15 research outputs found
Myelin disruption and ectopic Kv1 channels in mouse optic nerve axons of cuprizone-induced model of demyelination contribute to aberrant conduction
Role of Food Microwave Drying in Hybrid Drying Technology
Dehydration is the key to food preservation reducing volume and increasing shelf life. Dehydration technology has witnessed renaissance with the development of advanced technology such as microwave drying, freeze drying, fluidized bed drying, and refractance window drying. Combination of drying methods has increased the versatility of dehydration process of which field-based drying methods have always been hyped and microwave drying being the most adorned of all, considering its ease of fabrication and drying efficiency. Synergizing it with methods such as hot air drying, freeze drying, fluidized bed drying, or vacuum drying enhances its performance and the quality of the dried product. The merits and functionality of each method in hybrid drying with microwave have been discussed in the chapter
Disruption of Myelin Leads to Ectopic Expression of K(V)1.1 Channels with Abnormal Conductivity of Optic Nerve Axons in a Cuprizone-Induced Model of Demyelination
The molecular determinants of abnormal propagation of action potentials along axons and ectopic conductance in demyelinating diseases of the central nervous system, like multiple sclerosis (MS),are poorly defined. Widespread interruption of myelin occurs in several mouse models of demyelination, rendering them useful for research. Herein, considerable myelin loss is shown in the optic nerves of cuprizone-treated demyelinating mice. Immuno-fluorescence confocal analysis of the expression and distribution of voltage-activated K+ channels (K(V)1.1 and 1.2 alpha subunits) revealed their spread from typical juxta-paranodal (JXP) sites to nodes in demyelinated axons, albeit with a disproportionate increase in the level of K(V)1.1 subunit. Functionally, in contrast to monophasic compound action potentials (CAPs) recorded in controls, responses derived from optic nerves of cuprizone-treated mice displayed initial synchronous waveform followed by a dispersed component. Partial restoration of CAPs by broad spectrum (4-aminopyridine) or K(V)1.1-subunit selective (dendrotoxin K) blockers of K+ currents suggest enhanced K(V)1.1-mediated conductance in the demyelinated optic nerve. Biophysical profiling of K+ currents mediated by recombinant channels comprised of different K(V)1.1 and 1.2 stoichiometries revealed that the enrichment of K(V)1 channels K(V)1.1 subunit endows a decrease in the voltage threshold and accelerates the activation kinetics. Together with the morphometric data, these findings provide important clues to a molecular basis for temporal dispersion of CAPs and reduced excitability of demyelinated optic nerves, which could be of potential relevance to the patho-physiology of MS and related disorders
Meat-based ethnic delicacies of Meghalaya state in Eastern Himalaya: preparation methods and significance
Meghalaya, a northeastern state of India, has several authentic ethnic meat delicacies that have not been documented adequately. A survey was conducted among cooks, food stall owners, and consumers representing all three tribes of Meghalaya, namely, Khasi, Jaintia, and Garo. Detailed information was collected on a variety of traditional meat preparations, the method of preparation, and the general pattern for the consumption of such products. The socioeconomic values and traditions attached to the products were also explored. We have enlisted 15 such meat-based traditional products of Meghalaya. The method of preparation and significance have been recorded for doh jem, dohkhlieh, acharDohSniang, tungrymbai, dohSnam, and jadoh. Loss of these ethnic meat delicacies can be prevented only by increasing its availability and market value. An intervention of food science in optimizing the preparation methods, improving hygiene parameters, and packaging can promise a lucrative business in this sector for local people and may attract consumers from other parts of the country. Keywords: Eastern Himalaya, Ethnic foods, Khasi tribe, Meghalaya, Traditional meat preparation
Neurospheres derived from human embryoid bodies treated with retinoic Acid show an increase in nestin and ngn2 expression that correlates with the proportion of tyrosine hydroxylase-positive cells
Neurospheres Derived from Human Embryoid Bodies Treated with Retinoic Acid Show an Increase in Nestin and Ngn2 Expression That Correlates with the Proportion of Tyrosine Hydroxylase-Positive Cells
Functional characterization of recombinant K<sub>V</sub>1.1 homo-tetramers reveals distinctive biophysical profiles from those of K<sub>V</sub>1.1/1.2 heteromers.
<p>(<b>A</b>) Western blots of surface expressed concatenated K<sub>V</sub>1 channels in[HEK293 cells. Lanes: 1, non-transfected cells show no immuno-reactivity for K<sub>V</sub>1.1 (or K<sub>V</sub>1.2, not shown); 2, K<sub>V</sub>(1.1)<sub>4</sub> and 3, K<sub>V</sub>1.1-1.1-1.2-1.1 detected with anti-K<sub>V</sub>1.1 IgG giving a band size of ∼250 kD; 4 and 6, K<sub>V</sub>(1.2)<sub>4</sub> homo-tetramer was non-reactive with anti-K<sub>V</sub>1.1 IgG (4) but gave a distinct band when probed with K<sub>V</sub>1.2 IgG (6). Protein markers are indicated in lanes 5 and 7. (<b>B, D1–F1</b>) Representative recordings of macroscopic currents (300 ms pulse) from HEK293 cells transfected with the individual recombinant channels. (<b>B, C</b>) Activation rate of the voltage-dependent K<sup>+</sup> currents mediated by K<sub>V</sub>(1.1)<sub>4</sub> (left) and K<sub>V</sub>(1.2)<sub>4</sub> (middle) channels (within the range of 10–30% of max. current) at 5 mV from indicated voltages (below) with super-imposed (right) representative traces from. A notable difference between the rates of activation of K<sub>V</sub>(1.1)<sub>4</sub> and K<sub>V</sub>(1.2)<sub>4</sub> is revealed by fitting the data with a single exponential (see <b>C</b>). (<b>D2–F2</b>) Conductance-voltage relations of macroscopic currents measured, based on the K<sup>+</sup> current of the last 100 ms for each channel. Conductance at various command potentials were normalised and fitted with a single Boltzmann function. The difference in conductance values of K<sub>V</sub>(1.1)<sub>4</sub> and K<sub>V</sub>(1.2)<sub>4</sub> channel were statistically significant from −55 mV (P<0.05, Mann-Whitney <i>U</i>-test, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0087736#pone-0087736-t001" target="_blank">Table 1</a> for summary of the biophysical data).</p
Demyelination disrupts the conductivity of ON axons which can be partially restored by 4-AP.
<p>(A, B) A low magnification micrograph (4×) demonstrating the semi-dissected ON (ventral view) with stimulation (suction, Suc. pipette) and recording (Rec.) electrodes. Graded synchronous CAPs recorded from control animals contrasting with bi-component CAPs derived from experimental ON activated from elevated stimuli thresholds (<b>C</b>). Insert illustrates the experimental set-up for CAPs recordings. Rec. - recording electrode; Suc. - suction pipette used for stimulation. ON – optic nerve, OX – optic xiasm. (<b>B</b>) Typical CAPs evoked in control ON by paired-pulse stimulation (PPS). Note the second CAP from the refractory phase following the first CAP. The evoked CAPs recorded from cuprizone-treated (demyelinated) ON axons showed lower amplitudes and protracted late components compared to the untreated (myelinated) ON axons. (<b>C</b>) Stimulus-response relation of CAPs in controls and experimental ON, showing lower activation threshold and higher amplitudes of evoked CAPs in demyelianted ON. (<b>D</b>) Representative recordings of CAPs from ON of control and cuprizone fed mice before (1) in the presence of TEA (2, upper row) or 4-AP (lower row) and (1+2) superimposed traces. (F, G) Summary of the effects of TEA (15–20 min application) on the CAPs in control and cuprizone-treated ONs (n = 5 in each group) (<b>E</b>) The summary histogram of CAP amplitudes scored before and after application of 1 mM 4-AP. Note the significant enhancement of the CAP amplitudes in demyelinated ON caused by 4- AP (P<0.05, n = 5 in each group).</p
Demyelination alters the distribution and composition of K<sub>V</sub>1 channels in ON.
<p>Double [pan-Na (red)/K<sub>V</sub>1.2 (green)] immuno-labelling of control (<b>A1</b>) and experimental (<b>A2</b>) ON: note elongated JXPs with alterations in most of the nodal Na<sub>V</sub> channel clusters in samples from the cuprizone-treated mice. (<b>B1–2</b>) Double immuno-labelling of ON for K<sub>V</sub>1.1 (red) and K<sub>V</sub>1.2 (green) subunits of K<sub>V</sub>1 channels: control (<b>B1</b>) and experimental (<b>B2</b>) samples, respectively. Note the highly localized occurrence of these proteins in JXPs of controls contrasting with their diffuse location along the ON axons in demyelinated specimens. Yellow staining corresponds to JXP regions showing co-localization of these proteins. The scale bars for low and high magnifications are 6 and 2 µm, respectively. (<b>C</b>) Summary histogram of the intact JXP labelled with anti-K<sub>V</sub>1.2 antibody of control and experimental ON axons (n = 3 in each group). (<b>D</b>) A plot of the mean area of JXPs labelled for K<sub>V</sub>1.1 channels in control (2.4±0.5 µm<sup>2</sup>) compared to the increased area of fluorescence intensity of JXPs in demyelinated (8.2±1 µm<sup>2</sup>) axons. (<b>E</b>) The mean fluorescence area of JXPs labelled for Kv1.2 channels in control (3.8±0.4) was lower than that in the treated ON axons (8.2±1 µm<sup>2</sup>). (<b>F</b>) A summary histogram of K<sub>V</sub>1.1 and 1.2 co-localization in control (0.86±0.06) and demyelinated (0.27±0.04) ON demonstrating a significant (p<0.001) reduction in the degree of K<sub>V</sub>1.1/1.2 co-localization in ON axons of the experimental mice. (<b>G</b>) The degree of K<sub>V</sub>1.2/1.1 co-localization in ON axons of the experimental mice showed a reduction, which is still significant (P<0.05), when comparing the control (0.71±0.06) and the demyelinated ON (0.49±0.04) values. Data are taken from control and demylinated ON axons of 3 animals, in each group.</p
V<sub>½</sub> for activation and onset rate of currents mediated by the different recombinant channels expressed in HEK293 cells.
<p>Results are represented as means ±S.E.M. (n-values);</p>*<p>(p<0.05) and ** (p<0.005) numbers are significant compared to those from K<sub>V</sub>(1.1)<sub>4</sub>, (Mann Whitney <i>U</i>-test);</p>#<p>data are taken from Al-Sabi et al., (2010).</p