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Biomedical subjects

P Romano

Publications and source records attributed to P Romano.

At least 91 records · Page 5Linked to original sources
PubMed1993

Acetoin production in Saccharomyces cerevisiae wine yeasts.

One hundred strains of Saccharomyces cerevisiae were examined for the capacity to produce acetoin in synthetic medium and in grape must. The low production of acetoin was found to be the more common pattern in this species. Most strains exhibited a similar distribution in both media, production ranging from non-detectable amounts to 12 mg l-1. Only four strains produced high quantities of acetoin, up to 29.5 mg l-1 in synthetic medium and up to 194.6 mg l-1 in grape must. This biometric study showed the existence of two phenotypes, "low and high acetoin production", that could be selected for conferring a desirable flavour of the final product.

Acetoin↗
PubMed1993

Low levels of total cholesterol, high-density lipoprotein, and apolipoprotein A1 in association with anticardiolipin antibodies in patients with systemic lupus erythematosus.

OBJECTIVE: To determine if there is an association between low levels of high-density lipoprotein cholesterol (HDL), apolipoprotein A1 (Apo A1), total cholesterol, and anticardiolipin antibody (aCL) in patients with systemic lupus erythematosus (SLE) who are not taking corticosteroids. METHODS: We studied 75 outpatients with documented SLE who were attending our hospital clinics: 57 were aCL positive and 18 were aCL negative. Both IgG and IgM aCL levels were determined by enzyme-linked immunosorbent assay. Lipid fractions (total cholesterol, HDL, low-density lipoprotein, very-low-density lipoprotein, and triglycerides) were determined by standard enzymatic techniques. Apo A1 and Apo B levels were determined by nephelometry. RESULTS: Patients with SLE who were IgG aCL+ had low levels of serum cholesterol (mean +/- SD 173.6 +/- 34.6 mg/dl) and HDL (43.9 +/- 16.3 mg/dl) compared with aCL- SLE patients, normal donors, and patients with other diseases. Apo A1 levels were also low in the aCL+ group (95.5 +/- 50.9 mg/dl) compared with the aCL- group (152.7 +/- 32.6 mg/dl). There was no association of total cholesterol level or aCL titer with clinical activity. CONCLUSION: These data indicate that in SLE patients, there is an association between antibody against the phospholipid cardiolipin and low levels of cholesterol, HDL, and Apo A1.

Adolescent↗
PubMed1993

Biometric Study of Acetoin Production in Hanseniaspora guilliermondii and Kloeckera apiculata.

Gas chromatographic analysis by direct injection of samples yielded quantitative data on acetoin content. Ninety-six strains of Hanseniaspora guilliermondii and Kloeckera apiculata were investigated for the ability to produce acetoin in synthetic medium and in must. High-level production of acetoin was found to be a characteristic of both species. In synthetic medium, the two species were not significantly different with respect to sugar utilization and ethanol or acetoin production. In grape must, the two species were significantly different (P = 0.001) in acetoin production and K. apiculata exhibited a significantly negative correlation between acetoin production and either sugar consumption or ethanol production. Use of selected apiculate yeasts in mixed cultures with Saccharomyces cerevisiae seems promising for optimization of wine bouquet.

Journal Article↗
PubMed1993

The cell line data base and the new catalogue: detailed information on 2650 human and animal cell lines.

The Cell Line Data Base (CLDB), set up within the Interlab Project, is a relational database containing data on 2650 human and animal cell lines which are available in labs and cell banks all over Europe. The second edition of the catalogue, directly generated from the database, has been produced, and will be published in the first months of 1993. Furthermore, the electronic catalogue is available for IBM-compatible personal computers and the version for MacIntosh is under preparation.

Animals↗
PubMed1993

INO2, a regulatory gene in yeast phospholipid biosynthesis, affects nuclear segregation and bud pattern formation.

We have independently identified and DNA sequenced the INO2 locus by its close proximity to the KIN1 locus in Saccharomyces cerevisiae. Mutant strains in which the INO2 chromosomal locus has been deleted show pleiotropic phenotypes under growth conditions of inositol/choline availability. Many ino2 delta cells show delocalized cell growth resulting in large cells having aberrant shapes. These mutant cells may display nuclear segregation or positioning defects as well as defects in bud formation. Furthermore, homozygous ino2 delta-1 diploids fail to sporulate. Previous studies have shown that INO2 mutants are defective in phospholipid synthesis due to an inability to derepress the INO1 gene, the structural gene for inositol-1-phosphate synthase. To identify and determine the function of Ino2p in yeast cells, we raised antibodies to a beta-galactosidase/Ino2 fusion protein. The INO2 open reading frame codes for a 304 amino acid protein with a calculated molecular weight of 39.7 kDa. Immunoblot analysis reveals two Ino2-specific proteins of approximately 44 and 46 kDa. The 44 kDa species is localized to the nucleus. Ino2p is believed to function as a positive transcriptional activator in phospholipid synthesis. Our results suggest that it affects additional pathways important to polarized cell growth and division perhaps by functioning as a more general transcriptional factor.

Amino Acid Sequence↗
PubMed1992

Molecular Probe Database: a database on synthetic oligonucleotides.

The Molecular Probe Data Base (MPDB) is designed to collect and make available on-line information on synthetic oligonucleotides. This paper briefly describes the purpose of MPDB, its content and structure, forms and mode of data distribution, and a series of additional services available to scientists using MPDB.

Amino Acid Sequence↗
PubMed1992

The flocculation of wine yeasts: biochemical and morphological characteristics in Zygosaccharomyces--flocculation in Zygosaccharomyces.

The floc-forming ability of flocculent strains of Zygosaccharomyces bailii and Z. fermentati, isolated from musts, was tested for susceptibility to proteinase and sugar treatments. Z. fermentati was found highly resistant to the proteolytic enzymes tested, whereas Z. baili was only trypsin-resistant. The inhibition of flocculation by sugars distinguished two types: in Z. fermentati flocculation was completely inhibited by mannose, in Z. bailli by various sugars. By SEM observation, the cell surface of Zygosaccharomyces revealed the presence of a column structure, resulting from fusion of vesicles present on the cell surface.

Cell Adhesion↗
PubMed1991

Comparative evaluation of acid- and bile-induced damage to pedicled jejunal or colonic segments in the rat.

The choice of the esophageal substitute after surgical resection for peptic stricture lies between the colon and jejunum. The current study was designed to compare long-term resistance of the colonic and jejunal mucosa to gastric or mixed duodenogastric secretions. The following preparations were performed in Wistar rats: transposition of a colonic or jejunal patch (a) to the gastric body, with or without truncal vagotomy, or (b) to the gastric antrum and proximal duodenum, with or without truncal vagotomy. Jejunal and colonic patches were removed 4, 8, and 12 months after surgery. The only damage to the transposed mucosae was the alteration of microvilli. The alteration was more severe in colonic than in jejunal patches and was prevented by truncal vagotomy. Long-term resistance of the transposed mucosae to the environmental challenge may depend on their adaptation potentiality, involving both specific and nonspecific mechanisms. Nonspecific mechanisms include the increased production of mucus and the gastric-like transformation of the superficial epithelial layer. Specific mechanisms include the reduction of the mucosal surface size for jejunal segments and the shifting in mucin secretion patterns for colonic segments.

Animals↗
PubMed1991

Are genotoxic carcinogens more potent than nongenotoxic carcinogens?

In this report we have raised the question whether genotoxic carcinogens are more potent than nongenotoxic carcinogens when studied in long-term carcinogenicity assays in rodents. To build a large database of compounds for which both carcinogenicity and genotoxicity had been investigated, we have used a database produced by Gold and co-workers for carcinogenic potency data (975 chemicals) and a database produced by Würgler for genotoxicity data (2834 chemicals). Considering compounds positive or negative in at least three short-term tests and in at least 75% of available tests, we could define 67 genotoxic carcinogens and 46 nongenotoxic carcinogens. Carcinogenic potency of genotoxic carcinogens was about 50 times higher than carcinogenic potency of nongenotoxic carcinogens. Our results are different from the results of Tennant et al.; their database (24 genotoxic carcinogens and 12 nongenotoxic carcinogens compatible with our definition) seems to suggest that there is practically no difference in potency between genotoxic and nongenotoxic carcinogens. The two databases have only four compounds in common and are also different in terms of number of elements for different chemical classes. Nitrosocompounds, nitrogen mustards, hydrazine derivatives, and polycyclic aromatic hydrocarbons are not represented in the database of Tennant. The overall impression from our analysis is that the usefulness of short-term tests of genotoxicity could be significantly better than what has been suggested by the previous work of Tennant et al. because these tests tend to detect, at least for many important chemical classes, the most potent carcinogens. This consideration may not be valid for certain classes of chemicals.

Animals↗
PubMed1991

Analysis and comparison of information and data recorded in carcinogenicity and genotoxicity databases.

The Interlab Project is a university-industry joint project recently funded by the Italian government as part of the improvement of the Italian research infrastructure; among its short-term goals are the implementation of data banks of biomedical interest and the spread of informatic tools for biomedical research. Results of both long-term assays of carcinogenicity in rodents and short-term in vitro and in vivo tests of genotoxicity are relevant for a wide body of users, ranging from carcinogenesis research laboratories to industries and governmental agencies. To evaluate the most appropriate ways of spreading information on these experiments, a detailed analysis on information recorded in available databases has been carried out. Furthermore, the contents of the most known databases have been compared, with respect to a specific compound, to evaluate both the overall reliability of these systems, compared to longer and more complex assessments carried out manually starting from bibliographic searches, and the level of concordance among them.

Academies and Institutes↗
PubMed1991

Scanning electron microscopy study of small bowel biopsies in chronic diarrhoea in childhood.

In this study we have compared the results of Scanning Electron Microscopy (SEM) with Light- and Stereomicroscopy in a series of small bowel biopsies in children. In 9 cases displaying features of partial or subtotal atrophy, Light and Dissecting-Microscopy yielded similar results. The distinction between coeliac and non-coeliac chronic diarrhoea was only possible on clinical grounds, and by the immunological detection of specific antibodies. On SEM however coeliac patients showed characteristic alterations consisting of: absence of villi; prominent crypt outlets resulting in a mosaic appearance; concentric furrows running all around the openings; and downy brush feature at high power. The microvilli were loosely distributed and had an irregular pleomorphic outline; they often displayed a drumstick swelling of the tip and were bent. In contrast, non-coeliac chronic diarrhoea cases were characterized by a thick mucous layer on the mucosal surface, that made it impossible to visualize further changes. Peculiar vascular changes in lymphangiectasia and in sickle beta thalassemia could be detected only by Light Microscopy. In addition, in the lymphangiectasia case SEM allowed the detection of enteroadherent bacteria; and in the lambliasis case, of pseudomembranes. Absence of glycocalyx was noted both in controls and in patients. The results of this study point to a diagnostic utility of SEM particularly in the differential diagnosis of chronic diarrhoea; moreover they suggest that enteroadherent bacteria may not be pathogenic and that the absence of glycocalyx is not specific for allergic enteropathy as previously claimed.

Adolescent↗
PubMed1991

Glutaraldehyde-tanned mandril-grown grafts as venous substitutes.

The present study was performed to evaluate the potential of glutaraldehyde-tanned mandril-grown grafts as caval substitutes. Short-term experiments consisted of 30 tubular grafts (35 x 8 mm), either of tanned collagen or polytetrafluoroethylene, that were sutured in the infrarenal inferior vena cava of pigs and removed 1 hour after implantation. There was no significant difference between the extent of the thrombus-lined graft surface in the biologic group and that in the polytetrafluoroethylene group. The amount of inner thrombus on tanned collagen grafts was significantly correlated to platelet activity. Long-term experiments involved 30 similar segments of both materials, which were sutured in the inferior vena cava and harvested 7, 14, 28, 56, and 112 days after operation. The 112-day patency rate of collagen grafts was 67%. The 56-day patency rate of polytetrafluoroethylene grafts was 16%. The difference was statistically significant (p less than 0.01). Collagen grafts were lined by a thin neointima (200 micron) in all but two cases. The neointima was completely endothelialized within 4 weeks from implantation. In conclusion, tanned collagen grafts may represent a suitable material for venous replacement.

Analysis of Variance↗
PubMed1990

Mutagenic and carcinogenic potency indices and their correlation.

We have analyzed a significant number of studies existing in the literature, in which the ability of different short-term tests for predicting carcinogenicity in rodents was investigated. We have separated these studies into two groups. In the better known group of studies, qualitative predictivity was investigated (sensitivity and specificity). In the second group of studies (analyzed in greater detail), positive results were examined for the correlation between carcinogenic potency and potency of response in a given short-term test. There is substantial agreement between qualitative and quantitative predictivity; both appear to be situated between a low and moderate level. We have analyzed the interesting possibility of using the quantitative approach not only for positive data but for combined positive and negative data as well. We have stressed that short-term tests of genotoxicity should be asked to predict only initiation and irreversible alterations in the genome and not to predict a combination of these events, including promotion and modulation of differentiation. Even with regard to only initiation, genotoxicity data should be related to comparative metabolism, as well as to considerations of the significance of different end points and structure-activity relationship data. In conclusion, the information coming from short-term tests of genotoxicity is probably useful but should be used in conjunction with other types of information and only for predicting one particular class of events in the entire process of carcinogenesis.

Carcinogenicity Tests↗