Eye movements and verbal report in a single case of visual neglect

In this single case study, visuospatial neglect patient P1 demonstrated a dissociation between an intact ability to make appropriate reflexive eye movements to targets in the neglected field with latencies of <400 ms, while failing to report targets presented at such durations in a separate verbal detection task. In contrast, there was a failure to evoke the usually robust Remote Distractor Effect in P1, even though distractors in the neglected field were presented at above threshold durations. Together those data indicate that the tight coupling that is normally shown between attention and eye movements appears to be disrupted for low-level orienting in P1. A comparable disruption was also found for high-level cognitive processing tasks, namely reading and scene scanning. The findings are discussed in relation to sampling, attention and awareness in neglect.     

Anti-stress activity of Propionibacterium freudenreichii: identification of a reactivative protein

Propionibacterium freudenreichii subsp. shermanii is known to prevent mutations caused by various agents such as N-methyl-N'-nitro-N-nitrosoguanidine, 9-aminoacridine, 4-nitro-quinoline-1-oxide and by UV radiation in both prokaryotic and eukaryotic cells. It was also shown to prevent or repair damage caused by H(2)O(2) or UV radiation in Salmonella typhimurium and Escherichia coli, a characteristic previously designated as reactivative effect. In order to characterise this effect at the molecular level, we have purified the active component from a P. freudenreichii cell-free extract using a combination of ammonium sulfate precipitation, anion-exchange and size-exclusion chromatography. The isolated 35 kDa protein was then identified using both N-terminal and internal peptide sequencing as a cysteine synthase. The latter was localised in the P. freudenreichii proteomic map. It is constitutively expressed but also clearly induced during adaptation to detergent and heat, but not acid, stresses. The biological meaning of cysteine synthase in the context of adaptation to oxidative and non-oxidative stresses is discussed.     

The impact of acquired brain damage in terms of epidemiology,economics and loss in quality of life

Background  

Patients with acquired brain damage (ABD) have suffered a brain lesion that interrupts vital development in the physical, psychological and social spheres. Stroke and traumatic brain injury (TBI) are the two main causes. The objectives of this study were to estimate the incidence and prevalence of ABD in the population of the Basque Country and Navarre in 2008, to calculate the associated cost of the care required and finally to assess the loss in health-related quality of life.     

Can Gas Replace Protein Function? CO Abrogates the Oxidative Toxicity of Myoglobin

Outside their cellular environments, hemoglobin (Hb) and myoglobin (Mb) are known to wreak oxidative damage. Using haptoglobin (Hp) and hemopexin (Hx) the body defends itself against cell-free Hb, yet mechanisms of protection against oxidative harm from Mb are unclear. Mb may be implicated in oxidative damage both within the myocyte and in circulation following rhabdomyolysis. Data from the literature correlate rhabdomyolysis with the induction of Heme Oxygenase-1 (HO-1), suggesting that either the enzyme or its reaction products are involved in oxidative protection. We hypothesized that carbon monoxide (CO), a product, might attenuate Mb damage, especially since CO is a specific ligand for heme iron. Low density lipoprotein (LDL) was chosen as a substrate in circulation and myosin (My) as a myocyte component. Using oxidation targets, LDL and My, the study compared the antioxidant potential of CO in Mb-mediated oxidation with the antioxidant potential of Hp in Hb-mediated oxidation. The main cause of LDL oxidation by Hb was found to be hemin which readily transfers from Hb to LDL. Hp prevented heme transfer by sequestering hemin within the Hp-Hb complex. Hemin barely transferred from Mb to LDL, and oxidation appeared to stem from heme iron redox in the intact Mb. My underwent oxidative crosslinking by Mb both in air and under N₂. These reactions were fully arrested by CO. The data are interpreted to suit several circumstances, some physiological, such as high muscle activity, and some pathological, such as rhabdomyolysis, ischemia/reperfusion and skeletal muscle disuse atrophy. It appear that CO from HO-1 attenuates damage by temporarily binding to deoxy-Mb, until free oxygen exchanges with CO to restore the equilibrium.     

The Importance of Mentorship and Interest Group Involvement for the Orthopedic Surgery Applicant

BackgroundMentorship in medical education is important for students’ professional development career planning. Orthopedic Surgery Interest Groups (OSIG) exist as formal organizations and serve as a conduit for undergraduate mentorship, though the role of mentorship via OSIGs within orthopedic medicine has not been thoroughly evaluated. Similarly, OSIGs within institutions are not standardized nor well defined. We sought to answer: (1) What offerings does OSIG provide for students interested in orthopaedic surgery? (2) How does OSIG involvement impact the orthopaedic surgery residency applicant? (3) Does OSIG involvement increase match rates for orthopaedic surgery residency applicants?MethodsAn online survey was distributed to faculty advisors at all allopathic US medical schools with available contact information. Results were analyzed using SPSS.ResultsOf the 28 respondent organizations, the majority (53.6%) have between 1-25 student members. On average, OSIGS offer 3.64 + 1.59 (mode = 4) executive positions. The most important initiative for OSIG groups was clinical/surgical shadowing, followed by faculty mentorship, and guidance for the residency application. OSIG involvement does impact the applicant, as all faculty mentors believed this to be an important component of the residency application. Leadership positions within OSIG was not perceived as being equally important. OSIG involvement did increase match rates; the match rate for all students at the schools surveyed (n=17) was 81.21% while the match rate for students within OSIG (n=17) was 82.39% (p<0.05). Of all students who applied to orthopedic surgery residency programs, 98.9% were members of OSIG, and of all students who successfully matched into orthopedic surgery residency programs in the 2019-2020 cycle, 100% (p<0.05) of students (n=17) were involved in OSIG.ConclusionThis study indicates the importance of involvement in OSIG as a conduit for clinical exposure and mentorship throughout medical education, and is especially relevant for applicants given the impact of the COVID-19 pandemic on the residency application process. Data suggests that participation in an OSIG is a valuable experience for the medical student interested in orthopedics and that students involved in OSIGs are more likely to match into orthopedic residency programs. Level of Evidence: V     

INFLUENCE OF TEMPERATURE ON THE MORTALITY OF MYZUS PERSICAE (SULZER) DUE TO THE FUNGAL PATHOGEN ZOOPHTHORA PHALLOIDES BATKO

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Nymphs of Myzus persicae inoculated with Zoophthora phalloides were killed at each temperature tested in the range 10–22°C. Mortality was around 50% at 12, 15 and 18°C, but was considerably reduced outside this range. Deaths occurred soonest at 18°C (LT₅₀—6.8 days). The low temperature requirement of this fungus limits its potential as a biocontrol agent for aphids in Australia.     

Microparticle Shedding from Neural Progenitor Cells and Vascular Compartment Cells Is Increased in Ischemic Stroke

Purpose

Ischemic stroke has shown to induce platelet and endothelial microparticle shedding, but whether stroke induces microparticle shedding from additional blood and vascular compartment cells is unclear. Neural precursor cells have been shown to replace dying neurons at sites of brain injury; however, if neural precursor cell activation is associated to microparticle shedding, and whether this activation is maintained at long term and associates to stroke type and severity remains unknown. We analyzed neural precursor cells and blood and vascular compartment cells microparticle shedding after an acute ischemic stroke.

Methods

Forty-four patients were included in the study within the first 48h after the onset of stroke. The cerebral lesion size was evaluated at 3–7 days of the stroke. Circulating microparticles from neural precursor cells and blood and vascular compartment cells (platelets, endothelial cells, erythrocytes, leukocytes, lymphocytes, monocytes and smooth muscle cells) were analyzed by flow cytometry at the onset of stroke and at 7 and 90 days. Forty-four age-matched high cardiovascular risk subjects without documented vascular disease were used as controls.

Results

Compared to high cardiovascular risk controls, patients showed higher number of neural precursor cell- and all blood and vascular compartment cell-derived microparticles at the onset of stroke, and after 7 and 90 days. At 90 days, neural precursor cell-derived microparticles decreased and smooth muscle cell-derived microparticles increased compared to levels at the onset of stroke, but only in those patients with the highest stroke-induced cerebral lesions.

Conclusions

Stroke increases blood and vascular compartment cell and neural precursor cell microparticle shedding, an effect that is chronically maintained up to 90 days after the ischemic event. These results show that stroke induces a generalized blood and vascular cell activation and the initiation of neuronal cell repair process after stroke. Larger cerebral lesions associate with deeper vessel injury affecting vascular smooth muscle cells.     

Oscillatory Brain Activity Reveals Linguistic Prints in the Quantity Code

Number representations change through education, although it is currently unclear whether and how language could impact the magnitude representation that we share with other species. The most prominent view is that language does not play any role in modulating the core numeric representation involved in the contrast of quantities. Nevertheless, possible cultural hints on the numerical magnitude representation are currently on discussion focus. In fact, the acquisition of number words provides linguistic input that the quantity system may not ignore. Bilingualism offers a window to the study of this question, especially in bilinguals where the two number wording systems imply also two different numerical systems, such as in Basque-Spanish bilinguals. The present study evidences linguistic prints in the core number representational system through the analysis of EEG oscillatory activity during a simple number comparison task. Gamma band synchronization appears when Basque-Spanish bilinguals compare pairs of Arabic numbers linked through the Basque base-20 wording system, but it does not if the pairs are related through the base-10 system. Crucially, this gamma activity, originated in a left fronto-parietal network, only appears in bilinguals who learned math in Basque and not in equivalent proficiency bilinguals who learned math in Spanish. Thus, this neural index reflected in gamma band synchrony appears to be triggered by early learning experience with the base-20 numerical associations in Basque number words.