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Vicious Cycle (vicious + cycle)
Selected AbstractsEvidence for a vicious cycle of exercise and hypoglycemia in type 1 diabetes mellitusDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2004A. C. Ertl Abstract Exercise is a cornerstone of diabetes management as it aids in glycemic control, weight management, reducing blood pressure, and improving the quality of life of patients. Unfortunately, owing to the complexity and difficulties of regulating exogenous insulin in a physiologic manner during exercise, physical activity often results in hypoglycemia in patients with type 1 diabetes mellitus (type 1 DM). When glucose levels fall below threshold glycemic levels, neuroendocrine, autonomic nervous system (ANS), and metabolic glucose counterregulatory mechanisms are activated. These hypoglycemic counterregulatory mechanisms in type 1 DM can be blunted irreversibly by disease duration or by acute episodes of prior stress. These reduced (or absent) counterregulatory responses result in a threefold increase in severe hypoglycemia when intensive glycemic control is implemented in type 1 DM 1. Much recent work has been focused on determining the in vivo mechanisms responsible for causing the increased incidence of severe hypoglycemia in type 1 DM. Studies from several laboratories have demonstrated the role played by episodes of antecedent hypoglycemia in producing blunted glucose counterregulatory responses during subsequent exposures of hypoglycemia. Until recently, the mechanisms responsible for exercise related hypoglycemia in type 1 DM have been attributed to relative or absolute increases of insulin levels or incomplete glycogen repletion after physical activity. Owing to the qualitative similarity of neuroendocrine, ANS, and metabolic responses to hypoglycemia and exercise, we have hypothesized that neuroendocrine and ANS counterregulatory dysfunction may also play an important role in the pathogenesis of exercise-related hypoglycemia in type 1 DM. Vicious cycles can be created in type 1 DM, where an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and ANS responses to a subsequent episode of either stress, thereby creating further hypoglycemia (Figure 1). This article will review the recent work that has studied the contribution of counterregulatory dysfunction to exercise-induced hypoglycemia in type 1 DM. Copyright © 2004 John Wiley & Sons, Ltd. 1. Reciprocal vicious cycles may be created in type 1 diabetes mellitus (type 1 DM), whereby an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and autonomic nervous system responses to a subsequent episode of either stress, thereby creating further hypoglycemia [source] Incontinence in the aged: contact dermatitis and other cutaneous consequencesCONTACT DERMATITIS, Issue 4 2007Miranda A. Farage Urinary and faecal incontinence affects a significant portion of the elderly population. The increase in the incidence of incontinence is not only dependent on age but also on the onset of concomitant ageing issues such as infection, polypharmacy, and decreased cognitive function. If incontinence is left untreated, a host of dermatological complications can occur, including incontinence dermatitis, dermatological infections, intertrigo, vulvar folliculitis, and pruritus ani. The presence of chronic incontinence can produce a vicious cycle of skin damage and inflammation because of the loss of cutaneous integrity. Minimizing skin damage caused by incontinence is dependent on successful control of excess hydration, maintenance of proper pH, minimization of interaction between urine and faeces, and prevention of secondary infection. Even though incontinence is common in the aged, it is not an inevitable consequence of ageing but a disorder that can and should be treated. Appropriate clinical management of incontinence can help seniors continue to lead vital active lives as well as avoid the cutaneous sequelae of incontinence. [source] Evidence for a vicious cycle of exercise and hypoglycemia in type 1 diabetes mellitusDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2004A. C. Ertl Abstract Exercise is a cornerstone of diabetes management as it aids in glycemic control, weight management, reducing blood pressure, and improving the quality of life of patients. Unfortunately, owing to the complexity and difficulties of regulating exogenous insulin in a physiologic manner during exercise, physical activity often results in hypoglycemia in patients with type 1 diabetes mellitus (type 1 DM). When glucose levels fall below threshold glycemic levels, neuroendocrine, autonomic nervous system (ANS), and metabolic glucose counterregulatory mechanisms are activated. These hypoglycemic counterregulatory mechanisms in type 1 DM can be blunted irreversibly by disease duration or by acute episodes of prior stress. These reduced (or absent) counterregulatory responses result in a threefold increase in severe hypoglycemia when intensive glycemic control is implemented in type 1 DM 1. Much recent work has been focused on determining the in vivo mechanisms responsible for causing the increased incidence of severe hypoglycemia in type 1 DM. Studies from several laboratories have demonstrated the role played by episodes of antecedent hypoglycemia in producing blunted glucose counterregulatory responses during subsequent exposures of hypoglycemia. Until recently, the mechanisms responsible for exercise related hypoglycemia in type 1 DM have been attributed to relative or absolute increases of insulin levels or incomplete glycogen repletion after physical activity. Owing to the qualitative similarity of neuroendocrine, ANS, and metabolic responses to hypoglycemia and exercise, we have hypothesized that neuroendocrine and ANS counterregulatory dysfunction may also play an important role in the pathogenesis of exercise-related hypoglycemia in type 1 DM. Vicious cycles can be created in type 1 DM, where an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and ANS responses to a subsequent episode of either stress, thereby creating further hypoglycemia (Figure 1). This article will review the recent work that has studied the contribution of counterregulatory dysfunction to exercise-induced hypoglycemia in type 1 DM. Copyright © 2004 John Wiley & Sons, Ltd. 1. Reciprocal vicious cycles may be created in type 1 diabetes mellitus (type 1 DM), whereby an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and autonomic nervous system responses to a subsequent episode of either stress, thereby creating further hypoglycemia [source] Pathological gambling: an increasing public health problemACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2001Article first published online: 7 JUL 200 Gambling has always existed, but only recently has it taken on the endlessly variable and accessible forms we know today. Gambling takes place when something valuable , usually money , is staked on the outcome of an event that is entirely unpredictable. It was only two decades ago that pathological gambling was formally recognized as a mental disorder, when it was included in the DSM-III in 1980. For most people, gambling is a relaxing activity with no negative consequences. For others, however, gambling becomes excessive. Pathological gambling is a disorder that manifests itself through the irrepressible urge to wager money. This disorder ultimately dominates the gambler's life, and has a multitude of negative consequences for both the gambler and the people they interact with, i.e. friends, family members, employers. In many ways, gambling might seem a harmless activity. In fact, it is not the act of gambling itself that is harmful, but the vicious cycle that can begin when a gambler wagers money they cannot afford to lose, and then continues to gamble in order to recuperate their losses. The gambler's ,tragic flaw' of logic lies in their failure to understand that gambling is governed solely by random, chance events. Gamblers fail to recognize this and continue to gamble, attempting to control outcomes by concocting strategies to ,beat the game'. Most, if not all, gamblers try in some way to predict the outcome of a game when they are gambling. A detailed analysis of gamblers' selfverbalizations reveals that most of them behave as though the outcome of the game relied on their personal ,skills'. From the gambler's perspective, skill can influence chance , but in reality, the random nature of chance events is the only determinant of the outcome of the game. The gambler, however, either ignores or simply denies this fundamental rule (1). Experts agree that the social costs of pathological gambling are enormous. Changes in gaming legislation have led to a substantial expansion of gambling opportunities in most industrialized countries around the world, mainly in Europe, America and Australia. Figures for the United States' leisure economy in 1996 show gross gambling revenues of $47.6 billion, which was greater than the combined revenue of $40.8 billion from film box offices, recorded music, cruise ships, spectator sports and live entertainment (2). Several factors appear to be motivating this growth: the desire of governments to identify new sources of revenue without invoking new or higher taxes; tourism entrepreneurs developing new destinations for entertainment and leisure; and the rise of new technologies and forms of gambling (3). As a consequence, prevalence studies have shown increased gambling rates among adults. It is currently estimated that 1,2% of the adult population gambles excessively (4, 5). Given that the prevalence of gambling is related to the accessibility of gambling activities, and that new forms of gambling are constantly being legalized throughout most western countries, this figure is expected to rise. Consequently, physicians and mental health professionals will need to know more about the diagnosis and treatment of pathological gamblers. This disorder may be under-diagnosed because, clinically, pathological gamblers usually seek help for the problems associated with gambling such as depression, anxiety or substance abuse, rather than for the excessive gambling itself. This issue of Acta Psychiatrica Scandinavica includes the first national survey of problem gambling completed in Sweden, conducted by Volberg et al. (6). This paper is based on a large sample (N=9917) with an impressively high response rate (89%). Two instruments were used to assess gambling activities: the South Oaks Gambling Screen-Revised (SOGS-R) and an instrument derived from the DSM-IV criteria for pathological gambling. Current (1 year) and lifetime prevalence rates were collected. Results show that 0.6% of the respondents were classified as probable pathological gamblers, and 1.4% as problem gamblers. These data reveal that the prevalence of pathological gamblers in Sweden is significantly less than what has been observed in many western countries. The authors have pooled the rates of problem (1.4%) and probable pathological gamblers (0.6%), to provide a total of 2.0% for the current prevalence. This 2% should be interpreted with caution, however, as we do not have information on the long-term evolution of these subgroups of gamblers; for example, we do not know how many of each subgroup will become pathological gamblers, and how many will decrease their gambling or stop gambling altogether. Until this information is known, it would be preferable to keep in mind that only 0.6% of the Swedish population has been identified as pathological gamblers. In addition, recent studies show that the SOGS-R may be producing inflated estimates of pathological gambling (7). Thus, future research in this area might benefit from the use of an instrument based on DSM criteria for pathological gambling, rather than the SOGS-R only. Finally, the authors suggest in their discussion that the lower rate of pathological gamblers obtained in Sweden compared to many other jurisdictions may be explained by the greater availability of games based on chance rather than games based on skill or a mix of skill and luck. Before accepting this interpretation, researchers will need to demonstrate that the outcomes of all games are determined by other factor than chance and randomness. Many studies have shown that the notion of randomness is the only determinant of gambling (1). Inferring that skill is an important issue in gambling may be misleading. While these are important issues to consider, the Volberg et al. survey nevertheless provides crucial information about gambling in a Scandinavian country. Gambling will be an important issue over the next few years in Sweden, and the publication of the Volberg et al. study is a landmark for the Swedish community (scientists, industry, policy makers, etc.). This paper should stimulate interesting discussions and inspire new, much-needed scientific investigations of pathological gambling. Acta Psychiatrica Scandinavica Guido Bondolfi and Robert Ladouceur Invited Guest Editors References 1.,LadouceurR & WalkerM. The cognitive approach to understanding and treating pathological gambling. In: BellackAS, HersenM, eds. Comprehensive clinical psychology. New York: Pergamon, 1998:588 , 601. 2.,ChristiansenEM. Gambling and the American economy. In: FreyJH, ed. Gambling: socioeconomic impacts and public policy. Thousand Oaks, CA: Sage, 1998:556:36 , 52. 3.,KornDA & ShafferHJ. Gambling and the health of the public: adopting a public health perspective. J Gambling Stud2000;15:289 , 365. 4.,VolbergRA. Problem gambling in the United States. J Gambling Stud1996;12:111 , 128. 5.,BondolfiG, OsiekC, FerreroF. Prevalence estimates of pathological gambling in Switzerland. Acta Psychiatr Scand2000;101:473 , 475. 6.,VolbergRA, AbbottMW, RönnbergS, MunckIM. Prev-alence and risks of pathological gambling in Sweden. Acta Psychiatr Scand2001;104:250 , 256. 7.,LadouceurR, BouchardC, RhéaumeNet al. Is the SOGS an accurate measure of pathological gambling among children, adolescents and adults?J Gambling Stud2000;16:1 , 24. [source] A vicious cycle in the oral health status of schoolchildren in a primary school in rural CambodiaINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 3 2007Emiko Koito Shidara Abstract, Objective:, To investigate the oral health status and the risk factors contributing to dental caries and gum disease of schoolchildren in Cambodia. Methods:, A cross-sectional survey was conducted in a primary school in the Puok District, Siem Reap Province of Cambodia. An oral examination and self-reported questionnaire were used to evaluate oral health status of schoolchildren, ranging in age from 6,16. Of the 512 children that were enrolled in first through sixth grade at the primary school, 332 children (62.8%) participated. Results:, Of the schoolchildren that were involved in this study, the prevalence of dental caries in permanent dentition was 53.5% and gum disease was present in 46.2%. Among the participants 80% had plaque, 68.6% suffered from tooth pain and only 44.2% of the schoolchildren owned their own toothbrush. There was an association between the schoolchildren that suffered from tooth pain and those that had dental caries (P < 0.03). Plaque was related to dental caries in permanent dentition (P < 0.003), calculus (P < 0.0001) and gum disease (P < 0.0001) and was linked to the schoolchildren who did not own a toothbrush (P < 0.03) and who suffered from tooth pain (P < 0.03). Conclusion:, The following sequence of events may result in a vicious cycle in the oral healthcare of schoolchildren in rural Cambodia: the lack of a personal toothbrush leads to plaque buildup, which may increase the incidence of dental caries, which has been linked to tooth pain and gum disease. Ultimately, this poor oral healthcare impacts an individual's quality of life and can lead to more serious health issues later in life. [source] The cognitive-behavioral model of bulimia nervosa: A direct evaluationINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 1 2002Susan M. Byrne Abstract Objective This study represented the first attempt to directly evaluate Fairburn et al's (1986) cognitive-behavioral model of bulimia nervosa , the model on which the most widely used treatment for bulimia nervosa is based. Method The major predictions of the model were tested using structural equation modeling. Data were collected from the responses of 526 subjects to a number of self-report measures. Results The factors of self-esteem, overconcern with weight and shape, and dietary restraint accounted for a large proportion of the variance in binge eating and purging. The key pathway in the model was the link between overconcern with weight and shape and the adoption of purgative behaviors, which then fed into a vicious cycle of binge eating and purging. Contrary to Fairburn's hypothesis, high levels of dietary restraint did not predict increased binge eating. Discussion The results suggest that the components of Fairburn's model may operate to maintain the bulimic cycle in a slightly different way to that originally proposed. © 2002 by John Wiley & Sons, Inc. Int J Eat Disord 31: 17,31, 2002. [source] Relationship between cribra orbitalia and enamel hypoplasia in the early medieval Slavic population at Borovce, SlovakiaINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2008Z. Obertová Abstract Cribra orbitalia and enamel hypoplasia were examined in an early medieval (8th to beginning of 12th century AD) skeletal sample of 451 individuals from Borovce, Slovakia. More than 40% of these individuals died before reaching 20 years of age. The relationship between the occurrence of orbital and enamel lesions was analysed by focusing on the age-specific distribution, and on its influence on demographic parameters. Both features were found in 11.2% of the observed skulls. The presence of orbital and dental lesions showed a considerable impact on mortality as well as the life expectancy. Generally, the highest mortality was observed among 0,4 year old individuals. The greatest discrepancy in the demographic parameters, however, appeared between the affected and unaffected individuals aged 10,14 and 15,19 years. In these two age groups the co-occurrence of both lesions was most frequently recorded. These individuals obviously had a history of sickness, and thus could not cope with further bouts of disease and with the increased physiological demands of pubertal growth. The missing correlation in younger age categories can be largely explained by the difficulty of macroscopically examining the permanent dentition, since an interrelationship between the age at hypoplasia development and the occurrence of cribra orbitalia was detected. Several differences between the individuals with enamel defects and both conditions were observed in the distribution of age at hypoplasia formation. According to these results, several factors, such as impaired health status, growth demands and diet, influence the development of enamel hypoplasia and cribra orbitalia in a particular population. It is possible that after reaching a certain threshold, the underlying factors act synergistically in a kind of vicious cycle as the balance between the immune system, metabolism, and exogenous factors such as pathogens and nutrition, is disturbed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Nurse absenteeism and workload: negative effect on restraint use, incident reports and mortalityJOURNAL OF ADVANCED NURSING, Issue 6 2007Lynn Unruh Abstract Title.,Nurse absenteeism and workload: negative effect on restraint use, incident reports and mortality Aim., This paper is a report of a study to assess the impact of nurse absenteeism on the quality of patient care. Background., Nurse absenteeism is a growing management concern. It can contribute to understaffed units, staffing instability, and other factors that could have a negative impact on patient care. The impacts of absenteeism on the quality of nursing care have rarely been studied. Method., Retrospective monthly data from incident reports and staffing records in six inpatient units for 2004 were analysed. Dependent variables were the numbers of restraints, alternatives to restraints, incident reports, deaths, and length of stay. Explanatory variables were nurse absenteeism hours, patient days per nursing staff, and interaction between these variables. Controls were patient acuity and unit characteristics. Fixed effects regressions were analysed as regular or negative binomial models. Findings., Neither high Registered Nurse absenteeism nor high patient load was related to restraint use when taken separately. However, high Registered Nurse absenteeism was related to restraint use when patient load was high. Registered Nurse absenteeism was related to a lower use of alternatives to restraints. Incident reports were increased by high patient load, but not absenteeism, or absenteeism given patient load. When both patient load and absenteeism were high, deaths were higher also. Conclusion., Absenteeism alone may not be a strong factor in lowering quality, but the combination of high Registered Nurse absenteeism and high patient load could be a factor. Staffing and absenteeism may be part of a vicious cycle in which low staffing contributes to unit absenteeism, which contributes to low staffing, and so on. [source] A paradigm for the treatment of prostate cancer bone metastases based on an understanding of tumor cell,microenvironment interactionsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2005Robert D. Loberg Abstract The pliability of cancer cells to mutate into several different phenotypes in an attempt to find one that will survive and colonize at the metastatic site is a tremendous "hurdle" to overcome in designing novel cancer therapeutics. New targets of therapy are essential if we are to effectively overcome the evasiveness of cancer. The interaction between the tumor cell and the surrounding microenvironment creates a vicious cycle that perpetuates disease survival and progression. The future of cancer therapy resides in the ability to focus on the recruited and exploited relationships of the cancer cell with the host environment. These therapies target cancer cell growth early and interrupt the vicious cycle that is created by the tumor cells interacting with bone components by inhibiting osteoclasts, osteoblasts, stromal cells, and endothelial cells. They alter the bone microenvironment, creating a hostile "soil" that prevents the "seed" from developing into bone metastases and represent a potential new platform for the development of prostate cancer therapeutics. © 2005 Wiley-Liss, Inc. [source] Sleep disturbance experiences among perimenopausal women in TaiwanJOURNAL OF CLINICAL NURSING, Issue 15 2009Hsiu-Chin Hsu Aim., To generate a descriptive theory framework regarding the experiences of sleep disturbances among perimenopausal women in Taiwan. Background., Although studies show that some perimenopausal women are troubled by sleep problems, little information was found about the subjective experiences of sleep disturbances among these women. Research is required to explore women's feelings or perceptions in dealing with their sleep problems. These understandings will be important to help alleviate perimenopausal women's sleep problems. Design., A grounded theory research design was applied. Method., Twenty-one Taiwanese sleep disturbed women, aged 46,57 years, participated in in-depth interviews. Results., ,Getting back a good night's sleep' was the core theme for describing and guiding the process of the women's sleep disturbance experiences. During the process, ,disturbed sleep' was identified as the antecedent condition that included subcategories: easy awakening, difficulty falling asleep, inner worries, physical discomfort and genetic and bodily constitution. Analyses showed five categories (some with subcategories) of the sleep disturbed women: (i) worsening health status , physical exhaustion, impaired social interactions, emotional swings and decreased work performance; (ii) living with lonely nights , self-help and endurance; (iii) a search for resources to relieve sleep difficulties , doctor shopping, trying alternative therapies, exercising and seeking support; (iv) vicious cycle and (v) acceptance of insomnia. Conclusions., Women expected to relieve their sleep disturbance by finding comprehensive counselling or by their body constitution responding to treatment. Healthcare providers need to value women's individual concerns and subjective voices. Providers must seek out sleep counselling instead of simply prescribing drugs for their sleep difficulties. Relevance to clinical practice., It is crucial to integrate perimenopausal sleep care by implementing a multidimensional approach such as sleep assessment laboratories, sleep counselling, complementary alternative medicine, sleep strategies and support groups. [source] From bench to bedside , translational research in psoriasisJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2010JC Prinz Abstract For many years, psoriasis was firmly believed to be a disease of epidermal keratinocytes, but now is attributed to a combination of genetic and environmental factors that promote a T-cell mediated immune response in the skin. Psoriasis is now understood to be a systemic T-cell mediated autoimmune disease with the innate immune system playing an important role. Progress in understanding the pathogenesis of psoriasis has shown that following a stimulus, dendritic and T cell activation leads to the release of cytokines, chemokines and growth factors that initiate the proliferation and altered differentiation of keratinocytes. These factors subsequently lead to continuous activation of T cells and antigen-presenting cells, particularly dendritic cells, within the psoriatic plaque. This vicious cycle of psoriasis, in which the cytokines interleukin 12 (IL-12) and IL-23 play a pivotal role, is a logical target for biological therapy. [source] A qualitative study examining tensions in interdoctor telephone consultationsMEDICAL EDUCATION, Issue 8 2006Anupma Wadhwa Objective, Communication skills have gained increasing attention in medical education. Much of the existing literature and medical curricula addresses issues of doctor,patient communication. The critical importance of communication between health professionals, however, is now coming under the spotlight. The interdoctor telephone consultation is a common health care setting in which health professional communication skills are exercised. Breakdowns in this communication commonly occur and, surprisingly, this skill is not formally addressed in medical training. This study sought to clarify the communication issues that can occur during interdoctor telephone consultations in order to inform future educational initiatives in this domain. Methods, Data were collected and triangulated among 3 sources: documentation of 129 telephone consults received; 51 hours of field observations of consultants, and semi-structured interviews of 12 callers and 12 consultants. Analysis was performed using grounded theory methodology. Results, Overwhelmingly, participants described tensions with telephone consultation communication. Recurrent theme analysis revealed 5 key sources of tension: discursive features; context; fragmented clinical process; reason for call, and responsibility. Often, callers and consultants viewed similar instances in different and opposite manners, contributing to difficulties in the exchange. Further, a vicious cycle in which a participant's strategies to mitigate tension actually increased tension for the other participant was identified. Conclusions, Interdoctor telephone consultation has become an integral part of medical practice; however, tensions within this exchange can undermine its effectiveness. The results of this study provide a preliminary theory upon which an educational intervention to improve this communication skill can be based. [source] Public engagement in California: Escaping the vicious cycleNATIONAL CIVIC REVIEW, Issue 3 2006Daniel Yankelovich First page of article [source] Sleep disorders and gastrointestinal symptoms: chicken, egg or vicious cycle?NEUROGASTROENTEROLOGY & MOTILITY, Issue 2 2009M. Maneerattanaporn No abstract is available for this article. [source] Bronchial hyperresponsiveness, atopy, and bronchoalveolar lavage eosinophils in persistent middle lobe syndromePEDIATRIC PULMONOLOGY, Issue 9 2006Kostas N. Priftis MD Abstract Most cases of middle lobe syndrome (MLS) in children are considered to be due to asthma and may recover spontaneously; however, in persistent MLS, repeated episodes of infection often institute a vicious cycle that may lead to persistent symptoms and bronchial hyperresponsiveness (BHR). The present study was undertaken to investigate whether asthma, as an underlying diagnosis, is predictive of a favorable outcome of children with persistent MLS. We evaluated 53 children with MLS who underwent an aggressive management protocol that included fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL). These patients were compared to two other groups: one consisting of children with current asthma but no evidence of MLS (N,=,40) and another of non-asthmatic controls (N,=,42), matched for age and sex. Prevalence of sensitization (,1 aeroallergen) did not differ between patients with MLS and "non-asthmatics" but was significantly lower than that of "current asthmatics." A positive response to methacholine bronchial challenge was observed with increased frequency among children with MLS when compared to "current asthmatic" and non-asthmatic children. Multivariate logistic regression analysis revealed a positive correlation between an increased number of eosinophils in the BAL fluid (BALF) and a favorable outcome, whereas no correlation was detected between sensitization or BHR and BAL cellular components. In conclusion, children with MLS have an increased prevalence of BHR, even when compared to asthmatics, but exhibit prevalence of atopy similar to that of non-asthmatics. An increased eosinophilic BALF count is predictive of symptomatic but not radiographic improvement of MLS patients after aggressive anti-asthma management. Pediatr Pulmonol. © 2006 Wiley-Liss, Inc. [source] Asthma management: Reinventing the wheel in sickle cell disease,AMERICAN JOURNAL OF HEMATOLOGY, Issue 4 2009Claudia R. Morris Asthma is a common comorbidity in sickle cell disease (SCD) with a reported prevalence of 30,70%. The high frequency of asthma in this population cannot be attributed to genetic predisposition alone, and likely reflects in part, the contribution of overlapping mechanisms shared between these otherwise distinct disorders. There is accumulating evidence that dysregulated arginine metabolism and in particular, elevated arginase activity contributes to pulmonary complications in SCD. Derangements of arginine metabolism are also emerging as newly appreciated mechanism in both asthma and pulmonary hypertension independent of SCD. Patients with SCD may potentially be at risk for an asthma-like condition triggered or worsened by hemolysis-driven release of erythrocyte arginase and low nitric oxide bioavailability, in addition to classic familial asthma. Mechanisms that contributed to asthma are complex and multifactorial, influenced by genetic polymorphisms as well as environmental and infectious triggers. Given the association of asthma with inflammation, oxidative stress and hypoxemia, factors known to contribute to a vasculopathy in SCD, and the consequences of these factors on sickle erythrocytes, comorbid asthma would likely contribute to a vicious cycle of sickling and subsequent complications of SCD. Indeed a growing body of evidence documents what should come as no surprise: Asthma in SCD is associated with acute chest syndrome, stroke, pulmonary hypertension, and early mortality, and should therefore be aggressively managed based on established National Institutes of Health Guidelines for asthma management. Barriers to appropriate asthma management in SCD are discussed as well as strategies to overcome these obstacles in order to provide optimal care. Am. J. Hematol., 2009. © 2008 Wiley-Liss, Inc. [source] Critical management in patients with severe enterovirus 71 infectionPEDIATRICS INTERNATIONAL, Issue 3 2006JIEH-NENG WANG Abstract Objective: The aim of this study was to analyze clinical details occurring in children with severe enterovirus 71 (EV71) infection and synthesize the critical care experience for patients with severe EV71 infection. Methods: A retrospective clinical, laboratory, and hemodynamic study was performed in a pediatric intensive care unit in a university hospital. From March 1998 to April 2000, seven consecutive pediatric patients with severe EV71 infection were retrospectively analyzed as the comparison group. From May 2000 to March 2003, eight consecutive patients with severe EV71 infection who had received the protocol therapy were enrolled as the study group. Detailed information about clinical treatment and pharmacological therapy was collected for comparison. Results: The clinical presentations and laboratory findings between the comparison and the study groups were not significantly different. The amount of intravenous fluid in the first 24 h was significantly higher in the comparison group (9.2 ± 5.0 vs 4.9 ± 1.3 mL/kg per h). More patients in the study group received low doses of dopamine infusion, patients in the comparison group received more epinephrine, and none of them received milrinone. The acute-stage and long-term survival rates were higher in the study group (100% vs 43%, 87% vs 29%). Conclusion: Early cardiopulmonary support may prevent the vicious cycle of cardiopulmonary failure and improve the clinical outcome of severe EV71 infection. Milrinone may be the ideal inotropic agent for these patients. Echocardiography, a central line, and an arterial line could be an alternate method to replace direct intracardiac hemodynamic monitoring for guiding critical management. [source] Conservation ecology of Primula sieboldii: Synthesis of information toward the prediction of the genetic/demographic fate of a populationPLANT SPECIES BIOLOGY, Issue 1 2005IZUMI WASHITANI Abstract In an age of deepening biodiversity crisis, plant species biological studies integrating ecological and genetic approaches, especially exhaustive studies with a model plant species, are urgently needed for both assessing the present status and implementing effective conservation measures, as a comprehensive understanding of demographic/genetic interactions involved in the vicious cycle of plant population extinction is a prerequisite for any precise prediction regarding plant conservation. In this article, we summarize the major contributions to conservation ecological studies on a heterostylous clonal herb Primula sieboldii, focusing on gene flow and reproductive success, which are dependent on the life-history traits of the species and biological interactions with its effective pollinators, long-tongued bumblebees. [source] Latin America and the Social Contract: Patterns of Social Spending and TaxationPOPULATION AND DEVELOPMENT REVIEW, Issue 4 2009Karla Breceda This article analyzes the incidence of social spending and taxation by income quintile for seven Latin American countries, the United Kingdom, and the United States. Absolute levels of social spending in Latin America are fairly flat across income quintiles, a pattern similar to that in the United States and differing from the more progressive pattern of spending in the United Kingdom. The structure of taxation in Latin America is also similar to that of the United States. Because of high income inequality in Latin America and the US, the rich bear of most the burden, whereas the United Kingdom taxes the middle class to a greater extent. The analysis suggests that many Latin American countries are trapped in a vicious cycle in which the rich resist the expansion of the welfare state (because they bear most of its tax burden without receiving commensurate benefits), and their opposition to its expansion in turn maintains long-term inequalities. [source] The impact of branding on low-income adolescents: A vicious cycle?PSYCHOLOGY & MARKETING, Issue 11 2008Katja Jezkova Isaksen This study examines the impact of consumerism and consumer culture on low-income British adolescents. Specifically, it investigates the effects of branding and advertising on the formation of selfconcept clarity (SCC) and consumer susceptibility to interpersonal influence (CSII). A comparative study was conducted between two groups, low- and high-income teenagers, assessing SCC and CSII by means of quantitative scales. It was found that low-income teenagers are less clear in their self-concept and are more susceptible to interpersonal influence than their high-income counterparts. A significant negative correlation between the two scales revealed that the less clear one's self-concept is, the more susceptible one is to interpersonal influence. It is proposed that an inability to "keep up" with the latest fashion trends (due to restricted consumption opportunities) may result in a damaged self-concept among low-income teenagers, which leads to heightened susceptibility to consumption pressures and hence heightens the negative socio-psychological impacts of living in poverty. The results of the study are reviewed in terms of branding, advertising, and consumer behavior and a proposed conceptual model of branding's impact on low-income teenagers is presented as a "vicious cycle." © 2008 Wiley Periodicals, Inc. [source] Regulation and Role of the Presynaptic and Myocardial Na+/H+ Exchanger NHE1: Effects on the Sympathetic Nervous System in Heart FailureCARDIOVASCULAR THERAPEUTICS, Issue 2 2007Kirsten Leineweber ABSTRACT In acute myocardial ischemia and in chronic heart failure, sympathetic activation with excessive norepinephrine (NE) release from and reduced NE reuptake into sympathetic nerve endings is a prominent cause of arrhythmias and cardiac dysfunction. The Na+/H+ exchanger NHE1 is the predominant isoform in the heart. It contributes to cellular acid,base balance, and electrolyte, and volume homeostasis, and is activated in response to intracellular acidosis and/or activation of guanine nucleotide binding (G) protein-coupled receptors. NHE1 mediates its signaling via protein kinases A (PKA) or C (PKC). In cardiomyocytes, NHE1 is restricted to specialized membrane domains, where it regulates the activity of pH-sensitive proteins and modulates the driving force of the Na+/Ca2+ exchanger. During acute ischemia/reperfusion and in heart failure the activity/amount of NHE1 is increased, leading to intracellular Ca2+ overload and promoting structural (apoptosis, hypertrophy) and functional (arrhythmias, hypercontraction) myocardial damage. In sympathetic nerve endings, increased NHE1 activity results in the accumulation of axoplasmic Na+ that diminishes the inward and/or favors the outward transport of NE via the neuronal norepinephrine transporter (NET). The increased NE levels within the nerve,muscle junction facilitate the sustained stimulation of myocardial ,- and ,-adrenoceptors (ARs), which in turn aggravate the increases in myocardial NHE1 activity and the associated deleterious effects. Furthermore, the responsiveness of the ,-AR declines overtime, which results in further release of NE, initiating a vicious cycle. Accordingly, NHE1 is a potential candidate for targeted intervention to suppress this feedback loop. [source] Foot temperature in diabetic polyneuropathy: innocent bystander or unrecognized accomplice?DIABETIC MEDICINE, Issue 3 2005S. B. Rutkove Abstract Aim To explore mechanisms by which temperature could influence the pathogenesis and symptoms of diabetic polyneuropathy. Methods We conducted a literature review attempting to identify mechanisms by which diabetic polyneuropathy could be affected by temperature. Results Cooling can theoretically hasten the progression of diabetic polyneuropathy through several different mechanisms. Specifically, cooling can enhance neuronal ischaemia, increase formation of reactive oxygen species, slow axonal transport, increase protein kinase C activity, and interfere with immune function. Short-term temperature fluctuations (both warming and cooling) can initiate and exacerbate neuropathic pain by causing neuronal hyperexcitability and functional deafferentation. Although normal fluctuations of distal extremity temperature may be sufficient for these effects, impaired thermoregulation may make the distal extremities more susceptible to temperature extremes. Eventually, a ,vicious cycle' may ensue, resulting in neuronal deterioration with further disruption of temperature regulation. Limited epidemiological data suggest a higher prevalence of diabetic polyneuropathy in populations living in colder locations, supporting our hypothesis. Conclusions Variations in foot temperature may play an important but as yet unrecognized role in the development and symptoms of diabetic polyneuropathy. Further basic and clinical research exploring this concept could help elucidate the natural history of diabetic polyneuropathy and lead to novel therapeutic strategies. [source] Evidence for a vicious cycle of exercise and hypoglycemia in type 1 diabetes mellitusDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2004A. C. Ertl Abstract Exercise is a cornerstone of diabetes management as it aids in glycemic control, weight management, reducing blood pressure, and improving the quality of life of patients. Unfortunately, owing to the complexity and difficulties of regulating exogenous insulin in a physiologic manner during exercise, physical activity often results in hypoglycemia in patients with type 1 diabetes mellitus (type 1 DM). When glucose levels fall below threshold glycemic levels, neuroendocrine, autonomic nervous system (ANS), and metabolic glucose counterregulatory mechanisms are activated. These hypoglycemic counterregulatory mechanisms in type 1 DM can be blunted irreversibly by disease duration or by acute episodes of prior stress. These reduced (or absent) counterregulatory responses result in a threefold increase in severe hypoglycemia when intensive glycemic control is implemented in type 1 DM 1. Much recent work has been focused on determining the in vivo mechanisms responsible for causing the increased incidence of severe hypoglycemia in type 1 DM. Studies from several laboratories have demonstrated the role played by episodes of antecedent hypoglycemia in producing blunted glucose counterregulatory responses during subsequent exposures of hypoglycemia. Until recently, the mechanisms responsible for exercise related hypoglycemia in type 1 DM have been attributed to relative or absolute increases of insulin levels or incomplete glycogen repletion after physical activity. Owing to the qualitative similarity of neuroendocrine, ANS, and metabolic responses to hypoglycemia and exercise, we have hypothesized that neuroendocrine and ANS counterregulatory dysfunction may also play an important role in the pathogenesis of exercise-related hypoglycemia in type 1 DM. Vicious cycles can be created in type 1 DM, where an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and ANS responses to a subsequent episode of either stress, thereby creating further hypoglycemia (Figure 1). This article will review the recent work that has studied the contribution of counterregulatory dysfunction to exercise-induced hypoglycemia in type 1 DM. Copyright © 2004 John Wiley & Sons, Ltd. 1. Reciprocal vicious cycles may be created in type 1 diabetes mellitus (type 1 DM), whereby an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and autonomic nervous system responses to a subsequent episode of either stress, thereby creating further hypoglycemia [source] Knowledge-sharing reward dynamics in knowledge management systems: Game theory,based empirical validationHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 2 2010Xi Zhang Abstract There are several knowledge-sharing problems in knowledge-management system (KMS) contexts. Many organizations use rewards to motivate people to contribute knowledge, but there has been no conclusive evidence of the role of reward. We designed two game-theory models to explain why and how the different knowledge-sharing problems occur in a KMS and the effectiveness of rewards. We found that there are four types of Nash equilibriums in different knowledge-sharing situations (Perfect, Free-riding, Non-use, and Dormant). Complex situations also occur (e.g., the absence of consideration for knowledge quality leads to vicious cycles). People contribute low-quality knowledge that is not used, and thus the KMS spirals toward disuse. To provide proposition evidence, a case study in an enterprise resource planning vendor was conducted. Based on comparison with empirical evidence, proposition validity was ensured. To effectively facilitate knowledge sharing, our suggestion is that organizations not only add rewards but also apply some additional mechanisms, such as a quality-evaluating system, extended information technology support, and organizational policy. © 2010 Wiley Periodicals, Inc. [source] Global Transformations and New ConflictsIDS BULLETIN, Issue 2 2001Mary Kaldor Summaries The central argument of this article is that a central feature of post-Cold War conflicts has been the delegitimisation of public authority, interacting with globalisation, through a process which is almost the reverse of state and nation-building. The political economy of the ,new wars' involves a mix of state and non-state, national and international violence. It creates vicious cycles, reinforcing the decline in the formal sector, breaking down the distinction between public and private spheres, and mobilising identity cleavages through strategies of fear and hate directed against civilians. These vicious cycles can only be broken by peace strategies, whose centrepiece, over the longer run, is the restoration of legitimate authority and the democratisation of politics. These strategies cannot, in a world in which the state has been eroded, be confined just to the state, but must also involve many other layers of political authority, from the local to the global. [source] Anarchical Governance: Neoliberal Governmentality in Resonance with the State of ExceptionINTERNATIONAL POLITICAL SOCIOLOGY, Issue 4 2009Hiroyuki Tosa Beside the promotion of a politics of inclusion, implemented by governing at a distance, the global governmentality also promotes a politics of exclusion, such as establishing targeted governance that is aimed at deviant groups at the periphery of global politics. This highly disciplinary social control that is imposed upon the marginalized population sometimes leads to instances of the state of exception, in which people are forced to endure "bare lives." This kind of exception existing at the marginalized periphery of the neoliberal global governmentality becomes normal. This neoliberal governmentality creates an informal sector of an enormous scale, whose spatial representation is the global slum, and where vicious cycles of violence become normal. [source] | ||||||||||||||||||||||||||||||||||