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Biomedical subjects

A Galli

Publications and source records attributed to A Galli.

At least 181 records · Page 10Linked to original sources
PubMed1986

Inducibility of gene conversion in Saccharomyces cerevisiae treated with MMS.

At high survival levels (85%), point mutation and gene conversion frequencies were determined in strain D7 of Saccharomyces cerevisiae after treatment with methyl methanesulfonate (MMS) either after cells were incubated in complete medium before plating or following a split-dose protocol. It is shown that induction of gene conversion by MMS post-incubation leads to an additional enhancement in frequency. This increase is not observed for point mutation. By fractionation of the MMS dose (1 mM + 1 mM) with incubation in complete medium between the 2 doses the frequency of gene conversion is twice as high as with a single equal total dose (2 mM). This treatment does not modify the frequencies of point mutation. These data support the notion that an inducible recombinogenic function exists in wild-type yeast.

DNA Repair↗
PubMed1986

Specific inhibitors of the monooxygenase system of Saccharomyces cerevisiae modified the mutagenic effect of 4-nitroquinoline 1-oxide and the deethylation activity of the yeast.

A form of cytochrome P-450 is produced in Saccharomyces cerevisiae strain D7 during the logarithmic growth phase in 20% glucose liquid medium. This form was inhibited by metyrapone, tetrahydrofuran and by carbon monoxide, specific inhibitors of cytochrome P-450 in mammals. The inhibition was observed by means of the increase of the genetic activity of 4-nitroquinoline 1-oxide (4-NQO) on logarithmic growth phase cells of D7 strain, adding the inhibitors to the incubation mixture. 4-NQO is a strong direct mutagen on stationary phase cells that is detoxified by the monooxygenase system. The inhibition was measured by determining the decrease of the O-deethylation of 7-ethoxycoumarin in whole cells of yeast depending on different concentrations of inhibitors. A decrease of O-deethylation activity was found in the presence of tetrahydrofuran and metyrapone and this behaviour is typical of the cytochrome P-450 species induced by ethanol, as in mammals. Adding sodium phenobarbital to 0.5% glucose liquid medium, a form inhibited only by metyrapone was obtained. The presence of different inducible forms of cytochrome P-450 is evident.

4-Nitroquinoline-1-oxide↗
PubMed1986

Anterior transposition of the latissimus dorsi muscle through minimal incisions.

Latissimus dorsi transposition is a useful procedure for the correction of various congenital and acquired thoracic deformities. The authors describe a surgical technique which allows anterior transposition of the whole muscle through minimal incisions. The technique has been used in 33 patients with post-mastectomy or post-subcutaneous mastectomy deformities, Poland's syndrome, deep radionecrosis, quadrantectomy, or breast underdevelopment following burns. The technique has proven safe and reliable, although the control of bleeding is difficult. Results are evaluated and compared with those obtained using traditional techniques; the absence of any significant posterior deformity is pointed out. The authors also suggest the use of this technique for breast reconstruction in patients presenting skin deficiencies: a tissue expander placed under the muscular flap makes it possible to avoid the transposition of a skin island.

Breast↗
PubMed1985

Erythrocytes-mediated metabolic activation of cyclophosphamide in yeast mutagenicity test.

The degree of conversion of cyclophosphamide (CP) into mutagenic intermediates was studied using mouse erythrocytes as the metabolic activation system. The amount of mutagenic intermediates produced was measured indirectly in terms of induced frequencies of mitotic recombination, mitotic gene conversion, and reverse mutation in the diploid D7 strain of Saccharomyces cerevisiae. In the absence of S9 microsomal fraction or erythrocytes, CP did not induce any genetic response. In the presence of erythrocytes, on the other hand, CP clearly induced increases in the three genetic endpoints. The responses, however, were lower than those observed with the S9 activation system. The activating principle seems to be the oxyhemoglobin. In fact, neither p-nitroanisole O-demethylase activity nor genotoxic responses performed with red-blood cells from uninduced and PB-induced mice indicate that (possible) water-soluble forms of cytochrome P-450 were responsible for the activation of CP by erythrocytes.

Alanine Transaminase↗
PubMed1985

Conditions that influence the genetic activity of potassium dichromate and chromium chloride in Saccharomyces cerevisiae.

Potassium dichromate and chromium chloride were analyzed for their ability to induce mitotic gene conversion and point reverse mutation in D7 diploid strain of S. cerevisiae. We used cells from the stationary phase of growth with and without metabolic activation (S9 hepatic fraction) and cells from the logarithmic phase, that contain a high level of cytochrome P-450 and have a greater permeability. In the present work we confirmed the genetic activity of K2Cr2O7 in cells from the stationary phase, with and without S9 fraction and in cells from the logarithmic growth phase. A slight increase in genetic activity was observed in experiments with CrCl3 using phosphate buffer, but no genetic effects were noted in Tris-HCl buffer. Our studies suggest that phosphate ion may be the carrier responsible of the entrance of trivalent chromium in the cells. The higher cellular permeability may account for the different results obtained with both compounds in cells from the stationary and logarithmic phases of growth.

Biotransformation↗
PubMed1985

In-vitro and in-vivo protection of acetylcholinesterase by eseroline against inactivation by diisopropyl fluorophosphate and carbamates.

The protective action of eseroline--(3aS,8aR)-1,2,3,3a,8,8a-hexahydro-1,3 a, 8-trimethyl-pyrrolo[2,3-b]indol-5-ol--salicylate against (DFP) diisopropyl fluorophosphate and carbamate poisoning of cholinesterases (ChEs) has been examined in-vitro with human erythrocytes and purified preparations of electric eel acetylcholinesterase (AChE) and of horse serum butyrylcholinesterase (BuChE), and in-vivo using mice. Eseroline afforded 50% protection (ED 50) of erythrocyte AChE against inactivation by 1 microM DFP, physostigmine or neostigmine, at concentrations of 4.3, 22 and 23.5 microM, respectively, while for eel AChE protection against 10 and 30 microM DFP, 0.3 and 1 microM physostigmine and 1 microM neostigmine the eseroline ED 50 values were 0.3, 0.4, 0.7, 1.9 and 5.6 microM, respectively. On the other hand, up to 0.3 mM eseroline did not appreciably affect the inhibitory action of the same drugs on horse serum BuChE. Eseroline concentrations in the range 0.1-1 mM were able to reactivate 20-42% of erythrocyte AChE previously inhibited by 100 microM physostigmine, but failed to reactivate the DFP (10 microM)-pretreated enzyme to any extent. Finally, eseroline salicylate injected into mice (10 mg kg-1 s.c.) protected an average of 82 and 26% of the animals against lethal doses of DFP (7 mg kg-1 s.c.) and physostigmine sulphate (1 mg kg-1 i.p.) respectively, which were administered 15 min later. These results indicate that the protective activity of eseroline correlates well with its own anti-ChE profile, and that the effectiveness of the protection depends largely on the rate of AChE inhibition by the agents used to inactivate the enzyme.

Acetylcholinesterase↗
PubMed1985

Poland's syndrome: correction of thoracic anomaly through minimal incisions.

A method that minimizes residual scarring following Poland's syndrome correction by latissimus dorsi muscle transposition and placement of a submuscular breast implant is described. In order to reduce any resulting unsightly scarring and, in particular, eliminate the anterior thoracic scar, both a dorsal S-shape and an axillary incision were made and the muscle flap was raised. A prosthesis was then inserted and the muscle flap sutured to the anterior chest wall through an anterior incision symmetrical to the inferior border of the contralateral areola. The latter is a previously undescribed approach that produces good cosmetic results.

Adult↗
PubMed1985

Acid phosphatase and zinc in semen of subjects with no clinical evidence of prostatic disease.

We evaluated the distribution of values for prostatic acid phosphatase (EC 3.1.3.2) activity and zinc concentration in semen of 80 men without clinical evidence of prostatic disease. Both substances have log normal distributions. Reference intervals were defined by parametric tests after logarithmic transformation of data and by nonparametric tests. There is a correlation between zinc concentration and prostatic acid phosphatase activity in semen.

Acid Phosphatase↗
PubMed1985

[Course of the concentration of serum free amino acids as a function of time and the method of preservation].

In order to determine the optimal conditions for storage in the case of deferred serum amino acid assay, the authors studied the effect of storing the sample for four hours at two different temperatures: melting ice and ambient temperature, as well as the effect of storing the amino acids for three months according to four methods of storage; freezing at -20 degrees C and -80 degrees C of deproteinised and non-deproteinised serum. When the analysis was performed within four hours of collection of the specimen, the best conditions are obtained when the sample is kept at the temperature of melting ice. The optimal conservation consists of immediately deproteinising the sample and storing it frozen for 14 days.

Adult↗
PubMed1984

Immediate breast reconstruction following modified radical mastectomy.

Reducing postoperative psychological morbidity is an important goal in breast cancer patient care; a multidisciplinary approach is crucial in order to select candidates for immediate breast reconstruction. There is no oncologic reason for a delay after a modified radical mastectomy. Our procedure allows immediate breast reconstruction without significantly prolonging operative time and hospitalization. Complete muscular coverage of the implant and shifting of the redundant skin to the mastectomy site minimize the risk of postoperative complications and provide a natural looking reconstructed breast. Delayed reconstruction of the nipple-areolar complex performed at the time of contralateral mammaplasty ensures satisfactory breast symmetry. Satisfactory reconstruction of the nipple-areolar complex is achieved without additional scars by means of grafts taken from the opposite breast or utilizing the cryopreserved nipple and areola.

Breast↗
PubMed1984

Cytochrome P-450 inducibility by ethanol and 7-ethoxycoumarin O-deethylation in S. cerevisiae.

The level of cytochrome P-450 and some enzymatic activity cytochrome P-450 dependent in a diploid strain (D7) of S. cerevisiae are affected by the substrate supporting growth and its concentration and, in particular, by the growth phase of the culture. For these reasons we tested the hypothesis that the induction of the monooxygenase system in the D7 strain when grown in high concentration of glucose depended on one product of glycolysis, ethanol. There was a strict correlation between the level of cytochrome P-450 and the ethanol concentration. Moreover we developed a sensitive test measuring the ethoxycoumarin O-deethylation in order to detect the enzymatic activity cytochrome P-450 dependent in whole yeast cells, in different growth conditions.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1984

Effect of ranitidine on ileal myenteric plexus preparation and on acetyl- and butyrylcholinesterase.

Ranitidine at concentrations from 1 microM to 0.1 mM brought about a dose-dependent potentiation of the twitch responses elicited by electrical stimulation of the ileal myenteric preparation. At higher concentrations (0.3-3 mM) ranitidine also caused irregular slow contractions of the unstimulated ileal preparation which were potentiated by eserine and blocked by atropine and tetrodotoxin. In order to identify the mechanism of these apparently cholinomimetic actions, the effects of ranitidine on AChE and BuChE were studied. Ranitidine showed an instantaneous and promptly reversible inhibitory action at concentrations between 0.5 and 30 microM. Double reciprocal plots were prepared and equilibrium dissociation constants calculated. It appears that ranitidine exerts an inhibition of the "mixed" type on both AChE and BuChE, but the dissociation constants for BuChE were markedly higher than those for AChE. Since AChE inhibition occurs in the same concentration range potentiating the twitch responses on the ileal myenteric preparation, it may explain the cholinomimetic effect of ranitidine.

Acetylcholinesterase↗
PubMed1984

Comparative genetic activity of cis- and trans-1,2-dichloroethylene in yeast.

The cis and trans isomers of 1,2-dichloroethylene were tested for mutagenic effects in a diploid strain (D7) of the yeast Saccharomyces cerevisiae in suspension tests with and without a mammalian microsomal activation system, an S9 mouse liver fraction, and by an in vivo intrasanguineous host mediated assay. The effects of the same agents on aminopyrine N-demethylase activity and cytochrome P-450 level in liver were studied in nonpretreated and in phenobarbital + beta-naphtoflavone-pretreated mice. In the suspension test, both isomers exhibited dose dependent toxicity, and survival was lower with metabolic activation than without. In this test also, both isomers exhibited genetic activity as measured by increases in recombinants at the ade 2 locus in experiments with metabolic activation. In the host-mediated assay, only the cis isomer showed evidence of mutagenic activity with significant increases in convertants at the trp locus and revertants at the ilv locus. Such mutagenic activity was found both after acute and chronic doses and in liver, kidney, and lung tissue. The two isomers exhibited different effects with respect to aminopyrine N-demethylase activity and cytochrome P-450 level. In general, the trans isomer appeared to emphasize induction of enzyme activity or level while the cis isomer more frequently tended to inhibit activity or destroy the enzyme.

Aminopyrine N-Demethylase↗