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Results for “Gatekeeping”

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At least 307 records · Page 17Linked to original sources
PubMed2005

The lymphocyte homing receptors: gatekeepers of the multistep paradigm.

PURPOSE OF REVIEW: Lymphocyte trafficking is regulated by adhesion molecules mediating the initial shear-resistant binding of circulating cells to target tissue endothelium (Step 1). This review focuses on the current and emerging perspectives of the biology of these 'homing receptors.' RECENT FINDINGS: The conventional multistep paradigm holds that leukocyte migration represents a cascade of events, initiated by tethering and rolling interactions of leukocytes on the endothelial surface (Step 1). These interactions are indispensable, required to dampen velocities sufficiently to allow cells to sense the local chemokines and/or other inflammatory signals resulting in activation of integrin adhesiveness (Step 2), with ensuing firm adherence on the vessel wall (Step 3) followed by endothelial transmigration (Step 4). Mechanistic studies now suggest that some effectors of Step 1 interactions themselves activate integrin adhesiveness and trigger transmigration--in some cases by forming complexes with integrins--thus bypassing the need for chemokine signaling. These findings force a reconsideration of the multistep paradigm, and shift focus now to identifying all relevant effectors of Step 1 interactions using adherence assays performed under shear stress to mimic the dynamic conditions of blood flow. SUMMARY: Recent findings suggest that homing receptors are not merely molecular brakes. The cross-talk among the homing receptors and integrins opens a new 'avenue' to lymphocyte migration, suggesting that homing receptors may be sufficient alone, in some cases, to perform the function the name implies.

Animals↗
PubMed2006

When gatekeepers meet the sentinel: the impact of a prior authorization requirement for cefuroxime on the prescribing behaviour of community-based physicians.

AIMS: Prior authorization (PA), the requirement of physicians to obtain pre-approval as a prerequisite for coverage, may decrease drug utilization via a 'sentinel effect', a decrease in utilization caused by external review of prescribing. The purpose of this study was to assess the affect a PA restriction had on the utilization patterns of cefuroxime tablets in a managed care organization (MCO) in Israel. METHODS: Physician prescribing patterns were evaluated by conducting a retrospective drug utilization analysis. Data were derived from the electronic patient records of the MCO studied. All prescriptions for solid state antibiotics for patients diagnosed with an infectious disease written during three parallel 3-month segments, before, during and after a PA restriction for cefuroxime was enforced, were included. Frequency and proportion of antibiotic prescriptions for cefuroxime tablets, distribution of infectious diseases treated with cefuroxime, and the request rejection rate when PA was required were calculated. RESULTS: Prescriptions for cefuroxime declined from 5538 prescriptions (8.0% of eligible antibiotic prescriptions, 95% CI 7.8, 8.2) in the initial period to 1036 (1.2%, 95% CI 1.1, 1.3) during the PA period, rising to 3961 (4.3%, 95% CI 4.2, 4.4) in the post-PA period. Changes in the distribution of diseases treated with cefuroxime during the PA stage tended to regress after revocation to those observed in the pre-PA period. The rejection rate was found to be 8.5% (95% CI=6.9, 10.1). CONCLUSIONS: The implementation of a prior authorization requirement for cefuroxime tablets markedly reduced the use of this drug, probably due to a 'sentinel effect'.

Administration, Oral↗
PubMed1992

The use of the first person in academic writing: objectivity, language and gatekeeping.

Researchers have experienced difficulties in having papers which are based on qualitative research accepted for publication because the papers have been written in the first person. Arguments are presented to show why the use of the neutral, anonymous third person is deceptive when applied to quantitative research because it obliterates the social elements of the research process. With regard to research in the qualitative, critical and feminist paradigms, it is further argued that the use of the first person is required in keeping with the epistemologies of the research and in the pursuit of reflexivity. Links are made between these arguments and the process of reviewing for academic journals. Conclusions are drawn in favour of the use of the first person, where this is appropriate to the mode of research reported and where an author is giving a personal judgement arrived at on the basis of reasonable evidence. In keeping with this position, this paper is written in the first person.

Academic Dissertations as Topic↗
PubMed2005

Kisspeptin and its receptor: new gatekeepers of puberty.

The recent finding that the hormone kisspeptin plays a pivotal role in the onset of puberty is one of the biggest discoveries in human reproductive biology in 30 years. Mutations in the receptor for kisspeptin cause humans and mice to fail to reach puberty and to be sterile. It is the first time since the identification of gonadotrophin-releasing hormone that a single gene is found to have such a dramatic effect on reproduction. This discovery opens new possibilities in the treatment of reproductive disorders such as delayed or advanced puberty, infertility and sex hormone-dependent cancers.

Animals↗
PubMed1999

Physical activity initiatives for male factory workers: gatekeepers' perceptions of potential motivators and barriers.

OBJECTIVE: Worksites have been argued to be a key setting for physical activity promotion, particularly for lower-paid, less-skilled workers. These occupational groups are at increased risk of cardiovascular disease. There is no strong evidence in support of the efficacy of worksite fitness and physical activity interventions. This study assessed potential motivators and barriers to worksite physical activity initiatives for less-skilled workers. METHOD: We conducted telephone interviews with 13 Victorian WorkCover insurance providers and 30 manufacturing industry worksite managers. The manufacturing industry was selected as it contains a substantial portion of workers from this high-risk occupational group. RESULTS: Most insurers incorporated physical activity elements into injury-prevention programs. Few worksite managers reported programs to encourage workers to be more active; they identified reduced premiums and lower-cost programs through insurers as possible motivators. Both groups identified workers' reluctance to participate in physical activity, lack of awareness of potential benefits and program cost as major barriers for worksite physical activity. Other barriers included potential adverse effects on productivity and increased injury risk. CONCLUSIONS: Broader occupational health and safety policies and joint initiatives between insurers and worksite managers may have the potential to provide more opportunities for workers to be more active. However, the barriers identified outweighed the perceived benefits. IMPLICATIONS: Without structural and regulatory changes or new incentives, the adoption of physical activity initiatives in Australian manufacturing-industry workplaces is unlikely.

Attitude to Health↗
PubMed2025

The auxin gatekeepers: Evolution and diversification of the YUCCA family.

The critically important YUCCA (YUC) gene family is highly conserved and specific to the plant kingdom, primarily responsible for the final and rate-limiting step for indole-3-acetic acid (IAA) biosynthesis. IAA is an essential phytohormone, involved in virtually all aspects of plant growth and development. In addition, IAA is involved in fine-tuning plant responses to biotic and abiotic interactions and stresses. While the YUC gene family has significantly expanded throughout the plant kingdom, a detailed analysis of the evolutionary patterns driving this diversification has not been performed. Here, we present a comprehensive phylogenetic analysis of the YUC family, combining YUCs from species representing key evolutionary plant lineages. The evolutionary history of YUCs is complex and suggests multiple recruitment events via horizontal gene transfer from bacteria. We identify and hierarchically classify the YUC family into an early diverging grade, five distinct classes and 41 subclasses. Angiosperm YUC diversity and expansion are explained in the context of protein sequence conservation, as well as spatial and gene expression patterns. The presented YUC gene landscape offers new perspectives on the distribution and evolutionary trends of this crucial family, which facilitates further YUC characterization within plant development and response to environmental change.

Indoleacetic Acids↗