Effect of Para Substituted Anilines Chemical Structure on Methane Biosynthesis by the Methanogens.

The present paper aims to study the effect of aromatic structure on the inhibition of biogas production and more specifically the effect of para substituted anilines functional groups (chemical structure) on methane biosynthesis by the digested pig manure methanogens. The objective of this study was also to examine the structure-toxicity relationships of aromatic compounds to acetoclastic methanogens. Study Design: Anaerobic digestion of pig manure, anaerobic toxicity essay, The effects of functional group nature on inhibition of methane production by acetoclastic methanogens. Correlation of the methanogenic toxicity (IC50) with aromatic compounds hydrophobicity (logPoct). Place and Duration of Study: Department of Chemistry, University of Kinshasa (DR Congo), between August 2011 and May 2012. Methodology: The toxicity to acetoclastic methanogenic bacteria was performed with the standard method of serum bottles, digested pig manure was utilized as inoculums, acetate as substrate and the methane gas volume produced was measured by serum bottles liquid displacement systems (Mariotte flask system). Results: The obtained results indicate that relationships exist between para substituted anilines functional groups nature (chemical structure) and their inhibitory effects on methanogens. The toxicity of para bisubstituted anilines increases in the following order: SO3 < OH < H < CH3 < Cl < NO2 From this sequence of increasing toxicity, it can be seen that the methanogenic toxicity varies with the functional group nature which is in the para position of the main function. Indeed, p-Nitroaniline and benzene with 45.76 and 208.78 mg/l as IC50 values respectively were the most toxic compounds, while p-Aminophenol and p-Aminosulfonic acid (Sulfanilic acid) with 1800.39 and 2777.82 mg/l IC50 values were the less toxic. A very significant negative linear correlation between the toxicity of para substituted anilines compounds and their hydrophobicity was found. Conclusion: The results of this study indicate that relationships exist between para substituted anilines functional groups nature and their inhibitory effects in methane biosynthesis by the methanogens.

Inhibitory Effects of Phenolic Monomers on Methanogenesis in Anaerobic Digestion.

Aims: The purpose of this study was to evaluate the inhibitory effects of phenolic monomers on methanogenesis in anaerobic digestion and to assess the effect of hydroxyl groups’ number of phenolic monomers (aromatic structure) on inhibition of methane production by acetoclastic methanogens (archaea). Study Design: Anaerobic digestion of pig manure, anaerobic toxicity essay, The effect of the hydroxyl group’s number on the methanogenic toxicity as exhibited by monomeric tannins, Correlation of the methanogenic toxicity (IC50) with aromatic compounds hydrophobicity (logPoct), Correlation of the methanogenic toxicity (IC50) with Cresols boiling point (bp). Place and Duration of Study: Department of Chemistry, University of Kinshasa (DR Congo), between September 2011 and May 2012. Methodology: The toxicity to acetoclastic methanogenic bacteria was performed with the standard method of serum bottles; digested pig manure was utilized as inoculums and acetate as substrate. The methane gas volume produced was measured by serum bottles liquid displacement systems (Mariotte flask system). Results: The results of this study indicate that an increase in the number of hydroxyl groups on the aromatic compound was associated with a decrease in the compound’s toxicity to methanogens (archea). The toxicity of various phenolic monomers are decreasing in the following order: pyrogallol < hydroquinone < resorcinol < phenol < benzene with 3172, 2745, 1725, 1249 and 209 mg/l IC50 values respectively. A significant negative linear correlation between the toxicity of phenolic monomers together with the reference compound (benzene) and their hydrophobicity was found. Moreover, a high positive linear correlation has been found between the IC50 values of phenolic monomers and their boiling temperatures. Conclusion: The obtained results indicate that relationships exist between the phenolic monomers structure and their inhibitory effects in methane biosynthesis. The analysis of experimental results suggests that an increase in the number of hydroxyl groups on the aromatic compounds was associated with a decrease in the phenolic monomers toxicity.

Prevalence du cancer en Republique Democratique du Congo : donnees anatomopathologiques recueillies aux Cliniques Universitaires et a l'Hopital General de Reference de Kinshasa

Introduction. Les maladies chroniques non transmissibles; parmi lesquelles les cancers; constituent un poids de morbimortalite de plus en plus important dans les pays en voie de developpement. En Republique Democratique du Congo; l'absence de registre national de cancer est un handicap serieux a l'evaluation epidemioclinique reelle de ce groupe d'affections. C'est pour pallier a cette carence que ce travail a ete initie ; l'objectif etant de decrire les cancers les plus frequents sur base des donnees anatomopathologiques rapportees dans deux institutions hospitalieres de Kinshasa.Methodologie. Les registres et les protocoles de biopsies ont ete consultes aupres des laboratoires d'anatomie pathologique des Cliniques Universitaires; ainsi que de l'hopital General de Reference de Kinshasa. L'enquete a couvert la periode de 1969 a 2008 (40 ans). Resultats. Au total; 4137 cas de cancers ont ete repertories. L'age moyen des patients etait de 42;2 ans; plus jeune pour le sexe feminin; qui etait egalement plus affecte. Dans ce dernier groupe; les cancers du col uterin (27;7); du sein (13;7); des organes lymphoides (10); et de la peau (8;6); etaient les plus frequents. Parmi les sujets du sexe masculin : les cancers des organes lymphoides (15;9); le Sarcome de Kaposi (14;5); le cancer de la prostate (14); le cancer du foie (12;6); et enfin celui de la peau (11;7); ont ete les plus rapportes. Conclusion. Cette enquete; comme les donnees d'autres pays africains; revele la preponderance du sexe feminin et la survenue precoce des cancers dans ce groupe. Le cancer du col uterin et celui du sein sont les formes les plus frequentes; tandis que le profil des cancers masculins retient les organes lymphoides et la prostate en tete de liste. La creation et la tenue d'un registre national de cancer s'imposent comme un prealable a toute definition de strategie adequate de prevention du cancer dans notre pays

Convulsions associees a la fievre et developpement psychomoteur en soins de sante primaires a Kinshasa

Une etude prospective menee pendant 3 mois dans 2 centres des soins de sante primaires a Kinshasa; a permis de decrire les caracteristiques semiologiques des Convulsions Febriles (CF) presentees par 148 patients; ages de 5 a 71 mois. Les CF ont ete decrites en fonction de leur distribution; leur duree et leur repetition eventuelle. Les caracteres lateralises; prolonges et repetitifs etaient consideres comme des facteurs de gravite. Le Quotient de Developpement psychomoteur (QDP) des patients a ete evalue sur base de l'echelle de Gensini et Gavito; reprenant les domaines de lamotricite; de la communication; et de l'adaptation. Le QDP etait bas chez 6;7des patients. 5avaient un retard dans le domaine de la motricite; 3;4dans le domaine de la communication; et 2;7dans celui de l'adaptation. Nous n'avons pas note de lien significatif entre le QDP global; et les facteurs de gravite des CF. Toutefois; tous les enfants ayant un retard dans le domaine de la motricite; avaient presente des convulsions repetees avant leur admission: (p=0;02 [OR=1;096 (IC 95) : 1;060 -1;128)]. La motricite etait l'element le plus significativement atteint chez les malades ayant presente les CF. Cette observation merite d'etre validee par des etudes cas temoins; incluant un plus grand nombre de sujets

Essai d'exploration neuropsychologique par le Minimental test et ses subtests dans les infections du systeme nerveux central

Une exploration neuropsychologique a ete faite chez 60 sujets dont 30 malades et 30 autres presumes sains apparies selon l'age; le sexe et le niveau d'instruction. Les performances moyennes des sujets ont ete comparees par analyse de variance et la prediction diagnostique etudiee par la fonction de regression logistique

Le traitement des crises epileptiques dans les tableaux neurologiques aigus

Les crises epileptiques sont frequentes dans les tableaux neurologiques aigus. Leur traitement dans ce contexte pathologique est sujet a caution et releve de la reanimation cerebrale qui n'est pas a la portee de tous les patients. Un prerequis de connaissance sur la physiopathologie de l'oedeme cerebral et le traitement de l'etat de mal epileptique peut permettre au praticien d'eviter de tomber facilement dans l'abus therapeutique