Purification and characterisation of a carboxylesterase from the latex ofSynadenium grantii Hook, ‘f’

The latex ofSynadenium grantii was found to contain esterolytic activity. Polyacrylamide gel electrophoretic study coupled with substrate and inhibitor specificity studies revealed the presence of multiple forms of carboxylesterases and cholinesterases in the latex. One of the carboxylesterases of the latex was purified by acetone fractionation, carboxymethyl-Sephadex chromatography and Sepharose-6B gel filtration. The homogeneity of the enzyme was established by polyacrylamide gel electrophoresis, isoelectric focussing and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The enzyme consists of a single polypeptide chain with a molecular weight of 14,000. The amino acid analysis of the purified enzyme revealed that it contained a greater number of neutral and acidic, compared to basic amino acid residues. The isoelectric pH of the enzyme was found to be 4.0. The enzyme was a glycoprotein as revealed by periodic acid Schiff-staining technique. Studies with different organophosphate and carbamate inhibitors showed that this enzyme was sensitive to organophosphates. The product inhibition studies with this enzyme showed linear competitive inhibition with acetate and linear non-competitive inhibition with 1-naphthol

Prevalence, Related Factors, and Levels of Burnout Syndrome Among Nurses Working in Gynecology and Obstetrics Services: A Systematic Review and Meta-Analysis

Background: Although burnout levels and the corresponding risk factors have been studied in many nursing services, to date no meta-analytical studies have been undertaken of obstetrics and gynecology units to examine the heterogeneity of burnout in this environment and the variables associated with it. In the present paper, we aim to determine the prevalence, levels, and related factors of burnout syndrome among nurses working in gynecology and obstetrics services. Methods: A systematic review and meta-analysis of the literature were carried out using the following sources: CINAHL (Cumulative Index of Nursing and Allied Health Literature), LILACS (Latin American and Caribbean Health Sciences Literature), Medline, ProQuest (Proquest Health and Medical Complete), SciELO (Scientific Electronic Library Online), and Scopus. Results: Fourteen relevant studies were identified, including, for this meta-analysis, n = 464 nurses. The following prevalence values were obtained: emotional exhaustion 29% (95% CI: 11–52%), depersonalization 19% (95% CI: 6–38%), and low personal accomplishment 44% (95% CI: 18–71%). The burnout variables considered were sociodemographic (age, marital status, number of children, gender), work-related (duration of the workday, nurse-patient ratio, experience or number of miscarriages/abortions), and psychological (anxiety, stress, and verbal violence). Conclusion: Nurses working in obstetrics and gynecology units present high levels of burnout syndrome. In over 33% of the study sample, at least two of the burnout dimensions considered are apparent.This research was funded by the Excellence Research Project (P11HUM-7771) provided by the Andalusian Government (Spain)

Role of water in Protein Aggregation and Amyloid Polymorphism

A variety of neurodegenerative diseases are associated with the formation of amyloid plaques. Our incomplete understanding of this process underscores the need to decipher the principles governing protein aggregation. Most experimental and simulation studies have been interpreted largely from the perspective of proteins: the role of solvent has been relatively overlooked. In this Account, we provide a perspective on how interactions with water affect folding landscapes of A$\beta$ monomers, A$\beta_{16-22}$ oligomer formation, and protofilament formation in a Sup35 peptide. Simulations show that the formation of aggregation-prone structures (N$^*$) similar to the structure in the fibril requires overcoming high desolvation barrier. The mechanism of protofilament formation in a polar Sup35 peptide fragment illustrates that water dramatically slows down self-assembly. Release of water trapped in the pores as water wires creates protofilament with a dry interface. Similarly, one of the main driving force for addition of a solvated monomer to a preformed fibril is the entropy gain of released water. We conclude by postulating that two-step model for protein crystallization must also hold for higher order amyloid structure formation starting from N$^*$. Multiple N$^*$ structures with varying water content results in a number of distinct water-laden polymorphic structures. In predominantly hydrophobic sequences, water accelerates fibril formation. In contrast, water-stabilized metastable intermediates dramatically slow down fibril growth rates in hydrophilic sequences.Comment: 27 pages, 4 figures; Accounts of Chemical Research, 201

A novel approach for the identification of isozymes using inhibitors.

Carboxylesterase isozymes of a termite and a fungus, have been identified by exploiting their differential sensitivity towards organophosphate inhibitors. The inhibition curves obtained by plotting pI (negative logarithm of inhibitor concentration) versus per cent inhibition are used to distinguish the isozymes. The termite and its associated fungus possess 2 and 4 isozymes respectively. Each of the purified isozyme gave a single sigmoidal inhibition curve with its characteristic I50 value. The pattern of the inhibition curve of the crude extract is found to mimic that of the mixture of the purified isozymes in both termite and fungus. This method provides not only identification of isozymes but also serves as a criterion of homogeneity

Tissue esterases of Exoristina sorbillans (Uzi fly)

Polyacrylamide gel disc electrophoretic technique was used to examine the esterase pattern of nead, haemolymph, alimentary canal., ovary and testis of the Uzi fly. The zymograms revealed the varied pattern of esterases both in number and type. This varied pattern suggested several roles for these enzymes present in different tissues © 1984 Indian Academy of Sciences

Purification and properties of a carboxylesterase from germinated finger millet (Eleusine coracana Gaertn.)

A carboxylesterase (EC 3.1.1.1) was purified from germinated finger millet by ammonium sulphate fractionation, diethylaminoethyl-cellulose chromatography and Sephadex G-200 filtration. The homogeneity of the enzyme was established by Polyacrylamide gel electrophoresis, isoelectric focussing and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The enzyme has a single polypeptide chain with a molecular weight of 70,000. The amino acid analysis of the purified enzyme revealed that it contained a greater number of neutral and acidic, compared to, basic amino acid residues. The isoelectric pH of the enzyme was found to be 5·1. Studies with different organophosphate and carbamate inhibitors showed that this enzyme was more sensitive to organophosphate inhibitors than carbamates. The rate constants ki and l50 for different inhibitors were calculated. The product inhibition studies with this enzyme showed linear competitive inhibition with acetate and linear noncompetitive inhibition with 1-naphthol © 1985 Indian Academy of Sciences

Purification and characterization of acetylcholinesterase isozymes from the latex of Synadenium grantii Hook, 'f'

Three acetylcholinesterase isoenzymes were purified from S. grantii latex by a combination of acetone fractionation, CM-​Sephadex C-​50 chromatog., Sephadex G-​200 gel filtration, and PE-​Cellulose chromatog. The homogeneity of the isoenzymes was established by PAGE and isoelectrofocusing. The pI values were 5.0, 5.2, and 5.4. The mol. wt. of each enzyme was estd. to be 70,​000 by a gel-​filtration method. SDS-​PAGE indicated that each enzyme consisted of 2 subunits of mol. wt. ∼35,​000. These enzymes were glycoproteins and were more sensitive towards carbamate inhibitors compared to organophosphates. They exhibited substrate inhibition and showed identical substrate specificity and inhibitor sensitivity. The rate consts. for different inhibitors were calcd. These 3 enzymes were considered to be charge isoenzymic forms of the latex acetylcholinesterase

Antibacterial activity of green seaweeds on oral bacteria

328-333In present study, methanol extracts of the Chlorophycean group of seaweeds have been tested for their antibacterial activity against oral bacteria causing dental caries. Different concentrations of the extracts of the four species of seaweeds- <i style="mso-bidi-font-style: normal">Chaetomorpha antennina, Cladophora fascicularis, Spongomorpha indica and Ulva fasciata collected from sea coast of Visakhapatnam have been tested for their antibacterial activity against three oral pathogenic bacteria, Actinomyces viscosus (MTCC 7345), Streptococcus mitis (MTCC 2696), and Streptococcus mutans (MTCC 1943). The antibacterial sensitivity was studied by Agar disc diffusion method. Of these, U. fasciata has shown greater inhibition on all the three oral bacteria than C. antennina, C. fascicularis and S. indica. <i style="mso-bidi-font-style: normal">C. fascicularis has inhibited S. mitis and A. viscosus whereas C. antennina and <i style="mso-bidi-font-style: normal">S. indica inhibited only A. viscosus. The present findings reveal that these seaweeds have the potential antibacterial substances which can be used against oral pathogens as food additives, mouthwashes, chewing gums for preventing and treating dental caries