169,915 research outputs found
GENETIC BASIS OF ALCOHOL DEPENDENCE: TRIALLELIC POLYMORPHISM OF THE SEROTONIN TRANSPORTER GENE IN A POPULATION OF ALCOHOL DEPENDENT SUBJECTS FROM ITALY
No full textBackground: The involvement of genetic variants in the
neurobiology of addiction and in the pathways of reward circuits
is well established. Serotonin transporter (5-HTT) regulate
serotonergic neurotransmission and has been associated also
with alcohol dependence (AD). Aim of this study is to assess a
possible link between a tri-allelic polymorphism of the 5’-UTR
region of 5-HTT gene (SLC6A4) and AD. This tri-allelic
polymorphism is made up of the long (L) allele of 5-HTTLPR
polymorphism together with the A (La) or G (Lg) allele of the
rs25531 single nucleotide polymorphism (SNP) and the short
allele (S). Lg and S are the low-functioning alleles.
Methods: Genotyping was performed by PCR amplification of
the 5-HTTLPR region; this produces long (L) or short (S)
amplicons depending on the variable number of repeated
elements, that results, in most cases, in a 43 base pair
insertion/deletion. The rs25531 genotype was obtained by an
L specific PCR amplification followed by a mini sequencing
reaction. We investigated 439 Italian alcoholic outpatients
(male 350, female 89) at Alcohol Unit of Umberto I Hospital -
Sapienza University of Rome and 423 healthy controls (male
285, female 138).
Results: From allelic point of view, no statistically significant
difference could be evidenced between alcoholics and controls,
considering either overall population or males separated from
females. However, AD women showed higher frequency of
both the L (56.2%) and La (51.7%) allele than control women
(respectively 50.4% and 47.5%), although not statistically
significant probably because of the smallness of the sample
analysed. An higher frequency of the L allele statistically
significant (P <0.05), can be only observed in women with an
early first contact with alcohol (≤16 yo, 63.5%) compared to
control (50.4%).
Conclusions. According to our results, the 5HTTLPR and
rs25531 polymorphisms of the serotonin transporter gene
(SLC6A4) seems not to be generally involved in AD. However,
considering males and females together can lead to
underestimate important differences in allelic distribution. In
fact, at least some categories of female patients show an higher
percentage of “fully working” alleles (L and La). Genotypic
analysis and studies of larger populations are mandatory
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
Genetica della dipendenza da alcol: studio dei polimorfismi 5HTTLPR e RS25531 del gene codificante per il trasportatore della serotonina (5-HTT)
No full textPremessa: Nonostante il nutrito numero di pubblicazioni che lo vedono coinvolto, il ruolo del trasportatore della serotonina
(5-HTT), codificato dal gene SLC6A4, nella dipendenza da alcol (OMIM Entry - # 103780) non è ancora del tutto chiaro.
Scopo dello studio: Abbiamo valutato, in questo studio, il ruolo di due polimorfismi del gene SLC6A4 nella dipendenza da
alcol in una popolazione italiana: il polimorfismo di tipo VNTR 5-HTTLPR ed il polimorfismo a singolo nucleotide rs25531
entrambi situati nella regione 5'UTR; è noto che questi polimorfismi agiscono ambedue, seppur con meccanismi diversi,
sull 'efficacia trascrizionale di questo gene.
Materiali e metodi: Il genotipo relativo ai due polimorfismi in studio è stato caratterizzato, con metodiche di PCR e single
nucleotide primer extension, in una popolazione composta da 403 pazienti ambulatoriali alcol-dipendenti e da 427 soggetti
di controllo donatori di sangue del centro trasfusionale dell'Azienda Policlinico Umberto I di Roma.
Risultati : Abbiamo riscontrato un'associazione significativa tra il polimorfismo 5-HTTLPR e la popolazione alcol-dipendente
di sesso femminile che ha cominciato a bere in giovane eta (<25 anni) , con una odds ratio di 1,8 per I'allele L ed un valore
di probabilità associato di 0,026 ; una odds ratio di 2,2 è risultata per il genotipo LL, quello trascrizionalmente più attivo, con
un valore di probabilltà associato di 0,034. Nessuna differenza statisticamente significativa è emersa per il polimorfismo
rs25531 ne, a parte i risultati già descritti, per il polimorfismo 5-HTTLPR nella sua forma bi-allelica nonché in quella triallelica in associazione con il polimorfismo rs25531.
Conclusioni: I nostri risultati suggeriscono che differenze di genere e nell'eta di insorgenza della alcol-dipendenza possano
essere in relazione con fattori genetici
DRD2/ANKK1 TaqIA and SLC6A3 VNTR polymorphisms in alcohol dependence: association and gene-gene interaction study in a population of central Italy.
No full textDopamine is a neurotransmitter whose functions are mediated by five receptors expressed in several organs and tissues. Dopaminergic system dysfunctions are involved in the etiology or treatment of several pathological conditions, including drug addiction. Alcohol dependence (AD) is a widespread psychiatric disorder, affecting 5.4% of the general population lifetime. Family and twins studies support the role of a genetic component in AD. Since dopamine neurotransmission has been shown to be involved in drug reward, related genes are plausible candidates for susceptibility to AD. Here, we evaluated both the DRD2/ANKK1 TaqIA (rs1800497) and SLC6A3 40 bp-VNTR SNP and gene-gene interaction analysis in AD patients from a population of Central Italy. The study design was a case-control. In total, 280 alcoholic subjects (213 men and 67 woman) and 280 age- and sex-matched control subjects were recruited for this study. Case subjects met the DSM-IV criteria for AD and they are free from any psychiatric co-morbidities. Controls were subjects who had non-alcohol problem either never drank; those who have smoked at least one pack of cigarettes per day for at least 1 year were excluded. Genotyping was performed by allele-specific PCR and RFLP-PCR. SLC6A3 40 bp 3'UTR-VNTR displays no association with AD. DRD2/ANKK1 TaqIA genotype distribution is significantly associated to AD (O.R.=1.551, p=0.023), with A1* allele displaying an O.R.=1.403 (p=0.029). Gene-gene interaction analysis using three-way contingency table analysis by a log-linear model yielded no significant result. Our study in a population of Central Italy extends and confirms previous results and, for the first time, tested the gene-gene interaction between SLC6A3 and DRD2 in AD
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Imaging functional stress test for stable chest pain symptoms in patients at low pretest probability of coronary artery disease: Current practice and long-term outcome
No full textBackground: Stress testing in patients with low pretest probability (PTP) of coronary artery disease (CAD) has become an increasing practice, potentially leading to underestimation of its true clinical value. Our aim was to describe the current use of most employed imaging functional tests and their prognostic value. Methods and Results: We selected patients with low PTP of CAD (CAD consortium clinical score < 15%) who underwent exercise or dipyridamole stress echocardiography or single photon emission computed tomography for suspected angina. Main exclusions were age < 45, known CAD, and abnormal rest wall motion. Of the 2279 subjects undergoing stress test, 883 (39%) had low PTP, and 91 (10.3%) had a positive test for ischemia. After a median follow-up of 5.8 years, 36 patients had events (21 died, 14 had nonfatal myocardial infarction). The percentage of events in the abnormal and normal stress test groups were similar (5 [5.5%] vs 31 [3.9%], P = ns), as the annualized event rate (0.87% vs 0.62%, P = ns). Age was the only variable associated with outcome in the regression analysis (hazard ratio 1.072, 95% CI 1.034–1.113, P < 0.001). An abnormal result was not associated with worse outcome in each of the subgroups of functional tests. Conclusions: In our geographical area, a considerable proportion of patients undergoing imaging functional tests for stable chest pain have a low estimated PTP of CAD. Of these, 1 in 10 resulted positive for inducible ischemia. However, none of the most common imaging functional tests, single photon emission computed tomography (SPECT), and stress echocardiography offer prognostic information in these patients
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
Alcohol Dependence and Serotonin Transporter Functional Polymorphisms 5-HTTLPR and rs25531 in an Italian Population.
No full textAIMS:The role of the serotonin transporter gene (SLC6A4) in alcohol dependence (AD) is still unclear. In this paper, we have evaluated the association of the SLC6A4 gene polymorphisms 5-HTTLPR and rs25531 in AD and assessed the polymorphic patterns both in alcoholics and in healthy people of an Italian population.
METHODS:Genotyping of the 5-HTTLPR (L/S) and rs25531 (A/G) polymorphisms of the SLC6A4 gene was performed on 403 alcoholics outpatients and 427 blood donors.
RESULTS:Comparing AD and control populations and taking into account statistical correction for multiple testing, we found no statistically significant differences for 5-HTTLPR (L/S) and rs25531 polymorphisms in terms of either genotypes or alleles frequencies. By univariate ANOVA, a statistically significant difference was found in the onset of AD: the mean age of onset resulted to be of 25.4 years in males in respect to 28.1 in females. In particular in males, the early AD onset was different, in a statistically significant manner, depending on the presence of at least one S or Lg allele (24.6 years) in respect to La homozygotes (27.5 years) (P = 0.03).
CONCLUSIONS:These findings suggest that genetic factors contribute, together with gender and age, to the onset differences in alcohol-dependent phenotypes
TRANSFERRINA CARBOIDRATO CARENTE NEL MISUSO ALCOLICO: CONFRONTO TRA METODICHE ALTERNATIVE DI DOSAGGIO E RIVALUTAZIONE DEGLI INTERVALLI DI RIFERIMENTO.
No full textLa diagnosi oggettiva di abuso alcolico è di grande importanza in medicina clinica e legale. Sono di uso comune, attualmente, diversi metodi analitici per la misura della transferrina carboidrato carente (CDT). Oggetto del nostro studio è quello di rivalutare gli intervalli di riferimento per il dosaggio della CDT con metodica NLatex (N-Latex – SIEMENS, su analizzatore BN Pro Spec®) ed in elettroforesi capillare (EC) (Capillarys, Sebia) in una popolazione di 130 donatori, afferenti al Centro Trasfusionale del Policlinico Umberto I, astemi o moderati bevitori (1 Unità Alcolica/die per la donna e 2 per l’uomo). Si vogliono inoltre confrontare i due differenti metodi analitici su 100 campioni, selezionati in base al loro valore di CDT in EC (negativo: ≤1,3%, n=41; incerto: >1,3% e ≤1,6%, n=25; positivo: >1,6%, n=34) da soggetti alcolisti afferenti al Centro di Riferimento Alcologico della Regione Lazio (Roma, Policlinico Umberto I). Si intende infine considerare l’influenza del dosaggio della transferrina totale sul risultato della determinazione percentuale della CDT nel test N-Latex, sostituendo la misura della transferrina totale eseguita in nefelometria con quelle eseguite con metodo immunoturbidimetrico Siemens (TNRF, Flex® reagent cartridge, Dimension) e Roche/Hitachi (TRSF2, Tina-quant Transferrin, Cobas C). Gli intervalli di riferimento ottenuti come 95% unilaterale sinistro della distribuzione vanno per il metodo N-Latex dall’1,08% all’1,68%; per il metodo in EC dallo 0,3% all’1,0%. Utilizzando l’intervallo di riferimento Siemens (1,19%-2,47%), l’85,3% dei pazienti selezionati con CDT in EC >1,6% ha un valore N-Latex > 2,47% ed il 34,3% dei soggetti negativi ha valori di CDT in EC >1,3% e ≤1,6%. Utilizzando i nostri intervalli di riferimento, tutti i pazienti selezionati con CDT in EC >1,6% hanno un valore NLatex >1,69% ed il 34,3% dei pazienti positivi ha valori di CDT in EC >1,3% e ≤1,6%. Per il metodo N-Latex suggeriamo di riconsiderare l’intervallo di riferimento e di introdurre una fascia di risultati non conclusivi. Dai nostri dati i livelli di concordanza tra metodo SEBIA ed NLatex non cambiano utilizzando dosaggi alternativi della transferrina totale
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
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