NK cytotoxicity mediated by CD16 but not by NKp30 is functional in Griscelli syndrome

Griscelli syndrome (GS) type 2 is an autosomal recessive disorder represented by pigment dilution and impaired cytotoxic T lymphocyte (CTL) activity. NK activity has been scarcely investigated in GS patients. Here, we describe a new patient, possessing a hemophagocytic syndrome with a homozygous Q118X nonsense RAB27A mutation. Single specific primer-polymerase chain reaction (SSP-PCR) was developed based on this mutation and is currently used in prenatal genetic analysis. As expected, CTLs in the patient are not functional and NK cytotoxicity against K562 or 721.221 cells is diminished. Surprisingly, however, we demonstrate that CD16-mediated killing is intact in this patient and is therefore RAB27A independent, whereas NKp30-mediated killing is impaired and is therefore RAB27A dependent. We further analyzed the signaling pathways of these 2 receptors and demonstrated phosphorylation of Vav1 after CD16 activation but not after NKp30 engagement. Thus, we identify a novel homozygous mutation in the RAB27A gene of a new GS patient, observe for the first time that some activating NK receptors function in GS patients, and demonstrate a functional dichotomy in the killing mediated by these human NK-activating receptors.     

Post-traumatic stress disorder is not over-represented in a sample population of migraine patients

IntroductionExposure to extreme stress can result in a variety of clinical sequelae, in terms of severity and type, of which post-traumatic stress disorder (PTSD) is the prototype. PTSD was previously associated with chronic pain and primary pain disorders.ObjectiveTo evaluate the prevalence of PTSD among migraine patients and to assess its relation to migraine severity.MethodsWe evaluated 92 consecutive patients fulfilling the international headache society criteria for migraine with and without aura treated in the Headache Clinic of the Soroka University Medical Center in Beer-Sheva using the Clinician Administered PTSD Scale (CAPS), and headache severity scales (HIT-6 and MIDAS).ResultsThe prevalence of specific traumatic events in migraine patients was 16.3% (n = 15). Six patients (6.5%) of the 92 patients met the DSM-IV criteria for PTSD. Migraine patients with co-morbid PTSD had higher MIDAS scores than other migraine patients.ConclusionsMigraine patients do not suffer from PTSD more than the general population. When they do suffer from PTSD they report high levels of disability.     

Characteristics of exodeviations: II. Changes with treatment with orthoptics

This study examined retrospectively the records of 179 patients who had binocular visual dysfunction as a result of an exodeviation (either at distance or near or both). The patients were classified as having convergence insufficiency (N = 110), equal exodeviations (N = 49), or divergence excess (N = 18). The diagnostic groups and the different frequencies of deviation reacted differently to treatment with a standard orthoptic regimen. Nearly all the patients (97%) achieved some improvement in either objective or subjective areas or both. However, fewer were able to satisfy the criteria set for total success. Factors correlated with the success of the treatment were the initial angle of deviation at distance and the initial level of stereopsis. The results and implications of this study are discussed.     

Relational and non-relational memory – electrophysiological correlates of novelty detection, repetition detection and subsequent memory

The dissociability of novelty detection in relational (RM) and non-relational memory (NRM) is currently under debate. To further address the time courses and underlying brain correlates of novelty detection, event-related potentials (ERPs) were analysed for encoding and retrieval on three memory tasks in healthy subjects. Spatial and non-spatial RM as well as NRM were assessed separately. The ERPs related to RM and NRM were dissociable for hits and correct rejections in an early and late time window. An early old/new effect was observed for NRM. A late old/new effect replicated the frequently reported recollection-associated old/new effect in terms of direction and amplitudes. Four different novelty types (spatial relational, non-spatial relational, horizontal non-relational and inverted non-relational) were examined. The P3a related to novelty detection differed in horizontal vs. inverted distractors in NRM, but not in spatial vs. non-spatial RM. ERPs for repetition detection (hits during retrieval) and also for subsequent hits (encoding phase) differed between RM and NRM. These findings are discussed in relation to potential brain correlates in RM and NRM during encoding and retrieval.     

Involvement of the human thalamus in relational and non-relational memory

Damage to the human thalamus has been associated with selective anterograde recognition memory impairments. Recently, recognition memory has been subdivided into relational and non-relational memory. The aim of the present study was to assess the potentially differential involvement of the human thalamus in relational and non-relational memory. Ten patients with focal ischemic thalamic lesions were compared to individualized control groups of healthy subjects matched to each individual patient on age and IQ. Six patients showed poorer relational memory than their respective control samples. None of the 10 patients showed a significant deficit on the non-relational memory task. These observations suggest an involvement of the thalamus in relational memory, and are discussed in terms of disruption of mediotemporal-thalamic and thalamic-fronto-striatal circuits.     

Research in physical medicine and rehabilitation. VII. The role of the principal investigator

The roles and responsibilities of the principal investigator of a research project are described to allow the young researcher to make an intelligent decision regarding which role to take in a research project. Guidelines are given about which tasks may be delegated and how to do this. These tasks include formulation of the question, project design, obtaining funding, project startup and ongoing management, data analysis and publication. Particular attention is paid to design/analysis and publication, since these determine authorship on biomedical research articles.     

Lateralisation of language functioning by the Wada procedure and divided visual field presentation of a verbal task

In cases of intractable epilepsy, language and memory functioning in the hemisphere contralateral to the lesion is determined prior to unilateral temporal surgery. Patients with unilateral temporal lobe lesions were assessed using the intracarotid sodium amytal (Wada) procedure to determine the lateralisation of language and memory functioning. They also performed a divided visual field task in which letters were presented in pairs for brief durations on a computer screen in a phonemic matching task. The results showed only moderate agreement between the two methods with regard to identification of the speech-dominant hemisphere, indicating the divided visual field matching paradigm to be unsuitable as a basis for surgical decision-making.