Surgical and conservative treatment of patients with congenital scoliosis: α search for long-term results

<p>Abstract</p> <p>Background</p> <p>In view of the limited data available on the conservative treatment of patients with congenital scoliosis (CS), early surgery is suggested in mild cases with formation failures. Patients with segmentation failures will not benefit from conservative treatment. The purpose of this review is to identify the mid- or long-term results of spinal fusion surgery in patients with congenital scoliosis.</p> <p>Methods</p> <p>Retrospective and prospective studies were included, reporting on the outcome of surgery in patients with congenital scoliosis. Studies concerning a small numbers of cases treated conservatively were included too. We analyzed mid-term (5 to 7 years) and long-term results (7 years or more), both as regards the maintenance of the correction of scoliosis and the safety of instrumentation, the early and late complications of surgery and their effect on quality of life.</p> <p>Results</p> <p>A small number of studies of surgically treated patients were found, contained follow-up periods of 4-6 years that in the most cases, skeletal maturity was not yet reached, and few with follow-up of 36-44 years. The results of bracing in children with congenital scoliosis, mainly in cases with failure of formation, were also studied.</p> <p>Discussion</p> <p>Spinal surgery in patients with congenital scoliosis is regarded in short as a safe procedure and should be performed. On the other hand, early and late complications are also described, concerning not only intraoperative and immediate postoperative problems, but also the safety and efficacy of the spinal instrumentation and the possibility of developing neurological disorders and the long-term effect these may have on both lung function and the quality of life of children.</p> <p>Conclusions</p> <p>Few cases indicate the long-term results of surgical techniques, in the natural progression of scoliosis. Similarly, few cases have been reported on the influence of conservative treatment.</p> <p>In conclusion, patients with segmentation failures should be treated surgically early, according to the rate of deformity formation and certainly before the pubertal growth spurt to try to avoid cor- pulmonale, even though there is lack of evidence for that in the long-term. Furthermore, in patients with formation failures, further investigation is needed to document where a conservative approach would be necessary.</p

Relatively lower body mass index is associated with an excess of severe truncal asymmetry in healthy adolescents: Do white adipose tissue, leptin, hypothalamus and sympathetic nervous system influence truncal growth asymmetry?

<p>Abstract</p> <p>Background</p> <p>In healthy adolescents normal back shape asymmetry, here termed truncal asymmetry (TA), is evaluated by higher and lower subsets of BMI. The study was initiated after research on girls with adolescent idiopathic scoliosis (AIS) showed that higher and lower BMI subsets discriminated patterns of skeletal maturation and asymmetry unexplained by existing theories of pathogenesis leading to a new interpretation which has therapeutic implications <it>(double neuro-osseous theory)</it>.</p> <p>Methods</p> <p>5953 adolescents age 11–17 years (boys 2939, girls 3014) were examined in a school screening program in two standard positions, standing forward bending (FB) and sitting FB. The sitting FB position is thought to reveal intrinsic TA free from back humps induced by any leg-length inequality. TA was measured in both positions using a Pruijs scoliometer as angle of trunk inclinations (ATIs) across the back at each of three spinal regions, thoracic, thoracolumbar and lumbar. Abnormality of ATIs was defined as being outside 2 standard deviations for each age group, gender, position and spinal region, and termed <it>severe </it>TA.</p> <p>Results</p> <p>In the sitting FB position after correcting for age,<it>relatively lower BMIs </it>are statistically associated with a greater number of severe TAs than with relatively higher BMIs in both girls (thoracolumbar region) and boys (thoracolumbar and lumbar regions).</p> <p>The relative frequency of severe TAs is significantly higher in girls than boys for each of the right thoracic (56.76%) and thoracolumbar (58.82%) regions (p = 0.006, 0.006, respectively). After correcting for age, smaller BMIs are associated with more <it>severe TAs </it>in boys and girls.</p> <p>Discussion</p> <p>BMI is a surrogate measure for body fat and circulating leptin levels. The finding that girls with relatively lower BMI have significantly later menarche, and a significant excess of TAs, suggests a relation to energy homeostasis through the hypothalamus. The hypothesis we suggest for the pathogenesis of severe TA in girls and boys has the same mechanism as that proposed recently for AIS girls, namely: severe TAs are initiated by a <it>genetically-determined selectively </it>increased hypothalamic sensitivity (up-regulation, i.e. increased sensitivity) to leptin with asymmetry as an adverse response to stress (hormesis), mediated bilaterally mainly to the growing trunk via the sympathetic nervous system <it>(leptin-hypothalamic-sympathetic nervous system (LHS) concept)</it>. The putative autonomic dysfunction is thought to be increased by any lower circulating leptin levels associated with relatively lower BMIs. Sympathetic nervous system activation with asymmetry leads to asymmetries in ribs and/or vertebrae producing severe TA when beyond the capacity of postural mechanisms of the somatic nervous system to control the shape distortion of the trunk. A test of this hypothesis testing skin sympathetic responses, as in the Rett syndrome, is suggested.</p

Language in international business: a review and agenda for future research

A fast growing number of studies demonstrates that language diversity influences almost all management decisions in modern multinational corporations. Whereas no doubt remains about the practical importance of language, the empirical investigation and theoretical conceptualization of its complex and multifaceted effects still presents a substantial challenge. To summarize and evaluate the current state of the literature in a coherent picture informing future research, we systematically review 264 articles on language in international business. We scrutinize the geographic distributions of data, evaluate the field’s achievements to date in terms of theories and methodologies, and summarize core findings by individual, group, firm, and country levels of analysis. For each of these dimensions, we then put forward a future research agenda. We encourage scholars to transcend disciplinary boundaries and to draw on, integrate, and test a variety of theories from disciplines such as psychology, linguistics, and neuroscience to gain a more profound understanding of language in international business. We advocate more multi-level studies and cross-national research collaborations and suggest greater attention to potential new data sources and means of analysis

Pathogenesis of adolescent idiopathic scoliosis in girls - a double neuro-osseous theory involving disharmony between two nervous systems, somatic and autonomic expressed in the spine and trunk: possible dependency on sympathetic nervous system and hormones with implications for medical therapy

Anthropometric data from three groups of adolescent girls - preoperative adolescent idiopathic scoliosis (AIS), screened for scoliosis and normals were analysed by comparing skeletal data between higher and lower body mass index subsets. Unexpected findings for each of skeletal maturation, asymmetries and overgrowth are not explained by prevailing theories of AIS pathogenesis. A speculative pathogenetic theory for girls is formulated after surveying evidence including: (1) the thoracospinal concept for right thoracic AIS in girls; (2) the new neuroskeletal biology relating the sympathetic nervous system to bone formation/resorption and bone growth; (3) white adipose tissue storing triglycerides and the adiposity hormone leptin which functions as satiety hormone and sentinel of energy balance to the hypothalamus for long-term adiposity; and (4) central leptin resistance in obesity and possibly in healthy females. The new theory states that AIS in girls results from developmental disharmony expressed in spine and trunk between autonomic and somatic nervous systems. The autonomic component of this double neuro-osseous theory for AIS pathogenesis in girls involves selectively increased sensitivity of the hypothalamus to circulating leptin (genetically-determined up-regulation possibly involving inhibitory or sensitizing intracellular molecules, such as SOC3, PTP-1B and SH2B1 respectively), with asymmetry as an adverse response (hormesis); this asymmetry is routed bilaterally via the sympathetic nervous system to the growing axial skeleton where it may initiate the scoliosis deformity (leptin-hypothalamic-sympathetic nervous system concept = LHS concept). In some younger preoperative AIS girls, the hypothalamic up-regulation to circulating leptin also involves the somatotropic (growth hormone/IGF) axis which exaggerates the sympathetically-induced asymmetric skeletal effects and contributes to curve progression, a concept with therapeutic implications. In the somatic nervous system, dysfunction of a postural mechanism involving the CNS body schema fails to control, or may induce, the spinal deformity of AIS in girls (escalator concept). Biomechanical factors affecting ribs and/or vertebrae and spinal cord during growth may localize AIS to the thoracic spine and contribute to sagittal spinal shape alterations. The developmental disharmony in spine and trunk is compounded by any osteopenia, biomechanical spinal growth modulation, disc degeneration and platelet calmodulin dysfunction. Methods for testing the theory are outlined. Implications are discussed for neuroendocrine dysfunctions, osteopontin, sympathoactivation, medical therapy, Rett and Prader-Willi syndromes, infantile idiopathic scoliosis, and human evolution. AIS pathogenesis in girls is predicated on two putative normal mechanisms involved in trunk growth, each acquired in evolution and unique to humans

Os efeitos da exposição ocupacional ao chumbo sobre o sistema auditivo: uma revisão da literatura The effects of occupational exposure to lead on the auditory system: an analysis of the literature

Apesar do termo perda auditiva ocupacional ser relacionado, normalmente, à perda auditiva induzida por ruído, a literatura especializada aponta outros agentes presentes no ambiente de trabalho que podem ser nocivos à saúde auditiva do trabalhador. O chumbo é considerado um desses agentes, e seus efeitos sobre o sistema auditivo vêm sendo investigados por alguns pesquisadores. Existem inúmeros estudos acerca dos efeitos da intoxicação pelo chumbo no organismo, os quais demonstram que múltiplos órgãos podem ser afetados, porém, as investigações sobre os efeitos do chumbo no sistema auditivo são escassas, além de apresentarem resultados contraditórios. Estudos considerando a exposição simultânea ao chumbo e outros agentes, como o ruído, por exemplo, são praticamente inexistentes. O uso industrial desse metal é vasto e, normalmente, as condições de trabalho presentes num grande número de indústrias brasileiras expõem o trabalhador a elevadas concentrações de chumbo. Os estudos apresentados nesse artigo demonstram que as conseqüências da exposição ao chumbo sobre o sistema auditivo periférico e central ainda não são totalmente esclarecidas. Da mesma forma, devido à seriedade do risco potencial, evidenciam a necessidade de pesquisas futuras que investiguem a exposição simultânea a mais de um agente nocivo à saúde auditiva do trabalhador.<br>Despite the fact that the term occupational hearing loss is usually associated with noise-induced hearing loss, the scientific literature indicates that there are other work-related agents that can be damaging to the worker's auditory health. Lead is considered as one of these agents, and several researchers have investigated its effects on the auditory system. There are numerous studies on the effects from lead intoxication to the body, which demonstrate that multiple organs can be affected. However, investigations of the auditory effects of lead are scarce, and offer conflicting results. Studies that take into consideration the combined exposure to lead and other agents, as noise, are practically unexistent. The industrial uses of this metal are extensive and usually the work conditions in a large number of Brazilian industries expose the worker to high lead concentrations. The studies reviewed in the present paper indicate that the consequences of lead exposure to the peripheral and central auditory system are not yet fully understood. Moreover, due to the seriousness of the potential risk, they underscore the need for further research on the effects of more than one agent to workers' hearing health