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Biomedical subjects

A Mangoni

Publications and source records attributed to A Mangoni.

At least 37 records · Page 2Linked to original sources
PubMed1997

Short and long latency cortical potentials evoked by electrical stimulation of the oesophageal mucosa in normal alert humans.

Cerebral responses from the oesophagus were investigated in 16 normal male and female volunteers ranging in age from 20 to 54 years. The stimulus was applied by a naso-oesophageal probe equipped with bipolar ring electrodes. Short and long latency EP (SLEP and LLEP) were observed in all the subjects examined. SLEP consisted in a low threshold potential of 30 to 70 microV amplitude, biphasic or triphasic in shape and of approximately 5 to 10 ms duration; mean latency at the largest peak was 4.5 +/- 1.7 at 25 cm from the nostrils. Early components at about 2.5-3.5 ms and of small amplitude are also present. Recording from the neck at C7 with a common non-cephalic reference, SLEP components occurred from 2 to 6 ms earlier than that from the scalp, suggesting an oligo-synaptic transmission of the excitement via ganglion and lemniscal pathways to the cortex. SLEP was always followed by a complex potential formed of a succession of negative and positive waves with latencies ranging from 20 to 300 ms: the LLEP. This LLEP was usually not very stable and reproducible during the course of successive recordings and in the same subject because it tended to adjust. Preliminary observations concerning the topographical cortical distribution of oesophageal evoked potentials show a circumscribed localization of the SLEP in the parieto-temporal region of the hemisphere whereas LLEP was more widespread. It is the authors' opinion that oesophageal evoked potentials are generated both by the excitation of myelinic fibres with a wide range of conduction speed and of amyelinic fibres from the oesophageal mucosa and the paraoesophageal peripheral nerves of vagal origin.

Adult↗
PubMed1996

Expression of fatty acid synthase (FAS) as a predictor of recurrence in stage I breast carcinoma patients.

BACKGROUND: Fatty acid synthase (FAS) is a molecule found in tumor cells from breast carcinomas of patients whose prognosis is very poor. Recently, this molecule has been identified as the key enzyme in fatty acid biosynthesis. This study was done to test the strength of FAS as a prognostic indicator for disease free survival (DFS) and overall survival (OS). METHODS: Clinical records, histologic features, immunohistochemical expression of cathepsin D and c-erbB-2, and estrogen and progesterone receptor status of 110 Stage I breast carcinoma patients were all associated with FAS by a chi-square test. The patterns of DFS and OS were estimated over a ten-year follow-up period using the Kaplan-Meier method. Univariate and multivariate analysis were evaluated using a log logistic regression model. Multivariate regression analysis was based on the Cox proportional hazard model. To detect FAS, cathepsin D and c-erbB-2 expression as well as estrogen and progesterone receptor status, we used the unlabeled immunoperoxidase technique on formalin fixed, paraffin embedded tissue. RESULTS: FAS was significantly associated with a higher risk of recurrence because it predicted both DFS (P = 0.0001) and OS (P = 0.003) when evaluated as a continuous variable and DFS (P = 0.0001) when evaluated with other prognostic markers. Peritumoral lymphatic vessel invasion was the other most significant independent predictor for DFS (P = 0.001) and OS (P = 0.003). CONCLUSIONS: FAS is a reliable prognostic marker to predict DFS and OS in patients with early breast cancer.

Adult↗
PubMed1996

Picomole scale stereochemical analysis of sphingosines and dihydrosphingosines.

We have developed a simple picomole (low nanogram) scale HPLC scheme which can separate all eight isomers of sphingosine and dihydrosphingosine thus leading to the identification of their relative and absolute configurations. The amino group of the sample is derivatized to its fluorescent N-naphthimide which is analyzed by normal and chiral phase HPLC, coupled with fluorescence peak detection. If necessary, the results of this HPLC method can be further corroborated by measurements of circular dichroic (CD) spectra of the N-naphthimido-derivatives and/or N,O-chromophoric derivatives.

Chromatography, High Pressure Liquid↗
PubMed1995

Sterols from the Caribbean sponge Neofibularia nolitangere. Isolation of two novel polyhydroxysteroids.

The sterol composition of the Caribbean sponge Neofibularia nolitangere has been investigated. In addition to usual sterols this sponge elaborates comparable amounts of 24-methylene-4 alpha-methyl-5 alpha-cholest-8-en-3 beta-ol (1), which is very unusual among sponge sterols, and lesser quantities of two new polyoxygenated sterols, (24S)-24-ethyl-5 alpha-cholest-8-ene-5,6 beta,7 alpha-triol (2) and (24S)-24-ethyl-5 alpha-cholest-8(14)-ene-5,6 beta,7 alpha-triol (3).

Animals↗
PubMed1995

HIV infection and drug use: influence on cognitive function.

OBJECTIVE: To examine the involvement of cognitive function in HIV-seropositive drug users (DU) in a pre-AIDS state. DESIGN: Fifty-six HIV-positive DU were prospectively evaluated. They belonged to groups II, III and IV (subgroups A, C2 and E) of the 1987 Centers for Disease Control and Prevention classification, with anamnesis negative for neurological pathology. HIV-negative DU (n = 19) and non-DU (n = 27) were used as controls. Infection with HIV and use of toxic drugs were considered variables of influence on cognitive function. METHOD: Subjects underwent neuropsychological evaluation by tests designed to explore cortical and subcortical function. RESULTS: HIV-positive DU showed worse performance scores at the psychometric tests than HIV-negative non-DU, but there was no difference when compared with HIV-negative DU. Ex-DU showed better performance than active DU. No difference with regard to degree of disease evolution was observed among HIV-positive individuals (i.e., groups II and III versus group IV). CONCLUSIONS: There was no evidence of cognitive deficits in HIV-positive individuals in non-AIDS phases to indicate early involvement by HIV at the cerebral level. Progression of the disease, prior to the AIDS phase, did not determine a worsening of intellectual performance. Instead, cognitive function was affected by the chronic and current use of toxic substances. In HIV-positive DU, a decline in cognitive function was found to be attributable to the chronic use of toxic substances rather than HIV infection.

Cognition↗
PubMed1994

Reversible bilateral opercular syndrome secondary to AIDS-associated cerebral toxoplasmosis.

A case of reversible anterior bilateral opercular syndrome (Foix-Chavany-Marie syndrome) secondary to cerebral toxoplasma abscesses is described in a patient with AIDS. The symptoms regressed following antitoxoplasma and antiedema drug therapy. Although this is the first reported AIDS-related case, the syndrome is likely to recur in AIDS sufferers in whom multifocal cerebral lesions are common.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Novel 3-beta-methoxysteroids from the Senegalese sponge Microscleroderma spirophora.

The Senegalese sponge Microscleroderma spirophora has been found to produce exclusively very unusual 3 beta-methoxysteroids in place of the common 3 beta-hydroxysteroids. Six different methoxysteroids (three of which are novel compounds) have been isolated and identified by spectroscopic means (MS, IR, 1H and 13C NMR), and their taxonomic significance discussed. A new method for the determination of the configuration at C-24 in saturated 24-ethyl side chains is also proposed.

Animals↗
PubMed1994

Myotonia induced by potassium repletion in a diabetic patient with secondary hypokalemic paralysis.

In a woman suffering from insulin-dependent diabetes mellitus, hypokalemic paralysis developed acutely following an episode of diabetes decompensation. During the treatment of this episode, as soon as serum potassium levels were restored to normal values, a marked increase in muscular excitability with an electromyographic picture of myotonia was observed. The patient showed signs of chronic muscle denervation that accounted for an increased sensitivity to potassium-induced depolarization and contraction and that might have been responsible for the appearance of myotonia during potassium repletion.

Adult↗
PubMed1993

An electrophysiological method to assess the distribution of the sensory propagation velocity of the digital nerve in normal and diabetic subjects.

We report a new computer-assisted collision method to evaluate sensory conduction velocity (SCV) distribution in the digital nerve of the middle finger in normal subjects and in insulin-dependent diabetic subjects without any neurological impairment. Distribution curves were monomodally shaped in controls, indicating a greater proportion of fibers with relatively slow conduction velocity and a lesser proportion of fibers with faster velocity. In most diabetic nerves, a monomodal trend of the SCV distribution indicated a definite reduction in high and intermediate SCV. In a small proportion of nerves, the SCV distribution tended to be bimodal, with an absolute maximum corresponding to lower velocities and a relative maximum to intermediate-fast velocities. Slowing of the intermediate velocity, or loss of fibers of intermediate velocity, can be hypothesized to represent the early electrical evidence of a subclinical polyneuropathy in insulin-dependent diabetic subjects.

Action Potentials↗
PubMed1993

Peripheral autonomic involvement in the carpal tunnel syndrome.

The sympathetic skin response (SSR), evoked from the middle finger of both hands by electrical stimuli to the median nerve (MN) at the wrist, was studied in 21 patients with bilateral carpal tunnel syndrome (CTS) and in 16 patients with monolateral CTS (14 at the right and 2 at the left side) without clinical signs of autonomic involvement. In monolateral and bilateral CTS there was a decrease in the SSR areas of both sides. In monolateral CTS the decrease was greater contralaterally to the lesion. A decrease in the SSR in CTS generally indicates a local blockade of sympathetic nerve excitability due to MN entrapment. Contralateral reduction of the sympathetic response suggests an involvement of the efferent pathway of the autonomic reflex far from the lesion at the wrist. However, dispersion of the excitement over a long distance and throughout numerous synaptic connections may affect contralateral more than homolateral SSR excitability. Finally, sympathetic damage in CTS is in accord with the anatomo-functional correlation (in the peripheral nerve and ganglia) between somatic sensory, which were most markedly involved in our patients, and sympathetic afferent nerve fibers.

Adolescent↗
PubMed1993

Neuropsychological performance in HIV-1-infected drug abusers.

Twenty-five HIV-seropositive drug abusers (DA+HIV+) (groups II-III and IV [A, C2 and E] of the CDC classification) were evaluated by use of the WAIS scale to determine any possible involvement of cognitive functions in the not yet overt phases of AIDS. The results were compared with those obtained in two control populations composed of 19 seronegative drug abusers (DA+HIV-) and 24 healthy subjects (DA-HIV-) to evaluate, in addition to the disease, the possible effect of the use of alcohol and toxic substances on cognitive performance. In spite of the small number of subjects, the study indicated that drug abuse is the main factor, among those analyzed, in determining a decline in cognitive functions.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Guillain-Barré syndrome associated with high titers of anti-GM1 antibodies.

We found high titers of anti-GM1 antibodies (1/1280 or more) in 3 of 14 consecutive patients (21%) with Guillain-Barré syndrome (GBS) and in 2 additional patients who developed GBS, 10-11 days after starting parenteral treatment with gangliosides. Antibodies were IgG in 4 patients and IgM in one, and they all bound to asialo-GM1, and, in 3, to GD1b as well. Although the clinical features in all the patients with high anti-GM1 titers fulfilled the criteria for the diagnosis of GBS and in 4 of them, proteins but not cells were elevated in cerebrospinal fluid, electrodiagnostic studies in 3 patients showed prominent signs of axonal degeneration, that in one case were confirmed by morphological studies on sural nerve biopsy. No recent antecedent infection was reported by these patients, but in 3, including patients treated with gangliosides, anti-Campylobacter jejuni antibodies were elevated. In 3 patients a consistent decrease in anti-GM1 levels was observed after the acute phase of the disease suggesting that the frequent occurrence of these antibodies in patients with GBS and their frequent association with a prominent axonal impairment may have pathogenetic relevance.

Adolescent↗
PubMed1992

Three new D-ring unsaturated sterols from the Mediterranean sponge Topsentia aurantiaca: structure determination and complete nuclear magnetic resonance assignment.

Three novel sterols with a rare D-ring unsaturation were isolated from the marine sponge Topsentia aurantiaca and identified as 5 alpha-cholest-14-ene-3 beta,16 alpha-diol (2), 24R-ethyl-5 alpha-cholest-14-ene-3 beta,16 alpha-diol (3), and 24S-ethyl-5 alpha-cholest-14-ene-3 beta,16 alpha-diol (4). The sponge also elaborates a further D-ring unsaturated sterol, 5 alpha-cholest-15-en-3 beta-ol (1), which has been previously described only as a synthetic product. All the 1H and 13C nuclear magnetic resonances of compounds 1 and 2 were assigned to the relevant protons and carbons by bidimensional COSY, HETCOR, and HMQC nuclear magnetic resonance experiments.

Cholestanols↗
PubMed1992

Linear diterpenes from the Caribbean sponge Myrmekioderma styx.

Four new oxygenated diterpenes 1-4 were isolated from the Caribbean sponge Myrmekioderma styx. The structures of these compounds were deduced by ms, uv, ir, 1H- and 13C-nmr, 1H-1H COSY, XHCORR, and COLOC experiments. Compounds 1-4 are lethal to brine shrimp (Artemia salina).

Animals↗
PubMed1992

Low dose flunarizine in the prophylaxis of migraine.

In a period of one year (1990) we selected 40 patients suffering from migraine. For an open randomized study there were 2 groups of patients: the first were treated with 10mg of flunarizine per day and the second with 3 mg per day. The patients were treated for 4 months consecutively. There were 11 drop outs (27.5%): nine for poor compliance and 2 due to side effects. The efficacy of flunarizine in the prophylaxis of migraine was essentially identical in the two dosage groups while the incidence of side effects was considerably reduced in the patients treated with the lower dose.

Adolescent↗
PubMed1992

Altered vasopressin response to metoclopramide in multiple system atrophy: evidence of a cholinergic defect in the hypothalamus.

Multiple system atrophy (MSA) is a heterogeneous group of central neurological degenerations often associated with diffuse deterioration of the hypothalamic cholinergic neurons. In the hypothesis of an altered cholinergic regulation of vasopressin release, we evaluated vasopressin response to metoclopramide (20 mg i.v.), a cholinomimetic agonist, in 12 MSA patients. In the same patients the hemodynamic and osmolal control of vasopressin was also evaluated. We found that MSA patients had significantly lower basal plasma vasopressin values and higher plasma osmolality than control subjects. However, they displayed a normal vasopressin response to osmotic stimulation. During head-up tilting, orthostatic hypotension occurred in all patients, and the vasopressin response to hypotension was severely blunted in 5 of 12 patients, thus demonstrating the presence of a lesion of the afferent noradrenergic pathways. Metoclopramide increased vasopressin in control subjects, whereas MSA patients did not display any increase in vasopressin. These results clearly indicate that cholinergic neurons that regulate vasopressin release are damaged in MSA. Such an alteration may be dissociated from the lesion of the afferent noradrenergic pathways. As a consequence of the altered vasopressin release, MSA patients show lower plasma vasopressin levels with consequent propensity to dehydration and hypovolemia, which may further aggravate their hypotension.

Autonomic Nervous System Diseases↗
PubMed1992

Congenital basilar impression: correlated neurological syndromes.

A series of 8 cases operated on for symptomatic basilar impression associated with occipitalization of the atlas is reported (with or without atlantoaxial dislocation). Symptoms of onset (such as the frequent association between nuchal pain and vertigo) are emphasized and analyzed in relation to the pathogenetic mechanism that underlies the multiform symptomatology of the basilar impression. The diagnostic workup for basilar impression foresees X-rays, magnetic resonance imaging and computed tomography. The most important diagnostic problem is that of considering the possible existence of such a pathology in the presence of very common symptoms such as nuchal pain and vertigo. The surgical treatment has certainly been useful both to improve and to stabilize the symptomatology mainly when there is atlantoaxial dislocation. In fact in these cases the symptomatology is more severe and progressive for the alteration of the transverse ligament of the atlas secondary to abnormal mechanical stimuli.

Adult↗