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Antonietta Marchi

Publications and source records attributed to Antonietta Marchi.

8 recordsLinked to original sources
PubMed2007

Human respiratory coronavirus HKU1 versus other coronavirus infections in Italian hospitalised patients.

BACKGROUND: Human respiratory coronavirus (hCoV) HKU1 infections were reported for the first time in 2005 in Hong Kong. OBJECTIVE: To investigate epidemiological, clinical, and diagnostic features of HKU1 infections. STUDY DESIGN: Longitudinal, prospective study from November 2005 through May 2006 in a hospitalised patient population. RESULTS: Overall, 48/426 (11.3%) patients were found to be infected by hCoV acute respiratory tract infections (ARTI). Of these, 10 (19.2%) were caused by HKU1 (6 single infections and 4 coinfections) during the period January-May 2006. Diagnosis was made by using RT-PCR for all four hCoVs, and in parallel, in-house developed group-specific monoclonal antibodies (MAbs) for HKU1 and 229E. HKU1-specific MAb was able to retrospectively identify 8 of 10 HKU1 strains detected by RT-PCR. Phylogenetic analysis showed that four HKU1 strains were genotype A and six genotype B. In HKU1-infected patients, the predominant clinical symptom was rhinorrhea (nine patients). Within group II hCoV, HKU1-infected patients had a significantly lower rate of lower ARTI compared to OC43-infected patients. CONCLUSION: HKU1 hCoV strains circulated in northern Italy during the winter-spring season 2005-2006. Both HKU1 genotypes were detected. HKU1-specific MAb may contribute to the rapid diagnosis of HKU1 infections currently performed by RT-PCR.

Adolescent↗
PubMed2006

Insights into central and peripheral factors affecting the "oxidative performance" of skeletal muscle in aging.

During exercises with relatively small muscle masses, limitations to exercise performance by the cardiovascular system should be significantly reduced, allowing one to fully-test the "oxidative potential" of the investigated muscles. Ten elderly males (E, 77.8 +/- 2.9 years [x +/- SD]) and eight young controls (Y, 26.6 +/- 3.0) underwent incremental exercises to voluntary exhaustion on a dynamic leg-extension (dominant limb) machine (knee-extension, KE) and on a cycloergometer (CYCLO). During KE the load was increased every 3 min to loads corresponding to 20, 40 and 60% of the force of one-repetition maximum (1RM). The following variables were determined (vastus lateralis muscle): concentration changes of deoxygenated haemoglobin and myoglobin (Delta[deoxy(Hb + Mb)]) by near-infrared spectroscopy (NIRS), expressed as percentage of the maximal value obtained during transient limb ischemia, and taken as an index of O2 extraction; root mean square (RMS) and median power frequency (MDF) by electromyography. The total lifted load during KE and peak workload during CYCLO were lower in E versus Y (620.4 +/- 321.9 kg vs. 1347.4 +/- 458.7; 113.5 +/- 23.9 W vs. 224.3 +/- 41.0, respectively). During CYCLO Delta[deoxy(Hb + Mb)] peak (i.e. the value determined at exhaustion) was lower in E (44.5 +/- 17.7%) versus Y (67.1 +/- 22.9), whereas during KE Delta[deoxy(Hb + Mb)] peak was higher in E (56.8 +/- 20.9%) versus Y (38.6 +/- 15.8). "Thresholds", that is abrupt increases in RMS slopes, were detected in Y but not in E, suggesting less recruitment or a preferential atrophy of type 2 fibers in the elderly. These findings, associated with the preserved capacity of O2 extraction, suggest a shift towards oxidative metabolism in skeletal muscles of 78 year-old subjects, which could preserve, at least in part, their capacity to carry out exercise.

Adult↗
PubMed2006

Genetic variability of human coronavirus OC43-, 229E-, and NL63-like strains and their association with lower respiratory tract infections of hospitalized infants and immunocompromised patients.

In the winter-spring seasons 2003-2004 and 2004-2005, 47 (5.7%) patients with acute respiratory infection associated with human coronavirus (hCoV) 229E-, NL63-, and OC43-like strains were identified among 823 (597 immunocompetent and 226 immunocompromised) patients admitted to hospital with acute respiratory syndromes. Viral infections were diagnosed by either immunological (monoclonal antibodies) or molecular (RT-PCR) methods. Each of two sets of primer pairs developed for detection of all CoVs (panCoV) failed to detect 15 of the 53 (28.3%) hCoV strains identified. On the other hand, all hCoV strains could be detected by using type-specific primers targeting genes 1ab and N. The HuH-7 cell line was found to be susceptible to isolation and identification of OC43- and 229E-like strains. Overall, hCoV infection was caused by OC43-like, 229E-like, and NL63-like strains in 25 (53.2%), 10 (21.3%), and 9 (19.1%) patients, respectively. In addition, three patients (6.4%) were infected by untypeable hCoV strains. NL63-like strains were not found to circulate in 2003-2004, and 229E-like strains did not circulate in 2004-2005, while OC43-like strains were detected in both seasons. The monthly distribution reached a peak during January through March. Lower predominated over upper respiratory tract infections in each age group. In addition, hCoV infections interested only immunocompetent infants and young children during the first year of life, while all adults were immunocompromised patients. Coinfections of hCoVs and other respiratory viruses (mostly interesting the first year of life) were observed in 14 of the 47 (29.8%) patients and were associated with severe respiratory syndromes more frequently than hCoV single infections (P = 0.002). In conclusion, the use of multiple primer sets targeting different genes is recommended for diagnosis of all types of hCoV infection. In addition, the detection of still untypeable hCoV strains suggests that the number of hCoVs involved in human pathology might further increase. Finally, hCoVs should be screened routinely for in both infants and immunocompromised patients with acute respiratory infection.

Acute Disease↗
PubMed2005

Detection and pathogenicity of human metapneumovirus respiratory infection in pediatric Italian patients during a winter--spring season.

BACKGROUND: Some diagnostic, epidemiological and clinical features of the recently discovered human metapneumovirus remain to be investigated. OBJECTIVES: To study the best approach for the diagnosis of human metapneumovirus infections by both conventional and molecular methods, along with the human metapneumovirus circulation rate in northern Italy and the severity of human metapneumovirus respiratory infections in a pediatric patient population. STUDY DESIGN: Nasopharyngeal aspirates (NPA) were taken from 306 pediatric patients during the winter-spring season 2003-2004, and examined for conventional respiratory viruses by direct fluorescent staining and cell culture, while human coronavirus and human metapneumovirus were sought by RT-PCR. RESULTS: RT-PCR detected human metapneumovirus in 40/306 (13.1%) children positive for respiratory viruses, with an incidence intermediate between that of respiratory syncytial virus (58 patients, 18.9%) and that of influenzavirus infections (29 patients, 9.5%). Phylogenetic analysis showed cocirculation of both human metapneumovirus types (A and B) as well as their relevant subtypes (A1-A2 and B1-B2). Clinically, human metapneumovirus was found to be second to human respiratory syncytial virus alone, as a cause of respiratory tract infections, while duration of virus excretion appeared to correlate with severity of infection, and virus load in NPA with the stage of respiratory infection. CONCLUSION: (i) Human metapneumovirus is a major viral pathogen in the Italian pediatric patient population; (ii) the severity of lower respiratory tract infections approaches that of human respiratory syncytial virus; (iii) there are preliminary indications that the duration of virus excretion may reach 2-3 weeks and that the level of viral load in NPA correlates with the clinical stage of human metapneumovirus infection.

Animals↗
PubMed2003

Analysis of secondary V(D)J rearrangements in mature, peripheral T cells of ataxia-telangiectasia heterozygotes.

Ataxia-telangiectasia (AT) is a rare recessive disease with pleiotropic involvement of the nervous and lymphoid systems. AT heterozygotes have a population frequency of about 1%, and although not manifesting any overt clinical symptoms, they have an increased mortality, mainly because of cancer and ischemic heart disease. We and others have described a mature T lymphocyte population with an altered T cell receptor surface expression ("TCR variant") that reactivates the recombination activating genes (RAG) and is expanded in the blood of patients with AT. In view of the known role of V(D)J recombination in the onset of tumorigenic translocations, we proposed that the increased RAG activity was responsible for the predisposition of AT homozygotes to develop mature-type T leukemia/lymphoma. In the present report, we used cytofluorimetry to quantify the TCR variant population and the memory/naïve T-cell compartments in the blood of AT heterozygotes compared with AT patients and controls. We assessed the expression of different recombinase genes through RT-PCR/oligotyping and cytofluorometric analysis and searched for rearrangement intermediates by ligase-mediated PCR in T-cell lines from four heterozygous carriers. We found the TCR variant population was increased on average 2x in AT heterozygotes (vs 10x in homozygotes) compared with controls, and naïve CD4(+) T lymphocytes were reduced on average 0.5x (vs 0.1x in homozygotes). We were able to demonstrate recombinase gene expression in all four heterozygous T-cell lines, and rearrangement intermediates, indicative of ongoing V(D)J recombination, in two. These rearrangements were compatible with V-gene replacement, a mechanism of receptor editing described for Ig and TCRalpha genes, to our knowledge not previously documented for TCRbeta. In conclusion, we found that RAG reactivation and secondary V(D)J rearrangements, potential risk factors of mature-type leukemia in AT homozygotes, also take place in AT heterozygous carriers and might place this large population fraction at an increased risk of leukemia/lymphoma.

Ataxia Telangiectasia↗
PubMed2003

Web versus press with a high circulation: an Italian case study.

THE PROBLEM: the quality of health-related information available for general public on the web has been widely debated, often expressing concern, in the last few years, but also other mass media supply medical contents for health consumer. THE OBJECTIVE: To evaluate the quality of information available by the Italian people through Internet in comparison with the one published on the press with a high circulation. A general interest topic such as over-weight and obesity has been identified as a convenient field for the comparison. METHODS: A sample of web sites and articles have been collected--excluding the promotional ones- in order to compare their completeness and correctness. National guidelines were the golden standard. For the web sites, the availability of indications to let the user know the reliability of the site--we will refer to these as "transparency"--has been evaluated through 9 parameters. RESULTS: 45 informative sites and 35 articles have been found: the Italian population has a good chance of getting information. Web sites are much more complete than articles. Correctness of both is quite good. Transparency of web sites leaves much to desire, independently from the quality of the content. LESSON LEARNT: There is probably an excessive confidence about the transparency and caution of articles in dealing with health-related topics. CONCLUSION: The web publishers must necessarily be educated to apply the existing good practice rules, but in the meantime also the press with a high circulation, that is read by a high percentage of people, has to improve its quality in order to co-operate in supplying adequate information. In general, from the traditional exceptionalist approach for medical information on the internet, a definition of media quality standard could be derived.

Consumer Behavior↗