Characterization of the phone-calls made to a poison center related to household and cosmetics products exposition in pediatrics. / Caracterización de las consultas realizadas a un Centro de Información Toxicológica por productos de aseo y productos cosméticos en niños.

INTRODUCTION: Household cleaning products and cosmetics are necessary for daily life and widely used by the population. However, their use may not be risk-free, especially when they are not used or stored as recommended. It is important to characterize exposures, as this is useful for developing stra tegies to reduce morbidity, mortality, and health costs associated, especially in the child population. OBJECTIVE: To describe reports associated with household cleaning products and cosmetics exposure in patients under the age of 12, reported to the Poison Information Center of the Catholic University of Chile (CITUC). PATIENTS AND METHOD: Descriptive cross-sectional study of phone calls to CITUC during 2016. The analyzed variables were age, sex, product, caller, caller and incident location, ex posure circumstances, exposure route(s), symptoms, and severity from manual records and from the WHO's electronic record software 'INTOX Data Management System'. RESULTS: 3,415 cases met the inclusion criteria. Children under the age of five represented 91% of the exposures, and 58.5% were male. 99.4% were accidental exposures, and 98.6% occurred at home. Family members (57%) and health personnel (42%) made the calls. 68.3% of the patients had no symptoms after exposure. The four products with the highest incidence were household bleach (27.6%), floor cleaners and polishers (13.1%), dish soap (7.9%), and perfume/cologne (5.8%). The main exposure route was by ingestion (89.4%). CONCLUSIONS: Household cleaning products and cosmetics are common causes of exposures especially in children under the age of five. Although these products have a low morbidity and mortality rate, it is important to educate the population to prevent possible poisonings in the child population.

Determination of the temperature causing a nociceptive response in the tail of albino BALB/c mice.

INTRODUCTION: Designs for determining nociceptive response in rodents are of great use in neurology and experimental neuroscience. Immersing mice's tails in warm water is one of the most widely used procedures to evaluate this response; however, a wide range of temperatures are used in different studies. Knowing the temperature that produces a powerful nociceptive response in the tail of BALB/c mice is extremely useful. METHODS: Eight 2-month-old male BALB/c mice were used. A 14-cm high beaker was filled with water up to 13cm. The animals' tails were immersed in the container with a starting temperature of 36°C. The water temperature was raised in 1°C increments until we identified the temperatures that produced nociceptive responses. That response was determined by counting the time taken before the mouse shook its tail to remove it from the water. RESULTS: Six of the 8 mice began shaking their tails at the temperature of 51°C. All animals removed their tails from the water at the temperatures of 54°C, 55°C, and 56°C, taking a mean time of 8.54, 7.99, and 5.33seconds, respectively. ANOVA applied to the response times for each of the 3 temperatures indicated revealed a value of F=2.8 (P=.123). CONCLUSIONS: The response time was statistically similar for the temperatures of 54°C, 55°C, and 56°C; however, the data were less dispersed for the latter temperature.

Aquatic toxicity assessment of the additive 6-methylcoumarine using four experimental systems.

The toxicity assessment of chemicals is one of the main issues in the current policies in order to protect the health of the environment and human beings. Food and cosmetic additives have been extensively studied in relation to their toxicity to humans, but data about their ecotoxicological effects are scarce. The aim of this study was to evaluate the toxic effects of the additive 6-methylcoumarine in the aquatic milieu using a test battery comprising experimental model systems from different trophic levels. The inhibition of bioluminiscence was studied in the bacteria Vibrio fischeri (decomposer), the inhibition of growth was evaluated in the alga Chlorella vulgaris (producer) and immobilization was studied in the cladoceran Daphnia magna (first consumer). Finally, several end points were evaluated in the RTG-2 salmonid fish cell line, including neutral red uptake, protein content, methylthiazol tetrazolium salt metabolization, glucose-6-phosphate dehydrogenase activity, lactate dehydrogenase activity and leakage, and morphology. The sensitivity of the test systems employed was as follows: V. fischeri > D. magna > C. vulgaris > RTG-2 cell line. The results show that 6-methylcoumarine is not expected to produce acute toxic effects on the aquatic biota. However, chronic and synergistic effects with other chemicals cannot be excluded and should be further investigated.

Axon-glia interactions and the domain organization of myelinated axons requires neurexin IV/Caspr/Paranodin.

Myelinated fibers are organized into distinct domains that are necessary for saltatory conduction. These domains include the nodes of Ranvier and the flanking paranodal regions where glial cells closely appose and form specialized septate-like junctions with axons. These junctions contain a Drosophila Neurexin IV-related protein, Caspr/Paranodin (NCP1). Mice that lack NCP1 exhibit tremor, ataxia, and significant motor paresis. In the absence of NCP1, normal paranodal junctions fail to form, and the organization of the paranodal loops is disrupted. Contactin is undetectable in the paranodes, and K(+) channels are displaced from the juxtaparanodal into the paranodal domains. Loss of NCP1 also results in a severe decrease in peripheral nerve conduction velocity. These results show a critical role for NCP1 in the delineation of specific axonal domains and the axon-glia interactions required for normal saltatory conduction.

Non-tumoural parenchyma in Leydig cell tumours: pathogenetic considerations.

Little is known about the pathogenesis of Leydig cell tumours (LCTs) of the testis. The observation of several associated dysgenetic features in the non-tumoural parenchyma and in the contralateral testes of men with testicular germ cell neoplasms has served as the basis to propose that there may be a common mechanism for different male reproductive disorders. However, the possible relationship between LCTs and other testicular lesions has not been explored. Here we describe the presence of primary lesions in the non-tumoural parenchyma of testes with LCT, from which we try to establish possible pathogenetic associations. We studied the non-tumoural parenchyma adjacent to 16 LCT specimens. Parameters as Leydig cell hyperplasia (LCHY), qualitative evaluation of the germinal epithelium and spermatogenesis, the presence of Sertoli cell-only tubules (SCOT), and the Sertoli cell nuclear morphology were consistently assessed in all cases. SCOT associated with Sertoli cell dysgenetic morphology was the most frequent finding, present in 50% of the cases. Another interesting finding was the presence of LCHY in four cases (25%). Abnormal spermatogenesis was found in 81.25% of the cases, and it consisted of lesions of the adluminal or basal compartments of seminiferous tubules. The occurrence of either dysgenetic Sertoli cells or LCHY adjacent to LCTs could represent primary anomalies, resulting from a common insult also involved in tumourigenesis. The abnormalities in spermatogenesis observed here are likely to represent consequences of either tumour compression or abnormal hormonal production. The significance of these associations merits further investigation regarding a common pathogenesis.

Determination of the temperature causing a nociceptive response in the tail of albino BALB/c mice. / Determinación de la temperatura de respuesta nociceptiva sobre la cola de ratones albinos de la cepa Balb/c.

INTRODUCTION: Designs for determining nociceptive response in rodents are of great use in neurology and experimental neuroscience. Immersing mice's tails in warm water is one of the most widely used procedures to evaluate this response; however, a wide range of temperatures are used in different studies. Knowing the temperature that produces a powerful nociceptive response in the tail of BALB/c mice is extremely useful. METHODS: Eight 2-month-old male BALB/c mice were used. A 14-cm high beaker was filled with water up to 13 cm. The animals' tails were immersed in the container with a starting temperature of 36°C. The water temperature was raised in 1°C increments until we identified the temperatures that produced nociceptive responses. That response was determined by counting the time taken before the mouse shook its tail to remove it from the water. RESULTS: Six of the 8 mice began shaking their tails at the temperature of 51°C. All animals removed their tails from the water at the temperatures of 54°C, 55°C, and 56°C, taking a mean time of 8.54, 7.99, and 5.33seconds, respectively. ANOVA applied to the response times for each of the 3 temperatures indicated revealed a value of F=2.8 (P=.123). CONCLUSIONS: The response time was statistically similar for the temperatures of 54°C, 55°C, and 56°C; however, the data were less dispersed for the latter temperature.

Contactin-associated protein (Caspr) and contactin form a complex that is targeted to the paranodal junctions during myelination.

Specialized paranodal junctions form between the axon and the closely apposed paranodal loops of myelinating glia. They are interposed between sodium channels at the nodes of Ranvier and potassium channels in the juxtaparanodal regions; their precise function and molecular composition have been elusive. We previously reported that Caspr (contactin-associated protein) is a major axonal constituent of these junctions (Einheber et al., 1997). We now report that contactin colocalizes and forms a cis complex with Caspr in the paranodes and juxtamesaxon. These proteins coextract and coprecipitate from neurons, myelinating cultures, and myelin preparations enriched in junctional markers; they fractionate on sucrose gradients as a high-molecular-weight complex, suggesting that other proteins may also be associated with this complex. Neurons express two contactin isoforms that differ in their extent of glycosylation: a lower-molecular-weight phosphatidylinositol phospholipase C (PI-PLC)-resistant form is associated specifically with Caspr in the paranodes, whereas a higher-molecular-weight form of contactin, not associated with Caspr, is present in central nodes of Ranvier. These results suggest that the targeting of contactin to different axonal domains may be determined, in part, via its association with Caspr. Treatment of myelinating cocultures of Schwann cells and neurons with RPTPbeta-Fc, a soluble construct containing the carbonic anhydrase domain of the receptor protein tyrosine phosphatase beta (RPTPbeta), a potential glial receptor for contactin, blocks the localization of the Caspr/contactin complex to the paranodes. These results strongly suggest that a preformed complex of Caspr and contactin is targeted to the paranodal junctions via extracellular interactions with myelinating glia.

High concentrations of pralidoxime are needed for the adequate reactivation of human erythrocyte acetylcholinesterase inhibited by dimethoate in vitro.

Due to the current controversy about the real effectiveness of the oximes in the treatment of organophosphate poisoning, the reactivation capacity of pralidoxime has been evaluated in vitro on human erythrocyte acetylcholinesterase inhibited by dimethoate. In the in vitro model, a partial recovery of acetylcholinesterase activity was observed with concentrations from 0.066 mM pralidoxime, probably useful enough to prevent death in most cases in vivo. However, much more effectiveness was observed with concentrations up to 0.70 mM pralidoxime. Although pralidoxime should be applied as soon as possible after organophosphate exposure, the application of the antagonist can be useful even 24h after, particularly for organophosphates with biological half-life longer than one day. The protective capacity of pralidoxime after the application was reduced up to 50% in 6h and disappeared almost completely in 24h. Furthermore, the pesticide and its metabolites remained active and were able to inhibit the enzyme as soon as pralidoxime reduced its antagonist capacity. Our results in conjunction with the short half-life of pralidoxime suggest that the maintenance of higher plasmatic concentrations than the currently used should be considered in the management of severe poisoned patients, although adverse effects could be expected.

Prevalence of cardiac abnormalities in human immunodeficiency virus infection.

The prevalence of cardiac abnormalities in the spectrum of human immunodeficiency virus (HIV) infection is unknown. Sixty consecutive HIV-infected patients were studied using echocardiograms, electrocardiograms (50 patients) and ambulatory electrocardiographic monitoring (43 patients). Group A (25 patients) were seropositive but pre-AIDS, whereas group B (35 patients) had AIDS and included 24 with an active opportunistic infection (group B1) and 11 without it (group B2). Abnormalities were identified in 32 of 60 patients (53%) and were more frequent in group B (23 of 35, 66%) than in group A (9 of 25, 36%, p less than 0.05) but independent of active opportunistic infection (15 of 24, 62%, in group B1 vs 8 of 11, 73%, in group B2). Echocardiographic abnormalities were identified in 21 of 60 patients (35%), including 7 of 25 (28%) in group A vs 14 of 35 (40%) in group B (difference not significant), and 7 of 24 (29%) in group B1 vs 7 of 11 (64%) in group B2 (difference not significant). Those patients with an absolute CD4 lymphocyte count less than or equal to 100/mm3 had a higher prevalence of echocardiographic abnormalities (12 of 22) than those with CD4 counts greater than 100/mm3 (1 of 14, p less than 0.01). Left ventricular dilation or hypokinesis was identified in 14 of 60 patients (23%), including 4 of 25 (16%) in group A and 10 of 35 (29%) in group B. Electrocardiographic abnormalities were seen in 22 of 50 patients (44%) including 5 of 18 (28%) in group A and 17 of 32 (53%) in group B (difference not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Optimal lead subsets for reconstruction of QRS and ST-T in 35-lead precordial maps.

Precordial maps have been used for some 15 years to estimate the extent of myocardial injury in patients with acute anterior or lateral wall infarction. Estimates have been based on various QRS- and ST-T-derived parameters, including amplitude sum of ST elevations. Application of the electrodes, commonly 35, is cumbersome and time-consuming with the critically ill. A subset of 5 or 7 selected leads can be applied instead, and the remaining leads calculated from that subset with minimal loss of QRS and ST-T information. Maps were recorded from 100 patients within 72 hours of onset of anterior or lateral infarct. Optimal lead subsets for QRS and ST-T feature extraction were found by the sequential selection method of Lux. Subsets numbering between 2 and 15 leads were derived, with their lead-transform coefficients. Measures to estimate goodness of fit for reconstructed leads included correlations, error-to-signal ratios and root-mean-square errors. These measures were calculated separately over the QRS and ST-T complexes. Reconstructions from a 7-lead subset had a mean 0.92 correlation with ST-T in the original leads and root-mean-square error of only 0.04 mV. Sum of ST elevation differed by only 2% between original leads and reconstructions based on 5 or more leads. To confirm repeatability, lead-transform coefficients were also calculated from a training population of 50 patients and applied to the maps of the other 50.