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Various Studies (various + studies)
Selected AbstractsInteractions of orexins/hypocretins with adrenocortical functionsACTA PHYSIOLOGICA, Issue 3 2010S. M. Kagerer Abstract The neuropeptides orexin A and B (hypocretin-1 and -2) are involved in numerous central regulation processes such as energy homeostasis, sleeping behaviour and addiction. The expression of orexins and orexin receptors in a variety of tissues outside the brain and the presence of orexin A in the circulation indicate the existence of an additional peripheral orexin system. Furthermore, it is well established that orexins exert an influence on the regulation of the hypothalamus,pituitary,adrenal axis, acting both on its central and peripheral branch. In rat and human adrenal cortices the expression of both orexin receptors has been verified with a predominance of OX2R. The local expression of orexin receptors was observed to be gender specific and to be modified by plasma glucose and insulin concentrations, nutritional status as well as gonadal steroids. Various studies consistently demonstrated orexin A to enhance glucocorticoid secretion of rat and human adrenal cortices, while orexin B was found to be either less potent or ineffective. On the contrary, the influence of orexins on adrenocortical aldosterone production and cell proliferation is still more controversial. Recent findings indicate that orexins stimulate adrenocortical steroidogenesis by augmenting transcription of selective steroidogenic enzymes and proteins such as steroidogenic acute regulatory protein. Both, Gq and Gs, signalling pathways with a downstream activation of MAP kinases appear to be involved in this regulation. [source] The link between infant attention to goal-directed action and later theory of mind abilitiesDEVELOPMENTAL SCIENCE, Issue 6 2008Gisa Aschersleben Various studies have shown that infants in their first year of life are able to interpret human actions as goal-directed. It is argued that this understanding is a precondition for understanding intentional actions and attributing mental states. Moreover, some authors claim that this early action understanding is a precursor of later Theory of Mind (ToM) development. To test this, we related 6-month-olds' performance in an action interpretation task to their performance in ToM tasks at the age of 4 years. Action understanding was assessed using a modified version of the Woodward-paradigm (Woodward, 1999). At the age of 4 years, the same children were tested with the German version of the ToM scale developed by Wellman and Liu (2004). Results revealed a correlation between infants' decrement of attention to goal-directed action and their ability to solve a false belief task at the age of 4 years with no modulation by language abilities. Our results indicate a link between infant attention to goal-directed action and later theory of mind abilities. [source] Cytotoxicity assessment of gliotoxin and penicillic acid in Tetrahymena pyriformisENVIRONMENTAL TOXICOLOGY, Issue 2 2006C. Gräbsch Abstract Various studies have documented the associations between mold exposure and effects on health. Mycotoxins, which occur in spores and mold fragments, can be involved in processes that have pathological effects, such as adynamia of the immune system, recurrent infections of the respiratory tract, or asthma. Using Tetrahymena pyriformis, a single-cell organism well established as a suitable model for human respiratory epithelium-cell functionalities, we investigated dose,response relationships of the mycotoxins gliotoxin and penicillic acid. Our study focused on the viability (cell count, MTT assay), energy levels (adenosine-5,-triphosphate content), energy-providing processes (MTT reduction per cell), and cell respiration (oxygen consumption). Both mycotoxins acted as cytotoxins in a dose-dependent manner. Gliotoxin had a stronger inhibitory effect (EC50 0.38 ,M) than did penicillic acid (EC50 343.19 ,M). The energy-providing processes were not inhibited or were only weakly inhibited under the influence of gliotoxin, whereas penicillic acid caused stimulation of the physiological parameters. Summarizing the results, it is clear that the two investigated mycotoxins must have different modes of action. They are not only different in the strength of their toxic effects but also in a variety of physiological aspects. In addition, T. pyriformis showed differences in its ability to overcome the negative effects of particular mycotoxin exposures. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 111,117, 2006. [source] Historical changes in lake ice-out dates as indicators of climate change in New England, 1850,2000,INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 15 2002Glenn A. Hodgkins Abstract Various studies have shown that changes over time in spring ice-out dates can be used as indicators of climate change. Ice-out dates from 29 lakes in New England (USA) with 64 to 163 years of record were assembled and analysed for this study. Ice-out dates have become significantly earlier in New England since the 1800s. Changes in ice-out dates between 1850 and 2000 were 9 days and 16 days in the northern/mountainous and southern regions of New England respectively. The changes in the ice-out data over time were very consistent within each of the two regions of New England, and more consistent than four air-temperature records in each region. The ice-out dates of the two regions had a different response to changes in air temperature. The inferred late winter,early spring air-temperature warming in both regions of New England since 1850, based on linear regression analysis, was about 1.5°C. Published in 2002 by John Wiley & Sons, Ltd. [source] No correlation of five gene polymorphisms with periodontal conditions in a Greek populationJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2006D. Sakellari Abstract Background: Various studies have examined possible correlations between a number of cytokine gene polymorphisms and periodontal disease in populations of different origins. The present study sought the correlation between four single-nucleotide polymorphisms (IL1A+3954, IL1B+4845, TNFA,308, COL1A1 Sp1), a variable number of tandem repeats polymorphism (IL1RN intron 2) and periodontal conditions in subjects of Greek origin. Methods: One hundred and ninety-two healthy subjects, stratified as non-periodontitis and periodontitis (chronic and aggressive) cases, participated in the present study. Genotyping was performed by polymerase chain reaction-based techniques using the primers and conditions described in the literature. The frequencies of genotypes between study groups were compared using Genepop v3.3 genetic software and Instat statistical package. Results: No differences were observed among the groups concerning the distributions of genotypes under investigation. Conclusions: Carriage rates of the polymorphisms under investigation in systemically healthy subjects of Greek origin are well within the range reported for Caucasians but these polymorphisms cannot discriminate between non-periodontitis and periodontitis (chronic or aggressive) cases. [source] Association of low density lipoprotein receptor related protein-associated protein (LRPAP1) gene insertion/deletion polymorphism with gallstone diseaseJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2006MANJUSHA DIXIT Abstract Background and Aim:, Gallstones are byproducts of cholesterol supersaturated bile. Various studies have indicated that there might be a genetic predisposition to the disease. Receptor-associated protein (RAP) is a molecular chaperone for low density lipoprotein receptor-related protein (LRP), which plays a key role in cholesterol metabolism. Intron 5 insertion/deletion polymorphism of RAP gene (LRPAP1) has been implicated in other diseases sharing etiology with gallstone disease (GSD). Methods:, To analyze the association of insertion/deletion polymorphism in GSD, 130 gallstone patients and 202 healthy subjects took part in the present study. For genotyping, polymerase chain reaction was followed by 2% agarose gel electrophoresis. Results:, The results showed that frequencies of D and I allele were 65.77% and 34.23% in patients, 76.24% and 23.76% in controls, respectively. Frequency of I allele was significantly higher in the patient group than in the control group (P = 0.003). Conclusion:, In the present study I (insertion) allele was found to be associated with GSD. [source] Calcium channel subtypes differentially regulate fusion pore stability and expansionJOURNAL OF NEUROCHEMISTRY, Issue 4 2007Alvaro O. Ardiles Abstract Various studies have focused in the relative contribution of different voltage-activated Ca2+ channels (VACC) to total transmitter release. However, how Ca2+ entry through a given VACC subtype defines the pattern of individual exocytotic events remains unknown. To address this question, we have used amperometry in bovine chromaffin cells. L, N, and P/Q channels were individually or jointly blocked with furnidipine, ,-conotoxin GVIA, ,-agatoxin IVA, or ,-conotoxin MVIIC. The three channel types contributed similarly to cytosolic Ca2+ signals induced by 70 mmol/L K+. However, they exhibited different contributions to the frequency of exocytotic events and they were shown to differently regulate the final steps of the exocytosis. When compared with the other VACC subtypes, Ca2+ entry through P/Q channels effectively induced exocytosis, it decreased fusion pore stability and accelerated its expansion. Conversely, Ca2+ entry through N channels was less efficient in inducing exocytotic events, also slowing fusion pore expansion. Finally, Ca2+ entry through L channels inefficiently induced exocytosis, and the individual blockade of this channel significantly modified fusion pore dynamics. The distance between a given VACC subtype and the release sites could account for the differential effects of the distinct VACC on the fusion pore dynamics. [source] Specific IgE to allergens in cord blood is associated with maternal immunity to Toxoplasma gondii and rubella virusALLERGY, Issue 11 2008M. J. Ege Background:, Various studies have found reduced prevalences of atopic sensitization and atopic diseases in children previously exposed to infections or living conditions with a high microbial burden, such as the farming environment. Objective:, We sought to determine the relationships of cord blood immunoglobulin E (IgE) with maternal health conditions before and during pregnancy. Methods:, Pregnant women living in rural areas in five European countries were recruited in the third trimester of pregnancy. Information on maternal health during pregnancy was collected from maternity records and by questionnaires (n = 497). Specific IgE for inhalant and food allergens was assessed in cord blood and peripheral blood samples of the mothers. Results:, Inverse associations of cord blood IgE to seasonal allergens with positive maternal records for Toxoplasma gondii (adjusted odds ratio = 0.37 [0.17,0.81]) and rubella virus (adjusted odds ratio = 0.35 [0.13,0.96]) were found. The previously described effect of prenatal farm exposure on IgE to seasonal allergens was partly confounded by a positive maternal record for T. gondii. The number of maternal siblings, maternal contact to cats during pregnancy or during her first year of life, predicted a positive maternal record for T. gondii. Conclusions:, Maternal immunity to T. gondii and rubella may impact on atopic sensitization in the fetus. A positive T. gondii record explained the previously identified effect of prenatal farm exposure on IgE to seasonal allergens only to a minor extent. [source] Reinvestigating hyperpolarized 129Xe longitudinal relaxation time in the rat brain with noise considerationsNMR IN BIOMEDICINE, Issue 3 2008X. Zhou Abstract The longitudinal relaxation time of hyperpolarized (HP) 129Xe in the brain is a critical parameter for developing HP 129Xe brain imaging and spectroscopy and optimizing the pulse sequences, especially in the case of cerebral blood flow measurements. Various studies have produced widely varying estimates of HP 129Xe T1 in the rat brain. To make improved measurements of HP 129Xe T1 in the rat brain and investigate how low signal-to-noise ratio (SNR) contributes to these discrepancies, we developed a multi-pulse protocol during the washout of 129Xe from the brain. Afterwards, we applied an SNR threshold theory to both the multi-pulse protocol and an existing two-pulse protocol. The two protocols yielded mean,±,SD HP 129Xe T1 values in the rat brain of 15.3,±,1.2 and 16.2,±,0.9,s, suggesting that the low SNR might be a key reason for the wide range of T1 values published in the literature, a problem that might be easily alleviated by taking SNR levels into account. Copyright © 2007 John Wiley & Sons, Ltd. [source] A mutant form of PTEN linked to autismPROTEIN SCIENCE, Issue 10 2010Roberta E. Redfern Abstract The tumor suppressor, phosphatase, and tensin homologue deleted on chromosome 10 (PTEN), is a phosphoinositide (PI) phosphatase specific for the 3-position of the inositol ring. PTEN has been implicated in autism for a subset of patients with macrocephaly. Various studies identified patients in this subclass with one normal and one mutated PTEN gene. We characterize the binding, structural properties, activity, and subcellular localization of one of these autism-related mutants, H93R PTEN. Even though this mutation is located at the phosphatase active site, we find that it affects the functions of neighboring domains. H93R PTEN binding to phosphatidylserine-bearing model membranes is 5.6-fold enhanced in comparison to wild-type PTEN. In contrast, we find that binding to phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) model membranes is 2.5-fold decreased for the mutant PTEN in comparison to wild-type PTEN. The structural change previously found for wild-type PTEN upon interaction with PI(4,5)P2, is absent for H93R PTEN. Consistent with the increased binding to phosphatidylserine, we find enhanced plasma membrane association of PTEN-GFP in U87MG cells. However, this enhanced plasma membrane association does not translate into increased PI(3,4,5)P3 turnover, since in vivo studies show a reduced activity of the H93R PTEN-GFP mutant. Because the interaction of PI(4,5)P2 with PTEN's N-terminal domain is diminished by this mutation, we hypothesize that the interaction of PTEN's N-terminal domain with the phosphatase domain is impacted by the H93R mutation, preventing PI(4,5)P2 from inducing the conformational change that activates phosphatase activity. [source] Electrophysiological evidence for altered early cerebral somatosensory signal processing in schizophreniaPSYCHOPHYSIOLOGY, Issue 3 2004Till D. Waberski Abstract Various studies have indicated an impairment of sensory signal processing in schizophrenic patients. Anatomical and functional imaging studies have indicated morphological and metabolic abnormalities in the thalamus in schizophrenia. Other results give evidence for an additional role of cortical dysfunction in sensory processing in schizophrenia. Advanced analysis of human median nerve somatosensory evoked potentials (SEPs) reveals a brief oscillatory burst of low-amplitude and high-frequency activity (,600 Hz), the so-called high frequency oscillations (HFOs). The present study explores the behavior of HFOs in a cohort of schizophrenic patients in comparison to a group of controls. HFOs in the group of patients appeared with a delayed latency. In the low-frequency part of the SEPs an increase in amplitude was found. These results are interpreted to reflect a lack of somatosensory inhibition in the somatosensory pathway, either at a thalamic or a cortical level. [source] Genetic polymorphism as a background of animal behaviorANIMAL SCIENCE JOURNAL, Issue 2 2009Miho INOUE-MURAYAMA ABSTRACT Various studies have shown the associations between differences in human behavioral traits and genetic polymorphism of neurotransmitter-related proteins such as receptors, transporters and monoamine oxidase. To clarify the genetic background of animal behavior, corresponding regions in animals have been analyzed. The study has been especially focused on primates, as the evolutionally closest animal to humans, and on dogs, as the socially closest animal to humans. In primates, polymorphisms were discovered between or within species, and the functional effects on neural transmission were found to be different by alleles. Even in apes, the closest species to humans, function was different from that in humans. In dogs, allele distributions of several genes were different among breeds showing different behavioral traits, and genes associated with individual differences in aggressiveness and aptitude of working dogs were surveyed. The survey of behavior-related genes has also been carried out in other mammals such as horses and cetaceans. Genes controlling various behaviors in birds have also been reported. The marker genes for behavior will provide useful information for human evolution, welfare of zoo animals and effective selection of working dogs and industry animals. [source] Comparing performances of logistic regression and neural networks for predicting melatonin excretion patterns in the rat exposed to ELF magnetic fieldsBIOELECTROMAGNETICS, Issue 2 2010Samad Jahandideh Abstract Various studies have been reported on the bioeffects of magnetic field exposure; however, no consensus or guideline is available for experimental designs relating to exposure conditions as yet. In this study, logistic regression (LR) and artificial neural networks (ANNs) were used in order to analyze and predict the melatonin excretion patterns in the rat exposed to extremely low frequency magnetic fields (ELF-MF). Subsequently, on a database containing 33 experiments, performances of LR and ANNs were compared through resubstitution and jackknife tests. Predictor variables were more effective parameters and included frequency, polarization, exposure duration, and strength of magnetic fields. Also, five performance measures including accuracy, sensitivity, specificity, Matthew's Correlation Coefficient (MCC) and normalized percentage, better than random (S) were used to evaluate the performance of models. The LR as a conventional model obtained poor prediction performance. Nonetheless, LR distinguished the duration of magnetic fields as a statistically significant parameter. Also, horizontal polarization of magnetic fields with the highest logit coefficient (or parameter estimate) with negative sign was found to be the strongest indicator for experimental designs relating to exposure conditions. This means that each experiment with horizontal polarization of magnetic fields has a higher probability to result in "not changed melatonin level" pattern. On the other hand, ANNs, a more powerful model which has not been introduced in predicting melatonin excretion patterns in the rat exposed to ELF-MF, showed high performance measure values and higher reliability, especially obtaining 0.55 value of MCC through jackknife tests. Obtained results showed that such predictor models are promising and may play a useful role in defining guidelines for experimental designs relating to exposure conditions. In conclusion, analysis of the bioelectromagnetic data could result in finding a relationship between electromagnetic fields and different biological processes. Bioelectromagnetics 31:164,171, 2010. © 2009 Wiley-Liss, Inc. [source] Genetic Evidence for Natural Hybridization between Species of Dioecious Ficus on Island Populations1BIOTROPICA, Issue 3 2003Tracey L. Parrish ABSTRACT Natural hybrids between Ficus septica and two closely related dioecious species, F. fistulosa and F. hispida, were confirmed using amplified fragment length polymorphisms (AFLP) and chloroplast DNA markers. Ficus species have a highly species-specific pollination mutualism with agaonid wasps. Therefore, the identification of cases in which breakdown in this sophisticated system occurs and the circumstances under which it happens is of interest. Various studies have confirmed that Ficus species are able to hybridize and that pollinator-specificity breakdown can occur under certain conditions. This study is the first example in which hybrid identity and the presence of hybrids in the natural distribution of parental species for Ficus have been confirmed with molecular markers. Hybrid individuals were identified on three island locations in the Sunda Strait region of Indonesia. These findings support Janzen's (1979) hypothesis that breakdown in pollinator specificity is more likely to occur on islands. We hypothesized that hybrid events could occur when the population size of pollinator wasps was small or had been small in one of the parental species. Later generation hybrids were identified, indicating that backcrossing and introgression did occur to some extent and that therefore, hybrids could be fertile. The small number of hybrids found indicated that there was little effect of hybridization on parental species integrity over the study area. Although hybrid individuals were not common, their presence at multiple sites indicated that the hybridization events reported here were not isolated incidences. Chloroplast DNA haplotypes of hybrids were not derived solely from one species, suggesting that the seed donor was not of the same parental species in all hybridization events. [source] LUTS/BPH in clinical practice: the importance of nocturia and quality of sleepBJU INTERNATIONAL, Issue 2006EMMANUEL CHARTIER-KASTLER Various studies indicate that nocturia is one of the most bothersome of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH). Nocturia has a negative impact on quality of sleep (QoS), which might lead to daytime fatigue, reduced performance the next day and might ultimately affect the patient's overall quality of life (QoL). However, the evaluation of a patient with LUTS/BPH and assessment of benefits of LUTS/BPH treatment are mainly focused on voiding symptoms or flow rate, and the impact of nocturia on the patient's QoL is often neglected. At the Sixth International Consultation on Prostate Cancer and Prostate Diseases in 2005, a discussion forum about nocturia and its impact on QoS and QoL was organized, followed by a meeting of an expert consensus panel. Both recognized the importance of assessing nocturia and its impact on QoS and QoL in the initial evaluation of patients with LUTS/BPH, and in assessing the benefits of (new) LUTS/BPH treatments. However, currently used instruments that measure the severity of nocturia and its impact on QoS and QoL were not specifically designed for this purpose and lack sensitivity. At the expert consensus meeting, the expert panel stated that new instruments are required that can fully monitor the impact of nocturia on QoS and QoL. Potential new instruments that address these requirements are nocturia-specific questionnaires such as the Nocturia QoL questionnaire. Furthermore, the expert panel acknowledged the assessment of ,hours of undisturbed sleep' (HUS) as a potential new method to evaluate the impact of nocturia on QoS and QoL. HUS refers to the time from falling asleep to the first awakening to void. Sleep assessment tools such as sleep diaries and actigraphy are potential instruments to measure HUS. [source] The Wage Effects of Computer Use: Evidence from WERS 2004BRITISH JOURNAL OF INDUSTRIAL RELATIONS, Issue 4 2008Peter Dolton Computers and ICT have changed the way we live and work. The latest Workplace Employment Relations Survey (WERS) 2004 provides a snapshot of how using ICT has revolutionized the workplace. Various studies have suggested that the use of a computer at work boosted earnings by as much as 20 per cent. Others suggest this reported impact is due to unobserved heterogeneity. Using excellent data from the WERS employer,employee matched sample, we compare ordinary least squares (OLS) estimates with those from alternative estimation methods and those which include controls for workplace and occupation interactions. We show that OLS estimates overstate the return to computer use but that including occupation and workplace controls, reduces the return to around 3 per cent. We explore the return on different IT skills and find a small return to the use of the ,office IT function' and the intensity of computer use as measured by the number of tasks a computer is used for. [source] Exogenous bone marrow cells do not rescue non-irradiated mice from acute renal tubular damage caused by HgCl2, despite establishment of chimaerism and cell proliferation in bone marrow and spleenCELL PROLIFERATION, Issue 4 2008T.-C. Fang Objective: Various studies have shown that bone marrow stem cells can rescue mice from acute renal tubular damage under a conditioning advantage (irradiation or cisplatin treatment) favouring donor cell engraftment and regeneration; however, it is not known whether bone marrow cells (BMCs) can contribute to repair of acute tubular damage in the absence of a selection pressure for the donor cells. The aim of this study was to examine this possibility. Materials and methods: Ten-week-old female mice were assigned into control non-irradiated animals having only vehicle treatment, HgCl2 -treated non-irradiated mice, HgCl2 -treated non-irradiated mice infused with male BMCs 1 day after HgCl2, and vehicle-treated mice with male BMCs. Tritiated thymidine was given 1 h before animal killing. Results: Donor BMCs could not alleviate non-irradiated mice from acute tubular damage caused by HgCl2, deduced by no reduction in serum urea nitrogen combined with negligible cell engraftment. However, donor BMCs could home to the bone marrow and spleen and display proliferative activity. This is the first report to show that despite no preparative myeloablation of recipients, engrafted donor BMCs can synthesize DNA in the bone marrow and spleen. Conclusions: Exogenous BMCs do not rescue non-irradiated mice from acute renal tubular damage caused by HgCl2, despite establishment of chimerism and cell proliferation in bone marrow and spleen. [source] Treatment of diabetic nephropathy in its early stagesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2003Giacomo Deferrari Abstract Diabetic nephropathy is one of the most frequent causes of end-stage renal disease (ESRD), and, in recent years, the number of diabetic patients entering renal replacement therapy has dramatically increased. The magnitude of the problem has led to numerous efforts to identify preventive and therapeutic strategies. In normoalbuminuric patients, optimal glycemic control (HbA1c lower than 7.5%) plays a fundamental role in the primary prevention of ESRD [weighted mean relative risk reduction (RRR) ,37% for metabolic control versus trivial renoprotection for intensive anti-hypertensive therapy or ACE-inhibitors (ACE-I)]. In the microalbuminuric stage, strict glycemic control probably reduces the incidence of overt nephropathy (weighted mean RRR ,50%), while blood pressure levels below 130/80 mmHg are recommended according to the average blood pressure levels obtained in various studies. In normotensive patients, ACE-I markedly reduce the development of overt nephropathy almost regardless of blood pressure levels; in hypertensive patients, ACE-I are less clearly active (weighted mean RRR ,23% versus other drugs), whereas angiotensin-receptor blockers (ARB) appear strikingly renoprotective. Once overt proteinuria appears, it is uncertain whether glycemic control affects the progression of nephropathy. In type 1 diabetes, various anti-hypertensive treatments, mainly ACE-I, are effective in slowing down the progression of nephropathy; in type 2 diabetes, two recent studies demonstrate that ARB are superior to conventional therapy or calcium channel blockers (CCB). In clinical practice, pharmacological tools are not always used to the best benefit of the patients. Therefore, clinicians and patients need to be educated regarding the renoprotection of drugs inhibiting the renin-angiotensin system (RAS) and the overwhelming importance of achieving target blood pressure. Copyright © 2003 John Wiley & Sons, Ltd. [source] Effects of human interleukin-18 and interleukin-12 treatment on human lymphocyte engraftment in NOD-scid mouseIMMUNOLOGY, Issue 2 2002Hidenobu Senpuku Summary NOD/LtSz- prkdcscid/prkdcscid (non-obese diabetic-severe combine immunodeficiency; NOD-scid) mice grafted with human peripheral blood lymphoid cells have been used as an in vivo humanized mouse model in various studies. However, cytotoxic human T cells are induced in this model during immune responses, which gives misleading results. To assist in grafting of human lymphocytes without the induction of cytotoxic human T cells, we investigated the effects of T helper type 1 (Th1) and Th2 cytokines on human lymphocyte grafting and migration, as well as the production of immunoglobulin deposited in glomeruli and human immunodeficiency virus-1 (HIV-1) infection using NOD-scid mice. Administration of interleukin-18 (IL-18) and IL-12 enhanced the grafting of human CD4+ and CD8+ T cells in the mice, whereas co-administration prevented grafting due to interferon-,-dependent apoptosis. Immunoglobulin A (IgA) deposits were observed in mice treated with IL-18 alone, but not in those given phosphate-buffered saline, IL-12 alone, or IL-18 + IL-12. A high rate of HIV infection was also observed in the IL-18-treated group. Together, these results indicate that IL-18 may be effective for the grafting and migration of CD4+ and CD8+ T cells, except for the induction of apoptosis and regulation of class-switching IgA. IL-18-administered NOD-scid mice provide a useful small humanized model for the study of HIV infection and IgA nephropathy. [source] Association of vitamin D receptor genotypes with early onset rheumatoid arthritisINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 1 2001J. R. Garcia-Lozano The presence of certain vitamin D receptor (VDR) genotypes has been associated with low bone mineral density (BMD) in elderly populations as well as with accelerated bone loss in patients with rheumatoid arthritis (RA). In the present study, VDR genotypes from 120 Spanish patients with RA were investigated. Three VDR gene polymorphisms (BsmI, ApaI and TaqI) were investigated using polymerase chain reaction followed by enzymatic digestion. The distributions of VDR allelic frequencies were similar in patients and controls and therefore no influence of VDR polymorphisms on rheumatoid arthritis susceptibility could be demonstrated. However, in an analysis of the clinical features of the different VDR-related genetic subgroups, the BB/tt genotype, defined by the BsmI and TaqI restriction site polymorphisms, was identified to be weakly associated with an early onset RA in female patients. This VDR genotype has been associated with a low BMD level in various studies. When patients were stratified according to the presence of the shared HLA epitope SE, it was found that SE + female patients bearing the BB/tt genotype showed the earliest disease onset. The mechanisms by which the VDR polymorphism is associated with RA is unknown, but they could be related to the immunoregulatory properties of vitamin D. [source] Introduction: Drug Trafficking, Organised Crime, and Public Policy for Drug ControlINTERNATIONAL SOCIAL SCIENCE JOURNAL, Issue 169 2001Michel Schiray This introduction to studies carried out mainly in Brazil, India, and China aims to show the importance, for an understanding of the drug trade and its consequences, of research that compensates for the limitations of information available either in the media or from official specialist institutions. It sketches an overview of current academic activity around the world, noting the undeniable pre-eminence of the United States but also the exceptional efforts made by researchers in some closely involved countries, including Colombia and Italy, and, by contrast, the astonishing lack of engagement on the part of academic circles in most other countries. It selects for discussion some of the results of the various studies which might point the way for further research. It observes that the questions which arise vary considerably depending on the level considered , local, national or international; and identifies some of these. It demonstrates that the drug trade is linked to other criminal activities, and seeks to analyse the forms of organisation which control it. Lastly, it puts forward some basic questions about the potential contribution of research to national and international public policy for control. [source] Factors affecting abundance and distribution of submerged and floating macrophytes in Lake Naivasha, KenyaAFRICAN JOURNAL OF ECOLOGY, Issue 1 2009A. N. Ngari Abstract Macrophytes have been shown to perform important ecological roles in Lake Naivasha. Consequently, various studies regarding the impact of biotic factors on the macrophytes have been advanced but related studies on environmental parameters have lagged behind. In an attempt to address this gap, sampling on floating species and submergents was carried out in eight sampling sites in 2003 to investigate how they were influenced by a set of environmental factors. Soil texture (sandy sediments; P < 0.05, regression coefficient = ,0.749) and wind were the most important environmental parameters influencing the distribution and abundance of floating macrophytes. Combination of soil texture and lake-bed slope explained the most (86.3%) variation encountered in the submergents. Continuous translocation of the floating dominant water hyacinth to the western parts by wind has led to displacement of the submergents from those areas. In view of these findings, the maintenance and preservation of the steep Crescent Lake basin whose substratum is dominated by sand thus hosting most submergents remain important, if the whole functional purpose of the macrophytes is to be sustained. Résumé On a montré que les macrophytes jouent un rôle économique important dans le lac Naivasha. Par conséquent, diverses études ont été réalisées sur l'impact des facteurs biotiques sur les macrophytes, mais les études correspondantes sur les paramètres environnementaux sont à la traîne. Pour essayer de compenser cette lacune, en 2003, on a réalisé un échantillonnage des espèces flottantes et submergées sur huit sites d'échantillonnage pour étudier comment elles étaient influencées par un ensemble de facteurs environnementaux. La texture du sol (sédiments sableux, P < 0,05, coefficient de régression = 0,749) et le vent étaient les paramètres environnementaux les plus important quant à l'influence sur la distribution et l'abondance des macrophytes flottants. La combinaison de la texture du sol et de la pente du fond du lac expliquait la plus grande partie (86,3%) de la variation rencontrée chez les espèces submergées. Le déplacement continuel des jacinthes d'eau, qui est la plante flottante dominante, vers la partie ouest par le vent a entraîné le déménagement des espèces submergées hors de cette partie du lac. Au vu de ces résultats, il est important d'assurer l'entretien et la préservation de la pente raide du bassin du lac en forme de croissant si l'on peut conserver l'ensemble de la fonction des macrophytes. [source] Effects of specific nutrients on periodontal disease onset, progression and treatmentJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 7 2003Rodrigo F. Neiva Abstract Objectives: The aim of this paper is to review the available literature pertaining to the effects of specific nutritional elements (e.g. vitamin B-complex, vitamin C and dietary calcium) on general wound healing, periodontal disease status and response to periodontal therapy. Methods: Critical appraisal of various studies that have evaluated the effects of calcium, ascorbic acid and vitamin B-complex in wound healing and periodontal treatment. Results: Periodontal disease onset, progression and response to therapeutic interventions have been shown to be influenced by several systemic, local and environmental modifying factors. Nutritional supplementation has been suggested as a possible influencing factor on periodontal status and wound healing. Several studies have reported various degrees of association between nutritional elements/supplements and periodontal status, and others have reported possible positive influences of nutritional supplementation on periodontal therapeutic outcomes. Future research needs to more fully explore the presence and strength of association between nutrition and periodontal health. Conclusions: Data collected from the literature suggests that nutrient supplementation causes minimal or no side effects. However, the efficacy of prophylactic nutrient supplementation for the prevention of the onset and progression of periodontal disease, or for the enhancement of periodontal wound healing, remains to be determined. Zusammenfassung Es konnte gezeigt werden, dass der Beginn, der Verlauf und das Ansprechen auf therapeutische Intervention parodontaler Erkrankungen durch verschiedene modifizierende systemische, lokale und Umweltfaktoren beeinflusst werden. Ergänzungen zur Ernährung wurden als mögliche Einflussfaktoren für den parodontalen Status und die Wundheilung diskutiert. Diese Arbeit gibt eine Übersicht über die verfügbare Literatur zum Einfluss spezieller Elemente der Ernährung (z.B. Vitamin-B-Komplex, Vitamin C und Kalzium) auf die generelle Wundheilung, parodontale Erkrankungen sowie das Ansprechen auf parodontale Therapie. Verschiedene Studien haben über Zusammenhänge zwischen Elementen der Nahrung bzw. Ernährungsergänzungen und dem parodontalen Status berichtet. Andere berichten über mögliche positive Einflüsse von Ernährungsergänzungen auf das Ergebnis parodontaler Therapie. Besonderer Wert wird auf die kritische Bewertung der vorhandenen Studien gelegt und es werden Empfehlungen für zukünftigen Forschungsbedarf gegeben, um die Existenz und Ausprägung von Zusammenhängen zwischen Ernährung und parodontaler Gesundheit vollständig zu erfassen. Daten, die aus der Literatur gesammelt wurden, legen den Schluss nahe, dass eine Ergänzung der Ernährung minimale oder keine Nebenwirkungen hat. Allerdings die Wirksamkeit einer prophylaktischen Ernährungsergänzung für die Prävention der Entstehung und Progression von Parodontitis oder die Verbesserung der parodontalen Wundheilung muss noch bestimmt werden. Résumé L'apparition, la progression et la réponse de la maladie parodontale aux interventions thérapeutiques sont influencées par différents facteurs systémiques locaux et environnementaux. L'apport supplémentaire de substances nutritives a été suggéré comme facteur influençant l'état parodontal et la guérison. Cette étude revoit la littérature concernant les effets des éléments nutritionnels spécifiques comme le complexe vitaminique-B, le vitamine-C et le calcium diététique sur la guérison en général, l'état de la maladie parodontale et la réponse au traitement parodontal. Différentes études ont rapporté différents degrés d'association entre les éléments/suppléments nutritifs et l'état parodontal, et d'autres ont rapporté des influences positives possibles des suppléments nutritionnels sur la guérison thérapeutique parodontale. L'importance est axée sur l'appréciation critique d'études disponibles et sur une recommandation en recherches futures pour explorer davantage la présence et la force de l'association entre la nutrition et la santé parodontale. Des données collectées de la littérature suggèrent que l'apport de suppléments nutritifs n'est suivi que de peu ou pas d'effets secondaires. Cependant, l'efficacité d'un supplément nutritif prophylactique pour la prévention primaire et de la progression de la maladie parodontale, ou pour l'augmentation de la guérison parodontale reste à déterminer. [source] Beta-2 adrenergic receptor genetic polymorphisms and asthmaJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 6 2009N. Hizawa MD Summary Beta-2-Adrenergic receptors (,2AR) participate in the physiologic responses of the lung, including bronchodilation and bronchoprotection, through mechanisms such as mucociliary clearance, fluid accumulation and mediator release from mast cells and basophils. Thus, these receptors may also play an important role in the pathophysiology of asthma. The gene encoding ,2AR (ADRB2) is extremely polymorphic, and studies of this gene improves our understanding of asthma and possibly lead to new methods to prevent, diagnose and treat it. This review summarizes results from various studies on the possible relationship of ADRB2 polymorphisms to asthma and asthma-related phenotypes, including bronchodilator responses to inhaled ,2 -agonists. At present, it appears that, for asthma, ADRB2 polymorphisms are not aetiologically involved. However, they might affect disease severity and clinical response to both acute and chronic administration of ,2 -agonists. The development is that by assessing the ADRB2 genotype, it might be possible to predict the clinical course of asthma as well as responsiveness to chronic administration of ,2 -agonists. Carefully, performed and adequately powered clinical trials continue to be important for achieving those goals. [source] Phosphoinositide 3-kinase is not overexpressed in melanocytic lesionsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 3 2007Rajendra S. Singh Background:, Although various studies have stressed the role of phosphatase and tensin homologue deleted on chromosome 10 (PTEN)-PI3K-AKT pathway in the progression of melanocytic lesions, little is known about the expression pattern of PI3K in these lesions. Objective:, To investigate the expression pattern of PI3K in benign and dysplastic nevi, primary melanomas, and metastatic melanomas and the role of PTEN and PI3K in melanocytic tumor progression. Methods:, Tissue microarrays were constructed using formalin-fixed, paraffin-embedded archival tissue blocks from 89 melanocytic lesions: 17 benign nevi, 18 dysplastic nevi, 23 primary melanomas, and 31 metastatic melanomas. Expression of PTEN and PI3K (p85 and p110 subunits) was evaluated immunohistochemically, and the number of cells and labeling intensity were assessed semiquantitatively. Results:, Both benign and dysplastic nevi showed strong cytoplasmic staining with PTEN, which was subsequently less in melanomas and completely lost in the metastatic lesions. Eleven of 17 (64%) benign nevi, seven of 10 (70%) dysplastic nevi, four of 23 (17%) primaries, and one of 31 (3%) visceral or lymph node metastasis showed strong positivity. Loss of PTEN expression from benign and dysplastic nevi to melanoma was statistically significant (p = 0.001). Although few cells showed reactivity for phosphoinositide 3-kinase (PI3 kinase)-p85 subunit, strong positivity was not detected in the cytoplasm of benign, malignant, or metastatic lesions, except for a single visceral metastasis. Three of 13 (23%) nevi showed positivity for the p110 subunit. No positivity was observed in the dysplastic nevi. Two of 22 (9%) melanomas, one of 14 (7%) visceral metastasis, and three of 12 (25%) lymph node metastasis showed strong positivity. There was no statistical difference in PI3 kinase expression in benign and malignant melanocytic lesions (p = 0.2). Conclusion:, PI3K is not overexpressed in melanocytic lesions. [source] Measuring the Benefits of Examinee-Selected QuestionsJOURNAL OF EDUCATIONAL MEASUREMENT, Issue 1 2005Nancy L. Allen Allowing students to choose the question(s) that they will answer from among several possible alternatives is often viewed as a mechanism for increasing fairness in certain types of assessments. The fairness of optional topic choice is not a universally accepted fact, however, and various studies have been done to assess this question. We examine an important class of experiments that we call C1-A, "choose one, answer all," designs, and point out an important problem that they face. We suggest two analytical methods that can be used to circumvent this problem. We illustrate our ideas using the data from Bridgeman et al. (1997). Our reanalysis of these data show: (a) that differential topic difficulty exists in real choice data, (b) that it affects naïve analyses of such data and masks the effects, positive or negative, of examinee choice, (c) that in this study there is a measurable and positive effect of examinee choice that follows predicted patterns in most but not all cases, (d) that the beneficial strength of examinee choice varies from case to case, and (e) that while the benefits of choice in terms of average points scored on the essays are usually positive, there is a substantial amount of variation around these averages and it is not uncommon for "incorrect" choices to be associated with higher test performance. [source] Do psychological prices contribute to price rigidity?AGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 1 2006Evidence from German scanner data on food brands A substantial degree of price rigidity has been reported for branded foods in various studies with scanner data. One possible explanation for price rigidity is the existence of psychological pricing points. The authors analyze to what extent psychological pricing plays a role in grocery retailing and whether it contributes to the price rigidity of branded foods in Germany. Psychological pricing,defined here as just-below-the-round-figure-pricing,is empirically analyzed with scanner data of weekly prices for 20 food brands in 38 retail outlets from September 1996 to June 1999. Psychological pricing turned out to be extremely important in German food retailing. Branded food prices are remarkably sticky and psychological pricing points contribute strongly to price rigidity. Other factors like the sales phenomenon and firm-specific effects are additionally important. [EconLit Classifications: Q110, Q130]. © 2006 Wiley Periodicals, Inc. Agribusiness 22: 51,67, 2006. [source] The Radial Approach: Is This the Route to Take?JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 5 2008M.R.C.P., SUDHIR RATHORE M.D. The benefits of the transradial approach have clearly been demonstrated over the years in various studies. The reduced incidence of access site complications and early mobilization are some of the benefits making this technique popular with interventional cardiologists worldwide. With increasing experience and availability of dedicated equipment this technique is now been increasingly used for complex catheter interventions. However, there still remain some potential problems and complications with the transradial approach and it needs further research. The main purpose of this review is to highlight the benefits, complications, and potential problems with the transradial approach. [source] Fetal arrhythmia: Prenatal diagnosis and perinatal managementJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2009Yasuki Maeno Abstract The importance of managing fetal arrhythmia has increased over the past three decades. Although most fetal arrhythmias are benign, some types cause fetal hydrops and can lead to fetal death. With the aim of improving the outcome in such cases, various studies for prenatal diagnosis and perinatal management have been published. Detailed analysis of the type of arrhythmia in utero is possible using M-mode and Doppler echocardiography. In particular, a simultaneous record of Doppler waveform at the superior venous cava and the ascending aorta has become an important and useful method of assessing the interval between atrial and ventricular contractions. Common causes of fetal tachycardia (ventricular heart rate faster than 180 bpm), are paroxysmal supraventricular tachycardia (SVT) with 1:1 atrioventricular (AV) relation and atrial flutter with 2:1 AV relation. Of fetal SVT, short ventriculo-atrial (VA) interval tachycardia due to atrioventricular reentrant tachycardia is more common than long VA interval. Most fetuses with tachycardia are successfully treated in utero by transplacental administration of antiarrhythmic drugs. Digoxin is widely accepted as a first-line antiarrhythmic drug. Sotalol, flecainide and amiodarone are used as second-line drugs when digoxin fails to achieve conversion to sinus rhythm. Fetal bradycardia is diagnosed when the fetal ventricular heart rate is slower than 100 bpm, mainly due to AV block. Approximately half of all cases are caused by associated congenital heart disease, and the remaining cases that have normal cardiac structure are often caused by maternal SS-A antibody. The efficacy of prenatal treatment for fetal AV block is limited compared with treatment for fetal tachycardia. Beta stimulants and steroids have been reported as effective transplacental treatments for fetal AV block. Perinatal management based on prospective clinical study protocol rather than individual experience is crucial for further improvement of outcome in fetuses with tachycardia and bradycardia. [source] A precisely-dated lake-level rise marked by diatomite formation in northeastern IrelandJOURNAL OF QUATERNARY SCIENCE, Issue 1 2004G. M. Plunkett Abstract The intercorrelation of palaeoclimate events from various studies is often hindered by a lack of precise chronological control. Tephra isochrons can overcome this problem by providing direct site linkages. This paper outlines a study of Holocene peat and diatomite deposits that accumulated within the floodplain of Lough Neagh, Northern Ireland. The Icelandic Hekla 4 tephra has been identified at the base of diatomite deposits at a number of sites and provides firm dating evidence for a widespread flooding event in the area at ca. 2300 BC. The evidence is consistent with other studies in Ireland and elsewhere for increased wetness at this time. The results demonstrate that the terrestrial deposits around Lough Neagh contain an important record of Holocene lake-level change. Dendrochronological evidence from the Lough Neagh area provides additional information about lake-level fluctuations over the past two millennia. Copyright © 2004 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||||||||