Isolation of 2-ethyl-3-methylmaleimide N-β-D-glucopyranoside from Riesling wine

A glycosidic isolate of Riesling urine was separated with multilayer coil countercurrent chromatography (MLCCC). After acetylation and subsequent purification by high performance liquid chromatography (HPLC), the N-beta-D-glucopyranoside of 2-ethyl-3-methylmaleimide (3-ethyl-4-methyl-1H-pyrrole-2,5-dione) 2 was identified for the first time as natural wine constituent. The identification was carried out by mass spectrometry (EI-MS, DCI-MS) as well as nuclear magnetic resonance spectroscopy (H-1 NMR, 13C NMR, COSY, HMBC)

Isolation of the glucose ester of (E)-2,6-dimethyl-6-hydroxyocta-2,7-dienoic acid from Riesling wine

A glycosidic isolate of Riesling wine was separated with multilayer coil countercurrent chromatography (MLCCC). After acetylation and subsequent purification by high performance liquid chromatography (HPLC), the glucose ester of (E)-2,6-dimethyl-6-hydroxyocta-2,7-dienoic acid (linalool-8-carboxylic acid) 1 was identified for the first time as natural wine constituent. The possible role of I as wine aroma precursor is discussed

Effects of acute and sub-chronic ammonium nitrate exposure on rat liver and blood tissues

Use of fertilizers like ammonium nitrate (NH4NO3) for agricultural purposes has increasingly contaminated the ecosystem with nitrate and/or nitrites. Nitrite is a toxic substance that can cause multiple physiological effects if allowed to build up to high concentrations in animals such as methemoglobinemia. This work is concerned with the study of short term (3 days intoxication) and midterm (over 21 days) NH4NO3 exposure to wistar rats at the dose of 250 mg/Kg. Under these conditions, some hematological and biochemical parameters were affected. Methemoglobinemia, increase in serum nitrates as well as a hepatic cytotoxicity indicated by an increase in bilirubin and transaminases levels were observed

Dualsteric compounds modulate the signaling pattern of muscarinic M1 acetylcholine receptors

G protein-coupled receptors (GPCRs) are cell surface receptors which, upon a conformational change in the receptor protein induced by an extracellular stimulus, can transduce the signal onto intracellular adaptor proteins such as heterotrimeric G proteins [1]. GPCR-induced cell signaling can be rather complex as several GPCRs may activate multiple different adaptor proteins and can additionally be activated via distinct binding sites, i.e. the orthosteric transmitter binding site and other \u201callosteric\u201d binding sites [2]. In the present work, we wanted to investigate the influence of an allosteric binding site on receptor activation of muscarinic acetylcholine receptors (mAChRs). To this end, we employed the orthosteric full agonists acetylcholine and iperoxo as well as several dualsteric compounds consisting of iperoxo linked to an allosteric phthalimide (phth) or naphthalimide (naph) moiety through alkyl chains of different length or through a diamide linker (fri). Binding of the allosteric part to the receptor protein may restrict the conformational flexibility of the receptor protein and thus interfere with receptor activation [2]. Therefore, application of different linker length may control the signaling outcome. Here, we applied the human M1 mAChR which preferentially activates G proteins of the Gq/11 type but can also promiscuously stimulate Gs proteins. Gq/11- and Gs- dependent signaling pathways were analyzed by application of CHO cells stably transfected with the human M1 mAChR in IP1 and cAMP accumulation assays, respectively. In comparison to the orthosteric building block iperoxo, all dualsteric compounds under investigation showed a decrease in potency for both Gq-mediated and Gs-mediated signaling. Our findings show that the bulkier allosteric naph residue impaired both signaling pathways to a greater extent than the smaller substituent phth. Particularly, the compound iper-6-naph completely lost intrinsic activity for both Gq/11 and Gs activation at the M1 mAChR. Moreover, Gs-mediated pathway activation is more sensitive to spatial restriction in the allosteric vestibule than Gq-signaling. Interestingly, longer linker length led to improved signaling for both pathways (Gq and Gs) in both hybrid series. Iper-7-phth seems to be an exception as it had a higher intrinsic efficacy for Gs-dependent signaling than the other phth hybrids with longer linker chains. Strikingly, only iper-fri-phth, which corresponds to iper-8-phth in linker length, but is able to engage increased hydrogen bonding with the receptor protein, acted as a full agonist on M1 mAChR for both signaling pathways under investigation. Taken together, these data strongly suggest that, in comparison to Gq/11-mediated signaling, activation of the Gs protein in M1 mAChR is more sensitive to spatial restriction in the allosteric vestibule. Thus, it appears to be possible to control signaling of the M1 mAChR by allosteric constraint of the receptor\u2019s conformational flexibility. [1] Magalhaes, A. et al.: Br. J. Pharmacol. 2011, 165(6): 1717-36 [2] Bock, A. et al.: Nat. Commun. 2012, 3:1044 doi: 10.1038/ncomms202

Update on Neoadjuvant and Adjuvant BRAF Inhibitors in Papillary Craniopharyngioma: A Systematic Review.

Background/Objectives: The recent discovery of BRAF mutation in papillary craniopharyngiomas opened new avenues for targeted therapies to control tumour growth, decreasing the need for invasive treatments and relative complications. The aim of this systematic review was to summarize the recent scientific data dealing with the use of targeted therapies in papillary craniopharyngiomas, as adjuvant and neoadjuvant treatments. Methods: The PRISMA guidelines were followed with searches performed in Scopus, MEDLINE, and Embase, following a dedicated PICO approach. Results: We included 21 pertinent studies encompassing 53 patients: 26 patients received BRAF inhibitors (BRAFi) as adjuvant treatment, while 25 received them as neoadjuvant treatment. In the adjuvant setting, BRAFi were used to treat recurrent tumours after surgery or adjuvant radiation therapy. The most common regimen combined dabrafenib (BRAFi) with trametinib (MEK1 and 2 inhibitor) in 81% of cases. The mean treatment length was 8.8 months (range 1.6 to 28 months) and 32% were continuing BRAFi. A reduction of tumour volume variable from 24% to 100% was observed at cerebral MRI during treatment and volumetric reduction ≥80% was described in 64% of cases. Once the treatment was stopped, adjuvant treatments were performed to stabilize patients in remission in 11 cases (65%) or when a progression was detected in three cases (12%). In four cases no further therapies were administered (16%). Mean follow-up after the end of targeted therapy was 17.1 months. As neoadjuvant regimen, 36% of patients were treated with dabrafenib and trametinib with a near complete radiological response in all the cases with a mean treatment of 5.7 months. The neoadjuvant use of verumafenib (BRAFi) and cometinib (MEK1 inhibitor) induced a near complete response in 15 patients (94%), with a median volumetric reduction between 85% and 91%. Ten patients did not receive further treatments. Side effects varied among studies. The optimal timing, sequencing, and duration of treatment of these new therapies should be established. Moreover, questions remain about the choice of specific BRAF/MEK inhibitors, the optimal protocol of treatment, and the strategies for managing adverse events. Conclusions: Treatment is shifting to a wider multidisciplinary management, where a key role is played by targeted therapies, to improve outcomes and quality of life for patients with BRAF-mutated craniopharyngiomas. Future, larger comparative trials will optimize their protocol of use and integration into multimodal strategies of treatment

Liposomal irinotecan: formulation development and therapeutic assessment in murine xenograft models of colorectal cancer

ABSTRACT Purpose: The purpose is to demonstrate whether an appropriately designed liposomal formulation of irinotecan is effective in treating mice with liver-localized colorectal carcinomas. Experimental Design: Irinotecan was encapsulated in 1,2-distearoyl-sn-glycero-3-phosphocholine/cholesterol (55:45 molar ratio) liposomes using an ionophore (A23187)-generated transmembrane proton gradient. This formulation was evaluated in vivo by measuring plasma elimination of liposomal lipid and drug after i.v. administration. Therapeutic activity was determined in SCID/Rag-2M mice bearing s.c. LS180 tumors or orthotopic LS174T colorectal metastases. Results: Drug elimination from the plasma was significantly reduced when irinotecan was administered in the liposomal formulation. At 1 hour after i.v. administration, circulating levels of the liposomal drug were 100-fold greater than that of irinotecan given at the same dose. High-performance liquid chromatographic analysis of plasma samples indicated that liposomal irinotecan was protected from inactivating hydrolysis to the carboxylate form. This formulation exhibited substantially improved therapeutic effects. For the LS180 solid tumor model, it was shown that after a single injection of liposomal irinotecan at 50 mg/kg, the time to progress to a 400-mg tumor was 34 days (as compared with 22 days for animals treated with free drug at an equivalent dose). In the model of colorectal liver metastases (LS174T), a median survival time of 79 days was observed after treatment with liposomal irinotecan (50 mg/kg, given every 4 days for a total of three doses). Saline and free drug treated mice survived for 34 and 53 days, respectively. Conclusions: These results illustrate that liposomal encapsulation can substantially enhance the therapeutic activity of irinotecan and emphasize the potential for using liposomal irinotecan to treat liver metastases

Ventilation strategies and risk factors for intraoperative respiratory critical events and postoperative pulmonary complications in neonates and small infants: a secondary analysis of the NECTARINE cohort

BACKGROUND: Optimal ventilation strategies and use of neuromuscular blocking agents (NMBAs) in neonates and small infants undergoing anaesthesia remain unclear. We examined the association of perioperative ventilation strategies and administration of NMBAs on respiratory adverse events in the NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) cohort. METHODS: We performed a secondary analysis of NECTARINE, which included infants up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures. The primary endpoint was the association between ventilation mode and intraoperative respiratory adverse events. Secondary endpoints were use of NMBA, and 30-day postoperative pulmonary complications (PPCs). RESULTS: The dataset comprised 5609 patients undergoing 6542 procedures. Pressure-controlled ventilation was the primary ventilation modality, accounting for 52.4% (n=3428) of cases. The incidence of intraoperative respiratory critical events was 20.7% (95% confidence interval [CI] 19.7–21.7%), while PPCs were observed in 17% of cases (95% CI 16.0–18.1%). Preanaesthesia respiratory conditions and NMBA use after tracheal intubation were associated with higher incidence of PPCs. Of the children receiving NMBAs, reversal was reported in 29.8%. The absence of reversal was associated with a higher incidence of PPCs, with a relative risk of 1.50 (95% CI 1.17–1.93). Conversely, NMBA reversal was associated with a reduced relative risk of 0.43 (95% CI 0.26–0.70). CONCLUSIONS: Regardless of ventilation strategy used, mechanical ventilation and baseline respiratory conditions were risk factors for a greater incidence of adverse respiratory events and PPCs. Reversal of NMBAs before tracheal extubation was significantly associated with reduced PPCs in neonates and should be routine clinical practice. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT02350348

Difficult tracheal intubation in neonates and infants. NEonate and Children audiT of Anaesthesia pRactice IN Europe (NECTARINE): a prospective European multicentre observational study

Background: Neonates and infants are susceptible to hypoxaemia in the perioperative period. The aim of this study was to analyse interventions related to anaesthesia tracheal intubations in this European cohort and identify their clinical consequences. Methods: We performed a secondary analysis of tracheal intubations of the European multicentre observational trial (NEonate and Children audiT of Anaesthesia pRactice IN Europe [NECTARINE]) in neonates and small infants with difficult tracheal intubation. The primary endpoint was the incidence of difficult intubation and the related complications. The secondary endpoints were the risk factors for severe hypoxaemia attributed to difficult airway management, and 30 and 90 day outcomes. Results: Tracheal intubation was planned in 4683 procedures. Difficult tracheal intubation, defined as two failed attempts of direct laryngoscopy, occurred in 266 children (271 procedures) with an incidence (95% confidence interval [CI]) of 5.8% (95% CI, 5.1e6.5). Bradycardia occurred in 8% of the cases with difficult intubation, whereas a significant decrease in oxygen saturation (SpO2<90% for 60 s) was reported in 40%. No associated risk factors could be identified among comorbidities, surgical, or anaesthesia management. Using propensity scoring to adjust for confounders, difficult anaesthesia tracheal intubation did not lead to an increase in 30 and 90 day morbidity or mortality. Conclusions: The results of the present study demonstrate a high incidence of difficult tracheal intubation in children less than 60 weeks post-conceptual age commonly resulting in severe hypoxaemia. Reassuringly, the morbidity and mortality at 30 and 90 days was not increased by the occurrence of a difficult intubation event. Clinical trial registration: NCT02350348

Endoscopic versus microscopic transsphenoidal surgery in the treatment of pituitary tumors: systematic review and meta-analysis of randomized and non-randomized controlled trials

ABSTRACT We conducted a systematic review and meta-analysis of randomized and non-randomized controlled trials that compared pure endoscopic with microscopic transsphenoidal surgery (TSS) in the resection of pituitary tumors. Embase, PubMed, Lilacs, and Central Cochrane were used as our data sources. The outcomes were total tumor resection, achievement of biochemical control of functioning adenomas, hospital stay and surgery complications. The randomized trials were analyzed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Two randomized and three prospective controlled non-randomized studies were included. Two studies, including 68 patients, evaluated total tumor resection and the meta-analysis did not show differences between the groups [RR: 1.45 (95% CI: 0.87, 2.44)]. Three studies involving 65 patients analyzed the achievement of biochemical control and no statistical difference was found [RR: 0.94 (95% CI: 0.7, 1.26)]. All five studies compared the frequency of postoperative complications between intervention and control group and meta-analysis favored for a low rate of postoperative complications in the endoscopic TSS group [(RR: 0.37 (95% CI: 0.16, 0.83)]. Due to the low evidence level and low number of observations, the results of our meta-analysis should not be viewed as a final proof of inferiority or superiority of one approach in relation to the other. More data including higher numbers of observations are needed