Contribution of Na+Na^{+} current regulation to the regulation of Na+/K+ATPaseNa^{+}/K^{+}ATPase isoforms by thyroid hormone in rat neocortical neurons

Die Fragestellung dieser Arbeit war, ob das Schilddrüsenhormon (T3)die Expression verschiedener $Na^{+}/K^{+}$ATPase-Isoformen direkt oder über Zwischenschritte reguliert. Eine $\textit {Western Blot}$-Untersuchung zeigte durch Vergleich von Gehirngewebe aus $\textit {wild-typ}$ und $Pax8^{-/-}$-Mäusen, dass T3 die Expression der $\alpha$1- und $\alpha$3-, sowie der $\beta$2-$Na^{+}/K^{+}$ATPase-Isoformen in Neocortex und Hippocampus $\textit {in vivo}$ reguliert. Wie in Zellkulturen aus neugeborenen Rattengehirnen gezeigt werden konnte, tritt die Hochregulation der $Na^{+}/K^{+}$ATPase-$\alpha$1- und $\alpha$2- Isoformen nur in gemischten Kulturen aus Neuronen und Gliazellen auf, unter Bedingungen, unter denen auch eine Hochregulation der $Na^{+}$-Stromdichte in Nervenzellen (INav) beobachtet worden war. Die Abschwächung der Hochregulation der $Na^{+}/K^{+}$ATPase-Isoformen nach einer Co-Inkubation mit dem INav-Blocker Tetrodotoxin zeigte, dass die T3-Wirkung auf die $Na^{+}/K^{+}$ATPase Expression und damit auch den Grundumsatz als Folge eines vergrößerten $Na^{+}$-Einstroms erklärt werden kann

Characterization of Natural Cellulose Fibers from the Barks of Ziziphus nummularia as a Reinforcement for Lightweight Composite Applications

This study deals with the extraction and testing of natural cellulose fibers obtained from the barks of Ziziphus nummularia (Burm. f.) Wight & Arn. plants. The extraction of Z. nummularia fibers from its plant barks was done by water retting. The extracted fibers were analyzed for their chemical, crystalline, thermal, mechanical, and physical properties. Surface characteristics of the fibers were examined using a scanning electron microscope and an atomic force microscope. The test results showed that cellulose content was 52.34%. The crystalline index was 45.77% whereas the crystallite size was 2.01 nm. Thermogravimetric analysis showed a maximum degradation temperature of 348°C. The morphological properties showed that Z. nummularia fibers had a good surface roughness that helps in forming interlocks with the matrix on its usage in polymer matrix composites

Deficiency of Thyroid Hormone Reduces Voltage-Gated Na+ Currents as Well as Expression of Na+/K+-ATPase in the Mouse Hippocampus

Mice lacking functional thyroid follicular cells, Pax8−/− mice, die early postnatally, making them suitable models for extreme hypothyroidism. We have previously obtained evidence in postnatal rat neurons, that a down-regulation of Na+-current density could explain the reduced excitability of the nervous system in hypothyroidism. If such a mechanism underlies the development of coma and death in severe hypothyroidism, Pax8−/− mice should show deficits in the expression of Na+ currents and potentially also in the expression of Na+/K+-ATPases, which are necessary to maintain low intracellular Na+ levels. We thus compared Na+ current densities in postnatal mice using the patch-clamp technique in the whole-cell configuration as well as the expression of three alpha and two beta-subunits of the Na+/K+-ATPase in wild type versus Pax8−/− mice. Whereas the Na+ current density in hippocampal neurons from wild type mice was upregulated within the first postnatal week, the Na+ current density remained at a very low level in hippocampal neurons from Pax8−/− mice. Pax8−/− mice also showed significantly decreased protein expression levels of the catalytic α1 and α3 subunits of the Na+/K+-ATPase as well as decreased levels of the β2 isoform, with no changes in the α2 and β1 subunits

Deficiency of thyroid hormone reduces voltage-gated Na+Na^{+} currents as well as expression of Na+/K+Na^{+}/K^{+}-ATPase in the mouse hippocampus

Mice lacking functional thyroid follicular cells, $\it Pax8^{−/−}$ mice, die early postnatally, making them suitable models for extreme hypothyroidism. We have previously obtained evidence in postnatal rat neurons, that a down-regulation of $Na^{+}$-current density could explain the reduced excitability of the nervous system in hypothyroidism. If such a mechanism underlies the development of coma and death in severe hypothyroidism, $\it Pax8^{−/−}$ mice should show deficits in the expression of $Na^{+}$ currents and potentially also in the expression of $Na^{+}/K^{+}$-ATPases, which are necessary to maintain low intracellular $Na^{+}$ levels. We thus compared $Na^{+}$ current densities in postnatal mice using the patch-clamp technique in the whole-cell configuration as well as the expression of three alpha and two beta-subunits of the $Na^{+}/K^{+}$-ATPase in wild type versus $\it Pax8^{−/−}$ mice. Whereas the $Na^{+}$ current density in hippocampal neurons from wild type mice was upregulated within the first postnatal week, the $Na^{+}$ current density remained at a very low level in hippocampal neurons from $\it Pax8^{−/−}$ mice. $\it Pax8^{−/−}$ mice also showed significantly decreased protein expression levels of the catalytic $\alpha$1 and $\alpha$3 subunits of the $Na^{+}/K^{+}$-ATPase as well as decreased levels of the $\beta$2 isoform, with no changes in the $\alpha$2 and $\beta$1 subunits

Effect of different parameters on uncertainty during evaluation of strength of dissimilar metal weld

In scanning electron microscope tensile testing was carried out to assess the mechanical properties and consequent failure characteristics of dissimilar weld consisting of low alloy steel and low nitrogen austenitic stainless steel. These transition joints find wide spread application in pressurized heavy water reactors. A number of premature failures have been reported in recent past during service exploitation of same joints. Thus, it becomes essential to identify the governing criteria resulting in such type of de-generation. In present endeavour, two types of joints were considered; one weld was fabricated by buttering with 309L stainless steel and the other one was made by buttering with IN82 Ni base alloys. From experimentation, weld strength was evaluated along with uncertainty analysis. Effect of various contributing factors over uncertainty was discussed. It was quantitatively shown that microstructural characteristics influenced more dominantly than physical parameters to the uncertainty of joint efficiency

Triac Treatment Prevents Neurodevelopmental and Locomotor Impairments in Thyroid Hormone Transporter Mct8/Oatp1c1 Deficient Mice

Patients with inactive thyroid hormone (TH) transporter MCT8 display intellectual disability due to compromised central TH transport and action. As a therapeutic strategy, application of thyromimetic, MCT8-independent compounds Triac (3,5,3′-triiodothyroacetic acid), and Ditpa (3,5-diiodo-thyropropionic acid) was proposed. Here, we directly compared their thyromimetic potential in Mct8/Oatp1c1 double knock-out mice (Dko) modeling human MCT8 deficiency. Dko mice received either Triac (50 ng/g or 400 ng/g) or Ditpa (400 ng/g or 4000 ng/g) daily during the first three postnatal weeks. Saline-injected Wt and Dko mice served as controls. A second cohort of Dko mice received Triac (400 ng/g) daily between postnatal weeks 3 and 6. Thyromimetic effects were assessed at different postnatal stages by immunofluorescence, ISH, qPCR, electrophysiological recordings, and behavior tests. Triac treatment (400 ng/g) induced normalized myelination, cortical GABAergic interneuron differentiation, electrophysiological parameters, and locomotor performance only when administered during the first three postnatal weeks. Ditpa (4000 ng/g) application to Dko mice during the first three postnatal weeks resulted in normal myelination and cerebellar development but only mildly improved neuronal parameters and locomotor function. Together, Triac is highly-effective and more efficient than Ditpa in promoting CNS maturation and function in Dko mice yet needs to be initiated directly after birth for the most beneficial effects

Triac Treatment Prevents Neurodevelopmental and Locomotor Impairments in Thyroid Hormone Transporter Mct8/Oatp1c1 Deficient Mice

Patients with inactive thyroid hormone (TH) transporter MCT8 display intellectual disability due to compromised central TH transport and action. As a therapeutic strategy, application of thyromimetic, MCT8-independent compounds Triac (3,5,3′-triiodothyroacetic acid), and Ditpa (3,5-diiodo-thyropropionic acid) was proposed. Here, we directly compared their thyromimetic potential in Mct8/Oatp1c1 double knock-out mice (Dko) modeling human MCT8 deficiency. Dko mice received either Triac (50 ng/g or 400 ng/g) or Ditpa (400 ng/g or 4000 ng/g) daily during the first three postnatal weeks. Saline-injected Wt and Dko mice served as controls. A second cohort of Dko mice received Triac (400 ng/g) daily between postnatal weeks 3 and 6. Thyromimetic effects were assessed at different postnatal stages by immunofluorescence, ISH, qPCR, electrophysiological recordings, and behavior tests. Triac treatment (400 ng/g) induced normalized myelination, cortical GABAergic interneuron differentiation, electrophysiological parameters, and locomotor performance only when administered during the first three postnatal weeks. Ditpa (4000 ng/g) application to Dko mice during the first three postnatal weeks resulted in normal myelination and cerebellar development but only mildly improved neuronal parameters and locomotor function. Together, Triac is highly-effective and more efficient than Ditpa in promoting CNS maturation and function in Dko mice yet needs to be initiated directly after birth for the most beneficial effects

Triac Treatment Prevents Neurodevelopmental and Locomotor Impairments in Thyroid Hormone Transporter Mct8/Oatp1c1 Deficient Mice

Patients with inactive thyroid hormone (TH) transporter MCT8 display intellectual disability due to compromised central TH transport and action. As a therapeutic strategy, application of thyromimetic, MCT8-independent compounds Triac (3,5,3′-triiodothyroacetic acid), and Ditpa (3,5-diiodo-thyropropionic acid) was proposed. Here, we directly compared their thyromimetic potential in Mct8/Oatp1c1 double knock-out mice (Dko) modeling human MCT8 deficiency. Dko mice received either Triac (50 ng/g or 400 ng/g) or Ditpa (400 ng/g or 4000 ng/g) daily during the first three postnatal weeks. Saline-injected Wt and Dko mice served as controls. A second cohort of Dko mice received Triac (400 ng/g) daily between postnatal weeks 3 and 6. Thyromimetic effects were assessed at different postnatal stages by immunofluorescence, ISH, qPCR, electrophysiological recordings, and behavior tests. Triac treatment (400 ng/g) induced normalized myelination, cortical GABAergic interneuron differentiation, electrophysiological parameters, and locomotor performance only when administered during the first three postnatal weeks. Ditpa (4000 ng/g) application to Dko mice during the first three postnatal weeks resulted in normal myelination and cerebellar development but only mildly improved neuronal parameters and locomotor function. Together, Triac is highly-effective and more efficient than Ditpa in promoting CNS maturation and function in Dko mice yet needs to be initiated directly after birth for the most beneficial effects

Effect of solvent; enhancing the wettability and engineering the porous structure of a calcium phosphate/agarose composite for drug delivery

Tissue engineering deals with the regeneration of tissues for bone repair, wound healing, drug delivery, etc., and a highly porous 3D artificial scaffold is required to accommodate the cells and direct their growth. We prepared 3D porous calcium phosphate ((hydroxyapatite/beta-tricalcium phosphate)/agarose, (HAp/beta-TCP)/agarose) composite scaffolds by sol-gel technique with water (WBS) and ethanol (EBS) as solvents. The crystalline phases of HAp and beta-TCP in the scaffolds were confirmed by X-ray diffraction (XRD) analysis. The EBS had reduced crystallinity and crystallite size compared to WBS. WBS and EBS revealed interconnected pores of 1 mu m and 100 nm, respectively. The swelling ratio was higher for EBS in water and phosphate buffered saline (PBS). An in vitro drug loading/release experiment was carried out on the scaffolds using gentamicin sulphate (GS) and amoxicillin (AMX). We observed initial burst release followed by sustained release from WBS and EBS. In addition, GS showed more extended release than AMX from both the scaffolds. GS and AMX loaded scaffolds showed greater efficacy against Pseudomonas than Bacillus species. WBS exhibited enhanced mechanical properties, wettability, drug loading and haemocompatibility compared to EBS. In vitro cell studies showed that over the scaffolds, MC3T3 cells attached and proliferated and there was a significant increase in live MC3T3 cells. Both scaffolds supported MC3T3 proliferation and mineralization in the absence of osteogenic differentiation supplements in media which proves the scaffolds are osteoconducive. Microporous scaffolds (WBS) could assist the bone in-growth, whereas the presence of nanopores (EBS) could enhance the degradation process. Hence, WBS and EBS could be used as scaffolds for tissue engineering and drug delivery. This is a cost effective technique to produce scaffolds of degradable 3D ceramic-polymer composites