130,395 research outputs found
Antenatal steroids and risk of bronchopulmonary dysplasia: A lack of effect or a statistical artifact?
No full textINFEZIONE DA CITOMEGALOVIRUS IN NEONATO ELBW: TRATTAMENTO CON GANCICLOVIR
No full textL'infezione da Citomegalovirus post-trasfusionale in neonati di peso
Estremamente basso politrasfusi viene raramente accertata. Si descrive un caso di documentata infezione trattata con Ganciclovir.
B.L. e' nato presso l'Ospedale di Morbegno, alla 23a settimana di età gestazionale da parto vaginale per travaglio sorto improvvisamente.
Madre quartigravida, terzipara. Anamnesi familiare negativa per malattie ereditarie. Gravidanza decorsa regolarmente fino al momento del parto.
Sierologia materna per CMV: IgM negative, IgG a basso titolo.
Alla nascita peso 600 g.; lunghezza 31 cm.; circonferenza cranica 21,3 cm. Apgar a l'= 2 e a 5'= 7.
Il neonato e' stato preso in carico alla nascita dall'equipe di trasporto, posto in ventilazione meccanica e trasferito presso la Divisione di Patologia Neonatale dell'Ospedale di Lecco.
All'ingresso in reparto sono stati incannulati i vasi ombelicali e successivamente e' stato posizionato catetere venoso centrale (CVC) percutaneo.
Nei primi 15 giorni di vita sono state praticate infusioni quotidiane di liquidi biologici: 10 unita' di plasma fresco congelato per complessivi 73 ml e 7 unita' di GRC per complessivi 40 ml. In seguito sono state infuse altre 8 unita' di GRC ad intervalli di circa 7 giorni per ulteriori 66 ml.
I GRC sono stati somministrati con filtro per leucociti PALL RC 100 KL. La stimolazione intestinale con latte materno e' stata iniziata in 9a giornata. Durante il ricovero il bambino ha presentato:
- RDS che ha richiesto ventilazione meccanica per 3 settimane e successivamente displasia broncopolmonare trattata con Desametasone e 02 fino alla 42a settimana di età postconcezionale.
- Infezione da CMV esordita a 52 giorni di vita con evidente peggioramento delle condizioni generali: leucopenia, piastrinopenia, PCR positiva e quadro clinico suggestivo di sepsi. Nel sospetto di infezione a partenza dal Catetere Venoso Centrale, si e' iniziato trattamento con Vancomicina e Ceftazidime, e' stato rimosso il CVC e posizionato un altro cateterepercutaneoin sede diversa. Gli esami colturali (emocoltura e punta CVC) sono risultati negativi. Dopo 6 giorni dall'inizio della terapia antibiotica le condizioni generali sono rimaste gravi e sono comparse petecchie alle mani e all’addome, milza all'ombelicale trasversa e fegato a 1 cm. Persisteva leucopenia, le transaminasi erano nella norma, la PCR si era negativizzata.
È stato quindi posto il sospetto di infezione da CMV. Le prove sierologiche di ricerca antigenica rapida, eseguite presso l’Istituto di Virologia dell’Università di Milano, sono rimaste positive; l’ag p65 e l’ag p72 di CMV erano presenti in 46 e 30 cells su 200.000 PMN, rappresentando quindi un dato significativo di infezione in atto. La ricerca colturale su sangue è risultata positiva,
La sierologia classica ha evidenziato la presenza di IgM specifiche e tracce di IgG. Nella madre il quadro sierologico è rimasto immutato. Si è iniziato pertanto trattamento antivirale con Ganciclovir 7,5 mg/Kg in due somministrazioni al giorno, in associazione a gammaglobuline 500 mg/Kg/die per 3 giorni nella 1a
settimana e 400 mg/kg a giorni alterni nelle successive settimane. Dopo una settimana di trattamento si e' assistito ad un netto miglioramento delle condizioni generali, scomparsa delle petecchie,riduzione dell'epato-splenomegalia e negativizzazione degli antigeni p65 e p72. Dalla 4a settimana in considerazione del trend favorevole si è ridotta la somministrazione del Ganciclovir a 2 giorni la settimana e delle gammaglobuline ad una volta la settimana.
Durante il trattamento con Ganciclovir non si sono evidenziati effetti riferibili a mielotossicità.
I controlli seriati, eseguiti settimanalmente, degli antigeni p65 e p72 e colturali sono risultati sempre negativi durante tutto il periodo del trattamento. Negativi sono risultati anche i successivi controlli a 2, 4, 6 mesi.
Altri problemi presentati:
- durante l'intera degenza ospedaliera si sono verificati 3 episodi infettivi trattati con antibioticoterapia. Il bambino e' stato sottoposto a crioterapia e laserterapia per ROP III stadio bilaterale presso la Divisione di Oculistca Pediatrica dell'Ospedale Niguarda ed e' stato operato per ernia inguinale bilaterale presso la Divisione di Chirurgia Pediatrica dell’Ospedale di
Bergamo.
Dimissione a 5 mesi (1 mese di eta'corretta), con peso di 2965 g. in buone condizioni generali.
Il follow-up giunto fino al 6 mese di eta' corretta evidenzia sviluppo somatico regolare, la funzionalita' respiratoria è nella norma e non presenta esiti oculari riferibili a ROP o ad infezione da CMV.
Lo sviluppo neuromotorio e' complessivamente adeguato con permanenza dello schema estensorio sul piano nucale. I tracciati EEG sono nella norma. La funzione uditiva valutata con ABR è risultata integra.
I controlli ecografici cerebrali hanno evidenziato all'eta' corretta di 3 mesi una iperecogenicita' puntiforme a livello del talamo di destra, compatibile con piccola calcificazione.
OSSERVAZIONI CONCLUSIVE:
La modalita', i tempi d'insorgenza della malattia e l'andamento del quadro sierologico materno indirizzano verso la probabile infezione acquisita da CMV post-trasfusionale, anche se non si puo' escludere con assoluta certezza la trasmissione perinatale. La trasmissione attraverso il latte materno, puo° essere esclusa in considerazione al limitato tempo di latenza dall'inizio dell'alimentazione e l'esordio della malattia. La possibilità di monitorare l'antigenemia con risposta in 24 ore si e' dimostrato un importante strumento per seguire l'attivita' della malattia e ci ha permesso di modulare la terapia antivirale. In prospettiva di ridurre le infezioni posttrasfusionali è auspicabile che vengano selezionati donatori CMV-negativi quali fornitori preferenziali di emoderivati per i prematuri con peso molto basso
Antenatal steroids and risk of bronchopulmonary dysplasia : a lack of effect or a case of over-adjustment?
No full textAlthough antenatal steroids reduce risk factors for bronchopulmonary dysplasia (BPD) in preterm infants, their effect on BPD is conflicting. We hypothesised that the lack of protective effect found in some studies could derive from over-adjustment during analysis, caused by controlling for factors intermediate in the causal pathway between treatment and outcome. We prospectively studied a cohort of infants 23-32 weeks gestation <1500 g, admitted to 10 tertiary-level neonatal units in Lombardy (Italy) in 1999-2002; 1118 neonates out of 1314 survived to 36 weeks; 15.9% developed BPD (oxygen requirement at 36 weeks); 82% were treated with steroids. In univariable analysis, steroids were not significantly protective against BPD; some intermediate factors (mechanical ventilation, greater severity of illness as measured by Clinical Risk Index for Babies score, patent ductus arteriosus) were significantly positively associated with (i.e. were risk factors for) BPD (OR = 11.0, 1.55, 4.42, respectively, all P < 0.001), and negatively associated with (i.e. prevented by) steroids (OR = 0.58, 0.92, and 0.58, respectively, all P < 0.01). In multiple logistic regression models using propensity scores, without the above-mentioned intermediate risk factors, steroid-treated infants had a lower risk of BPD (OR 0.59 [95% CI 0.36, 0.97], P = 0.036); male sex (OR = 2.08), late-onset sepsis (OR = 4.26), and birthweight (OR = 0.63 for 100 g increase) were also associated with BPD, all P < 0.001. When intermediate risk factors for BPD were also added to the model, the effect of steroids disappeared; ventilation (OR = 3.03), increased illness severity (OR = 1.11), and patent ductus arteriosus (OR = 1.90) were significant risk factors. This study suggests that including variables that are potential mediators in the causal chain can obscure the ability to detect a protective effect of treatment. We observed such a phenomenon in our analyses of the relationship between antenatal steroids and BPD, suggesting that steroid effect is partly mediated through a reduction in the classical risk factors
Pain management during invasive procedures at Italian NICUs: has anything changed in the last five years?
No full textObjective: To ascertain the extent to which neonatal analgesia for invasive procedures has changed in the last 5 years since the publication of Italian guidelines. Methods: We compared survey data for the years 2004 and 2010 on analgesia policy and practices for common invasive procedures at Italian Neonatal Intensive Care Units (NICUs); 75 NICUs answered questionnaires for both years and formed the object of this analysis. Results: By 2010 analgesia practices for procedural pain had improved significantly for almost all invasive procedures (p < 0.05), both non-pharmacological and pharmacological methods being adopted by the majority of NICUs (unlike the situation in 2004). The routine use of medication for major invasive procedures was still limited, however (35% of lumbar punctures, 40% of tracheal intubations, 46% during mechanical ventilation). Postoperative pain treatment was still inadequate, and 41% of facilities caring for patients after surgery did not treat pain routinely. Pain monitoring had definitely improved since 2004 (p < 0.05), but not enough: only 21% and 17% of NICUs routinely assess pain during mechanical ventilation and after surgery, respectively. Conclusion: There have been improvements in neonatal analgesia practices in Italy since national guidelines were published, but pain is still undertreated and underscored, especially during major invasive procedures. It is mandatory to address the gap between the recommendations in the guidelines and clinical practice must be addressed through with effective quality improvement initiatives
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Hering-Breuer reflex in conscious newborn rats: effects of changes in ambient temperature during hypoxia
No full text In a previous study in conscious normoxic newborn rats, we found that the strength of the Hering-Breuer reflex (HB reflex) was greater (188%) at high (36°C) than at low (24°C) ambient temperature (Ta; D. Merazzi and J. P. Mortola. Pediatr. Res. 45: 370–376, 1999). We now asked what the effect would be of changes in Ta during hypoxia. Rat pups at 3–4 days of age were studied in a double-chamber airflow plethysmograph. The HB reflex was induced by negative body surface pressures of 5 or 10 cmH2O and quantified from the inhibition of breathing during maintained lung inflation. Rats were first studied at Ta = 32°C in normoxia, followed by hypoxia (10% O2breathing). During hypoxia, oxygen consumption (V˙o 2) averaged 47%, and HB reflex 115%, of the corresponding normoxic values, confirming that in the newborn, differently from the adult, hypoxia does not decrease the strength of the HB reflex. As hypoxia was maintained, lowering Ta to 24°C or increasing it to 36°C, on average, had no significant effects onV˙o 2 and the HB reflex. However, with 5-cmH2O inflations, the HB reflex during the combined hypoxia and hyperthermia was significantly stronger than in normoxia. We conclude that in conscious newborn rats during normoxia the Ta sensitivity of the HB reflex is largely mediated by the effects of Ta on thermogenesis andV˙o 2; in hypoxia, because thermogenesis is depressed andV˙o 2 varies little with Ta, the HB reflex is Ta independent. The observation that the reflex response to lung inflations during hypoxic hyperthermia can be greater than in normoxia may be of importance in the pathophysiology of apneas during the neonatal period. </jats:p
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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