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Biomedical subjects

P Mastrantonio

Publications and source records attributed to P Mastrantonio.

At least 37 records · Page 2Linked to original sources
PubMed2000

Antibiotic susceptibility and serotype distribution of Streptococcus pneumoniae causing meningitis in Italy, 1997-1999.

Because few data are available in Italy regarding antimicrobial susceptibility and serotype distribution of invasive Streptococcus pneumoniae strains, meningeal isolates collected at Italian hospitals during the years 1997-1999 were studied. The 12 most common serogroups, representing > 85% of the isolates, were 14, 23, 6, 4, 3, 9, 19, 8, 1, 12, 18, and 7 (in order of frequency). The serogroups identified in children < 5 years old were more limited in number: 80% are included in the 7-valent conjugate vaccines. Penicillin resistance was observed in 14 (9.5%) of 148 strains and increased from 5% in the first part of the study to 13% in the last part. Only 2 strains were fully penicillin resistant, and these belonged to serotype 9V. Thirty percent of the strains, mostly belonging to serogroups 14 or 6 and carrying either the ermB or the mef genes, were resistant to erythromycin.

Adolescent↗
PubMed2000

Cell-mediated immunity and antibody responses to Bordetella pertussis antigens in children with a history of pertussis infection and in recipients of an acellular pertussis vaccine.

Cell-mediated immunity (CMI) and antibody responses to Bordetella pertussis antigens were assessed 4-6 years after primary infant immunization with diphtheria-tetanus tricomponent acellular pertussis (DTaP) or diphtheria-tetanus (DT) vaccine in a country with high endemicity of B. pertussis infection. CMI to the B. pertussis antigens (especially to the pertussis toxin [PT]) was more frequent and/or intense in DTaP than in DT recipients. No lymphoproliferation differences were found between those with and without a history of pertussis although the DT recipients produced very little interferon-gamma after antigen (particularly PT and filamentous hemagglutinin [FHA]) stimulation. In contrast, seropositivity to PT, but not to pertactin or FHA, was more frequent in DT recipients with history of pertussis than in all other subjects. Thus, years after disease or vaccination, CMI response to PT or circulating PT antibodies appears to be the main distinctive feature of pertussis-protected DTaP recipients or pertussis-affected DT recipients.

Antibodies, Bacterial↗
PubMed2000

Characterization of surface layer proteins from different Clostridium difficile clinical isolates.

In a previous study we suggested that two surface proteins of a Clostridium difficile strain were involved in the formation of a regularly assembled surface layer (S-layer) external to the cell wall. In the present paper six C. difficile strains isolated from cases and healthy carriers were studied. By using freeze-etching and negative staining techniques two superimposed structurally different lattices were detected on the cell surface of the different C. difficile strains. In each strain, the outer S-layer lattice was arranged in a square symmetry and the inner S-layer lattice in hexagonal symmetry. The S-layer proteins from the different strains were isolated and characterized. Each strain showed two distinct S-layer glycoproteins ranging in molecular mass 36-56 kDa. Antigenic cross-reactivity among the S-layer proteins of higher molecular masses extracted from each strain was demonstrated whereas no antigenic relationship was observed among the different S-layer proteins of lower molecular masses. N-terminal sequence analysis showed the presence of common structural motifs conserved among the high S-layer proteins as well as among the low S-layer proteins. These data indicate that the presence of S-layer on C. difficile strains is common and that its glycoprotein subunits show a certain degree of heterogeneity.

Adult↗
PubMed2000

Minilaparoscopic ovarian drilling under local anesthesia in patients with polycystic ovary syndrome.

OBJECTIVE: To assess pain control in patients with polycystic ovary syndrome (PCOS) who are undergoing ovarian drilling during minilaparoscopy under local anesthesia and conscious sedation and to evaluate the efficacy of this protocol compared with the traditional approach in terms of operative and discharge times, subsequent ovulation, and pregnancy. DESIGN: Prospective randomized study. SETTING: University hospitals and private day-surgery unit. PATIENT(S): Sixty-two infertile women with PCOS. INTERVENTION(S): Group A underwent minilaparoscopic ovarian drilling under local anesthesia and conscious sedation. Group B (control group) was treated with traditional ovarian drilling by laparoscopy under general anesthesia. MAIN OUTCOME MEASURE(S): Intraoperative pain score in group A. Hormonal profile before and after surgery, operative and discharge times, postoperative analgesic requirements, and reproductive follow-up in both groups. RESULT(S): Group A showed a good intraoperative pain score. The hormonal profile after surgery did not differ between groups A and B. Operative times were also similar for both groups. The number of patients discharged within 2 hours after surgery was significantly higher in group A. The need for postoperative analgesics was significantly higher in group B. No statistically significant differences were noted between the groups in terms of pregnancy and ovulation rates. CONCLUSION(S): Intraoperative and postoperative local anesthesia plus conscious sedation allows outpatient bilateral ovarian drilling by minilaparoscopy to be performed without general anesthesia. The high pregnancy rates, the simplicity of the method, and the faster discharge time offer a new option for patients with PCOS who are resistant to clomiphene citrate. Moreover, ovarian cauterization can be performed simultaneously with a diagnostic minilaparoscopy and integrated into the infertility workup of these patients.

Adult↗
PubMed2000

Characterization of non-type B Haemophilus influenzae strains isolated from patients with invasive disease. The HI Study Group.

Forty-one non-type b Haemophilus influenzae isolates from cases of invasive disease were characterized. By PCR capsular genotyping, 33 nonencapsulated strains, 4 type f isolates, and 4 b(-) strains were identified. By pulsed-field gel electrophoresis, the nonencapsulated isolates exhibited great genetic heterogenicity, whereas the type f and the b(-) strains seemed to have a clonal spread. Occurrence of the hifA gene was found by PCR in 18% of the nonencapsulated, 50% of the b(-), and all of the type f strains. Hemagglutinating fimbriae were generally expressed by nonencapsulated isolates when fimbrial gene hifA was present. Two nonencapsulated isolates not susceptible to ampicillin were detected; no strains were positive for beta-lactamase production.

Ampicillin↗
PubMed2000

[Pregnancy management in women with thalassemia].

Thanks to the improvement of the techniques of assisted fecundation, of the obstetric management and of the fetal and neonatal monitoring now it's possible for a woman suffering from beta-thalassemia to have a child. Our purpose is to stress the importance to control the high maternal and fetal risk through the monitoring of several scales. The problems, connected with pregnancy of beta-thalassemic women are discussed, emphasizing the connection between pregnancy management and gestational and neonatal outcome. A variety of problems should be considered such as the informed consent about maternal and fetal risks, the problems caused by infectious agents or due to the use of some antiviral; the difficulties connected with heart and endocrine diseases are also discussed. Personal experience, from 1995 to 1999, on 4 beta-thalassemic pregnant women (three with the intermediate type and one with the major type) is reported.

Female↗
PubMed1999

Characterization of surface layer proteins from Clostridium difficile by liquid chromatography/electrospray ionization mass spectrometry.

Surface layers (S-layers) are regularly ordered protein subunits found as the outermost cell envelope component of many bacteria. Most S-layers are composed of a single protein or glycoprotein species with a molecular weight varying between 40 and 200 kDa. Clostridium difficile is the most common cause of antibiotic associated diarrhea (AAD) and pseudomembranous colitis (PMC) in humans. Detection of the S-layer in some C. difficile strains, and preliminary characterization of two glycoproteins, P36 and P47, involved in the composition of the S-layer of one of these strains (C. difficile C253), led us to investigate the most appropriate conditions for purification and chemical characterization of these proteins. This work describes the results obtained when liquid chromatography (LC) coupled to mass spectrometry (MS) using electrospray ionization was applied to the analysis of C. difficile S-layer proteins (SLPs). In this way the molecular weights of the two SLP components, P36 and P47, were detected to be 34,258 +/- 2 and 39,545 +/- 3 Da, respectively. These data deviate from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results by 1.85 and 7.5 kDa. To confirm the LC-MS results, an alternative molecular weight analysis was performed: the two S-layer proteins were isolated by semipreparative high performance liquid chromatography (HPLC), concentrated, and analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). The two SLP subunits were digested with protease V8, and the peptide maps were determined by LC-MS using a C18 column. Finally, preliminary results about peptide glycosylation were obtained.

Bacterial Outer Membrane Proteins↗
PubMed1999

Immunogenicity issues in the quality control of the new acellular pertussis vaccines.

Over the last few years our laboratory has been assessing the consistency of production of different batches of acellular pertussis vaccines to be marketed in Italy. Central to this is immunogenicity assay of the lots under control compared with those of a reference vaccine with documented clinical efficacy.However, the current assays based on the assessment of antibody (Ab) response in the mouse are unrelated to mechanisms of protection in children. The absence of a clear correlation between Ab responses and protection has also been documented in recent clinical trials. On this basis, we are currently considering the possibility of adding to the established criteria of immunogenicity in mice based on Ab responses, information from studies on cell-mediated immune responses to the vaccine constituents.

Animals↗
PubMed1999

Cell-mediated immune responses in four-year-old children after primary immunization with acellular pertussis vaccines.

Cell-mediated immune (CMI) responses to Bordetella pertussis antigens (pertussis toxin [PT], pertactin [PRN], and filamentous hemagglutinin [FHA]) were assessed in 48-month-old recipients of acellular pertussis [aP] vaccines (either from Chiron-Biocine [aP-CB] or from SmithKline Beecham [aP-SB]) and compared to CMI responses to the same antigens at 7 months of age, i.e., 1 month after completion of the primary immunization cycle. None of the children enrolled in this study received any booster of pertussis vaccines or was affected by pertussis during the whole follow-up period. Overall, around 75% of 4-year-old children showed a CMI-positive response to at least one B. pertussis antigen, independently of the type of aP vaccine received, and the proportion of CMI responders were at least equal at 48 and 7 months of age. However, longitudinal examination of individual responses showed that from 20 (against PT) to 37% (against FHA) of CMI responders after primary immunization became negative at 48 months of age. This loss was more than compensated for by conversion to positive CMI responses, ranging from 36% against FHA to 69% against PRN, in other children who were CMI negative at 7 months of age. In 60 to 80% of these CMI converters, a lack of decline or even marked elevation of antibody (Ab) titers against B. pertussis antigens also occurred between 20 and 48 months of age. In particular, the frequency of seropositivity to PRN and FHA (but not to PT) was roughly three times higher in CMI converters than in nonconverters. The acquisition of CMI response to B. pertussis antigens in 48-month-old children was not associated with a greater frequency of coughing episodes lasting >/=7 days and was characterized by a prevalent type 1 cytokine profile, with high gamma interferon and low or no production of interleukin-5, reminiscent of cytokine patterns following immunization with whole-cell pertussis vaccine or natural infection. Our data imply that vaccination-induced systemic CMI may wane by 4 years of age but may be acquired or naturally boosted by symptomless or minor clinical infection by B. pertussis. This might explain, at least in part, the persistence of protection against typical pertussis in aP vaccine recipients despite a substantial waning of both Ab and CMI responses induced by the primary immunization.

Antibodies, Bacterial↗
PubMed1999

Characterization of Bordetella pertussis strains of recent isolation.

During the clinical trial conducted in Italy to evaluate the efficacy of new acellular pertussis vaccines, the most favorable conditions for the recovery and characterization of Bordetella pertussis strains, isolated from children with cough, were adopted. The nasopharyngeal aspirates were collected and sent to the laboratory in refrigerated conditions within 24 hours. Charcoal agar selective and non selective plates were used, and most of the isolates were recovered after 3-4 days of incubation. Confirmation of all suspected colonies included the use of biochemical tests and specific agglutination reaction with B. pertussis antiserum. Serotyping of fimbriae, susceptibility to erythromycin and DNA fingerprinting by Pulsed Field Gel Electrophoresis (PFGE), were performed to characterize B. pertussis isolates and to determine relatedness among different strains. Serotype 1,3 was the most represented in the bacterial population examined. A predominant pulsetype (PTA) characterized most of the isolates accounting for 71.4% of the strains examined. Eight subclones (23.5%) and three unrelated pulsetypes were also found. No resistant strains to erythromycin were detected.

Bacterial Typing Techniques↗
PubMed1998

A prospective randomized study to evaluate leuprolide acetate treatment before laparoscopic myomectomy: efficacy and ultrasonographic predictors.

OBJECTIVE: Aims of our study were as follows: (1) to evaluate the therapeutic efficacy of the preoperative administration of a gonadotropin-releasing hormone analog before laparoscopic myomectomy and (2) to assess whether any ultrasonographic parameter of the fibroids (number, size, Doppler velocimetry, or echogenicity) was of prognostic value. STUDY DESIGN: A prospective randomized study was performed on 67 patients with symptomatic uterine fibroids that were mainly intramural; these patients were undergoing laparoscopic myomectomy. Patients were randomized either to preoperative administration of two injections of a depot formulation of leuprolide acetate 28 days apart (group A, n = 35) or to direct surgery (group B, n = 32). In each group we studied the number, volume, and echogenicity of the larger fibroids; the resistance index of uterine arteries and of fibroid vessels; hematologic parameters; operative time; and blood loss. RESULTS: The two groups did not differ significantly in basal ultrasonographic parameters and hematologic data. Postoperatively, the red blood cell count and the serum hemoglobin and iron levels were significantly (p < 0.05) lower in group B. Both blood loss (p < 0.01) and operative time (p < 0.05) were significantly lower in group A. However, the operative time was significantly longer when the main fibroid was markedly hypoechoic, probably because the increased softness of the tumor after leuprolide acetate pretreatment makes its enucleation much more cumbersome. CONCLUSION: Our data confirm the therapeutic efficacy of preoperative administration of a gonadotropin-releasing hormone analog before laparoscopic myomectomy in reducing the blood loss and in decreasing the operative time. This preoperative course of leuprolide acetate in hypoechoic fibroids, because of the further reduction of the density of the myomas, causes a significant (p < 0.05) increase in operative time.

Adult↗
PubMed1998

Antibody responses and persistence in the two years after immunization with two acellular vaccines and one whole-cell vaccine against pertussis.

OBJECTIVE: To evaluate the persistence of specific antibodies induced by primary immunization with three doses of two three-component acellular vaccines against pertussis with an observed efficacy of 84%, and one whole-cell vaccine with an observed efficacy of 36%. STUDY DESIGN: Serum samples were collected from a subsample of 1572 children from the Italian double-blind, placebo-controlled, randomized trial of vaccines used in 15,601 children at three time points: before administration of the first dose of vaccine, and 1 month and approximately 15 months after administration of the third dose. Further evaluation included pooled cross-sectional analysis of serum specimens associated with episodes of cough (which were not laboratory confirmed as pertussis infection) occurring among the entire population enrolled in the trial. RESULTS: With both acellular vaccines there was a fast and steep decrease in geometric mean antibody titers to pertussis toxin, filamentous hemagglutinin, and pertactin after vaccination. Mean titers were close to the limit of detection 15 months after primary immunization. The immunogenicity of the whole-cell study vaccine was poor 1 month after the third dose, and no antibody was detected in nearly all children 15 months after whole-cell vaccination. CONCLUSIONS: Although the study acellular pertussis vaccines induced a strong primary specific antibody response in almost all recipients, the duration of the response was limited. Sustained high-level production of antibody to the antigens tested does not account for the observed efficacy of acellular pertussis vaccines.

Animals↗
PubMed1998

Persistence of protection through 33 months of age provided by immunization in infancy with two three-component acellular pertussis vaccines. Stage II Working Group.

A large, randomized, placebo-controlled clinical trial in Italy on two three-component pertussis vaccines, given as DTaP in infancy, one manufactured by SmithKline and Beecham (SB) and one by Chiron Biocine (CB), found each vaccine to be 84% efficacious through the average age of 24 months. The cohort of children enrolled in the trial was followed with unmodified case ascertainment procedures for nine additional calendar months, during which partial unblinding occurred, for the unvaccinated randomized group. For the DTaP groups, the specific vaccine assignment remained double-blinded throughout the entire additional observation period. Pertussis was defined as paroxysmal cough lasting at least 21 days and confirmed by culture or serology. In the additional 9 months the observed absolute efficacy was 78% (95% CI, 62-87%) for SB DTaP vaccine and 89% (95% CI, 79-94%) for CB DTaP. The relative risk of developing pertussis in SB DTaP recipients compared to CB DTaP vaccinees was 1.99 (95% CI, 1.13-3.51). By combining observations from the initial and additional follow-up periods, the overall observed vaccine efficacy through an average age of 33 months of SB DTaP was 80% and of CB DTaP, 85%.

Child, Preschool↗
PubMed1998

Bordetella parapertussis infection in children: epidemiology, clinical symptoms, and molecular characteristics of isolates.

The clinical trial conducted in Italy to evaluate the efficacy of acellular pertussis vaccines provided an opportunity to estimate the frequency of clinical infections with Bordetella parapertussis and to compare the clinical characteristics of children suffering from Bordetella pertussis illness with those of children with B. parapertussis illness. This study dealt with 76 B. parapertussis infections diagnosed from a population of 15,601 children participating in the follow-up of suspected cases of pertussis. An overall incidence of 2.1 cases of laboratory-confirmed parapertussis per 1,000 person-years was observed. Children affected by B. parapertussis infections showed a less severe clinical picture both in the duration of symptoms and in the percentage of patients affected, even when compared with vaccinated children with pertussis. To characterize the isolated strains, we performed assays for susceptibility to erythromycin and sulfamethoxazole-trimethoprim, and we examined the genomic DNAs by pulsed-field gel electrophoresis. The results showed a high degree of genetic stability among B. parapertussis strains regardless of time of collection and geographical distribution.

Bordetella↗
PubMed1998

[Single umbilical artery (SUA) and congenital eye abnormalities. 2 case reports].

Two cases of single umbilical artery (SUA) are reported, associated respectively with unilateral microphthalmia the first case, with bilateral congenital glaucoma (buphthalmos) the second one. While the association between single umbilical artery and microphthalmia is reported in international literature, the association between single umbilical artery and congenital glaucoma (buphthalmos) described for the first time.

Eye Abnormalities↗