Defective bone repair in mast cell deficient mice with c-Kit loss of function

KitW-sh mice carry an inactivating mutation in the gene encoding the receptor for stem cell factor, which is expressed at high levels on the surface of haematopoietic precursor cells. The mutation results in mast cell deficiency, a variety of defects in innate immunity and poorly defined abnormalities in bone. The present study was designed to characterise healing of a cortical window defect in skeletally mature KitW-sh mice using high-resolution micro computed tomographic imaging and histological analyses. The cortical bone defect healed completely in all wild type mice but failed to heal in about half of the KitW-sh mice by 12 weeks post-operative. Defective healing was associated with premature and excessive expression of TRAP positive cells embedded in fibrous marrow but with little change in ALP activity. Immuno-histochemical analyses revealed reduced CD34 positive vascular endothelial cells and F4/80 positive macrophages at 1 and 2 weeks post-operative. Impaired bone healing in the KitW-sh mice was therefore attributed to altered catabolic activity, impaired re-vascularisation and compromised replacement of woven with compact bone.

siRNA-mediated silencing of Wnt5a regulates inflammatory responses in atherosclerosis through the MAPK/NF-κB pathways

Previous studies have demonstrated that the aberrant expression of Wnt5a occurs in atherosclerotic lesions. However, the precise role of Wnt5a in the pathogenesis of atherosclerosis remains largely unknown. The present study was undertaken to determine whether the RNA interference of Wnt5a in vivo by adenovirus (Ad)-mediated small interfering RNA (siRNA) transfection is capable of inhibiting the progression of atherosclerosis. Recombinant adenovirus carrying siRNA targeting Wnt5a (Ad-Wnt5a siRNA) was designed. Male apolipoprotein E-deficient (ApoE(-/-)) mice were fed a high-fat diet to induce the pathogenesis of atherosclerosis. Mice were randomly divided into 3 groups (n=15 in each group): the mock group, which received treatment with phosphate-buffered saline (PBS); the Ad-NC group, which received treatment with Ad-non-specific siRNA; and the Ad-Wnt5a siRNA group, which received treatment with Ad-Wnt5a siRNA. Treatment with Ad-Wnt5a siRNA markedly inhibited the mRNA and protein expression of Wnt5a in the aortic tissues. The knockdown of Wnt5a had no significant effect on blood lipid levels, but it suppressed atherosclerotic development and increased plaque stability, which was determined by hematoxylin and eosin staining, picrosirius red staining and Oil Red O staining. Furthermore, the mRNA and protein expression of inflammatory cytokines, including monocyte chemotactic protein-1 (MCP-1), cyclooxygenase-2 (COX-2), matrix metalloproteinase (MMP)-2 and MMP-9 was significantly downregulated in the Ad-Wnt5a siRNA group. In addition, the knockdown of Wnt5a inhibited the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. These results demonstrate that Ad-mediated Wnt5a silencing in vivo attenuates the development of atherosclerotic disease by reducing inflammatory mediators involved in the MAPK/NF-κB pathways.

Historical trends of atmospheric black carbon on Sanjiang Plain as reconstructed from a 150-year peat record

Black carbon (BC), one of the major components of atmosphere aerosol, could be the second dominant driver of climate change. We reconstructed historical trend of BC fluxes in Sanjiang Plain (Northeast China) through peat record to better understand its long-term trend and relationship of this atmosphere aerosol with intensity of human activities. The BC fluxes in peatland were higher than other sedimentary archives. Although global biomass burning decreased in last 150 years, regional large scale reclaiming caused BC fluxes of the Sanjiang Plain increased dramatically between 1950s' and 1980s', most likely resulting from using fire to clearing dense pastures and forests for reclaiming. The BC fluxes have increased since 1900s with increasing of the population and the area of farmland; the increase trend has been more clearly since 1980s. Based on Generalized additive models (GAM), the proportional influence of regional anthropogenic impacts have increased and became dominant factors on BC deposition.

Strain dynamics of ultrathin VO₂ film grown on TiO₂ (001) and the associated phase transition modulation

Tuning the metal insulator transition (MIT) behavior of VO2 film through the interfacial strain is effective for practical applications. However, the mechanism for strain-modulated MIT is still under debate. Here we directly record the strain dynamics of ultrathin VO2 film on TiO2 substrate and reveal the intrinsic modulation process by means of synchrotron radiation and first-principles calculations. It is observed that the MIT process of the obtained VO2 films can be modulated continuously via the interfacial strain. The relationship between the phase transition temperature and the strain evolution is established from the initial film growth. From the interfacial strain dynamics and theoretical calculations, we claim that the electronic orbital occupancy is strongly affected by the interfacial strain, which changes also the electron-electron correlation and controls the phase transition temperature. These findings open the possibility of an active tuning of phase transition for the thin VO2 film through the interfacial lattice engineering.

Transposon variation by order during allopolyploidisation between Brassica oleracea and Brassica rapa

Although many studies have shown that transposable element (TE) activation is induced by hybridisation and polyploidisation in plants, much less is known on how different types of TE respond to hybridisation, and the impact of TE-associated sequences on gene function. We investigated the frequency and regularity of putative transposon activation for different types of TE, and determined the impact of TE-associated sequence variation on the genome during allopolyploidisation. We designed different types of TE primers and adopted the Inter-Retrotransposon Amplified Polymorphism (IRAP) method to detect variation in TE-associated sequences during the process of allopolyploidisation between Brassica rapa (AA) and Brassica oleracea (CC), and in successive generations of self-pollinated progeny. In addition, fragments with TE insertions were used to perform Blast2GO analysis to characterise the putative functions of the fragments with TE insertions. Ninety-two primers amplifying 548 loci were used to detect variation in sequences associated with four different orders of TE sequences. TEs could be classed in ascending frequency into LTR-REs, TIRs, LINEs, SINEs and unknown TEs. The frequency of novel variation (putative activation) detected for the four orders of TEs was highest from the F1 to F2 generations, and lowest from the F2 to F3 generations. Functional annotation of sequences with TE insertions showed that genes with TE insertions were mainly involved in metabolic processes and binding, and preferentially functioned in organelles. TE variation in our study severely disturbed the genetic compositions of the different generations, resulting in inconsistencies in genetic clustering. Different types of TE showed different patterns of variation during the process of allopolyploidisation.

The structure of the symptoms of major depression: exploratory and confirmatory factor analysis in depressed Han Chinese women

BACKGROUND

The symptoms of major depression (MD) are clinically diverse. Do they form coherent factors that might clarify the underlying nature of this important psychiatric syndrome?

METHOD

Symptoms at lifetime worst depressive episode were assessed at structured psychiatric interview in 6008 women of Han Chinese descent, age ⩾30 years with recurrent DSM-IV MD. Exploratory factor analysis (EFA) and confirmatoryfactor analysis (CFA) were performed in Mplus in random split-half samples.

RESULTS

The preliminary EFA results were consistently supported by the findings from CFA. Analyses of the nine DSM-IV MD symptomatic A criteria revealed two factors loading on: (i) general depressive symptoms; and (ii) guilt/suicidal ideation. Examining 14 disaggregated DSM-IV criteria revealed three factors reflecting: (i) weight/appetite disturbance; (ii) general depressive symptoms; and (iii) sleep disturbance. Using all symptoms (n = 27), we identified five factors that reflected: (i) weight/appetite symptoms; (ii) general retarded depressive symptoms; (iii) atypical vegetative symptoms; (iv) suicidality/hopelessness; and (v) symptoms of agitation and anxiety.

CONCLUSIONS

MD is a clinically complex syndrome with several underlying correlated symptom dimensions. In addition to a general depressive symptom factor, a complete picture must include factors reflecting typical/atypical vegetative symptoms, cognitive symptoms (hopelessness/suicidal ideation), and an agitated symptom factor characterized by anxiety, guilt, helplessness and irritability. Prior cross-cultural studies, factor analyses of MD in Western populations and empirical findings in this sample showing risk factor profiles similar to those seen in Western populations suggest that our results are likely to be broadly representative of the human depressive syndrome.

[Short- or long-outcome of early tirofiban in ST-segment elevated acute myocardial infarction undergoing elective percutaneous coronary intervention]

OBJECTIVE

To explore the optimal timing of tirofiban early treatment in ST-segment elevated acute myocardial infarction (STEMI) undergoing elective percutaneous coronary intervention (PCI).

METHODS

A total of 118 consecutive STEMI patients were enrolled in the study. They were randomly assigned to the tirofiban early treatment group with tirofiban administrated routinely at ≥ 4 hours prior to angiography or the control group with tirofiban provisional administrated during or after angiography. Thrombolysis in myocardial infarction (TIMI) flow, creatine kinase MB isoenzyme (CK-MB) levels, acute thrombus events, efficacy and safety endpoints at Day 7, Day 30, 6 months and 1 year (efficacy endpoints: death, myocardial infarction, target vessel revascularization and ischemic stroke; safety endpoints: bleeding and thrombocytopenia) were observed and compared between the two groups.

RESULTS

A total of 104 STEMI patients underwent elective PCI with 52 patients in each group and the baseline characteristics were balanced between the two groups. Tirofiban was administered (5.9 ± 2.9) hours earlier in the tirofiban early treatment group than the control group. No statistical difference was observed between the two groups in TIMI flow before[grade 0: 18 (34.6%) vs 19 (36.5%) , grade 3: 28 (53.8%) vs 27 (51.9%)] and after PCI[grade 3: 52 (100.0%) vs 51 (98.1%)]. No difference was shown between the two groups in CK-MB levels before PCI [(12.9 ± 5.1) U/L vs (12.0 ± 5.2) U/L, P > 0.05]; and the increase of CK-MB 12-24 hours after PCI [(1.0 ± 6.2) U/L vs (2.3 ± 8.3) U/L, P > 0.05]. The incidence of acute thrombus events was similar (7.7% vs 15.4%, P > 0.05). No statistical difference was observed between the two groups in the efficacy endpoints at Day 7 (0.0% vs 7.7%, P > 0.05), Day 30 (0.0% vs 7.8%, P > 0.05), 6 months (2.0% vs 9.8%, P > 0.05) and 1 year (2.2% vs 9.8%, P > 0.05). Similar incidence was shown in the slight bleeding (15.4% vs 5.8%, P > 0.05) and the slight thrombocytopenia (0.0% vs 1.9%, P > 0.05), while no severe to moderate bleeding or severe thrombocytopenia happened in both groups.

CONCLUSION

Tirofiban early treatment is not better than the tirofiban bailout treatment during or after PCI in STEMI patients undergoing elective PCI. Trail registration ChiCTR-TRC-10000809.

Identification of a new HLA allele, HLA-B*13:70, in a Chinese individual

HLA-B*13:70 differs from HLA-B*13:02:01 by one nucleotide (A to G) at nucleotide position 329 in exon 2.

Systematic review with meta-analysis: the association between human papillomavirus infection and oesophageal cancer

BACKGROUND

Human papillomavirus (HPV) infection might be one of the potential risk factors for oesophageal cancer. However, the previous epidemiological findings were heterogeneous.

AIM

To explore the association between HPV infection and oesophageal cancer risk by means of meta-analysis.

METHODS

Studies on HPV infection and oesophageal cancer were identified, the prevalence of HPV infection and its association with oesophageal cancer risk were quantitatively summarised by meta-analysis.

RESULTS

A total of 8990 oesophageal squamous cell carcinoma (SCC) patients and 174 oesophageal adenocarcinomas patients were evaluated from 76 included studies. Summarised HPV prevalence in oesophageal SCC was 22.2% [95% confidence interval (CI), 18.3-26.7%], HPV-16 was the most frequently observed subtype with a summarised prevalence of 11.4% (95% CI: 8.2-15.7%). With respect to oesophageal adenocarcinoma, HPV prevalence was 35.0% (95% CI, 13.2-65.7%) and HPV-16 prevalence was 11.4% (95% CI: 8.2-15.7%). Due to the limited number of included studies on oesophageal adenocarcinoma, association analyses were performed to oesophageal SCC only. Significant association was observed between HPV infection and oesophageal SCC with a summarised odds ratio of 3.32 (95% CI, 2.26-4.87). According to HPV-16, the strength of the association was found to be 3.52 (95% CI, 2.04-6.07).

CONCLUSIONS

Human papillomavirus infection was observed to be associated with an increased risk of oesophageal SCC in this meta-analysis. However, due to the evident heterogeneity observed between the included studies and the strength of the association not as strong as observed for cervical cancer and laryngeal cancer, further studies are needed to clarify the relation and its underlying mechanisms.

Twelve years' experience and clinical results of using the radial artery for coronary revascularization

BACKGROUND

The radial artery (RA) is becoming a popular conduit for coronary artery bypass grafting (CABG), yet data reporting the long-term results are rare. We reported our clinical, angiographic and intravascular ultrasound findings on 93 patients who had the RA used as part of the conduit for the CABG procedures during a 12-year period from June 2001 to June 2013.

METHODS

A total of 118 radial artery conduits were harvested in 87 males and 6 females, age from 28 to 66 (mean 49.9) years. An "intra-operative Allen's test" was developed to safeguard blood supply to the arm and hand. A "double-clip & scissors-cut" technique was carried out to minimize the thermal injury to the radial artery from the diathermy. The left radial artery was used in 67 patients, the right in one, and bilateral radial arteries in 25 patients. One hundred and twenty-two out of 272 distal anastomoses (44.9%) were constructed with radial arteries, with an average of 2.9 grafts per patient (range 2-6).

RESULTS

Follow-up angiography and intravascular ultrasound study at 3-139 postoperative months (mean 59 months) revealed a 93.1% RA patency. String sign occurred in one patient in whom the RA was directed to a big right coronary artery with a stenosis of around 50%. The patency for the internal mammary artery was 96.4%.

CONCLUSIONS

The RA is an excellent conduit that broadens the options for total arterial CABG surgery. Good graft patency could be achieved through careful harvesting techniques and choice of proper target coronary vessels.

Age, estimated glomerular filtration rate and ejection fraction score predicts contrast-induced acute kidney injury in patients with diabetes and chronic kidney disease: insight from the TRACK-D study

BACKGROUND

The occurrence of contrast induced acute kidney injury (CIAKI) has a pronounced impact on morbidity and mortality. The aim of the present study was to appraise the diagnostic efficacy of age, estimated glomerular filtration rate (eGFR) and ejection fraction (AGEF) score (age/EF(%)+1 (if eGFR was <60 ml × min(-1)× 1.73 m(-2))) as an predictor of CIAKI in patients with diabetes mellitus (DM) and concomitant chronic kidney disease (CKD).

METHODS

The AGEF score was calculated for 2 998 patients with type 2 DM and concomitant CKD who had undergone coronary/peripheral arterial angiography. CIAKI was defined as an increase in sCr concentration of 0.5 mg/dl (44.2 mmol/L) or 25% above baseline at 72 hours after exposure to the contrast medium. Post hoc analysis was performed by stratifying the rate of CIAKI according to AGEF score tertiles. The diagnostic efficacy of the AGEF score for predicting CIAKI was evaluated with receiver operating characteristic (ROC) analysis.

RESULTS

The AGEF score ranged from 0.49 to 3.09. The AGEF score tertiles were defined as follows: AGEFlow ≤ 0.92 (n = 1 006); 0.92 <AGEFmid ≤ 1.16 (n = 1 000), and ACEFhigh >1.16 (n = 992). The incidence of CIAKI was significantly different in patients with low, middle and high AGEF scores (AGEFlow = 1.1%, AGEFmid = 2.3% and AGEFhigh = 5.8%, P < 0.001). By multivariate analysis, AGEF score was an independent predictor of CIAKI (odds ratio = 4.96, 95% CI: 2.32-10.58, P < 0.01). ROC analysis showed that the area under the curve was 0.70 (95% CI: 0.648-0.753, P < 0.001).

CONCLUSION

The AGEF score is effective for stratifying risk of CIAKI in patients with DM and CKD undergoing coronary/peripheral arterial angiography. (Clinical Trial identifier: NCT00786136).

Cognitive trio: relationship with major depression and clinical predictors in Han Chinese women

BACKGROUND

Previous studies support Beck's cognitive model of vulnerability to depression. However, the relationship between his cognitive triad and other clinical features and risk factors among those with major depression (MD) has rarely been systematically studied.

METHOD

The three key cognitive symptoms of worthlessness, hopelessness and helplessness were assessed during their lifetime worst episode in 1970 Han Chinese women with recurrent MD. Diagnostic and other risk factor information was assessed at personal interview. Odds ratios (ORs) were calculated by logistic regression.

RESULTS

Compared to patients who did not endorse the cognitive trio, those who did had a greater number of DSM-IV A criteria, more individual depressive symptoms, an earlier age at onset, a greater number of episodes, and were more likely to meet diagnostic criteria for melancholia, postnatal depression, dysthymia and anxiety disorders. Hopelessness was highly related to all the suicidal symptomatology, with ORs ranging from 5.92 to 6.51. Neuroticism, stressful life events (SLEs) and a protective parental rearing style were associated with these cognitive symptoms.

CONCLUSIONS

During the worst episode of MD in Han Chinese women, the endorsement of the cognitive trio was associated with a worse course of depression and an increased risk of suicide. Individuals with high levels of neuroticism, many SLEs and high parental protectiveness were at increased risk for these cognitive depressive symptoms. As in Western populations, symptoms of the cognitive trio appear to play a central role in the psychopathology of MD in Chinese women.

MSC-seeded dense collagen scaffolds with a bolus dose of VEGF promote healing of large bone defects

The functional repair of large skeletal defects remains a significant challenge to orthopaedic surgeons due to the lack of effective strategies to promote bone regeneration, particularly in the elderly. This study investigated the potential use of bone marrow derived mesenchymal stromal cells (MSC) in a dense collagen scaffold with a bolus dose of vascular endothelial growth factor (VEGF) to repair a defect in the femoral diaphysis of mice. MSC isolated from bone marrow of 4-month-old donor mice were seeded in type I collagen gels that were then compressed to form scaffolds with a fibrillar density similar to osteoid. The cells remained metabolically active in scaffolds incubated in vitro for up to 15 days and differentiated into osteoblasts that deposited calcium-phosphate mineral into the scaffold, which was quantified using micro-computed tomographic (micro-CT) imaging. When implanted in a 1 mm x 3 mm unicortical defect the MSC-loaded scaffolds were rapidly mineralised and integrated into host bone with administration of 10 ng of recombinant VEGF injected into the femoral canal at 4 days postoperative. Empty scaffolds and MSC-seeded scaffolds implanted in defects that did not receive a bolus dose of VEGF did not mineralise or integrate with native bone. The approach with MSC, hydrogels and a biologic factor already approved for human use warrants further pre-clinical investigation with a large animal model.

Ultra-stable radio frequency dissemination in free space

We demonstrate an ultra-stable radio frequency (RF) dissemination scheme over 80 m free space. The frequency dissemination stability is 3.2 × 10(-13)/s and 4.4 × 10(-17)/day, which can be applied to transfer frequency signal without compromising its stability in a global navigation satellite system (GNSS) or radio astronomy.

Effects of magnetic shear on toroidal rotation in tokamak plasmas with lower hybrid current drive

Application of lower hybrid (LH) current drive in tokamak plasmas can induce both co- and countercurrent directed changes in toroidal rotation, depending on the core q profile. For discharges with q(0) <1, rotation increments in the countercurrent direction are observed. If the LH-driven current is sufficient to suppress sawteeth and increase q(0) above unity, the core toroidal rotation change is in the cocurrent direction. This change in sign of the rotation increment is consistent with a change in sign of the residual stress (the divergence of which constitutes an intrinsic torque that drives the flow) through its dependence on magnetic shear.

An odd application of artificial vascular graft in the kidney transplantation of a patient with severe deep vein thrombosis: a case report

Transplantation of a living-related donor kidney was performed for a 41-year-old man. The planned right donor nephrectomy from the patient's 64-year-old father was uneventful. However the recipient's bilateral iliac veins and inferior vena cava were occluded, requiring a connection of the donor renal vein to the recipient's right great saphenous vein using an artificial vascular graft. On postoperative day 9, the patient recovered normal renal function with a serum creatinine that gradually decreased to 1.399 mg/dL. Color Doppler and computed tomography angiography imaging showed patency of the artificial vascular graft with no evidence of thrombosis. In addition, warfarin was used to improve his protein S deficiency.

Fiber-based multiple-access optical frequency dissemination

We demonstrate a fiber-based, multiple-access optical frequency dissemination scheme. Without using any additional laser sources, we reproduce the stable disseminated frequency at an arbitrary point along the fiber link. Relative frequency stabilities of 3×10(-16)/s and 4×10(-18)/10(4) s are obtained. A branching fiber network for high-precision synchronization of optical frequency is made possible by this method, and its applications are discussed.

GluR6-FasL-Trx2 mediates denitrosylation and activation of procaspase-3 in cerebral ischemia/reperfusion in rats

Global cerebral ischemia/reperfusion (I/R) facilitates the activation of procaspase-3 and promotes apoptosis in hippocampus. But the mechanisms have remained uncharacterized. Protein S-nitrosylation and denitrosylation is an important reversible posttranslational modification, which is a common mechanism in signal transduction and affects numerous physiological and pathophysiological events. However, it is not known whether S-nitrosylation/denitrosylation modification of procaspase-3 serves as a component of apoptosis and cell death induced by cerebral I/R. Here we show that procaspase-3 is significantly denitrosylated and activated after I/R in rat hippocampus. NS102, a glutamate receptor 6 (GluR6) antagonist, can inhibit the denitrosylation of procaspase-3 and diminish the increased Fas ligand (FasL) and thioredoxin (Trx)-2 expression induced by cerebral I/R. Moreover, downregulation of FasL expression by antisense oligodeoxynucleotides inhibits the denitrosylation and activation of procaspase-3. Auranofin, a TrxR inhibitor or TrxR2 antisense oligodeoxynucleotide, has similar effects. In primary hippocampal cultures, Lentiviral-mediated knockdown of FasL and TrxR2 before the oxygen and glucose deprivation/reoxygenation further verifies that FasL and TrxR2 are involved in the denitrosylation of procaspase-3. In situ TUNEL staining and cresyl violet staining validate that inhibiting denitrosylation of procaspase-3 may exert neuroprotective effect on apoptosis and cell death induced by cerebral I/R in hippocampal CA1 pyramidal neurons. This is the first evidence that cerebral I/R mediates procaspase-3 denitrosylation and activation through GluR6-FasL-Trx2 pathway, which leads to neuronal apoptosis and cell death.

Quercetin protects rat hepatocytes from oxidative damage induced by ethanol and iron by maintaining intercellular liable iron pool

Accumulating evidence has shown that ethanol-induced iron overload plays a crucial role in the development and progression of alcoholic liver disease. We designed the present study to investigate the potential protective effect of quercetin, a naturally occurring iron-chelating antioxidant on alcoholic iron overload and oxidative stress. Ethanol-incubated (100 mmol/L) rat primary hepatocytes were co-treated by quercetin (100 µmol/L) and different dose of ferric nitrilotriacetate (Fe-NTA) for 24 h. When the hepatic enzyme releases in the culture medium, redox status of hepatocytes and the intercellular labile iron pool (LIP) level were assayed. Our data showed that Fe-NTA dose dependently induced cellular leakage of aspartate transaminase and lactate dehydrogenase, glutathione depletion, superoxide dismutase inactivation, and overproduction of malondialdehyde) and reactive oxygen species (ROS) of intact and especially ethanol-incubated hepatocytes. The oxidative damage resulted from ethanol, Fe-NTA, and especially their combined treatment was substantially alleviated by quercetin, accompanying the corresponding normalization of intercellular LIP level. Iron in excess, thus, may aggravate ethanol hepatotoxicity through Fenton-active LIP, and quercetin attenuated ethanol-induced iron and oxidative stress. To maintain intercellular LIP contributes to the hepatoprotective effect of quercetin besides its direct ROS-quenching activity.

A step-by-step guide to the systematic review and meta-analysis of diagnostic and prognostic test accuracy evaluations

In evidence-based medicine (EBM), systematic reviews and meta-analyses have been widely applied in biological and medical research. Moreover, the most popular application of meta-analyses in this field may be to examine diagnostic (sensitivity and specificity) and prognostic (hazard ratio (HR) and its variance, standard error (SE) or confidence interval (CI)) test accuracy. However, conducting such analyses requires not only a great deal of time but also an advanced professional knowledge of mathematics, statistics and computer science. Regarding the practical application of meta-analyses for diagnostic and prognostic markers, the majority of users are clinicians and biologists, most of whom are not skilled at mathematics and computer science in particular. Hence, it is necessary for these users to have a simplified version of a protocol to help them to quickly conduct meta-analyses of the accuracy of diagnostic and prognostic tests. The aim of this paper is to enable individuals who have never performed a meta-analysis to do so from scratch. The paper does not attempt to serve as a comprehensive theoretical guide but instead describes one rigorous way of conducting a meta-analysis for diagnostic and prognostic markers. Investigators who follow the outlined methods should be able to understand the basic ideas behind the steps taken, the meaning of the meta-analysis results obtained for diagnostic and prognostic markers and the scope of questions that can be answered with Systematic Reviews and Meta-Analyses (SRMA). The presented protocols have been successfully tested by clinicians without meta-analysis experience.