Maternal deaths from bleeding associated with caesarean delivery: A national emergency.

Maternal deaths associated with caesarean deliveries (CDs) have been increasing in South Africa over the past decade. The objective of this report is to bring national attention to this increasing epidemic of maternal deaths due to bleeding associated with CD in the majority of provinces of the country. Individual chart reviews of women who died from bleeding at or after CD show that 71% had avoidable factors. Among the steps we can take are to improve surgical skills and experience, especially in rural hospitals, to improve clinical observations in the immediate postoperative period and in the postnatal wards, and to ensure that appropriate oxytocic agents are given to prevent postpartum haemorrhage. CEOs and medical managers of health facilities, district clinical specialists, heads of obstetrics and gynaecology, and midwifery training institutions must show leadership and accountability in providing an appropriate environment to ensure that women who require CD receive the procedure for the correct indications and in a safe manner to minimise risks.

[Morphological basics of systematics of Eurycercidae Kurz, 1875 sensu Dumont et Silva-Briano, 1998 (Cladocera: Anomopoda) family].

We analyzed data from the literature and our own results to discover common principles underlying the systematics of the Eucercidae Kurz, 1875 sensu Dumont et Silva-Briano, 1998 (Cladocera: Anomopoda) family, which is represented only by the genus Eurycercus Baird, 1983. The appropriateness of using various diagnostic features for identification of species was evaluated. We estimated the accuracy of using age variability of different morphometric parameters for determination of species. It was demonstrated that using oligomerous structures is more effective for differentiation of species than counting the structures the number ofwhich can vary considerably. The independence of the Bullatifrons Frey, 1975 subgenus was found to be questionable.

A novel nonsense mutation in the EYA1 gene associated with branchio-oto-renal/branchiootic syndrome in an Afrikaner kindred.

Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by the associations of hearing loss, branchial arch defects and renal anomalies. Branchiootic (BO) syndrome is a related disorder that presents without the highly variable characteristic renal anomalies of BOR syndrome. Dominant mutations in the human homologue of the Drosophila eyes absent gene (EYA1) are frequently the cause of both BOR and BO syndromes. We report a South African family of Afrikaner descent with affected individuals presenting with pre-auricular abnormalities and either hearing loss or bilateral absence of the kidneys. Genetic analysis of the pedigree detected a novel EYA1 heterozygous nonsense mutation in affected family members but not in unaffected family members or a random DNA panel. Through mutational analysis, we conclude that this particular mutation is the cause of BOR/BO syndrome in this family as a result of a truncation of the EYA1 protein that ablates the critical EYA homologous region. To the best of our knowledge, this is the first case of BOR/BO syndrome reported in Africa or in those of the Afrikaner descent.

Acute effects of nicotine on attention and response inhibition.

Smoking is highly prevalent among patients with Attention Deficit Hyperactivity Disorder (ADHD). Previous studies using the reversed continuous performance task (R-CPT) have suggested that nicotine reduces inattention. Since especially adults with ADHD have been claimed to suffer from a core deficit in inhibitory control, this study aimed at determining whether nicotine improves response inhibition in addition to attention. Sixteen healthy regular smokers participated in a pre/post treatment design in which transdermal patches containing 7 and 21 mg nicotine per day were administered in a counterbalanced, double-blind manner. In a second study, patches containing 0 mg (placebo) and 21 mg per day were administered to a different group of regular smokers. For replication purposes, the R-CPT and the profile of mood states (POMS) were administered. Furthermore, a different version of the continuous performance task (CPT-AX) and the stop-signal task, traditionally used to measure response inhibition, were presented. The high dose of nicotine was found to relieve self-reported Depression in Study 1 and Fatigue in Study 2. Performance data indicated acute effects of nicotine on attention-related, but not on inhibition-related measures. Especially the comparison with placebo revealed decreases in reaction time and variability of responding. The results imply that patients with ADHD smoke to reduce inattention.

Stopping and changing in adults with ADHD.

BACKGROUND: A lack of inhibitory control has been suggested to be the core deficit in children with attention deficit hyperactivity disorder (ADHD). This means that a primary deficit in behavioral inhibition mediates a cascade of secondary deficits in other executive functions, such as arousal regulation. Clinical observations have revealed that with increasing age symptoms of hyperactivity and impulsivity decline at a higher rate than those of inattention. This might imply that a deficit in attention rather than a lack of inhibitory control is the major feature in adult ADHD. METHOD: To study whether an attentional or inhibitory deficit predominates, the stop-signal task and the stop-change task were presented to 24 adults with ADHD combined subtype and 24 controls. RESULTS: Relative to controls, the stop-signal reaction time (SSRT) was significantly more prolonged than the go-stimulus reaction time (RT) in patients with ADHD. This disproportionate elongation of the SSRT was comparable across tasks, even though the stop-change task exerted more complex (or at least different) demands on the inhibitory system than the stop-signal task. ADHD patients had a higher proportion of choice errors, possibly reflecting more premature responses. Specifically in the stop-change task, patients had more variable choice responses and made more inappropriate change responses, which may also reflect enhanced impulsivity. CONCLUSIONS: The results support a core deficit in behavioral inhibition in adults with ADHD. We further suggest that there is more evidence for a critical role of deficient inhibitory control in adults than in children with ADHD.

Attention deficit and impulsivity: selecting, shifting, and stopping.

The present selective review addresses attention, inhibition, and their underlying brain mechanisms, especially in relation to attention deficit/hyperactivity disorders (AD/HD), and the effects of methylphenidate. In particular, event-related potential (ERP) studies suggest a deficit in the early-filtering aspect of selective attention in children with AD/HD. Results from stop tasks are consistent with impairments in stopping performance in AD/HD, but in children (as opposed to adults) these effects cannot be easily dissociated from more general impairments in attention to the task, and therefore an interpretation in terms of inhibitory control is not straightforward. On the other hand, the beneficial effects of methylphenidate are more specific to stopping, and there are no clearcut effects of methylphenidate on measures of selective attention. Even when group differences pertain specifically to stopping performance (as with adults with AD/HD), ERP evidence suggests at least a partial contribution of differences in switching attention to the stop signal, as revealed in measures of sensory cortex activation. ERP evidence from cued go/nogo tasks underlines the importance of taking into account the contribution of higher order control processes involved in anticipation of and preparation for task stimuli. It suggests that in certain conditions, expectancy, rather than response bias, contributes to increased behavioral response tendencies, and that a presumed index of response inhibition, the nogo N2, may rather reflect conflict monitoring. In sum, direct reflections of brain activity suggest that mechanisms of expectation and attention, rather than of response bias or inhibitory control, govern behavioral manifestations of impulsivity.

Electrophysiological correlates of attention, inhibition, sensitivity and bias in a continuous performance task.

OBJECTIVE: The aim was to verify the occurrence of proposed electrophysiological correlates of attention, inhibition, sensitivity and bias in a continuous performance task and to support their functional interpretation by using a manipulation intended to enhance subjects' response bias. METHODS: Electroencephalographic activity was recorded during administration of a transformed version of the AX continuous performance task in which cues signaled response alternatives. RESULTS: The previously reported parietal P3, NoGo-N2, NoGo-P3 and contingent negative variation were replicated. Besides, the frontal selection positivity and the lateralized readiness potential were demonstrated. With increasing Go-probability, the parietal P3 to the cue increased without changes in other cue-related correlates. In addition, reaction times decreased, non-parametric measures of sensitivity and bias decreased, the NoGo-N2 increased, and the parietal Go-P3 decreased. CONCLUSIONS: The proposed electrophysiological correlates were identified. Sub-threshold LRPs suggested a central inhibition mechanism. Cue-related correlates revealed that anticipation of a high-probability Go-stimulus involves attention rather than bias. This implies that the increased NoGo-N2 reflected an increase in conflict rather than an increase in inhibition. SIGNIFICANCE: Electrophysiological measures can greatly enhance our understanding of normal and abnormal information processing during continuous performance and related tasks.

Differences between low and high trait impulsivity are not associated with differences in inhibitory motor control.

OBJECTIVE: The present study investigates whether there is an association between trait impulsivity in the normal population and inhibitory motor control as assessed by the stop task. METHOD: Low- and high-impulsive participants (as assessed by the I7 questionnaire; both groups n = 31) performed the stop task. Differences in performance were analyzed by an independent samples t-test. Furthermore, a short meta-analysis was performed on this study and three previous studies with a similar aim. RESULTS: The low- and high-impulsive groups did not differ on the speed to stop the response (SSRT). However, the meta-analysis revealed that high-impulsives are marginally slower in stopping than low-impulsives (effect size = -0.26, p= 0.06). CONCLUSIONS: There is only minor evidence that impulsivity inthe common population is associated with poor inhibitory motor control.