1,721,031 research outputs found
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
Alport’s syndrome: HLA association and kidney graft outcome.
No full textAlport’s Syndrome (AS) is a genetic disease of type IV collagen involving nonhomogeneous patterns of inheritance characterized clinically by the association of progressive hematuric nephritis leading to end stage renal disease (ESRD), hearing loss and/or ophthalmologic abnormalities. Aim of this study was to
analyze in a cohort of AS patients (pts) undergoing kidney graft (KG) for ESRD: a) the presence of a possible correlation with HLA allele expression; b) the medium and long term outcome of KG. Among 899 first KG performed at our Center between January 1983 and December 2002, we have selected 24 KG (2.6%) with AS (19 males and 5 females with mean age at the time of
transplantation: 23±11.2 years). KG originated from a cadaver donor in 16 cases, from a living-related donor in 8 cases. All transplanted pts with AS had a follow-up period of at least 12 months after KG. Results showed that: i) the frequency of HLA-DRB1*16 allele was significantly increased in AS pts as
compared to healthy controls (31.8% vs 5.4%; p<0.05; relative risk:5.2); ii) patient and graft survivals in the AS group were respectively 94.4% and 88.2% at 5 years, 94.4% and 79% at 10 years, and were not different from those of a KG patient control group without AS matched for sex, age, number of HLA
mismatches, immunosuppressive regimen. Increased frequency of HLADRB1*16 allele in AS pts may be the expression of a linkage disequilibrium with genes coding for collagen synthesis such as COL11A2 or COL4A5-A3/A4 which are located inside and outside MHC region, respectively. Our data confirm that KG outcome is excellent in AS pts
Abdominal compartment syndrome in pediatric kidney transplantation.
No full textBackground: Transplantation of large kidney in small children can lead to many complications. One of these, often underrated, is abdominal compartment syndrome (ACS). An early diagnosis of ACS is recommended to prevent multi-organ failure.
Patient and Methods: From June 1985 to June 2007 we have performed 314 kidney transplants (KT) in pediatric patients (male/female: 167/147). Deceased donors were used in 289 procedures, while 25 KT were carried out from living related donors. In this cohort, the weight of 83 kidney recipients was less than
20 Kg. Of these patients, 16 received a large kidney.
Results: ACS occurred in 7 kidney recipients (hemodialysis/peritoneal dialysis: 5/2). All patients weighted less than 15 Kg. The kidney was procured from adult donors. The ACS signs included firm tense abdomen, hypotension, reduction in ventilation, decrease in lung compliance, increase in airways pressure (increase peak inspiratory pressure), impaired gas exchange with possible hypercarbia and acidosis. In one case a patient underwent abdominal decompression by re-exploration and closure with a PTFE mesh in the immediate
post-operative period. From 2005 we measured during transplantation the possible intra-abdominal hypertension via urinary bladder pressure.
Conclusions: In pediatric kidney recipients, especially for the condition “large kidney in small children”, the continuous measurement of urinary bladder pressure may be a simple, non invasive and inexpensive approach to provide an early detection of ACS
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
Impact of pretransplantation dialysis on early graft dysfunction in pediatric kidney recipients: Peritoneal dialysis versus hemodialysis.
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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
Correlation between angiotensin-converting enzyme gene insertion/deletion polymorphism and kidney graft long-term outcome in pediatric recipients: a single-center analysis.
No full textBACKGROUND: Despite numerous advances in the areas of organ preservation, histocompatibility, and immunosuppression, chronic deterioration of organ allograft function, referred to as "chronic rejection," still remains the main obstacle to long-term graft survival. The common feature of chronic rejection is a concentric generalized graft arteriosclerosis associated with interstitial fibrosis that reflects an allogeneic injury to graft arteries, possibly worsened by other alloantigen-independent risk factors. The presence of the angiotensin I-converting enzyme (ACE) gene-deleted (D) allele has been associated, when in homozygosity, with increased risk of cardiovascular diseases and with an accelerated progression of organ damage in a variety of kidney diseases. In this study, we analyzed whether the insertion/deletion polymorphism of the ACE gene, because of its negative prognostic impact on cardiovascular and renal pathology, could have any influence on kidney graft survival in pediatric recipients.
METHODS: DNA was isolated from peripheral blood mononuclear cells from 146 pediatric dialysis patients (mean age: 12.9 years) who received a first kidney graft at our center between December 1985 and July 1997. To rule out any bias due to acute graft losses, only 119 patients who reached a minimum of 12 months of graft survival were considered for statistical analysis. The insertion/deletion polymorphism of the ACE gene was detected using a polymerase chain reaction technique with two flanking primers. RESULTS: The results demonstrated that (i) the distribution of DD and non-DD (ID + II) genotypes was 36.1% (43 patients) and 63.8% (76 patients), respectively; (ii) actuarial graft survival at 7, 8, 9, and 10 years in patients with non-DD genotype was significantly higher than that in patients with DD genotype (7 years: 94.6% vs. 72.4%, P<0.05; 8 years: 94.6% vs. 62%, P<0.025; 9 years: 87.3% vs. 51.4%, P<0.025; 10 years: 76.3% vs. 25.7%, P<0.01). CONCLUSIONS: In conclusion, the above data indicate that DD genotype is associated in pediatric kidney graft recipients with a shorter long-term kidney graft survival and suggest a possible role of this genotype as a cofactor in the progression of nonimmunological injuries leading to chronic kidney graft failure
Prospective BK virus monitoring in pediatric kidney transplant recipients: Role of protocl/pre-emptive immunosuppression reduction on the course of infection.
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