Multitraits evaluation of a Solanum pennellii introgression tomato line challenged by combined abiotic stress

Rising daily temperatures and water shortage are two of the major concerns in agriculture. In this work, we analysed the tolerance traits in a tomato line carrying a small region of the Solanum pennellii wild genome (IL12-4-SL) when grown under prolonged conditions of single and combined high temperature and water stress. When exposed to stress, IL12-4-SL showed higher heat tolerance than the cultivated line M82 at morphological, physiological, and biochemical levels. Moreover, under stress IL12-4-SL produced more flowers than M82, also characterized by higher pollen viability. In both lines, water stress negatively affected photosynthesis more than heat alone, whereas the combined stress did not further exacerbate the negative impacts of drought on this trait. Despite an observed decrease in carbon fixation, the quantum yield of PSII linear electron transport in IL12-4-SL was not affected by stress, thereby indicating that photochemical processes other than CO₂ fixation acted to maintain the electron chain in oxidized state and prevent photodamage. The ability of IL12-4-SL to tolerate abiotic stress was also related to the intrinsic ability of this line to accumulate ascorbic acid. The data collected in this study clearly indicate improved tolerance to single and combined abiotic stress for IL12-4-SL, making this line a promising one for cultivation in a climate scenario characterized by frequent and long-lasting heatwaves and low rainfall.

Myogenesis in C2C12 Cells Requires Phosphorylation of ATF6α by p38 MAPK

Activating transcription factor 6α (ATF6α) is an endoplasmic reticulum protein known to participate in unfolded protein response (UPR) during ER stress in mammals. Herein, we show that in mouse C2C12 myoblasts induced to differentiate, ATF6α is the only pathway of the UPR activated. ATF6α stimulation is p38 MAPK-dependent, as revealed by the use of the inhibitor SB203580, which halts myotube formation and, at the same time, impairs trafficking of ATF6α, which accumulates at the cis-Golgi without being processed in the p50 transcriptional active form. To further evaluate the role of ATF6α, we knocked out the ATF6α gene, thus inhibiting the C2C12 myoblast from undergoing myogenesis, and this occurred independently from p38 MAPK activity. The expression of exogenous ATF6α in knocked-out ATF6α cells recover myogenesis, whereas the expression of an ATF6α mutant in the p38 MAPK phosphorylation site (T166) was not able to regain myogenesis. Genetic ablation of ATF6α also prevents the exit from the cell cycle, which is essential for muscle differentiation. Furthermore, when we inhibited differentiation by the use of dexamethasone in C2C12 cells, we found inactivation of p38 MAPK and, consequently, loss of ATF6α activity. All these findings suggest that the p-p38 MAPK/ATF6α axis, in pathophysiological conditions, regulates myogenesis by promoting the exit from the cell cycle, an essential step to start myoblasts differentiation.

The efficient physiological strategy of a novel tomato genotype to adapt to chronic combined water and heat stress

Climate change is increasing the frequency of high temperature shocks and water shortages, pointing to the need to develop novel tolerant varieties and to understand the mechanisms employed to withstand combined abiotic stresses. Two tomato genotypes, a heat-tolerant Solanum lycopersicum accession (LA3120) and a novel genotype (E42), previously selected as a stable yielding genotype under high temperatures, were exposed to single and combined water and heat stress. Plant functional traits, pollen viability and physiological (leaf gas exchange and chlorophyll a fluorescence emission measurements) and biochemical (antioxidant content and antioxidant enzyme activity) measurements were carried out. A Reduced Representation Sequencing approach allowed exploration of the genetic variability of both genotypes to identify candidate genes that could regulate stress responses. Both abiotic stresses had a severe impact on plant growth parameters and on the reproductive phase of development. Growth parameters and leaf gas exchange measurements revealed that the two genotypes used different physiological strategies to overcome individual and combined stresses, with E42 having a more efficient capacity to utilize the limiting water resources. Activation of antioxidant defence mechanisms seemed to be critical for both genotypes to counteract combined abiotic stresses. Candidate genes were identified that could explain the different physiological responses to stress observed in E42 compared with LA3120. Results here obtained have shown how new tomato genetic resources can be a valuable source of traits for adaptation to combined abiotic stresses and should be used in breeding programmes to improve stress tolerance in commercial varieties.

HepG2 and human healthy hepatocyte in vitro culture and co-culture in PCL electrospun platforms

The discovery of new drugs to treat pathological cells in the case of aggressive liver primary cancer is imposing the identification of high-throughput screening systems to predict the in vivo response of new therapeutic molecules, in order to reduce current use of animals and drug testing costs. Recently, micro/nanostructured scaffolds have been adopted to reproduce the hepatic microenvironment due to their higher similarity to the biological niche with respect to the traditional two-dimensional culture plate, so providing novel in vitro models for reliably understanding molecular mechanisms related to cancer cells activity. Herein, we propose the study of electrospun scaffolds made of polycaprolactone as in vitro model that can mimic the morphological organization of native extracellular matrix and the co-culture of hepatic cell lines-i.e., HepG2, human healthy hepatocytes (HHH). The micro- and nano-scale morphological features of fibers with diameter equal to (3.22 ± 0.42) μm and surface roughness of (17.84 ± 4.43) nm-allow the reproduction of the in vivo scenario influencing the adhesion and proliferation rate of the cultured cells. A much lower proliferation rate is observed for the HepG2 cells compared to the HHH cells, when cultured on the fibrous scaffolds over a time course of 4 weeks. Moreover, results on oxidative stress mechanisms indicate an antioxidant effect of fibers mainly in the case of co-colture, thus suggesting a promising use as new in vitro models to explore alternative therapeutic strategies in hepatocarcinoma treatment.

Navigator® and SmartPilot® View are helpful in guiding anesthesia and reducing anesthetic drug dosing

BACKGROUND

The recently introduced Navigator® (GE Healthcare, Helsinki, Finland) and SmartPilot® View (Dräger Medical, Lübeck, Germany) show the concentrations and predicted effects of combined anesthetic drugs, and should facilitate more precisely their titration. Our aim was to evaluate if Navigator® or SmartPilot® View guided anesthesia was associated with a good quality of analgesia, depth of hypnosis and may reduce anesthetic requirements.

METHODS

We performed a prospective non-randomized study. Sixty ASA I-II patients undergoing balanced general anesthesia for abdominal and plastic surgery were enrolled. Patients were divided in 4 groups. Group 1 (N. 15) and group 3 (N. 15) were cases in whom anesthesia was performed with standard monitoring plus the aid of Navigator® (Nav) or SmartPilot® View (SPV) display. Group 2 (N. 15) and group 4 (N. 15) were controls in whom anesthesia was performed with standard monitoring (heart rate, NIBP, SpO2, end-tidal CO2, end-expired sevoflurane concentration, train of four, Bispectral Index [Aspect Medical Systems, Natick, MA, USA] or Entropy [GE Healthcare]). Patients' vital parameters and end-expired sevoflurane concentration were recorded during anesthesia.

RESULTS

All patients recovered uneventfully and showed hemodynamic stability. End-tidal sevoflurane concentrations values [median (min-max)], during maintenance of anesthesia, were significantly (P<0.05) lower in SPV [1.1% (0.8-1.5)] and Nav [1%(0.8-1.8)] groups compared to SPV-control group [1.5%(1-2.5)] and Nav-control group [1.5%(0.8-2)]. BIS and entropy values were respectively higher in the SPV group [53 (46-57)] compared to the control group [43 (37-51)] (P<0.05) and Nav group [53 (43-60)] compared to the control group [41 (35-51)] (P<0.05). No significant differences in Remifentanil dosing were observed in the four groups.

CONCLUSION

Navigator® and SmartPilot® View may be of clinical use in monitoring adequacy of anesthesia. Both displays can optimize the administration and monitoring of anesthetic drugs during general anesthesia and may reduce the consumption of volatile anesthetic agents.

Femoral and sciatic nerves block (BiBlock) in orthopedic traumatologic lower limbs surgery in patients with multiple sclerosis

Multiple sclerosis is a progressive demyelinating disease which affects large areas of the brain and of the spinal cord. Stressful events, surgical procedures, general anaesthesia and central blocks seem to be responsible for relapses, with worsening of the disease. So, when we scheduled 2 patients with multiple sclerosis for lower limbs orthopedic traumatologic surgery, we decided to use a peripheral block, and in particular a BiBlock. The patients' evaluation in the immediate postoperative course and 30 days after surgery has shown no relapses of the disease. In the literature, however, data about anaesthesia and multiple sclerosis are few and controversial, sometimes in contrast. Anyway, the use of peripheral blocks has neither anatomic, nor metabolic interferences with the lesion sites of multiple sclerosis. In conclusion, peripheral block is safe and it is the technique of choice for this type of patients, when surgery allows it.

Desflurane and sevoflurane in elderly patients during general anesthesia: a double blind comparison

AIM

To investigate pulmonary wash-out of sevoflurane and desflurane and the quality of recovery from anesthesia in elderly patients.

METHODS

Thirty-six patients aged >65 years, ASA II, were assigned in a double blind fashion to either desflurane (n=18) or sevoflurane (n=18) anesthesia. All received propofol 2 mg/kg and remifentanil 0.2 microg/kg/min for induction and 0.6 mg/kg of rocuronium. When the trachea was intubated volatile anaesthetic was administered. All data were recorded 1, 3, 5, 15, 30 min after intubation and then every 15 min. All data were recorded 1, 2, 3, 4, 5 min after suspension of all agents. Once extubated simple orders and questions were given every minute, times of appropriate response were noted. The patients were then transferred to the recovery room, until discharge to the floor. Postoperative pain control was obtained by a continuous iv infusion of ketorolac 60 mg and tramadol 100 mg. The latter was incremented by supplemental boluses of 50 mg according to patient needs (VAS <4) up to a maximum of 300 mg/24h.

RESULTS

The F(A)/F(A0) ratio was lower in the desflurane group after halogenated agent suspension (p= or <0.05). Desflurane proved to have a faster wash out curve with respect to sevoflurane. Early recovery, as indicated by the time necessary to appropriately answer simple questions after the discontinuation of anesthetics, showed a significant advantage for desflurane (p= or <0.05). VAS was higher in the desflurane group as well as the needs for postoperative analgesia.

CONCLUSIONS

Patients receiving desflurane reported faster recovery from anesthesia but an earlier and more intense perception of pain after surgery.

Peri-intubation cardiovascular response during low dose remifentanil or sufentanil administration in association with propofol TCI. A double blind comparison

AIM

The aim of this study was to compare the effects on cardiovascular modifications induced by tracheal intubation when low dose infusion of remifentanil or sufentanil are used in association with propofol target controlled infusion.

METHODS

Sixty normotensive, ASA I-II-III, Mallampati Score <3 undergoing general anaesthesia for major elective abdominal surgery, received i.m. midazolam (0.05 mg/kg) and atropine (0.01 mg/kg) 30 min before induction. They were randomly divided in a double-blind fashion into two groups receiving for induction respectively target controlled infusion of propofol (site-effect 3.0 microg/ml) and sufentanil (0.01 microg/kg/min) or remifentanil (0.1 microg/kg/ min) infusion. Rocuronium (0.6 mg/kg) was administered. Following intubation, the lungs were mechanically ventilated with an oxygen/air mixture.

RESULTS

Bispectral index score and haemodynamic variables were recorded at baseline, after induction, during intubation and 1-3-5 min after the trachea was intubated. No differences in systolic and diastolic arterial pressure were observed in the sufentanil group, while the remifentanil group showed transient systolic and diastolic variations after intubating manoeuvers. The heart rate and bispectral index score were not affected in either group.

CONCLUSION

In healthy normotensive patients the use of a small dose of either remifentanil or sufentanil after standard midazolam premedication, proved to be an effective strategy to blunt the cardiovascular response to intubation.

Anaestethic problems in Sanfilippo syndrome. A rare case of adult patient

The authors report the case of a female patient (41 years old) affected by mucopolysaccharidosis type III or Sanfilippo syndrome submitted to a gynecologic surgical procedure and describe the main anesthesiologic problems. A sub-arachnoid anesthesia with hyperbaric Bupivacain 0.5% was used. This technique proved to be safe and convenient without peri- and postoperative complications.

Small doses of remifentanil and alfetanil in continuous total intravenous anesthesia in major abdominal surgery. A double blind comparison

AIM

The purpose of this study was to test the safety and efficacy of small doses of remifentanil and alfentanil in a continuous total intravenous anesthesia technique for patients undergoing major abdominal surgery.

METHODS

Sixty patients were enrolled in the study, and received in a double blind fashion either remifentanil (0.1 microg/kg/min) or alfentanil (alfentanil 0.75 microg/kg/min) in association with propofol (12 mg/kg/h at induction; 6-9 mg/kg/h for maintenance) and cisatracurium. Hemodynamic data, hypnosis monitoring data (Bispectral Index Score), ventilatory parameters and settings, drug utilisation were monitored during stress moments and during all the intraoperative period. Patients were evaluated also in the first 6 postoperative hours.

RESULTS

Mean amount of propofol for induction (BIS<60) was lower in the remifentanil group than in the alfentanil group. Significantly fewer patients receiving remifentanil responded to intubation in comparison with patients receiving alfentanil in terms of non invasive blood pressure (>30 mmHg) and heart rate variations. Significantly more patients receiving alfentanil had 1 or more responses to surgery. Incidence of hypotension was significantly higher in patients receiving remifentanil. There were no differences between the 2 groups in the times for spontaneous respiration, adequate respiration, adequate responsivness (OAA/s=5) and discharge from the recovery room. Time to extubation resulted slightly shorter (p<0.05) in patients who received remifentanil.

CONCLUSIONS

The use of remifentanil and alfentanil in association with propofol, in a continuous infusion total intravenous anesthesia technique, demonstrated to be safe and reliable strategies.