Dependence of calcium on thyroid hormone for the regulation of cellular functions

Recently, the thyroid hormone has been shown to cause increase in Ca2+concentration by mobilizing intracellular Ca2+. The mobilization of intracellular Ca2+in the absence of transmembrane Ca2+influx has been accepted as evidence for a cell-surface Ca2+ - receptor. The possible role of thyroid hormone in the regulation of cellular functions by Ca2+-channel was investigated using parameters proven to indispensably involve Ca2+: Bleeding and clotting times and rat uterine muscle activity in Ca2+-free Tyrode's solution. Adult female Wistar rats divided into four groups, namely; (i) Control, (ii) Thyroidectomized, (iii) Throidectomized-treated with thyroxine and (iv) Thyroxinetreated; were fed on rat chow. While groups i and ii were allowed access to tap water ad libitum for 60 days, groups iii and iv received tyroxine (10mg/kg body weight) every alternate day and tap water ad libitum for 60 days. All groups were kept in an air-conditioned room till they were euthanized. The results showed that thyroxine elicited biphasic contraction in Ca2+- depletion and potentiated uterine contraction during Ca2+ - loading (

Pulmonary Performance In Asymptomatic Young Nigerian Population Following The Administration Of Ascorbic Acid And Salbutamol

The relationship between vitamin C and pulmonary function has been reported to be a protection against pulmonary dysfunction. Sympathomimetics like salbutamol are respiratory smooth muscle relaxants. This study is aimed at investigating the roles of vitamin C and salbutamol on pulmonary function in a Nigerian population. Undergraduate medical students who gave their informed consent were clinically screened and thirty (30) selected. The subjects were grouped, and given Ascorbic acid and Salbutamol. Spirometry and peak flow measurements were done on each subject. Ascorbic acid was given orally at a dose of 1.50 mg /kg body weight; and salbutamol at a dose of 70 μg/kg body weight, orally. Measurements were taken an hour after each administration of the drugs. Results show mean PEFR in male and female control as 485.76 ± 51.40 L/min, and 329.87 ± 34.90 L/min respectively. Ascorbic acid increases PEFR much more than salbutamol VT, ERV, IC, VC and IRV were increased by ascorbic acid while Salbutamol decreased ERV, IC, VC and IRV. The study supports the performance enhancing role of ascorbic acid, more pronounced in the males than females. There do not seem to be any beneficial roles of salbutamol in asymptomatic individuals. Key words: Lung function, Ascorbic acid, Salbutamol Nigerian Journal of Physiological Sciences Vol.19(1&2) 2004: 48-5

Slower Rise and Smaller Peak Level of Blood Glucose in Healthy Young Male Adults Pre-Fed Moringa Oleifera Seed Powder

Ingestion of food with high glycaemic index is known to stress the insulin release mechanism that can produce Insulin resistance and eventually Diabetes Mellitus. How fast the end product of digestion of carbohydrate glucose surges into the bloodstream and the peak level attained are equally important for the glucose control mechanism of the body and ultimately the health of the individual involved. This study aims at exploring the effect of Moringa oleifera seed on the post-prandial rate of absorption of glucose and the peak glucose level attainable. Five healthy young male adult (18-35) volunteers had their Oral Glucose Tolerance Test (OGTT) conducted the first day as a control group followed the next day by a second OGTT with a pre-treatment with Moringa oleifera seed powder in a fix dose of 0.0175 gram per Kilogram body weight as the test/case group. The results indicate that it takes 60 minutes for the blood glucose to reach the peak concentration of 118.6 mg/dl in treatment group as against 30 minutes in the control group reaching 135mg/dl optimal concentration. The difference in this concentration and rate of surge are significant (p<0.05) A slower rise and a smaller optimal concentration of glucose are demonstrated as response to Moringa oleifera powder ingestion, a potentially clear beneficial effect. Keywords: Moringa Oleifera, Seed, Slower, Smaller, Glucose, Insulin-resistanc

Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

<div><p>Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway <i>i</i>.<i>e</i>., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times <i>vs</i>. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation.</p></div

Polarised Quark Distributions in the Nucleon from Semi-Inclusive Spin Asymmetries

We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) dx$.Comment: 17 page

Application of headspace solid-phase microextraction and gas chromatography for the analysis of furfural in crude palm oil

Processing of vegetative material containing pentoses has been shown to result in the formation of furfural. Furfural exhibits a spectrophotometric absorption peak at 518 nm when complexed with aniline acetate. Headspace solid-phase microextraction (HS-SPME) method has been successfully used to confirm the presence of furfural in crude palm oil (CPO). Solid phase microextraction (SPME) fiber composed of divinylbenzene/Carboxen/polydimethylsiloxane (DVB/PDMS/CAR) was used to absorb the volatiles in the headspace of the oil. The isolated compounds from the fiber was desorbed and separated on a capillary polar column of a gas chromatograph. Response surface methodology (RSM) was used to optimize the SPME fiber condition for maximum absorption of furfural from CPO. The optimized temperature and time for furfural extraction onto the SPME fiber are 70 °C for 40 min. Oils obtained from the mill were found to contain between 2 and 13% furfural

Genome-Wide Analyses of Recombination Prone Regions Predict Role of DNA Structural Motif in Recombination

HapMap findings reveal surprisingly asymmetric distribution of recombinogenic regions. Short recombinogenic regions (hotspots) are interspersed between large relatively non-recombinogenic regions. This raises the interesting possibility of DNA sequence and/or other cis- elements as determinants of recombination. We hypothesized the involvement of non-canonical sequences that can result in local non-B DNA structures and tested this using the G-quadruplex DNA as a model. G-quadruplex or G4 DNA is a unique form of four-stranded non-B DNA structure that engages certain G-rich sequences, presence of such motifs has been noted within telomeres. In support of this hypothesis, genome-wide computational analyses presented here reveal enrichment of potential G4 (PG4) DNA forming sequences within 25618 human hotspots relative to 9290 coldspots (p<0.0001). Furthermore, co-occurrence of PG4 DNA within several short sequence elements that are associated with recombinogenic regions was found to be significantly more than randomly expected. Interestingly, analyses of more than 50 DNA binding factors revealed that co-occurrence of PG4 DNA with target DNA binding sites of transcription factors c-Rel, NF-kappa B (p50 and p65) and Evi-1 was significantly enriched in recombination-prone regions. These observations support involvement of G4 DNA in recombination, predicting a functional model that is consistent with duplex-strand separation induced by formation of G4 motifs in supercoiled DNA and/or when assisted by other cellular factors

Early and reversible changes to the hippocampal proteome in mice on a high-fat diet

Funding LMW, FMC, CG, ACM and C-DM were funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS). FHM was supported by an EASTBIO DTP BBSRC studentship. DS was supported by a SULSA studentship.Peer reviewedPublisher PD

Quantifying unpredictability: A multiple-model approach based on satellite imagery data from Mediterranean ponds.

Fluctuations in environmental parameters are increasingly being recognized as essential features of any habitat. The quantification of whether environmental fluctuations are prevalently predictable or unpredictable is remarkably relevant to understanding the evolutionary responses of organisms. However, when characterizing the relevant features of natural habitats, ecologists typically face two problems: (1) gathering long-term data and (2) handling the hard-won data. This paper takes advantage of the free access to long-term recordings of remote sensing data (27 years, Landsat TM/ETM+) to assess a set of environmental models for estimating environmental predictability. The case study included 20 Mediterranean saline ponds and lakes, and the focal variable was the water-surface area. This study first aimed to produce a method for accurately estimating the water-surface area from satellite images. Saline ponds can develop salt-crusted areas that make it difficult to distinguish between soil and water. This challenge was addressed using a novel pipeline that combines band ratio water indices and the short near-infrared band as a salt filter. The study then extracted the predictable and unpredictable components of variation in the water-surface area. Two different approaches, each showing variations in the parameters, were used to obtain the stochastic variation around a regular pattern with the objective of dissecting the effect of assumptions on predictability estimations. The first approach, which is based on Colwell's predictability metrics, transforms the focal variable into a nominal one. The resulting discrete categories define the relevant variations in the water-surface area. In the second approach, we introduced General Additive Model (GAM) fitting as a new metric for quantifying predictability. Both approaches produced a wide range of predictability for the studied ponds. Some model assumptions-which are considered very different a priori-had minor effects, whereas others produced predictability estimations that showed some degree of divergence. We hypothesize that these diverging estimations of predictability reflect the effect of fluctuations on different types of organisms. The fluctuation analysis described in this manuscript is applicable to a wide variety of systems, including both aquatic and nonaquatic systems, and will be valuable for quantifying and characterizing predictability, which is essential within the expected global increase in the unpredictability of environmental fluctuations. We advocate that a priori information for organisms of interest should be used to select the most suitable metrics estimating predictability, and we provide some guidelines for this approach