Uptake of Fe III influences the topographical arrangement of N-glycan(s) in human transferrin

The relative prominence of sialyl and α-mannosyl residues of apo- and metal-bound transferrin were compared. Although the presence or absence of Fe^III did not significantly affect the rate of desialylation of the glycoprotein, equilibrium dialysis with serotonin revealed substantial differences between apo- and metalbound transferrins: binding of serotonin by Fe^III-transferrin (2.3 residues/mol) exceeded that of Cu^II- or Mn^II-transferrin (each 1.3 residues/mol); in comparison apo-transferrin (0.6 residues/mol) and Fe^III-asialo-transferrin (0.5 residues/mol) bound significantly less serotonin. In the case of α-mannosyl residues, differences between certain metal-bound transferrins were observed from Sepharose-concanavalin A chromatography. Thus 20–24% of Fe^III-transferrin passed through the lectin column compared to 12–16% for Mn^II-and Cu^II-transferrins. We conclude that incorporation of metal ions, particularly Fe^III, which is known to change the tertiary structure of transferrin, alters the position(s) of the N-glycan(s) relative to the polypeptide. Such a change may govern the destiny of apo- and metal-bound transferrin in the circulation.     

Topographic mapping of brain potentials in the newborn infant: the establishment of normal values and utility in assessing infants with neurological injury

AIM: To demonstrate that quantitative EEG (qEEG) can be used as a non-invasive measure of brain injury by establishing normative data in term infants and contrasting it with other modalities of brain imaging. DESIGN: qEEG during quiet sleep was performed on 13 healthy full-term infants comprising a normal group and on 10 infants with neurological abnormalities identified on brain imaging studies (abnormal group) at 36-47 wk postconceptional age. Quantitative analysis was performed and topographic maps were produced for each patient. The EEG data from the normal group, after spectral analysis, yielded power data in the delta, theta, alpha, and beta frequency bands and coherence information, which then formed the normative database. qEEG from the infants in the abnormal group was then compared to this normative data. RESULTS: The normal group's mean absolute power in the delta, theta, alpha, and beta bands for all EEG leads combined were 278.48+/-83.83, 31.71+/-10.12, 29.20+/-2.04, and 35.76+/-11.35 uv2, respectively. The median frequency was 1.49+/-0.07, 5.45+/-3.46, 9.74+/-5.11, and 18.01+/-3.38 Hz, respectively. The qEEG was abnormal in all 10 study infants, while abnormalities were noted in the clinical EEG in 4 of 10, in the neuroultrasound in 5 of 10, in the CT in one of 6, and in the MRI in 2 of 2 tested. CONCLUSIONS: qEEG appears to be a useful non-invasive method for measuring brain injury as it correlates well with other modalities of brain imaging and, if corroborated by further study, may, in fact, be more sensitive in determining abnormalities in brain function.     

Missing data imputation through GTM as a mixture of -distributions

The Generative Topographic Mapping (GTM) was originally conceived as a probabilistic alternative to the well-known, neural network-inspired, Self-Organizing Maps. The GTM can also be interpreted as a constrained mixture of distribution models. In recent years, much attention has been directed towards Student t-distributions as an alternative to Gaussians in mixture models due to their robustness towards outliers. In this paper, the GTM is redefined as a constrained mixture of t-distributions: the t-GTM, and the Expectation-Maximization algorithm that is used to fit the model to the data is modified to carry out missing data imputation. Several experiments show that the t-GTM successfully detects outliers, while minimizing their impact on the estimation of the model parameters. It is also shown that the t-GTM provides an overall more accurate imputation of missing values than the standard Gaussian GTM.     

应用大脑皮质体觉诱发反应地图验证循经感传的形成机制

The study is to observe the variation of functional motility in cortical somatosensory area I (SI) during propagated sensation and imitating sensation conduction along meridians with cortical somatosensory evoked potential(CSEP) topograpic map. The observation has been done on 42 volunteers and the results show that in those whose signs of propagated sensation along meiridians (PSM) were obvious when the sensation along the Gall Bladder Meiridian(GBM) passed to head and face, a red high potential signal appeared in the lower limbs representing area, which is near the middle line of cortical somatosensory evoked potential topograpic map, and a red high potential signal, jumping over the upper limbs representing area, also appeared in the face representing area, which is at the external part of cortical somatosensory evoked potential topograpic map, while in those whose PSM was not reported only a red high potential signal appeared in the lower limbs representing area. When Hegu (LI 4) was stimulated in those without PSM, usually an obvious evoked response appeared only in the upper limbs representing area. However, when Hegu was stimulted in those with PSM, the response area was larger in the upper limbs representing area and extending to face representing area. Mechanical compression can block PSM, and corresponding change will show in CSEP topographic map. This provides compelling evidence for the hypothesis Correspondence to: Professor Jin-sen Xu, Fujian Academy of TCM, Fuzhou 350003, China. Tel: (+86)591-8357-0748, Fax: (+86)591-8357-0007, Email: xujinsenjls@163.com that peripheral driver stimulation were the key element of producing PSM.     

Computer-assisted surgery for reconstruction of complex mandibular defects using osteomyocutaneous microvascular fibular free flaps: Use of a skin paddle-outlining guide for soft-tissue reconstruction. A technical report

Introduction

We present our pre-operative virtual planning of complex mandibular reconstruction with a microvascular fibular composite free flap and its harvesting using our novel cutaneous positioning guide based on the perforator vessels for our soft tissue reconstructive surgery.

A quantitative analysis of branching,growth cone turning,and directed growth in zebrafish retinotectal axon guidance

The topographic projection from the eye to the tectum (amphibians and fish)/superior colliculus (birds and mammals) is a paradigm model system for studying mechanisms of neural wiring development. It has previously been proposed that retinal ganglion cell axons use distinct guidance strategies in fish vs. mammals, with direct guidance to the tectal target zone in the former and overshoot followed by biased branching toward the target zone in the latter. Here we visualized individual retinal ganglion cell axons as they grew over the tectum in zebrafish for periods of 10‐21 hours and analyzed these results using an array of quantitative measures. We found that, although axons were generally guided directly toward their targets, this occurred without growth cone turning. Instead, axons branched dynamically and profusely throughout pathfinding, and successive branches oriented growth cone extension toward a target zone in a stepwise manner. These data suggest that the guidance strategies used between fish and mammals may be less distinct than previously thought. J. Comp. Neurol., 521:1409–1429, 2013. © 2012 Wiley Periodicals, Inc.     

Topographic approach to the study of the human body

Recent developments in medical imaging techniques such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) have been explosive. These modalities provide 3D information about the human body and assess tissue damage in various pathological conditions. To complement the diagnostic usefulness of these imaging techniques, we have designed a system of topographic coordinates based on the principles of global projection cartography in which lines of latitude and longitudes are assigned to the surface of the human body. We designated the median sagittal plane as corresponding to the Greenwich Meridian (zero longitude) in global cartography. From the median sagittal plane (M0), vertical lines of longitude or "great circles" divide the body into 12 zones that are 30 degrees apart. Parallel lines of latitude are assigned according to surface anatomy landmarks. Studying the 3D reconstruction of anatomical structures is important for: 1) devising a system of coordinates; 2) allowing biomedical measurements to be made; and 3) drawing maps that may be useful in some clinical procedures (e.g., biopsies).