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S Rosati

Publications and source records attributed to S Rosati.

At least 55 records · Page 3Linked to original sources
PubMed1995

Characterization of ovine lentivirus envelope glycoprotein expressed in Escherichia coli cell and baculovirus systems.

The ovine lentivirus (OLV) envelope protein NH2- and COOH-terminal subunits gp70 and the NH2-terminal subunit gp40 were expressed in Escherichia coli cell. The entire gp70 envelope protein was also expressed in insect cells by the recombinant baculovirus. Guinea pigs were immunized with each bacterially expressed recombinant protein, and a serum neutralization assay was used to determine their capacity to neutralize OLV. These results showed that the major neutralization epitopes are located in the NH2-terminal half of the gp70. The baculovirus expressed gp70 was found on the surface of insect cells and was immunobiologically active. Virus neutralization activity was also produced in sheep immunized with the baculovirus expressed recombinant protein.

Animals↗
PubMed1995

Comparison of ovine lentivirus detection by conventional and recombinant serological methods.

Recombinant (r) transmembrane protein (TM), major capsid protein P25, and matrix protein P16 of ovine lentivirus (OLV) were used as solid phase antigens in enzyme-linked immunosorbent assays (ELISAs) for the detection of specific antibodies against OLV in sheep sera. Sensitivity, specificity, and agreement of these three recombinant assays were compared with each other and with two currently available conventional OLV serological assays, the agar gel immunodiffusion (AGID) test and a whole-virus (WV) ELISA. Field sera from a total of 412 Midwestern United States sheep were tested and compared by the five OLV detection methods, including visibly healthy sheep selected for public sale (Group A, n = 171), samples from a breeding flock of Finnsheep and Finn-cross ewes (Group B, n = 184) and moribund sheep with clinical signs associated with OLV (Group C, n = 57). The rTM ELISA was the most sensitive OLV detection assay, both overall and within each group. Sera from 48.1% (198/412) of field samples were rTM ELISA positive. By contrast, positive rates for the rP25, rP16, and WV ELISAs and AGID test were 34.2%, 32.3%, 36.9%, and 26.9%, respectively. The rTM ELISA reactivity was 36.8% for Group A sera, 50.0% for Group B sera, and 75.4% for Group C sera. Among the 21 Group C sheep possessing OLV lung lesions at necropsy, 20 (95.2%) were rTM ELISA positive. The greatest test agreement occurred between the rP25 and the rP16 ELISAs. The data suggest that the recombinant TM immunoassay is the most accurate and sensitive of the five methods evaluated for the detection of serum anti-OLV antibodies in sheep, both at the subclinical infection and overt clinical disease stages.

Aging↗
PubMed1995

Development and application of an antibody ELISA for the marker protein of ovine pulmonary carcinoma.

Ovine pulmonary carcinoma (OPC) is a contagious pulmonary neoplasia with a suspected retroviral etiology. The major core protein (P27) of the putative OPC virus cross-reacts with antibodies to P27 of the Mason-Pfizer monkey virus (MPMV), a type-D retrovirus. This serological reactivity serves as the only accepted biological marker for OPC. In order to make a useful reagent for the detection of the OPC marker for serodiagnosis and epidemiological studies, the MPMV-P27 coding region was cloned and expressed in Escherichia coli. Gel purified recombinant MPMV-P27 protein was used to develop an immunoassay. This recombinant enzyme-linked immunosorbent assay (ELISA) was then used to screen 223 sera from US sheep and 176 sera from Italian sheep. In this study, we found: (1) a high prevalence of infection with the putative OPC retrovirus in sheep with chronic pneumonia; (2) a subclinical infection with OPC virus may be more common in US sheep than indicated by the rare recorded occurrence of pulmonary carcinoma; (3) an apparent association between ovine lentivirus (OLV) and OPC infection.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1995

Genetic and antigenic characterization of caev (caprine arthritis-encephalitis virus) recombinant transmembrane protein.

The env gene fragment of an Italian strain of Caprine Arthritis Encephalitis virus (CAEV) coding for the hydrophilic region of transmembrane protein was amplified, cloned and expressed in prokaryotic system as fusion protein with glutathione-S-transferase. Sequence analysis revealed 63 to 66% amino acid homology, when compared with three ovine lentiviruses and 83% when compared with one caprine lentivirus. The recombinant transmembrane protein was efficiently expressed, purified under denaturing conditions and used as antigen in western blotting and ELISA. Sera from clinically diseased goats strongly reacted in western blotting and naturally infected animals seroconverted between 20 and 33 weeks of age. An indirect ELISA performed with this antigen showed improved sensitivity in comparison with agar gel immunodiffusion test. Our results confirm that transmembrane protein is an important immunological marker in CAEV infection and its use as antigen may enhance the validity of serological diagnosis of Caprine Arthritis Encephalitis.

Amino Acid Sequence↗
PubMed1995

Genome analysis of North American small ruminant lentiviruses by polymerase chain reaction and restriction enzyme analysis.

The polymerase chain reaction (PCR) was used to amplify portions of the gag and env structural genes of 8 ovine and 1 caprine lentivirus isolates of North American origin. Three sets of primers were used to amplify p16, p25, and N'-gp40 gene fragments, and 1 set, annealing highly conserved portions of long terminal repeat (LTR) among small ruminant lentiviruses, was used as a positive control. Variable PCR amplification efficiency was observed. Different stringency conditions of hybridization with specific DNA probes were used to maximize detection of the PCR product. The p25 primers detected all strains, the gp40 primers detected 1 ovine and the caprine strain, and the p16 primers detected only 1 ovine isolate. All strains were detected by LTR primers. Restriction endonuclease analysis of 5 amplified p25 and 2 N'-gp40 gene fragments revealed extensive heterogeneity among these North American small ruminant lentiviruses.

Animals↗
PubMed1994

The Reed-Sternberg cells of Hodgkin disease are clonal.

Relatively little progress has been made in understanding the nature of the Reed-Sternberg (RS) cell and its morphologic variants in Hodgkin disease (HD). This is primarily due to the fact that RS cells represent a minute subpopulation within HD lesions. To investigate the clonal origin of RS cells and variants, we studied 27 HD lesions obtained from 11 patients. Using an image analyzer (CAS 200) we were able to demonstrate that CD30-positive RS cells are clonal elements with unique and individualized DNA profiles and that the DNA content of any given patient RS cell population is constant over time and in different pathologic sites. Using 1, 9, 11, and X alpha satellite chromosome probes and interphase cytogenetics, we also demonstrated that RS cells obtained from different tissue samples of the same patient have a unique and often abnormal chromosomal pattern. To definitively prove the hypothesis that CD30-positive RS cells are clonal elements, we investigated the presence of point mutations within p53 gene exons 5 through 9 and found that only a single patient possessed a nonsense p53 somatic point mutation (Arg to His). This same mutation could be identified in all of his available biopsies. Altogether, these findings demonstrate that RS cells and variants in HD are clonal and represent the neoplastic elements of this entity.

Base Sequence↗
PubMed1994

A comparison of whole virus and recombinant transmembrane ELISA and immunodiffusion for detection of ovine lentivirus antibodies in Italian sheep flocks.

Sera from two sheep experimentally infected with ovine lentivirus (OLV) and from 186 sheep selected from flocks with known high or low prevalence of infection or on the basis of virological or histopathological examination were simultaneously tested by whole virus (WV) ELISA, recombinant transmembrane (r-TM) ELISA and AGID assay. Antigens for both the WV ELISA and AGID were prepared from an Italian field isolate; recombinant antigen was derived from the N'-terminal region of the transmembrane envelope protein of strain K1514. The WV ELISA detected the highest number of seropositives, followed by the r-TM ELISA and AGID test. The sensitivity and specificity of the r-TM ELISA relative to the WV ELISA were 0.66 and 0.95, respectively. Immunoblot analysis of 14 WV ELISA-positive and r-TM ELISA-negative sera showed that the major core protein was immunodominant on WV antigen. It is concluded that the r-TM ELISA was more sensitive than the AGID test but less sensitive that the WV ELISA, particularly for detecting antibodies in the early stages of infection.

Animals↗
PubMed1994

Antibiotic susceptibility and serotyping of Pseudomonas aeruginosa strains isolated from surface waters, thermomineral waters and clinical specimens.

Different kind of mineral waters used for drinking purposes or hydromineral therapy and surface environmental waters for recreational use were tested for the presence of Pseudomonas aeruginosa. A comparison of antibiotic resistance patterns and serotyping between water strains and P. aeruginosa isolates from different infection sites of hospitalized humans (Pisa General Hospital) was performed. Altogether one hundred and fifty-six strains were characterized. All isolates were most resistant to furans. A very high degree of resistance to amoxicillin, clavulanic acid, ampicillin, chloramphenicol, tetracycline and trimethoprim was pointed out. Resistance to amikacin, cefotaxime and norfloxacin was observed only in strains from clinical specimens. Amikacin was the antibiotic to which 80% of multiple resistant strains showed sensitivity. The distribution of O-antigen serotypes varied by samples sources; 01, 06, 011 serotypes were the most frequently recovered. No isolates were found to be 08, 013, 014, 015 immunotype. The data indicate that serotyping can be a useful addition to antibiotic susceptibility testing for epidemiological purposes.

Anti-Bacterial Agents↗
PubMed1993

[Value of continuous electrocardiographic monitoring of patients with syncope. Results of a prospective study].

AIM: Syncope, a temporary loss of conscience, is a frequent cause for consulting the family doctor or more often being brought to the hospital emergency ward. In order to evaluate the importance of the continuous recording of ECG in the formulation of the diagnosis, the relevant data were extrapolated from more general data in the prospective study. MATERIAL: A total of 194 patients were enrolled whose diagnosis was divided into three distinct stages. Continuous echographic registration using Holter's method and/or bedside monitoring was included in the 2nd stage and was performed in 134 patients. RESULTS: 102 out of 134 patients (76.11%) showed rhythm alterations: varying degrees of atrio-ventricular block were recorded in 6 patients; supraventricular arrhythmia in 73 cases which were divided according to a modified to a modified version of Lawn's classification. Continuous ECG recording alone proved decisive in formulating a diagnosis in 6 patients (one of which together with echocardiogram): in 2 patients due to the presence of complex ventricular extrasystoles; in 4 due to torsion of the tip, sinusal arrest, cardiac arrest, supraventricular tachycardia with aberrant intraventricular conduction, respectively. CONCLUSIONS: Especially when standard surface ECG is carried out rapidly following an acute attack, continuous ECG recording is of scant diagnostic value due to the etiological definition of syncope. But due to its moderate cost and non-invasive character it is worth performing in syncopes of suspected cardiogenic etiology with a more severe prognosis.

Aged↗
PubMed1993

[Syncope in a general population: etiologic diagnosis and follow-up. Results of a prospective study].

OBJECTIVE: Syncope is a common clinical problem in a general population. A prospective study was performed, in our hospital, to evaluate the incidence of the disease and to standardize the diagnostic and clinical management. METHODS: 194 patients aged 10-92 years were recruited during one year. The diagnostic produce followed the three standard stages: First stage clinical evaluation (a complete history, physical and neurological examination, a base-line laboratory evaluation, a 12-lead electrocardiogram, carotid sinus stimulation); Second stage non invasive investigation (echocardiogram, 24-hour electrocardiographic monitoring, electroencephalography, Doppler echocardiography of epiaortic vessels, head-up tilt test, head CT scan); third stage invasive investigation (electrophysiologic study). RESULTS: Diagnosis was, sometimes, difficult because of the sporadic and transitory nature of the syncope. The etiological diagnosis were the following: cardiovascular causes 68.55% (cardiac 31.95%, reflex syncope 36.59%). Non-cardiovascular causes 10.82% (metabolic 5.15%, neurologic 3.5%, different 2.06%). Unknown cause 20.61%. Diagnosis was determined at the following stages: ist stage 63.40% (complete history and physical examination alone 4072%), 2nd stage 14.43%, 3rd stage 1.54%. The mean follow-up period was 21.71 +/- 6.22 months. Over this period 17 (8.76) patients died; all aged (> 65 years) end in this aged the incidence is 18.08%. If we look at patients with correct diagnosis of syncope (183 patients) the mortality rate is 8.19% (if we consider those aged > 65 the rate is 17.44%). The mortality rate of cardiac syncope of unknown (28.88% for aged > 65 years). 2 deaths among syncope of unknown cause. 17.48% had 1 or more episodes of recurrent syncope during this follow-up period with little prevalence for patients with syncope of unknown origin. Other major cardiovascular events was 18.03% in all patients with little prevalence for cardiac cause of syncope. CONCLUSIONS: 1) Frequently an accurate history, a physical examination and a standard ECG are enough to formulate a correct diagnosis. 2) Head-up tilt test must be considered in patients with a unknown diagnosis, before starting invasive investigation. 3) Prognosis is dependent on the specific cause. Since cardiac syncope has a serious prognosis, when it is not treated correctly, it can even lead to sudden death.

Adolescent↗
PubMed1992

Well-differentiated thymic carcinoma: a clinico-pathological study.

Well-differentiated thymic carcinoma (WDTC) is a recently described epithelial tumour of the thymus previously classified as cortical or predominantly epithelial thymoma. The authors have reviewed a series of 15 cases of WDTC with the aim of further defining the clinicopathological features of this neoplasm. Histologically, the number of lymphocytes was always low; perivascular spaces and epithelial palisading around blood vessels and/or along fibrous septa were prominent features; 6 cases (40%) were associated with areas of typical cortical thymoma. All cases showed slight to moderate cytological atypia and nuclear grooving was frequently detected. Mitotic activity was variable but usually low. Clinically, all but 3 cases (80%) were invasive at surgery; myasthenia gravis was present in 9 cases (60%); 5 patients (33.3%) died due to disease and 2 additional patients (13.3%) had tumor recurrence. Our study indicates that WDTC has fairly distinctive clinicopathological features and that it is histologically and histogenetically related to cortical thymoma. The definition "well-differentiated carcinoma" is justified because of low-grade cytological atypia and retention of some organotypical histological features, in a tumour otherwise often displaying aggressive and sometimes clear-cut malignant clinical behaviour.

Adult↗
PubMed1992

Microscopic thymoma: histological evidence of multifocal cortical and medullary origin.

Twenty cases of macroscopically non-neoplastic thymuses obtained from patients with myasthenia gravis have been studied histologically. Seven cases were characterized by lymphoid follicular hyperplasia and 13 by involutional changes of variable degree. In three cases (15%), one with lymphoid follicular hyperplasia and two with involutional changes, multiple microscopic epithelial lesions, 0.2-0.4 mm in diameter and consistent with foci of microscopic thymoma, were observed. Most of them were related to the thymic cortex and one, displaying a different histological pattern, was located in a medullary area. These observations provide morphological evidence of a possible multifocal origin of thymoma from distinct epithelial clones present in the different topographic areas of the human thymus.

Adolescent↗
PubMed1991

Preliminary investigation of suitable bacteria strains for the detection of bacteriophages in environmental polluted surface waters.

Different host-specific bacteriophages were monitored in several water systems together with the usual faecal contamination indicator bacteria (thermotolerant coliforms). The host bacteria used for the plaque assay were E. coli K12, E. coli K12 Hfr, E. coli CHfr and S. typhimurium LT2F+. S. typhimurium LT2F+ showed significantly lower phage counts than the three E. coli strains. The phages specific for E. coli K12 (somatic phages) were in high correlation (r = 0.86, r = 0.91; P less than 0.001) with other coliphages, but not with phages specific for S. typ. LT2F+ (r = 0.33; P less than 0.05). There was an high degree of correlation among phages of E. coli K12 Hfr, E. coli C Hfr and S. typhimurium LT2F+ (pilus F-carrying bacteria) (r = 0.96, r = 0.73, r = 0.75; P less than 0.001). Good correlation was seen between faecal coliforms and male-specific phages but not among faecal coliforms and E. coli K12-specific phages (r = 0.30; P less than 0.05). The relative suitability of host strains when using phages in the evaluation of faecal and viral pollution of aquatic environments is discussed.

Coliphages↗
PubMed1989

Macrophages and interdigitating reticulum cells in normal thymus and in thymoma: an immunohistochemical study.

The distribution and immunophenotype of macrophages and interdigitating reticulum cells were investigated on frozen sections of seven normal thymuses and 10 thymomas. In normal thymus, macrophages were mainly located in the cortex, were markedly PAM-1+/MAC+, weakly Leu-M3+ (CD14), T4+ (CD4), T9+ and OKM-1+ (CD11b). Interdigitating reticulum cells were mainly located in the medulla and were pan-Leu+ (CD45), T4+(CD4+), HLA-DR+; furthermore, they were also often TAC+ (CD25) and T9+. Thymomas were composed of cytokeratin-containing epithelial cells admixed with variable proportions of T6+ (CD1a) lymphocytes. As defined by the histological features two thymomas were lymphocyte-rich, five were mixed type and three were epithelial-rich; eight thymomas were mainly composed of cortical epithelial cells and two were composed of spindle epithelial cells suggesting a medullary origin. In all cases, thymoma-associated macrophages were markedly PAM-1+/MAC+; they were numerous, and regularly distributed throughout the tumour. The density of macrophages per unit area was similar to that of the normal thymus, and was not influenced by the histological type or by the lymphocyte content of the tumour. Interdigitating reticulum cells were few and were confined to the areas of medullary differentiation.

Adult↗