Type IIB Tampa: a variant of von Willebrand disease with chronic thrombocytopenia, circulating platelet aggregates, and spontaneous platelet aggregation

Type IIB von Willebrand disease is characterized by enhanced ristocetin- induced platelet aggregation and absence of large von Willebrand factor multimers from plasma. An alteration of the von Willebrand factor molecule resulting in increased reactivity with platelets appears to be the basis for these abnormalities. We have now identified a new variant of type IIB von Willebrand disease in a family in which the four affected members also have chronic thrombocytopenia, in vivo platelet aggregate formation, and spontaneous platelet aggregation in vitro. In spite of repeatedly prolonged bleeding times and persistent thrombocytopenia, their bleeding diathesis is only moderate.     

The concurrent validity of the 3-day Physical Activity Recall questionnaire administered to female adolescents aged 12–14 years

Aim:  This pilot study was conducted as part of an honours project and aimed to provide evidence of validity for the 3-day Physical Activity Recall (3dPAR) questionnaire in a sample of female adolescents aged 12–14 years ( N  = 20) for use by occupational therapists to assess adolescents' physical activity.
Methods:  Participants wore a Computer Science and Applications 7164 accelerometer for seven consecutive days and completed the 3dPAR questionnaire after the recording period.
Results:  A significant correlation was found between self-reported total metabolic equivalents and accelerometer total counts for 3 days ( r =  0.630, P  < 0.01) and self-reported vigorous physical activity and accelerometer minutes of vigorous physical activity for the 7 days ( r =  0.568, P  < 0.01) and corresponding 3 days ( r =  0.493, P  < 0.05) of monitoring.
Conclusions:  A validity coefficient has been established for the 3dPAR questionnaire when measuring total and vigorous physical activity in females aged 12–14 years over a 3-day period. It is anticipated that this study will assist in familiarising the occupational therapy field with the 3dPAR questionnaire as a potential self-report tool to assess and explore the complexity of adolescents' physical activity.     

Corpus callosum and limbic system: neuroanatomic MR evaluation of developmental anomalies

Agenesis of the corpus callosum is a complex malformation of the brain that has been associated with varying degrees of limbic system maldevelopment. We retrospectively reviewed the records of 11 patients with callosal agenesis (seven total, four partial) who underwent magnetic resonance (MR) imaging, with particular attention to the associated malformations of the limbic system. Comparison was made with selected images from MR examinations of healthy volunteers and with necropsy specimens from other patients with callosal agenesis. Ten of 11 patients demonstrated limbic anomalies (severe motion artifact precluded evaluation of these structures in one patient). MR depicted not only the abnormalities intrinsic to callosal agenesis but also the frequently associated malformations of the limbic system.     

Antitubercular nucleosides that inhibit siderophore biosynthesis: SAR of the glycosyl domain

Tuberculosis is the leading cause of infectious disease mortality in the world by a bacterial pathogen. We previously demonstrated that a bisubstrate inhibitor of the adenylation enzyme MbtA, which is responsible for the second step of mycobactin biosynthesis, exhibited potent antitubercular activity. Here we systematically investigate the structure-activity relationships of the bisubstrate inhibitor glycosyl domain resulting in the identification of a carbocyclic analogue that possesses a KIapp value of 2.3 nM and MIC99 values of 1.56 microM against M. tuberculosis H37Rv. The SAR data suggest the intriguing possibility that the bisubstrate inhibitors utilize a transporter for entry across the mycobacterial cell envelope. Additionally, we report improved conditions for the expression of MbtA and biochemical analysis, demonstrating that MbtA follows a random sequential enzyme mechanism for the adenylation half-reaction.