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1.
Nature ; 531(7595): 466-70, 2016 Mar 24.
Article in English | MEDLINE | ID: mdl-26982729

ABSTRACT

Microbial viruses can control host abundances via density-dependent lytic predator-prey dynamics. Less clear is how temperate viruses, which coexist and replicate with their host, influence microbial communities. Here we show that virus-like particles are relatively less abundant at high host densities. This suggests suppressed lysis where established models predict lytic dynamics are favoured. Meta-analysis of published viral and microbial densities showed that this trend was widespread in diverse ecosystems ranging from soil to freshwater to human lungs. Experimental manipulations showed viral densities more consistent with temperate than lytic life cycles at increasing microbial abundance. An analysis of 24 coral reef viromes showed a relative increase in the abundance of hallmark genes encoded by temperate viruses with increased microbial abundance. Based on these four lines of evidence, we propose the Piggyback-the-Winner model wherein temperate dynamics become increasingly important in ecosystems with high microbial densities; thus 'more microbes, fewer viruses'.


Subject(s)
Anthozoa/virology , Ecosystem , Host-Pathogen Interactions , Viruses/pathogenicity , Animals , Anthozoa/physiology , Bacteriophages/pathogenicity , Bacteriophages/physiology , Coral Reefs , Genes, Viral/genetics , Lysogeny , Models, Biological , Virulence/genetics , Viruses/genetics , Viruses/isolation & purification
2.
Clin Radiol ; 77(7): e500-e508, 2022 07.
Article in English | MEDLINE | ID: mdl-35487778

ABSTRACT

AIM: To determine the diagnostic accuracy of an automated artificial intelligence derived right ventricle/left ventricle diameter ratio (RV/LV) computed tomography pulmonary angiography (CTPA) analysis tool to detect pulmonary hypertension (PH) in patients with suspected PH referred to a specialist centre. MATERIALS AND METHODS: The present study was a retrospective analysis of a prospectively maintained database of 202 consecutive patients with suspected PH, who underwent CTPA within 12 months of right heart catheterisation (RHC). Automated ventricular segmentation and RV/LV calculation (Imbio LLC, Minneapolis, MN, USA) was undertaken on the CTPA images. PH diagnosis was made using the RHC reference standard. RESULTS: The automated RV/LV correlated more strongly with RHC metrics than main pulmonary artery (MPA) diameter and MPA to ascending aorta diameter ratio (MPA/AA) measured manually (mean pulmonary arterial pressure [mPAP] r=0.535, R2 = 0.287 p<0.001; pulmonary vascular resistance [PVR] r=0.607, R2 = 0.369 p<0.001). In the derivation cohort (n=100), the area under the receiver-operating curve for automated RV/LV discriminating PH was 0.752 (95% confidence interval [CI] 0.677-0.827, p<0.001). Using an optimised Youden's Index of ≥1.12 classified from derivation, automated RV/LV ratio analysis was more sensitive for the detection of PH with higher positive predictive value (PPV) when compared with manual MPA and MPA/AA in the validation cohort (n=102). Automated RV/LV compromise (1.12) and specific (1.335) thresholds were strongly predictive of mortality (log-rank 7.401, p=0.007 and log-rank 16.075, p<0.001 respectively). CONCLUSION: In suspected PH, automated RV/LV diameter thresholds have high sensitivity for PH, outperform manual MPA and MPA/AA and can predict survival.


Subject(s)
Hypertension, Pulmonary , Angiography/methods , Artificial Intelligence , Cardiac Catheterization , Heart Ventricles/diagnostic imaging , Humans , Hypertension, Pulmonary/diagnostic imaging , Pulmonary Artery/diagnostic imaging , Retrospective Studies , Tomography, X-Ray Computed/methods
3.
Osteoarthritis Cartilage ; 29(1): 89-99, 2021 01.
Article in English | MEDLINE | ID: mdl-33395574

ABSTRACT

OBJECTIVE: Cartilage health is maintained in response to a range of mechanical stimuli including compressive, shear and tensile strains and associated alterations in osmolality. The osmotic-sensitive ion channel Transient Receptor Potential Vanilloid 4 (TRPV4) is required for mechanotransduction. Mechanical stimuli inhibit interleukin-1ß (IL-1ß) mediated inflammatory signalling, however the mechanism is unclear. This study aims to clarify the role of TRPV4 in this response. DESIGN: TRPV4 activity was modulated glycogen synthase kinase (GSK205 antagonist or GSK1016790 A (GSK101) agonist) in articular chondrocytes and cartilage explants in the presence or absence of IL-1ß, mechanical (10% cyclic tensile strain (CTS), 0.33 Hz, 24hrs) or osmotic loading (200mOsm, 24hrs). Nitric oxide (NO), prostaglandin E2 (PGE2) and sulphated glycosaminoglycan (sGAG) release and cartilage biomechanics were analysed. Alterations in post-translational tubulin modifications and primary cilia length regulation were examined. RESULTS: In isolated chondrocytes, mechanical loading inhibited IL-1ß mediated NO and PGE2 release. This response was inhibited by GSK205. Similarly, osmotic loading was anti-inflammatory in cells and explants, this response was abrogated by TRPV4 inhibition. In explants, GSK101 inhibited IL-1ß mediated NO release and prevented cartilage degradation and loss of mechanical properties. Upon activation, TRPV4 cilia localisation was increased resulting in histone deacetylase 6 (HDAC6)-dependent modulation of soluble tubulin and altered cilia length regulation. CONCLUSION: Mechanical, osmotic or pharmaceutical activation of TRPV4 regulates HDAC6-dependent modulation of ciliary tubulin and is anti-inflammatory. This study reveals for the first time, the potential of TRPV4 manipulation as a novel therapeutic mechanism to supress pro-inflammatory signalling and cartilage degradation.


Subject(s)
Cartilage, Articular/metabolism , Chondrocytes/metabolism , Interleukin-1beta/metabolism , TRPV Cation Channels/metabolism , Animals , Biomechanical Phenomena , Cartilage, Articular/drug effects , Cartilage, Articular/physiopathology , Cattle , Chondrocytes/drug effects , Dinoprostone/metabolism , Glycosaminoglycans/metabolism , Histone Deacetylase 6/metabolism , Inflammation , Interleukin-1beta/drug effects , Leucine/analogs & derivatives , Leucine/pharmacology , Mechanotransduction, Cellular , Nitric Oxide/metabolism , Osmotic Pressure , Stress, Mechanical , Sulfonamides/pharmacology , TRPV Cation Channels/agonists , TRPV Cation Channels/antagonists & inhibitors
4.
Microb Ecol ; 81(3): 795-806, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33000311

ABSTRACT

Infectious diseases are one of the major drivers of coral reef decline worldwide. White plague-like disease (WPL) is a widespread disease with a complex etiology that infects several coral species, including the Brazilian endemic species Mussismilia braziliensis. Gene expression profiles of healthy and WPL-affected M. braziliensis were analyzed in winter and summer seasons. The de novo assembly of the M. braziliensis transcriptome from healthy and white plague samples produced a reference transcriptome containing 119,088 transcripts. WPL-diseased samples were characterized by repression of immune system and cellular defense processes. Autophagy and cellular adhesion transcripts were also repressed in WPL samples, suggesting exhaustion of the coral host defenses. Seasonal variation leads to plasticity in transcription with upregulation of intracellular signal transduction, apoptosis regulation, and oocyte development in the summer. Analysis of the active bacterial rRNA indicated that Pantoea bacteria were more abundant in WPL corals, while Tistlia, Fulvivirga, and Gammaproteobacteria Ga0077536 were more abundant in healthy samples. Cyanobacteria proliferation was also observed in WPL, mostly in the winter. These results indicate a scenario of dysbiosis in WPL-affected M. braziliensis, with the loss of potentially symbiotic bacteria and proliferation of opportunistic microbes after the start of the infection process.


Subject(s)
Anthozoa , Animals , Coral Reefs , Dysbiosis , Immune System , Symbiosis
5.
Nurs Educ Perspect ; 42(3): 162-164, 2021.
Article in English | MEDLINE | ID: mdl-31977969

ABSTRACT

ABSTRACT: Education in medication administration is essential to patient safety, but there is limited evidence to describe the best way to influence clinical practice by nursing students. In a medication administration pilot study, the state anxiety of 44 nursing students was evaluated presimulation and prior to giving medications in the clinical setting. Two-way analysis of variance for repeated measures indicated no significant differences between high-fidelity simulation, low-fidelity simulation, or video training groups. However, high- and low-fidelity simulation led to decreased anxiety in the clinical setting, whereas video training led to greater anxiety.


Subject(s)
Education, Nursing, Baccalaureate , High Fidelity Simulation Training , Simulation Training , Students, Nursing , Anxiety , Clinical Competence , Humans , Pilot Projects
6.
Br J Surg ; 107(7): 812-823, 2020 06.
Article in English | MEDLINE | ID: mdl-31965573

ABSTRACT

BACKGROUND: Major liver resection is associated with blood loss and transfusion. Observational data suggest that hypovolaemic phlebotomy can reduce these risks. This feasibility RCT compared hypovolaemic phlebotomy with the standard of care, to inform a future multicentre trial. METHODS: Patients undergoing major liver resections were enrolled between June 2016 and January 2018. Randomization was done during surgery and the surgeons were blinded to the group allocation. For hypovolaemic phlebotomy, 7-10 ml per kg whole blood was removed, without intravenous fluid replacement. Co-primary outcomes were feasibility and estimated blood loss (EBL). RESULTS: A total of 62 patients were randomized to hypovolaemic phlebotomy (31) or standard care (31), at a rate of 3·1 patients per month, thus meeting the co-primary feasibility endpoint. The median EBL difference was -111 ml (P = 0·456). Among patients at high risk of transfusion, the median EBL difference was -448 ml (P = 0·069). Secondary feasibility endpoints were met: enrolment, blinding and target phlebotomy (mean(s.d.) 7·6(1·9) ml per kg). Blinded surgeons perceived that parenchymal resection was easier with hypovolaemic phlebotomy than standard care (16 of 31 versus 10 of 31 respectively), and guessed that hypovolaemic phlebotomy was being used with an accuracy of 65 per cent (20 of 31). There was no significant difference in overall complications (10 of 31 versus 15 of 31 patients), major complications or transfusion. Among those at high risk, transfusion was required in two of 15 versus three of nine patients (P = 0·326). CONCLUSION: Endpoints were met successfully, but no difference in EBL was found in this feasibility study. A multicentre trial (PRICE-2) powered to identify a difference in perioperative blood transfusion is justified. Registration number: NCT02548910 ( http://www.clinicaltrials.gov).


ANTECEDENTES: La resección hepática mayor se asocia con pérdida de sangre y necesidad de transfusión. Datos observacionales sugieren que la flebotomía hipovolémica (hypovolaemic phlebotomy, HP) puede reducir estos riesgos. Este ensayo clínico aleatorizado (randomised clinical trial, RCT) de factibilidad comparó HP con el tratamiento estándar con el fin de proporcionar información para un futuro ensayo multicéntrico. MÉTODOS: Se reclutaron pacientes sometidos a resecciones hepáticas mayores entre junio 2016 y enero 2018. La aleatorización se realizó durante el intraoperatorio y los cirujanos eran ciegos al resultado de la asignación. Para la HP, se extrajeron 7-10 mL/kg de sangre total, sin reposición de líquidos intravenosos. Los resultados primarios fueron la factibilidad y la pérdida de sangre estimada (estimated blood loss, EBL). RESULTADOS: Un total de 62 pacientes se aleatorizaron a HP (n = 31) y a tratamiento estándar (n = 31), a un ritmo de 3,1 pacientes/mes, cumpliendo el co-objetivo primario de la factibilidad. La mediana de la diferencia de EBL fue 11 mL (P = 0,46). Entre los pacientes con alto riesgo de transfusión, la mediana de la diferencia de EBL fue 448 mL (P = 0,069). Los objetivos secundarios de factibilidad se consiguieron: reclutamiento (89%), cegamiento (98%), y objetivo de la flebotomía (7,6 ± 1,9 mL/kg). Los cirujanos que fueron cegados percibieron que la resección fue más fácil con la HP (52% versus 32%) y acertaron el uso de HP con una exactitud del 65%. No hubo diferencia significativa en las complicaciones globales (32% versus 48%), complicaciones mayores y transfusión. Entre aquellos pacientes de alto riesgo, la trasfusión se realizó en un 13% versus 33% (P = 0,33). CONCLUSIÓN: Se cumplieron los objetivos, pero no se identificó diferencia en EBL en este estudio de factibilidad. Ello justifica un ensayo multicéntrico (PRICE-2) con poder estadístico para identificar una diferencia en la transfusión de sangre perioperatoria.


Subject(s)
Blood Loss, Surgical/prevention & control , Hepatectomy/adverse effects , Hypovolemia/ethnology , Phlebotomy/methods , Feasibility Studies , Female , Hepatectomy/methods , Humans , Male , Middle Aged , Pilot Projects
7.
Diabet Med ; 37(6): 945-952, 2020 06.
Article in English | MEDLINE | ID: mdl-31265147

ABSTRACT

AIM: To develop a structured education programme for individuals with Type 1 diabetes who are engaging in regular exercise. METHOD: A multidisciplinary team of experts in supporting exercise and physical activity for people with Type 1 diabetes, alongside researchers with experience of developing self-management education, developed an exercise programme using the Medical Research Council framework. The programme was informed by a review of the evidence relating to Type 1 diabetes and exercise, the behaviour change literature (including the behaviour change taxonomy), and qualitative interviews with stakeholders. The programme and supporting resources were refined using an iterative process of testing, delivery and collecting feedback from participants and the wider development team. RESULTS: The outcome of the intervention development was the design of a feasible and acceptable intervention for people with Type 1 diabetes to support safe exercise. The pilot allowed refinement of the intervention prior to testing in a two-site feasibility randomized controlled trial. Key findings from the pilot informed minor restructuring of the timetable (timings and order) and adaptation of supporting educational materials (participant handbook and teaching materials). CONCLUSION: The 'EXercise in people with Type One Diabetes' (EXTOD) education programme has been developed using robust methodology for the generation of educational interventions. It now needs testing in a randomized controlled trial.


Subject(s)
Diabetes Mellitus, Type 1 , Exercise , Patient Education as Topic/methods , Program Development , Self-Management/education , Adult , Feasibility Studies , Female , Glycemic Control , Humans , Male , Middle Aged , Patient Acceptance of Health Care , Patient Safety , Pilot Projects , Qualitative Research , Stakeholder Participation
8.
Neurochem Res ; 45(6): 1375-1386, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31754956

ABSTRACT

The cystine/glutamate antiporter system Xc- (SXc-) mediates the exchange of intracellular L-glutamate (L-Glu) with extracellular L-cystine (L-Cys2). Both the import of L-Cys2 and the export of L-Glu take on added significance in CNS cells, especially astrocytes. When the relative activity of SXc- overwhelms the regulatory capacity of the EAATs, the efflux of L-Glu through the antiporter can be significant enough to trigger excitotoxic pathology, as is thought to occur in glioblastoma. This has prompted considerable interest in the pharmacological specificity of SXc- and the development of inhibitors. The present study explores a series of analogues that are structurally related to sulfasalazine, a widely employed inhibitor of SXc-. We identify a number of novel aryl-substituted amino-naphthylsulfonate analogues that inhibit SXc- more potently than sulfasalazine. Interestingly, the inhibitors switch from a competitive to noncompetitive mechanism with increased length and lipophilic substitutions, a structure-activity relationship that was previously observed with aryl-substituted isoxazole. These results suggest that the two classes of inhibitors may interact with some of the same domains on the antiporter protein and that the substrate and inhibitor binding sites may be in close proximity to one another. Molecular modeling is used to explore this possibility.


Subject(s)
Amino Acid Transport System y+/antagonists & inhibitors , Amino Acid Transport System y+/metabolism , Sulfasalazine/analogs & derivatives , Sulfasalazine/pharmacology , Amino Acid Transport System y+/chemistry , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/metabolism , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antiporters/antagonists & inhibitors , Antiporters/chemistry , Antiporters/metabolism , Binding Sites/drug effects , Binding Sites/physiology , Cell Line, Tumor , Humans , Molecular Docking Simulation/methods , Protein Structure, Secondary , Protein Structure, Tertiary , Sulfasalazine/metabolism
9.
Osteoarthritis Cartilage ; 27(7): 1064-1074, 2019 07.
Article in English | MEDLINE | ID: mdl-30922983

ABSTRACT

OBJECTIVE: Physiological mechanical loading reduces inflammatory signalling in numerous cell types including articular chondrocytes however the mechanism responsible remains unclear. This study investigates the role of chondrocyte primary cilia and associated intraflagellar transport (IFT) in the mechanical regulation of interleukin-1ß (IL-1ß) signalling. DESIGN: Isolated chondrocytes and cartilage explants were subjected to cyclic mechanical loading in the presence and absence of the cytokine IL-1ß. Nitric oxide (NO) and prostaglandin E2 (PGE2) release were used to monitor IL-1ß signalling whilst Sulphated glycosaminoglycan (sGAG) release provided measurement of cartilage degradation. Measurements were made of HDAC6 activity and tubulin polymerisation and acetylation. Effects on primary cilia were monitored by confocal and super resolution microscopy. Involvement of IFT was analysed using ORPK cells with hypomorphic mutation of IFT88. RESULTS: Mechanical loading suppressed NO and PGE2 release and prevented cartilage degradation. Loading activated HDAC6 and disrupted tubulin acetylation and cilia elongation induced by IL-1ß. HDAC6 inhibition with tubacin blocked the anti-inflammatory effects of loading and restored tubulin acetylation and cilia elongation. Hypomorphic mutation of IFT88 reduced IL-1ß signalling and abolished the anti-inflammatory effects of loading indicating the mechanism is IFT-dependent. Loading reduced the pool of non-polymerised tubulin which was replicated by taxol which also mimicked the anti-inflammatory effects of mechanical loading and prevented cilia elongation. CONCLUSIONS: This study reveals that mechanical loading suppresses inflammatory signalling, partially dependent on IFT, by activation of HDAC6 and post transcriptional modulation of tubulin.


Subject(s)
Chondrocytes/metabolism , Histone Deacetylase 6/metabolism , Interleukin-1beta/metabolism , Stress, Mechanical , Tubulin/metabolism , Animals , Biomarkers/metabolism , Blotting, Western , Cartilage, Articular/metabolism , Cattle , Cells, Cultured , Cilia/metabolism , Dinoprostone/metabolism , Humans , Microscopy, Confocal , Nitric Oxide/metabolism , Sensitivity and Specificity , Signal Transduction
10.
Osteoarthritis Cartilage ; 27(12): 1746-1754, 2019 12.
Article in English | MEDLINE | ID: mdl-31404657

ABSTRACT

OBJECTIVE: To evaluate racial and ethnic disparities in utilization of total knee arthroplasty (TKA) in relation to demographic, health, and socioeconomic status variables. DESIGN: Prospective study of 102,767 Women's Health Initiative postmenopausal women initially aged 50-79, examining utilization rates of primary TKA between non-Hispanic Black/African American, non-Hispanic White, and Hispanic/Latina women (hereafter referred to as Black, White, and Hispanic). A total of 8,942 Black, 3,405 Hispanic, and 90,420 White women with linked Medicare claims data were followed until time of TKA, death, or transition from fee-for-service coverage. Absolute disparities were determined using utilization rates by racial/ethnic group and relative disparities quantified using multivariable hazards models in adjusting for age, arthritis, joint pain, mobility disability, body mass index, number of comorbidities, income, education, neighborhood socioeconomic status (SES), and geographic region. RESULTS: TKA utilization was higher among White women (10.7/1,000 person-years) compared to Black (8.5/1,000 person-years) and Hispanic women (7.6/1,000 person-years). Among women with health indicators for TKA including diagnosis of arthritis, moderate to severe joint pain, and mobility disability, Black and Hispanic women were significantly less likely to undergo TKA after adjusting for age [Black: HR (95% confidence interval) = 0.70 (0.63-0.79); Hispanic: HR = 0.58 (0.44-0.77)]. Adjustment for SES modestly attenuated the measured disparity, but significant differences remained [Black: HR = 0.75 (0.67-0.89); Hispanic: HR = 0.65 (0.47-0.89)]. CONCLUSIONS: Compared to White women, Black and Hispanic women were significantly less likely to undergo TKA after considering need and appropriateness for TKA and SES. Further investigation into personal-level and provider-level factors that may explain these disparities is warranted.


Subject(s)
Arthralgia/surgery , Arthritis, Rheumatoid/surgery , Arthroplasty, Replacement, Knee/statistics & numerical data , Ethnicity/statistics & numerical data , Healthcare Disparities/ethnology , Mobility Limitation , Osteoarthritis, Knee/surgery , Black or African American/statistics & numerical data , Aged , Arthralgia/epidemiology , Arthritis, Rheumatoid/epidemiology , Female , Hispanic or Latino/statistics & numerical data , Humans , Medicare , Middle Aged , Osteoarthritis, Knee/epidemiology , Proportional Hazards Models , Social Class , United States/epidemiology , White People/statistics & numerical data , Women
11.
Acta Neuropathol ; 138(6): 1013-1031, 2019 12.
Article in English | MEDLINE | ID: mdl-31463572

ABSTRACT

MSTO1 encodes a cytosolic mitochondrial fusion protein, misato homolog 1 or MSTO1. While the full genotype-phenotype spectrum remains to be explored, pathogenic variants in MSTO1 have recently been reported in a small number of patients presenting with a phenotype of cerebellar ataxia, congenital muscle involvement with histologic findings ranging from myopathic to dystrophic and pigmentary retinopathy. The proposed underlying pathogenic mechanism of MSTO1-related disease is suggestive of impaired mitochondrial fusion secondary to a loss of function of MSTO1. Disorders of mitochondrial fusion and fission have been shown to also lead to mitochondrial DNA (mtDNA) depletion, linking them to the mtDNA depletion syndromes, a clinically and genetically diverse class of mitochondrial diseases characterized by a reduction of cellular mtDNA content. However, the consequences of pathogenic variants in MSTO1 on mtDNA maintenance remain poorly understood. We present extensive phenotypic and genetic data from 12 independent families, including 15 new patients harbouring a broad array of bi-allelic MSTO1 pathogenic variants, and we provide functional characterization from seven MSTO1-related disease patient fibroblasts. Bi-allelic loss-of-function variants in MSTO1 manifest clinically with a remarkably consistent phenotype of childhood-onset muscular dystrophy, corticospinal tract dysfunction and early-onset non-progressive cerebellar atrophy. MSTO1 protein was not detectable in the cultured fibroblasts of all seven patients evaluated, suggesting that pathogenic variants result in a loss of protein expression and/or affect protein stability. Consistent with impaired mitochondrial fusion, mitochondrial networks in fibroblasts were found to be fragmented. Furthermore, all fibroblasts were found to have depletion of mtDNA ranging from 30 to 70% along with alterations to mtDNA nucleoids. Our data corroborate the role of MSTO1 as a mitochondrial fusion protein and highlight a previously unrecognized link to mtDNA regulation. As impaired mitochondrial fusion is a recognized cause of mtDNA depletion syndromes, this novel link to mtDNA depletion in patient fibroblasts suggests that MSTO1-deficiency should also be considered a mtDNA depletion syndrome. Thus, we provide mechanistic insight into the disease pathogenesis associated with MSTO1 mutations and further define the clinical spectrum and the natural history of MSTO1-related disease.


Subject(s)
Cell Cycle Proteins/genetics , Cerebellar Diseases/genetics , Cytoskeletal Proteins/genetics , DNA, Mitochondrial , Mitochondrial Diseases/genetics , Muscular Dystrophies/genetics , Mutation , Adolescent , Adult , Atrophy , Cells, Cultured , Cerebellar Diseases/diagnostic imaging , Cerebellar Diseases/pathology , Cerebellar Diseases/physiopathology , Child , DNA Copy Number Variations , Female , Fibroblasts/metabolism , Fibroblasts/pathology , Humans , Male , Middle Aged , Mitochondrial Diseases/diagnostic imaging , Mitochondrial Diseases/pathology , Mitochondrial Diseases/physiopathology , Muscles/pathology , Muscular Dystrophies/diagnostic imaging , Muscular Dystrophies/pathology , Muscular Dystrophies/physiopathology , Phenotype , Young Adult
12.
Drug Dev Ind Pharm ; 45(1): 67-75, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30252537

ABSTRACT

A significant barrier to oral insulin delivery is its enzymatic degradation in the gut. Nano-sized polymer-insulin polyelectrolyte complexes (PECS) have been developed to protect insulin against enzymatic degradation. Poly(allylamine) (Paa) was trimethylated to yield QPaa. Thiolation of Paa and QPaa was achieved by attaching either N-acetylcysteine (NAC) or thiobutylamidine (TBA) ligands (Paa-NAC/QPaa-NAC and Paa-TBA/QPaa-TBA thiomers). PEC formulations were prepared in Tris buffer (pH 7.4) at various polymer: insulin mass ratios (0.2:1-2:1). PECS were characterized by %transmittance of light and photon correlation spectroscopy. Insulin complexation efficiency and enzyme-protective effect of these complexes were determined by HPLC. Complexation with insulin was found to be optimal at mass ratios of 0.4-1:1 for all polymers. PECS in this mass range were positively-charged (20-40 mV), nanoparticles (50-200 nm), with high insulin complexation efficiency (>90%). Complexation with TBA polymers appeared to result in disulfide bridge formation between the polymers and insulin. In vitro enzymatic degradation assays of QPaa, Paa-NAC, and QPaa-NAC PECS showed that they all offered some protection against insulin degradation by trypsin and α-chymotrypsin, but not from pepsin. QPaa-NAC complexes with insulin are the most promising formulation for future work, given their ability to offer protection against intestinal enzymes. This work highlights the importance of optimizing polymer structure in the delivery of proteins.


Subject(s)
Drug Delivery Systems/methods , Insulin/administration & dosage , Insulin/chemistry , Polymers/administration & dosage , Polymers/chemistry , Administration, Oral , Insulin/metabolism , Pepsin A/metabolism , Peptide Hydrolases/metabolism , Polymers/metabolism , Trypsin/metabolism
13.
Br J Dermatol ; 179(6): 1256-1262, 2018 12.
Article in English | MEDLINE | ID: mdl-28542733

ABSTRACT

This review looks at the many different factors thought to play a role in idiopathic inflammatory myopathies (IIM), concentrating mainly on the dermatomyositis (DM) subtype. Subject areas addressed include looking at the different clinical features of IIM, paying particular attention to the skin manifestations. There is a discussion around investigations needed with their perceived value, followed by a description of the immunohistochemical findings of DM. This review goes on to address other attributing factors such as genetic associations with the different subtypes of IIM, and environmental factors including infections, ultraviolet radiation and vitamin D deficiency and drugs. Finally, the potential immunopathogenesis of DM is summarized, looking at T cells, B cells, autoantibodies, dendritic cells, cytokines and nonimmune-mediated endoplasmic reticulum stress.


Subject(s)
Dermatomyositis/etiology , Muscle, Skeletal/immunology , Myositis/etiology , Skin/immunology , Autoantibodies/immunology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Cytokines/immunology , Cytokines/metabolism , Dendritic Cells/immunology , Dendritic Cells/metabolism , Dermatomyositis/pathology , Endoplasmic Reticulum Stress , Environmental Exposure/adverse effects , Genetic Predisposition to Disease , Humans , Muscle, Skeletal/cytology , Muscle, Skeletal/pathology , Myositis/pathology , Skin/cytology , Skin/pathology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Ultraviolet Rays/adverse effects , Vitamin D Deficiency/complications
14.
Epidemiol Infect ; 146(13): 1628-1634, 2018 10.
Article in English | MEDLINE | ID: mdl-30086802

ABSTRACT

In 2016, imported Zika virus (ZIKV) infections and the presence of a potentially competent mosquito vector (Aedes albopictus) implied that ZIKV transmission in New York City (NYC) was possible. The NYC Department of Health and Mental Hygiene developed contingency plans for a urosurvey to rule out ongoing local transmission as quickly as possible if a locally acquired case of confirmed ZIKV infection was suspected. We identified tools to (1) rapidly estimate the population living in any given 150-m radius (i.e. within the typical flight distance of an Aedes mosquito) and (2) calculate the sample size needed to test and rule out the further local transmission. As we expected near-zero ZIKV prevalence, methods relying on the normal approximation to the binomial distribution were inappropriate. Instead, we assumed a hypergeometric distribution, 10 missed cases at maximum, a urine assay sensitivity of 92.6% and 100% specificity. Three suspected example risk areas were evaluated with estimated population sizes of 479-4,453, corresponding to a minimum of 133-1244 urine samples. This planning exercise improved our capacity for ruling out local transmission of an emerging infection in a dense, urban environment where all residents in a suspected risk area cannot be feasibly sampled.


Subject(s)
Diagnostic Tests, Routine/methods , Population Surveillance/methods , Urine/virology , Zika Virus Infection/epidemiology , Zika Virus/isolation & purification , Humans , New York City/epidemiology , Prevalence , Sampling Studies , Sensitivity and Specificity
15.
J Eur Acad Dermatol Venereol ; 32(10): 1657-1661, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29489051

ABSTRACT

BACKGROUND: Actinic keratosis (AK) may show extension down follicles, not only in cases with full-thickness epidermal atypia ('bowenoid' AK), but also in cases with atypia limited to the epidermal basalis. Previous studies have demonstrated that, in bowenoid AK, follicular extension is usually superficial, being limited to the upper follicular segment. Little is known about the depth of follicular involvement in cases of invasive squamous cell carcinoma of the skin (iSCC) arising from AK and the role of the follicle in iSCC pathogenesis. OBJECTIVE: This study investigated the relationship between follicular extension of atypical keratinocytes in an AK and the development of iSCC from the follicular wall. The depth of follicular extension was correlated with the depth invasion of iSCC. Differences between the differentiated and classical pathways of iSCC were also examined. METHODS: We performed a retrospective histologic review of 193 biopsy specimens of iSCC with an associated AK. We assessed the presence and depth of follicular extension of atypical keratinocytes in the AK, using tumour (Breslow) thickness and the follicular unit level (infundibular, isthmic and subisthmic), as well as iSCC being present directly adjacent to the follicular basalis. RESULTS: Follicular extension was present in 25.9% of the cases (50 cases), usually extending into the lower follicular segment. The iSCC was present directly adjacent to the follicular basalis in 58% of the cases (29 cases), correlating highly with the depth of follicular extension (infundibular: 3/12; isthmic: 21/33; subisthmic 5/5). CONCLUSION: The depth of follicular extension of atypical keratinocytes in an AK correlates with the development of depth of invasion of an associated iSCC, irrespective of the pathway of origin. It is therefore important to note the presence and the depth of follicular extension when diagnosing an AK, as follicular extension likely accounts for a significant proportion of recurrent AK and the development of iSCC following superficial treatment modalities.


Subject(s)
Carcinoma, Squamous Cell/pathology , Hair Follicle/pathology , Keratosis, Actinic/pathology , Skin Neoplasms/pathology , Carcinoma, Squamous Cell/etiology , Humans , Keratinocytes/pathology , Keratosis, Actinic/complications , Keratosis, Actinic/therapy , Neoplasm Invasiveness , Retrospective Studies , Skin Neoplasms/etiology
16.
Clin Endocrinol (Oxf) ; 87(3): 257-263, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28425105

ABSTRACT

INTRODUCTION: Patients with microprolactinoma and idiopathic hyperprolactinaemia are not generally considered to be at risk of hypopituitarism and are therefore not routinely screened for this abnormality. In our clinical practice, we have observed a number of patients with nonmacroadenomatous hyperprolactinaemia to have anterior pituitary hormone deficits. AIMS: We aimed to establish the frequency and clinical significance of anterior pituitary hormone deficiencies, comparing patients with radiologically proven microprolactinomas and patients with idiopathic hyperprolactinaemia. STUDY DESIGN: We retrospectively examined the casenotes of 206 patients with hyperprolactinaemia from our centre. Patients who did not fit the profile of surgically naïve microprolactinoma or idiopathic hyperprolactinaemia or who had incomplete data were excluded, resulting in a study group of 56 patients. RESULTS: A total of 35 patients with MRI evidence of microprolactinoma were identified, three (8.57%) of whom had one or more anterior pituitary hormone deficiencies. A total of 21 patients with MRI-negative idiopathic hyperprolactinaemia were identified, nine (42%) of whom had one or more anterior pituitary hormone deficiencies (P<.01). Only one patient in the MRI-positive group had deficiency that required hormone replacement, in contrast six patients in the MRI-negative group had deficiencies that were of clinical significance and which required hormone replacement. SUMMARY: This study shows a clinically significant incidence of anterior pituitary hormone deficiency in patients with idiopathic hyperprolactinaemia. The authors recommend that dynamic pituitary assessment should be considered routinely in this patient group. A prospective study would be required to assess the underlying cause for these abnormalities, as they suggest a nontumour pan-pituitary process.


Subject(s)
Hyperprolactinemia/complications , Pituitary Hormones, Anterior/deficiency , Prolactinoma/complications , Female , Hormone Replacement Therapy , Humans , Hypopituitarism , Incidence , Magnetic Resonance Imaging , Male , Retrospective Studies
17.
Diabet Med ; 34(4): 558-562, 2017 04.
Article in English | MEDLINE | ID: mdl-27743404

ABSTRACT

AIM: To examine the impact of diabetes mellitus on procedural outcomes of patients who underwent percutaneous coronary intervention for chronic total occlusion. METHODS: We assessed the impact of diabetes mellitus on the outcomes of percutaneous coronary intervention for chronic total occlusion among 1308 people who underwent such procedures at 11 US centres between 2012 and 2015. RESULTS: The participants' mean ± sd age was 66 ± 10 years, 84% of the participants were men and 44.6% had diabetes. As compared with participants without diabetes, participants with diabetes were more likely to have undergone coronary artery bypass graft surgery (38 vs 31%; P = 0.006), and to have had previous heart failure (35 vs 22%; P = 0.0001) and peripheral arterial disease (19 vs 13%; P = 0.002). They also had a higher BMI (31 ± 6 kg/m2 vs 29 ± 6 kg/m2 ; P = 0.001), similar Japanese chronic total occlusion scores (2.6 ± 1.2 vs 2.5 ± 1.2; P = 0.82) and similar final successful crossing technique: antegrade wire escalation (46 vs 47%; P = 0.66), retrograde (30 vs 28%; P = 0.66) and antegrade dissection re-entry (24 vs 25%; P = 0.66). Technical (91 vs 90%; P = 0.80) and procedural (89 vs 89%; P = 0.93) success was similar in the two groups, as was the incidence of major adverse cardiac events (2.2 vs 2.5%; P = 0.61). CONCLUSIONS: In a contemporary cohort of people undergoing percutaneous coronary intervention for chronic total occlusion, nearly one in two (45%) had diabetes mellitus. Procedural success and complication rates were similar in people with and without diabetes.


Subject(s)
Coronary Occlusion/surgery , Diabetes Mellitus/epidemiology , Percutaneous Coronary Intervention/methods , Registries , Aged , Body Mass Index , Comorbidity , Coronary Artery Bypass/statistics & numerical data , Coronary Occlusion/epidemiology , Female , Heart Failure/epidemiology , Humans , Male , Middle Aged , Obesity/epidemiology , Peripheral Arterial Disease/epidemiology , Prognosis , Prospective Studies , Retrospective Studies , Treatment Outcome , United States
18.
Eur Cell Mater ; 34: 128-141, 2017 09 20.
Article in English | MEDLINE | ID: mdl-28929469

ABSTRACT

Tissue engineering-based therapies targeting cartilage diseases, such as osteoarthritis, require in vitro expansion of articular chondrocytes. A major obstacle for these therapies is the dedifferentiation and loss of phenotype accompanying chondrocyte expansion. Recent studies suggest that manipulation of hedgehog signalling may be used to promote chondrocyte re-differentiation. Hedgehog signalling requires the primary cilium, a microtubule-based signalling compartment, the integrity of which is linked to the cytoskeleton. We tested the hypothesis that alterations in cilia expression occurred as consequence of chondrocyte dedifferentiation and influenced hedgehog responsiveness. In vitro chondrocyte expansion to passage 5 (P5) was associated with increased actin stress fibre formation, dedifferentiation and progressive loss of primary cilia, compared to primary (P0) cells. P5 chondrocytes exhibited ~50 % fewer cilia with a reduced mean length. Cilia loss was associated with disruption of ligand-induced hedgehog signalling, such that P5 chondrocytes did not significantly regulate the expression of hedgehog target genes (GLI1 and PTCH1). This phenomenon could be recapitulated by applying 24 h cyclic tensile strain, which reduced cilia prevalence and length in P0 cells. LiCl treatment rescued cilia loss in P5 cells, partially restoring hedgehog signalling, so that GLI1 expression was significantly increased by Indian hedgehog. This study demonstrated that monolayer expansion disrupted primary cilia structure and hedgehog signalling associated with chondrocyte dedifferentiation. This excluded the possibility to use hedgehog ligands to stimulate re-differentiation without first restoring cilia expression. Furthermore, primary cilia loss during chondrocyte expansion would likely impact other cilia pathways important for cartilage health and tissue engineering, including transforming growth factor (TGF), Wnt and mechanosignalling.


Subject(s)
Chondrocytes/cytology , Cilia/metabolism , Hedgehog Proteins/metabolism , Signal Transduction , Actins/metabolism , Animals , Cartilage, Articular/cytology , Cattle , Cell Dedifferentiation/drug effects , Cell Proliferation/drug effects , Chondrocytes/drug effects , Chondrocytes/metabolism , Ligands , Lithium Chloride/pharmacology , Phenotype , Polymerization , Signal Transduction/drug effects , Weight-Bearing
19.
Curr Diab Rep ; 17(2): 8, 2017 02.
Article in English | MEDLINE | ID: mdl-28150161

ABSTRACT

PURPOSE OF REVIEW: Acromegaly is a clinical syndrome which results from growth hormone excess. Uncontrolled acromegaly is associated with cardiovascular mortality, due to an excess of risk factors including diabetes mellitus, hypertension and cardiomegaly. Diabetes mellitus is a frequent complication of acromegaly with a prevalence of 12-37%. This review will provide an overview of a number of aspects of diabetes mellitus and glucose intolerance in acromegaly including the following: 1. Epidemiology and pathophysiology of abnormalities of glucose homeostasis 2. The impact of different management options for acromegaly on glucose homeostasis 3. The management options for diabetes mellitus in patients with acromegaly RECENT FINDINGS: Growth hormone and IGF-1 have complex effects on glucose metabolism. Insulin resistance, hyperinsulinaemia and increased gluconeogenesis combine to produce a metabolic milieu which leads to the development of diabetes in acromegaly. Treatment of acromegaly should ameliorate abnormalities of glucose metabolism, due to reversal of insulin resistance and a reduction in gluconeogenesis. Recent advances in medical therapy of acromegaly have varying impacts on glucose homeostasis. These adverse effects influence management choices in patients with acromegaly who also have diabetes mellitus or glucose intolerance. The underlying mechanisms of disorders of glucose metabolism in patients with acromegaly are complex. The aim of treatment of acromegaly is normalisation of GH/IGF-1 with reduction of co-morbidities. The choice of therapy for acromegaly should consider the impact of therapy on several factors including glucose metabolism.


Subject(s)
Acromegaly/complications , Diabetes Mellitus/etiology , Acromegaly/metabolism , Acromegaly/therapy , Diabetes Mellitus/drug therapy , Diabetes Mellitus/epidemiology , Glucose/metabolism , Growth Hormone/physiology , Human Growth Hormone/analogs & derivatives , Human Growth Hormone/therapeutic use , Humans , Insulin Resistance , Insulin-Like Growth Factor I/physiology
20.
Haemophilia ; 23(5): e394-e402, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28641362

ABSTRACT

INTRODUCTION: The International Immune Tolerance Study (I-ITI) demonstrated comparable success rates between low (FVIII 50 IU/kg/TIW) and high dose (FVIII 200 IU/kg/day) regimens. While costlier, the high dose ITI regimen achieved shorter time-to-treatment success with fewer bleeding episodes compared to the low dose ITI regimen. Adding bypassing agent prophylaxis (BAP) to a low dose ITI regimen may reduce bleeding while still being less costly than high dose ITI. AIM AND METHODS: An economic model was developed to compare high dose ITI to low dose ITI with BAP. All model inputs were derived from clinical trials. The I-ITI study indicated a median time to negative inhibitor titre of 4.6 and 9.2 months and average number of bleeds/patient of 4.2 and 9.9 for the high and low dose regimens respectively. Based on the BAP trials, aPCC (85 U/kg/TIW) and rFVIIa (90 µg/kg/day) achieved a 62% and 45% reduction in bleeding frequency respectively. Cost analysis was from a US third party payer perspective and limited to drug costs. One-way, two-way and probabilistic sensitivity analyses were performed. RESULTS: Costs of low dose ITI with aPCC prophylaxis until negative inhibitor titre is achieved was 24.0% less compared to high dose ITI. Low dose ITI with rFVIIa prophylaxis cost 46.5% more compared to high dose ITI. Model results were robust in the majority of the sensitivity analyses. CONCLUSION: A low dose ITI regimen with aPCC prophylaxis may be cost saving compared to a high dose ITI regimen with the potential to reduce morbidity by lowering the risk for breakthrough bleeds.


Subject(s)
Cost-Benefit Analysis , Drug Costs , Factor VIII/administration & dosage , Hemophilia A/drug therapy , Hemorrhage/prevention & control , Immune Tolerance , Blood Coagulation Factor Inhibitors/immunology , Clinical Decision-Making , Disease Management , Factor VIII/adverse effects , Factor VIII/immunology , Hemophilia A/complications , Hemophilia A/immunology , Humans , Isoantibodies/immunology , Models, Economic , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , Recombinant Proteins/immunology
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