Oxygen-derived free radicals and hemolysis during open heart surgery

Reperfusion injury occurs during open-heart surgery after prolonged cardioplegic arrest. Cardiopulmonary bypass also is known to cause hemolysis. Since reperfusion of ischemic myocardium is associated with the generation of oxygen free radicals, and since free radicals can attack a protein molecule, it seems reasonable to assume that hemolysis might be the consequence of free radical attack on hemoglobin protein. The results of this study demonstrated that reperfusion following ischemic arrest caused an increase in free hemoglobin and free heme concentrations, simultaneously releasing free iron and generating hydroxyl radicals. In vitro studies using pure hemoglobin indicated that superoxide anion generated by the action of xanthine oxidase on xanthine could release iron from the heme ring and cause deoxygenation of oxyhemoglobin into ferrihemoglobin. This study further demonstrated that before the release of iron from the heme nucleus, oxyhemoglobin underwent deoxygenation to ferrihemoglobin. The released iron can catalyze the Fenton reaction, leading to the formation of cytotoxic hydroxyl radical (OH·). In fact, the formation of OH. in conjunction with hemolysis occurs during cardiac surgery, and when viewed in the light of the in vitro results, it seems likely that oxygen-derived free radicals may cause hemolysis during cardiopulmonary bypass and simultaneously release iron from the heme ring, which can catalyze the formation of OH·.     

Biodegradation of 4-nitrophenol by indigenous microbial populations in Everglades soils

The Everglades in South Florida are a unique ecological system. As a result of the widespread use of pesticides and herbicides in agricultural areas upstream from these wetlands, there is a serious potential for pollution problems in the Everglades. The purpose of this study was to evaluate the ability of indigenous microbial populations to degrade xenobiotic organic compounds introduced by agricultural and other activities. Such biodegradation may facilitate the remediation of contaminated soils and water in the Everglades. The model compound selected in this study is 4-nitrophenol, a chemical commonly used in the manufacture of pesticides. The mineralization of 4-nitrophenol at various concentrations was studied in soils collected from the Everglades. At concentrations of 10 and 100 microg/g soil, considerable mineralization occurred within a week. At a higher concentration, i.e., 10 mg/g soil, however, no mineralization of 4-nitrophenol occurred over a 4-month period; such a high concentration apparently produced an inhibitory effect. The rate and extent of 4-nitrophenol mineralization was enhanced on inoculation with previously isolated nitrophenol-degrading microorganisms. The maximum mineralization extent measured, however, was less than 30% suggesting conversion to biomass and/or unidentified intermediate products. These results indicate the potential for natural mechanisms to mitigate the adverse effects of xenobiotic pollutants in a complex system such as the Everglades.     

Metabolism of 3H-1α,25-dihydroxyvitamin D3 in cultured human keratinocytes

In the present investigation we studied the metabolism of 1α,25-dihydroxy-[1β-³H] vitamin D₃ (³H-1,25(OH)₂D₃) in culture-grown human keratinocytes (CHK). Our results showed that the cellular uptake of ³H-1,25(OH)₂D₃, upon incubation with CHK, occurred very rapidly; and it paralleled a decrease in the concentration of ³H-1,25(OH)₂D₃ in the medium. The amount of ³H-calcitroic acid, on the other hand, increased slowly in the medium, while the concentration of ³H-calcitroic acid in the cell remained undetectable during the whole period of incubation. When the cells were preincubated with 1,25(OH)₂D₃ (10^?8M), conversion of ³H-1,25(OH)₂D₃ to ³H-calcitroic acid increased almost twofold, indicating that 1,25(OH)₂D₃ catalyzed its own catabolism. © 1995 Wiley-Liss, Inc.     

Effects of nonionic surfactants on the solubilization and mineralization of phenanthrene in soil-water systems

The solubilization and mineralization of (14)C-phenanthrene in soil-water systems was examined with several commercially available surface-active agents, viz., an alkyl ethoxylate C(12)E(4); two alkylphenol ethoxylate surfactants: C(8)PE(9.5) and C(9)PE(10.5); two sorbitan ethoxylate surfactants: the sorbitan monolaurate (Tween 20) and the sorbitan monooleate (Tween 80); two pairs of nonionic ethoxylate surfactant mixtures: C(12)E(4)/C(12)E(23) at a 1:1 ratio, and C(12-15)E(3)/C(12-15)E(9) at a 1:3 ratio; and two surfactants possessing relatively high critical micelle concentration (CMC) values and low aggregation numbers: CHAPS and octyglucoside. Surface tension experiments were performed to evaluate surfactant sorption onto soil and the surfactant doses required to attain the CMC in the soil-water systems. Surfactant solubilization of (14)C-phenanthrene commenced with the onset of micellization. The addition of surface-active agents was observed not to be beneficial to the microbial mineralization of phenanthrene in the soil-water systems and, for supra-CMC surfactant doses, phenanthrene mineralization was completely inhibited for all the surfactants tested. A comparison of solubilization, surface tension, and mineralization data confirms that the inhibitory effect on microbial degradation of phenanthrene is related to the CMC of the surfactant in the presence of soil. Additional tests demonstrated the recovery of mineralization upon dilution of surfactant concentration to sub-CMC levels, and a relatively high exit rate for phenanthrene from micelles. These tests suggest that the inhibitory effect is probably related to a reversible physiological surfactant micelle-bacteria interaction, possibly through partial complexing or release of membrane material with disrupting membrane lamellar structure. This study indicates that nonionic surfactant solubilization of sorbed hydrophobic organic compounds from soil may not be beneficial for the concomitant enhancement of soil bioremediation. Additional work is needed to address physicochemical processes for bioavailability enhancement, and effects of solubilizing agents on microorganisms for remediation and treatment of hydrophobic organic compounds and nonaqueous phase liquids. (c) 1992 John Wiley & Sons Inc.     

Male‐specific alterations in structure of isolation call sequences of mouse pups with 16p11.2 deletion

16p11.2 deletion is one of the most common gene copy variations that increases the susceptibility to autism and other neurodevelopmental disorders. This syndrome leads to developmental delays, including speech impairment and delays in expressive language and communication skills. To study developmental impairment of vocal communication associated with 16p11.2 deletion syndrome, we used the 16p11.2del mouse model and performed an analysis of pup isolation calls (PICs). The earliest PICs at postnatal day 5 from 16p11.2del pups were found altered in a male‐specific fashion relative to wild‐type (WT) pups. Analysis of sequences of ultrasonic vocalizations (USVs) emitted by pups using mutual information between syllables at different positions in the USV spectrograms showed that dependencies exist between syllables in WT mice of both sexes. The order of syllables was not random; syllables were emitted in an ordered fashion. The structure observed in the WT pups was identified and the pattern of syllable sequences was considered typical for the mouse line. However, typical patterns were totally absent in the 16p11.2del male pups, showing on average random syllable sequences, while the 16p11.2del female pups had dependencies similar to the WT pups. Thus, we found that PICs were reduced in number in male 16p11.2 pups and their vocalizations lack the syllable sequence order emitted by WT males and females and 16p11.2 females. Therefore, our study is the first to reveal sex‐specific perinatal communication impairment in a mouse model of 16p11.2 deletion and applies a novel, more granular method of analysing the structure of USVs.     

Unwrapping the phase portrait features of adventitious crackle for auscultation and classification: a machine learning approach

Journal of Biological Physics - The paper delves into the plausibility of applying fractal, spectral, and nonlinear time series analyses for lung auscultation. The thirty-five sound signals of...     

Alkaline phosphatase and acid phosphatase levels in saliva and serum of patients with healthy periodontium,gingivitis, and periodontitis before and after scaling with root planing: A clinico-biochemical study

Periodontitis is commonly diagnosed based on clinical parameters. However, the analysis of a few unique biomarkers of the disease process present in the saliva and blood can further assist the estimation of the rate of disease progression.AimThe present study attempted to correlate the alkaline phosphatase (ALP) and acid phosphatase (ACP) levels in saliva and serum between patients with healthy periodontium, gingivitis, and chronic periodontitis.Materials and methodsThe present study was conducted in 135 subjects between 20 and 55 years of age. The subjects were divided into three groups, namely healthy (Group A), gingivitis (Group B), and chronic periodontitis (Group C). The clinical parameters were recorded using the plaque index (PI), gingival index (GI), and probing depth (PD). Saliva and serum were analyzed for ALP and ACP levels using an auto analyzer. All patients underwent scaling and root planning (SRP) along with oral hygiene instructions. Patients were then recalled after four weeks, and blood and saliva samples were collected to estimate ALP and ACP levels prior to clinical examination.ResultsThe clinical parameters exhibited a statistically significant decrease in the PI and GI in both group B and group C after SRP. A significant change in the PD and attachment levels (AL) was observed in the periodontitis group after SRP. The mean salivary & serum ALP levels exhibited a statistically significant decrease in group B & C after SRP. The mean serum ACP levels exhibited a statistically significant decrease in group B & C after SRP However, the salivary ACP levels decrease after SRP was only statistically significant in group C.ConclusionSerum and salivary ALP and ACP levels were markedly decreased in the gingivitis and periodontitis groups after SRP and were positively correlated with the clinical parameters.     

The Effect of New Zealand Kanuka,Manuka and Clover Honeys on Bacterial Growth Dynamics and Cellular Morphology Varies According to the Species

Treatment of chronic wounds is becoming increasingly difficult due to antibiotic resistance. Complex natural products with antimicrobial activity, such as honey, are now under the spotlight as alternative treatments to antibiotics. Several studies have shown honey to have broad-spectrum antibacterial activity at concentrations present in honey dressings, and resistance to honey has not been attainable in the laboratory. However not all honeys are the same and few studies have used honey that is well defined both in geographic and chemical terms. Here we have used a range of concentrations of clover honey and a suite of manuka and kanuka honeys from known geographical locations, and for which the floral source and concentration of methylglyoxal and hydrogen peroxide potential were defined, to determine their effect on growth and cellular morphology of four bacteria: Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. While the general trend in effectiveness of growth inhibition was manuka>manuka-kanuka blend>kanuka>clover, the honeys had varying and diverse effects on the growth and cellular morphology of each bacterium, and each organism had a unique response profile to these honeys. P. aeruginosa showed a markedly different pattern of growth inhibition to the other three organisms when treated with sub-inhibitory concentrations of honey, being equally sensitive to all honeys, including clover, and the least sensitive to honey overall. While hydrogen peroxide potential contributed to the antibacterial activity of the manuka and kanuka honeys, it was never essential for complete growth inhibition. Cell morphology analysis also showed a varied and diverse set of responses to the honeys that included cell length changes, cell lysis, and alterations to DNA appearance. These changes are likely to reflect the different regulatory circuits of the organisms that are activated by the stress of honey treatment.     

Synthesis of highly fluorescent nitrogen and phosphorus doped carbon dots for the detection of Fe3+ ions in cancer cells

Highly fluorescent nitrogen and phosphorus‐doped carbon dots with a quantum yield 59% have been successfully synthesized from citric acid and di‐ammonium hydrogen phosphate by single step hydrothermal method. The synthesized carbon dots have high solubility as well as stability in aqueous medium. The as‐obtained carbon dots are well monodispersed with particle sizes 1.5–4 nm. Owing to a good tunable fluorescence property and biocompatibility, the carbon dots were applied for intercellular sensing of Fe³⁺ ions as well as cancer cell imaging. Copyright © 2015 John Wiley & Sons, Ltd.