Randomized trial of salbutamol via metered-dose inhaler with spacer versus nebulizer for acute wheezing in children less than 2 years of age.

The aim of this study was to compare the efficacy of salbutamol delivered via a metered-dose inhaler with a spacer and facial mask (MDI-S) vs. a nebulizer (NEB) for the treatment of acute exacerbations of wheezing in children. In a single-blind, prospective, randomized clinical trial, 123 outpatients (1-24 months of age), presenting with "moderate to severe" wheezing, were seen in the emergency department. Children were randomly assigned to one of two salbutamol treatment groups. In the first hour, the MDI-S group received 2 puffs (100 microg/puff) every 10 min for 5 doses, and the NEB group received 0.25 mg/kg every 13 min for 3 doses. If the clinical score was >5 at the end of the first hour, the patients received another hour of the same treatment and also betamethasone (0.5 mg/kg intramuscular). On enrollment and after the first and the second hour of treatment each child had a validated clinical score assigned by a blinded investigator. There were no differences at the time of admission to the emergency department between groups in clinical score or demographic data. Success (clinical score 0.05). We conclude that in this study population, children less than 2 years of age with moderate-severe exacerbations of wheezing responded faster to salbutamol delivered by MDI with a spacer and facial mask than to salbutamol delivered by nebulizer.

Verapamil protection against mercuric chloride-induced renal glomerular injury in rats.

We have examined the effects of the calcium channel blocker verapamil on the renal glomerular structural damage produced by mercuric chloride in rats. Verapamil (75 micrograms/kg body wt iv) was administered 30 min prior to mercuric chloride injection (HgCl2, 5 mg/kg body wt sc). Verapamil prevented the glomerular proteinuria observed in HgCl2-treated rats. Isolated glomeruli from mercury-treated rats 1 h after injection presented a diminished cross-sectional area as compared with control glomeruli (control [micron2], 26,310 +/- 2545; HgCl2 [micron2], 18,474 +/- 1828) and increased glomerular calcium content (control, 23 +/- 6 nmol/mg protein; HgCl2, 43 +/- 7 nmol/mg protein). Verapamil pretreatment prevented glomerular cross-sectional area (GCSA) diminution and glomerular calcium content rise (GCSA [micron2] Vp + Hg, 28,281 +/- 4654, Ca2+ [nmol/mg protein] Vp + Hg, 18 +/- 5). Renal sections prepared for immunohistochemical detection and histochemical analysis showed increased deposits of fibronectin and lipids and enhanced cellularity in glomerular structures from HgCl2-treated rats. Renal sections from animals pretreated with verapamil showed fibronectin and lipid contents not different from control sections and their histological studies did not show any changes when compared with control. Verapamil pretreatment also protected glomeruli from enhanced leukocyte content (myeloperoxidase activity/mg protein): control, 59 +/- 7; HgCl2, 134 +/- 10; Vp + Hg, 79 +/- 11). HgCl2 also contracts GCSA in vitro; Vp prevented this GCSA diminution. The results described in this study indicate that mercuric chloride nephrotoxicity may be associated not only with changes in renal glomerular haemodynamics, but also with a direct effect on glomerular cells.

Osteitis caused by bacille Calmette-Guérin vaccination: an emergent problem in Chile?

SETTING: Osteitis caused by bacille Calmette-Guérin (BCGOST) vaccination has not been described in Latin American countries. OBJECTIVE: To evaluate the incidence, clinical features and prognosis of patients with BCGOST in one of the most populated areas of Santiago, Chile. DESIGN: A retrospective analysis of medical records kept over twenty years (1976-1995). RESULTS: In ten children (four in the last five years), diagnostic criteria of BCGOST were fulfilled. Six were boys, the mean age was 11 months (range 6.5-21), symptoms were present with a mean of 31 days (range 15-60) before diagnosis and the sites of predilection of osteitis were the lower extremity (8/10 cases). Culture was positive in one case, and nine patients had typical histopathological lesions (two with acid-fast bacilli). All had normal chest X-ray. Mantoux testing was performed in four cases (mean 21.5 mm, range 16-28). None of the ten patients had a history of underlying immunodeficiency. In this area BCG coverage was 90.2 +/- 9.7% of all newborn infants, and the annual risk of tuberculosis infection was 24.6/100,000 population per year. CONCLUSION: Our study demonstrated an estimated incidence for BCGOST in this area of 3.2/100,000 vaccinated newborns. Based on the epidemiological situation of tuberculosis in Chile (29.5/100,000), universal BCG vaccination in newborns should be encouraged.

Glomerular compromise in mercuric chloride-induced nephrotoxicity.

We have examined the effects of mercuric chloride on renal glomerular structure. Isolated glomeruli from mercury-treated rats (HgCl2, 5 mg/kg body wt, s.c.) 1 hour post injection presented a diminished cross-sectional area as compared with control glomeruli [control (micron2) = 26,310 +/- 2,545, HgCl2 (micron2) = 18,474 +/- 1,828] and higher glomerular calcium content (control = 23 +/- 6 nmoles/mg prot, HgCl2 = 43 +/- 7 nmoles/mg prot). Renal sections prepared for immunohistochemical and histochemical analysis showed larger deposits of fibronectin and lipids and enhanced cellularity in glomerular structures from HgCl2-treated rats. Moreover, mieloperoxidase activity measured in isolated glomeruli were also increased as compared with control preparations [MPO (U/mg prot): control = 59 +/- 7, HgCl2 = 134 +/- 10]. When the animals were studied 24 hours post HgCl2 injection, glomerular cross-sectional area values were not different from control values (25,276 +/- 1,983 micron2), while calcium contents were higher than values observed 1 hour after treatment (92 +/- 9 nmoles/mg prot). A similar pattern was observed in fibronectin deposits. Hypercellularity in glomerular structures and the higher mieloperoxidase levels were maintained at this time (MPO HgCl2-rats 24 h = 148 +/- 31 U/mg prot). The effects observed in this study are consistent with an inflammatory response in the glomerular structure of HgCl2-treated rats that could explain the altered renal function described in previous reports in our laboratory.

Mercuric chloride effects on rat renal redox enzymes activities: SOD protection.

This study was done to determine the effect of mercuric chloride treatment on the redox cycle enzymes in rat kidney ex-vivo. Glutathione peroxidase (GSH-Px) and catalase (Cat) activities were measured in kidney homogenates from rats with different nonprotein sulfhydrils levels and different mercury content. The results indicated that GSH-Px activity was enhanced in mercury-treated rats in direct relationship with kidney mercury content, whereas Cat activity was increased in the presence of the highest mercury kidney content obtained. Superoxide dismutase (SOD) was administered to rats prior to mercury chloride injection and renal function, development of lipid peroxidation and renal glutathione level were measured 1 h later. Renal function, renal glutathione, and renal lipid peroxidation production were maintained similar to control values. Moreover, SOD pretreatment also protected kidney from mercuric chloride histological alterations observed 24 h post mercury treatment. Thus, an inhibition of renal redox cycle enzymes "in vivo," did not appear to be an important determinant of the increased lipid peroxidation observed during mercuric chloride nephrotoxicity.

Effectiveness of N-acetylcysteine in protecting against mercuric chloride-induced nephrotoxicity.

Mercuric chloride (HgCl2)-induced nephrotoxicity, as measured by functional and biochemical parameters was evaluated in rats at different kidney non-protein sulfhydryls (NPS) levels. Diethylmaleate (DEM) induced a 75% of NPS diminution 1 h after the administration. Renal function (clearance) and biochemical measurements (gamma-glutamyltranspeptidase activity in urine, and lipoperoxides in kidney tissue) were impaired when the animals were HgCl2-treated. Values were highly impaired when the kidneys were NPS-depleted and were improved when NPS pools were previously increased although they were not similar to control values. DEM treatment promoted a higher accumulation of HgCl2 in both kidney and liver while NAC-treatment reduced significantly the metal content in these organs. These data are in favour of a positive relationship among mercury content and organ injury. On the other hand, mercury content increased while NPS levels diminished. NPS might play a role in the HgCl2 detoxification and thus avoids mercury accumulation and mercury effects.

[Tuberculin reaction in healthy infants vaccinated with BCG at birth]. / Reacción tuberculínica en lactantes sanos vacunados con BCG al nacer.

Tuberculin test with PPD RT-23 with Tween 80 (2 TU strength), was performed to 228 infants under two years of age. None of them had any history of contact with tuberculosis. All were healthy, well-nourished infants, and had been vaccinated with BCG at birth. A positive PPD reaction (greater than 6 mm), was found only in 8.8%, of them and 16.2% had no BCG scar on examination; 14.9% of the studied infants had negative PPD (0-5 mm) reactions together with absent BCG scars. These findings are significantly different from those previously reported by chilean authors, which showed higher proportion of positive (greater than = 6 mm) reaction to 2 TU PPD in infants from similar populations that had been vaccinated with different BCG preparations than our patients. These results suggest the need to evaluate the efficacy of the BCG vaccines that are currently being used in our country to determine the factors that may affect it and the protection that they afford.

[Therapy with ketotifen in breast-fed infants with asthma]. / Terapia con ketotifeno en el asma del lactante.

Fifty asthmatic infants under 10 months of age included in a double blind placebo controlled trial lasting nine months. The whole group received continuous bronchodilator therapy with fenoterol + ipratropium in the first month. This was gradually discontinued in the second month, and half of the children began to receive ketotifen 0.35 mg each 12 hours, and the other placebo. The treatment was maintained for months. During this period, both groups received bronchodilators only in the presence of wheezing attacks. Bronchodilator consumption, symptoms registered in a diary card, results of a medical examination practiced each 10 days, and symptoms/bronchodilator requirements relationship were considered in the evaluation. Both groups showed a significant reduction in their symptom after the continuous bronchodilator use period. Control group did not experience further improvement within the next months, despite raising bronchodilators use. Ketotifen group improved all parameters evaluated and diminished their bronchodilator consumption. These changes reached statistical significance after three months ketotifen treatment. In the follow-up posttreatment, ketotifen group remained with significative less symptoms (p less than 0.001).

Use of nebulized bronchodilators in infants under 1 year of age: analysis of four forms of therapy.

The main purpose of this study was to evaluate four different forms of treatment in young infants admitted for acute wheezing (AW). Seventy-nine infants less than one year of age were randomly assigned to one of five groups. Group 1 received nebulized fenoterol plus ipratropium bromide, group 2 fenoterol, group 3 fenoterol plus steroids, and group 4 aminophylline, IV, plus steroids and oral fenoterol; the control group, or group 5, received nebulized normal saline solution. Clinical evaluation was done by means of a scoring system. The effectiveness of treatments was estimated by a score decrease in the first 24 hours, by the percentage of patients whose scores did not decrease during the same period, and by the number of days in the hospital. All infants had significantly decreased scores, except those in the control group; the aminophylline group included a greater percentage of patients who did not abate their scores, and they stayed in the hospital for more days than those in the other groups. The fenoterol group had the shortest hospital stay. All four treatments produced objective clinical improvement in bronchial obstruction. However, the nebulized bronchodilator treatments were more effective than aminophylline IV in decreasing scores on the first day, and they resulted in shorter hospitalization.

Bronchodilator effect of fenoterol and ipratropium bromide in infants with acute wheezing: use of MDI with a spacer device.

Twenty-eight infants admitted to Exequiel González Cortes Children's Hospital because of acute wheezing (AW) were randomly assigned to three study groups. Fenoterol (FNT), ipratropium bromide (IB), and placebo were administered respectively to children in the different groups by means of metered dose inhalers (MDI) with spacers, using doses of 3 puffs every hour, for 4 hours. The degree of bronchial obstruction was assessed clinically and scored with the single-blind method every hour prior to each treatment. The criterion of a bronchodilator effect was a significant decrease in the degree of bronchial obstruction at subsequent scorings. The scores of the three groups were compared using the Student's t test for matched samples. The same test was also applied to the independent samples for determining the superiority of one treatment, FNT or IB, over the other. The results indicated a significant decrease in the scores of the groups receiving FNT and IB (P less than 0.05); this did not occur in the group in which placebo was used. FNT produced a more rapid and sustained effect than IB (P less than 0.05). Significant bronchodilator effect was obtained in infants with AW when repeated doses of FNT or IB were administered with MDI and spacers. This effect was significantly greater in the group treated with FNT.

Hiperactividad bronquial e infección respiratoria viral / Bronchial hyperactivity and viral respiratory infection

La interacción virus-vía respiratoria es un buen modelo de cómo una noxa puede desencadear en un sujeto genéticamente predispuesto, una compleja cadena de amplificación de respuesta, que se traducirá en cuadros clínicos muchas veces severos, en aquel grupo etario de mayor labilidad respiratoria. El terreno genético es claro, ya que no sólo es frecuente encontrar marcados antecedentes familiares, sino que además hay suficiente base experimental, que demustra una diferente respuesta a múltiples niveles (linfocitos T, IgE, CB, células efectoras, etc.), lo que explica que frente a una misma agresión viral, sólo el hiperreactor presenta esta respuesta de mayor amplitud. Las diferentes hipótesis planteadas convergen a un punto común: la disponibilidad de calcio intracelular, abriendo promisorias expectativas para el mejor manejo de esos niños

Metodos del estudio del asma bronquial en el nino. / Methods for the study of bronchial asthma in children

El asma bronquial es una enfermedad que dura toda la vida, aunque no siempre provoca molestias en el paciente. Los beneficios que recuban los ninos que la sufren dependeran en gran parte de un diagnostico oportuno y preciso, un cabal conocimiento de la manera en que la enfermedad afecta a cada sujeto, las caracteristicas evolutivas y la respuesta del enfermo al tratamiento recomendado. En esta publicacion se revisa brevemente la contribucion de la historia, el examen clinico y diferentes procedimientos de laboratorio en el manejo del asma bronquial, destacando entre otros la necesidad de interpretar muy objetivamente los resultados de los estudios para analizar el papel de la alergia en cada caso. Se subraya que el manejo adecuado del problema esta al alcance y puede ser abordado por el pediatria cuanto no cuente con la ayuda del subespecialista

Asma bronquial en ninos. (Resultados de dos anos de tratamiento en 265 casos). / Bronchial asthma in children. (Results of two years of treatment in 265 cases)

Se estudian las caracteristicas de una muestra representativa (265 pacientes) de los asmaticos en control en nuestros servicios, demostrandose que entre nuestros enfermos existe una alta proporcion de las formas mas severas de asma, lo que se traduce en que estos ninos, a su ingreso a tratamiento y control, presentaban un importante numero de hospitalizaciones y consultas al Servicio de Urgencia, asi como ausentismo escolar,intolerancia al ejercicio y alteraciones en el sueno. Una nueva evaluacion hecha luego de un minimo de dos anos de terapia demuestra una gran mejoria en todos los indices de gravedad del asma y en la condicion de vida de estos pacientes