1,693 research outputs found
Ouabain-induced cytoplasmic vesicles and their role in cell volume maintenance
Cellular swelling is controlled by an active mechanism of cell volume regulation driven by a Na+/K+-dependent ATPase and by
aquaporins which translocate water along the osmotic gradient. Na+/K+-pump may be blocked by ouabain, a digitalic derivative,
by inhibition of ATP, or by drastic ion alterations of extracellular fluid. However, it has been observed that some tissues are still able
to control their volume despite the presence of ouabain, suggesting the existence of other mechanisms of cell volume control. In
1977, by correlating electron microscopy observation with ion and water composition of liver slices incubated in differentmetabolic
conditions in the presence or absence of ouabain, we observed that hepatocytes were able to control their volume extruding water
and recovering ion composition in the presence of ouabain. In particular, hepatocytes were able to sequester ions and water in
intracellular vesicles and then secrete themat the bile canaliculus pole.We named this “vesicularmechanismof cell volume control.”
Afterward, thismechanism has been confirmed by us and other laboratories in several mammalian tissues.This review summarizes
evidences regarding this mechanism, problems that are still pending, and questions that need to be answered. Finally, we shortly
review the importance of cell volume control in some human pathological conditions
Deep learning as closure for irreversible processes: A data-driven generalized Langevin equation
The ultimate goal of physics is finding a unique equation capable of
describing the evolution of any observable quantity in a self-consistent way.
Within the field of statistical physics, such an equation is known as the
generalized Langevin equation (GLE). Nevertheless, the formal and exact GLE is
not particularly useful, since it depends on the complete history of the
observable at hand, and on hidden degrees of freedom typically inaccessible
from a theoretical point of view. In this work, we propose the use of deep
neural networks as a new avenue for learning the intricacies of the unknowns
mentioned above. By using machine learning to eliminate the unknowns from GLEs,
our methodology outperforms previous approaches (in terms of efficiency and
robustness) where general fitting functions were postulated. Finally, our work
is tested against several prototypical examples, from a colloidal systems and
particle chains immersed in a thermal bath, to climatology and financial
models. In all cases, our methodology exhibits an excellent agreement with the
actual dynamics of the observables under consideration
Stability study of dehydrocholesterols in dried spot of blood from patients with Smith–Lemli–Opitz syndrome, using filter-paper treated with butylated hydroxytoluene
Considering the clinical importance of implementing a screening
method for cholesterol and dehydrocholesterols in dried blood spot, this study aims to standardize the preanalytical variability of DHC in DBS for detecting SLOS by using filter paper impregnated with BHT as an antioxidant
Mouse Models of Follicular and Papillary Thyroid Cancer Progression
A significant number of well-differentiated thyroid cancers progress or recur, becoming resistant to current therapeutic options. Mouse models recapitulating the genetic and histological features of advanced thyroid cancer have been an invaluable tool to dissect the mechanisms involved in the progression from indolent, well differentiated tumors to aggressive, poorly differentiated carcinomas, and to identify novel therapeutic targets. In this review, we focus on the lessons learned from models of epithelial cell-derived thyroid cancer showing progression from hyperplastic lesions to locally invasive and metastatic carcinomas
Resting state functional thalamic connectivity abnormalities in patients with post-stroke sleep apnoea: a pilot case-control study
OBJECTIVE: Sleep apnoea is common
after stroke, and has adverse effects on the
clinical outcome of affected cases. Its pathophysiological
mechanisms are only partially known. Increases
in brain connectivity after stroke might influence
networks involved in arousal modulation
and breathing control. The aim of this study was to
investigate the resting state functional MRI thalamic
hyper connectivity of stroke patients affected
by sleep apnoea (SA) with respect to cases not
affected, and to healthy controls (HC).
PATIENTS AND METHODS: A series of stabilized
strokes were submitted to 3T resting state
functional MRI imaging and full polysomnography.
The ventral-posterior-lateral thalamic nucleus was
used as seed.
RESULTS: At the between groups comparison
analysis, in SA cases versus HC, the regions significantly
hyper-connected with the seed were
those encoding noxious threats (frontal eye
field, somatosensory association, secondary visual
cortices). Comparisons between SA cases
versus those without SA, revealed in the former
group significantly increased connectivity with
regions modulating the response to stimuli independently
to their potentiality of threat (prefrontal,
primary and somatosensory association, superolateral
and medial-inferior temporal, associative
and secondary occipital ones). Further
significantly functionally hyper connections were
documented with regions involved also in the modulation
of breathing during sleep (pons, midbrain,
cerebellum, posterior cingulate cortices), and in
the modulation of breathing response to chemical
variations (anterior, posterior and para-hippocampal
cingulate cortices).
CONCLUSIONS: Our preliminary data support
the presence of functional hyper connectivity in
thalamic circuits modulating sensorial stimuli, in
patients with post-stroke sleep apnoea, possibly
influencing both their arousal ability and breathing
modulation during sleep
Effects of growth hormone on exercise capacity and cardiopulmonary performance in patients with chronic heart failure.
BACKGROUND: Because GH exerted beneficial effects in various experimental models of heart failure, we investigated the effects of GH on physical exercise capacity and cardiopulmonary performance in patients with dilated cardiomyopathy and chronic heart failure (CHF).
METHODS: Twenty-two patients with CHF (New York Heart Association functional class II-III) underwent spirometry and a symptom-limited, cardiopulmonary exercise testing before and after 3 months of GH (n = 11; seven males; seven idiopathic; 57 +/- 11 yr; 4 IU sc every other day) or placebo (n = 11; eight males; six idiopathic; 54 +/- 10 yr) administration, in a randomized, double-blind trial. Background CHF therapy remained unchanged.
RESULTS: GH, but not placebo, increased IGF-I serum concentration (from 144 +/- 35 to 293 +/- 58 ng/ml; P < 0.005) and improved New York Heart Association functional class (from 2.4 +/- 0.5 to 1.8 +/- 0.4; P < 0.005), exercise duration (from 831 +/- 273 to 925 +/- 266 sec; P < 0.005), peak power output (from 245 +/- 127 to 280 +/- 132 W; P < 0.05), peak minute ventilation (from 52.5 +/- 16.1 to 61.3 +/- 17.3 liters/min; P < 0.05), peak oxygen consumption (from 19.8 +/- 5.6 to 25.1 +/- 5.6 ml/kg.min; P < 0.005), and anaerobic threshold (from 14.9 +/- 4.8 to 20.0 +/- 4.5 ml/kg.min; P < 0.005) without affecting lung function parameters. Furthermore, the slope of the relationship between minute ventilation and pulmonary carbon dioxide production (ventilatory efficiency) decreased from 34.7 +/- 5.1 to 31.7 +/- 5.3 (P < 0.005), whereas the slope of the relation between percent predicted heart rate reserve used and percent observed metabolic reserve used (chronotropic index) rose from 0.57 +/- 0.20 to 0.69 +/- 0.18 (P < 0.005).
CONCLUSION: Given the predictive value of physical exercise capacity and cardiopulmonary performance in CHF progression, these data provide additional insights into the mechanisms by which GH may potentially benefit CHF patients
Role of curcumin in idiopathic pulmonary arterial hypertension treatment: A new therapeutic possibility
The idiopathic pulmonary arterial hypertension is a complex disease that mainly affects pulmonary arterial
circulation. This undergoes a remodeling with subsequent reduction of flow in the small pulmonary
arteries. Because of this damage an increased vascular resistance gradually develops, and over time it carries
out in heart failure. The inflammatory process is a key element in this condition, mediated by various
cytokines. The inflammatory signal induces activation of NF-jB, and prompts TGF-b-related signaling
pathway. Clinical evolution leads to progressive debilitation, greatly affecting the patient quality of life.
The actual therapeutic approaches, are few and expensive, and include systemic drugs such as prostanoids,
phosphodiesterase inhibitors and antagonists of endothelin-1 (ERBs). Some researchers have long
investigated the anti-inflammatory effects of curcumin. It shows a role for inactivation of
NF-jB-mediated inflammation. On the basis of these findings we propose a potential role of curcumin
and its pharmacologically fit derivatives for treatment of idiopathic pulmonary arterial hypertension
Circulating miR-22, miR-24 and miR-34a as Novel Predictive Biomarkers to Pemetrexed-Based Chemotherapy in Advanced Non-Small Cell Lung Cancer
Pemetrexed has been widely used in patients with advanced non-small cell lung cancer (NSCLC). The clinical relevance of polymorphisms of folate pathway genes for pemetrexed metabolism have not been fully elucidated yet. The aim of this study was to evaluate the expression levels of circulating miR-22, miR-24, and miR-34a, possibly involved in folate pathway, in NSCLC patients treated with pemetrexed compared with healthy controls and to investigate their impact on patient clinical outcomes. A total of 22 consecutive patients with advanced NSCLC, treated with pemetrexed-based chemotherapy and 27 age and sex matched healthy controls were included in this preliminary analysis. miR-22, miR-24, and miR-34a targets were identified by TargetScan 6.2 algorithm, validating the involvement of these microRNAs in folate pathway. MicroRNAs were isolated from whole blood and extracted with miRNAeasy Mini Kit (Qiagen). miRNA profiling was performed using Real-Time PCR. SPSS 17 was used to data analysis. miR-22, miR-24, and miR-34a were found upregulated (P<0.05) in NSCLC patients versus healthy controls. Higher expression levels were recorded for miR-34a. Nevertheless, significantly higher miR-22 expression was observed in patients developing progressive disease (P=0.03). No significant associations with clinical outcome were recorded for miR-24 and miR-34a. Albeit preliminary, these data support the involvement of miR-22, miR-24, and miR-34a in advanced NSCLC. The correlation between high expression of miR-22 in whole blood and the lack of response in pemetrexed treated NSCLC patients indicates that miR-22 could represent a novel predictive biomarker for pemetrexed-based treatment
Sterol profiles in plasma and erythrocyte membranes in patients with Smith-Lemli-Opitz syndrome: a six-year experience
Background: This study reports our experience over the last
six years in the diagnosis of Smith-Lemli-Opitz syndrome
and other inborn errors of cholesterol biosynthesis.
Methods: Gas chromatography/mass spectrometry was used
to obtain sterol profiles in plasma and erythrocyte membranes
of suspected patients.
Results: Plasma sterol reference values calculated in unaffected
subjects (ns276) were in agreement with those previously
reported. Among patients investigated from 2005 to
2010, we report 16 patients affected by Smith-Lemli-Opitz
syndrome, three of whom represent new cases and 13 of
whom were follow-up patients. In this period we also identified
a new case of chondrodysplasia punctata 2 X-linked.
The estimated incidence obtained for Smith-Lemli-Opitz
syndrome was 1:93 suspected patients (1.08%). We also
studied the effect of storage on the dehydrocholesterols/
cholesterol ratio in plasma and erythrocyte membranes of
patients affected by Smith-Lemli-Opitz syndrome stored at
–208C for up to 22 and 20 months, respectively. A significant
negative linear correlation between storage time and the
dehydrocholesterols/cholesterol ratio was identified in both
plasma and erythrocyte membranes. The decrease in the
dehydrocholesterols/cholesterol ratio in erythrocyte membranes
was at least two-fold higher than in plasma.
Conclusions: The results of this study may be helpful for
diagnosis and interpretation of data in patients with findings
suggestive of a cholesterol biosynthesis defect
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