1,720,975 research outputs found
Viability of autologous human leukocytes labeled by 99mTc-HMPAO
Get PDFLa marcatura radioattiva e la re-iniezione di leucociti autologhi è una tecnica di medicina nucleare utilizzata nella rilevazione scintigrafica di infezione nascoste. Poiché i leucociti marcati devono essere re-iniettati nel paziente, è necessario operare in condizioni strettamente asettiche per la procedura di marcatura. Nel presente lavoro la separazione e la marcatura con 99mTc-HMPAO sono state eseguite utilizzando un sistema chiuso, in kit monouso che, semplificando il processo di preparazione, riduce al minimo la possibilità di una contaminazione microbiologica o radioattiva accidentale del campione e dell'operatore. Le procedure europee prevedono che, nel caso di resa di marcatura <40%, ulteriori controlli di qualità debbano essere effettuati, come ad esempio l'ispezione al microscopio e il test di esclusione del tripan blu per la vitalità cellulare. In un gruppo di 280 pazienti è stata eseguita la determinazione della vitalità leucocitaria in ogni paziente esaminato, al fine di garantire la miglior significatività clinica della scintigrafia ed assicurare un rigoroso rispetto della Good Medical Practice. Poiché i valori assoluti di vitalità dei leucociti della marcatura hanno evidenziato una elevata variabilità tra paziente e paziente, è stato eseguito un più accurato esame dei dati clinici raccolti, nel tentativo di spiegare questa elevata dispersione dei valori. Il rapporto leucociti non vitali/leucociti vitali PRIMA della marcatura radioattiva è stata preso in considerazione nel presente lavoro, ed è stata studiata una sua possibile relazione con altri parametri del paziente. Una correlazione diretta tra vitalità dei leucociti e gravità dell'infezione è stato riscontrata, e una interpretazione clinica è stata brevemente discussa.Radiolabeling and re-injection of autologous leukocytes is a nuclear medicine technique used in the scintigraphic detection of hidden infections. Since the labeled leukocytes have to be re-injected into the patient, strictly aseptic conditions are required for the labeling procedure. In the present paper the separation and labeling of mixed leukocytes with 99mTc-HMPAO were performed by using a closed, disposable kit, that, simplifying the preparation process, minimizes the possibility of accidental microbiological and radioactive contamination of the sample and operator. The recommended European procedure recommends that, if the labeling yield is <40%, further quality controls should be mandatorily performed, such as microscopic inspection and trypan blue exclusion test for cell viability. In a cohort of 280 patients the determination of leukocyte viability was performed for every examined patient, in order to ensure the best clinical significance of the scintigraphy and assure a stringent respect of Good Medical Practice. As the absolute values of leukocyte viability before the labeling demonstrated high patient variability, an accurate examination of collected clinical data was performed, in the attempt to explain this high dispersion of values. The non viable/viable leukocyte ratio BEFORE radioactive labeling was taken into consideration in the present work, and a possible relation with other patient parameters or clinical factors was studied. A direct correlation between leukocyte viability and infection severity was found, and a clinical explanation is briefly discussed
Procedure for high-yield separation and radioactive labelling by 51Cr and 111In of human platelets
Get PDFLe piastrine sono corpuscoli non nucleati del sangue circolante, prodotti nel midollo osseo e derivati dalla frammentazione dei precursori del midollo osseo chiamati megacariociti. Recentemente le piastrine hanno trovato largo impiego nella terapia clinica per la loro capacità di rilasciare fattori di crescita; il concentrato piastrinico, PRP (plasma ricco di piastrine) ha mostrato di possedere proprietà antinfiammatorie, antibatteriche, rigenerative ed emostatiche. La radiomarcatura e reiniezione di piastrine autologhe è anche una tecnica di medicina nucleare utile nella rilevazione scintigrafica di molte patologie cliniche , dai disturbi della milza alla visualizzazione dei trombi. Nel presente lavoro è stata
ottimizzata la procedura di separazione di piastrine dal sangue intero di soggetti umani, utilizzando un kit monouso finalizzato alla preparazione del PRP, che ha consentito una separazione delle piastrine con alta resa, in condizioni asettiche e in tempi brevi. Le piastrine ottenute sono state efficacemente marcate con 51Cr radioattivo sotto forma di sodio cromato e 111In sotto forma di 111In-ossina.Platelets are non-nucleated corpuscles of the circulating blood, produced in bone marrow and derived from fragmentation of bone marrow precursors called megakaryocytes. Recently the platelets have found wide use in clinical therapy for their ability to release growth factors; the platelet concentrate, PRP (Platelet Rich Plasma) has been shown to possess anti-inflammatory, antibacterial, regenerative and hemostatic properties. The radiolabelling and re-injection of autologous platelets is also a nuclear medicine technique useful in the scintigraphic detection of many clinical diseases, from splenic disorders
to thrombi visualization. In the present paper the procedure of platelets separation from whole blood of human subjects was optimized by using a disposable kit aimed to PRP preparation, that allowed a platelet separation with high yield, in aseptic conditions and in short times. The obtained platelets were efficiently labelled by using radioactive 51Cr in the form of sodium chromate and 111In in the form of 111In-oxine
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Adiponectin levels are reduced in children born small for gestational age and are inversely related to postnatal catch-up growth
Get PDFAdiponectin is an adipocytokine with insulin-sensitizing and antiatherogenic properties. Reduced concentrations of adiponectin precede the onset of type 2 diabetes and the development of atherosclerosis. Our aim was to quantify adiponectin concentrations in small for gestational age (SGA) children. Fifty-one SGA children, 24 obese, and 17 short-normal children with birth weight appropriate for gestational age (short-AGA) were studied. The statures of the SGA children were corrected for their midparental height and subdivided into two groups according to their corrected height: catch-up growth group, children with corrected height of 0 z-score or greater (n = 17); and noncatch-up growth group, subjects with corrected height less than 0 z-score (n = 34). SGA children showed adiponectin levels significantly lower than short-normal children (35.2 +/- 3.5 vs. 80.4 +/- 26.6 mug/ml; P < 0.0001) and obese children (77.5 +/- 39.4 μg/ml; P < 0.0001). Catch-up growth children showed adiponectin levels significantly lower than noncatch-up growth subjects (29.4 +/- 10.3 vs. 38.1 +/- 11.5 mug/ml; P = 0.01). Adiponectin concentrations were inversely related to height z-score, corrected stature, weight, and body mass index and were positively related to birth weight. Our results suggest that adiponectin levels are reduced in SGA children and are even lower in those with postnatal catch-up growth. Whether this finding implies a higher risk of developing type 2 diabetes and atherosclerosis remains to be established
Variations on the Author
Get PDF“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
Get PDFWe 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
Possible role of negative human papillomavirus E6/E7 mRNA as a predictor of regression of cervical intraepithelial neoplasia 2 lesions in hr-HPV positive women
Get PDFBackground: The aim of this study was to evaluate the regression rate of CIN2 p16 positive lesions in women over 25 years of age and identify possible predictors of regression. Methods: A total of 128 CIN2 p16 positive patients over 25 years old were considered. The women met the following inclusion criteria: HPV genotype 16, 18, 31, 33, 45 positive, HPV E6 / E7 mRNA test positive, without immune system pathologies, not pregnant and had completed at least two years of follow-up. At each follow-up examination patients were examined by colposcopy, HPV test, E6/E7mRNA, targeted biopsy and p16 protein detection. The final state after the two years of follow-up was classified as progression if the histology showed a CIN3, persistence if the lesion was a CIN2, regression if negative or LSIL. The predicted regression factors evaluated were: HPV E6/E7mRNA, protein p16. Results: Overall, we had 35.1% (45 cases) of progression to CIN3, 41.4% (53 cases) of persistence and 23.4% (30 cases) of regression. The regression rate was higher in women with negative mRNA 92.8% (26/28), OR 312 (34.12–1798.76) p = 0.0001, while women with p16 negative had a regression of 22.6% (7/31), OR 0.94 (95% CI 0.36–2.46), p was not significant. We found no significant difference in regression between p16 positive (23.7%) and p16 negative (22.6%) CIN2 p16 lesions. p16 had a VPN of 22.6 (CI 95% 0.159–0.310), indicating that a p16 negative lesion does not exclude a CIN2 +. Conclusions: We had a regression rate of 23.4%, which was low if we consider that in the literature the regression rates vary from 55 to 63%. The discrepancy in the results may indeed be explained by the fact that all lesions in our study were hr-HPV positive and belonged to “older women” reflecting a more "high-risk" population. As regression factors we studied p16 and HPV E6/E7 mRNA. The results of our study show that HPV mRNA, if negative, appears to be able to identify CIN2 lesions with a higher probability of regression and underlines how a p16 negative is not an indicator of regression
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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