Essential Role for miR-196a in Brown Adipogenesis of White Fat Progenitor Cells

Brown adipocytes can differentiate from white fat progenitor cells in mice exposed to cold or β3-adrenergic stimulation, and this process is regulated by a microRNA that regulates the expression of Hoxc8, a master regulator of brown adipogenesis

Disentangling astroglial physiology with a realistic cell model in silico

Electrically non-excitable astroglia take up neurotransmitters, buffer extracellular K+ and generate Ca2+ signals that release molecular regulators of neural circuitry. The underlying machinery remains enigmatic, mainly because the sponge-like astrocyte morphology has been difficult to access experimentally or explore theoretically. Here, we systematically incorporate multi-scale, tri-dimensional astroglial architecture into a realistic multi-compartmental cell model, which we constrain by empirical tests and integrate into the NEURON computational biophysical environment. This approach is implemented as a flexible astrocyte-model builder ASTRO. As a proof-of-concept, we explore an in silico astrocyte to evaluate basic cell physiology features inaccessible experimentally. Our simulations suggest that currents generated by glutamate transporters or K+ channels have negligible distant effects on membrane voltage and that individual astrocytes can successfully handle extracellular K+ hotspots. We show how intracellular Ca2+ buffers affect Ca2+ waves and why the classical Ca2+ sparks-and-puffs mechanism is theoretically compatible with common readouts of astroglial Ca2+ imaging

Low density of CD3+, CD4+ and CD8+ cells is associated with increased risk of relapse in squamous cell cervical cancer

The purpose of this study was to investigate the prognostic value of the primary in situ cellular immune response in cervical squamous cell carcinoma. A study of 102 women treated for stage IB and IIA disease, between 1990 and 2000, was performed. Paraffin-embedded cervical tissue processed at the time of diagnosis was immunostained for CD3+ (T cells), CD4+ (T helper/regulatory T cells) and CD8+ (cytotoxic T cells) cells. Immune cell profile densities were estimated using stereology. Both intra- and peritumoural cell densities were estimated. Using Cox's proportional hazards regression modelling we found an increase in cell density to decrease the risk of relapse for all three cell types. The density of peritumoural CD3+ cells seems to have the strongest potential for predicting relapse. An increase in CD3+ cell density from 795 to 2043 cells per mm2 (25–75 percentile) reduced the hazard ratio to 0.27

Acute effects of caffeine and cigarette smoking on ventricular long-axis function in healthy subjects

<p>Abstract</p> <p>Background</p> <p>Few data exist regarding the direct effects of caffeine and smoking on cardiac function. We sought to explore the acute effects of caffeine assumption, cigarette smoking, or both on left ventricular (LV) and right ventricular (RV) function in a population of young normal subjects.</p> <p>Methods</p> <p>Forty-five healthy subjects aged 25 ± 2 years underwent echocardiography. Fifteen of them were non-smokers and habitual coffee consumers (group 1), 15 were smokers and not habitual coffee consumers (group 2), and 15 were smokers and habitual coffee consumers (group 3). Peak systolic (S_a), early diastolic E_a, and late diastolic (A_a) velocity of mitral annulus were measured by pulsed Tissue Doppler, and left atrioventricular plane displacement was determined by M-mode. Tricuspid annular velocities and systolic excursion (TAPSE) were also determined. Measurements were performed at baseline and after oral assumption of caffeine 100 mg in group 1, one cigarette smoking in group 2, and both in group 3.</p> <p>Results</p> <p>No changes in ventricular function were observed in group 1 after caffeine administration. In group 2, cigarette smoking yielded an acute increase in mitral A_a(+12.1%, p = 0.0026), tricuspid S_a(+9.8%, p = 0.012) and TAPSE (+7.9%, p = 0.017), and a decrease in the mitral E_a/A_aratio (-8.5%, p = 0.0084). Sequential caffeine assumption and cigarette smoking in group 3 was associated with an acute increase in mitral A_a(+13.0%, p = 0.015) and tricuspid A_a(+11.6%, p < 0.0001) and a reduction in mitral E_a/A_aratio (-8.5%, p = 0.0084) tricuspid E_a(-6.6%, p = 0.048) and tricuspid E_a/A_aratio (-9.6%, p = 0.0003). In a two-way ANOVA model controlling for hemodynamic confounding factors, changes in the overall population remained significant for mitral A_aand E_a/A_aratio, and for tricuspid A_aand E_a/A_aratio.</p> <p>Conclusion</p> <p>In young healthy subjects, one cigarette smoking is associated to an acute impairment in LV diastolic function and a hyperdynamic RV systolic response. Caffeine assumption alone does not exert any acute effect on ventricular long-axis function, but potentiates the negative effect of cigarette smoking by abolishing RV supernormal response and leading to a simultaneous impairment in both LV and RV diastolic function.</p

Increased 30-Day Mortality in Very Old ICU Patients with COVID-19 Compared to Patients with Respiratory Failure without COVID-19

Purpose: The number of patients ≥ 80 years admitted into critical care is increasing. Coronavirus disease 2019 (COVID-19) added another challenge for clinical decisions for both admission and limitation of life-sustaining treatments (LLST). We aimed to compare the characteristics and mortality of very old critically ill patients with or without COVID-19 with a focus on LLST. Methods: Patients 80 years or older with acute respiratory failure were recruited from the VIP2 and COVIP studies. Baseline patient characteristics, interventions in intensive care unit (ICU) and outcomes (30-day survival) were recorded. COVID patients were matched to non-COVID patients based on the following factors: age (± 2 years), Sequential Organ Failure Assessment (SOFA) score (± 2 points), clinical frailty scale (± 1 point), gender and region on a 1:2 ratio. Specific ICU procedures and LLST were compared between the cohorts by means of cumulative incidence curves taking into account the competing risk of discharge and death. Results: 693 COVID patients were compared to 1393 non-COVID patients. COVID patients were younger, less frail, less severely ill with lower SOFA score, but were treated more often with invasive mechanical ventilation (MV) and had a lower 30-day survival. 404 COVID patients could be matched to 666 non-COVID patients. For COVID patients, withholding and withdrawing of LST were more frequent than for non-COVID and the 30-day survival was almost half compared to non-COVID patients. Conclusion: Very old COVID patients have a different trajectory than non-COVID patients. Whether this finding is due to a decision policy with more active treatment limitation or to an inherent higher risk of death due to COVID-19 is unclear.info:eu-repo/semantics/publishedVersio

Tissue functions mediated by β3-adrenoceptors—findings and challenges

As β3-adrenoceptor agonists metamorphose from experimental tools into therapeutic drugs, it is vital to obtain a comprehensive picture of the cell and tissue functions mediated by this receptor subtype in humans. Human tissues with proven functions and/or a high expression of β3-adrenoceptors include the urinary bladder, the gall bladder, and other parts of the gastrointestinal tract. While several other β3-adrenoceptor functions have been proposed based on results obtained in animals, their relevance to humans remains uncertain. For instance, β3-adrenoceptors perform an important role in thermogenesis and lipolysis in rodent brown and white adipose tissue, respectively, but their role in humans appears less significant. Moreover, the use of tools such as the agonist BRL 37344 and the antagonist SR59230A to demonstrate functional involvement of β3-adrenoceptors may lead in many cases to misleading conclusions as they can also interact with other β-adrenoceptor subtypes or even non-adrenoceptor targets. In conclusion, we propose that many responses attributed to β3-adrenoceptor stimulation may need re-evaluation in the light of the development of more selective tools. Moreover, findings in experimental animals need to be extended to humans in order to better understand the potential additional indications and side effects of the β3-adrenoceptor agonists that are beginning to enter clinical medicine

Uncoupling proteins, dietary fat and the metabolic syndrome

There has been intense interest in defining the functions of UCP2 and UCP3 during the nine years since the cloning of these UCP1 homologues. Current data suggest that both UCP2 and UCP3 proteins share some features with UCP1, such as the ability to reduce mitochondrial membrane potential, but they also have distinctly different physiological roles. Human genetic studies consistently demonstrate the effect of UCP2 alleles on type-2 diabetes. Less clear is whether UCP2 alleles influence body weight or body mass index (BMI) with many studies showing a positive effect while others do not. There is strong evidence that both UCP2 and UCP3 protect against mitochondrial oxidative damage by reducing the production of reactive oxygen species. The evidence that UCP2 protein is a negative regulator of insulin secretion by pancreatic β-cells is also strong: increased UCP2 decreases glucose stimulated insulin secretion ultimately leading to β-cell dysfunction. UCP2 is also neuroprotective, reducing oxidative stress in neurons. UCP3 may also transport fatty acids out of mitochondria thereby protecting the mitochondria from fatty acid anions or peroxides. Current data suggest that UCP2 plays a role in the metabolic syndrome through down-regulation of insulin secretion and development of type-2 diabetes. However, UCP2 may protect against atherosclerosis through reduction of oxidative stress and both UCP2 and UCP3 may protect against obesity. Thus, these UCP1 homologues may both contribute to and protect from the markers of the metabolic syndrome

The effects of trastuzumab on the CD4+CD25+FoxP3+ and CD4+IL17A+ T-cell axis in patients with breast cancer

In addition to the direct targeting effects on HER2-positive cells, trastuzumab may have a therapeutic role modulating the activity of the cellular immune system in patients with breast cancer. To investigate this further, the balance of T-regulatory (Treg), Th17, natural killer (NK) and NK T (NKT) cells before, during and after trastuzumab therapy was investigated. Sequential frequencies of circulating Treg cells, Th17 cells, NK and NKT cells were measured in peripheral blood of breast cancer patients and normal controls throughout therapy. Individuals with breast cancer had significantly higher Treg frequencies of peripheral blood compared with healthy controls (9.2 or 8.6 vs 6%; P<0.05), and no significant differences in Treg frequencies were observed between HER2-positive and HER2-negative individuals. The number of Th17 cells was lowest in HER2-positive patients compared with both healthy controls and HER2-negative patients (0.31 vs 0.75% or 0.84%; P=0.01). There appeared to be an inverse relationship between Treg and Th17 frequencies in metastatic breast cancer (MBC) with Treg levels significantly reduced during treatment with trastuzumab (P=0.04), whereas Th17 frequencies were concomitantly increased (P=0.04). This study supports earlier data that Treg cells are present at higher frequencies in breast cancer patients compared with healthy individuals. For the first time, we show that HER2-positive individuals with breast carcinomas have reduced numbers of circulating Th17 cells, which appear, in turn to have an inverse relationship with Treg frequency in MBC. The change in balance of the Treg : Th17 ratio appears to characterise the cancer state, and furthermore, is disrupted by trastuzumab therapy

Protection of flunarizine on cerebral mitochondria injury induced by cortical spreading depression under hypoxic conditions

A rat cortical spreading depression (CSD) model was established to explore whether cerebral mitochondria injury was induced by CSD under both normoxic and hypoxic conditions and whether flunarizine had a protective effect on cerebral mitochondria. SD rats, which were divided into seven groups, received treatment as follows: no intervention (control Group I); 1 M NaCl injections (Group II); 1 M KCl injections (Group III); intraperitoneal flunarizine (3 mg/kg) 30 min before KCl injections (Group IV); 14% O2 inhalation before NaCl injections (Group V); 14% O2 inhalation followed by KCl injections (Group VI); 14% O2 inhalation and intraperitoneal flunarizine followed by KCl injections (Group VII). Following treatment, brains were removed for the analysis of mitochondria transmembrane potential (MMP) and oxidative respiratory function after recording the number, amplitude and duration of CSD. The duration of CSD was significantly longer in Group VI than that in Group III. The number and duration of CSD in Group VII was significantly lower than that in Group VI. MMP in Group VI was significantly lower than that in Group III, and MMP in Group VII was significantly higher than that in Group VI. State 4 respiration in Group VI was significantly higher than that in Group III, and state 3 respiration in Group VII was significantly higher than that in Group VI. Respiration control of rate in Group VII was also significantly higher than that in Group VI. Thus, we concluded that aggravated cerebral mitochondria injury might be attributed to CSD under hypoxic conditions. Flunarizine can alleviate such cerebral mitochondria injury under both normoxic and hypoxic conditions