Cytotoxic Pt(II) complexes containing alizarin: a selective carrier for DNA metalation

Many efforts have been made in the last few decades to selectively transport antitumor agents to their potential target sites with the aim to improve efficacy and selectivity. Indeed, this aspect could greatly improve the beneficial effects of a specific anticancer agent especially in the case of orphan tumors like the triple negative breast cancer. A possible strategy relies on utilizing a protective leaving group like alizarin as the Pt(II) ligand to reduce the deactivation processes of the pharmacophore enacted by Pt resistant cancer cells. In this study a new series of neutral mixed-ligand Pt(II) complexes bearing alizarin and a variety of diamine ligands were synthesized and spectroscopically characterized by FT-IR, NMR and UV-Vis analyses. Three Pt(II) compounds, i.e., 2b, 6b and 7b, emerging as different both in terms of structural properties and cytotoxic effects (not effective, 10.49 ± 1.21 μM and 24.5 ± 1.5 μM, respectively), were chosen for a deeper investigation of the ability of alizarin to work as a selective carrier. The study comprises the in vitro cytotoxicity evaluation against triple negative breast cancer cell lines and ESI-MS interaction studies relative to the reaction of the selected Pt(II) complexes with model proteins and DNA fragments, mimicking potential biological targets. The results allow us to suggest the use of complex 6b as a prospective anticancer agent worthy of further investigations.

Highly efficient morpholine-based organocatalysts for the 1,4-addition reaction between aldehydes and nitroolefins: an unexploited class of catalysts

Many studies have demonstrated how the pyrrolidine nucleus is more efficient than the corresponding piperidine or morpholine as organocatalysts in the condensation of aldehydes with electrophiles via enamine. Focussing on morpholine-enamines, their low reactivity is ascribed to the presence of oxygen on the ring and to the pronounced pyramidalisation of nitrogen, decreasing the nucleophilicity of the enamine. Thus, the selection of efficient morpholine organocatalysts appears to be a difficult challenge. Herein, we reported on the synthesis of new organocatalysts belonging to the class of ß-morpholine amino acids that were tested in a model reaction, i.e., the 1,4-addition reaction of aldehydes to nitroolefins. Starting from commercially available amino acids and epichlorohydrin, we designed an efficient synthesis for the aforementioned catalysts, controlling the configuration and the substitution pattern. Computational studies indeed disclosed the transition state of the reaction, explaining why, despite all the limitations of the morpholine ring for enamine catalysis, our best catalyst works efficiently, affording condensation products with excellent yields, diastereoselection and good-to-exquisite enantioselectivity.

The Challenging Treatment of Cisplatin-Resistant Tumors: State of the Art and Future Perspectives

One of the main problems in chemotherapy using platinum drugs as anticancer agents is the resistance phenomenon. Synthesizing and evaluating valid alternative compounds is challenging. This review focuses on the last two years of progress in the studies of platinum (II)- and platinum (IV)-based anticancer complexes. In particular, the research studies reported herein focus on the capability of some platinum-based anticancer agents to bypass resistance to chemotherapy, which is typical of well-known drugs such as cisplatin. Regarding platinum (II) complexes, this review deals with complexes in trans conformation; complexes containing bioactive ligands, as well as those that are differently charged, all experience a different reaction mechanism compared with cisplatin. Regarding platinum (IV) compounds, the focus was on complexes with biologically active ancillary ligands that exert a synergistic effect with platinum (II)-active complexes upon reduction, or those for which controllable activation can be realized thanks to intracellular stimuli.

Enhancing Pt (IV) Complexes Anticancer Activity Upon Encapsulation in Stimuli Responsive Nanocages

Platinum-based chemotherapy is the first-line treatment for different cancer types and in particular for malignant pleural mesothelioma patients (a tumor histotype with urgent medical needs). Herein we present a strategy to stabilize, transport and intracellular release of a platinum^IV (Pt^IV ) prodrug using a breakable nanocarrier. Its reduction, and therefore activation as anticancer drug, is promoted by the presence of glutathione in neoplastic cells that also causes the destruction of the carrier. The nanocage presents a single internal cavity in which the hydrophobic complex (Pt(dach)Cl₂ (OH)₂ ), (dach = R,R-diaminocyclohexane) has been encapsulated. We have evaluated the in vitro uptake and the internalization kinetics in cancer model cells and using flow cytometry analysis, demonstrated the successful release and activation of the Pt based drug inside cancer cells. The in vitro findings were confirmed by the in vivo experiments on a mice model obtained by xenografting MPM487, a patient-derived malignant pleural mesothelioma. MPM487 confirmed the well-known resistance of malignant pleural mesothelioma to cisplatin treatment while an interesting 50% reduction of tumor growth was observed when mice were treated with the Pt^IV , entrapped in the nanocages, at an equivalent dose of platinum complex. This article is protected by copyright. All rights reserved.

Chiral 8-Amino-5,6,7,8-tetrahydroquinoline Derivatives in Metal Catalysts for the Asymmetric Transfer Hydrogenation of 1-Aryl Substituted-3,4-dihydroisoquinolines as Alkaloids Precursors

Chiral diamines based on an 8-amino-5,6,7,8-tetrahydroquinoline backbone, known as CAMPY (L1), or the 2-methyl substituted analogue Me-CAMPY (L2) were employed as novel ligands in Cp* metal complexes for the ATH of a series of substituted dihydroisoquinolines (DHIQs), known for being key intermediates in the synthesis of biologically active alkaloids. Different metal-based complexes were evaluated in this kind of reaction, rhodium catalysts, C3 and C4, proving most effective both in terms of reactivity and enantioselectivity. Although modest enantiomeric excess values were obtained (up to 69% ee in the case of substrate I), a satisfactory quantitative conversion was successfully fulfilled even in the case of the most demanding hindered substrates when La(OTf)₃ was used as beneficial additive, opening up the possibility for a rational design of novel chiral catalysts alternatives to the Noyori-Ikariya (arene)Ru(II)/TsDPEN catalyst.

Cytotoxicity of Alizarine versus Tetrabromocathecol Cyclometalated Pt(II) Theranostic Agents: A Combined Experimental and Computational Investigation

Platinum compounds cytotoxicity is strictly related to their ability to be converted into active mono- and di-aquated species and consequently to the replacement of labile ligands by water molecules. This activation process makes the platinum center prone to nucleophilic substitution by DNA purines. In the present work, quantum mechanical density functional theory (DFT) computations and experimental investigations were carried out in order to shed light on the relationship between the internalization, aquation, and DNA binding of two isostructural anionic theranostic complexes previously reported by our group, NBu₄[(PhPy)Pt(Aliz)], 1 (IC₅₀ 1.9 ± 1.6 μM), and NBu₄[(PhPy)Pt(BrCat)], 2 (IC₅₀ 52.8 ± 3.9 μM). Cisplatin and a neutral compound [(NH₃)₂Pt(Aliz)], 3, were also taken as reference compounds. The computed energy barriers and the endergonicity of the hydrolysis reactions showed that the aquation rates are comparable for 1 and 2, with a slightly higher reactivity of 1. The second hydrolysis process was proved to be the rate-determining step for both 1 and 2, unlike for compound 3. The nucleophilic attack by the N7 site of guanine to both mono- and di-aquated forms of the complexes was computationally investigated as well, allowing to rationalize the observed different cytotoxicity. Computational results were supported by photostability data and biological assays, demonstrating DNA as the main target for compound 1.

An experimental−theoretical approach to study the cytotoxicity of ionic Pt(II) complexes containing (O^O) chelating ancillary ligands.

Curcumin-based ionic Pt(ii) complexes: antioxidant and antimicrobial activity

Four new Pt(ii) ionic complexes assembled from N-donor ligands and curcumin display interesting antioxidant and antimicrobial properties.

In Vitro Activity of Monofunctional Pt-II Complex Based on 8-Aminoquinoline against Human Glioblastoma

A new cationic Pt(II) complex bearing 8-aminoquinoline as chelating ligand (called Pt-8AQ) was evaluated against two human carcinomas, one mesothelioma, and three glioblastoma cell lines. The in vitro comparison to the clinically approved CisPt showed a minor activity of Pt-8AQ against carcinoma and mesothelioma, whereas a significant activity of Pt-8AQ was observed on the proliferation of the three glioblastoma cell lines (U87-MG IC₅₀ = 3.68 ± 0.69 µM; U373-MG IC₅₀ = 11.53 ± 0.16 µM; U138-MG IC₅₀ = 8.05 ± 0.23 µM) that was higher than that observed with the clinically approved CisPt (U87-MG IC₅₀ = 7.27 + 1.80 µM; U373-MG IC₅₀ = 22.69 ± 0.05 µM; U138-MG IC₅₀ = 32.1 ± 4.44 µM). Cell cycle analysis proved that Pt-8AQ significantly affected the cell cycle pattern by increasing the apoptotic cells represented by the sub G0/G1 region related with a downregulation of p53 and Bcl-2. Moreover, an NMR investigation of Pt-8AQ interaction with 9-EtG, GSH, and Mets7 excluded DNA as the main target, suggesting a novel mechanism of action. Our study demonstrated the high stability of Pt-8AQ after incubation at 37 °C and a significant antineoplastic activity on glioblastomas. These features also make Pt-8AQ a good candidate for developing a new selective advanced cell chemotherapy approach in combination with MSCs.

Promising Non-cytotoxic Monosubstituted Chalcones to Target Monoamine Oxidase-B

A library of monosubstituted chalcones (1-17) bearing electron-donating and electron-withdrawing groups on both aromatic rings were selected. The cell viability on human tumor cell lines was evaluated first. The compounds unable to induce detectable cytotoxicity (1, 13, and 14) were tested using the monoamine oxidase (MAO) activity assay. Interestingly, they inhibit MAO-B, acting as competitive inhibitors, with 13 and 14 showing the best profiles. In particular, 13 exhibited a potency higher than that of safinamide, taken as a reference. Docking studies and crystallographic analysis showed that in human MAO-B 13 binds with the halogen-substituted aromatic ring in the entrance cavity, similar to safinamide, whereas 14 is accommodated in the opposite way. The main conclusion of this cell biology, biochemistry, and structural study is to highlights 13 as a chalcone derivative that is worth consideration for the development of novel MAO-B-selective inhibitors for the treatment of neurodegenerative diseases.

Alternative Strategy to Obtain Artificial Imine Reductase by Exploiting Vancomycin/D-Ala-D-Ala Interactions with an Iridium Metal Complex

Based on the supramolecular interaction between vancomycin (Van), an antibiotic glycopeptide, and D-Ala-D-Ala (DADA) dipeptides, a novel class of artificial metalloenzymes was synthesized and characterized. The presence of an iridium(III) ligand at the N-terminus of DADA allowed the use of the metalloenzyme as a catalyst in the asymmetric transfer hydrogenation of cyclic imines. In particular, the type of link between DADA and the metal-chelating moiety was found to be fundamental for inducing asymmetry in the reaction outcome, as highlighted by both computational studies and catalytic results. Using the [IrCp*(m-I)Cl]Cl ⊂ Van complex in 0.1 M CH₃COONa buffer at pH 5, a significant 70% (S) e.e. was obtained in the reduction of quinaldine B.

New sp3 diphosphine-based rhodium catalysts for the asymmetric conjugate addition of aryl boronic acids to 3-azaarylpropenones

The new diphosphine (R,R)-EPHOS featuring a stereogenic sp3 carbon combined with a C2 axial chirality was applied to the Rh-catalyzed asymmetric 1,4 addition of aryl boronic acids to 3-azaarylpropenones, affording the product with e.e. up to 94%.

Biological Properties of New Chiral 2-Methyl-5,6,7,8-tetrahydroquinolin-8-amine-based Compounds

The synthesis of a small library of 8-substituted 2-methyl-5,6,7,8-tetrahydroquinoline derivatives is presented. All the compounds were tested for their antiproliferative activity in non-cancer human dermal microvascular endothelial cells (HMEC-1) and cancer cells: human T-lymphocyte cells (CEM), human cervix carcinoma cells (HeLa), human dermal microvascular endothelial cells (HMEC-1), colorectal adenocarcinoma (HT-29), ovarian carcinoma (A2780), and biphasic mesothelioma (MSTO-211H). Compounds 3a, 5a, and 2b, showing significant IC₅₀ values against the whole panel of the selected cells, were further synthesized and tested as pure enantiomers in order to shed light on how their stereochemistry might impact on the related biological effect. The most active compound (R)-5a was able to affect cell cycle phases and to induce mitochondrial membrane depolarization and cellular ROS production in A2780 cells.

Exploring the copper binding ability of Mets7 hCtr-1 protein domain and His7 derivative: An insight in Michael addition catalysis

Mets7 is a methionine-rich motif present in hCtr-1 transporter that is involved in copper cellular trafficking. Its ability to bind Cu(I) was recently exploited to develop metallopeptide catalysts for Henry condensation. Here, the catalytic activity of Mets7-Cu(I) complex in Michael addition reactions has been evaluated. Furthermore, His7 peptide, in which Met residues have been substituted with His ones, was also prepared. This substitution allowed His7 to coordinate Cu (II), with the obtainment of a stable turn conformation as evicted by CD experiments. His7-Cu (II) proved also to be a better catalyst than Mets7-Cu(I) in the addition reaction. In particular, when the substrate was the (E)-1-phenyl-3-(pyridin-2-yl)prop-2-en-1-one, a conversion of 71% and a significative 58% of e.e. was observed.

Antiproliferative effects of chalcones on T cell acute lymphoblastic leukemia-derived cells: Role of PKCβ

In this study, a series of 20 chalcone derivatives was synthesized, and their antiproliferative activity was tested against the human T cell acute lymphoblastic leukemia-derived cell line, CCRF-CEM. On the basis of the structural features of the most active compounds, a new library of chalcone derivatives, according to the structure-activity relationship design, was synthesized, and their antiproliferative activity was tested against the same cancer cell line. Furthermore, four of these derivatives (compounds 3, 4, 8, 28), based on lower IC₅₀ values (between 6.1 and 8.9 μM), were selected for further investigation regarding the modulation of the protein expression of RACK1 (receptor for activated C kinase), protein kinase C (PKC)α and PKCβ, and their action on the cell cycle level. The cell cycle analysis indicated a block in the G0/G1 phase for all four compounds, with a statistically significant decrease in the percentage of cells in the S phase, with no indication of apoptosis (sub-G0/G1 phase). Compounds 4 and 8 showed a statistically significant reduction in the expression of PKCα and an increase in PKCβ, which together with the demonstration of an antiproliferative role of PKCβ, as assessed by treating cells with a selective PKCβ activator, indicated that the observed antiproliferative effect is likely to be mediated through PKCβ induction.

Vancomycin-Iridium (III) Interaction: An Unexplored Route for Enantioselective Imine Reduction

The chiral structure of antibiotic vancomycin (Van) was exploited as an innovative coordination sphere for the preparation of an IrCp* based hybrid catalysts. We found that Van is able to coordinate iridium (Ir(III)) and the complexation was demonstrated by several analytical techniques such as MALDI-TOF, UV, Circular dichroism (CD), Raman IR, and NMR. The hybrid system so obtained was employed in the Asymmetric Transfer Hydrogenation (ATH) of cyclic imines allowing to obtain a valuable 61% e.e. (R) in the asymmetric reduction of quinaldine 2. The catalytic system exhibited a saturation kinetics with a calculated efficiency of K_cat/K_M = 0.688 h⁻¹mM⁻¹.

Application of different laboratory techniques to monitor the behaviour of a Mycoplasma synoviae vaccine (MS-H) in broiler breeders

Background

Mycoplasma synoviae (MS) is a major poultry pathogen which causes severe economic losses in all the productive sectors. The prevalence of MS in European countries has increased in the last few years, leading to greater attention to the available methods to prevent its spread. The main strategy currently applied for its containment is the development and maintenance of MS-free breeder flocks. A live MS vaccine (MS-H) obtained by mutagenizing an Australian field strain has recently been introduced in Italy. The aim of the present study was to evaluate the vaccine behaviour in broiler breeder groups at different production stages and the effectiveness of the available laboratory tests in discriminating the MS-H from a field strain.

Results

The vaccine diffused extensively through the population, shown by the wide serological response (over 80% of positive samples in RSA and 85% in ELISA), the high serological titres, the positivity of all the tracheal samples collected during the production phase by MS PCR and the positivity by cultivation from tracheal swabs at the end-point (55 weeks after vaccination). In contrast, only one swab from a sternal bursa was positive in MS PCR, while all the joint and oviduct samples were negative. There was no evidence of vertical transmission. Different genotyping techniques were used to achieve a clear classification of the MS positive samples. The vlhA and the obg gene analysis showed that most of the strains were homologous with the vaccine, but some ambiguous samples were further investigated with the multi locus sequence typing (MLST) scheme which confirmed the homology.

Conclusions

The development of a multi-technique approach to monitor vaccinated avian flocks, based both on serological and biomolecular methods, is advised as well as the use of effective genotyping techniques to analyse the MS strains circulating in high densely populated poultry areas.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1669-8) contains supplementary material, which is available to authorized users.

Novel platinum agents and mesenchymal stromal cells for thoracic malignancies: state of the art and future perspectives

INTRODUCTION

Non-small cell lung cancer and malignant pleural mesothelioma represent two of the most intriguing and scrutinized thoracic malignancies, presenting interesting perspectives of experimental development and clinical applications.

AREAS COVERED

In advanced non-small cell lung cancer, molecular targeted therapy is the standard first-line treatment for patients with identified driver mutations; on the other hand, chemotherapy is the standard treatment for patients without EGFR mutations or ALK rearrangement or those with unknown mutation status. Once considered an ineffective therapy in pulmonary neoplasms, immunotherapy has been now established as one of the most promising therapeutic options. Mesenchymal stromal cells are able to migrate specifically toward solid neoplasms and their metastatic localizations when injected intravenously. This peculiar cancer tropism has opened up an emerging field to use them as vectors to deliver antineoplastic drugs for targeted therapies.

EXPERT OPINION

Molecular targeted therapy and immunotherapy are the new alternatives to standard chemotherapy. Mesenchymal stromal cells are a new promising tool in oncology and-although not yet utilized in the clinical practice, we think they will represent another main tool for cancer therapy and will probably play a leading role in the field of nanovectors and molecular medicine.

Cascade Reaction by Chemo- and Biocatalytic Approaches to Obtain Chiral Hydroxy Ketones and anti 1,3-Diols

A chemo- and biocatalytic cascade approach was applied for the stereoselective synthesis of hydroxy ketones and the corresponding 1,3-diols. A new class of tridentate N,N,O ligands was used with copper(II) complexes for the asymmetric β-borylation of α,β-unsaturated compounds. The complex containing ligand L5 emerged as the best performer, and it gave the organoborane derivatives with good ee values. The corresponding keto-alcohol compounds were then bioreduced by yeasts. The biotransformation set up with Rhodotorula rubra allowed (R)-keto-alcohols and (S,S)-diols to be obtained with up to 99 % ee and up to 99 % de in favor of the anti enantiomers.

Ruthenium(II) complexes bearing (NNN) ligand: catalytic evaluation of different solvent-mediated coordination modes

A new (NNN) tridentate ligand was prepared, and its ability to coordinate ruthenium(II) was evaluated. The presence of different functional groups on the ligand allows bi- or tri-coordinated complexes to be obtained depending on complexation conditions. The catalytic activity of both bidentate and tridentate complexes was studied in asymmetric transfer hydrogenation of different aryl ketones, showing a comparable behavior of the two complexes in terms of efficiency and stereoselectivity.

8-Amino-5,6,7,8-tetrahydroquinoline in iridium(iii) biotinylated Cp* complex as artificial imine reductase

The imine reductase formed by the (R)-CAMPY ligand bound to the S112M Sav mutant showed an 83% ee in the asymmetric transfer hydrogenation of 6,7-dimethoxy-1-methyl-3,4-dihydroisoquinoline.

Exploiting coordination geometry to selectively predict the σ-donor and π-acceptor abilities of ligands: a back-and-forth journey between electronic properties and spectroscopy

Coordination geometry switches the carbonyl stretching frequency into a selective probe of the σ-donor and π-acceptor abilities of ligands.

Malignant Pleural Mesothelioma: State of the art and advanced cell therapy

Malignant Pleural Mesothelioma (MPM) is an aggressive malignancy highly resistant to chemotherapy, with a response rate of 20% of patients and for this reason an efficient treatment is still a challenge. Platinum-based chemotherapy in association with a third-generation antifolate is the front-line standard of care whereas any second-line treatment was approved for MPM thus making it a pathology that evokes the need for new therapeutic agents. Different platinum-drugs were synthesised and tested as an option for patients who are not candidates to cisplatin-based therapy. Among these, monofunctional cationic antineoplastic platinum compounds received a special attention in the last decade. Alternative strategies to the commonly used combination-therapy resulted from the use of Mesenchymal Stromal Cells (MSC) widely used in the field of regenerative medicine and recently proposed as natural carriers for a selective delivery of chemotherapeutic agents and from the use of immune checkpoint and kinase inhibitors. The present short review shed light on the recent state of art and the future perspectives relative to MPM therapy.

Ctr-1 Mets7 motif inspiring new peptide ligands for Cu(i)-catalyzed asymmetric Henry reactions under green conditions

Hybrid catalysts were developed from the Cu(i) binding domain of Ctr1 protein and their activity was evaluated in an asymmetric Henry reaction.

The change in position of the sciatic nerve during the posterior approach to the hip

The aim of this cadaver study was to identify the change in position of the sciatic nerve during arthroplasty using the posterior surgical approach to the hip. We investigated the position of the nerve during this procedure by dissecting 11 formalin-treated cadavers (22 hips: 12 male, ten female). The distance between the sciatic nerve and the femoral neck was measured before and after dislocation of the hip, and in positions used during the preparation of the femur. The nerve moves closer to the femoral neck when the hip is flexed to > 30° and internally rotated to 90° (90° IR). The mean distance between the nerve and femoral neck was 43.1 mm (standard deviation (sd) 8.7) with the hip at 0° of flexion and 90° IR; this significantly decreased to a mean of 36.1 mm (sd 9.5), 28.8 mm (sd 9.8) and 19.1 mm (sd 9.7) at 30°, 60° and 90° of hip flexion respectively (p < 0.001). In two hips the nerve was in contact with the femoral neck when the hip was flexed to 90°.

This study demonstrates that the sciatic nerve becomes closer to the operative field during hip arthroplasty using the posterior approach with progressive flexion of the hip.

Cite this article: Bone Joint J 2015;97-B:1056–62.

Simple 1,3-diamines and their application as ligands in ruthenium(ii) catalysts for asymmetric transfer hydrogenation of aryl ketones

A new efficient synthesis of 1,3-diamines was realized and their ruthenium(ii) complexes were studied in ATH in aqueous media.

Exploring the low-energy landscape of large-scale signed social networks

Analogously to a spin glass, a large-scale signed social network is characterized by the presence of disorder, expressed in this context (and in the social network literature) by the concept of structural balance. If, as we have recently shown, the signed social networks currently available have a limited amount of true disorder (or frustration), it is also interesting to investigate how this frustration is organized, by exploring the landscape of near-optimal structural balance. What we obtain in this paper is that while one of the networks analyzed shows a unique valley of minima, and a funneled landscape that gradually and smoothly worsens as we move away from the optimum, another network shows instead several distinct valleys of optimal or near-optimal structural balance, separated by energy barriers determined by internally balanced subcommunities of users, a phenomenon similar to the replica-symmetry breaking of spin glasses. Multiple, essentially isoenergetic, arrangements of these communities are possible. Passing from one valley to another requires one to destroy the internal arrangement of these balanced subcommunities and then to reform it again. It is essentially this process of breaking the internal balance of the subcommunities which gives rise to the energy barriers.

[Investigation on BLS among public hospital physicians in Abruzzo]

BACKGROUND

The aim of this study is to determine the proportion of public hospital physicians in Abruzzo capable of performing basic life support manoeuvres, according to the latest guidelines.

METHODS

A questionnaire was formulated, in order to investigate whether the persons interviewed 1) had ever performed a cardio-pulmonary resuscitation; 2) had ever taken any BLS courses involving dedicated dummies; 3) believed to be competent in performing cardio-pulmonary resuscitation correctly and if affirmative, the physician was asked to answer three further questions to verify the level of competence. The questionnaire was to be filled in at the proper working place without the aid of books or other material.

RESULTS

Of the 1540 public hospital physicians contacted, 57.6% had participated in cardiopulmonary resuscitation manoeuvres, while only 30% had practised on dedicated dummies. Nevertheless, 69.5% believed to be able to perform the BLS techniques correctly. Of the latter, merely 18% answered all three additional questions correctly.

CONCLUSIONS

Cardio-pulmonary arrest is the emergency during which the timeliness of the first resuscitation manoeuvres and their correct performance are the decisive factors for a successful outcome. Without attending regular courses, qualified to teach the proper techniques in depth and recall the acquired procedures, the efficacy of BLS techniques risk to fall below a level of acceptance. Therefore, in the emergency field, it is essential to guarantee a continued training.

Metabolic effects of intraportal nutrition in humans

OBJECTIVE

We investigated the metabolic effects of intravenous nutrition through a portal (PN) or systemic (SN) peripheral vein.

METHODS

Twenty patients were randomized to receive PN or SN nutrition after colorectal surgery. The daily regimen included 900 kcal and 100 g of amino acid (AA). Visceral proteins and hepatic enzymes were measured on days 0, 1, 3, 5, and 7, and plasma arterovenous differences and limb flux of AA were measured on days 0, 3, and 7; urinary nitrogen and 3-CH3-histidine were analyzed daily.

RESULTS

Serum albumin on day 7 was still depressed (P = 0.01) in SN and fully restored in PN patients. Prealbumin levels increased significantly (P = 0.05) in the PN group only. Plasma levels of glutamine and asparagine were higher in PN than in SN patients, and this difference was statistically significant (P = 0.05). SN patients had significantly more negative limb-muscle balance of valine and tyrosine, whereas PN patients had a higher muscle release of citrulline and taurine.

CONCLUSIONS

In conclusion, short-term PN is safe and has some metabolic benefits: it accelerates recovery from postoperative hypoalbuminemia and hypopnealbuminemia and is associated with a higher plasma level of glutamine and an AA plasma pattern that is closer to normal. PN blunts the catabolic response of the muscle, decreasing loss of proteins and release of some AA involved in hepatic gluconeogenesis.

Haemodynamic effects of intravenous clonidine on propofol or thiopental induction

The study evaluated the effects of premedication with intravenous clonidine on thiopental or propofol requirements for induction and haemodynamic changes associated with both induction and endotracheal intubation. Clonidine administered intravenously before induction of anaesthesia reduced propofol or thiopental requirements. The association of clonidine and propofol caused, after injection of the induction drug, a decrease in mean arterial pressure which was significantly greater than with thiopental. Moreover, a major haemodynamic stability was registered before and after laryngoscopy in the clonidine-thiopental group. These findings might contraindicate the clonidine-propofol combination in patients with cardiovascular disease.

[Quality control in anesthesia. A new frontier]

For several years now, the need for improving healthcare quality has determined the adoption of a businesslike philosophy in American hospitals, through quality control and improvement systems. In Italy, the introduction of this business concept in public healthcare is recent, while quality assurance is still widely ignored. The anesthesiology wards have a central role in making the DRG mechanism work and therefore need computerised systems that can guarantee correct evaluation of results, analysis of efficacy and quality assurance. The development of a quality control and assurance system in anesthesiology, can be achieved by following a few simple guidelines: to identify the indicators, sensitise the personnel towards an attitude of improvement, adopt a computerised database, verify and elaborate data, correct the defects, verify the changes made to the system.

[The current status of obstetric analgesia and anesthesia in Italy]

BACKGROUND

There is a more and more vivid interest regarding methods of obstetric analgesia and anesthesia while there is a lack of epidemiological data about the Italian reality. Aim of the study was to evaluate the current state of obstetric analgesia and anesthesia and create an interest for anesthesiologists in a professionally and scientifically interesting field.

METHODS

DESIGN

transversal study of clinical observation of the Italian situation based on questionnaires composed of 20 multiple choice and closed questions, addressed to chief anesthesiologists of 220 randomized Italian hospitals.

SETTING

220 Italian hospitals having a capacity of more than 100 beds.

RESULTS

Out of the 220 questionnaires, 91 were returned. Merely 17 hospitals guaranteed a permanent peridural analgesic service. To improve this situation, anesthesiologists call for introducing chargeable services and increasing the medical staff. In spite of the widely documented advantages that regional anesthesia offers for maternal and fetal well-being, this technique is practised in only 26% of cesarean sections. This percentage is greatly higher than that obtained from a similar experience in 1991, where the use of regional anesthesia technique was of 3-4%. In 11 hospitals postoperative analgesia is not carried out on a regular basis.

CONCLUSIONS

Even though the general opinion is showing a growing interest for obstetric analgesia and anesthesia, it has not yet reached the same dignity as in other countries.

Intra-articular buprenorphine after knee arthroscopy. A randomised, prospective, double-blind study

BACKGROUND

Demonstration of peripheral opioid receptors in inflamed synovia supports the concept of peripheral opioid analgesia. The aim of this study was to evaluate the analgesic effect of intra-articular administration of buprenorphine after knee arthroscopy.

METHODS

In a double-blind randomised trial, 48 patients were assigned to four groups: group A patients received buprenorphine 100 micrograms i.a. and NaCl 0.9% i.m., group B patients received bupivacaine 0.25% 50 mg i.a. and NaCl 0.9% i.m., group C patients received NaCl 0.9% i.a. and buprenorphine 100 micrograms i.m., and group D patients received NaCl 0.9% i.a. and NaCl 0.9% i.m. Intensity of postoperative pain was evaluated by VAS at recovery (T0) and 1, 3, 6, 12, 24 h after operation (T1, T2, T3, T4, T5), at rest and during passive 10 degrees knee flexion. Total analgesic requirements and side effects related to study drugs were recorded.

RESULTS

The VAS scores were significantly higher in groups C and D than in group A and B patients. The differences were significant at T0, T1, T2 and T3. At T1, group C and D patients had greater analgesic requirement than groups A and B. No patients developed side effects.

CONCLUSION

Intra-articular buprenorphine and i.a. bupivacaine, both produced equally good postoperative pain control and allowed a significant reduction of analgesic requirement after knee arthroscopy.

Increased retinol binding protein in the sera of patients with severe ischemic damage of the liver after transplantation

OBJECTIVE

To study retinol binding protein variation in the serum of patients who have undergone liver transplantation.

METHODS

Retinol binding protein was retrospectively determined by the immunonephelometric method on serum from 14 patients who had undergone orthotopic liver transplantation 2 weeks after the surgery and then once a month during the first year posttransplantation. The patients were divided into two groups on the basis of early (first 10 days) postoperative graft function: group I, 6 patients with severe ischemic damage; and II 8 patients with moderate-severe liver dysfunction.

RESULTS

The men retinol binding protein level at one year of follow-up was persistently higher in group I than in group II (83.1 +/- 33.4 vs 44.6 +/- 20.7 mg/L, p < 0.001). Interestingly, retinol binding protein levels remained higher in patients of group I event when the other biochemical parameter of liver function returned to normal. The increase in retinol binding protein serum levels was independent of variation in other parameters of liver and kidney function, but was correlated with an increase in transthyretin and retinol levels.

CONCLUSION

Our results show a close relationship between a permanent high retinol binding protein level and severe graft injury after liver transplantation. However, the mechanism underlying the increase remains to be defined.

Amyotrophic lateral sclerosis: oxidative energy metabolism and calcium homeostasis in peripheral blood lymphocytes

There is evidence of oxidative injury in postmortem brain, spinal cord, and CSF of patients with sporadic amyotrophic lateral sclerosis (SALS patients). We investigated the oxidative metabolism and calcium homeostasis in peripheral blood lymphocytes from such patients and did not find statistical differences in the basal oxygen consumption rate (QO2), cytochrome c oxidase activity, catalase activity, and lactate production. However the increase in QO2, induced by an uncoupler of oxidative phosphorylation, was depressed and the basal (resting) level of free cytosolic calcium ([Ca2+]in) was higher in lymphocytes from SALS patients (p < 0.01). Further increase in free [Ca2+]in challenged by a K+ channel blocker or by an uncoupler of oxidative phosphorylation was similar in SALS and control lymphocytes. The results show that systemic changes consistent with the presence of mitochondrial and of calcium metabolism dysfunction are present in SALS.