Putative protective neural mechanisms in prereaders with a family history of dyslexia who subsequently develop typical reading skills

Developmental dyslexia affects 40–60% of children with a familial risk (FHD+) compared to a general prevalence of 5–10%. Despite the increased risk, about half of FHD+ children develop typical reading abilities (FHD+Typical). Yet the underlying neural characteristics of favorable reading outcomes in at‐risk children remain unknown. Utilizing a retrospective, longitudinal approach, this study examined whether putative protective neural mechanisms can be observed in FHD+Typical at the prereading stage. Functional and structural brain characteristics were examined in 47 FHD+ prereaders who subsequently developed typical (n = 35) or impaired (n = 12) reading abilities and 34 controls (FHD?Typical). Searchlight‐based multivariate pattern analyses identified distinct activation patterns during phonological processing between FHD+Typical and FHD?Typical in right inferior frontal gyrus (RIFG) and left temporo‐parietal cortex (LTPC) regions. Follow‐up analyses on group‐specific classification patterns demonstrated LTPC hypoactivation in FHD+Typical compared to FHD?Typical, suggesting this neural characteristic as an FHD+ phenotype. In contrast, RIFG showed hyperactivation in FHD+Typical than FHD?Typical, and its activation pattern was positively correlated with subsequent reading abilities in FHD+ but not controls (FHD?Typical). RIFG hyperactivation in FHD+Typical was further associated with increased interhemispheric functional and structural connectivity. These results suggest that some protective neural mechanisms are already established in FHD+Typical prereaders supporting their typical reading development.     

Evaluation of the bioequivalence and food effect on the bioavailability of CC-486 (oral azacitidine) tablets in adult patients with cancer

Cancer Chemotherapy and Pharmacology - CC-486 is an oral formulation of azacitidine that allows for extended dosing schedules to prolong azacitidine exposure to malignant cells and maximize...     

Cardiac conduction abnormalities and atrial arrhythmias associated with salicylate toxicity

Cardiac side effects from aspirin are uncommon; however, severe acid-base imbalance, pulmonary edema, ventricular ectopic activity and cardiopulmonary arrest have been reported in patients with toxic serum salicylate concentrations. We saw a patient with salicylate toxicity who developed a variety of sinus and atrioventricular nodal conduction disturbances and atrial arrhythmias with a relatively low toxic serum salicylate concentration. The cardiac rhythm returned to normal as the serum salicylate concentration decreased, and results of subsequent electrophysiologic testing and Holter monitoring were normal. A low serum albumin level may have resulted in altered salicylate binding in this patient, thereby increasing the availability of unbound (active) drug for toxic effects.     

Isozyme variation in Simulium (Edwardsellum) damnosum s.l. (Diptera: Simuliidae) from Kenya

Isozyme variation of the Simulium damnosum sibling species complex was studied by cellulose acetate electrophoresis (CAE) from four Kenyan river systems. Two enzymes, PGM and HK, were diagnostic and differentiated the larvae collected in Western and Nyanza provinces from the larvae collected at Mt. Kenya. Allele frequency differences of the enzyme PGI allowed about 75% separation of the geographically distinct populations.     

Hypertension in neuroblastoma induced by imipramine

Hypertension is a well-known finding in some patients with neuroblastoma. However, it has not previously been described in association with the use of Imipramine. We report the occurrence of severe hypertension (blood pressure 190/160) in a 4-year-old girl with neuroblastoma who was given Imipramine to control a behavior disorder. It was determined later that this patient's tumor was recurring at the time of her hypertensive episode. Since she had no blood pressure elevation at initial diagnosis and none following discontinuation of the Imipramine (when she was in florid relapse), we believe that this drug rather than her underlying disease alone caused her hypertension. The mechanism for this reaction is believed to be increased levels of vasoactive catecholamines due to interference of their physiologic inactivation by Imipramine. From this experience, we urge extreme caution in the use of tricyclic antidepressants in children with active neuroblastoma.     

Monoclonal antibody for avian thymic hormone.

Avian thymic hormone (ATH), a parvalbumin with immunomodulating properties, was used as antigen for development of a hybridoma cell line. Hybridoma screening by enzyme-linked immunosorbent assay (ELISA) led to the culture, purification, and characterization of an hybridoma, designated 4A6, which secretes IgG1 that is specific for ATH. The monoclonal antibody (MAb) was characterized by techniques involving indirect competitive and non-competitive ELISA, Western Blot analysis, and immunohistological staining. The MAb was highly specific for ATH with no cross-reactivity to other chicken tissue extracts or commercially available parvalbumins.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.     

Senile plaques,amyloid β-protein,and acetylcholinesterase fibres: laminar distributions in Alzheimer's disease striate cortex

Summary The laminar distributions of senile plaques and amyloid -protein (AP) within the striate cortex of patients with Alzheimer's disease (AD) were studied with enhanced Bielschowsky (roughly equivalent to the Campbell technique) and immunohistochemical methods. The laminar distribution of acetylcholinesterase (AChE) fibres within the striate cortex of both AD patients and control patients was studied with an enzyme histochemical method. Quantification of Bielschowsky-stained plaque numbers along intersect lines drawn parallel to laminar boundaries revealed a significant aggregation of plaques at the interface of layers IVc and V. Lines drawn through layer VI intersected significantly fewer plaques than lines through other laminae. Immunoperoxidase staining for AP revealed a similar distribution fo senile plaques, and additional, prominent, diffuse deposits of AP within layers I and IVc. AChE fibres were markedly depleted in the striate cortex of AD cases. In control cases, AChE fibres were, like AP immunoreactivity, concentrated within layers I and IVc. The results indicate that enhanced silver methods may not reveal the complete distribution of AP. The codistribution of AP-immunoreactive diffuse amyloid deposits and AChE fibres to the same cortical laminae is consistent with the possibility that these deposits may be formed from degenerating cholinergic elements. The formation of a line of senile plaques at the interface of two cortical laminae within the striate cortex, in an anatomically analogous situation to a similar line of plaques within the dentate gyrus, suggests that formation of well-defined plaques may be accelerated by the interaction of specific neuronal systems.Supported by a Fellowship from the British Columbia Health Care Research Foundation to TGB. This work is part of the PhD. dissertation of Dr. Beach (University of British Columbia, 1991)     

Should results of ultrasound Doppler studies be reported in units of frequency or velocity?

There is a current tendency to report the results of ultrasound Doppler studies in units of velocity instead of Doppler frequency. This is probably motivated by the intuitive feeling that blood flow studies should naturally be reported in cm/s and the notion that "velocity" is a normalizing factor for Doppler ultrasound studies. In order to determine velocity, the Doppler angle theta or angle formed by the ultrasound beam and flow velocity vector, must be known. It is not possible, using currently available systems, to obtain an accurate estimate of this angle. The physics related to the Doppler equation are reviewed in this paper along with examples to illustrate the origin and magnitude of errors that could arise when reporting in units of velocity. Guidelines are provided for thinking about and reporting results of Doppler studies in units of velocity. An understanding of the Doppler equation and its use in clinical studies are promoted in this paper to enhance the diagnostic usefulness of Doppler ultrasound studies and to reduce serious errors which could lead to faulty information dictating patient management.