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1.
South Afr J HIV Med ; 25(1): 1542, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38628908

RESUMO

Background: In South Africa, infants who are HIV-exposed are tested for HIV at birth and 10 weeks of age. The COVID-19 pandemic lockdown restrictions resulted in reduced access to healthcare services and uncertain impact on early infant HIV testing. Objectives: To describe the effects of the COVID-19 pandemic lockdown restrictions on early infant HIV testing and diagnosis in Cape Town, South Africa. Method: This retrospective cohort study compares HIV-exposed infants born during the first COVID-19 pandemic lockdown (2020) to those born in the same period the year before (2019). Laboratory and other data were abstracted from the Provincial Health Data Centre. Results: A total of 2888 infants were included: 1474 born in 2020 and 1413 in 2019. Compared to 2019, there was an increase in the 10-week HIV polymerase chain reaction (PCR) uptake in 2020 (71% vs. 60%, P < 0.001). There was also an increase in the proportion of infants who demised without 10-week testing or were lost to follow-up in 2020 compared to 2019 (8% vs. 5%, P = 0.017). Differences detected in birth HIV PCR positivity rates between the two groups (1.1% vs. 0.5%, P = 0.17) did not reach statistical significance; however, a significant increase in vertical transmission of HIV by 10 weeks old was found in the 2020 cohort (1.2% vs. 0.5%. P = 0.046). Conclusion: Vertical transmission of HIV at 10 weeks increased in the Cape Town Metropolitan during the initial COVID-19 lockdown. There was also an increase in the proportion of deaths without testing by 10 weeks in the 2020 group.

2.
Alzheimers Dement (N Y) ; 10(2): e12466, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38596483

RESUMO

INTRODUCTION: The Finnish Geriatric Intervention Study (FINGER) led to the global dementia risk reduction initiative: World-Wide FINGERS (WW-FINGERS). As part of WW-FINGERS, the Australian AU-ARROW study mirrors aspects of FINGER, as well as US-POINTER. METHOD: AU-ARROW is a randomized, single-blind, multisite, 2-year clinical trial (n = 600; aged 55-79). The multimodal lifestyle intervention group will engage in aerobic exercise, resistance training and stretching, dietary advice to encourage MIND diet adherence, BrainHQ cognitive training, and medical monitoring and health education. The Health Education and Coaching group will receive occasional health education sessions. The primary outcome measure is the change in a global composite cognitive score. Extra value will emanate from blood biomarker analysis, positron emission tomography (PET) imaging, brain magnetic resonance imaging (MRI), and retinal biomarker tests. DISCUSSION: The finalized AU-ARROW protocol is expected to allow development of an evidence-based innovative treatment plan to reduce cognitive decline and dementia risk, and effective transfer of research outcomes into Australian health policy. Highlights: Study protocol for a single-blind, randomized controlled trial, the AU-ARROW Study.The AU-ARROW Study is a member of the World-Wide FINGERS (WW-FINGERS) initiative.AU-ARROW's primary outcome measure is change in a global composite cognitive score.Extra significance from amyloid PET imaging, brain MRI, and retinal biomarker tests.Leading to development of an innovative treatment plan to reduce cognitive decline.

3.
bioRxiv ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38585834

RESUMO

Inflammation is a key contributor to stroke pathogenesis and drives exacerbated brain damage leading to poor outcome. Interleukin-1 (IL-1) is an important regulator of post-stroke inflammation, and blocking its actions is beneficial in pre-clinical stroke models and safe in the clinical setting. IL-1α and IL-1ß are the two major IL-1 type 1 receptor (IL-1R1) agonists from the IL-1 family. The distinct roles of both isoforms, and particularly that of IL-1α, remain largely unknown. Here we show that IL-1α and IL-1ß have different spatio-temporal expression profiles in the brain after experimental stroke, with early microglial IL-1α expression (4 h) and delayed IL-1ß expression in infiltrated neutrophils and a small microglial subset (24-72 h). We examined the specific contribution of microglial-derived IL-1α in experimental permanent and transient ischemic stroke through cell-specific tamoxifen-inducible Cre-loxP-mediated recombination. Microglial IL-1α deletion did not influence acute brain damage, cerebral blood flow, IL-1ß expression, neutrophil infiltration, microglial nor endothelial activation after ischemic stroke. However, microglial IL-1α knock out (KO) mice showed reduced peri-infarct vessel density and reactive astrogliosis at 14 days post-stroke, alongside a worse functional recovery. RNA sequencing analysis and subsequent pathway analysis on ipsilateral/contralateral cortex 4 h after stroke revealed a downregulation of the neuronal CREB signaling pathway in microglial IL-1α KO compared to WT mice. Our study identifies for the first time a critical role for microglial IL-1α on neuronal activity, neurorepair and functional recovery after stroke, highlighting the importance of targeting specific IL-1 mechanisms in brain injury to develop more effective therapies.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38619045

RESUMO

Placenta-derived human amniotic epithelial cells (hAEC) exhibit anti-inflammatory and anti-fibrotic effects in cirrhosis models. We conducted a first-in-human phase I clinical trial to assess the safety and tolerability of hAEC in adults with compensated cirrhosis. We examined increasing and repeated doses of hAEC in 9 patients in 3 cohorts. Cohort 1 patients received 0.5 × 106/kg hAEC in one IV infusion. Cohort 2 patients received 1 × 106/kg hAEC in one IV infusion. The patients in cohort 3 received 1 × 106/kg hAEC on days 0 and 28. Here, we report follow-up to post-infusion day 56 (D56), during which no serious adverse events occurred. Six patients experienced no study-related adverse events, while 3 patients reported mild (grade 1) headaches that were possibly infusion-related. A transient decrease in serum platelet count occurred in all patients, which returned to baseline screening values by day 5. FIB-4 values to assess fibrosis were significantly lower at D56. Although not statistically significant, serum AST levels and liver stiffness measurements at D56 were lower than those at baseline. The hepatic venous pressure gradient, a measure of portal hypertension, declined in 4 patients, did not change in 3 patients, and increased in 2 patients. In conclusion, intravenous infusion of allogeneic hAEC in patients with compensated cirrhosis at the doses used in this study was safe and well tolerated, with no difference observed between 1 and 2 doses. Decreased hepatic inflammation, liver stiffness, and portal hypertension support larger studies aimed at identifying patients who may benefit from this therapy. Clinical Trial registration: The trial was prospectively entered on the Australian Clinical Trials Registry (ANZCTR12616000437460).

5.
J Invest Dermatol ; 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38582367

RESUMO

Chronic non-healing wounds negatively impact on quality of life and are a significant financial drain on health systems. The risk of infection that exacerbates co-morbidities in patients necessitates regular application of wound care. Understanding mechanisms underlying impaired wound healing are therefore a key priority to inform effective new generation treatments. Here, we demonstrate that 14-3-3-mediated suppression of signaling through ROCK is a critical mechanism that inhibits the healing of diabetic wounds. Accordingly, pharmacological inhibition of 14-3-3 by topical application of the sphingo-mimetic drug RB-11 to diabetic wounds on a mouse model of type II diabetes, accelerated wound closure more than two-fold relative to vehicle control, phenocopying our previous observations in 14-3-3ζ knockout mice. We also demonstrate that accelerated closure of the wounded epidermis by 14-3-3 inhibition causes enhanced signaling through the Rho-ROCK pathway and that the underlying cellular mechanism involves the efficient recruitment of dermal fibroblasts into the wound and the rapid production of extracellular matrix proteins to re-establish the injured dermis. Our observations that the 14-3-3/ROCK inhibitory axis characterizes impaired wound healing and that its suppression facilitates fibroblast recruitment and accelerated re-epithelialization suggest new possibilities for treating diabetic wounds by pharmacologically targeting this axis.

6.
Scand J Med Sci Sports ; 34(3): e14581, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38511417

RESUMO

The International Olympic Committee (IOC) recently published a framework on fairness, inclusion, and nondiscrimination on the basis of gender identity and sex variations. Although we appreciate the IOC's recognition of the role of sports science and medicine in policy development, we disagree with the assertion that the IOC framework is consistent with existing scientific and medical evidence and question its recommendations for implementation. Testosterone exposure during male development results in physical differences between male and female bodies; this process underpins male athletic advantage in muscle mass, strength and power, and endurance and aerobic capacity. The IOC's "no presumption of advantage" principle disregards this reality. Studies show that transgender women (male-born individuals who identify as women) with suppressed testosterone retain muscle mass, strength, and other physical advantages compared to females; male performance advantage cannot be eliminated with testosterone suppression. The IOC's concept of "meaningful competition" is flawed because fairness of category does not hinge on closely matched performances. The female category ensures fair competition for female athletes by excluding male advantages. Case-by-case testing for transgender women may lead to stigmatization and cannot be robustly managed in practice. We argue that eligibility criteria for female competition must consider male development rather than relying on current testosterone levels. Female athletes should be recognized as the key stakeholders in the consultation and decision-making processes. We urge the IOC to reevaluate the recommendations of their Framework to include a comprehensive understanding of the biological advantages of male development to ensure fairness and safety in female sports.


Assuntos
Medicina Esportiva , Esportes , Feminino , Humanos , Masculino , Identidade de Gênero , Atletas , Testosterona
7.
Front Immunol ; 15: 1356651, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38469300

RESUMO

Cryptococcus neoformans and C. gattii, the etiologic agents of cryptococcosis, cause over 100,000 deaths worldwide every year, yet no cryptococcal vaccine has progressed to clinical trials. In preclinical studies, mice vaccinated with an attenuated strain of C. neoformans deleted of three cryptococcal chitin deacetylases (Cn-cda1Δ2Δ3Δ) were protected against a lethal challenge with C. neoformans strain KN99. While Cn-cda1Δ2Δ3Δ extended the survival of mice infected with C. gattii strain R265 compared to unvaccinated groups, we were unable to demonstrate fungal clearance as robust as that seen following KN99 challenge. In stark contrast to vaccinated mice challenged with KN99, we also found that R265-challenged mice failed to induce the production of protection-associated cytokines and chemokines in the lungs. To investigate deficiencies in the vaccine response to R265 infection, we developed a KN99-R265 coinfection model. In unvaccinated mice, the strains behaved in a manner which mirrored single infections, wherein only KN99 disseminated to the brain and spleen. We expanded the coinfection model to Cn-cda1Δ2Δ3Δ-vaccinated mice. Fungal burden, cytokine production, and immune cell infiltration in the lungs of vaccinated, coinfected mice were indicative of immune evasion by C. gattii R265 as the presence of R265 neither compromised the immunophenotype established in response to KN99 nor inhibited clearance of KN99. Collectively, these data indicate that R265 does not dampen a protective vaccine response, but rather suggest that R265 remains largely undetected by the immune system.


Assuntos
Coinfecção , Criptococose , Cryptococcus gattii , Cryptococcus neoformans , Vacinas , Camundongos , Animais , Evasão da Resposta Imune
8.
J Geriatr Phys Ther ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38436969

RESUMO

BACKGROUND AND PURPOSE: The international Consensus on Therapeutic Exercise aNd Training (i-CONTENT) tool is a new instrument developed to evaluate the therapeutic quality of exercise interventions. Home-based exercise has been shown to improve physical fitness in older adults, but its effects may be influenced by therapeutic quality. The purpose of this systematic review was to describe the therapeutic quality of home-based exercise interventions for community-dwelling older adults and examine the relationship between therapeutic quality and changes in physical fitness. METHODS: Six electronic databases and 2 clinical trial registries were searched for randomized controlled trials investigating the effects of home-based exercise on physical fitness in community-dwelling older adults (≥60 years). Therapeutic quality was evaluated using the i-CONTENT tool for items of patient selection, type of exercise, safety, type/timing of outcomes, exercise dose, and adherence. International Consensus on Therapeutic Exercise aNd Training items were used to explain heterogeneity in meta-regression analyses. Risk of bias, certainty of evidence and credibility of analyses were assessed. RESULTS: Thirty-six trials (n = 6157 participants) were identified. Most studies (≥66.7%) had high or probably high therapeutic quality for i-CONTENT items, except exercise dose (47.2%) and adherence (16.7%). Interventions improved upper- (N = 20 trials; standardized mean difference [SMD] = 0.39; 95% CI, 0.13-0.64; low certainty of evidence) and lower-body strength (N = 28; SMD = 0.42; 95% CI, 0.08-0.77; very low certainty), and aerobic fitness (N = 8; SMD = 0.42; 95% CI, 0.08-0.77; very low certainty). For exercise dose, low- or probably low-quality studies negatively influenced effects on upper- (estimated ß = -.48; P = .049; moderate credibility) and lower-body strength (estimated ß = -.77; P = .048; moderate credibility). For adherence, low- or probably low-quality studies negatively influenced effects on aerobic fitness (estimated ß = -.97; P = .02; low credibility). CONCLUSIONS: Home-based exercise may improve upper- and lower-body strength, as well as aerobic fitness in older adults. However, the effectiveness of interventions is affected by inadequate dosing of exercise programs and adherence issues. Physical therapists should have the best available evidence to support their clinical decision making, especially when designing and monitoring home programs.

9.
Artif Organs ; 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459758

RESUMO

BACKGROUND: The efficacy of extracorporeal membrane oxygenation (ECMO) as a bridge to left ventricular assist device (LVAD) remains unclear, and recipients of the more contemporary HeartMate 3 (HM3) LVAD are not well represented in previous studies. We therefore undertook a multicenter, retrospective study of this population. METHODS AND RESULTS: INTERMACS 1 LVAD recipients from five U.S. centers were included. In-hospital and one-year outcomes were recorded. The primary outcome was the overall mortality hazard comparing ECMO versus non-ECMO patients by propensity-weighted survival analysis. Secondary outcomes included survival by LVAD type, as well as postoperative and one-year outcomes. One hundred and twenty-seven patients were included; 24 received ECMO as a bridge to LVAD. Mortality was higher in patients bridged with ECMO in the primary analysis (HR 3.22 [95%CI 1.06-9.77], p = 0.039). Right ventricular assist device was more common in the ECMO group (ECMO: 54.2% vs non-ECMO: 11.7%, p < 0.001). Ischemic stroke was higher at one year in the ECMO group (ECMO: 25.0% vs non-ECMO: 4.9%, p = 0.006). Among the study cohort, one-year mortality was lower in HM3 than in HeartMate II (HMII) or HeartWare HVAD (10.5% vs 46.9% vs 31.6%, respectively; p < 0.001) recipients. Pump thrombosis at one year was lower in HM3 than in HMII or HVAD (1.8% vs 16.1% vs 16.2%, respectively; p = 0.026) recipients. CONCLUSIONS: Higher mortality was observed with ECMO as a bridge to LVAD, likely due to higher acuity illness, yet acceptable one-year survival was seen compared with historical rates. The receipt of the HM3 was associated with improved survival compared with older generation devices.

10.
Artigo em Inglês | MEDLINE | ID: mdl-38482574

RESUMO

During spaceflight fluids shift headward, causing internal jugular vein (IJV) distension and altered hemodynamics, including stasis and retrograde flow, that may increase the risk of thrombosis. This study's purpose was to determine the effects of acute exposure to weightlessness (0-G) on IJV dimensions and flow dynamics. We used 2D ultrasound to measure IJV cross-sectional area (CSA) and Doppler ultrasound to characterize venous blood flow patterns in the right and left IJV in 13 healthy participants (6 female) while 1) seated and supine on the ground, 2) supine during 0-G parabolic flight, and 3) supine during level flight (at 1-G). On Earth in 1-G moving from seated to supine posture increased CSA in both left (+62 [95% CI: +42 to 81] mm2, P<.0001) and right (+86 [95% CI: +58 to 113] mm2, P<.00012) IJV. Entry into 0-G further increased IJV CSA in both left (+27 [95% CI: +5 to 48] mm2, P=.02) and right (+30 [95% CI: +0.3 to 61] mm2, P=.02) relative to supine in 1-G. We observed stagnant flow in the left IJV of one participant during 0-G parabolic flight that remained during level flight but was not present during any imaging during preflight measures in the seated or supine postures; normal venous flow patterns were observed in the right IJV during all conditions in all participants. Alterations to cerebral outflow dynamics in the left IJV can occur during acute exposure to weightlessness and thus, may increase the risk of venous thrombosis during any duration of spaceflight.

11.
bioRxiv ; 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38464243

RESUMO

Hyperinflammatory disease is associated with an aberrant immune response resulting in cytokine storm. One such instance of hyperinflammatory disease is known as macrophage activation syndrome (MAS). The pathology of MAS can be characterised by significantly elevated serum levels of interleukin (IL)-18 and interferon (IFN)-γ. Given the role for IL-18 in MAS, we sought to establish the role of inflammasomes in the disease process. Using a murine model of CpG-DNA induced MAS, we discovered that the expression of the NLRP3 inflammasome was increased and correlated with IL-18 production. Inhibition of the NLRP3 inflammasome, or downstream caspase-1, prevented MAS-mediated upregulation of plasma IL-18 but interestingly did not alleviate key features of hyperinflammatory disease including hyperferritinaemia and splenomegaly. Furthermore IL-1 receptor blockade with IL-1Ra did not prevent the development of CpG-induced MAS, despite being clinically effective in the treatment of MAS. These data demonstrate that in the development of MAS, the NLRP3 inflammasome was essential for the elevation in plasma IL-18, a key cytokine in clinical cases of MAS, but was not a driving factor in the pathogenesis of CpG-induced MAS.

12.
Sci Rep ; 14(1): 4248, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38378802

RESUMO

In the enduring challenge against disease, advancements in medical technology have empowered clinicians with novel diagnostic platforms. Whilst in some cases, a single test may provide a confident diagnosis, often additional tests are required. However, to strike a balance between diagnostic accuracy and cost-effectiveness, one must rigorously construct the clinical pathways. Here, we developed a framework to build multi-platform precision pathways in an automated, unbiased way, recommending the key steps a clinician would take to reach a diagnosis. We achieve this by developing a confidence score, used to simulate a clinical scenario, where at each stage, either a confident diagnosis is made, or another test is performed. Our framework provides a range of tools to interpret, visualize and compare the pathways, improving communication and enabling their evaluation on accuracy and cost, specific to different contexts. This framework will guide the development of novel diagnostic pathways for different diseases, accelerating the implementation of precision medicine into clinical practice.


Assuntos
Comunicação , Medicina de Precisão , Processos Mentais
13.
BJA Open ; 9: 100261, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38390395

RESUMO

Background: Careful administration of either spinal (intrathecal) or general anaesthesia probably has a greater impact on outcomes after hip fracture surgery than which method is used per se. Intraoperative hypotension is associated with poorer outcomes, but appears less prevalent using lower doses of spinal anaesthesia. Methods: In this observational single-centre study, intraoperative noninvasive blood pressure data were analysed from 280 patients undergoing unilateral hip fracture surgery after the administration of hyperbaric spinal bupivacaine 0.5%, 1.3 ml (0.65 mg). Results: Mean cohort mean arterial pressure (MAP) remained within 10% of baseline (spinal injection) MAP for 97/98 (99.0%) subsequent aggregated 1-min recording intervals. The prevalences of lowest MAP <70 mm Hg and <55 mm Hg were significantly lower than historical equivalents (Anaesthesia Sprint Audit of Practice 1 and 2) (52.9% and 10.4% vs 71.9% and 23.8%, respectively, both <0.0001). The proportions of 10 551 MAP readings <70 mm Hg and <55 mm Hg were 6.7% and 0.4%, respectively. Forty-five (16.1%) patients had relatively persistent hypotension (MAP ≤70 mm Hg for five or more intraoperative readings), and were statistically more likely to be frail (Nottingham Hip Fracture Score ≥7/10, 37.8% vs 19.6%, P=0.0109) and be taking alpha-/beta-blockers (44.4% vs 24.3%, P=0.0099) than the remaining 'normotensive' cohort. Surgical anaesthesia remained effective for up to 190 min, with only one patient requiring supplemental local anaesthesia during skin closure. Conclusions: Low doses of hyperbaric spinal 0.5% bupivacaine (1.3 ml, 6.5 mg) are associated with minimal reductions in blood pressure during surgery and provide adequate duration of surgical anaesthesia. Randomised comparisons of lower vs higher/standard doses of spinal anaesthesia are now required to confirm outcome benefits in this vulnerable patient group. Clinical trial registration: NCT05799300.

14.
Nat Chem Biol ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321209

RESUMO

Glycosylation is a critical post-translational protein modification that affects folding, half-life and functionality. Glycosylation is a non-templated and heterogeneous process because of the promiscuity of the enzymes involved. We describe a platform for sequential glycosylation reactions for tailored sugar structures (SUGAR-TARGET) that allows bespoke, controlled N-linked glycosylation in vitro enabled by immobilized enzymes produced with a one-step immobilization/purification method. We reconstruct a reaction cascade mimicking a glycosylation pathway where promiscuity naturally exists to humanize a range of proteins derived from different cellular systems, yielding near-homogeneous glycoforms. Immobilized ß-1,4-galactosyltransferase is used to enhance the galactosylation profile of three IgGs, yielding 80.2-96.3% terminal galactosylation. Enzyme recycling is demonstrated for a reaction time greater than 80 h. The platform is easy to implement, modular and reusable and can therefore produce homogeneous glycan structures derived from various hosts for functional and clinical evaluation.

15.
Kidney360 ; 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38323855

RESUMO

BACKGROUND: OPTIMIZE was a randomized, open-label study evaluating different tenapanor initiation methods. OPTIMIZE evaluated tenapanor alone and in combination with phosphate binders (PBs) to achieve target serum phosphate (P) ≤5.5 mg/dL. METHODS: Patients with inadequately controlled P receiving maintenance dialysis from 42 US locations who were taking PBs with baseline P >5.5 mg/dL and ≤10.0 mg/dL, or were PB-naive with baseline P >4.5 mg/dL and ≤10.0 mg/dL, were included in OPTIMIZE. Participants taking PBs at baseline were randomized to switch from PBs to tenapanor (Straight Switch; n = 151) or reduce PB dosage by ≥50% and add tenapanor (Binder Reduction; n = 152); PB-naive patients started tenapanor alone (Binder-Naive; n = 30). Participants received tenapanor 30 mg twice a day for 10 weeks (part A), followed by an elective, 16-week open-label extension (part B). Outcomes included changes from baseline in P, intact fibroblast growth factor 23 (iFGF23), parathyroid hormone (PTH), serum calcium, and medication burden; patient-reported outcomes; and safety. RESULTS: By part A endpoint, 34.4% (Straight Switch), 38.2% (Binder Reduction), and 63.3% (Binder-Naive) of patients achieved P ≤5.5 mg/dL. Mean P reduction and median pill burden reduction from baseline to part A endpoint were 0.91± 1.7 mg/dL and 4 pills/day for the Straight Switch and 0.99± 1.8 mg/dL and 1 pill/day for the Binder Reduction group. The mean P reduction for Binder-Naive patients was 0.87± 1.5 mg/dL. Among Straight Switch and Binder Reduction patients who completed patient experience questionnaires, 205 of 243 (84.4%) reported an improved phosphate-management routine. Diarrhea was the most common adverse event (133 of 333 [39.9%]). CONCLUSIONS: Tenapanor as monotherapy or in combination with PBs effectively lowered P toward the target range in patients who were PB naïve or who were not at goal despite PB use. FUNDING: Ardelyx, Inc. TRIAL REGISTRATION: NCT04549597.

16.
Stroke ; 55(4): 1015-1024, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38275117

RESUMO

BACKGROUND: The dynamics of blood clot (combination of Hb [hemoglobin], fibrin, and a higher concentration of aggregated red blood cells) formation within the hematoma of an intracerebral hemorrhage is not well understood. A quantitative neuroimaging method of localized coagulated blood volume/distribution within the hematoma might improve clinical decision-making. METHODS: The deoxyhemoglobin of aggregated red blood cells within extravasated blood exhibits a higher magnetic susceptibility due to unpaired heme iron electrons. We propose that coagulated blood, with higher aggregated red blood cell content, will exhibit (1) a higher positive susceptibility than noncoagulated blood and (2) increase in fibrin polymerization-restricted localized diffusion, which can be measured noninvasively using quantitative susceptibility mapping and diffusion tensor imaging. In this serial magnetic resonance imaging study, we enrolled 24 patients with acute intracerebral hemorrhage between October 2021 to May 2022 at a stroke center. Patients were 30 to 70 years of age and had a hematoma volume >15 cm3 and National Institutes of Health Stroke Scale score >1. The patients underwent imaging 3×: within 12 to 24 (T1), 36 to 48 (T2), and 60 to 72 (T3) hours of last seen well on a 3T magnetic resonance imaging system. Three-dimensional anatomic, multigradient echo and 2-dimensional diffusion tensor images were obtained. Hematoma and edema volumes were calculated, and the distribution of coagulation was measured by dynamic changes in the susceptibilities and fractional anisotropy within the hematoma. RESULTS: Using a coagulated blood phantom, we demonstrated a linear relationship between the percentage coagulation and susceptibility (R2=0.91) with a positive red blood cell stain of the clot. The quantitative susceptibility maps showed a significant increase in hematoma susceptibility (T1, 0.29±0.04 parts per millions; T2, 0.36±0.04 parts per millions; T3, 0.45±0.04 parts per millions; P<0.0001). A concomitant increase in fractional anisotropy was also observed with time (T1, 0.40±0.02; T2, 0.45±0.02; T3, 0.47±0.02; P<0.05). CONCLUSIONS: This quantitative neuroimaging study of coagulation within the hematoma has the potential to improve patient management, such as safe resumption of anticoagulants, the need for reversal agents, the administration of alteplase to resolve the clot, and the need for surgery.


Assuntos
Acidente Vascular Cerebral Hemorrágico , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral Hemorrágico/complicações , Imagem de Tensor de Difusão , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/complicações , Hemorragia Cerebral/complicações , Imageamento por Ressonância Magnética/métodos , Hematoma/complicações , Coagulação Sanguínea , Hemoglobinas , Fibrina
17.
Med Sci Sports Exerc ; 56(5): 902-916, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38181220

RESUMO

PURPOSE: Short periods of reduced energy availability are commonly undertaken by athletes to decrease body mass, possibly improve the power-to-mass ratio, and enhance physical performance. Our primary aim was to investigate the impact of 10 d of low energy availability (LEA) followed by 2 d of optimal energy availability (OEA) on physical performance parameters in trained females. Second, physiological markers at the whole-body and molecular level related to performance were evaluated. METHODS: Thirty young trained eumenorrheic females were matched in pairs based on training history and randomized to a 10-d intervention period of LEA (25 kcal·fat-free mass (FFM) -1 ·d -1 ) or OEA (50 kcal·FFM -1 ·d -1 ) along with supervised exercise training. Before the intervention, participants underwent a 5-d run-in period with OEA + supervised exercise training. After the LEA intervention, 2 d of recovery with OEA was completed. Participants underwent muscle biopsies, blood sampling, physical performance tests, body composition measurements, and resting metabolic rate measurements. A linear mixed model was used with group and time as fixed effects and subject as random effects. RESULTS: Compared with OEA, LEA resulted in reduced body mass, muscle glycogen content, repeated sprint ability, 4-min time-trial performance, and rate of force development of the knee extensors (absolute values; P < 0.05). Two days of recovery restored 4-min time-trial performance and partly restored repeated sprint ability, but performance remained inferior to the OEA group. When the performance data were expressed relative to body mass, LEA did not enhance performance. CONCLUSIONS: Ten days of LEA resulted in impaired performance (absolute values), with concomitant reductions in muscle glycogen. Two days of recovery with OEA partially restored these impairments, although physical performance (absolute values) was still inferior to being in OEA. Our findings do not support the thesis that LEA giving rise to small reductions in body mass improves the power-to-mass ratio and thus increases physical performance.


Assuntos
Composição Corporal , Exercício Físico , Humanos , Feminino , Exercício Físico/fisiologia , Glicogênio/metabolismo , Metabolismo Energético/fisiologia , Ingestão de Energia/fisiologia
18.
J Cell Physiol ; 239(4): e31182, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38214457

RESUMO

Ribosomes are essential cellular machinery for protein synthesis. It is hypothesised that ribosome content supports muscle growth and that individuals with more ribosomes have greater increases in muscle size following resistance training (RT). Aerobic conditioning (AC) also elicits distinct physiological adaptations; however, no measures of ribosome content following AC have been conducted. We used ribosome-related gene expression as a proxy measure for ribosome content and hypothesised that AC and RT would increase ribosome-related gene expression. Fourteen young men and women performed 6 weeks of single-legged AC followed by 10 weeks of double-legged RT. Muscle biopsies were taken following AC and following RT in the aerobically conditioned (AC+RT) and unconditioned (RT) legs. No differences in regulatory genes (Ubf, Cyclin D1, Tif-1a and Polr-1b) involved in ribosomal biogenesis or ribosomal RNA (45S, 5.8S, 18S and 28S rRNAs) expression were observed following AC and RT, except for c-Myc (RT > AC+RT) and 5S rRNA (RT < AC+RT at pre-RT) with 18S external transcribed spacer and 5.8S internal transcribed spacer expression decreasing from pre-RT to post-RT in the RT leg only. When divided for change in leg-lean soft tissue mass (ΔLLSTM) following RT, legs with the greatest ΔLLSTM had lower expression in 11/13 measured ribosome-related genes before RT and decreased expression in 9/13 genes following RT. These results indicate that AC and RT did not increase ribosome-related gene expression. Contrary to previous research, the greatest increase in muscle mass was associated with lower changes in ribosome-related gene expression over the course of the 10-week training programme. This may point to the importance of translational efficiency rather than translational capacity (i.e. ribosome content) in mediating long-term exercise-induced adaptations in skeletal muscle.


Assuntos
Treinamento de Força , Masculino , Humanos , Feminino , Ribossomos/genética , Biossíntese de Proteínas/genética , Músculo Esquelético/metabolismo , Hipertrofia/genética , Hipertrofia/metabolismo
19.
EMBO Rep ; 25(2): 704-724, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38263327

RESUMO

TFEB is a master regulator of autophagy, lysosome biogenesis, mitochondrial metabolism, and immunity that works primarily through transcription controlled by cytosol-to-nuclear translocation. Emerging data indicate additional regulatory interactions at the surface of organelles such as lysosomes. Here we show that TFEB has a non-transcriptional role in mitochondria, regulating the electron transport chain complex I to down-modulate inflammation. Proteomics analysis reveals extensive TFEB co-immunoprecipitation with several mitochondrial proteins, whose interactions are disrupted upon infection with S. Typhimurium. High resolution confocal microscopy and biochemistry confirms TFEB localization in the mitochondrial matrix. TFEB translocation depends on a conserved N-terminal TOMM20-binding motif and is enhanced by mTOR inhibition. Within the mitochondria, TFEB and protease LONP1 antagonistically co-regulate complex I, reactive oxygen species and the inflammatory response. Consequently, during infection, lack of TFEB specifically in the mitochondria exacerbates the expression of pro-inflammatory cytokines, contributing to innate immune pathogenesis.


Assuntos
Autofagia , Inflamação , Humanos , Inflamação/metabolismo , Citosol/metabolismo , Transporte Ativo do Núcleo Celular , Lisossomos/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Proteínas Mitocondriais/metabolismo , Proteases Dependentes de ATP/metabolismo
20.
J Sport Health Sci ; 13(1): 47-60, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37385345

RESUMO

PURPOSE: The aim of this umbrella review was to determine the impact of resistance training (RT) and individual RT prescription variables on muscle mass, strength, and physical function in healthy adults. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched and screened eligible systematic reviews reporting the effects of differing RT prescription variables on muscle mass (or its proxies), strength, and/or physical function in healthy adults aged >18 years. RESULTS: We identified 44 systematic reviews that met our inclusion criteria. The methodological quality of these reviews was assessed using A Measurement Tool to Assess Systematic Reviews; standardized effectiveness statements were generated. We found that RT was consistently a potent stimulus for increasing skeletal muscle mass (4/4 reviews provide some or sufficient evidence), strength (4/6 reviews provided some or sufficient evidence), and physical function (1/1 review provided some evidence). RT load (6/8 reviews provided some or sufficient evidence), weekly frequency (2/4 reviews provided some or sufficient evidence), volume (3/7 reviews provided some or sufficient evidence), and exercise order (1/1 review provided some evidence) impacted RT-induced increases in muscular strength. We discovered that 2/3 reviews provided some or sufficient evidence that RT volume and contraction velocity influenced skeletal muscle mass, while 4/7 reviews provided insufficient evidence in favor of RT load impacting skeletal muscle mass. There was insufficient evidence to conclude that time of day, periodization, inter-set rest, set configuration, set end point, contraction velocity/time under tension, or exercise order (only pertaining to hypertrophy) influenced skeletal muscle adaptations. A paucity of data limited insights into the impact of RT prescription variables on physical function. CONCLUSION: Overall, RT increased muscle mass, strength, and physical function compared to no exercise. RT intensity (load) and weekly frequency impacted RT-induced increases in muscular strength but not muscle hypertrophy. RT volume (number of sets) influenced muscular strength and hypertrophy.


Assuntos
Treinamento de Força , Adulto , Humanos , Terapia por Exercício , Exercício Físico/fisiologia , Hipertrofia , Músculo Esquelético/fisiologia
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