Viral agents causing lower respiratory tract infections in hospitalized children: evaluation of the Speed-Oligo® RSV assay for the detection of respiratory syncytial virus.

Respiratory syncytial virus (RSV) is the viral agent which is more frequently involved in lower respiratory tract infections (LRTIs) in infants under 1 year of age in developed countries. A new oligochromatographic assay, Speed-Oligo® RSV, was designed and optimized for the specific detection and identification of RSV subtypes A and B. The test was evaluated in 289 clinical samples from 169 hospitalized children using an immunochromatography (IC) test, virus isolation by culture, and an in-house real-time polymerase chain reaction (RT-PCR). Other viruses causing LRTIs were investigated by cell culture or PCR-based tests. Sixty-two patients were infected by RSV (36.7%). In addition, adenovirus, influenza B, parainfluenza 2, and human metapneumovirus were detected in rates ranging from 5 to 8%. A proportion of 10.1% of the patients had mixed infections. The sensitivity, specificity, and positive and negative predictive values were, respectively, 94.9, 99.4, 98.9, and 97.4% for Speed-Oligo® RSV, 92.9, 96.3, 92.9, and 96.3% for RT-PCR/RSV, and 58.4, 98.1, 93.3, and 82.6% for IC. Our rates of viral detection and co-infection were similar to those of previously reported series. Finally, we find that Speed-Oligo® RSV is a rapid and easy-to-perform technique for the detection of RSV and the identification of subtypes A and B.

Melatonin increases following convulsive seizures may be related to its anticonvulsant properties at physiological concentrations.

Melatonin ( N-acetyl-5-methoxytryptamine, aMT) is an indoleamine produced by several organs and tissues including the pineal gland. Melatonin (aMT) modulates the activity of the brain, mainly acting on both GABA and glutamate receptors. Previous studies have shown the participation of melatonin in the control of convulsive crises, suggesting that aMT concentration increases during seizures, and that patients with seizures of diverse origins show an alteration of the aMT rhythm. However, what is not known is the duration of the aMT response to seizures, and whether aMT changes during seizures could be a marker of the disease. For this reason, the serum levels of aMT in 54 children with a convulsive crisis, febrile and epileptic, were analyzed during the crisis, as well as at 1 h and 24 hours after the seizure. The results show that aMT significantly increases during the seizure (Day group, 75.64+/-45.91 and Night group, 90.69+/-51.85 pg/mL), with normal values being recovered 1 h later (Day group, 26.33+/-10.15 and Night group, 27.78+/-7.82 pg/mL) and maintained for up to 24 hours, when the circadian variation of aMT returns to the normal acrophase. Due to the interindividual variation of aMT levels among healthy people, a single determination of the indoleamine concentration is not a suitable marker of the existence of a convulsive crisis unless the circadian profile of aMT secretion in the patient is known. The results obtained also support the view that the stimulation of aMT production by the convulsive crisis may participate in the response of the organism against the seizures.

[Familial study of factor XI deficiency. Presurgical prophylactic treatment with desmopressin plus antifibrinolytics]. / Estudio familiar de déficit de factor XI. Tratamiento profiláctico prequirúrgico con desmopresina y antifibrinolíticos.

Factor XI deficiency is a rare inherited coagulation disorder. It rarely produces spontaneous bleeding although patients with this disorder are at risk for hemorrhagic complications after trauma or surgery. Because there is no clear correlation between the tendency to bleed and the severity of the disease itself, predicting hemorrhagic complications after surgery in patients with mild disease is difficult. This hereditary deficiency is characterized by prolongation of activated partial thromboplastin time with normal prothrombin time, and the demonstration of selective plasma factor XI deficit. Currently available products in the therapeutic arsenal are transfusion of fresh-frozen plasma, virus-inactivated factor XI concentrates, desmopressin (DDAVP) and antifibrinolytic drugs, whether alone or in combination. We describe a family with two affected children, in which the deficiency was identified as an autosomal recessive trait. Of the two patients, one required prophylactic treatment with desmopressin and tranexamic acid before surgery; the treatment was successful and no related complications were observed. The long-term outcome of individuals with this disease seems to be good with continuous follow up and early control of hemorrhagic episodes. Prophylactic therapy is not required, except when surgery is anticipated.

[Continuous treatment with colony stimulating factors (G-CSF) for neutropenia associated with type Ib glycogenosis]. / Tratamiento continuo con factores estimulantes de colonias (G-CSF) de la neutropenia asociada a la glucogenosis tipo Ib.

In the last few years, granulocyte colony stimulating factors (G-CSF), or hematopoietic growth factors, have created new possibilities for treating severe neutropenias, with high clinical efficacy and minimal adverse effects. Moreover, due to genetic recombinant techniques, the therapeutic use of these glycoproteins is increasing. We report the case of a 4-year-old girl who was diagnosed with glycogenosis IB at the age of 7 months. From the age of 2 years, she presented severe established neutropenia secondary to the main disease. Subcutaneus G-CSF therapy was started. The patient has shown no serious infections, has maintained normal growth and development, and has not required hospitalization. Adverse effects have been minimal. The therapeutic efficacy demonstrated by this case justifies the continuous use of G-CSF, although the lack of long-term perspectives should not be forgotten.

Melatonin's role as an anticonvulsant and neuronal protector: experimental and clinical evidence.

The pineal gland classically has been considered as a vestigial and mystic organ. In the last decades, and with the incorporation of new methodologic procedures, it could be proved that it also has physiologic actions that vary depending on the level of the phylogenetic scale. Its best-known secretion, melatonin, has been related to many different actions, such as sleep promotion, control of biologic rhythms, hormonal inhibition, and an inhibiting action on central nervous system regulation mechanisms. In animal experimentation, there are papers even accepting an anticonvulsant effect. In humans, evidence is reduced to few experiences. In addition to this clinical experience, there is other evidence that clearly relates melatonin to convulsive phenomena. This relationship must be mediated by the following mechanisms attributed to melatonin: altered brain GABAergic neurotransmission, its known interaction with benzodiazepinic brain receptors, through tryptophan metabolite activity (kynurenine, kynurenic acid), or even by its efficacy as a free-radical scavenger.

Utility of high doses of melatonin as adjunctive anticonvulsant therapy in a child with severe myoclonic epilepsy: two years' experience.

Recent data indicate that melatonin inhibits brain glutamate receptors and nitric oxide production, thus suggesting that it may exert a neuroprotective and antiexcitotoxic effect. Melatonin has been seen to prevent seizures in several animal models and to decrease epileptic manifestations in humans. The lack of response to conventional anticonvulsants in an epileptic child led us to use melatonin in this case. A female child who began to have convulsive seizures at the age of 1.5 months and was diagnosed as having severe myoclonic epilepsy was unsuccessfully treated with different combinations of anticonvulsants, including valproic acid, phenobarbital, clonazepam, vigabatrin, lamotrigin, and clobazam. Melatonin was thus added to the treatment. Imaging studies (CT, SPECT, and MNR), EEG recordings, blood biochemical, and hematological analyses, including measures of the circadian rhythm of melatonin, were made. The child was initially treated with various anticonvulsants. Severe neurological and psychomotor deterioration combined with increased seizure activity showed a lack of response to the treatment. At the age of 29 mon the patient was in a pre-comatose stage at which time melatonin was added to treatment. After 1 month of melatonin plus phenobarbital therapy and for a year thereafter, the child's seizures were under control. On reducing the melatonin dose after this time, however, seizures resumed and the patient's condition was re-stabilized after restoring melatonin. Prior to our attempts to reduce melatonin, all analyses, including EEG recordings and SPECT, were normal. As far as the results of neurological examination are concerned, only mild hypotony without focalization remained. Changes in the therapeutic schedules during the second year of melatonin treatment, including the withdrawal of phenobarbital, did not result in the same degree of seizure control, although progressively the child became satisfactorily controlled. At the present moment the child continues to have mild hypotony and shows attention disorder and irritability. Melatonin has proven to be useful as adjunctive therapy in the clinical control of this case of severe infantile myoclonic epilepsy. The results suggest that melatonin may have a useful role in mechanisms of neuroprotection and also indicate its use in other cases of untreatable epilepsy. Further studies using more patients and placebo-treatment would be beneficial in understanding the potential use of melatonin as a co-therapy in some cases of seizures.

[The effect of melatonin as anti-convulsant and neuron protector]. / Efeto de la melatonina como anticonvulsivante y protector neuronal.

INTRODUCTION: Melatonin is the principal hormone secreted by the pineal gland. In human beings the pineal gland is found on the posterior aspect of the midbrain. Melatonin is synthesized from tryptophan following a circadian rhythm, with low levels during the day and high levels during the night. It regulates many biological processes in relation to the cycles of light and darkness. DEVELOPMENT: Its first known function was that of inducing sleep. In experimental animals its effect as a depressor of the central nervous system and its anti-convulsive action have been shown. Few studies have been done in human beings, although there is some evidence of its beneficial effect in epileptic patients, improving both the frequency of the crises and the EEG tracing. In our experience we gave melatonin to a girl with severe myoclonic epilepsy which did not respond to usual treatment, obtaining improvement in both the number of crises daily and in psycho-motor development. Several possible modes of action have been described for melatonin; increase in Gabaergic transmission at a cerebral level, where GABA is the main inhibitory neurotransmitter; interaction with benzodiazepinic cerebral receptors; it may owe its effect to the activity of its metabolites, particularly kinurenic and kinurenic acid; it may induce hormone changes in the organism. Recent studies show the marked anti-oxidant activity of melatonin. Its considerable capacity to accept free radicles resulting from biological processes has been shown and it thus acts as a cell protector. CONCLUSIONS: It seems reasonable to assume that melatonin has anticonvulsant and neuroprotector properties. Further study may define its pharmacological usefulness in these disorders.