Molecular modelling and enzymatic studies of acetylcholinesterase and butyrylcholinesterase recognition with paraquat and related compounds.

The potent herbicide paraquat and three other analogues MPP+, MPDP+ and MPTP have a known toxicological profile linked to the ability to damage dopaminergic neurons. Other biological effects were recently addressed to this class of compounds, including the ability to interact with enzymatic targets involved in the Central Nervous System, such as the acetylcholinesterase (AChE) and the butyrylcholinesterase (BuChE). A combined molecular modelling and enzymatic study focusing onto their interaction against the AChE and BuChE is reported. The former study was performed by docking techniques using target known co-crystallographic models. The latter study was carried out by the widely adopted Ellman's method. In both studies the anti-Alzheimer FDA approved drug tacrine was used as reference inhibitor. Our results indicate that paraquat, MPTP, MPDP+ and MPP+ recognize both enzymatic cleft in a similar fashion compared to the reference inhibitor. A structure-activity correlation was found with the net charge of the ligands, indicating a major role of the electrostatic term in the recognition and inhibition of these compounds. Our data completed their enzymatic profile, added new information on the molecular mechanisms underlying their neurotoxicity useful for the rational design of new cholinesterase inhibitors.

Transudative right pleural effusion due to compression of the brachiocephalic vein caused by an intrathoracic goitre.

The case presented in this report is of a female patient who suffered recurrent transudative right pleural effusions, due to a giant benign intrathoracic goitre. The latter caused compression of the brachiocephalic vein, which is a very rare cause of pleural fluid accumulation. Magnetic resonance imaging played a crucial diagnostic role.

Inflammatory pseudotumour of the lung presenting as an airway obstructive syndrome.

The inflammatory pseudotumour of the lung is a rare and non-malignant neoplasm, which can be asymptomatic or characterized by variable clinical expressions. This report refers to a case occurring in a young woman and presenting as a persistent airway obstructive syndrome. With regard to histopathologic characterization, the present case can be classified as a fibrous histiocytic subtype.

Tracheal rupture secondary to orotracheal intubation.

A case of tracheal rupture due to orotracheal intubation performed for anaesthesiological procedures is described. It is very likely that this rare complication was favoured by some anatomical factors, which were responsible for a difficult intubation. Tracheal rupture was diagnosed by endoscopy and treated by a decompressive tracheostomy.

The plant oncogene rolD stimulates flowering in transgenic tobacco plants.

The Agrobacterium rhizogenes T-DNA oncogene rolD under the control of its own 5' regulatory region was transferred to day-neutral tobacco plants. The main trait induced by rolD in transgenic plants is a striking precocity in flower setting and a strong enhancement of the flowering potential. In rolD plants, early flowering is followed by the very rapid growth of numerous lateral inflorescences. The analysis of several morphological and histological parameters suggests that some characteristic morphological abnormalities observed in rolD plants can be accounted for by their early reproductive phase transition and points to the involvement in the transition of a greater portion of the plant body than is the case for untransformed tobacco. The in vitro morphogenic potential of tissues from rolD plants was also tested. Superficial thin cell layer explants from rolD plants show an earlier and much enhanced flower organogenesis, compared to controls, both on flowering and on hormone-free medium.

Kartagener's syndrome in a woman with a normal ciliary structure and an intracranial meningioma.

Kartagener's syndrome is usually associated with ciliary abnormalities. We describe a case of Kartagener's syndrome observed in a woman with an intracranial meningioma and a normal axonemal structure. This finding confirms that ultrastructural defects of bronchial cilia are not always present in Kartagener's syndrome.

Serum neuron-specific enolase in various pathological conditions.

Quantitative determination of neuron-specific enolase in the serum was performed by RIA method in 18 neurological patients and in 22 patients with pulmonary diseases. The data confirmed that the specificity of this marker is not absolute for the detection both of the nature and of the seat of origin of the disease. Further problems are posed in patients which simultaneously suffer from endocrine, nervous and pulmonary abnormality.