1000 resultados para Biological Naturalism
Resumo:
The inßuence of the sperm motility stimulant pentoxifylline (PF) on preimplantation embryo development in hamsters was evaluated. Eight-cell embryos were cultured in hamster embryo culture medium (HECM)-2, with or without PF (0· 0233·6 mM). There was 90%, 37% and 29% inhibition of blastocyst development by 3·6 (used for human sperm), 0·9 and 0 ·45 mM PF, respectively. However, 23 µM PF (exposed to hamster oocytes during IVF) signicantly (P < 0·05) improved blastocyst development (63· 6% v. 51· 8%); morulae development was, however, not curtailed by 0·45 mM or 0·9 mM PF (51·8%±6·0 or 50·5%±11·3, respectively). Post-implantation viability of PF-treated embryos was assessed by embryo transfer; 43% of 80 PF-treated embryos implanted compared with 40% of 79 control embryos. Of the 9 recipients, 6 females delivered pups (19, i.e. 16% of transferred embryos or 53% of implanted embryos). These data show that in hamsters, continuous presence of PF at 0·45-3·6 mM is detrimental to 8-cell embryo development whereas 23 µM PF improves the development of embryos to viable blastocysts which produce live offspring.
Resumo:
The identification of sequence (amino acids or nucleotides) motifs in a particular order in biological sequences has proved to be of interest. This paper describes a computing server, SSMBS, which can locate anddisplay the occurrences of user-defined biologically important sequence motifs (a maximum of five) present in a specific order in protein and nucleotide sequences. While the server can efficiently locate motifs specified using regular expressions, it can also find occurrences of long and complex motifs. The computation is carried out by an algorithm developed using the concepts of quantifiers in regular expressions. The web server is available to users around the clock at http://dicsoft1.physics.iisc.ernet.in/ssmbs/.
Resumo:
Rheumatoid arthritis (RA) and other chronic inflammatory joint diseases already begin to affect patients health-related quality of life (HRQoL) in the earliest phases of these diseases. In treatment of inflammatory joint diseases, the last two decades have seen new strategies and treatment options introduced. Treatment is started at an earlier phase; combinations of disease-modifying anti-rheumatic drugs (DMARDs) and corticosteroids are used; and in refractory cases new drugs such as tumour necrosis factor (TNF) inhibitors or other biologicals can be started. In patients with new referrals to the Department of Rheumatology of the Helsinki University Central Hospital, we evaluated the 15D and the Stanford Health Assessment Questionnaire (HAQ) results at baseline and approximately 8 months after their first visit. Altogether the analysis included 295 patients with various rheumatic diseases. The mean baseline 15D score (0.822, SD 0.114) was significantly lower than for the age-matched general population (0.903, SD 0.098). Patients with osteoarthritis (OA) and spondyloarthropathies (SPA) reported the poorest HRQoL. In patients with RA and reactive arthritis (ReA) the HRQoL improved in a statistically significant manner during the 8-month follow-up. In addition, a clinically important change appeared in patients with systemic rheumatic diseases. HAQ score improved significantly in patients with RA, arthralgia and fibromyalgia, and ReA. In a study of 97 RA patients treated either with etanercept or adalimumab, we assessed their HRQoL with the RAND 36-Item Health Survey 1.0 (RAND-36) questionnaire. We also analysed changes in clinical parameters and the HAQ. With etanercept and adalimumab, the values of all domains in the RAND-36 questionnaire increased during the first 3 months. The efficacy of each in improving HRQoL was statistically significant, and the drug effects were comparable. Compared to Finnish age- and sex-matched general population values, the HRQoL of the RA patients was significantly lower at baseline and, despite the improvement, remained lower also at follow-up. Our RA patients had long-standing and severe disease that can explain the low HRQoL also at follow-up. In a pharmacoeconomic study of patients treated with infliximab we evaluated medical and work disability costs for patients with chronic inflammatory joint disease during one year before and one year after institution of infliximab treatment. Clinical and economic data for 96 patients with different arthritis diagnoses showed, in all patients, significantly improved clinical and laboratory variables. However, the medical costs increased significantly during the second period by 12 015 (95% confidence interval, 6 496 to 18 076). Only a minimal decrease in work disability costs occurred mean decrease 130 (-1 268 to 1 072). In a study involving a switch from infliximab to etanercept, we investigated the clinical outcome in 49 patients with RA. Reasons for switching were in 42% failure to respond by American College of Rheumatology (ACR) 50% criteria; in 12% adverse event; and in 46% non-medical reasons although the patients had responded to infliximab. The Disease Activity Score with 28 joints examined (DAS28) allowed us to measure patients disease activity and compare outcome between groups based on the reason for switching. In the patients in whom infliximab was switched to etanercept for nonmedical reasons, etanercept continued to suppress disease activity effectively, and 1-year drug survival for etanercept was 77% (95% CI, 62 to 97). In patients in the infliximab failure and adverse event groups, DAS28 values improved significantly during etanercept therapy. However, the 1-year drug survival of etanercept was only 43% (95% CI, 26 to 70) and 50% (95% CI, 33 to 100), respectively. Although the HRQoL of patients with inflammatory joint diseases is significantly lower than that of the general population, use of early and aggressive treatment strategies including TNF-inhibitors can improve patients HRQoL effectively. Further research is needed in finding new treatment strategies for those patients who fail to respond or lose their response to TNF-inhibitors.
Resumo:
Several studies link the consumption of whole-grain products to a lowered risk of chronic diseases, such as certain types of cancer, type II diabetes, and cardiovascular diseases. However, the final conclusions of the exact protective mechanisms remain unclear, partly due to a lack of a suitable biomarker for the whole-grain cereals intake. Alkylresorcinols (AR) are phenolic lipids abundant in the outer parts of wheat and rye grains usually with homologues of C15:0- C25:0 alkyl chains, and are suggested to function as whole-grain biomarkers. Mammalian lignan enterolactone has also previously been studied as a potential whole-grain biomarker. In the present work a quantified gas chromatography-mass spectrometry method for the analysis of AR in plasma, erythrocytes, and lipoproteins was developed. The method was used to determine human and pig plasma AR concentrations after the intake of whole-grain wheat and rye products compared to low-fibre wheat bread diets to assess the usability of AR as biomarkers of whole-grain intake. AR plasma concentrations were compared to serum ENL concentrations. AR absorption and elimination kinetics were investigated in a pig model. AR occurrence in human erythrocyte membranes and plasma lipoproteins were determined, and the distribution of AR in blood was evaluated. Plasma AR seem to be absorbed via the lymphatic system from the small intestine, like many other lipophilic compounds. Their apparent elimination half-life is relatively short and is similar to that of tocopherols, which have a similar chemical structure. Plasma AR concentrations increased significantly after a one- to eight-week intake of whole-grain wheat and further on with whole-grain rye bread. The concentrations were also higher after habitual Finnish diet compared to diet with low-fibre bread. Inter-individual variation after a one-week intake of the same amount of bread was high, but the mean plasma AR concentrations increased with increasing AR intake. AR are incorporated into erythrocyte membranes and plasma lipoproteins, and VLDL and HDL were the main AR carriers in human plasma. Based on these studies, plasma AR could function as specific biomarkers of dietary whole-grain products. AR are exclusively found in whole-grains and are more suitable as specific biomarkers of whole-grain intake than previously investigated mammalian lignan enterolactone, that is formed from several plants other than cereals in the diet. Plasma AR C17:0/C21:0 -ratio could distinguish whether whole-grain products in the diet are mainly wheat or rye. AR could be used in epidemiological studies to determine whole-grain intake and to better assess the role of whole-grains in disease prevention.
Resumo:
Nature is a school for scientists and engineers. Inherent multiscale structures of biological materials exhibit multifunctional integration. In nature, the lotus, the water strider, and the flying bird evolved different and optimized biological solutions to survive. In this contribution, inspired by the optimized solutions from the lotus leaf with superhydrophobic self-cleaning, the water strider leg with durable and robust superhydrophobicity, and the lightweight bird bone with hollow structures, multifunctional metallic foams with multiscale structures are fabricated, demonstrating low adhesive superhydrophobic self-cleaning, striking loading capacity, and superior repellency towards different corrosive solutions. This approach provides an effective avenue to the development of water strider robots and other aquatic smart devices floating on water. Furthermore, the resultant multifunctional metallic foam can be used to construct an oil/water separation apparatus, exhibiting a high separation efficiency and long-term repeatability. The presented approach should provide a promising solution for the design and construction of other multifunctional metallic foams in a large scale for practical applications in the petro-chemical field. Optimized biological solutions continue to inspire and to provide design idea for the construction of multiscale structures with multifunctional integration. Inspired by the optimized biological solutions from the lotus leaf with superhydrophobic self-cleaning, the water strider leg with durable and robust superhydrophobicity, and the lightweight bird bone with hollow structures, multifunctional metallic foams with multiscale structures are fabricated, demonstrating low adhesive superhydrophobic self-cleaning, striking loading capacity, stable corrosion resistance, and oil/water separation.
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Sequence motifs occurring in a particular order in proteins or DNA have been proved to be of biological interest. In this paper, a new method to locate the occurrences of up to five user-defined motifs in a specified order in large proteins and in nucleotide sequence databases is proposed. It has been designed using the concept of quantifiers in regular expressions and linked lists for data storage. The application of this method includes the extraction of relevant consensus regions from biological sequences. This might be useful in clustering of protein families as well as to study the correlation between positions of motifs and their functional sites in DNA sequences.
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Clozapine is the most effective drug in treating therapy-resistant schizophrenia and may even be superior to all other antipsychotics. However, its use is limited by a high incidence (approximately 0.8%) of a severe hematological side effect, agranulocytosis. The exact molecular mechanism(s) of clozapine-induced agranulocytosis is still unknown. We investigated the mechanisms behind responsiveness to clozapine therapy and the risk of developing agranulocytosis by performing an HLA (human leukocyte antigens) association study in patients with schizophrenia. The first group comprised patients defined by responsiveness to first-generation antipsychotics (FGAs) (n= 19). The second group was defined by a lack of response to FGAs but responsiveness to clozapine (n=19). The third group of patients had a history of clozapine-induced granulocytopenia or agranulocytosis (n=26). Finnish healthy blood donors served as controls (n= 120). We found a significantly increased frequency of HLA-A1 among patients who were refractory to FGAs but responsive to clozapine. We also found that the frequency of HLA-A1 was low in patients with clozapine-induced neutropenia or agranulocytosis. These results suggest that HLA-A1 may predict a good therapeutic outcome and a low risk of agranulocytosis and therefore HLA typing may aid in the selection of patients for clozapine therapy. Furthermore, in a subgroup of schizophrenia, HLA-A1 may be in linkage disequilibrium with some vulnerability genes in the MHC (major histocompatibility complex) region on chromosome 6. These genes could be involved in antipsychotic drug response and clozapine-induced agranulocytosis. In addition, we investigated the effect of clozapine on gene expression in granulocytes by performing a microarray analysis on blood leukocytes of 8 schizophrenic patients who had started clozapine therapy for the first time. We identified an altered expression in 4 genes implicated in the maturation or apoptosis of granulocytes: MPO (myeloperoxidase precursor), MNDA (myeloid cell nuclear differentiation antigen), FLT3LG (Fms-related tyrosine kinase 3 ligand) and ITGAL (antigen CD11A, lymphocyte function-associated antigen 1). The altered expression of these genes following clozapine administration may suggest their involvement in clozapine-induced agranulocytosis. Finally, we investigated whether or not normal human bone marrow mesenchymal stromal cells (MSC) are sensitive to clozapine. We treated cultures of human MSCs and human skin fibroblasts with 10 µM of unmodified clozapine and with clozapine bioactivated by oxidation. We found that, independent of bioactivation, clozapine was cytotoxic to MSCs in primary culture, whereas clozapine at the same concentration stimulated the growth of human fibroblasts. This suggests that direct cytotoxicity to MSCs is one possible mechanism by which clozapine induces agranulocytosis.
Resumo:
This chapter describes biological and environmental determinants of the health of Australians, providing a background to the development of successful public health activity. You will recall from the introduction to Section 2 that health determinants are the biomedical, genetic, behavioural, socioeconomic and environmental factors that impact on health and wellbeing. These determinants can be influenced by interventions and by resources and systems (Australian Institute of Health and Welfare (AIHW) AIHW 2012a). Many factors combine to affect the health of individuals and communities. People’s circumstances and the environment determine whether a population is healthy or not. Factors such as where people live, the state of their environment, genetics, their education level and income, and their relationships with friends and family are all likely to impact on their health. The determinants of population health reflect the context of people’s lives; however, people have limited control over many of these determinants (WHO 2007).
Resumo:
Synthetic analogues of naturally occurring triterpenoids; glycyrrhetinic acid, arjunolic acid, and boswellic acids, by modification of A-ring with a cyano- and enone-functionality, have been reported. A novel method of synthesis of α-cyanoenones from isoxazoles is reported. Bioassays using primary mouse macrophages and tumor cell lines indicate potent anti-inflammatory and cytotoxic activities associated with cyano-enones of boswellic acid and glycyrrhetinic acid.
Resumo:
A Finite Element Method based forward solver is developed for solving the forward problem of a 2D-Electrical Impedance Tomography. The Method of Weighted Residual technique with a Galerkin approach is used for the FEM formulation of EIT forward problem. The algorithm is written in MatLAB7.0 and the forward problem is studied with a practical biological phantom developed. EIT governing equation is numerically solved to calculate the surface potentials at the phantom boundary for a uniform conductivity. An EIT-phantom is developed with an array of 16 electrodes placed on the inner surface of the phantom tank filled with KCl solution. A sinusoidal current is injected through the current electrodes and the differential potentials across the voltage electrodes are measured. Measured data is compared with the differential potential calculated for known current and solution conductivity. Comparing measured voltage with the calculated data it is attempted to find the sources of errors to improve data quality for better image reconstruction.
Resumo:
A new dinuclear nickel(II) complex, [Ni-2(LH2)(H2O)(2)(OH)(NO3)](NO3)(3) (1), of an ``end-off'' compartmental ligand 2,6-bis(N-ethylpiperazine-iminomethyl)-4-methyl-phenolato, has been synthesized and structurally characterized. The X-ray single crystal structure analysis shows that the piperazine moieties assume the expected chair conformation and are protonated. The complex 1 exhibits versatile catalytic activities of biological significance, viz. catecholase, phosphatase, and DNA cleavage activities, etc. The catecholase activity of the complex observed is very dependent on the nature of the solvent. In acetonitrile medium, the complex is inactive to exhibit catecholase activity. On the other hand, in methanol, it catalyzes not only the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) but also tetrachlorocatechol (TCC), a catechol which is very difficult to oxidize, under aerobic conditions. UV vis spectroscopic investigation shows that TCC oxidation proceeds through the formation of an intermediate. The intermediate has been characterized by an electron spray ionizaton-mass spectrometry study, which suggests a bidentate rather than a monodentate mode of TCC coordination in that intermediate, and this proposition have been verified by density functional theory calculation. The complex also exhibits phosphatase (with substrate p-nitrophenylphosphate) and DNA cleavage activities. The DNA cleavage activity exhibited by complex 1 most probably proceeds through a hydroxyl radical pathway. The bioactivity study suggests the possible applications of complex 1 as a site specific recognition of DNA and/or as an anticancer agent.
Resumo:
A new dinuclear nickel(II) complex, [Ni-2(LH2)(H2O)(2)(OH)(NO3)](NO3)(3) (1), of an "end-off" compartmental ligand 2,6-bis(N-ethylpiperazine-iminomethyl)-4-methyl-phenolato, has been synthesized and structurally characterized. The X-ray single crystal structure analysis shows that the piperazine moieties assume the expected chair conformation and are protonated. The complex 1 exhibits versatile catalytic activities of biological significance, viz. catecholase, phosphatase, and DNA cleavage activities, etc. The catecholase activity of the complex observed is very dependent on the nature of the solvent. In acetonitrile medium, the complex is inactive to exhibit catecholase activity. On the other hand, in methanol, it catalyzes not only the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) but also tetrachlorocatechol (TCC), a catechol which is very difficult to oxidize, under aerobic conditions. UV vis spectroscopic investigation shows that TCC oxidation proceeds through the formation of an intermediate. The intermediate has been characterized by an electron spray ionizaton-mass spectrometry study, which suggests a bidentate rather than a monodentate mode of TCC coordination in that intermediate, and this proposition have been verified by density functional theory calculation. The complex also exhibits phosphatase (with substrate p-nitrophenylphosphate) and DNA cleavage activities. The DNA cleavage activity exhibited by complex 1 most probably proceeds through a hydroxyl radical pathway. The bioactivity study suggests the possible applications of complex 1 as a site specific recognition of DNA and/or as an anticancer agent.
Resumo:
16-electrode phantoms are developed and studied with a simple instrumentation developed for Electrical Impedance Tomography. An analog instrumentation is developed with a sinusoidal current generator and signal conditioner circuit. Current generator is developed withmodified Howland constant current source fed by a voltage controlled oscillator and the signal conditioner circuit consisting of an instrumentation amplifier and a narrow band pass filter. Electronic hardware is connected to the electrodes through a DIP switch based multiplexer module. Phantoms with different electrode size and position are developed and the EIT forward problem is studied using the forward solver. A low frequency low magnitude sinusoidal current is injected to the surface electrodes surrounding the phantom boundary and the differential potential is measured by a digital multimeter. Comparing measured potential with the simulated data it is intended to reduce the measurement error and an optimum phantom geometry is suggested. Result shows that the common mode electrode reduces the common mode error of the EIT electronics and reduces the error potential in the measured data. Differential potential is reduced up to 67 mV at the voltage electrode pair opposite to the current electrodes. Offset potential is measured and subtracted from the measured data for further correction. It is noticed that the potential data pattern depends on the electrode width and the optimum electrode width is suggested. It is also observed that measured potential becomes acceptable with a 20 mm solution column above and below the electrode array level.