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Biomedical subjects

A Lazzaro

Publications and source records attributed to A Lazzaro.

15 recordsLinked to original sources

Central diabetes insipidus due to acute monocytic leukemia: case report and review of the literature.

We describe a 69-year-old man who presented with a four-month history of polyuria and polydipsia. Plasma vasopressin levels were undetectable, and a dehydration test was abnormal. Based on these findings, a diagnosis of central diabetes insipidus has been established. Hematologic studies showed acute monocytic leukemia. A relationship between the hematologic and endocrine disturbance has been hypothesized, and histological examination at autopsy showed leukemic infiltration of the pituitary stalk. This patient represents the third case in the world literature of central diabetes insipidus associated with acute monocytic leukemia.

Diabetes Insipidus

Ganglioside derivative LIGA20 reduces NMDA neurotoxicity in neonatal rat brain.

The semisynthetic ganglioside derivative LIGA20 (II3Neu5-AcGgOse4-2-d-erythro-1,3-dihydroxy-2-dichloro-ac eta mide-4-trans-octadacene) was found to be about ten times more potent than the natural ganglioside GM1 in protecting neurones in culture against glutamate toxicity. Here we show that, in vivo, LIGA20 attenuated toxicity of the glutamate receptor agonist N-methyl-D-aspartate (NMDA). In seven-day-old rats NMDA was injected intracerebroventricularly, while LIGA20 or GM1 were administered subcutaneously. The loss in brain weight, five days following treatment, was used to estimate NMDA toxicity. Significant protection was observed with 2.5 mg kg-1 of LIGA20, while at least ten times this dose was needed for GM1, thus suggesting the superior in vivo pharmacological action of LIGA20.

Animals

Monosialoganglioside GM1 reduces NMDA neurotoxicity in neonatal rat brain.

Monosialoganglioside GM1 prevents excitatory amino acid (EAA)-related neuronal death in cultured central nervous system (CNS) neurons and reduces the severity of acute brain damage in different experimental models of cerebral ischemia. Using a model of brain damage induced by intracerebroventricular administration of N-methyl-D-aspartate (NMDA) in neonate rats, we evaluated whether GM1 is capable of exerting antiexcitotoxic effects following its systemic administration in vivo. Newborn rats subjected to brain damage by NMDA and contemporaneously treated subcutaneously with GM1 showed significantly reduced (i) loss in hemispheric weight, (ii) loss in tissue choline acetyltransferase activity, and (iii) morphological damage in various brain areas. These results indicate that systemic GM1 treatment is efficacious in reducing EAA-related neuronal damage in vivo and suggest that such a phenomenon may underlie its capability to ameliorate neurological outcome following cerebral ischemia.

Animals

Effects of monosialoganglioside GM1 in experimental models of ischemic brain damage.

Systemic administration of monosialoganglioside GM1 is efficacious in reducing excitatory amino acid (EAA)-related neurotoxicity in vivo following intracerebroventricular injection of N-methyl-D-aspartate (NMDA) in 7-day-old rats. Five days later, NMDA-treated animals showed extensive brain damage which was accompanied by significant decreases in brain weight, choline acetyltransferase activity and 3H-ouabain binding. All these neurotoxic effects were significantly reduced with ganglioside treatment. Since excessive activation of EAAS is implicated in hypoxic-ischemic brain damage, these results favor the hypothesis that a similar effect is involved in the ability of ganglioside to ameliorate outcome following cerebral ischemia.

Animals

Protective effects of a monosialoganglioside derivative following transitory forebrain ischemia in rats.

We evaluated the effects of treatment with the inner ester derivative of the monosialoganglioside GM1 on cortical electroencephalographic activity and hippocampal CA1 morphology after transitory, near-complete cerebral ischemia in rats. Ischemia was induced by the four-vessel occlusion method, and we studied only the 58 rats that showed flattening of the cortical electroencephalogram for the entire 30 minutes of occlusion. The ganglioside (n = 30) or saline (n = 28) was administered intravenously immediately after release of the carotid clips and then intramuscularly for 21 days of observation. Cortical electroencephalographic activity was monitored throughout the experiment. After 21 days of recirculation we assessed hippocampal CA1 damage by light microscopy. The results indicate that treatment with the ganglioside reduces postischemic secondary damage to the cortical circuitry (as indicated by significantly higher cortical electroencephalographic activity late after reperfusion) and limits neuronal loss in the CA1 region. Our results lend support to the possible therapeutic use of ganglioside in human pathologic conditions associated with cerebrovascular insufficiencies.

Animals

Monosialoganglioside effects following cerebral ischemia: relationship with anti-neuronotoxic and pro-neuronotrophic effects.

Increasing evidence is available indicating that systemically administered GM1 is able to provide for functional recovery in different experimental models of CNS injury, including cerebral ischemia. Current evidence indicates that the GM1 effects are associated, in the acute phase, with attenuation of secondary neuronal damage due to its capability to antagonize excitatory amino acid-related neurotoxicity in vivo as in vitro. Furthermore, the ganglioside is able to facilitate occurrence of long-term reparative processes, an effect most likely reflecting the potentiation of the action of neuronotrophic factors. This bifaceted action of GM1 makes the ganglioside ideally suited for clinical treatment of patients afflicted by cerebrovascular insufficiencies.

Animals

Hypoxic-ischemic damage and the neuroprotective effects of GM1 ganglioside.

In vitro studies have shown that monosialoganglioside GM1 reduces excitatory amino acid-related neurotoxicity by limiting the downstream consequences of abusive excitatory amino acid receptor stimulation. Systemic administration of GM1 appears to be efficacious in reducing acute neuronal damage and in facilitating medium- and long-term functional recovery after brain injury. We propose that GM1 protective effects in the acute injury phase results from attenuation of excitotoxicity, whereas the functional recovery seen at longer term could reflect GM1 potentiation of neuronotrophic factors. The potential therapeutic efficacy of GM1 administration in humans is suggested by clinical studies demonstrating improved neurologic outcome in stroke patients.

Amino Acids

[Prevention of recurrent respiratory infections in adults].

The authors compared the results obtained by using antibiotic therapy, vaccine, thymomodulin (a calf thymus acid lysate) and association of vaccine-thymomodulin in order to prevent acute infectious episodes in a group of 85 patients suffering with recurrent respiratory infections. The use of thymomodulin, alone and in association with vaccine, at the dose of 120 mg/die for 20 days/month during the period of observation (4 months), determined a higher reduction, (p less than 0.001) if compared with the other treatments, of the number and the duration of infectious episodes and moreover of the antibiotics' intake. Also the respiratory symptoms, and in particular the fits of coughing, showed an improvement. The pulmonary function indices and the laboratory parameters were unchanged in all groups studied.

Adult