Gastric cancer surveillance in a high-risk population in tuscany (Central Italy): preliminary results.

BACKGROUND/AIMS: The surveillance of subjects at high risk for developing gastric cancer (GC) may represent an effective strategy for reducing specific morbidity and mortality. The aim of this study was to identify GC at its initial phase and to identify precancerous lesions in a group of GC high-risk subjects. METHODS: We enrolled first-degree relatives of patients affected by GC who resided in a GC high-risk area (Tuscany, Central Italy). The study's protocol included the collection of several individual measurements, including a blood sample for the determination of specific biomarkers, an upper digestive tract endoscopy with detailed gastric biopsies and Helicobacter pylori (Hp) treatment followed by a specific check. RESULTS: We enrolled 167 subjects who were members of 128 different familial groups with GC history. We identified 1 case of initial-phase GC, 1 gastric dysplasia type II, 32 intestinal metaplasia, 10 gastric atrophy, and 21 atrophic chronic gastritis. 81 subjects were Hp-positive and underwent eradication therapy. CONCLUSION: This study of a GC high-risk Italian population reveals positive results in terms of population compliance, the identification of specific gastric lesions requiring close follow-up and successful therapy for Hp infection. To define future surveillance strategies, a longer follow-up of these patients is necessary.

Viral outcome of simian-human immunodeficiency virus SHIV-89.6P adapted to cynomolgus monkeys.

Simian-human immunodeficiency virus (SHIV) 89.6P is considered to be one of the most pathogenic chimeric viruses in rhesus macaques. However, when crossing from one to another species of monkeys the pathogenicity of this virus may be affected. By using SHIV-89.6P(cy243), a virus obtained by passaging SHIV-89.6P in cynomolgus macaques, we investigated the dynamics of viral replication and the impact of the inoculum size (from 10 up to 50 monkey infectious dose) on the progression of the infection in 22 cynomolgus macaques. SHIV-89.6P(cy243 )caused massive depletion of CD4+ T-cells within 4 weeks of the inoculum, followed by an irreversible immune deficiency in a high proportion of the infected monkeys. This study demonstrates that SHIV-89.6P(cy243) is pathogenic in cynomolgus macaques and that the dynamics of the viral replication and the rate of clinical progression depend on the size of the inoculum. Our findings provide unique and relevant data, particularly with regard to the value of the in vivo titration used to select the most appropriate infectious dose to study the "virus-host" interplay.

Cross-reactivity between the major Parietaria allergen and rotavirus VP4 protein.

BACKGROUND: The present study investigates immunological cross-reactivity between Par o 1, the major pollen allergen of Parietaria, and the VP4 protein of rotavirus, a microorganism that is world-wide the main etiological agent of gastroenteritis in children. METHODS: IgG and IgE cross-reactivity was assessed by direct binding and competitive inhibition assays (ELISA and DARIA), using recombinant VP4 from rhesus infectious rotavirus (RR), synthetic peptides and Par o 1-specific antibodies affinity purified from pooled and individual human sera. RESULTS: Antibodies specifically binding Par o 1, affinity purified from the sera of 35 individuals with skin test positivity to Parietaria and from 14 pools, were extensively cross-reactive with RRVP4. Cross-reactive binding was specifically inhibited by synthetic peptides derived from the C-terminal sequences of the VP4 proteins from human and rhesus infectious rotavirus. CONCLUSIONS: This study reports the first evidence of cross-reactivity between an allergen and a viral antigen.

Vaccination with DNA containing tat coding sequences and unmethylated CpG motifs protects cynomolgus monkeys upon infection with simian/human immunodeficiency virus (SHIV89.6P).

Recent evidence suggests that a CD8-mediated cytotoxic T cell response against the Tat protein of human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) controls primary infection after pathogenic virus challenge, and correlates with the status of long-term nonprogressor in humans. Due to the presence of unmethylated CpG sequences, DNA vaccination can boost the innate immunity driving more potent T cell-mediated immune responses. Therefore, cynomolgus monkeys were vaccinated with a tat-expressing vector containing defined unmethylated CpG sequences (pCV-tat). Here it is shown that the intramuscular inoculation of the pCV-tat contained primary infection with the highly pathogenic SHIV89.6P virus preventing the CD4(+) T cell decline in all the vaccinated monkeys. Undetectable virus replication and negative virus isolation correlated in all cases with the presence of anti-Tat CTLs. However, a CD8-mediated non cytolytic antiviral activity was also present in all protected animals. Of note, this activity was absent in the controls but was present in the monkey inoculated with the CpG-rich vector alone that was partially protected against viral challenge (i.e. no virus replication but positive virus isolation). These results suggest that a CTL response against Tat protects against primary infection by blocking virus replication at its early stage, in the absence of sterilizing immunity. Nevertheless, the boost of the innate immunity by CpG sequences can contribute to this protection both by driving more potent CTL responses and by inducing other CD8-mediated antiviral activities. Thus, the CpG-rich tat DNA vaccine may represent a promising candidate for preventive and therapeutic vaccination against AIDS.

CD4-independent infection of two CD4(-)/CCR5(-)/CXCR4(+) pre-T-cell lines by human and simian immunodeficiency viruses.

The infection of CD4-negative cells by variants of tissue culture-adapted human immunodeficiency virus type 1 (HIV-1) or HIV-2 strains has been shown to be mediated by the CXCR4 coreceptor. Here we show that two in vitro-established CD4(-)/CCR5(-)/CXCR4(+) human pre-T-cell lines (A3 and A5) can be productively infected by wild-type laboratory-adapted T-cell-tropic HIV-1 and HIV-2 strains in a CD4-independent, CXCR4-dependent fashion. Despite the absence of CCR5 expression, A3 and A5 cells were susceptible to infection by the simian immunodeficiency viruses SIVmac239 and SIVmac316. Thus, at least in A3 and A5 cells, one or more of the chemokine receptors can efficiently support the entry of HIV and SIV isolates in the absence of CD4. These findings suggest that to infect cells of different compartments, HIV and SIV could have evolved in vivo to bypass CD4 and to interact directly with an alternative receptor.

Antigenic and molecular characterization of wild type 1 poliovirus causing outbreaks of poliomyelitis in Albania and neighboring countries in 1996.

Mass vaccination has led poliomyelitis to become a rare disease in a large part of the world, including Western Europe. However, in the past 20 years wild polioviruses imported from countries where polio is endemic have been responsible for outbreaks in otherwise polio-free European countries. We report on the characterization of poliovirus isolates from a large outbreak of poliomyelitis that occurred in Albania in 1996 and that also spread to the neighboring countries of Yugoslavia and Greece. The epidemics involved 145 subjects, mostly young adults, and caused persisting paralysis in 87 individuals and 16 deaths. The agent responsible for the outbreak was isolated from 74 patients and was identified as wild type 1 poliovirus by both immunological and molecular methods. Sequence analysis of the genome demonstrated the involvement of a single virus strain throughout the epidemics, and genotyping analysis showed 95% homology of the strain with a wild type 1 poliovirus strain isolated in Pakistan in 1995. Neutralization assays with both human sera and monoclonal antibodies were performed to analyze the antigenic structure of the epidemic strain, suggesting its peculiar antigenic characteristics. The presented data underline the current risks of outbreaks due to imported wild poliovirus and emphasize the need to improve vaccination efforts and also the need to implement surveillance in countries free of indigenous wild poliovirus.

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.

Poliovirus Sabin type 1 neutralization epitopes recognized by immunoglobulin A monoclonal antibodies.

Immunity to poliomyelitis is largely dependent on humoral neutralizing antibodies, both after natural (wild virus or vaccine) infection and after inactivated poliovirus vaccine inoculation. Although the production of local secretory immunoglobulin A (IgA) antibody in the gut mucosa may play a major role in protection, most of information about the antigenic determinants involved in neutralization of polioviruses derives from studies conducted with humoral monoclonal antibodies (MAbs) generated from parenterally immunized mice. To investigate the specificity of the mucosal immune response to the virus, we have produced a library of IgA MAbs directed at Sabin type 1 poliovirus by oral immunization of mice with live virus in combination with cholera toxin. The epitopes recognized by 13 neutralizing MAbs were characterized by generating neutralization-escape virus mutants. Cross-neutralization analysis of viral mutants with MAbs allowed these epitopes to be divided into four groups of reactivity. To determine the epitope specificity of MAbs, virus variants were sequenced and the mutations responsible for resistance to the antibodies were located. Eight neutralizing MAbs were found to be directed at neutralization site N-AgIII in capsid protein VP3; four more MAbs recognized site N-AgII in VP1 or VP2. One IgA MAb selected a virus variant which presented a unique mutation at amino acid 138 in VP2, not previously described. This site appears to be partially related with site N-AgII and is located in a loop region facing the VP2 N-Ag-II loop around residue 164. Only 2 of 13 MAbs proved able to neutralize the wild-type Mahoney strain of poliovirus. The IgA antibodies studied were found to be produced in the dimeric form needed for recognition by the polyimmunoglobulin receptor mediating secretory antibody transport at the mucosal level.

Unimmunized Gypsy populations and implications for the eradication of poliomyelitis in Europe.

The certification of poliomyelitis eradication in Europe will eventually require that countries demonstrate there is a minimal risk of wild poliovirus reintroduction and sustained transmission through unimmunized subpopulations such as ethnic minorities. A serologic survey among a Gypsy community in Italy found that despite only 26% documented immunization coverage, serum neutralizing antibodies to poliovirus types 1, 2, and 3 were detected in 81%, 94%, and 63% of the 86 persons studied. While the high level of immunity found in this community may have been due to secondary spread of vaccine virus, the possibility of unrecognized circulation of wild polioviruses cannot be excluded. Targeted immunization of such groups may be the most efficient means of eliminating the risk of importation-associated outbreaks.

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.

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.

Antigenicity, immunogenicity and passive protection induced by immunization of mice with baculovirus-expressed VP7 protein from rhesus rotavirus.

The major neutralization antigen VP7 of rhesus rotavirus (RRV) was expressed in a baculovirus recombinant system. The expressed VP7 showed the same molecular mass as native VP7, and was recognized by hyperimmune sera as well as neutralizing and non-neutralizing monoclonal antibodies (MAbs) raised against RRV. Intraperitoneal administration of the expressed VP7 in mice elicited the production of serum antibodies which were able to immunoprecipitate VP7 from RRV-infected cell lysates and to neutralize the virus in vitro. Sera from immunized mice competed for binding to RRV in an ELISA with both neutralizing and non-neutralizing MAbs specific for VP7. Using a passive protection model of rotavirus disease, vaccination of mice with the recombinant VP7 induced partial protection from infection. These results suggest that the baculovirus-expressed VP7 may be useful in priming a protective immune response to rotavirus infection.

[The Coulter counter S-plus model: accuracy and normal values in platelet count]. / Il Coulter counter mod. S-plus: affidabilità e valori normali del conteggio piastrinico.

An evaluation of performance characteristics and accuracy of clinical results for automated multiparameter whole-blood platelet Counter Coulter Mod. S-Plus is described. Instrument precision is assessed in terms of reproducibility, linearity, carry-over. The results of all are impressive. Comparison of results with those obtained by manual reference method show excellent correlation. Normal values are defined for the platelet's parameters.