194 research outputs found
Expression of Mcm2, geminin and Ki67 in normal oral mucosa, oral epithelial dysplasias and their corresponding squamous-cell carcinomas
Proteins necessary for the normal regulation of the cell cycle include minichromosome maintenance protein 2 (Mcm2) and geminin.
These are overexpressed in several premalignant and malignant tumours. The Mcm2/Ki67 ratio can be used to estimate the
population of cells that are in early G1 (licensed to proliferate), and the geminin/Ki67 ratio can determine the relative length of G1.
A high ratio indicates a short G1 and a high rate of cell proliferation. Mcm2 and geminin have been scarcely explored in oral epithelial
dysplasia (OED) and oral squamous-cell carcinoma (OSCC). The purpose of this study was to identify the expression pattern of
Mcm2, Ki67 and geminin in normal oral mucosa (NOM), OED and their subsequent OSCC, to determine if expression could help
predict the prognosis of OED. Paraffin sections of 41 OED cases that progressed to carcinoma, 40 OED without malignant
progression, 38 OSCC and 15 NOM were immunostained with antibodies against Mcm2, geminin and Ki67. Labelling indices (LIs)
increased progressively from NOM, OED and OSCC (Mcm2, Po0.001; geminin, Po0.001 and Ki67, Po0.001). In all the OED cases
(n ¼ 81) the levels of expression of Mcm2 (LI, 73.6), geminin (LI, 24.4) and Ki67 (LI, 44.5) were elevated indicating a constant cellcycle
re-entry. When the OED groups were compared, Mcm2 protein expression was higher in the OED with malignant progression
(P ¼ 0.04), likewise there was a significant increase in the Mcm2/Ki67 and geminin/Ki67 ratios (P ¼ 0.04 and 0.02 respectively). Mcm2
and geminin proteins seem to be novel biomarkers of growth and may be useful prognostic tools for OED
Is U.S. health care an appropriate system? A strategic perspective from systems science
<p>Abstract</p> <p>Context</p> <p>Systems science provides organizational principles supported by biologic findings that can be applied to any organization; any incongruence indicates an incomplete or an already failing system. U.S. health care is commonly referred to as a system that consumes an ever- increasing percentage of the gross domestic product and delivers seemingly diminishing value.</p> <p>Objective</p> <p>To perform a comparative study of U.S. health care with the principles of systems science and, if feasible, propose solutions.</p> <p>Design</p> <p>General systems theory provides the theoretical foundation for this observational research.</p> <p>Main Outcome Measures</p> <p>A degree of compliance of U.S. health care with systems principles and its space-time functional location within the dynamic systems model.</p> <p>Results of comparative analysis</p> <p>U.S. health care is an incomplete system further threatened by the fact that it functions in the zone of chaos within the dynamic systems model.</p> <p>Conclusion</p> <p>Complying with systems science principles and the congruence of pertinent cycles, U.S. health care would likely dramatically improve its value creation for all of society as well as its resiliency and long-term sustainability.</p> <p>Immediate corrective steps could be taken: Prioritize and incentivize <it>health </it>over <it>care</it>; restore fiscal soundness by combining health and life insurance for the benefit of the insured and the payer; rebalance horizontal/providers and vertical/government hierarchies.</p
Ectopic Wnt/Beta–Catenin Signaling Induces Neurogenesis in the Spinal Cord and Hindbrain Floor Plate
The most ventral structure of the developing neural tube, the floor plate (FP), differs in neurogenic capacity along the neuraxis. The FP is largely non-neurogenic at the hindbrain and spinal cord levels, but generates large numbers of dopamine (mDA) neurons at the midbrain levels. Wnt1, and other Wnts are expressed in the ventral midbrain, and Wnt/beta catenin signaling can at least in part account for the difference in neurogenic capacity of the FP between midbrain and hindbrain levels. To further develop the hypothesis that canonical Wnt signaling promotes mDA specification and FP neurogenesis, we have generated a model wherein beta–catenin is conditionally stabilized throughout the FP. Here, we unambiguously show by fate mapping FP cells in this mutant, that the hindbrain and spinal cord FP are rendered highly neurogenic, producing large numbers of neurons. We reveal that a neurogenic hindbrain FP results in the altered settling pattern of neighboring precerebellar neuronal clusters. Moreover, in this mutant, mDA progenitor markers are induced throughout the rostrocaudal axis of the hindbrain FP, although TH+ mDA neurons are produced only in the rostral aspect of rhombomere (r)1. This is, at least in part, due to depressed Lmx1b levels by Wnt/beta catenin signaling; indeed, when Lmx1b levels are restored in this mutant, mDA are observed not only in rostral r1, but also at more caudal axial levels in the hindbrain, but not in the spinal cord. Taken together, these data elucidate both patterning and neurogenic functions of Wnt/beta catenin signaling in the FP, and thereby add to our understanding of the molecular logic of mDA specification and neurogenesis
Shadoo (Sprn) and prion disease incubation time in mice
Prion diseases are transmissible neurodegenerative disorders of mammalian species and include scrapie, bovine spongiform encephalopathy (BSE), and variant Creutzfeldt-Jakob disease (vCJD). The prion protein (PrP) plays a key role in the disease, with coding polymorphism in both human and mouse influencing disease susceptibility and incubation time, respectively. Other genes are also thought to be important and a plausible candidate is Sprn, which encodes the PrP-like protein Shadoo (Sho). Sho is expressed in the adult central nervous system and exhibits neuroprotective activity reminiscent of PrP in an in vitro assay. To investigate the role of Sprn in prion disease incubation time we sequenced the open reading frame (ORF) in a diverse panel of mice and saw little variation except in strains derived from wild-trapped mice. Sequencing the untranslated regions revealed polymorphisms that allowed us to carry out an association study of incubation period in the Northport heterogeneous stock of mice inoculated with Chandler/RML prions. We also examined the expression level of Sprn mRNA in the brains of normal and prion-infected mice and saw no correlation with either genotype or incubation time. We therefore conclude that Sprn does not play a major role in prion disease incubation time in these strains of mice
A phase I study with MAG-camptothecin intravenously administered weekly for 3 weeks in a 4-week cycle in adult patients with solid tumours
In MAG-camptothecin (MAG-CPT), the topoisomerase inhibitor camptothecin is linked to a water-soluble polymer. Preclinical experiments showed enhanced antitumour efficacy and limited toxicity compared to camptothecin alone. Prior phase I trials guided the regimen used in this study. The objectives were to determine the maximum tolerated dose, dose-limiting toxicities, safety profile, and pharmacokinetics of weekly MAG-CPT. Patients with solid tumours received MAG-CPT intravenously administered weekly for 3 weeks in 4-week cycles. At the starting dose level ( 80 mg m(-2) week(-1)), no dose-limiting toxicities occurred during the first cycle (n = 3). Subsequently, three patients were enrolled at the second dose level ( 120 mg m(-2) week(-1)). Two of three patients at the 80 mg m(-2) week(-1) cohort developed haemorrhagic cystitis ( grade 1/3 dysuria and grade 2/3 haematuria) during the second and third cycles. Next, the 80 mg m(-2) week(-1) cohort was enlarged to a total of six patients. One other patient at this dose level experienced grade 1 haematuria. At 120 mg m(-2) week(-1), grade 1 bladder toxicity occurred in two of three patients. Dose escalation was stopped at 120 mg m(-2) week(-1). Cumulative bladder toxicity was dose-limiting toxicity at 80 mg m(-2) week(-1). Pharmacokinetics revealed highly variable urinary camptothecin excretion, associated with bladder toxicity. Due to cumulative bladder toxicity, weekly MAG-CPT is not a suitable regimen for treatment of patients with solid tumours
Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.
The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
An Industry Perspective on Canadian Patients\u27 Involvement in Medical Tourism: Implications for Public Health
Background:
The medical tourism industry, which assists patients with accessing non-emergency medical careabroad, has grown rapidly in recent years. A lack of reliable data about medical tourism makes it difficult to createpolicy, health system, and public health responses to address the associated risks and shortcomings, such as spreadof infectious diseases, associated with this industry. This article addresses this knowledge gap by analyzinginterviews conducted with Canadian medical tourism facilitators in order to understand Canadian patients’involvement in medical tourism and the implications of this involvement for public health.
Methods:
Semi-structured phone interviews were conducted with 12 medical facilitators from 10 companies in2010. An exhaustive recruitment strategy was used to identify interviewees. Questions focused on businessdimensions, information exchange, medical tourists’ decision-making, and facilitators’ roles in medical tourism.Thematic analysis was undertaken following data collection.Results: Facilitators helped their Canadian clients travel to 11 different countries. Estimates of the number ofclients sent abroad annually varied due to demand factors. Facilitators commonly worked with medical touristsaged between 40 and 60 from a variety of socio-economic backgrounds who faced a number of potential barriersincluding affordability, fear of the unfamiliar, and lack of confidence. Medical tourists who chose not to usefacilitators’ services were thought to be interested in saving money or have cultural/familial connections to thedestination country. Canadian doctors were commonly identified as barriers to securing clients.
Conclusions:
No effective Canadian public health response to medical tourism can treat medical tourists as aunified group with similar motivations for engaging in medical tourism and choosing similar mechanisms fordoing so. This situation may be echoed in other countries with patients seeking care abroad. Therefore, a call for acomprehensive public health response to medical tourism and its effects should be coupled with a clearunderstanding that medical tourism is a highly diverse practice. This response must also acknowledge facilitators asimportant stakeholders in medical tourism
Developing cancer warning statements for alcoholic beverages
Background: There is growing evidence of the increased cancer risk associated with alcohol consumption, but this is not well understood by the general public. This study investigated the acceptability among drinkers of cancer warning statements for alcoholic beverages. Methods: Six focus groups were conducted with Australian drinkers to develop a series of cancer-related warning statements for alcohol products. Eleven cancer warning statements and one general health warning statement were subsequently tested on 2,168 drinkers via an online survey. The statements varied by message frame (positive vs negative), cancer reference (general vs specific), and the way causality was communicated (‘increases risk of cancer’ vs ‘can cause cancer’). Results: Overall, responses to the cancer statements were neutral to favorable, indicating that they are unlikely to encounter high levels of negative reaction from the community if introduced on alcoholic beverages. Females, younger respondents, and those with higher levels of education generally found the statements to be more believable, convincing, and personally relevant. Positively framed messages, those referring to specific forms of cancer, and those using ‘increases risk of cancer’ performed better than negatively framed messages, those referring to cancer in general, and those using the term ‘can cause cancer’. Conclusion: Cancer warning statements on alcoholic beverages constitute a potential means of increasing awareness about the relationship between alcohol consumption and cancer risk
Dysregulation of lysophosphatidic acids in multiple sclerosis and autoimmune encephalomyelitis
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