20 research outputs found

    3D printed microneedles for insulin skin delivery

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    In this study, polymeric microneedle patches were fabricated by stereolithography, a 3D printing technique, for the transdermal delivery of insulin. A biocompatible resin was photopolymerized to build pyramid and cone microneedle designs followed by inkjet print coating of insulin formulations. Trehalose, mannitol and xylitol were used as drug carriers with the aim to preserve insulin integrity and stability but also to facilitate rapid release rates. Circular dichroism and Raman analysis demonstrated that all carriers maintained the native form of insulin, with xylitol presenting the best performance. Franz cell release studies were used for in vitro determination of insulin release rates in porcine skin. Insulin was released rapidly within 30 min irrespectively of the microneedle design. 3D printing was proved an effective technology for the fabrication of biocompatible and scalable microneedle patches

    Cyclic phosphonium ionic liquids

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    Ionic liquids (ILs) incorporating cyclic phosphonium cations are a novel category of materials. We report here on the synthesis and characterization of four new cyclic phosphonium bis(trifluoromethylsulfonyl)amide ILs with aliphatic and aromatic pendant groups. In addition to the syntheses of these novel materials, we report on a comparison of their properties with their ammonium congeners. These exemplars are slightly less conductive and have slightly smaller self-diffusion coefficients than their cyclic ammonium congeners

    Corrigendum: Plasticity in One Hemisphere, Control From Two: Adaptation in Descending Motor Pathways After Unilateral Corticospinal Injury in Neonatal Rats

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    After injury to the corticospinal tract (CST) in early development there is large-scale adaptation of descending motor pathways. Some studies suggest the uninjured hemisphere controls the impaired forelimb, while others suggest that the injured hemisphere does; these pathways have never been compared directly. We tested the contribution of each motor cortex to the recovery forelimb function after neonatal injury of the CST. We cut the left pyramid (pyramidotomy) of postnatal day 7 rats, which caused a measurable impairment of the right forelimb. We used pharmacological inactivation of each motor cortex to test its contribution to a skilled reach and supination task. Rats with neonatal pyramidotomy were further impaired by inactivation of motor cortex in both the injured and the uninjured hemispheres, while the forelimb of uninjured rats was impaired only from the contralateral motor cortex. Thus, inactivation demonstrated motor control from each motor cortex. In contrast, physiological and anatomical interrogation of these pathways support adaptations only in the uninjured hemisphere. Intracortical microstimulation of motor cortex in the uninjured hemisphere of rats with neonatal pyramidotomy produced responses from both forelimbs, while stimulation of the injured hemisphere did not elicit responses from either forelimb. Both anterograde and retrograde tracers were used to label corticofugal pathways. There was no increased plasticity from the injured hemisphere, either from cortex to the red nucleus or the red nucleus to the spinal cord. In contrast, there were very strong CST connections to both halves of the spinal cord from the uninjured motor cortex. Retrograde tracing produced maps of each forelimb within the uninjured hemisphere, and these were partly segregated. This suggests that the uninjured hemisphere may encode separate control of the unimpaired and the impaired forelimbs of rats with neonatal pyramidotomy

    Deterministic Evolutionary Trajectories Influence Primary Tumor Growth: TRACERx Renal.

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    The evolutionary features of clear-cell renal cell carcinoma (ccRCC) have not been systematically studied to date. We analyzed 1,206 primary tumor regions from 101 patients recruited into the multi-center prospective study, TRACERx Renal. We observe up to 30 driver events per tumor and show that subclonal diversification is associated with known prognostic parameters. By resolving the patterns of driver event ordering, co-occurrence, and mutual exclusivity at clone level, we show the deterministic nature of clonal evolution. ccRCC can be grouped into seven evolutionary subtypes, ranging from tumors characterized by early fixation of multiple mutational and copy number drivers and rapid metastases to highly branched tumors with >10 subclonal drivers and extensive parallel evolution associated with attenuated progression. We identify genetic diversity and chromosomal complexity as determinants of patient outcome. Our insights reconcile the variable clinical behavior of ccRCC and suggest evolutionary potential as a biomarker for both intervention and surveillance

    Tracking Cancer Evolution Reveals Constrained Routes to Metastases: TRACERx Renal.

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    Clear-cell renal cell carcinoma (ccRCC) exhibits a broad range of metastatic phenotypes that have not been systematically studied to date. Here, we analyzed 575 primary and 335 metastatic biopsies across 100 patients with metastatic ccRCC, including two cases sampledat post-mortem. Metastatic competence was afforded by chromosome complexity, and we identify 9p loss as a highly selected event driving metastasis and ccRCC-related mortality (p = 0.0014). Distinct patterns of metastatic dissemination were observed, including rapid progression to multiple tissue sites seeded by primary tumors of monoclonal structure. By contrast, we observed attenuated progression in cases characterized by high primary tumor heterogeneity, with metastatic competence acquired gradually and initial progression to solitary metastasis. Finally, we observed early divergence of primitive ancestral clones and protracted latency of up to two decades as a feature of pancreatic metastases

    Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

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    Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

    Global volumetric reductions across amygdala nuclei in chronic TBI

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    BACKGROUND: Traumatic brain injury (TBI) may increase susceptibility to neurodegenerative diseases later in life, that is, the accelerated aging hypothesis. This is supported by recent research demonstrating subcortical gray matter atrophy patterns in chronic TBI (M=9 years post-injury) that are similar to some neurodegenerative diseases. Atrophy appears to be global across hippocampal subfields and selective across thalamic nuclei. There have been no investigations into differential atrophy patterns across amygdalar nuclei in chronic TBI. OBJECTIVE: Given the close proximity between the amygdala and hippocampus, and amygdala atrophy implicated in some neurodegenerative conditions, the aims of the present investigation are to determine 1) whether the pattern of amygdala atrophy in chronic TBI follows a global or selective pattern and 2) whether time since injury predicts specific nuclei atrophy. METHOD: 40 TBI and 33 non-TBI participants completed T1 weighted 3T magnetic resonance imaging scans. Amygdalae were segmented into 10 nuclei using freesurfer, summed bilaterally and adjusted for estimated intracranial volume and sex. Unpaired t-tests (alpha Holm adjusted) and Cohen’s D were used to compare groups. Partial correlations (adjusting for age) were used to test the relationship between nuclei and time since injury. RESULTS: Amygdala volumes were smaller in the TBI group than the non-TBI group and this pattern was consistent across all 10 amygdala nuclei suggesting a global pattern. No correlations between amygdala nuclei and time since injury were significant. CONCLUSION: Global changes across amygdala nuclei is evident in chronic TBI. This is similar to the global pattern of atrophy observed across hippocampal subfields and in contrast to selective thalamic atrophy that is evident in these same individuals. Lack of a relationship between nuclei and time since injury does not support the accelerate

    Plasticity in One Hemisphere, Control From Two: Adaptation in Descending Motor Pathways After Unilateral Corticospinal Injury in Neonatal Rats

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    After injury to the corticospinal tract (CST) in early development there is large-scale adaptation of descending motor pathways. Some studies suggest the uninjured hemisphere controls the impaired forelimb, while others suggest that the injured hemisphere does; these pathways have never been compared directly. We tested the contribution of each motor cortex to the recovery forelimb function after neonatal injury of the CST. We cut the left pyramid (pyramidotomy) of postnatal day 7 rats, which caused a measurable impairment of the right forelimb. We used pharmacological inactivation of each motor cortex to test its contribution to a skilled reach and supination task. Rats with neonatal pyramidotomy were further impaired by inactivation of motor cortex in both the injured and the uninjured hemispheres, while the forelimb of uninjured rats was impaired only from the contralateral motor cortex. Thus, inactivation demonstrated motor control from each motor cortex. In contrast, physiological and anatomical interrogation of these pathways support adaptations only in the uninjured hemisphere. Intracortical microstimulation of motor cortex in the uninjured hemisphere of rats with neonatal pyramidotomy produced responses from both forelimbs, while stimulation of the injured hemisphere did not elicit responses from either forelimb. Both anterograde and retrograde tracers were used to label corticofugal pathways. There was no increased plasticity from the injured hemisphere, either from cortex to the red nucleus or the red nucleus to the spinal cord. In contrast, there were very strong CST connections to both halves of the spinal cord from the uninjured motor cortex. Retrograde tracing produced maps of each forelimb within the uninjured hemisphere, and these were partly segregated. This suggests that the uninjured hemisphere may encode separate control of the unimpaired and the impaired forelimbs of rats with neonatal pyramidotomy

    A pragmatic randomized trial of a primary care antimicrobial stewardship intervention in Ontario, Canada

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    Abstract Background More than 90% of antibiotics are prescribed in primary care, but 50% may be unnecessary. Reducing unnecessary antibiotic overuse is needed to limit antimicrobial resistance. We conducted a pragmatic trial of a primary care provider-focused antimicrobial stewardship intervention to reduce antibiotic prescriptions in primary care. Methods Primary care practitioners from six primary care clinics in Toronto, Ontario were assigned to intervention or control groups to evaluate the effectiveness of a multi-faceted intervention for reducing antibiotic prescriptions to adults with respiratory and urinary tract infections. The intervention included provider education, clinical decision aids, and audit and feedback of antibiotic prescribing. The primary outcome was total antibiotic prescriptions for these infections. Secondary outcomes were delayed prescriptions, prescriptions longer than 7 days, recommended antibiotic use, and outcomes for individual infections. Generalized estimating equations were used to estimate treatment effects, adjusting for clustering by clinic and baseline differences. Results There were 1682 encounters involving 54 primary care providers from January until May 31, 2019. In intervention clinics, the odds of any antibiotic prescription was reduced 22% (adjusted Odds Ratio (OR) = 0.78; 95% Confidence Interval (CI) = 0.64.0.96). The odds that a delay in filling a prescription was recommended was increased (adjusted OR=2.29; 95% CI=1.37, 3.83), while prescription durations greater than 7 days were reduced (adjusted OR=0.24; 95% CI=0.13, 0.43). Recommended antibiotic use was similar in control (85.4%) and intervention clinics (91.8%, p=0.37). Conclusions A community-based, primary care provider-focused antimicrobial stewardship intervention was associated with a reduced likelihood of antibiotic prescriptions for respiratory and urinary infections, an increase in delayed prescriptions, and reduced prescription durations. Trial registration clinicaltrials.gov ( NCT03517215 )
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