Prevalence of red blood cell antibodies among transfused patients at Komfo Anokye teaching (Kath) hospital, Ghana

Red blood cell (RBC) alloimmunisation is a common problem in transfused patients because of the possibility of haemolytic reaction and limited availability of compatible blood. In highincome countries, pre-transfusion antibody screening is performed routinely. In Ghana, patients are transfused with ABO Rh ‘D’ compatible blood without screening for immune antibodies. We therefore studied the prevalence and specificities of RBC antibodies in transfused patients at Komfo Anokye Teaching hospital, Ghana. The study was cross-sectional, involving previously transfused patients who required another transfusion. Participants’ basic data on demography and transfusion history were recorded. Blood samples were screened and subsequently typed for RBC antibodies using a column gel agglutination test. A total of 106 transfused patients, 52 male and 54 females were enrolled. The patients had previously received a median of 4 RBC units (range 1-14). Of these, ten patients (9.4%) had 11 RBC alloantibodies, whose specificities were 2 anti-K; 2 anti-C; one each of anti-D, -E, -M, and -S; and 3 were pan-reactive. The number of transfusion episodes was significantly associated with the rate of alloimmunisation (p=0.000). In conclusion the overall alloimmunisation rate in the study was 9.4% and this was significantly associated with increasing number of transfusion episodes. Antibodies were mainly directed against antigens in the Rhesus system and K antigen. We recommend that antibody screening be incorporated into routine pre-transfusion testing procedures in Ghana. Keywords: Alloimmunisation, multi transfusion, Alloantibod

Ileal Mucosal and Fecal Pancreatitis Associated Protein Levels Reflect Severity of Salmonella Inflection in Rats

Background Microbial infections induce ileal pancreatitis-associated protein/regenerating gene III (PAP/RegIII) mRNA expression. Despite increasing interest, little is known about the PAP/RegIII protein. Therefore, ileal mucosal PAP/RegIII protein expression, localization, and fecal excretion were studied in rats upon Salmonella infection. Results Salmonella infection increased ileal mucosal PAP/RegIII protein levels in enterocytes located at the crypt-villus junction. Increased colonization and translocation of Salmonella was associated with higher ileal mucosal PAP/RegIII levels and secretion of this protein in feces. Conclusions PAP/RegIII protein is increased in enterocytes of the ileal mucosa during Salmonella infection and is associated with infection severity. PAP/RegIII is excreted in feces and might be used as a new and non-invasive infection marke

Regular Patterns in Cerebellar Purkinje Cell Simple Spike Trains

Background. Cerebellar Purkinje cells (PC) in vivo are commonly reported to generate irregular spike trains, documented by high coefficients of variation of interspike-intervals (ISI). In strong co

Magnesium butyrate is a readily available magnesium source in dairy cow nutrition

The aim of the present study was to measure the apparent absorption of magnesium (Mg) originating from Mg-butyrate. Six mid-lactation Holstein Friesian dairy cows were used with dietary treatments arranged in a cross-over design. Two different diets were fed during the experiment, consisting of a low Mg diet without Mg-butyrate (L-Mg, 3.1 g Mg/kg dry matter) or a high Mg diet with Mg-butyrate (H-Mg, 3.9 g Mg/kg dry matter). Cows offered the L-Mg diet ingested 54.7 g Mg/day while the cows fed the H-Mg diets ingested 66.3 g Mg/day (P < 0.001). The fecal excretion of Mg, however, was similar between the two experimental diets (P = 0.174). Consequently, apparent Mg absorption was found to be 7.9 % units greater (P = 0.038) when the cows were fed the diet supplemented with Mg-butyrate. The greater Mg absorption after feeding the H-Mg diet was, however, not reflected by a greater urinary Mg concentration (P = 0.228). The fractional Mg absorption from Mg-butyrate was calculated to be 71.6 %, which indicates that Mg from Mg-butyrate is readily available for absorption. In conclusion, Mg-butyrate is an attractive alternative to supplement dairy rations with Mg

Silencing the majority of cerebellar granule cells uncovers their essential role in motor learning and consolidation.

Cerebellar granule cells (GCs) account for more than half of all neurons in the CNS of vertebrates. Theoretical work has suggested that the abundance of GCs is advantageous for sparse coding during memory formation. Here, we minimized the output of the majority of GCs by selectively eliminating their CaV2.1 (P/Q-type) Ca2+ channels, which mediate the bulk of their neurotransmitter release. This resulted in reduced GC output to Purkinje cells (PCs) and stellate cells (SCs) as well as in impaired long-term plasticity at GC-PC synapses. As a consequence modulation amplitude and regularity of simple spike (SS) output were affected. Surprisingly, the overall motor performance was intact, whereas demanding motor learning and memory consolidation tasks were compromised. Our findings indicate that a minority of functionally intact GCs is sufficient for the maintenance of basic motor performance, whereas acquisition and stabilization of sophisticated memories require higher numbers of normal GCs controlling PC firing

Aspiration Versus Stent Retriever Thrombectomy for Posterior Circulation Stroke

BACKGROUND AND PURPOSE: Whereas a clear benefit of endovascular treatment for anterior circulation stroke has been established, randomized trials assessing the posterior circulation have failed to show efficacy. Previous studies in anterior circulation stroke suggest that advanced thrombectomy devices were of great importance in achieving clinical benefit. Little is known about the effect of thrombectomy techniques on outcomes in posterior circulation stroke. In this study, we compare first-line strategy of direct aspiration to stent retriever thrombectomy for posterior circulation stroke. METHODS: We analyzed data of patients with a posterior circulation stroke who were included in the Multicentre Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands Registry between March 2014 and December 2018, a prospective, nationwide study, in which data were collected from consecutive patients who underwent endovascular treatment for ischemic stroke in the Netherlands. We compared patients who underwent first-line aspiration versus stent retriever thrombectomy. Primary outcome was functional outcome according to the modified Rankin Scale. Secondary outcomes were reperfusion grade, complication rate, and procedure duration. Associations between thrombectomy technique and outcome measures were estimated with multivariable ordinal logistic regression analyses. RESULTS: Overall, 71 of 205 patients (35%) were treated with aspiration, and 134 (65%) with stent retriever thrombectomy. Patients in the aspiration group had a lower pc-ASPECTS on baseline computed tomography, and general anesthesia was more often applied in this group. First-line aspiration was associated with better functional outcome compared with stent retriever thrombectomy (adjusted common odds ratio for a 1-point improvement on the modified Rankin Scale 1.94 [95% CI, 1.03-3.65]). Successful reperfusion (extended Thrombolysis in Cerebral Infarction ≥2B) was achieved more often with aspiration (87% versus 73%, P=0.03). Symptomatic hemorrhage rates were comparable (3% versus 4%). Procedure times were shorter in the aspiration group (49 versus 69 minutes P<0.001). CONCLUSIONS: In this retrospective nonrandomized cohort study, our findings suggest that first-line aspiration is associated with a shorter procedure time, better reperfusion, and better clinical outcome than stent retriever thrombectomy in patients with ischemic stroke based on large vessel occlusion in the posterior circulation

Gating of Long-Term Potentiation by Nicotinic Acetylcholine Receptors at the Cerebellum Input Stage

The brain needs mechanisms able to correlate plastic changes with local circuit activity and internal functional states. At the cerebellum input stage, uncontrolled induction of long-term potentiation or depression (LTP or LTD) between mossy fibres and granule cells can saturate synaptic capacity and impair cerebellar functioning, which suggests that neuromodulators are required to gate plasticity processes. Cholinergic systems innervating the cerebellum are thought to enhance procedural learning and memory. Here we show that a specific subtype of acetylcholine receptors, the α7-nAChRs, are distributed both in cerebellar mossy fibre terminals and granule cell dendrites and contribute substantially to synaptic regulation. Selective α7-nAChR activation enhances the postsynaptic calcium increase, allowing weak mossy fibre bursts, which would otherwise cause LTD, to generate robust LTP. The local microperfusion of α7-nAChR agonists could also lead to in vivo switching of LTD to LTP following sensory stimulation of the whisker pad. In the cerebellar flocculus, α7-nAChR pharmacological activation impaired vestibulo-ocular-reflex adaptation, probably because LTP was saturated, preventing the fine adjustment of synaptic weights. These results show that gating mechanisms mediated by specific subtypes of nicotinic receptors are required to control the LTD/LTP balance at the mossy fibre-granule cell relay in order to regulate cerebellar plasticity and behavioural adaptation

SK2 channels in cerebellar Purkinje cells contribute to excitability modulation in motor-learning-specific memory traces

Neurons store information by changing synaptic input weights. In addition, they can adjust their membrane excitability to alter spike output. Here, we demonstrate a role of such "intrinsic plasticity" in behavioral learning in a mouse model that allows us to detect specific consequences of absent excitability modulation. Mice with a Purkinje-cell-specific knockout (KO) of the calcium-activated K+ channel SK2 (L7-SK2) show intact vestibulo-ocular reflex (VOR) gain adaptation but impaired eyeblink conditioning (EBC), which relies on the ability to establish associations between stimuli, with the eyelid closure itself depending on a transient suppression of spike firing. In these mice, the intrinsic plasticity of Purkinje cells is prevented without affecting long-term depression or potentiation at their parallel fiber (PF) input. In contrast to the typical spike pattern of EBC-supporting zebrin-negative Purkinje cells, L7-SK2 neurons show reduced background spiking but enhanced excitability. Thus, SK2 plasticity and excitability modulation are essential for specific forms of motor learning