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1.
AJNR Am J Neuroradiol ; 44(4): 434-440, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36958803

RESUMO

BACKGROUND AND PURPOSE: Infarct evolution after endovascular treatment varies widely among patients with stroke and may be affected by baseline characteristics and procedural outcomes. Moreover, IV alteplase and endovascular treatment may influence the relationship of these factors to infarct evolution. We aimed to assess whether the infarct evolution between baseline and follow-up imaging was different for patients who received IVT and EVT versus EVT alone. MATERIALS AND METHODS: We included patients from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN)-NO IV trial with baseline CTP and follow-up imaging. Follow-up infarct volume was segmented on 24-hour or 1-week follow-up DWI or NCCT. Infarct evolution was defined as the follow-up lesion volume: CTP core volume. Substantial infarct growth was defined as an increase in follow-up infarct volume of >10 mL. We assessed whether infarct evolution was different for patients with IV alteplase and endovascular treatment versus endovascular treatment alone and evaluated the association of baseline characteristics and procedural outcomes with infarct evolution using multivariable regression. RESULTS: From 228 patients with CTP results available, 145 patients had follow-up imaging and were included in our analysis. For patients with IV alteplase and endovascular treatment versus endovascular treatment alone, the baseline median CTP core volume was 17 (interquartile range = 4-35) mL versus 11 (interquartile range = 6-24) mL. The median follow-up infarct volume was 13 (interquartile range, 4-48) mL versus 17 (interquartile range = 4-50) mL. Collateral status and occlusion location were negatively associated with substantial infarct growth in patients with and without IV alteplase before endovascular treatment. CONCLUSIONS: No statistically significant difference in infarct evolution was found in directly admitted patients who received IV alteplase and endovascular treatment within 4.5 hours of symptom onset versus patients who underwent endovascular treatment alone. Collateral status and occlusion location may be useful predictors of infarct evolution prognosis in patients eligible for IV alteplase who underwent endovascular treatment.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Ativador de Plasminogênio Tecidual/uso terapêutico , Isquemia Encefálica/patologia , Resultado do Tratamento , Procedimentos Endovasculares/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/cirurgia , Infarto , Trombectomia
2.
Occup Med (Lond) ; 71(4-5): 223-230, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34291807

RESUMO

BACKGROUND: Brazil has a long history of heavy asbestos consumption. However, the number of asbestos-related diseases (ARDs) falls far below the one expected compared with other asbestos consumer countries. AIMS: To examine underreporting of ARDs, that is mesothelioma, asbestosis and pleural plaques, in Brazil's Mortality Information System (SIM). METHODS: Health information systems (HIS) were mapped, datasets retrieved and records of ARD deaths extracted. Records were pair-matched using anonymous linkage to create a single database. ARD-reported cases missing in SIM were considered unreported. The study's period ranged from 2008 to 2014, when every HIS contributed to the ARD records pool. RESULTS: A total of 1298 registered ARD deaths were found, 996 cases of mesothelioma (77%) and 302 (23%) of asbestosis and pleural plaques. SIM was the major single data source of ARD but 335 mesothelioma deaths were missing, an average underreporting of 33%, with no clear time trend. For asbestosis and pleural plaques, underreporting of ARD oscillated from 55% in 2010 to 25% in 2014, a declining trend. ARD underreporting was not associated with sex or age. CONCLUSIONS: One-third of underreported ARD deaths in the universal SIM is unacceptably high and, apparently, it has not been improving substantially over time. After recoveries from multiple databases, the number of cases is still below, which could be expected based on asbestos consumption. Interoperability of multiple information systems could enhance case detection and improve the precision of mortality estimates, which are crucial for surveillance and for evaluation of remedial policies.


Assuntos
Amianto , Asbestose , Neoplasias Pulmonares , Mesotelioma , Doenças Pleurais , Neoplasias Pleurais , Amianto/efeitos adversos , Brasil/epidemiologia , Humanos , Mesotelioma/etiologia , Doenças Pleurais/etiologia , Neoplasias Pleurais/etiologia
3.
Arch Environ Occup Health ; 76(1): 1-11, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32048551

RESUMO

Cashew nut shells (CNS) is already used in the energy matrix of some industries. However, it is necessary to know the harmful health effects generated by exposure to pollutants of its combustion, especially in the workers exposed to industrial pollutants. In addition, it is known that the incidence of asthma grows among workers in industries, and due to its previously reported biological effects of anethole, these will also be objects of the present study. We used 64 Balb/C mice, randomly divided into eight groups. Groups were sensitized and challenged with saline or ovalbumin, then subjected to intranasal instillation of 30 µg PM4.0 (occupational exposure) from the combustion of CNS or saline, and then were subsequently treated with oral anethole 300 mg/kg or 0.1% Tween 80. Our results serve as a starting point for the development of public policies for the prevention of diseases in workers that are exposed to the pollutants coming from industries.


Assuntos
Poluentes Ocupacionais do Ar/efeitos adversos , Anacardium , Indústria de Processamento de Alimentos , Exposição Ocupacional/efeitos adversos , Material Particulado/efeitos adversos , Derivados de Alilbenzenos , Animais , Anisóis , Modelos Animais de Doenças , Pulmão/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Polissorbatos , Distribuição Aleatória
4.
Braz J Microbiol ; 51(3): 1151-1157, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31898244

RESUMO

The development of insects is strongly influenced by their resident microorganisms. Symbionts play key roles in insect nutrition, reproduction, and defense. Bacteria are important partners due to the wide diversity of their biochemical pathways that aid in the host development. We present evidence that the foam produced by nymphs of the spittlebug Mahanarva fimbriolata harbors a diversity of bacteria, including some that were previously reported as defensive symbionts of insects. Analysis of the microbiomes in the nymph gut and the soil close to the foam showed that the microorganisms in the foam were more closely related to those in the gut than in the soil, suggesting that the bacteria are actively introduced into the foam by the insect. Proteobacteria, Actinobacteria, and Acidobacteria were the predominant groups found in the foam. Since members of Actinobacteria have been found to protect different species of insects by producing secondary metabolites with antibiotic properties, we speculate that the froth produced by M. fimbriolata may aid in defending the nymphs against entomopathogenic microorganisms.


Assuntos
Bactérias/isolamento & purificação , Microbioma Gastrointestinal , Hemípteros/microbiologia , Microbiologia do Solo , Animais , Bactérias/classificação , Bactérias/genética , Trato Gastrointestinal/microbiologia , Hemípteros/fisiologia , Ninfa/microbiologia , Simbiose
5.
Opt Express ; 26(13): 17608-17623, 2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-30119572

RESUMO

Hafnium oxide thin films with varying oxygen content were investigated with the goal of finding the optical signature of oxygen vacancies in the film structure. It was found that a reduction of oxygen content in the film leads to changes in both, structural and optical characteristics. Optical absorption spectroscopy, using nanoKelvin calorimetry, revealed an enhanced absorption in the near-ultraviolet (near-UV) and visible wavelength ranges for films with reduced oxygen content, which was attributed to mid-gap electronic states of oxygen vacancies. Absorption in the near-infrared was found to originate from structural defects other than oxygen vacancy. Luminescence generated by continuous-wave 355-nm laser excitation in e-beam films showed significant changes in the spectral profile with oxygen reduction and new band formation linked to oxygen vacancies. The luminescence from oxygen-vacancy states was found to have microsecond-scale lifetimes when compared with nanosecond-scale lifetimes of luminescence attributed to other structural film defects. Laser-damage testing using ultraviolet nanosecond and infrared femtosecond pulses showed a reduction of the damage threshold with increasing number of oxygen vacancies in hafnium oxide films.

7.
Genet Mol Res ; 15(4)2016 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-28002613

RESUMO

The consumption of healthy and natural foods has increased over the last few years, primarily because these foods are rich in substances with biological properties of interest, such as exerting anticancer effects and decreasing oxidative stress in living tissues. These foods support adequate nutrition, maintain health, and improve quality of life. Vanillic acid (VA) is a phenolic compound used widely in the food industry as a flavoring, preservative, and food additive. VA can be found in various cereals, whole grains, fruits, herbs, green tea, juices, beers, and wines and possesses antioxidant, hepatoprotective, cardioprotective, and antiapoptotic activities. Studying the cytotoxicity as well as the mutagenic and antimutagenic effects of different concentrations of VA in Rattus norvegicus hepatoma cells (HTC) can identify new cellular activities of this substance. Concentrations up to 100 µM VA are not cytotoxic to HTC cells in a MTT [3-(4,5-dimethilthiazol-2-yl)-2,5-diphenil tetrazolium bromide] assay after 96-h exposure; therefore, VA does not compromise mitochondrial activity. Similarly, concentrations up to 500 µM do not compromise plasma membrane integrity. VA at 10 and 50 µM showed no mutagenic/clastogenic effects, as no significant micronuclei induction was observed. VA 10 µM presented no antiproliferative activity and reduced the cytotoxicity induced by benzo[a]pyrene. The antimutagenic activity of 10 µM VA was observed by the simultaneous, pre-, and post-treatments, as the phenolic compound significantly reduced the frequency of micronuclei induced by the mutagen. These results indicate that VA exerts different responses in HTC cells. Low concentrations present no cytotoxic, mutagenic, or antiproliferative effects and protect cells from DNA damage.


Assuntos
Antimutagênicos/farmacologia , Ácido Vanílico/farmacologia , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Extratos Vegetais/farmacologia , Ratos
8.
Braz. j. med. biol. res ; 48(7): 588-594, 07/2015. tab
Artigo em Inglês | LILACS | ID: lil-751349

RESUMO

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmec typing, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureus isolates from skin infections. Methicillin-resistant S. aureus (MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.


Assuntos
Animais , Masculino , Camundongos , Ratos , Nefropatias/metabolismo , Rim/metabolismo , Podócitos/metabolismo , Transdução de Sinais , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Expressão Gênica , Redes Reguladoras de Genes , Immunoblotting , Nefropatias/induzido quimicamente , Nefropatias/genética , Rim/patologia , Rim/fisiopatologia , Microscopia Eletrônica , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Puromicina , Podócitos/patologia , Podócitos/ultraestrutura , Proteômica/métodos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
Braz J Med Biol Res ; 48(7): 588-94, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25992644

RESUMO

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmec typing, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureus isolates from skin infections. Methicillin-resistant S. aureus (MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 µg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.


Assuntos
Toxinas Bacterianas/genética , Dermatite Atópica/microbiologia , Exotoxinas/genética , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Cavidade Nasal/microbiologia , Pele/microbiologia , Adolescente , Criança , Estudos Transversais , DNA Bacteriano , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase , Valores de Referência , Índice de Gravidade de Doença , Infecções Cutâneas Estafilocócicas/microbiologia
10.
J Hosp Infect ; 86(2): 151-4, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24433925

RESUMO

This study aimed to characterize meticillin-resistant Staphylococcus aureus (MRSA) lineages circulating in a Brazilian teaching hospital. MRSA isolates from nasal swabs were evaluated to assess antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec), Panton-Valentine leucocidin status, pulsed-field gel electrophoresis profile and multi-locus sequence type (MLST) analysis. Eighty-three MRSA isolates were analysed. SCCmec III (43.4%) and IV (49.4%) were predominant. ST1-IV (USA400) was more common in internal medicine (P = 0.002) whereas 'clone M' (SCCmec III) was more common in the medical and surgical intensive care unit (P = 0.004), and all isolates were ST5-IV (USA800) in dermatology (P < 0.001). These data improved the understanding of the MRSA epidemiology inside the hospital and helped to establish effective control measures.


Assuntos
Portador Sadio/epidemiologia , Infecção Hospitalar/epidemiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Brasil/epidemiologia , Portador Sadio/microbiologia , Infecção Hospitalar/microbiologia , Genes Bacterianos , Genótipo , Hospitais de Ensino , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem Molecular , Mucosa Nasal/microbiologia , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética
11.
Spec Care Dentist ; 33(6): 301-3, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24164229

RESUMO

The purpose of this study was to describe an unusual case of a lingual schwannoma associated with a mixed connective tissue disease (MCTD). A case report. A lingual schwannoma with loss of lingual sensitivity and slightly increased size in an 18-year-old patient with MCTD was correctly diagnosed through a biopsy and no reoccurrence was observed one year after the surgical removal of the tumor and sensitivity returned 3 months after surgery. This case was considered uncommon, making the clinical diagnosis challenging in view of the diversity of possibilities for its differential diagnosis, thus showing the importance of a biopsy to confirm the diagnosis and long term follow up in such cases.


Assuntos
Doenças da Túnica Conjuntiva/fisiopatologia , Neurilemoma/fisiopatologia , Língua/fisiopatologia , Adolescente , Doenças da Túnica Conjuntiva/complicações , Feminino , Humanos , Neurilemoma/complicações
13.
Int J Neurosci ; 120(12): 739-45, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20964556

RESUMO

Antiretroviral therapy has revolutionized the treatment of the human immunodeficiency virus because it has improved the clinical outcomes of patients. It is essential that these drugs cross the blood-brain barrier, since the virus is present in the central nervous system (CNS). Efavirenz passes through this barrier satisfactorily and can reduce the deleterious central effects of the human immunodeficiency virus. However, patients treated with efavirenz have been observed to experience psychiatric symptoms such as mania, depression, suicidal thoughts, psychosis, and hallucinations. The aim of this review is to describe the pharmacokinetic and pharmacodynamic properties of efavirenz and its major neuropsychiatric symptoms and the neurochemical pathways associated with these changes in the CNS. The databases Medline and Lilacs were used to search for review articles and preclinical and clinical research articles published from January 1996 to 2010. The search terms used were efavirenz, central nervous system, neuropsychiatry, neurotransmitters, adverse effects, and neurochemistry. Subject categories considered included effects on viral replication, pharmacokinetic and pharmacodynamic properties of efavirenz, and neuropsychiatric adverse effects including time course, duration, and probable mechanisms involved. The mechanisms involved in these changes include interference with cytochrome P450 enzymes, cytokines, tryptophan-2-3-dioxygenase, and brain creatine kinase.


Assuntos
Complexo AIDS Demência/tratamento farmacológico , Fármacos Anti-HIV/efeitos adversos , Benzoxazinas/efeitos adversos , Encéfalo/efeitos dos fármacos , Transtornos Neurocognitivos/induzido quimicamente , Alcinos , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacocinética , Benzoxazinas/química , Benzoxazinas/farmacocinética , Encéfalo/enzimologia , Encéfalo/fisiopatologia , Ciclopropanos , Humanos , Transtornos Neurocognitivos/enzimologia , Transtornos Neurocognitivos/fisiopatologia
14.
Transplant Proc ; 40(10): 3545-7, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19100434

RESUMO

BACKGROUND: Hepatic artery thrombosis (HAT) is a serious complication after orthotopic liver transplantation (OLT) and remains a significant cause of graft loss. HAT following OLT has been reported in 3% to 9% of patients. Among the surgical factors considered to be associated with HAT, arterial reconstruction might be the most important. The goal of this study was to compare the incidence of HAT between interrupted suture (IS) and continuous suture (CS) techniques during hepatic artery reconstruction in liver transplantation. METHODS: We performed a retrospective analysis of 200 consecutive liver transplantations occurring between May 2002 and December 2006, including medical records for: age, gender, cold ischemic time, warm ischemic time, type and number of arterial anastomosis. Hepatic artery anastomoses were performed using a 7-0 prolene with a running CS in the first 105 patients (CS group), and with an IS in the last 95 patients (IS group). RESULTS: Statistical analysis of age, gender, cold and warm ischemia time, and number of hepatic artery anastomoses was not different between the CS and IS groups. Eleven episodes of HAT were identified in the CS group (10%) and two episodes (2%) in the IS cohort, a significant difference (P = .0173). CONCLUSIONS: Our results suggested that IS might be a better choice for hepatic artery anastomosis with a lower incidence of HAT.


Assuntos
Anastomose Cirúrgica/métodos , Artéria Hepática/cirurgia , Transplante de Fígado/métodos , Trombose/epidemiologia , Adulto , Anastomose Cirúrgica/efeitos adversos , Feminino , Seguimentos , Hepatite C/cirurgia , Humanos , Cirrose Hepática Alcoólica/cirurgia , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Clin Exp Pharmacol Physiol ; 33(12): 1158-63, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17184495

RESUMO

1. The effects of the essential oil of Croton nepetaefolius (EOCN) and its major constituent, 1,8-cineole, on the compound action potential (CAP) of nerve were investigated. 2. Experiments were performed in sciatic nerves dissected from Wistar rats, mounted in a moist chamber and stimulated at a frequency of 0.2 Hz, with electric pulses of 100 micros duration at 20-40 V. Evoked CAP were displayed on an oscilloscope and recorded on a computer. The CAP control parameters were as follows: peak-to-peak amplitude 8.1 +/- 0.6 mV (n = 15); conduction velocity 83.3 +/- 4.2 m/s (n = 15); chronaxie 58.0 +/- 6.8 msec (n = 6); and rheobase 2.8 +/- 0.1 V (n = 6). 3. Lower concentrations of EOCN (100 and 300 microg/mL) and 1,8-cineole (153 and 307 microg/mL; i.e. 1 and 2 mmol/L, respectively) had no significant effects on CAP control parameters throughout the entire recording period. However, at the end of 180 min exposure of the nerve to the drug, peak-to-peak amplitude was significantly (P < 0.05) reduced to 27.4 +/- 6.7 and 1.7 +/- 0.8% of control values by 500 and 1000 microg/mL EOCN, respectively (n = 6), and to 76.5 +/- 4.4, 70.0 +/- 3.9 and 14.8 +/- 4.1% of control values by 614, 920 and 1227 microg/mL (i.e. 4, 6 and 8 mmol/L) 1,8-cineole, respectively (n = 6). Regarding conduction velocity, at the end of the 180 min exposure period, this parameter was significantly reduced to 85.8 +/- 7.3 and 48.7 +/- 12.3% (n = 6) of control values by 500 and 1000 microg/mL EOCN, respectively, and to 86.4 +/- 4.5 and 76.1 +/- 5.2% (n = 6) by 920 and 1227 microg/mL 1,8-cineole, respectively. Chronaxie and rheobase were significantly increased by the higher concentrations of both EOCN and 1,8-cineole. 4. It is concluded that EOCN and its main constituent 1,8-cineole block nerve excitability in a concentration-dependent manner, an effect that was totally reversible with 1,8-cineole but not with EOCN. This suggests that other constituents of EOCN, in addition to 1,8-cineole, may contribute to the mediation of this effect of EOCN.


Assuntos
Anestésicos Locais , Óleo de Cróton/farmacologia , Cicloexanóis/farmacologia , Monoterpenos/farmacologia , Nervo Isquiático/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Óleo de Cróton/química , Cicloexanóis/química , Eletrofisiologia , Eucaliptol , Técnicas In Vitro , Masculino , Monoterpenos/química , Ratos , Ratos Wistar
16.
Ann Trop Med Parasitol ; 100(1): 49-54, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16417713

RESUMO

Genital manifestations in schistosomiasis haematobium are common and are associated with considerable morbidity. Although Schistosoma mansoni may also cause genital disease, the frequency of this complication is not known. Cervical biopsies (N=401) and Pap smears (N=981) were therefore collected from women living in two S. mansoni-endemic areas (in the states of Alagoas and Ceará, in north-eastern Brazil). The women were screened for the presence of sexually transmitted diseases and for the presence, in their cervical smears and/or biopsies, of S. mansoni eggs. Attempts at schistosomiasis control, which began in both study areas in 1977, have led to generally low intensities of infection (<30 eggs/g faeces in 99% of infections) and community prevalences of infection that range between 1% and 52%. As no schistosome ova were detected in any of the biopsies or smears, it appears that the risk, among women, of genital manifestations of S. mansoni infection is small in areas where the parasite load in the population is low (as the result of interventions to control intestinal schistosomiasis).


Assuntos
Doenças Endêmicas , Esquistossomose mansoni/epidemiologia , Doenças do Colo do Útero/parasitologia , Adolescente , Adulto , Idoso , Animais , Biópsia/métodos , Brasil/epidemiologia , Colo do Útero/parasitologia , Colo do Útero/patologia , Colposcopia/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Teste de Papanicolaou , Vigilância da População , Prevalência , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/patologia , Doenças do Colo do Útero/epidemiologia , Doenças do Colo do Útero/patologia , Esfregaço Vaginal
17.
Am J Respir Crit Care Med ; 164(10 Pt 1): 1920-6, 2001 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11734447

RESUMO

Emphysema causes a permanent destruction of alveolar walls leading to airspace enlargement, loss of elastic recoil, decrease in surface area for gas exchange, lung hyperexpansion, and increased work of breathing. The most accepted hypothesis of how emphysema develops is based on an imbalance of protease and antiprotease activity leading to the degradation of elastin within the fiber network of the extracellular matrix. Here we report novel roles for mechanical forces and collagen during the remodeling of lung tissue in a rat model of elastase-induced emphysema. We have developed a technique to measure the stress-strain properties of tissue sections while simultaneously visualizing the deformation of the immunofluorescently labeled elastin-collagen network. We found that in the elastase treated tissue significant remodeling leads to thickened elastin and collagen fibers and during stretching, the newly deposited elastin and collagen fibers undergo substantially larger distortions than in normal tissue. We also found that the threshold for mechanical failure of collagen, which provides mechanical stability to the normal lung, is reduced. Our results indicate that mechanical forces during breathing are capable of causing failure of the remodeled extracellular matrix at loci of stress concentrations and so contribute to the progression of emphysema.


Assuntos
Colágeno/fisiologia , Modelos Animais de Doenças , Elastina/fisiologia , Enfisema/etiologia , Enfisema/fisiopatologia , Mecânica Respiratória/fisiologia , Análise de Variância , Animais , Fenômenos Biomecânicos , Remodelação Óssea , Colágeno/ultraestrutura , Progressão da Doença , Elastina/ultraestrutura , Enfisema/metabolismo , Enfisema/patologia , Capacidade Residual Funcional , Imuno-Histoquímica , Modelos Lineares , Masculino , Elastase Pancreática , Troca Gasosa Pulmonar , Ratos , Ratos Sprague-Dawley , Estresse Mecânico , Trabalho Respiratório
18.
J Appl Physiol (1985) ; 91(2): 737-47, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11457789

RESUMO

We measured lung impedance in rats in closed chest (CC), open chest (OC), and isolated lungs (IL) at four transpulmonary pressures with a optimal ventilator waveform. Data were analyzed with an homogeneous linear or an inhomogeneous linear model. Both models include tissue damping and elastance and airway inertance. The homogeneous linear model includes airway resistance (Raw), whereas the inhomogeneous linear model has a continuous distribution of Raw characterized by the mean Raw and the standard deviation of Raw (SDR). Lung mechanics were compared with tissue strip mechanics at frequencies and operating stresses comparable to those during lung impedance measurements. The hysteresivity (eta) was calculated as tissue damping/elastance. We found that 1) airway and tissue parameters were different in the IL than in the CC and OC conditions; 2) SDR was lowest in the IL; and 3) eta in IL at low transpulmonary pressure was similar to eta in the tissue strip. We conclude that eta is primarily determined by lung connective tissue, and its elevated estimates from impedance data in the CC and OC conditions are a consequence of compartment-like heterogeneity being greater in CC and OC conditions than in the IL.


Assuntos
Pulmão/fisiologia , Resistência das Vias Respiratórias/fisiologia , Animais , Elasticidade , Técnicas In Vitro , Masculino , Matemática , Modelos Biológicos , Pressão , Ratos , Ratos Sprague-Dawley , Estresse Mecânico
19.
J Appl Physiol (1985) ; 89(1): 3-14, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10904029

RESUMO

The dynamic stiffness (H), damping coefficient (G), and harmonic distortion (k(d)) characterizing tissue nonlinearity of lung parenchymal strips from guinea pigs were assessed before and after treatment with elastase or collagenase between 0.1 and 3.74 Hz. After digestion, data were obtained both at the same mean length and at the same mean force of the strip as before digestion. At the same mean length, G and H decreased by approximately 33% after elastase and by approximately 47% after collagenase treatment. At the same mean force, G and H increased by approximately 7% after elastase and by approximately 25% after collagenase treatment. The k(d) increased more after collagenase (40%) than after elastase (20%) treatment. These findings suggest that, after digestion, the fraction of intact fibers decreases, which, at the same mean length, leads to a decrease in moduli. At the same mean force, collagen fibers operate at a higher portion of their stress-strain curve, which results in an increase in moduli. Also, G and H were coupled so that hysteresivity (G/H) did not change after treatments. However, k(d) was decoupled from elasticity and was sensitive to stretching of collagen, which may be of value in detecting structural alterations in the connective tissue of the lung.


Assuntos
Colagenases/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Elastase Pancreática/farmacologia , Resistência das Vias Respiratórias/efeitos dos fármacos , Animais , Colágeno/metabolismo , Tecido Conjuntivo/efeitos dos fármacos , Tecido Conjuntivo/metabolismo , Elasticidade , Elastina/metabolismo , Cobaias , Técnicas In Vitro , Masculino , Dinâmica não Linear , Estresse Mecânico
20.
Artigo em Inglês | MEDLINE | ID: mdl-11970423

RESUMO

We investigate the fluid flow through two-dimensional ramified structures by direct simulation of the Navier-Stokes equations. We show that for trees with n generations, the flow distribution strongly depends on the Reynolds number Re. Specifically, for a tree without loops the flow becomes highly heterogeneous at high Re. For a tree with loops, on the other hand, the flow distribution tends to be more uniform at increased Re conditions. We show that these apparently contradictory behaviors have the same origin, namely, the effect of inertia on the momentum transport in the channels of the ramified geometry. In order to simulate the propagation of the flow imbalance throughout the tree without loops, we develop a simple model that incorporates the basic fluid dynamics features of the system. For large trees, the results of the model indicate that the distribution of flow at the outlet branches can be described by a self-affine landscape. Finally, we argue that the nonuniform partitioning of flow found for the structure without loops may contribute to the morphogenesis and functioning of the bronchial tree.

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