post-infection (p.i.). These organs, collected at the same stage of infection, were examined histologically. The histopathological analysis revealed focal alterations in all tissues examined. Liver contained focal ballooned hepatocytes, but without modifying the average diameter of the majority of hepatocytes. Sinusoidal lumen was significantly diminished at this stage but portal and centrolobular veins became congested. Lungs exhibited hemorrhagic foci in the alveolar space, vascular congestion and focal alveolitis. Cerebellar tissue showed rare foci of neuronal compactation (Purkinje cells) and perivascular oedema. In kidneys it was observed an increase in glomerular volume with augmented endocapillary and mesangial cellularity, with reactivity to anti-IgM in all glomeruli of infected mice. In conclusion, DENV-2 was found in all tissues examined early in the evolution of infection. Presence of viruses in tissues has mainly led to hemodynamic alterations with generalized vascular congestion and increased permeability, and mast cell recruitment in lungs. The latter could participate in the vascular modifications in tissues.


Assuntos
Vírus da Dengue/isolamento & purificação , Dengue/patologia , Modelos Animais de Doenças , Animais , Técnicas de Cultura de Células , Cerebelo/patologia , Cerebelo/virologia , Culicidae/virologia , Dengue/virologia , Vírus da Dengue/imunologia , Vírus da Dengue/ultraestrutura , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Rim/patologia , Rim/virologia , Fígado/patologia , Fígado/virologia , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 56A(9): 1703-10, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10952132

RESUMO

Ground and excited state properties of a pre-twisted 7-diethylaminocoumarin dye (BC I) belonging to the family of coumarinyl benzopyrano pyridines are reported in isooctane-AOT-formamide reversed micelles. In reversed micelles, BC I, albeit soluble in formamide, is found to remain out of the polar solvent pool. But the photophysical properties of the probe dye are sensitive to the changes in the polarity of the interfacial region caused by increase in F0 = [formamide]/[AOT]. The spectroscopic properties and dynamics are indicative of dual emission due to the solubilization of the dye in two different environments (the nonpolar solvent and the interfacial region). Results of the steady-state fluorescence anisotropy experiments also support the presence of two different environments. The present study once again proves that molecular size is an important parameter in the study of the photophysical properties of the flexible aminocoumarin dyes in reversed micelles.


Assuntos
Cumarínicos/química , Ácido Dioctil Sulfossuccínico/química , Polarização de Fluorescência/métodos , Corantes Fluorescentes/química , Formamidas/química , Piridinas/química , Micelas
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