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M Gatti

Publications and source records attributed to M Gatti.

At least 37 records · Page 2Linked to original sources
PubMed2001

Early and long-term results of surgical treatment of splenic artery aneurysms.

BACKGROUND: This retrospective study was conducted to describe the presentation, surgical treatment, and follow-up of patients with splenic artery aneurysms. METHODS: From 1982 to 2000, 1,952 patients with abdominal aneurysms were referred to our department; 15 had splenic artery aneurysms. None had ruptured. All were operated on. RESULTS: Fourteen complete and 1 partial aneurysmectomies were carried out. Arterial continuity was restored in 10, by end-to-end anastomosis, and 4 had splenectomies. In 1 patient the spleen was preserved without arterial reconstruction. There were no deaths. Morbidity was restricted to 1 patient with a limited, asymptomatic splenic infarction. Eleven patients were followed up for a mean 19.7 months. No deaths or major complications were recorded. Reconstructed splenic arteries were patent in all cases without atrophy or new cases of splenic infarction. CONCLUSIONS: Elective surgery for splenic artery aneurysms is safe. Arterial reconstruction allows good early and long-term results. In some cases splenectomy may be unavoidable.

Aneurysm↗
PubMed2001

Genotypic and phenotypic heterogeneity of Streptococcus thermophilus strains isolated from dairy products.

AIMS: Forty strains of Streptococcus thermophilus isolated from dairy products were identified and typed by a polyphasic approach which included phenotypic and genotypic criteria. METHODS AND RESULTS: Strains were identified by sugar fermentation pattern and species-specific PCR. Phenotypic diversity was evaluated by a chemometric model taking into account some biochemical characteristics (e.g. acidifying and peptidase activities) of technological interest. Genotypic diversity was evidenced by PCR fingerprinting. The overall phenotypic and genotypic information was elaborated on a multivariate statistical basis by principal components analysis and cluster analysis, respectively. When acidifying and peptidase activities were considered, PCA indicated that most of the strains isolated from Pecorino Toscano cheese were separable from the others. Similarly, most of the starter culture strains tended to separate from the cheese isolates. CONCLUSIONS: A wide strain heterogeneity among Strep. thermophilus strains isolated from dairy products was observed. SIGNIFICANCE AND IMPACT OF THE STUDY: A computerized analysis of genotypic and phenotypic information could be applied successfully to differentiate and characterize reliably and rapidly isolates occurring in different dairy products and to comprehend the technological role of specific Strep. thermophilus strains in dairy technology.

Animals↗
PubMed2001

Differentiation of Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus delbrueckii subsp. lactis by SDS-PAGE of cell-wall proteins.

AIMS: In the present study, a method based on SDS-PAGE fingerprinting of surface layer proteins was developed to identify Lactobacillus delbrueckii subsp. bulgaricus and subsp. lactis dairy isolates. METHODS AND RESULTS: The two subspecies, identified by species-specific PCR, were characterized by different SDS-PAGE cell-wall protein profiles; subspecies bulgaricus showed one band of about 31 kDa which, in some cases, was observed at a doublet, and subspecies lactis showed one band of about 21 kDa or 18 kDa. CONCLUSION: The sensitivity of this procedure for discriminating between the two subspecies was very high. The different types of SDS-PAGE profile for cell-wall proteins of the strains studied in this work did not seem to be correlated to the different dairies of origin. SIGNIFICANCE AND IMPACT OF THE STUDY: The method appears to be an efficient taxonomic tool. It has the advantage of easy gel interpretation over fingerprinting of whole-cell protein extracts, and may be used as an alternative to established PCR-based techniques which, though rapid and safe, require expensive instruments and reagents.

Bacterial Proteins↗
PubMed2001

Carotid endarterectomy in rare bilateral carotid-vertebral anastomosis.

In the embryo, the anterior and the posterior cerebral circulations are connected by several longitudinal anastomotic vessels. These anastomoses disappear progressively, until the carotid and vertebrobasilar systems are connected only by a pair of posterior communicating arteries. These embryonal anastomoses rarely persist in adults and may have an important physiologic role during carotid surgery. We report a case in which a patient with bilateral embryonal carotid-vertebral anastomoses underwent right carotid endarterectomy for asymptomatic internal carotid stenosis.

Aged↗
PubMed2001

Pre-targeted locoregional radioimmunotherapy with 90Y-biotin in glioma patients: phase I study and preliminary therapeutic results.

The aim of this study was to determine the maximum-tolerated dose, of a pre-targeting three-step (3-S) method employing 90Y-biotin in the locoregional radioimmunotherapy (RIT) of recurrent high grade glioma, and to investigate the antitumor efficacy of this new treatment. Twenty-four patients with recurrent glioma underwent second surgical debulking and implantation of a catheter into the surgical resection cavity (SRC), in order to introduce the radioimmunotherapeutic agents [biotinylated monoclonal antibody (MoAb), avidin and 90Y-biotin]. Eight patients with anaplastic astrocytoma (AA) and 16 patients with glioblastoma (GBM) were injected with biotinylated anti-tenascin MoAb (2 mg), then with avidin (10 mg; 24 h later) and finally 90Y-biotin (18 h later). Each patient received two of these treatments 8-10 weeks apart. The injected activity ranged from 0.555 to 1.110 GBq (15-30 mCi). Dosage was escalated by 0.185 GBq (5 mCi) in four consecutive groups. The treatment was well tolerated without acute side effects up to 0.740 GBq (20 mCi). The maximum tolerated activity was 1.110 GBq (30 mCi) limited by neurological toxicity. None of the patients developed hematologic toxicity. In three patients infection occurred around the catheter. The average absorbed dose to the normal brain was minimal compared with that received at the SRC interface. At first control (after 2 months), partial (PR) and minor (MR) responses were observed in three GBM (1 PR; 2 MR) and three AA patients (1 PR; 2 MR) with an overall objective response rate of 25%. Stable disease (SD) was achieved in seven GBM and five AA patients (50%). There was disease progression in six GBM patients (25%), but in none of the AA patients. At the dosage of 0.7-0.9 GBq per cycle, locoregional 3-S-RIT was safe and produced an objective response in 25% of patients. Based on these encouraging results, phase II studies employing 3-S-RIT soon after first debulking are justified.

Adult↗
PubMed2001

Arrhythmogenic right ventricular dysplasia: cardiomyopathy current opinions on diagnostic and therapeutic aspects.

Right Ventricular Dysplasia constitutes a genetic cardiomyopathy characterized by fibrous-adipose substitution of the right and rarely of the left ventricular myocardium. This disorder is associated with ventricular arrhythmias ranging from frequent ventricular ectopic beats, nonsustained and sustained ventricular tachycardia of left bundle branch morphology and sudden death. Therefore, the syndrome has been labelled Arrhythmogenic RVD Cardiomyopathy. Diagnostic criteria, preliminary genetic data, and clinical manifestations are summarized and critical addressed, using data from the literature and from our own experience. The most important aspects of the ECG in this syndrome are reviewed and stressed with particular attention to initial versus advanced clinical subsets. The typical anatomical abnormalities and biopsy or pathology material are presented.

Arrhythmogenic Right Ventricular Dysplasia↗
PubMed2001

The role of centrosomes and astral microtubules during asymmetric division of Drosophila neuroblasts.

Drosophila neuroblasts are stem cells that divide asymmetrically to produce another large neuroblast and a smaller ganglion mother cell (GMC). During neuroblast division, several cell fate determinants, such as Miranda, Prospero and Numb, are preferentially segregated into the GMC, ensuring its correct developmental fate. The accurate segregation of these determinants relies on proper orientation of the mitotic spindle within the dividing neuroblast, and on the correct positioning of the cleavage plane. In this study we have analyzed the role of centrosomes and astral microtubules in neuroblast spindle orientation and cytokinesis. We examined neuroblast division in asterless (asl) mutants, which, although devoid of functional centrosomes and astral microtubules, form well-focused anastral spindles that undergo anaphase and telophase. We show that asl neuroblasts assemble a normal cytokinetic ring around the central spindle midzone and undergo unequal cytokinesis. Thus, astral microtubules are not required for either signaling or positioning cytokinesis in Drosophila neuroblasts. Our results indicate that the cleavage plane is dictated by the positioning of the central spindle midzone within the cell, and suggest a model on how the central spindle attains an asymmetric position during neuroblast mitosis. We have also analyzed the localization of Miranda during mitotic division of asl neuroblasts. This protein accumulates in morphologically regular cortical crescents but these crescents are mislocalized with respect to the spindle orientation. This suggests that astral microtubules mediate proper spindle rotation during neuroblast division.

Animals↗
PubMed2001

Drosophila male meiosis as a model system for the study of cytokinesis in animal cells.

Drosophila male meiosis offers unique opportunities for mutational dissection of cytokinesis. This system allows easy and unambiguos identification of mutants defective in cytokinesis through the examination of spermatid morphology. Moreover, cytokinesis defects and protein immunostaining can be analyzed with exquisite cytological resolution because of the large size of meiotic spindles. In the past few years several mutations have been isolated that disrupt meiotic cytokinesis in Drosophila males. These mutations specify genes required for the assembly, proper constriction or disassembly of the contractile ring. Molecular characterization of these genes has identified essential components of the cytokinetic machinery, highlighting the role of the central spindle during cytokinesis. This structure appears to be both necessary and sufficient for signaling cytokinesis. In addition, many data indicate that the central spindle microtubules cooperatively interact with elements of the actomyosin contractile ring, so that impairment of either of these structures prevents the formation of the other.

Animals↗
PubMed2000

Relationships between the central spindle and the contractile ring during cytokinesis in animal cells.

During late anaphase and telophase, animal cells develop a bundle of antiparallel, interdigitating microtubules between the two daughter nuclei. Recent data indicate that this structure, called the central spindle, plays an essential role during cytokinesis. Studies in Drosophila and on vertebrate cells strongly suggest that the molecular signals for cytokinesis specifically emanate from the central spindle midzone. Moreover, the analysis of Drosophila mutants defective in cytokinesis has revealed a cooperative interaction between the central spindle microtubules and the contractile ring: when either of these structures is perturbed, the proper assembly of the other is disrupted. Based on these results we propose a model for the role of the central spindle during cytokinesis. We suggest that the interaction between central spindle microtubules and cortical actin filaments leads to two early events crucial for cytokinesis: the positioning of the contractile ring, and the stabilization of the plus ends of the interdigitating microtubules that comprise the central spindle. The latter event would provide the cell with a specialized microtubule scaffold that could mediate the translocation of plus-end-directed molecular motors to the cell's equator. Among the cargoes transported by these motors could be proteins involved in the regulation and execution of cytokinesis.

Actins↗
PubMed2000

Isolation of Mobiluncus species from the human vagina.

We report the results of a study concerning the characteristics of 52 strains of Mobiluncus spp. isolated from 982 vaginal secretions from patients with suspected bacterial vaginosis. 158 of these women presented the features of this bacterial infection. Of the strains isolated, 39 belonged to the species Mobiluncus curtisii, (25 of these which to M. curtisii subsp. curtisii and 14, to M. curtisii subsp. holmesii), and 13, to Mobiluncus mulieris. The vaginal isolates of Mobiluncus spp. were identified by comparing their biochemical profiles with those of the type strains M. curtisii subsp. holmesii (ATCC 35,242), M. curtisii subsp. curtisii (ATCC 35,241) and M. mulieris (ATCC 35,243). All strains of M. mulieris proved to be sensitive to the antimicrobial agents assayed, while strains of M. curtisii were seen to be resistant only to metronidazole.

Adult↗
PubMed2000

Genetic and molecular analysis of wings apart-like (wapl), a gene controlling heterochromatin organization in Drosophila melanogaster.

Mutations in the X-linked gene wings apart-like (wapl) result in late larval lethality associated with an unusual chromosome morphology. In brain cell metaphases of wapl mutants, sister chromatids of all chromosomes are aligned parallel to each other instead of assuming the typical morphology observed in wild type. This effect is due to a loosening of the adhesion between sister chromatids in the heterochromatic regions of the chromosomes. Despite this aberrant chromosome morphology, mutant brains exhibit normal mitotic parameters, suggesting that heterochromatin cohesion is not essential for proper centromere function. On the basis of these observations, we examined the role of wapl in meiotic chromosome segregation in females. wapl exhibits a clear dominant effect on achiasmate segregation, giving further support to the hypothesis that proximal heterochromatin is involved in chromosome pairing during female meiosis. We also examined whether wapl modulates position-effect variegation (PEV). Our analyses showed that wapl is a dominant suppressor of both white and Stubble variegation, while it is a weak enhancer of brown variegation. wapl maps to region 2D of the X chromosome between Pgd and pn. We identified the wapl gene within a previously conducted chromosomal walk in this region. The wapl transcriptional unit gives rise to two alternatively spliced transcripts 6.5- and 5-kb long. The protein encoded by the larger of these transcripts appears to be conserved among higher eukaryotes and contains a tract of acidic amino acids reminiscent of many chromatin-associated proteins, including two [HP1 and SU(VAR)3-7] encoded by other genes that act as suppressors of PEV.

Animals↗
PubMed2000

Molecular diversity within Lactobacillus helveticus as revealed by genotypic characterization.

Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium that is used in the manufacture of Swiss type and long-ripened Italian cheeses, such as Emmental, Grana, and Provolone cheeses. Substantial differences in several technologically important characteristics are found among L. helveticus strains isolated from natural dairy starter cultures. In the present study we investigated the genotypic diversity of 74 strains isolated from different dairy cultures used for manufacturing Grana and Provolone cheeses and six collection strains. A restriction fragment length polymorphism analysis of both total genomic DNA and the 16S rRNA gene (ribotyping) was used as genotypic fingerprinting. A multivariate statistical analysis of the data enabled us to identify significant genotypic heterogeneity in L. helveticus. We found that genotypic fingerprinting could be used to distinguish strains; in particular, it was possible to associate the presence of specific strain genotypes with dairy ecosystem sources (e.g., Grana or Provolone cheese). Our data contribute to the description of microbial heterogeneity in L. helveticus and provide a more solid basis for understanding the functional and ecological significance of the presence of different L. helveticus biotypes in natural dairy starter cultures.

Base Sequence↗
PubMed2000

Pyroglutamic acid in cheese: presence, origin, and correlation with ripening time of Grana Padano cheese.

Pyroglutamic acid is present in many cheese varieties and particularly in high amounts (0.5 g/100 g of cheese) in extensively ripened Italian cheeses (Grana Padano and Parmigiano Reggiano) that are produced with thermophilic lactic acid bacteria as starters. The mechanism of pyroglutamic acid formation in cheese seems to be mostly enzymatic, as demonstrated by the presence of only L-pyroglutamic acid enantiomer. Thermophilic lactobacilli are involved in pyroglutamic acid production, as suggested by the low pyroglutamic acid content found in Bagos, a ripened Italian mountain cheese produced without addition of starter. Because milk pasteurization did not influence the pyroglutamic acid content in the ripened Grana Padano cheese, the formation of pyroglutamic acid mainly depends on the whey starter microflora rather than that of raw milk. Pyroglutamic acid concentration is linearly correlated (R2 = 0.94) with the age of Grana Padano cheese.

Animals↗
PubMed1999

HCV genotyping by three methods: analysis of discordant results based on sequencing.

BACKGROUND: Correct genotyping of hepatitis C virus (HCV) RNA-positive serum samples may have important clinical and therapeutic implications. OBJECTIVES: Three methods were compared to improve accuracy of HCV genotyping. STUDY DESIGN: A panel of 144 HCV RNA-positive sera prospectively tested by a modified Okamoto's type-specific reverse transcription-nested polymerase chain reaction (RT-nPCR) (Okamoto H, Tokita H, Sakamoto M, Kojima M, Iizuka H, Mishiro S. J Gen Virol 1993; 74: 2385-2390) was retrospectively analyzed by two recently described methods which were reported to identify all HCV types and the majority of HCV subtypes: (i) a restriction fragment length polymorphism (RFLP) analysis of PCR products amplified from the 5' untranslated region (5'UTR) of the viral genome (Pohjanpelto P, Lappalainen M, Widell A, Asikainen K, Paunio M. Clin Diagn Virol 1996; 7: 7-16); and (ii) a type-specific RT-nPCR relevant to the core region (Ohno T, Mizokami M, Wu R, Saleh M, Ohba K, Orito E, Mukaide M, Williams R, Lau J. J Clin Microbiol 1997; 35: 201-207). The panel (according to results given by the modified Okamoto's method) consisted of: (i) 105 sera belonging to five different HCV subtypes; (ii) 20 specimens containing a mixture of > or = 2 genotypes; and (iii) 19 untypeable clinical samples. RESULTS: There was agreement of the three methods for 78/144 (54.2%) blood samples, whereas discordant results were obtained for the remaining 66 samples, 56 of which could be typed by sequencing. Of these, 51 (91.7%) were correctly typed by RFLP, 37 (66.0%) by Ohno's and 27 (48.2%) by the modified Okamoto's procedure. The overall genotyping sensitivity of each method over the total number of 134 samples whose genotype was ascertained, was 96.2% for RFLP, 85.8% for Ohno's and 78.3% for the modified Okamoto's procedure. CONCLUSIONS: RFLP analysis, notwithstanding some limitations in subtyping efficiency of genotype 1 samples, appears superior to the two RT-nPCR methods because: (i) it is able to type a larger number of samples; (ii) it is more efficient in identifying genotypes 2a/c, which are widespread in Italy; (iii) it is highly sensitive (together with Ohno's method) in recognizing genotypes 3 and 4.

5' Untranslated Regions↗
PubMed1999

Presence of peptidase activities in different varieties of cheese.

Lactic acid bacteria (LAB) counts, PepX activity towards H-Phe-Pro-beta NA, and aminopeptidase activity towards H-Arg-beta NA. HCl, H-Lys-beta NA, H-Leu-beta NA, H-Pro-beta NA, H-Glu-beta NA derivatives have been evaluated in 32 commercial samples of cheese, one processed cheese, and one yoghurt. The presence of intracellular exo-peptidase activities in cheese extracts free from bacterial cells was detected, even after 1 year of ripening. An inverse ratio between the presence of viable lactic microflora and peptidase activity in the cheese extracts was observed. The importance of LAB starter exo-peptidases in the degradation of casein oligopeptides, and the key role of autolysis in the release of peptidases in the cheese, are discussed.

Cheese↗
PubMed1999

Effectiveness of chemometric techniques in discrimination of lactobacillus helveticus biotypes from natural dairy starter cultures on the basis of phenotypic characteristics

Lactobacillus helveticus is the dominant organism in natural starter cultures used for the production of typical Italian cheeses. In this study, 74 L. helveticus strains, isolated from grana and provolone cheese natural whey starters, were distinguished with respect to their origin by using both cell wall protein profiles and chemometric evaluation of some phenotypic parameters, such as the ability to acidify cultures and the presence of nonspecific proteolytic and peptidase activities. Cell wall protein patterns allowed L. helveticus strains to be distinguished with respect to their source of isolation. Among the different phenotypes studied, no single specific parameter permitted the two groups of strains to be separated. A good discrimination between the two groups of L. helveticus species was obtained by multivariate statistical techniques, which permitted the extraction of all of the discriminating information retained in the phenotypic activities. Associations between strain phenotype expression and dairy environmental ecosystem source are discussed.

Journal Article↗
PubMed1999

The role of anillin in meiotic cytokinesis of Drosophila males.

Anillin is a 190 kDa actin-binding protein that concentrates in the leading edges of furrow canals during Drosophila cellularization and in the cleavage furrow of both somatic and meiotic cells. We analyzed anillin behavior during D. melanogaster spermatogenesis, and focused on the relationships between this protein and the F-actin enriched structures. In meiotic anaphases anillin concentrates in a narrow band around the cell equator. Cytological analysis of wild-type meiosis and examination of mutants defective in contractile ring assembly (chickadee and KLP3A), revealed that the formation of the anillin cortical band occurs before, and does not require the assembly of the F-actin based contractile ring. However, once the acto-myosin ring is assembled, the anillin band precisely colocalizes with this cytokinetic structure, accompanying its contraction throughout anaphase and telophase. In chickadee and KLP3A mutant ana-telophases the cortical anillin band fails to constrict, indicating that its contraction is normally driven by the cytokinetic ring. These findings, coupled with the analysis of anillin behavior in twinstar mutants, suggested a model on the role of anillin during cytokinesis. During anaphase anillin would concentrate in the cleavage furrow before the assembly of the contractile ring, binding the equatorial cortex, perhaps through its carboxy-terminal pleckstrin homology (PH) domain. Anillin would then interact with the actin filaments of the acto-myosin ring through its actin-binding domain, anchoring the contractile ring to the plasma membrane throughout cytokinesis.

Actins↗