Cerebral Oxygenation Dynamics During Incremental Exercise: Comparison of Arm Cranking and Leg Cycling

This study aimed to compare cerebral oxyhemoglobin (O₂Hb) levels during incremental exercise by cycling vs. arm cranking in 12 healthy adult men aged 20.8 ± 0.2 years old. O₂Hb was measured by near-infrared spectroscopy. Regions of interest included the left and right prefrontal cortices (LtPFC and RtPFC, respectively), the left and right premotor cortices (LtPMC and RtPMC, respectively), and the supplementary motor area (SMA) bilaterally. After 4 min of rest, 4 min of warm-up was performed by using ergometer followed by incremental exercise (increasing work rate by 5 W/min for arm cranking and 20 W/min for cycling exercise). All values were averaged every tenth of the participant's exercise time period from beginning of incremental exercise to end point. At the middle exercise intensity (50% exercise time), the averaged O₂Hb values obtained at all regions of interest seemed to be higher during arm cranking exercise as compared to cycling; however, there were no significant differences between two types of exercise. At the end point of incremental exercise (100% exercise time), the O₂Hb obtained at all regions of interest was significantly higher during arm cranking exercise compared to cycling (LtPFC 0.081 ± 0.019 vs. -0.001 ± 0.013 mM·cm, RtPFC 0.076 ± 0.021 vs. 0.018 ± 0.015 mM·cm, SMA 0.012 ± 0.040 vs. 0.040 ± 0.016 mM·cm; arm cranking vs. cycling; p < 0.05, respectively). We conclude that exercise-induced cerebral oxygenation is greater with arm cranking than with leg cycling.

Impact of immunoreactive substances contained in apheresis platelet concentrate on postoperative respiratory function in surgical patients receiving platelet transfusion: a prospective cohort study

OBJECTIVES

To construct an alternative policy for the donor selection of platelet concentrate (PC), a clinical study exploring the features of lung injury following PC administration is needed.

BACKGROUND

Although a male-donor-only policy for plasma products appears to have efficiently reduced transfusion-related acute lung injury (TRALI), this policy may not be applied to PC because of supply shortages.

METHODS AND MATERIALS

We prospectively examined pulmonary function after the transfusion of PC in informed surgical patients treated at a tertiary university hospital in Japan. The contributions of immunoreactive substances contained in the PC to respiratory function after PC transfusion was then statistically examined.

RESULTS

Eighty-six patients (56 men, 30 women) were enrolled in the analysis. Fifty-four cases experienced respiratory failure (PaO2 /FiO2 <300 mmHg) after transfusion. Five cases were diagnosed as possible TRALI based on permeability pulmonary oedema, while 23 cases were diagnosed as transfusion-associated circulatory overload (TACO) based on chest radiograph findings. A multivariate logistic regression analysis identified the presence of anti-granulocyte antibody as a significant predictor of possible TRALI [P = 0.023; odds ratio (OR), 13.0; 95% confidence interval (CI), 1.4-118.3]. Meanwhile, anti-leukocyte antibody class II was identified as a significant independent predictor of TACO (P = 0.010; OR, 18.4; 95% CI, 2.0-170.1).

CONCLUSIONS

Our data suggest that antibodies contained in PC may contribute to the deterioration of respiratory function after PC transfusion, although the diagnoses of TACO and TRALI may have overlapped among the patients with pulmonary distress in this cohort.

Online social network size is reflected in human brain structure

The increasing ubiquity of web-based social networking services is a striking feature of modern human society. The degree to which individuals participate in these networks varies substantially for reasons that are unclear. Here, we show a biological basis for such variability by demonstrating that quantitative variation in the number of friends an individual declares on a web-based social networking service reliably predicted grey matter density in the right superior temporal sulcus, left middle temporal gyrus and entorhinal cortex. Such regions have been previously implicated in social perception and associative memory, respectively. We further show that variability in the size of such online friendship networks was significantly correlated with the size of more intimate real-world social groups. However, the brain regions we identified were specifically associated with online social network size, whereas the grey matter density of the amygdala was correlated both with online and real-world social network sizes. Taken together, our findings demonstrate that the size of an individual's online social network is closely linked to focal brain structure implicated in social cognition.

Enhanced therapeutic efficacy of G207 for the treatment of glioma through Musashi1 promoter retargeting of gamma34.5-mediated virulence

G207 is a conditionally replicating derivative of herpes simplex virus type1 (HSV-1) engineered with deletions of both ICP34.5 loci and a lacZ insertion disabling the ICP6 gene. G207 exhibits an efficient oncolytic activity in vitro and in vivo, yet minimal toxicity in normal tissue, and is now in clinical trial for malignant glioma. According to the results of clinical trials, however, although G207 was proved to be safe, the efficacy was not so impressive. Deletion of the ICP34.5 gene coding for virulence made G207 extremely safe, but it markedly reduced the cytotoxicity mediated by HSV-1. To enhance the therapeutic efficacy of G207 without diminishing its safety, we used a defective vector containing Musashi1 promoter/ICP34.5, with G207 as helper virus. P/musashi1 was functional selectively in human glioma cell lines (U87MG, U251, T98G) in this study and dvM345 showed a much higher therapeutic efficacy both in culture and in the in vivo glioma model, than G207 alone, without diminishing its favorable toxicity profile. These results suggest that transcriptional regulation of ICP34.5 by P/musashi1 can be used to target HSV-1 virulence toward gliomas while maintaining the desirable neuroattenuated phenotype.

Inhibition of saccade initiation by preceding smooth pursuit

In this study, we investigated the influence of smooth-pursuit eye movements on saccade initiation in response to a sudden jump of a continuously moving target. We replicated the finding by Tanaka et al. (1998) that saccadic eye movements in the direction opposite to preceding pursuit have longer latencies than those in the same direction. We confirmed that this asymmetry is indeed due to an inhibitory effect of smooth pursuit on saccade initiation in the opposite direction rather than facilitation of saccade initiation in the same direction. The inhibitory effect decreased strongly when subjects knew the jump direction in advance. This supports the notion that the prolonged latencies of backward saccades are not due to orbital mechanics or low-level motor processing. Furthermore, we found that the range of saccade directions inhibited by a pursuit movement is broad, covering all directions that did not have the same horizontal component as the pursuit direction. This is in contrast with the predictions of "Inhibition of Saccade Return" (ISR, Hooge and Frens 2000), which is restricted to a smaller confined area.

[A case of peculiar type of post-encephalitic/encephalopathic epilepsy: efficacy of bromide in the control of intractable seizures]

A 5-year-old boy with a peculiar type of post-encephalitic/encephalopathic epilepsy is reported. He had been healthy showing normal development before its onset. Five days after the onset of an upper respiratory infection, he had a severe generalized seizure, that evolved into intractable seizures. They were highly resistant to almost all anticonvulsants and occasionally resulted in status epilepticus. High-dose phenobarbital therapy successfully controlled the convulsions, but was discontinued because of drug-induced aplastic anemia. Alternative bromide therapy was markedly effective in controlling the seizures.

Crystal structure of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011 complexed with 1-deoxynojirimycin at 2.0 A resolution

1-Deoxynojirimycin, a pseudo-monosaccharide, is a strong inhibitor of glucoamylase but a relatively weak inhibitor of cyclodextrin glucanotransferase (CGTase). To elucidate this difference, the crystal structure of the CGTase from alkalophilic Bacillus sp. 1011 complexed with 1-deoxynojirimycin was determined at 2.0 A resolution with the crystallographic R value of 0.154 (R(free) = 0.214). The asymmetric unit of the crystal contains two CGTase molecules and each molecule binds two 1-deoxynojirimycins. One 1-deoxynojirimycin molecule is bound to the active center by hydrogen bonds with catalytic residues and water molecules, but its binding mode differs from that expected in the substrate binding. Another 1-deoxynojirimycin found at the maltose-binding site 1 is bound to Asn-667 with a hydrogen bond and by stacking interaction with the indole moiety of Trp-662 of molecule 1 or Trp-616 of molecule 2. Comparison of this structure with that of the acarbose-CGTase complex suggested that the lack of stacking interaction with the aromatic side chain of Tyr-100 is responsible for the weak inhibition by 1-deoxynojirimycin of the enzymatic action of CGTase.

Dynamic properties, interactions and adaptive modifications of vestibulo-ocular reflex and optokinetic response in mice

Dynamic properties of horizontal vestibulo-ocular reflex (VOR) and optokinetic response (OKR) were studied in mice. The VOR was examined in the dark (VORD), in the light (VORL) and in the condition in which most of the visual field moves synchronously with the head motion (VORF). A mouse and/or a surrounding screen with vertical stripes was rotated sinusoidally, and the gain and phase of eye movements were measured in wide dynamic stimulation ranges. The working conditions of VOR and OKR were supplementary; OKR worked at low speeds of head turn and VOR at high speeds. Examination of VORL and VORF revealed non-linear interaction of VOR and OKR. The continuous sinusoidal head oscillation coupled with the in-phase or the out-of-phase oscillation of the surrounding screen, decreased or increased the VORD gain, and increased or decreased the VORD phase lead, respectively. Continuous oscillation of the surrounding screen increased the OKR gain and decreased the phase delay. These changes of VOR and OKR work to reduce the retinal slip. The present study provides fundamental information concerning the dynamic properties of VOR and OKR and the nature of their adaptive modifications in mice, which have been extensively used in genetic manipulation recently.