Ophthalmoplegia-ataxia-areflexia in pediatrics. Three new patients and review of the literature

OBJECTIVE: The objective of this study was to investigate if pediatric patients with benign brainstem encephalitis (Bickerstaff Syndrome) or with Miller-Fisher Syndrome are the extremes of the same nosological entity which, in adults, has been named ophalmoplegia-ataxia-areflexia syndrome. PATIENTS AND METHODS: The subjects included in the study were three patients of our institution and 24 patients found in the revision of the English and Spanish pediatric literature who fulfilled the diagnostic criteria of ophtalmoplegia-ataxia-areflexia syndrome. The topographical location of the lesion in the nervous system was based on previously established criteria by using clinical and complementary studies. RESULTS: Of the 27 patients included in the study we were able to reach an accurate topographical diagnosis in 9. None had an exclusive involvement of the peripheral nervous system, (6) had exclusively central nervous system involvement and 2 showed involvement of both system. In 12, the topographical location of the lesion could be only ascertained as probable; 3 of them in the peripheral nervous system, 2 in the central nervous system and mixed involvement in 7. In the remaining 7 patients there were insufficient clinical data to allow topographical classification. CONCLUSIONS: The ophtalmoplegia-ataxia-areflexia syndrome can also be found in pediatric patients. The lesion in the majority of patients in this age group is located in the central nervous system, either alone or combined with peripheral nervous system involvement.     

"No allogeneic blood transfusion" protocol for the surgical correction of craniosynostoses. II. Clinical application

The authors describe the results obtained in 13 consecutive cases of craniosynostosis operated on according to a protocol devised at avoiding allogeneic blood transfusion. The protocol is based on pre- and postoperative treatment with erythropoietin, preoperative autologous blood donation, preoperative normovolemic hemodilution and intraoperative blood salvage. Nine subjects were affected by simple forms of craniosynostosis, whereas the remaining 4 presented with oxycephaly or craniofacial syndromes. Five of the 13 children were under 7 months and a further 3, under 10 months of age at the time of the surgical operation. Seven children weighed less than 10 kg. Allogeneic blood transfusion was avoided in 11 of the 13 children considered. Two failures - defined as the necessity to reinfuse the patient with an allogeneic blood transfusion - were recorded, 1 of them resulting from an unexpected hemorrhage during surgery. The results obtained indicate that this protocol designed to avoid allogeneic blood transfusion can be safely applied in the great majority of children with craniosynostosis, even when the surgical correction is carried out early in life.     

Design of CMOS checkers with improved testability of bridging and transistor stuck-on faults

This work presents a design technique for CMOS static and dynamic checkers (to be used in self-checking circuits), that allows the detection of all internal single transistor stuck-on and bridging faults causing unacceptable degradations of the circuit dynamic performance (but not logical errors). Such a technique exploits simple voltage detector circuits to make sure that the intermediate faulty voltages inevitably produced by the faults of interest are always propagated at the checker output as logic errors.With the use of our technique, the main disadvantages of static checkers, so far preventing their use in practical applications, are overcome.The method has been applied to the particular case of two-rail (static as well as dynamic) checkers and its validity has been verified by means of electrical level simulations.     

Growth factor-induced Ca2+ responses are differentially modulated by nitric oxide via activation of a cyclic GMP-dependent pathway

Nitric oxide (NO) plays a modulatory role on cell growth and differentiation, biological processes that occur under the control of various signal transduction mechanisms, including those triggered by activation of membrane receptors for polypeptide growth factors. The increases in intracellular Ca2+ concentration elicited by the activation of these receptors are sustained by release of the cation from intracellular stores and by stimulation of this influx from the extracellular medium. Using NIH 3T3 cells overexpressing the human epidermal growth factor receptor, we investigated both of these processes stimulated by the administration of epidermal and platelet-derived growth factors as the receptor agonists. Pharmacological and functional analyses carried out on Fura-2-loaded cells showed that Ca2+ influx elicited by both growth factors is the summation of two distinct pathways, with the major pathway dependent on and the minor pathway independent of store depletion. Exposure of the cells to either No donors or NO synthase inhibitors induced increase and inhibition, respectively, of the two components of Ca2+ influx. When Ca2+ release was investigated, the above drugs were also active but in the opposite direction. The effects of NO were mimicked by the cGMP analogue 8-Br-cGMP and abolished by two cGMP-dependent protein kinase I inhibitors, whereas the cAMP analogue 8-Br-cAMP and two protein kinase A inhibitors had no appreciable effects. In addition, growth factors induced an increase in cGMP formation, an effect that was prevented by NO synthase inhibitors. In conclusion, NO appears to exert a feedback modulatory control on CA2+ responses to growth factor administration. Such a control might contribute to the inhibitory effect of NO on growth previously reported with various cell types.     

Elemental and mineral characterisation of Coastal Antarctic Aerosols in snow using PIXE and SEM-EDAX

The chemical constituents of snow from a 3 m pit sampled at a coastal Antarctic site were characterised by means of PIXE and SEM-EDAX. Oxygen isotope dating revealed that the pit spanned an 8-year period, from 1986 to 1994. Concentrations measured by PIXE ranged from less than 1 ng g⁻¹ of H₂O for Cu, and Zn to several tens of ng g⁻¹ for Si, S and Cl. The major elements found were Si, S, Al, and Na, which contributed more than 75% of the element loading. Snow layers with elevated Cl concentration were regularly found along the pit. The mineralogy of the insoluble particles determined by SEM-EDAX analyses showed that quartz, plagioclase and clays were the prevalent minerals. The proportion of each element in the insoluble phase was comparable with that previously found in similar studies.     

Neutron Stress Imaging of Drawn Copper Tube: Comparison with Finite-Element Model

Seamless tubes are used for various mechanical applications, often produced by several cold drawing steps to reach the required dimensions. The first process step, for example, extrusion or rolling, typically results in ovality and eccentricity of the tube caused by nonsymmetric material flow and being present during the cold drawing process, i.e., no homogeneous deformation. Because of this nonsymmetrical deformation, and deviations over the length of the tube caused by moving tools, this process step generates inhomogeneous residual stresses. To understand the interconnection between geometrical changes in the tubes and the resulting residual stresses, the residual strain distribution in a copper tube was measured by neutron diffraction. The aim of this study is to evaluate residual stresses generated during cold drawing of copper tubes. This research comprises experimental measurements and numerical analysis. An industrially produced copper tube was cold drawn, and the profile of residual strain over circumference and across wall thickness was measured by neutron diffraction. In parallel, a three-dimensional finite-element model (FEM) was developed to calculate the residual macrostress state generated by the forming process. Good agreement between experimental results and numerical computations was obtained. This article is based on a presentation given in the symposium entitled “Neutron and X-Ray Studies for Probing Materials Behavior,” which occurred during the TMS Spring Meeting in New Orleans, LA, March 9–13, 2008, under the auspices of the National Science Foundation, TMS, the TMS Structural Materials Division, and the TMS Advanced Characterization, Testing, and Simulation Committee.     

Sex differences in left-handedness: A meta-analysis of 144 studies.

Human handedness, a marker for language lateralization in the brain, continues to attract great research interest. A widely reported but not universal finding is a greater male tendency toward left-handedness. Here the authors present a meta-analysis of k = 144 studies, totaling N = 1,787,629 participants, the results of which demonstrate that the sex difference is both significant and robust. The overall best estimate for the male to female odds ratio was 1.23 (95% confidence interval = 1.19, 1.27). The widespread observation of this sex difference is consistent with it being related to innate characteristics of sexual differentiation, and its observed magnitude places an important constraint on current theories of handedness. In addition, the size of the sex difference was significantly moderated by the way in which handedness was assessed (by writing hand or by other means), the location of testing, and the year of publication of the study, implicating additional influences on its development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)