Simulation,Mastery Learning and Healthcare

Healthcare organizations, becoming increasingly complex, need to use simulation techniques as a tool to provide consistently safe care. Mastery learning techniques minimize variation in learner outcome, thus improving the consistency and cost-effectiveness of care. Today?s organizations (and their teams of decision makers) exist within varying states of transformation. These transformational times afford opportunities to use mastery learning concepts at an organizational level and to affect necessary change(s). Evolving technologies, including simulation, have provided mechanisms to enhance system performance, reducing reliance on custom-built “problem-solving” solutions for individual system needs. As such, simulation has emerged as an increasingly necessary organizational tool in improving value-driven, consistent processes of care. Both computer-based and non-computer-based algorithms of healthcare simulations offer distinct advantages in improving system performance over traditional methods of quality improvement. Simulation as a process engineering tool, integrated with mastery learning techniques, provides powerful platforms for improving value-based care.     

In Vivo Capillary Structure and Blood Cell Flux in the Normal and Diabetic Mouse Eye

PurposeTo characterize the early structural and functional changes in the retinal microvasculature in response to hyperglycemia in the Ins2^Akita mouse.MethodsA custom phase-contrast adaptive optics scanning light ophthalmoscope was used to image retinal capillaries of 9 Ins2^Akita positive (hyperglycemic) and 9 Ins2^Akita negative (euglycemic) mice from postnatal weeks 5 to 18. A 15 kHz point scan was used to image capillaries and measure red blood cell flux at biweekly intervals; measurements were performed manually. Retinal thickness and fundus photos were captured monthly using a commercial scanning laser ophthalmoscope/optical coherence tomography. Retinal thickness was calculated using a custom algorithm. Blood glucose and weight were tracked throughout the duration of the study.ResultsElevated blood glucose (>250 mg/dL) was observed at 4 to 5 weeks of age in Ins2^Akita mice and remained elevated throughout the study, whereas euglycemic littermates maintained normal glucose levels. There was no significant difference in red blood cell flux, capillary anatomy, lumen diameter, or occurrence of stalled capillaries between hyperglycemic and euglycemic mice between postnatal weeks 5 and 18. Hyperglycemic mice had a thinner retina than euglycemic littermates (p < 0.001), but retinal thickness did not change with duration of hyperglycemia despite glucose levels that were more than twice times normal.ConclusionsIn early stages of hyperglycemia, retinal microvasculature structure (lumen diameter, capillary anatomy) and function (red blood cell flux, capillary perfusion) were not impaired despite 3 months of chronically elevated blood glucose. These findings suggest that hyperglycemia alone for 3 months does not alter capillary structure or function in profoundly hyperglycemic mice.     

White matter organization and neurocognitive performance variability in schizophrenia

BackgroundWhite matter alterations in schizophrenia are associated with deficits in neurocognitive performance. Recently, across task within-individual variability (WIV) has emerged as a useful construct for assessing the profile in cognitive performance in schizophrenia. However, the neural basis of WIV has not been studied in patients with schizophrenia.MethodsTwenty-five patients with schizophrenia (SZ) and 27 healthy comparison subjects (HC) performed a computerized neurocognitive battery (CNB) and underwent diffusion tensor imaging (DTI). WIV for performance accuracy and speed on the CNB was calculated across-tasks. Voxel-wise group comparisons of white matter fractional anisotropy (FA) were performed using tract-based spatial statistics (TBSS). The relationship between accuracy and speed WIV on the CNB and white matter FA was examined within the regions that differentiated patients and healthy comparison subjects.ResultsSZ had higher WIV for performance accuracy and speed as compared to HC. FA in SZ compared to HC was reduced in bilateral frontal, temporal and occipital white matter including a large portion of the corpus callosum. In white matter regions that differed between patients and comparison subjects, higher FA in the left cingulum bundle and left fronto-occipital fasciculus were associated with lower CNB speed WIV for HC, but not SZ. Accuracy WIV was not associated with differences in white matter FA between SZ and HC.ConclusionsWe provide evidence that WIV is greater in patients with SZ and that this greater within-individual variability in performance in patients is associated with disruptions of WM integrity in specific brain regions.     

Cross-sectional study of the effects of parturition and lactation on bone mineral density later in life

OBJECTIVE: The present cross-sectional study investigated the effects of parturition and lactation on bone mineral density (BMD) later in life. METHODS: The subjects were 456 premenopausal and 713 postmenopausal Japanese women aged 40-69 years old. They were classified into six subgroups at 5-year increments. Age, height, weight, menopausal status, age at menopause (in postmenopausal women), years since menopause (in postmenopausal women), parity, and total lactation period were recorded. Lumbar spine BMD (L2-4) was measured by dual-energy X-ray absorptiometry (DEXA). In each subgroup, correlations of parturition and lactation with BMD were investigated using Pearson's correlation test and multiple regression analyses. RESULTS: In premenopausal women aged 40-44 years old (n=143), total lactation period was inversely correlated with BMD (r= -0.293, P<0.01). This relationship remained significant after adjusting for age, height, weight, and parity (P<0.05). Although the total lactation period was inversely correlated with BMD in the group aged 60-64 years old (r= -0.194, P<0.05, n=218), this relationship disappeared after adjusting for age, YSM, height, weight, and parity. However, in the other subgroups, there were no significant correlations between total lactation period and BMD. There were no significant correlations observed between parity and BMD in any groups. CONCLUSION: Reproductive history of lactation and parity does not seem to be a major determinant of BMD later in life.     

Omega-3 Fatty Acid Inhibition of Prostate Cancer Progression to Hormone Independence Is Associated With Suppression of mTOR Signaling and Androgen Receptor Expression

Currently, progression of prostate cancer to androgen independence remains the primary obstacle to improved survival. In order to improve overall survival, novel treatment strategies that are based upon specific molecular mechanisms that prolong the androgen-dependent state and that are useful for androgen-independent disease need to be identified. Both epidemiological as well as preclinical data suggest that omega-3 fatty acids are effective primary tumor prevention agents; however, their efficacy at preventing and treating refractory prostate cancer has not been as thoroughly investigated. We used an in vitro model of androgen ablation to determine the effect of treatment with omega-3 fatty acids on the progression to an androgen-independent state. The omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were able to prevent progression of LNCaP cells while the omega-6 fatty acid arachidonic acid (AA) actually promoted cell growth under conditions of hormone depletion. These results correlated with a decrease in the expression of the androgen receptor as well as suppression of the Akt/mTOR signaling pathway. Connecting the mechanisms by which omega-3 fatty acids affect phenotypic outcome is important for effective exploitation of these nutrient agents as a therapeutic approach. Understanding these processes is critical for the development of effective dietary intervention strategies that improve overall survival.     

fMRI investigation of the cognitive structure of the Concealed Information Test

We studied the cognitive basis of the functional magnetic resonance imaging (fMRI) pattern of deception in three participants performing the Concealed Information Test (CIT). In all participants, the prefrontoparietal lie activation was similar to the pattern derived from the meta-analysis (N?=?40) of our previously reported fMRI CIT studies and was unchanged when the lie response was replaced with passive viewing of the target items. When lies were replaced with irrelevant responses, only the left inferior gyrus activation was common to all subjects. This study presents a systematic strategy for testing the cognitive basis of deception models, and a qualitative approach to single-subject truth-verification fMRI tests.     

fMRI investigation of the cognitive structure of the Concealed Information Test

We studied the cognitive basis of the functional magnetic resonance imaging (fMRI) pattern of deception in three participants performing the Concealed Information Test (CIT). In all participants, the prefrontoparietal lie activation was similar to the pattern derived from the meta-analysis (N = 40) of our previously reported fMRI CIT studies and was unchanged when the lie response was replaced with passive viewing of the target items. When lies were replaced with irrelevant responses, only the left inferior gyrus activation was common to all subjects. This study presents a systematic strategy for testing the cognitive basis of deception models, and a qualitative approach to single-subject truth-verification fMRI tests.