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1.
Liver Int ; 44(1): 39-51, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37698034

RESUMO

BACKGROUND & AIMS: The burden of metabolic dysfunction-associated steatotic liver disease (MASLD) is growing rapidly, as is the number of older adults globally. However, relatively few studies have been performed evaluating the prevalence and risk factors for MASLD in older adults. As such, we aimed to identify the prevalence of MASLD in older adults, as well as sociodemographic, clinical, functional and biochemical associations. METHODS: The study population included older adults without a history of cardiovascular disease, dementia or independence-limiting functional impairment who had participated in the ASPirin in Reducing Events in the Elderly (ASPREE) randomised trial. MASLD was defined using the Fatty Liver Index (FLI). Associations were identified using Poisson regression with robust variance for FLI ≥ 60 vs FLI < 30. RESULTS: 9097 Australian participants aged ≥70 years had complete biochemical and anthropometric data to identify MASLD. The study population had a mean age of 75.1 ± 4.3 years and was 45.0% male. Almost one-third (33.0%) had prevalent MASLD, and the prevalence decreased with increasing age (adjusted RR [aRR] 0.96, 95% CI: 0.96-0.97). MASLD was also negatively associated with social advantage (aRR 0.94, 95% CI: 0.90-0.99) and exercise tolerance and was positively associated with diabetes mellitus (aRR: 1.22, 95% CI: 1.16-1.29), hypertension (aRR: 1.31, 95% CI: 1.22-1.41), male sex (aRR: 1.66, 95% CI: 1.57-1.74), pre-frailty (aRR: 1.99, 95% CI: 1.82-2.12) and frailty (aRR: 2.36, 95% CI: 2.16-2.56). MASLD and nonalcoholic fatty liver disease (NAFLD) results were 100% concordant. CONCLUSION: This study in a large cohort of relatively healthy community-dwelling older adults shows that MASLD is common, decreases with age and is associated with poorer metabolic health, social disadvantage and frailty.


Assuntos
Fragilidade , Doenças Metabólicas , Hepatopatia Gordurosa não Alcoólica , Idoso , Feminino , Humanos , Masculino , Antropometria , Austrália/epidemiologia , Fragilidade/epidemiologia , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Estudos Transversais
2.
Ann Intern Med ; 176(7): 913-921, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37335992

RESUMO

BACKGROUND: Daily low-dose aspirin increases major bleeding; however, few studies have investigated its effect on iron deficiency and anemia. OBJECTIVE: To investigate the effect of low-dose aspirin on incident anemia, hemoglobin, and serum ferritin concentrations. DESIGN: Post hoc analysis of the ASPREE (ASPirin in Reducing Events in the Elderly) randomized controlled trial. (ClinicalTrials.gov: NCT01038583). SETTING: Primary/community care in Australia and the United States. PARTICIPANTS: Community-dwelling persons aged 70 years or older (≥65 years for Black persons and Hispanic persons). INTERVENTION: 100 mg of aspirin daily or placebo. MEASUREMENTS: Hemoglobin concentration was measured annually in all participants. Ferritin was measured at baseline and 3 years after random assignment in a large subset. RESULTS: 19 114 persons were randomly assigned. Anemia incidence in the aspirin and placebo groups was 51.2 events and 42.9 events per 1000 person-years, respectively (hazard ratio, 1.20 [95% CI, 1.12 to 1.29]). Hemoglobin concentrations declined by 3.6 g/L per 5 years in the placebo group and the aspirin group experienced a steeper decline by 0.6 g/L per 5 years (CI, 0.3 to 1.0 g/L). In 7139 participants with ferritin measures at baseline and year 3, the aspirin group had greater prevalence than placebo of ferritin levels less than 45 µg/L at year 3 (465 [13%] vs. 350 [9.8%]) and greater overall decline in ferritin by 11.5% (CI, 9.3% to 13.7%) compared with placebo. A sensitivity analysis quantifying the effect of aspirin in the absence of major bleeding produced similar results. LIMITATIONS: Hemoglobin was measured annually. No data were available on causes of anemia. CONCLUSION: Low-dose aspirin increased incident anemia and decline in ferritin in otherwise healthy older adults, independent of major bleeding. Periodic monitoring of hemoglobin should be considered in older persons on aspirin. PRIMARY FUNDING SOURCE: National Institutes of Health and Australian National Health and Medical Research Council.


Assuntos
Anemia , Aspirina , Idoso , Humanos , Estados Unidos/epidemiologia , Idoso de 80 Anos ou mais , Aspirina/efeitos adversos , Incidência , Austrália/epidemiologia , Hemorragia/epidemiologia , Anemia/epidemiologia , Anemia/prevenção & controle , Anemia/tratamento farmacológico , Ferritinas , Hemoglobinas , Método Duplo-Cego
3.
Molecules ; 29(7)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38611870

RESUMO

The possibilities of comparing computational results of noncovalent interactions with experimental data are discussed, first with respect to intramolecular interactions. For these a variety of experimental data such as heats of formation, crystal sublimation heats, comparison with energy minimized structures, and spectroscopic data are available, but until now largely have not found widespread application. Early force field and QM/MP2 calculations have already shown that the sublimation heats of hydrocarbons can be predicted with an accuracy of ±1%. Intermolecular interactions in solution or the gas phase are always accompanied by difficult to compute entropic contributions, like all associations between molecules. Experimentally observed T∆S values contribute 10% to 80% of the total ∆G, depending on interaction mechanisms within the complexes, such as, e.g., hydrogen bonding and ion pairing. Free energies ∆G derived from equilibrium measurements in solution allow us to define binding increments ∆∆G, which are additive and transferable to a variety of supramolecular complexes. Data from more than 90 equilibrium measurements of porphyrin receptors in water indicate that small alkanes do not bind to the hydrophobic flat surfaces within a measuring limit of ∆G = ±0.5 kJ/mol, and that 20 functions bearing heteroatoms show associations by dispersive interactions with up to ∆G = 8 kJ/mol, roughly as a function of their polarizability. Aromatic systems display size-dependent affinities ∆G as a linear function of the number of π-electrons.

4.
Osteoporos Int ; 34(2): 327-337, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36434431

RESUMO

Low serum alkaline phosphatase (ALP) was found in 9% of patients attending an osteoporosis clinic, 0.6% of hospital patients, and 2/22 with an atypical femoral fracture. Hypophosphatasia was diagnosed in 3% of osteoporosis clinic patients with low ALP. Low ALP is a screening tool for hypophosphatasia, a condition potentially aggravated by antiresorptive therapy. INTRODUCTION: Hypophosphatasia (HPP) is an inherited disorder associated with impaired primary mineralisation of osteoid (osteomalacia). HPP may be misdiagnosed as osteoporosis, a reduction in the volume of normally mineralized bone. Both illnesses may result in fragility fractures, although stress and atypical fractures are more common in HPP. Antiresorptive therapy, first-line treatment for osteoporosis, is relatively contraindicated in HPP. Misdiagnosis and mistreatment can be avoided by recognising a low serum alkaline phosphatase (ALP). Our aim was to determine the prevalence of a low ALP (< 30 IU/L) in patients attending an osteoporosis clinic, in a hospital-wide setting, and in a group of patients with atypical femoral fractures (AFF). METHODS: This was a retrospective study of patients attending an osteoporosis clinic at a tertiary hospital during 8 years (2012-2020). Patients were categorised into those with a transiently low ALP, those with low ALP on ≥ 2 occasions but not the majority of measurements, and those with a persistently low ALP. ALP levels were also assessed in hospital-wide records and a group of patients with AFF. RESULTS: Of 1839 patients attending an osteoporosis clinic, 168 (9%) had ≥ 1 low ALP, 50 (2.7%) had low ALP for ≥ 2 months, and seven (0.4%) had persistently low ALP levels. HPP was diagnosed in five patients, four of whom had persistently low ALP levels. The prevalence of HPP was 0.3% in the osteoporosis clinic and 3% in patients with ≥ 1 low ALP. Low ALP occurred in 0.6% of all hospital patients and 2/22 with AFF. CONCLUSION: Persistently low ALP in osteoporosis clinic attendees is easy to identify and signals the possibility of hypophosphatasia, a condition that may be mistaken for osteoporosis and incorrectly treated with antiresorptive therapy.


Assuntos
Fraturas Ósseas , Hipofosfatasia , Osteoporose , Humanos , Hipofosfatasia/complicações , Hipofosfatasia/diagnóstico , Hipofosfatasia/tratamento farmacológico , Fosfatase Alcalina , Estudos Retrospectivos , Fraturas Ósseas/complicações , Osteoporose/diagnóstico , Osteoporose/tratamento farmacológico , Osteoporose/epidemiologia
5.
Stroke ; 53(11): e467-e471, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36189678

RESUMO

BACKGROUND: Depressive symptoms are a common stroke sequela, yet their neurobiological substrates are still unclear. We sought to determine if they are associated with specific lesion locations. METHODS: In a prospective observational study, 270 patients with stroke were tested twice with the Hospital Anxiety and Depression Scale around day 6 and again 6 months poststroke and voxel-based lesion behavior mapping was performed. RESULTS: Frequency of depressive symptoms (depression subscale of the Hospital Anxiety and Depression Scale >7) after 6 months was 19.6 %. Higher Hospital Anxiety and Depression Scale scores for depression around day 6 were the only variable associated with depressive symptoms after 6 months in a multiple logistic regression. Lesions in the right putamen were significantly associated with depressive symptoms after 6 months in the voxel-based lesion behavior mapping. CONCLUSIONS: Lesions in the right basal ganglia might increase the risk of depressive symptoms 6 months poststroke.


Assuntos
Depressão , Acidente Vascular Cerebral , Humanos , Depressão/diagnóstico por imagem , Depressão/epidemiologia , Depressão/etiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia , Gânglios da Base , Análise Multivariada , Estudos Prospectivos
6.
Neuroimage ; 251: 119001, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35172200

RESUMO

Diaschisis is a phenomenon observed in stroke that is defined as neuronal dysfunction in regions spared by the infarction but connected to the lesion site. We combined lesion network mapping and task-based functional MRI in 71 patients with post-stroke aphasia to investigate, whether diaschisis and its resolution contribute to early loss and recovery of language functions. Language activation acquired in the acute, subacute and chronic phase was analyzed in compartments with high and low normative resting-state functional connectivity to the lesion site on an individual basis. Regions with high compared to regions with low lesion connectivity showed a steeper increase in language reactivation from the acute to the subacute phase. This finding is compatible with the assumption of resolution of diaschisis. Additionally, language performance in the subacute phase and improvement from the subacute to the chronic phase significantly correlated with the diaschisis effect and its resolution, respectively, suggesting a behavioral relevance of this effect. We therefore assume that undamaged but functionally connected regions become dysfunctional due to missing input from the lesion contributing to the aphasic deficit. Since these regions are structurally intact, dysfunction resolves over time contributing to the rapid early behavioral improvement observed in aphasic stroke patients. Our results demonstrate that diaschisis and its resolution might be a relevant mechanism of early loss and recovery of language function in acute stroke patients.


Assuntos
Afasia , Diásquise , Acidente Vascular Cerebral , Afasia/diagnóstico por imagem , Afasia/etiologia , Humanos , Idioma , Imageamento por Ressonância Magnética/métodos , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/patologia
7.
Brain ; 144(10): 3264-3276, 2021 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-34142117

RESUMO

The study of pathological laughter and crying (PLC) allows insights into the neural basis of laughter and crying, two hallmarks of human nature. PLC is defined by brief, intense and frequent episodes of uncontrollable laughter or crying provoked by trivial stimuli. It occurs secondary to CNS disorders such as stroke, tumours or neurodegenerative diseases. Based on case studies reporting various lesions locations, PLC has been conceptualized as dysfunction in a cortico-limbic-subcortico-thalamo-ponto-cerebellar network. To test whether the heterogeneous lesion locations are indeed linked in a common network, we applied 'lesion network-symptom-mapping' to 70 focal lesions identified in a systematic literature search for case reports of PLC. In lesion network-symptom-mapping normative connectome data (resting state functional MRI, n = 100) is used to identify the brain regions that are likely affected by diaschisis based on the lesion locations. With lesion network-symptom-mapping we were able to identify a common network specific for PLC when compared with a control cohort (n = 270). This bilateral network is characterized by positive connectivity to the cingulate and temporomesial cortices, striatum, hypothalamus, mesencephalon and pons, and negative connectivity to the primary motor and sensory cortices. In the most influential pathophysiological model of PLC, a centre for the control and coordination of facial expressions, respiration and vocalization in the periaqueductal grey is assumed, which is controlled via two pathways: an emotional system that exerts excitatory control of the periaqueductal grey descending from the temporal and frontal lobes, basal ganglia and hypothalamus; and a volitional system descending from the lateral premotor cortices that can suppress laughter or crying. To test whether the positive and negative PLC subnetworks identified in our analyses can indeed be related to an emotional system and a volitional system, we identified lesions causing emotional (n = 15) or volitional facial paresis (n = 46) in a second literature search. Patients with emotional facial paresis show preserved volitional movements but cannot trigger emotional movements in the affected hemiface, while the reverse is true for volitional facial paresis. Importantly, these lesions map differentially onto the PLC subnetworks: the 'positive PLC subnetwork' is part of the emotional system and the 'negative PLC subnetwork' overlaps with the volitional system for the control of facial movements. Based on this network analysis we propose a two-hit model of PLC: a combination of direct lesion and indirect diaschisis effects cause PLC through the loss of inhibitory cortical control of a dysfunctional emotional system.


Assuntos
Encefalopatias/diagnóstico por imagem , Encefalopatias/psicologia , Encéfalo/diagnóstico por imagem , Choro/psicologia , Riso/psicologia , Rede Nervosa/diagnóstico por imagem , Idoso , Encéfalo/fisiopatologia , Encefalopatias/fisiopatologia , Choro/fisiologia , Feminino , Humanos , Riso/fisiologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/fisiologia
8.
Stroke ; 52(3): 830-837, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33504189

RESUMO

BACKGROUND AND PURPOSE: Poststroke depression is a common stroke sequel, yet its neurobiological substrates are still unclear. We sought to determine whether specific lesion locations are associated with depressive symptoms after stroke. METHODS: In a prospective study, 270 patients with first ever stroke were repeatedly tested with the depression subscale of the Hospital Anxiety and Depression Scale within the first 4 weeks and 6 months after stroke. Voxel-based lesion behavior mapping based on clinical imaging was performed to test for associations between symptoms of depression and lesion locations. RESULTS: Frequency of poststroke depression (Hospital Anxiety and Depression Scale-D score >7) after 6 months was 19.6%. Higher Hospital Anxiety and Depression Scale-D scores for depression within the first 4 weeks were the only independent predictor for poststroke depression after 6 months in a multiple logistic regression also including age, sex, lesion volume, stroke severity, Barthel-Index, and the anxiety subscale of the Hospital Anxiety and Depression Scale. Nonparametric permutation-test based voxel-based lesion behavior mapping identified a cluster of voxels mostly within the left ventrolateral prefrontal cortex where lesions were significantly associated with more depressive symptoms after 6 months. No such association was observed within the right hemisphere despite better lesion coverage. CONCLUSIONS: Lesions in the left ventrolateral prefrontal cortex increase the risk of depressive symptoms 6 months poststroke. Lesions within the right hemisphere are unrelated to depressive symptoms. Recognition of left frontal lesions as a risk factor should help in the early diagnosis of poststroke depression through better risk stratification. The results are in line with evidence from functional imaging and noninvasive brain stimulation in patients without focal brain damage indicating that dysfunction in the left lateral prefrontal cortex contributes to depressive disorders.

9.
Artigo em Inglês | MEDLINE | ID: mdl-34927274

RESUMO

OBJECTIVE: To develop evidence-based recommendations to guide the surgical management and postoperative follow-up of adults with primary hyperparathyroidism. METHODS: Representatives from relevant Australian and New Zealand Societies used a systematic approach for adaptation of guidelines (ADAPTE) to derive an evidence-informed position statement addressing eight key questions. RESULTS: Diagnostic imaging does not determine suitability for surgery but can guide the planning of surgery in suitable candidates. First-line imaging includes ultrasound and either parathyroid 4DCT or scintigraphy, depending on local availability and expertise. Minimally invasive parathyroidectomy is appropriate in most patients with concordant imaging. Bilateral neck exploration should be considered in those with discordant/negative imaging findings, multi-gland disease and genetic/familial risk factors. Parathyroid surgery, especially re-operative surgery, has better outcomes in the hands of higher volume surgeons. Neuromonitoring is generally not required for initial surgery but should be considered for re-operative surgery. Following parathyroidectomy, calcium and parathyroid hormone levels should be re-checked in the first 24 h and repeated early if there are risk factors for hypocalcaemia. Eucalcaemia at 6 months is consistent with surgical cure; parathyroid hormone levels do not need to be re-checked in the absence of other clinical indications. Longer-term surveillance of skeletal health is recommended. CONCLUSIONS: This position statement provides up-to-date guidance on evidence-based best practice surgical and postoperative management of adults with primary hyperparathyroidism.

10.
Artigo em Inglês | MEDLINE | ID: mdl-34931708

RESUMO

OBJECTIVE: To formulate clinical consensus recommendations on the presentation, assessment, and management of primary hyperparathyroidism (PHPT) in adults. METHODS: Representatives from relevant Australian and New Zealand Societies used a systematic approach for adaptation of guidelines (ADAPTE) to derive an evidence-informed position statement addressing nine key questions. RESULTS: PHPT is a biochemical diagnosis. Serum calcium should be measured in patients with suggestive symptoms, reduced bone mineral density or minimal trauma fractures, and in those with renal stones. Other indications are detailed in the manuscript. In patients with hypercalcaemia, intact parathyroid hormone, 25-hydroxy vitamin D, phosphate, and renal function should be measured. In established PHPT, assessment of bone mineral density, vertebral fractures, urinary tract calculi/nephrocalcinosis and quantification of urinary calcium excretion is warranted. Parathyroidectomy is the only definitive treatment and is warranted for all symptomatic patients and should be considered for asymptomatic patients without contraindications to surgery and with >10 years life expectancy. In patients who do not undergo surgery, we recommend annual evaluation for disease progression. Where the diagnosis is not clear or the risk-benefit ratio is not obvious, multidisciplinary discussion and formulation of a consensus management plan is appropriate. Genetic testing for familial hyperparathyroidism is recommended in selected patients. CONCLUSIONS: These clinical consensus recommendations were developed to provide clinicians with contemporary guidance on the assessment and management of PHPT in adults. It is anticipated that improved health outcomes for individuals and the population will be achieved at a decreased cost to the community.

11.
Biotechnol Bioeng ; 118(7): 2637-2648, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33844269

RESUMO

A carbon-free energy supply is essential to sustain our future. Biophotovoltaics (BPV) provides a promising solution for hydrogen supply by directly coupling light-driven water splitting to hydrogen formation using oxygenic photoautotrophic cyanobacteria. However, BPV is currently limited by its low photon-to-current efficiency, and current experimental setups at a miniaturized scale hinder the rational investigation of the process and thus system optimization. In this article, we developed and optimized a new technical-scale (~250 ml working volume) BPV platform with defined and controllable operating parameters. Factors that interfered with reproducible and stable current output signals were identified and adapted. We found that the classical BG11 medium, used for the cultivation of cyanobacteria and also in many BPV studies, caused severe interferences in the bioelectrochemical experiments. An optimized nBG11 medium guaranteed a low and stable background current in the BPV reactor, regardless of the presence of light and/or mediators. As proof-of-principle, a very high long-term light-dependent current output (peak current of over 20 µA) was demonstrated in the new set-up over 12 days with living Synechocystis sp. PCC6803 cells and validated with appropriate controls. These results report the first reliable BPV platform generating reproducible photocurrent while still allowing quantitative investigation, rational optimization, and scale-up of BPV processes.


Assuntos
Hidrogênio/metabolismo , Luz , Synechocystis/crescimento & desenvolvimento , Meios de Cultura/química
12.
Intern Med J ; 51(2): 264-267, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33631858

RESUMO

Rhabdomyolysis is a clinical syndrome with significant morbidity and mortality that occurs as a result of traumatic and non-traumatic aetiologies. Acute kidney injury, the need for dialysis, and death, can occur due to rhabdomyolysis. This study explores the aetiologies, clinical outcomes and associated factors for poor outcomes in a cohort of patients with rhabdomyolysis in a tertiary trauma centre in Australia.


Assuntos
Injúria Renal Aguda , Rabdomiólise , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Austrália/epidemiologia , Estudos de Coortes , Humanos , Estudos Retrospectivos , Rabdomiólise/diagnóstico , Rabdomiólise/epidemiologia , Rabdomiólise/terapia , Centros de Traumatologia
13.
Nephrology (Carlton) ; 26(9): 725-732, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34089212

RESUMO

BACKGROUND: Albumin-adjusted calcium remains widely used in clinical practice with guidelines for chronic kidney disease (CKD) mineral bone disorder recommending the use of serum calcium for monitoring. This is despite ionized calcium being the biologically active fraction. This study aimed to investigate the ability of total calcium and albumin-adjusted calcium to correctly assign calcium status in stage 5/5D CKD across non-dialysis, haemodialysis and peritoneal dialysis patients. METHODS: Over a 6-months, 352 paired serum and ionized calcium samples were collected from stage 5 (n = 58) and 5D (n = 294, 196 haemodialysis, 98 peritoneal dialysis) CKD patients in a tertiary-hospital setting. Albumin-adjusted calcium was calculated using the modified-Payne formula. Ionized calcium was the reference standard. The agreement between the two methods in assigning calcium status was assessed using Cohen's weighted kappa (κ) statistic. RESULTS: Albumin-adjusted calcium was a poor predictor of calcium status compared to ionized calcium in stage 5/5D CKD (observed agreement 0.42, weighted κ 0.20, 95% CI 0.15-0.26). Dialysis dependence was associated with worse agreement (observed agreement 0.38, weighted κ 0.14, 95% CI 0.09-0.19). Total calcium was more reliable, however, remained inaccurate. Calcium status was not more accurately classified in those with higher albumin levels ≥30 g/L (observed agreement 0.47, weighted κ 0.23, 95% CI 0.10-0.36). CONCLUSION: Total calcium provides better approximation of calcium status than albumin-adjusted calcium in stage 5/5D CKD. Albumin-adjusted calcium tends to 'overcorrect' serum calcium upward. Clinicians should use ionized calcium where accurate measure of calcium is indicated, with total calcium used as the next best option where resources are limited.


Assuntos
Cálcio/sangue , Hipercalcemia/diagnóstico , Hipocalcemia/diagnóstico , Falência Renal Crônica/sangue , Albumina Sérica/metabolismo , Idoso , Feminino , Taxa de Filtração Glomerular , Humanos , Hipercalcemia/sangue , Hipercalcemia/epidemiologia , Hipocalcemia/sangue , Hipocalcemia/epidemiologia , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Diálise Renal , Reprodutibilidade dos Testes , Estudos Retrospectivos
14.
Nucleic Acids Res ; 47(12): 6504-6518, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31127279

RESUMO

The synthesis of ribosomal RNA (rRNA) is a tightly regulated central process in all cells. In bacteria efficient expression of all seven rRNA operons relies on the suppression of termination signals (antitermination) and the proper maturation of the synthesized rRNA. These processes depend on N-utilization substance (Nus) factors A, B, E and G, as well as ribosomal protein S4 and inositol monophosphatase SuhB, but their structural basis is only poorly understood. Combining nuclear magnetic resonance spectroscopy and biochemical approaches we show that Escherichia coli SuhB can be integrated into a Nus factor-, and optionally S4-, containing antitermination complex halted at a ribosomal antitermination signal. We further demonstrate that SuhB specifically binds to the acidic repeat 2 (AR2) domain of the multi-domain protein NusA, an interaction that may be involved in antitermination or posttranscriptional processes. Moreover, we show that SuhB interacts with RNA and weakly associates with RNA polymerase (RNAP). We finally present evidence that SuhB, the C-terminal domain of the RNAP α-subunit, and the N-terminal domain of NusG share binding sites on NusA-AR2 and that all three can release autoinhibition of NusA, indicating that NusA-AR2 serves as versatile recruitment platform for various factors in transcription regulation.


Assuntos
Proteínas de Bactérias/química , Proteínas de Escherichia coli/química , Escherichia coli/genética , Monoéster Fosfórico Hidrolases/química , RNA Ribossômico/biossíntese , Proteínas de Ligação a RNA/química , Fatores de Elongação da Transcrição/química , Proteínas de Bactérias/metabolismo , Sítios de Ligação , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas de Escherichia coli/metabolismo , Modelos Moleculares , Fatores de Alongamento de Peptídeos/química , Fatores de Alongamento de Peptídeos/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Domínios e Motivos de Interação entre Proteínas , RNA Ribossômico/química , Proteínas de Ligação a RNA/metabolismo , Proteínas Ribossômicas/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Transcrição Gênica , Fatores de Elongação da Transcrição/metabolismo
15.
Artigo em Alemão | MEDLINE | ID: mdl-34212207

RESUMO

While the mouth and teeth play a lifelong central role in a person's development and wellbeing, psychosocial aspects of disease and health are still only reluctantly included in dental explanatory models. Only dental anxiety with its disease quality of a specific phobia is generally recognized as a mental disorder requiring intervention. It is interpreted as an emotional reaction to aspects of dental treatment, which results in distress for the affected person and appears to be unreasonably intense given the actual dangers involved. Apart from that, the tendency to provide a somatic explanation for symptoms in the dental context persists. This bears implications for the expectations of those affected as well as for interdisciplinary cooperation. In order to improve interdisciplinary support and mutual understanding, the following article introduces the clinical pictures of craniomandibular dysfunction, bruxism, occlusal dysaesthesia, and somatoform prosthesis intolerance alongside dental anxiety. Psychosocial factors can profoundly influence the development, course, and management of these conditions.


Assuntos
Ansiedade ao Tratamento Odontológico , Saúde Bucal , Alemanha , Humanos
16.
J Biol Chem ; 294(2): 593-607, 2019 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-30446621

RESUMO

Monocarboxylate transporters (MCTs) mediate the proton-coupled exchange of high-energy metabolites, including lactate and pyruvate, between cells and tissues. The transport activity of MCT1, MCT2, and MCT4 can be facilitated by the extracellular carbonic anhydrase IV (CAIV) via a noncatalytic mechanism. Combining physiological measurements in HEK-293 cells and Xenopus oocytes with pulldown experiments, we analyzed the direct interaction between CAIV and the two MCT chaperones basigin (CD147) and embigin (GP70). Our results show that facilitation of MCT transport activity requires direct binding of CAIV to the transporters chaperones. We found that this binding is mediated by the highly conserved His-88 residue in CAIV, which is also the central residue of the enzyme's intramolecular proton shuttle, and a charged amino acid residue in the Ig1 domain of the chaperone. Although the position of the CAIV-binding site in the chaperone was conserved, the amino acid residue itself varied among different species. In human CD147, binding of CAIV was mediated by the negatively charged Glu-73 and in rat CD147 by the positively charged Lys-73. In rat GP70, we identified the positively charged Arg-130 as the binding site. Further analysis of the CAIV-binding site revealed that the His-88 in CAIV can either act as H donor or H acceptor for the hydrogen bond, depending on the charge of the binding residue in the chaperone. Our results suggest that the CAIV-mediated increase in MCT transport activity requires direct binding between CAIV-His-88 and a charged amino acid in the extracellular domain of the transporter's chaperone.


Assuntos
Basigina/metabolismo , Anidrase Carbônica IV/metabolismo , Glicoproteínas/metabolismo , Glicoproteínas de Membrana/metabolismo , Chaperonas Moleculares/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Mapas de Interação de Proteínas , Sequência de Aminoácidos , Animais , Basigina/química , Células HEK293 , Humanos , Proteínas de Membrana , Modelos Moleculares , Domínios Proteicos , Ratos , Alinhamento de Sequência , Simportadores/metabolismo , Xenopus
17.
Intern Med J ; 50(11): 1397-1403, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31841261

RESUMO

BACKGROUND: Australian hospital data on hyperglycaemia without previously known diabetes are lacking. AIMS: To determine the prevalence of hyperglycaemia without previously recognised diabetes among all patients screened in the emergency department (ED). Secondary aims are to describe the extent of haemoglobin A1c testing for evaluation of new diabetes, adequate glucose monitoring, treatment of significant hyperglycaemia and documented follow-up plans. METHODS: Patients presenting to ED at the Alfred (tertiary hospital in Melbourne) have undergone screening random plasma glucose (RPG) with their first plasma biochemistry since 2015. Of the 16 268 adults screened from July to December 2015, a retrospective, cross-sectional study was undertaken evaluating those with hyperglycaemia (RPG >7.8 mmol/L) but without previously recognised diabetes as determined from coding data. After patient records were reviewed to correct for coding errors, a nested cohort of 200 such patients were further evaluated. Glucose monitoring was deemed adequate if undertaken for ≥48 h. Significant hyperglycaemia (RPG >11 mmol/L) was considered appropriately treated if insulin/hypoglycaemic agents were prescribed. Documented follow-up plans were acceptable if found in the discharge summary. RESULTS: Among all patients screened, 1178 had hyperglycaemia without coded diabetes. After adjusting for coding errors, the prevalence was 5.2%. Within the nested cohort, only 7.5% had a follow-up haemoglobin A1c ordered, 9.5% underwent adequate glucose monitoring, 6.5% had appropriate treatment of significant hyperglycaemia and 2% had documentation of a follow-up plan. CONCLUSIONS: Hyperglycaemia without previously recognised diabetes is commonly seen and justifies ED screening. However, management of newly detected hyperglycaemia in these patients is suboptimal and requires improvement.


Assuntos
Diabetes Mellitus Tipo 2 , Diabetes Mellitus , Hiperglicemia , Adulto , Austrália/epidemiologia , Glicemia , Automonitorização da Glicemia , Estudos Transversais , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/terapia , Serviço Hospitalar de Emergência , Humanos , Hiperglicemia/diagnóstico , Hiperglicemia/epidemiologia , Prevalência , Estudos Retrospectivos
18.
J Vasc Surg ; 70(5): 1564-1575, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31653377

RESUMO

OBJECTIVE: The cause of perioperative myocardial infarction (PMI) is postulated to involve hemodynamic stress or coronary plaque destabilization. We aimed to evaluate perioperative factors in patients with peripheral artery disease (PAD) undergoing major vascular surgery to determine the likely mechanisms and predictors of PMI. METHODS: This was a prospective cohort study of 133 patients undergoing major vascular surgery including open abdominal aortic aneurysm (AAA) repair (n = 40) and major suprainguinal or infrainguinal arterial bypasses (non-AAA; n = 93). Preoperative assessment with history, physical examination, and peripheral artery tonometry was performed in addition to plasma sampling of biomarkers associated with inflammation and coronary plaque instability. The primary outcome was occurrence of a 30-day cardiovascular event (CVE; composite of PMI [troponin I elevation >99th percentile reference of ≥0.1 µg/L], stroke, or death). RESULTS: Of 133 patients, 36 patients (27%) developed a 30-day CVE after vascular surgery, and all were PMI. Patients with 30-day CVE were older (75 ± 8 years vs 69 ± 10 years, mean ± standard deviation; P = .001), had higher prevalence of hypertension (94% vs 79%; P = .01) and preoperative beta-blocker therapy (50% vs 29%; P = .02), and had longer duration of surgery (5.1 ± 1.8 hours vs 4.0 ± 1.1 hours; P < .0001). Significant elevations in cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), troponin I, high-sensitivity troponin T, matrix metalloproteinase 3, and osteoprotegerin occurred in those who developed 30-day CVE (all P < .05). Multivariate binary logistic regression identified AAA surgery and log-transformed NT-proBNP to be independent preoperative predictors of 30-day CVE (area under the receiver operating characteristic curve = 0.81). CONCLUSIONS: In patients with peripheral artery disease undergoing major vascular surgery, the likely mechanism of PMI appears to be the hemodynamic stress related to the type and duration of surgery. NT-proBNP was a useful independent predictor of CVE and thus may serve as an important biomarker of cardiovascular fitness for surgery.


Assuntos
Infarto do Miocárdio/epidemiologia , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Complicações Pós-Operatórias/epidemiologia , Cuidados Pré-Operatórios/métodos , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/sangue , Aneurisma da Aorta Abdominal/mortalidade , Aneurisma da Aorta Abdominal/cirurgia , Biomarcadores/sangue , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/etiologia , Duração da Cirurgia , Doença Arterial Periférica/sangue , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/mortalidade , Doença Arterial Periférica/cirurgia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Medição de Risco/métodos , Fatores de Risco , Procedimentos Cirúrgicos Vasculares/métodos
20.
Clin Chem ; 64(12): 1713-1722, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30352866

RESUMO

BACKGROUND: Clinical laboratories measure total calcium and adjust for albumin concentrations to predict calcium status. We compared total and adjusted calcium (Adj-Ca) with ionized calcium (Ca2+) for correct assignment of calcium status. The effect of restriction of Adj-Ca reporting in patients with hypoalbuminemia was determined on the basis of frequency of misclassifications. METHODS: Extraction of laboratory results was performed for 24 months. Adj-Ca was calculated from a modified Payne formula. A further prospective data set for 6 months was collected after stopping reporting of Adj-Ca for patients with an albumin <3.0 g/dL. The agreement between Ca2+ and Adj-Ca or total Ca was assessed with Cohen's kappa statistic. RESULTS: In 5553 hospitalized patients, 13604 paired Ca2+ results were analyzed retrospectively. Prospective collection in 1113 paired samples was from 450 patients. Adj-Ca was a poor predictor of calcium status compared to the Ca2+ reference standard in both data sets (agreement 56.9% in the first, 65.6% in the second data set). Renal failure and low albumin concentrations were associated with worse agreement between Adj-Ca and Ca2+. Restriction of reporting of Adj-Ca to albumin concentrations >3.0g/dL improved correct classification of calcium status from 65.6% to 77.6% (P < 0.0001). Total Ca performed better than Adj-Ca for low albumin (<3.0g/dL) and performed similarly in samples with albumin >3.0g/dL. CONCLUSIONS: Adj-Ca is unreliable for the classification of calcium status in hospital patients when compared to Ca2+. Adj-Ca overestimates calcium for patients with renal impairment and albumin concentrations <3.0g/dL. Restriction of reporting Adj-Ca for albumin below 3.0 g/dL reduces the number of misclassified patients.


Assuntos
Análise Química do Sangue/métodos , Cálcio/sangue , Albumina Sérica Humana/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Creatinina/sangue , Interpretação Estatística de Dados , Feminino , Humanos , Hipercalcemia/sangue , Hipocalcemia/sangue , Laboratórios Hospitalares , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Estudos Retrospectivos , Centros de Atenção Terciária , Adulto Jovem
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