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1.
Sci Rep ; 12(1): 10262, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715474

RESUMO

Limited information is available about the effect of mid-pregnancy viral infections on the placental expression of efflux transporters and offspring behavior. We hypothesized that maternal exposure to polyinosinic-polycytidylic acid [poly(I:C)], a synthetic double-stranded RNA viral mimic, would impair placental cell turnover, the expression of selected ABC transporters and adult offspring behavior. C57BL/6 mice were administered poly(I:C) (10 mg/Kg;ip) or vehicle at gestational day (GD) 13.5 (mid-pregnancy). Dams were euthanized for blood collection 4 h after injection, fetal and placental collection at GD18.5 or allowed to deliver spontaneously at term. At GD 13.5, poly(I:C) induced an acute pro-inflammatory response characterized by an increase in maternal plasma levels of IL-6, CXCL-1 and CCL-2/MCP-1. At GD 18.5, poly(I:C) decreased cell proliferation/death in the labyrinthine and increased cell death in the junctional zones, characterizing a disruption of placental cell turnover. Abca1 and Abcg1 immunolabelling was decreased in the labyrinthine zone, whereas Abca1, Abcg1 and breast cancer resistance transporter (Bcrp) expression increased in the junctional zone. Moreover, adult offspring showed motor and cognitive impairments in the Rotarod and T-water maze tests. These results indicate that viral infection during mid-pregnancy may disrupt relevant placental efflux transporters, as well as placental cell turnover and offspring behavior in adult life.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Disfunção Cognitiva , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Disfunção Cognitiva/metabolismo , Feminino , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Neoplasias/metabolismo , Placenta/metabolismo , Poli I-C/farmacologia , Gravidez
2.
Reprod Toxicol ; 98: 82-91, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32916274

RESUMO

Bacterial infection alters placental ABC transporters expression. These transporters provide fetal protection against circulating xenobiotics and environmental toxins present in maternal blood. We hypothesized that lipopolysaccharide (LPS-bacterial mimic) alters the yolk sac morphology and expression of key ABC transporters in a gestational-age dependent manner. Yolk sac samples from C57BL/6 mice were obtained at gestational ages (GD) 15.5 and GD18.5, 4 or 24 h after LPS exposure (150ug/kg; n = 8/group). Samples underwent morphometrical, qPCR and immunohistochemistry analysis. The volumetric proportions of the histological components of the yolk sac did not change in response to LPS. LPS increased Abcg2 expression at GD15.5, after 4 h of treatment (p < 0.05). No changes in Abca1, Abcb1a/b, Abcg1, Glut1, Snat1, Il-1ß, Ccl2 and Mif were observed. Il-6 and Cxcl1 were undetectable in the yolk sac throughout pregnancy. Abca1, breast cancer resistance protein (Bcrp, encoded by Abcg2) and P-glycoprotein (P-gp/ Abcb1a/b) were localized in the endodermal (uterine-facing) epithelium and to a lesser extent in the mesothelium (amnion-facing), whereas Abca1 was also localized to the endothelium of the yolk sac blood vessels. LPS increased the labeling area and intensity of Bcrp in the yolk sac's mesothelial cells at GD15.5 (4 h), whereas at GD18.5, the area of Bcrp labeling in the mesothelium (4 and 24 h) was decreased (p < 0.05). Bacterial infection has the potential to change yolk sac barrier function by affecting Bcrp and Abcg2 expression in a gestational-age dependent-manner. These changes may alter fetal exposure to xenobiotics and toxic substances present in the maternal circulation and in the uterine cavity.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Lipopolissacarídeos/farmacologia , Saco Vitelino/efeitos dos fármacos , Animais , Feminino , Idade Gestacional , Camundongos Endogâmicos C57BL , Gravidez , Saco Vitelino/metabolismo
3.
Sci Rep ; 9(1): 11488, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391498

RESUMO

Malaria in Pregnancy (MiP) is characterized by placental accumulation of Plasmodium-infected erythrocytes, intrauterine growth restriction (IUGR) and preterm delivery (PTD). Placental ATP-binding cassette (ABC) transporters mediate the efflux of nutrients, cytokines and xenobiotics. The expression and activity of these transporters are highly responsive to infection. We hypothesized that MiP would perturb the expression of placental ABC transporters, promoting PTD. Peripheral blood, spleens, livers and placentas of pregnant mice, infected with Plasmodium berghei ANKA on gestational day (GD) 13.5, were collected and analyzed on GD18.5. The primary consequences of human MiP, including IUGR, PTD (20%) and placental inflammation, were recapitulated in our mouse model. Electron microscopy revealed attenuated presence of labyrinthine microvilli and dilated spongiotrophoblasts -granular endoplasmic reticulum cisternae. Additionally, a decrease in placental Abca1 (ABCA1), Abcb1b (P-glycoprotein), Abcb9 and Abcg2 (BCRP) expression was observed in MiP mice. In conclusion, MiP associated with PTD impairs placental ABC transporters' expression, potentially modulating placental nutrient, environmental toxin and xenobiotic biodistribution within the fetal compartment, and may, at some degree, be involved with pregnancy outcome in MiP.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Malária/complicações , Trabalho de Parto Prematuro/imunologia , Placenta/patologia , Plasmodium berghei/imunologia , Animais , Modelos Animais de Doenças , Feminino , Humanos , Malária/imunologia , Malária/parasitologia , Troca Materno-Fetal/imunologia , Camundongos , Nutrientes/metabolismo , Trabalho de Parto Prematuro/parasitologia , Trabalho de Parto Prematuro/patologia , Placenta/metabolismo , Gravidez , Xenobióticos/metabolismo
4.
Adv Exp Med Biol ; 1062: 361-371, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29845545

RESUMO

The literature on sero-epidemiological studies of flaviviral infections in the African continent is quite scarce. Much of the viral epidemiology studies have been focussing on diseases such as HIV/AIDS because of their sheer magnitude and impact on the lives of people in the various affected countries. Increasingly disease outbreaks caused by arboviruses such as the recent cases of chikungunya virus, dengue virus and yellow fever virus have prompted renewed interest in studying these viruses. International agencies from the US, several EU nations and China are starting to build collaborations to build capacity in many African countries together with established institutions to conduct these studies. The Tofo Advanced Study Week (TASW) was established to bring the best scientists from the world to the tiny seaside town of Praia do Tofo to rub shoulders with African virologists and discuss cutting-edge science and listen to the work of researchers in the field. In 2015 the 1st TASW focussed on Ebola virus. The collections of abstracts from participants at the 2nd TASW which focused on Dengue and Zika virus as well as presentations on other arboviruses are collated in this chapter.


Assuntos
Infecções por Arbovirus/epidemiologia , Arbovírus/isolamento & purificação , África/epidemiologia , Animais , Anticorpos Antivirais/sangue , Infecções por Arbovirus/sangue , Infecções por Arbovirus/virologia , Arbovírus/genética , Arbovírus/imunologia , Humanos , Estudos Soroepidemiológicos
5.
Aquat Toxicol ; 104(3-4): 291-8, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21652016

RESUMO

In the present study, in vivo and in vitro exposures were used to assess the genotoxicity of lead (Pb) to the freshwater fish Prochilodus lineatus. The comet assay using blood, liver and gill cells, and the occurrence of micronuclei (MN) and other erythrocytic nuclear abnormalities (ENA) were used to assess the genotoxic potential of lead in vivo. Metallothionein content (MT) was measured in fish liver in order to evaluate the protection of fish against Pb toxicity. Fish erythrocytes were exposed to Pb in vitro (1, 3 and 6 h) and the number of viable cells, DNA integrity, using the comet assay, and lysosomal membrane stability, measured by the neutral red retention assay (NRRA) were analyzed. The results of the comet assay after in vivo toxicity tests (6, 24 and 96 h) showed that Pb was genotoxic for all the three tissues analyzed after 96 h exposure. A significant increase in liver MT content was observed after 6 and 24 h of Pb exposure. MN frequency did not increase after Pb exposures, but the frequency of the other ENA, such as kidney-shaped nuclei, segmented nuclei and lobed nuclei, showed a significant increase after 24 and 96 h, indicating that ENA is a better biomarker for Pb exposure than MN alone after short-term exposures. The results of the comet assay performed with erythrocytes in vitro exposed to lead confirmed its genotoxic effect and showed that DNA damage increased with increasing exposure time. Moreover, the NRRA clearly indicated that Pb induces a destabilization of the lysosomal membrane. These results demonstrate the potential genotoxicity and cytotoxicity of lead after acute exposures.


Assuntos
Peixes/fisiologia , Chumbo/toxicidade , Mutagênicos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Monitoramento Ambiental , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Água Doce/química , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Chumbo/análise , Chumbo/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Metalotioneína/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
6.
Eur Eat Disord Rev ; 18(1): 58-66, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20054878

RESUMO

PURPOSE: The impact of weight on quality of life (IWQOL-Lite) is a self-administered instrument that assesses quality of life in obesity. It is composed of 31 items and five domains (physical function, self-esteem, sexual life, public distress, and work). The aim of the present study was to evaluate reliability (test-retest), internal structure, construct validity and discriminant validity. METHODS: IWQOL-Lite scores were obtained from 89 people in a Weight Watchers institution (clinical sample) and 156 community volunteers (community sample). The participants were selected based on the same criteria: gender (female) and age (> 24 years), except for BMI. The community sample also completed the SF-36, a generic measure of health-related quality of life. RESULTS: The Brazilian IWQOL-Lite demonstrated good test-retest reliability, internal consistency, discriminative validity and convergent validity. CONCLUSIONS: The IWQOL-Lite is the first specific instrument validated in Brazil for assessing quality of life in obesity. The results reveal that IWQOL-Lite is an instrument with good psychometric properties. Nevertheless, in some cases results were dissimilar to those reported in earlier studies using the original American English.


Assuntos
Inquéritos Epidemiológicos , Obesidade/psicologia , Psicometria/normas , Qualidade de Vida/psicologia , Inquéritos e Questionários/normas , Adulto , Brasil , Estudos Transversais , Feminino , Nível de Saúde , Humanos , Pessoa de Meia-Idade , Seleção de Pacientes , Reprodutibilidade dos Testes , Autoimagem
7.
Rev Port Cir Cardiotorac Vasc ; 17(2): 109-13, 2010.
Artigo em Português | MEDLINE | ID: mdl-21298123

RESUMO

Traditional open repair of aortic arch aneurysms is a complex and demanding surgery that requires cardiopulmonary bypass, hypothermia and circulatory arrest, being associated with considerable morbidity and mortality. Even with significant advances in pre-operative assessment and optimization, advanced anaesthetic techniques and intensive care, conventional aortic arch repairs remain amongst the highest risk of across all surgical specialties. Therefore, a hybrid approach with sequential transposition of the supra-aortic branches and endovascular stent-graft placement is a less invasive alternative treatment that opens the indication for repair to more critical patients. We report our institution's first experience in the hybrid surgery of aortic arch aneurysms.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Vasculares/métodos
8.
Arq. bras. med. vet. zootec ; Arq. bras. med. vet. zootec. (Online);59(2): 358-362, abr. 2007.
Artigo em Português | LILACS | ID: lil-455746

RESUMO

Avaliou-se o tecido de granulação formado com o uso de membrana amniótica e pericárdio canino como curativo biológico oclusivo em feridas cutâneas experimentais. Utilizaram-se 15 cães; em cada animal, foram produzidas três feridas na região torácica dorsal. As feridas craniais e caudais receberam aloenxerto de membrana amniótica e pericárdio canino, respectivamente, e as feridas intermediárias (controle) curativo não aderente. No sétimo dia, sobre todas as feridas, foram feitas auto-enxertias cutâneas. Foram realizadas avaliações clínicas, histológicas, incluindo contagem e diâmetro médio dos vasos sangüíneos do tecido de granulação bem como coleta de secreção das feridas e dos enxertos. Concluiu-se que a aplicação do curativo de membrana amniótica e de pericárdio canino sobre feridas cutâneas durante sete dias não estimula o aparecimento da granulação necessária para a aplicação à enxertia cutânea, podendo, apenas, ser utilizado como curativo biológico oclusivo.


The granulation tissue formed with the use of amniotic membrane (ME) and canine pericardium (PE) as an occlusive biological dressing in experimental cutaneous wounds was evaluated Fifteen dogs, having three wounds on the dorsal thoracic region of each (FA -amniotic, FC -control and FP-pericardium) were used. Clinical and histological evaluations were carried out, including counting and measuring the average diameter of the blood vessels of the granulation tissue, as well as bacteriological exams (swabs) of the wounds and the grafts. The granulation tissue formed after seven days of using the canine amniotic membrane showed a vascular histological aspect, being able to be favorable to the cutaneous grafting. It was concluded that the use of amniotic membrane and canine pericardium dressing on cutaneous wounds during seven days did not stimulate the presence of granulation necessary for the use of cutaneous grafting, however, it can be used as an occlusive biological graft.


Assuntos
Animais , Masculino , Feminino , Âmnio/transplante , Curativos Biológicos/efeitos adversos , Cães , Pericárdio/transplante , Tecido de Granulação/transplante , Transplante de Tecidos/métodos
9.
Int J Cosmet Sci ; 28(2): 95-101, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18492143

RESUMO

A new method for high-resolution analyses of hair surface charge density under ambient conditions is presented in this paper. Electrostatic force microscopy (EFM) is used here to analyze changes in surface charge density in virgin hair, bleached hair, and hair treated with a cationic polymer. The atomic force microscopy technique is used concomitantly to analyze morphological changes in hair roughness and thickness. The EFM images depict exactly how the polymer is distributed on the surface of the hair fiber. The EFM's powerful analytical tools enabled us to evaluate the varying degrees of interaction between the hair fiber surface charge density and the cationic polymer. The surface charge density and the polymer's distribution in the hair fibers are presented in the light of EFM measurements.

10.
Braz J Med Biol Res ; 38(2): 215-20, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15785832

RESUMO

Gastroesophageal reflux (GER) disorder was studied in children and adolescents with chronic and/or recurrent rhinosinusitis not associated with bronchial asthma. Ten children with a clinical and radiological diagnosis of chronic and/or recurrent rhinosinusitis, consecutively attended at the Pediatric Otolaryngology Outpatient Clinic, Federal University of São Paulo, were evaluated. Prolonged esophageal pH monitoring was used to investigate GER disorder. The mean age of the ten patients evaluated (eight males) was 7.4 +/- 2.4 years. Two patients presented vomiting as a clinical manifestation and one patient presented retrosternal pain with a burning sensation. Twenty-four-hour esophageal pH monitoring was performed using the Sandhill apparatus. An antimony probe electrode was placed in the lower third of the esophagus, confirmed by fluoroscopy and later by a chest X-ray. The parameters analyzed by esophageal pH monitoring included: total percent time of the presence of acid esophageal pH, i.e., pH below 4 (<4.2%); total number of acid episodes (<50 episodes); number of reflux episodes longer than 5 min (3 or less), and duration of the longest reflux episode (<9.2 min). One patient (1/10, 10%) presented a 24-h esophageal pH profile compatible with GER disorder. This data suggest that an association between chronic rhinosinusitis not associated with bronchial asthma and GER disorder may exist in children and adolescents, especially in those with compatible GER disorder symptoms. In these cases, 24-h esophageal pH monitoring should be performed before indicating surgery, since the present data suggest that 10% of chronic rhinosinusitis surgeries can be eliminated.


Assuntos
Refluxo Gastroesofágico/etiologia , Rinite/complicações , Sinusite/complicações , Criança , Pré-Escolar , Doença Crônica , Feminino , Refluxo Gastroesofágico/diagnóstico , Humanos , Concentração de Íons de Hidrogênio , Masculino , Recidiva
11.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;38(2): 215-220, fev. 2005. tab
Artigo em Inglês | LILACS | ID: lil-393658

RESUMO

Gastroesophageal reflux (GER) disorder was studied in children and adolescents with chronic and/or recurrent rhinosinusitis not associated with bronchial asthma. Ten children with a clinical and radiological diagnosis of chronic and/or recurrent rhinosinusitis, consecutively attended at the Pediatric Otolaryngology Outpatient Clinic, Federal University of São Paulo, were evaluated. Prolonged esophageal pH monitoring was used to investigate GER disorder. The mean age of the ten patients evaluated (eight males) was 7.4 ± 2.4 years. Two patients presented vomiting as a clinical manifestation and one patient presented retrosternal pain with a burning sensation. Twenty-four-hour esophageal pH monitoring was performed using the Sandhill apparatus. An antimony probe electrode was placed in the lower third of the esophagus, confirmed by fluoroscopy and later by a chest X-ray. The parameters analyzed by esophageal pH monitoring included: total percent time of the presence of acid esophageal pH, i.e., pH below 4 (<4.2 percent); total number of acid episodes (<50 episodes); number of reflux episodes longer than 5 min (3 or less), and duration of the longest reflux episode (<9.2 min). One patient (1/10, 10 percent) presented a 24-h esophageal pH profile compatible with GER disorder. This data suggest that an association between chronic rhinosinusitis not associated with bronchial asthma and GER disorder may exist in children and adolescents, especially in those with compatible GER disorder symptoms. In these cases, 24-h esophageal pH monitoring should be performed before indicating surgery, since the present data suggest that 10 percent of chronic rhinosinusitis surgeries can be eliminated.


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Asma/complicações , Refluxo Gastroesofágico/etiologia , Rinite/complicações , Sinusite/complicações , Doença Crônica , Refluxo Gastroesofágico/diagnóstico , Concentração de Íons de Hidrogênio , Recidiva
12.
J Microsc ; 215(Pt 1): 13-23, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15230871

RESUMO

The surface topography of human hair, as defined by the outer layer of cellular sheets, termed cuticles, largely determines the cosmetic properties of the hair. The condition of the cuticles is of great cosmetic importance, but also has the potential to aid diagnosis in the medical and forensic sciences. Atomic force microscopy (AFM) has been demonstrated to offer unique advantages for analysis of the hair surface, mainly due to the high image resolution and the ease of sample preparation. This article presents an algorithm for the automatic analysis of AFM images of human hair. The cuticular structure is characterized using a series of descriptors, such as step height, tilt angle and cuticle density, allowing quantitative analysis and comparison of different images. The usefulness of this approach is demonstrated by a classification study. Thirty-eight AFM images were measured, consisting of hair samples from (a) untreated and bleached hair samples, and (b) the root and distal ends of the hair fibre. The multivariate classification technique partial least squares discriminant analysis is used to test the ability of the algorithm to characterize the images according to the properties of the hair samples. Most of the images (86%) were found to be classified correctly.


Assuntos
Cabelo/ultraestrutura , Algoritmos , População Negra , Folículo Piloso/ultraestrutura , Humanos , Microscopia de Força Atômica/métodos , Sensibilidade e Especificidade , Estados Unidos , População Branca
15.
J Cosmet Sci ; 54(3): 271-81, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12858226

RESUMO

A new method for morphological hair analysis at high resolution and under ambient conditions is presented in this paper. The AFM has been used in these experiments to analyze morphological changes in hair roughness and thickness after UV radiation. Through the powerful analytical AFM tools, changes in hair morphology can be proven. A new quantitative methodology to evaluate hair structure is presented in this paper.


Assuntos
Cabelo/efeitos da radiação , Microscopia de Força Atômica , Raios Ultravioleta , Cabelo/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura , Propriedades de Superfície
16.
Mol Biochem Parasitol ; 117(2): 169-77, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11606227

RESUMO

We isolated a gene that is differentially expressed during Trypanosoma cruzi metacyclogenesis by the representation of differential expression (RDE) method, using differentiating epimastigotes cultured in chemically defined medium. This gene, the metacyclogenin gene, encodes a 630-nucleotide mRNA that is specifically associated with the polysomes of epimastigotes allowed to differentiate for 24 h. We sequenced and characterized the metacyclogenin gene and found that there were at least three copies of the gene organized into tandem 2.8 kb repeats in the genome of T. cruzi Dm28c. We analyzed the repeats and found that they contained two other genes, one encoding tryparedoxin peroxidase and the other encoding a 0.6 kb mRNA (named associated gene or AG) with sequences showing no significant similarity to those in the GenBank database. Northern blot analysis of polysomal RNA extracted from replicating and differentiating epimastigotes showed that metacyclogenin and AG genes displayed similar patterns of expression. Their products were detected only in differentiating epimastigotes, whereas tryparedoxin peroxidase was detected only in the polysomal RNA fraction of replicating and differentiating epimastigotes. In Northern blots of total RNA from differentiating and replicating epimastigotes, the genes studied were detected in both cell populations. The differential expression of the metacyclogenin gene was confirmed by immunocytochemistry studies showing that the protein is detected only in differentiating (adhered) epimastigote. The results suggest that mRNA mobilization to polysomes is an important mechanism in the regulation of gene expression in T. cruzi.


Assuntos
Clonagem Molecular/métodos , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Protozoários/genética , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/metabolismo , Sequência de Aminoácidos , Animais , Meios de Cultura , DNA Complementar/genética , Genoma de Protozoário , Estágios do Ciclo de Vida , Dados de Sequência Molecular , Mapeamento Físico do Cromossomo , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Análise de Sequência de DNA , Trypanosoma cruzi/genética
17.
Rev Bras Enferm ; 54(2): 268-70, 2001.
Artigo em Português | MEDLINE | ID: mdl-12240654

RESUMO

This article outlines the trajectory of the Brazilian Association of Nursing (ABEn) in Alagoas and its influence in the organization of the nursing profession in this federal state. It points out that ABEn-AL was the first institution to organize nursing in Alagoas, since it was founded prior to any nursing graduation course or even any nursing syndicate. Therefore, ABEn is considered a decisive landmark in the political and professional organization of nursing in the state of Alagoas.


Assuntos
Sociedades de Enfermagem/história , Brasil , História do Século XX , Sociedades de Enfermagem/organização & administração
18.
J Struct Biol ; 136(3): 181-9, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12051898

RESUMO

Treatment of tachyzoites of Toxoplasma gondii with the calcium ionophore A23187 induced dramatic ultrastructural changes that were observed by light and electron microscopy. Light microscopy showed a higher percentage (22%) of tachyzoites with the conoid extruded when compared to control parasites. Electron microscopy confirmed the conoid extrusion by both transmission and scanning electron microscopy. Freeze-fracture replicas showed that the plasma membrane adjacent to cytoplasmic dense granules appeared devoid of intramembranous particles. Membrane-limited vesicles and filopodium-like structures at the cell surface were observed in treated cells. 3-D reconstruction from serial sections confirmed the data and showed a heterogeneity in dense granule shape not reported in control cells.


Assuntos
Calcimicina/farmacologia , Toxoplasma/ultraestrutura , Animais , Membrana Celular/ultraestrutura , Técnica de Fratura por Congelamento , Processamento de Imagem Assistida por Computador , Membranas Intracelulares/ultraestrutura , Ionóforos/farmacologia , Microscopia Eletrônica , Toxoplasma/efeitos dos fármacos , Toxoplasma/fisiologia
20.
Pathobiology ; 68(3): 113-23, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11174068

RESUMO

We investigated the involvement of protein kinase C (PKC) in the in vitro invasiveness of the A-172, U-87 and U-373 human glioma cell lines, as well as the role of ornithine decarboxylase (ODC) and/or extracellular-signal-regulated kinase (ERK) in the actions of PKC. Thus, cells were treated under serum-free conditions with the PKC activator phorbol 12-myristate 13-acetate (PMA), or with the PKC inhibitors bisindolylmaleimide I (GF 109203X) or calphostin C in the absence or presence of the ODC inhibitor D,L-alpha-difluoromethylornithine (DFMO), and/or the mitogen-activated protein kinase/extracellular-signal-regulated kinase inhibitor 2'-amino-3'-methoxyflavone (PD 098059). Subsequently, cells were assessed for membrane-type 1 matrix metalloproteinase (MT1-MMP) mRNA contents, 72-kD latent, and 59/62-kD activated matrix metalloproteinase 2 (MMP-2) in conditioned media, as well as invasiveness. For these purposes, we used Northern blot analysis, gelatine zymography, and an in vitro filter invasion assay, respectively. Data were related to those found with untreated cells. PKC activity was 2- to 3-fold stimulated by PMA (100 nM for 30 min), and about 2-fold inhibited by calphostin C (40 nM for 2 h) or GF 109203X (5 microM for 20 min). This was accompanied by a similar increase or decrease, respectively, in MT1-MMP mRNA expression, 59/62-kD MMP-2 activity, and in vitro invasion. Inhibition of ODC activity (about 2-fold by 24 h DFMO 5 mM), ERK activation (almost completely by 20 min PD 098059 50 microM), or both these enzymes simultaneously led to a reduction by about half in levels of MT1-MMP mRNA, 59/62-kD MMP-2 activity, and invasion in untreated as well as PMA-stimulated cells. The use of these compounds did not significantly alter the inhibitory effects of GF 109203X or calphostin C. Modulation of PKC and/or ERK activity resulted in corresponding changes in ERK and/or ODC activities, but interference with ODC affected neither ERK nor PKC. Our data suggest a regulatory role for PKC, in co-operation with ERK and ODC, in glioma cell invasion, by modulation of MT1-MMP mRNA expression and MMP-2 activation.


Assuntos
Glioma/enzimologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Ornitina Descarboxilase/metabolismo , Proteína Quinase C/metabolismo , Meios de Cultivo Condicionados/metabolismo , Eflornitina/farmacologia , Flavonoides/farmacologia , Humanos , Indóis/farmacologia , Maleimidas/farmacologia , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinases da Matriz Associadas à Membrana , Metaloendopeptidases/genética , Metaloendopeptidases/metabolismo , Naftalenos/farmacologia , Invasividade Neoplásica , RNA Mensageiro/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/enzimologia
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