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Biomedical subjects

M Donati

Publications and source records attributed to M Donati.

At least 19 recordsLinked to original sources
PubMed2005

Development of a hamster model of Chlamydophila pneumoniae infection.

The aim of this study was to develop a new experimental model of Chlamydophila pneumoniae infection in the hamster. Intraperitoneal injection of C. pneumoniae purified elementary bodies (EBs) in the hamsters caused a systemic infection, since it was possible to isolate viable chlamydiae from several organs up to 14 days after infection. In particular, spleen infection was detectable up to 7 days post infection in 100% of animals. In contrast, cultures of the organs obtained from intranasally infected animals were far less frequently positive. Systemic infection probably occurred via macrophages, as demonstrated by the presence of intracellular chlamydial inclusions in peritoneal macrophages of peritoneally inoculated animals four days after infection. Furthermore, by infecting LLC-MK2 cells with supernatant preparations obtained from these macrophages, it was possible to observe the development of chlamydial intra-cytoplasmic inclusions after 96 h. Immunization of 18 hamsters with heat-inactivated purified EBs completely protected 16 animals and substantially reduced infection levels in the remaining two. Sera obtained from immunized hamsters prior to challenge reacted mainly against two C. pneumoniae proteins of about 60 kDa, when tested by immunoblot.

Animals↗
PubMed2004

Use of IgG Avidity test in case definitions of toxoplasmosis in pregnancy.

A survey network for congenital toxoplasmosis (TOXO-NET) was set up in December 1996 in Piedmont (Italy). Participants were asked to classify the infections in pregnant mothers and newborns by the criteria of the European Network on Congenital Toxoplasmosis published by Lebech in 1996. Because the IgG Avidity test is largely employed as a 2nd level test in toxoplasmosis diagnosis and it could be helpful to date infection, the co-ordinators of TOXO-NET suggested including it in the "case definition" of "probable" infection and "unlikely" infection. 117 cases of toxoplasmosis in pregnancy divided into the risk categories under Lebech's criteria were re-examined using the "new" case definitions. 77 out of 117 (65.8%) Toxoplasma gondii infections during pregnancy could be defined with only one serum sample using the IgG Avidity test. The IgG Avidity test proved a useful method to classify the Toxoplasma gondii infections in pregnancy, especially when we had only one serum sample.

Animals↗
PubMed2002

Comparative in vitro activity of garenoxacin against Chlamydia spp.

The in vitro susceptibilities of 33 isolates of Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia psittaci to a new quinolone drug, garenoxacin (BMS-284756), in comparison with levofloxacin, ciprofloxacin, doxycycline, erythromycin and roxithromycin, were determined. Garenoxacin was the most active of the quinolone drugs tested, with identical MIC and MBC, which ranged from 0.007 to 0.03 mg/L. The MIC and MBC of the other two quinolones tested, levofloxacin and ciprofloxacin, were also identical, ranging from 0.25 to 2 mg/L. The MICs and MBCs of doxycycline, erythromycin and roxithromycin were also determined.

Animals↗
PubMed2002

[Plug-technique for umbilical hernia repair in the adult].

BACKGROUND: Umbilical hernia represents 6% of all abdominal wall hernias in the adult. Surgical repair should always be carried out due to possible occurrence of complications. Aim of this paper is to evaluate the efficacy of the plug-technique. METHODS: From October 1995 to April 2000, the authors performed 21 operations for acquired umbilical hernia with a defect smaller than 4 cm. Local anesthesia was used and a light intravenous sedation added in particularly anxious patients. The repair was achieved by insertion of a polypropylene dart plug sutured to the margins of the hernial defect. RESULTS: All patients were up and about straightaway and were discharged within 24 hours of surgery. Postoperative pain was mild and required hospital analgesia in only 19% of cases and domiciliary analgesia in 24%. During a follow-up ranging from 6 to 60 months (mean 30), only one recurrence has been recorded. CONCLUSIONS: This tension-free technique allows immediate rehabilitation, with few complications and a low recurrence rate.

Adult↗
PubMed2001

Comparative study of the immune response in mice immunized with four live attenuated strains of mumps virus by intranasal or intramuscular route.

The observation of many cases of mumps and mumps-associated CNS complications in vaccinees prompted us to perform an evaluation of the efficacy of four attenuated mumps virus (Urabe, Jeryl Lynn, Rubini and S12) vaccines. Two doses of vaccine were necessary to induce a good immunity in animals. The humoral and cell-mediated response induced in mice immunized intramuscularly or intranasally with these vaccines has been evaluated. Although the Urabe and Jeryl Lynn strains appear more immunogenic than the other strains and induce higher levels of IgG when administered intramuscularly, the S-12 strain administered intranasally induces a good IgG response. A marked specific CTL activity against mumps virus was observed in mice immunized intranasally with all the strains and, particularly, with the S12 strain. Thus, the intranasal immunization could be considered a possible alternative and efficient route of vaccination against mumps.

Administration, Intranasal↗
PubMed2001

Localization of a new neutralizing epitope on the mumps virus hemagglutinin-neuraminidase protein.

Four protein fragments which span the entire hemagglutinin-neuraminidase protein (HN) of mumps virus were expressed in HeLa cells and cell extracts were tested for their capability to induce neutralizing antibodies in mice. Fragment HN3 (aa 213-372) was able to induce the production of hemagglutination-inhibiting and neutralizing antibodies. When a subfragment of HN3, the synthetic peptide NSTLGVKSAREF (aa 329-340 of HN) was used for immunization, hemagglutination-inhibiting and neutralizing antibodies against mumps wild type virus but not against the Urabe Am9 vaccine virus were raised. The peptide could, therefore, contain a new epitope, which may be critical for protective host humoral immune response.

Animals↗
PubMed2001

Helicobacter pylori infection and gastric function in patients with fundic atrophic gastritis.

In the present study we evaluated the relation among histology, H. pylori, IgG to H. pylori, gastric emptying, and acid secretion in 43 patients with fundic atrophic gastritis. On the basis of gastric acid secretion, patients were divided into three subgroups: patients with preserved acid secretion (Group 1), patients with hypochlorhydria (Group 2), and patients with achlorhydria (Group 3). Fundic glandular atrophy was more severe in hypoachlorhydric patients than in those with preserved acid secretion (P < 0.05 vs Group 2, P < 0.005 vs Group 3). H. pylori colonization was found in 94% of patients in Group 1, in 61% of patients in Group 2, and in only 8% of patients in Group 3 (P < 0.001 vs Group 1, P < 0.05 vs Group 2). Conversely, serological positivity to H. pylori was high in all three subgroups of patients (100% in Group 1, 77% in Group 2, 92% in Group 3). Gastric emptying was delayed in atrophic patients, particularly in those with hypoachlorhydria. Our data suggest that fundic atrophic gastritis represents a possible end stage of H. pylori infection, characterized by a progressive disappearance of the bacterium and a progressive deterioration of gastric functions.

Achlorhydria↗
PubMed2001

Neutralization of Toscana virus is partially mediated by antibodies to the nucleocapsid protein.

The envelope glycoproteins G1/G2 of Toscana virus (TOSV) seem to have the most important protective role in stimulating antibodies against the disease in humans, as well as antibodies against the Nucleoprotein (N), a partial neutralizing activity. Mice immunized with TOSV recombinant Nucleoprotein developed a strong humoral response to the TOSV that revealed the presence of neutralizing antibody than in vitro assay. The neutralizing antibody titre of mice immunized with the whole TOSV was analyzed before and after absorption of the sera with the recombinant N protein. A decrease of the neutralizing activity was observed in the treated sera. Similar results were obtained absorbing human anti-TOSV positive sera with the recombinant N protein. This study was designed to identify the nature of antibodies produced against the N protein of TOSV in mice and to establish correlation with antibodies produced in humans by natural infection.

Animals↗
PubMed2000

Response to varicella immunization in pediatric liver transplant recipients.

BACKGROUND: Individuals undergoing therapeutic immunosuppression are at risk of severe varicella-zoster virus (VZV) infection, particularly those without evidence of previous infection. METHODS: Eleven children, median age 10 months (range 5.5 months to 7 years and 9 months) received one dose of varicella vaccine (Varilrix, SmithKline Beecham plc, UK) before liver transplantation (median interval 95 days, range 40-289 days). The serological response to varicella vaccine was evaluated retrospectively and matched with the outcome and management of any subsequent exposures to VZV. RESULTS: Three children responded postimmunization, six children showed no response, and in two children the outcome was difficult to interpret having received blood products. Four children required varicella-zoster immunoglobulin prophylaxis posttransplantation, two of whom developed mild chickenpox. CONCLUSIONS: Only 3 of 11 children developed a clear antibody response to varicella vaccine. Administration of varicella vaccine did not affect the management of subsequent VZV exposures.

Antibody Formation↗
PubMed2000

Intranasal immunization with mumps virus DNA vaccine delivered by influenza virosomes elicits mucosal and systemic immunity.

To improve the efficiency of liposome-mediated DNA transfer as a tool for gene therapy or vaccinology, we have further developed a new delivery system based on the modified immunopotentiating reconstituted influenza virus (IRIV). In this study, we engineered a plasmid DNA vector expressing the mumps virus hemagglutinin or the fusion protein. The administration of this DNA vaccine delivered by influenza virosomes, in combination with the mucosal adjuvant Escheriagen via the intranasal route, was efficient for inducing an immune response, both mucosally and systemically, in mice. The production of IgG2a mumps virus-specific antibodies and the secretion of interleukin 10 (IL-10) by antigen-specific T cells indicated that not only Th1 but also Th2 responses were induced by this DNA vaccine formulation. These results suggest that cationic virosomes in combination with Escheriagen may have great potential as an efficient delivery system for intranasal DNA immunization and provide an immune barrier at the mucosal sites.

Administration, Intranasal↗
PubMed2000

Long-term survival of ex-thalassemic patients with persistent mixed chimerism after bone marrow transplantation.

Twenty-six transplanted thalassemic patients out of 295 analyzed, showed the presence of persistent mixed chimerism, over a period of time varying between 2 and 11 years after BMT. Despite the presence of large numbers of residual host cells, these transplanted thalassemic patients no longer require red blood cell transfusions and have a functional graft, producing sufficient levels of hemoglobin A ranging from 8.3-14.7 g/dl. These ex-thalassemic patients with persistent mixed chimerism, although they did not achieve complete donor engraftment are no longer exposed to the risk of graft rejection. The mechanisms underlying this apparent state of tolerance or education in these patients are at the present time unknown. However, these observations may be useful for physicians involved in defining optimal strategies for clinical gene therapy, in utero hematopoietic stem cell transplantation and adoption of less toxic conditioning regimens in mini-transplantation.

Bone Marrow Transplantation↗
PubMed2000

Bone marrow transplantation from alternative donors for thalassemia: HLA-phenotypically identical relative and HLA-nonidentical sibling or parent transplants.

Twenty-nine patients with thalassemia and a median age of 6 years (range 1.1-33 years) were given a BMT from an alternative donor. Six of the 29 donors were HLA-phenotypically identical and two were mismatched relatives, 13 were mismatched siblings and eight were mismatched parents. Six patients received no antigen (relatives), 15 patients one antigen, five patients two antigen and three patients three antigen disparate grafts. Twenty-three patients were in class 2 or class 3, whereas six patients were in class 1. Thirteen patients were given BUCY, nine patients BUCY plus ALG, six patients BUCY plus TBI or TLI and one patient BUCY with prior cytoreductive-immunosuppressive treatment as conditioning. As GVHD prophylaxis four patients received MTX, 22 CsA + MTX + methylprednisolone (MP) and three patients CsA + MP. Thirteen of 29 patients (44.8%) had sustained engraftment. The probability of graft failure or rejection was 55%. There were no significant differences between antigen disparities and graft failure. The incidence of grade II-IV acute GVHD was 47.3% and chronic GVHD was 37.5%. The incidence of acute GVHD was higher in patients receiving one or two antigen disparate in the GVHD direction grafts (vs no antigen) (P EQ 0.04; odds ratio 10.8; 95% CI 1.5-115). The probability of overall and event-free survival was 65% and 21%, respectively, with median follow-up of 7.5 years (range 0.6-17 years) for surviving patients. The degree of HLA disparity between patient and donor did not have a significant effect on survival. The incidence of nonhematologic toxicity was low. Transplant-related mortality was 34%. GVHD (acute or chronic) was a major contributing cause of death (50%) followed by infections (30%). We conclude that at present, due to high graft failure and GVHD rates, BMT from alternative donors should be restricted to patients who have poor life expectancies because they cannot receive adequate conventional treatment or because of alloimmunization to minor blood antigens.

Acute Disease↗