Adeno-tonsillar surgery in Italy.

Indications to surgery for adeno-tonsillar inflammatory disorders and analysis of the effectiveness of surgical treatment, compared with watchful waiting strategy, continue to be the subject of scientific debate. The present investigation focuses on the surgical activity of 14 Italian Otorhinolaryngological Units between 1999 and 2004. Surgical interventions (adeno-tonsillectomy, adenoidectomy, tonsillectomy) on 26915 children (age range: 2-11 years) were considered. Data on adeno-tonsillar interventions were analysed in relation to other interventions of ENT interest, performed in the same units and in the same period. Adeno-tonsillar interventions accounted for 35.4% of all operations of ENT interest. Adeno-tonsillectomy accounted for 56.6% of overall adeno-tonsillar operations, adenoidectomy 31.6%, tonsillectomy 11.8%. The percentage for the three interventions was homogeneous in the period of the study and in the recruited units. The percentage of children who underwent adeno-tonsillar surgery in paediatric units was higher as compared to general units, as far as concerns the overall number of operations performed. In southern Italy, the number of adeno-tonsillar interventions, in general, and of adeno-tonsillectomy, in particular, was higher compared to that in northern Italy. Results of the present study suggest that environmental factors, cultural issues and local health demands, may influence indications and, therefore, the different incidence of the operations under consideration in the units taking part in the investigation.

A case of highly aggressive adenoid cystic carcinoma of the external auditory canal.

Tumours of the external auditory canal are extremely rare and only 20% of these are of glandular origin. The most frequent histotype is adenoid cystic carcinoma. The rarity of external auditory canal glandular tumours explains the lack of large series reported in the literature and the corresponding large number of case reports from different Authors. Adenoid cystic carcinoma, presenting in the external auditory canal, exhibits the same characteristics as those affecting the major salivary glands, this tumour has an aggressive behaviour characterized by local invasivity and with a metastatic risk of approximately 30%. A rare case of adenoid cystic carcinoma of the external ear is reported. The patient, a 75-year-old male, had right intermittent otorrhea for 6 years. On examination, a vegetating, ulcerated formation which easily bled was found protruding from the right external auditory meatus. Clinical, radiological and pathological features of the tumour are described. A subtotal petrosectomy combined with homolateral elective lymph node neck dissection was performed. Parotid gland, condyle of the mandible and VII cranial nerve were spared since these were free from disease.

X-ray magnetochiral dichroism: a new spectroscopic probe of parity nonconserving magnetic solids.

We report the first experimental detection of x-ray magnetochiral dichroism in magnetoelectric Cr2O3. This dichroism, which does not require any polarized x-ray beam, is related to the time-reversal odd part of the optical activity tensor dominated by electric dipole-electric quadrupole E1E2 interference terms. The experiments were carried out using either a single crystal or a powdered pellet required to grow a single antiferromagnetic domain by magnetoelectric annealing. This new element (edge) specific spectroscopy offers unique access to the atomic orbital anapole moment Omega-z.

A "stripping" ligand tactic for use with the kinetic locking-on strategy: its use in the resolution and bioaffinity chromatographic purification of NAD(+)-dependent dehydrogenases.

The kinetic locking-on strategy utilizes soluble analogues of the target enzymes' specific substrate to promote selective adsorption of individual NAD(+)-dependent dehydrogenases on their complementary immobilized cofactor derivative. Application of this strategy to the purification of NAD(+)-dependent dehydrogenases from crude extracts has proven that it can yield bioaffinity systems capable of producing one-chromatographic-step purifications with yields approaching 100%. However, in some cases the purified enzyme preparation was found to be contaminated with other proteins weakly bound to the immobilized cofactor derivative through binary complex formation and/or nonspecific interactions, which continuously "dribbled" off the matrix during the chromatographic procedure. The fact that this problem can be overcome by including a short pulse of 5'-AMP (stripping ligand) in the irrigant a couple of column volumes prior to the discontinuation of the specific substrate analogue (locking-on ligand) is clear from the results presented in this report. The general effectiveness of this auxiliary tactic has been assessed using model studies and through incorporation into an actual purification from a crude cellular extract. The results confirm the usefulness of the stripping-ligand tactic for the resolution and purification of NAD(+)-dependent dehydrogenases when using the locking-on strategy. These studies have been carried out using bovine liver glutamate dehydrogenase (GDH, EC 1.4.1.3), yeast alcohol dehydrogenase (YADH, EC 1.1.1.1), porcine heart mitochondrial malate dehydrogenase (mMDH, EC 1.1.1.37), and bovine heart L-lactate dehydrogenase (l-LDH, EC 1.1.1.27).

Biospecific affinity chromatographic purification of octopine dehydrogenase from molluscs.

The development of a biospecific affinity chromatographic method for the purification of octopine dehydrogenase from molluscs is described. The method utilizes immobilized NAD+ derivatives in conjunction with soluble specific substrates to promote binding. Using this method, octopine dehydrogenase has been purified to electrophoretic homogeneity in a single chromatographic step from three different marine invertebrate sources [the queen scallop, Chlamys opercularis (adductor muscle), the great scallop, Pecten maximus (adductor muscle), and the squid Loligo vulgaris (mantle muscle)]. However, the system is not applicable to the purification of octopine dehydrogenase from some other marine invertebrate sources investigated (the mussel Mytilus edulis and the topshell Monodonta lineata).

Further studies on the bioaffinity chromatography of NAD(+)-dependent dehydrogenases using the locking-on effect.

Previous studies have capitalized on ordered kinetic mechanisms in the design of biospecific affinity chromatographic methods for highly efficient purifications and mechanistic studies of enzymes. The most direct tactic has been the use of immobilised analogues of the following, usually enzyme-specific substrates, e.g., lactate/pyruvate in the case of lactate dehydrogenase for which NAD+ is the leading substrate. Such immobilised specific substrates are, however, often difficult or impossible to synthesise. The locking-on strategy reverses the tactic by using the more accessible immobilised leading substrate, immobilised NAD+, as adsorbent with soluble analogues of the enzyme-specific ligands (e.g., lactate in the case of lactate dehydrogenase) providing a substantial reinforcement of biospecific adsorption sufficient to effect adsorptive selection of an enzyme from a group of enzymes such as the NAD(+)-specific enzymes. The value of this approach is demonstrated using model studies with lactate dehydrogenase (LDH, EC 1.1.1.27), alcohol dehydrogenase (ADH, EC 1.1.1.1), glutamate dehydrogenase (GDH, EC 1.4.1.3) and malate dehydrogenase (MDH, EC 1.1.1.37). Purification of bovine liver GDH in high yield from crude extracts is described using the tactic.

The lactate dehydrogenase of the icefish heart: biochemical adaptations to hypoxia tolerance.

Cardiac lactate dehydrogenase from the hemoglobin- and myoglobin-free antarctic icefish has been purified by affinity chromatography. Structural and kinetic properties of the enzyme were found close or identical to those of its skeletal muscle counterpart and other M-type lactate dehydrogenases. A model involving a dual oxidative-anaerobic metabolism of the icefish heart is proposed.