RESUMEN
The dynamic interaction of complex fluid interfaces is highly sensitive to near-contact interactions occurring at the scale of ten of nanometers. Such interactions are difficult to analyze because they couple self-consistently to the dynamic morphology of the evolving interface, as well as to the hydrodynamics of the interstitial fluid film. In this work, we show that, above a given magnitude threshold, near-contact interactions trigger nontrivial microvorticity patterns, which in turn affect the effective near-contact interactions, giving rise to persistent fluctuating ripples at the fluid interface. In such a regime, near-contact interactions may significantly affect the macroscopic arrangement of emulsion configurations, such as those arising in soft-flowing microfluidic crystals.
RESUMEN
We present a lattice Boltzmann realization of Grad's extended hydrodynamic approach to nonequilibrium flows. This is achieved by using higher-order isotropic lattices coupled with a higher-order regularization procedure. The method is assessed for flow across parallel plates and three-dimensional flows in porous media, showing excellent agreement of the mass flow with analytical and numerical solutions of the Boltzmann equation across the full range of Knudsen numbers, from the hydrodynamic regime to ballistic motion.
RESUMEN
The blood-brain barrier (BBB) is a complex structure that protects the central nervous system from peripheral insults. Understanding the molecular basis of BBB function and dysfunction holds significant potential for future strategies to prevent and treat neurological damage. The aim of our study was (1) to investigate BBB alterations following excitotoxicity and (2) to test the protective properties of melatonin. Ibotenate, a glutamate analog, was injected intracerebrally in postnatal day 5 (P5) rat pups to mimic excitotoxic injury. Animals were than randomly divided into two groups, one receiving intraperitoneal (i.p.) melatonin injections (5mg/kg), and the other phosphate buffer saline (PBS) injections. Pups were sacrificed 2, 4 and 18 h after ibotenate injection. We determined lesion size at 5 days by histology, the location and organization of tight junction (TJ) proteins by immunohistochemical studies, and BBB leakage by dextran extravasation. Expression levels of BBB genes (TJs, efflux transporters and detoxification enzymes) were determined in the cortex and choroid plexus by quantitative PCR. Dextran extravasation was seen 2h after the insult, suggesting a rapid BBB breakdown that was resolved by 4h. Extravasation was significantly reduced in melatonin-treated pups. Gene expression and immunohistochemical assays showed dynamic BBB modifications during the first 4h, partially prevented by melatonin. Lesion-size measurements confirmed white matter neuroprotection by melatonin. Our study is the first to evaluate BBB structure and function at a very early time point following excitotoxicity in neonates. Melatonin neuroprotects by preventing TJ modifications and BBB disruption at this early phase, before its previously demonstrated anti-inflammatory, antioxidant and axonal regrowth-promoting effects.
Asunto(s)
Barrera Hematoencefálica/efectos de los fármacos , Melatonina/farmacología , Fármacos Neuroprotectores/farmacología , Animales , Animales Recién Nacidos , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Permeabilidad Capilar/efectos de los fármacos , Permeabilidad Capilar/fisiología , Modelos Animales de Enfermedad , Fármacos actuantes sobre Aminoácidos Excitadores/toxicidad , Expresión Génica/efectos de los fármacos , Ácido Glutámico/análogos & derivados , Ácido Glutámico/toxicidad , Inmunohistoquímica , Distribución Aleatoria , Ratas Sprague-DawleyRESUMEN
This corrects the article DOI: 10.1103/PhysRevE.92.043308.
RESUMEN
We investigate the accuracy and performance of the regularized version of the single-relaxation-time lattice Boltzmann equation for the case of two- and three-dimensional lid-driven cavities. The regularized version is shown to provide a significant gain in stability over the standard single-relaxation time, at a moderate computational overhead.
RESUMEN
The new research survey "Okkio alla salute", conducted in children in the 3rd year of elementary school, has confermed the worrisome phenomenon of the high number of obese and overweight children. Therefore, it is necessary, also in light of the few available resources, to fight back against this phenomenon that has been demonstrated to be a cause of disabling illnesses in adults. There must therefore be collaboration between Departments of Prevention and Hygiene and Nutrition services (SIAN) to build valid and efficient pathways. In this presentation we describe some national projects carried out by various local health agencies to address this health problem.
Asunto(s)
Conducta Alimentaria , Obesidad/prevención & control , Sobrepeso/prevención & control , HumanosRESUMEN
In children unable to perform reliable spirometry, the interrupter resistance (R(int) ) technique for assessing respiratory resistance is easy to perform. However, few data are available on the possibility to use R(int) as a surrogate for spirometry. We aimed at comparing R(int) and spirometry at baseline and after bronchodilator administration in a large population of asthmatic children. We collected retrospectively R(int) and spirometry results measured in 695 children [median age 7.8 (range 4.8-13.9) years] referred to our lab for routine assessment of asthma disease. Correlations between R(int) and spirometry were studied using data expressed as z-scores. Receiver operator characteristic curves for the baseline R(int) value (z-score) and the bronchodilator effect (percentage predicted value and z-score) were generated to assess diagnostic performance. At baseline, the relationship between raw values of R(int) and FEV(1) was not linear. Despite a highly significant inverse correlation between R(int) and all of the spirometry indices (FEV(1) , FVC, FEV(1) /FVC, FEF(25-75%) ; P < 0.0001), R(int) could detect baseline obstruction (FEV(1) z-score ≤ -2) with only 42% sensitivity and 95% specificity. Post-bronchodilator changes in R(int) and FEV(1) were inversely correlated (rhô = -0.50, P < 0.0001), and R(int) (≥35% predicted value decrease) detected FEV(1) reversibility (>12% baseline increase) with 70% sensitivity and 69% specificity (AUC = 0.79). R(int) measurements fitted a one-compartment model that explained the relationship between flows and airway resistance. We found that R(int) had poor sensitivity to detect baseline obstruction, but fairly good sensitivity and specificity to detect reversibility. However, in order to implement asthma guidelines for children unable to produce reliable spirometry, bronchodilator response measured by R(int) should be systematically studied and further assessed in conjunction with clinical outcomes.
Asunto(s)
Resistencia de las Vías Respiratorias/efectos de los fármacos , Asma/diagnóstico , Broncodilatadores , Espirometría , Adolescente , Asma/tratamiento farmacológico , Broncodilatadores/uso terapéutico , Niño , Preescolar , Femenino , Humanos , Masculino , Modelos Biológicos , Curva ROC , Pruebas de Función Respiratoria , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
In the present study we evaluated B-cell subsets and their functional development in 74 newborns from birth to 6 months of life. Moreover, we evaluated natural antibody production in vitro. The results documented a predominance of naive B-lymphocytes at all time-points evaluated, decreasing from birth to 6 months (p=0.009). The percentages of CD27+IgD+ and CD27+IgDneg memory B-cells were very low at birth and significantly increased only at 6 months (p=0.02 and p less than 0.001, respectively). We found a significant increase only in in vitro stimulated IgG production at 6 months as compared to birth (p less than 0.001). Moreover, a lower secretion of anti-Pn IgM antibodies up to 6 months of age, as compared to controls was observed. Our results underline that the susceptibility and severe course of infection in the neonate can be attributed, at least in part, to the lack of pre-existing immunological memory and competent adaptive immunity.
Asunto(s)
Subgrupos de Linfocitos B/inmunología , Recién Nacido/inmunología , Adolescente , Anticuerpos Antibacterianos/sangre , Cápsulas Bacterianas/inmunología , Niño , Preescolar , Femenino , Humanos , Inmunoglobulinas/sangre , Memoria Inmunológica , Lactante , Masculino , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/análisisRESUMEN
AIM: To report hypoglycaemia, a life-threatening adverse event, associated with trimethoprim-sulfamethoxazole. A sulfonylurea-like effect, leading to insulin raise, was investigated. METHODS: Two cases of trimethoprim-sulfamethoxazole-associated hypoglycaemia in 2 patients with a diagnosis of new HIV-1-infection presenting with Pneumocystis jiroveci pneumonia are reported. The patients had no predisposing factors, such as renal or liver impairment, interfering with trimethoprim-sulfamethoxazole elimination, thus leading to hypoglycaemia. Insulin plasma levels were measured in both patients. RESULTS: Severe hypoglycaemia was associated with increased serum levels of insulin up to 84 microU/ml (normal values < 10 microU/ml). Continuous dextrose infusion was necessary, further suggesting the sulfonylurea-like effect of sulfamethoxazole. Interestingly, plasma levels of insulin progressively raised after trimethoprim-sulfamethoxazole administration. CONCLUSIONS: Only 18 cases of trimethoprim-sulfamethoxazole associated hypoglycaemia are reported in the literature. Hypoglycaemia is a life-threatening condition, likely underreported, to consider when trimethoprim-sulfamethoxazole administration is required, even in the absence of predisposing factors or other hypoglycaemic agents. Physician should bear in mind the potential trimethoprim-sulfamethoxazole-associated adverse event especially when prolonged treatments and elevated dosage are used.
Asunto(s)
Antiinfecciosos/efectos adversos , Glucemia/efectos de los fármacos , Hipoglucemia/inducido químicamente , Combinación Trimetoprim y Sulfametoxazol/efectos adversos , Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Adulto , Femenino , Glucosa/administración & dosificación , Humanos , Hipoglucemia/sangre , Hipoglucemia/tratamiento farmacológico , Insulina/sangre , Masculino , Pneumocystis carinii/patogenicidad , Neumonía por Pneumocystis/tratamiento farmacológico , Neumonía por Pneumocystis/microbiología , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Adulto JovenRESUMEN
We describe the brain MR imaging findings of a woman who developed neurologic symptoms due to an acute hyperammonemic encephalopathy resulting from late onset ornithine transcarbamylase deficiency (OCTD). MR images revealed injury (hyperintense foci on long TR images) to the subcortical white matter of the left precentral and supramarginal gyrus and in the left frontal lobe. These findings presumably reflect the distribution of brain injury from hypoperfusion secondary to severe hyperammonemia. If MR findings suggesting hypoperfusion are detected in a patient with hyperammonemia, the diagnosis of OCTD should be considered. Knowledge of the physiopathological mechanisms of OTCD and of MR imaging of hyperammonemic injury may help expedite diagnosis and treatment and prevent the exitus of patients with this genetic disorder.
RESUMEN
Transient hypogammaglobulinemia of infancy (THI) is a heterogeneous disorder characterized by reduced serum IgG levels in early infancy. A putative diagnosis is initially made after exclusion of other causes of hypogammaglobulinemia while a definitive diagnosis of THI can only be made a posteriori in patients with normalization of IgG levels. The aim of this study is to characterize clinical and immunological features of children with an initial diagnosis of THI in correlation to natural outcome, and to assess predictive laboratory parameters of clinical evolution for this disorder. We prospectively analysed clinical and immunological characteristics of 77 THI children at initial diagnosis and of 57 patients at follow-up. Memory B cell subsets and in vitro immunoglobulin production were evaluated. Seventy patients (91 percent) showed clinical symptoms. Patients suffered from infections (91 percent), allergies (47 percent) and autoimmune disease (4 percent). During follow-up 41/57 children (72 percent) normalized IgG values, mostly within 24 months of age (p less than 0.001), allowing the diagnosis of THI. The 16 children who did not normalize their IgG levels showed a higher frequency of severe infections and autoimmune disease (p less than 0.01). Moreover, they expressed a reduced frequency of IgM and switched memory B cells (p less than 0.01) and an inability to produce IgG in vitro (p less than 0.02). We conclude that most patients with an initial diagnosis of THI spontaneously recover within 24 months of age and have a benign clinical course, while a subgroup of children with undefined hypogammaglobulinemia share a clinical and immunological profile with other primary immunodeficiencies. Early recognition of children with hypogammaglobulinemia during infancy who are likely to suffer from permanent immunodeficiencies later in life would allow prompt and appropriate laboratory and clinical interventions.
Asunto(s)
Agammaglobulinemia/epidemiología , Síndromes de Inmunodeficiencia/epidemiología , Envejecimiento/inmunología , Linfocitos B/inmunología , Preescolar , Progresión de la Enfermedad , Femenino , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Inmunoglobulinas/biosíntesis , Memoria Inmunológica/inmunología , Lactante , Italia/epidemiología , Masculino , Estudios Prospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: To investigate whether an active partnership among school, parents, and pediatricians allows early identification and treatment of asthmatic children. METHODS: An asthma educational program (Happy Air), based on a strong family-physician-school interrelationship, was performed in six primary schools (2,765 children) before administering a screening questionnaire to the parents. RESULTS: A high response rate (96%) demonstrated 2,649 responders available for the asthma screening: 135 children (5%) received a diagnosis of asthma, of which 37 (27%) were recognized de novo. CONCLUSION: The active participation of school and parents is the determining factor for the success of an asthma screening program.
Asunto(s)
Asma/diagnóstico , Educación en Salud , Tamizaje Masivo , Instituciones Académicas , Niño , Humanos , Italia , Padres , Médicos de Familia , Estudiantes , Encuestas y CuestionariosRESUMEN
A vaginose bacteriana é a mais comum das infecções do trato genital feminino.O metronidazol, droga de escolha no tratamento, possui boa resposta terapêutica, mas, devido à sua toxicidade após doses contínuas, tem sua capacidade de combate e reversão da doença limitada pela efemeridade do tratamento.Desenvolveu-se a forma farmacêutica comprimido matricial bioadesivo vaginal contendo metronidazol que levou em conta, tanto a redução das quantidades administradas da droga, quanto o uso de atributos que desfavoreçam a permanência da flora patógena no meio vaginal, como a liberação prolongada e a acentuada adesão da forma à mucosa.Foram obtidos durante o estudo três formulações chamadas de lotes de bancada (LB I, LB II e LB III) com variações quali-quantitativas dos excipientes utilizados.Nos LB I e LB II utilizou-se o hidropropilmetilcelulose e carbopol como constituintes da matriz, porém no LB III foi utilizado uma composição de hidropropilmetilcelulose, etilcelulose e carbopol.As formulações apresentaram resultados dentro das especificações frente aos testes físico-químicos habituais de acordo com a Farmacopéia brasileira.Os comprimidos LB I e LB II liberaram todo seu conteúdo após seis e 12 horas, respectivamente, a partir de matrizes de caráter notadamente adesivo e ao fim dos ensaios mantiveram-se na forma de pequena estrutura gelificada.Mesmo sob essas condições, e após 48 horas de ensaio, a formulação LB III não liberou todo seu conteúdo, pode-se levar em conta a mudança da natureza dos componentes da matriz assim como a necessidade de um desenvolvimento e validação de método mais específico para dissolução
Asunto(s)
Comprimidos/farmacología , Sistemas de Liberación de Medicamentos , Metronidazol/administración & dosificaciónRESUMEN
In order to validate an Isocapnic Voluntary Hyperventilation (IVH) test applicable to daily practice and to adapt the stimulus to height, 9 healthy and 15 asthmatic children performed a Resting Ventilation Rate (RVR)-corrected IVH. They performed a three-minute IVH with room temperature dry air achieving twice (IVH2) and three times (IVH3) their RVR. Mean Maximal Expiratory Flow (MEF) in the middle half of Forced Vital Capacity (FVC) (MEF25-75%) and mean MEF at 25% of FVC (MEF25%) are decreased in the asthmatic group 10 minutes IVH3 (p = 0.02 and < 0.002) compared to healthy group. Mean FEV1 of both group are not different. Comparing Forced Expiratory Flows variation after IVH to baseline intrasubject coefficient of variation, sensitivity of the test is 80% and specificity 100% when variations of MEF25-75% and MEF25% together with FEV1 variations are considered. This suggests an easy way to adapt an hyperventilation stimulus to size and emphasizes the utility of taking account of MEF25-75% and MEF25% in detecting non specific bronchial hyperreactivity in asthmatic children.
Asunto(s)
Asma/fisiopatología , Hiperreactividad Bronquial , Pruebas de Provocación Bronquial , Hiperventilación , Adolescente , Factores de Edad , Asma/diagnóstico , Niño , Volumen Espiratorio Forzado , Humanos , Flujo Espiratorio Máximo , Ventilación Pulmonar/fisiología , Capacidad VitalRESUMEN
A fifteen-month-old child was admitted with a week history of isolated fever. On CSF (Cerebral Spinal Fluid) examination, hyperproteinorachy, hyperglycorachy and hypochlorurachy were found. The diagnosis of tuberculosis meningitis was suspected but usual tests were unable to find Mycobacterium tuberculosis in CSF, urine and sputum. Only the Polymerase Chain Reaction detected the Mycobacterium tuberculosis genome in the CSF. A specific treatment was started immediately. Apyrexia was obtained within 2 days; the outcome was favorable, without sequelae.
Asunto(s)
Reacción en Cadena de la Polimerasa , Tuberculosis Meníngea/diagnóstico , Humanos , Lactante , Masculino , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis Meníngea/líquido cefalorraquídeoRESUMEN
A 6 year-old girl presented an acute onset of mononucleosis-like syndrome which progressed at day 19 to encephalitis, coma and death at day 27. Epstein-Barr virus (EBV) serology suggested that she suffered from a primary EBV infection. Therapeutic attempt with acyclovir did not improve the fatal course of the disease.
Asunto(s)
Encefalitis/etiología , Infecciones por Herpesviridae/complicaciones , Herpesvirus Humano 4 , Enfermedad Aguda , Aciclovir/uso terapéutico , Niño , Femenino , Infecciones por Herpesviridae/diagnóstico , Infecciones por Herpesviridae/tratamiento farmacológico , HumanosRESUMEN
Sludge samples from five municipal sewage treatment plants in Liguria (Italy) were examined periodically during a whole year. Four of them are located in Genova and receive the sewage corresponding respectively to 20,000-53,000-125,000 and 285,000 equivalent inhabitants. The last one is in Chiavari and receives the sewage corresponding to 40,000 equivalent inhabitants. All plants included a preliminary screening treatment, primary sedimentation and a secondary activated sludge process. Sludge was thickened by centrifuge. The bacteriological and chemical characteristics of the sludge after centrifuging (detection and estimation of total and fecal coliforms, fecal streptococci and enumeration and isolation of Salmonella, pH, moisture, total and volatile residue, nitrogen, phosphorus, heavy metals) were measured in order to establish the possibility of land disposal. Dry solids contained on average 34 g/kg total nitrogen and 1,4 g/kg phosphorus. Among heavy metals copper and zinc reached high levels: 544 and 1587 mg/kg of dry solids. Other metals were present at lower concentrations (As 6, Cd 2, Cr 70, Hg 2, Ni 53, pb 416 mg/kg). Comparing these results with those of a research carried out contemporarily in another region (Emilia Romagna) it was observed that in Ligury there is a higher content of copper and bacteria (with an average of 69 Salmonella in 1 g of dry solids). The results showed that sludge produced in the five treatment plants in Ligury (Italy) was apt to be used as fertilizer in soil, but that care has to be taken for what concerns microbial contamination. For what regards the differences among the five sewage treatment plants under observation some heavy metals (arsenic and chromium) reached very high average levels (10-14 mg/kg of arsenic and 70-118 mg/kg of chromium) in the sludge of two of them, which treat the sewage from highly industrialized areas. On the contrary lead and cadmium were present at the same levels in all plants (416 mg/kg of lead and 2 mg/kg of cadmium) with the exception of one (Ge-Quinto) where cadmium was practically absent (0,2 mg/kg). The overall average concentrations of heavy metals resulted definitively lower than maximum concentration proposed by CEE (1986) and by some italian region as Lombardia. Some differences among plants for what regards microbiological parameters were noted only for total coliforms.
Asunto(s)
Fertilizantes/efectos adversos , Aguas del Alcantarillado , Microbiología del Suelo , Contaminantes del Suelo , Eliminación de Residuos Líquidos , Microbiología Ambiental , Monitoreo del Ambiente , ItaliaRESUMEN
All 56 neonatal deaths that occurred during 1987 in Ille-et-Vilaine department (France) were systematically analysed, and the history of pregnancy, delivery, neonatal resuscitation, circumstances under which death occurred in neonatal care unit as well as autopsy findings were studied. Each case was then discussed by a multidisciplinary staff and consensus was obtained regarding diagnosis and cause of death. There were 2 separate categories: 26 deaths (46%) were due to related to malformation, or to metabolic dysfunction; 30 deaths were a result of other causes (54%): 9 low birth weight, 5 respiratory disorders, 5 neurologic disorders, 6 infectious diseases, 2 hemorrhagic shock and 3 were of unknown etiology. Information on causes of neonatal death in a specific region may aid in determining public health priorities for that region; if similar studies were carried out in each department, and results compared, this could aid in setting the guidelines for more efficient health treatments and lead to national choices about neonatal public health.