PURPOSE: The mouse eye is a widely used model for retinal disease and has potential to become a model for myopia. Studies of retinal disease will benefit from imaging the fundus in vivo. Experimental models of myopia often rely on manipulation of the visual experience. In both cases, knowledge of the optical quality of the eye, and in particular, the retinal image quality degradation imposed by the ocular aberrations is essential. In this study, we measured the ocular aberrations in the wild type mouse. METHODS: Twelve eyes from six four-week old black C57BL/6 wild type mice were studied. Measurements were done on awake animals, one being also measured under anesthesia for comparative purposes. Ocular aberrations were measured using a custom-built Hartmann-Shack system (using 680-nm illumination). Wave aberrations are reported up to fourth order Zernike polynomials. Spherical equivalent and astigmatism were obtained from the 2nd order Zernike terms. Modulation Transfer Functions (MTF) were estimated for the best focus, and through-focus, to estimate depth-of-focus. All reported data were for 1.5-mm pupils. RESULTS: Hartmann-Shack refractions were consistently hyperopic (10.12+/-1.41 D, mean and standard deviation) and astigmatism was present in many of the eyes (3.64+/-3.70 D, on average). Spherical aberration was positive in all eyes (0.15+/-0.07 microm) and coma terms RMS were significantly high compared to other Zernike terms (0.10+/-0.03 microm). MTFs estimated from wave aberrations show a modulation of 0.4 at 2c/deg, for best focus (and 0.15 without cancelling the measured defocus). For that spatial frequency, depth-of-focus estimated from through-focus modulation data using the Rayleigh criterion was 6D. Aberrations in the eye of one anesthetized mouse were higher than in the same eye of the awake animal. CONCLUSIONS: Hyperopic refractions in the mouse eye are consistent with previous retinoscopic data. The optics of the mouse eye is far from being diffraction-limited at 1.5-mm pupil, with significant amounts of spherical aberration and coma. However, estimates of MTFs from wave aberrations are higher than previously reported using a double-pass technique, resulting in smaller depth-of-field predictions. Despite the large degradation imposed by the aberrations these are lower than the amount of aberrations typically corrected by available correction techniques (i.e., adaptive optics). On the other hand, aberrations do not seem to be the limiting factor in the mouse spatial resolution. While the mouse optics are much more degraded than in other experimental models of myopia, its tolerance to large amounts of defocus does not seem to be determined entirely by the ocular aberrations. 相似文献
ObjectiveTest effectiveness and acceptability of interventions short essay-type training in health emergency management (EM).DesignCombined case series and controlled study before and after training sessions.LocationHealth Center (HC).ParticipantsTeam on duty, two monitors-facilitators, and a mannequin.Main measuresVariables: response times, staff performance, resource usage and opinion. Structure: scenarios and key messages. Instrument development: 1. Initial/final questionnaire and events. 2. Essential/non-essential times; 3. Post-test opinion questionnaire. Performance of six consecutive 15 min tests fortnightly (including corrections) and poll after each test. A month later, repeat in random order and under similar conditions. Analysis: repeated measures.ResultsA total of 93 (2/3) workers completed the initial survey, and 74 the final, with 46 participants (25 doctors, 7 nurses, 21 non-health completed 95 direct interventions. Matching participants > 80% between series. A reduction was seen in the “detection of collapse to first defibrillation” interval (10 to 4 min). EM events improved 2-3 fold and “sense of security during a real EM” increased from 23% to 71% among participants. The vast majority of participants said “useful corrections made by the facilitator.” The proportions of those who “would like to see tests introduced” and those who said “re-training was needed in EM” were moderately increased (67.4% vs 85% in health care workers). The “would like to attempt basic life support” was unchanged.ConclusionDespite being reduced in number and duration, this model of intervention has shown positive trends in terms of use and acceptability for implementation in the HC. 相似文献
Ts65Dn mice (TS), the most commonly used model of Down syndrome (DS), exhibit phenotypic characteristics of this condition. Both TS mice and DS individuals present cognitive disturbances, age‐related cholinergic degeneration, and increased brain expression of β‐amyloid precursor protein (AβPP). These neurodegenerative processes may contribute to the progressive cognitive decline observed in DS. Melatonin is a pineal indoleamine that has been reported to reduce neurodegenerative processes and improve cognitive deficits in various animal models. In this study, we evaluated the potentially beneficial effects of long‐term melatonin treatment on the cognitive deficits, cholinergic degeneration, and enhanced AβPP and β‐amyloid levels of TS mice. Melatonin was administered for 5 months to 5‐ to 6‐month‐old TS and control (CO) mice. Melatonin treatment improved spatial learning and memory and increased the number of choline acetyltransferase (ChAT)‐positive cells in the medial septum of both TS and CO mice. However, melatonin treatment did not significantly reduce AβPP or β‐amyloid levels in the cortex or the hippocampus of TS mice. Melatonin administration did reduce anxiety in TS mice without inducing sensorimotor alterations, indicating that prolonged treatment with this indoleamine is devoid of noncognitive behavioral side effects (e.g., motor coordination, sensorimotor abilities, or spontaneous activity). Our results suggest that melatonin administration might improve the cognitive abilities of both TS and CO mice, at least partially, by reducing the age‐related degeneration of basal forebrain cholinergic neurons. Thus, chronic melatonin supplementation may be an effective treatment for delaying the age‐related progression of cognitive deterioration found in DS. 相似文献
This article briefly outlines a collaboration among communities on Hawai‘i Island and a university-based research team to develop, implement, and evaluate a school-based substance use prevention curriculum called Ho‘ouna Pono. In addition to providing a rationale for the project, the goal of this paper is fourfold. First, an overview of the Ho‘ouna Pono research results to date (2007–2013) is provided. Second, within this overview, the ways in which selected results informed program development are highlighted. Third, the curriculum is briefly described, and finally, the role of the students and community in the video production is described. 相似文献
Recent evidence suggests that miRNAs could be used as serum markers in a variety of normal and pathological conditions. In this study, we aimed to identify novel miRNAs associated with skeletal metastatic disease in a preclinical model of lung cancer bone metastasis. We assessed the validity of these miRNAs as reliable serum biochemical markers to monitor the extent of disease and response to treatment in comparison to imaging techniques and standard biochemical markers of bone turnover. Using a murine model of human lung cancer bone metastasis after zoledronic acid (ZA) treatment, PINP (procollagen I amino-terminal propeptide) was the only marker that exhibited a strong correlation with osteolytic lesions and tumor burden at early and late stages of bone colonization. In contrast, BGP (osteocalcin) and CTX (carboxyterminal telopeptide) demonstrated a strong correlation only at late stages. We performed qPCR based screening of a panel of 380 human miRNAs and quantified bone metastatic burden using micro-CT scans, X-rays and bioluminescence imaging. Interestingly, levels of miR-326 strongly associated with tumor burden and PINP in vehicle-treated animals, whereas no association was found in ZA-treated animals. Only miR-193 was associated with biochemical markers PINP, BGP and CTX in ZA-treated animals. Consistently, miR-326 and PINP demonstrated a strong correlation with tumor burden. Our findings, taken together, indicate that miR-326 could potentially serve as a novel biochemical marker for monitoring bone metastatic progression. 相似文献
Introduction: Mitochondrial-derived peptides (MDPs) are encoded within the mitochondrial genome. They signal within the cell or are released to act as autocrine/paracrine/endocrine cytoprotective factors playing a key role in the cellular stress response. The first reported and better characterized MDP is humanin (HN), which exerts robust protective effects against a myriad of cytotoxic stimuli in many cell types. These effects have led to the evaluation of HN and its analogs as therapeutic targets for several chronic diseases.
Areas covered: We describe the latest findings on the mechanism of action of HN and discuss the role of HN as therapeutic target for neurodegenerative and cardiovascular diseases, diabetes, male infertility, and cancer. Since HN can be detected in circulation, we also depict its value as a biomarker for these diseases.
Expert opinion: HN analogs and peptide mimetics have been developed over the last decade and show promising results in preclinical models of degenerative diseases. Local administration of gene therapy vectors that overexpress or silence endogenous HN could also hold therapeutic potential. Controversy on the role of HN in cancer progression and chemoresistance should be addressed before the translation of these therapeutic approaches. 相似文献