Validation of a robust LLE-GC-MS method for determination of trihalomethanes in environmental samples.

An analytical liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS) method was developed and validated for the determination of trihalomethanes (THMs) in environmental samples. The compounds studied were trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and tribromomethane (TBM). The calibration curves for the THMs showed high linearity in the range of 1-1000 µg L-1. Studies of intra-day and inter-day precision, limit of detection (LOD), limit of quantification (LOQ), accuracy, and recovery were performed with low (10 µg L-1), medium (40 µg L-1), and high (200 µg L-1) concentrations of THMs. The intra-day and inter-day precision RSD varied in the ranges of 0.17-6.95% and 0.26-15.70%, respectively. No statistical differences were observed between the analysis of the concentration of certified reference materials (CRM 4M8140-U) and the values reported by CRM, indicating the good accuracy of the proposed method. The recovery was 88.75-119.21%. The LOD and LOQ were smaller than 0.13 and 0.40 µg L-1. Compared with reported LLE-GC-MS methods, the validated method had similar LOD and enhanced LOQ, precision, accuracy, and recovery. Also, the method is robust, selective to THMs, and the total time for the extraction and GC separation of THMs is about 18 min. The method was useful for detecting and quantifying low concentrations of TCM (40-80 µg L-1) formed by water chlorination in the presence of Microcystis aeruginosa cyanobacteria, thus demonstrating its applicability for monitoring THMs in real samples.

Análise da produção científica sobre atletismo no Brasil: uma revisão sistemática / Scientific production of track and field in Brazil: a systematic review

O objetivo deste estudo foi analisar a produção científica brasileira sobre o Atletismo entre 1999 e 2013. Foram identificados 162 artigos, e selecionados 55 estudos que abordaram o Atletismo como temática principal do estudo. Destes, 43 artigos (78,2%) foram relacionados com a Biodinâmica do Movimento Humano e 12 (21,8%) com a Pedagogia do Movimento. Analisando os estudos selecionados (caraterização a posteriori das análises), 30,9% (17) correspondiam à pesquisas na área de fisiologia do exercício, 20% (11) a lesões no esporte, 10% (6) sobre biomecânica, 7,3% (4) a psicologia do esporte e 7,3% (4) a nutrição esportiva. As áreas com menos pesquisas foram o treinamento esportivo, a iniciação esportiva e a história/sociologia do esporte com 5,5% (3) cada uma. A pedagogia do esporte e do dopping, ficaram com a menor proporção de estudos, sendo 3,6% (2) cada uma. Seis estudos não apresentavam uma única modalidade como foco central na investigação, outros 15 enfocaram corridas de fundo e meio undo, 8 em corridas de rua e maratonas, 7 em corridas de velocidade, 6 em atletismo paralímpico e, com menor percentual, as provas de salto horizontal, arremessos e lançamentos e o atletismo escolar que tiveram 1 estudo cada. Conclui-se que é importante considerar os critérios de avaliação dos cursos de PósGraduação adotados pela CAPES, pois no modo atual o sistema parece limitar a investigação na área da Pedagogia do Movimento. Necessita-se também qualificar a pesquisa sobre o Atletismo no Brasil e desenvolver pesquisas com melhor aporte metodológico (estudos longitudinais, de intervenção, de validação de métodos, de revisão de literatura e qualitativos) bem como melhorar a amostragem e diversificar as investigações em diferentes provas do Atletismo...(AU)

The aim of this study was to analyze the Brazilian scientific production on Athletics between 1999 and 2013. A total of 162 articles were identified, and 55 studies were selected that approached Athletics as the main theme of the article. Of these, 43 articles (78.2%) were related to Biodynamics of the Human Movement, and 12 (21.8%) with Pedagogy of the Human Movement. Analyzing the studies, 30.9% (17) corresponded to research in the physiology of the exercise, 20% (11) corresponded to studies on sports injuries, 10% (6) on sports biomechanics, 7.3% ( 4) sports psychology and 7.3% (4) sports nutrition. The areas with the least research were sports training, sports initiation and sport history / sociology, with 5.5% (3) in each one, and the lowest proportion of studies occurred in the area of sports pedagogy and doping, with 3.6% (2) of the studies found in the literature review. Six studies did not present a single modality as a central focus in the investigation, another fifteen focused in middle and long-distance events, eight road running and marathon, seven sprints, six studies focused on Brazilian Paralympic athletes, and with a lower percentage jumping and throwing events and school athletics with one study each. It is concluded that it is important to consider the evaluation criteria of the courses and thus, the entry of teachers into the country's postgraduate programs, as this seems to limit research in the area of Pedagogy of Human Movement. It is also necessary to qualify the research on Athletics in Brazil, to develop researches with better methodological aproach, that is, longitudinal studies, intervention studies, validation studies of methods, studies of literature review and qualitative studies, to improve the sample in the studies and diversify the research evidence...(AU)

Disrupted seasonal biology impacts health, food security and ecosystems.

The rhythm of life on earth is shaped by seasonal changes in the environment. Plants and animals show profound annual cycles in physiology, health, morphology, behaviour and demography in response to environmental cues. Seasonal biology impacts ecosystems and agriculture, with consequences for humans and biodiversity. Human populations show robust annual rhythms in health and well-being, and the birth month can have lasting effects that persist throughout life. This review emphasizes the need for a better understanding of seasonal biology against the backdrop of its rapidly progressing disruption through climate change, human lifestyles and other anthropogenic impact. Climate change is modifying annual rhythms to which numerous organisms have adapted, with potential consequences for industries relating to health, ecosystems and food security. Disconcertingly, human lifestyles under artificial conditions of eternal summer provide the most extreme example for disconnect from natural seasons, making humans vulnerable to increased morbidity and mortality. In this review, we introduce scenarios of seasonal disruption, highlight key aspects of seasonal biology and summarize from biomedical, anthropological, veterinary, agricultural and environmental perspectives the recent evidence for seasonal desynchronization between environmental factors and internal rhythms. Because annual rhythms are pervasive across biological systems, they provide a common framework for trans-disciplinary research.

Islet versus pancreas transplantation in Brazil: Defining criteria for pancreas allocation decision.

BACKGROUND: Many studies have evaluated whether there are characteristics related to pancreas donors and the islet isolation process that can influence pancreatic islet yield. However, this analysis has not yet been performed in Brazil, one of the world leaders in whole pancreas organ transplantation (WOPT), where pancreas allocation for pancreatic islet transplantation (PIT) has no officially defined criteria. Definition of parameters that would predict the outcome of islet isolation from local pancreas donors would be useful for defining allocation priority in Brazil. OBJECTIVE: To analyze the relationship between multiple donor-related and islet isolation variables with the total number of isolated pancreatic islet equivalents (IEQ) in a brazilian sample of pancreas donors. METHODS: Several variables were analyzed in 74 pancreata relative to the outcome of total IEQs obtained at the end of the process. RESULTS: In univariate analysis, body mass index (BMI) (p = 0.003), the presence of fatty infiltrates in the pancreas as observed during harvesting (p = 0.042) and pancreas digestion time (p = 0.046) were identified as variables related to a greater IEQ yield. In a multivariate analysis a statistically significant contribution to the variability of islet yield was found only for the BMI (p = 0.017). A ROC curve defined a BMI = 30 as a cut-off point, with pancreata from donors with BMI > 30 yielding more islets than donors with BMI < 30 (p< 0.001). CONCLUSION: These data reinforce the importance of the donor BMI as a defining parameter for successful islet isolation and establishes this variable as a potential pancreas allocation criterion in Brazil, where there is unequal competition for good quality organs between WOPT and PIT.

Polycystic ovary syndrome: a transgenerational evolutionary adaptation.

Polycystic ovary syndrome has a common association with anovulatory infertility, while the physical symptoms are often associated with the increased androgens that are part of the endocrine profile. There is a well-recognised association with lipid and glucose metabolism anomalies and, when undergoing ovulation induction, ovarian hyperstimulation syndrome. This common condition is familial, but a contributory gene has yet to be found. The question of why a gene that predisposes to anovulation, diabetes and heart disease might have perpetuated so frequently is addressed. Three hypotheses for evolutionary advantage are discussed. The food deprivation hypothesis considers the role of the observed increase in ovulation when women with the condition lose weight in relation to seasonality. The refeeding hypothesis considers the androgenic and slightly enhanced anabolic metabolism in relation to periods of privation and the advantage of preferential early ovulation when refeeding after a period of privation. The transgenerational privation hypothesis considers the effect of persistent, severe, yet subfatal privation on individuals both in utero and throughout life. While an androgenic, anabolic state would improve efficiency in the use of food for protein synthesis and fat storage, benefiting the fetus both in relation to its in utero development and neonatal survival, survival and reproductive capacity as an adult benefits by a genotype expressing itself in women of successive generations.

Preliminary observations on the association between simple metopic ridging in children without trigonocephaly and the Chiari I malformation.

Historically, there have been no accounts of an association between simple metopic ridging and the Chiari I malformation. We prospectively evaluated 50 children with simple metopic ridges and found that 30% of these patients had a Chiari I malformation. During the period in which this screening for simple metopic ridges was performed, only 9% of the total patient population (324) was diagnosed as having a Chiari I malformation. We hypothesize that small decreases in anterior fossa volume in children with a simple metopic ridge and no other clinical findings of trigonocephaly may increase their chance of having a Chiari I malformation that becomes symptomatic. In addition, simple metopic ridging should perhaps be added to the list of bony anomalies associated with the Chiari I malformation, such as atlantal assimilation and retroverted odontoid processes. Future studies aimed at calculating anterior fossa volumes in children with a Chiari I malformation and imaging all children with simple metopic ridges are now necessary to ascertain if there is an increased risk of these patients becoming symptomatic with a hindbrain hernia or having a hindbrain hernia, respectively.

Histological appearance of a chronically stimulated vagus nerve in a pediatric patient.

Histological analysis of chronically stimulated human vagus nerves is lacking in the literature. In this study, we describe the first microscopic findings in a chronically stimulated left vagus nerve from a pediatric patient. Our results show many histological changes in and around the stimulated nerve with severe demyelination. Further long-term clinical and postmortem examinations of chronically stimulated vagus nerves in both children and adults are needed to ascertain whether prolonged exposure to electrical current can cause clinical dysfunction of this nerve.

Comparative context of Plio-Pleistocene hominin brain evolution.

One of the distinguishing features of Homo sapiens is its absolutely and relatively large brain. This feature is also seen in less extreme form in some fossil Homo species. However, are increases in brain size during the Plio-Pleistocene only seen in Homo, and is brain enlargement among Plio-Pleistocene primates confined to hominins? This study examines evidence for changes in brain size for species and lineage samples of three synchronic East African fossil primate groups, the two hominin genera Homo and Paranthropus, and the cercopithecoid genus Theropithecus. Hominin endocranial capacity data were taken from the literature, but it was necessary to develop an indirect method for estimating the endocranial volume of Theropithecus. Bivariate and multivariate regression equations relating measured endocranial volume to three external cranial dimensions were developed from a large (ca. 340) sample of modern African cercopithecoids. These equations were used to estimate the endocranial volumes of 20 Theropithecus specimens from the African Plio-Pleistocene. Spearman's rho and the Hubert nonparametric test were used to search for evidence of temporal trends in both the hominin and Theropithecus data. Endocranial volume apparently increased over time in both Homo and Paranthropus boisei, but there was no evidence for temporal trends in the endocranial volume of Theropithecus. Thus, hypotheses which suggest a mix of environmental, social, dietary, or other factors as catalysts for increasing brain in Plio-Pleistocene primates must accommodate evidence of brain enlargement in both Homo and Paranthropus, and explain why this phenomenon appears to be restricted to hominins.

Sagittal suture as an external landmark for the superior sagittal sinus.

OBJECT: Historically, the sagittal suture has been used as an external landmark to indicate the middle portion of the superior sagittal sinus (SSS). The goal of this study was to verify this relationship. METHODS: The authors examined 30 adult cadavers to reveal the location of the SSS with respect to the sagittal suture. Their findings demonstrated that the SSS is deviated to the right of the sagittal suture in the majority of observed specimens, although the maximum displacement to the right side was never more than 11 mm. CONCLUSIONS: This information should be useful to the neurosurgeon who must be aware of the SSS and its relationship with superficial skull landmarks.

Analysis of the posterior fossa in children with the Chiari 0 malformation.

OBJECTIVE: We previously reported the resolution of syringohydromyelia without cerebellar tonsillar ectopia in five patients after posterior fossa decompression of the so-called Chiari 0 malformation. A sixth patient is described. In this study, the anatomy of the posterior fossa is analyzed using radiological imaging, enabling features of the posterior fossa in this uncommon subgroup of children to be characterized. METHODS: Multiple measurements were made on magnetic resonance imaging studies in six children with Chiari 0 malformation to determine the position of the brainstem relative to the foramen magnum. Fifty children with normal magnetic resonance imaging studies of the brain were used as controls. RESULTS: All children with a Chiari 0 malformation were found to have the following positive results: obices that were located more than 2 standard deviations below normal, an increase in the anteroposterior midsagittal distance of the spinomedullary junction at the level of the foramen magnum, an increase in the angle between the floor of the fourth ventricle and clivus, and an increase in the anteroposterior midsagittal distance of the foramen magnum. CONCLUSION: The findings of this study suggest that the contents of the posterior fossa are indeed compromised and/or distorted in patients with syringohydromyelia but no tonsillar ectopia. In this group, the brainstem was caudally displaced more than 3 standard deviations below normal.

Surgical landmarks for the proximal portion of the axillary nerve.

OBJECT: The proximal segment of the axillary nerve (ANp) is often difficult to identify without extensive dissection deep into the axilla. The present study was performed to find reliable surgical landmarks for this nerve. METHODS: Thirty dissections of human cadavers were performed to determine the relationships between the ANp and specific anatomical structures. The authors found that the ANp is consistently located within an anatomical triangle constructed by lines passing between the coracobrachialis and pectoralis minor muscles and the axillary artery. In addition, the ANp was routinely found 4 cm distal to the coracoid process of the scapula. CONCLUSIONS: These findings should assist the surgeon in locating the ANp during brachial plexus reconstruction.

Spinal lipomas.

Lipomas of the spinal cord are among the most fascinating lesions encountered by the pediatric neurosurgeon. An understanding of spinal lipomas may, however, be difficult because the terminology used to describe the accumulations of spinal fat is confusing, inconsistently applied, and at times contradictory. An anatomical characterization of lipomas may assist in understanding these lesions. Lipomas of the spinal cord are very rare and cause symptoms related to mass effect and secondary compressive myelopathy. Lipomas of the conus medullaris (or lipomyelomeningocele) are the most common form of fatty masses in the spine and can be divided into dorsal, caudal, and transitional forms. These lesions are a manifestation of occult spinal dysraphism and a common cause of the tethered cord syndrome (TCS). The natural history of untreated lipomyelomeningocele, although incompletely understood, appears to be progressive neurological deterioration with loss of bladder control. Timely, careful surgical intervention may prevent significant neurological deterioration and progressive disability in the majority of children harboring these lesions. In surgical intervention the surgeon seeks to disrupt the connection between the fibrofatty mass and underlying cord as well as to reestablish normal anatomical planes. Several intraoperative video segments illustrating lipomyelomeningocele resection are included in this paper. Lipomas of the terminal filum (fatty filum) are truly occult and are also associated with TCS. Surgical treatment of filum lipomas carries significantly lower risk than that for lipomas of the conus medullaris. Again, the goal of surgery is to disrupt the connection between the abnormal fibrofatty tissue and the underlying spinal cord.

Dermal sinus tracts of the spine.

Dermal sinus tracts in the spine range from asymptomatic pits to tracts with significant disease. These tracts may be associated with lesions that tether the spinal cord and can either become infected or produce neurological deficits. Over time the treatment of these lesions has varied little: complete resection and intradural exploration are the standard surgical interventions. The authors review their experience with 23 dermal sinus tracts treated in the last 19 years by the senior author. The clinical findings, radiographic appearance, treatment, and pathological findings of these lesions will be discussed. The authors will also provide a summary of the literature covering these lesions.

The position of the conus medullaris in children with a Chiari I malformation.

The purpose of this study is to determine whether there is a relationship between the conus level and patients with a Chiari I malformation. This retrospective MRI study evaluated conus levels and degrees of tonsillar ectopia in 26 children ages 5-16 years with a Chiari I malformation. Our results show that there seems to be no relationship between the conus level and the amount of tonsillar ectopia that a child with a Chiari I malformation might have. In fact, there seemed to be an inverse relationship between these two entities. Interestingly, we have also found that of all coni located at the L2-L3 disc space or below, these patients had a syrinx associated with their Chiari I malformation and that all malformations without a syrinx had a 'normally' positioned conus medullaris.

Pediatric atlantoaxial instability: management with screw fixation.

Sixteen pediatric patients (age range 3-15 years; mean 9.4 years) with atlantoaxial instability underwent screw fixation at Columbus Children's Hospital between 1992 and 1998. Three patients with type II odontoid fractures underwent odontoid screw fixation. The remaining group of 13 patients had posterior C1-2 transarticular screw fixation and Sonntag C1-2 fusion. The group included 3 patients with rotatory C1-2 fixation, 4 patients with os odontoideum, 4 patients with congenital atlantoaxial instability and 2 patients with traumatic C1-2 instability. Postoperatively, all patients were placed in a Miami-J collar only. At 3 months follow-up, all patients achieved fusion. Bony fusion across the fracture line was clearly evident in patients with odontoid screws. The only complications in this series were a transient swallowing difficulty that resolved spontaneously in 2 weeks, and another patient's C1-2 fusion had extended to C2-3 at 9 months follow-up. This study demonstrates that children at 3 years of age and older, who sustain a type II odontoid fracture with an intact transverse ligament, can be safely managed with odontoid screws if the fracture is less than 4 weeks old. Posterior C1-2 transarticular screw fixation can be done safely and results in a high fusion rate in children older than 4 years of age. The technical difficulties of screw fixation in children are discussed.

Habitual energy expenditure of human climbing and clambering.

Despite many studies on the energetics of terrestrial, aquatic and aerial locomotion, little work has been done on the costs of arboreal locomotion. There is increasing interest in modelling the bioenergetics of extinct mammalian species, including hominids, but as early hominids are thought to have combined terrestrial bipedalism with arboreal climbing and clambering, absence of data on the energetics of climbing in higher primates limits work on hominid locomotor energetics. In this study, the energetics of climbing and clambering in humans has been investigated to assess the differences in energetic cost between terrestrial bipedal walking and vertical climbing and clambering. Energy expenditure during climbing and clambering, walking and standing was measured in 29 active, non-obese young adults. Anthropometric data were also collected. Analysis using paired t-tests showed that there is a highly significant difference (p < 0.001) between mean walking and mean climbing and clambering expenditure, 24 +/- 7 versus 48 +/- 18 kJ/min respectively. Body mass, percentage body fat and fat-free mass were all positively correlated with energy expenditure. It was concluded that any energetic advantages that accrue from terrestrial bipedal locomotion may be offset by the great cost of arboreal activity, implying that the conditions under which bipedalism may have evolved were contingent upon the time allocation associated with arboreal and terrestrial locomotion.

The pupillary light response: assessment of function mediated by intracranial retinal transplants.

We have adapted a pupillometry measurement system to test the functional efficacy of retinae previously transplanted over the midbrain of neonatal rats in mediating a pupillary light reflex in the host eye. This has permitted us to examine factors influencing various parameters of the response, and to study transplant-mediated responses in comparison with responses mediated by way of the normal consensual pathway. Despite the unusual location of these transplanted retinae and the absence of supportive tissues normally associated with retinae in situ, it is clear that pupilloconstriction in the host eye can be elicited by transplant illumination. Under the optimal conditions here defined, response parameters for individual animals were stable with repeated testing over extended periods. When considered as individual cases, response amplitude, constriction rate and response latency were intensity dependent, although responses elicited by transplant illumination were less sensitive than normal, typically by 2-3 log units. Large-amplitude transplant-mediated pupillary responses could, however, be elicited repeatedly throughout long trains of stimuli, unlike normal responses, which rapidly failed to recover to baseline under similar test conditions. Finally, even though some cellular elements of the visual cycle are absent in transplanted retinae, pupilloconstriction in the host eye could be elicited repeatedly by transplant illumination as long as two years after transplantation took place. These observations indicate the applicability of this preparation as an assay for the effects of experimental manipulations on information processing and response plasticity in the visual system, and as a tool for examining, in general, the necessary conditions for optimal function of grafts that work by synthesizing and relaying neural signals.

The EMS pilot's role in field emergencies.

The role of the EMS pilot in field emergencies will vary from service to service. Generally, his overall responsibilities are to ensure that a safe environment exists at accident scenes, provide thorough orientation presentations, monitor on-site activity, and expect the unexpected.