Routine laboratory investigations in infants and children presenting with fever and seizures at the University Hospital of the West Indies / Investigaciones de rutina en el laboratorio en relación con infantes y niños que se presentan con fiebre y convulsiones en el Hospital Universitario de West Indies

A retrospective chart review of the case notes of all children aged 6 months to 8 years presenting with fever and seizures to the University Hospital of the West Indies (UHWI) between January 2000 and December 2004 was conducted. Descriptive analyses were performed. Fifty-nine children (median age 1.58 years, range 0.58 to 6.83 years) were entered into the study. The main laboratory abnormalities were metabolic acidosis (23%), anaemia (10%), leukocytosis (35%) and hypomagnesaemia (3%). These were not significantly associated with meningitis or an underlying bacterial infection. There were no significant episodes of hyponatraemia, hypocalcaemia or hypoglycaemia. Meningitis was uncommon and occurred in only two (3.4%) children both younger than 16 months of age and who had other abnormal clinical signs. This study demonstrated that routine performance of haematological and biochemical investigations in children presenting with seizures and fever were of limited value. Lumbar punctures in children older than age 18 months with no other abnormal clinical signs were also found to be of low yield. Current American Academy of Paediatrics (AAP) recommendations that serum electrolytes, calcium, phosphate, magnesium, complete blood count and blood glucose should not be performed routinely in a child with a first simple febrile seizure can be safely applied to this study population.

Se llevó a cabo un estudio retrospectivo de las historias clínicas en busca de notas sobre los casos de todos los niños de 6 meses a 8 años de edad que se presentaron con fiebre y convulsiones en el Hospital Universitario de West Indies (HUWI) entre enero de 2000 y diciembre de 2004. Se realizaron análisis descriptivos. Cincuenta y nueve niños (edad mediana (1.58 años, rango 0.58 a 6.83 años) formaron parte de este estudio. Las principales anormalidades halladas mediante el laboratorio fueron: acidosis metabólica (23%), anemia (10%), leucocitosis (35%), e hipomagnesemia (3%). Éstas no estuvieron significativamente asociadas con meningitis o alguna infección bacteriana subyacente. No hubo episodios significativos de hiponatremia, hipocalcemia o hipoglicemia. La meningitis fue poco común, ocurriendo sólo en dos niños (3.4%), ambos con menos de 16 meses de edad y con otros signos clínicos anormales. Este estudio demostró que el trabajo de rutina realizado en las investigaciones hematológicas y bioquímicas en los niños que se presentaron con fiebre y convulsiones, tuvo un valor limitado. También se halló que las punciones lumbares realizadas a niños de más de 18 meses sin ningún otro signo clínico anormal, tuvieron poco valor. Las recomendaciones actuales de la Academia Americana de Pediatría (AAP) en cuanto a que las pruebas de electrolitos en suero, las mediciones de calcio, fosfato, magnesio, el conteo sanguíneo completo, y la prueba de glucosa en sangre, no deben ser realizadas rutinariamente en un niño con una primera simple convulsión febril, pueden ser aplicadas con seguridad a esta población bajo estudio.

Routine laboratory investigations in infants and children presenting with fever and seizures at the University Hospital of the West Indies.

A retrospective chart review of the case notes of all children aged 6 months to 8 years presenting with fever and seizures to the University Hospital of the West Indies (UHWI) between January 2000 and December 2004 was conducted. Descriptive analyses were performed. Fifty-nine children (median age 1.58 years, range 0.58 to 6.83 years) were entered into the study. The main laboratory abnormalities were metabolic acidosis (23%), anaemia (10%), leukocytosis (35%) and hypomagnesaemia (3%). These were not significantly associated with meningitis or an underlying bacterial infection. There were no significant episodes of hyponatraemia, hypocalcaemia or hypoglycaemia. Meningitis was uncommon and occurred in only two (3.4%) children both younger than 16 months of age and who had other abnormal clinical signs. This study demonstrated that routine performance of haematological and biochemical investigations in children presenting with seizures and fever were of limited value. Lumbar punctures in children older than age 18 months with no other abnormal clinical signs were also found to be of low yield Current American Academy of Paediatrics (AAP) recommendations that serum electrolytes, calcium, phosphate, magnesium, complete blood count and blood glucose should not be performed routinely in a child with a first simple febrile seizure can be safely applied to this study population.

Acute lead poisoning associated with backyard lead smelting in Jamaica / Envenenamiento agudo con plomo asociado con la fundición casera de plomo en Jamaica

Long-term backyard smelting of lead in a district known as Mona Commons, Kingston, Jamaica, has produced lead burdens as high as 30 000 mg/kg in soils near to the smelter, and indoor dust loadings of 373 microg/f2 in the residents' home. The blood lead levels (BPb) of 107 children from the district were in the range 2.2-202 microg/dL. Fifty-nine per cent of these had BPb levels above 10 microg/dL and the population mean was an unacceptably high 25.1 microg/dL. The highest levels were observed for five siblings, two of whom presented with lead encephalopathy. This severe chronic exposure to lead was exacerbated by a significant history of pica, and chronic nutritional anaemia. Chelation therapy significantly reduced the BPb levels but due to lead storage in other organs, the values after several months were still higher than desirable. This study emphasizes the importance of reducing the exposure of children to lead.

Acute lead poisoning associated with backyard lead smelting in Jamaica.

Long-term backyard smelting of lead in a district known as Mona Commons, Kingston, Jamaica, has produced lead burdens as high as 30 000 mg/kg in soils near to the smelter, and indoor dust loadings of 373 microg/f2 in the residents' home. The blood lead levels (BPb) of 107 children from the district were in the range 2.2-202 microg/dL. Fifty-nine per cent of these had BPb levels above 10 microg/dL and the population mean was an unacceptably high 25.1 microg/dL. The highest levels were observed for five siblings, two of whom presented with lead encephalopathy. This severe chronic exposure to lead was exacerbated by a significant history of pica, and chronic nutritional anaemia. Chelation therapy significantly reduced the BPb levels but due to lead storage in other organs, the values after several months were still higher than desirable. This study emphasizes the importance of reducing the exposure of children to lead.

IL-13, IL-4Ralpha, and Stat6 are required for the expulsion of the gastrointestinal nematode parasite Nippostrongylus brasiliensis.

Although IL-4 induces expulsion of the gastrointestinal nematode parasite, Nippostrongylus brasiliensis, from immunodeficient mice, this parasite is expelled normally by IL-4-deficient mice. This apparent paradox is explained by observations that IL-4 receptor alpha chain (IL-4Ralpha)-deficient mice and Stat6-deficient mice fail to expel N. brasiliensis, and a specific antagonist for IL-13, another activator of Stat6 through IL-4Ralpha, prevents worm expulsion. Thus, N. brasiliensis expulsion requires signaling via IL-4Ralpha and Stat6, and IL-13 may be more important than IL-4 as an inducer of the Stat6 signaling that leads to worm expulsion. Additional observations made in the course of these experiments demonstrate that Stat6 signaling is not required for IL-4 enhancement of IgG1 production and actually inhibits IL-4-induction of mucosal mastocytosis.

Clinical diagnoses of children with extremely short stature and their response to growth hormone.

This study was undertaken to determine the prevalence of clinical diagnoses in a group of children with extremely short stature (standard deviation score for height, < -2.5) and to determine whether the classification might help in predicting response to human growth hormone (hGH) treatment. We classified 49 children referred consecutively to our outpatient clinic for evaluation of short stature with heights < -2.5 standard deviation score and bone ages < 9 years for girls or < 10 years for boys (to avoid an effect of puberty on the response to hGH). The diagnostic categories were growth hormone (GH) deficiency, constitutional delay, familial short stature, and primordial short stature. After referral, Turner syndrome was diagnosed in two children. The remaining 47 children were classified according to primary criteria, considered essential for the diagnosis, and secondary criteria, considered necessary but of lesser importance. There were five children, four children, no children, and one child classified, respectively, with GH deficiency, constitutional delay, familial short stature, and primordial short stature by using the most rigorous definitions of the diagnoses. There was significant overlap in the diagnoses other than GH deficiency. Growth hormone deficiency defined by the primary criterion of peak stimulated GH values < 5 micrograms/L was the most definitive. Of the 47 children, 7 were classified as GH deficient by this criterion and 5 were classified as GH deficient by the primary and secondary criteria. The mean pretreatment growth rate (3.1 +/- 1.9 cm/yr) of the group with stimulated GH values < 5 micrograms/L was significantly less than that in the other groups (4.2 +/- 1.5 cm/yr). The mean growth rate of the children with GH deficiency during treatment with hGH was greater than that in the other groups and was 3.4 times greater than the pretreatment growth rate. The mean growth rate of children in the other groups during hGH treatment was twofold greater than the pretreatment growth rate. We conclude that except for GH deficiency, children with an extreme degree of short stature are not easily classified by standard diagnostic criteria, and that most short children have a positive response to hGH therapy regardless of the diagnosis; therefore a specific clinical diagnosis should not be used to exclude children from hGH therapy.

Metabolic and histologic investigation of the nature of nephrocalcinosis in children with hypophosphatemic rickets and in the Hyp mouse.

To investigate the biochemical nature of nephrocalcinosis in children with hypophosphatemic rickets treated with orally administered phosphate and vitamin D, we studied five such patients, aged 3.7 to 12.3 years, during treatment and again 3 days after it had been discontinued. Treatment was associated with significant increases in mean serum phosphate concentration and urine phosphate/creatinine ratio, from 0.71 to 1.03 mmol/L and from 3.61 to 9.42 mmol/mmol, respectively. Significant correlation was found between urine phosphate/creatinine and oxalate/creatinine ratios (r = 0.670; p less than 0.01); however, the mean urine oxalate/creatinine ratio of 65.0 mumol/mmol while patients were taking phosphate orally was not significantly different from the ratio of 59.0 mumol/mmol when treatment was discontinued. Kidney biopsy specimens from three of the patients showed that the renal calcifications were located mainly intratubularly and were composed exclusively of calcium phosphate. In a further investigation of the nature of phosphate-induced nephrocalcinosis, six 6-week-old male Hyp mice, the murine analog of the human disease, received oral phosphate therapy with drinking water for 48 days; six others served as control animals. Mice in the experimental group excreted more phosphate (p less than 0.001) and less calcium (p less than 0.01) than control mice did, and medullary nephrocalcinosis, with a high kidney calcium content, developed (p less than 0.001). Histologic sections showed that the renal calcifications were located intratubularly and were composed of calcium phosphate. We conclude that, both in children with hypophosphatemic rickets and in the Hyp mouse, the development of nephrocalcinosis is associated with high oral phosphate intake and subsequent deposition of calcium phosphate precipitates in the kidney.

Long-term treatment with growth hormone of children with short stature and normal growth hormone secretion.

Children with short stature but normal growth rate and/or normal growth hormone response to sleep and secretagogues were treated with recombinant methionyl human growth hormone, 0.3 mg/kg per week. In each year of treatment, about 80% of the subjects maintained an increase in growth rate greater than the defined limit (greater than 1 cm/yr above pretreatment growth rate) for continuation of human growth hormone treatment. Comparison of the group that continued to respond to human growth hormone with the group that did not maintain an accelerated growth rate did not reveal differences in bone age delay, sleep or secretagogue-stimulated human growth hormone secretion, degree of short stature either absolute or relative to target height, and somatomedin C concentration before or after initiation of therapy. The group that failed to respond to the human growth hormone treatment in the first year of treatment was younger and had a higher pretreatment growth rate. Review of the longitudinal growth curves revealed five patterns of response to human growth hormone treatment: (1) failure to increase growth rate in two subjects with height SD scores within 1 SD of target height, (2) failure to increase growth rate in five subjects with height SD scores greater than 1 SD less than the target height, (3) acceleration in growth rate in three subjects that was not maintained until achievement of a height within 1 SD of the target height, (4) acceleration of growth rate in five subjects that was maintained until achievement of a height within 1 SD of the target height, and (5) acceleration in growth rate that was maintained during the 3 years of treatment in 15 subjects who had not attained a height within 1 SD of the target height. We conclude that human growth hormone treatment of some but not all short children with "normal" growth hormone secretion will result in sustained acceleration of growth rate and attainment of prepubertal heights that are closer to but do not exceed their genetic height potential. A clinical trial of human growth hormone may be necessary to determine which subjects will benefit from the treatment.

Growth hormone secretory profiles: variation on consecutive nights.

To evaluate the reproducibility of overnight growth hormone (GH) testing and the effect of daytime administration of levodopa and clonidine on overnight GH secretion, we examined consecutive 12-hour overnight GH profiles of 48 short subjects, ages 5 to 16 years, who had GH stimulation testing with levodopa and clonidine. In six subjects (12%) the overnight pool GH concentration on the second night increased by greater than 100% from the first-night result (night-to-night changes of +1.2 to +5.2 ng/ml). In the remaining subjects, night-to-night changes in pool GH concentrations ranged from -1.2 to +1.8 ng/ml (-60% to +88% changes from the first night value). Night-to-night changes were less than 25% of the first-night value in 17 subjects (35%), 25% to 50% in 18 subjects (38%), and 50% to 100% in 7 subjects (15%). Night-to-night changes in pool GH concentrations correlated with differences in peak nighttime GH concentrations but not with differences in duration of observed sleep. There was no discernible effect of daytime levodopa-clonidine administration on overnight pool GH concentrations. These results demonstrate the potential for night-to-night variation in overnight GH profiles and suggest the need for some means of confirming that overnight GH testing reflects normal physiologic GH secretion. Without such confirmation, the results from a single overnight GH profile should be interpreted with caution.

Participacion de la comunidad en sistemas de abastecimento de agua y saneamiento, en zonas rurbanas. / Community participation in water supply and sanitation systems in rurban areas

Se insiste en este articulo sobre la importancia, para el buen funcionamiento y la duracion de un sistema de abastecimiento de agua y saneamiento, que los usuarios comprendan las ventajas que les va a reportar, deseen disfrutar de ellas y esten convencidos de que son capaces de soportar los gastos. Para conseguir estas condiciones es imprescindible la participacion de la comunidad entendida como una actividad responsable, llevada a cabo por los propios interesados que han recibido una capacitacion que les permite contribuir con su trabajo