Variaciones en la incidencia de bronquiolitis tras la aparición del SARS-CoV-2 / Variations in the incidence of bronchiolitis after the onset of SARS-CoV-2

Introducción. Durante la temporada 2020-2021 se ha asistido a una disminución de la incidencia de hospitalizaciones por bronquiolitis. Los cambios en la evolución de la pandemia de SARS-CoV-2 y en la aplicación de medidas preventivas podrían relacionarse con un aumento de la incidencia de bronquiolitis grave durante la temporada 2021-2022. Objetivo. Determinar la incidencia de hospitalizaciones por bronquiolitis en un hospital terciario durante la temporada 2021-2022 y compararla con temporadas previas. Método. Estudio epidemiológico de tipo observacional, descriptivo y ambispectivo. A través de la base de datos de un hospital terciario, se compararon la incidencia, la etiología y los indicadores de gravedad de las hospitalizaciones por bronquiolitis. Se analizaron 3 cohortes en época epidémica: la temporada 2020-2021 y la 2021-2022 (prospectivas); y la temporada 2018-2019 (retrospectiva). También se analizó una cohorte prospectiva entre los meses de abril y octubre de 2021. Resultados. La incidencia acumulada de hospitalizaciones fue de 113,6/10.000 niños menores de 2 años en la temporada pre-covídica; de 3,6/10.000 en la temporada 2020-2021; y de 65,7/10.000 en la temporada 2021-2022. El porcentaje de ingresos en UCIP fue de 36,6%, 0 % y 30,8%, respectivamente. La incidencia acumulada de hospitalizaciones en el periodo no epidémico fue de 60,8/10.000, precisando ingreso en UCIP el 19%. El microorganismo más frecuente fue el virus respiratorio sincitial en todas las cohortes. Conclusiones. La incidencia durante los meses típicamente epidémicos de bronquiolitis bajó drásticamente la temporada en la que apareció el SARS-CoV-2, aumentando notablemente el año posterior, aunque sin alcanzar la incidencia previa a la pandemia. Se ha observado una incidencia alta de casos de bronquiolitis entre abril y octubre de 2021 (AU)

Introduction. A decrease has been observed during the 2020-2021 season in the incidence of hospitalizations for bronchiolitis. Changes in the evolution of the SARS-CoV-2 pandemic and in the application of preventive measures could be related to an increase in the incidence of severe bronchiolitis during the 2021-2022 season. Objective. To determine the incidence of bronchiolitis hospitalizations in a tertiary hospital during the 2021-2022 season and to compare it with previous seasons. Method. An observational, descriptive and ambispective epidemiological study. A tertiary hospital database was used to compare the incidence, etiology, and severity indicators of bronchiolitis hospitalizations. 3 cohorts were analyzed in epidemic times: the 2020-2021 season and the 2021-2022 season (prospective); and the 2018-2019 season (retrospective). A prospective cohort between the months of April and October 2021 was also analyzed. Results. The cumulative incidence of hospitalizations was 113.6/10,000 children under 2 years of age in the pre-covid season; 3.6/10,000 in the 2020-2021 season; and 65.7/10,000 in the 2021-2022 season. The percentage of admissions in PICU was 36.6%, 0% and 30.8%, respectively. The cumulative incidence of hospitalizations in the non-epidemic period was 60.8/10,000, with 19% requiring admission to the PICU. The most frequent microorganism was the respiratory syncytial virus in all cohorts. Conclusions. The incidence during the typically epidemic months of bronchiolitis drastically decreased the season in which SARS-CoV-2 appeared, noticeably increasing the next year, although without reaching the pre-pandemic incidence. A high incidence of bronchiolitis cases was observed between April and October 2021 (AU)

Identification and antimicrobial susceptibility of Streptomyces and other unusual Actinobacteria clinical isolates in Spain.

Two hundred and eighty-six isolates from human clinical samples were identified between 1996 and 2019 as belonging to 8 families, 19 genera and 88 species of Actinobacteria. The most identified genera were Streptomyces (182 strains from 45 species), Actinomadura (29 strains, 5 species), Nocardiopsis (21 strains, 6 species) and Dietzia (18 strains, 5 species). The rest of the identified genera (15) contained 27 species with 36 isolates. Of the species studied, only 13/88 had been documented previously as isolates from clinical samples, and in some cases, as true pathogens. In this sense, a literature review of the species found in infections or in clinical samples without clear involvement in pathology has been carried out. Finally, the susceptibility to 8 antimicrobial agents has been studied. Streptomyces showed high resistance (80.8%) against cefotaxime and cotrimoxazole (55.5%), and no isolate resistance to amikacin and linezolid have been found. Lower percentages of resistance have been found in other genera, except in Dietzia (100% against cotrimoxazole and 44.4% against erythromycin). The greatest resistance in these genera was to cotrimoxazole (29.8) and erythromycin (27,9%), and no resistance to linezolid has been found in these genera. In Microbispora, Nonomuraea and Umezawaea, no resistant isolates have been found against any antibiotic studied. Only 3/104 isolates were resistant to amikacin in Amycolatopsis, Crossiella, and Micromonosopora. One isolate of Amycolatopsis was resistant to imipenem.

Novel edible toys as iron carrier to prevent iron deficiency of postweaned pigs.

The current preventive treatment for iron deficiency in pigs is inefficient, resulting in a high prevalence of iron-deficient or anemic postweaned pigs. The aim of this study was to develop and characterize edible toys (ETs) to be used as oral iron supplements, and to assess their effect on feeding behavior and iron status of postweaned pigs. Three types of ETs, varying in sweetness, were produced by ionic gelation, using whey, sodium alginate, ferrous sulfate and atomized bovine erythrocytes. ET control (ETC) was developed without sweetener, ET1 contained 15% w/v sucrose and ET2 contained 0.03% w/v of Sucram (98% sodium saccharin, 1% neosperidine dihydrocalcone and 1% maltol). ETs were mainly composed of carbohydrates and protein, with a similar concentration of iron (2.2-2.7 mg/g). The ETs were offered to 24 postweaned pigs to measure acceptability and preference. The animals preferred ETC and ET2 over ET1. To assess the nutritional benefit of the ETs, 24 postweaned pigs were distributed into three groups: ETC (without iron), ETC-Fe (ETC with iron) and ET2-Fe (with iron and Sucram). Iron-loaded ET (ETC-Fe and ET2-Fe) significantly increased the concentration of red blood cells (from 6.1 to 7.5·106 x mm3 for ETC-Fe and from 6.2 to 7.8 for ET2-Fe), hematocrit (from 32.8 to 37.9% for ETC-Fe and from 32.3 to 35.1 for ET2-Fe), serum iron (from 28.6 to 120.6 µmol/L for ETC-Fe and from 34.9 to 145.4 for ET2-Fe) and serum ferritin (from 7.8 to 18.5 µg/L for ETC-Fe and from 8.1 to 20.2 for ET2-Fe). In conclusion, the ETs developed in this study were accepted by the pigs and provided adequate iron to improve the iron status of postweaned pigs.

Promoting gender, equity, human rights and ethnic equality in neglected tropical disease programmes.

Limited attention to tackling neglected tropical diseases (NTDs) through the lenses of gender, equity, ethnicity and human rights inadvertently undermines progress due to the exclusion of subgroups in populations living in conditions of vulnerability. Supporting national NTD programmes to make equity analysis part of their routine activities and revitalising intersectoral collaboration will be essential to achieve effective, sustainable service delivery with a person-centred approach. Gender, equity, human rights and ethnic equality for NTD programmes should therefore be incorporated in multisectoral engagements.

Acquisition of flavour preferences in pigs through interactions with conspecifics that had previously consumed flavoured protein solutions.

It is known that pigs can acquire flavour preferences by brief social interactions with conspecifics that previously consumed a flavoured solid feed. However, there is no information about whether a flavoured solution could support flavour preferences through social transmission. Ninety-six pigs (49 days old) were housed in 12 pens (8 pigs/pen). Four animals per pen were randomly selected to act as observers and four as demonstrators. Demonstrator animals were temporarily moved to an empty pen where a protein solution was offered (porcine digestive peptides (PDPs), 4% weight/volume) with the addition of 0.075% aniseed (six pens) or garlic (six pens) powdered artificial flavours for 30 min. Afterwards, demonstrators were returned to interact with observer animals for 30 min. A choice test (30 min) between aniseed and garlic PDP was performed for each observer group after the interaction. Observers showed a higher intake of solutions previously consumed by their demonstrator conspecifics (648 v. 468 ml; SEM 61.36, P < 0.05). As with flavoured solid feeds, protein solutions containing artificial flavours can create preferences in pigs for those flavours through social transmission from conspecifics.

The use of porcine digestible peptides and their continuity effect in nursery pigs.

A total of 552 entire male and female nursery pigs were selected to be used in 2 different experiments that aimed to study if milk ingredients can be replaced by highly preferred protein sources (Exp. 1) and if pre- and postnatal exposure of those protein ingredients through the maternal diet may increase pig performance (Exp. 2). In Exp. 1, 240 pigs were separated after weaning (28 d) into 2 groups depending on the presence of lactose in their diets. Pigs ( =120) fed diets with the precence of lactose (lactose +) were given prestarter (0-14 d) and starter (15-33 d) diets with 142 and 50 g/kg of sweet milk whey, respectively; the lactose-free group ( = 120) was offered an isoenergetic diet with 20 g/kg of porcine-digestible peptides (PDP; Palbio 62SP; Bioibérica S.A., Palafolls, Spain) and wheat replacing sweet milk whey. Choice and 1-feeder tests were performed in another group of animals ( = 72) to evaluate the preference and acceptance for both diets. Pigs preferred ( = 0.039) the lactose+ over the lactose-free diet after a 30-min choice test and consumed more ( = 0.001) lactose+ than lactose-free diet in a 1-feeder test. However, no difference ( > 0.467) in performance was observed between groups for the entire nursery period. In Exp. 2, 120 animals were obtained from sows that, during late gestation (14 d) and lactation (28 d), were fed diets containing 20 g/kg of PDP and another 120 animals were obtained from sows fed an isoenergetic diet without PDP inclusion. Placenta samples were collected at farrowing to assess the volatile compounds present in the placental fluid of sows. After weaning, all pigs received a feed containing 20 g/kg of PDP in the prestarter and starter diets. A principal components analysis of the total volatile compounds showed the exclusive presence of sulfur-containing compounds and a higher presence of terpene compounds in the placental fluid of PDP-supplemented sows. In addition, pigs coming from sows fed diets supplemented with PDP tended to show a higher ADFI ( = 0.07) and ADG ( = 0.06) than did pigs coming from control sows during the 15 to 33 d after-weaning period. These results suggest that dietary incorporation of sweet milk whey may be replaced by a specific protein source without affecting performance of pigs after weaning. However, more experiments are needed to elucidate the mechanism for the sow's diets' influence over pig's performance.

Influence of dietary electrolyte balance on feed preference and growth performance of postweaned piglets.

A total of 672 male and female piglets (21 d postweaning; approximately 13 kg BW) were selected to be used in 3 different experiments to assess the influence of dietary electrolyte balance (dEB; Na + K - Cl, in mEq/kg of diet) on feed preference and growth performance. In Exp. 1, piglets were fed 4 isoenergetic diets differing in dEB level: 16, 133, 152, and 269 mEq/kg diets. Changes on dEB were obtained by changing the levels of sodium and chloride with calcium chloride, calcium carbonate, and sodium bicarbonate. Piglets fed the 16 and 133 mEq/kg diets achieved a greater ADG (P < 0.04), BW (P < 0.04), and apparent total-tract digestibility of CP and Zn (P < 0.05) than did piglets fed the 269 mEq/kg diet. The 16 mEq/kg level also reduced blood total CO (P < 0.01), bicarbonate (P < 0.01), and base excess (P < 0.02) concentrations compared with the rest of the dietary treatments. Three diets differing in dEB were designed for Exp. 2 and 3: -16, 151, and 388 mEq/kg diets. In Exp. 2, greater ADFI (P = 0.03), BW (P = 0.02), ADG (P < 0.001), and G:F (P < 0.01) were observed for piglets fed the -16 mEq/kg diet than those fed the 388 mEq/kg diet. Subsequently, their short-term preference for these diets was assessed by using a 2-d choice-test protocol (30 min). Piglets preferred (P < 0.001) the 388 mEq/kg diet to the -16 mEq/kg diet, independently of the dietary treatment they received before. Pigs also preferred (P < 0.001) the 151 mEq/kg diet when compared with the -16 mEq/kg diet. Experiment 3 assessed the long-term preference and short-term consumption of the -16 and 388 mEq/kg diets. Similar to Exp. 2, animals showed a greater (P < 0.001) intake of the 388 mEq/kg diet than they did of the -16 mEq/kg diet during both the preference (14 d) and 1-feeder (2 h) tests conducted. Results show that low rather than high dEB levels optimize growth performance of piglets. When they have the opportunity to choose, piglets are unable to select the diet that optimizes their performance, either in short- or in long-term preference tests, showing also a greater short-term consumption of high instead of low dEB levels.

Diagnóstico prenatal y evolución en fetos con agenesia de ductus venoso / Prenatal diagnosis and evolution in fetuses with ductus venosus agenesis

Antecedentes: El ductus venoso es una derivación vascular (shunt) presente en el feto que permite el paso de sangre oxigenada de la vena umbilical (VU) hacia la circulación coronaria y cerebral. Su agenesia se asocia con defectos cromosómicos, síndromes genéticos, defectos estructurales y complicaciones prenatales como crecimiento intrauterino retardado y muerte fetal. Resultados: Se analizaron 15 agenesias de ductus venoso (ADV) en gestaciones únicas entre enero de 2010 y diciembre de 2013. El 80 por ciento de ellas fueron diagnosticadas en la exploración rutinaria de la semana 12. Se realizó estudio de cariotipo en el 53 por ciento de los casos (8/15), bien por riesgo alto de cromosomopatía en el cribado combinado y/o translucencia nucal aumentada (75 por ciento) o malformaciones asociadas (25 por ciento). Sólo hubo un diagnóstico de trisomía 21 y postnatalmente de una microdelección del cromosoma 7. Realizaron interrupción legal del embarazo un total de 4 pacientes (por trisomía 21 o por alteraciones estructurales). Entre las 11 gestaciones restantes un 27 por ciento se diagnosticó RCIU, hubo una muerte neonatal a las 12 horas de vida por síndrome de aspiración meconial e hipertensión pulmonar. En un 60 por ciento se objetivó la presencia de un drenaje umbilicohepático y entre los 6 restantes con shunt portosistémico, 4 tenían conexión entre la VU y la VCI. Conclusión: La ADV es una anomalía infrecuente del sistema venoso fetal, de difícil diagnóstico y con mal pronóstico en aquellos casos en que se asocia con otros marcadores y/o anomalías estructurales que pueden aparecer tardíamente, por lo que debe realizarse un seguimiento adecuado.

Background: The ductus venosus (DV) is a unique shunt that allows direct passage of oxygenated blood from the umbilical vein (UV) to the coronary and cerebral circulation by a preferential passage through the foramen ovale. DV agenesis (DVA) is associated with chromosomal abnormalities, genetic syndromes, structural defects and prenatal complications such as intrauterine growth retardation (IUGR) or even stillbirth. Results: We report 15 cases of DVA in singleton pregnancies between January 2010 and December 2013. 80 percent of them were diagnosed on routine examination during the 11-14 weeks scan. Karyotyping was performed in 53 percent of cases (8/15) by high risk of chromosomal abnormalities in the first trimester combined screening and/or an increased nuchal translucency thickness in 6/8 (75 percent), or associated malformations 2/8 (25 percent). There was only one fetus diagnosed of trisomy 21 by amniocentesis and another fetus was postnatally diagnosed of a microdeletion of chromosome 7. 4 patients performed legal abortions (the trisomy 21 and in 3 cases for severe structural malformations). Among the remaining 11 pregnancies, 3 (27 percent) were diagnosed with IUGR and there was a neonatal death at 12 hours of life for meconium aspiration syndrome and pulmonary hypertension. 60 percent of the fetus presented an intrahepatic drainage and among the remaining 6 with portosystemic shunt, in 4 a connection between the UV and the inferior vena cava was observed. Conclusion: DVA is a rare anomaly of the fetal venous system, difficult diagnosis and poor prognosis in cases associated with other markers and/or structural abnormalities that may even appear late. A detailed survey of fetal anatomy and follow up of these fetuses is necessary.

Dietary energy density affects the preference for protein or carbohydrate solutions and piglet performance after weaning.

Physiological state or dietary nutrient content can be determinants of the sensory perception with consequences for feed preferences. The aim of the present study was to assess whether the preference for protein or carbohydrate of piglets is affected by dietary energy density. In total, 240 weanling piglets (28 d old; initial BW 7.2 ± 1.1 kg) were allocated to 24 pens (10 pigs/pen) according to BW. Piglets were split up into 2 groups and had ad libitum access to a high energy (HE; 3.90 Mcal DE/kg; crude fat 129 g/kg) or a low energy (LE; 3.35 Mcal DE/kg; crude fat 60 g/kg) diet with similar CP content (190 g/kg). Piglet performance and preference for protein [porcine digestible peptides (PDP; Palbio 62SP, Bioibérica, Palafolls, Spain) 20 g/L] or carbohydrate (sucrose 20 g/L) solutions were measured on days 14 and 21 after weaning using a double-choice test (DCHT). The LE diet promoted a higher (P < 0.05) ADFI and ADG than the HE diet. Final BW on day 21 was higher (P < 0.001) for piglets fed the LE diet than piglets fed the HE diet (12.8 vs. 11.5 kg). Preference (P > 0.05) was not observed for protein or carbohydrate solutions on day 14 or 21 in piglets fed the LE diet. On the other hand, piglets fed the HE diet had higher (75% on day 14 and 65% on day 21; P < 0.01) preference for the sucrose solution. Dietary energy level and consequent nutrient imbalances, such as dietary protein-to-energy ratio, may affect feed preference for protein or carbohydrate solutions in piglets.

Flavor preferences conditioned by postingestive effect of sucrose and porcine digestive peptides in postweaning pigs.

Pigs can learn to prefer a flavor if it has been previously associated to positive consequences. The aim of this experiment was to study flavor preferences conditioned by the postingestive effect of nutrients in pigs. In total, 240 weanling piglets were allocated in 24 pens (10 piglets/pen) and distributed to 2 groups of animals (12 pens per group). Pigs in Group 1 (G1) were trained during 8 d with one flavor [positive conditioned stimulus (CS+)] into a protein solution [4% porcine digestible peptides (PDP)] on odd days and another flavor [negative conditioned stimulus (CS-)] into 100 mM of monosodium glutamate (MSG) solution on even days (5-L bottle for 24 h). In the second group of pigs [Group 2 (G2)], CS+ was mixed into a 4% sucrose solution in odd days and CS- into 1% sucrose + 0.08% saccharine on even days. Therefore, treatments were defined as CS+, the flavor associated with PDP or sucrose, on odd days, which were assumed to have a higher postingestive effect than MSG or saccharine + sucrose, the ingredients associated to CS-. Concentration of ingredients in the solutions were chosen to ensure that hedonic attraction for PDP and MSG solutions and for sucrose and saccharine + sucrose were similar (checked in previous double-choice studies). The amount of solution offered during training period was prepared to be totally consumed each day to equalize flavors intake. Flavors (0.0375% anise or garlic) were counterbalanced across replicates to act as CS+ or CS-. Double-choice test between flavors dissolved in water (CS+ and CS-) were performed by selecting 2 pigs/pen on days 1, 6, and 8 after the training period. Solution intake was measured after 30 min. Piglets showed higher intakes for CS+ than CS- in G2 [212 vs. 76 mL and 168 vs. 86 mL (P < 0.05) and 195 vs. 78 mL (P = 0.15)] on days 1, 6, and 8, respectively. Differences between CS+ and CS- consumption were observed in G1 on day 8 (231 vs. 130 mL; P < 0.05). In conclusion, weanling pigs can acquire flavor preferences through associative learning between a flavor and postingestive effects of some nutrients.

Delirium en una anciana / Elderly woman delirium

Presentamos el caso de una anciana con unepisodio grave de delirium a propósito de unaimportante infección urinaria.La clínica del proceso y la sintomatología abigarradanos indican la importancia de la valoraciónintegral en el mayor, especialmente cuandola semiología de la enfermedad es típicamentegeriátrica.Describimos el cuadro sindrómico, la actuacióny el diagnostico precoz para resolver la patología

We present the case of an elder sick personwith a serious episode of delirium concerning animportant urinary infectionThe clinic of the process and the motley symptomatologyindicate us the importance of the integralvaluation in the adult, especially when thesemiology of the illness is typically geriatricWe describe the sindromic square, the performanceand the precocious diagnosis to solve thepathology

Differential effect of nitric oxide on glutathione metabolism and mitochondrial function in astrocytes and neurones: implications for neuroprotection/neurodegeneration?

Primary culture rat astrocytes exposed to the long acting nitric oxide donor (Z)-1-[2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO) for 24 h approximately double their concentration of glutathione (GSH) and show no sign of cell death. In contrast, GSH was depleted by 48%, and significant loss of mitochondrial respiratory chain complex activity and cell death were observed in primary culture rat neurones subjected to DETA-NO for 18 h. Northern blot analysis suggested that mRNA amounts of both subunits of glutamate-cysteine ligase (GCL), the rate-limiting enzyme in GSH synthesis, were elevated in astrocytes following nitric oxide (NO) exposure. This correlated with an increase in astrocytic GCL activity. Neurones on the other hand did not exhibit increased GCL activity when exposed to NO. In addition, the rate of GSH efflux was doubled and gamma-glutamyltranspeptidase (gamma-GT) activity was increased by 42% in astrocytes treated with NO for 24 h. These results suggest that astrocytes, but not neurones, up-regulate GSH synthesis as a defence mechanism against excess NO. It is possible that the increased rate of GSH release and activity of gamma-GT in astrocytes may have important implications for neuroprotection in vivo by optimizing the supply of GSH precursors to neurones in close proximity.

The effect of short-term low-dose perchlorate on various aspects of thyroid function.

Perchlorate (ClO4) salts are found in rocket fuel, fireworks, and fertilizer. Because of ground water contamination, ClO4 has recently been detected in large public water supplies in several states in the 4-18 microg/L (parts per billion [ppb]) range. The potential adverse effect of chronic low level ClO4 ingestion on thyroid function is of concern to the Environmental Protection Agency (EPA). The daily ingestion of ClO4 at these levels would be magnitudes below the therapeutic effect level of hundreds of milligrams of ClO4 used in treating hyperthyroidism. Studies were carried out in nine healthy male volunteers who had normal thyroid function and negative thyroid antibodies to determine whether the ingestion of 10 mg of ClO4 daily (approximately 300 times the estimated maximum amount of ClO4 consumed from the affected water supplies) would affect any aspect of thyroid function. They ingested 10 mg of ClO4 dissolved in a liter of spring water during waking hours for 14 days. Baseline serum thyrotropin (TSH), free thyroxine index (FTI), total triiodothyronine (TT3), 4-, 8-, and 24-hour thyroid 123I uptakes (RAIU), serum and 24-hour urine ClO4, 24-hour urine iodine, complete blood count (CBC), and chemistry profile were determined. All blood and urine tests were repeated on days 7 and 14 of ClO4 administration and thyroid RAIU on day 14 of ClO4 administration. All tests were repeated 14 days after ClO4 was discontinued. No effect of ClO4 on serum thyroid hormone or TSH concentrations, urinary iodine excretion, CBC, or blood chemistry was observed. Urine and serum ClO4 levels were appropriately elevated during the course of ClO4 ingestion in all subjects, demonstrating compliance. By day 14 of ClO4 administration, the 4-, 8-, and 24-hour thyroid RAIU values decreased in all nine subjects by a mean value of 38% from baseline and rebounded above baseline values by 25% at 14 days after ClO4 withdrawal (p < 0.01 analysis of variance (ANOVA) and Tukey). It is well known that the major effect of ClO4 on the thyroid is a decrease in the thyroid iodide trap by competitive inhibition of the sodium iodide symporter (NIS). The present study demonstrates the sensitivity of the thyroid iodide trap to ClO4 because a low dose of 10 mg daily significantly decreased the thyroid RAIU without affecting circulating thyroid hormone or TSH concentrations. It is possible, however, that the daily consumption of low levels of ClO4 in drinking water over a prolonged period of time could adversely affect thyroid function but no evidence of hypothyroidism was observed at 10 mg of ClO4 daily in this 2-week study. It is now of interest to determine a no effect level for ClO4 on the inhibition of the thyroid RAIU and to carry out a long-term ClO4 exposure study.

Natural history and surgical outcomes for isolated discrete subaortic stenosis in children.

OBJECTIVE: To document the natural history and surgical outcomes for discrete subaortic stenosis in children. DESIGN: Retrospective review. SETTING: Tertiary care paediatric cardiology centres. PATIENTS: 92 children diagnosed between 1985 and 1998. MAIN OUTCOME MEASURES: Echocardiographic left ventricular outflow gradient (echograd), and aortic insufficiency (AI). RESULTS: The mean (SEM) age at diagnosis was 5.3 (0.4) years; the mean echograd was 30 (2) mm Hg, with AI in 22% (19/87) of patients. The echograd and incidence of AI increased to 35 (3) mm Hg and 53% (36/68) (p < 0.05) 3.6 (0.3) years later. The echograd at diagnosis predicted echograd progression and appearance of AI. 42 patients underwent surgery 2.2 (0.4) years after diagnosis. Preoperatively echograd and AI incidence increased to 58 (6) mm Hg and 76% (19/25) (p < 0.05). The echograd was 26 (4) mm Hg 3.7 (0.4) years postoperatively, with AI in 82% (31/38) of patients. Surgical morbidities included complete heart block, need for prosthetic valves, and iatrogenic ventricular septal defects. Eight patients underwent reoperation for recurrent subaortic stenosis. The age at diagnosis of 44 patients followed medically and 42 patients operated on did not differ (5.5 (0.6) v 5. 0 (0.6) years, p < 0.05). However, the echograd at diagnosis in the former was less (21 (2) v 40 (5) mm Hg, p < 0.05) and did not increase (23 (2) mm Hg) despite longer follow up (4.1 (0.4) v 2.2 (0. 4) years, p < 0.05). The incidence of AI at diagnosis and at last medical follow up was also less (14% (6/44) v 34% (13/38); 40% (17/43) v 76% (19/25), p < 0.05). CONCLUSIONS: Many children with mild subaortic stenosis exhibit little progression of obstruction or AI and need not undergo immediate surgery. Others with more severe subaortic stenosis may progress precipitously and will benefit from early resection despite risks of surgical morbidity and recurrence.

Thyroid health status of ammonium perchlorate workers: a cross-sectional occupational health study.

Since pharmaceutical exposures to perchlorate are known to suppress thyroid function in patients with hyperthyroidism, a study of employees at a perchlorate manufacturing plant was conducted to assess whether occupational exposure to perchlorate suppresses thyroid function. Exposure to perchlorate was assessed by measurement of ambient air concentrations of total and respirable perchlorate particles, and systemic absorption was assessed by measurement of urinary perchlorate excretion. Airborne exposures ranged from 0.004 to 167 mg total particulate perchlorate per day. Urinary perchlorate measurements demonstrated that exposure to the airborne particulate perchlorate resulted in systemic absorption. Workers were grouped into four exposure categories with mean absorbed perchlorate dosages of 1, 4, 11 and 34 mg perchlorate per day. Thyroid function was assessed by measurement of serum thyroid-stimulating hormone, free thyroxine index, thyroxine, triiodothyronine, thyroid hormone binding ratio, thyroid peroxidase antibodies, and by clinical examination. No differences in thyroid-function parameters were found between the four groups of workers across approximately three orders of magnitude of exposure and of dose. Thus human thyroid function was not affected by these levels of absorbed perchlorate. In addition, no clinical evidence of thyroid abnormalities was found in any exposure group. The blood-cell counts were normal in all groups, indicating no evidence of hematotoxicity in this exposure range. The absence of evidence of an effect on thyroid function or blood cells from occupational airborne perchlorate exposure at a mean absorption of 34 mg/day demonstrates a no-observed-adverse-effect-level (NOAEL) that can assist in the evaluation of human health risks from environmental perchlorate contamination.

Ammonium persulfate: a new and safe method for measuring urinary iodine by ammonium persulfate oxidation.

The chloric acid method is most commonly used to obtain accurate and reproducible measurements of iodine and removes interfering substances. Unfortunately, chloric acid is a potential hazard requiring an explosion proof hood among other precautions. We have developed a simple, convenient, and economic method for measuring urinary iodine using 1 mol/L ammonium persulfate, a non-explosive, non-hazardous chemical, as the oxidizing reagent. The oxidation procedure can be completed in 30 minutes at a temperature of 91-95 degrees C. The iodine in the urine is then measured by a modification of the traditional colorimetric method of Sandell-Kolthoff. 110 urine samples collected from a mixed population of healthy males and females, ranging in age from 6 to 79 years and living in the United States were analyzed for iodine content by two methods: the proposed ammonium persulfate method and the chloric acid method. The ammonium persulfate method has an intra assay CV of 9.1% at 0.42 +/- 0.04 micromol/L (mean +/- SD), 7.8% at 1.46 +/- 0.11 micromol/L and 4.0% at 3.54 +/- 0.14 micromol/L. The inter assay CV is 10.2% at 0.46 +/- 0.05 micromol/L and 7.9% at 3.27 +/- 0.26 micromol/L. Recovery of iodine added to urine in vitro was 107%, 94% and 97% for 0.42 micromol/L, 0.77 micromol/L and 3.64 micromol/L, respectively. The lower limit of detectability was 0.0034 microgI. Values for iodine in 110 urines measured by the reference chloric acid method ranged from 0.06 to 8.03 micromol/L and by the ammonium persulfate method from 0.05 to 7.4 micromol/L. The persulfate method (y) correlated extremely closely with the reference chloric acid method (x) by the Pearson correlation (y = 0.923x + 0.810 micromol/L, and r = 0.994, Syx = 1.841). In conclusion a new, safe, simple method for measuring urinary iodine is described which uses ammonium persulfate as the oxidizing agent for the removal of interfering substances.