Biochemical, immunological, and cell genetic studies in glycogenosis type II.

Fibroblasts from patients with the adult, juvenile, and infantile form of glycogenosis type II (Pompe disease) were cultured under standardized conditions, and the activity of acid alpha-glucosidase (E.C.3.2.1.20) towards glycogen, maltose, and 4-methylumbelliferyl-alpha-D-glucopyranoside was measured. Glycogen levels in muscle biopsies and in cultured fibroblasts from patients were determined. Residual enzyme activities varying from 7%-22% were detected in fibroblasts from patients with the adult form but not from patients with the infantile form of glycogenosis II. An inverse correlation was found between the severity of the clinical manifestation and the degree of residual enzyme activity in the fibroblasts. The kinetic and electrophoretic properties of acid alpha-glucosidase in fibroblasts from the adult patients and from control individuals were similar. Immunological studies suggested that the decrease of acid alpha-glucosidase activity is caused by a mutation that affects the production or degradation of the enzyme rather than its catalytic activity. Complementation studies were carried out by fusing fibroblasts from patients with the adult, juvenile, and infantile form of glycogenosis II, but neither conventional assays on multikaryons nor enzyme assays on single binuclear heterokaryons gave any evidence for genetic heterogeneity among these forms.     

Oxytocin shapes parental motion during father–infant interaction

An infant-oriented parental repertoire contributes to an infant''s development and well-being. The role of oxytocin (OT) in promoting affiliative bonds and parenting has been established in numerous animal and human studies. Recently, acute administration of OT to a parent was found to enhance the carer''s, but at the same time also the infant''s, physiological and behavioural readiness for dyadic social engagement. Yet, the exact cues that are involved in this affiliative transmission process remain unclear. The existing literature suggests that motion and vocalization are key social signals for the offspring that facilitates social participation, and that distance and motion perception are modulated by OT in humans. Here, we employed a computational method on video vignettes of human parent–infant interaction including 32 fathers that were administered OT or a placebo in a crossover experimental design. Results indicate that OT modulates parental proximity to the infant, as well as the father''s head speed and head acceleration but not the father''s vocalization during dyadic interaction. Similarly, the infant''s OT reactivity is positively correlated with father''s head acceleration. The current findings are the first to report a relationship between the OT system and parental motion characteristics, further suggesting that the cross-generation transmission of parenting in humans might be underlaid by nuanced, infant-oriented, gestures relating to the carer''s proximity, speed and acceleration within the dyadic context.     

Fear and Intimacy: Citizenship in a Recife Slum,Brazil

In Brazil, citizenship rights and the institutionalisation of citizen participation have advanced significantly under the democratic regime. However, many of the urban poor are still alienated from the state and its legal system. This article argues that, to understand the citizenship of these ‘half-citizens’, it is necessary to take account of an unofficial realm of practices. I show how residents of a slum in Recife interpret and deal with the state project of registered citizenship, which finds its material expression in the compulsory carrying of identity cards. Carrying these cards is surrounded by fear of violent police control. However, obtaining identity cards through informal procedures is associated with a longing for personalised relationships with the police and other state representatives. The relationship of these residents with their identity cards is thus both fearful and affectionate, which allows us to understand their citizenship as a confluence of fear and intimacy.     

Effect of K+ and Cl− ion gradients upon apex regeneration in Acetabularia mediterranea

Summary The concentration of the growth inhibitors produced by the cap of apical segments of maize roots, placed horizontally, was greater in the lower half of the cap than in its upper half. These endogenous regulators were moving both basipetally and laterally, but the downward transport occurred only inside the apex of the geostimulated roots.     

SEMIAUTOMATED FLUORIMETRIC DETERMINATION OF TYROSINE IN RAT BRAIN AND HUMAN PLASMA

Abstract— The evidence is presented to show that the fiuorimetric method of W aalkes & U denfriend (1957) cannot be used directly for the determination of free tyrosine in acid deproteinized extracts of rat brain, owing to the reaction of peptide bound tyrosine in some proteins present in the acid extracts. A method is given to obtain a fraction containing free tyrosine in the acid extracts of rat brain and to determine its tyrosine content fluorimetrically by autoanalysis. An autoanalysis method is also given for the fiuorimetric determination of free tyrosine directly in 5₀ trichloroacetic acid extracts of the plasma.