How reliable is assessment of true vocal cord-arytenoid unit mobility in patients affected by laryngeal cancer? a multi-institutional study on 366 patients from the ARYFIX collaborative group.

PURPOSE: In clinical practice the assessment of the "vocal cord-arytenoid unit" (VCAU) mobility is crucial in the staging, prognosis, and choice of treatment of laryngeal squamous cell carcinoma (LSCC). The aim of the present study was to measure repeatability and reliability of clinical assessment of VCAU mobility and radiologic analysis of posterior laryngeal extension. METHODS: In this multi-institutional retrospective study, patients with LSCC-induced impairment of VCAU mobility who received curative treatment were included; pre-treatment endoscopy and contrast-enhanced imaging were collected and evaluated by raters. According to their evaluations, concordance, number of assigned categories, and inter- and intra-rater agreement were calculated. RESULTS: Twenty-two otorhinolaryngologists evaluated 366 videolaryngoscopies (total evaluations: 2170) and 6 radiologists evaluated 237 imaging studies (total evaluations: 477). The concordance of clinical rating was excellent in only 22.7% of cases. Overall, inter- and intra-rater agreement was weak. Supraglottic cancers and transoral endoscopy were associated with the lowest inter-observer reliability values. Radiologic inter-rater agreement was low and did not vary with imaging technique. Intra-rater reliability of radiologic evaluation was optimal. CONCLUSIONS: The current methods to assess VCAU mobility and posterior extension of LSCC are flawed by weak inter-observer agreement and reliability. Radiologic evaluation was characterized by very high intra-rater agreement, but weak inter-observer reliability. The relevance of VCAU mobility assessment in laryngeal oncology should be re-weighted. Patients affected by LSCC requiring imaging should be referred to dedicated radiologists with experience in head and neck oncology.

Synthesis of novel S- and O-disaccharide analogs of heparan sulfate for heparanase inhibition.

Heparan sulfate (HS), a glycosaminoglycan related to heparin, is a linear polysaccharide, consisting of repeating disaccharide units. This compound is involved in multiple biological processes such as inflammation, coagulation, angiogenesis and viral infections. Our work focuses on the synthesis of simple HS analogs for the study of structure-activity relationships, with the aim of modulating these biological activities. Thioglycoside analogs, in which the interglycosidic oxygen is replaced by a sulfur atom, are very interesting compounds in terms of therapeutic applications. Indeed, the thioglycosidic bond leads to an improvement of their stability and can allow the inhibition of enzymes involved in physiological and pathological processes. In our previous work, we developed a synthetic sequence which led to a non-sulfated thiodisaccharide analog of HS. In this paper, we report our results of the development of a new synthetic method allowing access to the novel sulfated S-disaccharide, as well as to their oxygenated analogues (O-disaccharide and sulfated O-disaccharide). These 4 compounds were also tested for the inhibition of heparanase, an enzyme involved in biological processes like tumor growth and inflammation. The obtained IC50 values in the micromolar range showed the impact of the interglycosidic sulfur atom and the 6-sulfate group.

The pharmacological effect of Bothrops neuwiedii pauloensis (jararaca-pintada) snake venom on avian neuromuscular transmission

The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada) venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 æg/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 æg/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 æM acetylcholine alone and cumulative concentrations of 1 æM to 10 mM were unaffected. At venom concentrations higher than 50 æg/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24ºC, the venom (50 æg/ml) produced only partial neuromuscular blockade (30.7 ± 8.0 percent, N = 3) after 120 min and the initial inhibition and the secondary increase of the twitch responses caused by the venom were prolonged and pronounced and the response to KCl was unchanged. These results indicate that B.n. pauloensis venom is neurotoxic, acting primarily at presynaptic sites, and that enzyme activity may be involved in this pharmacological action

The pharmacological effect of Bothrops neuwiedii pauloensis (jararaca-pintada) snake venom on avian neuromuscular transmission.

The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada) venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 micro g/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 micro g/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 micro M acetylcholine alone and cumulative concentrations of 1 micro M to 10 mM were unaffected. At venom concentrations higher than 50 micro g/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24 degrees C, the venom (50 g/ml) produced only partial neuromuscular blockade (30.7 +/- 8.0%, N = 3) after 120 min and the initial inhibition and the secondary increase of the twitch responses caused by the venom were prolonged and pronounced and the response to KCl was unchanged. These results indicate that B.n. pauloensis venom is neurotoxic, acting primarily at presynaptic sites, and that enzyme activity may be involved in this pharmacological action.

Magnetic cues trigger extensive refuelling.

Long stretches of sea and desert often interrupt the migration routes of small songbirds, whose fat reserves must be restored before these can be crossed as they provide no opportunity for refuelling. To investigate whether magnetic cues might enable inexperienced migratory birds to recognize a region where they need to replenish their body fat, we caught and held thrush nightingales (Luscinia luscinia) in Sweden just before their first migration and exposed them to a magnetic field simulating that at a migratory stopover in northern Egypt, before the Sahara Desert. We found that this magnetic field stimulated the birds to extend their fat-deposition period, indicating that magnetic cues may help small migratory birds to confront large ecological barriers.

An optimized procedure for detection of proteins on carrier ampholyte isoelectric focusing and immobilized pH gradient gels with imidazole and zinc salts: its application to the identification of isoelectric focusing separated isoforms by in-gel proteolysis and mass spectrometry analysis.

A method for the characterization of proteins separated by isoelectric focusing in carrier ampholytes (CA-IEF) or immobilized pH gradient (IPG) gels by in-gel digestion and mass spectrometry is described. Proteins are detected by an improved imidazole-Sodium dodecyl sulfate (SDS)-zinc staining adapted for IEF and IPG gels. Sensitivity is close to that of mass spectrometry-compatible silver staining, but simpler and faster. Proteins were digested in imidazole-SDS-zinc stained CA-IEF and IPG gels in the presence of a zinc-chelating agent. Mass spectra were clearly interpretable as carrier ampholytes which were efficiently removed before digestion; high-sequence coverage that allowed isoform characterization was obtained by analyzing both the aqueous and the organic phase extracts.

Characterization of a recombinant monoclonal antibody by mass spectrometry combined with liquid chromatography.

In this report, we present the characterization of a humanized monoclonal antibody specific for the human epidermal growth factor receptor (hEGFR). Direct analysis by matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) of peptide mixtures and chromatographically isolated fractions allowed identification of 94.0% and 85.4% of the amino acid sequence of light and heavy chains, respectively. Microheterogeneity sources were identified in light and heavy chains and a previously unreported posttranslational modification for immunoglobulins was found. One N-glycosylation site was identified in the heavy chain with non-sialylated bianntenary fucosylated structures. This study is one of the first to assess the potential of MALDI-MS in combination with more conventional protein chemistry techniques for the characterization of monoclonal antibodies.

Smectite reduces gastroesophageal reflux in newborn infants.

We assessed the efficacy of a natural clay (smectite) on the frequency and the duration of acid (pH less than 4) and very acid (pH less than 3) gastroesophageal reflux (GER) measured by 24-hour continuous pH recording (CPR). Twenty newborn infants were enrolled in this double-blind controlled study owing to pathological CPR in supine position. After inclusion, all the patients were maintained in the 30-degree elevated prone position and received either smectite (3 g/day; n = 10) or placebo (n = 10) for 7 days. On the 8th day, a second 24-hour CPR was performed in supine position. The postural therapy alone (placebo group) was followed by a significant decrease in the numbers of acid GER (p less than 0.05) during the second CPR. The combination of postural therapy and smectite treatment was followed by a decrease in the number of acid (p less than 0.05) and very acid GER (p = 0.01), the percentages of time spent at pH below 4 (p less than 0.05) and 3 (p less than 0.01) and the maximal duration of acid GER (p less than 0.05).