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Tip 2 diabetes mellitusta nefropatik komplikasyon açısından sistatin C düzeyleri
No full textBu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.SUMMARY Diabetes mellitus, is one of the most prevalent metabolic disorder around the world. It is related with acute and chronic complications that affects the eyes, kidneys and blood vessels. These complications affect the patient's life adversely. Renal disease is a common microvascular complication of both type 1 and type 2 diabetes. Diabetic nephropathy is an important cause of morbidity and mortality. About 20-30% of patients develop diabetic nephropathy. Diabetic patient care have the priority of screening early signs of microvascular complications. Measurements should be made to prevent progression to overt complication. For this reason, screening microalbuminuria regularly should be a part of diabetic preventive care. Apart from microalbuminuria, renal function should also be checked regularly in patients with diabetes. To detect early deterioration of renal function, mesurement or estimation of creatinine clearance is more reliable. In the last years, for the determination of glomerular filtration rate, researches have been done on new endogen filtration markers, low molecular proteins intensively. As a consequence, the blood level of some small proteins, such as lysozyme, alpha-1 microglobulin, beta-2 microglobulin and cystatin C have been proposed as indices of renal function. Especially, cystatin C for the advantages of being produced by all nucleated cells at a constant rate, independent of sex and muscle mass and removed from circulating blood by glomerular filtration, intensively studied in the last few years. In our study, we aimed to evaluate the clinical efficiency of cystatin C and whether it can be used instead of endogen creatinine clearance. Our study included randomly selected 71 men (mean age±SD, 58.7±6.7) and 71 women (mean age±SD, 58.1 ± 9.2) of totally 142 type 2 diabetic patients. 81Control group consisted of 14 men (mean age±SD, 59.2 + 8.1), 18 women (mean age±SD, 56.1 ± 10.5) who were free of clinical complaints and signs and accepted as healthy. Serum cystatin C, serum glucose, blood urea nitrogen, serum and urine creatinine, serum total cholesterol, serum triglyceride, serum HDL-cholesterol, urine albumin, whole blood HbAic measurements were performed on "Synchron LX20" chemistry analyzer; beta-2 microglobulin measurement were on "Immulite One" immunoanalyzer. LDL-cholesterol, endogen creatinine clearance and estimated creatinine clearance by Cockroft Gault formula were calculated. Diabetic patient group was classified by 3 distinct ways; according to HbAic numbers (good and bad glycemic controlled); albumin excretion rates (normoalbuminuric,) and creatinine clearance measurements (£90 mL/min, 60-90 mL/min, 30-60 mL/min, 30 mL/min). No significant correlation was found between the means of cystatin C (p=0.148) and beta-2 microglobulin (p=0.073) among control group and HbAic groups (good and bad glycemic controlled). There was a significant difference between means of control group, normoalbuminuric group, inicroalbuminuric group and macroalbuminuric group cystatin C, creatinine and beta-2 microglobulin concentrations at p=0.000 level. At the whole study group, among the creatinine clearance and cystatin C, beta-2 microglobulin and creatinine, a significant, negative and good correlation was detected (r=-0.671, p=0.000; r=-0.589, p=0.000 ve r=-0.587, p = 0.000 respectively). 82On the ROC curves drawn at two different levels of creatinine clearance for determination of analytical performance of cystatin C, beta-2 microglobulin and creatinine analytes for type 2 diabetes, the areas under curves and standard errors were 0.934±0.28 and 0.861±0.37 for cystatin C, 0.891±0.34 and 0.818±0.38 for CTeatinine, 0.893±0.36 and 0.814±0.39 for beta-2 microglobulin. No statistically significant difference were found between areas under curves (p>0.05). At the whole group, among the creatinine clearance and estimated creatinine clearance a significant, positive, well correlation at r=0.864 level were found. Groups arranged according to creatinine clearance levels, cystatin C, beta-2 microglobulin and creatinine means were different at p=0.000 level. As the creatinine clearance levels decreased, cystatin C, beta-2 microglobulin and creatinine concentrations increased. As a consequence, our study shows that serum cystatin C was not superior to creatinine for detecting early renal failure in type 2 diabetic patients. For evaluation of glomerular filtration rate in diabetic patients, serum creatinine and endogen creatinine clearance measurements might have continued. Laboratories can give estimated creatinine clearance results beside serum creatinine results. 83Diabetes Mellitus töm dünyada görülen en yaygın metabolik hastalıklardan biridir. Akut olan ve gözleri, böbrekleri, sinirleri ve kan damarlarını içeren kronik geç komplikasyonlarla ilişkilidir. Bu komplikasyonlar hastanın yaşam kalitesini olumsuz etkilemektedir. Renal hastalık, tip 1 ve tip 2 diyabetin yaygın mikrovasküler komplikasyonudur. Diyabetik nefropati, önemli bir mortalite ve morbidite nedenidir. Diyabetli hastalarm yaklaşık %20-30'unda diyabetik nefropati gelişir. Diyabetli hastalarm bakımında, mikrovasküler hastalarm erken bulgularının taranması önceliklidir. Açık komplikasyonlara ilerlemeyi önlemek adına ölçümler yapılmalıdır. Bu sebepten dolayı mikroalbüminüriyi düzenli olarak taramak, rutin diyabetik önleyici bakımın bir parçası haline gelmelidir. Diyabetli hastalarda mikroalbüminüri dışmda da renal fonksiyonlar izlenmelidir. Renal fonksiyondaki erken bozulmayı göstermede GFR ölçütü olarak, kreatinin klirensinin ölçümü veya hesaplanması renal fonksiyonu göstermede daha güvenilirdir. Son yıllarda GFR'nin belirlenmesi için yeni endojen filtrasyon belirteçleri olan düşük molekül ağırlıklı proteinler üzerinde araştırmalar yoğun olarak yapılmaktadır. Sonuç olarak lizozim, aı mikroglobulin, P2 mikroglobulin ve sistatin C gibi bazı küçük proteinlerin kan düzeyleri renal fonksiyonun indeksi olarak sunulmuştur, özellikle sistatin C, vücuttaki tüm hücrelerde sabit hızda üretilmesi, cinsiyetten ve kas kütlesinden bağımsız olması ve kandan glomerüler filtrasyon yoluyla uzaklaştırılması gibi avantajları nedeniyle son yıllarda yoğun olarak araştalmaktadır. Çalışmamızda, tip 2 diyabetli hastalarm nefropati komplikasyonu açısından sistatin C'nin klinik etkinliğinin ve endojen kreatinin klkensinin yerine kullanılıp kullanılamayacağının değerlendirilmesi amaçlandı. 78Çalışmamıza, rastgele seçilmiş 71 erkek (ortalama yaş±SD, 58.7+6.7), 71 kadm (ortalama yaş±SD, 58.1 ± 9.2) olmak üzere toplam 142 tip 2 diyabet hastası katıldı. Kontrol grubu klinik şikayet ve bulgusu olmayan, sağlıklı kabul edilen 14 erkek (ortalama yaş±SD, 59.2 ±8.1), 18 kadm (ortalama yaş±SD, 56.1 ± 10.5) bireyden oluşturuldu. Serum sistatin C, glukoz, BUN, kreatinin, total kolesterol, trigliserit, HDL- kolesterol, HbAıc ölçümleri "Synchron LX20" kimya analizöründe; pV mikroglobulin, ölçümü "Immulite One" immünölçüm analizöründe yapıldı. LDL, kreatinin klirensi ve Cockroft-Gault formülü ile kreatinin klirensi hesaplandı. Diyabetli hasta grubu, HbAıc yüzdelerine göre (iyi glisemik kontrollü, kötü glisemik kontrollü), albumin atılım düzeylerine göre (normoalbuminürk, mikroalbuminürik, makroalbuminürik) ve kreatinin klirensi ölçümlerine göre (£90 mL/dk, 60-90 mLdk, 30-60 mL/dk, 30 mL/dk) 3 farklı şekilde gruplandınldı. Kontrol grubu ve HbAıc gruplanmn (iyi ve kötü glisemik kontrollü grup) sistatin C ve beta-2 mikroglobulin ortalamaları arasında ise istatistiksel olarak anlamlı fark saptanmadı (sırasıyla p=0.148, p=0.073). Kontrol grubu, normoalbüminürik grup, mikroalbuminürik grup ve makroalbuminürik grup sistatin C, kreatinin ve beta-2 mikroglobulin ortalamaları arasında p=0.000 düzeyinde anlamlı fark vardı. Tüm çalışma grubunda kreatinin klirensi ile sistatin C, beta-2 mikroglobulin ve kreatinin arasında negatif yönde, güçlü derecede ve istatistiksel olarak ileri düzeyde anlamlı bir ilişki saptandı (sırası ile r=-0.671, p=0.000; r=-0.589, pH).00Q ve r=-0.587, p = 0.000). Tip 2 diyabetli bireylerde, kreatinin, sistatin C ve beta-2 mikroglobulin analitierinin performanslarının belirlenmesi için çizilen ROC eğrilerinde; sistatin C için eğrinin altında kalan alanlar ve standart hatalar (SE) sırasıyla 0.934±0.28 79ve 0.861±0.37, kreatinin için 0.891±0.34 ve 0.818±0.38, beta-2 mikroglobulin için 0.893±0.36 ve 0.814±0.39'dur. Eğri altında kalan alanlar arasında istatistiksel olarak anlamlı fark bulunmadı (p>0.05). Kreatinin klirensi ile hesaplamalı kreatinin klirensi arasında tüm grupta pozitif yönde r=0.864 düzeyinde ve istatistiksel olarak ileri derecede anlamlı bir ilişki saptandı (p=0.000). Kreatinin klirenslerine göre düzenlenen grupların sistatin C, beta-2 mikroglobulin ve kreatinin ortalamalarının tümü p=0.000 düzeyinde farklı bulundu. Kreatinin klirensi düştükçe, kreatinin, sistatin C ve beta-2 mikroglobulin konsantrasyonları artmaktadır. Sonuç olarak bizim çalışmamız serum sistatin C'nin tip 2 diyabetli hastalarda, erken renal yetmezliği saptamada kreatinine göre üstün olmadığım göstermektedir. Diyabetli hastaların GFR değerlendirmesinde, serum kreatinin ve endojen kreatinin klirensi ölçümüne devam edilmesi kanısına vardık. Laboratuvarlar serum kreatinin sonuçlarının yarımda hesaplamalı kreatinin klirensi sonucunu verebilir. 8
Tip 2 diyabetik hastalarda mikroRNA’lar
No full textÇok sayıda dokudan salgılanarak çok sayıda doku ve hücrede etki gösteren mikroribonükleik asitler (mikroRNA/miRNA/miR-) kalp, karaciğer, beyin ve böbrek gibi organlardaki bozukluk ve hastalıklarda, endotel hasarı ve fibrozis başta olmak üzere çeşitli olayların gelişmesinde veya engellenmesinde rol oynamaktadır. Önemli bir halk sağlığı sorunu olan diyabetik nefropatinin (DN) tanı ve takibinde kullanılan mikroalbuminüri ancak renal hasar geliştikten sonra pozitif sonuç vermektedir. miRNA?ların renal hasarın erken tanısında yararlı olabileceği öngörülmektedir. Çalışmamızda, diyabetle ilişkili olduğu saptanan, insanda araştırılmış olan “miRNA-21-3p, miRNA-29a-3p, miRNA-29b-3p, miRNA-29c-3p, miRNA-126-3p, miRNA-192-5p, miRNA-320c” ve farelerde araştırılan “miRNA-129-1-3p, miRNA-137, miRNA-212-3p” olmak üzere 10 miRNA?yı değerlendirmeyi amaçladık. Çalışma grubu, 50 sağlıklı kontrol (erkek: n=24; yaş: 55±11; kadın: n=26; yaş: 54±13) ve 100 tip 2 diyabetik hastadan (erkek: n= 46; yaş: 60±11; kadın: n=54; yaş: 56±11)] oluşturuldu. Diyabetik hastalar 51?i normoalbuminürik (NAlb), 25?i mikroalbuminürik (MikAlb) ve 24?ü makroalbuminürik (MakAlb) olmak üzere alt gruplara ayrıldı. Diyabetik grup (T2DM), 51 NAlb ve 49 diyabetik nefropatili (DN) hastayı kapsadı. Tüm bireylerin plazmalarında RT-PCR yöntemi ile miRNA?lar analiz edildi. Serumda açlık glukozu, total kolesterol, trigliseritler, LDL-kolesterol, HDL-kolesterol, sistatin C, kreatinin, albumin; tam kanda HbA1c ve 24 saatlik idrarda mikroalbumin ve kreatinin düzeyleri ölçüldü. 24 saatlik idrar toplanarak kreatinin klirensi hesaplandı. Serum kreatinin ve serum sistatin C düzeylerine göre glomerüler filtrasyon hızları hesaplandı (eGFR). Her miRNA?nın ekspresyonu tüm diyabetik grupların kendi arasında ve kontrol grubuyla karşılaştırıldı ve ekspresyonların biyokimyasal ölçüm sonuçlarıyla korelasyonları değerlendirildi. İnsanlarda araştırılmış olan ilk 7 miRNA?dan yalnız miRNA-21 çalışma grubu bireylerinin yarısında, diğerleri tüm bireylerde saptandı. Farelerde araştırılmış olan miRNA-129-1-3p ve miRNA-137 çalışma gruplarının az bir kısmında saptandı ve yeterli sayıda olmadığı için değerlendirilmedi. miRNA-212 ise tüm bireylerin yaklaşık yarısında saptanabildi. Tüm grupların yaklaşık yarısında saptanan, miRNA-21?de gözlenen azalmalar diyabetik, DN ve MakAlb grupta kontrollere göre istatistiksel olarak anlamlı bulundu (T2DM: 5 kat, p=0,004; DN: 7, p=0,005; NAlb: 4, p=0,519 ve MikAlb: 5, p=0,559; MakAlb: 7, p=0,005). Tüm gruplardaki tüm bireylerde saptanan miRNA?lardan biri olan miRNA-192?de diyabetik hastaların tümünde 2 kat (p=0,029), DN grubunda 2,4 kat (p=0,027) azalma istatiksel olarak anlamlı bulundu. NAlb grubundaki 1,5 kat azalma ise anlamlı bulunmadı. miRNA-29 ailesinde, -b?de kontrollere göre MikAlb?de azalma ve diğer gruplarında artma gözlendi. 1 kat olarak gözlenen bu farklılıklar istatistiksel olarak anlamlı bulunmadı. –a ve -c?de MikAlb gruptaki azalmalar istatistiksel olarak anlamlı bulunmadı (sırasıyla, 2,5 ve 3 kat). miRNA-126?da, tüm gruplardaki farklılıklar kontrollere göre istatistiksel olarak anlamlı bulunmadı (T2DM: 1; NAlb: 1 kat artma; DN: 1,5, MikAlb: 1; MakAlb: 1,5 kat azalma). miRNA-320c?de, gruplarda kontrollere göre gözlenen azalmalar istatistiksel olarak anlamlı bulunmadı (T2DM: 2; DN: 2; NAlb: 2; MikAlb: 2, MakAlb: 1,5 kat). miRNA-212?de, tüm gruplarda kontrollere göre gözlenen farklılıklar istatistiksel olarak anlamlı bulunmadı (NAlb: 1; T2DM: 2 kata yakın artma; DN: 3; MikAlb: 5; MakAlb: 2 kat azalma). Renal fonksiyon belirteçleriyle korelasyonlar incelendiğinde, sistatin C?ye göre eGFR ile miRNA-21, miRNA-192 ve miRNA-126 pozitif ilişki gösterdi (sırasıyla, r=0,262, p=0,018; r=0,203, p=0,013 ve r=0,417, p=0,034). MDRD eGFR ile miRNA-21 ve miRNA-29c anlamlı korelasyon gösterdi (sırasıyla, r=0,243, p=0,029 ve r=0,188, p=0,021) CKD-EPI-Kreatinin ile yalnız miRNA-192?nin ilişkisi anlamlı bulundu (r=0,185, p=0,023). GFR değerleri ile miRNA-29a, –b ve miRNA-212 anlamlı korelasyon göstermedi. Mikroalbuminüri ile miRNA-21, miRNA-192, miRNA-29c ve miRNA-320 anlamlı negatif ilişki gösterdi (sırasıyla, r=-0,323, p=0,003; r=-0,267, p=0,001; r=-0,173, p=0,034 ve r=-0,172, p=0,032). HbA1c ile miRNA-21 anlamlı negatif ilişki gösterdi (r=-0,274, p=0,013). miRNA-21 ve miRNA-192?nin plazma düzeyleri DN?yi sağlıklı kişilerden ayırmadaki tanısal performansları istatistiksel olarak anlamlı bulundu (sırasıyla, AUC=0,726, p=0,0001 ve AUC=0,717, p=0,0001). miRNA-21 için gruplardaki saptanma oranları düşük olmakla birlikte, GFR ve mikroalbuminüri ile ilişkileri dikkate alındığında, bulgularımız miRNA-21 ve miRNA-192?nin diyabetik nefropatiyle ilişkili miRNA?lardan olduğunu desteklemektedir. Azalmalar istatistiksel olarak anlamlı bulunmasa da miRNA-29c DN tanısı açısından yararlı olabilir. miRNA-29c, miRNA-29b, miRNA-126, miRNA-212 ve miRNA-320c?nin DN ile ilişkilerinin belirlenmesi açısından daha çok araştırma gereklidir. miRNA-29a?nın ise DN ile ilişkisi desteklenmemektedir. Posttranskripsiyonel etkili mikroRNA?ların, ilaç keşfi için biyobelirteç olarak terapötik amaçlı kullanılma durumlarına odaklanan araştırmaların yanı sıra plazma ve idrarda tanısal amaçlı da kullanılabilmeleri için daha çok sayıda araştırmaya ihtiyaç vardırMicroribonucleic acids (microRNA/miRNA/miR-) are produced by cells of many tissues, and impact on the cells of many tissues. They have different roles in the development or prevention of various events, especially endothelial damage and fibrosis, and in disorders and diseases of organs such as the heart, liver, brain and kidney. Microalbuminuria, used in the diagnosis and follow-up of diabetic nephropathy (DN) which is an important public health issue, gives positive results only after renal damage develops. miRNAs are predicted to be useful in the early diagnosis of renal damage. In our study, we aimed to evaluate 10 miRNAs which were found to be related to diabetes in human (miRNA-21a-3p, miRNA-29a-3p, miRNA-29b-3p, miRNA-29c-3p, miRNA-126-3p, miRNA-192-5p and miRNA-320c), and in animal studies (miRNA-129-1-3p; miRNA-137, miRNA-212-3p.) The study group was composed of 50 healthy controls (male: n=24; age: 55±11; women: n=26; age: 54±13) and 100 type 2 diabetic patients (male: n=46; age: 60 ± 11; female: n=54; age: 56±11). Diabetic patients were divided into three subgroups as normoalbuminuric (NAlb) (n=51), microalbuminuric (MicAlb) (n=25) and macroalbuminuric (MacAlb) (n=24) according to the urinary abumin levels. The diabetic group (T2DM) included 51 patients with NAlb and 49 patients with diabetic nephropathy (DN). Plasma miRNAs were analyzed by RT-PCR method. Serum fasting glucose, total cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, cystatin C, creatinine, albumin; HbA1c, urinary albumin and creatinine in 24-hour urine were measured. Creatinine clearance was determined by collecting 24-hour urine. The glomerular filtration rates (eGFR) were estimated according to serum creatinine and serum cystatin C levels. The expression of each miRNA was compared between all diabetic groups and the control group, and the correlations of the expressions with the biochemical measurement results were evaluated. Only miRNA-21 from the first 7 miRNAs investigated in humans were detected in half of the study group, others were detected in all individuals. miRNA-129-1-3p and miRNA-137 studied in mouse were detected in a small number of the individuals, and were not evaluated because of lack of sufficient numbers. miRNA-212 could be detected in approximately half of all individuals. The expressions of miRNA-21 which were detected in approximately half of all groups showed statistically significant decreases in the diabetic, DN and MacAlb groups than those in the controls (T2DM: 5-fold, p=0,004; DN: 7, p=0,005; NAlb: 4, p=0,519; MicAlb: 5, p=0,559; MacAlb: 7, p=0,005). The decrease in the expression of miRNA-192, one of the miRNAs detected in all groups, was statistically significant in all diabetic patients (2-fold, p=0,029) and in the DN group (2,4-fold, p=0,027). A 1,5-fold decrease in NAlb group was not statistically significant. In the miRNA-29 family, -b decreased in the MicAlb and increased in the other groups compared with the controls. These differences were approximately one fold and were not statistically significant. The decreases in -a and -c in the MicAlb group were not statistically significant (2,5 and 3-fold, respectively). The differences of the expressions of miRNA-126 in all groups were not statistically significant (T2DM: 1; NAlb: 1-fold increase; DN: 1,5, MicAlb: 1; MacAlb: 1,5-fold decrease). The decreases in miRNA-320c compared with the controls were not statistically significant. (T2DM: 2; DN: 2; NAlb: 2; MicAlb: 2; MacAlb: 1,5-fold). The differences in miRNA-212 expressions that observed in all groups were not statistically significant when compared with the controls ( 1-fold in NAlb, and approximately 2-fold increase in T2DM; DN: 3; MicAlb: 5; MacAlb: 2-fold decreases). Correlations of expressions with renal function markers examined. The eGFR based on cys C showed a positive correlation with miRNA-21, miRNA-192 and miRNA-126 (r=0,262, p=0,018; r=0,203, p=0,013 and r=0,417, p=0,034, respectively). miRNA-21 and miRNA-29c were significantly correlated with MDRD eGFR (r=0,243, p=0,029 and r=0,188, p=0,021, respectively).The correlation of CKD-EPI-creatinine with miRNA-192 was significant (r=0,185, p=0,023). miRNA-29a, –b and miRNA-212 did not show significant correlation with eGFR values. miRNA-21, miRNA-192, miRNA-29c and miRNA-320 were significantly negatively correlated with microalbuminuria (r=-0,323, p=0,003; r=-0,267, p=0,001; r=-0,173, p=0,034 and r=-0,172, p=0,032, respectively). HbA1c and miRNA-21 showed significant negative correlations (r= -0,274, p=0,013). Plasma levels of miRNA-21 and miRNA-192 were found to be statistically significant in distinguishing the DN from healthy subjects (AUC=0,726, p=0,0001 and AUC=0,717, p=0,0001, respectively). Although we couldn?t determined the expressions of miRNA in the whole group, our results supporrted that miRNA-21 and miRNA-192 could be related to diabetic nephropathy with respect to their correlations with the GFR and microalbuminuria. Our results for the expression of miRNA-29c can be helpful for monitoring the diabetes complications for DN, show that more research could be performed for prediction of DN. More research is needed to determine the association of miRNA-29c, miRNA-29b, miRNA-126, miRNA-212 and miRNA-320c with DN. The association of miRNA-29a with DN was not supported in our study
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
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
Charts of operational process specifications (OPSpecs charts): Quality-planning tools for analytical and medical needs
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Use of total patient data for indirect estimation of reference intervals for 40 clinical chemical analytes in Turkey
No full textIn the present study we used patient data to calculate laboratory-specific indirect reference intervals. These values were compared with reference intervals obtained for a healthy group according to recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine and manufacturer suggestions. Laboratory results ( 422,919 records) from all subjects of 18-45 years of age over a 1-year period were retrieved from our laboratory information system and indirect reference intervals for 40 common analytes were estimated using a modified Bhattacharya procedure. Indirect reference intervals for most of the biochemical analytes were comparable, with small differences in lower [alkaline phosphatase (ALP) ( male), alanine aminotransferase ( ALT), creatine kinase, iron ( male), total iron-binding capacity, folic acid, calcium ( female), lactate dehydrogenase (LDH), lipoprotein ( a) [Lp(a)], thyroid-stimulating hormone (TSH), total triiodothyronine ( T-3), direct bilirubin, apolipoprotein A-I ( apoA-I), glucose, homocysteine, total cholesterol, ferritin, total protein, ceruloplasmin, sodium, blood urea nitrogen (BUN) and uric acid ( female)] and/or upper limits [albumin, ALP ( male), amylase, apoA-I, creatine kinase-MB (CK-MB), total iron-binding capacity, phosphorus, glucose, total cholesterol, g-glutamyltransferase (g-GT), magnesium, total protein, high-density lipoprotein cholesterol (HDL-C), total T-3, ALP ( male), ALT, aspartate aminotransferase (AST) ( male), direct bilirubin ( male), creatine kinase, iron, folic acid ( female), Lp( a), uric acid and triglycerides], to the reference intervals determined for healthy subjects in our laboratory. The indirect reference intervals, with the exception of a few parameters ( creatinine, direct total bilirubin, calcium, BUN and potassium), were not similar to the reference intervals suggested by the manufacturers. We conclude that laboratory-specific reference intervals can be determined from stored data with a relatively easy and inexpensive method. Indirect reference intervals derived from stored data may be particularly suitable for the evaluation of results for the presenting population
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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