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1.
Artigo em Inglês | MEDLINE | ID: mdl-33845454

RESUMO

SUMMARY: A 26-year-old Caucasian female with no past medical history or family history of auto-immune disease presented to the emergency department with new onset painless left foot drop. A panel of blood tests revealed blood glucose of 49.9 mmol/L and raised blood ketone levels. The patient was referred to the diabetes team who made a clinical diagnosis of type 1 diabetes (T1DM) and insulin treatment was initiated. Elevated levels of diabetes auto-antibodies were subsequently detected. Nerve conduction studies demonstrated a left common peroneal nerve lesion with conduction block at the fibular head. After 2 weeks of insulin treatment, a significant improvement of her foot drop was observed and after 8 weeks she was walking normally. The most probable cause of her foot drop was acute diabetic mononeuropathy. To our knowledge, there are no similar cases in adult patients reported in the literature. Our case highlights the importance of physicians being aware of atypical presentation of new onset T1DM. LEARNING POINTS: There is an increasing incidence of T1DM with more than half of patients presenting after the age of 20. Diabetic peripheral neuropathy can present both acutely and as a mononeuropathy. Although rare, clinicians should be aware of mononeuropathy as a presenting symptom of T1DM to avoid delay in the treatment initiation. This case highlights an unusual presentation of T1DM and illustrates the importance of the early diagnosis and management of T1DM.

2.
Glob Chang Biol ; 27(2): 282-296, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33124178

RESUMO

Climate change in the Arctic is outpacing the global average and land-use is intensifying due to exploitation of previously inaccessible or unprofitable natural resources. A comprehensive understanding of how the joint effects of changing climate and productivity modify lake food web structure, biomass, trophic pyramid shape and abundance of physiologically essential biomolecules (omega-3 fatty acids) in the biotic community is lacking. We conducted a space-for-time study in 20 subarctic lakes spanning a climatic (+3.2°C and precipitation: +30%) and chemical (dissolved organic carbon: +10 mg/L, total phosphorus: +45 µg/L and total nitrogen: +1,000 µg/L) gradient to test how temperature and productivity jointly affect the structure, biomass and community fatty acid content (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) of whole food webs. Increasing temperature and productivity shifted lake communities towards dominance of warmer, murky-water-adapted taxa, with a general increase in the biomass of primary producers, and secondary and tertiary consumers, while primary invertebrate consumers did not show equally clear trends. This process altered various trophic pyramid structures towards an hour glass shape in the warmest and most productive lakes. Increasing temperature and productivity had negative fatty acid content trends (mg EPA + DHA/g dry weight) in primary producers and primary consumers, but not in secondary nor tertiary fish consumers. The massive biomass increment of fish led to increasing areal fatty acid content (kg EPA + DHA/ha) towards increasingly warmer, more productive lakes, but there were no significant trends in other trophic levels. Increasing temperature and productivity are shifting subarctic lake communities towards systems characterized by increasing dominance of cyanobacteria and cyprinid fish, although decreasing quality in terms of EPA + DHA content was observed only in phytoplankton, zooplankton and profundal benthos.


Assuntos
Ácidos Graxos Ômega-3 , Lagos , Animais , Biomassa , Cadeia Alimentar , Fitoplâncton , Temperatura
4.
PLoS One ; 14(8): e0221338, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31430331

RESUMO

Resource polymorphism-whereby ancestral generalist populations give rise to several specialised morphs along a resource gradient-is common where species colonise newly formed ecosystems. This phenomenon is particularly well documented in freshwater fish populations inhabiting postglacial lakes formed at the end of the last ice age. However, knowledge on how such differential exploitation of resources across contrasting habitats might be reflected in the biochemical compositions of diverging populations is still limited, though such patterns might be expected. Here, we aimed to assess how fatty acids (FA)-an important biochemical component of animal tissues-diverged across a polymorphic complex of European whitefish (Coregonus lavaretus) and their closely related monomorphic specialist congener vendace (Coregonus albula) inhabiting a series of six subarctic lakes in northern Fennoscandia. We also explored patterns of FA composition in whitefish's predators and invertebrate prey to assess how divergence in trophic ecology between whitefish morphs would relate to biochemical profiles of their key food web associates. Lastly, we assessed how information on trophic divergence provided by differential FA composition compared to evidence of resource polymorphism retrieved from more classical stomach content and stable isotopic (δ13C, δ15N) information. Examination of stomach contents provided high-resolution information on recently consumed prey, whereas stable isotopes indicated broad-scale patterns of benthic-pelagic resource use differentiation at different trophic levels. Linear discriminant analysis based on FA composition was substantially more successful in identifying whitefish morphs and their congener vendace as distinct groupings when compared to the other two methods. Three major FA (myristic acid, stearic acid, and eicosadienoic acid) proved particularly informative, both in delineating coregonid groups, and identifying patterns of pelagic-benthic feeding throughout the wider food web. Myristic acid (14:0) content and δ13C ratios in muscle tissue were positively correlated across fish taxa, and together provided the clearest segregation of fishes exploiting contrasting pelagic and benthic niches. In general, our findings highlight the potential of FA analysis for identifying resource polymorphism in animal populations where this phenomenon occurs, and suggest that this technique may provide greater resolution than more traditional methods typically used for this purpose.


Assuntos
Ácidos Graxos/análise , Comportamento Alimentar/fisiologia , Cadeia Alimentar , Valor Nutritivo/fisiologia , Salmonidae/fisiologia , Animais , Conteúdo Gastrointestinal/química , Lagos , Países Escandinavos e Nórdicos
5.
Diabetologia ; 60(10): 2092-2102, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28776084

RESUMO

AIMS/HYPOTHESIS: We examined the associations between depressive symptoms and diabetes distress with glycaemic control and diabetes complications over 2 years, after diagnosis of type 2 diabetes. METHODS: In a multi-ethnic, primary care cohort (n = 1735) of adults, all with recent (<6 months) diagnosis of type 2 diabetes, we measured the associations between depressive symptoms (Patient Health Questionnaire-9 [PHQ-9] score ≥10) and diabetes distress (Problem Areas in Diabetes [PAID] score ≥40), with change in 2 year HbA1c as the primary outcome and with incident rates of diabetes complications as secondary outcomes. Multivariate models were used to account for potential confounders. RESULTS: Of the 1651 participants (95.2%) of the total primary care cohort with available baseline PHQ-9 and PAID scores, mean ± SD age was 56.2 ± 11.1 years, 55.1% were men and 49.1% were of non-white ethnicity; 232 (14.1%) and 111 (6.7%) had depressive symptoms and diabetes distress, respectively. After adjustment for confounders, depressive symptoms were not associated with worsening HbA1c. After adjustment for age, sex, ethnicity, vascular risk factors and diabetes treatments, depressive symptoms were associated with increased risk of incident macrovascular complications (OR 2.78 [95% CI 1.19, 6.49], p = 0.018) but not microvascular complications. This was attenuated (p = 0.09) after adjustment for IL-1 receptor antagonist concentration. Diabetes distress was not associated with worsening HbA1c or incident complications. CONCLUSIONS/INTERPRETATION: In the first 2 years of type 2 diabetes, the effect of depressive symptoms and diabetes distress on glycaemic control is minimal. There was, however, an association between depressive symptoms and incidence of macrovascular complications. Elevated innate inflammation may be common to both depression and macrovascular diabetes complications, but these findings require replication.


Assuntos
Glicemia/análise , Depressão/complicações , Diabetes Mellitus Tipo 2/complicações , Hipoglicemiantes/uso terapêutico , Adulto , Idoso , Depressão/psicologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/psicologia , Feminino , Hemoglobinas Glicadas , Orthohantavírus , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
6.
Sci Rep ; 7(1): 8765, 2017 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-28821736

RESUMO

Ecological speciation - whereby an ancestral founder species diversifies to fill vacant niches - is a phenomenon characteristic of newly formed ecosystems. Despite such ubiquity, ecosystem-level effects of such divergence remain poorly understood. Here, we compared the trophic niche of European whitefish (Coregonus lavaretus) and their predators in a series of contrasting subarctic lakes where this species had either diversified into four ecomorphologically distinct morphs or instead formed monomorphic populations. We found that the trophic niche of whitefish was almost three times larger in the polymorphic than in the monomorphic lakes, due to an increase in intraspecific specialisation. This trophic niche expansion was mirrored in brown trout (Salmo trutta), a major predator of whitefish. This represents amongst the first evidence for ecological speciation directly altering the trophic niche of a predator. We suggest such mechanisms may be a common and important - though presently overlooked - factor regulating trophic interactions in diverse ecosystems globally.


Assuntos
Biodiversidade , Ecossistema , Cadeia Alimentar , Animais , Ecologia , Salmonidae
7.
Sci Total Environ ; 599-600: 1768-1778, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28545204

RESUMO

Resource polymorphism, whereby ancestral trophic generalists undergo divergence into multiple specialist morphs, is common in salmonid fish populations inhabiting subarctic lakes. However, the extent to which such resource specialization into the three principal lake habitats (littoral, profundal, and pelagic) affects patterns of contaminant bioaccumulation remains largely unexplored. We assessed total mercury concentrations (THg) of European whitefish (Coregonus lavaretus (L.)) and their invertebrate prey in relation to potential explanatory variables across 6 subarctic lakes, of which three are inhabited by polymorphic (comprised of four morphs) and three by monomorphic populations. Among invertebrate prey, the highest THg concentrations were observed in profundal benthic macroinvertebrates, followed by pelagic zooplankton, with concentrations lowest in littoral benthic macroinvertebrates in both lake types. Broadly similar patterns were apparent in whitefish in polymorphic systems, where average age-corrected THg concentrations and bioaccumulation rates were the highest in pelagic morphs, intermediate in the profundal morph, and the lowest in the littoral morph. In monomorphic systems, age-corrected THg concentrations were generally lower, and showed pronounced lake-specific variation. In the polymorphic systems, we found significant relationships between whitefish muscle tissue THg concentration and gill raker count, resource use, lipid content and maximum length, whilst no such relationships were apparent in the monomorphic systems. Across all polymorphic lakes, the major variables explaining THg in whitefish were gill raker count and age, whereas in monomorphic systems, the factors were lake-specific. Whitefish resource polymorphism across the three main lake habitats therefore appears to have profound impacts on THg concentration and bioaccumulation rate. This highlights the importance of recognizing such intraspecific diversity in both future scientific studies and mercury monitoring programs.


Assuntos
Cadeia Alimentar , Lagos/química , Mercúrio/metabolismo , Salmonidae/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Ecossistema , Brânquias , Salmonidae/anatomia & histologia , Países Escandinavos e Nórdicos
8.
Glob Chang Biol ; 22(1): 310-24, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26395251

RESUMO

Managed adaptation could reduce the risks of climate change to the world's ecosystems, but there have been surprisingly few practical evaluations of the options available. For example, riparian woodland is advocated widely as shade to reduce warming in temperate streams, but few studies have considered collateral effects on species composition or ecosystem functions. Here, we use cross-sectional analyses at two scales (region and within streams) to investigate whether four types of riparian management, including those proposed to reduce potential climate change impacts, might also affect the composition, functional character, dynamics and energetic resourcing of macroinvertebrates in upland Welsh streams (UK). Riparian land use across the region had only small effects on invertebrate taxonomic composition, while stable isotope data showed how energetic resources assimilated by macroinvertebrates in all functional guilds were split roughly 50:50 between terrestrial and aquatic origins irrespective of riparian management. Nevertheless, streams draining the most extensive deciduous woodland had the greatest stocks of coarse particulate matter (CPOM) and greater numbers of 'shredding' detritivores. Stream-scale investigations showed that macroinvertebrate biomass in deciduous woodland streams was around twice that in moorland streams, and lowest of all in streams draining non-native conifers. The unexpected absence of contrasting terrestrial signals in the isotopic data implies that factors other than local land use affect the relative incorporation of allochthonous subsidies into riverine food webs. Nevertheless, our results reveal how planting deciduous riparian trees along temperate headwaters as an adaptation to climate change can modify macroinvertebrate function, increase biomass and potentially enhance resilience by increasing basal resources where cover is extensive (>60 m riparian width). We advocate greater urgency in efforts to understand the ecosystem consequences of climate change adaptation to guide future actions.


Assuntos
Mudança Climática , Florestas , Invertebrados/fisiologia , Rios , Animais , Biomassa , Ecossistema , Cadeia Alimentar , Luz Solar , Árvores , País de Gales
10.
Proc Natl Acad Sci U S A ; 112(22): 7033-8, 2015 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-26038557

RESUMO

Decomposition of organic material by soil microbes generates an annual global release of 50-75 Pg carbon to the atmosphere, ∼7.5-9 times that of anthropogenic emissions worldwide. This process is sensitive to global change factors, which can drive carbon cycle-climate feedbacks with the potential to enhance atmospheric warming. Although the effects of interacting global change factors on soil microbial activity have been a widespread ecological focus, the regulatory effects of interspecific interactions are rarely considered in climate feedback studies. We explore the potential of soil animals to mediate microbial responses to warming and nitrogen enrichment within a long-term, field-based global change study. The combination of global change factors alleviated the bottom-up limitations on fungal growth, stimulating enzyme production and decomposition rates in the absence of soil animals. However, increased fungal biomass also stimulated consumption rates by soil invertebrates, restoring microbial process rates to levels observed under ambient conditions. Our results support the contemporary theory that top-down control in soil food webs is apparent only in the absence of bottom-up limitation. As such, when global change factors alleviate the bottom-up limitations on microbial activity, top-down control becomes an increasingly important regulatory force with the capacity to dampen the strength of positive carbon cycle-climate feedbacks.


Assuntos
Mudança Climática , Retroalimentação , Cadeia Alimentar , Fungos/fisiologia , Isópodes/fisiologia , Modelos Teóricos , Microbiologia do Solo , Análise de Variância , Animais , Massachusetts , Nitrogênio/metabolismo
11.
J Anim Ecol ; 84(3): 861-870, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25482029

RESUMO

The stable isotopes of carbon ((12)C, (13)C) and nitrogen ((14)N, (15)N) represent powerful tools in food web ecology, providing a wide range of dietary information in animal consumers. However, identifying the temporal window over which a consumer's isotopic signature reflects its diet requires an understanding of elemental incorporation, a process that varies from days to years across species and tissue types. Though theory predicts body size and temperature are likely to control incorporation rates, this has not been tested empirically across a morphologically and phylogenetically diverse range of taxa. Readily available estimates of this relationship would, however, aid in the design of stable isotope food web investigations and improve the interpretation of isotopic data collected from natural systems. Using literature-derived turnover estimates from animal species ranging in size from 1 mg to 2000 kg, we develop a predictive tool for stable isotope ecologists, allowing for estimation of incorporation rates in the structural tissues of entirely novel taxa. In keeping with metabolic scaling theory, we show that isotopic turnover rates of carbon and nitrogen in whole organisms and muscle tissue scale allometrically with body mass raised approximately to the power -0.19, an effect modulated by body temperature. This relationship did not, however, apply to incorporation rates in splanchnic tissues, which were instead dependent on the thermoregulation tactic employed by an organism, being considerably faster in endotherms than ectotherms. We believe the predictive turnover equations we provide can improve the design of experiments and interpretation of results obtained in future stable isotopic food web studies.


Assuntos
Isótopos de Carbono/metabolismo , Isótopos de Nitrogênio/metabolismo , Animais , Temperatura Corporal , Regulação da Temperatura Corporal , Peso Corporal , Dieta/veterinária , Cadeia Alimentar , Modelos Biológicos , Especificidade de Órgãos
12.
PLoS One ; 9(1): e86246, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24465985

RESUMO

Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder) or Betula pendula (silver birch) trees propagated under ambient (380 ppm) or elevated (ambient +200 ppm) CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i) two litter discs, one of each CO2 treatment ('choice'), or (ii) one litter disc of each CO2 treatment alone ('no-choice'). Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species' responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing-a key ecosystem function-under atmospheric change.


Assuntos
Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Ecossistema , Herbivoria , Invertebrados/fisiologia , Plantas/metabolismo , Análise de Variância , Animais , Fotossíntese , Folhas de Planta/metabolismo
13.
Ecology ; 94(11): 2518-28, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24400503

RESUMO

The relative contribution of top-down and bottom-up processes regulating primary decomposers can influence the strength of the link between the soil animal community and ecosystem functioning. Although soil bacterial communities are regulated by bottom-up and top-down processes, the latter are considered to be less important in structuring the diversity and functioning of fungal-dominated ecosystems. Despite the huge diversity of mycophagous (fungal-feeding) soil fauna, and their potential to reverse the outcomes of competitive fungal interactions, top-down grazing effects have never been found to translate to community-level changes. We constructed soil mesocosms to investigate the potential of isopods grazing on cord-forming basidiomycete fungi to influence the community composition and functioning of a complex woodland soil microbial community. Using metagenomic sequencing we provide conclusive evidence of direct top-down control at the community scale in fungal-dominated woodland soil. By suppressing the dominant cord-forming basidiomycete fungi, isopods prevented the competitive exclusion of surrounding litter fungi, increasing diversity in a community containing several hundred fungal species. This isopod-induced modification of community composition drove a shift in the soil enzyme profile, and led to a restructuring of the wider mycophagous invertebrate community. We highlight characteristics of different soil ecosystems that will give rise to such top-down control. Given the ubiquity of isopods and basidiomycete fungi in temperate and boreal woodland ecosystems, such top-down community control could be of widespread significance for global carbon and nutrient cycling.


Assuntos
Fungos/enzimologia , Isópodes/fisiologia , Microbiologia do Solo , Solo/química , Animais , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungos/classificação , Fungos/fisiologia , Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica
14.
Endocrine ; 38(1): 113-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20960111

RESUMO

There are no consensus guidelines on the optimum long-term care of patients with primary adrenal failure. Published data suggest increased morbidity and mortality in patients treated with current therapy. Investigations of bone mineral density (BMD) in adults with adrenal failure have reported conflicting results. The objectives of this study were to determine the prevalence of auto-immune and other co-morbidities, describe the treatment regimens and to assess the BMD of adults with auto-immune Addison's disease (AAD). A retrospective, cohort study of adults with primary adrenal failure was used. Electronic and paper records were used to collect demographic, biochemical, BMD data and details of other co-morbidities. 48 patients (35% male; 65% female; 50 ± 16, years, mean ± SD) with primary adrenal failure were identified. There was high prevalence of other auto-immune co-morbidities (hypothyroidism 58%, vitamin B(12) deficiency 29%, type 1 diabetes 10%). The presence of cardiovascular risk factors including dyslipidaemia (65% had total cholesterol >5 mmol/l) and excess weight (65% had a BMI >25 kg/m(2)) were high. Using WHO criteria, 17.9 and 53.5% of patients had spinal osteoporosis and osteopenia, respectively, at the spine. This did not relate to the duration or dose of glucocorticoid replacement. Our data shows a high prevalence of both auto-immune and non-autoimmune co-morbidities in patients with AAD. In addition to common auto-immune diseases, patients should be screened for other cardiovascular risk factors. Further studies are needed to assess the cause of the observed increased prevalence of reduced BMD at the lumbar spine. There is a need for internationally agreed long-term management guidelines.


Assuntos
Doença de Addison , Doenças Autoimunes/epidemiologia , Diabetes Mellitus Tipo 1/epidemiologia , Hidrocortisona/uso terapêutico , Hipotireoidismo/epidemiologia , Deficiência de Vitamina B 12/epidemiologia , Doença de Addison/tratamento farmacológico , Doença de Addison/epidemiologia , Doença de Addison/imunologia , Adulto , Idoso , Densidade Óssea , Comorbidade , Dislipidemias/epidemiologia , Feminino , Humanos , Incidência , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
16.
Nephrol Dial Transplant ; 24(9): 2645-55, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19420102

RESUMO

BACKGROUND: Podocyturia is a marker of diabetic nephr- opathy, a possible determinant of its progression and a powerful risk factor for cardiovascular disease. A reduction in podocyte adhesion to the glomerular basement membrane (GBM) via downregulation of alpha3beta1 integrin expression, the main podocyte anchoring dimer to the GBM, may represent one of the mechanisms of podocyturia in glomerular disease. This study investigated the role of mechanical forces and transforming growth factor beta1 (TGFbeta1) in podocyte adhesion and integrin expression. METHODS: Conditionally immortalized murine podocytes were exposed to mechanical stretch and/or TGFbeta1 for 48 h. Podocyte adhesion, apoptosis and alpha3beta1 integrin expression were assessed. RESULTS: Stretch and TGFbeta1 significantly reduced podocyte adhesion and alpha3beta1 integrin expression, events paralleled by increased apoptosis. Blockade of beta1 integrin, with a specific antibody, demonstrated a reduced podocyte adhesion indicating that beta1 integrin downregulation was required for the loss of podocyte adhesion. This was linked to an increase in podocyte apoptosis. The role of apoptosis in podocyte adhesion was further investigated using caspase-3 inhibitors. Podocyte apoptosis inhibition did not affect stretch- and TGFbeta1-mediated integrin downregulation and the loss of podocyte adhesion, suggesting that alpha3beta1 integrin downregulation is sufficient to alter cell adhesion. Although stretch significantly increased podocyte TGFbeta type I, II and III receptors but not podocyte TGFbeta1 secretion, the combination of stretch and TGFbeta1 did not show any additive or synergistic effects on podocyte adhesion and alpha3beta1 integrin expression. CONCLUSIONS: These results suggest that downregulation of alpha3beta1 integrin expression, by mechanical forces or TGFbeta1, is per se sufficient to reduce podocyte adhesion. Apoptosis may represent a parallel important determinant of the podocyte loss from the GBM.


Assuntos
Integrina alfa3beta1/fisiologia , Podócitos/efeitos dos fármacos , Podócitos/fisiologia , Fator de Crescimento Transformador beta1/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Matriz Extracelular/fisiologia , Membrana Basal Glomerular/citologia , Membrana Basal Glomerular/efeitos dos fármacos , Membrana Basal Glomerular/fisiologia , Glicosilação , Integrina alfa3beta1/química , Nefropatias/etiologia , Nefropatias/patologia , Nefropatias/fisiopatologia , Camundongos , Podócitos/citologia , Receptores de Fatores de Crescimento Transformadores beta/classificação , Receptores de Fatores de Crescimento Transformadores beta/fisiologia , Estresse Mecânico
17.
Ann Intern Med ; 149(10): 708-19, 2008 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-19017589

RESUMO

BACKGROUND: Although psychological issues can interfere with diabetes care, the effectiveness of psychological treatments in improving diabetes outcomes is uncertain. OBJECTIVE: To determine whether motivational enhancement therapy with or without cognitive behavior therapy improves glycemic control in type 1 diabetes compared with usual care. DESIGN: Randomized, controlled trial. SETTING: 8 diabetes centers in London and Manchester, United Kingdom. PATIENTS: 344 adults with type 1 diabetes for longer than 2 years, with hemoglobin A(1c) levels of 8.2% to 15%, and without complications or severe comorbid disease. INTERVENTION: Nurse-delivered motivational enhancement therapy (4 sessions over 2 months), motivational enhancement therapy plus cognitive behavior therapy (12 sessions over 6 months), or usual care. MEASUREMENTS: 12-month change in hemoglobin A(1c) levels (primary outcome), hypoglycemic events, depression, quality of life, fear of hypoglycemia, diabetes self-care activities, and body mass index (secondary outcomes). RESULTS: In an analysis including all randomly assigned patients, the 12-month change in hemoglobin A(1c) levels compared with usual care was -0.46% (95% CI, -0.81% to -0.11%) in the motivational enhancement therapy plus cognitive behavior therapy group and -0.19% (CI, -0.53% to 0.16%) in the motivational enhancement therapy group alone. There was no evidence of treatment effects on secondary outcomes. LIMITATIONS: Of 1659 screened patients, only 507 were eligible and 344 participated. Data on the primary outcome were unavailable for 11.3% of the participants. Study design did not permit distinction of the additive effect of cognitive behavior therapy plus motivational enhancement therapy from the effect of greater intensity and duration of the combined intervention compared with the motivational enhancement therapy alone. CONCLUSION: Nurse-delivered motivational enhancement therapy and cognitive behavior therapy is feasible for adults with poorly controlled type 1 diabetes. Combined therapy results in modest 12-month improvement in hemoglobin A(1c) levels compared with usual care, but motivational enhancement therapy alone does not.


Assuntos
Terapia Cognitivo-Comportamental , Diabetes Mellitus Tipo 1/psicologia , Diabetes Mellitus Tipo 1/terapia , Motivação , Adulto , Idoso , Terapia Combinada , Depressão/prevenção & controle , Diabetes Mellitus Tipo 1/sangue , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/prevenção & controle , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Cuidados de Enfermagem , Sensibilidade e Especificidade , Adulto Jovem
18.
J Am Soc Nephrol ; 18(8): 2226-32, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17634438

RESUMO

Nephropathy is one of the major microvascular complications of diabetes, and both hemodynamic and metabolic stimuli participate in its development and progression toward ESRD. There is now a greater understanding of the molecular pathways that are activated by high glomerular capillary pressure and hyperglycemia and how they interplay to produce kidney pathology. The observation that overexpression of glucose transporter 1 (GLUT-1) in mesangial cells could induce a "diabetic cellular phenotype" has led to the postulation that the expression of GLUT-1 could be upregulated in glomeruli that are exposed to high pressure. This review suggests a mechanism by which mechanical forces may aggravate a metabolic insult by stimulating excessive cellular glucose uptake. Proposed is the existence of a self-maintaining cycle whereby a hemodynamic stimulus on glomerular cells induces GLUT-1 overexpression followed by greater glucose uptake and activation of intracellular glucose metabolic pathways, resulting in excess TGF-beta1 production. TGF-beta1 in turn, maintains overexpression of GLUT-1, perpetuating a signaling sequence that has, as its ultimate effect, increased extracellular matrix synthesis. This mechanical and metabolic coupling suggests a novel pathophysiologic mechanism of injury in the kidney in diabetes and possibly other glomerular diseases.


Assuntos
Glicemia/metabolismo , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/fisiopatologia , Metabolismo Energético/fisiologia , Animais , Humanos , Glomérulos Renais/metabolismo , Glomérulos Renais/fisiologia , Estresse Mecânico
19.
Clin Endocrinol (Oxf) ; 66(5): 632-5, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17492949

RESUMO

OBJECTIVES: Oral oestrogen preparations increase total cortisol concentration by increasing circulating cortisol-binding globulin (CBG) levels. Transdermal oestrogen treatments are being used increasingly in clinical practice. These topical preparations may have less of an effect on CBG and hence on total serum cortisol levels by reducing hepatic oestrogen exposure. The purpose of this study was to compare the effects of oral and topical oestrogen treatments on CBG, total serum cortisol and salivary cortisol levels. DESIGN AND PATIENTS: This was a single-centre, cross-sectional study of 37 women aged 33 +/- 6 years (mean +/- SD). Fourteen women were using oral oestrogen therapy, eight were using transdermal therapy and 15 were oestrogen-naïve control subjects. MEASUREMENTS: Following a screening visit, the subjects attended the endocrine investigation unit following an overnight fast. Blood and salivary samples were taken from 0830 to 0930 h between days 10 and 18 of the menstrual cycle (where appropriate). RESULTS: Total serum cortisol concentrations were 67% higher in those receiving oral oestrogen when compared to control subjects (660.9 +/- 89.9 vs. 395.4 +/- 53.2 nmol/l, P < 0.001). Values in those receiving transdermal oestrogen (334.7 +/- 72.0 nmol/l) were no different from the control group. CBG levels were higher in those on oral oestrogen therapy (110.9 +/- 19.6 mg/l, P < 0.001) when compared with either those on transdermal oestrogen (51.0 +/- 5.4 mg/l) or the control population (49.0 +/- 11.8 mg/l). Similar salivary cortisol concentrations were recorded in the three groups (controls 13.8 +/- 2.6 nmol/l, oral oestrogen 15.5 +/- 2.6 nmol/l, transdermal oestrogen 15.7 +/- 3.9 nmol/l). CONCLUSIONS: Oral oestrogen-containing preparations increase total cortisol levels by increasing circulating CBG concentration. These effects were not seen in patients using transdermal oestrogen replacement. Although further studies are indicated, it is probably unnecessary to routinely discontinue transdermal oestrogen replacement when performing an assessment of the hypothalamic-pituitary-adrenal (HPA) axis or evaluating adequacy of hydrocortisone replacement.


Assuntos
Proteínas de Transporte/sangue , Terapia de Reposição de Estrogênios/métodos , Estrogênios/administração & dosagem , Hidrocortisona/sangue , Pós-Menopausa , Administração Cutânea , Administração Oral , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Hidrocortisona/análise , Pessoa de Meia-Idade , Saliva/química
20.
Hypertension ; 41(5): 1063-71, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12654706

RESUMO

Microalbuminuria in diabetes is a risk factor for early death and an indicator for aggressive blood pressure (BP) lowering. We compared a combination of 2 mg perindopril/0.625 mg indapamide with enalapril monotherapy on albumin excretion rate (AER) in patients with type 2 diabetes, albuminuria, and hypertension in a 12-month, randomized, double-blind, parallel-group international multicenter study. Four hundred eighty-one patients with type 2 diabetes and hypertension (systolic BP > or =140 mm Hg, <180 mm Hg, diastolic BP <110 mm Hg) were randomly assigned (age 59+/-9 years, 77% previously treated for hypertension). Results from 457 patients (intention-to-treat analysis) were available. After a 4-week placebo period, patients with albuminuria >20 and <500 microg/min were randomly assigned to a combination of 2 mg perindopril/0.625 mg indapamide or to 10 mg daily enalapril. After week 12, doses were adjusted on the basis of BP to a maximum of 8 mg perindopril/2.5 mg indapamide or 40 mg enalapril. The main outcome measures were overnight AER and supine BP. Both treatments reduced BP. Perindopril/indapamide treatment resulted in a statistically significant higher fall in both BP (-3.0 [95% CI -5.6, -0.4], P=0.012; systolic BP -1.5 [95% CI -3.0, -0.1] diastolic BP P=0.019) and AER -42% (95% CI -50%, -33%) versus -27% (95% CI -37%, -16%) with enalapril. The greater AER reduction remained significant after adjustment for mean BP. Adverse events were similar in the 2 groups. Thus, first-line treatment with low-dose combination perindopril/indapamide induces a greater decrease in albuminuria than enalapril, partially independent of BP reduction. A BP-independent effect of the combination may increase renal protection.


Assuntos
Albuminúria/tratamento farmacológico , Anti-Hipertensivos/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Indapamida/uso terapêutico , Perindopril/uso terapêutico , Adulto , Idoso , Albuminúria/etiologia , Albuminúria/urina , Anti-Hipertensivos/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Tosse/induzido quimicamente , Diabetes Mellitus Tipo 2/fisiopatologia , Tontura/induzido quimicamente , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Enalapril/efeitos adversos , Enalapril/uso terapêutico , Feminino , Seguimentos , Humanos , Indapamida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Perindopril/efeitos adversos , Resultado do Tratamento
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