Dopamine D1 and D2 Receptor Gene Expression and cGMP, IP3 and Ca2+ Regulation in the Brain Regions of Hypoxic Neonatal Rats: Role of Glucose, Oxygen and Epinephrine Supplementation

Department of Biotechnology, Cochin University of Science and Technology

Brain Cholinergic and Dopaminergic Functions in Streptozotocin Induced Diabetic Rats: Effects of Curcumin and Vitamin D3 Supplementation

Department of Biotechnology, Cochin University of Science and Technology

Acidity, basicity and catalytic activity of La−Zn mixed oxides

Surface acidity/Basicity of mixed oxides of La and Zn activated at three different temperatures were determined. The data have been correlated with the catalytic activity for liquid phase reduction of cyclohexanone in isopropanol.

Catalytic oxidation of cyclohexane over Cu-Zn-Cr ternary spinel systems

Spinel systems with the composition of Cu 1−x Zn x Cr 2 O 4 [x = 0 CCr, x = 0.25 CZCr-1, x = 0.5 CZCr-2, x = 0.75 CZCr-3 and x = 1 ZCr] were prepared by homogeneous co-precipitation method and were characterized by X-ray diffraction (XRD) and FT-IR spectroscopy. Elemental analysis was done by EDX, and surface area measurements by the BET method. The redox behavior of these catalysts in cyclohexane oxidation at 243 K using TBHP as oxidant was examined. Cyclohexanone was the major product over all catalysts with some cyclohexanol. 69.2% selectivity to cyclohexanol and cyclohexanone at 23% conversion of cyclohexane was realized over zinc chromite spinels in 10 h.

Dopamine Receptor Subtypes,IP3, cAMP and cGMP Functional Regulation in Parkinsonism Induced by Unilateral Infusion of Rotenone in Rats: Recovery with Bone Marrow Cells,Serotonin and GABA Supplementation

In the present study, the effects of 5-HT, GABA and Bone Marrow Cells infused intranigrally to substantia nigra individually and in combinations on unilateral rotenone infused Parkinsonism induced rats. Scatchard analysis of DA, DA D1 and D2 receptors in the corpus striatum, cerebral cortex, cerebellum, brain stem and hippocampus showed a significant increase in the Brain regions of rotenone infused rat compared to control. Real Time PCR amplification of DA D1, D2, Bax and ubiquitin carboxy-terminal hydrolase were up regulated in the brain regions of rotenone infused rats compared to control. Gene expression studies of -Synuclien, cGMP and Cyclic AMP response element-binding protein showed a significant down regulation in Rotenone infused rats compared to control. Behavioural studies were carried out to confirm the biochemical and molecular studies.Our study demonstrated that BMC administration alone cannot reverse the above said molecular changes occurring in PD rat. 5-HT and GABA acting through their specific receptors in combination with bone marrow cells play a crucial role in the functional recovery of PD rats. 5-HT, GABA and Bone marrow cells treated PD rats showed significant reversal to control in DA receptor binding and gene expression. 5-HT and GABA have co-mitogenic property. Proliferation and differentiation of cells re-establishing the connections in Parkinson's disease facilitates the functional recovery. Thus, it is evident that 5-HT and GABA along with BMC to rotenone infused rats renders protection against oxidative, related motor and cognitive deficits which makes them clinically significant for cellbased therapy. The BMC transformed to neurons when co-transplanted with 5-HT and GABA which was confirmed with PKH2GL and nestin. These newly formed neurons have functional significance in the therapeutic recovery of Parkinson’s disease.

Adrenergic and Glutamergic Receptor Gene Expression and Their Functional regulation in the Cerebral Cortex of Hypoxia Induced Neonatal Rats:Role of Oxygen,Epinephrine and Glucose Supplementation

In the present work, the role of oxygen, epinephrine and glucose supplementation in regulating neurotransmitter contents, adrenergic and glutamate receptor binding parameters in the cerebral cortex of experimental groups of neonatal rats were investigated. The study of neurotransmitters and their receptors in the cerebral cortex and the EEG pattern in the brain regions of neonatal rats were taken as index for brain damage due to hypoxia, oxygen and epinephrine. Real-Time PCR work was done to confirm the binding parameters. Second messenger, cyclic Adenosine Monophosphate (cAMP) was assayed to find the functional correlation of the receptors. Behavioural studies were carried out to confirm the biochemical and molecular studies. The efficient and timely supplementation of glucose plays a crucial role in correcting the molecular changes due to hypoxia, oxygen and epinephrine. The addictive neuronal damage effect due to oxygen and epinephrine treatment is another important observation. The corrective measures from the molecular study brought to practice will lead to maintain healthy intellectual capacity during the later developmental stages, which has immense clinical significance in neonatal care.

Hysteresis in a system driven by either generalized force or displacement variables: martensitic phase transition in single-crystalline Cu-Zn-Al

We report on experiments aimed at comparing the hysteretic response of a Cu-Zn-Al single crystal undergoing a martensitic transition under strain-driven and stress-driven conditions. Strain-driven experiments were performed using a conventional tensile machine while a special device was designed to perform stress-driven experiments. Significant differences in the hysteresis loops were found. The strain-driven curves show reentrant behavior yield point which is not observed in the stress-driven case. The dissipated energy in the stress-driven curves is larger than in the strain-driven ones. Results from recently proposed models qualitatively agree with experiments.

Glutamatergic Nmda And Ampa Receptors Functional Regulation In Streptozotocin Induced Diabetic Rats: Effect Of Vitamin D3 And Curcumin Supplementation

The present study was designed to investigate the protective effect of curcumin and vitamin D3 in the functional regulation of glutamatergic NMDA and AMPA receptors in streptozotocin (STZ) induced diabetic rats. Alterations in glutamatergic neurotransmission in the brain were evaluated by analyzing the glutamate content, glutamate receptors - NMDA and AMPA receptors binding parameters and gene expression, GAD and GLAST gene expression. Immunohistochemistry studies using confocal microscope were carried out to confirm receptor density and gene expression results of NMDA and AMPA receptors. The role of glutamatergic receptors in pancreas was studied using the following parameters; glutamate content, GLAST expression, glutamate receptors - NMDA and AMPA receptor binding and gene expression. Increasing evidence in both experimental and clinical studies suggests that oxidative stress plays a major role in the pathogenesis of diabetes. In the present study SOD assay and GPx gene expression were done to evaluate the activity of antioxidant enzymes in the brain regions and pancreas. NeuroD1 and Pdx1 gene expression were performed in pancreas of experimental rats to evaluate pancreatic islet survival. Gene expression profiles of caspase 8, Bax, and Akt in brain regions and pancreas were studied to understand the possible mechanism behind curcumin and vitamin D3 mediated neuroprotection and islet survival. Gene expression studies of vitamin D3 receptor localisation in the pancreas was done to understand the mechanism of vitamin D3 in insulin secretion. Curcumin and vitamin D3 mediated insulin secretion via Ca2+ release were studied using confocal microscope.

Effect of preparation on magnetic properties of Mn-Zn ferrite

Mixed ferrites belonging to the type Mn0.9Zn0.1Fe2O4 have been prepared by the double sintering method and by the chemical co-precipitation for comparing their magnetic properties. Sintered and precipitated ferrites exhibit different characteristics, especially in their magnetic properties like magnetization (Ms), coercive field (Hc) and Curie temperature (Tc). The sintered particles were size reduced in order to compare with the nanosized co-precipitated particles. The effect of grinding has also been studied. Particles have been collected at regular intervals of grinding and their properties have been studied. The increase in the coercive field has been recorded by a hysteresis curve tracer confirming size reduction. X-ray diffraction studies confirmed the structure and consequent size reduction

Búsqueda de selección en el polimorfismo 677C>T (c.665C>T) del gen de la metilentetrahidrofolato reductasa (MTHFR) en una población Colombiana

Se realizó un estudio genético – poblacional en dos grupos etarios de población colombiana con la finalidad de evaluar las diferencias genéticas relacionadas con el polimorfismo MTHFR 677CT en busca de eventos genéticos que soporten la persistencia de este polimorfismo en la especie humana debido que este ha sido asociado con múltiples enfermedades. De esta manera se genotipificaron los individuos, se analizaron los genotipos, frecuencias alélicas y se realizaron diferentes pruebas genéticas-poblacionales. Contrario a lo observado en poblaciones Colombianas revisadas se identificó la ausencia del Equilibrio Hardy-Weinberg en el grupo de los niños y estructuras poblacionales entre los adultos lo que sugiere diferentes historias demográficas y culturales entre estos dos grupos poblacionales al tiempo, lo que soporta la hipótesis de un evento de selección sobre el polimorfismo en nuestra población. De igual manera nuestros datos fueron analizados junto con estudios previos a nivel nacional y mundial lo cual sustenta que el posible evento selectivo es debido a que el aporte de ácido fólico se ha incrementado durante las últimas dos décadas como consecuencia de las campañas de fortificación de las harinas y suplementación a las embarazadas con ácido fólico, por lo tanto aquí se propone un modelo de selección que se ajusta a los datos encontrados en este trabajo se establece una relación entre los patrones nutricionales de la especie humana a través de la historia que explica las diferencias en frecuencias de este polimorfismo a nivel espacial y temporal.  

Effect of supplementation with MgCO3 and L-tryptophan on the welfare and on the carcass and meat quality of two halothane pig genotypes (NN and nn)

Sixty-one animals with different Halothane genes (homozygous halothane positive, n=34; and homozygous halothane negative, n=27) were fed with three diets (controlgroup, with no supplement; magnesium (Mg) group with 1.28g MgCO3/kg and tryptophan (Trp) group with 5g L-Trp/kg) during the last 5 days before slaughter. Animals were submitted to minimal stress ante mortem conditions. Pig behaviour was recorded at the experimental farm, raceway to the CO2 stunning system and during the stunning period. Corneal reflexes were recorded after stunning as well. There were no differences in feed intake among diets (p>0.05) during the 5 days of treatment. The halothane positive (nn) group had lower intake than the halothane negative (NN) group (p<0.01). The behaviour of the pigs in the raceway did not differ (p>0.05) among treatments or halothane genotype. A significant (p<0.001) interaction diet*halothane was found in the time to appear the first retreat attempt during the exposure to the CO2 system. In the nn group, the time of performing the first retreat attempt was later in the Mg (p<0.05) than the Control group. Moreover, in the Mg group, the nn had a later (p<0.05) first retreat attempt than the NN. Thus, Mg supplementation could have a positive effect on welfare of nn pigs. The nn had a lower proportion of animals that showed corneal reflexes after stunning than NN, indicating a higher effectiveness of the stunning method in nn pigs. Neither Mg nor Trp affected carcass quality and meat quality parameters, although significant differences were found between genotypes

Síntesi i estructura de lligands hexaazamacrocíclics i dels seus complexos de Zn. Estudis de catàlisi i de fenòmens de reconeixement molecular amb substrats aniònics

Es realitza una breu introducció a la Química Supramolecular, la qual estudia les estructures i funcions de les associacions que resulten de la unió d'espècies moleculars a través d'enllaços intermoleculars, no covalents. El reconeixement molecular, reactivitat i transport són les funcions bàsiques de les espècies supramoleculars. El present treball tracta de la química supramolecular d'anions i del potential efecte catalític de complexos de Zinc amb lligands hexaazamacrocilics en reaccions de hidròlisis d'esters de fosfat. Els lligands descrits en aquest treball són lligands macrocíclics hexadentats formats per amines secundàries o terciàries enllaçades a cadenes alquíliques de dos o tres àtoms de carbonis formant dos braços, que estan unides per un espaiador, El conjunt de lligands que s'estudien permeten estudiar els diferents factors, geomètrics, electrònics i estèrics que controlen els fenòmens de reconeixement molecular. El treball descriu en detall els procediments de síntesi i la caracterització d'aquest conjunt de lligands. S'ha realitzat un estudi sistemàtic dels diferents factors que afecten als fenòmens de reconeixement molecular entre lligands macrocíclics (L), descrits anteriorment i substrats aniònics (S): fosfats, polifosfats i dicarboxilats. Els estudis s'han realitzat tant en dissolució aquosa, a partir de mesures potenciomètriques, com en estat sòlid per difracció de Raig-X a partir de la obtenció de les estructures cristal·lines dels complexos. La força de l'enllaç en els complexos ternaris H:L:S es racionalitza en termes d'enllaç per pont d'hidrogen, interaccions electrostàtiques i interaccions per -Stacking. Així mateix es racionalitza la importància de les dimensions i forma de la cavitat en el grau d'interacció. Actualment hi ha un gran interès en l'estudi del paper que juguen els ions metàl·lics en el centre actiu dels metal·loenzims hidrolítics tal com la carboxipeptidasa, que catalitza la hidròlisi d'aminoàcids C-terminals de substrats polipeptídics, l'anhidrasa carbònica, que catalitza la reacció d'hidratació del CO2 per donar hidrogencarbonat, la fosfatasa alcalina, que actua catalitzant la hidròlisi no específica de monoesters de fosfats a pH alcalí. El Zn(II) és un metall que es troba sovint formant part dels centres actius dels metal·loenzims i és el segon element de transició més abundant en els organismes vius. Per aquest motiu són útils els models sintètics que puguin actuar com a mimetitzadors de reaccions bioinorgàniques en les que els metal·loenzims juguen un paper com a catalitzadors. Els models sintètics són complexos de metalls de transició formats per un lligand o lligands en el seu entorn de coordinació més immediat que tinguin efectes electrònics i estèrics els més similar possible als que es produeixen en el centre actiu dels enzims. Donat la importància dels complexos de Zn(II) com a models biomimètics de metal·loenzims hidrolítics, s'han sintetitzat i caracteritzat complexos dinuclears de Zn(II) amb lligands hexaazamacrocíclics descrits anteriorment. S'ha realitzat un estudi de la seva activitat catalítica en la hidròlisi d'un ester activat, l'acetat de p-nitrofenil, un substrat característic que s'utilitza per analitzar l'activitat catalítica dels models biomimètics.