70 research outputs found
Interaction of thiocyanate with horseradish peroxidase. <SUP>1</SUP>H and <SUP>15</SUP>N nuclear magnetic resonance studies
Interaction of thiocyanate with horseradish peroxidase (HRP) was investigated by relaxation rate measurements (at 50.68 MHz) of the 15N resonance of thiocyanate nitrogen and by following the hyperfine shifted ring methyl proton resonances (at 500 MHz) of the heme group of SCN-.HRP solutions. At pH 4.0, the apparent dissociation constant (KD) for thiocyanate binding to HRP was deduced to be 158 mM from the relaxation rate measurements. Chemical shift changes of 1- and 8-ring methyl proton resonances in the presence of various amounts of thiocyanate at pH 4.0 yielded KD values of 166 and 136 mM, respectively. From the pH dependence of KD and the 15N resonance line width, it was observed that thiocyanate binds to HRP only under acidic conditions (pH < 6). The binding was found to be facilitated by protonation of an acid group on the enzyme with pKa 4.0. The pH dependence of the 15N line width as well as the apparent dissociation constant were quantitatively analyzed on the basis of a reaction scheme in which thiocyanate in deprotonated ionic form binds to the enzyme in protonated acidic form. The KD for thiocyanate binding to HRP was also evaluated in the presence of an excess of exogenous substrates such as resorcinol, cyanide, and iodide ions. It was found that the presence of cyanide (which binds to heme iron at the sixth coordination position) and resorcinol did not have any effect on the binding of thiocyanate, indicating that the binding site of the thiocyanate ion is located away from the ferric center as well as from the aromatic donor binding site. The KD in the presence of iodide, however, showed that iodide competes with thiocyanate for binding at the same site. The distance of the bound thiocyanate ion from the ferric center was deduced from the 15N relaxation time measurements and was found to be a 6.8 Å. From the distance as well as the change in the chemical shifts and line width of 1- and 8-methyl proton resonances, it is suggested that the binding site of thiocyanate may be located near heme, placed symmetrically with respect to 1- and 8-methyl groups of the heme of HRP. Similarity in the modes of binding of iodide and thiocyanate suggests that the oxidation of thiocyanate ion by H2O2 may also proceed via the two-electron transfer pathway under acidic conditions, as is the case for iodide
Loungu (Carpenter worm): Indigenous Delicious Insects with Immense Dietary Potential in Nagaland state, India
Carpenter worms of genus Cossus (Lepidoptera: Cossidae) are common wood-boring insects that can cause significant damage to several economically important plant species across the globe. Nevertheless, these worms are a popular delicacy among the indigenous population of Nagaland state of India since age old days. The carpenter worms (locally known as ‘Loungu’) are culturally significant during the Te-l Khukhu festival of Southern Angami region, annually held during July. The direct larval consumption is also cited for medicinal value. Rearing of carpenter worm is gaining popularity in hill tracts of Nagaland, because of its potential as a viable source of income for the rural population. The present study aimed to determine the eventual nutritional value of the larva by approximating its nutritional potential for the first time. Proximate analysis presents a significantly higher value of crude fat (37%), crude protein (48%), crude fibre (12.90%) and an appreciable calorific value. Close correlation between increased polyphenol value with its higher antioxidant capacity and pigment content is strongly evident. Nevertheless, the larva also provides appreciable quantities of dietary minerals reflected in terms of higher zinc and iron content. Analysis of thin layer chromatography undertaken in the study interestingly identified some of the essential amino acids, viz., methionine, lysine, leucine, histidine, threonine etc. This is the first report pioneering other detail studies to establish the significant value of carpenter worm larvae as an exotic dietary supplement among the indigenous Naga population, thereby providing more impetus for its promotion and commercialization
Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder
Background: Sunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample. Methods: Data for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P ≤ 0.001. Results: The 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger. Conclusion: UVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition
Variations in seasonal solar insolation are associated with a history of suicide attempts in bipolar I disorder
Background: Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries. Methods: Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun’s electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries). Results: This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01. Conclusion: A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed
Efficacy and safety of aripiprazole in the treatment of bipolar disorder: a systematic review
Abstract BACKGROUND: The current article is a systematic review concerning the efficacy and safety of aripiprazole in the treatment of bipolar disorder. METHODS: A systematic Medline and repositories search concerning the usefulness of aripiprazole in bipolar disorder was performed, with the combination of the words 'aripiprazole' and 'bipolar'. RESULTS: The search returned 184 articles and was last updated on 15 April 2009. An additional search included repositories of clinical trials and previous systematic reviews specifically in order to trace unpublished trials. There were seven placebo-controlled randomised controlled trials (RCTs), six with comparator studies and one with add-on studies. They assessed the usefulness of aripiprazole in acute mania, acute bipolar depression and during the maintenance phase in comparison to placebo, lithium or haloperidol. CONCLUSION: Aripiprazole appears effective for the treatment and prophylaxis against mania. The data on bipolar depression are so far negative, however there is a need for further study at lower dosages. The most frequent adverse effects are extrapyramidal signs and symptoms, especially akathisia, without any significant weight gain, hyperprolactinaemia or laboratory test changes
Magnetic susceptibility study and ground-state zero-field splitting in manganese(III) porphyrins
This article does not have an abstract
Effect of axial interaction in high-spin iron(III) porphyrins. Paramagnetic anisotropy and zero-field splitting in (tetraphenylporphyrin)iron(III) thiocyanate and iodide
This article does not have an abstract
Characterization of draft mitochondrial genome of guava trunk borer, Aristobia reticulator (Fabricius, 1781) (Coleoptera: Cerambycidae: Lamiinae) from India
Aristobia reticulator (Fabricius, 1781) is an important coleopteran pest of guava and litchi in India and China. The draft mitochondrial genome (mitogenome) of A. reticulator is ca. 15,838 bp long and consists of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA (tRNA) genes, and a control region (MK423971). The nucleotide composition of the mitogenome was significantly A + T-biased (A: 39.3%, T: 39.2%, G: 8.7%, C: 12.8%). All 22 tRNA genes show typical secondary cloverleaf structures. The mitogenome gene content and gene order was as described for a majority of coleopteran species. Phylogenetic analysis revealed that A. reticulator was closely related to Anoplophora chinensis (Forster), Anoplophora glabripennis (Motschulsky), and Anoplophora lurida (Pascoe, 1857) of the coleopteran tribe Lamiini (Cerambycidae, Lamiinae)
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