Comparison of amplicor, in-house polymerase chain reaction, and conventional culture for the diagnosis of tuberculosis in children.

A total of 251 clinical specimens (235 gastric aspirates and 16 bronchoalveolar lavages) from 88 children were prospectively tested in a blinded manner for the presence of Mycobacterium tuberculosis complex, by use of the Amplicor M. tuberculosis test and by means of in-house polymerase chain reaction (PCR). The results were compared with those obtained by conventional culture and by direct microscopy. All of the children underwent extended follow-up to verify or exclude the clinical diagnosis of tuberculosis. The results of the different tests, when compared to the final clinical diagnosis, were a sensitivity of 60% and a specificity of 96.8% for in-house PCR, 44% and 93.7% respectively for the Amplicor test, 44% and 100% for mycobacterial culture and 12% and 100% for microscopy. Amplicor tests presented false-positive findings in children without tuberculous infection. We conclude that both in-house PCR and the Amplicor test are rapid methods that can be helpful for difficult or urgent diagnosis of tuberculosis in children. However, efforts should be aimed toward improvement of the sensitivity and specificity of an easy-to-use PCR kit.

[Effectiveness of smears and cultures in gastric aspirate samples in the diagnosis of tuberculosis]. / Rentabilidad de la baciloscopia y el cultivo en muestras de jugo gástrico para el diagnóstico de la tuberculosis.

AIM: To evaluate the effectiveness of smears and cultures in gastric juice samples in the diagnosis of childhood pulmonary tuberculosis and to assess the relationship between clinical, radiological and epidemiological parameters in children with tuberculosis. MATERIALS AND METHODS: Blind, prospective, controlled study of 421 gastric aspirate samples from 139 children referred because of suspected tuberculosis. Children were classified according to clinicoradiological factors, irrespective of microbiological results. To verify the clinical diagnosis an extended followup was carried out. RESULTS: Smears were positive in 6 of the 46 children with active tuberculosis (sensitivity: 13%) and in 3 of the 93 children in the control groups (specificity: 96.8%). Cultures were positive in 15 children with active disease (sensitivity: 32.6%) and effectiveness was greater when the chest radiograph showed parenchymal involvement. Mycobacterium tuberculosis was also isolated in two children with tuberculous infection who showed no apparent signs of the disease and in one of these children, CT scan revealed mediastinal adenopathies which were not evident on the chest radiograph. Mean growth time for positive cultures was 42 days. CONCLUSIONS: The sensitivity of smears and cultures in gastric aspirate samples of children with pulmonary tuberculosis is low. Results of culture take several weeks and smears can give false positive results. Some children with tuberculous infection without apparent signs of the disease show microbiological activity that can be caused by mediastinal adenopathies that are not evident on chest radiographs.

[Clinico-radiological correlation of pulmonary complications of pediatric HIV infection]. / Correlación clínico-radiológica de las complicaciones pulmonares de la infección VIH en Pediatría.

Fifty-five percent of children with HIV infection, aged two months to ten years, were admitted at our hospitals because of respiratory conditions. Pulmonary complications found at admission in these children were lymphoid interstitial pneumonitis, Pneumocystis carinii pneumonia, fungal over-infection, tuberculosis, and bacterial complications. Also, non-specific infectious bronchial conditions, probably of viral origin. The most representative chest-X rays of these pulmonary conditions were analyzed; together with data from clinical records a clinico-radiological diagnosis was obtained.

[Computed tomography and polymerase chain reaction in tuberculosis infection in childhood]. / Tomografía computarizada y reacción en cadena de la polimerasa en la infección tuberculosa de la infancia.

The recognition of children with tuberculous infection without disease is often difficult. Minimal active disease may be present in many cases but unrecognised on chest radiography or by microbiologic methods. We have performed computed tomography in 22 children with tuberculous infection, a normal chest radiograph and negative microbacterial culture. In 16 children we also performed DNA amplification by polymerase chain reaction in gastric aspirates. It was found that 14 of 22 (63%) infected children had enlarged lymph nodes. Adenopathies were more frequent in children less than 8 years-old and in the right paratracheal positions. Polymerase chain reaction was positive in 4 of 8 studied children with abnormal computed tomography and in none of the children with normal computed tomography. The demonstration of unrecognised active disease raises the question of the adequate treatment for the children with tuberculous infection. It is proposed that a two drug regimen would be more appropriate than isoniazid alone in children less than 8 years old.

[Recurrent ingestion of foreign bodies. Unusual presentation of Munchausen by Proxy syndrome]. / Ingestión reiterada de cuerpos extraños. Forma inusual de presentación del síndrome de Munchausen por poderes.

A case with unusual presentation of Munchausen syndrome by proxy is reported. It was shown through reiterated ingestion of foreign bodies (two earrings, probably a button but not confirmed, a 5 cm. screw and two sewing needles) perpetrated by a 22-year-old mother with a psychiatric record of behavior disorders and family dysfunctions on a 10-month-old infant with a history of prematurity, repeated visits to emergency rooms, and nonjustified multiple hospital admissions. The difficulties in the diagnosis and the need for an early detection are brought up, making considerations in regard to indicators, diagnostic criteria, and management procedure.

[Portal blood flow studied in children with portal hypertension using Doppler duplex echocardiography]. / Estudio del flujo sanguíneo portal, en niños con hipertensión portal, mediante ecografía Doppler dúplex.

UNLABELLED: The study of portal morphology and hemodynamics is due the fact that the principle symptoms of portal hypertension are due primarily to alterations in the circulation of the venous portal system. The Doppler duplex echography (bidimensional echography in real time plus pulsatile Doppler) allows one to study these circulatory alterations in a non-invasive manner. MATERIAL AND METHOD: For these studies, an echograph (Toshiba, model Sonolayer SSH-60A) was used to study the morphology and the blood flow of the portal vein and the hepatic artery in 83 children. These children were divided into 4 groups: a) 9 children with atresia of the biliary ducts, b) 11 children with cavernoma of the portal vessel, c) 5 children with neonatal hepatitis and d) 58 healthy children. The parameters studied included the calibre, cross-sectional area, perimeter, velocity, blood flow volume, index of congestion and fluctuation and the direction of the portal flow, as well as the index of resistance of the hepatic artery. RESULTS: The results obtained in groups a, b and c were compared to healthy children of the same weight. When compared to normal children, it was found that children with portal hypertension had a decrease in the velocity and volume of the blood flow with respiration. There were no differences in the size of the portal vein nor in the index of resistance of the hepatic artery. The values obtained in children with neonatal hepatitis did not differ from those found in healthy children. CONCLUSIONS: We conclude that the Doppler duplex echography is an excellent method for the diagnosis and follow-up of portal hypertension, as well as for the detection of this condition early in asymptomatic patients.

[Evaluation of the portal blood flow in healthy children by Doppler duplex echography]. / Valoración del flujo sanguíneo portal, en niños sanos, mediante ecografía Doppler duplex.

We have measured the dimensions and blood flow of the portal vein, as well as the resistance rate of the hepatic artery in eighty-two healthy children by using Duplex Doppler Echography. From the data obtained, we have observed that the parameters of size and blood flow of the portal vein increase with the age, weight and height of the child, with a greater correlation with weight and height than with age. We did not observed any difference between males and females nor any variation in the resistance rate of the hepatic artery with age, weight or height.

[New applications of echography: Doppler ultrasonography]. / Nuevas aplicaciones de la ecografía: la ultrasonografía Doppler.

The Doppler effect, the different types of Doppler echography its functions and the parameters to evaluate the blood flow are defined. The clinical applications of Doppler in paediatrics are analyzed which are grouped in four great chapters: 1) cerebral blood flow. 2) renal flood flow: a.-native kidney, b.-transplanted kidney. 3) hepatic blood flow: a.-native liver, b.-transplanted liver. 4) characterization of mass, tissue and structures. Exploration technique of different organs are described and findings in different clinical sectors are referred to, emphasizing normal patterns.

[Real time and pulsed Doppler echography in the diagnosis of hydrocephaly in the preterm newborn infant]. / La ecografía en tiempo real y Doppler pulsado en el diagnóstico del recién nacido pretérmino afecto de hidrocefalia.

An evaluation of the cerebral blood flow by means of a Toshiba model Sonolayers-S SSH-60 A ultrasonograph was carried out in 44 children preterm born through the major fontanella and was divided in two groups: 1.) twenty-nine children neurologically normal in which the resistance index always achieves higher marks than the children born at term at the expense of a lesser diastolic flow, and a which a physiologic diastolic modification is described. 2.) a last group of fifteen preterm new born with obstructive hydrocephalus. In this group, the Doppler echography has no diagnostic value, due to the fact that the diastolic flow is too low.

[A study of cerebral blood flow in preterm newborns. The physiologic modification of diastole]. / Estudio del flujo sanguíneo cerebral en el recién nacido pretérmino. La modificación fisiológica de la diástole.

An evaluation of cerebral blood flow (CBF) was carried out with a Toshiba Sonolayers-S SSH-60 A echography in 127 infants with open major fontanelle which were divided in 3 groups: a) 69 non premature newborn, in which a physiological variation of all CBF parameters was found; b) 29 neurologically normal preterm infants, where the resistance index always was higher than in the preceding group, at the expense of a lower diastolic flow, in which for the first time the "physiological variation of diastole" independent of the gestational age is reported. This variation results in changes in the cerebral flow in the situations of exercise, rest or stress; c) 29 preterm infants with some abnormality, who also showed the physiologic variation of diastole with a poor flow quality were found.

[Duplex Doppler echography as a non-invasive method of evaluating cerebral blood flux, in full-term newborns, in the immediate neonatal period]. / La ecografía Doppler dúplex como método incruento de valoración del flujo sanguíneo cerebral, del recién nacido a término, en el período neonatal inmediato.

The Doppler effect and its application on the human body is described as well as its specific use in pediatric age: cerebral blood flow, liver and renal transplants, vascular-renal and portal hypertension and characterization of mass, tissue and structure. The results of 107 studies with Doppler duplex echograph on 86 neonates are analysed. The anterior and posterior cerebral arteries were sounded. The parameters taken into consideration were ten maximum systolic velocity (VS), the final diastolic velocity (VD), Bada's pulsatility index (IP) and the morphology of the curve. In 35 normal newborns the results were: maximum systolic velocity 24.08 +/- 4.30 cm/s, the final diastolic velocity 8.77 +/- 1.86 cm/s, Bada's pulsatility index. In the caesarean born neonates in both forms of anaesthesia, and those born by EVA delivery (stimulation, suction and analgesia) slight increases were observed, in comparison with the normal newborn group, in the maximum systolic velocity and Bada's pulsatility index.