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1.
Allergol Int ; 71(3): 345-353, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35367136

RESUMO

BACKGROUND: We investigated whether multiple food allergies could be safely prevented by simultaneously administering very small amounts of multiple foods. METHODS: Infants 3-4 months old with atopic dermatitis from 14 primary care pediatric clinics in Japan were enrolled in this randomized, placebo-controlled trial. The infants were administered either mixed allergenic food powder (MP) containing egg, milk, wheat, soybean, buckwheat, and peanuts, or placebo powder (PP). The amount of powder was increased in a stepwise manner on weeks 2 and 4, and continued until week 12. The occurrence of food allergy episodes after powder intervention was assessed at 18 months old. This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry (number UMIN000027837). RESULTS: A total of 163 participants were randomly allocated to either the MP group (n = 83) or the PP group (n = 80). The incidence of food allergy episodes by 18 months was significantly different between the MP and PP groups (7/83 vs. 19/80, respectively; risk ratio 0.301 [95% CI 0.116-0.784]; P = 0.0066). Egg allergies were reduced in the MP group. In addition, food allergy episodes from any of the other five foods were significantly reduced, although the reductions in those due to individual foods were not significant. CONCLUSIONS: Gradually increasing the intake of very small amounts of multiple foods in early infancy can safely reduce the incidence of egg allergies. Other foods may also suppress food allergies, but no definitive conclusions could be reached.


Assuntos
Hipersensibilidade a Ovo , Hipersensibilidade Alimentar , Alérgenos , Arachis , Criança , Hipersensibilidade a Ovo/prevenção & controle , Emolientes , Hipersensibilidade Alimentar/epidemiologia , Hipersensibilidade Alimentar/prevenção & controle , Humanos , Lactente , Pós
2.
Pediatr Infect Dis J ; 36(10): 942-946, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28471866

RESUMO

OBJECTIVES: To establish a strategy for congenital cytomegalovirus (cCMV) screening and to establish confirmatory assays approved as in vitro diagnostics by the regulatory authorities, we evaluated the clinical risks and performance of diagnostic assays developed by commercial companies, since cCMV infection has significant clinical consequences. STUDY DESIGN: Newborns with clinical manifestations considered to be consequences of cCMV infection (n = 575) were screened for the presence of cytomegalovirus (CMV) DNA in urine specimens collected onto filter paper placed in their diapers using the polymerase chain reaction-based assay reported previously. Liquid urine specimens were obtained from all of 20 CMV-positive newborns and 107 of the CMV-negative newborns identified in the screening. We used these 127 specimens, as well as 12 from cCMV cases identified in a previous study and 41 from healthy newborns, to compare the performance of 2 commercial assays and 1 in-house assay. RESULTS: The risk-based screening allowed the identification of cCMV cases at least 10-fold more efficiently than our previous universal screening, although there appears to be a limit to the identification of asymptomatically infected newborns. Although CMV-specific IgM during pregnancy was found frequently in mothers of cCMV newborns, CMV-IgM alone is not an effective diagnostic marker. The urine-filter-based assay and the 3 diagnostic assays yielded identical results. CONCLUSIONS: Although risk-based and universal newborn screening strategies for cCMV infection each have their respective advantages and disadvantages, urine-filter-based assay followed by confirmatory in vitro diagnostics assays is able to identify cCMV cases efficiently.


Assuntos
Infecções por Citomegalovirus , Citomegalovirus/genética , Triagem Neonatal/métodos , Virologia/métodos , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/virologia , DNA Viral/urina , Feminino , Humanos , Recém-Nascido , Tipagem Molecular , Gravidez , Distribuição Aleatória
3.
Proc Natl Acad Sci U S A ; 114(9): E1737-E1744, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28196885

RESUMO

A crucial issue in neonatal medicine is the impact of preterm birth on the developmental trajectory of the brain. Although a growing number of studies have shown alterations in the structure and function of the brain in preterm-born infants, we propose a method to detect subtle differences in neurovascular and metabolic functions in neonates and infants. Functional near-infrared spectroscopy (fNIRS) was used to obtain time-averaged phase differences between spontaneous low-frequency (less than 0.1 Hz) oscillatory changes in oxygenated hemoglobin (oxy-Hb) and those in deoxygenated hemoglobin (deoxy-Hb). This phase difference was referred to as hemoglobin phase of oxygenation and deoxygenation (hPod) in the cerebral tissue of sleeping neonates and infants. We examined hPod in term, late preterm, and early preterm infants with no evidence of clinical issues and found that all groups of infants showed developmental changes in the values of hPod from an in-phase to an antiphase pattern. Comparison of hPod among the groups revealed that developmental changes in hPod in early preterm infants precede those in late preterm and term infants at term equivalent age but then, progress at a slower pace. This study suggests that hPod measured using fNIRS is sensitive to the developmental stage of the integration of circular, neurovascular, and metabolic functions in the brains of neonates and infants.


Assuntos
Encéfalo/metabolismo , Hemoglobinas/metabolismo , Oxiemoglobinas/metabolismo , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro/metabolismo , Masculino , Nascimento Prematuro/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Nascimento a Termo/metabolismo
4.
Tohoku J Exp Med ; 241(2): 149-153, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28202857

RESUMO

Infants with Down Syndrome (DS) are at risk of developing a transient abnormal myelopoiesis (TAM). TAM is characterised by increased circulating blast cells but usually self-limiting. DS patients with TAM sometimes show fetal hydrops and effusion in body cavities, but the mechanism remains unclear. We report here a case of infant with DS who had pericardial effusion, TAM, and eosinophilia. In her pericardial effusion, white blood cell count was 6.0 × 103/µL, 41% of which were eosinophils. After administration of prednisolone, pericardial effusion gradually decreased, and TAM and eosinophilia improved. In order to elucidate the immunological mechanism, we measured the levels of 17 cytokines in her pericardial effusion fluid and serum. In her pericardial fluid, there were high levels of 12 cytokines, and they were higher than those in her serum. In particular, IL-6 (44,573 pg/mL), IL-8 (4,865 pg/mL), and IL-13 (579.41 pg/mL) were at extremely high levels in her pericardial fluid. After administration of prednisolone, the levels of 8 of the 12 elevated cytokines in her pericardial fluid decreased and all of the elevated cytokines decreased in her serum. Corticosteroids can be effective to reduce cytokine levels and the amount of effusion in patients with DS. It is presumed that effusion seen in DS with TAM could be related to an abnormal production of cytokines at the effusion site.


Assuntos
Citocinas/sangue , Síndrome de Down/sangue , Síndrome de Down/complicações , Reação Leucemoide/sangue , Reação Leucemoide/complicações , Derrame Pericárdico/sangue , Derrame Pericárdico/complicações , Adulto , Quimiocinas/sangue , Progressão da Doença , Feminino , Humanos , Lactente
5.
Ann Hematol ; 95(1): 141-144, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26453073

RESUMO

Mutations in ACTN1, the gene encoding the actin-crosslinking protein α-actinin-1, cause autosomal dominant macrothrombocytopenia. α-Actinin-1 exists as antiparallel dimers, composed of an N-terminal actin-binding domain (ABD), four spectrin-like repeats (SLRs), which form the spacer rod, and a C-terminal calmodulin-like (CaM) domain. All of the previously reported ACTN1 mutations associated with macrothrombocytopenia reside within the ABD and the CaM domain and not within the SLR domain. In this report, we describe a mutation in SLR2 of α-actinin-1 (p.Leu395Gln) associated with familial macrothrombocytopenia. A 3-year-old boy and his mother both had this mutation. They showed a mild form of thrombocytopenia without severe bleeding, accompanied by an elevated mean platelet volume. Consistent with the previous reports of mutations that reside in the ABD or the CaM domain, immunofluorescence examination revealed disorganization of the actin cytoskeleton in Gln395 mutant-transduced Chinese hamster ovary cells. Our findings suggest a novel mechanism for the pathogenesis of ACTN1-related macrothrombocytopenia that does not involve functional domain mutations.


Assuntos
Actinina/genética , Mutação/genética , Trombocitopenia/diagnóstico , Trombocitopenia/genética , Actinina/química , Animais , Células CHO , Pré-Escolar , Cricetinae , Cricetulus , Feminino , Humanos , Masculino , Linhagem , Estrutura Secundária de Proteína
6.
Pediatr Int ; 57(5): 864-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25865080

RESUMO

BACKGROUND: Preterm infants are at significant risk of reduced bone mineral content and subsequent bone disease (metabolic bone disease of prematurity, MBDP). MBDP is frequently found in very low-birthweight (VLBW) infants, but long-term height prognosis is not well known. METHODS: VLBW infants from two major neonatal intensive care units were studied. Medical records were reviewed. A total of 143 subjects were analyzed after excluding subjects who died, or who had severe complications that could affect linear growth, Silver-Russell syndrome, severe cholestasis, and/or chromosomal abnormality. The relationship between MBDP and height at age 3 was investigated. RESULTS: Height standard deviation score (SDS) at age 3 negatively correlated with peak serum alkaline phosphatase (ALP) activity in early life (r = -0.30, P = 0.0003) and positively correlated with serum phosphorus (P) at peak ALP (r = 0.33, P = 0.0002). In addition, serum P independently affected height SDS at 3 years of age (ß = 0.19, P = 0.018), and was significantly different between infants with and without catch-up growth in height (difference: 0.23 mmol/L, 95%CI: 0.09-0.36, P = 0.0010). CONCLUSIONS: MBDP, particularly hypophosphatemia in the early period of life, is associated with linear growth until 3 years of age in VLBW infants.


Assuntos
Densidade Óssea/fisiologia , Doenças Ósseas Metabólicas/metabolismo , Osso e Ossos/metabolismo , Doenças do Prematuro/epidemiologia , Recém-Nascido Prematuro , Recém-Nascido de muito Baixo Peso , Minerais/metabolismo , Doenças Ósseas Metabólicas/diagnóstico , Pré-Escolar , Progressão da Doença , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Doenças do Prematuro/metabolismo , Masculino , Prognóstico
7.
Pediatr Int ; 56(6): 934-937, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25521983

RESUMO

Herein is described a case of neonatal neuroblastoma with cyclic blood pressure fluctuation and elevated catecholamines. The fluctuations stabilized after treatment with α-adrenergic blocker and the perioperative course was uneventful. The possibility of catecholamine-related symptoms including hypertension, heart failure, and blood pressure fluctuations should be considered in the treatment for neuroblastoma; if they are present, treatment with α-blockers is effective.


Assuntos
Hipertensão/etiologia , Neuroblastoma/complicações , Neuroblastoma/fisiopatologia , Neoplasias Retroperitoneais/complicações , Neoplasias Retroperitoneais/fisiopatologia , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/terapia , Recém-Nascido , Neuroblastoma/diagnóstico , Neoplasias Retroperitoneais/diagnóstico
8.
Pediatr Int ; 56(4): 623-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25252054

RESUMO

Neonatal subgaleal hemorrhage (SGH) is a serious adverse event that is often underestimated and sometimes goes unrecognized. It can cause bleeding complications and jeopardize the patient's life. Early diagnosis and prompt treatment are important in optimizing the outcome in neonates with SGH. Herein we describe the case of a newborn who developed severe SGH and died. We report unenhanced computed tomography (CT) of ongoing SGH, which showed a low-density region in the surrounding area of the head. The density could be explained by unclotted active bleeding and low hematocrit. Even if a patient with clinically suspected SGH has a low-density region on CT, the presence of SGH should not be excluded.


Assuntos
Hemorragia/diagnóstico por imagem , Periósteo , Couro Cabeludo , Crânio , Tomografia Computadorizada por Raios X , Evolução Fatal , Humanos , Recém-Nascido , Masculino
9.
Neuroimage ; 85 Pt 1: 272-8, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23631984

RESUMO

Near-infrared spectroscopy (NIRS) imaging studies have revealed the functional development of the human brain in early infancy. By measuring spontaneous fluctuations in cerebral blood oxygenation with NIRS, we can examine the developmental status of the functional connectivity of networks in the cortex. However, it has not been clarified whether premature delivery and/or chromosomal abnormalities affect the development of the functional connectivity of the cortex. In the current study, we investigated the spontaneous brain activity of sleeping infants who were admitted to a neonatal intensive care unit at term age. We classified them into the 3 following infant groups: (i) term-or-late-preterm, (ii) early-preterm, and (iii) Down's syndrome (DS). We used multichannel NIRS to measure the spontaneous changes in oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) at 10 measurement channels, which covered the frontal, temporal, and occipital regions. In order to reveal the functional connectivity of the cortical networks, we calculated the temporal correlations of the time-course signals among all of the pairs of measurement channels. The functional connectivity was classified into the 4 following types: (i) short-range, (ii) contralateral-transverse, (iii) ipsilateral-longitudinal, and (iv) control. In order to examine whether the local properties of hemodynamics reflected any pathological conditions, we calculated the phase differences between the oxy- and deoxy-Hb time-course signals in the 3 groups. The statistical analyses of the functional connectivity data showed main effects of group and the types of connectivity. For the group effect, the mean functional connectivity of the infants in the term-or-late-preterm group did not differ from that in the early-preterm group, and the mean functional connectivity of the infants in the DS group was lower than that in the other 2 groups. For the effect of types of connectivity, short-range connectivity was highest compared to any of the other types of connectivity, and the second highest connectivity was the contralateral-transverse one. The phase differences between the oxy- and deoxy-Hb changes showed that there were significant differences between the DS group and the other 2 groups. Our findings suggested that the development of the functional connectivity of cortical networks did not differ between term-or-late-preterm infants and early-preterm infants around term-equivalent ages, while DS infants had alterations in their functional connectivity development and local hemodynamics at term age. The highest short-range connectivity and the second highest contralateral-transverse connectivity suggested that the precursors for the basic cortical networks of functional connectivity were present at term age.


Assuntos
Córtex Cerebral/fisiopatologia , Síndrome de Down/fisiopatologia , Neuroimagem Funcional/métodos , Recém-Nascido Prematuro/fisiologia , Vias Neurais/fisiopatologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adulto , Análise de Variância , Circulação Cerebrovascular/fisiologia , Interpretação Estatística de Dados , Feminino , Idade Gestacional , Hemodinâmica/fisiologia , Hemoglobinas/metabolismo , Humanos , Lactente , Recém-Nascido , Oxiemoglobinas/metabolismo , Gravidez
10.
Int J Pediatr Otorhinolaryngol ; 76(2): 189-93, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22138378

RESUMO

OBJECTIVE: The increasingly younger age of onset of allergic rhinitis (AR) has recently become a problem. This study examined the prevalence of inhaled antigen sensitization and nasal eosinophils in children younger than two years old, with measurement of the serum concentrations of aeroallergen-specific IgE antibodies to house dust mites, cat fur, and Japanese cedar pollen, measurement of nasal eosinophil counts, and a questionnaire administered to the children's parents. METHODS: The subjects were a group of healthy children undergoing 18-month infant health checks provided by the local government, and sick children younger than two years old at the pediatric hospital. RESULTS: Among 408 healthy infants, 44 (10.7%) had antigen-specific IgE antibodies, 29 (7.1%) had nasal eosinophils, and eight (2.0%) had both specific IgE antibodies and nasal eosinophils. Nasal assessment revealed that 125 children had rhinorrhea. Of the infants who showed both sensitization to antigens and nasal eosinophils, six (1.5%) had confirmed rhinorrhea. Among 186 sick children younger than two years old at the pediatric hospital, aeroallergen-specific IgE antibodies were detected in five (2.6%). The presence of nasal eosinophils was confirmed in six children (3.2%), which percentage was smaller than that of the healthy group. No infant had either sensitization to antigens or nasal eosinophils. CONCLUSION: The findings described above indicate that the minimum prevalence of AR might be 1.5% in 18-month-old children and that around 10% of affected children have aeroallergen-specific IgE antibodies in Japan. The incidence of AR in young children might increase further.


Assuntos
Alérgenos/imunologia , Anticorpos Anti-Idiotípicos/imunologia , Rinite Alérgica Sazonal/epidemiologia , Rinite Alérgica Sazonal/imunologia , Administração por Inalação , Distribuição por Idade , Animais , Antígenos/imunologia , Gatos , Pré-Escolar , Estudos de Coortes , Eosinófilos/imunologia , Feminino , Humanos , Imunização , Imunoglobulina E/imunologia , Lactente , Japão/epidemiologia , Masculino , Programas de Rastreamento , Cavidade Nasal , Prevalência , Rinite Alérgica Sazonal/diagnóstico , Medição de Risco , Índice de Gravidade de Doença , Distribuição por Sexo
11.
Anesth Analg ; 112(1): 143-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21048090

RESUMO

BACKGROUND: We tested the hypothesis that inhibition of cyclooxygenase (COX) attenuates in vivo ventilator-induced lung injury (VILI) in a prospective, randomized laboratory investigation in a university-affiliated laboratory. Adult male rats were anesthetized and randomized with or without nonselective COX inhibition (ibuprofen) and were subjected to injurious mechanical ventilation (positive end-expiratory pressure = 0; peak inspiratory pressure = 21 mm Hg). METHODS: We investigated the profile of VILI (respiratory mechanics, cytokines, eicosanoids), expression of COX enzymes, and activation of nuclear factor (NF)-κB in ibuprofen- versus vehicle-treated animals. Injurious ventilation caused lung injury (i.e., decrement in compliance, tissue edema, and elevated inflammatory cytokines, eicosanoids, and COX-2). RESULTS: Pretreatment with ibuprofen that effectively inhibited eicosanoid synthesis and COX-2 activity increased survival and attenuated lung edema and decrement in respiratory mechanics. Ibuprofen had no modulatory effect on ventilator-induced activation of NF-κB or inflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-1ß, IL-6, GRO/KC [growth-related oncogene/keratinocyte chemoattractant]). COX activity seems important in the pathogenesis of VILI in the in vivo rat. Inhibition of COX provides significant protection (i.e., survival, pulmonary function) in VILI, but without affecting levels of important mediators (tumor necrosis factor-α, IL-1ß, IL-6, GRO/KC) or activation of NF-κB. CONCLUSIONS: These data confirm that nonselective COX inhibition provides partial protection against VILI and that the NF-κB signaling pathway is not exclusively eicosanoid dependent. Studies of COX inhibition in ventilator-associated lung injury might benefit from multimodal targeting that includes a comprehensive focus on inflammatory cytokines and NF-κB.


Assuntos
Inibidores de Ciclo-Oxigenase/uso terapêutico , Lesão Pulmonar Induzida por Ventilação Mecânica/tratamento farmacológico , Lesão Pulmonar Induzida por Ventilação Mecânica/enzimologia , Animais , Gasometria/métodos , Masculino , Estudos Prospectivos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
13.
J Matern Fetal Neonatal Med ; 23(6): 522-8, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19672791

RESUMO

OBJECTIVE: To determine whether skin and subcutaneous blood flow measurements using a novel laser Doppler flow meter are useful for evaluating the cardiovascular status of very low birth weight (VLBW) infants during the early postnatal period. METHODS: In eight VLBW infants and eight non-VLBW infants born at Tokyo University Hospital between May 2007 and April 2008, forehead and lower limb skin blood flows were measured continuously for 72 h. Data were averaged every 8 h, and the t-test was used for analysis. RESULTS: In VLBW infants, forehead blood flow started to increase from the start of measurement to 32 h (16.6 +/- 3.9 ml/min vs. 24.1 +/- 2.1 ml/min; p = 0.002 compared with 8 h) and remained constant thereafter. Lower limb blood flow increased rapidly after 24 h (22.2 +/- 5.5 ml/min vs. 29.5 +/- 5.0 ml/min; p = 0.002 compared with 8 h) and continued increasing thereafter. In contrast, blood flows remained constant in non-VLBW infants. CONCLUSIONS: The results showed that skin and subcutaneous perfusion in VLBW infants increased spontaneously at around 24 h. Differences in blood flow changes between VLBW and non-VLBW infants demonstrate that these parameters successfully identified physiological changes in tissue perfusion in VLBW infants.


Assuntos
Recém-Nascido de muito Baixo Peso/fisiologia , Fluxo Sanguíneo Regional , Pele/irrigação sanguínea , Tela Subcutânea/irrigação sanguínea , Cardiotônicos/administração & dosagem , Estudos de Casos e Controles , Dopamina/administração & dosagem , Relação Dose-Resposta a Droga , Testa/irrigação sanguínea , Testa/fisiologia , Idade Gestacional , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Humanos , Recém-Nascido , Recém-Nascido de muito Baixo Peso/crescimento & desenvolvimento , Fluxometria por Laser-Doppler , Parto/fisiologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Fatores de Tempo
14.
Fetal Diagn Ther ; 24(4): 458-61, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19039229

RESUMO

Complete urorectal septum malformation sequence (URSMS) is usually a lethal anomaly that is characterized by urethral obstruction, imperforate anus, ambiguous genitalia, renal agenesis or dysplasia, and mullerian duct maldevelopment. This anomaly is thought to be caused by the cessation of urorectal septum migration toward the caudal cloacal membrane. Teratogenic factors or a genetic abnormality is postulated as the etiology. To date, only 4 patients with URSMS have survived the neonatal period; however, 2 of these infants died before the age of 1 year. We report the survival in a case with complete URSMS who had moderate pulmonary hypoplasia and preserved left renal function. The cloacal remnant was dilated more than expected because the wall of the muscle layer was torn, perhaps in early fetal life, and timely placement of vesico-amniotic shunts prevented severe pulmonary hypoplasia caused by oligohydramnios.


Assuntos
Anormalidades Múltiplas/cirurgia , Anus Imperfurado/cirurgia , Cloaca/anormalidades , Pneumopatias/cirurgia , Obstrução Uretral/cirurgia , Anormalidades Urogenitais/cirurgia , Anormalidades Múltiplas/diagnóstico , Anus Imperfurado/diagnóstico , Feminino , Humanos , Lactente , Recém-Nascido , Pneumopatias/congênito , Pneumopatias/diagnóstico , Imageamento por Ressonância Magnética , Gravidez , Reto/anormalidades , Ultrassonografia Pré-Natal , Obstrução Uretral/diagnóstico , Anormalidades Urogenitais/diagnóstico , Adulto Jovem
15.
Am J Respir Crit Care Med ; 174(3): 279-89, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16675780

RESUMO

RATIONALE: Many authors have suggested that the mechanism by which atelectasis contributes to injury is through the repetitive opening and closing of distal airways in lung regions that are atelectatic. However, neither the topographic nor mechanistic relationships between atelectasis and distribution of lung injury are known. OBJECTIVES: To investigate how atelectasis contributes to ventilator-induced lung injury. METHODS: Surfactant depletion was performed in anesthetized rats that were then allocated to noninjurious or injurious ventilation for 90 min. MEASUREMENTS: Lung injury was quantified by gas exchange, compliance, histology, wet-to-dry weight, and cytokine expression, and its distribution by histology, stereology, cytokine mRNA expression, in situ hybridization, and immunohistochemistry. Functional residual capacity, percent atelectasis, and injury-induced lung water accumulation were measured using gravimetric and volumetric techniques. MAIN RESULTS: Atelectasis occurred in the dependent lung regions. Injurious ventilation was associated with alveolar and distal airway injury, while noninjurious ventilation was not. With injurious ventilation, alveolar injury (i.e., histology, myeloperoxidase protein expression, quantification, and localization of cytokine mRNA expression) was maximal in nondependent regions, whereas distal airway injury was equivalent in atelectatic and nonatelectatic regions. CONCLUSIONS: These data support the notion that lung injury associated with atelectasis involves trauma to the distal airways. We provide topographic and biochemical evidence that such distal airway injury is not localized solely to atelectatic areas, but is instead generalized in both atelectatic and nonatelectatic lung regions. In contrast, alveolar injury associated with atelectasis does not occur in those areas that are atelectatic but occurs instead in remote nonatelectatic alveoli.


Assuntos
Pneumopatias/etiologia , Alvéolos Pulmonares/patologia , Atelectasia Pulmonar/etiologia , Respiração Artificial/efeitos adversos , Animais , Lavagem Broncoalveolar , Citocinas/genética , Citocinas/metabolismo , Inflamação/etiologia , Inflamação/patologia , Pneumopatias/metabolismo , Pneumopatias/patologia , Medidas de Volume Pulmonar , Masculino , Peroxidase/metabolismo , Reação em Cadeia da Polimerase , Surfactantes Pulmonares , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley
16.
Am J Physiol Lung Cell Mol Physiol ; 289(4): L554-64, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15923208

RESUMO

Continuous positive airway pressure, aimed at preventing pulmonary atelectasis, has been used for decades to reduce lung injury in critically ill patients. In neonatal practice, it is increasingly used worldwide as a primary form of respiratory support due to its low cost and because it reduces the need for endotracheal intubation and conventional mechanical ventilation. We studied the anesthetized in vivo rat and determined the optimal circuit design for delivery of continuous positive airway pressure. We investigated the effects of continuous positive airway pressure following lipopolysaccharide administration in the anesthetized rat. Whereas neither continuous positive airway pressure nor lipopolysaccharide alone caused lung injury, continuous positive airway pressure applied following intravenous lipopolysaccharide resulted in increased microvascular permeability, elevated cytokine protein and mRNA production, and impaired static compliance. A dose-response relationship was demonstrated whereby higher levels of continuous positive airway pressure (up to 6 cmH(2)O) caused greater lung injury. Lung injury was attenuated by pretreatment with dexamethasone. These data demonstrate that despite optimal circuit design, continuous positive airway pressure causes significant lung injury (proportional to the airway pressure) in the setting of circulating lipopolysaccharide. Although we would currently avoid direct extrapolation of these findings to clinical practice, we believe that in the context of increasing clinical use, these data are grounds for concern and warrant further investigation.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas/efeitos adversos , Insuficiência Respiratória/etiologia , Sepse/complicações , Animais , Pressão Positiva Contínua nas Vias Aéreas/métodos , Dexametasona/farmacologia , Modelos Animais de Doenças , Glucocorticoides/farmacologia , Lipopolissacarídeos/farmacologia , Masculino , Atelectasia Pulmonar/terapia , Ratos , Ratos Sprague-Dawley , Insuficiência Respiratória/tratamento farmacológico
17.
Am J Respir Crit Care Med ; 171(7): 743-52, 2005 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15640366

RESUMO

RATIONALE: Ventilator-induced lung injury has been predominantly studied in adults. OBJECTIVES: To explore the effects of age and lung development on susceptibility to such injury. METHODS: Ex vivo isolated nonperfused rat lungs (infant, juvenile, and adult) were mechanically ventilated where VT was based on milliliters per kilogram of body weight or as a percentage of the measured total lung capacity (TLC). In vivo anesthetized rats (infant, adult) were mechanically ventilated with pressure-limited VTs. Allocation to ventilation strategy was randomized. MEASUREMENTS: Ex vivo injury was assessed by pressure-volume analysis, reduction in TLC, and histology, and in vivo injury by lung compliance, cytokine production, and wet- to dry-weight ratio. MAIN RESULTS: Ex vivo ventilation (VT 30 ml.kg(-1)) resulted in a significant reduction (36.0 +/- 10.1%, p < 0.05) in TLC in adult but not in infant lungs. Ex vivo ventilation (VT 50% TLC) resulted in a significant reduction in TLC in both adult (27.8 +/- 2.8%) and infant (10.6 +/- 7.0%) lungs, but more so in the adult lungs (p < 0.05); these changes were paralleled by histology and pressure-volume characteristics. After high stretch in vivo ventilation, adult but not infant rats developed lung injury (total lung compliance, wet/dry ratio, tumor necrosis factor alpha). Surface video microscopy demonstrated greater heterogeneity of alveolar distension in ex vivo adult versus infant lungs. CONCLUSION: These data provide ex vivo and in vivo evidence that comparable ventilator settings are significantly more injurious in the adult than infant rat lung, probably reflecting differences in intrinsic susceptibility or inflation pattern.


Assuntos
Pneumopatias/fisiopatologia , Lesão Pulmonar , Surfactantes Pulmonares/metabolismo , Respiração Artificial/efeitos adversos , Animais , Animais Recém-Nascidos , Peso Corporal , Modelos Animais de Doenças , Pneumopatias/etiologia , Masculino , Probabilidade , Troca Gasosa Pulmonar , Surfactantes Pulmonares/análise , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Valores de Referência , Testes de Função Respiratória , Fatores de Risco , Sensibilidade e Especificidade , Capacidade Pulmonar Total
18.
Pediatr Nephrol ; 18(2): 115-8, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12579399

RESUMO

Diagnosis of urinary infection in young children is often delayed, which may result in renal damage. However, it remains to be clarified how soon the treatment should be started to prevent renal changes. The present study prospectively enrolled young children with diagnosis of their first febrile urinary infection who underwent technetium-99m dimercaptosuccinate renal cortical scintigraphy within 120 h of initiation of treatment. Patients with abnormal renoscintigraphy received antibiotics for 2 weeks and scintigraphy was repeated 1 year later. Twenty-two children were enrolled from July 1995 through March 2000. Acute-phase renoscintigraphy identified focal defects in 0 of the 14 children who were treated within 24 h of the disease, 1 of the 3 treated in 24-48 h, and 2 of the 5 treated in 48-72 h. Repeat renoscintigraphy showed disappearance of the focal defects in all 3 children. The present study has shown that early treatment within 24 h of onset of the fever due to urinary infection should deter renal changes. Fever for more than 24 h prior to diagnosis indicates a high risk for renal changes and needs an immediate effective treatment to avoid renal damage.


Assuntos
Nefropatias/prevenção & controle , Infecções Urinárias/tratamento farmacológico , Pré-Escolar , Feminino , Humanos , Lactente , Córtex Renal/diagnóstico por imagem , Nefropatias/diagnóstico por imagem , Masculino , Estudos Prospectivos , Renografia por Radioisótopo , Ácido Dimercaptossuccínico Tecnécio Tc 99m , Fatores de Tempo
19.
Life Sci ; 71(12): 1439-47, 2002 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-12127164

RESUMO

Reduction of perivascular pH in acidemia produces hyporesponsiveness of vascular bed to vasoconstrictors. In the present study, we examined the effects of modest acidification on dilatory responses of isolated rat thoracic aorta. Acetylcholine produced endothelium-dependent relaxation in phenylephrine-precontracted aorta, which was markedly enhanced by acidification of Krebs-Henseleit solution from pH 7.4 to 7.0. A similar augmentation was observed in the relaxing responses to NO donors (SNP, SIN-1, SNAP), 8-Br-cGMP and NS-1619 (a putative K(Ca) channel opener and/or Ca channel inhibitor) in endothelium-denuded, phenylephrine-contracted aorta. However, papaverine-induced relaxation was not affected by the change in pH. At pH 7.4, the relaxing responses to acetylcholine and SNP were partially inhibited by charybdotoxin (K(Ca) channel inhibitor) but not glibenclamide (K(ATP) channel inhibitor), while at pH 7.0 the relaxation induced by either drug was not affected by K(+) channel inhibitors. Relaxation induced by 8-Br-cGMP or NS-1619 was not inhibited by charybdotoxin or glibenclamide. Acidification to pH 7.0 increased the cGMP production in response to acetylcholine in endothelium-intact aorta and to SNP in endothelium-denuded aorta. These results show that modest acidification augments NO-mediated relaxation in rat aorta, probably due to an enhancement of cGMP-dependent but K(+) channel-unrelated relaxation mechanisms.


Assuntos
Acidose/fisiopatologia , Óxido Nítrico/fisiologia , Vasodilatação/fisiologia , Acetilcolina/farmacologia , Animais , Aorta Torácica/fisiopatologia , GMP Cíclico/fisiologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Masculino , Relaxamento Muscular/fisiologia , Músculo Liso Vascular/fisiopatologia , Doadores de Óxido Nítrico/farmacologia , Canais de Potássio/fisiologia , Ratos , Ratos Wistar , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia
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