Spatial subsidies increase local productivity and boost consumer abundance beyond the limits imposed by local resources. In marine ecosystems, deeper water and open ocean subsidies promote animal ...aggregations and enhance biomass that is critical for human harvesting. However, the scale of this phenomenon in tropical marine systems remains unknown. Here, we integrate a detailed assessment of biomass production in 3 key locations, spanning a major biodiversity and abundance gradient, with an ocean-scale dataset of fish counts to predict the extent and magnitude of plankton subsidies to fishes on coral reefs. We show that planktivorous fish-mediated spatial subsidies are widespread across the Indian and Pacific oceans and drive local spikes in biomass production that can lead to extreme productivity, up to 30 kg ha-1 day-1. Plankton subsidies form the basis of productivity "sweet spots" where planktivores provide more than 50% of the total fish production, more than all other trophic groups combined. These sweet spots operate at regional, site, and smaller local scales. By harvesting oceanic productivity, planktivores bypass spatial constraints imposed by local primary productivity, creating "oases" of tropical fish biomass that are accessible to humans.
Frailty is a geriatric syndrome that diminishes the potential for functional recovery after a transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) procedure; ...however, its integration in clinical practice has been limited by a lack of consensus on how to measure it.
This study sought to compare the incremental predictive value of 7 different frailty scales to predict poor outcomes following TAVR or SAVR.
A prospective cohort of older adults undergoing TAVR or SAVR was assembled at 14 centers in 3 countries from 2012 to 2016. The following frailty scales were compared: Fried, Fried+, Rockwood, Short Physical Performance Battery, Bern, Columbia, and the Essential Frailty Toolset (EFT). Outcomes of interest were all-cause mortality and disability 1 year after the procedure.
The cohort was composed of 1,020 patients with a median age of 82 years. Depending on the scale used, the prevalence of frailty ranged from 26% to 68%. Frailty as measured by the EFT was the strongest predictor of death at 1 year (adjusted odds ratio OR: 3.72; 95% confidence interval CI: 2.54 to 5.45) with a C-statistic improvement of 0.071 (p < 0.001) and integrated discrimination improvement of 0.067 (p < 0.001). Moreover, the EFT was the strongest predictor of worsening disability at 1 year (adjusted OR: 2.13; 95% CI: 1.57 to 2.87) and death at 30 days (adjusted OR: 3.29; 95% CI: 1.73 to 6.26).
Frailty is a risk factor for death and disability following TAVR and SAVR. A brief 4-item scale encompassing lower-extremity weakness, cognitive impairment, anemia, and hypoalbuminemia outperformed other frailty scales and is recommended for use in this setting. (Frailty Assessment Before Cardiac Surgery & Transcatheter Interventions; NCT01845207).
Synapses: The Brain's Energy-Demanding Sites Faria-Pereira, Andreia; Morais, Vanessa A
International journal of molecular sciences,
03/2022, Letnik:
23, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The brain is one of the most energy-consuming organs in the mammalian body, and synaptic transmission is one of the major contributors. To meet these energetic requirements, the brain primarily uses ...glucose, which can be metabolized through glycolysis and/or mitochondrial oxidative phosphorylation. The relevance of these two energy production pathways in fulfilling energy at presynaptic terminals has been the subject of recent studies. In this review, we dissect the balance of glycolysis and oxidative phosphorylation to meet synaptic energy demands in both resting and stimulation conditions. Besides ATP output needs, mitochondria at synapse are also important for calcium buffering and regulation of reactive oxygen species. These two mitochondrial-associated pathways, once hampered, impact negatively on neuronal homeostasis and synaptic activity. Therefore, as mitochondria assume a critical role in synaptic homeostasis, it is becoming evident that the synaptic mitochondria population possesses a distinct functional fingerprint compared to other brain mitochondria. Ultimately, dysregulation of synaptic bioenergetics through glycolytic and mitochondrial dysfunctions is increasingly implicated in neurodegenerative disorders, as one of the first hallmarks in several of these diseases are synaptic energy deficits, followed by synapse degeneration.
Summary
Green tea has been associated with positive effects in the treatment of obesity and other associated comorbidities such as type 2 diabetes. These benefits are thought to be related to the ...anti‐inflammatory and antioxidant effects of green tea and to the reduction in body fat percentage exhibited by its bioactive compounds. The predominant active compounds in green tea are flavonoid monomers known as catechins, in particular epigallocatechin‐3‐gallate, which is the most abundant and most effective catechin in metabolic care, particularly among obese patients. The objective of this review was to investigate the effects of green tea on body composition, oxidative stress, inflammation and insulin resistance, risk factors for the development of type 2 diabetes in obese individuals and the mechanisms that underlie the modulatory actions of green tea compounds on these risk factors. Although green tea has therapeutic potential in the treatment of obese individuals, the findings of this review demonstrate the need for a greater number of studies to confirm the positive effects of green tea, especially regarding the modulation of obesity.
SARS-CoV-2 is a new beta coronavirus, similar to SARS-CoV-1, that emerged at the end of 2019 in the Hubei province of China. It is responsible for coronavirus disease 2019 (COVID-19), which was ...declared a pandemic by the World Health Organization on March 11, 2020. The ability to gain quick control of the pandemic has been hampered by a lack of detailed knowledge about SARS-CoV-2-host interactions, mainly in relation to viral biology and host immune response. The rapid clinical course seen in COVID-19 indicates that infection control in asymptomatic patients or patients with mild disease is probably due to the innate immune response, as, considering that SARS-CoV-2 is new to humans, an effective adaptive response would not be expected to occur until approximately 2–3 weeks after contact with the virus. Antiviral innate immunity has humoral components (complement and coagulation-fibrinolysis systems, soluble proteins that recognize glycans on cell surface, interferons, chemokines, and naturally occurring antibodies) and cellular components (natural killer cells and other innate lymphocytes). Failure of this system would pave the way for uncontrolled viral replication in the airways and the mounting of an adaptive immune response, potentially amplified by an inflammatory cascade. Severe COVID-19 appears to be due not only to viral infection but also to a dysregulated immune and inflammatory response. In this paper, the authors review the most recent publications on the immunobiology of SARS-CoV-2, virus interactions with target cells, and host immune responses, and highlight possible associations between deficient innate and acquired immune responses and disease progression and mortality. Immunotherapeutic strategies targeting both the virus and dysfunctional immune responses are also addressed.
Frailty assessment can help predict which older adults will experience adverse events after cardiac surgical procedures. Low muscle mass is a core component of frailty that is suboptimally captured ...by self-reported weight loss; refined measures using computed tomographic (CT) images have emerged and are predictive of outcomes in noncardiac surgical procedures. The objective of this study was to evaluate the association between CT muscle area and length of stay (LOS) after cardiac surgical procedures.
Frail patients who had a perioperative abdominal or thoracic CT scan were identified. The CT scans were analyzed to measure cross-sectional lean muscle area at the L4 vertebra (psoas muscle area PMA, lumbar muscle area LMA) and the T4 vertebra (thoracic muscle area TMA). The associations of PMA, LMA, and TMA with frailty markers and postoperative LOS were investigated.
Eighty-two patients were included; the mean age was 69.2 ± 9.97 years. Low muscle area was correlated with lower handgrip strength and short physical performance battery (SPPB) scores indicative of physical frailty. Postoperative LOS was correlated with PMA (R = -0.47, p = 0.004), LMA (R = -0.41, p = 0.01), and TMA (R = -0.29, p = 0.03). After adjustment for the predicted risk of prolonged LOS, age, sex, and body surface area, PMA remained significantly associated with LOS (β = -2.35, 95% CI -4.48 to -0.22). The combination of low PMA and handgrip strength, indicative of sarcopenia, yielded the greatest incremental value in predicting LOS.
Low PMA is a marker of physical frailty associated with increased LOS in older adults undergoing cardiac surgical procedures. Further research is necessary to validate PMA as a prognostic marker and therapeutic target in this vulnerable population.
Studies have shown that an even protein intake distribution across meals increased 24-h muscle protein synthesis in young adults compared with a skewed intake. Whether this short-term result ...translates into long-term preservation of lean mass (LM) in older adults remains unknown.
The aim was to examine the extent to which protein quantity and distribution are associated with LM and appendicular LM (aLM), and their 2-y decline, in community-dwelling older adults.
Baseline and 2-y follow-up data from 351 men and 361 women (aged 67-84 y) in the NuAge study (Quebec Longitudinal Study on Nutrition as a Determinant of Successful Aging) with available body-composition data (by dual-energy X-ray absorptiometry) were used. Food intake was assessed with the use of three 24-h food recalls collected at baseline and 3 collected at the 2-y follow-up. Protein distribution across meals was calculated as the CV of protein ingested per meal, with lower values reflecting evenness of protein intake. Linear mixed-model analysis was performed to examine changes in LM and aLM across time, by sex, as conditioned by the quantity and distribution of protein intake, adjusted for potential covariates.
Over 2 y, LM declined in both men (-2.5% ± 4.0%) and women (-2.0% ± 3.4%) (P < 0.05), whereas aLM loss was not significant (men: -1.5% ± 4.8%; women: -1.2% ± 5.3%; P > 0.05). The decline in LM was not independently affected by the quantity and distribution of protein intake. Yet men and women with evenly distributed protein intakes and men with high protein intakes showed higher LM or aLM throughout the entire follow-up period, even after potential confounders were controlled for (P < 0.05).
Our results suggest that greater protein intakes and a more even distribution across meals are modifiable factors associated with higher muscle mass in older adults but not with losses over 2 y. Interventional studies should determine longer-term effects on preserving LM with aging.
We previously demonstrated that 1) obesity impairs and 2) sex influences insulin sensitivity of protein metabolism, while 3) poor glycemic control in type 2 diabetes accelerates protein turnover in ...daily fed-fasted states. We hypothesized that type 2 diabetes alters the insulin sensitivity of protein metabolism and that sex modulates it.
Hyperinsulinemic ( approximately 570 pmol/l), euglycemic (5.5 mmol/l), and isoaminoacidemic (kept at postabsorptive concentrations) clamps were performed in 17 hyperglycemic type 2 diabetic subjects and 23 subjects without diabetes matched for age and body composition, after 7 days on a inpatient, protein-controlled, isoenergetic diet. Glucose and leucine kinetics were determined using tracers.
In type 2 diabetes, postabsorptive (baseline) glycemia was 8-9 mmol/l, glucose production (R(a)) and disposal (R(d)) were elevated, and once clamped, endogenous glucose R(a) remained greater and R(d) was less (P < 0.05) than in control subjects. Baseline leucine kinetics did not differ despite higher insulin levels. The latter was an independent predictor of leucine flux within each sex. With clamp, total flux increased less (P = 0.016) in type 2 diabetic men, although protein breakdown decreased equally ( approximately 20%) in male groups but less in female groups. Whereas protein synthesis increased in male control subjects and in both female groups, it did not in male subjects with type 2 diabetes. In men, homeostasis model assessment of insulin resistance predicted 44%, and, in women, waist-to-hip ratio predicted 40% of the change in synthesis.
During our clamp, men with type 2 diabetes have greater insulin resistance of protein metabolism than that conferred by excess adiposity itself, whereas women do not. These results may have implications for dietary protein requirements.
The market of functional foods has experienced a huge growth in the last decades due to the increased consumers’ awareness in a healthy lifestyle. Dried fruits constitute good snacks, in alternative ...to salty or sweet ones, and food ingredients due to their taste and nutritional/health benefits. Bioactive molecules are interesting sources to develop functional foods, as they play a major role in improving the health status and minimizing disease risks. The bioactive compounds most widely discussed in literature are presented in this review, for example, polyphenols, phytosterols, and prebiotics. Different technologies to dry bioproducts for producing functional foods or ingredients are presented. New drying techniques for the preservation of bioactive compounds are proposed, focusing more specifically on dielectric drying. A discussion on the techniques that can be used to optimize drying processes is performed. An overview on dehydrated plant based foods with probiotics is provided. The microorganisms used, impregnation procedures, drying methods, and evaluated parameters are presented and discussed. The principal bioactive compounds responsible for nutritional and health benefits of plant derived dried food products—fruits and vegetables, fruits and vegetables by-products, grains, nuts, and algae—are presented. Phytochemical losses occurring during pretreatments and/or drying processes are also discussed.
Functional status declines with aging, thus impeding autonomy. Recently, a more even mealtime distribution of dietary protein was positively associated with muscle mass, but the relation of this ...distribution to physical performance remains unknown.
We examined the relation between mealtime protein-intake distribution and physical performance and its 3-y decline in community-dwelling older adults.
Three-year follow-up data from 827 men and 914 women (67–84 y) in the longitudinal study on nutrition and aging Quebec longitudinal study on Nutrition as a Determinant of Successful Aging (NuAge study); Quebec, Canada were analyzed. Physical performance, which was measured yearly, was grouped into the following 2 functional composite scores: muscle strength (handgrip, arm, and leg) and mobility (timed-up-and-go, chair stand, and walking speed). Dietary data were collected in 2 sets of three 24-h food recalls at baseline and year 2. The individual mealtime protein distribution was calculated as the CV (i.e., SD divided by the mean) of grams of protein per meal. A mixed model analysis was used to examine trajectories of muscle strength and mobility across time by sex as conditioned by the protein distribution and adjusted for potential covariates.
Physical performance deteriorated over 3 y with muscle strength declining more than the mobility score in men (−1.51 ± 1.68 compared with −0.66 ± 2.81) and women (−1.35 ± 1.77 compared with −0.78 ± 2.63) (means ± SD, P < 0.001). More-evenly distributed protein intake, independent of the total quantity, was associated with a higher muscle-strength score in both sexes throughout follow-up. It was also associated with a greater mobility score, but only in men and only before adjustment for covariates. Strength and mobility rates of decline were not affected by protein-intake distribution in either sex.
In addition to the previously observed association with lean mass, an even distribution of daily protein intake across meals is independently associated with greater muscle strength, but not with the mobility score, in older adults. A longer-term investigation of the role of protein intake and its distribution on physical performance is warranted, as are intervention studies, to support future recommendations.
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