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Diagnosis of congenital CMV infection via dried blood spots
No full textCytomegalovirus (CMV) infection is the most frequent congenital infection in humans and can cause permanent damage-particularly neurological-in about 20% of those infected, with or without symptoms at birth. Laboratory diagnosis is essential on account of the relatively non-specific clinical manifestations in symptomatic newborns but also because of the high frequency of asymptomatic cases that are nevertheless at risk of lesions later in life. However, these tests need samples taken within 3 weeks of birth to distinguish congenital infection from the more common, but clinically benign, perinatal infection. Tests for viral DNA have proved a valid means of diagnosing congenital CMV infection in neonatal blood dried on paper (DBS) widely used in screening for metabolic and genetic diseases, as an alternative to the conventional urine culture method. The DBS test is simpler, faster and less costly than viral isolation; in addition the samples can be safely stored for long periods, so diagnosis can be made even after several years. The sensitivity and specificity of the DBS test, compared to the reference method, have been reported to range between 71 and 100% and 99 and 100%, respectively, depending on the different studies and diagnostic criteria applied. The most interesting applications reported so far involve retrospective determination of the impact of congenital CMV in sensorineural deafness, abnormalities of cortical development, neonatal cholestasis and surveys of the prevalence of this infection in various populations. The test might be useful in the future for neonatal screening with a view to treating neonates and so avoiding the damage this disease can cause
Fattori di patogenicità in ceppi di Escherichia coli isolati da processi infettivi in sedi diverse
No full textEscherichia coli, il batterio commensale più rappresentativo della flora aerobia facoltativa intestinale dell’uomo è anche, paradossalmente, l’organismo isolato più frequentemente come causa di infezioni intestinali e di infezioni extraintestinali da gram-negativi.
Esistono elementi distintivi tra ceppi commensali e ceppi patogeni sia per l’aspetto filogenetico sia per la presenza di specifici fattori di patogenicità (FP).
I geni codificanti molti dei FP noti sono di provenienza esogena, acquisiti, nel corso dell’evoluzione, dal genoma di altre specie. Talvolta sono veicolati da plasmidi e fagi, spesso sono integrati nel cromosoma batterico in associazioni definite isole di patogenicità. La loro presenza è predominante nei ceppi ascrivibili ai due gruppi filogenetici B2 e D.
Nei ceppi di E. coli responsabili di infezioni extraintestinali, diversamente dai ceppi patogeni intestinali, è poco noto il rapporto tra specifici fattori di patogenicità e sindrome.
Per studiare l’influenza di specifici FP nell’insorgere di processi infettivi in determinate sedi extraintestinali, abbiamo esaminato la distribuzione di ventinove FP in 94 isolati clinici di E. coli, 25 provenienti da emocolture, 32 da UTI, 25 da feci e 12 da campioni respiratori (BAL o aspirato endotracheale).
I FP esaminati comprendevano determinanti di adesività, tossine, tipi capsulari, siderofori, fattori di invasività, di resistenza serica ecc. e la loro presenza è stata evidenza mediante amplificazione di specifici marcatori genici.
La distribuzione media dei FP per ceppo è risultata pari a 8 nei gruppi filogenetici B2 e D, e 3 nei gruppi filogenetici B1 ed A.
I filogruppi B2 e D risultano presenti con uguale frequenza nei ceppi di isolamento ematico ma forse con diversa derivazione, se si considera che il gruppo B2 è particolarmente frequente nei ceppi di origine urinaria mentre il D in quelli di isolamento fecale.
Alcuni FP come le fimbrie di tipo S e F1C, il fattore necrotizzante di tipo1 e l’-emolisina sono stati rilevati esclusivamente in ceppi del gruppo B2, mentre le fimbrie di tipo P, alcuni fattori capsulari ed il fattore d’invasione dell’endotelio cerebrale sono presenti anche in ceppi di filotipo D. Altri FP come l’aerobactina ed il fattore di sieroresistenza risultano ugualmente diffusi in tutti i gruppi filogenetici o addirittura ( l’adesina non fimbriale tipo M e la colicina C) prevalenti tra i filotipi commensali B1 ed A
Surveillance of Poliomyelitis in Italy : immunity status of population against polio and environmental circulation of Poliovirus - Lombardia
No full textSEROLOGIC ASCERTAINMENT OF THE RISK OF VERTICAL CMV TRANSMISSION IN PREGNANCY
No full textBackground of the study: The transmission of infection from mother to fetus and the severity of damage are mainly linked to primary infection in pregnancy. Evaluation of the risk of vertical transmission in pregnancy must consider infection ascertainment, distinction between primary and reactivated infection and dating. The avoidance of invasive procedures is preferable.
Obiettive: To identity serological tests useful far ascerlaining the risk of vertical transmission In pregnancy.
Design: The series included 43 pregnant women (9 in the first, 18 in the second and 16 in the third trimester) with suspected CMV infection. CMV infection was diagnosed by isolation and PCR amplification on samples of urine, blood and amniotic fluid. Serological tests included CMV-IgM determination, IgG avidity test and IgM immunoblotting (in 23 cases only). Transmission of infection was assessed in the babies examining urine, saliva or blood samples or dried blood spots on Guthrie cards. Results: Eighteen women were IgM positive of whom 9 were also positive at isolation tests. The rate of vertical transmission from these women was 29% (5/17) compared to 8% (2/23) in IgM negative cases. Dating of infection on the basis of avidity test results and pregnancy stage showed that transmission occurred in 3 of 4 women with infection acquired in pregnancy, 3 of 18 with doubtful dating, and in 1 of 18 who acquired infection (primary) before pregnancy. IgM immunoblotting identified 7 reactivated infections out of 15 cases with high avidity IgG. Transinission occurred ori 2 of the 7 women with reactivated infections (both HIV+) and in 1 woman with a primary infection possibly acquired in the first months of pregnancy.
Conclusion: The risk of vertical transmission of CMV infection can be ascertained in different stage.s of pregnancy by a combination of the cited serological tests
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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