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Biomedical subjects

G Serra

Publications and source records attributed to G Serra.

At least 73 records · Page 4Linked to original sources
PubMed1995

An AT-deletion causing a frameshift in the arylsulfatase A gene of a late infantile metachromatic leukodystrophy patient.

A metachromatic leukodystrophy (MLD) patient affected with the late infantile form was found to be homozygous for an AT-deletion (2324delAT) in the arylsulfatase A gene. The mutation causes a frameshift at the beginning of exon 8 leading to an early termination codon. The parents and unaffected brother of the patient were heterozygous for the microdeletion. The mutation was not detected in another 31 MLD Italian patients. No aberrant transcript caused by the mutation was revealed by the reverse transcription-polymerase chain reaction method.

Amino Acid Sequence↗
PubMed1995

Reduced serum levels of dehydroepiandrosterone sulphate in adrenal incidentalomas: a marker of adrenocortical tumour.

BACKGROUND AND OBJECTIVE: Reduced serum levels of dehydroepiandrosterone sulphate (DHEAS) have been shown in patients with Cushing's syndrome resulting from adrenocortical adenoma, in contrast with normal DHEAS levels in patients with Cushing's disease. The aim of this study was to verify whether patients with incidentally discovered adrenocortical adenomas also have reduced levels of DHEAS. DESIGN: Evaluation of serum DHEAS, serum and urinary cortisol, plasma ACTH and low dose dexamethasone suppression test in patients with adrenal incidentaloma and Cushing's syndrome. PATIENTS: Thirty-two patients with adrenal incidentaloma and, as controls, 17 patients with overt Cushing's syndrome, were studied. RESULTS: Serum DHEAS levels lower than normal were found in 21/24 (87.5%) patients with adrenocortical incidentaloma, but in only 1/8 patients with a mass of non-adrenocortical origin. This patient had massive bilateral metastatic infiltration of both adrenal glands and primary adrenal failure. The prevalence of low DHEAS levels in the two groups was significantly different (P = 0.0001). In patients with adrenocortical incidentaloma, the prevalence of low DHEAS levels was significantly higher (P = 0.0001) than that found for some hormonal alterations indicating pre-clinical hypercortisolism (high urinary cortisol, unsuppressed serum cortisol after low dose dexamethasone administration and low plasma ACTH). Low DHEAS levels were found in all patients with Cushing's syndrome due to adrenocortical adenoma but in none of those with Cushing's disease. CONCLUSIONS: Our results indicate that the finding of low DHEAS levels can be considered a marker of the adrenocortical origin of an adrenal incidentaloma, provided adrenal failure has been excluded.

17-alpha-Hydroxyprogesterone↗
PubMed1995

[Anxious-excited depression: a mixed affective syndrome].

A mixed affective syndrome is described which meets the criteria for major depression but not those of the DSM III-R for a mixed state. The clinical picture is characterized by lack of motor retardation and fluent verbalization; the facial expression is animated and sometimes dramatic. Patients suffer considerably and are often tearful. They complain of inner tension and restlessness, racing thoughts and despair. Emotional lability and momentary irritability are observed. Insomnia occurs initially or with frequent early waking. Suicidal ideation occurs and makes the syndrome of concern in view of its impulsive nature. Antidepressants increase restlessness, insomnia, aggressiveness and the impulsiveness of suicidal ideation. Low-dose neuroleptics, lithium and anticonvulsivants are highly effective. A few sessions of ECT offer rapid improvement.

Anxiety Disorders↗
PubMed1994

Antidepressant-like effect of selective dopamine D1 receptor agonists in the behavioural despair animal model of depression.

We compared the effect of two selective dopamine D1 receptor agonists, SKF 38393 ((+/-)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol.HCl) and A68930 ((1R,3S)-1-aminomethyl-5,6-dihydroxy-3-phenylisochroman.HCl), and that of imipramine in the behavioural despair model of depression. The dopamine D1 receptor agonists and imipramine showed an anti-immobility effect. Moreover we found that the 'antidepressant' effect of imipramine in the behavioural despair test was antagonized by SCH 23390, a selective dopamine D1 receptor blocker. The results further support the hypothesis that dopamine D1 receptor stimulation plays an important role in the mechanism of action of antidepressants and suggest that dopamine D1 receptor agonists might be considered as potential antidepressant drugs.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1993

Muscular weakness in the mdx mouse.

mdx mice are believed to be virtually free from neuromuscular symptoms, despite the presence of a degenerative/regenerative process that involves all skeletal muscles. We analyzed both the spontaneous motility and treadmill motor activity of mdx mice aged 15 days to 6 months. Our results indicate that there is an early period, between the end of the second and up to the fifth week of life, when mdx mice experience extreme weakness. After this critical period, both spontaneous motility and endurance of mdx mice, although lower than those of controls, do not show statistically significant differences up to 6 months of age. We also carried out a detailed histological analysis of proximal and distal muscle groups in mdx mice during this early critical motility period. The occurrence of extensive necrosis followed by regeneration and involving proximal muscles before distal ones was documented in mice as young as 16-17 days of age and reached a peak at day 18. We conclude that dystrophin deficiency induces muscle degeneration and significant weakness in mdx mice, but only in an early period. Later on, during development, mdx mice adapt to the lack of this protein and do not show detectable in vivo functional muscle impairment up to 6 months of age.

Aging↗
PubMed1993

[Lipiodol chemoembolization in the treatment of hepatic carcinoma. Our experience].

Of the alternative methods of treatment to surgery in the treatment of liver cancer, chemoembolization with Lipiodol appears to have obtained encouraging results. After a preoperative study to confirm the diagnosis and staging of the tumour, lipiodolisation is performed: a mix of Adriamycin, Iopamidol and Lipiodol is injected using selective catheterism of the hepatic artery; gelfoam is then added. Lipiodol selectively localises in the hepatocarcinoma and has a distal embolising effect on the vessels of the tumour, thus necrotising it, acting as a carrier for chemotherapy. Since july 1990 a total of 15 hepatocarcinoma have been observed: 6 in healthy livers and 9 in cirrhotic livers; 3 patients recovered after radical surgery, 1 patient underwent associated surgery and chemoembolization, whereas in 11 the only therapy was chemoembolization, at six monthly intervals. Lipiodolisation enabled a better diagnosis to be made and was found to be a valuable therapeutic aid both when used alone in Inoperable patients and in association with non-radical surgery.

Carcinoma, Hepatocellular↗
PubMed1993

A neurophysiological study on the P300 component of event-related potentials in Hakim-Adams syndrome.

We have explored the variability of P300 event-related potentials in patients affected by Hakim-Adams syndrome, with raised or intermittent intracranial pressure, treated with surgical cerebrospinal fluid shunting. The clinical utility of P300 is confirmed in the light of the improvement of neurophysiological data after the surgical procedure, parallel with amelioration of neuropsychological performances.

Aged↗
PubMed1993

A MERRF/MELAS overlap syndrome associated with a new point mutation in the mitochondrial DNA tRNA(Lys) gene.

Several members of a three-generation kindred from Sardinia were affected by a maternally inherited syndrome characterized by features of both myoclonus epilepsy with ragged-red fibers (MERRF) and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). Clinically, symptoms such as myoclonus epilepsy, neural deafness and ataxia were variably associated with stroke-like episodes and/or migrainous attacks. Morphologically, numerous MELAS-associated SDH-stained vessels were observed in muscle biopsies, either alone or in combination with ragged-red fibers, the morphological hallmark of MERRF. Sequence analysis of the mtDNA tRNA genes revealed the presence of a single, heteroplasmic T-->C transition at nt 8356, in the region of the tRNA(Lys) gene corresponding to the T-psi-C stem. The T-->C(8356) transition was exclusively found in the maternal lineage of our family, and the relative amount of the mutant mtDNA species in muscle was correlated with the severity of the clinical presentation. Therefore, we propose that the T-->C(8356) transition is responsible for the mitochondrial encephalomyopathy found in our family, and must be added to the expanding list of the pathogenetically relevant mutations of human mtDNA.

Acidosis, Lactic↗
PubMed1992

The NMDA receptor antagonist MK-801 prevents imipramine-induced supersensitivity to quinpirole.

Chronic treatment with imipramine enhanced the locomotor stimulant response to quinpirole (0.3 mg/kg s.c.), a dopamine D2/D3 receptor agonist. Chronic, but not acute, blockade of the NMDA receptor with the non-competitive antagonist MK-801 (0.3 mg/kg i.p.) prevented the imipramine-induced potentiation of the quinpirole effect. The results suggest that NMDA receptors play a role in the development of supersensitivity to dopamine receptor agonists produced by chronic antidepressant treatment.

Animals↗
PubMed1992

Biochemical diagnosis and outcome of 2 years treatment in a patient with combined methylmalonic aciduria and homocystinuria.

We describe a patient with methylmalonic aciduria and homocystinuria due to a defect in cobalamin metabolism of the Cbl-C type mutant (McKusick 277400). Our case was diagnosed within the first 2 months of life by amino acid analysis (ion-exchange chromatography) and by biochemical studies in cultured fibroblasts ([14C]propionate incorporation, methionine and serine formation). We discuss the clinical course and the biochemical evolution after 2 years of hydroxycobalamin treatment that led to an improvement in general clinical condition and neurological performance.

Amino Acids↗
PubMed1992

A comparative study of protein immobilization techniques for optical immunosensors.

This paper presents the results of a study of a number of antibody immobilization techniques for application to optical immunosensors. In particular, well-known methods such as covalent binding and physical adsorption have been extended to the Langmiur-Blodgett method in an attempt to improve the density and possibly the uniformity of orientation of monoclonal antibodies on an optical surface. The surface density of active immobilized antibodies was determined from enzyme immunoassay and their thickness and refractive index were deduced from ellipsometry. It is shown that, although high surface densities (500 ng/cm2) of antibody can be obtained, the major obstacle to the detection of low concentrations of antigens or haptens is the non-specific binding of foreign molecules to the sensing surface.

Adsorption↗
PubMed1992

Role of alpha 1 receptors in the behavioural supersensitivity to D2 agonists induced by chronic treatment with imipramine.

Chronic treatment with imipramine increased the locomotor response to quinpirole, a selective D2 receptor agonist. This effect was blocked by minute doses of prazosin (0.1-1 mg/kg), a selective alpha 1 receptor blocker, in a dose-dependent manner. Conversely, in control rats the locomotor response to quinpirole was enhanced by the stimulation of alpha 1 receptors with the selective agonist St 587. The results suggest that alpha 1 receptor stimulation plays a permissive role in the supersensitivity of D2 receptors following chronic treatment with imipramine.

Adrenergic alpha-Antagonists↗
PubMed1992

[Fentanyl prevents the pain at the site of propofol injection].

The effect of fentanyl, administered immediately before propofol, when pain is experienced at the site of propofol injection was studied in 28 children undergoing elective surgery. The intravenous administration of fentanyl (2 micrograms/kg) significantly reduced such pain compared with a control group receiving saline. The results suggest that the administration of fentanyl may be a valid procedure in relieving pain on injection of propofol.

Child↗
PubMed1991

Repeated treatment with imipramine potentiates cocaine-induced dopamine release and motor stimulation.

The stimulatory effect of cocaine on locomotor activity and on dopamine efflux from the ventral striatum was studied in rats chronically treated with the antidepressant imipramine. Chronic imipramine (20 mg/kg per day for 3 weeks) potentiated by about 2-fold cocaine-stimulated motor activity and extracellular dopamine concentrations. The results indicate that chronic imipramine facilitates mesolimbic dopamine neurotransmission by potentiating the mechanism which is thought to mediate the rewarding effects of cocaine.

3,4-Dihydroxyphenylacetic Acid↗