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Biomedical subjects

G Galli

Publications and source records attributed to G Galli.

At least 19 recordsLinked to original sources
PubMed1992

Defibrotide has antiischemic activity in perfused rabbit hearts, preventing tissue Ca++ overloading.

Defibrotide (D), a polydeoxyribonucleotide obtained from mammalian lungs, reduced the ischemic contracture due to low perfusion (0.2 ml/min) of the isovolumic left heart of the rabbit and abolished the irregularity of the rhythm of the heart, thereby restoring the cardiomechanical activity upon reperfusion (20 ml/min). D stimulated the release of PG-like material. Indomethacin infusion completely prevented both the antiischemic activity of D and its ability to increase the generation of prostaglandins in the rabbit heart. Measurement by atomic absorption spectroscopy of calcium content in ischemic heart tissue and its mitochondrial fraction indicated that the ischemic procedure significantly increased tissue calcium content in both. D, Prostacyclin (PGI2) and Nifedipine protected the heart from ischemic ventricular contracture and prevented accumulation of calcium in the heart. The effect of D on preventing Ca++ overload was completely abolished by indomethacin infusion. The results indicate that the beneficial effects of Defibrotide in experimental ischemia are primarily due to a release of Prostaglandin E2 (PGE2) and PGI2, which in turn may inhibit the detrimental effects of calcium overload in myocytes and mitochondria.

Animals↗
PubMed1992

Cystic mesenchymal hamartoma of the liver.

Two cases of multicystic mesenchymal hamartoma of the liver in children are described. In both cases noninvasive imaging techniques (ultrasound, CT or MR, radionuclide scan) showed a bulky cystic mass suggesting a correct preoperative diagnosis, while selective arteriography defined the operability of the tumor.

Child, Preschool↗
PubMed1992

A particle beam-liquid chromatography-mass spectrometry method for the determination of lipoxygenase metabolites of arachidonic acid.

An application of the particle beam-liquid chromatography-mass spectrometry technique to the quantification of hydroxyeicosatetraenoic acids (15-, 12-, and 5-HETE) in biological samples is presented. The acids are extracted with Ethyl acetate and then transformed into pentafluorobenzyl esters, thus increasing the sensitivity of their detection by negative chemical ionization mass spectrometry. Reverse-phase HPLC separation of HETEs is performed in about 10 min with a water-methanol gradient. The procedure shows a detection limit of nearly 0.5 pmol, about one order of magnitude lower than that of the widely used HPLC/UV methods. The quantitative determination is linear (r2 greater than 0.998) for all of the HETEs in the range tested (3-1500 pmol) and a CV lower than 8.5% was observed for repeated analysis of samples. As an application of the method, HETEs formed from endogenous arachidonate were evaluated in extracts obtained from coincubates of platelets and neutrophils stimulated with calcium ionophore A23187.

Adult↗
PubMed1992

Evidence for the presence of 7-hydroperoxycholest-5-en-3 beta-ol in oxidized human LDL.

Low density lipoprotein (LDL) cholesterol is known to be oxidized both in vitro and in vivo giving rise to oxygenated sterols. Conflicting results, however, have been reported concerning both the nature and the relative concentrations of these compounds in oxidized human LDL. We examined the extracts obtained from Cu(2+)-oxidized LDL. Thin layer chromatography analysis showed that the sterol mixture became more complex with reaction time. Analysis of the components by thin layer chromatography and mass spectrometry allowed to establish that 7 alpha- and 7 beta-hydroperoxycholest-5-en-3 beta-ol (7 alpha OOH and beta OOH) are largely prevalent among the oxysterols at early times of oxidation. These hydroperoxy derivatives have not been previously identified in oxidized LDL. The concentration of 7-hydroperoxycholest-5-en-3 beta-ol decreased with oxidation time with a concomitant increase of cholest-5-en-3 beta, 7 alpha-diol (7 alpha OH), cholest-5-en-3 beta, 7 beta-diol (7 beta OH), cholesta-3,5-dien-7-one (CD) and cholest-5-en-3 beta-ol-7-one (7CO). After 24 h of oxidation a minor component of the LDL sterols was cholestan-3 beta-ol-5,6-oxide (EP).

Cholesterol↗
PubMed1992

Purification of recombinant human growth hormone by isoelectric focusing in a multicompartment electrolyzer with Immobiline membranes.

Recombinant human growth hormone (r-hGH) expressed in Escherichia coli, was 70-80% purified by a combination of ion-exchange chromatography and metal ion affinity chromatography. For the last purification step, a multicompartment electrolyzer was used, containing three compartments delimited by isoelectric membranes and two additional anodic and cathodic chambers. The central compartment was situated between two membranes having isoelectric points (pI) of 5.08 (anodic) and of 5.16 (cathodic), i.e. equidistant from the pI value of hGH (pI 5.12). r-hGH was isoelectric between these two membranes and could not leave the central chamber, while more acidic and more cathodic impurities collected in the two lateral chambers under the influence of the electric field. The r-hGH, thus purified, exhibited a single band by isoelectric focusing (IEF) in immobilized pH gradients (IPG) and gave recoveries greater than 90%. The problem of isoelectric precipitation in a practically ion-free environment was alleviated by focusing in 30% glycerol added with 1% neutral detergent (Nonidet-P40). The latter was eliminated by passage through a Q-Sepharose column after collecting the pI 5.12 band from the electrolyzer. Also the pre-hormone (pre-hGH) can be purified in a similar manner (30% glycerol, 1% Nonidet P-40) between two membranes having pIs 4.77 (anodic) and 4.87 (cathodic) (pre-hGH pI 4.82). This paper demonstrates the possibility of purifying by a focusing process also poorly soluble proteins at the pI.

Growth Hormone↗
PubMed1992

Lateral discoid meniscus: treatment and results.

Forty-six patients (47 knees) who had symptomatic discoid lateral menisci were operated on between August 1981 and May 1989. The patients were categorized according to Watanabe's classifications: complete (80.8%), incomplete (10.6%), and Wrisberg type (8.5%). The treatment of the discoid meniscus is based on total or partial meniscectomy, achieved by the percutaneous or arthrometric technique. Of the 47 knees, 30 underwent a follow-up evaluation. Using Ikeuchi's knee scale, 27 cases (90%) had either excellent or good ratings, and 3 (10%) received fair ratings. There were no poor outcomes. The results in the knees treated by partial meniscectomy were better than those in the knees treated with total meniscectomy.

Adolescent↗
PubMed1992

A collaborative trial for the evaluation of blood cholesterol measurement in clinical laboratories in Italy.

A collaborative trial for the evaluation of blood cholesterol measurement in Italy was carried out, with the use of two lyophilized controls, whose target values, respectively 4.42 and 6.21 mmol/l, were established by means of "definitive" methodology (isotope dilution/mass spectrometry). Results from 480 participants showed a somewhat broad dispersion (CV 6.1% and 6.3% respectively), and a definite bias (-0.25 mmol/l and -0.61 mmol/l respectively) with respect to the target values. The different analytical systems were characterized by different combinations of inaccuracy and imprecision; however, the bias observed for the higher concentration sample was a constant finding. The behaviour of the control materials, in comparison with that exhibited by patients' sera, was assessed in a manual enzymatic procedure and in the Kodak Ektachem 700 and Technicon Chem 1 systems. The peculiar property of one control material to behave differently from patients' sera in some analytical systems, i.e. the lack of commutability, was found to be partially responsible for the observed bias in the three methods studied. The importance of testing for commutability of the control materials to be used for the control of accuracy is stressed.

Blood Chemical Analysis↗
PubMed1991

Prochymosin expression in Bacillus subtilis.

Prochymosin (PC) sequence was cloned in Bacillus subtilis using two kinds of plasmid constructions. In plasmid pSM316 the cDNA was inserted to obtain the intracellular expression of the enzyme. The enzyme turned out to be expressed in an insoluble form which could be converted to native enzyme under proper denaturing and refolding conditions. The levels of intracellular expression of PC were further enhanced by modifying the 5' region of the gene in a way that a two-cistron expression system was created. For the PC secretion, the cDNA was fused to the subtilisin leader sequence and expressed under the control of the B. subtilis neutral protease promoter. A properly folded PC was secreted by the cells, although to low levels.

Amino Acid Sequence↗
PubMed1991

Calcitonin gene-related peptide increases the production of glycosaminoglycans but not of collagen type I and III in cultures of rat fat-storing cells.

We investigated whether calcitonin gene-related peptide (CGRP) was able to affect the production of collagen and glycosaminoglycans (GAG) in cultures of rat fat-storing cells (FSC). Rat CGRP (1 nM-1 microM) induced a dose-dependent increase of total GAG production in FSC cultures with an EC50 of 28 nM. One uM human CGRP (8-37) shifted the dose-response curve of rat CGRP to the right (EC50 = 257 nM) without depressing the maximal response. Salmon calcitonin (1 nM-1 microM) did not significantly modify total GAG accumulation in FSC cultures. Collagen type I and III production was not significantly affected by either CGRP or calcitonin in FSC cultures. These findings suggest that peripheral sensory neuropeptides may modulate liver fibrogenesis.

Adipose Tissue↗
PubMed1991

A new human growth hormone production process using a recombinant Bacillus subtilis strain.

We constructed a series of hybrid plasmids which directed the synthesis of different human growth hormone (hGH) precursor sequences in Bacillus subtilis. In addition to the 191 amino acids of the hormone, the precursors had in common an amino-terminal extension characterized by the presence of a methionine at position 1 and of the tetrapeptide Ile-Glu-Gly-Arg preceding the first residue (Phe) of hGH. The sequence between the methionine and the tetrapeptide was specific for each precursor and, because of the presence of charged residues, conferred particular properties to the molecules. Long homopolymeric tail-containing precursors such as MRRRRRRIILM-IEGR appeared insoluble whereas shorter sequences of the type MRR-IEGR and MEELM-IEGR augmented the solubility of the precursors with respect to Met-hGH. The soluble precursors could be easily purified from the bulk proteins taking advantage of the charged residues present on the N-terminal tail. After purification, the natural hGH was obtained by treating the precursors with the protease Factor Xa which cleaves after the arginine residue of the tetrapeptide IEGR. A protocol for the production and purification of authentic hGH from a strain expressing one of these soluble precursors is reported.

Amino Acid Sequence↗
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↗