ACTIVITY LEVELS OF DIFFERENT CELL TYPES IN AN EPILEPTOGENIC MODEL OF CORTICAL MICROGYRIA: A cFOS INVESTIGATION

A large percentage of individuals with intractable epilepsies have an accompanying cortical malformation, the underlying cellular mechanisms of which are not fully understood. In an animal model for one such malformation, polymicrogyria, epileptogenesis occurs most easily in a region of tissue just adjacent to the microgyria termed the paramicrogyral region (PMR). Previous studies implicate somatostatin containing interneurons (SOM) as a potential contributor to this pathology, and show increased excitation of SOM in the PMR. We hypothesis that SOM are more active in the PMR when compared to SOM within the homologous region of the control cortex. In addition to this parvalbumin containing interneurons (PV) are less active than SOM in the PMR. Using a freeze-lesion model for polymicrogyria in transgenic mice that express green fluorescent protein (GFP) under the control of the cFOS promoter we assessed the activity levels of SOM and PV in the PMR and control cortex. A Kainic Acid (KA) injection was used to induce a seizure in the mice. The difference in activity levels of SOM and PV were measured with and without KA injection. These studies did not support our hypothesis. The measured activity of the cortex, as assayed by GFP expression, did not change in the PMR when compared to a control cortex, even after KA injection. In contrast to previous findings the population of PV did not decrease in the PMR when compared to a homologous region in a control cortex. SOM were more active than PV across subject group and condition. Both interneuron populations were found to be less active after KA injection. The lack of change in cortical activity is due to a high signal to noise ratio which was produced by not suppressing the social and neural activity of the mice before they were perfused by socially isolating the animals for 1-7 days before perfusing, and perfusing the mice before peak protein expression, which occurs 90 minutes after the stimulation of neural activity. The decrease in PV population has been observed in layer V, this investigation imaged the whole somatosensory cortex not just layer V, any change in neuronal population in layer V was masked by imaging a larger sample of the cortex. SOM were more active than PV across subject group and condition, this stands in contrast to the mixed evidence in the literature that PV has a higher spontaneous firing rate than SOM. The reduced activity in PV interneurons is in line with our hypothesis that SOM disinhibit pyramidal cells by inhibiting the activity of PV during the onset of a seizure. The reduced activity of SOM in this model is believed to be a product of SOM’s sensitivity to excitotoxicity in the cortex and a product of SOM experiencing depolarization block coincident with ictal activity in pyramidal cells

Ultrasonographic assessment of urinary tract lesions due to Schistosoma haematobium in Niger after four consecutive years of treatment with praziquantel

Une étude comparative sur l'étendue des lésions du tractus urinaire détectées par échographie a été entreprise dans 2 villages du Niger situés près de périmètres irrigués. La prévalence de la schistosomiase urinaire était respectivement de 64,3 % et de 58,8 %. Après un traitement au praziquantel de 4 années consécutives, les lésions vésicales atteignaient 20 % dans le village traité et 54 % dans le témoin, les lésions rénales 6 % dans le village traité et 36 % dans le témoin. Ces résultats montrent que la morbidité de la schistosomiase urinaire peut être réduite par un traitement annuel sur plusieurs années sans autre forme d'interventio

The effects of the complete replacement of barley and soybean meal with hard wheat by-products on diet digestibility, growth and slaughter traits of a local Algerian rabbit population

[EN] Eighty one rabbits were used to study the utilisation of hard wheat by-products on the growth of rabbits from a local Algerian population. At weaning (28 d, 501±99 g), the animals were individually caged and received ad libitum one of the three experimental diets for 49 d. The control diet included 26% wheat bran (W26: control diet), alfalfa, bar- ley and soybean meal. The two other diets were formulated by substituting barley and soybean meal with hard wheat by-products, and contained 60% (W60) or 67% (W67) of these by-products (50 or 57% bran and 10% middling). On average, diets contained 11.8% crude fibre and crude protein decreased from 18.3 (W26) to 16.1% (W67). Growth traits and slaughter performances were recorded. Another group of thirty animals was used to determine dietary nutrient di- gestibility from 42 to 46 d of age. Dry matter digestibility and digestible energy content were lower in the W60 and W67 diets than in the control diet (W26) (71.3 and 71.5% vs. 74.9%, and 11.9 and 11.9 vs. 12.5 MJ/kg, respectively; P<0.01). In contrast, crude fibre digestibility was lower in W26 (21.9%) than in the other two diets (29.6 and 32.2% for W60 and W67, respectively; P<0.01). The growth rates were similar for all three groups (28.0, 27.1 and 26.0 g/d for W26, W60 and W67) as were the feed conversion ratios (3.14, 3.17 and 3.10, respectively). Dressing out percentage (66.4±2.0% on average for the cold carcass) was not affected by the amount of wheat by-products in the diet. The total mortality rate was high (23%), probably corresponding to the low crude fibre content of the three experimental diets, but was not connected to the amount of wheat by-products.Lakabi-Ioualitene, D.; Lounaouci-Ouyed, G.; Berchiche, M.; Lebas, F.; Fortun-Lamothe, L. (2010). The effects of the complete replacement of barley and soybean meal with hard wheat by-products on diet digestibility, growth and slaughter traits of a local Algerian rabbit population. World Rabbit Science. 16(2). doi:10.4995/wrs.2008.63216

Multimode solutions of first-order elliptic quasilinear systems obtained from Riemann invariants

Two new approaches to solving first-order quasilinear elliptic systems of PDEs in many dimensions are proposed. The first method is based on an analysis of multimode solutions expressible in terms of Riemann invariants, based on links between two techniques, that of the symmetry reduction method and of the generalized method of characteristics. A variant of the conditional symmetry method for constructing this type of solution is proposed. A specific feature of that approach is an algebraic-geometric point of view, which allows the introduction of specific first-order side conditions consistent with the original system of PDEs, leading to a generalization of the Riemann invariant method for solving elliptic homogeneous systems of PDEs. A further generalization of the Riemann invariants method to the case of inhomogeneous systems, based on the introduction of specific rotation matrices, enables us to weaken the integrability condition. It allows us to establish a connection between the structure of the set of integral elements and the possibility of constructing specific classes of simple mode solutions. These theoretical considerations are illustrated by the examples of an ideal plastic flow in its elliptic region and a system describing a nonlinear interaction of waves and particles. Several new classes of solutions are obtained in explicit form, including the general integral for the latter system of equations

Synthesis of novel α-glucans with potential health benefits through controlled glucose release in the human gastrointestinal tract

The glycemic carbohydrates we consume are currently viewed in an unfavorable light in both the consumer and medical research worlds. In significant part, these carbohydrates, mainly starch and sucrose, are looked upon negatively due to their rapid and abrupt glucose delivery to the body which causes a high glycemic response. However, dietary carbohydrates which are digested and release glucose in a slow manner are recognized as providing health benefits. Slow digestion of glycemic carbohydrates can be caused by several factors, including food matrix effect which impedes α-amylase access to substrate, or partial inhibition by plant secondary metabolites such as phenolic compounds. Differences in digestion rate of these carbohydrates may also be due to their specific structures (e.g. variations in degree of branching and/or glycosidic linkages present). In recent years, much has been learned about the synthesis and digestion kinetics of novel α-glucans (i.e. small oligosaccharides or larger polysaccharides based on glucose units linked in different positions by α-bonds). It is the synthesis and digestion of such structures that is the subject of this review