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1.
Phys Rev Lett ; 125(23): 237202, 2020 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-33337211

RESUMO

The correlation length ξ, a key quantity in glassy dynamics, can now be precisely measured for spin glasses both in experiments and in simulations. However, known analysis methods lead to discrepancies either for large external fields or close to the glass temperature. We solve this problem by introducing a scaling law that takes into account both the magnetic field and the time-dependent spin-glass correlation length. The scaling law is successfully tested against experimental measurements in a CuMn single crystal and against large-scale simulations on the Janus II dedicated computer.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31871077

RESUMO

We analyzed the use of isavuconazole (ISA) as treatment or prophylaxis for invasive fungal disease (IFD) in children with hemato-oncologic diseases. A multicentric retrospective analysis was performed among centers belonging to the Italian Association for Pediatric Hematology and Oncology (AIEOP). Pharmacokinetic (PK) monitoring was applied by a high-performance liquid chromatography-tandem mass spectrometry (HLPC-MS/MS) assay. Twenty-nine patients were studied: 10 during chemotherapy and 19 after allogeneic hematopoietic stem cell transplantation (HSCT). The patients consisted of 20 males and 9 females with a median age of 14.5 years (age range, 3 to 18 years) and a median body weight of 47 kg (body weight range, 15 to 80 kg). ISA was used as prophylaxis in 5 patients and as treatment in 24 cases (20 after therapeutic failure, 4 as first-line therapy). According to European Organization for Research and Treatment of Cancer (EORTC) criteria, we registered 5 patients with proven IFD, 9 patients with probable IFD, and 10 patients with possible IFD. Patients with a body weight of <30 kg received half the ISA dose; the others received ISA on the adult schedule (a 200-mg loading dose every 8 h on days 1 and 2 and a 200-mg/day maintenance dose); for all but 10 patients, the route of administration switched from the intravenous route to the oral route during treatment. ISA was administered for a median of 75.5 days (range, 6 to 523 days). The overall response rate was 70.8%; 12 patients with IFD achieved complete remission, 5 achieved partial remission, 5 achieved progression, and 3 achieved stable IFD. No breakthrough infections were registered. PK monitoring of 17 patients revealed a median ISA steady-state trough concentration of 4.91 mg/liter (range, 2.15 to 8.54 mg/liter) and a concentration/dose (in kilograms) ratio of 1.13 (range, 0.47 to 3.42). Determination of the 12-h PK profile was performed in 6 cases. The median area under the concentration-time curve from 0 to 12 h was 153.16 mg·h/liter (range, 86.31 to 169.45 mg·h/liter). Common Terminology Criteria for Adverse Events grade 1 to 3 toxicity (increased transaminase and/or creatinine levels) was observed in 6 patients, with no drug-drug interactions being seen in patients receiving immunosuppressants. Isavuconazole may be useful and safe in children with hemato-oncologic diseases, even in the HSCT setting. Prospective studies are warranted.


Assuntos
Antifúngicos/farmacocinética , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas , Infecções Fúngicas Invasivas/tratamento farmacológico , Nitrilas/farmacocinética , Piridinas/farmacocinética , Triazóis/farmacocinética , Administração Intravenosa , Administração Oral , Adolescente , Antifúngicos/sangue , Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus/crescimento & desenvolvimento , Criança , Pré-Escolar , Esquema de Medicação , Feminino , Neoplasias Hematológicas/microbiologia , Neoplasias Hematológicas/patologia , Humanos , Infecções Fúngicas Invasivas/microbiologia , Infecções Fúngicas Invasivas/patologia , Masculino , Testes de Sensibilidade Microbiana , Mucor/efeitos dos fármacos , Mucor/crescimento & desenvolvimento , Nitrilas/sangue , Nitrilas/farmacologia , Penicillium/efeitos dos fármacos , Penicillium/crescimento & desenvolvimento , Piridinas/sangue , Piridinas/farmacologia , Estudos Retrospectivos , Transplante Homólogo , Triazóis/sangue , Triazóis/farmacologia
3.
Mycoses ; 62(3): 252-260, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30565742

RESUMO

Invasive fungal infections (IFI) of the Central Nervous System (IFI-CNS) and Paranasal Sinuses (IFI-PS) are rare, life-threatening infections in haematologic patients, and their management remains a challenge despite the availability of new diagnostic techniques and novel antifungal agents. In addition, analyses of large cohorts of patients focusing on these rare IFI are still lacking. Between January 2010 and December 2016, 89 consecutive cases of Proven (53) or Probable (36) IFI-CNS (71/89) and IFI-PS (18/89) were collected in 34 haematological centres. The median age was 40 years (range 5-79); acute leukaemia was the most common underlying disease (69%) and 29% of cases received a previous allogeneic stem cell transplant. Aspergillus spp. were the most common pathogens (69%), followed by mucormycetes (22%), Cryptococcus spp. (4%) and Fusarium spp. (2%). The lung was the primary focus of fungal infection (48% of cases). The nervous system biopsy was performed in 10% of IFI-CNS, and a sinus biopsy was performed in 56% of IFI-PS (P = 0.03). The Galactomannan test on cerebrospinal fluid has been performed in 42% of IFI-CNS (30/71), and it was positive in 67%. Eighty-four pts received a first-line antifungal therapy with Amphotericine B in 58% of cases, Voriconazole in 31% and both in 11%. Moreover, 58% of patients received 2 or more lines of therapy and 38% were treated with a combination of 2 or more antifungal drugs. The median duration of antifungal therapy was 60 days (range 5-835). A surgical intervention was performed in 26% of cases but only 10% of IFI-CNS underwent neurosurgical intervention. The overall response rate to antifungal therapy (complete or partial response) was 57%, and 1-year overall survival was 32% without significant differences between IFI-CNS and IFI-PS. The overall mortality was 69% but the IFI attributable mortality was 33%. Mortality of IFI-CNS/PS remains high but, compared to previous historical data, it seems to be reduced probably due to the availability of newer antifungal drugs. The results arising from this large contemporary cohort of cases may allow a more effective diagnostic and therapeutic management of these very rare IFI complications in haematologic patients.


Assuntos
Antifúngicos/uso terapêutico , Infecções Fúngicas do Sistema Nervoso Central/epidemiologia , Desbridamento , Fungos/classificação , Fungos/isolamento & purificação , Neoplasias Hematológicas/complicações , Sinusite/epidemiologia , Adolescente , Adulto , Idoso , Infecções Fúngicas do Sistema Nervoso Central/microbiologia , Infecções Fúngicas do Sistema Nervoso Central/terapia , Líquido Cefalorraquidiano/microbiologia , Criança , Pré-Escolar , Estudos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Seios Paranasais/microbiologia , Sinusite/microbiologia , Sinusite/terapia , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
4.
Phys Rev Lett ; 120(26): 267203, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004737

RESUMO

Experiments on spin glasses can now make precise measurements of the exponent z(T) governing the growth of glassy domains, while our computational capabilities allow us to make quantitative predictions for experimental scales. However, experimental and numerical values for z(T) have differed. We use new simulations on the Janus II computer to resolve this discrepancy, finding a time-dependent z(T,t_{w}), which leads to the experimental value through mild extrapolations. Furthermore, theoretical insight is gained by studying a crossover between the T=T_{c} and T=0 fixed points.

5.
Bone Marrow Transplant ; 53(1): 58-63, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29084200

RESUMO

Several guidelines have been published about management of chronic GvHD (cGvHD), but the clinical practice still remains demanding. The Gruppo Italiano Trapianto di Midollo Osseo (GITMO) has planned a prospective observational study on cGvHD, supported by a dedicated software, including the updated recommendations. In view of this study, two surveys have been conducted, focusing the management of cGvHD and ancillary therapy in cGvHD, to address the current 'real life' situation. The two surveys were sent to all 57 GITMO centers, performing allografting in Italy; the response rate was 57% and 66% of the interviewed centers, respectively. The first survey showed a great disparity especially regarding steroid-refractory cGvHD, although extracorporeal photo-apheresis resulted as the most indicated treatment in this setting. Another challenging issue was the strategy for tapering steroid: our survey showed a great variance, and this disagreement could be a real bias in evaluating outcomes in prospective studies. As for the second survey, the results suggest that the ancillary treatments are not standardized in many centers. All responding centers reported a strong need to standardize management of cGvHD and to participate in prospective trials. Before starting observational and/or interventional studies, a detailed knowledge of current practice should be encouraged.


Assuntos
Doença Enxerto-Hospedeiro/terapia , Doença Crônica , Feminino , Doença Enxerto-Hospedeiro/patologia , Humanos , Itália , Masculino
6.
Phys Rev Lett ; 118(15): 157202, 2017 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-28452502

RESUMO

We first reproduce on the Janus and Janus II computers a milestone experiment that measures the spin-glass coherence length through the lowering of free-energy barriers induced by the Zeeman effect. Secondly, we determine the scaling behavior that allows a quantitative analysis of a new experiment reported in the companion Letter [S. Guchhait and R. Orbach, Phys. Rev. Lett. 118, 157203 (2017)].PRLTAO0031-900710.1103/PhysRevLett.118.157203 The value of the coherence length estimated through the analysis of microscopic correlation functions turns out to be quantitatively consistent with its measurement through macroscopic response functions. Further, nonlinear susceptibilities, recently measured in glass-forming liquids, scale as powers of the same microscopic length.

7.
Bone Marrow Transplant ; 50(3): 414-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25581411

RESUMO

Hepatic focal nodular hyperplasia (FNH) is a nonmalignant condition rarely affecting children previously treated for cancer, especially those who received hematopoietic SCT (HSCT). Some aspects of its pathogenesis still remain unclear and a strong association with specific risk factors has not yet been identified. We report here a single institution's case series of 17 patients who underwent HSCT and were diagnosed with FNH, analyzing retrospectively their clinical features and the radiological appearance of their hepatic lesions. We aimed to compare the diagnostic accuracy of ultrasound (US) and magnetic resonance imaging (MRI) and to explore the role of transient elastography (FibroScan) to evaluate the degree of hepatic fibrosis in FNH patients. Our analysis showed an association of FNH with age at transplant ⩽12 years (hazard ratio (HR) 9.10); chronic GVHD (HR 2.99); hormone-replacement therapy (HR 4.02) and abdominal radiotherapy (HR 4.37). MRI proved to be a more accurate diagnostic tool compared with US. Nine out of 12 patients who underwent FibroScan showed hepatic fibrosis. Our study points out that FNH is an emerging complication of HSCT, which requires a lifelong surveillance to follow its course in cancer patients.


Assuntos
Hiperplasia Nodular Focal do Fígado/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Criança , Pré-Escolar , Feminino , Hiperplasia Nodular Focal do Fígado/patologia , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Masculino , Estudos Retrospectivos , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/métodos
8.
Phys Rev Lett ; 113(1): 012501, 2014 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-25032921

RESUMO

The properties of pygmy dipole states in 208Pb were investigated using the 208Pb(17O, 17O'γ) reaction at 340 MeV and measuring the γ decay with high resolution with the AGATA demonstrator array. Cross sections and angular distributions of the emitted γ rays and of the scattered particles were measured. The results are compared with (γ, γ') and (p, p') data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering and of the inelastic excitation of the 2+ and 3- states. For the dipole transitions a form factor obtained by folding a microscopically calculated transition density was used for the first time. This has allowed us to extract the isoscalar component of the 1- excited states from 4 to 8 MeV.

10.
Pathol Res Pract ; 207(2): 86-90, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21176866

RESUMO

Pathological studies would aid in finding the real causes of death and in outlining adequate strategies for treatment regarding patients with poor clinical outcome of influenza A H1N1 swine flu. We describe the autopsy findings of six cases of influenza A H1N1 swine flu. The lungs in these cases had an alveolitis with hyaline membranes. Immunohistochemistry for influenza was positive only in lungs (in pneumocytes, in macrophages, in some multinucleate cells in alveoli, and in blood vessel walls) of two cases. Disseminated petechial brain hemorrhage was observed in four of the cases and focally in one case. Focal myocarditis was observed in one case. Coagulation infarcts (ischemic) were observed in the pancreas of two cases and in the spleen of two cases. Our results indicate that there was marked replication of the virus in alveoli in the more recently infected cases, which could explain the extensive diffuse alveolar damage. In our cases, there were important vascular phenomena that resulted in hemorrhage and thrombosis, but without marked decrease of platelet count and coagulation cascade disruptions. This would be attributed to hemodynamic disruption. However, it is possible that the hemorrhagic petechial lesions in the brain are due to vascular lesions or to an increase of endothelial permeability.


Assuntos
Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/patologia , Pulmão/patologia , Adulto , Autopsia , Encéfalo/patologia , Feminino , Humanos , Imuno-Histoquímica , Infarto/patologia , Infarto/virologia , Influenza Humana/mortalidade , Influenza Humana/virologia , Hemorragias Intracranianas/patologia , Hemorragias Intracranianas/virologia , Pulmão/irrigação sanguínea , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Miocardite/patologia , Miocardite/virologia , Miocárdio/patologia , Pâncreas/irrigação sanguínea , Pâncreas/patologia , Baço/irrigação sanguínea , Baço/patologia , Adulto Jovem
11.
Case Rep Med ; 2010: 206132, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20589085

RESUMO

Osteonecrosis (ON) is a critical complication in the treatment of childhood leukemia and lymphoma. It particularly affects survivors of acute lymphoblastic leukemia and non-Hodgkin lymphoma reflecting the cumulative exposure to glucocorticosteroid therapy. ON is often multiarticular and bilateral, specially affecting weight-bearing joints. A conventional approach suggests a surgical intervention even if pharmacological options have also recently been investigated. We reported two cases of long time steroid-treated patients who underwent Bone Marrow Transplantation (BMT) for hematological disease. Both patients developed femoral head osteonecrosis (ON) that was diagnosed by magnetic resonance imaging (MRI) and the ON was also accompanied with pain and a limp. Despite of the conventional strategies of therapy, we successfully started a short-term treatment with bisphosphonates in order to decrease the pain and the risk of fracture.

12.
Diagn Cytopathol ; 38(4): 260-3, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19813269

RESUMO

The objective of the present study was to study the prevalence of abnormal anal cytology in patients with AIDS. Anal smears, obtained with a cytobrush, of 102 HIV-positive patients of the Emilio Ribas Institute (Sao Paulo, Brazil) were collected, and only after that, the patients were submitted to anoscopy. Thirty-two patients had LSIL and 14 others had HSIL. Squamous intra-epithelial lesions were also observed in 38% of the patients without condyloma (18/47): in 9 of the 33 patients without history of condyloma (27%) and in 9 of the 14 patients who had previously treated condyloma (64%). An invasive squamous cell carcinoma was observed in one patient without history of condyloma. In all 13 patients with HSIL, biopsies guided by high resolution anoscopy confirmed high grade dysplasia. Our findings suggest that anal cytology is mandatory in AIDS even in patients without macroscopic anal lesions or without previous history of anal condyloma.


Assuntos
Síndrome da Imunodeficiência Adquirida/patologia , Canal Anal/patologia , Síndrome da Imunodeficiência Adquirida/complicações , Adulto , Feminino , Soropositividade para HIV/complicações , Soropositividade para HIV/patologia , Humanos , Masculino
13.
Bone Marrow Transplant ; 41 Suppl 2: S65-70, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18545247

RESUMO

GvHD remains a source of significant morbidity and mortality in the setting of allogeneic haematopoietic SCT. Improving outcomes in stem cell transplant recipients requires additional therapeutic modalities for GvHD, especially for patients who fail to respond to initial therapy with steroids. Moreover, while the absence of acute GvHD (aGvHD) is associated with a higher risk of relapse of the underlying malignant disease, severe aGvHD usually induces the occurrence of life-threatening complications such as severe infections. This article summarizes the current state of aGvHD prophylaxis and treatment.


Assuntos
Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/prevenção & controle , Imunossupressores/uso terapêutico , Criança , Doença Enxerto-Hospedeiro/classificação , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Esteroides/uso terapêutico , Linfócitos T Reguladores , Tacrolimo/uso terapêutico , Transplante Homólogo , Fator de Necrose Tumoral alfa/antagonistas & inibidores
14.
Bone Marrow Transplant ; 42(6): 421-5, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18574446

RESUMO

Acute GVHD (aGVHD) is a major cause of morbidity and mortality after unrelated BMT (UBMT). Our purpose was to analyze the role of extracorporeal photochemotherapy (ECP) in controlling grade II-IV aGVHD in children given UBMT. Of 41 consecutive children, 31 developed grade II-IV aGVHD after UBMT: 16 had a good response to steroids (GR group), whereas 15 underwent ECP (ECP group) within 100 days of UBMT. Eligibility criteria for starting ECP were steroid resistance, dependence or viral reactivations. Criteria for judging response to aGVHD treatment were that the resolution of all signs were considered a complete response (CR), at least a 50% improvement was classified as a partial response (PR) and stable or progressive disease was judged as no response (NR). On completing ECP, the CR rate was 73%, whereas the GR group had a CR rate of 56% by day 100. The 2-year overall survival and progression-free survival rates were 57 and 67% in the GR group vs 85 and 87% in the ECP group. Our data seem to suggest that ECP may improve outcome in patients after UBMT. These findings need to be confirmed in a larger population.


Assuntos
Transplante de Medula Óssea , Doença Enxerto-Hospedeiro/mortalidade , Transtornos Linfoproliferativos/mortalidade , Doença Aguda , Adolescente , Adulto , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/terapia , Humanos , Lactente , Transtornos Linfoproliferativos/terapia , Masculino , Fotoferese , Estudos Retrospectivos , Taxa de Sobrevida , Transplante Homólogo
15.
Mycoses ; 51(6): 497-504, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18331444

RESUMO

A reliable diagnosis of invasive aspergillosis (IA) is hampered by the difficulty in obtaining suitable tissue samples. To evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the LightCycler PCR for the diagnosis of IA, 536 blood samples were collected over a 22-month period from 62 paediatric patients (median age 10 years, range 1-18) considered at risk of IA. The galactomannan antigen (GM) and fungal DNA were assessed on serial blood samples. IA was diagnosed in eight of 62 patients (13%): proven, five, probable, three. Sensitivity, specificity, PPV and NPV of LightCycler PCR varied according to the number of positive samples used to define positivity: 88%; 37%; 17% and 95% for single sample positivity; and 63%, 81%, 33% and 94% for serial sample positivity respectively. The concordance between positivity of LightCycler PCR assay and the diagnosis of IA was 79%. The single positivity of LightCycler PCR assay showed a good sensitivity for the diagnosis of IA in paediatric patients. The high NPV makes LightCycler PCR a promising tool in addition to GM testing to design a strategy of pre-emptive antifungal therapy, although further validation studies are needed.


Assuntos
Aspergilose/diagnóstico , Neoplasias Hematológicas/complicações , Reação em Cadeia da Polimerase/métodos , Adolescente , Criança , Pré-Escolar , DNA Fúngico/sangue , Feminino , Galactose/análogos & derivados , Humanos , Lactente , Masculino , Mananas/sangue , Valor Preditivo dos Testes , Sensibilidade e Especificidade
16.
Bone Marrow Transplant ; 41(4): 363-70, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17982496

RESUMO

We investigated the incidence, risk factors and outcome of haemorrhagic cystitis (HC) in paediatric patients undergoing HSCT and the predictive value of BK viruria and viraemia for developing HC. Over a period of 54 months, 74 patients were recruited. The cumulative incidence of HC was 22%. Among 15 patients prospectively monitored for BK viruria and viraemia, four patients developed HC of grade > or =II. This group, which had two consecutive BK positive samples, showed a sensitivity of 100%, a specificity of 82%, a positive predictive value of 67%, and negative predictive value of 100% for developing HC. Analysed by a receiver-operator characteristic curve (ROC), a urine BK load >9 x 10(6) genomic copies/ml had a sensitivity of 95% and specificity of 90%; while a blood BK load >1 x 10(3) genomic copies/ml had a sensitivity of 40% and a specificity of 93% for HC, respectively. In univariate analysis, BK positivity was the only factor significantly associated with HC. After a median follow-up of 1.8 years, patients with HC showed a lower overall survival, 40 vs 65%, P 0.01, and a lower event-free survival, 42 vs 62%, P 0.03, compared to patients without HC. We conclude that BK detection in urine and/or plasma is a specific predictor for developing HC.


Assuntos
Vírus BK/patogenicidade , Cistite/virologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Infecções por Polyomavirus/complicações , Infecções Tumorais por Vírus/complicações , Adolescente , Criança , Pré-Escolar , Cistite/epidemiologia , Cistite/fisiopatologia , Intervalo Livre de Doença , Feminino , Humanos , Incidência , Lactente , Itália/epidemiologia , Masculino , Infecções por Polyomavirus/epidemiologia , Estudos Prospectivos , Transplante Homólogo/efeitos adversos , Infecções Tumorais por Vírus/epidemiologia , Carga Viral , Viremia
17.
Ecotoxicol Environ Saf ; 66(3): 447-50, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16797706

RESUMO

Organophosphate intoxication induces an acute cholinergic syndrome, but the long-term effects of these compounds in the cardiocirculatory system are not known. The objective of the present work is to investigate if experimental chronic exposition to repetitive sublethal doses of organophosphate methamidophos can induce morphological changes in rat's hearts. Wistar albino adult male rats received a weekly enteral sublethal dose of the organophosphate methamidophos for 12 consecutive weeks. After that we have performed histological and morphometric studies of their hearts. We have observed hypertrophy of cardiac myocites in treated animals, which was confirmed by morphometric studies (measure of smaller diameter of cardiac myocites). One of the possible explanations for the cardiac hypertrophy would be persistent systemic arterial hypertension in treated animals. However, another possible explanation would be direct sympathetic stimulation.


Assuntos
Cardiomegalia/induzido quimicamente , Inibidores da Colinesterase/toxicidade , Inseticidas/toxicidade , Miócitos Cardíacos/efeitos dos fármacos , Compostos Organotiofosforados/toxicidade , Animais , Cardiomegalia/patologia , Colinesterases/sangue , Ventrículos do Coração/citologia , Masculino , Miócitos Cardíacos/patologia , Ratos , Ratos Wistar
18.
Ecotoxicol Environ Saf ; 64(2): 251-5, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16002140

RESUMO

Subtle neurological disturbances have been described in organophosphorus intoxication. Experimental studies have reported neuronal necrosis, particularly in animals experiencing seizures. The objective of the present work was to investigate if in rats (without seizures) exposed to an organophosphate agent, morphological changes occur in specific regions of the brain. The animals received 2.5 or 5.0 mg/kg methamidophos once a week for 2 months and were decapitated after 2 months 7 days of drug administration. We observed atrophy of the molecular layer of the parietal cortex without neuronal loss in specific cerebral regions. This would be due to atrophy or loss of neuronal ramifications but without neuronal loss.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Inibidores da Colinesterase/toxicidade , Compostos Organotiofosforados/toxicidade , Animais , Atrofia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Inibidores da Colinesterase/administração & dosagem , Masculino , Microscopia/métodos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Compostos Organotiofosforados/administração & dosagem , Lobo Parietal/efeitos dos fármacos , Lobo Parietal/patologia , Ratos , Ratos Wistar
19.
Ecotoxicol Environ Saf ; 55(2): 152-6, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12742361

RESUMO

The authors studied the effects of nicotine in developing skeletal muscles of rats. Pregnant Wistar rats received an enteral dose of nicotine (2.5, 5.0 or 10mg/kg, respectively, in groups G2, G5, and G10) from the 10th to the 18th or 20th days of pregnancy. Myotube atrophy was observed mainly in 20-day-old fetuses of G10. Twenty-day-old control fetus and of G2 and G5 had a high sarcoplasmic expression of desmin (weaker in G10). Vimentin expression was similar in 18-day-old fetuses of the control, G2, and G5 groups, but it was weaker in 20-day-old fetuses of the G2 and G5 groups. This would indicate an acceleration of the maturation pattern of vimentin expression in these intoxicated fetus. In conclusion, high doses of nicotine induce myotube atrophy and decrease of the expression of intermediate filaments, whereas relatively low doses of nicotine (G2 and G5) induce an early decrease of vimentin expression with no myofiber atrophy.


Assuntos
Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/citologia , Músculo Esquelético/crescimento & desenvolvimento , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Animais , Desmina/metabolismo , Feminino , Imuno-Histoquímica , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/efeitos dos fármacos , Gravidez , Ratos , Ratos Wistar , Receptores Nicotínicos/efeitos dos fármacos , Receptores Nicotínicos/metabolismo , Vimentina/metabolismo
20.
Ecotoxicol Environ Saf ; 53(1): 48-51, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12481856

RESUMO

The objective of the present investigation was to study the protection afforded by a single administration of pralidoxime against the muscle necrosis induced by the organophosphate compound metamidophos at different times after intoxication. The fiber necrosis of the diaphragm muscle was quantified by a morphometric technique, comparing the area fraction occupied by necrotic muscle fibers in animals that received pralidoxime at different times after intoxication, i.e., 0, 1, 3, 6, and 12 h. Pralidoxime administration protected metamidophos-induced muscle necrosis in all groups studied except for the 12-h group. The earlier the administration of pralidoxime the greater the protection against muscle necrosis. This protection was not accompanied by complete reactivation of plasma cholinesterase activity. Results support the current opinion that pralidoxime should be administered as soon as possible after organophosphate intoxication, because in addition to reversing the muscarinic effects, early administration of pralidoxime also prevents muscle necrosis--which could impair muscular function and respiratory condition. The time difference between recovery of plasma cholinesterase activity and muscle necrosis protection indicates that this method is not completely trustworthy for patient follow-up, since some improvement may occur in spite of the low plasma cholinesterase activity.


Assuntos
Antídotos/farmacologia , Inseticidas/toxicidade , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Compostos Organotiofosforados/toxicidade , Compostos de Pralidoxima/farmacologia , Animais , Antídotos/administração & dosagem , Colinesterases/efeitos dos fármacos , Colinesterases/farmacologia , Masculino , Compostos de Pralidoxima/administração & dosagem , Ratos , Ratos Wistar
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