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Biomedical subjects

G M Rossolini

Publications and source records attributed to G M Rossolini.

At least 91 records · Page 5Linked to original sources
PubMed1991

Nonradioactive DNA probe for detection of gene for methicillin resistance in Staphylococcus aureus.

A DNA probe was developed by inserting, in the SmaI site of pBluescript sK, a 528-bp fragment of the gene responsible for intrinsic resistance to beta-lactam antibiotics in Staphylococcus aureus (mec determinant). The mec probe provided a useful tool for the rapid identification of the intrinsic resistance trait and for establishing guidelines for testing the in vitro susceptibility of S. aureus to beta-lactams.

DNA Probes↗
PubMed1991

The Aeromonas hydrophila cphA gene: molecular heterogeneity among class B metallo-beta-lactamases.

An Aeromonas hydrophila gene, named cphA, coding for a carbapenem-hydrolyzing metallo-beta-lactamase, was cloned in Escherichia coli by screening an Aeromonas genomic library for clones able to grow on imipenem-containing medium. From sequencing data, the cloned cphA gene appeared able to code for a polypeptide of 254 amino acids whose sequence includes a potential N-terminal leader sequence for targeting the protein to the periplasmic space. These data were in agreement with the molecular mass of the original Aeromonas enzyme and of the recombinant enzyme produced in E. coli, evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude beta-lactamase preparations followed by renaturation treatment for proteins separated in the gel and localization of protein bands showing carbapenem-hydrolyzing beta-lactamase activity by a modified iodometric technique. The deduced amino acid sequence of the CphA enzyme showed regions of partial homology with both the beta-lactamase II of Bacillus cereus and the CfiA beta-lactamase of Bacteroides fragilis. Sequence homologies were more pronounced in the regions encompassing the amino acid residues known in the enzyme of B. cereus to function as ligand-binding residues for the metal cofactor. The CphA enzyme, however, appeared to share a lower degree of similarity with the two other enzymes, which, in turn, seemed more closely related to each other. These results, therefore, suggest the existence of at least two molecular subclasses within molecular class B metallo-beta-lactamases.

Aeromonas↗
PubMed1989

Immunity to diphtheria, six to 15 years after a basic three-dose immunization schedule.

The results of a study of the immunity to diphtheria of 283 girls (9-18 years of age) vaccinated at the age of two years with three doses of vaccine, are reported. The rabbit skin test was used to determine the titre of serum diphtheria antitoxin. 55.8% of the subjects were found to be protected (titre greater than or equal to 0.1 IU/ml), 38.9% were only relatively immune (titre greater than or equal to 0.01- less than 0.01 IU/ml), and 5.3% were unprotected (titre less than 0.01 IU/ml). The antitoxin titres showed a tendency to decrease with time. Even so, 6-15 years after vaccination, the percentages of protected and partially protected subjects were still high (95%).

Adolescent↗
PubMed1989

Immunity to diphtheria in a sample of adult population from central Italy.

A sample of 643 healthy subjects from central Italy aged 20 to 80, were screened for diphtheria antitoxin. Serum diphtheria antitoxin was assayed by a new passive haemagglutination technique using turkey red blood cells sensitized with diphtheria toxoid, after having performed a correlation study between this technique and the reference in vivo neutralization test. Of the studied population 26.7% showed a lack of serum antitoxin titres considered to be protective. The rate of susceptible subjects increased with age, showing the highest value (38.9%) in the sixth decade of age. Males proved less protected than females; 53.2% of the male population aged 50-59 were lacking a protective anti-diphtheria immunity. On the basis of present results, a periodical revaccination of the entire adult population with reduced doses of diphtheria toxoid would be advisable.

Adult↗
PubMed1988

Antibody response to wild rubella virus structural proteins following immunization with RA 27/3 live attenuated vaccine.

Antibody response to individual structural proteins (E1, E2, and C) of the M-33 wild rubella virus strain was assayed by an immunoblot technique in 12 girls, following immunization with RA 27/3 live attenuated rubella vaccine. Of the 12 immunized subjects, before vaccination 9 had no demonstrable rubella specific antibodies while the remaining 3 had a low level of rubella specific antibodies, reacting only with the E1 protein. At one month after vaccination all the immunized subjects presented anti-E1, anti-E2, and anti-C specific antibodies. However, at 1-2 weeks after vaccination the 9 girls who were seronegative before immunization still had no detectable antibodies to any of the rubella virus structural proteins, while the 3 subjects whose preimmunization sera had reacted with the E1 protein presented an accelerated immune response, showing anti-E2 and anti-C specific antibodies and a more intensely marked anti-E1 specific band.

Adolescent↗
PubMed1988

Antitetanus immunity in a sample of adult population from the Siena area (Italy).

1045 subjects (427 males and 618 females) from the Siena area, aged 20-85, were screened for tetanus antitoxin by the means of a passive haemogglutination assay. 32% of subjects was found protected against tetanus (antitoxin titre greater than or equal to 0.1 I.U./ml), 34.7% resulted partially protected (titre greater than or equal to 0.01 - less than 0.1 I.U./ml), and 33.3% was found unprotected (titre less than 0.01 I.U./ml). The protection rate was higher among males (44.9%) than among females (23%) and showed a definite age-related decrease. Within each age group, the protection rate was higher among males. The lowest protection rate (3.2%) was observed among females aged 70 or more. Analysis of the protection rate according to the individuals' occupation showed the highest value (44.9%) among workmen and the lowest (12.1%) among housewives. The anamnestic criterion was found exceedingly unreliable to assess the individual's immune status. Results, which are consistent with present tetanus italian epidemiology, are discussed for their implications relating to a possible improvement of current antitenus immunization policy.

Adult↗
PubMed1988

Rubella epidemiology over a 14-year period in Siena (Italy): a retrospective serological survey.

A retrospective rubella serological survey spanning a 14-year period (1973-1986) was carried out on 5,726 subjects (2,339 diseased patients and 3,387 healthy females) of various ages and mostly living in the town of Siena or in its surroundings. Rubella antibodies were assayed by a haemagglutination-inhibition technique. The infection rate, as inferred from the analysis of the seropositivity rate according to age, peaked in the 6 to 10 year age group and was apparently very low in subjects aged over 30. The overall seropositivity rate of healthy females of childbearing age was 88.4%. Notwithstanding the fact that rubella vaccination has been recommended for all school-girls since 1973, no significant difference was noticed between the seropositivity rates of healthy females aged 18-23 observed in the period 1973-78 (i.e. before the first immunized subjects reached this age group) and in the period 1981-86 (i.e. when this age group had already been included among the first vaccinees). Serological diagnosis of acute rubella infection was achieved in 44 (1.9%) of the 2,339 diseased patients. Most diagnoses occurred in spring months.

Adolescent↗
PubMed1987

Specific antibody patterns over a two-year period after rubella immunization with RA 27/3 live attenuated vaccine.

Screening for rubella antibodies was carried out on 1557 schoolgirls aged 9-20. Of seronegative subjects 70% (442/631) were immunized with RA 27/3 rubella vaccine and some of the vaccinees underwent a serological and clinical follow-up over a two year period. Adverse reactions occurred in 27% of vaccinees, usually 1-2 weeks after immunization; late reactions were never observed. The vaccine-induced seroconversion rate evaluated at 4-5 weeks after immunization was 99.7%. Both one and two years after immunization the seropositivity rate of vaccinees was 100%. The maximum geometric mean antibody titre (GMT) was observed at 4-5 weeks after vaccination and a significant GMT decrease was evident on both the following annual controls. Specific antibody patterns in vaccinees were highly variable and in a small number of subjects a remarkable antibody titre decrease was noticed.

Adolescent↗
PubMed1987

Seroepidemiological research on hepatitis A (HA) in the city of Siena.

The circulation of Hepatitis A Virus in the city of Siena and the tight neighbouring area appears to be fairly rare. In fact, the number of cases suffering from Hepatitis A, admitted into the Clinic of Infectious Diseases of the University of Siena, has been 33 out of 4,905 patients (yrs 1975-1985). Of these, only 6 were patients resident in Siena. Seroepidemiological research, carried out with the ELISA method on 275 people of an age between 1 and 20 years, has confirmed a specifically low immunization as regards to Hepatitis Virus A (in fact the total antibodies were present only in 1.54% of the cases tested). This report is a long way off the one indicated in other Italian cities in the south as well as the central north of Italy; it can be put in relation to the peculiar demographical situation of the city or to the general fall of Hepatitis A Virus infection also indicated in other areas of the world.

Adolescent↗
PubMed1987

Antitetanus immunity in newborn findings in a sample of population in the Siena area (Italy).

Immunity against tetanus in newborn and in mother-newborn couples was studied in a sample of population from the Siena area, Italy. Mother-newborn antitetanus antibody transfer and the decrease of passively acquired antitoxin, in newborn after birth, were evaluated too. Antitetanus immunity was detected by a passive haemagglutination assay. A high rate of immunologically unprotected newborns was found owing to the low immunisation rate in mothers. The important role played by general prophylactic measures in neonatal tetanus prevention is remarked and a systematic antitetanus immunity screening, during pregnancy, is suggested in order to enhance antitetanus protection in newborns and mothers by immunisation practices.

Epidemiologic Methods↗
PubMed1986

Enzyme activities and ultrastructure of intestinal epithelium in the mouse treated with chloramphenicol.

Several enzyme activities in the enteric mucous membrane (maltase, lactase, leucineaminopeptidase) were assayed and intestinal epithelium ultrastructure was evaluated in mice treated with chloramphenicol, per os, in different doses (50 mg/Kg and 100 mg/Kg), for 10 days. Of the enzyme activities assayed, only leucineaminopeptidase was found to be significantly lower in treated animals than in controls. Enterocyte ultrastructure and mitochondrial morphometrical parameters were not found to be significantly modified in treated animals.

Administration, Oral↗
PubMed1985

Production of serum-opacity factor by Streptococcus pyogenes strains isolated from pharyngitis in children. Prevalence of "rheumatogenic" M types among OF-negative strains.

Two hundred ten S. pyogenes strains isolated in 1979, 1980 and 1984 from children with pharyngitis were here examined for properties which might be relevant to their rheumatogenic potential. Strains were first tested for the production of streptococcal serum-opacity factor and, among those scored as OF-negative, the presence was then verified of M types which have been epidemiologically related to rheumatic fever. Members of "rheumatogenic" M types are present among strains causing pharyngitis in children, which, however, also include a considerable proportion of OF-positive, probably non-rheumatogenic, strains. The results are discussed in the light of the low incidence of rheumatic fever in this country.

Child↗
PubMed1985

[Enzyme activity and ultrastructure of the intestinal epithelium in mice treated with rifampicin].

Some enzymatic activities and the ultrastructure of the intestinal epithelium of mouse were valued after a treatment with rifampicin, per os, in different doses (25 mg/Kg and 50 mg/Kg), for 90 days. Neither alteration of maltase, lactase, leucine aminopeptidase (LAP), nor modification of the morphology of jejunal mucous membrane enterocytes and of their mitochondria were noticed in treated animals, as to controls.

Animals↗
PubMedDate not supplied

Evaluation of in vitro antimicrobial activity of lomefloxacin against staphylococci, enterococci, Enterobacteriaceae, and Pseudomonas aeruginosa.

In vitro antimicrobial activity of lomefloxacin and other antibiotics (norfloxacin, beta-lactams, cotrimoxazole, netilmicin, and miokamycin) was evaluated against 317 clinical isolates including Staphylococcus aureus, enterococci, Enterobacteriaceae, and Pseudomonas aeruginosa. Lomefloxacin showed a high in vitro activity against a wide variety of bacterial species. Against Enterobacteriaceae, lomefloxacin displayed the highest activity (MIC90S, less than or equal to 1 microgram/ml), and it was usually more active than ampicillin and netilmicin, and often more active than cotrimoxazole. Lomefloxacin showed a good antimicrobial activity also against both methicillin-susceptible and methicillin-resistant S. aureus, as it was able to inhibit 90% of staphylococcal strains at a concentration less than or equal to 2 micrograms/ml. Against enterococci and P. aeruginosa, lomefloxacin was usually less active (MIC90S, 8 micrograms/ml). As compared to norfloxacin, lomefloxacin displayed an overall similar activity against staphylococci and enterococci, but appeared less active against Gram-negative bacteria. Bactericidal activity of lomefloxacin against E. coli, when assayed by a novel method, proved to be high, and results indicate that an oral dose of 200 mg of lomefloxacin should exert a very high bactericidal activity against E. coli in urinary tract infections, even in those sustained by large bacterial populations.

4-Quinolones↗