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1.
Chemistry ; 30(20): e202303810, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38327129

RESUMO

2,4-dimethylfuran has a rare disubstitution pattern in the five-membered heterocyclic furan ring that is highly interesting chemically but challenging to access synthetically. We present a heterogeneously catalysed route to synthesise 2,4-dimethylfuran from commonly available 2,5-dimethylfuran using a zeolite packed-bed flow reactor. As supported by DFT calculations, the reaction occurs inside the zeolite channels, where the acid sites catalyse proton transfer followed by migration of a methyl group. The zeotype Ga-silicate (MFI type) appears superior to an aluminium-containing ZSM-5 by demonstrating higher selectivities and slower catalyst deactivation. This work provides new opportunities for the continuous valorisation of bio-feedstock molecules in the perspective of the emerging biorefinery era.

2.
Diabetologia ; 66(8): 1431-1441, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37221247

RESUMO

AIM/HYPOTHESIS: This study aimed to investigate the safety and efficacy of treatment with allogeneic Wharton's jelly-derived mesenchymal stromal cells (MSCs) in recent-onset type 1 diabetes. METHODS: A combined Phase I/II trial, composed of a dose escalation followed by a randomised double-blind placebo-controlled study in parallel design, was performed in which treatment with allogeneic MSCs produced as an advanced therapy medicinal product (ProTrans) was compared with placebo in adults with newly diagnosed type 1 diabetes. Inclusion criteria were a diagnosis of type 1 diabetes <2 years before enrolment, age 18-40 years and a fasting plasma C-peptide concentration >0.12 nmol/l. Randomisation was performed with a web-based randomisation system, with a randomisation code created prior to the start of the study. The randomisation was made in blocks, with participants randomised to ProTrans or placebo treatment. Randomisation envelopes were kept at the clinic in a locked room, with study staff opening the envelopes at the baseline visits. All participants and study personnel were blinded to group assignment. The study was conducted at Karolinska University Hospital, Stockholm, Sweden. RESULTS: Three participants were included in each dose cohort during the first part of the study. Fifteen participants were randomised in the second part of the study, with ten participants assigned to ProTrans treatment and five to placebo. All participants were analysed for the primary and secondary outcomes. No serious adverse events related to treatment were observed and, overall, few adverse events (mainly mild upper respiratory tract infections) were reported in the active treatment and placebo arms. The primary efficacy endpoint was defined as Δ-change in C-peptide AUC for a mixed meal tolerance test at 1 year following ProTrans/placebo infusion compared with baseline performance prior to treatment. C-peptide levels in placebo-treated individuals declined by 47%, whereas those in ProTrans-treated individuals declined by only 10% (p<0.05). Similarly, insulin requirements increased in placebo-treated individuals by a median of 10 U/day, whereas insulin needs of ProTrans-treated individuals did not change over the follow-up period of 12 months (p<0.05). CONCLUSIONS/INTERPRETATION: This study suggests that allogeneic Wharton's jelly-derived MSCs (ProTrans) is a safe treatment for recent-onset type 1 diabetes, with the potential to preserve beta cell function. TRIAL REGISTRATION: ClinicalTrials.gov NCT03406585 FUNDING: The sponsor of the clinical trial is NextCell Pharma AB, Stockholm, Sweden.


Assuntos
COVID-19 , Diabetes Mellitus Tipo 1 , Células-Tronco Mesenquimais , Adulto , Humanos , Adolescente , Adulto Jovem , Diabetes Mellitus Tipo 1/tratamento farmacológico , SARS-CoV-2 , Insulina/uso terapêutico , Peptídeo C , Resultado do Tratamento , Método Duplo-Cego , Cordão Umbilical
3.
Langmuir ; 38(42): 12859-12870, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36221959

RESUMO

A two-step seeded-growth method was refined to synthesize Au@Pd core@shell nanoparticles with thin Pd shells, which were then deposited onto alumina to obtain a supported Au@Pd/Al2O3 catalyst active for prototypical CO oxidation. By the strict control of temperature and Pd/Au molar ratio and the use of l-ascorbic acid for making both Au cores and Pd shells, a 1.5 nm Pd layer is formed around the Au core, as evidenced by transmission electron microscopy and energy-dispersive spectroscopy. The core@shell structure and the Pd shell remain intact upon deposition onto alumina and after being used for CO oxidation, as revealed by additional X-ray diffraction and X-ray photoemission spectroscopy before and after the reaction. The Pd shell surface was characterized with in situ infrared (IR) spectroscopy using CO as a chemical probe during CO adsorption-desorption. The IR bands for CO ad-species on the Pd shell suggest that the shell exposes mostly low-index surfaces, likely Pd(111) as the majority facet. Generally, the IR bands are blue-shifted as compared to conventional Pd/alumina catalysts, which may be due to the different support materials for Pd, Au versus Al2O3, and/or less strain of the Pd shell. Frequencies obtained from density functional calculations suggest the latter to be significant. Further, the catalytic CO oxidation ignition-extinction processes were followed by in situ IR, which shows the common CO poisoning and kinetic behavior associated with competitive adsorption of CO and O2 that is typically observed for noble metal catalysts.

4.
Pediatr Diabetes ; 23(3): 341-350, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34981619

RESUMO

OBJECTIVE: To study BMI changes and glycemic control in children and adolescents during the first 5 years following diagnosis of type 1 diabetes. RESEARCH DESIGN AND METHODS: The 295 children and adolescents (<18 years) diagnosed with type 1 diabetes started on multiple injection treatment and were followed during the first 5 years of treatment with respect to glycemic control and weight change. Growth curves preceding the onset of diabetes were obtained from the school health services and child care centers. BMI was recalculated into BMI SD scores (BMISDS). RESULTS: Prior to the onset of diabetes, the BMISDS was 0.46 ± 1.24 (mean ± SD), which decreased to -0.61 ± 1.36 (p < 0.001) at presentation. At 1 year, BMISDS was 0.59 ± 0.99 (p > 0.05) and increased to 0.80 ± 1.03 at 5 years; 0.97 ± 0.93 in females versus 0.68 ± 1.08 in males (p < 0.001). BMISDS at 1 year and 5 years were directly proportional to and highly predicted by BMISDS prior to the onset of type 1 diabetes, (r = 0.76; p < 0.001) vs. (r = 0.58; p < 0.001). HbA1c at 1 year was 50 ± 10 mmol/mol, which increased to 58 ± 12 mmol/mol (p < 0.001) at 5 years; females had HbA1c 60 ± 14 mmol/mol versus males 56 ± 11 mmol/mol (r = 0.35, p < 0.001). There was a correlation, irrespective of gender, between HbA1c and BMISDS at 1 year (r = 0.18, p < 0.003), but not at 5 years (r = 0.036, (p > 0.5). CONCLUSION: During the first 5 years of treatment of type 1 diabetes in children and adolescents it is possible to achieve good glycemic control without excess weight gain.


Assuntos
Diabetes Mellitus Tipo 1 , Adolescente , Glicemia , Índice de Massa Corporal , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/epidemiologia , Feminino , Hemoglobinas Glicadas/análise , Controle Glicêmico , Humanos , Hipoglicemiantes/uso terapêutico , Masculino
5.
Anal Chem ; 93(39): 13187-13195, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34551243

RESUMO

On-line composition analysis of complex hydrocarbon mixtures is highly desirable to determine the composition of process streams and to study chemical reactions in heterogeneous catalysis. Here, we show how the combination of time-resolved Fourier transform infrared spectroscopy and ion-molecule-reaction mass spectrometry (IMR-MS) can be used for compositional analysis of processed plant biomass streams. The method is based on the biomass-derived model compound 2,5-dimethylfuran and its potential catalytic conversion to valuable green aromatics, for example, benzene, toluene, and xylenes (BTX) over zeolite ß. Numerous conversion products can be determined and quantified simultaneously in a temporal resolution of 4 min-1 without separation of individual compounds. The realization of this method enables us to study activity, selectivity, and changes in composition under transient reaction conditions. For example, increasing isomerization of 2,5-dimethylfuran to 2,4-dimethylfuran, 2-methyl-2-cyclopenten-1-one, and 2-methyl-2-cyclopenten-1-one is observed as the catalyst is exposed to the reactant, while BTX and olefin formation is decreasing.


Assuntos
Hidrocarbonetos , Espectrometria de Massas , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Scand J Public Health ; 49(4): 433-440, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31826709

RESUMO

Aims: The aims of this study are to describe informal care activities and to estimate the societal cost of informal care of community-dwelling frail elderly people in Sweden. Methods: This study was performed within the frame of the TREEE project that included 408 frail elderly patients. At index hospitalisation (baseline), primary informal caregivers of the patients were provided with a questionnaire on informal care during a period of three months. Questions concerning other (secondary) informal caregivers were also included. A rough estimate of the total cost of informal care of frail elderly people in Sweden was obtained by combining data from this study with published data and official statistics. Results: In total, 176 informal caregivers responded, and 89% had provided informal care. The informal caregivers (primary and secondary) provided care for an average of 245 hours over three months. Taking care of the home was the dominating activity. In total, the mean cost of informal care was estimated to approximately 18,000 SEK (€1878) over three months, corresponding to an annual cost of approximately 72,000 SEK (€7477) per frail elderly person. The total annual societal costs of informal care of community dwelling frail elderly people aged 75 years and older in Sweden was estimated to be approximately 11,000 million SEK (€1150 million). Conclusions: The care of frail elderly people provided by informal caregivers is extensive and represents a great economic value. Although our calculations are associated with uncertainty, the size indicates that supporting informal caregivers should be a priority for society.


Assuntos
Cuidadores , Idoso Fragilizado/estatística & dados numéricos , Custos de Cuidados de Saúde/estatística & dados numéricos , Vida Independente , Assistência ao Paciente/economia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Cuidadores/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Suécia
7.
Int J Mol Sci ; 22(23)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34884797

RESUMO

The anti-inflammatory role of regulatory B cells (Breg cells) has been associated with IL-35 based on studies of experimental autoimmune uveitis and encephalitis. The role of Breg cells and IL-35+ Breg cells for type 1 diabetes (T1D) remains to be investigated. We studied PBMCs from T1D subjects and healthy controls (HC) and found lowered proportions of Breg cells and IL-35+ Breg cells in T1D. To elucidate the role of Breg cells, the lymphoid organs of two mouse models of T1D were examined. Lower proportions of Breg cells and IL-35+ Breg cells were found in the animal models of T1D compared with control mice. In addition, the systemic administration of recombinant mouse IL-35 prevented hyperglycemia after multiple low dose streptozotocin (MLDSTZ) injections and increased the proportions of Breg cells and IL-35+ Breg cells. A higher proportion of IFN-γ+ cells among Breg cells were found in the PBMCs of the T1D subjects. In the MLDSTZ mice, IL-35 administration decreased the proportions of IFN-γ+ cells among the Breg cells. Our data illustrate that Breg cells may play an important role in the development of T1D and that IL-35 treatment prevents the development of hyperglycemia by maintaining the phenotype of the Breg cells under an experimental T1D condition.


Assuntos
Anti-Inflamatórios/farmacologia , Linfócitos B Reguladores/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Hiperglicemia/prevenção & controle , Interleucinas/farmacologia , Adulto , Animais , Anti-Inflamatórios/sangue , Células Cultivadas , Modelos Animais de Doenças , Feminino , Humanos , Hiperglicemia/induzido quimicamente , Interferon gama/sangue , Interleucinas/sangue , Contagem de Linfócitos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Estreptozocina/toxicidade
8.
Inorg Chem ; 59(6): 3551-3561, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32125149

RESUMO

While the Hieber anion [Fe(CO)3(NO)]- has been reincarnated in the last years as an active catalyst in organic synthesis, there is still a debate about the oxidation state of the central Fe atom and the resulting charge of the NO ligand. To shed new light on this question and to understand the Fe-NO interaction in the Hieber anion, it is investigated in comparison to the formal 3d8 reference Fe(CO)5 and the formal 3d10 reference [Fe(CO)4]2- by the combination of valence-to-core X-ray emission spectroscopy (VtC-XES), X-ray absorption near-edge structure spectroscopy (XANES), and high-energy-resolution fluorescence-detected XANES. In order to extract information about the electronic structure, time-dependent density functional theory and ground-state density functional theory calculations are applied. This combination of experimental and computational methods reveals that the electron density at the Fe center of the Hieber resembles that of the isoelectronic [Fe(CO)4]2-. These observations challenge recent descriptions of the Hieber anion and reopen the debate about the experimentally and computationally determined Fe oxidation state and charge on the NO ligand.

9.
Phys Chem Chem Phys ; 22(13): 6809-6817, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32159551

RESUMO

Desorption products from zeolites with medium (MFI) and small (CHA) pores and with and without ion-exchanged copper were studied during linear heating after the pre-adsorption of methanol using a chemical flow reactor with a gas phase Fourier transform infrared spectrometer. The methanol desorption profiles were deconvoluted and compared with those predicted from first-principles calculations. In situ diffuse reflectance infrared Fourier transform spectroscopy was used to study the samples during methanol desorption following a step-wise increase of the sample temperature. It is shown that well-dispersed copper species in the Cu-zeolite samples interact more strongly with methanol and its derivatives as compared to the bare zeolites, resulting in methanol desorption at higher temperatures. Moreover, the introduction of Cu leads to CO formation and desorption in larger amounts at lower temperatures compared to the bare zeolites. The formation and desorption of dimethyl ether (DME) from pre-adsorbed methanol takes place at different temperatures depending on both the influence of Cu and the zeolite topology. The Cu sites in zeolites lead to higher DME formation/desorption temperatures, while a small shift of DME desorption towards higher temperatures is observed for the CHA framework structure compared to the MFI framework structure.

10.
Phys Chem Chem Phys ; 22(3): 1640-1654, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31894792

RESUMO

Polarised Raman spectroscopy is used to characterise the local structure in single crystals of zeotypes, namely silicalite-1 and ZSM-5, which share the MFI framework structure. Attributes favourable for applying polarised Raman spectroscopy are the orthogonal axes of these single crystals and their size, i.e. 10 to 30 micrometers in all three directions. We show that the intensity of certain vibrational modes in silicalite-1 depends on the polarisation of the incident light, reflecting the anisotropic character of the molecular bonds contributing to these vibrations. Using these observations, and by estimating the depolarisation ratio (ρ) and the pseudo-order factor (f), we propose a more accurate assignment of the Raman active modes. More precisely, Raman intensities peaked at 294, 360, 383 and 472 cm-1 are attributed to bending modes in 10-, 6-, 5- and 4-membered rings, respectively. In the region of stretching modes, the vibration at 832 cm-1 is assigned to Si-O-Si bonds shared between 5-membered rings, which have an orientation parallel to the a-axis of the crystal. By virtue of having a strongly polarised character, the modes at 472 and 832 cm-1 can be used as orientational indicators. The proposed assignment is supported by the good agreement between experimental and simulated polar plots, where Raman intensities are plotted as a function of the polarisation angle of the incident light. Finally, upon partial substitution of Si atoms by Al, the crystalline structure is maintained and almost no spectroscopic changes are observed. The only significant difference is the increased width of most vibrational modes, which is consistent with the local lower symmetry. This is also seen in the angular dependence of selected vibrational modes that compared to the case of pure silicalite-1 appear less polarised. In the Raman spectrum of ZSM-5 a new feature at 974 cm-1 is observed, which we attribute to Al-OH stretching. In the high frequency range, the O-H stretching modes are observed which arise from the Si-O(H)-Al Brønsted acid sites. The intensity of the characteristic mode at 3611 cm-1 reveals an anisotropic character as well, which is in line with previous findings from solid state NMR that Al atoms distribute nonrandomly within the MFI framework structure.

11.
Exp Cell Res ; 384(1): 111617, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505166

RESUMO

BACKGROUND: Islet stellate cells (ISCs) play a critical role in islet fibrosis, contributing to the progression of pancreatic diseases. Previous studies have focused on fibrosis-associated activated ISCs obtained by standard islet explant techniques. However, in vitro models of quiescent ISCs (qISCs) are lacking. This study aims to develop a method to isolate qISCs and analyze their phenotype during activation. METHODS: Immunofluorescence staining was applied to localize ISCs in normal human, rat, and mouse islets. qISCs were isolated from rat islets using density gradient centrifugation (DGC) method. qRT-PCR, immunoblotting, proliferation, and migration assays were employed for their characterization. RESULTS: Desmin-positive ISCs were detected in normal human, rat, and mouse islets. Freshly isolated qISCs, obtained by density gradient centrifugation, displayed a polygonal appearance with refringent cytoplasmic lipid droplets and expressed transcriptional markers indicating a low activation/quiescent state. With increasing culture time, the marker expression pattern changed, reflecting ISC activation. qISCs contained more lipid droplets and exhibited lower proliferation and migration abilities compared to spindle-shaped ISCs obtained by traditional explant techniques. CONCLUSIONS: This study describes a new method for efficient isolation of qISCs from rat islets, representing a useful in vitro tool to study the biology of ISCs in more physiological conditions.


Assuntos
Células Estreladas do Pâncreas/citologia , Animais , Biomarcadores/metabolismo , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Desmina/metabolismo , Fibrose/metabolismo , Fibrose/fisiopatologia , Humanos , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Estreladas do Pâncreas/metabolismo , Ratos , Ratos Sprague-Dawley
12.
Exp Cell Res ; 380(1): 1-8, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30998947

RESUMO

BACKGROUND: Islet stellate cells (ISCs) activation is mainly associated with islet fibrosis, which contributes to the progression of type 2 diabetes. However, the molecular mechanism underlying this process is not fully understood. METHODS: In order to investigate this process the current study examined ectopic fat accumulation in rats with high-fat diet (HFD) induced obesity. Levels of lipotoxicity-induced ISC activation and islet function were assessed via intraperitoneal glucose and insulin tolerance tests, and immunohistochemistry. The expression of lipid metabolism- and ISC activation-related markers was evaluated in cultured ISCs treated with palmitic acid (PA) using quantitative PCR and western blotting. We also overexpressed sterol regulatory element-binding protein (SREBP)-1c in ISCs by lentiviral transduction, and assessed the effects on insulin release in co-cultures with isolated rat islets. RESULTS: HFD increased body weight and ectopic fat accumulation in pancreatic islets. Lipotoxicity caused progressive glucose intolerance and insulin resistance, upregulated α-smooth muscle actin, and stimulated the secretion of extracellular matrix. Lipotoxicity reduced the expression of lipid metabolism-related molecules in ISCs treated with PA, especially SREBP-1c. Overexpression of SREBP-1c in ISCs improved islet viability and insulin secretion in co-cultures. CONCLUCIONS: These results indicate that lipotoxicity-induced ISC activation alters islet function via regulation of lipid metabolism, suggesting that therapeutic strategies targeting activated ISC may be an effective treatment for prevention of ISC activation-associated islet dysfunction.


Assuntos
Diabetes Mellitus Tipo 2/genética , Metabolismo dos Lipídeos/genética , Obesidade/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Animais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Humanos , Insulina/genética , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Obesidade/complicações , Obesidade/metabolismo , Obesidade/patologia , Células Estreladas do Pâncreas/metabolismo , Células Estreladas do Pâncreas/patologia , Ratos
13.
Int J Gynecol Cancer ; 30(11): 1719-1725, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32863275

RESUMO

OBJECTIVES: To compare total costs for hospital stay and post-operative recovery between robotic and abdominal hysterectomy in the treatment of early-stage endometrial cancer provided in an enhanced recovery after surgery (ERAS) setting. Costs were evaluated in relation to health impact, taking a societal perspective. METHODS: Cost analysis was based on data from an open randomized controlled trial in an ERAS setting at a Swedish tertiary referral university hospital: 50 women with low-risk endometrial cancer scheduled for surgery between February 2012 and May 2016 were included; 25 women were allocated to robotic and 25 to abdominal hysterectomy. We compared the total time in the operating theater, procedure costs, post-operative care, length of hospital stay, readmissions, informal care, and sick leave as well as the health-related quality of life until 6 weeks after surgery. The comparison was made by using the EuroQoL group form with five dimensions and three levels (EQ-5D). The primary outcome measure was total cost; secondary outcomes were quality-adjusted life-years (QALYs) and cost per QALY. The costs were calculated in Swedish Krona (SEK). RESULTS: Age (median (IQR) 68 (63-72) vs 67 (59-75) years), duration of hospital stay (ie, time to discharge criteria were met) (median (IQR) 36 (36-36) vs 36 (36-54) hours), and sick leave (median (IQR) 25 (17-30) vs 31 (36-54) days) did not differ between the robotic and abdominal group. Time of surgery was significantly longer in the robotic group than in the abdominal group (median (IQR) 70 (60-90) vs 56 (49-84) min; p<0.05). The robotic group recovered significantly faster as measured by the EQ-5D health index and gained 0.018 QALYs until 6 weeks after surgery. Total costs were 20% higher for the robotic procedure (SEK71 634 vs SEK59 319). The total cost per QALY gained for women in the robotic group was slightly under SEK700 000. CONCLUSIONS: Robotic hysterectomy used in an ERAS setting in the treatment of early endometrial cancer improved health within 6 weeks after the operation at a high cost for the health gained compared with abdominal hysterectomy. The productivity loss and informal care were lower for robotic hysterectomy, while healthcare had a higher procedure cost that could not be offset by the higher cost due to complications in the abdominal group.


Assuntos
Neoplasias do Endométrio/cirurgia , Custos Hospitalares/estatística & dados numéricos , Histerectomia/economia , Procedimentos Cirúrgicos Robóticos/economia , Idoso , Análise Custo-Benefício , Feminino , Humanos , Histerectomia/métodos , Tempo de Internação/economia , Pessoa de Meia-Idade , Complicações Pós-Operatórias/economia , Anos de Vida Ajustados por Qualidade de Vida , Procedimentos Cirúrgicos Robóticos/métodos , Licença Médica/economia , Inquéritos e Questionários
14.
Am J Physiol Endocrinol Metab ; 317(1): E139-E146, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31063397

RESUMO

The peptide ghrelin is mainly produced in some of the epithelial cells in the stomach, but also, during starvation, by the ε-cells in the endocrine pancreas. Ghrelin, as an endogenous ligand for the growth hormone secretagogue receptor (GHS-R1α), exerts a variety of metabolic functions including stimulation of appetite and weight gain. Its complete role is not yet fully understood, including whether it has any vascular functions. The present study evaluated if ghrelin affects pancreatic and islet blood flow. Ghrelin and the GHS-R1α receptor antagonist GHRP-6 were injected intravenously in rats followed by blood flow measurements using a microsphere technique. Ghrelin decreased, while GHRP-6 in fasted, but not fed, rats selectively increased islet blood flow fourfold. GHS-R1α was identified not only on glucagon-producing cells but also seemed to be present in the islet arterioles. GHRP-6 in fasted rats, only, also improved the peak insulin response to glucose in vivo, thereby substantially blunting the hyperglycemia. GHRP-6 doubled glucose-stimulated insulin release in vitro of both islets obtained from fed and fasted rats. Our results indicate a novel role for endogenous ghrelin acting directly or indirectly as a local vasoconstrictor in the islets during fasting, thereby restricting the insulin response to hyperglycemia. This is to the best of our knowledge the first report that shows this physiological mechanism to restrict insulin delivery from the islets by acting on the vasculature; a mode of action that can be envisaged to complement the previously well-described mechanisms of ghrelin acting directly on the islet endocrine cells.


Assuntos
Grelina/metabolismo , Ilhotas Pancreáticas/irrigação sanguínea , Ilhotas Pancreáticas/metabolismo , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Células Cultivadas , Grelina/sangue , Grelina/farmacologia , Secreção de Insulina/efeitos dos fármacos , Masculino , Oligopeptídeos/farmacologia , Pâncreas/irrigação sanguínea , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Ratos , Ratos Sprague-Dawley , Fluxo Sanguíneo Regional/efeitos dos fármacos , Circulação Esplâncnica/efeitos dos fármacos , Circulação Esplâncnica/fisiologia
15.
Diabetologia ; 61(4): 896-905, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29209740

RESUMO

AIMS/HYPOTHESIS: Genetic studies show coupling of genes affecting beta cell function to type 1 diabetes, but hitherto no studies on whether beta cell dysfunction could precede insulitis and clinical onset of type 1 diabetes are available. METHODS: We used 40-day-old BioBreeding (BB) DRLyp/Lyp rats (a model of spontaneous autoimmune type 1 diabetes) and diabetes-resistant DRLyp/+ and DR+/+ littermates (controls) to investigate beta cell function in vivo, and insulin and glucagon secretion in vitro. Beta cell mass was assessed by optical projection tomography (OPT) and morphometry. Additionally, measurements of intra-islet blood flow were performed using microsphere injections. We also assessed immune cell infiltration, cytokine expression in islets (by immunohistochemistry and qPCR), as well as islet Glut2 expression and ATP/ADP ratio to determine effects on glucose uptake and metabolism in beta cells. RESULTS: DRLyp/Lyp rats were normoglycaemic and without traces of immune cell infiltrates. However, IVGTTs revealed a significant decrease in the acute insulin response to glucose compared with control rats (1685.3 ± 121.3 vs 633.3 ± 148.7; p < 0.0001). In agreement, insulin secretion was severely perturbed in isolated islets, and both first- and second-phase insulin release were lowered compared with control rats, while glucagon secretion was similar in both groups. Interestingly, after 5-7 days of culture of islets from DRLyp/Lyp rats in normal media, glucose-stimulated insulin secretion (GSIS) was improved; although, a significant decrease in GSIS was still evident compared with islets from control rats at this time (7393.9 ± 1593.7 vs 4416.8 ± 1230.5 pg islet-1 h-1; p < 0.0001). Compared with controls, OPT of whole pancreas from DRLyp/Lyp rats revealed significant reductions in medium (4.1 × 109 ± 9.5 × 107 vs 3.8 × 109 ± 5.8 × 107 µm3; p = 0.044) and small sized islets (1.6 × 109 ± 5.1 × 107 vs 1.4 × 109 ± 4.5 × 107 µm3; p = 0.035). Finally, we found lower intra-islet blood perfusion in vivo (113.1 ± 16.8 vs 76.9 ± 11.8 µl min-1 [g pancreas]-1; p = 0.023) and alterations in the beta cell ATP/ADP ratio in DRLyp/Lyp rats vs control rats. CONCLUSIONS/INTERPRETATION: The present study identifies a deterioration of beta cell function and mass, and intra-islet blood flow that precedes insulitis and diabetes development in animals prone to autoimmune type 1 diabetes. These underlying changes in islet function may be previously unrecognised factors of importance in type 1 diabetes development.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/metabolismo , Modelos Animais de Doenças , Células Secretoras de Insulina/citologia , Insulina/metabolismo , Difosfato de Adenosina/química , Trifosfato de Adenosina/química , Animais , Glicemia/metabolismo , Feminino , Genótipo , Glucose/metabolismo , Ilhotas Pancreáticas/metabolismo , Células de Langerhans/metabolismo , Masculino , Pâncreas/metabolismo , Perfusão , Ratos , Ratos Endogâmicos BB , Ratos Wistar
16.
Diabetologia ; 61(6): 1333-1343, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29589073

RESUMO

AIMS/HYPOTHESIS: Excessive weight is a risk factor for type 2 diabetes, but its role in the promotion of autoimmune diabetes is not clear. We investigated the risk of latent autoimmune diabetes in adults (LADA) in relation to overweight/obesity in two large population-based studies. METHODS: Analyses were based on incident cases of LADA (n = 425) and type 2 diabetes (n = 1420), and 1704 randomly selected control participants from a Swedish case-control study and prospective data from the Norwegian HUNT Study including 147 people with LADA and 1,012,957 person-years of follow-up (1984-2008). We present adjusted ORs and HRs with 95% CI. RESULTS: In the Swedish data, obesity was associated with an increased risk of LADA (OR 2.93, 95% CI 2.17, 3.97), which was even stronger for type 2 diabetes (OR 18.88, 95% CI 14.29, 24.94). The association was stronger in LADA with low GAD antibody (GADA;

Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Autoimune Latente em Adultos/complicações , Diabetes Autoimune Latente em Adultos/diagnóstico , Diabetes Autoimune Latente em Adultos/epidemiologia , Obesidade/complicações , Sobrepeso/complicações , Adulto , Idoso , Autoanticorpos/sangue , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Humanos , Resistência à Insulina , Células Secretoras de Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Obesidade/epidemiologia , Razão de Chances , Sobrepeso/epidemiologia , Estudos Prospectivos , Fatores de Risco , Suécia , Adulto Jovem
17.
Am J Transplant ; 18(7): 1735-1744, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29288549

RESUMO

Macroencapsulation devices provide the dual possibility of immunoprotecting transplanted cells while also being retrievable, the latter bearing importance for safety in future trials with stem cell-derived cells. However, macroencapsulation entails a problem with oxygen supply to the encapsulated cells. The ßAir device solves this with an incorporated refillable oxygen tank. This phase 1 study evaluated the safety and efficacy of implanting the ßAir device containing allogeneic human pancreatic islets into patients with type 1 diabetes. Four patients were transplanted with 1-2 ßAir devices, each containing 155 000-180 000 islet equivalents (ie, 1800-4600 islet equivalents per kg body weight), and monitored for 3-6 months, followed by the recovery of devices. Implantation of the ßAir device was safe and successfully prevented immunization and rejection of the transplanted tissue. However, although beta cells survived in the device, only minute levels of circulating C-peptide were observed with no impact on metabolic control. Fibrotic tissue with immune cells was formed in capsule surroundings. Recovered devices displayed a blunted glucose-stimulated insulin response, and amyloid formation in the endocrine tissue. We conclude that the ßAir device is safe and can support survival of allogeneic islets for several months, although the function of the transplanted cells was limited (Clinicaltrials.gov: NCT02064309).


Assuntos
Órgãos Bioartificiais , Diabetes Mellitus Tipo 1/terapia , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/citologia , Pâncreas Artificial , Adolescente , Glicemia/análise , Cápsulas , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Monitorização Fisiológica , Prognóstico
18.
J Synchrotron Radiat ; 25(Pt 5): 1389-1394, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30179177

RESUMO

High-energy surface X-ray diffraction (HESXRD) provides surface structural information with high temporal resolution, facilitating the understanding of the surface dynamics and structure of the active phase of catalytic surfaces. The surface structure detected during the reaction is sensitive to the composition of the gas phase close to the catalyst surface, and the catalytic activity of the sample itself may affect the surface structure, which in turn may complicate the assignment of the active phase. For this reason, planar laser-induced fluorescence (PLIF) and HESXRD have been combined during the oxidation of CO over a Pd(100) crystal. PLIF complements the structural studies with an instantaneous two-dimensional image of the CO2 gas phase in the vicinity of the active model catalyst. Here the combined HESXRD and PLIF operando measurements of CO oxidation over Pd(100) are presented, allowing for an improved assignment of the correlation between sample structure and the CO2 distribution above the sample surface with sub-second time resolution.

19.
Langmuir ; 34(33): 9754-9761, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30060663

RESUMO

This work investigates the possibility to form catalytically active bimetallic Pd-Ag nanoparticles synthesized in the water pools of a reversed microemulsion using methanol, a more environmental- and user-friendly reductant compared to hydrazine or sodium borohydride, which are commonly used for this type of synthesis. The nanoparticles were characterized with regards to crystallinity and size by X-ray diffraction and transmission electron microscopy. CO chemisorption and oxidation followed by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used for investigating the elemental composition of the surface and catalytic activity, respectively. Moreover, the structural composition of the bimetallic particles was determined by scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy. The particles were shown to be crystalline nanoalloys of around 5-12 nm. CO adsorption followed by in situ DRIFTS suggests that the particle surfaces are composed of the same Pd-Ag ratios as the entire particles, regardless of elemental ratio (i.e., no core-shell structures can be detected). This is also shown by numerical simulations using a Monte Carlo based model. Furthermore, CO oxidation confirms that the synthesized particles are catalytically active.

20.
BMC Geriatr ; 18(1): 32, 2018 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-29386007

RESUMO

BACKGROUND: Older people with multi-morbidity are increasingly challenging for today's healthcare, and novel, cost-effective healthcare solutions are needed. The aim of this study was to assess the cost-effectiveness of comprehensive geriatric assessment (CGA) at an ambulatory geriatric unit for people ≥75 years with multi-morbidity. METHOD: The primary outcome was the incremental cost-effectiveness ratio (ICER) comparing costs and quality-adjusted life years (QALYs) of a CGA strategy with usual care in a Swedish setting. Outcomes were estimated over a lifelong time horizon using decision-analytic modelling based on data from the randomized AGe-FIT trial. The analysis employed a public health care sector perspective. Costs and QALYs were discounted by 3% per annum and are reported in 2016 euros. RESULTS: Compared with usual care CGA was associated with a per patient mean incremental cost of approximately 25,000 EUR and a gain of 0.54 QALYs resulting in an ICER of 46,000 EUR. The incremental costs were primarily caused by intervention costs and costs associated with increased survival, whereas the gain in QALYs was primarily a consequence of the fact that patients in the CGA group lived longer. CONCLUSION: CGA in an ambulatory setting for older people with multi-morbidity results in a cost per QALY of 46,000 EUR compared with usual care, a figure generally considered reasonable in a Swedish healthcare context. A rather simple reorganisation of care for older people with multi-morbidity may therefore cost effectively contribute to meet the needs of this complex patient population. TRIAL REGISTRATION: The trial was retrospectively registered in clinicaltrial.gov, NCT01446757 . September, 2011.


Assuntos
Assistência Ambulatorial/economia , Assistência Integral à Saúde/economia , Técnicas de Apoio para a Decisão , Avaliação Geriátrica/métodos , Anos de Vida Ajustados por Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Análise Custo-Benefício , Feminino , Humanos , Masculino , Estudos Retrospectivos , Método Simples-Cego , Suécia
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