Biomedical subjects

T Lodi

Publications and source records attributed to T Lodi.

28 records · Page 2Linked to original sources

PubMed1992

Allelism of IMP1 and GAL2 genes of Saccharomyces cerevisiae.

Cloning and characterization of the previously described Saccharomyces cerevisiae IMP1 gene, which was assumed to be a nuclear determinant involved in the nucleomitochondrial control of the utilization of galactose, demonstrate allelism to the GAL2 gene. Galactose metabolism does not necessarily involve the induction of the specific transport system coded by GAL2/IMP1, because a null mutant takes up galactose and grows on it. Data on galactose uptake are presented, and the dependence on ATP for constitutive and inducible galactose transport is discussed. These results can account for the inability of imp1/gal2 mutants to grow on galactose in a respiration-deficient background. Under these conditions, uptake was affected at the functional level but not at the biosynthetic level.

Alleles↗

PubMed1991

Catabolite repression by galactose in overexpressed GAL4 strains of Saccharomyces cerevisiae.

Catabolite repression by galactose was investigated in several strains of Saccharomyces cerevisiae grown on different carbon sources. Galactose repressed as much as glucose; raffinose was less effective. Full derepression was achieved with lactate. The functions tested were L-lactate ferricytochrome c oxidoreductase, NAD-glutamate dehydrogenase, and respiration. Galactose repression was observed only in the GAL4 but not in the gal4 strain. The presence of multiple copies of the GAL4 gene enhanced the repression by galactose. Different alleles of the GAL4 gene and the copy number did not affect glucose repression.

Alleles↗

PubMed1991

Complex transcriptional regulation of the Saccharomyces cerevisiae CYB2 gene encoding cytochrome b2: CYP1(HAP1) activator binds to the CYB2 upstream activation site UAS1-B2.

Expression of the Saccharomyces cerevisiae gene encoding cytochrome b2 (EC 1.2.2.3), CYB2, was investigated by direct analysis of mRNA transcripts and by measurement of the expression of lacZ fused to the CYB2 control regions. These studies indicated that regulation of the CYB2 gene is subject to several metabolic controls at the transcriptional level: inhibition due to glucose fermentation, induction by lactate, and inhibition in anaerobiosis or in absence of heme biosynthesis. Furthermore, we have shown that the CYB2 promoter contains one cis negative regulatory region and two heme-dependent positive regions, one of which is controlled by the transcriptional regulator CYP1 (HAP1) which is involved in the modulation of the expression of several oxygen-regulated genes. The CYP1 (HAP1)-binding sequence was located by gel retardation and DNase I footprinting experiments and compared with the binding sequences previously characterized in detail (UAS1CYC1, UAS'CYP3 (CYC7), and UASCTT1).

Base Sequence↗

PubMed1985

Antimycin A- and hydroxamate-insensitive respiration in yeasts.

In this paper evidence is presented for the mitochondrial localization of the antimycin A (AA) + salicylhydroxamate (SHAM)-insensitive respiration of the yeasts Kluyveromyces lactis, Endomycopsis capsularis and Hansenula saturnus. Such a respiration, which can be sustained by NADH and NADPH but not by succinate, is inhibited by high concentrations of azide. AA + SHAM-insensitive respiration is not phosphorylating and its postulated physiological role is to oxidize NADH.

Antifungal Agents↗

PubMed1984

Modification of nuclear gene expression by inhibition of mitochondrial translation during sporulation in MAT alpha/MATa diploids of Saccharomyces cerevisiae.

Sporulation of S. cerevisiae MAT alpha-/MATa was accompanied by a novel pattern of protein synthesis as shown by the disappearance of some "mitotic" polypeptides and by the appearance of a new set of "meiotic" polypeptides. Inhibition of mitochondrial protein synthesis by erythromycin within the 1st h caused the disappearance of several "meiotic" polypeptides. These meiotic polypeptides were also sensitive to cycloheximide and were localized in the cytosol, demonstrating that they were not mitochondrial translational products. Since erythromycin affected neither protein synthesis nor sporulation in a mitochondrially inherited eryr mutant, we conclude that mitochondrial protein synthesis is needed for the expression of some nuclear genes during sporulation.

Diploidy↗

PubMed1984

Methylthiomethyl, a new carboxyl protecting group in peptide synthesis.

N alpha-protected amino acid methylthiomethyl esters (MTM) were obtained in good yields under mild conditions using the "ButBr/Me2SO" reagent. Selective removal of the N-protecting group was achieved in HCl/anhydrous ethyl ether and the MTM ester hydrochlorides were successfully used in the synthesis of dipeptides.

Dimethyl Sulfoxide↗

PubMed1983

Respiratory pathways in Hansenula saturnus.

Hansenula saturnus is a petite-negative yeast species which displays a different pattern of respiration depending on the age of the cultures. The respiration is sensitive to antimycin A (AA) in the early exponential phase, is sensitive to the simultaneous addition of AA and salicylhydroxamic acid (SHAM) in the middle exponential phase and is sensitive to SHAM in the late exponential and stationary phase. The three respiratory activities are all associated to the mitochondrial fraction. The presence of AA in the growth medium determines the induction of the AA + SHAM-insensitive respiration which is 50% inhibited by 5 mM azide. On the contrary, the presence of erythromycin in the growth medium, which inhibits mitochondrial protein synthesis in this yeast species and the synthesis of cytochromes aa3 and b, totally prevents the appearance of AA + SHAM-insensitive respiration. Moreover, the antibiotic affects cell viability, suggesting a role of the mitochondrial protein synthesis in the cell cycle of H. saturnus.

Antimycin A↗

PubMed1983

Mitochondrial NAD, L-lactate dehydrogenase and NAD, D-lactate dehydrogenase in the yeast Saccharomyces cerevisiae.

Mitochondrial NAD-linked L- and D-lactate dehydrogenase activities have been found in the yeast Saccharomyces cerevisiae grown at high (3%) but were absent at low (0.6%) glucose concentrations. The inhibition of mitochondrial protein synthesis by chloramphenicol and of primary respiration by antimycin A determines the appearance of the two activities even at low (0.6%) glucose concentration. Two respiratory deficient strains belonging respectively to the mit- class (which maintains mitochondrial protein synthesis) and to the rho- class (which loses mitochondrial protein synthesis) display the activities even at low (0.6%) glucose concentration. L- and D-lactate have been detected in the growth medium when the cultures had been undertaken at high glucose concentrations, but were absent at low glucose concentrations.

Anaerobiosis↗

PubMedDate not supplied

[D2 gastrectomy in the surgical treatment of gastric cancer].

The study is conducted on a series of 57 patients treated with D2 gastrectomy with curative intent for gastric cancer between January 2000 and December 2004, at Policlinico Multimedica (Milan). Postoperative mortality was 2%. Recurrence rate was 10%. The overall survival of the series is 36% at 4 years follow-up. Negative prognostic factors were: high grade tumor, locally advanced primary disease, presence of lymph node metastases, advanced stage of disease and recurrent disease at follow-up. The data of the study are comparable to those in the literature.

Adult↗

PubMedDate not supplied

[Intraperitoneal hyperthermic chemotherapy. Preliminary experience with 22 consecutive patients].

The study analyses the results of surgical treatment and intraperitoneal hyperthermic chemotherapy on a group of 22 patients, affected by peritoneal carcinomatosis of different origins, and treated at Policlinico Multimedica (Milan) between June 2001 and December 2004. Surgical major complications were present in the 23% of the patients, and post-operative mortality rate was 13%. None of the patients presented chemotherapy related toxicity. Six patients died within 2 and 40 months after surgery, while 13 are alive within 4 and 40 months after operation.

Adult↗