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Biomedical subjects

G Galli

Publications and source records attributed to G Galli.

At least 145 records · Page 8Linked to original sources
PubMed1991

Production processes of recombinant IL-1 beta from Bacillus subtilis: comparison between intracellular and exocellular expression.

The human IL-1 beta coding sequence derived from a cDNA library was inserted into two different plasmid expression vectors, pSM214 and pSM308, which promote the synthesis of recombinant products intracellularly and exocellularly, respectively. The hybrid constructs pSM261 and pSM320 were obtained. Bacillus subtilis SMS118 was transformed with these plasmids and the recombinant strains were grown in 1 litre bioreactors. Different growth conditions were analyzed to optimize yields both in terms of biomass and IL-1 beta production. In the pSM261-harbouring strain, IL-1 beta was synthesized in the cytoplasm to levels ranging from 1 to 2.7 mg g-1 of cells, corresponding to up to 40 mg l-1 of the culture. In contrast, SMS118(pSM320) was able to secrete 0.27 mg of natural IL-1 beta per g of cells (6.7 mg l-1 of culture). Processes for the purification of IL-1 beta from the supernatant and the biomass of the two cultures were also developed and compared in terms of yield and simplicity of the purification schemes. From our data it turns out that the route of intracellular expression is very efficient and superior to the one which results in secretion of IL-1 beta. This indicates that the use of B. subtilis as a recombinant host in biotechnology is not strictly dependent on its ability to secrete proteins into the culture medium.

Amino Acid Sequence↗
PubMed1991

Effects of acute valproic acid administration on carnitine plasma concentrations in epileptic patients.

Serial plasma samples collected after an acute administration of valproic acid, (VPA, 15 mg/kg as oral solution) in epileptic patients were selected for this study. The plasma samples were selected from three different groups of patients; patients on phenobarbital and phenytoin with clinical VPA intolerance (group A); patients on phenobarbital and phenytoin without clinical VPA toxicity (group B); and patients without phenobarbital and phenytoin and without clinical VPA toxicity (group C). Plasma samples from 6 patients per group were analyzed for carnitines and ammonia. Ammonia levels during acute study increased significantly (P less than 0.05) in patients who experienced VPA intolerance, while no changes were found in the other patients. After acute VPA administration, total carnitine was unchanged but free carnitine was decreased (P less than 0.05) and carnitine esters were increased (P less than 0.05) in all groups of patients studied. No difference in carnitine profiles was seen between patients with or without evidence of VPA administration has an important effect on carnitine metabolism. However, unlike the acute effect on ammonia metabolism, this acute effect does not seem to be correlated with any associated antiepileptic therapy, nor does it predict clinical VPA intolerance.

Adult↗
PubMed1991

Inhibition of antipyrine metabolism by low-dose contraceptives with gestodene and desogestrel.

To examine the effects of the two newest monophasic oral contraceptives on liver microsomal drug metabolism, plasma kinetics and urinary metabolite excretion of antipyrine, a model substrate for liver microsomes, were evaluated. Plasma lipid and lipoprotein levels, and in particular the high-density lipoprotein subfractions, were also monitored in view of their apparent regulation by a P450-dependent system. Ten healthy volunteers were treated with each contraceptive for a period of 3 months in a crossover trial. Both contraceptives significantly reduced antipyrine clearance by 34.6% (gestodene) and 43.3% (desogestrel) by impairing the oxidative metabolism, particularly to the 4-hydroxy and 3-hydroxymethyl metabolites, with little difference between the two associations. In addition, with both a comparable highly significant rise of plasma triglyceride levels, apolipoproteins A-I and A-II and the high-density lipoprotein-3 subfraction was observed. Treatment with these new monophasic contraceptives may reduce the metabolism of concomitantly given drugs undergoing oxidative transformations.

Adult↗
PubMed1991

Familial hypomelanosis of Ito.

Two siblings presented the typical skin changes of hypomelanosis of Ito (HI) associated with mental and cerebellar signs. Their mother showed only the skin changes of HI but no neurological disturbances. HI is a hereditary disorder, in which familiarity may go unnoticed because of the different expressions of neural and cutaneous features.

Adult↗
PubMed1991

Comparison between computed tomography and magnetic resonance imaging in the postoperative evaluation of acromegalic patients.

Twelve acromegalic patients who underwent transphenoidal resection of a GH-secreting pituitary adenoma were evaluated postoperatively by Computed Tomography (CT) and Magnetic Resonance (MR). CT and MR findings were compared with surgical and clinical results. MR was more accurate than CT in delineating postoperative abnormalities of the infundibulum, diaphragma sellae and optic chiasm. In three cases MR differentiated packing materials from adenomatous tissue. In cases with biochemical evidence of residual or recurrent tumor, MR clearly demonstrated intra- or extrasellar adenomatous tissue and the spatial relationship between the soft tissue mass and the cavernous sinuses. CT was superior to MR only in demonstrating sellar floor disruption. MR imaging detected the anatomical causes of clinical abnormalities in almost all acromegalic patients with incomplete recovery after surgery. On the basis of MR results it is possible to plan additional surgery, radiation therapy or medical treatment. MR may be the radiological procedure of choice for both surgical treatment planning and postoperative follow-up.

Acromegaly↗
PubMed1991

Pharmacokinetics of a controlled release preparation of naproxen.

The pharmacokinetics of a controlled release preparation of naproxen (750 mg) was compared with that of standard release naproxen, in 12 healthy volunteers. The plasma levels of naproxen and urinary recoveries of naproxen and metabolites were determined both after single doses and chronic administration. The experimental data show that the bioavailability of the controlled release preparation is equal to that of standard release naproxen; however, the controlled release preparation allows more constant plasma levels of naproxen and, when administered once a day for prolonged periods, is capable of maintaining effective concentrations for most of the dosing period.

Adult↗
PubMed1990

Replica filter assay of human beta-adrenergic receptors expressed in E.coli.

We have developed a replica filter assay that permits the direct identification of bacterial colonies expressing membrane receptors. E.coli transformed with appropriate phage or plasmid vectors containing human beta-adrenergic receptor cDNAs were grown on LB/agar plates. Bacterial colonies transferred onto nitrocellulose filters showed specific [125I]-iodocyanopindolol binding. beta-adrenergic receptors expressed in bacteria retained their pharmacological properties when transferred onto filters. This strategy, which is considerably simplified and more rapid compared to similar methods based upon expression of receptor genes in eukaryotic cells, may be a useful tool for cloning membrane receptors.

Brain Chemistry↗
PubMed1990

Differential effects of beclobrate on lipid/lipoprotein distribution in normal and hypercholesterolemic rats.

Beclobrate, a new fibric acid derivative, displays remarkable lipid lowering activity in rodents. In order to evaluate changes in the distribution and liver handling of lipoproteins, beclobrate was tested in rats fed on a normal or hypercholesterolemic diet. On the normal diet, beclobrate lowered total plasma cholesterol by 22-33.4% (10-50 mg/kg); the cholesterol reduction occurred mainly in high density lipoproteins (HDL) (by 24-45% with the three tested doses). The metabolic clearance of 125I-labelled beta-very low density lipoproteins (beta-VLDL) injected into these animals almost doubled (0.20 1/h vs. 0.13 1/h in controls) after treatment with 20 mg/kg of beclobrate. In addition, beclobrate administration dramatically increased the activity of the high-affinity receptors for beta-VLDL in isolated liver membranes (Bmax: 208 +/- 17.6 vs. 146 +/- 2.6 ng/mg of protein for controls). On the hypercholesterolemic diet, beclobrate treatment (50 mg/kg) was associated with a 25% reduction in total cholesterol accompanied, however, by a 166% rise in HDL cholesterol. In these animals, the composition of VLDL, typically cholesterol-enriched, became close to normal. The increased HDL was characterized by a remarkable enrichment with particles containing apolipoprotein E (apo E), which is compatible with either an improved peripheral cholesterol removal or an enhanced direct secretion of apo E. The two models offer different opportunities for evaluating the mechanism of action of this new lipid lowering agent. Lipoprotein catabolism and receptor-mediated clearance were characteristically improved in normolipidemic rats whereas major effects on HDL metabolism could be demonstrated in hypercholesterolemic rats.

Animals↗
PubMed1990

Production and biologic interactions of prostacyclin and platelet-activating factor in acute myocardial ischemia in the perfused rabbit heart.

This study showed that the 1-O-hexadecyl form of platelet-activating factor (PAF) is released along with 6-keto-prostacyclin1 alpha (6-keto-PGF1 alpha) in the perfusates of ischemic-isolated rabbit heart. During the early phase of the reperfusion, the release of PAF and 6-keto-PGF1 alpha was particularly increased (PAF, from 5.4 +/- 1.2 to 19.7 +/- 2.0 ng/min; 6-keto-PGF1 alpha, from 2.3 +/- 0.1 to 27.4 +/- 1.8 ng/min) and this event was coupled with the characteristic mechanical alterations of myocardial performance and perfusion pressure (PP). These changes were effectively antagonized by pretreatment of the hearts with both prostacyclin (PGI2, 20 ng/ml) and the PGI2-releaser defibrotide (400 micrograms/ml). The protecting activity observed with PGI2 was paralleled by a reduction in the rate of PAF release during reperfusion (from 19.7 +/- 2.0 to 6.8 +/- 0.2 ng/min). In defibrotide-treated preparations, inhibition of PAF formation was associated with a pronounced stimulation of 6-keto-PGF1 alpha generation, which was particularly marked on reperfusion (from 27.4 +/- 1.8 to 197.5 +/- 8.2 ng/min). Indomethacin (1 microgram/ml) ablated the antiischemic effect of defibrotide but did not potentiate the rate of formation of PAF despite inhibition of 6-keto-PGF1 alpha biosynthesis. From these results, we conclude that in a model of severe myocardial ischemia, in which the major determinants of cardiac performance are under control, generation of PAF and PGI2 appears to play an important biologic role in determination of the severity of myocardial ischemic damage.

Animals↗
PubMed1990

Effectiveness and safety of the low-molecular-weight heparin CY 216 in the prevention of fatal pulmonary embolism and thromboembolic death in general surgery. A multicentre, double-blind, randomized, controlled clinical trial versus placebo (STEP). STEP Study Group.

Deep venous thrombosis is very frequent after general surgery, and its major complication, pulmonary embolism, is today the most frequent cause of postoperative death. The reduction of this cause of mortality is mainly based on its prevention rather than its therapy. This purpose was achieved by using physical and pharmacological means. During the past 15 years, low-dose heparin has been one of the most important means in the prevention of deep venous thrombosis, associated with early mobilization of surgical patients, but its actual efficacy against fatal pulmonary embolism was never statistically proved. In the early 80s new heparins became available, and their first experimental and clinical use demonstrated a longer half-life, a higher anti-Xa activity, and a lower haemorrhagic risk. On the basis of these data, we started a study in order to assess efficacy and tolerance of the new low-molecular-weight heparin CY 216 in preventing fatal pulmonary and thromboembolic death in patients undergoing general surgery. The study was designed as a multicentre, double-blind, randomized, controlled clinical trial versus placebo. A total of 4,498 patients, aged over 40 years undergoing general surgery, with anaesthesia lasting at least 45 min, were consecutively enrolled in the 18 centres which took part in the trial. 2,247 accounted for the CY-216-treated group and 2,251 for the placebo group. The patients received either subcutaneous injections of 0.3 ml of CY 216, equivalent to 7,500 anti-Xa units, or of 0.3 ml of a saline solution supplied in an identical form. The first dose was administered 2 h before surgery, the second 12 h later, and then once daily for at least 7 days. A post-mortem examination was carried out in every patient who died. The trial began in February 1986 and ended in June 1988. Statistical analysis showed that the two groups of patients were well matched for age, sex, type of disease, site and duration of operations, as well as for the incidence of risk factors which could predispose to the thromboembolic disease. Twenty-six deaths were recorded and validated. Eight (0.36%) belonged to the CY 216 group and 18 (0.80%) to the placebo group. In the CY 216 group, pulmonary embolism was the direct cause of death in 2 patients (0.09%), while the remaining 6 deaths could not be ascribed either directly or indirectly to thrombosis. In the placebo group, pulmonary embolism was the cause of death in 4 cases (0.18%; p less than 0.05) and contributed to death in 4.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1990

Pharmacokinetic evaluation of conventional and controlled-release product of naproxen.

The bioavailability and pharmacokinetics of a new controlled-release tablet (CRT) of naproxen (750 mg tablet) have been determined, relative to an equivalent dose of conventional product (CT), by a cross-over study in twenty healthy volunteers. The two dosage forms were bioequivalent in terms of total AUC; however, the Cmax of the controlled-release product was lower, and the Tmax longer than that of the conventional product. The mean residence time and the absorption and elimination half-lives of the CRT were also substantially longer than those of the CT. The pharmacokinetic features offered by the novel formulation suggest that it may be suitable for once-daily dosing.

Absorption↗
PubMed1990

Multiple-dose pharmacokinetics of naproxen from a controlled-release tablet in healthy volunteers.

The pharmacokinetics of a new controlled-release tablet of naproxen (750 mg) given once daily has been studied in healthy volunteers, in comparison with two doses of the conventional naproxen tablets (375 and 500 mg) administered twice daily. Steady-state plasma concentrations of naproxen were achieved after two days of repeated administration of both the controlled-release and the conventional tablets. On day seven, peak concentration, cowest concentration and the steady-state average plasma concentration values of the controlled-release tablet were significantly higher than those of 375 mg conventional tablet and comparable to those of 500 mg conventional tablet. Areas under the plasma concentration-time curve indicated an equal extent of absorption between the new and the conventional formulation. Overall the controlled-release tablet administered once daily mimicked a twice daily regimen so suggesting that the new formulation could be suitable for once daily dosing.

Adult↗