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Biomedical subjects

P Pinelli

Publications and source records attributed to P Pinelli.

At least 73 records · Page 4Linked to original sources
PubMed1973

Neuromuscular block after intra-arterially injected acetylcholine. 2. Effects of ACTH treatments as possible detectors of desensitization level in the receptor site.

It has been suggested that the effect of ACTH in myasthenia gravis may be ascribed to an action involving neuromuscular transmission which favours repolarization processes, with a tendency towards hyperpolarization of the membranes of muscle fibres and motor nerve endings. A similar mechanism has been postulated for the action of ACTH in epilepsy (Klein, 1970). A direct or indirect action on nerve membrane would interfere with depolarization. There is evidence of raised concentration of intracellular potassium and increased outflow of sodium ions which would cause hyperpolarization of the membrane. This paper studies the effect of ACTH on the late block of neuromuscular transmission caused by acetylcholine (ACTH).

Acetylcholine↗
PubMedDate not supplied

The effect of anticholinesterases on motor unit potentials in myasthenia gravis.

In most patients with myasthenia gravis, the mean duration and amplitude of motor unit potentials sampled in the extensor digitorum communis muscle, as well as the amplitude of the pattern of activity during full effort, increased after application of anticholinesterase. This appears to be a sensitive test for early detection of failure in neuromuscular transmission. In a series of 12 patients, the mean amplitude of motor unit potentials increased 30%-130% in 9, and the mean duration increased 10%-25% in 7. In 3 patients who failed to show an increase in amplitude in the extensor digitorum communis muscle, the amplitude of motor unit potentials increased in a facial or extraocular muscle after intravenous application of edrophonium. This increase in the amplitude or duration of motor unit potentials was even evident in 4 patients who failed to show a decrement in response of the opponens pollicis muscle to repetitive stimuli delivered to the median nerve at 3/sec and 5/sec. In 5 patients, responses evoked by stimuli delivered at 15/sec showed marked facilitation.

Acetylcholine↗
PubMedDate not supplied

Identification and quantification of galloyl derivatives, flavonoid glycosides and anthocyanins in leaves of Pistacia lentiscus L.

Separation, identification and quantification of polyphenols was carried out on leaves of Pistacia lentiscus L., an evergreen member of the family Anacardiaceae, using semi-preparative HPLC, HPLC-photodiode array detection and HPLC-MS analysis, together with 1H- and 13C NMR. Three major classes of secondary metabolites were detected: (i) gallic acid and galloyl derivatives of both glucose and quinic acid; (ii) flavonol glycosides, i.e. myricetin and quercetin glycosides; and (iii) anthocyanins, namely delphinidin 3-O-glucoside and cyanidin 3-O-glucoside. Low amounts of catechin were also detected. The concentration of galloyl derivatives was extremely high, representing 5.3% of the leaf dry weight, and appreciable amounts of myricetin derivatives were also detected (1.5% on a dry weight basis). These findings may be useful in establishing a relationship between the chemical composition of the leaf extract and the previously reported biological activity of P. lentiscus, and may also assign a new potential role of P. lentiscus tissue extracts in human health care.

Anthocyanins↗