Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
New Phytol ; 242(6): 2411-2429, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38659154

RESUMO

Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions.


Assuntos
Briófitas , Mudança Climática , Ciclo do Nitrogênio , Água , Briófitas/fisiologia , Água/metabolismo , Ciclo do Carbono , Carbono/metabolismo , Nitrogênio/metabolismo , Ecossistema
2.
Sens Actuators B Chem ; 4022024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38559378

RESUMO

Two NAD(P)H-biosensing probes consisting of 1,3,3-trimethyl-3H-indolium and 3-quinolinium acceptors, linked by thiophene, A, and 3,4-ethylenedioxythiophene, B, bridges are detailed. We synthesized probes C and D, replacing the thiophene connection in probe A with phenyl and 2,1,3-benzothiadiazole units, respectively. Probe E was prepared by substituting probe A's 3-quinolinium unit with a 1-methylquinoxalin-1-ium unit. Solutions are non-fluorescent but in the presence of NADH, exhibit near-infrared fluorescence at 742.1 nm and 727.2 nm for probes A and B, respectively, and generate absorbance signals at 690.6 nm and 685.9 nm. In contrast, probes C and D displayed pronounced interference from NADH fluorescence at 450 nm, whereas probe E exhibited minimal fluorescence alterations in response to NAD(P)H. Pre-treatment of A549 cells with glucose in the presence of probe A led to a significant increase in fluorescence intensity. Additionally, subjecting probe A to lactate and pyruvate molecules resulted in opposite changes in NAD(P)H levels, with lactate causing a substantial increase in fluorescence intensity, conversely, pyruvate resulted in a sharp decrease. Treatment of A549 cells with varying concentrations of the drugs cisplatin, gemcitabine, and camptothecin (5, 10, and 20 µM) led to a concentration-dependent increase in intracellular fluorescence intensity, signifying a rise in NAD(P)H levels. Finally, fruit fly larvae were treated with different concentrations of NADH and cisplatin illustrating applicability to live organisms. The results demonstrated a direct correlation between fluorescence intensity and the concentration of NADH and cisplatin, respectively, further confirming the efficacy of probe A in sensing changes in NAD(P)H levels within a whole organism.

3.
J Mater Chem B ; 12(2): 448-465, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38063074

RESUMO

A series of near-infrared fluorescent probes, labeled A to E, were developed by combining electron-rich thiophene and 3,4-ethylenedioxythiophene bridges with 3-quinolinium and various electron deficient groups, enabling the sensing of NAD(P)H. Probes A and B exhibit absorptions and emissions in the near-infrared range, offering advantages such as minimal interference from autofluorescence, negligible photo impairment in cells and tissues, and exceptional tissue penetration. These probes show negligible fluorescence when NADH is not present, and their absorption maxima are at 438 nm and 470 nm, respectively. In contrast, probes C-E feature absorption maxima at 450, 334 and 581 nm, respectively. Added NADH triggers the transformation of the electron-deficient 3-quinolinium units into electron-rich 1,4-dihydroquinoline units resulting in fluorescence responses which were established at 748, 730, 575, 625 and 661 for probes AH-EH, respectively, at detection limits of 0.15 µM and 0.07 µM for probes A and B, respectively. Optimized geometries based on theoretical calculations reveal non-planar geometries for probes A-E due to twisting of the 3-quinolinium and benzothiazolium units bonded to the central thiophene group, which all attain planarity upon addition of hydride resulting in absorption and fluorescence in the near-IR region for probes AH and BH in contrast to probes CH-EH which depict fluorescence in the visible range. Probe A has been successfully employed to monitor NAD(P)H levels in glycolysis and specific mitochondrial targeting. Furthermore, it has been used to assess the influence of lactate and pyruvate on the levels of NAD(P)H, to explore how hypoxia in cancer cells can elevate levels of NAD(P)H, and to visualize changes in levels of NAD(P)H under hypoxic conditions with CoCl2 treatment. Additionally, probe A has facilitated the examination of the potential impact of chemotherapy drugs, namely gemcitabine, camptothecin, and cisplatin, on metabolic processes and energy generation within cancer cells by affecting NAD(P)H levels. Treatment of A549 cancer cells with these drugs has been shown to increase NAD(P)H levels, which may contribute to their anticancer effects ultimately leading to programmed cell death or apoptosis. Moreover, probe A has been successfully employed in monitoring NAD(P)H level changes in D. melanogaster larvae treated with cisplatin.


Assuntos
NAD , Neoplasias , Animais , NAD/metabolismo , Cisplatino , Drosophila melanogaster/metabolismo , Elétrons , Mitocôndrias/metabolismo , Corantes Fluorescentes/metabolismo , Ácido Pirúvico/metabolismo , Tiofenos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo
4.
ACS Appl Bio Mater ; 6(8): 3199-3212, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37556116

RESUMO

We have developed two highly sensitive cyanine dyes, which we refer to as probes A and B. These dyes are capable of quick and sensitive sensing of NAD(P)H. The dyes were fabricated by connecting benzothiazolium and 2,3-dimethylnaphtho[1,2-d]thiazol-3-ium units to 3-quinolinium through a vinyl bond. In the absence of NAD(P)H, both probes have low fluorescence and absorption peaks at 370 and 400 nm, correspondingly. This is because of their two electron-withdrawing acceptor systems with high charge densities. However, when NAD(P)H reduces the probes' electron-withdrawing 3-quinolinium units to electron-donating 1,4-dihydroquinoline units, the probes absorb at 533 and 535 nm and fluoresce at 572 and 586 nm for A and B correspondingly. This creates well-defined donor-π-acceptor cyanine dyes. We successfully used probe A to monitor NAD(P)H levels in live cells during glycolysis, under hypoxic conditions induced by CoCl2 treatment and after treatment with cancer drugs, including cisplatin, camptothecin, and gemcitabine. Probe A was also employed to visualize NAD(P)H in Drosophila melanogaster first-instar larvae. We observed an increase in NAD(P)H levels in A549 cancer cells both under hypoxic conditions and after treatment with cancer drugs, including cisplatin, camptothecin, and gemcitabine.


Assuntos
Drosophila melanogaster , NAD , Animais , NAD/química , Corantes Fluorescentes/química , Cisplatino , Mitocôndrias
5.
J Mater Chem B ; 11(27): 6296-6307, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37249441

RESUMO

We report a novel method for synthesizing red and deep red cyanine dyes with large Stokes shifts, probes A and B, for live cell NAD(P)H detection. The probes were prepared using thiophene-based organic dyes featuring a π-conjugated bridge of thiophene and 3,4-ethylenedioxythiophene units linking the 1-methylquinolinium acceptor and formyl acceptor, respectively. These probes display weak absorption peaks at 315 nm (A) and 334 nm (B) and negligible fluorescence in the absence of NADH. However, upon the presence of NADH, new absorption and fluorescence peaks appear at 477 nm and 619 nm for probe A and at 486 nm and 576 nm for probe B, respectively. This is due to the NADH-facilitated reduction of the 1-methylquinolinium unit into 1-methyl-1,4-dihydroquinoline, which then acts as the electron donor for the probes, leading to the formation of well-defined electron donor-acceptor dye systems. Probe A has a large Stokes shift of 144 nm, which allows for better separation between the excitation and emission spectra, reducing spectral overlap and improving the accuracy of fluorescence measurements. The probes are highly selective for NAD(P)H, water-soluble, biocompatible, and easily permeable to cells. They are also photostable and were successfully used to monitor changes in NADH concentration in live cells during glycolysis in the presence of glucose, lactate, and pyruvate, treatment of FCCP and cancer drug cisplatin, and under hypoxia triggered by CoCl2. Furthermore, the probes were able to image NAD(P)H in Drosophila melanogaster larvae. Notably, cisplatin treatment increased the NAD(P)H concentration in A459 cells over time. Overall, this work presents a significant advancement in the field of live cell imaging by providing a simple and cost-effective method for detecting changes in NAD(P)H concentration under varying chemical stimuli.


Assuntos
Corantes Fluorescentes , NAD , Animais , Tiofenos , Cisplatino , Drosophila melanogaster
6.
Plants (Basel) ; 12(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36840108

RESUMO

Cocoplum (Chrysobalanus icaco) is an ecologically significant native species to Southern Florida. Application of precision agriculture technologies such as optical sensors reduces the cost of over-fertilization and nutrient runoff. The aim of this work was to establish a base line sensor value for fertilizer treatment in cocoplum by monitoring chlorophyll content using the Soil Plant Analytical Development (SPAD), atLEAF, and Normalized Difference Vegetation Index (NDVI) sensors. Initial slow-released fertilizer treatment 8N-3P-9K was used at 15 g (control), 15 g (supplemented with +15 g × 2; T1), 15 g (+15 g; T2), 30 g (+15 g × 2; T3), 30 g (+15 g; T4), and 45 g (+15 g × 2; T5). Evaluations were conducted at 0 (base reading), 30, 60, 90, 120, 150, and 180 days after treatment. Growth parameters, optical non-destructive chlorophyll meters, leaf and soil total nitrogen and total carbon, and total nitrogen of leachate were analyzed. The results demonstrated that the treatment using 30 g slow-released fertilizer (8N-3P-9K) supplemented twice with 15 g in November and March after the first fertilization in October provided the least contamination through runoff while still providing adequate nutrients for plant growth compared to higher fertilizer concentrations. These results demonstrate that the highest treatment of nitrogen can cause considerable losses of N, causing extra costs to producers and environmental damage due to the flow of nutrients. Thus, techniques that help in N monitoring to avoid the excessive use of nitrogen fertilization are necessary. This study can serve as a basis for future research and for nurseries and farms, since it demonstrated from the monitoring of the chlorophyll content by optical sensors and by foliar and substrate analysis that lower treatments of nitrogen fertilization are sufficient to provide nutrients suitable for the growth of cocoplum plants.

7.
Cortex ; 158: 4-23, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36403380

RESUMO

The case of JP, reported by Ackerly and Benton in 1948 with a detailed follow-up by Ackerly in 1964, stands as the index case of developmental prefrontal damage and its impact on social adaptation. Although the 1948 case report included findings from a 1933 pneumoencephalogram and exploratory craniotomy, a definitive cause was never established for JP's prefrontal damage. Etiologies were never determined for the left-sided seizures that occurred when JP was age four, nor for the progressive anterograde amnesia that JP developed in middle age. Given Ackerly's thoroughness and long-term follow-up of his patient, it was hoped that a brain cutting would have been done, though no report of a post-mortem examination was published. The lead author of this paper (SB) set out to discover what had happened to JP after Ackerly's 1964 report and whether a brain cutting had in fact occurred. Using a variety of investigative approaches, it was discovered that a post-mortem brain examination had taken place. Those present at the brain cutting were identified, and the still-living witnesses to the brain cutting were interviewed. Previously unpublished, relevant materials were uncovered from archival sources. A film of the brain cutting, as well as photos, were located. A film of Ackerly interviewing JP prior to JP's death at age sixty-four also was found. The authors studied autopsy findings in the newly discovered video and still images. These findings were judged consistent with massive perinatal hemorrhagic damage to both frontal lobes. JP's left-sided seizures were likely due to activation of a focus from his congenital brain damage. The anterograde amnesia that was documented when JP was twenty-five and that was noted to worsen when he was forty-nine remains unexplained but may have been related to slowly progressive hydrocephalus. This paper expands what is known about the case of JP, making it the only report of a person with congenital frontal injury followed for their entire life including post-mortem brain examination.


Assuntos
Amnésia Anterógrada , Lesões Encefálicas , Masculino , Pessoa de Meia-Idade , Humanos , Encéfalo , Lobo Frontal , Convulsões
8.
Cureus ; 14(7): e27452, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36051737

RESUMO

Lower extremity operative wounds can be difficult to treat and are associated with social challenges. New treatment options are needed to mitigate the clinical and social challenges and potentially lower the treatment cost and time. A synthetic hybrid-scale fiber matrix, which has an architecture similar to native tissue, a tailored resorption rate, and excellent durability and handling characteristics, is gaining popularity due to its effectiveness in treating different kinds of wounds. In this retrospective study, nine patients with a total of nine lower extremity wounds and multiple comorbidities were included. The hybrid-scale fiber matrix was cut to wound size, fenestrated as deemed appropriate, and secured to the wound bed using staples or sutures. Wound healing was monitored at subsequent visits, and the synthetic fiber matrix was re-applied as needed. Healing was considered complete when 100% epithelialization and closure of the wound site occurred. Overall, seven out of nine wounds exhibited complete healing and wound closure. For fully healed wounds, the average time to heal was 135.6 days, and good scar quality was observed. This retrospective case series demonstrates the versatility of synthetic hybrid-scale fiber matrices as part of an effective treatment regimen for difficult-to-treat lower extremity operative wounds.

9.
J Clin Endocrinol Metab ; 101(5): 2063-8, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26990941

RESUMO

CONTEXT: Congenital hypothyroidism (CH) may arise from dual foci thyroid ectopia. OBJECTIVE: To ascertain the incidence of dual ectopia in CH and compare the phenotype to single ectopia or thyroid agenesis. DESIGN AND SETTING: Single center, retrospective study of babies referred through UK Newborn Bloodspot Screening between 2006 and 2012. PATIENTS: A total of 837 377 babies were screened for CH, with 730 referred for diagnostic confirmation (134 thyroid ectopia, 73 thyroid agenesis). INTERVENTION: Thyroid isotope scans were classified as single or dual ectopia. Biochemical, clinical, and sociodemographic data were collected. MAIN OUTCOME MEASURES: The incidence of thyroid dual ectopia and comparison of clinical parameters with single ectopia and agenesis. RESULTS: Thyroid ectopia occurs with an incidence of 16 per 100 000 births. Twenty-one of 134 (15.7%) babies with thyroid ectopia had dual foci, an incidence of 2.5 per 100 000 births. Dual ectopia infants had lower mean bloodspot TSH compared to single ectopia and agenesis groups (P < .001). On venous sampling, the ectopia group differences were absent, but the difference with the agenesis group remained (TSH, P < .001; free T4, P < .001). There were no between-group differences for gestation, ethnicity, maternal age, or levothyroxine requirements at 12 months. CONCLUSIONS: Thyroid dual ectopia has an incidence of 2.5 per 100 000 births. Early functional activity in the ectopia groups with detectable serum free T4 concentrations is lost at 12 months when T4 requirements are the same as the agenesis group.


Assuntos
Hipotireoidismo Congênito/diagnóstico , Disgenesia da Tireoide/epidemiologia , Glândula Tireoide/anormalidades , Hipotireoidismo Congênito/sangue , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Triagem Neonatal , Estudos Retrospectivos , Testes de Função Tireóidea , Tireotropina/sangue , Tiroxina/sangue
10.
J Foot Ankle Surg ; 55(2): 226-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26763868

RESUMO

The modified Lapidus arthrodesis is a long-established surgical technique for management of hallux valgus that provides reproducible results and quality patient outcomes. The data from 367 consecutive patients undergoing unilateral modified Lapidus arthrodesis from January 1, 2007 to December 31, 2008 at participating centers were retrospectively evaluated. The included patients were categorized into early weightbearing (≤ 21 days) and delayed weightbearing (> 21 days) groups. A total of 24 nonunions (6.5%) were identified, with 13 (7.1%) in the early weightbearing group and 11 (6.0%) in the delayed weightbearing group. To date, the present study is the largest multicenter investigation to evaluate early weightbearing after modified Lapidus arthrodesis and the only large study to directly compare early and delayed weightbearing. The findings of the present study have shown that early weightbearing for modified Lapidus arthrodesis does not increase the risk of nonunion when evaluating various fixation constructs.


Assuntos
Artrodese/reabilitação , Hallux Valgus/cirurgia , Suporte de Carga , Adolescente , Adulto , Idoso , Artrodese/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Estudos Retrospectivos , Adulto Jovem
11.
Prim Care Diabetes ; 5(1): 9-17, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21071296

RESUMO

AIM: To synthesise key outcomes data from cost-effectiveness studies in diabetes, in the UK setting, and describe a narrative for the evidence-base, in order to understand the direction that future health economics research in this field could be heading. METHODS: The peer-reviewed literature was searched at http://www.pubmed.com for health economics analyses in diabetes in the UK setting published between 1995 and 2008, using the keywords: "costs", "cost-effectiveness", "diabetes", "UK". Studies on screening for diabetes or prevention of diabetes were excluded, along with studies that looked purely at cost of diabetes treatment or monitoring. RESULTS: There were over 350 hits on MEDLINE. A total of 23 articles were identified and reviewed. 18 studies were in type 2, two in type 1 and three studies in both types 1 and type 2 diabetes. All studies evaluated treatment from the perspective of the NHS, with the time horizons varying from 12 months to patient lifetimes. 13 studies estimated quality-adjusted life expectancy (QALE). The majority of studies used health economics modelling techniques to project clinical benefit and cost outcomes beyond the context of clinical trials, with Markov-type models predominating. The United Kingdom Prospective Study of Diabetes was the most frequently cited source of clinical effectiveness and cost data. Most studies were funded by the pharmaceutical industry and evaluated more expensive products, rather than cheaper generic therapies such as human insulin and metformin monotherapy. CONCLUSION: Treatment-to-target in patients with diabetes in the UK is generally cost-effective and sometimes cost-saving vs. standard care. Ongoing health economics analysis in diabetes is essential as new clinical data are published. Future analysis of clinical and cost outcomes in diabetes could be expected to look beyond the impact of interventions on HbA1c in isolation, as manufacturers seek to differentiate innovative products in the market. Furthermore, it is anticipated that the competitiveness in the market for interventions in diabetes will lead to future cost-effectiveness analysis taking more interest in comparisons of off-patent medication and generic, fixed-dose combination therapies.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Custos de Cuidados de Saúde/tendências , Hipoglicemiantes/uso terapêutico , Análise Custo-Benefício/tendências , Diabetes Mellitus Tipo 1/economia , Diabetes Mellitus Tipo 2/economia , Custos de Medicamentos/tendências , Medicina Baseada em Evidências , Previsões , Humanos , Hipoglicemiantes/economia , Modelos Econômicos , Resultado do Tratamento , Reino Unido
12.
Value Health ; 12(1): 1-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18657104

RESUMO

OBJECTIVE: To estimate the long-term cost-effectiveness of adding pioglitazone versus placebo to standard treatment in high-risk patients with type 2 diabetes. METHODS: The validated CORE Diabetes Model was modified to project long-term clinical and cost outcomes associated with pioglitazone versus placebo, based on results from PROactive. The model retained basic structure and functionality, with interdependent Markov submodels, Monte Carlo simulation and user interface. Adjustments to submodels were made to accommodate the PROactive primary end points. The analysis was from the perspective of a third party US health-care payer perspective, projected over a lifetime horizon using a 3% annual discount. RESULTS: Over a lifetime horizon, addition of pioglitazone was associated with increased life expectancy (0.237 life-years) and quality-adjusted life expectancy (QALE) [0.166 quality-adjusted life-years (QALYs)] versus placebo. Estimated long-term complication rates showed that pioglitazone reduced the number of events versus placebo for most outcomes. Lifetime total direct costs were marginally higher with pioglitazone versus placebo ($272,694 vs. $265,390, difference $7,305). The incremental cost-effectiveness ratio for pioglitazone versus placebo was $44,105 per QALY gained. Probabilistic sensitivity analysis indicated a 55% likelihood that pioglitazone would be considered cost-effective in the United States, with a willingness to pay of $50,000 per QALY gained. CONCLUSIONS: The addition of pioglitazone to existing therapy in high-risk patients with type 2 diabetes was projected to improve life expectancy, QALE and complication rates compared with placebo. Addition of pioglitazone was in the range generally considered acceptable.


Assuntos
Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Tipo 2/economia , Hipoglicemiantes/economia , Expectativa de Vida , Tiazolidinedionas/economia , Simulação por Computador , Análise Custo-Benefício , Complicações do Diabetes/economia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Quimioterapia Combinada , Feminino , Humanos , Hipoglicemiantes/uso terapêutico , Masculino , Pessoa de Meia-Idade , Pioglitazona , Anos de Vida Ajustados por Qualidade de Vida , Tiazolidinedionas/uso terapêutico , Estados Unidos
13.
Diabetes Care ; 31(8): 1510-5, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18443195

RESUMO

OBJECTIVE: To assess the cost-effectiveness of intensive versus conventional therapy for 8 years as applied in the Steno-2 study in patients with type 2 diabetes and microalbuminuria. RESEARCH DESIGN AND METHODS: A Markov model was developed to incorporate event and risk data from Steno-2 and account Danish-specific costs to project life expectancy, quality-adjusted life expectancy (QALE), and lifetime direct medical costs expressed in year 2005 Euros. Clinical and cost outcomes were projected over patient lifetimes and discounted at 3% annually. Sensitivity analyses were performed. RESULTS: Intensive treatment was associated with increased life expectancy, QALE, and lifetime costs compared with conventional treatment. Mean +/- SD undiscounted life expectancy was 18.1 +/- 7.9 years with intensive treatment and 16.2 +/- 7.3 years with conventional treatment (difference 1.9 years). Discounted life expectancy was 13.4 +/- 4.8 years with intensive treatment and 12.4 +/- 4.5 years with conventional treatment. Lifetime costs (discounted) for intensive and conventional treatment were euro45,521 +/- 19,697 and euro41,319 +/- 27,500, respectively (difference euro4,202). Increased costs with intensive treatment were due to increased pharmacy and consultation costs. Discounted QALE was 1.66 quality-adjusted life-years (QALYs) higher for intensive (10.2 +/- 3.6 QALYs) versus conventional (8.6 +/- 2.7 QALYs) treatment, resulting in an incremental cost-effectiveness ratio of euro2,538 per QALY gained. This is considered a conservative estimate because accounting prescription of generic drugs and capturing indirect costs would further favor intensified therapy. CONCLUSIONS: From a health care payer perspective in Denmark, intensive therapy was more cost-effective than conventional treatment. Assuming that patients in both arms were treated in a primary care setting, intensive therapy became dominant (cost- and lifesaving).


Assuntos
Análise Custo-Benefício , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/economia , Dinamarca , Hospitalização/economia , Hospitalização/estatística & dados numéricos , Humanos , Expectativa de Vida , Cadeias de Markov , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Resultado do Tratamento
14.
Curr Med Res Opin ; 23(3): 609-22, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17355742

RESUMO

OBJECTIVES: The aim of this study was to evaluate the long-term clinical and economic outcomes associated with exenatide or insulin glargine, added to oral therapy in individuals with type 2 diabetes inadequately controlled with combination oral agents in the UK setting. METHODS: A published and validated computer simulation model of diabetes was used to project long-term complications, life expectancy, quality-adjusted life expectancy and direct medical costs. Probabilities of diabetes-related complications were derived from published sources. Treatment effects and patient characteristics were extracted from a recent randomised controlled trial comparing exenatide with insulin glargine. Simulations incorporated published quality of life utilities and UK-specific costs from 2004. Pharmacy costs for exenatide were based on 20, 40, 60, 80 and 100% of the US value (as no price for the UK was available at the time of analysis). Future costs and clinical benefits were discounted at 3.5% annually. Sensitivity analyses were performed. RESULTS: In the base-case analysis exenatide was associated with improvements in life expectancy of 0.057 years and in quality-adjusted life expectancy of 0.442 quality-adjusted life years (QALYs) versus insulin glargine. Long-term projections demonstrated that exenatide was associated with a lower cumulative incidence of most cardiovascular disease (CVD) complications and CVD-related death than insulin glargine. Using the range of cost values, evaluation results showed that exenatide is likely to fall in a range between dominant (cost and life saving) at 20% of the US price and cost-effective (with an ICER of 22,420 pounds per QALY gained) at 100% of the US price, versus insulin glargine. CONCLUSIONS: Based on the findings of a recent clinical trial, long-term projections indicated that exenatide is likely to be associated with improvement in life expectancy and quality-adjusted life expectancy compared to insulin glargine. The results from this modelling analysis suggest that that exenatide is likely to represent good value for money by generally accepted standards in the UK setting in individuals with type 2 diabetes inadequately controlled on oral therapy.


Assuntos
Efeitos Psicossociais da Doença , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/economia , Hipoglicemiantes/uso terapêutico , Insulina/análogos & derivados , Peptídeos/uso terapêutico , Peçonhas/uso terapêutico , Adulto , Glicemia/análise , Análise Custo-Benefício , Complicações do Diabetes/epidemiologia , Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Tipo 2/diagnóstico , Relação Dose-Resposta a Droga , Esquema de Medicação , Estudos de Avaliação como Assunto , Exenatida , Feminino , Humanos , Hipoglicemiantes/economia , Insulina/economia , Insulina/uso terapêutico , Insulina Glargina , Insulina de Ação Prolongada , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Modelos Econômicos , Peptídeos/economia , Prognóstico , Anos de Vida Ajustados por Qualidade de Vida , Medição de Risco , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Reino Unido , Peçonhas/economia
15.
Curr Med Res Opin ; 22(11): 2095-100, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17076969

RESUMO

OBJECTIVES: We performed a cost-consequence analysis in a French setting of the renoprotective benefit of irbesartan in hypertensive type 2 diabetes patients over a 25-year period. RESEARCH DESIGN AND METHODS: A previously published Markov model simulated progression from microalbuminuria to overt nephropathy, doubling of serum creatinine, end-stage renal disease and death. Three treatment strategies with analogous blood pressure control were compared: (A) control--conventionally medicated antihypertensive therapy (excluding angiotensin converting enzyme inhibitors, other angiotensin-2-receptor antagonists and dihydropyridine calcium channel blockers) initiated at microalbuminuria; (B) early irbesartan--(300 mg daily added to control, initiated with microalbuminuria) and (C) late irbesartan--(300 mg daily, initiated with overt nephropathy). Probabilities came from the Irbesartan in Reduction of Microalbuminuria-2 study, Irbesartan in Diabetic Nephropathy Trial and other sources. Clinical and economic outcomes were projected over 25 years. Annual discount rates were 3%. RESULTS: Compared to control, early use of irbesartan added (mean +/- standard deviation) 1.51 +/- 0.08 undiscounted life years (discounted: 0.94 +/- 0.05 years), while late irbesartan added 0.07 +/- 0.01 (0.04 +/- 0.01) years/patient. Early irbesartan added 1.03 +/- 0.06 discounted quality-adjusted life years (QALYs), while late irbesartan added 0.06 +/- 0.01 QALYs. Early and late irbesartan treatments were projected to save 22,314 +/- 1273 euro and 6619 +/- 820 euro/patient, respectively versus control. Sensitivity analysis showed that even over short time horizons both irbesartan treatments were superior to the control group. CONCLUSIONS: In France, early irbesartan treatment improved quality and length of life and reduced costs in hypertensive patients with type 2 diabetes and microalbuminuria. Late irbesartan therapy is beneficial, but earlier irbesartan leads to better outcomes.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Angiopatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Custos de Cuidados de Saúde , Hipertensão/tratamento farmacológico , Tetrazóis/uso terapêutico , Albuminúria/complicações , Albuminúria/tratamento farmacológico , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/economia , Compostos de Bifenilo/administração & dosagem , Compostos de Bifenilo/economia , Análise Custo-Benefício , Angiopatias Diabéticas/complicações , Nefropatias Diabéticas/etiologia , Progressão da Doença , Esquema de Medicação , França , Humanos , Hipertensão/complicações , Irbesartana , Falência Renal Crônica/tratamento farmacológico , Cadeias de Markov , Anos de Vida Ajustados por Qualidade de Vida , Tetrazóis/administração & dosagem , Tetrazóis/economia , Resultado do Tratamento
16.
Curr Med Res Opin ; 22(3): 575-86, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16574040

RESUMO

OBJECTIVE: To quantify changes in clinical and cost outcomes associated with increasing levels of body mass index (BMI) in a US setting. RESEARCH METHODS AND PROCEDURES: A semi-Markov model was developed to project and compare life expectancy (LE), quality-adjusted life expectancy (QALE) and direct medical costs associated with distinct levels of BMI in simulated adult cohorts over a lifetime horizon. Cohort definitions included age (20-65 years), gender, race, and BMI (24-45 kg m(-2)). Cohorts were exclusively male or female and either Caucasian or African-American. Mortality rates were adjusted according to these factors using published data. BMI progression over time was modeled. BMI-dependent US direct medical costs were derived from published sources and inflated to year 2004 values. A third party reimbursement perspective was taken. QALE and costs were discounted at 3% per annum. RESULTS: In young Caucasian cohorts LE decreased as BMI increased. However, in older Caucasian cohorts the BMI associated with greatest longevity was higher than 25 kg m(-2). A similar pattern was observed in young adult African-American cohorts. A survival paradox was projected in older African-American cohorts, with some BMI levels in the obese category associated with greatest longevity. QALE in all four race/gender cohorts followed similar patterns to LE. Sensitivity analyses demonstrated that simulating BMI progression over time had an important impact on results. Direct costs in all four cohorts increased with BMI, with a few exceptions. CONCLUSIONS: Optimal BMI, in terms of longevity, varied between race/gender cohorts and within these cohorts, according to age, contributing to the debate over what BMI level or distribution should be considered ideal in terms of mortality risk. Simulating BMI progression over time had a substantial impact on health outcomes and should be modeled in future health economic analyses of overweight and obesity.


Assuntos
Modelos Teóricos , Obesidade/economia , Obesidade/mortalidade , Sobrepeso , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Idoso , Índice de Massa Corporal , Estudos de Coortes , Custos e Análise de Custo , Feminino , Humanos , Expectativa de Vida , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida , Análise de Sobrevida , Estados Unidos , População Branca/estatística & dados numéricos
18.
Nephrol Dial Transplant ; 20(6): 1103-9, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15855214

RESUMO

BACKGROUND: To review published studies on the cost-effectiveness of the use of irbesartan for treatment of advance overt nephropathy in patients with type 2 diabetes and hypertension. METHODS: Articles were identified based on a search of the PubMed databases using the keywords 'irbesartan', 'ESRD', 'cost-effectiveness', 'nephropathy' and 'costs', and by personal communication with the authors. Only studies published in the last 10 years were included. All costs data from the cost-effectiveness studies were inflated to 2003 Euros using published governmental conversion tables. RESULTS: Seven published studies were identified, spanning the following country settings: the US, Belgium and France, Germany, Hungary, Italy, Spain, and the UK. In each, the same pharmacoeconomic model was adapted using country-specific data to project and evaluate the clinical and cost outcomes of the treatment arms of the Irbesartan in Diabetic Nephropathy Trial (IDNT) (irbesartan, amlodipine or standard blood pressure control). Mean time to onset of ESRD was 8.23 years for irbesartan, 6.82 years for amlodipine and 6.88 years for the control (values were the same for Belgium, France, Germany, Hungary, Italy and Spain as transition probabilities for progression to ESRD were all derived from the IDNT). Mean cumulative incidence of ESRD was 36% with irbesartan, 49% with amlodipine and 45% with control treatment. Treatment with irbesartan was projected to improve life expectancy compared to both amlodipine and control in all seven published studies. Analysis of total lifetime costs showed that irbesartan treatment was cost saving compared to the other two treatment regimens, due to the associated reduction in ESRD cases. Cost savings with irbesartan became evident very early; after 2-3 years of treatment in most settings. CONCLUSIONS: Modelling studies based on the IDNT published to date suggest that irbesartan treatment in patients with type 2 diabetes, hypertension and advanced nephropathy is both life- and cost-saving compared to amlodipine or control.


Assuntos
Anti-Hipertensivos/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Nefropatias Diabéticas/tratamento farmacológico , Tetrazóis/uso terapêutico , Anti-Hipertensivos/economia , Análise Custo-Benefício , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/economia , Farmacoeconomia , Humanos , Irbesartana , Falência Renal Crônica/etiologia , Expectativa de Vida , Cadeias de Markov
19.
Pediatrics ; 113(6): e578-85, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15173540

RESUMO

BACKGROUND: It has been proposed that infection by group A beta-hemolytic streptococci (GABHS) can trigger acute symptom exacerbations among patients with Tourette's syndrome (TS) or obsessive-compulsive disorder (OCD), via autoimmune mechanisms. OBJECTIVE: To examine the temporal relationship between newly acquired GABHS infections (and other immunologic indices) and acute exacerbations of tics and obsessive-compulsive symptoms. METHODS: Pediatric patients (7-17 years of age) with TS and/or OCD (N = 47) and healthy control subjects (N = 19) were prospectively monitored for newly acquired GABHS infections, nonspecific markers of acute inflammatory responses, and D8/17-reactive cells (a marker of rheumatic fever). Objective monthly ratings of tic and obsessive-compulsive symptom severity were used to determine the timing of symptom exacerbations. RESULTS: The overall rate of acute exacerbations of neuropsychiatric symptoms was 0.56 exacerbations per patient per year. The average rate of new GABHS infections, using a stringent definition, was 0.42 infections per subject per year among patients, compared with 0.28 infections per subject per year for control subjects. The association between symptom exacerbations and new GABHS infections among patients was no greater than that expected on the basis of chance. At baseline, patients demonstrated significantly higher levels of D8/17-reactive cells and neopterin, compared with control subjects, but there was no consistent pattern of change when exacerbation time points were compared with baseline or follow-up time points. CONCLUSIONS: The results suggest no clear relationship between new GABHS infections and symptom exacerbations in an unselected group of patients with TS and/or OCD.


Assuntos
Doenças Autoimunes do Sistema Nervoso/microbiologia , Transtorno Obsessivo-Compulsivo/microbiologia , Infecções Estreptocócicas/complicações , Streptococcus pyogenes , Transtornos de Tique/microbiologia , Doença Aguda , Adolescente , Doenças Autoimunes do Sistema Nervoso/complicações , Proteína C-Reativa/análise , Criança , Feminino , Antígenos HLA-DR/sangue , Humanos , Estudos Longitudinais , Masculino , Transtornos Mentais/microbiologia , Neopterina/sangue , Transtorno Obsessivo-Compulsivo/complicações , Streptococcus pyogenes/isolamento & purificação , Transtornos de Tique/complicações
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...