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A Nastasi

Publications and source records attributed to A Nastasi.

At least 37 records · Page 2Linked to original sources
PubMed1996

Phage types and ribotypes of Salmonella enteritidis in southern Italy.

Differently from other European countries, Southern Italy was affected by a considerable increase in human infections due to Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) only after 1990. On the present investigation, two groups of S. Enteritidis strains isolated during the low-incidence period 1980-1984 and the epidemic period 1990-1993, respectively, have been submitted to phage-typing and ribotyping in order to ascertain whether the epidemic increase was determined by the spread of a foreign bacterial clone or not. Among the 150 isolates relative to the aforesaid two periods, 12 different phage types (PTs) were observed. PT4 was the most common phage type among the strains isolated in 1980-1984 (61%) as well as in those of the epidemic period 1990-1993 (72%). PT8 was the second most frequent (33%) phage type in 1980-1984. It was substituted by PT1 (19%) in the 1990-1993 period. Analysis of rDNA patterns obtained after Hinc II digestions and Escherichia coli rRNA hybridizations showed 8 different patterns, A to H. The great majority of the strains studied (140 isolates, 93%) belonged to the ribotype A, showing a similar frequency both in 1980-1984 (36 of 39, 92%) and in 19901993 (104 of 111, 94%). The predominance of PT4 and ribotype A among both preepidemic and epidemic strains is in agreement with the hypothesis that host genetic diversity decline and modern farming practices in the poultry industry have facilitated a widespread dissemination of preexisting endemic strains. This hypothesis urges to plan new strategies in preventing S. Enteritidis infections.

Bacterial Typing Techniques↗
PubMed1996

Alterations in the progression of cells through the cell cycle after exposure to alpha particles or gamma rays.

A G1-phase delay after exposure to alpha particles has not been report ed previously, perhaps because immortalized cell lines or cell lines from tumor cells were used in past studies. Therefore, we compared the effects of alpha particles (0.19 or 0.57 Gy) and approximately equitoxic doses of gamma rays (2 or 4 Gy) on progression of cells through the cell cycle in normal human skin fibroblasts. Cell cycle analyses were performed using flow cytometry by measuring incorporation of bromodeoxyuridine (BrdUrd) in each phase of the cell cycle up to 44 h after irradiation. We observed an alpha-particle-induced G1-phase delay in human skin fibroblasts even at the lowest dose, 0.19 Gy. At equitoxic doses, more pronounced and persistent G1-phase delays and arrests were observed in gamma-irradiated cultures in that increased fractions of the G1-phase cells remained BrdUrd- over the course of the study after gamma-ray exposure compared to cells exposed to alpha particles. In addition, G1-phase cells that became BrdUrd+ after gamma irradiation re-arrested in G1 phase, whereas BrdUrd+ G1-phase cells in alpha-particle-irradiated cultures continued cycling. In contrast, comparable percentages of cells were delayed in G2 phase after either alpha-particle or gamma irradiation. Both gamma and alpha-particle irradiation caused increases in cellular p53 and p2lCip1 shortly after the exposures, which suggests that the G1-phase delay that occurs in response to alpha-particle irradiation is dependent on p53 like the initial G1-phase delay induced by gamma rays.

Alpha Particles↗
PubMed1995

Epidemiological evaluation by PCR ribotyping of sporadic and outbreak-associated strains of Salmonella enterica serotype Typhimurium.

Salmonella enterica serotype Typhimurium has a very large diffusion worldwide within human and non-human hosts. The simultaneous circulation in the same geographical areas of many bacterial clones requires the use of reliable, reproducible and highly discriminatory typing techniques for epidemiological studies. Molecular biological methods, such as plasmid profile analysis, restriction endonuclease digestion of plasmid and chromosomal DNA and hybridization-based procedures have proven to be useful tools for strain differentiation. More recently, detection of polymorphisms in the intergenic spacer regions of rRNA genes by polymerase chain reaction (PCR ribotyping) has been successfully applied to characterize bacterial strains. In this study, PCR ribotyping was performed on 45 epidemiologically related and unrelated strains of S. enterica serotype Typhimurium isolated in northern and southern Italy during 1992. Isolates were simultaneously characterized by traditional ribotyping. Results suggest that PCR ribotyping is a rapid, easy-to-perform and reproducible typing method able to determine relatedness among isolates of this serotype.

Bacterial Typing Techniques↗
PubMed1994

Epidemic dissemination of Salmonella enterica spp. enterica serovar Bovismorbificans in southern Italy in the years 1989-1991.

Epidemic strains of Salmonella enterica subsp. enterica serovar Bovismorbificans isolated in southern Italy during the years 1989-1991 were submitted to a molecular epidemiological study in comparison with isolates identified in the years 1980-1988 in the same geographic area. Genomic DNA fragments obtained by digestion with BglI or Eco RI hybridized with Escherichia coli rRNA to produce three distinct, but highly related patterns. Ribotype 1, which had never been identified before 1989, was found to characterize most of the strains identified between 1989 and 1991. Such a finding supports the hypothesis of emergence and spread of a new bacterial clone associated with the increased number of human infections reported in the same years in southern Italy.

DNA, Bacterial↗
PubMed1994

Short-term effects of low protein-normal sodium diet on renal function in chronic renal failure.

To investigate the short-term renal effects of protein restriction and unchanged salt intake in chronic renal failure (CRF), patients with moderate CRF (creatinine clearance 41 +/- 5 ml/min) and healthy controls (CON) ate a normal protein diet (NPD) for four weeks, and thereafter a low protein diet (LPD, 0.4 g/kg body wt/day) for three weeks. The two diets were isocaloric and with a salt intake of 10 to 13 g/day. No differences in body weight, serum proteins and plasma sodium were recorded throughout the study. During LPD, inulin and PAH clearances in CON demonstrated a progressive 25% decline of basal GFR and RPF; on the contrary, in CRF, basal renal function did not change in presence of a significant reduction of proteinuria. In CON patients after protein restriction, fractional free-water generation (CH2O/CIn) and fractional urinary excretion of sodium (FENa) measured under maximal water diuresis increased progressively, both being doubled at the end of LPD, while in CRF, CH2O/CIn did not change and FENa values remained unmodified and much higher (above 4%) than in CON after both diets. The renal response to an acute oral protein load (OPL) and i.v. low-doses of dopamine (D) was measured at the end of each period; in the two groups, GFR and RPF significantly increased following OPL + D after both diets. In CRF, however, the vasodilatory response was blunted overall being reduced after both LPD and NPD, and, unlike CON, it did not increase after LPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Nutritional problems in cirrhotic patients. Evaluation of dietetic aspects].

The aim of the study was to evaluate: a) the influence of the diagnosis of liver cirrhosis on the alimentary behaviour of cirrhotic patients; b) the compliance and the effect during observation-time of a personalized diet; c) the modifications, induced by the diet, of some clinical and biochemical parameters, specifically of these correlated to hepatic encephalopathy in 20 non-alcoholic cirrhotic patients. They were entered the study, in stage A-B of liver disease, according to Child-Pugh criteria. No patients received a previous specific dietetic prescription. After the collection of the alimentary intake before and after the diagnosis of liver disease, we prescribed normoprotein and hyposodium diets, reducing or increasing the caloric intake for the patients who were not at their ideal weight. From our study it stands out that the diagnosis induced all patients to reduce their caloric intake, especially of lipids. The appropriate dietetic prescription followed by short run controls led to a general improvement of the evaluated parameters, which was not kept during the following months; as a matter of fact, at the long run control all patients tended to return to their previous alimentary habits, neglecting, in the course of time, the diets they had been prescribed. We can, consequently, maintain that the cirrhotic needs a steady clinical and dietetic control since he seems to undervalue the prescribed therapies.

Analysis of Variance↗
PubMed1993

rRNA gene restriction patterns and biotypes of Shigella sonnei.

Shigella sonnei is a major agent of diarrhoeal disease in developed as well as in developing countries. Several phenotypic methods to define strain differences have been applied to this species of Shigella including, more recently, analysis of extrachromosomal and chromosomal DNA. In this study, 432 endemic and epidemic strains isolated between 1975 and 1991 in Italy, France and Switzerland were submitted to rRNA gene restriction pattern analysis, after digestion of whole-cell DNA by Hinc II, and to concomitant biotyping. Thirteen ribotypes, H1 to H13, and five biotypes, a, d, e, f, g, were detected. Ninety-five percent of the sporadic strains were assigned to ribotypes H1 to H4, which could be subtyped, except for H4, in different biotypes. Strains from each of seven different outbreaks had indistinguishable ribotype-biotype patterns. In contrast, 65 strains, isolated in Sicily in 1980 over an extended period of apparently epidemic increase of isolations and which had previously been considered to be a single bacterial clone on the basis of resistance pattern and phage type, were found to belong to two different and scarcely related ribotypes. Ribotyping and biochemical subtyping appear to be a useful epidemiological tool in studies on the circulation and distribution of strains of S. sonnei.

Bacterial Typing Techniques↗
PubMed1993

Epidemiology of Salmonella typhimurium: ribosomal DNA analysis of strains from human and animal sources.

Salmonella typhimurium is the most frequently identified serovar of Salmonella in Italy. This serovar is characterized by the widespread dissemination among human and non-human sources of phenotypically and genetically well-differentiated clones. In this study 457 strains of S. typhimurium isolated in Italy in the years 1982-91 from human and animal sources were submitted to characterization by the rDNA fingerprinting technique. Application of this typing method, after digestion of chromosomal DNA with HincII endonuclease, confirmed the greatest genetic differentiation of clones of S. typhimurium, allowing reliable identification of 45 rDNA patterns linked into 9 major clusters. rDNA pattern clusters or ribotypes specific to man were not recognized, whereas some rDNA patterns were characteristically related to ducks, pigeons and pet birds. The ribotyping results for isolates from animal hosts suggest that pig and cattle are the main source of human infection.

Animals↗
PubMed1991

rDNA fingerprinting as a tool in epidemiological analysis of Salmonella typhi infections.

Characterization of 169 strains of Salmonella typhi of phage types C1, C4, D1 and D9 isolated in 1975-88 was carried out by rDNA gene restriction pattern analysis. Twenty-four isolates had been recovered during four large waterbone outbreaks in the last 20 years in Sicily; 145 strains, isolated from apparently sporadic cases of infection in Southern Italy in the same period of time, were also examined. Application of rRNA-DNA hybridization technique after digestion of chromosomal DNA with Cla I showed the identity of patterns of the epidemic strains of phage types C1 and D1, confirming attribution of the outbreaks to single bacterial clones. Patterns of the two available strains of lysotype D9 were slightly different, whilst the 12 epidemic strains of phage type C4 could be assigned to two distinct patterns scarcely related to each other and, consequently, to two different clones. A considerable heterogeneity was detected among all apparently sporadic isolates of the four phage types under study. This fingerprinting method appears a reliable tool to complement phage typing in characterizing isolates of S. typhi. In particular, epidemiological features of spread of this salmonella serovar in areas, where simultaneous circulation of indigenous and imported strains occurs, can be elucidated.

Bacteriophage Typing↗
PubMed1991

Reemergence of Shigella dysenteriae type 2 in Sicily: an epidemiological evaluation.

Three strains of Shigella dysenteriae type 2 were isolated from a small household outbreak which occurred in Palermo, Sicily, during summer 1990. Two isolates were recovered from hospitalized patients and one from an asymptomatic carrier. The infection could not be associated with travel to foreign countries or contact with travellers returned from abroad. Since 1953 S. dysenteriae has been never isolated in Southern Italy. The isolates from dysentery cases were susceptible to antibiotics and carried a plasmid of 120 MDa associated with a small cryptic plasmid; in contrast, the strain isolated from the healthy carrier contained an additional plasmid of approximately 40 MDa, which codified for resistance to ampicillin, streptomycin, sulfamethoxazole and trimethoprim. All strains showed some atypical biochemical properties, but their rRNA-DNA patterns of hybridization were closely similar to that of the reference strains of type 2 and easily distinguishable from those of the other types of non-Shiga bacillus reference strains. Epidemiological isolation features of these strains suggest a possible circulation of this Shigella species in Sicily. Genetic characterization of these strains may be useful for surveillance of infections by this organism.

Adult↗
PubMed1990

Salmonella serovars identified at the Centre for Enterobacteriaceae of Palermo over the 5-year period 1983-87.

Salmonellosis is become an increasing public health problem in many countries. Serotyping and assessment of antibiotic resistance are useful tools, which assist in understanding the epidemiology of Salmonella infections. In this respect, the Centre of Enterobacteriaceae of Southern Italy provides helpful information on the changing pattern of Salmonella serovars in this geographic area. This paper reports the distribution of serovars and their antibiotic susceptibility in the years 1983-1987. In particular, because of their peculiar trends during this 5-year period, epidemiological features of Mbandaka, Corvallis, Dublin, Infantis and Wien serovars are described.

Animals↗
PubMed1990

rRNA probing of chromosomal DNA of epidemic and sporadic isolates of Salmonella enterica subsp. enterica serovar Kottbus from northern and southern Italy.

Fifty-two strains of Salmonella enterica subsp. enterica serovar Kottbus, identified at the Centres of Enterobacteriaceae of Northern and Southern Italy, were investigated by molecular genetic methods. Thirteen isolates were recovered during two food-poisoning outbreaks that occurred in May 1987 in Lombardy. The rDNA gene restriction patterns, obtained by probing endonuclease cleaved chromosomal DNA with photobiotin labeled Escherichia coli rRNA, revealed some heterogeneity among strains isolated from Southern Italy, whereas Northern Italy isolates exhibited virtually identical banding patterns.

Blotting, Southern↗
PubMed1990

Characterization of strains of Salmonella enterica subsp. enterica serovar Wien isolated in Italy: an epidemiological evaluation.

In the years 1987-1988, 110 strains of Wien serovar were isolated from a gastroenteritis outbreak in a neonatal unit in Palermo (Sicily). These strains showed different drug resistance patterns and plasmid profiles. Analysis of endonuclease restriction fragments of chromosomal DNA by hybridization with E. coli rRNA has demonstrated that a single bacterial clone or its derivatives were responsible for the outbreak. Furthermore, the study of 139 strains, isolated since 1970 from different geographic locations of the Mediterranean area, has confirmed a notable degree of homogeneity within Wien serovar, even though the detection of genetic polymorphisms in some isolates suggests that a number of distinct bacterial strains contributes to maintain the circulation of Wien serovar.

Blotting, Southern↗
PubMed1989

Zenker's diverticulum: a cause for complete esophageal obstruction and its management.

Besides the gastroenterologists, we as gastroenterology nurses and associates are probably the first line of help for patients with this disorder. By having a sound background knowledge of the mechanisms by which Zenker's diverticulum can occur and the possible complications that can arise, we can coordinate a task force of appropriate paramedical personnel: the nutritionist who can instruct the patient on good healthy dietetics, the social worker who may be able to arrange "meals on wheels," the physical therapist who can teach the patient to re-think the way he or she swallows and good deep breathing exercises. We can give our patients a sound understanding of their problem by educating them in language that they understand. By so doing we will be encouraging them in their own preventative measures to promote wellness, which is one of endoscopy's major aims in health care.

Aged↗
PubMed1989

Molecular study on nosocomial Pseudomonas aeruginosa strains.

Nosocomial Pseudomonas aeruginosa isolates were typed by DNA fingerprinting techniques. Chromosomal DNA banding patterns, after endonuclease digestion, of six isolates from a neonatal care unit confirmed the results of O-serotyping and antimicrobial susceptibility pattern analysis. In contrast, the characterization by chromosomal DNA fingerprinting of P. aeruginosa strains isolated from patients treated in a burn unit disagreed with the two classic typing methods: in fact, isolates that varied in serotype and antibiograms showed identical restriction endonuclease profiles, whereas two indistinguishable isolates cultured from individual patients were easily and reproducibly differentiated by molecular analysis.

Bacterial Typing Techniques↗