Towards resolving familial relationships within the Gadiformes, and the resurrection of the Lyconidae.
von der Heyden S, Matthee CA.
Evolutionary Genomics Group, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.
Evolution of structure in gamma-class carbonic anhydrase and structurally related proteins.
Protein structure contains evolutionary information and it is more highly conserved than sequence. The evolution of structure in gamma-class carbonic anhydrase (gamma-CA) and its structurally related proteins (gammaCASRPs) were discussed. To obtain a reliable analysis, we defined a subset that contains all specificities and organisms as the nonredundant set using QR factorization based on the multiple structural alignment of the known crystallographic structures of gammaCASRPs with Q(H) as the structural homology measure. Then, we applied unweighted pair group method with arithmetic averages (UPGMA) to reconstruct structural phylogeny. We found that gamma-CA most likely arose through duplication events; the domain of gamma-CA underwent a process of alpha-helical content from amino-terminal end to carboxyl-terminal end of the left-handed beta-helix (LbetaH); the capacity of gamma-CA to bind Zn occurred early in evolution and only later included the ability to catalyze the reversible hydration of CO(2) efficiently for the occurrence of two loops involving Glu 62 and Glu 84, respectively, and a long helix at the carboxyl-terminal end of the LbetaH. In addition, the main conserved regions in these structures are in the structurally constrained residues of LbetaH domain, and the topology of the structural dendrogram can be rather easily understood in terms of functional diversification.
Fu X, Yu LJ, Mao-Teng L, Wei L, Wu C, Yun-Feng M.
Institute of Resource Biology & Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Non-primary motor areas in the human frontal lobe are connected directly to hand muscles.
Structural studies in primates have shown that, in addition to the primary motor cortex (M1), premotor areas are a source of corticospinal tracts. The function of these putative corticospinal neuronal tracts in humans is still unclear. We found frontal non-primary motor areas (NPMAs), which react to targeted non-invasive magnetic pulses and activate peripheral muscles as fast as or even faster than those in M1. Hand muscle movements were observed in all our subjects about 20 ms after transcranial stimulation of the superior frontal gyrus (Brodmann areas 6 and 8). Stimulation of NPMA could activate both proximal and distal upper limb muscles with the same delay as a stimulation of the M1, indicating converging motor representations with direct functional connections to the hand. We suggest that these non-primary cortical motor representations provide additional capacity for the fast execution of movements. Such a capacity may play a role in motor learning and in recovery from motor deficits.
Teitti S, Määttä S, Säisänen L, Könönen M, Vanninen R, Hannula H, Mervaala E, Karhu J.
Clinical Neurophysiology, NBS Laboratory, Kuopio University Hospital, Finland.
Psychopathy as a disorder of the moral brain: Fronto-temporo-limbic grey matter reductions demonstrated by voxel-based morphometry.
Major advances have been made in the understanding of the neurobiology of psychopathy in the past years, yet the distribution and extent of neuroanatomical abnormalities underlying the disorder are still poorly known. It is also unclear if different dimensions of the construct of psychopathy (e.g., emotional callousness, antisocial behavior) correspond to structural abnormalities in distinct regions of the brain. We tested the following hypotheses: (1) psychopathy is related to grey matter reductions in regions of the brain that underlie moral conduct and (2) the severity of psychopathy is related to the degree of structural abnormalities. Optimized voxel-based morphometry and the screening version of the Psychopathy Checklist (PCL: SV) were employed to investigate a matched sample of 15 community psychiatric patients with high PCL: SV scores, and 15 healthy normal volunteers. The analyses controlled for total grey matter, white matter and cerebrospinal fluid volumes. Grey matter reductions were observed in the frontopolar, orbitofrontal and anterior temporal cortices, superior temporal sulcus region, and insula of the patients. The degree of structural abnormalities was significantly related to the interpersonal/affective dimension of psychopathy. The pattern of grey matter reductions in patients with high psychopathy scores comprised a distributed fronto-temporal network which plays a critical role in moral sensibility and behavior.
de Oliveira-Souza R, Hare RD, Bramati IE, Garrido GJ, Azevedo Ignácio F, Tovar-Moll F, Moll J.
Cognitive and Behavioral Neuroscience Unit, labs-D\’Or Hospital Network, Rio de Janeiro, Brazil; Gaffrée e Guinle University Hospital, Rio de Janeiro, Brazil.
Chronic smoking and the BOLD response to a visual activation task and a breath hold task in patients with schizophrenia and healthy controls.
Many psychiatric patient groups smoke heavily, but little is known regarding the effects of this habit on functional brain imaging results. The present report assesses the effect of chronic smoking on the blood oxygen level-dependent (BOLD) response to a simple visual activation (VA) task and a breath hold (BH) task in patients with schizophrenia. Eight healthy controls and twelve patients with schizophrenia were studied. Half of each group had never smoked and the other half of each group had smoked for more than 10 pack years. Responses to the VA task were assessed in the visual cortex and responses to the BH task were assessed in gray matter generally. There were four fMRI-dependent measures: (1) median percent signal change; (2) activation volume (in voxels); (3) time-to-peak of the impulse response function (IRF); and (4) time-to-trough of the IRF. All measures were tested as dependent variables in an ANCOVA with diagnosis and smoking status as crossed factors and age as a covariate. Heavy smokers had 22% larger percent signal change for the VA task and 50% larger percent signal change for the BH task. Patients had a 40% larger percent signal change for the breath hold task. Other statistically significant effects of smoking history on activation volume and the timing of the brain responses were noted. If replicated, the results may have important implications for fMRI studies comparing groups with markedly different smoking habits, such as studies comparing patients with schizophrenia, 60-90% of whom smoke, and healthy controls, who smoke with a much lower frequency.
Friedman L, Turner JA, Stern H, Mathalon DH, Trondsen LC, Potkin SG.
PO Box 51, Newbury, OH 44065, USA.
A vascular anatomical network model of the spatio-temporal response to brain activation.
Neuronal activity-induced changes in vascular tone and oxygen consumption result in a dynamic evolution of blood flow, volume, and oxygenation. Functional neuroimaging techniques, such as functional magnetic resonance imaging, optical imaging, and PET, provide indirect measures of the neural-induced vascular dynamics driving the blood parameters. Models connecting changes in vascular tone and oxygen consumption to observed changes in the blood parameters are needed to guide more quantitative physiological interpretation of these functional neuroimaging modalities. Effective lumped-parameter vascular balloon and Windkessel models have been developed for this purpose, but the lumping of the complex vascular network into a series of arterioles, capillaries, and venules allows only qualitative interpretation. We have therefore developed a parallel vascular anatomical network (VAN) model based on microscopically measurable properties to improve quantitative interpretation of the vascular response. The model, derived from measured physical properties, predicts baseline blood pressure and oxygen saturation distributions and dynamic responses consistent with literature. Furthermore, the VAN model allows investigation of spatial features of the dynamic vascular and oxygen response to neuronal activity. We find that a passive surround negative vascular response (\”negative BOLD\”) is predicted, but that it underestimates recently observed surround negativity suggesting that additional active surround vasoconstriction is required to explain the experimental data.
Boas DA, Jones SR, Devor A, Huppert TJ, Dale AM.
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
Reconstruction of central cortical surface from brain MRI images: Method and application.
Reconstruction of the central surface representation of the cerebral cortex is an important means to study the structure and function of the human brain. In this paper, we propose a novel method based on an elastic transform vector field to drive a deformable model for the reconstruction of the central cortical surface. Both simulated brain cortexes and real brain images are used to evaluate this approach. We applied the surface reconstruction method and a hybrid volumetric and surface registration algorithm to detect simulated brain atrophy. Experimental results show that the central cortical surface representation has better performance in detecting simulated atrophy than the traditionally used inner or outer cortical surface representations.
Liu T, Nie J, Tarokh A, Guo L, Wong ST.
The Center for Biotechnology and Informatics (CBI), The Methodist Hospital Research Institute, Houston, TX, USA; Department of Radiology, The Methodist Hospital, Weill Cornell Medical College, Houston, TX, USA.
Morphologic, cytometric and functional characterisation of abalone (Haliotis tuberculata) haemocytes.
This work presents the first detailed microscopic and functional analysis of the haemocytes of an abalone; the European Haliotis tuberculata. It is shown that in contrast to the situation in bivalves, only very few basophilic \”granulocytes\” could be found and exclusively with a histological stain. Neither flow cytometry, phase contrast observation nor transmission electron microscopy were able to detect any granular cells. The large majority of cells was constituted of \”hyalinocytes\”, which could be sorted by flow cytometry, for the first time, into small (blast-like) and large cells. This permits a detailed analysis of haemocytes and especially of the lowly represented blast-like cells. The differences in haemolymph cell composition between bivalves and gastropods is reviewed in depth and discussed in view of the new data we present. Most of the abalone haemocytes analysed harbour many vacuoles, large glycogen deposits, lipid inclusions and acidic compartments. However, although the number of these \”inclusions\” was rather variable in between individual hyalinocytes, these experiments did not allow to discern subpopulations using these criteria, and the population appears more as a \”differentiation continuum\”. Haemocytes adhere very rapidly and are immunologically active as they quickly phagocytose latex beads and zymozan particles. This study is the first step towards understanding the H. tuberculata immune system by adapting new tools to gastropods and in providing a first detailed morpho-functional study of their haemocytes.
Travers MA, Mirella da Silva P, Le Goïc N, Marie D, Donval A, Huchette S, Koken M, Paillard C.
CNRS UMR 6539 \”Laboratoire des sciences de l\’Environnement MARin\”, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, 29280 Plouzané, France.
Effect of endotoxin on the immunity of Indian major carp, Labeo rohita.
Endotoxin, a lipopolysaccharide component of outer cell wall membrane of the Gram-negative bacteria is a factor responsible for a number of biological effects including immunostimulatory activities in different animal species including fish. In this study, L. rohita yearlings of weight ranging from 80 to 100g were injected intraperitoneally with 0.5, 1, 2, 5, 10 and 20EU/fish dose of endotoxin to find out its effect on the immunity. The L. rohita yearlings were found to resist the endotoxin dose up to 20EU/fish and at the lower doses, i.e., at 1 and 2EU/fish; it acted as an immune potentiator. Different serum and immune parameters like protein, globulin, lysozyme, respiratory burst activity, myeloperoxidase activity, natural agglutination titre were found to be significantly high (p<0.01) at a dose of 1EU/fish. While at 10 and 20EU/fish, most of these parameters were lower thereby indicating the immuno-suppressive nature of the endotoxin at these higher doses.
Nayak SK, Swain P, Nanda PK, Dash S, Shukla S, Meher PK, Maiti NK.
Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyaganga-751 002, Bhubaneswar, Orissa, India.
Effect of location of the His-tag on the production of soluble and functional Buthus martensii Karsch insect toxin.
The low yield and poor folding efficiency in vivo of soluble and active recombinant cysteine-rich proteins expressed in Escherichia coli are a major challenge for large-scale protein production and purification. Expression vectors containing Buthus martensii Karsch insect toxin (BmK IT) fused to the C terminus of the intein Ssp DnaB were constructed in an attempt to overcome this problem. Following purification and intein self-cleavage, the fusion protein His(6)-intein-IT produced insoluble BmK IT, while intein-IT-His(6) generated soluble and properly folded BmK IT. This result indicated that the positioning of the His(6) tag has a key role in the production of soluble and functional BmK IT.
Xu CG, Fan XJ, Fu YJ, Liang AH.
Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Wucheng Road 36, Taiyuan, Shanxi 030006, PR China.