44 research outputs found

    Metabolic multi-stability and hysteresis in a model aerobe-anaerobe microbiome community

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    Changes in the composition of the human microbiome are associated with health and disease. Some microbiome states persist in seemingly unfavorable conditions, e.g., the proliferation of aerobe-anaerobe communities in oxygen-exposed environments in wounds or small intestinal bacterial overgrowth. However, it remains unclear how different stable microbiome states can exist under the same conditions, or why some states persist under seemingly unfavorable conditions. Here, using two microbes relevant to the human microbiome, we combine genome-scale mathematical modeling, bioreactor experiments, transcriptomics, and dynamical systems theory, to show that multi-stability and hysteresis (MSH) is a mechanism that can describe the shift from an aerobe-dominated state to a resilient, paradoxically persistent aerobe-anaerobe state. We examine the impact of changing oxygen and nutrient regimes and identify factors, including changes in metabolism and gene expression, that lead to MSH. When analyzing the transitions between the two states in this system, the familiar conceptual connection between causation and correlation is broken and MSH must be used to interpret the dynamics. Using MSH to analyze microbiome dynamics will improve our conceptual understanding of the stability of microbiome states and the transitions among microbiome states

    Effect of the mechanical activation on size reduction of crystalline acetaminophen drug particles

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    The decrease in particle size may offer new properties to drugs. In this study, we investigated the size reduction influence of the acetaminophen (C8H9O2N) particles by mechanical activation using a dry ball mill. The activated samples with the average size of 1 ÎĽm were then investigated in different time periods with the infrared (IR), inductively coupled plasma (ICP), atomic force microscopy (AFM), and X-ray diffraction (XRD) methods. The results of the IR and XRD images showed no change in the drug structure after the mechanical activation of all samples. With the peak height at full width at half maximum from XRD and the Scherrer equation, the size of the activated crystallite samples illustrated that the AFM images were in sound agreement with the Scherrer equation. According to the peaks of the AFM images, the average size of the particles in 30 hours of activation was 24 nm with a normal particle distribution. The ICP analysis demonstrated the presence of tungsten carbide particle impurities after activation from the powder sample impacting with the ball and jar. The greatest reduction in size was after milling for 30 hours

    Effect of the mechanical activation on size reduction of crystalline acetaminophen drug particles

    Get PDF
    The decrease in particle size may offer new properties to drugs. In this study, we investigated the size reduction influence of the acetaminophen (C8H9O2N) particles by mechanical activation using a dry ball mill. The activated samples with the average size of 1 µm were then investigated in different time periods with the infrared (IR), inductively coupled plasma (ICP), atomic force microscopy (AFM), and X-ray diffraction (XRD) methods. The results of the IR and XRD images showed no change in the drug structure after the mechanical activation of all samples. With the peak height at full width at half maximum from XRD and the Scherrer equation, the size of the activated crystallite samples illustrated that the AFM images were in sound agreement with the Scherrer equation. According to the peaks of the AFM images, the average size of the particles in 30 hours of activation was 24 nm with a normal particle distribution. The ICP analysis demonstrated the presence of tungsten carbide particle impurities after activation from the powder sample impacting with the ball and jar. The greatest reduction in size was after milling for 30 hours.Peer ReviewedPostprint (published version

    Patient and Caregiver Benefit From a Comprehensive Dementia Care Program: 1-Year Results From the UCLA Alzheimer's and Dementia Care Program.

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    Background/objectivesPersons with Alzheimer disease and related dementias (ADRDs) require comprehensive care that spans health systems and community-based organizations. This study examined the clinical outcomes of a comprehensive dementia care program and identified subgroups who were more likely to benefit.DesignObservational, baseline and 1 year after intervention.SettingUrban, academic medical center.ParticipantsA total of 554 persons with dementia and their caregivers who had 1-year follow-up evaluations and data on clinical outcomes.InterventionHealth system-based comprehensive dementia care management program using nurse practitioner dementia care managers.MeasurementsPatient measures included the Mini-Mental State Examination (MMSE), the Functional Activities Questionnaire, Basic and Instrumental Activities of Daily Living scales, the Cornell Scale for Depression in Dementia, and the Neuropsychiatric Inventory Questionnaire (NPI-Q) Severity. Caregiver measures included the Modified Caregiver Strain Index, the Patient Health Questionnaire-9, NPI-Q Distress, and the Dementia Burden Scale-Caregiver). We used established minimal clinically important differences and lowest tertiles of baseline symptoms to define improving symptoms and maintaining low symptoms as clinical benefit for patients and caregivers.ResultsAt year 1, persons with ADRD improved on all scales, except MMSE and functional status measures; caregivers improved on all scales. Using validated instruments, 314/543 (58%) of patients, 282/447 (63%) of caregivers, and 376/501 (75%) of patients or caregivers demonstrated clinical benefit. In adjusted multivariate models, at year 1, more behavioral symptoms and fewer depression symptoms at baseline were associated with patient improvement; and fewer baseline depression symptoms were associated with maintaining low behavioral symptoms. Male caregiver sex, higher baseline caregiver burden, and caring for patients with fewer baseline depression symptoms were associated with caregiver improvement. Male caregiver sex and patients with fewer depression symptoms, fewer behavioral symptoms, and more functional impairment at baseline were associated with caregivers maintaining low burden at 1 year.ConclusionsHealth system-based comprehensive dementia care management is a promising approach to improving clinical outcomes, with benefits for both patients and caregivers. J Am Geriatr Soc 67:2267-2273, 2019

    Obese- and allergic-related asthma phenotypes among children across the United States

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    ObjectivesPediatric asthma is heterogeneous with phenotypes that reflect differing underlying inflammation and pathophysiology. Little is known about the national prevalence of certain obesity- and allergy-related asthma phenotypes or associated characteristics. We therefore assessed the national prevalence, risk factors, and caregiver-reported severity of four asthma phenotypes: not-allergic-not-obese, allergic-not-obese, obese-not-allergic, and allergic-and-obese.MethodsWe analyzed data from the 2007-2008 National Survey of Children's Health (NSCH) of 10-17 year-olds with caregiver-reported asthma. We described sociodemographic and health risk factors of each phenotype and then applied logistic and ordinal regression models to identify associated risk factors and level of severity of the phenotypes.ResultsAmong 4427 children with asthma in this NSCH cohort, the association between race and phenotype was statistically significant (p < 0.0001); white children with asthma were most likely to have allergic-not-obese asthma while black and Hispanic children with asthma were most likely to have the obese-nonallergic phenotype (p < 0.001). Attention-deficit disorder/attention-deficit hyperactivity disorder was more likely to be present in allergic-not-obese children (odds ratio (OR) 1.50, confidence interval (CI) 1.14-1.98, p = 0.004). The phenotype with the highest risk for more severe compared to mild asthma was the obese-and-allergic asthma phenotype (OR 3.34, CI 2.23-5.01, p < 0.001).ConclusionsAllergic-not-obese asthma comprised half of our studied asthma phenotypes, while obesity-related asthma (with or without allergic components) comprised one-fifth of asthma phenotypes in this cohort representative of the US population. Children with both obese and allergic asthma are most likely to have severe asthma. Future management of childhood asthma might consider more tailoring of treatment and management plans based upon different childhood asthma phenotypes

    Caregiver outcomes of a dementia care program.

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    The University of California, Los Angeles Alzheimer's and Dementia Care (ADC) program enrolls persons living with dementia (PLWD) and their family caregivers as dyads to work with nurse practitioner dementia care specialists to provide coordinated dementia care. At one year, despite disease progression, overall the PLWDs' behavioral and depressive symptoms improved. In addition, at one-year, overall caregiver depression, strain, and distress related to behavioral symptoms also improved. However, not all dyads enrolled in the ADC program showed improvement in these outcomes. We conducted a mixed qualitative-quantitative study to explore why some participants did not benefit and what could be changed in this and other similar dementia management programs to increase the percentage who benefit. Semi-structured interviews (N=12) or surveys (N=41) were completed with 53 caregivers by telephone, mail and online. Seven areas for potential program improvement were identified from the first 12 interviews. These included: recommendations that did not match caregivers' perceived care needs, barriers to accessing care and utilizing resources, differing care needs based on stage of dementia, needing services not offered by the ADC, needing more education or support, behavioral recommendations that the caregiver felt did not work, and poor rapport of the dementia expert with caregivers. Despite having been identified as having had no clinical benefit from participating in the program, most caregivers (85%) reported that the program was very beneficial or extremely beneficial. Respondents identified the close, longitudinal relationship and access to a dementia care expert as particularly beneficial. This dichotomy highlights that perceived benefit for most of the interviewed caregivers was not captured with the formal instruments used by the program
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