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Značaj solubilnog transferiskog receptora u laboratorijskoj dijagnostici statusa gvožđa u organizmu
No full textThe distinction between iron-deficiency anemia and anemia that accompanies infection, nflammation, or malignancy is not clear; the commonly used laboratory tests do not necessary distinguish these common causes of anemia. As such, serum ferritin is a excellent indicator of the size of storage compartment, but has marked limitations in inflammation as acute phase reactant. The transferrin receptor protein has two identical polypeptide chains, 95 kDa each, and is present on the surfaces of body cells. Soluble transferrin receptor (sTfR) has been identified in human serum and plasma and it reflects compartment of functional iron and reliable index of iron depletion. Combination of ferritin and sTFR in a ratio gives sensitive index of iron status. The mean ratio has values lt 100 in the presence of adequate stores to over 2000 at the significant functional depletion. The ratio also appears to be of major value in the differentiation of iron-deficiency anemia from the anemia of chronic disease, having diagnostic accuracy of 92 %. Use of sTfR will substitute the need for bone-marrow examination.Konvencionalnim laboratorijskim testovima često se ne može diferencirati anemija izazvana nedostatkom gvožđa od anemije udružene sa infekcijom inflamacijom i malignitetom. Serumski feritin je odličan pokazatelj rezerve gvožđa u organizmu ali kao reaktant akutne faze otežava interpretaciju rezultata.Transferinski receptor je protein sastavljen od dva polipeptidna lanca MM 95 kDa, koji se nalazi na površini svih ćelija. Solubilni transferinski receptor (sTfR) nađen u serumu odražava stanje funkcionalnog kompartmana gvožđa u organizmu. Kombinacijom feritina i sTFR moguće je dobiti osetljiv indeks za procenu statusa gvožđa u organizmu. Srednja vrednost indeksa sTfR/feritin iznosi lt 100 u slučaju adekvatne rezerve gvožđa do preko 2000 kada postoji značajan utrošak funkcionalnog gvožđa. Indeks sTfR/feritin može biti najvažniji parametar u diferencijaciji anemije izazvane nedostatkom gvožđa, od anemije u hroničnim bolestima, sa dijagnostičkom tačnošću 92%. Određivanje solubilnog transferinskog receptora kao laboratorijskog testa u proceni statusa gvožđa u organizmu smanjilo bi potrebu ispitivanja kostne srži
Praktični aspekti u određivanju antikoagulantnog dejstva direktnih oralnih antikoagulantnih lekova
Full text linkThe classical oral anticoagulants are increasingly being replaced in clinical practice by new antithrombotic drugs, which act by enabling direct inhibition of coagulation factor IIa (FIIa) or factor Xa (FXa). These drugs have multiple acronyms, including NOACs (new, non–vitamin K antagonist) or DOACs (direct oral anticoagulants), and currently include dabigatran (FIIa inhibitor), and rivaroxaban, apixaban, and edoxaban (FXa inhibitors). These drugs are approved for stroke prevention in patients with non-valvular atrial fibrillation and the prevention and treatment of venous thromboembolism. The "mantra" that DOACs do not require laboratory monitoring is not entirely correct because laboratory testing for drug effects is needed in many situations, because they influence hemostasis tests and in situations in which urgent measurement of DOACs is required. This should be very important to consider in the clinical situation for numbers of indications and increasing numbers of patients on DOACs therapy. The main aim of this article is to provide practical issues to general laboratory testing for DOACs, as well as to help avoid diagnostic errors associated with hemostasis testing. The assays for DOAC quantification must be available in medical centers on a whole day basis, to facilitate optimal drug management in conditions when things go wrong or in urgent cases of immediate reversal of anticoagulation or appropriate administration of a specific antidote.Nova generacija oralnih antikoagulantnih lekova omogućava direktnu inhibiciju FIIa ili FXa, i sve više zamenjuje klasične antikoagulanse u kliničkoj praksi za različita stanja. Ovi lekovi su označeni sa nekoliko akronima, uključujući NOAC, DOAC, i odnose se na nove (ne-vitamin K antagoniste) i direktne oralne antikoagulanse, a trenutno uključuju dabigatran (FIIa inhibitor), i rivaroksaban, apiksaban i edoksaban (FXa inhibitori) . Direktni oralni antikoagulantni lekovi odobreni su za prevenciju moždanog udara kod pacijenata sa ne-valvularnom atrijalnom fibrilacijom i za prevenciju i lečenje venskog tromboembolizma. "Mantra" da direktni oralni antikoagulantni lekovi ne zahtevaju laboratorijsko praćenje ne može se prihvatiti u mnogim kliničkim situacijama. Štaviše, pošto ovi lekovi "ne zahtevaju" laboratorijsko praćenje, neki kliničari su to prihvatili kao da ne utiču na testove u hemostazi. Postoji više situacija u kojima je potrebno rutinsko i hitno određivanje DOAC-a, pri čemu će se broj laboratorijskih zahteva povećavati u budućnosti jer sve više zamenjuju konvencionalne antikoagulanse za sve veći broj indikacija, kod sve većeg broja pacijenata. Glavni cilj ovog rada je da odgovori na praktična pitanja u opštem laboratorijskom ispitivanju DOAC-a, kao i da pomogne u uklanjanju i smanjenju dijagnostičkih grešaka povezanih sa ispitivanjem hemostaze. Testovi za kvantifikaciju DOAC-a moraju biti dostupni u medicinskim centrima 24 sata, kako bi se olakšalo optimalno lečenje u uslovima kada stvari pođu po zlu ili u hitnim slučajevima trenutnog ukidanja antikoagulantne terapije ili odgovarajuće primene specifičnog antidota
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
Anti-VIP/gp120 antibodies in athletes, cancer patients and patients with HIV infection
No full textVazoaktivni intestinalni peptid (VIP) ima brojne biološke uloge u organizmu,
deluje kao imunomodulator, vazodilatator, bronhodilatator, neurotransmiter i
regulator genske ekspresije. VIP takoĎe ima vaţnu ulogu u kancerogenezi
malignih oboljenja, jer deluje kao faktor rasta za ćelije karcinoma dojke i
prostate, koje na svojoj površini eksprimiraju veliki broj VPAC1 receptora.
Obzirom na učešće VIP-a u brojnim biohemijskim procesima u organizmu,
njegov nivo u u cirkulaciji je pod strogom fiziološkom kontrolom, koja se
ostvarje posredstvom prirodnih anti-VIP autoantitela.
Ustanovljeno je da pacijenti inficirani HIV-om imaju povišen nivo
neutrališućih anti-VIP/gp120 antitela u asimptomatskoj fazi bolesti. Anti-
VIP/gp120 antitela usporavaju progresiju sindroma stečene imunodeficijencije
(SIDE) i predstavljaju poslednju liniju odbrane organizma u HIV infekciji. NTM
peptid iz konzerviranog C2 domena glikoproteina gp120 HIV virusa sadrţi
epitop koji vezuje anti-VIP/gp120 antitela i ima visok stepen strukturne i
informacione sličnosti sa VIP-om. NTM sadrţi aminokiselinski motiv FTD (Phe-
Thr-Asp), koji je uključen u direktnu interakciju VIP-a sa VPAC1 receptorima.
Ovaj domen glikoproteina gp120 ima strukturnu sličnost i sa drugim humanim
proteinima uključujući i imunoglobuline, zbog čega ga imuni sistem prepoznaje
kao sopstveni antigen. Molekularna mimikrija izmeĎu glikoproteina gp120 i
ljudskih proteina osnovna je prepreka u dizajniranju vakcine, koja bi omogućila
povećanu produkciju anti-VIP/gp120 antitela. Fizička aktivnost povećava nivo
VIP-a u cirkulaciji, što za posledicu ima i porast anti-VIP/gp120 antitela i
predstavlja jedini stimulans za produkciju ovih prirodnih autoantitela.
Populacione i kliničke studije potvrdile su pozitivne efekte, koje fizička
aktivnost ima u prevenciji nastanka tumora dojke i prostate, ali i u sprečavanju
pojave recidiva u fazi remisije bolesti. Molekularni mehanizmi na kojima se
zasniva protektivno delovanje fizičke aktivnosti još uvek su nepoznati. Polazeći od činjenice da profesionalni sportisti i osobe inficirane HIV-om, kod kojih je
nivo anti-VIP/gp120 antitela povišen, imaju smanjen rizik od nastanka
karcinoma dojke i prostate u poreĎenju sa opštom populacijom, moţe se
pretpostaviti da ova antitela igraju značajnu ulogu u prevenciji ovih bolesti...VIP is pleiotropic peptide exerting a wide range of biological activities,
such as pulmonary and coronary vasodilatation, bronchodilation, antiinflammatory
effects, immunomodulatory effects and regulation of gene
expression. Also, VIP plays an important role in pathogenesis of breast and
prostate cancer acting as an autocrine growth factor which up regulates the
expression of vascular endothelial cell growth factor in cancer cells, carrying a
large number of VPAC1 receptors on the cell surface. Involvement of VIP in
numerous biochemical processes in the organism requires strong control of its
level in the circulation, which is performed by natural anti-VIP antibodies.
Therefore, it is reasonable to expect that the natural autoantibodies controlling
VIP have an important protective role against breast and prostate cancer.
Increased level of neutralizing anti-VIP/gp120 antibodies has been
documented in HIV patients in its asymptomatic phase of disease. The studies
indicate that anti-VIP/gp120 antibodies slow down AIDS progression and
represent the last line of defense against the disease progression. The anti-
VIP/gp120 antibodies bind to NTM peptide from the conserved C2 domain of
the HIV glycoprotein gp120. The NTM peptide has high level of structural and
informational similarities with VIP and encompasses the structural motif FTD
(Phe-Thr-Asp), which is involved in direct interaction between VIP and VPAC1
receptor. Due to structural similarity between the C2 domain of the glycoprotein
gp120 and other human proteins, including immunoglobulins, the immune
system recognizes it as a self antigen. As a result of this molecular mimicry
between the gp120 and host proteins, anti-VIP/gp120 antibodies cannot be
induced with vaccination. The physical activity elicits anti-VIP/gp120 antibodies
by increasing the level of VIP in circulation and therefore, represents the unique
stimulus for production of these natural autoantibodies.
Epidemiological and clinical studies confirmed positive effects of physical
activity in prevention of breast and prostate cancer. Molecular mechanisms
involved in protective role of physical activity are still elusive. Nevertheless, the fact that professional athletes and HIV-infected patients with increased level of
anti-VIP/gp120 antibodies have lower incidence of breast and prostate cancer
comparing to general population, indicates that these antibodies have
significant role in prevention of these diseases..
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
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
The significance of biochemical markers and morphometric characteristics of leucocytes in laboratory diagnosis of subclinical cobalamin deficiency
No full textSubklinički deficit vitamina B12 (engl. Subclinical Cobalamin Deficiency,
SCCD) podrazumeva da je koncentracija jednog ili više biomarkera statusa vitamina
B12 izvan granica referentnog opsega u odsustvu kliničkih manifestacija deficita. Do
sada se mali broj studija bavio ovim oblikom nedostatka kobalamina kod starijih
pacijenata sa rizikom za deficit vitamina B12, a koji nemaju kliničku sliku deficita.
Otkrivanje ranih promena u statusu vitamina B12 značajno je za ovu populaciju, jer se
neurološki simptomi deficita mogu javiti u odsustvu hematoloških simptoma i mogu biti
ireverzibilni, ukoliko se terapija ne primeni na vreme. Kako se SCCD potvrđuje
isključivo na osnovu laboratorijskog testiranja statusa vitamina B12, značajno je
analizirati odnos rutinskih i novih biomarkera (metilmalonske kiseline (MMA) i
morfometrijskih parametara leukocita) u populaciji sa rizikom za pojavu deficita
kobalamina.
CILJEVI: Cilj studije jeste ispitivanje značaja biohemijskih markera i morfometrijskih
karakteristika leukocita u laboratorijskoj dijagnostici subkliničkog deficita vitamina
B12 u odsustvu kliničkih simptoma. Takođe, cilj rada je i utvrđivanje povezanosti
metilmalonske kiseline sa postojećim parametrima za ispitivanje statusa vitamina B12 i
morfometrijskim parametrima neutrofila i monocita, dobijenih na Coulter® LH750
hematološkom analizatoru, kao potencijalno ranih markera promena u statusu vitamina
B12.
MATERIJALI I METODE: Studija je obuhvatila 590 pacijenata sa rizikom za deficit
kobalamina, kao i 148 zdravih dobrovoljaca. Pacijenti sa rizikom za deficit kobalamina
bili su stariji od 60 godina i/ili osobe sa gastrointestinalnim smetnjama i simptomima.
Za potrebe studije urađene su sledeće analize: krvna slika sa morfometrijskim
parametrima leukocita, kobalamin, folat, folat u eritrocitima, antitela protiv unutrašnjeg
faktora, homocistein (Hcy), serumsko gvožđe, solubilni transferinski receptori, feritin,
transferin, ukupni kapacitet vezivanja gvožđa, saturacija transferina gvožđem,
haptoglobin, laktat dehidrogenaza, kreatinin, procenjena brzina glomerularne filtracije...In the absence of clinical manifestations, concentration of one or
more biomarkers of vitamin B12 status out of reference range is considered as
subclinical cobalamin deficiency (SCCD). So far, the small number of studies have
explored SCCD in elderly patients at risk of vitamin B12 deficiency, but without
clinical picture. The recognition of early changes in cobalamin status is important for
this population because neurological symptoms of deficiency can be present without
hematological manifestations. Also, neurological symptoms of deficiency can be
irreversible without timely therapy. Considering that SCCD depends solely on
laboratory testing of vitamin B12 status, it is important to analyse relationship between
biomarkers routinely used and novel markers (methylmalonic acid (MMA) and
morphometric parameters of leucocytes) in the population at risk of cobalamin
deficiency.
AIMS OF STUDY: The study objective is the research of significance of biochemical
markers and morphometric parameters of leucocytes in laboratory diagnosis of
subclinical cobalamin deficiency in the absence of clinical manifestations. Also, the
study aim is to analyse relationships between methylmalonic acid and biomarkers
routinely used, and morphometric parameters of neutrophils and monocytes, obtained
by Coulter® LH750 hematology analyser, as potential early markers of changes in
vitamin B12 status.
MATERIALS AND METHODS: The study population included 590 patients at risk
of cobalamin deficiency and 148 healthy volunteers. The patients at risk of cobalamin
deficiency were older than 60 years and /or had gastrointestinal symptoms or disorders.
For the study purpose, the following tests were done: complete blood count with
morphometric parameters of leucocytes, cobalamin, folate, red blood cell folate,
intrinsic factor antibody, homocysteine (Hcy), serum iron, soluble transferrin receptors,
ferritin, transferrin, total iron binding-capacity, transferrin saturation, haptoglobin,
lactate dehydrogenase, creatinine, estimated glomerular filtration rate..
The significance of biochemical markers and morphometric characteristics of leucocytes in laboratory diagnosis of subclinical cobalamin deficiency
Full text linkSubklinički deficit vitamina B12 (engl. Subclinical Cobalamin Deficiency,SCCD) podrazumeva da je koncentracija jednog ili više biomarkera statusa vitaminaB12 izvan granica referentnog opsega u odsustvu kliničkih manifestacija deficita. Dosada se mali broj studija bavio ovim oblikom nedostatka kobalamina kod starijihpacijenata sa rizikom za deficit vitamina B12, a koji nemaju kliničku sliku deficita.Otkrivanje ranih promena u statusu vitamina B12 značajno je za ovu populaciju, jer seneurološki simptomi deficita mogu javiti u odsustvu hematoloških simptoma i mogu bitiireverzibilni, ukoliko se terapija ne primeni na vreme. Kako se SCCD potvrđujeisključivo na osnovu laboratorijskog testiranja statusa vitamina B12, značajno jeanalizirati odnos rutinskih i novih biomarkera (metilmalonske kiseline (MMA) imorfometrijskih parametara leukocita) u populaciji sa rizikom za pojavu deficitakobalamina.CILJEVI: Cilj studije jeste ispitivanje značaja biohemijskih markera i morfometrijskihkarakteristika leukocita u laboratorijskoj dijagnostici subkliničkog deficita vitaminaB12 u odsustvu kliničkih simptoma. Takođe, cilj rada je i utvrđivanje povezanostimetilmalonske kiseline sa postojećim parametrima za ispitivanje statusa vitamina B12 imorfometrijskim parametrima neutrofila i monocita, dobijenih na Coulter® LH750hematološkom analizatoru, kao potencijalno ranih markera promena u statusu vitaminaB12.MATERIJALI I METODE: Studija je obuhvatila 590 pacijenata sa rizikom za deficitkobalamina, kao i 148 zdravih dobrovoljaca. Pacijenti sa rizikom za deficit kobalaminabili su stariji od 60 godina i/ili osobe sa gastrointestinalnim smetnjama i simptomima.Za potrebe studije urađene su sledeće analize: krvna slika sa morfometrijskimparametrima leukocita, kobalamin, folat, folat u eritrocitima, antitela protiv unutrašnjegfaktora, homocistein (Hcy), serumsko gvožđe, solubilni transferinski receptori, feritin,transferin, ukupni kapacitet vezivanja gvožđa, saturacija transferina gvožđem,haptoglobin, laktat dehidrogenaza, kreatinin, procenjena brzina glomerularne filtracije...In the absence of clinical manifestations, concentration of one ormore biomarkers of vitamin B12 status out of reference range is considered assubclinical cobalamin deficiency (SCCD). So far, the small number of studies haveexplored SCCD in elderly patients at risk of vitamin B12 deficiency, but withoutclinical picture. The recognition of early changes in cobalamin status is important forthis population because neurological symptoms of deficiency can be present withouthematological manifestations. Also, neurological symptoms of deficiency can beirreversible without timely therapy. Considering that SCCD depends solely onlaboratory testing of vitamin B12 status, it is important to analyse relationship betweenbiomarkers routinely used and novel markers (methylmalonic acid (MMA) andmorphometric parameters of leucocytes) in the population at risk of cobalamindeficiency.AIMS OF STUDY: The study objective is the research of significance of biochemicalmarkers and morphometric parameters of leucocytes in laboratory diagnosis ofsubclinical cobalamin deficiency in the absence of clinical manifestations. Also, thestudy aim is to analyse relationships between methylmalonic acid and biomarkersroutinely used, and morphometric parameters of neutrophils and monocytes, obtainedby Coulter® LH750 hematology analyser, as potential early markers of changes invitamin B12 status.MATERIALS AND METHODS: The study population included 590 patients at riskof cobalamin deficiency and 148 healthy volunteers. The patients at risk of cobalamindeficiency were older than 60 years and /or had gastrointestinal symptoms or disorders.For the study purpose, the following tests were done: complete blood count withmorphometric parameters of leucocytes, cobalamin, folate, red blood cell folate,intrinsic factor antibody, homocysteine (Hcy), serum iron, soluble transferrin receptors,ferritin, transferrin, total iron binding-capacity, transferrin saturation, haptoglobin,lactate dehydrogenase, creatinine, estimated glomerular filtration rate..
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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