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Biomedical subjects

S Ruggieri

Publications and source records attributed to S Ruggieri.

At least 37 records · Page 2Linked to original sources

Lipid characteristics of RSV-transformed Balb/c 3T3 cell lines with different spontaneous metastatic potentials.

To determine whether a metastatic phenotype may be correlated with a characteristic lipid pattern, we compared the lipid composition of low metastasizing Balb/c 3T3 cells transformed by the B77 strain of Rous sarcoma virus (B77-3T3 cells) with that of a subclone isolated by growth in 0.6% agar, the B77-AA6 cells, which exhibit a high capacity for spontaneous metastasis. B77-3T3 cells revealed characteristics in their lipid composition common to other systems of transformed cells, i.e., an accumulation of ether-linked lipids, a reduction of the more complex gangliosides, an increase of oleic acid (18:1) and a decrease of arachidonic (20:4) and C22 polyunsaturated fatty acids in phospholipids. High metastatic B77-AA6 cells showed: a) an even more marked decrease of complex gangliosides; b) a more pronounced increase of 18:1 and decrease of 20:4 and 22 polyunsaturated fatty acids in certain phospholipid classes; and c) a higher percentage of alkyl-acyl subfractions in both phosphatidylcholine and phosphatidylethanolamine than B77-3T3 cells. Comparing the data for other systems of metastatic cells with those of lipid studies of spontaneously metastasizing B77-AA6 cell system leads us to conclude that the metastatic phenotype is characterized by a change in ether-linked lipids, rather than in fatty acids.

Animals

Morphological characteristics and ganglioside composition of substratum adhesion sites in a hepatoma cell line (CMH5123 cells) during different phases of growth.

This study compares the ganglioside composition of tissue culture substrate-attached material (SAM) with that of cell bodies in a line of transformed hepatocytes derived from the minimal deviation Morris hepatoma 5123 c (CMH5123 cells). We examined both confluent cultures (late-phase cultures) and cells which were allowed to attach for only 3 h (early-phase cultures). We also determined to what extent ganglioside compositions of SAM and cell bodies from early- and late-phase cultures of CMH5123 cells are affected by the block of complex ganglioside biosynthesis induced by treatment with chelating agents (EGTA + EDTA). The morphological characteristics of SAM were monitored by scanning electron microscopy during the different steps of this study. In early-phase cultures, SAM was composed of fragments of filopodia and small vesicles probably representing newly formed substratum adhesion sites. In contrast, SAM of late-phase cultures was made up of large pools of membranous material resulting from the breakage of thick retraction fibers connecting the cell body with broad, mature adhesion sites. SAM of early-phase cultures yielded ganglioside profiles with a higher content of GM1 and GD1 a than those of cell bodies, while in late-phase cultures there was no difference between SAM and cell body gangliosides. When cells were grown in the presence of chelating agents, SAM of early-phase cultures was composed of vesicles and filopodial fragments similar to those found in early-phase cultures grown in regular media; these morphological features also appeared in SAM of confluent cultures (in contrast to the membranous material characteristic of late-phase cultures grown in regular media). In early-phase cultures grown in the presence of chelating agents, gangliosides of SAM were enriched in complex homologs relative to their content in cell bodies. These ganglioside characteristics were also found in SAM of confluent cultures grown in the presence of chelating agents, reflecting the presence of newly formed adhesion sites. On the basis of these results, we may conclude that the molecular assembly of newly formed adhesion sites implies the preferential distribution of several surface components involved in cell adhesion, including complex gangliosides.

Animals

A pharmacological study of dopaminergic receptors in planaria.

The dopaminergic receptors of planaria have been studied with pharmacological and biochemical criteria. Dopamine D1 selective agonists (CY 208243 (10 micrograms/ml) and SKF 38393 (10 micrograms/ml] induced in planaria typical screw-like hyperkinesias, that were inhibited by a D1 antagonist (SCH 23390 (10 micrograms/ml], but not by a D2 antagonist (sulpiride (1000 micrograms/ml]. Dopamine D2 selective agonists (PHNO (5 micrograms/ml), lisuride (5 micrograms/ml] on the contrary induced a typical "C" like curling, that was inhibited by pretreatment with D2 selective blocking agents, but not by D1 selective blocking agents. With agonists with a D1/D2 mixed action (apomorphine 60 micrograms/ml) or with amphetamine (100 micrograms/ml), the D1 type movements appeared to be more evident. Dopamine D1-selective agonists, mixed action agonists or D2-selective agonists, all induced a significant increase in levels of cAMP, that was prevented by pretreatment with the specific DA blocking agent.

Animals

One year treatment with lisuride delivery pump in Parkinson's disease.

1. A group of 14 fluctuating Parkinsonian patients underwent the subcutaneous Lisuride treatment, administered by an insulin delivery pump. Clinical response has been studied during a one year period. 2. Some patients (8 out of 14) were in combined therapy, assuming a relative small amount of oral L-Dopa together with subcutaneous Lisuride. 3. Lisuride confirmed, also by the subcutaneous route, its antiparkinsonian properties, without any loss of therapeutical efficacy during the 12 month period considered. 4. 7 patients dropped-out from the study, due to psychiatric or systemic side-effects and to "technical" management of the pump. 5. The only 2 patients assuming a 24 hour regimen of Lisuride infusion were among the withdrawn subjects. They were also the only to complain severe psychiatric disturbances.

Adult

A comparative study of some properties of cytidine deaminase from Escherichia coli and chicken liver.

The molecular and kinetic properties of cytidine deaminase from E. coli and chicken liver show several interesting differences and similarities: 1. Both enzymes possess an oligomeric structure, and linear kinetics. 2. The chicken liver enzyme is strictly dependent on the presence of reducing agents and presents a microheterogeneity in the pure preparation. 3. Both enzymes display identical specificity and share a rapid-equilibrium random Uni-Bi mechanism of catalysis. 4. The chicken liver enzyme is inhibited competitively by dTTP, CMP and dCMP.

Animals

Cardiovascular effects of lisuride continuous intravenous infusion in fluctuating Parkinson's disease.

The cardiovascular effects of a continuous intravenous infusion of lisuride plus oral domperidone were studied in 16 fluctuating parkinsonian patients as compared to their usual oral therapy with levodopa plus carbidopa. The study was performed using a 24-h ambulatory recording and an automatic noninvasive device for blood pressure monitoring. During lisuride infusion, a significant increase of systolic blood pressure was observed; however, in three patients, a decrease of systolic-diastolic blood pressure occurred; furthermore, a mild increase of atrial arrhythmias and, in two patients, a short run of atrial fibrillation were noted. Asymptomatic orthostatic hypotension, observed in seven patients during levodopa therapy, disappeared during lisuride infusion. Paradoxical hypertensive effects and disappearance of orthostatic hypotension observed in our patients seem related to the concurrent administration of domperidone.

Adult

A spectrophotometric method for the assay of pyrimidine 5'-nucleotidase in human erythrocytes.

A new spectrophotometric assay for human erythrocyte pyrimidine 5'-nucleotidase using a continuous spectrophotometric method is described. The activity is detected by measuring uracil, which is produced by a coupled assay including cytidine deaminase and uridine nucleosidase. The results obtained with the continuous spectrophotometric method have been confirmed by high pressure liquid chromatography (HPLC) analysis. This procedure, not based upon inorganic phosphate formation and avoiding the use of radioactive material, offers significant advantages with respect to commonly adopted assays.

5'-Nucleotidase

Essential fatty acid deficiency during acute puromycin nephrosis ameliorates late renal injury.

Puromycin aminonucleoside (PA) nephrosis is associated with a significant increase in the glomerular macrophage number during peak proteinuria. The significance of this observation remains uncertain. An essential fatty acid-deficient (EFAD) diet depletes normal rat glomeruli of resident macrophages and alters glomerular eicosanoid metabolism. In this study, we found that an EFAD diet, administered only for the duration of the acute nephrotic phase, significantly ameliorated the recurrent albuminuria, renal dysfunction, and morphological injury characteristic of the late, recurrent phase of chronic aminonucleoside nephrosis. Glomerular macrophage number, isolated glomerular thromboxane B2 production, and circulating leukocyte and monocyte counts were significantly reduced in nephrotic rats on the EFAD diet 2 wk after PA injection, which temporally corresponds to peak albuminuria. The exact mechanism(s) by which the EFAD diet conferred protection in the late phase of chronic aminonucleoside nephrosis and lowered glomerular macrophage number during the acute nephrotic phase remain to be elucidated.

Acute Disease

Characteristics of ether-linked glycerophospholipids in Friend erythroleukaemia cells differentiated by dimethyl sulphoxide or hexamethylenebisacetamide and in non-inducible clones treated with the inducers.

The present study deals with changes in ether-linked glycerophospholids which accompany differentiation of Friend erythroleukaemia (FEL) cells by dimethyl sulphoxide (DMSO) and hexamethylenebisacetamide (HMBA). We also tested clones of FEL cells non-inducible by DMSO or HMBA for ether-linked lipid changes not related to the differentiation process. FEL cells contained appreciable proportions of alkenylacyl and alkylacyl subfractions in phosphatidylethanolamine (PE) and phosphatidylcholine (PC). Compared with FEL cells, clones non-inducible by DMSO or HMBA had a greater amount of alkenylacyl PE associated with a lack of alkenylacyl PC. The differentiation of FEL cells by DMSO or HMBA was accompanied by a reduction of alkylacyl PE and PC. DMSO- and HMBA-differentiated FEL cells showed changes in alkenyl- and alkyl-chain profiles, some of which were also observed in non-inducible FEL cells treated with DMSO or HMBA.

Acetamides

Lipid characteristics of Friend erythroleukaemia cells differentiated by dimethyl sulphoxide or hexamethylenebisacetamide, and of non-inducible clones treated with the inducers.

We studied the lipid changes in Friend erythroleukaemia (FEL) cells differentiated by dimethyl sulphoxide (DMSO) or hexamethylenebisacetamide (HMBA). We also examined clones of FEL cells non-inducible to differentiation by DMSO or HMBA for lipid changes not related to the differentiation process. A decrease in triacylglycerols was found in both DMSO- or HMBA-differentiated FEL cells, whereas a decrease in phosphatidylethanolamine was observed only in DMSO-differentiated FEL cells. The characteristics of the phospholipid fatty acid profiles of FEL cells, which proved to be similar to those of other transformed cells, were not significantly affected by erythroid differentiation.

Acetamides

Recent observations on the structure and the properties of yeast NMN adenylyltransferase.

A homogeneous preparation of yeast NMN adenylyltransferase (EC 2.7.7.1) showed microheterogeneity, which was revealed by FPLC (Fast Protein Liquid Chromatography) ion exchange chromatography. The resolved components have been characterized with respect to electrophoretic behavior and adenine content. The results led to a hypothesis about a possible role of poly(ADP-ribosylation) in modulating the enzyme activity.

Adenine

Comparison between L-dopa and lisuride intravenous infusions: a clinical study.

L-Dopa is still the most effective drug for the treatment of Parkinson's Disease, but after 5 years or more of therapy fluctuations in motor performance and abnormal involuntary movements commonly appear. Continuous intravenous infusions of L-Dopa abolish or strikingly reduce such fluctuations. Unfortunately, this is not suitable for daily treatment because of the low solubility of L-Dopa. Lisuride is a potent dopamine agonist and is very soluble in water. In this study the clinical effects of L-Dopa and lisuride continuous intravenous infusions were compared in a group of 20 fluctuating parkinsonian patients. L-Dopa controlled fluctuations in almost all the subjects, whereas only seven patients were continuously mobile while taking lisuride. Another seven patients showed a fluctuating response and the remaining six did not satisfactorily respond to lisuride. Dyskinesias were present in all patients during "on" phases, with both levodopa and lisuride treatment.

Adult

Subcutaneous lisuride infusion in Parkinson's disease: clinical results using different modes of administration.

The continuous dopaminergic stimulation provided by infusion of dopamine agonist drugs, is a very effective strategy to control ON-OFF fluctuation in Parkinson's disease. Lisuride is a potent dopamine agonist drug, very soluble in water and can be administered subcutaneously. Many authors have shown that the subcutaneous infusion of lisuride can control fluctuations when applied in combination with oral levodopa as a 24 hour continuous infusion regimen. In this study, lisuride was given without any other antiparkinsonian medicament and using a 12 hour infusion regimen wherever possible. 13 fluctuating Parkinsonian patients were studied. 6 out of these 13 were satisfactory treated with lisuride alone and the remaining 7 with a combination of Lisuride + oral levodopa. Only in 3 out of 13 patients the 24 hour infusion regimen was required.

Administration, Oral

Pharmacokinetics of lisuride after subcutaneous infusion.

Six parkinsonian patients received a constant subcutaneous infusion of 60 micrograms lisuride per hour in the abdominal region for 2 hours. Plasma levels of the unchanged drug were measured by radio-immunoassay. During infusion, a steady state plasma level of 0.78 +/- 0.19 ng/ml was achieved. After discontinuation of the infusion, concentrations declined with a half-life of 1.4 +/- 0.4 hour. The total clearance of lisuride was 20 +/- 6 ml/min/kg. Due to the low interpatient variability of plasma levels, a good control of clinical effects is to be expected.

Administration, Oral