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Appropriate Controls (appropriate + control)
Selected AbstractsChanging Views of Serpent Handling: A Quasi-Experimental StudyJOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 3 2000Ralph W. Hood Knowledge about serpent handling sects (SHS) even among social scientists and legislators has been largely influenced by biased media reports. Our own field research suggests that factual knowledge about SHS is effective in changing stereotypes about serpent handling and in altering views as to the rights of believers to handle serpents in church. In a quasi-experimental study, participants were pretested with respect to both prejudicial and reasoned evaluative views about SHS. Participants saw either a video of contemporary SHS in which handlers demonstrated and explained their faith, or a control tape in which contemporary SHS were shown but serpent handling was neither demonstrated nor defended. As predicted, viewing the serpent handling video was effective in reducing stereotyping of SHS and in changing attitudes regarding the sincerity of the believers and the right of SHS to practice their faith without legal constraints. Appropriate controls indicated that changes were not simply a function of a pretest by treatment interaction. The relevance of these data for altering laws against the practice of serpent handling is discussed. [source] Effects of a herbal gel containing carvacrol and chalcones on alveolar bone resorption in rats on experimental periodontitisPHYTOTHERAPY RESEARCH, Issue 4 2008Marco Antonio Botelho Abstract Carvacrol and dimeric chalcones are the respective bioactive components of Lippia sidoides and Myracrodruon urundeuva, popular medicinal plants of Northeastern Brazil with proven antimicrobial and antiinflammatory properties. Periodontal disease is associated with inflammation and microbiological proliferation, thus the study aimed to investigate the effect of a topical gel based on carvacrol and chalcones in the experimental periodontal disease (EPD) in rats. Animals were treated with carvacrol and/or chalcones gel, immediately after EPD induction, three times a day for 11 days. Appropriate controls were included in the study. Animals were weighed daily. They were killed on day 11, the mandibles dissected and alveolar bone loss was measured. The periodontium were examined at histopathology and the neutrophil influx into the gingiva was assayed using myeloperoxidase activity. The bacterial flora were assessed through culture of the gingival tissue. Alveolar bone loss was significantly (p < 0.05) inhibited by combined carvacrol and chalcones gel, compared with the vehicle and non-treated groups. The treatment with the combined gel reduced tissue lesion at histopathology, decreased myeloperoxidase activity in gingival tissue and inhibited the growth of oral microorganisms as well as the weight loss. Carvacrol and chalcones combination gel has a beneficial effect upon EPD in this model. Copyright © 2008 John Wiley & Sons, Ltd. [source] Role of peroxynitrite in methamphetamine-induced dopaminergic neurotoxicity and sensitization in miceADDICTION BIOLOGY, Issue 3 2000Syed F. Ali Methamphetamine (METH)-induced dopaminergic neurotoxicity is thought to be associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Recently, we have reported that copper/zinc(CuZn)-superoxide dismutase transgenic mice are resistant to METH-induced neurotoxicity. In the present study, we examined the role of the neuronal nitric oxide synthase (nNOS), susceptibility of nNOS knockout (KO) mice and sensitization to psychostimulants after neurotoxic doses of METH. Male SwissWebster mice were treated with or without 7-nitroindazole (7-NI) along with METH (5 mg/kg,ip,q 3h × 3) and were sacrificed 72 h after the last METH injection. Dopamine (DA) and dopamine transporter (DAT) binding sites were determined in striatum from saline and METH-treated animals. 7-NI completely protected against the depletion of DA, and DAT in striatum. In follow-up experiments nNOS KO mice along with appropriate control (C57BL/6N, SV129 and B6JSV129) mice were treated with METH (5 mg/kg,ip, q 3h × 3) and were sacrificed 72 h after dosing. This schedule of METH administrations resulted in only 10,20% decrease in tissue content of DA and no apparent change in the number of DAT binding sites in nNOS KO mice. However, this regime of METH resulted in a significant decrease in the content of DA as well as DAT binding sites in the wild-type animals. Pre-exposure to single or multiple doses of METH resulted in a marked locomotion sensitization in response to METH. However, the nNOS KO mice show no sensitization in response to METH after single or multiple injections of METH. Therefore, these studies strongly suggest the role of peroxynitrite, nNOS and DA system in METH-induced neurotoxicity and behavioral sensitization. [source] Accountability in the Regulatory StateJOURNAL OF LAW AND SOCIETY, Issue 1 2000Colin Scott Accountability has long been both a key theme and a key problem in constitutional scholarship. The centrality of the accountability debates in contemporary political and legal discourse is a product of the difficulty of balancing the autonomy given to those exercising public power with appropriate control. The traditional mechanisms of accountability to Parliament and to the courts are problematic because in a complex administrative state, characterized by widespread delegation of discretion to actors located far from the centre of government, the conception of centralized responsibility upon which traditional accountability mechanisms are based is often fictional. The problems of accountability have been made manifest by the transformations wrought on public administration by the new public management (NPM) revolution which have further fragmented the public sector. In this article it is argued that if public lawyers are to be reconciled to these changes then it will be through recognizing the potential for additional or extended mechanisms of accountability in supplementing or displacing traditional accountability functions. The article identifies and develops two such extended accountability models: interdependence and redundancy [source] Degradation processes in Al/SiCp/MgAl2O4 composites prepared from recycled aluminum with fly ash and rice hull ashMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 11 2007M. I. Pech-Canul The degradation characteristics of Al/SiCp/spinel composites prepared with fly ash (FA) and rice hull ash (RHA) under environmental conditions were investigated. Composite specimens were prepared with recycled aluminum via reactive infiltration in the temperature range 1050,1150,°C for 50,70 min and, in argon atmosphere at a pressure slightly above that of the atmospheric pressure. Results reveal that although both FA and RHA help in preventing SiCp dissolution and the subsequent chemical degradation of the composites, due to the interaction of native carbon in FA with liquid aluminum, FA-composites are susceptible to corrosion via Al4C3. Moreover, this phase accelerates the degradation process and increases the damage severity. The primary corrosion mechanism in both types of composites is attributed to microgalvanic coupling between the intermetallic Mg2Si and the matrix. Accordingly, an appropriate control of the Si/(Si,+,Mg) molar ratio in the aluminum alloy hinders the Mg2Si corrosion mechanism in both types of composites and a proper FA calcination prevents chemical degradation in FA composites. [source] Government and Science: A Troubled, Critical Relationship and What Can Be Done about ItPUBLIC ADMINISTRATION REVIEW, Issue 1 2008W. Henry Lambright The U.S. government,science relationship, which helped win World War II, put a man on the moon, unravel the human genome, and nurture economic growth, is troubled. Money is one reason. However, far more than funding, the tensions between government and science are about politics and policy management. Many scientists and their allies argue that the Bush administration has crossed the line separating appropriate control of information from political interference. That is, there has been a "politicization of science." This essay examines the current debate about politicization in historical context; discusses the tensions among scientists, politicians, and administrators; and suggests possible ways to strengthen the government,science partnership in the future. [source] Glucose counterregulation in Type 2 diabetes mellitusDIABETIC MEDICINE, Issue 7 2001B. E. De Galan Abstract Glucose counterregulatory failure and hypoglycaemia unawareness frequently complicate treatment of Type 1 diabetes mellitus, especially when aiming for intensive metabolic control. Since tight metabolic control reduces microvascular long-term complications in Type 2 diabetes mellitus, the integrity of glucose counterregulation in Type 2 diabetic patients is important. Using a Medline search, we identified 12 studies in which counterregulatory responses to insulin-induced hypoglycaemia were compared between Type 2 diabetic patients and appropriate controls. A review of these studies showed that some patients with Type 2 diabetes mellitus develop mild counterregulatory dysfunction and reduced awareness of insulin-induced hypoglycaemia. Some studies suggested an association between counterregulatory impairment and intensity of metabolic control. We speculate that the relatively low frequency of (severe) hypoglycaemic events in Type 2 diabetes may explain why glucose counterregulation remains unaffected in most patients. We hypothesize that residual ,-cell reserve and insulin resistance provide protection against severe hypoglycaemia and limit impaired counterregulation. Diabet. Med. 18, 519,527 (2001) [source] Determining toxicity of lead and zinc runoff in soils: Salinity effects on metal partitioning and on phytotoxicityENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2003Daryl P. Stevens Abstract When assessingcationic metal toxicity in soils, metals are often added to soil as the chloride, nitrate, or sulfate salts. In many studies, the effects of these anions are ignored or discounted; rarely are appropriate controls included. This study used five soils varying in pH, clay content, and organic matter to determine whether salinity from counter-ions contributed to or confounded metal phytotoxicity. Varying rates of Pb and Zn were applied to soils with or without a leaching treatment to remove the metal counter-ion (NO3 -). Lactuca sattva (lettuce) plants were grown in metal-treated soils, and plant dry weights were used to determine median effective concentrations where there was a 50% reduction in yield (EC50s) on the basis of total metals measured in the soil after harvest. In two of the five soils, leaching increased the EC50s significantly for Zn by 1.4- to 3.7-fold. In three of the five soils, leaching increased the EC50s significantly for Pb by 1.6- to 3.0-fold. The shift in EC50s was not a direct result of toxicity of the nitrate ion but was an indirect effect of the salinity increasing metal concentrations in soil solution and increasing its bioavailability for a given total metal concentration. In addition, calculation of potential salinity changes in toxicological studies from the addition of metals exhibiting strong sorption to soil suggested that if the anion associated with the metal is not leached from the soil, direct salinity responses could also lead to significant overestimation of the EC50 for those metals. These findings question the relevance of the application of single-metal salts to soils as a method of assessing metal phytotoxicity when, in many cases in our environment, Zn and Pb accumulate in soil over a period of time and the associated counter-ions are commonly removed from the soil during the accumulation process (e.g., roof and galvanized tower runoff). [source] Enhancing catch-and-release science with biotelemetryFISH AND FISHERIES, Issue 1 2008Michael R. Donaldson Abstract Catch-and-release (C&R) angling is widely practised by anglers and is a common fisheries management strategy or is a by-product of harvest regulations. Accordingly, there is a growing body of research that examines not only the mortality associated with C&R, but also the sublethal physiological and behavioural consequences. Biotelemetry offers a powerful means of remotely monitoring the behaviour, physiology and mortality of fish caught and released in their natural environment, but we contend that its usefulness is still underappreciated by scholars and managers. In this study, we review the applications of biotelemetry in C&R science, identify novel research directions, opportunities and challenges. There are now about 250 C&R studies but only one quarter of these utilize biotelemetry. In fact, almost all of the C&R studies that have used biotelemetry have been conducted within the last decade. We found that the majority of C&R telemetry studies used either radio or acoustic telemetry, while comparatively few studies have used satellite technologies. Most C&R biotelemetry studies have been used to assess mortality rates, behavioural impairments or to evaluate the effects of displacement on fish. A small fraction of studies (<8%) have used physiological sensors despite the fact that these tools are highly applicable to understanding the multiple sublethal consequences of C&R and are useful for providing mechanistic insights into endpoints such as death. We conclude that C&R science has the potential to benefit greatly from biotelemetry technology, particularly with respect to providing more robust short-term and delayed mortality estimates and adopting a more integrative and comparative approach to understanding the lethal and sublethal impacts of C&R. However, there are still a number of challenges including (i) the need for appropriate controls and methodological approaches, (ii) the need for accounting for tagging and handling stress and mortality, and (iii) the need for certainty in assessing mortality. However, the benefits associated with C&R biotelemetry outweigh its disadvantages and limitations and thereby offer C&R researchers a suite of new tools to enhance fisheries management and conservation. [source] Lipopolysaccharide is a frequent and significant contaminant in microglia-activating factorsGLIA, Issue 1 2008Jonathan R. Weinstein Abstract Lipopolysaccharide (LPS/endotoxin) is a potent immunologic stimulant. Many commercial-grade reagents used in research are not screened for LPS contamination. LPS induces a wide spectrum of proinflammatory responses in microglia, the immune cells of the brain. Recent studies have demonstrated that a broad range of endogenous factors including plasma-derived proteins and bioactive phospholipids can also activate microglia. However, few of these studies have reported either the LPS levels found in the preparations used or the effect of LPS inhibitors such as polymyxin B (PMX) on factor-induced responses. Here, we used the Limulus amoebocyte lysate assay to screen a broad range of commercial- and pharmaceutical-grade proteins, peptides, lipids, and inhibitors commonly used in microglia research for contamination with LPS. We then characterized the ability of PMX to alter a representative set of factor-induced microglial activation parameters including surface antigen expression, metabolic activity/proliferation, and NO/cytokine/chemokine release in both the N9 microglial cell line and primary microglia. Significant levels of LPS contamination were detected in a number of commercial-grade plasma/serum- and nonplasma/serum-derived proteins, phospholipids, and synthetic peptide preparations, but not in pharmaceutical-grade recombinant proteins or pharmacological inhibitors. PMX had a significant inhibitory effect on the microglia-activating potential of a number of commercial-, but not pharmaceutical-grade, protein preparations. Novel PMX-resistant responses to ,2 -macroglobulin and albumin were incidentally observed. Our results indicate that LPS is a frequent and significant contaminant in commercial-grade preparations of previously reported microglia-activating factors. Careful attention to LPS levels and appropriate controls are necessary for future studies in the neuroinflammation field. © 2007 Wiley-Liss, Inc. [source] In situ methods of measurement,an important line of evidence in the environmental risk frameworkINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 2 2007Jim Wharfe Abstract A tiered framework provides a structured approach to assess and manage risk and underpins much of the legislation concerning chemicals and environmental management. Management decisions regarding appropriate controls can have high cost implications to the regulated community. The risk framework provides an evidence-based approach to reduce uncertainty in decision making. Traditional assessment is heavily dependent on laboratory-generated toxicity test data and estimations of exposure and effect. Despite many well documented demonstrations of in situ methodologies, they are rarely used by regulators to help improve assessment or to validate risk. Emerging legislation puts greater emphasis on environmental outcomes and represents a significant shift from the reliance on chemical measures alone toward biological responses that improve assessment and demonstrate ecological benefit. Diagnostic methods, that could include in situ-based measures, will help assess and manage environments failing to achieve good status and it is likely that a weight of evidence approach will be needed to help inform management decisions. The potential application of such measures in the risk framework is reviewed in the context of current and emerging legislation concerning chemicals. Effect measures on the basis of in situ methods provide an alternative line of evidence and can help reduce uncertainty in decision making. Criteria are presented to help select appropriate methods in a multiple-line, weight of evidence approach. [source] New insights into the pathophysiology of postoperative cognitive dysfunctionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 8 2010L. KRENK There is evidence that postoperative cognitive dysfunction (POCD) is a significant problem after major surgery, but the pathophysiology has not been fully elucidated. The interpretation of available studies is difficult due to differences in neuropsychological test batteries as well as the lack of appropriate controls. Furthermore, there are no internationally accepted criteria for defining POCD. This article aims to provide an update of current knowledge of the pathogenesis of POCD with a focus on perioperative pathophysiology and possible benefits achieved from an enhanced postoperative recovery using a fast-track methodology. It is concluded that the pathogenesis of POCD is multifactorial and future studies should focus on evaluating the role of postoperative sleep disturbances, inflammatory stress responses, pain and environmental factors. Potential prophylactic intervention may include minimal invasive surgery, multi-modal non-opioid pain management and pharmacological manipulation of the inflammatory response and sleep architecture. [source] Heart rate variability does not tap putative efficacy of Thought Field TherapyJOURNAL OF CLINICAL PSYCHOLOGY, Issue 10 2001John P. Kline Callahan (2001) has offered a series of case reports in an effort to validate the rationale and methods of Thought Field Therapy (TFT). These case reports employ subjective ratings, that is, the Subjective Units of Distress (SUD) rating scale as well as a gross measure of heart rate variability (HRV). My criticisms center around (a) inappropriately strong inferences given exclusive reliance on case reports, a potentially biased sample, and lack of appropriate controls; (b) misinterpretation of statistical artifact as systematic effect; (c) lack of systematic evaluation of HRV changes; and (d) erroneous interpretation of HRV. Callahan's article provides no evidence for the efficacy of TFT nor does it provide evidence for the credibility of TFT's rationale. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1187,1192, 2001. [source] An immunohistological study of anhydrous topical ascorbic acid compositions on ex vivo human skinJOURNAL OF COSMETIC DERMATOLOGY, Issue 2 2006Geoffrey K Heber MBBS Summary Background, Ascorbic acid has numerous essential and beneficial functions in normal and photoaged skin. Ionisation of ascorbic acid in aqueous topical formulations leads to oxidative degradation. Ascorbic acid in an anhydrous vehicle would inherently have greater stability. Objective, The objective of this study was to observe the effects of two anhydrous formulations containing microfine particles of ascorbic acid on neocollagenesis and cytokeratin production in ex vivo human skin. Methods, Vitamin C preparations were applied topically onto the surface of freshly excised human abdominal skin. Following an exposure time of 48 h with appropriate controls, skin discs were cut into sections, placed on slides and assessed using immunohistochemical (antibodies: collagen type I, III, cytokeratin) staining. Analysis was performed using microscopy and descriptive rating. Results, Both formulations resulted in increased production of collagen types I and III and cytokeratin. Conclusion, The application of anhydrous formulations containing microfine particles of ascorbic acid to ex vivo human skin in this study resulted in neocollagenesis and increased production of cytokeratin. This approach appears to enable biological effects of ascorbic acid in the skin using a vehicle which would provide it greater stability than an aqueous vehicle. [source] Cerebral dominance and schizophrenia-spectrum disorders in adults with intellectual disabilityJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 6 2000D. Rowe Abstract Studies of the general population without intellectual disability have suggested an association between atypical handedness and schizophrenia-spectrum disorders (SSDs). Mixed handedness is taken as an index of diminished cerebral dominance or laterality. The present study addressed the question of whether such findings extend to the neurodevelopmentally ,at risk' population of adults with intellectual disability and SSDs compared with appropriate controls. Fourteen patients with a dual diagnosis of intellectual disability and SSD were compared with 14 controls with intellectual disability alone. Assessments of self-reported hand preference and relative hand skill were completed. Self-report of hand preference revealed highly significantly greater mixed-handedness in the SSD group. Furthermore, relative hand skill performance was significantly diminished for the dominant hand. The discrepancy between dominant and non-dominant hand functioning was lower in the SSD group and this association was highly significant. The results of the present study support the usefulness of such detailed laterality assessment in this population. Mixed laterality, over and above that of the population with general intellectual disability and developmental disorder, was associated with SSD. These results are consistent with the neurodevelopmental hypothesis of schizophrenia and its cognitive neuropsychiatric/neuropsychological sequelae. [source] The ,ghosts' that pester studies on learning in mosquitoes: guidelines to chase them offMEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2006W. J. ALONSO Abstract The identification of memory and learning in medically important mosquito species has been of epidemiological interest mainly because of the implications of learning on the pattern of contact between vectors and hosts. Empirical results either showing or suggesting the existence of cognitive abilities in mosquitoes have been reported in a number of experimental studies, mainly based on the observation of individual fidelity towards subsets of specific resources, such as hosts, resting sites or breeding sites. A closer inspection of the design of these experiments shows that, with the exception of recent studies providing stronger evidence of learning in the genus Culex (Diptera: Culicidae), methodological shortcomings still hinder the possibility of eliminating alternative interpretations for these findings, in some cases because the experiments were not specifically designed to identify the phenomenon, but mostly because of a lack of appropriate controls or replication. By highlighting these limitations, while acknowledging the practical difficulties that are inherent to the field, we aim to help expel from future research the ,ghosts' that still preclude the achievement of more definite conclusions about the prevalence of memory and learning in this group of insects. [source] INVITED REVIEW: Molecular analysis of predation: a review of best practice for DNA-based approachesMOLECULAR ECOLOGY, Issue 4 2008R. A. KING Abstract Molecular analysis of predation, through polymerase chain reaction amplification of prey remains within the faeces or digestive systems of predators, is a rapidly growing field, impeded by a lack of readily accessible advice on best practice. Here, we review the techniques used to date and provide guidelines accessible to those new to this field or from a different molecular biology background. Optimization begins with field collection, sample preservation, predator dissection and DNA extraction techniques, all designed to ensure good quality, uncontaminated DNA from semidigested samples. The advantages of nuclear vs. mitochondrial DNA as primer targets are reviewed, along with choice of genes and advice on primer design to maximize specificity and detection periods following ingestion of the prey by the predators. Primer and assay optimization are discussed, including cross-amplification tests and calibratory feeding experiments. Once primers have been made, the screening of field samples must guard against (through appropriate controls) cross contamination. Multiplex polymerase chain reactions provide a means of screening for many different species simultaneously. We discuss visualization of amplicons on gels, with and without incorporation of fluorescent primers. In more specialized areas, we examine the utility of temperature and denaturing gradient gel electrophoresis to examine responses of predators to prey diversity, and review the potential of quantitative polymerase chain reaction systems to quantify predation. Alternative routes by which prey DNA might get into the guts of a predator (scavenging, secondary predation) are highlighted. We look ahead to new technologies, including microarrays and pyrosequencing, which might one day be applied to this field. [source] Measuring rDNA diversity in eukaryotic microbial systems: how intragenomic variation, pseudogenes, and PCR artifacts confound biodiversity estimatesMOLECULAR ECOLOGY, Issue 24 2007DANIEL J. THORNHILL Abstract Molecular approaches have revolutionized our ability to study the ecology and evolution of micro-organisms. Among the most widely used genetic markers for these studies are genes and spacers of the rDNA operon. However, the presence of intragenomic rDNA variation, especially among eukaryotes, can potentially confound estimates of microbial diversity. To test this hypothesis, bacterially cloned PCR products of the internal transcribed spacer (ITS) region from clonal isolates of Symbiodinium, a large genus of dinoflagellates that live in symbiosis with many marine protists and invertebrate metazoa, were sequenced and analysed. We found widely differing levels of intragenomic sequence variation and divergence in representatives of Symbiodinium clades A to E, with only a small number of variants attributed to Taq polymerase/bacterial cloning error or PCR chimeras. Analyses of 5.8S-rDNA and ITS2 secondary structure revealed that some variants possessed base substitutions and/or indels that destabilized the folded form of these molecules; given the vital nature of secondary structure to the function of these molecules, these likely represent pseudogenes. When similar controls were applied to bacterially cloned ITS sequences from a recent survey of Symbiodinium diversity in Hawaiian Porites spp., most variants (~87.5%) possessed unstable secondary structures, had unprecedented mutations, and/or were PCR chimeras. Thus, data obtained from sequencing of bacterially cloned rDNA genes can substantially exaggerate the level of eukaryotic microbial diversity inferred from natural samples if appropriate controls are not applied. These considerations must be taken into account when interpreting sequence data generated by bacterial cloning of multicopy genes such as rDNA. [source] Effect of lactational exposure to 1,2,3,4- tetrachlorodibenzo-p-dioxin on cytochrome P-450 1A1 mRNA in the neonatal rat liver: Quantitative analysis by the competitive RT-PCR methodPEDIATRICS INTERNATIONAL, Issue 5 2001Yumi Kono AbstractBackground and Methods: The aim of this study was to assess the effect of lactational exposure to dioxins in neonates on the cytochrome P450 1A1 (CYP1A1) induction in the level of gene expression. Maternal rats were treated with a single dose of 50 or 100 ,mol/kg 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD), a low potent congener of dioxins, on the first day post-partum (day 1). Induction of CYP1A1 mRNA expression was quantitatively analyzed by the competitive reverse transcription,polymerase chain reaction (RT,PCR) method. Results: The CYP1A1 mRNA was detectable at extremely low amounts in the liver of control neonates and mothers. The mRNA ratios of CYP1A1 to ,-actin in neonates were dose-dependently increased by the treatment of 1,2,3,4-TCDD of their mothers. Its peak occurred on day 6 and was sustained at the same level on day 10. Increases of the ratio with 100 ,mol/kg 1,2,3,4-TCDD on day 2, 6 and 10 were 26-, 40- and 40-fold of the appropriate controls, respectively. These levels paralleled the activity of ethoxyresorufin-o-deethylase, representing CYP1A mediated monooxygenase. In the mother, the mRNA ratio was increased only to threefold of the control, 10 days after treatment. Conclusion: Current RT-PCR procedure enabled to assess both constitutive and induced levels of CYP1A1 mRNA in the neonatal rat livers. Although the dose of 1,2,3,4-TCDD selected in this study was about 5000 times higher than the daily intake of dioxins in breast-fed infants, CYP1A1 mRNA was highly induced for a longer period of time in neonatal rats receiving 1,2,3,4-TCDD via lactation than the treated maternal rats. [source] On the importance of controls in enzyme assays , an odd exampleBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 2 2001Subita Sudarshana An interesting example of interference in the arginase assay is presented. This can be exploited to convey the importance of taking precautions and appropriate controls to the students of enzymology. © 2001 IUBMB. Published by Elsevier Science Ltd. All rights reserved. [source] Investigation into the effects of cidofovir on an in vitro model of recurrent respiratory papillomatosisCLINICAL OTOLARYNGOLOGY, Issue 3 2006A.J. Donne Problem. Recurrent respiratory papillomatosis (RRP) has no cure, and cidofovir is currently the most contemporary adjuvant treatment. Cidofovir has reported activity against Human Papilloma Virus type 16, but no laboratory studies have yet been performed on HPV type 6 which is the main cause of RRP. This work describes the generation of a novel HPV 6 related cell line and its use to evaluate the effects of Cidofovir. Method. HPV6b E6 cDNA was stably introduced into HPV negative C33A cervical carcinoma cells to produce the C33AT6E6 cell line. Two different doses of Cidofovir were applied to parent C33A, C33AT6E6 and C33AT16E6 (type 16 cell line) with appropriate controls. Growth and FACS cell cycle analysis were performed after 3 and 6 days of continuous exposure followed by 2 and 3 days post-drug withdrawal. Result.PCR analysis confirmed HPV6 E6 expression in C33AT6E6 cells. High dose cidofovir was toxic at 3 and 6 days exposure in all cells tested. Low dose exposure was toxic for C33AT16E6 cells at 3 days whereas C33A and C33AT6E6 only showed minimal toxicity at 6 days. C33A and C33AT6E6 cells also showed earlier recovery following drug withdrawal. Conclusion.Cidofovir showed varying degrees of non-specific toxicity against all three cell lines tested. However, HPV16 E6 expressing cells were more sensitive than either parent or HPV6 E6 expressing cells indicating that cidofovir has no selective advantage for the RRP related HPV6 E6 expressing cell line. [source] | ||||||||||||||||