RESUMEN
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.
RESUMEN
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.
Asunto(s)
Antifúngicos/farmacocinética , Neoplasias Hematológicas/terapia , Trasplante de Células Madre Hematopoyéticas , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Nitrilos/farmacocinética , Piridinas/farmacocinética , Triazoles/farmacocinética , Administración Intravenosa , Administración Oral , Adolescente , Antifúngicos/sangre , Antifúngicos/farmacología , Aspergillus/efectos de los fármacos , Aspergillus/crecimiento & desarrollo , Niño , Preescolar , Esquema de Medicación , Femenino , Neoplasias Hematológicas/microbiología , Neoplasias Hematológicas/patología , Humanos , Infecciones Fúngicas Invasoras/microbiología , Infecciones Fúngicas Invasoras/patología , Masculino , Pruebas de Sensibilidad Microbiana , Mucor/efectos de los fármacos , Mucor/crecimiento & desarrollo , Nitrilos/sangre , Nitrilos/farmacología , Penicillium/efectos de los fármacos , Penicillium/crecimiento & desarrollo , Piridinas/sangre , Piridinas/farmacología , Estudios Retrospectivos , Trasplante Homólogo , Triazoles/sangre , Triazoles/farmacologíaRESUMEN
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.
Asunto(s)
Antifúngicos/uso terapéutico , Infecciones Fúngicas del Sistema Nervioso Central/epidemiología , Desbridamiento , Hongos/clasificación , Hongos/aislamiento & purificación , Neoplasias Hematológicas/complicaciones , Sinusitis/epidemiología , Adolescente , Adulto , Anciano , Infecciones Fúngicas del Sistema Nervioso Central/microbiología , Infecciones Fúngicas del Sistema Nervioso Central/terapia , Líquido Cefalorraquídeo/microbiología , Niño , Preescolar , Estudios Epidemiológicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Senos Paranasales/microbiología , Sinusitis/microbiología , Sinusitis/terapia , Análisis de Supervivencia , Resultado del Tratamiento , Adulto JovenRESUMEN
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.
RESUMEN
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.
Asunto(s)
Enfermedad Injerto contra Huésped/terapia , Enfermedad Crónica , Femenino , Enfermedad Injerto contra Huésped/patología , Humanos , Italia , MasculinoRESUMEN
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.
RESUMEN
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.
Asunto(s)
Hiperplasia Nodular Focal/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Adolescente , Niño , Preescolar , Femenino , Hiperplasia Nodular Focal/patología , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Masculino , Estudios Retrospectivos , Acondicionamiento Pretrasplante/efectos adversos , Acondicionamiento Pretrasplante/métodosRESUMEN
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.
Asunto(s)
Anemia Aplásica/terapia , Trasplante de Células Madre Hematopoyéticas/métodos , Aspergilosis Pulmonar/terapia , Aloinjertos , Anemia Aplásica/complicaciones , Linfocitos B/inmunología , Preescolar , Femenino , Haplotipos , Humanos , Depleción Linfocítica , Aspergilosis Pulmonar/etiología , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Linfocitos T/inmunologíaRESUMEN
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.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Gripe Humana/patología , Pulmón/patología , Adulto , Autopsia , Encéfalo/patología , Femenino , Humanos , Inmunohistoquímica , Infarto/patología , Infarto/virología , Gripe Humana/mortalidad , Gripe Humana/virología , Hemorragias Intracraneales/patología , Hemorragias Intracraneales/virología , Pulmón/irrigación sanguínea , Pulmón/virología , Masculino , Persona de Mediana Edad , Miocarditis/patología , Miocarditis/virología , Miocardio/patología , Páncreas/irrigación sanguínea , Páncreas/patología , Bazo/irrigación sanguínea , Bazo/patología , Adulto JovenRESUMEN
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.
RESUMEN
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.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/patología , Canal Anal/patología , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Adulto , Femenino , Seropositividad para VIH/complicaciones , Seropositividad para VIH/patología , Humanos , MasculinoRESUMEN
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.
Asunto(s)
Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/prevención & control , Inmunosupresores/uso terapéutico , Niño , Enfermedad Injerto contra Huésped/clasificación , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Humanos , Esteroides/uso terapéutico , Linfocitos T Reguladores , Tacrolimus/uso terapéutico , Trasplante Homólogo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
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.
Asunto(s)
Trasplante de Médula Ósea , Enfermedad Injerto contra Huésped/mortalidad , Trastornos Linfoproliferativos/mortalidad , Enfermedad Aguda , Adolescente , Adulto , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Enfermedad Injerto contra Huésped/terapia , Humanos , Lactante , Trastornos Linfoproliferativos/terapia , Masculino , Fotoféresis , Estudios Retrospectivos , Tasa de Supervivencia , Trasplante HomólogoRESUMEN
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.
Asunto(s)
Aspergilosis/diagnóstico , Neoplasias Hematológicas/complicaciones , Reacción en Cadena de la Polimerasa/métodos , Adolescente , Niño , Preescolar , ADN de Hongos/sangre , Femenino , Galactosa/análogos & derivados , Humanos , Lactante , Masculino , Mananos/sangre , Valor Predictivo de las Pruebas , Sensibilidad y EspecificidadRESUMEN
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.
Asunto(s)
Virus BK/patogenicidad , Cistitis/virología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Infecciones por Polyomavirus/complicaciones , Infecciones Tumorales por Virus/complicaciones , Adolescente , Niño , Preescolar , Cistitis/epidemiología , Cistitis/fisiopatología , Supervivencia sin Enfermedad , Femenino , Humanos , Incidencia , Lactante , Italia/epidemiología , Masculino , Infecciones por Polyomavirus/epidemiología , Estudios Prospectivos , Trasplante Homólogo/efectos adversos , Infecciones Tumorales por Virus/epidemiología , Carga Viral , ViremiaRESUMEN
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.
Asunto(s)
Cardiomegalia/inducido químicamente , Inhibidores de la Colinesterasa/toxicidad , Insecticidas/toxicidad , Miocitos Cardíacos/efectos de los fármacos , Compuestos Organotiofosforados/toxicidad , Animales , Cardiomegalia/patología , Colinesterasas/sangre , Ventrículos Cardíacos/citología , Masculino , Miocitos Cardíacos/patología , Ratas , Ratas WistarRESUMEN
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.
Asunto(s)
Encéfalo/efectos de los fármacos , Encéfalo/patología , Inhibidores de la Colinesterasa/toxicidad , Compuestos Organotiofosforados/toxicidad , Animales , Atrofia , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/patología , Inhibidores de la Colinesterasa/administración & dosificación , Masculino , Microscopía/métodos , Neuronas/efectos de los fármacos , Neuronas/patología , Compuestos Organotiofosforados/administración & dosificación , Lóbulo Parietal/efectos de los fármacos , Lóbulo Parietal/patología , Ratas , Ratas WistarRESUMEN
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.
Asunto(s)
Fibras Musculares Esqueléticas/efectos de los fármacos , Músculo Esquelético/citología , Músculo Esquelético/crecimiento & desarrollo , Nicotina/farmacología , Agonistas Nicotínicos/farmacología , Animales , Desmina/metabolismo , Femenino , Inmunohistoquímica , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/efectos de los fármacos , Embarazo , Ratas , Ratas Wistar , Receptores Nicotínicos/efectos de los fármacos , Receptores Nicotínicos/metabolismo , Vimentina/metabolismoRESUMEN
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.