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1.
N Engl J Med ; 387(16): 1477-1487, 2022 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-36198143

RESUMEN

BACKGROUND: In persons with type 1 diabetes and high glycated hemoglobin levels, the benefits of intermittently scanned continuous glucose monitoring with optional alarms for high and low blood glucose levels are uncertain. METHODS: In a parallel-group, multicenter, randomized, controlled trial involving participants with type 1 diabetes and glycated hemoglobin levels between 7.5% and 11.0%, we investigated the efficacy of intermittently scanned continuous glucose monitoring as compared with participant monitoring of blood glucose levels with fingerstick testing. The primary outcome was the glycated hemoglobin level at 24 weeks, analyzed according to the intention-to-treat principle. Key secondary outcomes included sensor data, participant-reported outcome measures, and safety. RESULTS: A total of 156 participants were randomly assigned, in a 1:1 ratio, to undergo intermittently scanned continuous glucose monitoring (the intervention group, 78 participants) or to monitor their own blood glucose levels with fingerstick testing (the usual-care group, 78 participants). At baseline, the mean (±SD) age of the participants was 44±15 years, and the mean duration of diabetes was 21±13 years; 44% of the participants were women. The mean baseline glycated hemoglobin level was 8.7±0.9% in the intervention group and 8.5±0.8% in the usual-care group; these levels decreased to 7.9±0.8% and 8.3±0.9%, respectively, at 24 weeks (adjusted mean between-group difference, -0.5 percentage points; 95% confidence interval [CI], -0.7 to -0.3; P<0.001). The time per day that the glucose level was in the target range was 9.0 percentage points (95% CI, 4.7 to 13.3) higher or 130 minutes (95% CI, 68 to 192) longer in the intervention group than in the usual-care group, and the time spent in a hypoglycemic state (blood glucose level, <70 mg per deciliter [<3.9 mmol per liter]) was 3.0 percentage points (95% CI, 1.4 to 4.5) lower or 43 minutes (95% CI, 20 to 65) shorter in the intervention group. Two participants in the usual-care group had an episode of severe hypoglycemia, and 1 participant in the intervention group had a skin reaction to the sensor. CONCLUSIONS: Among participants with type 1 diabetes and high glycated hemoglobin levels, the use of intermittently scanned continuous glucose monitoring with optional alarms for high and low blood glucose levels resulted in significantly lower glycated hemoglobin levels than levels monitored by fingerstick testing. (Funded by Diabetes UK and others; FLASH-UK ClinicalTrials.gov number, NCT03815006.).


Asunto(s)
Automonitorización de la Glucosa Sanguínea , Diabetes Mellitus Tipo 1 , Hemoglobina Glucada , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Glucemia/análisis , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hemoglobina Glucada/análisis , Hipoglucemia/inducido químicamente , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación
2.
Br J Haematol ; 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38867615

RESUMEN

Immune responses to primary COVID-19 vaccination were investigated in 58 patients with follicular lymphoma (FL) as part of the PETReA trial of frontline therapy (EudraCT 2016-004010-10). COVID-19 vaccines (BNT162b2 or ChAdOx1) were administered before, during or after cytoreductive treatment comprising rituximab (depletes B cells) and either bendamustine (depletes CD4+ T cells) or cyclophosphamide-based chemotherapy. Blood samples obtained after vaccine doses 1 and 2 (V1, V2) were analysed for antibodies and T cells reactive to the SARS-CoV-2 spike protein using the Abbott Architect and interferon-gamma ELISpot assays respectively. Compared to 149 healthy controls, patients with FL exhibited lower antibody but preserved T-cell responses. Within the FL cohort, multivariable analysis identified low pre-treatment serum IgA levels and V2 administration during induction or maintenance treatment as independent determinants of lower antibody and higher T-cell responses, and bendamustine and high/intermediate FLIPI-2 score as additional determinants of a lower antibody response. Several clinical scenarios were identified where dichotomous immune responses were estimated with >95% confidence based on combinations of predictive variables. In conclusion, the immunogenicity of COVID-19 vaccines in FL patients is influenced by multiple disease- and treatment-related factors, among which B-cell depletion showed differential effects on antibody and T-cell responses.

3.
Diabet Med ; 41(3): e15232, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37750427

RESUMEN

OBJECTIVE: We previously showed that intermittently scanned continuous glucose monitoring (isCGM) reduces HbA1c at 24 weeks compared with self-monitoring of blood glucose with finger pricking (SMBG) in adults with type 1 diabetes and high HbA1c levels (58-97 mmol/mol [7.5%-11%]). We aim to assess the economic impact of isCGM compared with SMBG. METHODS: Participant-level baseline and follow-up health status (EQ-5D-5L) and within-trial healthcare resource-use data were collected. Quality-adjusted life-years (QALYs) were derived at 24 weeks, adjusting for baseline EQ-5D-5L. Participant-level costs were generated. Using the IQVIA CORE Diabetes Model, economic analysis was performed from the National Health Service perspective over a lifetime horizon, discounted at 3.5%. RESULTS: Within-trial EQ-5D-5L showed non-significant adjusted incremental QALY gain of 0.006 (95% CI: -0.007 to 0.019) for isCGM compared with SMBG and an adjusted cost increase of £548 (95% CI: 381-714) per participant. The lifetime projected incremental cost (95% CI) of isCGM was £1954 (-5108 to 8904) with an incremental QALY (95% CI) gain of 0.436 (0.195-0.652) resulting in an incremental cost-per-QALY of £4477. In all subgroups, isCGM had an incremental cost-per-QALY better than £20,000 compared with SMBG; for people with baseline HbA1c >75 mmol/mol (9.0%), it was cost-saving. Sensitivity analysis suggested that isCGM remains cost-effective if its effectiveness lasts for at least 7 years. CONCLUSION: While isCGM is associated with increased short-term costs, compared with SMBG, its benefits in lowering HbA1c will lead to sufficient long-term health-gains and cost-savings to justify costs, so long as the effect lasts into the medium term.


Asunto(s)
Diabetes Mellitus Tipo 1 , Adulto , Humanos , Diabetes Mellitus Tipo 1/terapia , Glucemia , Análisis Costo-Beneficio , Automonitorización de la Glucosa Sanguínea/métodos , Hemoglobina Glucada , Monitoreo Continuo de Glucosa , Medicina Estatal , Inglaterra/epidemiología , Hipoglucemiantes
4.
Diabet Med ; 41(3): e15249, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37897112

RESUMEN

AIMS: The FLASH-UK trial showed lower HbA1c with intermittently scanned continuous glucose monitoring (isCGM), as compared with self monitoring of blood glucose (SMBG), in adults with type 1 diabetes and HbA1c ≥58 mmol/mol (≥7.5%). Here, we present results from the pre-specified subgroup analysis for the 24-week HbA1c (primary outcome) and selected sensor-based secondary outcomes. METHODS: This was a multi-centre, parallel-design, randomised controlled trial. The difference in treatment effect between subgroups (baseline HbA1c [≤75 vs. >75 mmol/mol] [≤9.0 vs >9.0%], treatment modality [pump vs injections], prior participation in structured education, age, educational level, impaired awareness of hypoglycaemia, deprivation index quintile sex, ethnic group and Patient Health Questionnaire-9 [PHQ-9] detected depression category) were evaluated. RESULTS: One hundred fifty-six participants (females 44%, mean [SD] baseline HbA1c 71 [9] mmol/mol 8.6 [0.8%], age 44 [15]) were randomly assigned, in a 1:1 ratio to isCGM (n = 78) or SMBG (n = 78). The mean (SD) baseline HbA1c (%) was 8.7 (0.9) in the isCGM group and 8.5 (0.8) in the SMBG group, lowering to 7.9 (0.8) versus 8.3 (0.9), respectively, at 24 weeks (adjusted mean difference -0.5, 95% confidence interval [CI] -0.7 to -0.3; p < 0.001]. For HbA1c, there was no impact of treatment modality, prior participation in structured education, deprivation index quintile, sex or baseline depression category. The between-group difference in HbA1c was larger for younger people (a reduction of 2.7 [95% CI 0.3-5.0; p = 0.028] mmol/mol for every additional 15 years of age). Those with HbA1c 76-97 mmol/mol (>9.0%-11.0%) had a marginally non-significant higher reduction in HbA1c of 8.4 mmol/mol (3.3-13.5) compared to 3.1 (0.3-6.0) in those with HbA1c 58-75 mmol/mol (p = 0.08). For 'Time in range' (% 3.9-10 mmol/L), the difference was larger for those with at least a bachelor's degree. For 'Time below range' (% <3.9 mmol/L), the difference was larger for those using injections, older people and those with less than bachelor's degree. CONCLUSIONS: Intermittently scanned continuous glucose monitoring is generally effective across a range of baseline characteristics.


Asunto(s)
Diabetes Mellitus Tipo 1 , Adulto , Femenino , Humanos , Anciano , Glucemia/análisis , Hemoglobina Glucada , Automonitorización de la Glucosa Sanguínea/métodos , Monitoreo Continuo de Glucosa , Reino Unido , Hipoglucemiantes/uso terapéutico
5.
Immunity ; 42(6): 1143-58, 2015 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-26070485

RESUMEN

Tissue effector cells of the monocyte lineage can differentiate into different cell types with specific cell function depending on their environment. The phenotype, developmental requirements, and functional mechanisms of immune protective macrophages that mediate the induction of transplantation tolerance remain elusive. Here, we demonstrate that costimulatory blockade favored accumulation of DC-SIGN-expressing macrophages that inhibited CD8(+) T cell immunity and promoted CD4(+)Foxp3(+) Treg cell expansion in numbers. Mechanistically, that simultaneous DC-SIGN engagement by fucosylated ligands and TLR4 signaling was required for production of immunoregulatory IL-10 associated with prolonged allograft survival. Deletion of DC-SIGN-expressing macrophages in vivo, interfering with their CSF1-dependent development, or preventing the DC-SIGN signaling pathway abrogated tolerance. Together, the results provide new insights into the tolerogenic effects of costimulatory blockade and identify DC-SIGN(+) suppressive macrophages as crucial mediators of immunological tolerance with the concomitant therapeutic implications in the clinic.


Asunto(s)
Moléculas de Adhesión Celular/metabolismo , Rechazo de Injerto/prevención & control , Trasplante de Corazón , Lectinas Tipo C/metabolismo , Macrófagos/inmunología , Receptores de Superficie Celular/metabolismo , Linfocitos T Reguladores/inmunología , Animales , Linfocitos T CD8-positivos/inmunología , Moléculas de Adhesión Celular/genética , Células Cultivadas , Factores de Transcripción Forkhead/metabolismo , Rechazo de Injerto/etiología , Tolerancia Inmunológica , Interleucina-10/metabolismo , Lectinas Tipo C/genética , Factor Estimulante de Colonias de Macrófagos/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Terapia Molecular Dirigida , Receptores de Superficie Celular/genética , Transducción de Señal , Receptor Toll-Like 4/metabolismo , Tolerancia al Trasplante , Regulación hacia Arriba
6.
Environ Geochem Health ; 45(11): 8489-8501, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37646920

RESUMEN

Stormwater infiltration basins have been used extensively around the world to restore urban hydrology towards more natural flow and water quality regimes. There is, however, significant uncertainty in the fate of infiltrated water and accompanying contaminants that depends on multiple factors including media characteristics, interactions with downslope vegetation, legacy contaminants, and presence of underground infrastructure. Understanding the influence of such factors is thus central to the design and siting of infiltration basins. An extensive field program was established to collect monthly data on ground water quality, including nutrients and major ion concentrations, in a bore network downstream of a stormwater infiltration basin in Victoria, Australia. The groundwater samples were analysed for temperature, pH, EC, turbidity, major ions (Na+, Ca2+, K+, Mg2+, Cl-, SO42-, NO3-, CO32-, HCO3-), NOx and heavy metals. The collected data were used to understand the origin and fate of water and solutes in the subsurface and their interactions with the soil matrix. The results revealed that Ca-HCO3, Na-Cl water types predominate in the study area, grouped in 3 clusters; shallow fresh groundwater in the vicinity of the basin (near basin), deep saline groundwater further downstream of the basin (near-stream) and a mid-section where rock-water interaction (Na-HCO3 water) through cation exchange control the chemistry of groundwater. The results also suggest that as the water moves downstream of the basin, it experiences significant evapotranspiration and concentration due to the presence of deep-rooted vegetation. The results suggest that while infiltration basins can remove infiltrated contaminants, the infiltrated stormwater can mobilise legacy contaminants such as nitrate. Overall, the efficacy of infiltration basins in urban regions depends substantially on the downstream vegetation, urban underground infrastructure and the presence of legacy contaminants in the soils. These all need to be considered in the design of stormwater infiltration basins.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Contaminantes Químicos del Agua/análisis , Agua Subterránea/química , Calidad del Agua , Cationes/análisis , Suelo/química , Victoria , Monitoreo del Ambiente/métodos
7.
Nature ; 513(7517): 183-8, 2014 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-25209797

RESUMEN

Molecular 'assembly lines', in which organic molecules undergo iterative processes such as chain elongation and functional group manipulation, are found in many natural systems, including polyketide biosynthesis. Here we report the creation of such an assembly line using the iterative, reagent-controlled homologation of a boronic ester. This process relies on the reactivity of α-lithioethyl tri-isopropylbenzoate, which inserts into carbon-boron bonds with exceptionally high fidelity and stereocontrol; each chain-extension step generates a new boronic ester, which is immediately ready for further homologation. We used this method to generate organic molecules that contain ten contiguous, stereochemically defined methyl groups. Several stereoisomers were synthesized and shown to adopt different shapes-helical or linear-depending on the stereochemistry of the methyl groups. This work should facilitate the rational design of molecules with predictable shapes, which could have an impact in areas of molecular sciences in which bespoke molecules are required.


Asunto(s)
Técnicas de Química Sintética/métodos , Policétidos/síntesis química , Técnicas de Química Sintética/normas , Espectroscopía de Resonancia Magnética , Conformación Molecular , Policétidos/química
8.
Sensors (Basel) ; 20(23)2020 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-33291592

RESUMEN

The desire to remain living in one's own home rather than a care home by those in need of 24/7 care is one that requires a level of understanding for the actions of an environment's inhabitants. This can potentially be accomplished with the ability to recognise Activities of Daily Living (ADLs); however, this research focuses first on producing an unobtrusive solution for pose recognition where the preservation of privacy is a primary aim. With an accurate manner of predicting an inhabitant's poses, their interactions with objects within the environment and, therefore, the activities they are performing, can begin to be understood. This research implements a Convolutional Neural Network (CNN), which has been designed with an original architecture derived from the popular AlexNet, to predict poses from thermal imagery that have been captured using thermopile infrared sensors (TISs). Five TISs have been deployed within the smart kitchen in Ulster University where each provides input to a corresponding trained CNN. The approach is evaluated using an original dataset and an F1-score of 0.9920 was achieved with all five TISs. The limitations of utilising a ceiling-based TIS are investigated and each possible permutation of corner-based TISs is evaluated to satisfy a trade-off between the number of TISs, the total sensor cost and the performances. These tests are also promising as F1-scores of 0.9266, 0.9149 and 0.8468 were achieved with the isolated use of four, three, and two corner TISs, respectively.


Asunto(s)
Actividades Cotidianas , Redes Neurales de la Computación , Humanos , Monitoreo Fisiológico
9.
J Am Chem Soc ; 141(12): 4815-4819, 2019 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-30865436

RESUMEN

Reliable design of artificial metalloenzymes (ArMs) to access transformations not observed in nature remains a long-standing and important challenge. We report that a monomeric streptavidin (mSav) Rh(III) ArM permits asymmetric synthesis of α,ß-unsaturated-δ-lactams via a tandem C-H activation and [4+2] annulation reaction. These products are readily derivatized to enantioenriched piperidines, the most common N-heterocycle found in FDA approved pharmaceuticals. Desired δ-lactams are achieved in yields as high as 99% and enantiomeric excess of 97% under aqueous conditions at room temperature. Embedding a Rh cyclopentadienyl (Cp*) catalyst in the active site of mSav results in improved stereocontrol and a 7-fold enhancement in reactivity relative to the isolated biotinylated Rh(III) cofactor. In addition, mSav-Rh outperforms its well-established tetrameric forms, displaying 11-33 times more reactivity.


Asunto(s)
Materiales Biomiméticos/química , Lactamas/síntesis química , Metaloproteínas/metabolismo , Estreptavidina/química , Técnicas de Química Sintética , Lactamas/química , Metaloproteínas/química , Modelos Moleculares , Conformación Proteica
10.
Hum Mol Genet ; 26(12): 2321-2334, 2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-28398512

RESUMEN

Mutations of various genes cause hereditary spastic paraplegia (HSP), a neurological disease involving dying-back degeneration of upper motor neurons. From these, mutations in the SPAST gene encoding the microtubule-severing protein spastin account for most HSP cases. Cumulative genetic and experimental evidence suggests that alterations in various intracellular trafficking events, including fast axonal transport (FAT), may contribute to HSP pathogenesis. However, the mechanisms linking SPAST mutations to such deficits remain largely unknown. Experiments presented here using isolated squid axoplasm reveal inhibition of FAT as a common toxic effect elicited by spastin proteins with different HSP mutations, independent of microtubule-binding or severing activity. Mutant spastin proteins produce this toxic effect only when presented as the tissue-specific M1 isoform, not when presented as the ubiquitously-expressed shorter M87 isoform. Biochemical and pharmacological experiments further indicate that the toxic effects of mutant M1 spastins on FAT involve casein kinase 2 (CK2) activation. In mammalian cells, expression of mutant M1 spastins, but not their mutant M87 counterparts, promotes abnormalities in the distribution of intracellular organelles that are correctable by pharmacological CK2 inhibition. Collectively, these results demonstrate isoform-specific toxic effects of mutant M1 spastin on FAT, and identify CK2 as a critical mediator of these effects.


Asunto(s)
Adenosina Trifosfatasas/genética , Transporte Axonal/genética , Adenosina Trifosfatasas/metabolismo , Animales , Transporte Axonal/fisiología , Quinasa de la Caseína II/metabolismo , Células Cultivadas , Decapodiformes , Modelos Animales de Enfermedad , Fibroblastos , Humanos , Microtúbulos/metabolismo , Neuronas Motoras/metabolismo , Proteínas Mutantes/metabolismo , Mutación , Isoformas de Proteínas/genética , Transporte de Proteínas/fisiología , Ratas , Paraplejía Espástica Hereditaria/genética , Paraplejía Espástica Hereditaria/metabolismo , Espastina
11.
12.
J Immunol ; 199(2): 774-781, 2017 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-28600293

RESUMEN

It is now well understood that thrombocytes (nucleated platelets) express TLRs and respond to both bacterial and viral products. Release of proinflammatory molecules can be expected following relatively short exposure times to LPS, lipoteichoic acid (LTA), thymidine homopolymer phosphorothioate oligonucleotide [Poly(dT)], and polyinosinic-polycytidylic acid [Poly(I:C)]. This study reports the varied expressions of genes encoded for components of the TLR, nucleotide binding oligomerization domain-like receptor, and retinoic acid-inducible gene RIG-like receptor signaling pathways in response to the TLR ligands listed above. Highly sensitive RNA-sequencing technologies were used to analyze the complete transcriptome of thrombocytes treated with all four microbial products for a period of 1 h. A total of 14,326 gene transcripts were found in chicken thrombocytes across all ligand exposures. After 1 h of stimulation with ligands, 87, 138, 1013, and 22 genes were upregulated for LTA, LPS, Poly(dT), and Poly(I:C), and 12, 142, 249, and 16 genes were downregulated for LTA, LPS, Poly(dT), and Poly(I:C), respectively, with at least a 1-fold change relative to unexposed thrombocytes. Summarizations of biological processes, protein classes, and biochemical pathways reveal the role of chicken thrombocytes in proinflammatory responses linked to key signaling pathways. TLR, nucleotide binding oligomerization domain-like receptor, and retinoic acid-inducible gene RIG-like receptor pathways were mapped based on the transcriptome results with gene expression for common signal and proinflammatory mediators highlighted. The information reported in this study is useful for defining a limited set of proinflammatory molecules to evaluate in cases of either bacterial or viral disease monitoring.


Asunto(s)
Antígenos Bacterianos/inmunología , Antígenos Virales/inmunología , Plaquetas/inmunología , Receptores de Reconocimiento de Patrones/genética , Receptores de Reconocimiento de Patrones/inmunología , Animales , Antígenos Bacterianos/química , Antígenos Virales/química , Plaquetas/efectos de los fármacos , Pollos , Proteína 58 DEAD Box/inmunología , Proteína 58 DEAD Box/metabolismo , Regulación hacia Abajo , Perfilación de la Expresión Génica , Inflamación , Lipopolisacáridos/inmunología , Poli I-C/inmunología , Polidesoxirribonucleótidos/inmunología , Receptores de Reconocimiento de Patrones/metabolismo , Análisis de Secuencia de ARN , Transducción de Señal , Ácidos Teicoicos/inmunología , Receptores Toll-Like/inmunología , Receptores Toll-Like/metabolismo , Transcriptoma , Regulación hacia Arriba
13.
J Environ Manage ; 247: 242-252, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31247371

RESUMEN

Streams draining urban catchments ubiquitously undergo negative physical and ecosystem changes, recognized to be primarily driven by frequent stormwater runoff input. The common management intervention is rehabilitation of channel morphology. Despite engineering design intentions, ecohydraulic benefits of urban channel rehabilitation are largely unknown and likely limited. This investigation uses an ecohydraulic modeling approach to investigate the performance of alternative channel design configurations intended to restore key ecosystem functioning in urban streams. Channel reconfiguration design scenarios, specified to emulate the range of channel topographic complexity often used in rehabilitation are compared against a reference 'natural' scenario using ecologically relevant hydraulic metrics. The results showed that the ecohydraulic conditions were incremental improved with the addition of natural oscillations to an increasing number of individual topographic variables in a degraded channel. Results showed that reconfiguration reduced excessive frequency of bed mobility, loss of habitat and hydraulic diversity particularly as more topographic variables were added. However, the results also showed that none of the design scenarios returned the ecohydraulics to their reference conditions. This indicate that channel-based restoration can offer some potential changes to hydraulic habitat conditions but are unlikely to completely mitigate the effects of hydrologic change. We suggest that while reach-scale channel modification may be beneficial to restore urban stream, addressing altered hydrology is critical to fully recover natural ecosystem processes.


Asunto(s)
Ecosistema , Ríos , Hidrología
14.
J Environ Manage ; 233: 1-11, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30551024

RESUMEN

The potential for catchment-scale stormwater control measures (SCMs) to mitigate the impact of stormwater runoff issues and excess stormwater volume is increasingly recognised. There is, however, limited understanding about their potential in reducing in-channel disturbance and improving hydraulic conditions for stream ecosystem benefits. This study investigates the benefits that SCM application in a catchment have on in-stream hydraulics. To do this, a two-dimensional hydraulic model was employed to simulate the stream hydraulic response to scenarios of SCM application applied in an urban catchment to return towards pre-development hydrologic pulses. The hydraulic response analysis considered three hydraulic metrics associated with key components of stream ecosystem functions: benthic mobilization, hydraulic diversity and retentive habitat availability. The results showed that when applied intensively, the developed SCM scenarios could effectively restore the in-stream hydraulics to close to natural levels. Compared to an unmanaged urban case (no SCMs), SCM scenarios yielded channels with reduced bed mobility potential, close to natural hydraulic diversity and improvement of retentive habitat availability. This indicates that mitigating the effect of stormwater driven hydrological change could result in significant improvements in the physical environment to better support ecosystem functioning. We therefore suggest that intensive implementation of SCMs is an important action in an urbanizing catchment to maintain the flow regime and hydraulic conditions that sustain the 'natural' stream habitat functioning. We propose that stormwater management and protection of stream ecosystem processes should incorporate hydraulic metrics to measure the effectiveness of management strategies.


Asunto(s)
Lluvia , Ríos , Ecosistema , Hidrología , Movimientos del Agua
15.
Am J Physiol Heart Circ Physiol ; 314(1): H3-H10, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-28939650

RESUMEN

The contribution of central command to the peripheral vasoconstrictor response during exercise has been investigated using primarily handgrip exercise. The purpose of the present study was to compare muscle sympathetic nerve activity (MSNA) responses during passive (involuntary) and active (voluntary) zero-load cycling to gain insights into the effects of central command on sympathetic outflow during dynamic exercise. Hemodynamic measurements and contralateral leg MSNA (microneurography) data were collected in 18 young healthy participants at rest and during 2 min of passive and active zero-load one-legged cycling. Arterial baroreflex control of MSNA burst occurrence and burst area were calculated separately in the time domain. Blood pressure and stroke volume increased during exercise ( P < 0.0001) but were not different between passive and active cycling ( P > 0.05). In contrast, heart rate, cardiac output, and total vascular conductance were greater during the first and second minute of active cycling ( P < 0.001). MSNA burst frequency and incidence decreased during passive and active cycling ( P < 0.0001), but no differences were detected between exercise modes ( P > 0.05). Reductions in total MSNA were attenuated during the first ( P < 0.0001) and second ( P = 0.0004) minute of active compared with passive cycling, in concert with increased MSNA burst amplitude ( P = 0.02 and P = 0.005, respectively). The sensitivity of arterial baroreflex control of MSNA burst occurrence was lower during active than passive cycling ( P = 0.01), while control of MSNA burst strength was unchanged ( P > 0.05). These results suggest that central feedforward mechanisms are involved primarily in modulating the strength, but not the occurrence, of a sympathetic burst during low-intensity dynamic leg exercise. NEW & NOTEWORTHY Muscle sympathetic nerve activity burst frequency decreased equally during passive and active cycling, but reductions in total muscle sympathetic nerve activity were attenuated during active cycling. These results suggest that central command primarily regulates the strength, not the occurrence, of a muscle sympathetic burst during low-intensity dynamic leg exercise.


Asunto(s)
Ciclismo , Encéfalo/fisiología , Ejercicio Físico/fisiología , Contracción Muscular , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/inervación , Sistema Nervioso Simpático/fisiología , Vasoconstricción , Adulto , Presión Arterial , Barorreflejo , Gasto Cardíaco , Vías Eferentes/fisiología , Femenino , Humanos , Extremidad Inferior , Masculino , Fuerza Muscular , Adulto Joven
16.
Am J Physiol Regul Integr Comp Physiol ; 314(1): R114-R121, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29070505

RESUMEN

Negative and positive muscle sympathetic nerve activity (MSNA) responders have been observed during mental stress. We hypothesized that similar MSNA response patterns could be identified during the first minute of static handgrip and contribute to the interindividual variability throughout exercise. Supine measurements of multiunit MSNA (microneurography) and continuous blood pressure (Finometer) were recorded in 29 young healthy men during the first (HG1) and second (HG2) minute of static handgrip (30% maximal voluntary contraction) and subsequent postexercise circulatory occlusion (PECO). Responders were identified on the basis of differences from the typical error of baseline total MSNA: 7 negative, 12 positive, and 10 nonresponse patterns. Positive responders demonstrated larger total MSNA responses during HG1 ( P < 0.01) and HG2 ( P < 0.0001); however, the increases in blood pressure throughout handgrip exercise were similar between all groups, as were the changes in heart rate, stroke volume, cardiac output, total vascular conductance, and respiration (all P > 0.05). Comparing negative and positive responders, total MSNA responses were similar during PECO ( P = 0.17) but opposite from HG2 to PECO (∆40 ± 46 vs. ∆-21 ± 62%, P = 0.04). Negative responders also had a shorter time-to-peak diastolic blood pressure during HG1 (20 ± 20 vs. 44 ± 14 s, P < 0.001). Total MSNA responses during HG1 were associated with responses to PECO ( r = 0.39, P < 0.05), the change from HG2 to PECO ( r = -0.49, P < 0.01), and diastolic blood pressure time to peak ( r = 0.50, P < 0.01). Overall, MSNA response patterns during the first minute of static handgrip contribute to interindividual variability and appear to be influenced by differences in central command, muscle metaboreflex activation, and rate of loading of the arterial baroreflex.


Asunto(s)
Variación Biológica Poblacional , Encéfalo/fisiología , Fuerza de la Mano , Contracción Muscular , Músculo Esquelético/inervación , Sistema Nervioso Simpático/fisiología , Adaptación Fisiológica , Adulto , Barorreflejo , Células Quimiorreceptoras/metabolismo , Metabolismo Energético , Hemodinámica , Humanos , Masculino , Músculo Esquelético/metabolismo , Factores de Tiempo , Adulto Joven
17.
J Am Chem Soc ; 139(34): 11877-11886, 2017 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-28812893

RESUMEN

The stereoselective reagent-controlled homologation of boronic esters is one of a small number of iteratable synthetic transformations that if automated could form the basis of a veritable molecule-making machine. Recently, α-stannyl triisopropylbenzoates and α-sulfinyl chlorides have emerged as useful building blocks for the iterative homologation of boronic esters. However, α-stannyl benzoates need to be prepared using stoichiometric amounts of the (+)- or (-)-enantiomer of the scarcely available and expensive diamine sparteine; also, these building blocks, together with the byproducts that are generated during homologation, are perceived as being toxic. On the other hand, α-sulfinyl chlorides are difficult to prepare with high levels of enantiopurity and are prone to undergo deleterious acid-base side-reactions under the reaction conditions for homologation, leading to low stereospecificity. Here, we show that the use of a hybrid of these two building blocks, namely, α-sulfinyl triisopropylbenzoates, largely overcomes the above drawbacks. Through either the sulfinylation of α-magnesiated benzoates with either enantiomer of Andersen's readily available menthol-derived sulfinate or the α-alkylation of enantiopure S-chiral α-sulfinyl benzoates, we have prepared a range of highly enantiopure mono- and disubstituted α-sulfinyl benzoates, some bearing sensitive functional groups. Barbier-type reaction conditions have been developed that allow these building blocks to be converted into lithium (t-BuLi) and magnesium (i-PrMgCl·LiCl) carbenoids in the presence of boronic esters, thus allowing efficient and highly stereospecific homologation. The use of magnesium carbenoids allows carbon chains to be grown with the incorporation of sensitive functional groups, such as alkyl/aryl halides, azides, and esters. The use of lithium carbenoids, which are less sensitive to steric hindrance, allows sterically encumbered carbon-carbon bonds to be forged. We have also shown that these building blocks can be used consecutively in three- and four-step iterative homologation processes, without intervening column chromatography, to give contiguously substituted carbon chains with very high levels of enantio- and diastereoselectivity.

18.
Malar J ; 15(1): 400, 2016 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-27502213

RESUMEN

BACKGROUND: Parts of Zambia with very low malaria parasite prevalence and high coverage of vector control interventions are targeted for malaria elimination through a series of interventions including reactive case detection (RCD) at community level. When a symptomatic individual presenting to a community health worker (CHW) or government clinic is diagnostically confirmed as an incident malaria case an RCD response is initiated. This consists of a CHW screening the community around the incident case with rapid diagnostic tests (RDT) and treating positive cases with artemether-lumefantrine (AL, Coartem™) in accordance with national policy. Since its inception in 2011, Zambia's RCD programme has relied on anecdotal feedback from staff to identify issues and possible solutions. In 2014, a systematic qualitative programme review was conducted to determine perceptions around malaria rates, incentives, operational challenges and solutions according to CHWs, their supervisors and district-level managers. METHODS: A criterion-based sampling framework based on training regime and performance level was used to select nine rural health posts in four districts of Southern Province. Twenty-two staff interviews were completed to produce English or bilingual (CiTonga or Silozi + English) verbatim transcripts, which were then analysed using thematic framework analysis. RESULTS: CHWs, their supervisors and district-level managers strongly credited the system with improving access to malaria services and significantly reducing the number of cases in their area. The main implementation barriers included access (e.g., lack of rain gear, broken bicycles), insufficient number of CHWs for programme coverage, communication (e.g. difficulties maintaining cell phones and "talk time" to transmit data by phone), and inconsistent supply chain (e.g., inadequate numbers of RDT kits and anti-malarial drugs to test and treat uncomplicated cases). CONCLUSIONS: This review highlights the importance of a community surveillance system like RCD in shaping Zambia's malaria elimination campaign by identifying community-based infections that might otherwise remain undetected. At this stage the system must ensure it can meet growing public demand by providing CHWs the tools and materials they need to consistently carry out their work and expand programme reach to more isolated communities. Results from this review will be used to plan programme scale-up into other parts of Zambia.


Asunto(s)
Erradicación de la Enfermedad , Monitoreo Epidemiológico , Investigación sobre Servicios de Salud , Malaria/epidemiología , Malaria/prevención & control , Agentes Comunitarios de Salud , Humanos , Entrevistas como Asunto , Zambia/epidemiología
19.
J Am Chem Soc ; 137(13): 4398-403, 2015 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-25625684

RESUMEN

The iterative homologation of boronic esters using chiral lithiated benzoate esters and chloromethyllithium has been applied to the highly efficient syntheses of two natural products, (+)-kalkitoxin and (+)-hydroxyphthioceranic acid. The chiral lithiated benzoate esters (>99% ee) were generated from the corresponding stannanes, which themselves were prepared by Hoppe-Beak deprotonation of ethyl 2,4,6-triisopropyl-benzoate with s-BuLi in the presence of (+)- or (-)-sparteine and trapping with Me3SnCl followed by recrystallization. In addition, it was found that purification between several homologations could be avoided, substantially increasing both chemical and manpower efficiency. In the case of (+)-kalkitoxin, six iterative homologations were conducted on commercially available p-MeOC6H4CH2Bpin to build up the core of the molecule before the C-B bond was converted into the desired C-N bond, without purification of intermediates. In the case of (+)-hydroxyphthioceranic acid, 16 iterative homologations were conducted on p-MeOC6H4Bpin with only four intermediate purifications before oxidation of the C-B bond to the desired alcohol. The stereocontrolled and efficient syntheses of these complex molecules highlight the power of iterative chemical synthesis using boronic esters.


Asunto(s)
Ácidos Borónicos/química , Ácidos Borónicos/síntesis química , Ácidos Grasos/química , Ácidos Grasos/síntesis química , Lípidos/química , Lípidos/síntesis química , Tiazoles/química , Tiazoles/síntesis química , Técnicas de Química Sintética , Estereoisomerismo
20.
Malar J ; 14: 222, 2015 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-26017275

RESUMEN

BACKGROUND: Accurate and timely malaria data are crucial to monitor the progress towards and attainment of elimination. Lusaka, the capital city of Zambia, has reported very low malaria prevalence in Malaria Indicator Surveys. Issues of low malaria testing rates, high numbers of unconfirmed malaria cases and over consumption of anti-malarials were common at clinics within Lusaka, however. The Government of Zambia (GRZ) and its partners sought to address these issues through an enhanced surveillance and feedback programme at clinic level. METHODS: The enhanced malaria surveillance programme began in 2011 to verify trends in reported malaria, as well as to implement a data feedback loop to improve data uptake, use, and quality. A process of monthly data collection and provision of feedback was implemented within all GRZ health clinics in Lusaka District. During clinic visits, clinic registers were accessed to record the number of reported malaria cases, malaria test positivity rate, malaria testing rate, and proportion of total suspected malaria that was confirmed with a diagnostic test. RESULTS AND DISCUSSION: Following the enhanced surveillance programme, the odds of receiving a diagnostic test for a suspected malaria case increased (OR = 1.54, 95 % CI = 0.96-2.49) followed by an upward monthly trend (OR = 1.05, 95 % CI = 1.01-1.09). The odds of a reported malaria case being diagnostically confirmed also increased monthly (1.09, 95 % CI 1.04-1.15). After an initial 140 % increase (95 % CI = 91-183 %), costs fell by 11 % each month (95 % CI = 5.7-10.9 %). Although the mean testing rate increased from 18.9 to 64.4 % over the time period, the proportion of reported malaria unconfirmed by diagnostic remained high at 76 %. CONCLUSIONS: Enhanced surveillance and implementation of a data feedback loop have substantially increased malaria testing rates and decreased the number of unconfirmed malaria cases and courses of ACT consumed in Lusaka District within just two years. Continued support of enhanced surveillance in Lusaka as well as national scale-up of the system is recommended to reinforce good case management and to ensure timely, reliable data are available to guide targeting of limited malaria prevention and control resources in Zambia.


Asunto(s)
Monitoreo Epidemiológico , Malaria/epidemiología , Vigilancia en Salud Pública/métodos , Preescolar , Pruebas Diagnósticas de Rutina/estadística & datos numéricos , Humanos , Lactante , Recién Nacido , Malaria/diagnóstico , Malaria/parasitología , Prevalencia , Zambia/epidemiología
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