Algorithms for difficult airway management: a review

Difficult airway management and maintenance of oxygenation remain the two most challenging tasks for anesthetists, while also being controversial items in terms of clinically based-evidence to support relevant guidelines in the literature. Nevertheless, different expert groups and scientific societies from several countries have published guidelines dedicated to the management of difficult airways. These documents have been demonstrated to be useful in reducing airway management related critical accidents, despite their limited use in litigations and legal issues. The aim of this review is to compare different airway management guidelines published by the United States, United Kingdom, France, Italy, Germany, and Canada while trying to elucidate the main differences, weaknesses, and strengths for identifying critical concepts in the management of difficult airways.     

Antiproliferative activity of phenylbutyrate ester of haloperidol metabolite II [(±)-MRJF4] in prostate cancer cells

Complex mechanisms of prostate cancer progression prompt to novel therapeutic strategies concerning a combination of drugs or of single molecules able to interact with more crucial targets. Histone deacetylase inhibitors and sigma ligands with mixed σ₁ antagonist and σ₂ agonist properties were proposed as new potential tools for treatment of prostate cancer. (±)-MRJF4 was synthesized as phenylbutyrate ester of haloperidol metabolite II, which is a molecule consisting of a histone deacetilase inhibitor (4-phenylbutyric acid) and a sigma ligand (haloperidol metabolite II). Antiproliferatives activities of 4-phenylbutyric acid, haloperidol metabolite II, equimolar mixture of both compounds and (±)-MRJF4 were evaluated in vitro on LNCaP and PC3 prostate cancer cells. Preliminary binding studies of (±)-MRJF4 for σ₁, σ₂, D₂ and D₃ receptors and inhibition HDAC activity were reported. MTT cell viability assays highlighted a notable increase of antiproliferative activity of (±)-MRJF4 (IC₅₀ = 11 and 13 μM for LNCaP and PC3, respectively) compared to 4-phenylbutyric acid, haloperidol metabolite II and the respective equimolar pharmacological association. (±)-MRJF4 was also used in combination with σ₁ agonist (+)-pentazocine and σ₂ antagonist AC927 in order to evaluate the role of σ receptor subtypes in prostate cancer cell death.     

Umbellulone modulates TRP channels

Inhalation of umbellulone (UMB), the offensive principle of the so-called “headache tree” (California bay laurel, Umbellularia californica Nutt.), causes a painful cold sensation. We therefore studied the action of UMB and some derivatives devoid of thiol-trapping properties on the “cold” transient receptor potential cation channels TRPA1 and TRPM8. UMB activated TRPA1 in a dose-dependent manner that was attenuated by cysteine-to-serine isosteric mutation in TRPA1 (C622S), while channel block was observed at higher concentration. However, although activation by mustard oil was completely prevented in these mutants, UMB still retained activating properties, indicating that it acts on TRPA1 only as a partial electrophilic agonist. UMB also activated TRPM8, but to a lower extent than TRPA1. Removing Michael acceptor properties of UMB (reduction or nucleophilic trapping) was detrimental for the activation of TRPA1, but increased the blocking potency. This was, however, attenuated by acetylation of the hydroxylated analogs. All UMB derivatives, except the acetylated derivatives, were also TRPM8 activators. They acted, however, in a bimodal manner, inhibiting the channel more potently than UMB, and with tetrahydro-UMB being the most potent TRPM8 activator. In conclusion, UMB is a bimodal activator of TRPA1 and a weak activator of TRPM8. Non-electrophilic derivatives of UMB are better TRPM8 activators than the natural product and also potent blockers of this channel as well as of TRPA1. The lack of effects of the acetylated UMB derivatives suggests that steric hindrance may prevent access to the recognition site for the bicyclic monoterpene pharmacophore on TRPA1 and TRPM8.     

A novel nonsense mutation in the APTX gene associated with delayed DNA single-strand break removal fails to enhance sensitivity to different genotoxic agents

APTX is the gene involved in ataxia with oculomotor apraxia type 1 (AOA1), a recessive disorder with early-onset cerebellar ataxia, oculomotor apraxia and peripheral neuropathy. The encoded protein, aprataxin, is a DNA repair protein processing the products of abortive ligations, 5'-adenylated DNA. We describe a novel nonsense mutation in APTX, c.892C>T (p.Gln298X), segregating in two AOA1 patients and leading to the loss of aprataxin protein in patient's cells. These cells, while exhibiting reduced catalase activity, are not hypersensitive to toxicity elicited by H(2)O(2) exposure at either physiologic or ice-bath temperature. On the other hand, the rate of repair of DNA single-strand-breaks (SSBs) induced in both conditions is always significantly slower in AOA1 cells. By using the alkylating agent methyl methane sulphonate (MMS) we confirmed the association of the APTX mutation with a DNA repair defect in the absence of detectable changes in susceptibility to toxicity. These results, while consistent with a role of aprataxin in the repair of SSBs induced by H(2)O(2), or MMS, demonstrate that other mechanisms may be recruited in AOA1 cells to complete the repair process, although at a slower rate. Lack of hypersensitivity to the oxidant, or MMS, also implies that delayed repair is not per se a lethal event.     

Evaluating the role of the genetic variations of PTPN22, NFKB1, and FcGRIIIA genes in inflammatory bowel disease: a meta-analysis

BACKGROUND: We tested several polymorphisms of genes involved in the mucosal immune system in a population of inflammatory bowel disease (IBD) patients to investigate their possible implication in disease predisposition. METHODS: Polymorphisms of 3 candidate genes (PTPN22, NFkB1, and FcGRIIIA) were investigated in 649 IBD patients (343 with Crohn's disease [CD] and 306 with ulcerative colitis [UC]), 176 unaffected relatives, and 256 healthy controls. Allele and genotype frequencies were correlated with clinical characteristics and major variants of the CARD15 gene. Our findings were pooled in a meta-analysis with the available studies in the literature. RESULTS: No significant difference for the PTPN22 and NFkB1 variants was found. In contrast, allele and genotype frequencies of the G559T allele of the FcGRIIIA gene were significantly different in CD patients compared to controls (allele T 12% versus 8%, odds ratio [OR] = 1.58, 95% confidence interval [CI] 1.06-2.35; GT genotype 23% versus 16%, OR = 1.64, 95% CI = 1.08-2.5). However, no significant overtransmission of the T allele was confirmed at the family-based analysis. For all genes, neither an interaction with CARD15 gene, nor a significant difference at genotype/phenotype analysis was demonstrated, included response to medical therapy. CONCLUSIONS: Although involved in autoimmune diseases, the PTPN22 and NFkB1 genes do not seem involved in the IBD predisposition, also according to meta-analysis results. The association with the G559T polymorphism of the FcGRIIIA gene in CD patients deserves further investigation.     

Correlation between genetic and biological aspects in primary non-metastatic breast cancers and corresponding synchronous axillary lymph node metastasis

This study investigated the changes, if any, in the level of expression of a well defined panel of cell proliferation, differentiation and apoptosis markers between the primary breast tumor and the corresponding synchronous lymph node metastasis from a population of patients with a comparable disease status, in terms of clinical features, and natural history. Ninety pure invasive ductal carcinomas with 10 or more axillary lymph nodes involved and without evidence of distant metastasis were included in this study. Primary tumor and corresponding metastatic lymph node tissue specimens were evaluated for the expression of Cyclin B1, MMP1 metalloproteinase, ICAM-1, RARβ, Ki67, ER, PgR, p53, bcl-2 and c-erbB2 by immunohistochemistry using standard methods. The bivariate Pearson correlation analysis demonstrated a close relationship between primary and matching corresponding metastatic node. A high grade of correlation has been maintained even when staining results where categorized as positive/negative according to each one marker cut-off level of staining expression. We report the most extensive immunohistochemical analysis of biological determinants in a well defined population of patients with invasive ductal carcinomas and involvement of 10 or more axillary nodes and no distant metastasis. We found a close correlation between the primary tumor and corresponding metastatic node in terms of the expression of all 10 of the markers investigated in this study. The not complete concordance observed could be explained by the gene expression modulation by extrinsic factors and by the microenvironment in which the cancer cells reside.     

Novel sigma receptor ligands: synthesis and biological profile

The aim of the present study was to investigate the biological profile of new substituted 1-phenyl-2-cyclopropylmethylamines. High affinity for both sigma subtypes was achieved when 4-phenylpiperidin-4-ol (4a-e) and 4-benzylpiperidine moieties were present (5a-e). (1R,2S/1S,2R)-2-[4-Hydroxy-4-phenylpiperidin-1-yl)methyl]-1-(4-methylphenyl)cyclopropanecarboxylate (4b) showed high affinity for the sigma1 sites (Ki = 1.5 nM) and the most favorable sigma1/sigma2 selectivity (Ki(sigma2)/Ki(sigma1) = 33.9). Binding affinity studies showed that 4b binding on N-methyl-d-aspartate (NMDA), dopaminergic (D1, D2, D3), muscarinic, histaminergic H1, adrenergic (alpha1, alpha2), serotoninergic (5-HT2A, 5-HT2C, 5-HT3, 5-HT4, 5-HT6), DA (DAT), and 5-HT (SERT) transporters was not significant. Interestingly, sigma ligands differently induced the expression of tissue transglutaminase (TG-2) in primary astroglial cell cultures. We suggest that 4b may act as a sigma1/sigma2 agonist and that the sigma ligands may modulate TG-2 differently.