Miracle-dz/UniFAR-FTUs huggingface dataset:
The training stimulus experienced by the leg muscles during cycling in humans

Considerable variability exists between people in their health‐ and performance‐related adaptations to conventional endurance training. We hypothesized that some of this variability might be due to differences in the training stimulus received by the working muscles. In 71 young sedentary women we observed large variations in the ratio of one‐leg cycling muscle aerobic capacity to two‐leg cycling whole‐body maximal oxygen uptake ( ; Ratio1:2; range 0.58–0.96). The variability in Ratio1:2 was primarily due to differences between people in one‐leg (r= 0.71, P < 0.0005) and was not related to two‐leg (r= 0.15, P= 0.209). Magnetic resonance imaging (n= 30) and muscle biopsy sampling (n= 20) revealed that one‐leg was mainly determined by muscle volume (r= 0.73, P < 0.0005) rather than muscle fibre type or oxidative capacity. A high one‐leg was associated with favourable lipoprotein profiles (P= 0.033, n= 24) but this was not the case for two‐leg . Calculations based on these data suggest that conventional two‐leg exercise at 70% requires subjects with the lowest Ratio1:2 to work their legs at 60% of single‐leg , whilst those with the highest Ratio1:2 work their legs at only 36% of maximum. It was concluded that endurance training carried out according to current guidelines will result in highly variable training stimuli for the leg muscles and variable magnitudes of adaptation. These conclusions have implications for the prescription of exercise to improve health and for investigations into the genetic basis of muscle adaptations.
Prenatal and perinatal zinc restriction: effects on body composition, glucose tolerance and insulin response in rat offspring

Maternal undernutrition increases the risk of adult chronic diseases, such as obesity and type 2 diabetes. This study evaluated the effect of maternal zinc restriction in predisposing the offspring to adiposity and altered insulin response in later life. Seventy‐day‐old female Wistar/NIN rats received a control (ZnC) or zinc‐restricted (ZnR) diet for 2 weeks. Following mating with control males, a subgroup of the ZnR dams were rehabilitated with ZnC diet from parturition. Half the offspring born to the remaining ZnR dams were weaned onto the ZnC diet and the other half continued on the ZnR diet throughout their life. Body composition, glucose tolerance, insulin response and plasma lipid profile were assessed in male and female offspring at 3 and 6 months of age. The ZnR offspring weighed less than control offspring at birth and weaning and continued so until 6 months of age. Rehabilitation regimens corrected the body weights of male but not female offspring. Maternal zinc restriction increased the percentage of body fat and decreased lean mass, fat‐free mass and fasting plasma insulin levels in both male and female offspring at 6 months of age. Also, glucose‐induced insulin secretion was decreased in female but not male offspring. Despite the differences in fasting insulin and the area under the curve for insulin, the fasting glucose and the area under the curve for glucose were in general comparable among offspring of different groups. Rehabilitation from parturition or weaning partly corrected the changes in the percentage of body fat but had no such effect on other parameters. Changes in plasma lipid profile were inconsistent among the offspring of different groups. Thus chronic maternal zinc restriction altered the body composition and impaired the glucose‐induced insulin secretion in the offspring.
Fibroblast growth factor 2‐stimulated proliferation is lower in muscle precursor cells from old rats

In aged skeletal muscle, impairments in regrowth and regeneration may be explained by a decreased responsiveness of muscle precursor cells (MPCs) to environmental cues such as growth factors. We hypothesized that impaired responsiveness to fibroblast growth factor 2 (FGF2) in MPCs from old animals would be explained by impaired FGF2 signalling. We determined that 5‐bromo‐2′‐deoxyuridine (BrdU) incorporation and cell number increase less in MPCs from 32‐ compared with 3‐month‐old rats. In the presence of FGF2, we demonstrated that there were age‐associated differential expression patterns for FGF receptor 1 and 2 mRNAs. Measurement of downstream signalling revealed that that mitogen‐activated protein kinase/ERK kinase 1/2 (MEK1/2)–extracellular signal‐regulated kinase 1/2, protein kinase C and p38 were FGF2‐driven pathways in MPCs. Uniquely, protein kinase C signalling was shown to play the largest role in FGF2‐stimulated proliferation in MPCs. c‐Jun N‐terminal kinase (JNK) signalling was ruled out as an FGF2‐stimulated proliferation pathway in MPCs. Inhibition of JNK had no effect on FGF2 signalling to BrdU incorporation, and FGF2 treatment was associated with increased phosphorylation of p38, which inhibits, rather than stimulates, BrdU incorporation in MPCs. Surprisingly, the commonly used vehicle, dimethyl sulphoxide, rescued proliferation in MPCs from old animals. These findings provide insight for the development of effective treatment strategies that target the age‐related impairments of MPC proliferation in old skeletal muscle.
Does enhanced respiratory–sympathetic coupling contribute to peripheral neural mechanisms of angiotensin II–salt hypertension?

Hypertension caused by chronic infusion of angiotensin II (Ang II) in experimental animals is likely to be mediated, at least in part, by an elevation of ongoing sympathetic nerve activity (SNA). However, the contribution of SNA relative to non‐neural mechanisms in mediating Ang II‐induced hypertension is an area of intense debate and remains unresolved. We hypothesize that sympathoexcitatory actions of Ang II are directly related to the level of dietary salt intake. To test this hypothesis, chronically instrumented rats were placed on a 0.1 (low), 0.4 (normal) or 2.0% NaCl diet (high) and, following a control period, administered Ang II (150 ng kg−1 min−1, s.c.) for 10–14 days. The hypertensive response to Ang II was greatest in rats on the high‐salt diet (Ang II–salt hypertension), which was associated with increased ‘whole body’ sympathetic activity as measured by noradrenaline spillover and ganglionic blockade. Indirect and direct measures of organ‐specific SNA revealed a distinct ‘sympathetic signature’ in Ang II–salt rats characterized by increased SNA to the splanchnic vascular bed, transiently reduced renal SNA and no change in SNA to the hindlimbs. Electrophysiological experiments indicate that increased sympathetic outflow in Ang II–salt rats is unlikely to involve activation of rostral ventrolateral medulla (RVLM) vasomotor neurons with barosensitive cardiac rhythmic discharge. Instead, another set of RVLM neurons that discharge in discrete bursts have exaggerated spontaneous activity in rats with Ang II–salt hypertension. Although their discharge is not cardiac rhythmic at resting levels of arterial pressure, it nevertheless appears to be barosensitive. Therefore, these burst‐firing RVLM neurons presumably serve a vasomotor function, consistent with their having axonal projections to the spinal cord. Bursting discharge of these neurons is respiratory rhythmic and driven by the respiratory network. Given that splanchnic SNA is strongly coupled to respiration, we hypothesize that enhanced central respiratory–vasomotor neuron coupling in the RVLM could be an important mechanism that contributes to exaggerated splanchnic sympathetic outflow in Ang II–salt hypertension. This hypothesis remains to be tested directly in future investigations.
Strain‐dependent differences in electrogenic secretion of electrolytes across mouse colon epithelium

Mice have proven to be powerful models for the study of human physiology and pathophysiology. With the advent of techniques for genomic manipulation, the possibilities for studying inherited diseases in this convenient laboratory mammal are increasing by the day. It has been reported that when knocking out or otherwise modifying genes of interest in mice, the phenotype obtained can vary markedly depending on the genetic background of the animals used in the study. The aim of this work was to study whether the genetic background can influence the characteristics of fluid and electrolyte transepithelial transport in the distal colon of three mouse strains most in use in our and other laboratories. Ussing chamber recordings revealed that the colons of C57Bl/6J, Sv 129 and Black Swiss animals have distinctive responses to the calcium agonists carbachol and histamine that are not explained by the presence of different types of muscarinic and histaminergic receptors in these tissues. We have also found differences in the cAMP‐activated, KCNMA1‐channel‐dependent potassium secretion between the strains. We interpret this to indicate a unique distribution of KCNMA1 channels in lower parts of the crypt of Sv 129 colonic epithelium compared with that of C57Bl/6J and Black Swiss animals. The reported differences should be taken into account when choosing the genetic background of animals to be used for genetic modification.
Proteome analysis of spinal cord during the clinical course of monophasic experimental autoimmune encephalomyelitis

The induction of autoimmune encephalomyelitis (EAE) in Lewis rats results in a period of exacerbation followed by complete recovery. Therefore, this model is widely used for studying the evolution of multiple sclerosis. In the present investigation, differentially expressed proteins in the spinal cord of Lewis rats during the evolution of EAE were assessed using the combination of 2DE and MALDI‐TOF MS. The majority of the differentially expressed proteins were identified during the acute phase of EAE, in relation to naïve control animals. On the other hand, recovered rats presented a similar protein expression pattern in comparison with the naïve ones. This observation can be explained, at least in part, by the intense catabolism existent in acute phase due to nervous tissue damage. In recovered rats, we have described the upregulation of proteins that are apparently involved in the recovery of damaged tissue, such as light and medium neurofilaments, glial fibrillary acidic protein, tubulins subunits, and quaking protein. These proteins are involved mainly in cell growth, myelination, and remyelination as well as in astrocyte and oligodendrocyte maturation. The present study has demonstrated that the inflammatory response, characterized by an increase of the proliferative response and infiltration of autoreactive T lymphocytes in the central nervous system, occurs simultaneously with neurodegeneration.
Human skeletal muscle feed arteries studied in vitro: the effect of temperature on α1‐adrenergic responsiveness

Heat and cold exposure can decrease and increase total peripheral resistance, respectively, in humans. With unique access to human skeletal muscle feed arteries, we sought both to characterize these vessels and to determine the interaction between temperature and α1‐adrenergic receptor responsiveness. We hypothesized that α1‐mediated vasocontraction of human feed arteries would be attenuated in response to 39 or 35°C. Skeletal muscle feed arteries were harvested from thirty‐two human volunteers and studied using isometric techniques. Vessel function was assessed using KCl, sodium nitroprusside (SNP), phenylephrine (PE) and ACh dose–response curves to characterize non‐receptor‐ and receptor‐mediated vasocontraction and vasorelaxation. Single doses of PE (1 mm) and KCl (100 mm) were administered at 37°C and then, in a balanced design, repeated at both 35 and 39°C. The KCl and PE dose–response curves elicited significant vasocontraction (2009 ± 407 and 1974 ± 508 mg developed tension, respectively), whereas SNP and ACh induced the expected vasorelaxation (102 ± 6 and 73 ± 10% relaxation, respectively). Altering the temperature had no effect on inherent smooth muscle function (KCl response), but both a reduction (35°C) and an increase in temperature (39°C) decreased the vasocontractile response to 1 mm PE (37°C, 1478 ± 338 mg; 35°C, 546 ± 104 mg; and 39°C, 896 ± 202 mg; P < 0.05) or across PE dose (P < 0.05, 35 and 39 versus 37°C). Despite clear heterogeneity between both the human volunteers and the feed arteries themselves, this novel approach to the procurement of human vessels revealed a robust ‘inverted U’ response to altered temperature, such that α1‐mediated vasocontraction was attenuated with either warming or cooling.
Relevance of the volume‐axis intercept, V0, compared with the slope of end‐systolic pressure–volume relationship in response to large variations in inotropy and afterload in rats

The end‐systolic pressure–volume relationship (ESPVR) is proposed and used as a reliable index of left ventricular (LV) contractility despite the fact that its afterload independence has been challenged. Furthermore, the physiological relevance of its volume‐axis intercept, V0, remains unclear. Systemic haemodynamics and pressure–volume loops obtained by inferior vena cava occlusion were recorded in 21 rats anaesthetized by isoflurane inhalation and instrumented with a conductance pressure–volume catheter in response to incremental i.v. doses of adrenaline, dobutamine, phenylephrine, metoprolol, papaverine and isoflurane inhalation. In conditions with large variations (±100%) of both inotropy and afterload, infusion of negative inotropic drugs was associated with a dose‐dependent rightward shift of ESPVR accompanied by a decrease in its slope (end‐systolic elastance, Ees), whereas positive inotropic agents produced an isolated decrease in V0. With the predominant vasoactive drugs, there was a dose‐dependent change in Ees without major horizontal shifts, demonstrating that this slope mainly represents LV afterload rather than inotropy. When contractility was altered, V0 was negatively correlated to the preload‐adjusted contractility index, PAdP/dtmax, demonstrating that a reduced V0 provides a good reflection of increased LV contractility. From these results, we computed a logarithmically adjusted Ees/V0 ratio, which resulted in reasonably strong concordance with PAdP/dtmax, including all the investigated drugs and dosages [n= 288; bias, 0.8 ± 16.2% (SD)]. Concordance with Ees (bias, 7.2 ± 58.7%) or V0 (bias, −0.6 ± 33.4%), used alone or with other commonly used contractility indices, was far less significant. In contrast to Ees, V0 provides a relatively good LV contractility index because it is much less sensitive to afterload.
Drugs awareness for parents

Describes the Parents’ Drugs Awareness Evenings run by Cambridgeshire County Council as part of the Department of Education and Employment’s drugs education support. Emphasizes that such initiatives need to take place alongside others aimed at training teachers and governors. Outlines the need to set down clear aims and basic concepts for those attending parents’ evenings. Describes the content of the evenings, including sessions of audience participation, definitions of drugs, solvent abuse, alcohol use and abuse, primary school pupils’ knowledge of drugs, and advice on what parents can do to help their children.
Identification of differentially expressed proteins by treatment with PUGNAc in 3T3‐L1 adipocytes through analysis of ATP‐binding proteome

O‐GlcNAc (2‐acetamino‐2‐deoxy‐β‐D‐glucopyranose), an important modification for cellular processes, is catalyzed by O‐GlcNAc transferase and O‐GlcNAcase. O‐(2‐acetamido‐2‐deoxy‐D‐glucopyranosylidene) amino‐N‐phenylcarbamate (PUGNAc) is a nonselective inhibitor of O‐GlcNAcase, which increases the level of protein O‐GlcNAcylation and is known to induce insulin‐resistance in adipose cells due to uncharacterized targets of this inhibitor. In this study, using ATP affinity chromatography, we applied a targeted proteomic approach for identification of proteins induced by treatment with PUGNAc. For optimization of proteomic methods using ATP affinity chromatography, comparison of two cell lines (3T3‐L1 adipocytes and C2C12 myotubes) and two different digestion steps was performed using four different structures of immobilized ATP‐bound resins. Using this approach, based on DNA sequence homologies, we found that the identified proteins covered almost half of ATP‐binding protein families classified by PROSITE. The optimized ATP affinity chromatography approach was applied for identification of proteins that were differentially expressed in 3T3‐L1 adipocytes following treatment with PUGNAc. For label‐free quantitation, a gel‐assisted method was used for digestion of the eluted proteins, and analysis was performed using two different MS modes, data‐independent (671 proteins identified) and data‐dependent (533 proteins identified) analyses. Among identified proteins, 261 proteins belong to nucleotide‐binding proteins and we focused on some nucleotide‐binding proteins, ubiquitin‐activation enzyme 1 (E1), Hsp70, vasolin‐containing protein (Vcp), and Hsp90, involved in ubiquitin‐proteasome degradation and insulin signaling pathways. In addition, we found that treatment with PUGNAc resulted in increased ubiquitination of proteins in a time‐dependent manner, and a decrease in both the amount of Akt and the level of phosphorylation of Akt, a key component in insulin signaling, through downregulation of Hsp90. In this study, based on a targeted proteomic approach using ATP affinity chromatography, we found four proteins related to ubiquitination and insulin signaling pathways that were induced by treatment with PUGNAc. This result would provide insight into understanding functions of PUGNAc in 3T3‐L1 cells.
Effects of ventricular pacing protocol on electrical restitution assessments in guinea‐pig heart

The steep slope of the rate adaptation of ventricular action potential duration (APD) is thought to indicate profibrillatory tendency. In cardiac patients, APD restitution is commonly assessed by extrasystolic (S1–S2) stimulations rather than dynamic pacing, because the latter may provoke myocardial ischaemia. In this study, ventricular APD and effective refractory period (ERP) were measured in perfused guinea‐pig hearts to determine whether S1–S2 stimulations and dynamic pacing may have similar value in APD restitution assessments aimed to predict arrhythmic risk. The maximal restitution slope was greater upon S1–S2 stimulation than dynamic pacing at the epicardium (S1–S2, 1.2 ± 0.08; dynamic, 0.72 ± 0.06; P= 0.0004) and endocardium (S1–S2, 1.45 ± 0.08; dynamic, 0.95 ± 0.06; P= 0.0003). This difference was partly accounted for by an effect of the previous pacing history, as evidenced by flattening of APD restitution upon reductions in the regular beating interval prior to S2 application. Furthermore, shorter ERP than APD relationships enabled ventricular capture at shorter diastolic intervals during S1–S2 stimulation than dynamic pacing at the epicardium (S1–S2, −1 ± 3 ms; dynamic, 35 ± 3 ms; P < 0.0001) and endocardium (S1–S2, −1 ± 7 ms; dynamic, 38 ± 3 ms; P < 0.0001), thereby contributing to greater maximal restitution slope values. Flecainide, a Na+ channel blocker, increased the ERP‐to‐APD ratio and eliminated early premature beats (diastolic interval of ∼0 ms), thereby flattening the S1–S2 restitution curve, but had no effect on dynamic restitution. In hypokalaemia‐induced arrhythmogenicity, a reduction in ventricular fibrillation threshold was paralleled by increased steepness of dynamic APD restitution, while no change in the maximal restitution slope was revealed by S1–S2 stimulations. In summary, changes in electrical restitution obtained from extrasystolic stimulations may dissociate from those revealed by dynamic pacing. These findings therefore challenge the value of electrical restitution assessments based on extrasystolic stimulation alone, as commonly performed in the clinical setting.
Study of rat hypothalamic proteome by HPLC/ESI ion trap and HPLC/ESI‐Q‐TOF MS

The proteomic profile of hypothalamus, a key organ of CNS, is explored here by employing two widely used MS techniques, i.e. HPLC/ESI‐ion trap and HPLC/ESI‐quadrupole‐TOF MS. Strong cation exchange is used for the fractionation of peptides and protein search engine MASCOT is employed for data query. One hundred and thirty six proteins with 10 973 peptides were identified by HPLC/ESI‐ion trap MS, while 140 proteins with 32 183 peptides were characterized by HPLC/ESI‐quadrupole‐TOF MS. Among the total 198 proteins identified in both experiments, 78 proteins were common in both sets of conditions. The rest of the 120 proteins were identified distinctly in both MS strategies, i.e. 58 unique proteins were found using the quadrupole‐TOF while 62 were found with the HPLC/ESI‐ion trap. Moreover, these proteins were classified into groups based on their functions performed in the body. Results presented here identified some important signal and cellular defense proteins inevitable for survival in stressed conditions. Additionally, it is also shown that any single MS strategy is not reliable for good results due to loss of data depending on sensitivity of the instrument used.
SpliceProt: A protein sequence repository of predicted human splice variants

The mechanism of alternative splicing in the transcriptome may increase the proteome diversity in eukaryotes. In proteomics, several studies aim to use protein sequence repositories to annotate MS experiments or to detect differentially expressed proteins. However, the available protein sequence repositories are not designed to fully detect protein isoforms derived from mRNA splice variants. To foster knowledge for the field, here we introduce SpliceProt, a new protein sequence repository of transcriptome experimental data used to investigate for putative splice variants in human proteomes. Current version of SpliceProt contains 159 719 non‐redundant putative polypeptide sequences. The assessment of the potential of SpliceProt in detecting new protein isoforms resulting from alternative splicing was performed by using publicly available proteomics data. We detected 173 peptides hypothetically derived from splice variants, which 54 of them are not present in UniprotKB/TrEMBL sequence repository. In comparison to other protein sequence repositories, SpliceProt contains a greater number of unique peptides and is able to detect more splice variants. Therefore, SpliceProt provides a solution for the annotation of proteomics experiments regarding splice isofoms. The repository files containing the translated sequences of the predicted splice variants and a visualization tool are freely available at http://lbbc.inca. gov.br/spliceprot.
Mechanisms of kidney repair by human mesenchymal stromal cells after ischemia: A comprehensive view using label‐free MSE

Acute kidney injury (AKI) is one of the more frequent and lethal pathological conditions seen in intensive care units. Currently available treatments are not totally effective but stem cell‐based therapies are emerging as promising alternatives, especially the use of mesenchymal stromal cells (MSC), although the signaling pathways involved in their beneficial actions are not fully understood. The objective of this study was to identify signaling networks and key proteins involved in the repair of ischemia by MSC. Using an in vitro model of AKI to investigate paracrine interactions and label‐free high definition 2D‐NanoESI‐MSE, differentially expressed proteins were identified in a human renal proximal tubule cell lineage (HK‐2) exposed to human MSC (hMSC) after an ischemic insult. In silico analysis showed that hMSC stimulated antiapoptotic activity, normal ROS handling, energy production, cytoskeleton organization, protein synthesis, and cell proliferation. The proteomic data were validated by parallel experiments demonstrating reduced apoptosis in HK‐2 cells and recovery of intracellular ATP levels. qRT‐PCR for proteins implicated in the above processes revealed that hMSC exerted their effects by stimulating translation, not transcription. Western blotting of proteins associated with ROS and energy metabolism confirmed their higher abundance in HK‐2 cells exposed to hMSC.