Antigenic sites of poliovirus type 3 eliciting IgA monoclonal antibodies in orally immunized mice.

A panel of neutralizing IgA monoclonal antibodies was produced from mice orally inoculated with poliovirus type 3 Sabin and cholera toxin as adjuvant. Low levels of neutralizing antibodies were elicited in mice after several boosts, but only in the presence of cholera toxin. Characterization of IgA MAbs by neutralization-escape virus mutants showed that all but one neutralizing MAbs against type 3 poliovirus were directed to antigenic site N-AgIII, which was previously found by us to be the major target of mucosal immune response to Sabin 1 in the mouse. Our data indicate that residue 236 of VP3, not previously reported, is also involved in forming site N-AgIII in addition to formerly described VP3 (aa 58-59) and VP1 (aa 286-290) residues. Unlike poliovirus type 1 IgA MAbs, all IgA MAbs herein described neutralized the wild-type parental poliovirus.

[Flaccid paralysis surveillance in the Latium Region]. / La sorveglianza della paralisi flaccida nella Regione Lazio.

The goal of World Health Organization is to reach the global eradication of poliomyelitis during the first decade of the third millennium. To achieve the certification of the eradication of the disease the main strategy is the Acute Flaccid Paralysis (AFP) surveillance. In Italy the active AFP surveillance was performed at national level since 1997. In the Latium region the active surveillance was performed since January 1997 by the laboratory of virology of Institute of Hygiene G Sanarelli which established a regional hospital network. During the years of survey 7 cases were found in 1997 (0.87/100,000), 4 in 1998 (0.5/100,000), 2 in 1999 (0.25/100,000) and 2 in 2000. No wild polioviruses were detected.

Surveillance of acute flaccid paralysis in Italy: 1996-1997. AFP Study Group. Acute flaccid paralysis.

The last case of poliomyelitis due to transmission of indigenous wild poliovirus occurred in Italy in 1982. To achieve the certification of the eradication of poliomyelitis in Italy, an active surveillance of acute flaccid paralysis (AFP) in the population aged less than 15 years was set up following the World Health Organization (WHO) guidelines. The survey started in 1996 with a pilot study involving 4 out of 21 regions, and was gradually extended to a national level in 1997. The two-year survey identified five patients with diagnosis of vaccine associated paralytic poliomyelitis (VAPP). Polioviruses type 2 and 3 Sabin-like were isolated and characterized in three of them. In the remaining two cases, samples were collected late after the onset of symptoms, and poliovirus could not be isolated. No wild polioviruses were detected during the survey. The rate of non-polio AFP found in Italy in 1997 was 0.61 cases per 100,000, which is lower than the level of 1.0 case per 100,000 considered as acceptable by the WHO. This was mainly due to the delay in organizing the hospital network and starting the active search of AFP cases in the largest and most densely populated regions. Therefore, the overall rate of AFP found in Italy underestimates the global effectiveness of the program, which however will be better evaluated in the next few years. This study is the first systematic attempt to determine the rate of AFP in Italy.

Seroepidemiological evaluation of 1989-91 mass vaccination campaigns against measles, in Italy.

In 1989-91 anti-measles vaccination campaigns were conducted in several Italian regions to vaccinate all children aged between 13 months and 10-12 years without a history of measles or measles vaccination. This study was conducted to evaluate serological status after the mass vaccination campaigns. In 1994, capillary blood samples were collected from randomly selected children, aged 2-14 years, living in 13 local health units. Antibody titres were determined by ELISA. Blood spot samples were analysed for 4114 (75.6%) of 5440 selected children. Among the 835 that reported measles before 1990, 806 (96.5%) were immune and of the 2798 vaccinated, 2665 (95.2%) were immune. The Edmoston-Zagreb (E-Z) strain vaccine was associated with a lower level of immunity than the Schwarz (SW) strain. A history of measles identified almost all immune children. Vaccination with the SW strain conferred persistent immunity (at least 5 years) in 98% of vaccinees. The strategy was able to unite natural and induced immunity.

Measles vaccine in egg allergic children: poor immunogenicity of the Edmoston-Zagreb strain.

Despite the fact that a number of recent studies have shown that measles/ mumps/rubella vaccine is safe for egg allergic children, many pediatricians are still concerned about immunization in egg allergic children. In Europe, a measles vaccine with the Edmoston-Zagreb strain (EZMV) grown in human fibroblast culture has been developed and recommended for children with egg allergy. However, some doubt arises on the efficacy of this strain due to its weak immunogenicity. The aim of this study was to investigate the immunogenicity of the EZMV in comparison to the measles vaccine with the Schwarz strain (SWMV) grown in a chick embryo fibroblast culture. Thirty-nine children affected by severe immediate manifestations due to IgE mediated egg allergy were enrolled. The children received at random the SWMV (Morupar, Sclavo) or the EZMV (Triviraten, Berna) in one 0.5 ml subcutaneous injection, and were checked for any immediate allergic reactions in the following 4 hours. Blood samples were taken for the detection of specific antibody response 5 months after the immunization. In SWMV seroconverted children (18/19) the geometric mean antibody titer was 3 times higher than that observed in EZMV seroconverted children (17/20) (p < 0.01). No allergic reactions occurred following the immunization with the two different vaccines. This data confirms the safety of SWMV in egg allergic children. In addition, the present study provides further data on the lower immunogenicity of the EZMV in comparison to the SWMV.

Prevention of allergies of infants: breast-feeding and special formulas. Influence on the response to immunization.

Infant formulas containing partially hydrolyzed cow milk-proteins are used for the prevention of allergy when maternal milk is not available, and, in preterm infants, also for improving gastric emptying. The nutritional adequacy of such formulas has not yet been completely defined. As the type of feeding may influence the antibody response to immunization, the aim of the present study was to evaluate the antibody response to oral polio virus immunization in term infants and to acellular pertussis and hepatitis B immunization in preterm infants, exclusively fed a partially hydrolyzed cow-milk formula during the first 5 months of life, in comparison with exclusively breast-fed infants. Active immune response occurred in all the infants after the second dose of immunization and no significant difference in the antibody titres was found according to the type of milk. On the basis of these results, it seems that protein nutrition based exclusively on a partially hydrolyzed formula does not impair the response to immunization in both preterm and term infants.

Comparison of capillary blood versus venous blood samples in the assessment of immunity to measles.

Seroepidemiological investigations are essential for assessing the efficacy of measles vaccination programmes. However, when large-scale sampling is needed, a major difficulty is the problem of taking venous blood, especially in children. An alternative method is the collection of capillary blood samples spotted on filter papers. The eluted extract from these 'blood' spots can be used instead of serum samples for measles laboratory diagnosis or investigations. Measles antibody detection is readily carried out by ELISA on serum samples. The same technique can be used on eluates from capillary blood spots. Measles antibody titres determined on matched serum and blood spot samples from 27 children were compared. A strong correlation was found between the results obtained with the two methods of blood sampling.

Topoisomerase-II-mediated DNA cleavage within the human ribosomal genes.

The interaction of topoisomerase II (topo II) with human ribosomal DNA (rDNA) was investigated in vivo using the antitumoral drug VM26, a specific inhibitor of topo II, that stabilizes the transient cleavable complex. rDNA-protein complexes isolated from nucleoli of TG cells were analyzed for double strand breaks with probes that covered almost all intergenic transcribed spacer (IGS) and all transcribed sequences of tandem repeat ribosomal DNA genes. Preferential cleavage sites were present in only a part of nucleolar rDNA, i.e., the transcribed region. Proteins, purified from the same complexes, were analyzed by Western-blot and stained by an antiserum against both topo II forms, showing the presence of topo II beta.