Rheological Behaviour of Instant Hot Chocolate Beverage: Part 1. Optimization of the Effect of Different Starches and Gums

In this study, effects of different starches (tapioca (TS), wheat (WS), corn (CS), potato (PS), modified corn (MCS) and modified potato (MPS)) and gums (xanthan gum (XG), guar gum (GG), alginate (A), salep (S), locust bean gum (LBG) and carrageen (C)) on the rheological properties of model hot chocolate beverage were studied. Swelling power (SP) of the starches and water absorption capacity (WAC) of the gums were determined. Hot chocolate beverages showed pseudoplastic behaviour. Ostwald de Waele model accurately described flow behaviour of each beverage sample. K, n, R ² values for Ostwald model were in the range of 4.8–160.3 mPa.sⁿ, 0.5117–0.9745, 0.9972–0.9998, respectively. The highest synergic effect in the model was observed between the interaction of MCS and XG. The XG-PS, XG-TS, XG-CS combinations showed the highest K and viscosity values, respectively.     

Signaling mechanisms in red blood cells: A view through the protein phosphorylation and deformability

Intracellular signaling mechanisms in red blood cells (RBCs) involve various protein kinases and phosphatases and enable rapid adaptive responses to hypoxia, metabolic requirements, oxidative stress, or shear stress by regulating the physiological properties of the cell. Protein phosphorylation is a ubiquitous mechanism for intracellular signal transduction, volume regulation, and cytoskeletal organization in RBCs. Spectrin-based cytoskeleton connects integral membrane proteins, band 3 and glycophorin C to junctional proteins, ankyrin and Protein 4.1. Phosphorylation leads to a conformational change in the protein structure, weakening the interactions between proteins in the cytoskeletal network that confers a more flexible nature for the RBC membrane. The structural organization of the membrane and the cytoskeleton determines RBC deformability that allows cells to change their ability to deform under shear stress to pass through narrow capillaries. The shear stress sensing mechanisms and oxygenation-deoxygenation transitions regulate cell volume and mechanical properties of the membrane through the activation of ion transporters and specific phosphorylation events mediated by signal transduction. In this review, we summarize the roles of Protein kinase C, cAMP-Protein kinase A, cGMP-nitric oxide, RhoGTPase, and MAP/ERK pathways in the modulation of RBC deformability in both healthy and disease states. We emphasize that targeting signaling elements may be a therapeutic strategy for the treatment of hemoglobinopathies or channelopathies. We expect the present review will provide additional insights into RBC responses to shear stress and hypoxia via signaling mechanisms and shed light on the current and novel treatment options for pathophysiological conditions.     

Investigation of Heavy Metal Level and Mineral Nutrient Status in Widely Used Medicinal Plants’ Leaves in Turkey: Insights into Health Implications

The use of plants in treatments has been as old as humanity and it has preserved its popularity for centuries til now because of their availability, affordability and safeness. However, despite their widespread use, safety and quality issues have been major concerns in the world due to industrial- and anthropogenic-based heavy metal contamination risks. Thus, this study was attempted to analyze the heavy metal levels and mineral nutrient status of widely used medicinal plants in Turkey to have insights about their health implications on humans. The plant concentrations of B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn were analyzed by ICP-OES in the leaves of 44 medical plants purchased from herbal markets of three different districts of Istanbul/Turkey. The measured lowest to highest concentrations were 0.065–79.749 mg kg⁻¹ B, 921.802–12,854.410 mg kg⁻¹ Ca, 0.020–0.558 mg kg⁻¹ Cd, 0.015–4.978 mg kg⁻¹ Cr, 0.042–8.489 mg kg⁻¹ Cu, 34.356–858.446 mg kg⁻¹ Fe, 791.323–15,569.349 mg kg⁻¹ K, 102.236–2837.836 mg kg⁻¹ Mg, 4.915–91.519 mg kg⁻¹ Mn, 10.224–3213.703 mg kg⁻¹ Na, 0.001–5.589 mg kg⁻¹ Ni, 0.003–3.636 mg kg⁻¹ Pb and 2.601–36.102 mg kg⁻¹ Zn. Those levels in plants were in acceptable limits though some elements in some plants have high limits which were not harmful. Variations (above acceptable limits) in element concentrations also indicated that these plants could be contaminated with other metals and that genetic variations may influence accumulation of these elements at different contents. Overall, analyzed medicinal plants are expected not to pose any serious threat to human health.

     

Proteomic analysis of Bacillus subtilis strains engineered for improved production of heterologous proteins

The use of bacterial systems for recombinant protein production has advantages of simplicity, time and cost over competing systems. However, widely used bacterial expression systems (e.g. Escherichia coli, Pseudomonas fluorescens) are not able to secrete soluble proteins directly into the culture medium. This limits yields and increases downstream processing time and costs. In contrast, Bacillus spp. secrete native enzymes directly into the culture medium at grams‐per‐litre quantities, although the yields of some recombinant proteins are severely limited. We have engineered the Bacillus subtilis genome to generate novel strains with precise deletions in the genes encoding ten extracytoplasmic proteases that affect recombinant protein secretion, which lack chromosomal antibiotic resistance genes. The deletion sites and presence of single nucleotide polymorphisms were confirmed by sequencing. The strains are stable and were used in industrial‐scale fermenters for the production of the Bacillus anthracis vaccine protein, protective antigen, the productivity of which is extremely low in the unmodified strain. We also show that the deletion of so‐called quality control proteases appears to influence cell‐wall synthesis, resulting in the induction of the cell‐wall stress regulon that encodes another quality control protease.     

The effect of melatonin on glycoprotein levels and oxidative liver injury in experimental diabetes

In this present study, the duration of melatonin (Mel) administered to diabetic rats was prolonged so as to examine its effects on the biochemical liver parameters of diabetic rats. In the experiment, Male Sprague Dawley rats were divided randomly into five groups; the control, diabetic + Mel, diabetic, diabetic + insulin, and diabetic + Mel + insulin. Diabetes mellitus was induced by administration of a single dose of streptozotocin (60 mg/kg) intraperitoneally and rats were given vehicle as a solvent for Mel every day for 12 weeks. In the diabetic + Mel group, diabetic rats were administered Mel (10 mg/kg/day) for 12 weeks to treat diabetes. The diabetic + insulin group were diabetic rats given insulin (6 U/kg) subcutaneously for 12 weeks. The diabetic + Mel + insulin rats received insulin and Mel at the same dose and time. At the end of the experiment, the animals were decapitated and liver tissues were taken. The protective effect of Mel on liver tissue of diabetic rats was investigated, total antioxidant status, total oxidant status, reactive oxygen species, oxidative stress index, adenosine deaminase, xanthine oxidase, paraoxonase 1, sodium/potassium ATPase, myeloperoxidase, γ-glutamyl transferase, sorbitol dehydrogenase, tumor necrosis factor-alpha, homocysteine, nitric oxide, glucose-6-phosphate dehydrogenase, and glycoprotein levels were determined in liver tissues. Treatment with Mel and/or insulin has been found to have a protective effect on biochemical parameters. The results showed that administration of Mel to diabetic rats prevented the distortion of the studied biochemical parameters of liver tissues.     

Clastogenicity of selective serotonin-reuptake inhibitors

OBJECTIVE: Selective serotonin-reuptake inhibitors (SSRIs) are used in the treatment of various forms of psychiatric disorders. Preclinical studies in laboratory animals have indicated that SSRIs were not genotoxic, but clear results from in vitro testing of SSRIs in a human cell system are currently scarce. The purpose of this study was to investigate whether SSRIs might be genotoxic. Sertraline was chosen as model SSRI, since it appears to be at least as well-tolerated as other SSRIs and may even have a more favourable side-effect profile. Unlike fluoxetine, fluvoxamine and paroxetine, sertraline has low potential for pharmacokinetic drug interactions. So, sertraline would be considered first in the treatment of psychiatric disorders requiring SSRI therapy in the future. We therefore examined peripheral lymphocytes from sertraline-treated patients for both sister chromatid exchanges (SCEs), cells with a high frequency of SCEs (HFC) and chromosome aberrations (CA) to evaluate the clastogenicity of SSRIs. METHOD: Ten sertraline-treated patients meeting 'Structured Clinical Interview for DSM-IV' criteria for both generalized anxiety disorder and major depression were compared with 18 healthy volunteers and 18 non-treated patients with similar psychopathology. Sertraline hydrochloride was administered orally at 50 mg daily for 10 months to 1 year. The participants were selected on the basis of similar responses to a questionnaire assessing risk of genotoxicity related to other aspects of life. All participants had very similar lifestyles, medical histories, biological and dietary factors. All subjects were non-smokers. RESULT: A statistically significant difference between patients with both generalized anxiety disorder and major depression (sertraline-treated or non-treated) and healthy volunteer groups was found by both SCE frequencies and HFC percentages. Both patient groups showed higher frequencies of SCEs than the healthy controls. No statistically significant difference was found between SCE frequencies or HFC percentages observed in sertraline-treated and non-treated patient groups. No statistical difference was found between groups with respect to the frequency of CA. CONCLUSION: There are no adequate studies analysing the clastogenicity of SSRIs, in particular of sertraline. The SCE frequency, the percentage HFC and the frequency of CA in patients with both generalized anxiety disorder and major depression exposed to daily doses of sertraline do not indicate a possible clastogenic hazard. The increased SCE frequencies in patients with both generalized anxiety disorder and major depression in our study-irrespective of sertraline treatment-indicate a possible genotoxic effect. However, our observations were based on a limited number of patients; the results may be explained by psychogenic stress.     

Analysis of Airborne Pollen Fall in Edirne,Turkey

In the atmosphere of Edirne 12 691 pollen grains belonging to 42 taxa were identified by using of Durham sampler in 2000 and 2001. A total of 6 189 pollen grains per cm2 were recorded in 2000 and a total of 6 502 pollen grains per cm2 in 2001. Total pollen grains consisted of 71.81% grains from arboreal plants, 25.88% grains from non-arboreal plants and 2.31% unidentified pollen grains. Pollen from the following taxa were also found to be prevalent in the atmosphere of Edirne: Gramineae, Pinus sp., Quercus sp.,Cupressaceae/Taxaceae, Platanus sp., Salix sp., Morus sp., Populus sp., Carpinus sp., Juglans sp.,Chenopodiaceae/Amaranthaceae, Fraxinus sp., Fagus sp., Ulmus sp., Ailanthus sp., Alnus sp., Ostrya sp.,Helianthus sp. The season of maximum pollen fall was from April to June, with a prevalence of arboreal pollen in the first month, and of pollen from non-arboreal plants in the last months of the year.