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1.
Malar J ; 19(1): 425, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228693

RESUMO

BACKGROUND: Malaria remains a major public health concern in the Democratic Republic of the Congo (DRC) and its control is affected by recurrent conflicts. Médecins Sans Frontières (MSF) initiated several studies to better understand the unprecedented incidence of malaria to effectively target and implement interventions in emergency settings. The current study evaluated the main vector species involved in malaria transmission and their resistance to insecticides, with the aim to propose the most effective tools and strategies for control of local malaria vectors. METHODS: This study was performed in 52 households in Shamwana (Katanga, 2014), 168 households in Baraka (South Kivu, 2015) and 269 households in Kashuga (North Kivu, 2017). Anopheles vectors were collected and subjected to standardized Word Health Organization (WHO) and Center for Disease Control (CDC) insecticide susceptibility bioassays. Mosquito species determination was done using PCR and Plasmodium falciparum infection in mosquitoes was assessed by ELISA targeting circumsporozoite protein. RESULTS: Of 3517 Anopheles spp. mosquitoes collected, Anopheles gambiae sensu lato (s.l.) (29.6%) and Anopheles funestus (69.1%) were the main malaria vectors. Plasmodium falciparum infection rates for An. gambiae s.l. were 1.0, 2.1 and 13.9% for Shamwana, Baraka and Kashuga, respectively. Anopheles funestus showed positivity rates of 1.6% in Shamwana and 4.4% in Baraka. No An. funestus were collected in Kashuga. Insecticide susceptibility tests showed resistance development towards pyrethroids in all locations. Exposure to bendiocarb, malathion and pirimiphos-methyl still resulted in high mosquito mortality. CONCLUSIONS: This is one of only few studies from these conflict areas in DRC to report insecticide resistance in local malaria vectors. The data suggest that current malaria prevention methods in these populations are only partially effective, and require additional tools and strategies. Importantly, the results triggered MSF to consider the selection of a new insecticide for indoor residual spraying (IRS) and a new long-lasting insecticide-treated net (LLIN). The reinforcement of correct usage of LLINs and the introduction of targeted larviciding were also included as additional vector control tools as a result of the studies.


Assuntos
Anopheles/parasitologia , Resistência a Inseticidas , Malária Falciparum/transmissão , Malária/transmissão , Mosquitos Vetores/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Animais , República Democrática do Congo , Feminino , Povos Indígenas , Refugiados
2.
Trans R Soc Trop Med Hyg ; 115(11): 1339-1344, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34324683

RESUMO

BACKGROUND: Insecticide resistance has become a widespread problem causing a decline in the effectiveness of vector control tools in sub-Saharan Africa. In this situation, ongoing monitoring of vector susceptibility to insecticides is encouraged by the WHO to guide national malaria control programmes. Our study was conducted from April to November 2018 in Tchonka (Sud-Kivu, Democratic Republic of the Congo) and reported primary data on the resistance status of Anopheles funestus and Anopheles gambiae. METHODS: Insecticide susceptibility bioassays were performed on wild populations of A. funestus and A. gambiae using WHO insecticide-impregnated papers at discriminating concentration. In addition, PCR was performed to identify mosquito species and to detect kdr and ace-1R mutations involved in insecticide resistance. RESULTS: Bioassay results show resistance to all tested insecticides except pirimiphos-methyl, propoxur, fenitrothion and malathion with a mortality rate ranging from 95.48 to 99.86%. The addition of piperonyl butoxide (PBO) increased the susceptibility of vectors to deltamethrin and alpha-cypermethrin by exhibiting a mortality ranging from 91.50 to 95.86%. The kdr mutation was detected at high frequencies (approximately 0.98) within A. gambiae while ace-1R was not detected. CONCLUSIONS: This study provides useful data on the insecticide resistance profiles of malaria vector populations to better manage vector control. Our results highlight that, despite the high level of resistance, organophosphorus compounds and pyrethroids + PBO remain effective against the vectors.


Assuntos
Anopheles , Inseticidas , Malária , Piretrinas , Animais , Anopheles/genética , República Democrática do Congo/epidemiologia , Humanos , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Malária/prevenção & controle , Controle de Mosquitos , Mosquitos Vetores/genética , Piretrinas/farmacologia
3.
Afr J Prim Health Care Fam Med ; 10(1): e1-e11, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29781688

RESUMO

BACKGROUND:  Patient-provider communication is an interpersonal interaction between a patient and a health care provider. OBJECTIVE:  This study explored patients' communication preferences and perceptions on what factors influence the patient-provider communication in primary health care settings in Rwanda. METHODS:  In-depth semi-structured interviews with 15 individuals including 8 with limited literacy. A thematic inductive analysis was used. RESULTS:  Patients valued communication with providers and expressed the need for interacting with caring, empathic providers who can share all the information they want and involve them in their own care. Health literacy and power issues were factors that may influence patient-provider communication. Patients with limited literacy appeared to rely highly on health care providers for making decisions about and managing their health care. CONCLUSION:  The expressed preferences, including those of patients with limited literacy, aligned well with the patient-centred care model. There were indications of a power imbalance weighing on the provider's side. Although patients with limited literacy were reliant on providers for decision-making, they were ready to be more involved in the care, suggesting a potential for improved patient involvement even for patients with paternalistic care preferences. These patients' insights can impact policies and curricula to optimise clinical practice. Generated knowledge will contribute to the indispensable yet underdeveloped field of health communication in sub-Saharan Africa. PRACTICE IMPLICATIONS:  Findings call for more inclusion of patient perspectives in the patient-provider encounter. This could require more training of professionals and research on the topic, both in Rwanda and in other regions.


Assuntos
Comunicação , Atenção à Saúde , Relações Médico-Paciente , Adulto , Empatia , Feminino , Letramento em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Participação do Paciente , Preferência do Paciente , Assistência Centrada no Paciente , Ruanda , Adulto Jovem
4.
Biochim Biophys Acta ; 795(1): 125-9, 1984 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-6466691

RESUMO

Male Sprague-Dawley rats were exposed to increasing concentrations (15-22 mg/l) of ethanol vapor over a 4-day period. Phospholipids were analyzed in liver mitochondria isolated from ethanol-treated and pair-weighted control animals. After a 2-day inhalation period, the proportion of monoenoic acids in total phospholipids increased, whereas that of arachidonic acid decreased. These changes were more striking in phosphatidylcholine (PC) than in phosphatidylethanolamine (PE). The decrease in 20:4 may be related to increased lipid peroxidation. After a 4-day inhalation period, quite different changes in phospholipid fatty acids were found. They consisted in a trend towards a more unsaturated system, the proportion of 20:4 being increased in PC and that of 22:6 in PE. This increase in polyunsaturated acids might be related to a direct ethanol effect on lipid structure and/or metabolism that would be linked to the high blood alcohol level present at this stage of ethanol intoxication.


Assuntos
Etanol/farmacologia , Lipídeos de Membrana/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Animais , Etanol/administração & dosagem , Membranas Intracelulares/metabolismo , Peróxidos Lipídicos/metabolismo , Masculino , Ratos
5.
Biochim Biophys Acta ; 1086(3): 279-86, 1991 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-1742319

RESUMO

In primary culture of rat hepatocytes, simvastatin, a powerful HMGCoA reductase inhibitor, inhibited acetate incorporation into cellular and secreted cholesterol and cholesteryl-esters, without any significant effect on triacylglycerol synthesis and secretion. When applied to the culture for 24 h at 10(-7) M, a concentration shown to inhibit cholesterol synthesis by 61%, simvastatin increased apolipoprotein BH and BL synthesis and secretion and strongly decreased apolipoprotein AI synthesis and secretion whereas apolipoprotein AIV remained unaffected. The synthesis and secretion of apolipoprotein E was only slightly affected in contrast with other situations where cholesterol synthesis decreased. All of these modifications occurred at a post-transcriptional level, as the corresponding messenger RNAs of the apolipoproteins did not vary. These results suggest that either the drug itself or variations in cholesterol synthesis might be involved in apo B and apo AI synthesis and secretion.


Assuntos
Colesterol/metabolismo , Lipoproteínas/biossíntese , Lipoproteínas/metabolismo , Fígado/metabolismo , Lovastatina/análogos & derivados , Animais , Animais Recém-Nascidos , Células Cultivadas , Ésteres do Colesterol/metabolismo , Ácidos Graxos/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases , Fígado/citologia , Fígado/efeitos dos fármacos , Lovastatina/farmacologia , Masculino , Metionina/metabolismo , Ratos , Ratos Endogâmicos , Sinvastatina , Triglicerídeos/metabolismo
6.
Biochim Biophys Acta ; 753(3): 439-44, 1983 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-6684482

RESUMO

Male Sprague-Dawley rats were exposed to increasing concentrations (15-22 mg/l) of ethanol vapor over a 4-day period. The hepatic lipid peroxide level as well as the sensitivity of mitochondria and microsomes to peroxidative attacks were studied during the early stage of alcohol intoxication, at the end of the inhalation period and, finally, during withdrawal. The level of hepatic lipid peroxide started to increase significantly after the first day of ethanol inhalation, whereas the in vitro mitochondrial sensitivity to peroxidation induced by ADP X Fe3+ in the presence of an O(2)-generating system was still unaltered after a 2-day inhalation period. Both the hepatic peroxide level and the mitochondrial sensitivity to peroxidation were significantly enhanced at the end of the 4-day inhalation period. Such an enhancement was still apparent 24 h after withdrawal, a time at which no more ethanol was present in the blood. Lipid peroxidation returned to normal values only 48 h after withdrawal. Microsomes were less affected than mitochondria by the ethanol treatment. It is suggested that the alterations of lipid peroxidation are related to the presence and/or the metabolism of ethanol at an early stage of inhalation, whereas changes in the membrane structure would be responsible for the maintenance of enhanced lipid peroxidation 24 h after ethanol withdrawal.


Assuntos
Etanol/farmacologia , Peróxidos Lipídicos/biossíntese , Microssomos Hepáticos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Síndrome de Abstinência a Substâncias/metabolismo , Animais , Etanol/sangue , Humanos , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Oxirredução , Ratos , Ratos Endogâmicos
7.
FEBS Lett ; 397(2-3): 155-8, 1996 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-8955337

RESUMO

Incubation of HepG2 cells in the presence of dibutyryl cAMP (db-cAMP), a cell permeable analogue of cyclic AMP, or forskolin, an agent which elevates intracellular cAMP, resulted in a 50% decrease in apoE mRNA levels within 24 h. Results of nuclear run-on transcription assays showed that db-cAMP down-regulates apoE gene expression at the transcriptional level. By transfection analysis with a plasmid containing the -614/+804 human apoE gene fused to the secreted placental alkaline phosphatase (SPAP) reporter gene, we showed that the SPAP activity was decreased by 50% when HepG2 cells were incubated in the presence of db-cAMP or forskolin, indicating that this promoter region mediated this negative effect. In contrast, when the smaller fragment -200/+1 of apoE promoter was linked to the CAT reporter gene, db-cAMP treatment of HepG2 cells resulted in a 2-fold increase in CAT activity, suggesting that positive cAMP-responsive elements were present in the proximal apoE promoter. These data indicate that transcriptional modulation of apoE gene expression by agents known to elevate the intracellular cAMP level is complex and involves several negative and positive elements located in the -614 to +804 region of the apoE gene whose global effect is negative on apoE gene transcription.


Assuntos
Apolipoproteínas E/genética , AMP Cíclico/metabolismo , Regulação da Expressão Gênica , Apolipoproteínas E/biossíntese , Bucladesina/farmacologia , Colforsina/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glucagon/farmacologia , Humanos , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transfecção , Células Tumorais Cultivadas
8.
FEBS Lett ; 376(1-2): 99-102, 1995 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-8521977

RESUMO

The regulation of apolipoprotein A-I (apo A-I) gene expression by 12-O-tetradecanoylphorbol 13-acetate (TPA) was investigated in the human hepatoma cell line Hep G2. TPA treatment decreased apo A-I mRNA levels in a time-dependent manner, by up to 50% versus control cells within 24 h. Nuclear run-on transcription assays demonstrated a transcriptional effect of TPA. Using transfection analysis with a plasmid construct containing the -1378/+11 apo A-I promoter fused to the secreted placental alkaline phosphatase (SPAP) reporter gene, we showed that the SPAP activity was decreased to 50% when Hep G2 cells were incubated in the presence of TPA. The inhibitory effect of TPA was still maintained when fragment -253 to -4 of apo A-I promoter was linked to the CAT reporter gene. These data indicate that transcriptional modulation of apolipoprotein A-I gene expression following phorbol ester treatment is transduced by gene elements located between -253 and -4 of the apo A-I promoter.


Assuntos
Apolipoproteína A-I/genética , Carcinoma Hepatocelular/metabolismo , Regulação Neoplásica da Expressão Gênica , Acetato de Tetradecanoilforbol/farmacologia , Sequência de Bases , Linhagem Celular , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Transcrição Gênica/genética , Transfecção/genética
9.
J Acquir Immune Defic Syndr (1988) ; 6(8): 898-903, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8315575

RESUMO

Numerous studies have established the correlation between antibodies to the core protein p24 of HIV-1 and the progression of the acquired immunodeficiency syndrome. In this study, we analyzed the immune response to two recombinant gag proteins, p24 and p17, in order to evaluate their diagnostic or prognostic significance. Immune response to the immunodominant domain of the transmembrane glycoprotein gp41 was used as a reference. Sera collected from individuals from France and Burundi (Central Africa) at various CDC stages of HIV-1 infection were tested using three sandwich enzyme-linked immunoassays developed with a synthetic peptide corresponding to the immunodominant domain of gp41, SP gp41, or recombinant p24 and p17 cloned and expressed in Escherichia coli. These assays allowed detection of titer antibodies to the three cited antigens. Antibodies to SP gp41 were detected in every HIV-1-positive patient from France and Burundi, generally at a high and stable level. Results obtained with p24 confirmed the value of antibodies to p24 as a prognostic marker only in European and North American populations, since the African population had very high levels of these antibodies even at an advanced stage of the disease. They also confirmed that initial antibody response to p24 is more predictive of outcome than antibody titer change over time. Although antibodies to p17 decline during progression to AIDS, they are frequently absent in French patients at early, asymptomatic stages and therefore could not be used as a prognostic marker. In contrast, antibodies to p17 are significantly less common in African patients with AIDS when compared with symptomless HIV-1-infected African individuals.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Produtos do Gene gag/imunologia , Anticorpos Anti-HIV/biossíntese , Antígenos HIV/imunologia , Proteína do Núcleo p24 do HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Proteínas Virais , Síndrome da Imunodeficiência Adquirida/epidemiologia , Síndrome da Imunodeficiência Adquirida/imunologia , Burundi/epidemiologia , França/epidemiologia , Anticorpos Anti-HIV/sangue , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/epidemiologia , Humanos , Incidência , Estudos Longitudinais , Prevalência , Prognóstico , Proteínas Recombinantes/imunologia , Proteínas da Matriz Viral/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana
10.
AIDS Res Hum Retroviruses ; 7(9): 767-71, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1720632

RESUMO

In this study the presence of a highly immunogenic domain located at the C-terminus of the external glycoproteins (EGP) of human and simian immunodeficiency viruses (HIV-1, HIV-2, and SIVMAC) is shown using synthetic oligopeptides as antigens in enzyme immunoassays. This epitope is probably located within the last 13 and 15 residues of the EGP of HIV-1 and HIV-2, respectively. The C terminal epitope of the EGP of SIVMAC may involve residues located more upstream. Among the HIV-2/SIV serotype, we observed that the reactivity to the C-terminal epitope of gp120 was dependent of both species and geographical origin of the samples tested. It seems that this gp 120 C-terminal epitope could distinguish subtypes among the HIV-2/SIV serotype. Further studies, using site-directed enzyme immunoassays with synthetic peptides representing the C-terminus of the EGP derived from a wide variety of HIV2/SIV strains must be performed to confirm this observation. These kinds of assays may constitute important tools for use in seroepidemiological studies and broaden our understanding of the distribution and phylogenetic relationship of primate lentiviruses.


Assuntos
Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , HIV-2/imunologia , Vírus da Imunodeficiência Símia/imunologia , Sequência de Aminoácidos , Animais , Epitopos , Anticorpos Anti-HIV , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/imunologia , HIV-1/genética , HIV-2/genética , Humanos , Lentivirus/classificação , Lentivirus/genética , Lentivirus/imunologia , Dados de Sequência Molecular , Peptídeos/genética , Peptídeos/imunologia , Primatas , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/genética
11.
AIDS Res Hum Retroviruses ; 12(6): 519-25, 1996 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-8679307

RESUMO

The objective of the present study was to identify p24 antigenic domains recognized during natural human immunodeficiency virus type 1 (HIV-1) infection, the determination of the major epitopes of p24 having significant applications for both the improvement of diagnostic approaches and the development of vaccines. Reactivity of 20 HIV-1-infected patients and 8 HIV-1-negative patients was analyzed using an enzyme-linked immunosorbent assay (ELISA) developed with 45 overlapping synthetic pentadecapeptides, spanning amino acids 133 to 363 of HIV-1 p55gag precursor. Two peptides covering aa 178-192 and 288-302 of p55 were recognized by 40 and 45% of HIV-1 antibody-positive human samples, respectively. A peptide covering aa 272-322 of p55 was synthesized and recognized by most human sera in indirect ELISA. However, inhibition assays indicated that this sequence does not contain all of the immunodominant domains of p24 since it was not sufficient to block binding of human sera to whole p24. A three-dimensional model of p24 derived from the Mengovirus VP2 suggests that the two distant sequences recognized by human sera containing antibodies to HIV-1 could possibly be a part of a conformational epitope built up by two loops corresponding to aa 183-186 and 289-292.


Assuntos
Linfócitos B/imunologia , Proteína do Núcleo p24 do HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Sequência de Aminoácidos , Ensaio de Imunoadsorção Enzimática , Epitopos , HIV-1/química , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/síntese química , Peptídeos/imunologia
12.
Res Microbiol ; 151(3): 191-200, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10865946

RESUMO

The polymorphism of clinical presentations associated with Helicobacter pylori infection is potentially due to differences in the virulence of individual strains. H. pylori virulence has been associated with the ability to induce secretion of interleukin-8 (IL-8), the vacA genotypes, and the cagA status. The aim of this study was to determine the virulence profiles of 153 French H. pylori isolates on the basis of vacA genotypes, cagA status, and IL-8 induction ability. A total of 153 H. pylori isolates from patients with chronic gastritis (n = 74) or gastro-duodenal ulcers (n = 79) was examined for vacA genotypes and cagA status by polymerase chain reaction (PCR) and dot blot, and for their ability to induce IL-8 secretion by HEp-2 cells. The prevalence of vacA genotypes was: s1/m1 44.3%, s1/m2 24.9%, and s2/m2 23.5%. The cagA gene was present in 64% of the strains. IL-8 secretion was induced by 58.7% of the isolates. The presence of the cagA gene was significantly correlated with the s1/m1 vacA genotype and with the induction of IL-8. Thirty-four strains were atypical (cagA-positive/IL-8 noninducer or cagA-negative/IL-8 inducer). vacA genotypes, cagA status, and IL-8 induction ability are not correlated with the presence or absence of ulcer. The cagA status is not sufficient to predict the proinflammatory ability of H. pylori.


Assuntos
Antígenos de Bactérias , Proteínas de Bactérias/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Interleucina-8/biossíntese , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Feminino , Gastrite/microbiologia , Genes Bacterianos , Genótipo , Helicobacter pylori/classificação , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Humanos , Immunoblotting , Interleucina-8/imunologia , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/microbiologia , Reação em Cadeia da Polimerase/métodos
13.
Res Microbiol ; 149(2): 95-107, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9766213

RESUMO

In order to study a 19-kDa protein (p19) of Campylobacter jejuni, we purified this protein to homogeneity from C. jejuni strain 81,176 by anion exchange chromatography. The molecular weight of the native protein is 19,000 daltons. P19 was found to be acidic with an isoelectric point of 4.8 and was located in the periplasmic space of the bacteria. The 20 N-terminal amino acids were sequenced and no significant similarities with known proteins were shown. A monoclonal antibody showed that p19 is conserved in the 2 species C. jejuni and C. coli. Analysis of sera from 23 patients with a Campylobacter-related infection indicated that p19 is not immunogenic during natural infection in man. The gene encoding p19 was cloned and no strong homologies with known sequences were identified. The preparation of a knockout mutant in p19 will enable the investigation of the function of this cell wall component of Campylobacter.


Assuntos
Proteínas de Bactérias/isolamento & purificação , Infecções por Campylobacter/imunologia , Campylobacter coli/química , Campylobacter jejuni/química , Proteínas de Membrana/isolamento & purificação , Periplasma/química , Proteínas Periplásmicas , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sequência de Bases , Western Blotting , Campylobacter coli/genética , Campylobacter jejuni/genética , Criança , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , DNA Bacteriano/química , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Ponto Isoelétrico , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Peso Molecular , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
14.
FEMS Immunol Med Microbiol ; 27(3): 263-8, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10683472

RESUMO

In order to identify the C. jejuni immunogens of interest for the diagnosis of Campylobacter infections, we analyzed the humoral response of 153 patients by using complement fixation (CF) and western blot assays. A first group of 79 sera was from C. jejuni infected patients suffering from enteritis (n=16), Guillain-Barré syndrome (GBS) (n=40) and arthritis (n=23). A second group of 49 sera was from healthy blood donors and a third group consisted of 25 sera from children under 4 years old. Using the CF test, 88.6% of the C. jejuni infected patients were seropositive versus 28.5% of the healthy blood donors and none of the children. The Western blot assay allowed detection of antibodies directed against seven selected antigens ranging from 14 to 67 kDa. Three of these antigens with a molecular size of 29, 37 and 43 kDa were detected by 86.0%, 84.8% and 91.1% of the C. jejuni infected patients, respectively. These three antigens seem to be good candidates for the development of assays suitable for direct and indirect diagnosis of Campylobacter infections.


Assuntos
Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Infecções por Campylobacter/diagnóstico , Campylobacter jejuni/imunologia , Adulto , Western Blotting , Infecções por Campylobacter/microbiologia , Pré-Escolar , Testes de Fixação de Complemento , Humanos
15.
FEMS Immunol Med Microbiol ; 24(1): 27-33, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10340709

RESUMO

The bacterial pathogen Helicobacter pylori is highly adapted to the human stomach and the clinical isolates show a high diversity which could be due to adaptative changes of the strains passing from one host to another. In order to study these variations, experimental infection of mice was developed and provided three out of the eleven tested strains able to infect C57BL/6 mice: the Sydney strain which is known to be well adapted to mice and two freshly isolated strains from infected patients. Mice were orally infected with one of these three strains (infecting strains) and were killed 45 days later. H. pylori strains were isolated from the stomachs of mice (emerging strains). The three infecting strains were compared to the three emerging strains for protein and lipopolysaccharide profiles, antigenic profiles revealed by Western blot with monospecific sera and genetic status by testing for the cagA gene and the vacA genotype. During the 45 days of infection, H. pylori underwent phenotypic variations which may be attributed to the adaptation from a human to a mouse environment or from an in vitro to a mouse environment. Those variations consisted of an over-expression at the cell surface of a 180-kDa protein and of a decreased expression of proteins of 260 and 120 kDa. Moreover, antigenic variations were shown for the two freshly isolated strains from human: the CagA and VacA antigens were in the saline extracts of the infecting strains only while the UreA, UreB, HspA and HspB were in the saline extracts of both the infecting and the emerging strains. These variations may contribute to the adaptation of the strains to the mouse environment.


Assuntos
Antígenos de Bactérias , Helicobacter pylori/química , Helicobacter pylori/fisiologia , Animais , Variação Antigênica , Proteínas de Bactérias/análise , Proteínas de Bactérias/genética , Western Blotting , Eletroforese em Gel de Poliacrilamida , Feminino , Genótipo , Helicobacter pylori/patogenicidade , Humanos , Lipopolissacarídeos/análise , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Reação em Cadeia da Polimerase , Fatores de Tempo , Virulência
16.
Lipids ; 33(5): 455-60, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9625592

RESUMO

In this study, the effects of caffeine on lipoprotein lipase (LPL) gene expression were investigated in the 3T3-F442A preadipocyte cell line during the adipocyte differentiation process by determining LPL enzymatic activity and its messenger RNA (mRNA) level. The results demonstrate that caffeine acts on the gene expression of LPL, an early marker of adipocyte differentiation. It has a biphasic action: it increases gene expression in terms of mRNA when it is added to preadipocytes during the early stage of differentiation, but this is accompanied by a reduction of enzymatic activity. On the other hand, when caffeine is added for long periods during differentiation and/or when it is added to mature adipocytes, it induces marked inhibition of mRNA levels, correlated with a marked reduction of secreted enzymatic activity. The inhibitory effect of caffeine on LPL mRNA level can be reproduced by theophylline, a phosphodiesterase inhibitor, and by dibutyryl cyclic AMP, a non-metabolizable analog of cyclic AMP. However, the effect of caffeine and theophylline lasts longer than that of cyclic AMP, suggesting that a mechanism other than inhibition of cyclic AMP hydrolysis may be involved in the action of caffeine.


Assuntos
Adipócitos/enzimologia , Cafeína/farmacologia , Diferenciação Celular/fisiologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Lipase Lipoproteica/biossíntese , Triglicerídeos/metabolismo , Células 3T3 , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Animais , Bucladesina/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Cinética , Camundongos , RNA Mensageiro/biossíntese , RNA Mensageiro/metabolismo , Teofilina/farmacologia , Fatores de Tempo
17.
Arch Pediatr ; 11(2): 85-92, 2004 Feb.
Artigo em Francês | MEDLINE | ID: mdl-14761728

RESUMO

AIM: This study was conducted on a sample of 644 pupils between the ages of five and ten years at school in the Orléans-Tours education authority with the aim of studying the nocturnal sleep duration and timetable of young children according to age and socio-economic environment. METHOD: In order to find out about children's sleeping habits (duration, time of going to bed and getting up, and weekly variations) a standard grid was used to carry out a cross-sectional survey in the children's families. This was filled in each day from Monday to Sunday during the same school week for all the children. RESULTS: Sleep duration decreased with age from maternelle to CM2 (nursery to last year of primary education). Data relating to sleep duration from CE2 (third year of primary school - 8-year-old -) showed differences according to whether the school belonged to an Educational Priority Zone (EPZ) or not. It was noticed that between five- and ten-year-old children from EPZ lost 62 minutes of sleep, whereas those not from EPZ only lost 29 minutes. These results would suggest that in addition to developmental factors, environmental factors also play a role in sleep duration. The differences observed were due to later bed times for children from EPZ. Weekly variations in sleep were generally very similar for all the children. At the weekend all the children tended to go to bed later, however this was more noticeable Saturday night for children not living in EPZ. Children slept the longest on Tuesday night due to the fact they got up later Wednesday morning (Wednesday is a day off in the majority of French schools). However, children from the age of nine (CM1 - forth year of primary education -) in EPZ did not benefit from this recuperation time, as they went to bed later but still got up early the next morning. CONCLUSION: This study showed that in addition to the physiological and developmental factors that influence children's sleep, the socio-economic context also plays a role. These results as a whole highlight the importance that practitioners and families should pay to maintaining a regularity in the child's routine and in the amount of sleep necessary at each age.


Assuntos
Sono , Fatores Etários , Criança , Pré-Escolar , Estudos Transversais , Humanos , Fatores Socioeconômicos , Fatores de Tempo
18.
Phys Med Biol ; 58(13): 4483-500, 2013 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-23760022

RESUMO

The investigation of neurophysiological mechanisms underlying the functional specificity of brain regions requires the development of technologies that are well adjusted to in vivo studies in small animals. An exciting challenge remains the combination of brain imaging and behavioural studies, which associates molecular processes of neuronal communications to their related actions. A pixelated intracerebral probe (PIXSIC) presents a novel strategy using a submillimetric probe for beta(+) radiotracer detection based on a pixelated silicon diode that can be stereotaxically implanted in the brain region of interest. This fully autonomous detection system permits time-resolved high sensitivity measurements of radiotracers with additional imaging features in freely moving rats. An application-specific integrated circuit (ASIC) allows for parallel signal processing of each pixel and enables the wireless operation. All components of the detector were tested and characterized. The beta(+) sensitivity of the system was determined with the probe dipped into radiotracer solutions. Monte Carlo simulations served to validate the experimental values and assess the contribution of gamma noise. Preliminary implantation tests on anaesthetized rats proved PIXSIC's functionality in brain tissue. High spatial resolution allows for the visualization of radiotracer concentration in different brain regions with high temporal resolution.


Assuntos
Encéfalo/metabolismo , Imagem Molecular/instrumentação , Monitorização Ambulatorial/instrumentação , Tomografia por Emissão de Pósitrons/instrumentação , Radioisótopos/farmacocinética , Silício/química , Tecnologia sem Fio/instrumentação , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Masculino , Miniaturização , Imagem Molecular/veterinária , Monitorização Ambulatorial/veterinária , Tomografia por Emissão de Pósitrons/veterinária , Ratos , Ratos Sprague-Dawley , Sensibilidade e Especificidade , Transdutores/veterinária
19.
Med Mal Infect ; 41(10): 540-5, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21907512

RESUMO

OBJECTIVE: The study objective was to identify bacteria responsible for facial cellulitis of dental origin. DESIGN: Adult patients, admitted for facial cellulitis of dental origin were included. The pus sample was taken by swabbing during the surgical incision and drainage performed under general anesthesia. The bacteriological diagnosis was performed by microscopic examination and bacterial culture in aerobic and anaerobic atmosphere. RESULTS: Two hundred and seven bacterial species were isolated from 100 samplings, that is to say 2.07 bacterial species per sample. 19% of the samples contained only aerobic germs, 36% only anaerobic ones, and 45% contained mixed aerobic and anaerobic flora. Streptococcus (65.38%) and Capnocytophaga (11.54%) were the most frequently isolated aerobic bacteria. The anaerobic bacteria accounted for 62.32% of isolates and the most frequently isolated were Prevotella (55%) and Fusobacterium (16.28%). Bacterial species were not significantly different according to the age (P-value=0.06) and sex (P-value=0.584). There was a significant statistical association between aerobic or anaerobic bacteria and clinical symptoms such as cheek edema (P-value=0.03) and pus at tooth root (P-value=0.02). Patients previously treated by antibiotic therapy presented significantly more infections due to the same respiratory germ type (P-value=0.009). CONCLUSIONS: Even though the bacterial flora responsible for facial cellulitis of dental origin is polymorphic, anaerobic bacteria were predominant.


Assuntos
Infecções Bacterianas , Celulite (Flegmão)/microbiologia , Doenças Estomatognáticas/complicações , Doenças Estomatognáticas/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Face , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
20.
Infect Immun ; 69(3): 1625-9, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11179336

RESUMO

Helicobacter pylori virulence is associated with the presence of the cag pathogenicity island (PAI). The cag PAI is involved in the ability to induce interleukin-8 (IL-8) secretion by human cells, which is implicated in the inflammatory response of the gastric mucosa to H. pylori infection. The aim of this study was to determine whether the genetic structure of the cag PAI is conserved and whether it is linked to IL-8 induction ability. Detection of specific markers (cagA, picB, cag13-cag14, virD4, and IS605) by PCR and dot blot hybridization and long-distance PCR determination of the presence of cagI, cagII, and the middle region of the cag PAI were performed on 153 strains isolated from adults suffering from ulcers (n = 79) or gastritis (n = 74). IL-8 induction ability was evaluated by coculture of the strains with HEp-2 cells. Eighty-three strains (54.3%) had an entire cag PAI, 12 strains (7.8%) had the cag PAI split in two, 49 strains (32%) had no cag PAI, and 9 strains exhibited other structural combinations. The presence of an entire cag PAI was statistically correlated with the presence of IS605 (P = 0.006) and the ability to induce IL-8 secretion but not with clinical presentation of the infection. The structure of the cag PAI appears to be rather conserved and is related to the proinflammatory power of a strain. The existence of strains inducing IL-8 secretion regardless of the cag PAI structure suggests that this region is not the only requirement for IL-8 secretion.


Assuntos
Antígenos de Bactérias , Proteínas de Bactérias/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Interleucina-8/metabolismo , Fatores de Virulência , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Genes Bacterianos , Humanos , Masculino , Pessoa de Meia-Idade
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