Evaluating the case-positive, control test-negative study design for influenza vaccine effectiveness for the frailty bias

Publication date: Available online 28 February 2016
Source:Vaccine
Author(s): H. Keipp Talbot, Hui Nian, Qingxia Chen, Yuwei Zhu, Kathryn M. Edwards, Marie R. Griffin
IntroductionPrevious influenza vaccine effectiveness studies were criticized for their failure to control for frailty. This study was designed to see if the test-negative study design overcomes this bias.MethodsAdults≥50 years of age with respiratory symptoms were enrolled from November 2006 through May 2012 during the influenza season (excluding the 2009–2010 H1N1 pandemic season) to perform yearly test-negative control influenza vaccine effectiveness studies in Nashville, TN. At enrollment, both a nasal and throat swab sample were obtained and tested for influenza by RT-PCR. Frailty was calculated using a modified Rockwood Index that included 60 variables ascertained in a retrospective chart review giving a score of 0 to 1. Subjects were divided into three strata: non frail (≤0.08), pre-frail (>0.08 to <0.25), and frail (≥0.25). Vaccine effectiveness was calculated using the formula [1-adjusted odds ratio (OR)]×100%. Adjusted ORs for individual years and all years combined were estimated by penalized multivariable logistic regression.ResultsOf 1023 hospitalized adults enrolled, 866 (84.7%) participants had complete immunization status, molecular influenza testing and covariates to calculate frailty. There were 83 influenza-positive cases and 783 test-negative controls overall, who were 74% white, 25% black, and 59% female. The median frailty index was 0.167 (Interquartile: 0.117, 0.267). The frailty index was 0.167 (0.100, 0.233) for the influenza positive cases compared to 0.183 (0.133, 0.267) for influenza negative controls (p=0.07). Vaccine effectiveness estimates were 55.2% (95%CI: 30.5, 74.2), 60.4% (95%CI: 29.5, 74.4), and 54.3% (95%CI: 28.8, 74.0) without the frailty variable, including frailty as a continuous variable, and including frailty as a categorical variable, respectively.ConclusionsUsing the case positive test negative study design to assess vaccine effectiveness, our measure of frailty was not a significant confounder as inclusion of this measure did not significantly change vaccine effectiveness estimates.



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Does frequent residential mobility in early years affect the uptake and timeliness of routine immunisations? An anonymised cohort study

Publication date: Available online 27 February 2016
Source:Vaccine
Author(s): Hayley A. Hutchings, Annette Evans, Peter Barnes, Melanie A. Healy, Michelle James-Ellison, Ronan A. Lyons, Alison Maddocks, Shantini Paranjothy, Sarah E. Rodgers, Frank Dunstan
BackgroundThere are conflicting findings regarding the impact of residential mobility on immunisation status. Our aim was to determine whether there was any association between residential mobility and take up of immunisations and whether they were delayed in administration.MethodsWe carried out a cohort analysis of children born in Wales, UK. Uptake and time of immunisation were collected electronically. We defined frequent movers as those who had moved: 2 or more times in the period prior to the final scheduled on-time date (4 months) for 5 in 1 vaccinations; and 3 or more times in the period prior to the final scheduled on-time date (12 months) for MMR, pneumococcal and meningitis C vaccinations. We defined immunisations due at 2–4 months delayed if they had not been given by age 1; and those due at 12–13 months as delayed if they had not been given by age 2.ResultsUptake rates of routine immunisations and whether they were given within the specified timeframe were high for both groups. There was no increased risk (odds ratios (95% confidence intervals) between frequent movers compared to non-movers for the uptake of: primary MMR 1.08 (0.88–1.32); booster Meningitis C 1.65 (0.93–2.92); booster pneumococcal 1.60 (0.59–4.31); primary 5 in 1 1.28 (0.92–1.78); and timeliness: primary MMR 0.92 (0.79–1.07); booster Meningitis C 1.26 (0.77–2.07); booster pneumococcal 1.69 (0.23–12.14); and primary 5 in 1 1.04 (0.88–1.23).DiscussionFindings suggest that children who move home frequently are not adversely affected in terms of the uptake of immunisations and whether they were given within a specified timeframe. Both were high and may reflect proactive behaviour in the primary healthcare setting to meet Government coverage rates for immunisation.



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Study on the relationship between miR-520g and the development of breast cancer

OBJECTIVE: Breast cancer (BC) is one of the most common malignant tumors occurred in women. There is no sensitive and specific marker for early diagnosis, treatment and prognosis of breast cancer. It is suggested that miRNA may be a potential tumor marker for breast cancer. Mir-520g is considered to be associated with many tumors. This study aims to test the expression of mir-520g in peripheral blood of BC patients and healthy control. We also explored the relationship between mir-520g and several prognostic factors in breast cancer patients.

PATIENTS AND METHODS: The peripheral blood of 86 cases with breast cancer (including 18 cases with stage 0, 24 cases of phase I, 20 cases of stage II, 24 cases of stage III) and 26 cases of healthy subjects were collected. The miR-520g level was measured by real-time quantitative PCR (RT qPCR) method. The correlation between plasma miR-520g level and the clinical stage, molecular subtype, receptors' expression and other factors related to the prognosis of the patients were examined.

RESULTS: Plasma mir-520g expression levels were significantly higher in BC patients with lymph node metastatic and low differentiation degree grade (p = 0.033 and 0.016), and plasma miR-520g expression was significantly higher in breast cancer patients with mammary gland invasion (p < 0.01) and low expressed p53 (p = 0.0039).

CONCLUSIONS: Highly expressed mir-520g is associated with lymph node metastasis and low differentiation of breast cancer, and also is associated with mammary gland invasion in breast cancer. This study suggests that mir-520g may be associated with some important prognostic factors in breast cancer patients, and may have a potential value for breast cancer marker.

L'articolo Study on the relationship between miR-520g and the development of breast cancer sembra essere il primo su European Review.

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Preoperative neutrophil-to-lymphocyte ratio (NLR) may be predictive of pathologic stage in patients with bladder cancer larger than 3 cm

OBJECTIVE: Bladder cancer (BCa) is the most common malignancy of the urinary tract. In this study, we aimed to evaluate the ability of preoperative neutrophil-to-lymphocyte ratio (NLR) to predict pathologic stage of at the time of first transurethral resection of bladder tumor (TUR-BT) in patients with BCa larger than 3 cm.

PATIENTS AND METHODS: Records of consecutive patients undergoing TUR-BT for BCa with a diameter >3 cm were reviewed. A total of 222 patients were eligible for analysis, and were divided into two groups: 162 patients in non-muscle-invasive BCa (NMIBC) group and 60 patients in muscle-invasive BCa (MIBC) group. Differences in preoperative blood parameters and NLR were evaluated between groups with an unequal variance t-test.

RESULTS: In the NMIBC group, 59 patients had low-grade and 103 high-grade papillary urothelial carcinomas. 60 patients had T2 stage carcinoma. The mean age of the patients was 71.8 and 75.7 years, and mean NLR was 3.44 ± 2.03 and 4.6 ± 2.8 in NMIBC and MIBC groups, respectively. In terms of NLR, there was a statistically significant difference between the NMIBC and MIBC groups (p = 0.005).

CONCLUSIONS: Our results showed that NLR might act as a significant predictive biomarker on the staging of BCa. Also, NLR could be used as a cost-effective, simple, common usable biomarker in urology clinic practice.

L'articolo Preoperative neutrophil-to-lymphocyte ratio (NLR) may be predictive of pathologic stage in patients with bladder cancer larger than 3 cm sembra essere il primo su European Review.

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Expression of CD27, CD28 and IL-17A in peripheral blood from patients with colorectal carcinoma

OBJECTIVE: To compare the different expressions of CD27, CD28, IL-17A, IFN-γ and TNF-α in the peripheral blood sampled from patients with colorectal carcinoma and healthy volunteers.

PATIENTS AND METHODS: Vδ2 T cells were isolated from the peripheral blood mononuclear cells (PBMCs) of patients with the colorectal carcinoma (CRC, n = 30) and healthy controls (HC, n = 21). The proportion of CD27, CD28, IL-17A, IFN-γ and TNF-α of Vδ2 T cells was detected by the flow cytometry.

RESULTS: We found that the proportion of IL-17A of Vδ2 T cells in PBMCs was higher in the CRC vs. the HC group (p < 0.05). A significant positive correlation was observed between the expression of IFN-γ and TNF-α of Vδ2 T cells. In the CRC patients, the proportions of IL-17A of CD27- Vδ2 T cells and CD28+ Vδ2 T cells were higher than those of CD27+ Vδ2 T cells and CD28- Vδ2 T cells, whereas the expression of IFN-γ and TNF-α of CD27-Vδ2 T cells was lower than that of CD27+ Vδ2 T cells.

CONCLUSIONS: Vδ2 T cells from PBMCs had higher expression of IL-17A in CRC patients than that in the HC group. The expression of IFN-γ and TNF-α of Vδ2 T cells from PBMCs was positively correlated. The cytokine profiles of peripheral Vδ2 T cells were likely determined by a CD27 and CD28 involving mechanism.

L'articolo Expression of CD27, CD28 and IL-17A in peripheral blood from patients with colorectal carcinoma sembra essere il primo su European Review.

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Relationship between leptin and regulatory T cells in systemic lupus erythematosus: preliminary results

OBJECTIVE: Crescent literature data demonstrated a role of adipokines in immune responses, particularly leptin is involved in wide spectrum of pro-inflammatory functions. Several evidences suggested that leptin is able to inhibit T regulatory cells proliferation and function in vitro models. In the present study, we investigate the relationship between leptin and circulating T regulatory cells (Tregs) in patients affected by systemic lupus erythematosus (SLE).

PATIENTS AND METHODS: 13 SLE patients and 11 healthy controls were enrolled. Metabolic syndrome and cardiovascular parameters were evaluated. Serum leptin levels were detected by commercial ELISA kit and circulating regulatory T cells were determined by FACS analysis as CD4+CD25highFOP3+ lymphocytes.

RESULTS: Metabolic syndrome, defined by ATPIII criteria, was more prevalent in SLE compared to controls (38.4% vs. 0%, p = 0.04), as well as arterial hypertension (38.4% vs. 0%, p = 0.04). We did not find significant differences in mean leptin levels among SLE and controls (13.13±1.51 ng/ml vs. 9.48±8.67 ng/ml, p = 0.6). Mean Tregs percentage of total CD4 were 1.27±0.9 in SLE vs. 2.8±1.2 in healthy controls (p = 0.001). We found a negative correlation between leptin levels and Tregs percentage of total CD4 in SLE patients (r = 0.4, p = 0.01).

CONCLUSIONS: Our results, suggest a role of leptin in the regulation of circulating T regulatory cells amount in human SLE.

L'articolo Relationship between leptin and regulatory T cells in systemic lupus erythematosus: preliminary results sembra essere il primo su European Review.

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A potential clinical usefulness of measuring serum bilirubin levels in patients with polymyositis

OBJECTIVE: Accumulated data have indicated that bilirubin has antiinflammatory, antioxidative, and immunosuppressive properties. Polymyositis (PM) belongs to an autoimmune disease characterized by chronic inflammation in skeletal muscle. Until now, to the best of our knowledge, there are no literature investigating bilirubin levels in patients with PM. Therefore, the aim of this investigation was to assess a relationship between bilirubin and PM.

PATIENTS AND METHODS: Our study included newly diagnosed 77 patients with PM who were admitted to the Affiliated Hospital of Youjiang Medical University for Nationalities (Guangxi, China) and 108 healthy subjects as controls. Clinical characteristics and laboratory parameters of patients were analyzed, retrospectively.

RESULTS: The serum concentrations of total bilirubin (TB), conjugate bilirubin (CB), unconjugated bilirubin (UCB) were significantly lower in patients with PM than healthy controls. Serum concentrations of TB were negatively correlated with erythrocyte sedimentation rate (ESR), creatine kinase (CK) and lactic dehydrogenase (LDH) in patients with PM (r=-0.494, p＜0.001; r=-0.274, p=0.017; r=-0.282, p=0.014), and serum concentrations of UCB were negatively correlated with ESR and CK in PM patients (r=-0.424, p＜0.001; r=-0.234, p=0.041). Both serum TB and UBC concentrations were positively correlated with manual muscle test (MMT) score in patients with PM (r=0.328, p=0.004; r=0.333, p=0.004). In multiple linear regression analysis, serum UBC levels were independently associated with MMT score (r=0.239, p=0.003).

CONCLUSIONS: We observed significantly lower serum concentrations of TB, CB and UCB in patients with PM, and suggested a potential association between serum concentrations of UBC and disease activity in PM patients.

L'articolo A potential clinical usefulness of measuring serum bilirubin levels in patients with polymyositis sembra essere il primo su European Review.

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The effect of permissive hypotension in combined traumatic brain injury and blunt abdominal trauma: an experimental study in swines

OBJECTIVE: Optimal hemodynamic resuscitation strategy of the trauma patient with uncontrolled hemorrhage and severe head injury in the pre-hospital setting remains a special challenge. Permissive hypotension prior to definite surgical haemostasis promotes coagulation, decreases blood loss and favors survival. However, hypotension is associated with poor outcome in severe head injury. The purpose of this experimental animal study was to assess the impact of permissive hypotension on survival, hemodynamic profile and brain oxygenation parameters before and/or after definite surgical haemostasis.

PATIENTS AND METHODS: Six-week-old pigs (n=12) underwent general anesthesia and brain injury was produced by the fluid percussion model. Animals were instrumented to measure hemodynamic parameters and cerebral blood flow. All animals (n=12) were subjected to laparotomy and a surgical knot was placed through the abdominal aorta wall. Uncontrolled hemorrhage was simulated by pulling out the intentionally left protruding free ends of the suture (goal MAP=30 mmHg). Animals were randomly divided into two groups; group A (n=6) was subjected to aggressive fluid resuscitation (goal SAP >80 mmHg) and group B (n=6) was left hypotensive (permissive hypotension). Animals who survived one hour of hypotensive shock underwent definite surgical haemostasis and were resuscitated for one hour. We measured survival, hemodynamic and brain oxygenation parameters at different time points before and after surgical haemostasis.

RESULTS: All animals from Group A and 50% from Group B died before surgical haemostasis. In surviving animals (Group B, 50%, p=0.033), MAP, CO, rCBF, SjO2 and AVDO2 were restored to pre-procedural levels.

CONCLUSIONS: Permissive hypotension by delaying fluid resuscitation up to definite surgical haemostasis improves survival, hemodynamics and allows restoration of cerebral oxygenation in severe head injury.

L'articolo The effect of permissive hypotension in combined traumatic brain injury and blunt abdominal trauma: an experimental study in swines sembra essere il primo su European Review.

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A new cyclic RGD peptide dimer for integrin αvβ3 imaging

OBJECTIVE: To design a new Arg-Gly-Asp (RGD) peptide that can specifically bind integrin αvβ3 and evaluate the possibility of using 131I-labeled peptide for imaging αvβ3-positive tumors.

MATERIALS AND METHODS: The structure of the RGD monomer was selected using V-life software. Based on the RGD monomer, a dimer of cyclic RGD [c(RGD)2] linked by Tyr-(D)Ser-Lys-(D)Ser-Ser with a Gly-Gly-(D)Ala-Gly side chain on the lysine residue was synthesized. 131I-c(RGD)2 was synthesized using the chloramine-T (ChT) method, and the octanol-water partition coefficient was experimentally measured. To evaluate its binding affinity and selectivity, its equilibrium dissociation constant (Kd) with U87 MG glioma cells was measured in vitro, while whole body imaging and biodistribution were assessed in vivo in mice bearing U87 MG xenografts.

RESULTS: The optimal structure of the monomer was cyclic [-Cys-Arg-Gly-Asp-(D)Ser-Cys-]. The 131I-c(RGD)2 molecule exhibited good stability and was highly hydrophilic. The Kd value was (3.87 ± 0.05) × 10-9 M, suggesting a high αvβ3-binding affinity and specificity. The tumors were clearly visualized at 3 and 6 h post-injection. Biodistribution data of the 131I-c(RGD)2 molecule showed rapid clearance from the blood and predominant accumulation in the tumor and kidney. The tumor-to-normal tissue (T/NT) ratio increased over time. At 24 h post-injection, the tumor-to-liver, tumor-to-muscle, and tumor-to-blood ratios were 4.92, 4.29, and 5.00, respectively.

CONCLUSIONS: These results suggest that the 131I-c(RGD)2 molecule may serve as a promising tracer for the detection of αvβ3-positive tumors.

L'articolo A new cyclic RGD peptide dimer for integrin αvβ3 imaging sembra essere il primo su European Review.

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Impression cytological study for ocular surface disorders of late stage eye burns

OBJECTIVE: This study aims to explore the ocular surface of late stage eye burns by impression cytology (IC) and analyze the cytological changes and their relationship to ocular surface abnormalities.

PATIENTS AND METHODS: 68 eyes with late stage eye burns (thermal burn: 28 eyes; alkali burn: 26 eyes; acid burn: 14 eyes), procured from 68 patients (aged ranges from 17 to 70 years old). Ocular surface abnormalities were assessed under slit lamp and graded. These were broadly classified as eyelid, corneal, conjunctival, and tear film abnormalities. Impression cytological examination was taken by cellulose acetate filter paper for all eyes. Samples were analyzed and scored under light microscope, including the status of epithelial cells, goblet cells, mucus and inflammatory cells. All the results and data were compared and analyzed by SPSS software (version 16.0).

RESULTS: According to the IC results, loosed cell-to-cell density and nuclear abnormality, keratinization, reduced goblet cell amount, disorder of mucus, and existing of inflammatory cells were observed in almost all the cases. The IC results were significantly correlated to the ocular surface injury severity (r=0.458, p<0.01). The ocular surface injury severity mostly contains three aspects: the corneal neovascularization scales, the present or absent of recurrent epithelial erosion and the tear film break-up time. Eyes with the foreword three symptoms were inclined to have higher IC scores. The epithelial cell-to-cell density, goblet cell and mucus amount were all correlated to tear film break-up time. However, inflammatory cell density showed no significant correlation to the conjunctival hyperemia grade. But inflammatory cell density correlated to the corneal opacity grade and epithelial stability status.

CONCLUSIONS: IC examinations could reflect the cytological disorders and relative injury severity of the ocular surface in late stage eye burns. It provides further information which will be useful in surgery and therapy.

L'articolo Impression cytological study for ocular surface disorders of late stage eye burns sembra essere il primo su European Review.

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A correlation between selenium and carnitine levels with Hypo-osmotic swelling test for sperm membrane in low-grade varicocele patients

OBJECTIVE: The hypo-osmotic swelling (HOS) test predicts membrane integrity by determining the ability of the sperm membrane to maintain equilibrium between the sperm cell and its environment. The aim of our study was to determine the correlation between selenium and carnitine levels in the seminal fluid with HOS test for sperm membrane in low-grade varicocele patients.

PATIENTS AND METHODS: Study numbered 64 examinees who suffered from low-grade varicocele and were divided into two groups, according to fertility potential and HOS test outcome. The study also included a control group of 64 healthy subjects, with no varicocele.

RESULTS: From the Shapiro-Wilk's test, it is clear that carnitine distribution differs significantly from normal (0.938, p = 0.03). In distribution of selenium, Kolmogorov-Smirnov test clearly shows statistically significant deviation from the normal curve (z = 0.225, p < 0.000), likewise Shapiro-Wilk's statistic (0.787, p < 0.000). According to the results, the second group had significantly higher levels of carnitine and selenium than the first group of examinees (p < 0.05); therefore, when we compared epididymal markers with HOS tests outcomes, we found significant differences between the two groups. There were no significant differences between second group and healthy subjects (p > 0.05).

CONCLUSIONS: HOS test outcome in varicocele patients is directly proportional to the carnitine and selenium levels, which could play a major role in both determining fertility parameters and in the treatment of its impairment. This result is especially important for sub-clinical varicocele in infertile patients with normal semen analysis, since there is no evidence of benefit from any treatment so far.

L'articolo A correlation between selenium and carnitine levels with Hypo-osmotic swelling test for sperm membrane in low-grade varicocele patients sembra essere il primo su European Review.

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Effect of complete hilar versus only renal artery clamping on renal histomorphology following ischemia/reperfusion injury in an experimental model

OBJECTIVE: To evaluate the effect of temporary complete hilar versus only renal artery clamping with different duration of warm ischemia on renal functions, and possibly identify a "safe" clamping type and duration of renal ischemia.

MATERIALS AND METHODS: Fifty male rabbits have been incorporated to study. Rabbits were subjected to ischemia/reperfusion injury by temporary vascular clamping. Reagents were randomized to 3 experimental groups (only renal artery clamping, complete hilar clamping, sham surgery) and sub-groups were determined according to different clamping times (30 and 60 minutes). Median laparotomy and left renal hilus dissection were performed to sham group. Only artery or complete hilar clamping was performed for 30 or 60 minutes by microvascular bulldog clamps to other reagents. Rabbits were sacrificed 10 days after primary surgery and left nephrectomy performed. Nephrectomy materials were evaluated for the level of nitric-oxide synthase (NOS) immunoreactivity, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity and an electron microscopic examination was performed.

RESULTS: NOS immunoreactivity was correlated with the temporary clamping time. We also observed that complete hilar vascular clamping entails an increase on NOS immunoreactivity. MDA levels were similar for all experimental surgery groups (p = 0.42). The SOD activity was decreased among all subgroups compared with sham surgery. But the significant decrease occurred in 30 minutes only artery and 30 minutes complete hilar clamping groups in proportion to sham surgery (p = 0.026 and p = 0.019, respectively).

CONCLUSIONS: This current study suggested that only renal artery clamping under 30 minutes is more appropriate during renal surgical procedures requiring temporary vascular clamping.

L'articolo Effect of complete hilar versus only renal artery clamping on renal histomorphology following ischemia/reperfusion injury in an experimental model sembra essere il primo su European Review.

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Mutations reducing replication from R-loops suppress the defects of growth, chromosome segregation and DNA supercoiling in cells lacking topoisomerase I and RNase HI activity

Publication date: Available online 27 February 2016
Source:DNA Repair
Author(s): Valentine Usongo, Makisha Martel, Aurélien Balleydier, Marc Drolet
R-loop formation occurs when the nascent RNA hybridizes with the template DNA strand behind the RNA polymerase. R-loops affect a wide range of cellular processes and their use as origins of replication was the first function attributed to them. In E. coli, R-loop formation is promoted by the ATP-dependent negative supercoiling activity of gyrase (gyrA and gyrB) and is inhibited by topoisomerase (topo) I (topA) relaxing transcription-induced negative supercoiling. RNase HI (rnhA) degrades the RNA moiety of R-loops. The depletion of RNase HI activity in topA null mutants was previously shown to lead to extensive DNA relaxation, due to DNA gyrase inhibition, and to severe growth and chromosome segregation defects that were partially corrected by overproducing topo III (topB). Here, DNA gyrase assays in crude cell extracts showed that the ATP-dependent activity (supercoiling) of gyrase but not its ATP-independent activity (relaxation) was inhibited in topA null cells lacking RNase HI. To characterize the cellular event(s) triggered by the absence of RNase HI, we performed a genetic screen for suppressors of the growth defect of topA rnhA null cells. Suppressors affecting genes in replication (holC2:aph and dnaT18:aph) nucleotide metabolism (dcd49:aph), RNA degradation (rne59:aph) and fimbriae synthesis (fimD22:aph) were found to reduce replication from R-loops and to restore supercoiling, thus pointing to a correlation between R-loop-dependent replication in topA rnhA mutants and the inhibition of gyrase activity and growth. Interestingly, the position of fimD on the E. coli chromosome corresponds to the site of one of the five main putative origins of replication from R-loops in rnhA null cells recently identified by next-generation sequencing, thus suggesting that the fimD22:aph mutation inactivated one of these origins. Furthermore, we show that topo III overproduction is unable to complement the growth defect of topA rnhA null mutants at low temperatures that stabilizes hyper-negatively supercoiled DNA.



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Cross-Modal Transfer of Statistical Information Benefits from Sleep

Publication date: Available online 27 February 2016
Source:Cortex
Author(s): Simon J. Durrant, Dr Scott A. Cairney, Dr Penelope A. Lewis
Extracting regularities from a sequence of events is essential for understanding our environment. However, there is no consensus regarding the extent to which such regularities can be generalised beyond the modality of learning. One reason for this could be the variation in consolidation intervals used in different paradigms, also including an opportunity to sleep. Using a novel statistical learning paradigm in which structured information is acquired in the auditory domain and tested in the visual domain over either 30min or 24hr consolidation intervals, we show that cross-modal transfer can occur, but this transfer is only seen in the 24hr group. Importantly, the extent of cross-modal transfer is predicted by the amount of SWS obtained. Additionally, cross-modal transfer is associated with the same pattern of decreasing MTL and increasing striatal involvement which has previously been observed to occur across 24 hours in unimodal statistical learning. We also observed enhanced functional connectivity after 24 hours in a network of areas which have been implicated in cross-modal integration including the precuneus and the middle occipital gyrus. Finally, functional connectivity between the striatum and the precuneus was also enhanced, and this strengthening was predicted by SWS. These results demonstrate that statistical learning can generalise to some extent beyond the modality of acquisition, and together with our previously published unimodal results, support the notion that statistical learning is both domain-general and domain-specific.



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Editorial Board/Title Page

Publication date: March 2016
Source:Cortex, Volume 76





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Contralesional distractors enhance ipsilesional target processing after right-hemispheric stroke

Publication date: Available online 27 February 2016
Source:Cortex
Author(s): Simone Vossel, Gereon R. Fink
Stroke can result in marked impairments in the processing of information presented in contralesional space. The present prospective study investigated how a contralesional distractor affects ipsilesional perception in patients with a right-hemispheric stroke. In a simple target detection task, the influence of the distractor on reaction times was examined in stroke patients and compared to the performance of healthy elderly controls. Distractor interference effects were related to measures of neglect and extinction using a regression analysis. Moreover, the magnitude of the behavioural distractor effect entered a voxel-based lesion-symptom mapping analysis with the hypothesis that parietal and temporoparietal lesions are related to altered distractor processing. While the presence of a distractor in the opposite hemifield slowed down reaction times in healthy controls for left and right targets, this effect was only observed for contralesional left targets in the group of right-hemispheric patients. In stark contrast, the presence of a distractor in the contralesional hemifield expedited ipsilesional (i.e., right) target detection. This effect was significantly related to lesions in the anterior middle temporal and temporoparietal cortex, external and internal capsule, as well as the superior longitudinal fascicle. These results elucidate the nature of the disruption of attentive processing in the contralesional hemifield after right-hemispheric stroke. More specifically, they shed light on the abnormal prioritisation of ipsilesional information: our data suggest that damage to the temporal and temporoparietal cortex and white matter tracts may transform contralesional stimulation into an unspecific saliency signal contributing to facilitated information processing in ipsilesional space.



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A third-person perspective on co-speech action gestures in Parkinson’s disease

Publication date: Available online 27 February 2016
Source:Cortex
Author(s): Stacey Humphries, Judith Holler, Trevor J. Crawford, Elena Herrera, Ellen Poliakoff
A combination of impaired motor and cognitive function in Parkinson's disease (PD) can impact on language and communication, with patients exhibiting a particular difficulty processing action verbs. Co-speech gestures embody a link between action and language and contribute significantly to communication in healthy people. Here, we investigated how co-speech gestures depicting actions are affected in PD, in particular with respect to the visual perspective—or the viewpoint – they depict. Gestures are closely related to mental imagery and motor simulations, but people with PD may be impaired in the way they simulate actions from a first-person perspective and may compensate for this by relying more on third-person visual features. We analysed the action-depicting gestures produced by mild-moderate PD patients and age-matched controls on an action description task and examined the relationship between gesture viewpoint, action naming, and performance on an action observation task (weight judgement). Healthy controls produced the majority of their action gestures from a first-person perspective, whereas PD patients produced a greater proportion of gestures produced from a third-person perspective. We propose that this reflects a compensatory reliance on third-person visual features in the simulation of actions in PD. Performance was also impaired in action naming and weight judgement, although this was unrelated to gesture viewpoint. Our findings provide a more comprehensive understanding of how action-language impairments in PD impact on action communication, on the cognitive underpinnings of this impairment, as well as elucidating the role of action simulation in gesture production.



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Role of features and categories in the organization of object knowledge: Evidence from adaptation fMRI

Publication date: Available online 6 February 2016
Source:Cortex
Author(s): Jingyi Geng, Tatiana T. Schnur
There are two general views regarding the organization of object knowledge. The feature-based view assumes that object knowledge is grounded in a widely distributed neural network in terms of sensory/function features (e.g., Warrington & Shallice, 1984), while the category-based view assumes in addition that object knowledge is organized by taxonomic and thematic categories (e.g., Schwartz et al., 2011). Using an functional magnetic resonance imaging (fMRI) adaptation paradigm, we compared predictions from the feature- and category-based views by examining the neural substrates recruited as subjects read word pairs that were identical, taxonomically related, thematically related or unrelated while controlling for the function features involved across the two categories. We improved upon previous study designs and employed an fMRI adaptation task, obtaining results overall consistent with both the category-based and feature-based views. Consistent with the category-based view, we observed for both hypothesized regions of interest (ROI) and exploratory (whole-brain analyses) reduced activity in the left anterior temporal lobe (ATL) for taxonomically related versus unrelated word pairs, and for the exploratory analysis only, reduced activity in the right ATL. In addition, the exploratory analyses revealed reduced activity in the left temporo-parietal junction (TPJ) for thematically related versus unrelated word pairs. Consistent with the feature-based view, we found in the exploratory analyses that activity in the bilateral precentral gyri (i.e., function regions) including part of premotor cortex reduced as the function relatedness ratings increased. However, we did not find a relationship between adaptation effects in the bilateral ATLs and left TPJ and corresponding ratings of taxonomic/thematic relationships suggesting that the adaptation effects may potentially not reflect aspects of taxonomy that have been traditionally assumed. Together, our findings indicate that both feature and category information are important for the organization of object knowledge although the exact nature of those organization principles is an important question for future research.



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Emotional caricatures in frontotemporal dementia

Publication date: March 2016
Source:Cortex, Volume 76
Author(s): Camilla N. Clark, Jason D. Warren




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Cover Figure

Publication date: March 2016
Source:Cortex, Volume 76





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Should People with Patent Foramen Ovale Go to High Altitude? A Case Report of an Alpinist with a Patent Foramen Ovale Exposed to Extreme Altitude

High Altitude Medicine & Biology , Vol. 0, No. 0.


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Naproxen, a Nonsteroidal Anti-Inflammatory Drug Can Affect Daily Hypobaric Hypoxia-Induced Alterations of Monoamine Levels in Different Areas of the Brain in Male Rats

High Altitude Medicine & Biology , Vol. 0, No. 0.


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