1,983 research outputs found
Perioperative steroids administration in pediatric cardiac surgery: a meta-analysis of randomized controlled trials
No full textOBJECTIVE:: To evaluate the effects of prophylactic perioperative corticosteroid administration, compared with placebo, on postoperative mortality and clinical outcomes (renal dysfunction, duration of mechanical ventilation, and ICU length of stay) in pediatric patients undergoing cardiac surgery with cardiopulmonary bypass. DATA SOURCES:: MEDLINE and Cochrane Library were screened through August 2013 for randomized controlled trials in which perioperative steroid treatment was adopted. STUDY SELECTION:: Included were randomized controlled trials conducted on pediatric population that reported clinical outcomes about mortality and morbidity. DATA EXTRACTION:: Eighty citations (PubMed, 48 citations; Cochrane, 32 citations) were identified, of which 14 articles were analyzed in depth and six articles fulfilled eligibility criteria and reported mortality data (232 patients), two studies reported ICU length of stay and mechanical ventilation duration (60 patients), and two studies reported renal dysfunction (49 patients). DATA SYNTHESIS:: A nonsignificant trend of reduced mortality was observed in steroid-treated patients (11 [4.7%] vs 4 [1.7%] patients; odds ratio, 0.41; 95% CI, 0.14-1.15; p = 0.089). Steroids had no effects on mechanical ventilation time (117.4 ± 95.9 hr vs 137.3 ± 102.4 hr; p = 0.43) and ICU length of stay (9.6 ± 4.6 d vs 9.9 ± 5.9 d; p = 0.8). Perioperative steroid administration reduced the prevalence of renal dysfunction (13 [54.2%] vs 2 [8%] patients; odds ratio, 0.07; 95% CI, 0.01-0.38; p = 0.002). CONCLUSION:: Despite a demonstrated attenuation of cardiopulmonary bypass-induced inflammatory response by steroid administration, a systematic review of randomized controlled trials performed so far reveals that steroid administration has potential clinical advantages (lower mortality and significant reduction of renal function deterioration). A larger prospective randomized study is needed to verify clearly the effects of steroid prophylaxis in pediatric patients. Copyright © 2014 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies
Iron entry in neurons and astrocytes: a link with synaptic activity
No full textIron plays a fundamental role in the development of the central nervous system (CNS) as well as in several neuronal functions including synaptic plasticity. Accordingly, neuronal iron supply is tightly controlled: it depends not only on transferrin-bound iron but also on non-transferrin-bound iron (NTBI), which represents a relevant quote of the iron physiologically present in the cerebrospinal fluid (CSF). Different calcium permeable channels as well as the divalent metal transporter 1 (DMT1) have been proposed to sustain NTBI entry in neurons and astrocytes even though it remains an open issue. In both cases, it emerges that the control of iron entry is tightly linked to synaptic activity. The iron-induced oxidative tone can, in physiological conditions, positively influence the calcium levels and thus the synaptic plasticity. On the other hand, an excess of iron, with the ensuing uncontrolled production of reactive oxygen species (ROS), is detrimental for neuronal survival. A protective mechanism can be played by astrocytes that, more resistant to oxidative stress, can uptake iron, thereby buffering its concentration in the synaptic environment. This competence is potentiated when astrocytes undergo activation during neuroinflammation and neurodegenerative processes. In this minireview we focus on the mechanisms responsible for NTBI entry in neurons and astrocytes and on how they can be modulated during synaptic activity. Finally, we speculate on the relevance they may have in both physiological and pathological conditions
Coma and respiratory failure in a child with severe vitamin B(12) deficiency
No full textOBJECTIVE: Psychofunctional follow-up of severe vitamin B(12) deficit. DESIGN: Case report. SETTING: Pediatric intensive care unit. Patient: Ten-month-old boy. INTERVENTION: Follow-up at 3 yrs. MEASUREMENTS AND MAIN RESULTS: A 10-month-old boy was admitted to the pediatric intensive care unit with respiratory failure, muscular hypotonia, and involuntary movements. Although a central nervous system infection was excluded, computed tomography scan showed a diffuse cortical-subcortical atrophy. Vitamin B(12) deficiency was suspected because of a red-cell count of 1,350,000/mm(3) and a hemoglobin value 5.9 g/dL (MCV 116). The baby had been exclusively breast-fed, but his mother had been a strict vegan for 10 yrs. Chronic dietary vitamin B(12) deprivation was confirmed by blood and urinary samples. Treatment with vitamin B(12) led in 2 wks to rapid and complete hematological improvement and to partial regression of neurologic symptoms. During the following 3 yrs the boy had normal vitamin intake and underwent intensive rehabilitative treatment. The brain atrophy regressed, but linguistic and psychomotor delay persisted. CONCLUSIONS: Rapid clinical improvement after vitamin supply does not correlate with a complete recovery
The Nasolabial Flap in Nose Reconstruction: Tips and Tricks Towards Expanded Usage and Optimized Cosmesis
No full textBackground: The nose is the most critical aesthetic element of the face and even the smallest loss of substance can create a deformity of concern. The forehead flap has been the workhorse for nasal reconstruction for centuries but requires multiple surgical steps and leads to prominent donor-site scarring. The nasolabial flap allows a single-step reconstruction with a donor-site scar concealed in the nasolabial crease but is conventionally designated for small defects involving the ala. Methods: The authors analysed all surgical records of patients undergone nasal reconstruction by nasolabial flap between May 2005 and December 2021 by the Plastic Surgery Unit of a major regional hospital in Lombardy. Defects were classified according to Burget's subunit principle and the 3-component approach. Reconstruction features and finesses were reported and analysed. Results: In the 16-year period under analysis, 378 patients with nasal defects of various aetiologies received nose reconstruction by nasolabial flap. All nasal subunits were involved; 20 patients had multisubunit defects. In all the cases the reconstruction with nasolabial flap, alone or combined with other solutions, was intended to be one-stage. Conclusions: The authors present several tips and tricks about preoperative planning and design, choice of the pedicle, flap harvesting and sculpting with preservation/restoration of grooves and convexities, conjoining multiple flaps, downsizing extensive defects by a rhinoplasty-like framework reduction. With a careful planning and refined technique, the range of application of the nasolabial flap can include defects involving any nasal subunit and larger and/or multisubunit defects
Real hypersurfaces with Reeb Jacobi operator of Codazzi type in the complex hyperbolic two-plane Grassmannians
No full textUtilizing the concept of Reeb Jacobi operator of Codazzi type, we investigate Hopf real hypersurfaces in the complex hyperbolic two-plane Grassmannian which admit a constant Reeb function α along the Reeb direction of ξ. If the Reeb function α is constant along the Reeb direction, then the Reeb vector field either belongs to the distribution or the distribution . By virtue of this fact, we have proved a new result about Reeb Jacobi operator of Codazzi type according to the Reeb vector field or , respectively
Effect of infusion and withdrawl of glucose and insulin on gas exchange in injured ventilated patients
No full textTo evaluate the effect induced on gas exchange and on urea excretion by glucose and insulin infusion in injured patients. The magnitude and time necessary for the full development of the metabolic effect were investigated.
Six injured patients were investigated. During the first 24 hours, the fasting period, patients received 1 mg/kg∗min of glucose; during the second 24 hours, the treatment period, infusion was increased to about the 95% of the energy production rate; during the last 8 hours, (stop period) the infusion rate was again set to 1 mg/kg∗min. Gas exchange was determined in two consecutive 12-hour series, for 30 minutes every hour, either during a stabilized treatment or after its variation. Urea excretion was determinated on 4-hour samples.
With respect to the fasting period, during the last 4 hours of the treatment period, the energy production rate did not vary; urea excretion (−25%) and oxygen consumption (−9%) decreased significantly. Carbon dioxide production (+16%), total respiratory quotient, and minute ventilation (+5%) increased significantly. Carbon dioxide production varied linearly with time (glucose infusion +1.74 mL/min∗m2∗h, P <.05; glucose withdrawal −1.89 mL/min∗m2∗h, P < .01). Minute ventilation decreased only during the withdrawal period by 65 mL/ min∗m2∗h (P < .05).
The infusion of glucose and insulin, in an amount slightly lower than the metabolic expenditure, leads to a consistently reduced amino acid catabolism and to a decreased oxygen consumption, without affecting energy requirements. Although it leads to an increase of carbon dioxide production, the measured change is so small and slow that it is not harmful unless there is severe respiratory insufficienc
Translational regulation of BACE-1 expression in neuronal and non-neuronal cells
No full textAs the main beta-secretase of the central nervous system, BACE-1 is a key protein in the pathogenesis of Alzheimer's disease. Excessive expression of the protein might cause an overproduction of the neurotoxic beta-amyloid peptide. Therefore, a tight regulation of BACE-1 expression is expected in vivo. In addition to a possible transcriptional control, the BACE-1 transcript leader contains features that might constitute mechanisms of translational regulation of protein expression. Moreover, recent work has revealed an increase of BACE-1 protein and beta-secretase activity in some Alzheimer's disease patients, although a corresponding increase of transcript has not been reported. Here we show that BACE-1 translation could be modulated at multiple stages. The presence of several upstream ATGs strongly reduces the translation of the main open reading frame. This inhibition could be overcome with conditions that favour skipping of upstream ATGs. We also report an alternative splicing of the BACE-1 transcript leader that reduces the number of upstream ATGs. Finally, we show that translation driven by the BACE-1 transcript leader is increased in activated astrocytes independently of the splicing event, indicating yet another mechanism of translational control. Our findings might explain why increases in BACE-1 protein or activity are reported in the brain of Alzheimer's disease patients even in the absence of changes in transcript levels
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