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Potential Causes (potential + cause)
Selected AbstractsCauses and consequences of post-growth age-dependent differences in small intestine size in a migratory sandpiper (Calidris mauri, Western Sandpiper)FUNCTIONAL ECOLOGY, Issue 1 2006R. W. STEIN Summary 1Calidris mauri Cabanis (Western Sandpiper) exhibits a pronounced post-growth age-dependent difference in small intestine size during southward migration, such that the later-migrating juveniles have larger small intestines than do the adults. Potential causes and consequences of this age-dependent difference are examined. 2Premigrant juveniles of full structural size had small intestines that were 10% longer than those of the premigrant adults, even though the juveniles had not attained asymptotic body mass. The elongated small intestines of premigrant juveniles appear to be growth-related. 3Adults and juveniles exhibited parallel increases in intestinal length (7·0%) and circumference (9·5%) in association with the initiation of migration; these effects are consistent with migratory hyperphagia. 4Refuelling juveniles had small intestines that were 8·5% longer than those of the refuelling adults. Retaining an enlarged small intestine during migration confers increased digestive capacity to the juveniles, which may be under selection to minimize stopover duration. 5Refuelling juveniles had a higher prevalence of cestode infection than refuelling adults in one of two years, and the length-corrected mass of the small intestine was 9·7% heavier in infected individuals. Cestode infection may be an important determinant of migration-related mortality for juveniles, by compromising their health and increasing stopover duration. [source] Optimal Left Ventricular Lead Position Predicts Reverse Remodeling and Survival After Cardiac Resynchronization TherapyCONGESTIVE HEART FAILURE, Issue 2 2009David Tepper MD Background., A nonoptimal LV pacing lead position may be a potential cause for nonresponse to CRT. Methods., The site of latest mechanical activation was determined by speckle tracking radial strain analysis and related to the LV lead position on chest x-ray in 244 CRT candidates. Echocardiographic evaluation was performed after 6 months. Long-term follow-up included all-cause mortality and hospitalizations for heart failure. Results., Significant LV reverse remodeling (reduction in LV end-systolic volume from 189±83 mL to 134±71 mL, P<.001) was noted in the group of patients with a concordant LV lead position (n=153, 63%), whereas patients with a discordant lead position showed no significant improvements. In addition, during long-term follow-up (32±16 months), less events (combined for heart failure hospitalizations and death) were reported in patients with a concordant LV lead position. Moreover, a concordant LV lead position appeared to be an independent predictor of hospitalization-free survival after long-term CRT (hazard ratio: 0.22, P=.004). Conclusions., Pacing at the site of latest mechanical activation, as determined by speckle tracking radial strain analysis, resulted in superior echocardiographic response after 6 months of CRT and better prognosis during long-term follow-up. [source] Outcome after prolonged convulsive seizures in 186 children: low morbidity, no mortalityDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2004Piia Metsäranta BM Prolonged convulsive seizures are a common neurological emergency and a potential cause of neuronal damage and functional sequelae. We explored the role of seizure duration and various background factors for neurological sequelae in children with prolonged convulsive seizures. The population-base of this study was all children (age < 16 years) who had been admitted to the Tampere University Hospital, Finland between 1993 and 1999 with convulsive seizures lasting more than 5 minutes. Patients were followed up individually (mean length of follow-up 2 years 1 month, range 0 to 7 years 8 months). All available data on the prolonged seizure episodes and clinical follow-up were analyzed retrospectively by a detailed review of all medical charts and records. In 186 children (94 males, 92 females; mean age 4 years 5 months, SD 3 years 10 months, range 1 month to 15 years 4 months) there were 279 separate convulsive seizure episodes lasting over 5 minutes, yielding an annual incidence of 47.5 out of every 100000 episodes. Seizure aetiology was idiopathic in 26.2% of episodes, febrile in 41.9%, remote symptomatic in 28%, and acute symptomatic in 3.9% of episodes. Mean duration of all seizure episodes was 42.5 minutes (SD 46.1 minutes) and was significantly correlated with the aetiology: shortest in the febrile group (mean 35.4 minutes) and longest in the acute symptomatic group (mean 88.6 minutes; p < 0.001). There was no mortality related directly to these acute seizure episodes. The most common sequela was an onset of epilepsy in 40 children (22%). Permanent neurological sequelae were noted in only four patients (2.2%; mean seizure duration 16 minutes) and non-permanent sequelae in six patients (3.2%; mean seizure duration 38 minutes). Neurological sequelae of prolonged convulsive seizures in children are rare and are related to aetiological factors rather than the duration of a single seizure. The role of acute seizures in the evolution of epilepsy in children remains obscure. [source] Fundal gastritis as a potential cause of reflux oesophagitisDISEASES OF THE ESOPHAGUS, Issue 1 2000M. Newton The transient lower oesophageal sphincter relaxations which allow reflux may be due to altered afferent pathways from the fundus. We aimed to determine whether fundal inflammation is the underlying cause. Two endoscopic biopsies were taken from each of the gastric antrum and fundus in 25 asymptomatic controls with a normal endoscopy (median age 54 range 13,83 years), and 33 patients with erosive oesophagitis (median age 52, 11,78 years). No patient had taken acid suppression therapy or antibiotics for at least 1 month. Sections were stained with haematoxylin and eosin and Giemsa stain and examined in a blinded fashion by one pathologist for the presence of gastritis (Sydney classification) and Helicobacter pylori. Chronic gastritis was common in both groups, but was usually mild. In Helicobacter pylori -negative subjects, there was significantly less chronic gastritis in the antrum and the fundus in oesophagitis patients than in controls (p < 0.05). When present, gastric atrophy was usually antral and mild in severity. There was no difference in the incidence of gastric atrophy in patients with oesophagitis compared with controls (24% compared with 40%; p > 0.05). Chronic gastritis is not more common in patients with oesophagitis, and is unlikely to play a part in the pathogenesis of this disease. [source] Differential tolerance among cryptic species: A potential cause of pollutant-related reductions in genetic diversityENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2004Axayácatl Rocha-Olivares Abstract Differential mortality of cryptic species (i.e., morphologically similar but genetically distinct sibling species) may contribute to observed reductions in genetic diversity at contaminated sites if the members of a complex of cryptic species exhibit differential responses to the contaminants that are present. We conducted toxicity bioassays with both polynuclear aromatic hydrocarbon and metal contamination on Cletocamptus fourchensis and C. stimpsoni from two intensively sampled locations. Previous molecular and detailed morphological analyses segregated these as cryptic species from the cosmopolitan C. deitersi. We found that these species occur together at two field sites and that they exhibit unique toxic responses to heavy metals, suggesting differential tolerances at contaminated sites. These findings suggest that reported losses of genetic diversity at contaminated sites may represent a reduction in species diversity rather than a loss of the presumed less-tolerant genotypes within a species. They also suggest that members of a cryptic species complex should not be used in laboratory toxicity tests unless populations are genetically characterized. Future studies using genetic diversity as a marker of contaminant effects should consider the possibility of undetected cryptic species. [source] A methodology for inferring the causes of observed impairments in aquatic ecosystems,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2002Glenn W. Suter II Abstract Biological surveys have become a common technique for determining whether aquatic communities have been injured. However, their results are not useful for identifying management options until the causes of apparent injuries have been identified. Techniques for determining causation have been largely informal and ad hoc. This paper presents a logical system for causal inference. It begins by analyzing the available information to generate causal evidence; available information may include spatial or temporal associations of potential cause and effect, field or laboratory experimental results, and diagnostic evidence from the affected organisms. It then uses a series of three alternative methods to infer the cause: Elimination of causes, diagnostic protocols, and analysis of the strength of evidence. If the cause cannot be identified with sufficient confidence, the reality of the effects is examined, and if the effects are determined to be real, more information is obtained to reiterate the process. [source] Anoxia,ischemia: A mechanism of seizure termination in ictal asystoleEPILEPSIA, Issue 1 2010Stephan U. Schuele Summary Cerebral anoxia,ischemia (CAI) is a potent inhibitor of cerebral hyperactivity and a potential mechanism of seizure self-termination. Prolonged ictal asystole (IA) invariably leads to CAI and has been implicated as a potential cause of sudden unexplained death in epilepsy (SUDEP). IA was seen in eight consecutive patients (0.12% of all patients monitored). Ten of their seizures with IA had evidence of CAI on electroencephalography (EEG), manifested by bilateral hypersynchronous slowing (BHS), and were compared to 18 seizures without signs of CAI. The ictal EEG pattern resolved in all 10 CAI events with onset of the BHS. The period from IA onset to seizure end was reduced in events with BHS compared to events without BHS (10.5 s vs. 28.3 s, respectively; p = 0.005), and the total seizure duration tended to be shorter. Anoxia,ischemia as a result of IA may represent an effective endogenous mechanism for seizure termination and may explain why the hearts of patients with ictal asystole reported to date in the literature resumed beating spontaneously. [source] Epilepsy as a Consequence of Cerebral Malaria in Area in Which Malaria Is Endemic in Mali, West AfricaEPILEPSIA, Issue 5 2006Edgard Brice Ngoungou Summary:,Purpose: Cerebral malaria (CM) is suspected to be a potential cause of epilepsy in tropical areas, but little information is available. The purpose of this study was to evaluate the role of CM in epilepsy among children in Mali. Methods: An exposed,nonexposed study was performed to identify children who had epilepsy after malaria in the 0- to 15-year age group. The exposure factor was CM defined according to World Health Organization (WHO) criteria, and the nonexposure factor was symptomatic malaria without the characteristics of CM (NCM). All the children underwent a screening questionnaire and were examined by a medical physician. After the screening phase, a specialist in neuropediatrics examined the children suspected to have epilepsy. EEG and computed tomography (CT) scans were performed in some of these patients. Results: In total, 101 subjects who had had CM and 222 who had had NCM were included. Fifty-four children (CM, 34; NCM, 20) were suspected to have epilepsy, and six were confirmed (CM, five; NCM, one). The incidence rate was 17.0 per 1000 person-years in the CM group and 1.8 per 1000 person-year in the NCM group; thus the relative risk (RR) was 9.4 [95% confidence interval (CI), 1.3,80.3; p = 0.02]. After adjustment on age and duration of follow-up, the RR was 14.3 (95% CI, 1.6,132.0; p = 0.01). Conclusions: The risk of sequelar epilepsy is significantly higher in the CM group compared with the NCM group. A reevaluation of this cohort should be carried out later to search for temporal epilepsy that appeared after age 10 years. [source] Two clinical manifestations of desmopathy of the accessory ligament of the deep digital flexor tendon in the hindlimb of 23 horsesEQUINE VETERINARY JOURNAL, Issue 6 2005E. ELIASHAR Summary Reasons for performing study: Desmopathy of the accessory ligament of the deep digital flexor tendon (ALDDFT) in the hindlimb is an unusual cause of lameness in horses, and reports of the condition are sparse. Objectives: To describe the clinical and ultrasonographic findings, therapy and outcome of 23 horses treated for desmopathy of the ALDDFT in the hindlimb. Methods: Records of 23 horses with ultrasonographic evidence of desmopathy of the ALDDFT in one or both hindlimbs from 3 referral centres were reviewed retrospectively. Age, breed, sex, duration and nature of clinical signs, results of clinical and lameness examinations, treatment and outcome were recorded. Results: In 13 horses (Group A), there was an acute onset of unilateral lameness. Ten horses (Group B) had an insidious or sudden onset of postural abnormality. There were 10 cobs, 5 British native-breed ponies and 8 horses of various larger breeds. Twenty horses were used for general purposes, and mean age was 12 years. Enlargement of the ALDDFT in the affected hindlimb(s) was identified in all horses. In 44% of horses, ultrasonographic abnormalities were localised to part of the ALDDFT. Treatment included box-rest and controlled exercise, and 10 horses were subjected to desmotomy or desmectomy of the ALDDFT. Seventy-three percent of horses in Group A returned to full function, while 90% of those in Group B remained lame. Conclusions: Two distinct clinical conditions are associated with the ALDDFT of the hindlimb. Traumatically induced injury resulting in acute onset lameness appears to have a favourable prognosis, with most horses returning to previous work. However, postural changes, once present, are irreversible and indicate a poor prognosis. Potential relevance: Desmopathy of the ALDDFT should be recognised as a potential cause of hindlimb lameness and this study provides clinical and prognostic information. Knuckling and/or semiflexion of the metatarsophalangeal joint may accompany the condition; therefore, if a horse is presented with a flexural deformity of this joint, desmopathy of the ALDDFT should be considered as a primary differential diagnosis. [source] Effects of stylopharyngeus muscle dysfunction on the nasopharynx in exercising horsesEQUINE VETERINARY JOURNAL, Issue 4 2004C. TESSIER Summary Reasons for performing study: Nasopharyngeal collapse has been observed in horses as a potential cause of exercise intolerance and upper respiratory noise. No treatment is currently available and affected horses are often retired from performance. Objective: To determine the effect of bilateral glossopharyngeal nerve block and stylopharyngeus muscle dysfunction on nasopharyngeal function and airway pressures in exercising horses. Methods: Endoscopic examinations were performed on horses at rest and while running on a treadmill at speeds corresponding to HRmax50, HRmax75 and HRmax, with upper airway pressures measured with and without bilateral glossopharyngeal nerve block. Results: Bilateral glossopharyngeal nerve block caused stylopharyngeus muscle dysfunction and dorsal nasopharyngeal collapse in all horses. Peak inspiratory upper airway pressure was significantly (P = 0.0069) more negative at all speeds and respiratory frequency was lower (P = 0.017) in horses with bilateral glossopharyngeal nerve block and stylopharyngeus muscle dysfunction compared to control values. Conclusions: Bilateral glossopharyngeal nerve anaesthesia produced stylopharyngeus muscle dysfunction, dorsal pharyngeal collapse and airway obstruction in all horses. Potential relevance: The stylopharyngeus muscle is probably an important nasopharyngeal dilating muscle in horses and dysfunction of this muscle may be implicated in clinical cases of dorsal nasopharyngeal collapse. Before this information can be clinically useful, further research on the possible aetiology of stylopharyngeus dysfunction and dysfunction of other muscles that dilate the dorsal and lateral walls of the nasopharynx in horses is needed. [source] Contemporary issues and future directions for research into pathological gamblingADDICTION, Issue 8 2000Article first published online: 2 SEP 200 The recent healthy increase in research into all aspects of gambling is noted. The dominant theme accounting for most of this research is the mental disorder model of pathological gambling and measures that have been derived from this conceptualization. It is suggested that an alternative approach focusing on the construct of choice or subjective control over gambling may be a research direction that will ensure that progress is maintained. In this paper a context for the discussion is provided by first identifying briefly fundamental conceptual and methodological issues associated with the mental disorder model. In particular it is argued that the heterogeneity of the diagnosis of pathological gambling makes the research task of assessing truly independent variables extremely difficult. Subsequently an illustrative schema is presented that demonstrates both the potential advantages and some of the complexities associated with the dependent variable of self-control over gambling behaviour. The main advantages are argued to be (a) the focus of research is narrowed to one potential cause of harmful impacts rather than the great diversity of impacts themselves, (b) prospective studies of regular gamblers in real gambling venues may be a key source of insight into the development of pathological gambling and (c) it promotes the development of theoretical links with the mainstream of the discipline of psychology. Despite the conceptual difficulties that may be associated with the variable of self-control, it is suggested that these may be overcome because contemporary research into the addictive behaviours has demonstrated considerable success in the definition and measurement of control and related themes such as craving, restraint and temptation. [source] Abnormal CTLA-4 function in T cells from patients with systemic lupus erythematosusEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2010Elizabeth C. Jury Abstract CTLA-4 is a critical gatekeeper of T-cell activation and immunological tolerance and has been implicated in patients with a variety of autoimmune diseases through genetic association. Since T cells from patients with the autoimmune disease systemic lupus erythematosus (SLE) display a characteristic hyperactive phenotype, we investigated the function of CTLA-4 in SLE. Our results reveal increased CTLA-4 expression in FOXP3, responder T cells from patients with SLE compared with other autoimmune rheumatic diseases and healthy controls. However, CTLA-4 was unable to regulate T-cell proliferation, lipid microdomain formation and phosphorylation of TCR-, following CD3/CD28 co-stimulation, in contrast to healthy T cells. Although lupus T cells responded in vitro to CD3/CD28 co-stimulation, there was no parallel increase in CTLA-4 expression, which would normally provide a break on T-cell proliferation. These defects were associated with exclusion of CTLA-4 from lipid microdomains providing an anatomical basis for its loss of function. Collectively our data identify CTLA-4 dysfunction as a potential cause for abnormal T-cell activation in patients with SLE, which could be targeted for therapy. [source] Orthostatic Headaches in the Syndrome of the Trephined: Resolution Following CranioplastyHEADACHE, Issue 7 2010Bahram Mokri MD Objective., To draw attention to the syndrome of the trephined as a potential cause for orthostatic headaches without cerebrospinal fluid (CSF) leak. Background., Orthostatic headaches typically result from CSF leaks but sometimes may occur in conditions without any evidence of CSF leakage. Methods., A 37-year-old right-handed woman became comatose after a motor vehicle accident with cerebral contusions and massive left cerebral edema. A large frontoparietal craniectomy was carried out. In 5 months, she made good neurologic recovery. Freeze-preserved bone flap was placed back. In several weeks she was functionally near normal. Two years later, she began to complain of orthostatic headache and gradually additional manifestations appeared including progressive gait unsteadiness, imprecise speech, cognitive difficulties, and an increasing left hemiparesis along with progressive sinking of the skull defect and shift of the midline and ventricular distortion. She underwent removal of resorptive sinking bone flap and construction of an acrylic cranioplasty. Results., At 6-month follow-up, there was complete resolution of the orthostatic headaches, remarkable neurologic improvement along with resolution of midline shift and ventricular distortion. Conclusion., The syndrome of the trephined is yet another cause of orthostatic headaches without CSF leak. [source] Mouse models in non-alcoholic fatty liver disease and steatohepatitis researchINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 1 2006Quentin M. Anstee Summary Non-alcoholic fatty liver disease (NAFLD) represents a histological spectrum of liver disease associated with obesity, diabetes and insulin resistance that extends from isolated steatosis to steatohepatitis and cirrhosis. As well as being a potential cause of progressive liver disease in its own right, steatosis has been shown to be an important cofactor in the pathogenesis of many other liver diseases. Animal models of NAFLD may be divided into two broad categories: those caused by genetic mutation and those with an acquired phenotype produced by dietary or pharmacological manipulation. The literature contains numerous different mouse models that exhibit histological evidence of hepatic steatosis or, more variably, steatohepatitis; however, few replicate the entire human phenotype. The genetic leptin-deficient (ob/ob) or leptin-resistant (db/db) mouse and the dietary methionine/choline-deficient model are used in the majority of published research. More recently, targeted gene disruption and the use of supra-nutritional diets to induce NAFLD have gained greater prominence as researchers have attempted to bridge the phenotype gap between the available models and the human disease. Using the physiological processes that underlie the pathogenesis and progression of NAFLD as a framework, we review the literature describing currently available mouse models of NAFLD, highlight the strengths and weaknesses of established models and describe the key findings that have furthered the understanding of disease pathogenesis. [source] Do older adults presenting with memory complaints wish to be told if later diagnosed with Alzheimer's disease?INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 5 2006Paul Elson Abstract Background Many patients with Alzheimer's disease are not told their diagnosis. Studies have shown that relatives possess mixed views regarding whether or not patients should be told while elderly peers favour disclosure. Recent studies have shown that patients with diagnosed dementia also favour being told. The present study sought the views of patients prior to diagnosis. Method Participants were a consecutive sample of patients aged 65 and over suffering from memory complaints. They were asked what they considered to be causing their memory problems and whether or not they would want to know the cause. They were then specifically asked if they would want to know if diagnosed with Alzheimer's disease and what were their reasons for this. Results Two-thirds of patients were uncertain regarding the cause of their memory difficulties although the remainder did offer some valid explanations. Eighty-six per cent wanted to know the cause while 69% wanted to know if diagnosed with Alzheimer's disease and a variety of reasons were offered to support their preference. Conclusion The majority of older adults presenting to services with memory complaints had little understanding of the potential cause of their problems. Most were nevertheless keen to know the cause, even if this transpired to be Alzheimer's disease. The clinical implications of the findings are discussed and suggestions made for future research. Copyright © 2006 John Wiley & Sons, Ltd. [source] Foundational Value of Statistics Education for Management CurriculumINTERNATIONAL STATISTICAL REVIEW, Issue 3 2007Hirokuni Tamura Traitement humain de l'information; Education/Enseignement; Prise de décision; Prévision; Modèles statistiques Summary The purpose of this paper is to propose a unique and distinct value of statistics education for management. The 1986 inaugural conference on Making Statistics More Effective in Schools of Business (MSMESB) proposed valuable guidelines for reforming statistics education in schools of business. However, a survey conducted by McAlevey & Everett (2001) identified that their impact has been minimal, and argued that structural problems many business schools have are the potential cause. We argue these structural problems exist because the value of the body of statistical tools for management is ambiguous and has not been made explicit. The unique and distinct value of statistics for management can be identified as the body of tools necessary to meet the inherent needs of a manager charged with making predictive judgments facing data. The need arises because human information-processing capacity is quite limited, as the findings of researchers in cognitive psychology testify. These findings also affirm that the basic statistical concepts needed for processing data cannot be learned from management experiences. The model of a manager faced with data, while considering the evidence of inherent limitations of human information-processing capacity, establishes the foundational value of statistics training in the management curriculum. Statistics education in business schools will be made more effective when management educators recognize such value of the discipline, lend their support and reward the ownership commitment for continuous improvement and innovations of the business statistics curriculum. Résumé Le but de cet article est de proposer une valeur unique et particulière de l'enseignement des statistiques dans le domaine de la gestion. La conférence inaugurale de 1986 traitant des moyens d'améliorer l'efficacité de cet enseignement dans les écoles de gestion a proposé des lignes directrices valables pour la réforme de l'enseignement des statistiques dans les écoles de gestion. Néanmoins, un sondage effectué par McAlevey & Everett (2001), a identifié leur impact comme étant minimal et en attribue la cause probable aux problèmes structurels des écoles de gestion. Nous considérons que ces problèmes existent parce que la valeur du corpus statistique de gestion est ambigüe et n'a pas été mise en lumière. La valeur unique et distincte des statistiques de gestion peut être identifiée comme un corpus d'outils nécessaires pour répondre aux besoins inhérents d'un gestionnaire chargé de faire des prévisions au moyen d'informations brutes. Ce besoin vient du fait que la capacité humaine de traitement de l'information est limitée ainsi qu'en témoignent les recherches en psychologie cognitive. Ces résultats affirment également que les concepts statistiques basiques nécessaires pour le traitement de l'information ne peuvent être acquis par l'expérience de la gestion. Le modèle du gestionnaire confronté de l'information, une fois l'évidence des limites des capacités humaines en matière de traitement de l'information est prise en compte, établi la valeur fondatrice de l'entrainement aux statistiques dans un curriculum de gestion. L'enseignement des statistiques dans les écoles de commerce sera plus efficace quand les responsables de l'éducation reconnaitront cette valeur de la discipline, y apporteront leur soutien et récompenseront les actions visant à l'amélioration et l'innovation constante au sein du curriculum statistique de gestion. [source] Mitochondrial A, A potential cause of metabolic dysfunction in Alzheimer's diseaseIUBMB LIFE, Issue 12 2006Xi Chen Abstract Deficits in mitochondrial function are a characteristic finding in Alzheimer's disease (AD), though the mechanism remains to be clarified. Recent studies revealed that amyloid , peptide (A,) gains access into mitochondrial matrix, which was much more pronounced in both AD brain and transgenic mutant APP mice than in normal controls. A, progressively accumulates in mitochondria and mediates mitochondrial toxicity. Interaction of mitochondrial A, with mitochondrial enzymes such as amyloid , binding alcohol dehydrogenase (ABAD) exaggerates mitochondrial stress by inhibiting the enzyme activity, releasing reactive oxygen species (ROS), and affecting glycolytic, Krebs cycle and/or the respiratory chain pathways through the accumulation of deleterious intermediate metabolites. The pathways proposed may play a key role in the pathogenesis of this devastating neurodegenerative disorder, Alzheimer's disease. iubmb Life, 58: 686-694, 2006 [source] Oxidative damage is a potential cause of cone cell death in retinitis pigmentosaJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2005JiKui Shen Retinitis pigmentosa (RP) is a prevalent cause of blindness caused by a large number of different mutations in many different genes. The mutations result in rod photoreceptor cell death, but it is unknown why cones die. In this study, we tested the hypothesis that cones die from oxidative damage by performing immunohistochemical staining for biomarkers of oxidative damage in a transgenic pig model of RP. The presence of acrolein- and 4-hydroxynonenal-adducts on proteins is a specific indicator that lipid peroxidation has occurred, and there was strong immunofluorescent staining for both in cone inner segments (IS) of two 10-month-old transgenic pigs in which almost all rods had died, compared to faint staining in two 10-month-old control pig retinas. In 22- and 24-month-old transgenic pigs in which all rods and many cones had died, staining was strong in cone axons and some cell bodies as well as IS indicating progression in oxidative damage between 10 and 22 months. Biomarkers for oxidative damage to proteins and DNA also showed progressive oxidative damage to those macromolecules in cones during the course of RP. These data support the hypothesis that the death of rods results in decreased oxygen consumption and hyperoxia in the outer retina resulting in gradual cone cell death from oxidative damage. This hypothesis has important therapeutic implications and deserves rapid evaluation. © 2005 Wiley-Liss, Inc. [source] Synthetic retinoids as inducers of apoptosis in ovarian carcinoma cell linesJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2004William F. Holmes Apoptosis is also known as programmed cell death. Apoptosis plays an essential role in maintaining normal tissue and cell physiology in multicellular organisms. Clearance of aberrant or pre-cancerous cells occurs through the induction of apoptosis. It has been reported that many tumors and tumor cell lines have dysfunctional apoptosis signaling, causing these tumors to escape immune monitoring and internal cellular control mechanisms. One potential cause of this dysfunctional apoptosis is the tumor suppressor p53, an important regulator of growth arrest and apoptosis that is mutated in over 50% of all cancers. Retinoids have great potential in the areas of cancer therapy and chemoprevention. While some tumor cells are sensitive to the growth inhibitory effects of natural retinoids such as all- trans -retinoic acid (ATRA), many ovarian tumor cells are not. 6-[3-(1-Admantyl)]-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) and fenretinide N -[4-hydroxyphenyl] retinamide (4-HPR) are conformationally restricted synthetic retinoids that induce growth arrest and apoptosis in both ATRA-sensitive and ATRA-resistant ovarian tumor cell lines. Recently, we have identified the molecular pathways of apoptosis induced by treatment of ovarian carcinoma cells with mutated p53 by CD437 and 4-HPR. © 2004 Wiley-Liss, Inc. [source] Pharmacoepidemiologic study of potential drug interactions in outpatients of a university hospital in ThailandJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 1 2005B. Janchawee PhD Summary Background:, Drug,drug interaction is a potential cause of adverse drug reactions. The incidence of such drug interactions in university hospitals in Thailand is unknown. Purpose:, To estimate the rate of potential drug,drug interactions in outpatients of a typical Thai university hospital, and to identify risk factors for such interactions in Thai patients. Methods:, One-year outpatients' prescription data were retrieved from the hospital computer records. Potential drug interactions were identified using the existing drug-interaction database system. Potential interactions within a specific prescription and involving drugs prescribed 1-, 3- and 7-day earlier were searched for. Possible associations between occurrence of an interaction and a patient's age and gender and the number of items on the prescription were explored. Results:, The overall rate of potential drug interactions was 27·9% with a maximal value of 57·8% at the Department of Psychiatry. The rate of the most potentially significant interactions was 2·6%, being the highest in the Department of Medicine (6·0%), with isoniazid vs. rifampin as the most common interacting combination. The rate increased with the patient's age and prescription size (P = 0·000). The odd's ratio of having at least one potential drug interaction was 1·8 (64·2%) when age increased by 20 years (P = 0·000) and 2·8 (165·7%) when another drug was added (P = 0·000). The rate of potential drug interactions was the same for both genders. The rate of potential drug interactions detected across prescriptions was higher than within prescriptions and was dependent on the time interval between prescriptions. Conclusions:, Potential drug interactions were common in our sample of patients. The rate of such interactions increased with the number of drugs prescribed and the patient's age. [source] Horizontal transmission of Beauveria bassiana (Bals.) VuillAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2000David W. Long Summary 1 Factors influencing horizontal transmission of the entomopathogen Beauveria bassiana in the Colorado potato beetle (CPB) were examined through a series of laboratory studies. 2 Cadaver density, cadaver life stage, ambient temperature and conidial density were the factors manipulated. 3 Mortality and sporulation of burrowing CPB prepupae both increased significantly with increased sporulating second-instar cadaver density on the soil surface. 4 Mortality rates were significantly higher when prepupae were released into laboratory arenas containing third-instar cadavers compared to second-instar cadavers. 5 Mortality and sporulation decreased significantly as temperature increased from 15 °C to 30 °C, however, no temperature-dependent behavioural response by prepupae could be identified as a potential cause. 6 An 86.1% decrease in conidial density per cadaver had no significant effect on mortality or sporulation of prepupae, indicating that this level of environmental degradation of cadavers may not significantly reduce the probability of horizontal transmission. [source] Involvement of Jugular Valve Insufficiency in Cerebral Venous Air EmbolismJOURNAL OF NEUROIMAGING, Issue 3 2007Max Nedelmann MD ABSTRACT Background. Cerebral venous air entrapment is a rare finding on cranial computed tomography (CT) scan. Peripheral air embolism is discussed as a potential cause. However, the mechanism of retrograde passage through internal jugular valves and veins is unclear. Case Report. The case of a patient is reported, who had air entrapment in the left cavernous sinus. Prior to CT scanning, a peripheral intravenous line had been placed. Ultrasound revealed excessive insufficiency of the left internal jugular valve. To further study the mechanism of embolism, an echo contrast agent was injected into the cubital vein. A Valsalva maneuver resulted in retrograde transition of microbubbles across the insufficient valve. Valvular function on the unaffected right side was intact. Conclusions. This case report gives insight into the mechanism of cerebral venous air embolism. This is the firstcase describing jugular valve insufficiency as the missing link between peripheral air embolism and cerebral venous air entrapment. [source] Observation of three cases of temporomandibular joint osteoarthritis and mandibular morphology during adolescence using helical CTJOURNAL OF ORAL REHABILITATION, Issue 4 2004K. Yamada summary, Temporomandibular joint (TMJ) osteoarthritis (OA) is a potential cause of craniofacial deformity. If TMJ OA appears during orthodontic treatment, the mandible usually rotates posteriorly, resulting in an unsatisfactory profile, especially in patients with pre-treatment mandibular retrusion. Although it is important to confirm the kind of TMJ pathosis at the start of orthodontic treatment, the relationship between TMJ OA, condylar remodelling and changes in craniofacial morphology remains unclear because of a lack of longitudinal studies. Elucidating this relationship might allow better prediction of post-treatment craniofacial morphology. In the present case reports, helical computed tomography and cephalometry were used to analyse relationships between the pattern and location of condylar remodelling and the changes in craniofacial morphology in three patients with TMJ OA. [source] Classic pyomyositis of the extremities as an unusual manifestation of Blastomyces dermatitidis: a report of two casesMYCOSES, Issue 4 2010Michael Y. Lin Summary Pyomyositis is an infection of skeletal muscle that, by definition, arises intramuscularly rather than secondarily from adjacent infection. It is usually associated with bacterial infection, particularly Staphylcococcus aureus. Fungi are rare causes, and Blastomyces dermatitidis has not been reported previously. In this case series, we report two cases of pyomyositis caused by B. dermatitidis. Cases were prospectively identified through routine clinical care at a single academic referral hospital. Two patients with complaints of muscle pain and subacute cough were treated at our hospital in 2007. Both patients were found to have pyomyositis caused by B. dermatitidis, in the quadriceps muscles in one patient, and in the calf muscle in another , by radiological imaging and fungal culture. Both were also diagnosed with pneumonia caused by B. dermatitidis (presumptive in one, confirmed in the other). There was no evidence of infection of adjacent structures, suggesting that the route of infection was likely direct haematogenous seeding of the muscle. A review of the literature confirmed that although B. dermatitidis has been described as causing axial muscle infection secondary to adjacent infection such as vertebral osteomyelitis, our description of isolated muscle involvement (classic pyomyositis) caused by B. dermatitidis, particularly of the extremity muscles, is unique. We conclude that B. dermatitidis is a potential cause of classic pyomyositis. [source] Print uniformity of corrugated board in flexo printing: effects of corrugated board and halftone dot deformationsPACKAGING TECHNOLOGY AND SCIENCE, Issue 7 2008Martin Holmvall Abstract Print non-uniformity is a major concern for flexo post-printers. Many of these non-uniformities are suspected to be caused by the corrugated board structure itself. Striping is the most obvious one, but also other print quality problems might be structure-related. This work focuses on how deformations of the board might lead to print non-uniformities, and if the deformation of halftone dots is the mechanism behind striping in halftone flexo post-printing. Finite element models were used to analyse the effects of deformations of corrugated boards and compressed halftone dots in the printing nip. Distortions of the board due to non-uniform hygro-thermal strains were shown to be a potential cause of print non-uniformities. Striping in halftone prints was found to be caused by differences in dot gain between areas above ridges and valleys of the flute structure. Copyright © 2008 John Wiley & Sons, Ltd. [source] Information, Agreement Design, and the Durability of Civil War SettlementsAMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 2 2010Michaela Mattes Civil war is usually examined from the perspective of commitment problems. This approach provides considerable insight regarding which civil war agreement provisions reduce the chance of renewed fighting. Yet, additional insight can be gained by examining information asymmetries as a potential cause of civil war recurrence. We argue that significant uncertainty regarding military capabilities may persist after fighting ends and that this uncertainty may lead to the breakdown of peace. However, carefully designed peace agreements can guard against renewed civil war by calling for international monitoring, making the belligerents submit military information to third parties, and providing for verification of this information. Our empirical analysis of 51 civil war settlements between 1945 and 2005 shows that these provisions significantly reduce the risk of new civil war. Encouraging the adoption of these provisions may be a useful policy in the international community's effort to establish peace in civil-war-torn societies. [source] ORIGINAL RESEARCH,SEXUAL PAIN DISORDERS: Interstitial Cystitis/Painful Bladder Syndrome as a Cause of Sexual Pain in Women: A Diagnosis to ConsiderTHE JOURNAL OF SEXUAL MEDICINE, Issue 3 2007Kristene Whitmore MD ABSTRACT Introduction., Sexual pain, or dyspareunia, is a common symptom among women. Dyspareunia presents in many ways, and arises from a range of causes. Interstitial cystitis/painful bladder syndrome (IC/PBS) is one potential cause that may frequently be overlooked by clinicians. Interstitial cystitis is increasingly recognized as more common than was once thought. However, it can be difficult to identify, as the symptoms of IC/PBS (urinary urgency and frequency, dyspareunia, nocturia, and pelvic pain) overlap with other urogynecologic conditions. Aim., This article will review the association between dyspareunia and IC/PBS, and will provide an approach to the diagnosis and treatment of IC/PBS in women with sexual pain. Methods and Main Outcome Measures., Review of the medical literature and expert medical opinion. Results., Many women with IC/PBS experience dyspareunia, often in conjunction with chronic pelvic pain. When IC/PBS is suspected, there are simple measures to aid in the diagnosis of this condition, and treatments are readily available. Conclusions., When a woman presents with the symptoms of urinary urgency and frequency, dyspareunia, nocturia, and/or pelvic pain, IC/PBS should be part of the diagnostic evaluation. Whitmore K, Siegel JF, and Kellogg-Spadt S. Interstitial cystitis/painful bladder syndrome as a cause of sexual pain in women: A diagnosis to consider. J Sex Med 2007;4:720,727. [source] Reflux as a cause of tracheoesophageal puncture failureTHE LARYNGOSCOPE, Issue 1 2009Kavita M. Pattani MD Abstract Objective: To evaluate the response to empiric reflux management in treatment of tracheoesophageal punctures (TEP) failures. Methods: A retrospective chart review of patients with failed TEP was performed (n = 37). Only those patients without any documented anatomic cause for failure (n = 22) were then further reviewed to determine if empiric treatment for reflux improved voicing. Evidence of reflux was determined by either using video flexible scope of the neopharynx, barium swallows, 24-hour pH probes, and /or transnasal esophagoscopy (TNE). In 13 of 22 patients who had voicing difficulties and no evidence of reflux on these tests, empiric treatment with antireflux medications had been documented. The 22 patients were closely monitored to determine the role of reflux therapy and subsequent voicing outcomes. Results: Of the 22 patients studied, 9 were noted to have granulation tissue on the tracheal side of the prosthesis. All nine patients had complete resolution of the granulation tissue after antireflux treatment, and seven of nine were able to voice again. Of the patients with no obvious reason for TEP failure who were empirically treated for reflux, 62% (8 of 13) had TEP voice after treatment. Seventy-seven percent of our patients (17 of 22) had a positive response to treatment with aggressive reflux therapy. Conclusions: Previous studies have demonstrated patients with a total laryngectomy and/or radiation therapy have increased reflux. This study addresses reflux as a potential cause of TEP voicing problems. We noted 41% (9 of 22) of patients with voicing difficulties had granulation tissue surrounding the prosthesis as a result of reflux. Aggressive antireflux therapy proved beneficial in eradicating this problem. Prophylactic antireflux therapy may be warranted for patients undergoing TEP to reduce voicing problems. Laryngoscope, 119:121,125, 2009 [source] Viruses in soils: morphological diversity and abundance in the rhizosphereANNALS OF APPLIED BIOLOGY, Issue 1 2009M.M. Swanson Abstract Soil viruses are potentially of great importance as they may influence the ecology and evolution of soil biological communities through both an ability to transfer genes from host to host and as a potential cause of microbial mortality. Despite this importance, the area of soil virology is understudied. Here, we report the isolation and preliminary characterisation of viruses from soils in the Dundee area of Scotland. Different virus morphotypes including tailed, polyhedral (spherical), rod shaped, filamentous and bacilliform particles were detected in the soil samples. An apparent predominance of small spherical and filamentous bacteriophages was observed, whereas tailed bacteriophages were significantly less abundant. In this report, we also present observations and characterisation of viruses from different soil functional domains surrounding wheat roots: rhizosheath, rhizosphere and bulk soil. In spite of the differences in abundance of bacterial communities in these domains, no significant variations in viral population structure in terms of morphology and abundance were found. Typically, there were approximately 1.1,1.2 × 109 virions g,1 dry weight, implicating remarkable differences in virus-to-bacteria ratios in domains close to roots, rhizosphere and rhizosheath (approximately 0.27) and in bulk soil (approximately 4.68). [source] Development of a Highly Productive and Scalable Plasmid DNA Production PlatformBIOTECHNOLOGY PROGRESS, Issue 5 2006K. Listner With the applications of DNA vaccines extending from infectious diseases to cancer, achieving the most efficient, reproducible, robust, scalable, and economical production of clinical grade plasmid DNA is paramount to the medical and commercial success of this novel vaccination paradigm. A first generation production process based on the cultivation of Escherichia coli in a chemically defined medium, employing a fed-batch strategy, delivered reasonable volumetric productivities (500,750 mg/L) and proved to perform very well across a wide range of E. coli constructs upon scale-up at industrial scale. However, the presence of monosodium glutamate (MSG) in the formulation of the cultivation and feed solution was found to be a potential cause of process variability. The development of a second generation process, based on a defined cultivation medium and feed solution excluding MSG, was undertaken. Optimization studies, employing a plasmid coding for the HIV gag protein, resulted in cultivation conditions that supported volumetric plasmid titers in excess of 1.2 g/L, while achieving specific yields ranging from 25 to 32 ,g plasmid DNA/mg of dry cell weight. When used for the production of clinical supplies, this novel process demonstrated applicability to two other constructs upon scale-up in 2,000-L bioreactors. This second generation process proved to be scalable, robust, and highly productive. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||