Platelet membrane glycoprotein changes during the preparation and storage of platelet concentrates

Previous studies of platelet membrane glycoproteins during blood bank storage have reported conflicting results. This study assessed two major plasma membrane glycoproteins (GP Ib and GP IIb), an alpha-granule membrane protein (GMP-140), and the concentration of platelet membrane microparticles in cell-free plasma during routine hospital blood bank platelet storage. 125I-monoclonal antibody binding was used to measure membrane glycoproteins on the surface of intact platelets and to measure the concentration of membrane microparticles in cell-free plasma. Platelet concentrates were stored at room temperature in polyolefin bags for 7 days. In this blood bank, two types of rotators are routinely used for platelet concentrate storage: a 2-rpm circular tumbler rotator and a 6-rpm elliptical rotator. Different results were obtained with the rotators. With the tumbler rotator, there was no loss of platelets and antibody binding to GP Ib remained normal. With the elliptical rotator, one third of platelets were lost into clumps during storage, and a 50 percent decrease of antibody binding to GP Ib occurred in the remaining single platelets. There was no loss of antibody binding to GP IIb with either rotator. Antibody binding to GMP-140 increased equally in both rotators indicating that the remaining single platelets had secreted about 16 percent of their alpha-granule contents. The plasma concentration of platelet membrane microparticles was greater in the bags stored in the elliptical rotator. These results indicate that it is possible to maintain the normal concentration of platelet membrane glycoproteins Ib and IIb during 7 days of room-temperature blood bank storage.(ABSTRACT TRUNCATED AT 250 WORDS)     

In Vivo Feedback Predicts Parent Behavior Change in the Attachment and Biobehavioral Catch-up Intervention

Understanding mechanisms and active ingredients of intervention is critical to training clinicians, particularly when interventions are transported from laboratories to communities. One promising active ingredient of parenting programs is clinicians’ in vivo feedback regarding parent–child interactions. The present study examined whether a form of in vivo feedback, in the moment commenting, predicted treatment retention and parent behavior change when the Attachment and Biobehavioral Catch-up (ABC) intervention was implemented in a community setting. Observational data were collected from 78 parent–child dyads (96% mothers; M age = 29 years; 81% minority; infants’ M age = 12 months; 90% minority) across 640 sessions conducted by 9 clinicians (100% female, M age = 39; 67% minority) in Hawaii. Parental behavior was assessed with a semistructured play task before and after intervention. Clinicians’ in-the-moment feedback to parents was assessed from intervention session videos. Clinicians’ frequency and quality of in-the-moment feedback predicted change in parental intrusiveness and sensitivity at posttreatment. Frequency of in-the-moment feedback also predicted likelihood of retention. Hierarchical linear modeling demonstrated strong support for these associations at the between-clinician level, and limited additional support at the within-clinician (i.e., between-case) level. Thus, a hypothesized active ingredient of treatment, in-the-moment feedback, predicted community-based ABC outcomes. The results complement lab-based evidence to suggest that in vivo feedback may be a mechanism of change in parenting interventions. Helping clinicians to provide frequent, high-quality in vivo feedback may improve parenting program outcomes in community settings.     

Systemic Risk Score Evaluation in Ischemic Stroke Patients (SCALA)

Background and purpose Stratification of patients with transient ischemic attack (TIA) or ischemic stroke (IS) by risk of recurrent stroke can contribute to optimized secondary prevention. We therefore aimed to assess cardiovascular risk factor profiles of consecutive patients hospitalized with TIA/IS to stratify the risk of recurrent stroke according to the Essen Stroke Risk Score (ESRS) and of future cardiovascular events according to the ankle brachial index (ABI) as a marker of generalized atherosclerosis Methods In this cross-sectional observational study, 85 neurological stroke units throughout Germany documented cardiovascular risk factor profiles of 10 consecutive TIA/IS patients on standardized questionnaires. Screening for PAD was done with Doppler ultrasonography to calculate the ABI. Results A total of 852 patients (57% men) with a mean age of 67±12.4 years were included of whom 82.9 % had IS. The median National Institutes of Health stroke sum score was 4 (TIA: 1). Arterial hypertension was reported in 71%, diabetes mellitus in 26%, clinical PAD in 10%, and an ABI ≤ 0.9 in 51%. An ESRS ≥ 3 was observed in 58%, which in two previous retrospective analyses corresponded to a recurrent stroke risk of ≥ 4%/year. The correlation between the ESRS and the ABI was low (r = 0.21). Conclusion A high proportion of patients had asymptomatic atherosclerotic disease and a considerable risk of recurrent stroke according to the ABI and ESRS category. The prognostic accuracy as well as the potential benefit of various risk stratification scores in secondary stroke prevention require validation in a larger prospective study.     

Increased prevalence of obstructive sleep apnoea in patients with Charcot-Marie-Tooth disease: a case control study

Obstructive sleep apnoea (OSA) has previously been described in a large family suffering from Charcot-Marie-Tooth disease type 1 (CMT1). In the present study, we used a case control design to establish whether this suggested link between OSA and CMT1 may also be found when studying genetically non-related patients. 12 patients with CMT1 and 24 control patients matched for age, sex and body mass index (BMI) were included in the study. Neurological disability was graded with a previously established 6 point score. All patients underwent overnight polysomnography. The mean apnoea-hypopnoea index (AHI) of patients with CMT1 was 10.5 (16.3) which was significantly higher than that of the control group (1.5 (1.3)). Five out of 12 patients with CMT1 had an AHI > or =10/h compared with 1 of 24 control patients (p<0.01). In patients with CMT1, a significant correlation between AHI and neurological disability was found (Spearman r = 0.62; p = 0.031) while BMI and age were not related to AHI. CMT1, in particular CMT1A, predisposes with disease progression to the development of OSA. Pathophysiologically, one may assume that CMT1 related pharyngeal neuropathy increases the collapsibility of the upper airway which in turn leads to recurring obstructive respiratory events.     

Positional sleep apnea in patients with ischemic stroke

BACKGROUND: In non-stroke patients, the severity of sleep apnea (SA) is known to be frequently related to the sleeping position, a condition called positional SA. In the present study, we investigated whether in acute stroke the occurrence of apneas was related to the positioning of patients, and whether a similar finding could be observed after rehabilitation. With the purpose of identifying patients potentially being in need of a SA treatment beyond rehabilitation, we furthermore looked for epidemiologic and clinical parameters being related to persistent SA 6 months after stroke. PATIENTS AND METHODS: Fifty-five acute stroke patients underwent cardiorespiratory polygraphy within 72 hours after onset of neurological symptoms and after 6 months. Apart from the total AHI (AHITOT), the AHI with the patient in supine position and the AHI with the patient in other positions were determined. In all patients, demographic data, NIH-stroke scale score and cumulative vascular risk factors were assessed. RESULTS: In the initial sleep study, 78% of patients had an AHI>or=10/h, of whom 65% fulfilled the criteria of positional SA. On follow-up, the incidence of SA declined to 49% with positional SA being present in 33%. Multivariate logistic regression analysis identified AHITOT on admission [OR=1.07 (1.002-1.13)] and cumulative vascular risk factors [OR=3.48 (1.34-9.05)] as independent predictors of persistent SA 6 months after stroke. CONCLUSION: According to our results, positional SA is a predominant feature in acute stroke and its incidence decreases significantly during the following months. These findings may have implications for SA treatment in patients with acute stroke.