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Biomedical subjects

R Scelsi

Publications and source records attributed to R Scelsi.

At least 73 records · Page 4Linked to original sources

Chronic treatment with phenytoin in rats: effects of peripheral nervous system.

60 albino Sprague-Dawley female rats, 250 g of body weight, were treated for 6 months with phenytoin 30 mg/100 g/die per os (mean plasma levels: 10-20 gamma/ml). Between 75 and 90 days of treatment motor and sensory nerve conduction velocities were examined along the tail (Miyoshi and Goto, 1973; Fiaschi et al., 1977) in 15 treated animals and in 10 untreated control animals. A slowing of sensory conduction velocity was shown in 6 treated animals (40%); in 2 of them (13%) the motor conduction velocity was also showed. 25 treated rats were controlled with the same neurophysiologic methods after 165-180 days of PHT treatment in comparison with 10 controls; a slowing of sensory conduction velocity was observed in 14 treated rats (56%) and a slowing of motor conduction in 5 of them (20%). The hystological and ultrastructural study carried out on the sciatic nerves of all animals revealed changes of myelinated fibres only in the animals with slowed motor conduction velocity. The non-myelinated fibres were apparently normal.

Animals↗

Histochemical and ultrastructural aspects of m. vastus lateralis in sedentary old people (age 65--89 years).

Biopsies for histochemical and ultrastructural studies were taken from the M. vastus lateralis of 45 healthy sedentary men and women aged 65--89 years. With increasing age the histochemical reactions reveal changes inthe fibre type distribution characterized by a decrease in the percentage and predominant atrophy of type II fibres. The most frequent changes in the oldest subjects are: targetoid fibres, type I fibre predominance, and type grouping phenomena; expressions of denervation. Myopathic alterations are observed unusually. Electron microscopic findings are characterized by myofibrillar disorder, streaming of Z line and rod formation, and dilatation and increase of sarcoplasmic reticulum. As the age increases, the fibres become richer in intracellular lipid droplets and lysosomes. Intramuscular microcirculatory alterations, consisting of arteriolosclerotic changes and increase in width of the capillary basement membrane, are also observed and discussed.

Aged↗

Acetylcholine esterase sensitivity to chronic administration of diphenylhydantoin and effects on cerebral enzymatic activities related to energy metabolism.

The effect of chronic treatment (8 months) with diphenylhydantoin (DPH) on rat brain was studied. The activity of some enzymes related to energy transduction (lactate dehydrogenase, citrate synthase, and malate dehydrogenase; NADH-cytochrome c reductase and cytochrome oxidase) and neurotransmission (acetylcholine esterase) was evaluated both in the whole brain homogenate and/or in the crude mitochondrial fraction. A clear-cut decrease of acetylcholine esterase activity was observed, the decrease continuing even after treatment was discontinued. Effects on energy metabolism and on lactate dehydrogenase, malate dehydrogenase, and cytochrome oxidase are discussed.

Acetylcholinesterase↗

Toxic polyneuropathy due to n-hexane.

Three women developed a predominantly motor polyneuropathy following industrial exposure to an adhesive agent containing 80.4% of n-hexane as a volatile substance. Histological and electron-microscopic studies were carried out on sural nerve and on soleus muscle. In the nerve, there were polymorphous changes in both myelin sheaths and axons of large diameter fibres. Irregular and swollen myelin sheaths and segmental swelling of axons with dissolution of neurotubules and evident increase of neurofilaments were frequently observed. Polymorphous inclusion bodies were often present in Schwann cell cytoplasm. The small myelinated and unmyelinated fibres did not show significant changes. The muscles showed denervation atrophy and focal degenerative myopathic changes, with presence of lymphocytic infiltrates and phagocytosis. This study confirms the noxious effect of n-hexane on the peripheral nerve, with development, in our cases, of a toxic polyneuropathy and denervation muscular atrophy with consistent myopathic changes.

Adolescent↗

Intrathecal IgG synthesis in multiple sclerosis and other neurological diseases: a comparative evaluation by IgG-index and isoelectric focusing.

Intrathecal IgG synthesis has been investigated by determining the IgG index and by isoelectric focusing in 30 cases of definite multiple sclerosis, in 15 cases of probable multiple sclerosis and in 128 patients affected by other neurological diseases. The blood-brain barrier function was evaluated at the same time by serum albumin/CSF albumin quotient and isoelectric focusing. The IgG index was found elevated in 73.3% of definite multiple sclerosis patients, while oligoclonal IgG bands occurred in 90%. In the other neurological diseases the IgG index was abnormally increased in 35.1% but IgG bands were present only in cerebrospinal fluid (CSF) in 1.5% and both in the CSF and serum in 7% of patients. The high capacity of isoelectric focusing to detect IgG oligoclonal bands in the CSF is pointed out as an extremely useful diagnostic tool in multiple sclerosis.

Adult↗

[Cerebral enzymatic activities related to energy transduction processes. A model for the evaluation of pharmacological changes in the brain of the adult rat].

A test model of studying the effects of chronic pharmacological treatment on cerebral metabolism related to energy transduction was developed. The most useful biochemical parameters were the cerebral enzymatic activities related to the glycolytic pathway (lactate dehydrogenase), the Krebs' cycle (citrate synthetase and malate dehydrogenase) and the electron transfer chain (total NADH-cytochrome c reductase and cytochrome oxidase). The model is based on the natural growth-dependent changes occurring in the rat during aging (from 10 to 60 weeks of life). As test drug, 10-methoxy-1,6-dimethyl-ergoline-8 beta-methanol-(5-bromonicotinate) (nicergoline, Sermion) was administered daily for three periods of 16 weeks each (10-26, or 28-44, or 44-60 weeks of life) by two different administration routes (oral and i.p.), and at two different dose levels: oral 1 or 4, i.p. 0.25 or 1 mg/kg. Biochemical data were obtained blindly after 4, 8, 12 and 16 weeks of treatment. The drug tested exerted different effects which were dependent on the various administration periods and the administration routes. No dose-effect relationship was established.

Animals↗

Subclinical myopathic findings in patients affected by malignant tumours. An autopsy study.

Histoenzymologic studies on representative muscles and the peripheral microcirculation from selected autopsies of non cachectic patients dying of neoplasms, without signs of neuromuscular involvement, demonstrate a high incidence of neuromuscular and microcirculatory changes. A correlation between neuromuscular changes and the peripheral microcirculation particularly evident in myopathic cases is discussed.

Adult↗

A case of progressive external ophthalmoplegia (Kiloh-Nevin type) with abnormal mitochondria. Clinical, histochemical and ultrastructural findings.

A case of progressive external ophthalmoplegia is described, in which the onset of the illness was at 28--30 years, with fatigability and muscular pains in the lower limbs as presenting symptoms. At 36--37 years weakness of the mimic muscles also appeared and fatigability and muscular pains spread to the upper limbs: EMG examination showed signs of light myopathic involvement of the shoulder-girdle muscles, so that a muscular biopsy was performed (right deltoid). Histoenzymologic studies showed the presence of generally atrophic dark fibres, which can be brought about to red-ragged fibres. Ultrastructural study showed bizarrely shaped mitochondria, with dense matrix and circular and confluent cristae, which were found in fibres with plenty of indifferent sarcoplasm and with anomalies in myofibrils. No mitochondrial inclusions were seen.

Adult↗

Mitochondrial abnormalities in some human muscular diseases and in experimental ischemic myopathy.

Morphologic abnormalities have been observed in two cases of human polymyositis and in three cases of ocular myopathies. Similar findings can be observed in experimental ischemic myopathy. "Ragged red" fibres, with anomalous distribution of oxidative enzymes, mitochondrial alterations, with presence of intracristal paracrystalline inclusions and degenerative myofibrillar changes are the similar features. The similarity between some of these alterations, expecially mitochondrial changes, is remarkable, but it is difficult to correlate them to the primary etiology of described human myopathies.

Adult↗

Myoclonus epilepsy with cerebellar Lafora bodies. Report of a case.

A case is reported of an 18 year old man with progressive myoclonus epilepsy. Histopathological examination revealed the presence of numerous Lafora bodies in the cerebellar granular layer, without other significant changes in the central nervous system or in other organs.

Adolescent↗

A case of late onset lipid storage myopathy. Electromyographic, histochemical and ultrastructural findings.

A 65-year-old woman showed the clinical picture of a myogenic myopathy, confirmed electromyographically. Detailed histopathological, histochemical and ultrastructural studies were performed on deltoid and quadriceps femoris biopsy specimens. Many muscle fibres were found to contain vacuolar spaces with lipid droplets: perivascular inflammatory changes were also observed. The affected fibres were consistently type I. Under the electron microscope the fibres contained large numbers of lipid droplets, usually next to normal mitochondria. A slight improvement occurred after prednisone therapy.

Age Factors↗