His bundle pacing insights from electroanatomical mapping: Topography and pacing targets.

OBJECTIVES: To characterize 3D electroanatomical mapping (EAM) of the His bundle (HB) region. BACKGROUND: Visualization of selective (S) and nonselective (NS) HB capture areas by EAM has not been described and may help guide HB pacing (HBP). METHODS: EAM was performed via NavX system in 17 patients (pts) undergoing HBP. HB cloud, S-HB, NS-HB, and right bundle (RB) capture areas were mapped. RESULTS: S-HBP areas were identified in 11, NS-HBP in 14, and RB in 11 pts. Two NS-HBP areas (upper and lower) either separated by S-HBP (8 pts) or almost contiguous (5 pts) were observed. S-HBP area measured: 1.1 ± 0.9 cm2 , NS upper: -1.2 ± 0.9 cm2 , NS lower: -1.2 ± 0.9 cm2 , RB: -1.7 ± 1.3 cm2 , total His cloud: -4.1 ± 2.7 cm2 . Electrocardiogram (ECG) pacemaps were different between upper and lower NS-HBP areas in 13/14 pts (p = .006). ECG differences between NS clouds were present in inferior leads in 9 pts (more negative QRS complex from lower NS area) and in precordial leads in 5 pts. There was no correlation between HBP lead location and capture threshold. R-wave amplitude was higher at more distal locations on HB cloud (p = .02). CONCLUSION: (1) Pacemapping identifies distinct regions that may correspond to HB anatomy. (2) A linear S-HBP area is typically surrounded by two separate NS areas. (3) Pace-map ECGs from upper and lower NS-HBP areas have different morphologies. (4) These EAM features and pace-mapping may be helpful to the implanter.

Preliminary study of the social and demographic profile of street food in Côte d'Ivoire: Eaters of garba.

The study aims to establish the sociodemographic profile of consumers of garba (a street food sold in Côte d'Ivoire), understand its frequency of consumption, and develop a typology of its consumers. We interviewed 547 consumers at 10 points of sale. A factorial analysis of the data collected was performed and a decision tree produced for the social and demographic variables, followed by a multiple correspondence analysis (MCA) and then a hierarchical ascending clustering (HAC). Garba is consumed more by men (70.6%), students (42%), and single people (68.2%). The consumers are mainly Christian (51.7%) or Muslims (35.8%). The principal deciding factors explaining the frequency of individual consumption are age, occupation, and marital status. Four classes of consumers are defined according to the socioprofessional category of the individuals. Garba is highly consumed in 47% of cases, moderately consumed in 35.1% of cases and poorly consumed in 17.9%. Garba is frequently consumed by all sociodemographic levels. Its consumers can be divided into four classes. In view of its high frequency of consumption, a study of its nutritional quality is necessary to ensure guarantee consumer health.

Direct Visualization of the His Bundle Pacing Lead Placement by 3-Dimensional Electroanatomic Mapping: Technique, Anatomy, and Practical Considerations.

BACKGROUND: His bundle pacing (HBP) remains technically challenging and is currently guided by electrograms and 2-dimensional fluoroscopy. Our objective was to describe a new technique for HBP directly guided by electroanatomic mapping (EAM). METHODS: Twenty-eight patients were included. The atrioventricular septum was mapped via EAM, and His bundle (HB) electrograms, selective, and nonselective HB capture sites were tagged. Pacing leads were connected to EAM, navigated to tagged HB target sites and deployed. Intracardiac electrograms and pacing parameters were recorded. Lead location was tagged on the cloud of HB sites, which was divided into 3 arbitrary segments. In 5 patients, atrioventricular nodal ablation was performed with direct visualization of the HBP lead by EAM. RESULTS: Reproducible navigation of the pacing lead to predetermined HBP locations guided by EAM was achieved in all patients. The lead was successfully deployed in 25 patients. HB cloud area was 360 (212) mm2. There was no correlation between HBP threshold and lead location on the His cloud. The intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlated with its EAM position on the His cloud ( P=0.045). Procedure, fluoroscopy, and mapping times were 116.0 (38.8), 8.6 (6.3), and 9.0 (11.4) minutes, respectively. HBP threshold at implant was 1.5 (2.3) V at 1.5 (1.0) ms. Distance between HB lead and ablation sites was 10.0 (1.3) mm in patients undergoing atrioventricular nodal ablation. CONCLUSIONS: Direct guidance of HBP by EAM allows for direct visualization of the pacing lead on the HB cloud and reproducible navigation to predetermined HB capture sites. Intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlates with His cloud location. EAM can be applied during standard HBP procedures or combined with atrioventricular nodal ablation.

Implication of the glutamate-cystine antiporter xCT in schizophrenia cases linked to impaired GSH synthesis.

xCT is the specific chain of the cystine/glutamate antiporter, which is widely reported to support anti-oxidant defenses in vivo. xCT is therefore at the crossroads between two processes that are involved in schizophrenia: oxidative stress and glutamatergic neurotransmission. But data from human studies implicating xCT in the illness and clarifying the upstream mechanisms of xCT imbalance are still scarce. Low glutathione (GSH) levels and genetic risk in GCLC (Glutamate-Cysteine Ligase Catalytic subunit), the gene of limiting synthesizing enzyme for GSH, are both associated with schizophrenia. In the present study, we aimed at determining if xCT regulation by the redox system is involved in schizophrenia pathophysiology. We assessed whether modulating GCLC expression impact on xCT expression and activity (i) in fibroblasts from patients and controls with different GCLC genotypes which are known to affect GCLC regulation and GSH levels; (ii) in rat brain glial cells, i.e., astrocytes and oligodendrocytes, with a knock-down of GCLC. Our results highlight that decreased GCLC expression leads to an upregulation of xCT levels in patients' fibroblasts as well as in astrocytes. These results support the implication of xCT dysregulation in illness pathophysiology and further indicate that it can result from redox changes. Additionally, we showed that these anomalies may already take place at early stages of psychosis and be more prominent in a subgroup of patients with GCLC high-risk genotypes. These data add to the existing evidence identifying the inflammatory/redox systems as important targets to treat schizophrenia already at early stages. SCHIZOPHRENIA: ANTIOXIDANT DEFICIT INCREASES A KEY NEUROTRANSMITTER TRANSPORTER: Deficit of antioxidant synthesis in schizophrenia leads to oxidative stress and changes in neurotransmitter transporter. Led by Kim Do, a team of researchers from Lausanne University in Switzerland investigated the role of the cell-surface transport protein xCT in schizophrenia. They found that an enzyme responsible for antioxidant production is disturbed in patients. This leads to decreased antioxidant levels and consequently to oxidative stress-i.e. the accumulation of reactive oxygen molecules, damaging the cells component and impairing cell functioning-which in turn affects the functioning of the antioxidant pathway, including xCT. xCT, which exports the neurotransmitter glutamate, is thus overproduced in schizophrenia. The resulting increase of neurotransmitter activity, alongside the increase in oxidative stress, is thought to play a major role in the pathophysiology of schizophrenia, including at early stages of the disease.

Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology?

Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease.

Glutathione deficit impairs myelin maturation: relevance for white matter integrity in schizophrenia patients.

Schizophrenia pathophysiology implies both abnormal redox control and dysconnectivity of the prefrontal cortex, partly related to oligodendrocyte and myelin impairments. As oligodendrocytes are highly vulnerable to altered redox state, we investigated the interplay between glutathione and myelin. In control subjects, multimodal brain imaging revealed a positive association between medial prefrontal glutathione levels and both white matter integrity and resting-state functional connectivity along the cingulum bundle. In early psychosis patients, only white matter integrity was correlated with glutathione levels. On the other side, in the prefrontal cortex of peripubertal mice with genetically impaired glutathione synthesis, mature oligodendrocyte numbers, as well as myelin markers, were decreased. At the molecular levels, under glutathione-deficit conditions induced by short hairpin RNA targeting the key glutathione synthesis enzyme, oligodendrocyte progenitors showed a decreased proliferation mediated by an upregulation of Fyn kinase activity, reversed by either the antioxidant N-acetylcysteine or Fyn kinase inhibitors. In addition, oligodendrocyte maturation was impaired. Interestingly, the regulation of Fyn mRNA and protein expression was also impaired in fibroblasts of patients deficient in glutathione synthesis. Thus, glutathione and redox regulation have a critical role in myelination processes and white matter maturation in the prefrontal cortex of rodent and human, a mechanism potentially disrupted in schizophrenia.

On the definition of the concepts thinking, consciousness, and conscience.

A complex system (CS) is defined as a set of elements, with connections between them, singled out of the environment, capable of getting information from the environment, capable of making decisions (i.e., of choosing between alternatives), and having purposefulness (i.e., an urge towards preferable states or other goals). Thinking is a process that takes place (or which can take place) in some of the CS and consists of (i) receiving information from the environment (and from itself), (ii) memorizing the information, (iii) the subconscious, and (iv) consciousness. Life is a process that takes place in some CS and consists of functions i and ii, as well as (v) reproduction with passing of hereditary information to progeny, and (vi) oriented energy and matter exchange with the environment sufficient for the maintenance of all life processes. Memory is a complex of processes of placing information in memory banks, keeping it there, and producing it according to prescriptions available in the system or to inquiries arising in it. Consciousness is a process of realization by the thinking CS of some set of algorithms consisting of the comparison of its knowledge, intentions, decisions, and actions with reality--i.e., with accumulated and continuously received internal and external information. Conscience is a realization of an algorithm of good and evil pattern recognition.

[Arteriography in Raynaud's phenomenon]. / L'artériographie dans le phénomène de Raynaud.

Bilateral angiographic examination of the upper limbs is performed under general anesthesia in 64 patients of a group of 138 Raynaud's phenomenons. Clinical severity of the Raynaud's phenomenon is evaluated according to the 3 grades of Porter's classification but including a grade 4 corresponding to digital gangrene. Aetiology of Raynaud's phenomenon is in relation with connective tissue diseases in 11 cases and with other aetiologies in 22 cases. Aetiology is not defined in 31 cases. Angiographic findings are: Arterial lesions are present in all 64 patients, including 11 cases of "Raynaud's disease" defined by clinical and capillaroscopic signs. Frequency of the forearm artery lesions (31% of patients), a majority concerning ulnar artery. Absence of palmar anastomosis in 55% of the cases. Frequency and severity of digital (mean 1.4/hand) and collateral digital (mean: 7.4/hand) artery lesions. Arterial lesions are in relation with the clinical severity of the Raynaud's phenomenon but generally not with its aetiology. Authors consider that angiographic examination may be indicated in Raynaud's phenomenons in relation with defined aetiology but generally not in the other cases.

Similarity principles for the biology of pelagic animals.

A similarity principle is formulated according to which the statistical pattern of the pelagic population is identical in all scales sufficiently large in comparison with the molecular one. From this principle, a power law is obtained analytically for the pelagic animal biomass distribution over the animal sizes. A hypothesis is presented according to which, under fixed external conditions, the oxygen exchange intensity of an animal is governed only by its mass and density and by the specific absorbing capacity of the animal's respiratory organ. From this hypothesis a power law is obtained by the method of dimensional analysis for the exchange intensity mass dependence. The known empirical values of the exponent of this power law are interpreted as an indication that the oxygen-absorbing organs of the animals can be represented as so-called fractal surfaces. In conclusion the biological principle of the decrease in specific exchange intensity with increase in animal mass is discussed.

Statistical hydromechanics of the solar differential rotation.

An axisymmetric hydrodynamic model of the solar differential rotation is suggested that differs from the previous axisymmetric models (with arbitrarily given anisotropic viscosity) in the use of the hydrodynamic equations (the Friedmann-Keller equations) for the statistical second moments of the fluctuations of velocity and entropy-i.e., turbulent fluxes of momentum and entropy. The model gives a correct reproduction of the differential rotation (without unreal temperature differences on the Sun's surface peculiear to the anisotropic viscosity models) and makes possible calculations of the second moments.