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At least 451 records · Page 25Linked to original sources
PubMed2001

Overexpression of the FK506-binding immunophilin FKBP51 is the common cause of glucocorticoid resistance in three New World primates.

Many New World primates have high circulating levels of cortisol to compensate for the expression of glucocorticoid receptors (GRs) with low activity. Recent work in squirrel monkeys has suggested that this may be due to either the expression of GRs that are transcriptionally incompetent or the expression of an FK506-binding immunophilin that inhibits GR binding. The goal of this study was to resolve this controversy by determining the molecular basis of glucocorticoid resistance not only in species of squirrel monkeys but also in other glucocorticoid-resistant New World primates. First, the transcriptional activity of the GR from the Bolivian squirrel monkey was compared to that of the human GR. Incubation of COS-7 cells transfected with the squirrel monkey GR with 10 nM dexamethasone resulted in a robust stimulation of MMTV-luciferase activity (up to 260-fold), which was similar in magnitude to that achieved with the human GR. Second, the effect of FK506 on GR binding was determined in cytosol from cells from two species of squirrel monkeys as well as glucocorticoid-resistant cotton-top tamarins and owl monkeys. Incubation with 10 microM FK506 increased GR binding by at least 4-fold in cytosol from cells of each of the New World primates but had no effect on GR binding in cytosol from human WI-38 VA13 cells. Third, Western blots showed elevated expression of FKBP51 in New World primate cells and liver samples from two squirrel monkey species. On the other hand, the levels of FKBP52 were significantly lower in cells and liver from New World primates. The sequences of FKBP51 from the cotton-top tamarin, owl monkey and squirrel monkey are closely related and share differences from the human, rhesus monkey, mouse, and lemur FKBP51 sequences in the same 18 positions. Fourth, the relative activities of FKBP51 from the cotton-top tamarin, owl monkey and squirrel monkey were determined in cytosol mixing and GR transactivation studies and showed that FKBP51 from each of these primates was a potent inhibitor of GR activity. These results indicate that the elevated expression of FKBP51 contributes to glucocorticoid resistance in three New World primate genera.

Amino Acid Sequence↗
PubMed1999

Phylogenetic analysis of HERV-K LTR-like elements in primates: presence in some new world monkeys and evidence of recent parallel evolution in these species and in homo sapiens.

Solitary long terminal repeats (LTRs) of the human endogenous retroviruses K family (HERV-K) have been found to be coexpressed with sequences of closely located genes. We identified forty-three HERV-K LTR-like elements in primates (African great apes, two Old World monkeys, and two New World monkeys) and analyzed them along with human-specific HERV-K LTRs. We report detection of HERV-K LTR-like elements from New World monkeys, as represented by the squirrel monkey and the night monkey, for the first time. Analysis revealed a high degree of sequence homology with human-specific HERV-K LTRs. A phylogenetic tree obtained by the neighbor-joining method revealed that five sequence (SMS-1, 2, 5, 6, 7) from the squirrel monkey and three sequences (NM6-4, 5, 9) from the night monkey are more closely related to human-specific HERV-K LTRs than they are to those of apes (the chimpanzee and gorilla) and Old World monkeys (the African green monkey and rhesus monkey). The findings are consistent with the concept the HERV-K LTR-like elements have proliferated independently and recently in the genome of primates, and that such proliferation has been more recent in Homo sapiens and in these representatives of New World monkeys than in some Old World monkeys.

Animals↗
PubMed2004

Coronary artery disease in the developing world.

BACKGROUND: Coronary artery disease (CAD) is the leading cause of cardiovascular mortality worldwide, with >4.5 million deaths occurring in the developing world. Despite a recent decline in developed countries, both CAD mortality and the prevalence of CAD risk factors continue to rise rapidly in developing countries. The objectives of the current article are to review (1) the literature regarding CAD mortality and the prevalence of CAD risk factors in the developing world, and (2) prevention and control measures. METHODS: We conducted a MEDLINE search of the English language literature for the years 1990 to 2002 to identify articles pertaining to the prevalence of CAD in developing countries. The search was performed using the following key terms: coronary artery disease, developing countries, ischemic heart disease, incidence, prevalence, prevention and risk factors. We also obtained relevant statistical information from The World Health Organization's Internet database. RESULTS: There is a paucity of data regarding CAD and its prevalence in the developing world. However, it is projected that CAD mortality rates will double from 1990 to 2020, with approximately 82% of the increase attributable to the developing world. Existing data suggest that rapid socioeconomic growth in developing countries is increasing exposure to risk factors for CAD, such as diabetes, genetic factors, hypercholesterolemia, hypertension, and smoking. There is a relative lack of prevention and control measures to decrease exposure to these risk factors in developing countries. CONCLUSION: Documented information on the prevalence of CAD in developing countries is sparse, but there is sufficient data to suggest an impending epidemic. Prevention and targeted control of risk factors for CAD could potentially reduce the impact of CAD in the developing world as it has in industrialized nations.

Coronary Artery Disease↗
PubMed1997

Biosystematics of Old World Triatominae.

Morphometric analysis of Old World species of Linshcosteus and Triatoma showed the two genera to be well separated. However, although the analysis showed clear distinction between the five species of Linshcosteus, there was considerable overlap between the eight Old World species of Triatoma, including specimens of T. rubrofasciata from Old and New World populations. The results are interpreted as supporting the idea of a New World origin for the Old World species of Triatoma, with an independent Old World origin for Linshcosteus.

Africa↗
PubMed2003

Position of the American Dietetic Association: Addressing world hunger, malnutrition, and food insecurity.

It is the position of the American Dietetic Association (ADA) that access to adequate amounts of safe, nutritious, and culturally appropriate food at all times is a fundamental human right. Hunger continues to be a worldwide problem of staggering proportions. The Association supports programs and encourages practices that combat hunger and malnutrition, produce food security, promote self-sufficiency, and are environmentally and economically sustainable. The Association is aware that hunger exists in a world of plenty and that poverty, gender inequity, ethnocentrism, racism, and the lack of political will are key constraints to solving the problems of global hunger and malnutrition. Recognizing that simplistic approaches are inadequate, the ADA identifies sustainable development as the long-term strategy to ending world hunger and achieving food security. Sustainable development requires political, economic, and social changes that include empowering the disenfranchised, widening access to assets and other resources, narrowing the gap between rich and poor, and adjusting consumption patterns so as to foster good stewardship of nature. Additionally, because the health status of future generations is related to the well-being of their mothers, achieving food security will also require increased access for women to education, adequate health care and sanitation, and economic opportunities. This position paper reviews the complex issues of global food insecurity and discusses long-term solutions for achieving world food security. Achieving the end of world hunger has been and is now within our grasp. There is sufficient food to feed everyone, and solutions can be realized now that will benefit all of humanity. As noted in the paper, most people who examine the costs of ending versus not ending world hunger are bewildered by the question of why humanity did not solve the problem a long time ago. The Association supports programs and encourages practices that combat hunger and malnutrition, produce food security, promote self-sufficiency, respect local cultures, and are environmentally and economically sustainable. The ADA recognizes that decisions and actions that dietetics professionals make as practitioners and consumers can help reduce the extent of poverty and hunger both here and abroad. This paper provides information, resources, and strategies to assist dietetics professionals in improving the public's understanding of key issues, becoming advocates of the poor, and influencing the political will to end world hunger.

Agriculture↗
PubMed2000

The use of micro-worlds for human factors research in extended spaceflight.

This article provides an analysis of the utility of micro-worlds for human factors research in extended spaceflight. It outlines potential areas of application of the micro-world research paradigm in the context of spaceflight. While the research literature provides several examples of micro-worlds that simulate different work environments of high complexity, little work has been done with this tool in the operational environment of spaceflight. The author presents a micro-world, called CAMS, that has been especially developed for use in space-related research. The results from a research programme (comprising seven studies using CAMS) are presented. Based on a comparative analysis of the benefits and limitations of micro-worlds compared to other simulation types, the author argues that micro-worlds can be a very effective tool, provided their inherent limitations are taken into consideration.

Astronauts↗
PubMed2003

Mathematical formulation of Leibnizian world: a theory of individual-whole or interior-exterior reflective systems.

A world model, suggested by Leibniz's monadology, is formulated as a mathematical axiomatic system. The purpose of this world model is to provide a general scheme for describing a system of individuals having consciousness or internal worlds that communicate with each other and make a unified whole world, and moreover, the latter is reflected into the respective internal worlds and appears as an external world. Examples of such monadological structure of interior-exterior (or individual-whole) reflection can be observed in bio- or socio-systems and recently in computer networks. Moreover, a most elemental version of this structure can be found in the basic level of quantum physics. The model not only gives a prototype of monadological systems but also has an evolutionary ability to produce a hierarchy of monadological systems, which are interpreted as corresponding to various levels of consciousness.

Mathematics↗
PubMed2003

Helicobacter in the developing world.

Helicobacter pylori in the developing world is associated with many unique challenges not encountered in an industrialized setting. The 20% prevalence of infection with H. pylori among adolescents in the United States pales in comparison to infection rates exceeding 90% by 5 years of age in parts of the developing world. While H. pylori within the developed world is associated with gastritis, which may lead to peptic ulcer and gastric carcinoma, the infection in the developing world appears to also be linked with chronic diarrhea, malnutrition and growth faltering as well as predisposition to other enteric infections, including typhoid fever and cholera. Once identified, treatment of H. pylori within the developing world presents increased difficulties due to the frequency of antibiotic resistance as well as the frequency of recurrence after successful treatment. Control, and possibly eradication, of H. pylori could likely be achieved through increased standards of living and improved public health, as it has in the industrialized world. However, these measures are distant objectives for most developing countries, making long-term control of the organism dependent on the development and administration of an effective vaccine.

Adult↗
PubMed1998

Small worlds and medical expertise: implications for medical cognition and knowledge engineering.

This paper proposes and defends the small worlds hypothesis, which states that expert physicians organize diagnostic knowledge on the basis of similarities between disease categories, forming 'small worlds' consisting of small subsets of diseases and their distinguishing features. Examining existing data from several previous studies, the authors provide support for the small worlds hypothesis and for a characterization of the process of expert medical diagnostic reasoning as a succession of limited comparisons involving related diagnostic hypotheses. In one study, subjects were presented clinical endocrine cases one statement at a time and were prompted to think aloud after presentation of each statement. A combination of discourse and protocol analysis techniques were used to investigate hypothesis generation and evaluation. In another study, dialogues from doctor-patient interviews were examined. It was found that expert subjects rapidly select relatively small sets of plausible diagnostic hypotheses (small worlds) and focus on the most relevant medical findings that distinguish among the diseases in such small worlds. Results from both studies indicate that expert physicians use efficient strategies for discriminating among these alternative hypotheses in a stepwise process. In contrast, non-experts often generate large numbers of possible diagnostic hypotheses, belonging to widely differing disease categories. The results provide empirical support for the theoretical basis of small worlds. The implications of these results for the study of medical expertise and knowledge engineering are discussed, as well as considerations for the development of decision support systems.

Clinical Competence↗
PubMed2003

Some consequences of the RNA world hypothesis.

It is now generally accepted that our familiar biological world was preceded by an RNA world in which ribosome-catalyzed, nucleic-acid coded protein synthesis played no part. If the RNA world was the first biological world there is little that one can learn from biochemistry about prebiotic chemistry, except that the formation and polymerization of nucleotides were once prebiotic processes. If the RNA world was not the first biological world, the above conclusion may not be justified, and one can speculate that the monomers of earlier genetic polymers might be recognizable as important biochemicals. This suggests that the construction of replicating polymers from simple, not necessarily standard, aminoacids should be explored.

Amino Acids↗
PubMed2002

Cough and bronchial responsiveness in firefighters at the World Trade Center site.

BACKGROUND: Workers from the Fire Department of New York City were exposed to a variety of inhaled materials during and after the collapse of the World Trade Center. We evaluated clinical features in a series of 332 firefighters in whom severe cough developed after exposure and the prevalence and severity of bronchial hyperreactivity in firefighters without severe cough classified according to the level of exposure. METHODS: "World Trade Center cough" was defined as a persistent cough that developed after exposure to the site and was accompanied by respiratory symptoms severe enough to require medical leave for at least four weeks. Evaluation of exposed firefighters included completion of a standard questionnaire, spirometry, airway-responsiveness testing, and chest imaging. RESULTS: In the first six months after September 11, 2001, World Trade Center cough occurred in 128 of 1636 firefighters with a high level of exposure (8 percent), 187 of 6958 with a moderate level of exposure (3 percent), and 17 of 1320 with a low level of exposure (1 percent). In addition, 95 percent had symptoms of dyspnea, 87 percent had gastroesophageal reflux disease, and 54 percent had nasal congestion. Of those tested before treatment of World Trade Center cough, 63 percent of firefighters (149 of 237) had a response to a bronchodilator and 24 percent (9 of 37) had bronchial hyperreactivity. Chest radiographs were unchanged from precollapse findings in 319 of the 332 with World Trade Center cough. Among the cohort without severe cough, bronchial hyperreactivity was present in 77 firefighters with a high level of exposure (23 percent) and 26 with a moderate level of exposure (8 percent). CONCLUSIONS: Intense, short-term exposure to materials generated during the collapse of the World Trade Center was associated with bronchial responsiveness and the development of cough. Clinical and physiological severity was related to the intensity of exposure.

Adult↗
PubMed2000

Training in virtual environments: transfer to real world tasks and equivalence to real task training.

Virtual environments (VEs) are extensively used in training but there have been few rigorous scientific investigations of whether and how skills learned in a VE are transferred to the real world. This research aimed to measure and evaluate what is transferring from training a simple sensorimotor task in a VE to real world performance. In experiment 1, real world performances after virtual training, real training and no training were compared. Virtual and real training resulted in equivalent levels of post-training performance, both of which significantly exceeded task performance without training. Experiments 2 and 3 investigated whether virtual and real trained real world performances differed in their susceptibility to cognitive and motor interfering tasks (experiment 2) and in terms of spare attentional capacity to respond to stimuli and instructions which were not directly related to the task (experiment 3). The only significant difference found was that real task performance after training in a VE was less affected by concurrently performed interference tasks than was real task performance after training on the real task. This finding is discussed in terms of the cognitive load characteristics of virtual training. Virtual training therefore resulted in equivalent or even better real world performance than real training in this simple sensorimotor task, but this finding may not apply to other training tasks. Future research should be directed towards establishing a comprehensive knowledge of what is being transferred to real world performance in other tasks currently being trained in VEs and investigating the equivalence of virtual and real trained performances in these situations.

Acoustic Stimulation↗
PubMed2002

Differentiation of old and new world leishmania species at complex and species levels by PCR.

The variable and conserved sequence boxes of kinetoplast DNA (kDNA) of 11 standard strains of 6 complexes of New and Old World Leishmania were amplified using PCR. Four strains from 2 complexes of Old World Leishmania - L. major (MRHO/IR/64/Nadim-1), with 2 bands at 850 and 620 bp, L. major (MHOM/SU/73/5-ASKH), with a band at 620 bp, L. donovani, with a band at 800 bp and L. infantum, with a band at 650 bp - could be differentiated from each other and from the New World strains, with the exception of L. infantum. Seven Leishmania strains from 4 complexes of New World Leishmania - L. mexicana and L. pifanoi, with a band at 730 bp, L. guyanensis, with 2 bands at 730 and 650 bp, L. peruviana, with a band at 710 bp and L. amazonensis, L. garnhami and L. braziliensis, each with a band at 650 bp - were identified. Of these strains, L. guyanensis and L. peruviana could be differentiated from each other and from the Old World strains. These results show that using PCR amplification of kDNA we could differentiate between New and Old World Leishmania at both complex and strain levels. The amplified kDNA PCR products, together with other techniques, could be useful as a diagnostic tool for the identification of Leishmania species.

Animals↗
PubMed1999

Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.

Haplotypes constructed from Y-chromosome markers were used to trace the origins of Native Americans. Our sample consisted of 2,198 males from 60 global populations, including 19 Native American and 15 indigenous North Asian groups. A set of 12 biallelic polymorphisms gave rise to 14 unique Y-chromosome haplotypes that were unevenly distributed among the populations. Combining multiallelic variation at two Y-linked microsatellites (DYS19 and DXYS156Y) with the unique haplotypes results in a total of 95 combination haplotypes. Contra previous findings based on Y- chromosome data, our new results suggest the possibility of more than one Native American paternal founder haplotype. We postulate that, of the nine unique haplotypes found in Native Americans, haplotypes 1C and 1F are the best candidates for major New World founder haplotypes, whereas haplotypes 1B, 1I, and 1U may either be founder haplotypes and/or have arrived in the New World via recent admixture. Two of the other four haplotypes (YAP+ haplotypes 4 and 5) are probably present because of post-Columbian admixture, whereas haplotype 1G may have originated in the New World, and the Old World source of the final New World haplotype (1D) remains unresolved. The contrasting distribution patterns of the two major candidate founder haplotypes in Asia and the New World, as well as the results of a nested cladistic analysis, suggest the possibility of more than one paternal migration from the general region of Lake Baikal to the Americas.

Asia↗
PubMed1998

Contributions of the doubly labeled water method to studies of energy balance in the Third World.

Of >250 studies on energy metabolism using the doubly labeled water (DLW) technique, approximately 12 full papers describe work performed in the Third World. Unfortunately, the term "Third World" is imprecise and the focuses of individual studies were too varied to allow much comparison among the data. There is a need to develop a more uniform approach. Useful investigations will allow comparisons of energy metabolism to be made in a consistent way across a variety of socioeconomic groups within the same country, and between the Third World and the developed world, with a commitment to the long term. In this way, the DLW method, if combined with other measurements of activity, energy intake, and body composition, will provide useful information on energy requirements and the consequences of inadequate or excessive energy intakes for the individual. Such investigations should be done, with standard protocols where possible, not just for the DLW method but also for those methods with which DLW should be integrated. Only if these suggestions are followed will real "value for money" be obtained from DLW studies in the Third World or elsewhere. In the context of these criteria, studies in the Third World using the DLW method have been only partly successful.

Adolescent↗
PubMedDate not supplied

Pathogenesis of severe acute respiratory infections in the developing world: respiratory syncytial virus and parainfluenza viruses.

Respiratory syncytial virus (RSV) and parainfluenza viruses (PIVs) are the most frequently isolated pathogens in infants and children with acute lower respiratory infection (LRI) in the developed world. Less information is available about their importance in LRI in the developing world, but they are probably important there also. The pathogenesis of viral bronchiolitis and pneumonia involves inoculation and early replication in the upper respiratory tract, followed by aspiration into the lower respiratory tract when both the mucosal and systemic immune systems are involved in a specific response. Both disease and recovery reflect processes of viral replication (with attendant cellular destruction) and of immune response (with attendant direct cellular destruction and release of pathogenic, along with beneficial, mediators). Factors predisposing to bacterial superinfection are poorly understood except in animal models. Conditions leading to heightened susceptibility to severe disease in the developed world are particularly common in the developing world. Increasing information on RSV and PIV infections in the developing world will likely point to their importance. Strategies for prevention of severe illnesses due to these viruses will follow from concepts elucidated through animal models and studies of infants in the developed world.

Acute Disease↗
PubMed1995

Comparison of New and Old World leishmanins in an endemic region of Brazil.

The control of leishmaniasis depends on a knowledge of the magnitude of the disease and of exposure to it. Delayed-type hypersensitivity testing can detect prior exposure to the parasite, but there is little agreement regarding the choice of an antigen for such testing. New and Old World leishmanins were tested in a study of patients with confirmed prior cutaneous leishmaniasis (CL), patients with confirmed prior American visceral leishmaniasis (AVL), and controls from areas in Espírito Santo, Brazil, where leishmaniasis is not endemic. Biobrás antigen (a suspended mixture of Leishmania braziliensis guyanensis, Leishmania mexicana amazonensis, and Leishmania mexicana promastigotes) detected 100% of prior CL infections and thus was superior to the Old World antigen, Leishmania major, which detected only 19% of these infections (P < .00001). Soluble New World antigens of Leishmania chagasi evoked a response in 96% of cases of prior AVL, whereas the Old World counterpart, Leishmania infantum, evoked a response in 71% of cases (P < .042). Testing of family members of patients with prior AVL showed greater utility of the New World leishmanins and suggested subclinical exposure of a large number of healthy people in the hyperendemic region. New World skin-test antigens should be used in future epidemiological studies in the Americas to more accurately determine the extent of exposure.

Adolescent↗
PubMed2003

Practically relevant research: capturing real world tasks, environments, and outcomes.

PURPOSE: Development of strategies to optimize the functional performance of older adults requires understanding the behavior of older people doing tasks in real-world settings and capturing these interactions in research protocols. This is a major challenge as there is some degree of tension between capturing the contextual variables and constraints that operate in the real world and the scale of research that can be realistically conducted within controlled experimental settings. This article presents a research approach that can be used to help ensure the ecological validity of research protocols. The intent is to demonstrate how an ecologically valid approach affords greater insight into the performance of older adults in real world settings. METHODS: The approach involves techniques such as task analysis and simulation. Examples from two research projects examining aging and the performance of real-world computer-based work tasks are used to demonstrate the application of this approach. RESULTS: The article demonstrates how an ecologically valid research approach yields information about human performance that can be translated into solutions for real-world problems. IMPLICATIONS: Ecologically valid research protocols offer the potential for providing answers to real-world problems and advancing theory regarding aging and functional performance.

Activities of Daily Living↗