Gregorios Kouraklis

Real-time ultrasound-guided catheterisation of the internal jugular vein: a prospective comparison with the landmark technique in critical care patients

IntroductionCentral venous cannulation is crucial in the management of the critical care patient. This study was designed to evaluate whether real-time ultrasound-guided cannulation of the internal jugular vein is superior to the standard landmark method.MethodsIn this randomised study, 450 critical care patients who underwent real-time ultrasound-guided cannulation of the internal jugular vein were prospectively compared with 450 critical care patients in whom the landmark technique was used. Randomisation was performed by means of a computer-generated random-numbers table, and patients were stratified with regard to age, gender, and body mass index.ResultsThere were no significant differences in gender, age, body mass index, or side of cannulation (left or right) or in the presence of risk factors for difficult venous cannulation such as prior catheterisation, limited sites for access attempts, previous difficulties during catheterisation, previous mechanical complication, known vascular abnormality, untreated coagulopathy, skeletal deformity, and cannulation during cardiac arrest between the two groups of patients. Furthermore, the physicians who performed the procedures had comparable experience in the placement of central venous catheters (p = non-significant). Cannulation of the internal jugular vein was achieved in all patients by using ultrasound and in 425 of the patients (94.4%) by using the landmark technique (p < 0.001). Average access time (skin to vein) and number of attempts were significantly reduced in the ultrasound group of patients compared with the landmark group (p < 0.001). In the landmark group, puncture of the carotid artery occurred in 10.6% of patients, haematoma in 8.4%, haemothorax in 1.7%, pneumothorax in 2.4%, and central venous catheter-associated blood stream infection in 16%, which were all significantly increased compared with the ultrasound group (p < 0.001).ConclusionThe present data suggest that ultrasound-guided catheterisation of the internal jugular vein in critical care patients is superior to the landmark technique and therefore should be the method of choice in these patients.

Real-time ultrasound-guided subclavian vein cannulation versus the landmark method in critical care patients: A prospective randomized study*

Objective:Subclavian vein catheterization may cause various complications. We compared the real-time ultrasound-guided subclavian vein cannulation vs. the landmark method in critical care patients. Design:Prospective randomized study. Setting:Medical intensive care unit of a tertiary medical center. Patients:Four hundred sixty-three mechanically ventilated patients enrolled in a randomized controlled ISRCTN-registered trial (ISRCTN-61258470). Interventions:We compared the ultrasound-guided subclavian vein cannulation (200 patients) vs. the landmark method (201 patients) using an infraclavicular needle insertion point in all cases. Catheterization was performed under nonemergency conditions in the intensive care unit. Randomization was performed by means of a computer-generated random-numbers table and patients were stratified with regard to age, gender, and body mass index. Measurements and Main Results:No significant differences in the presence of risk factors for difficult cannulation between the two groups of patients were recorded. Subclavian vein cannulation was achieved in 100% of patients in the ultrasound group as compared with 87.5% in the landmark one (p < .05). Average access time and number of attempts were significantly reduced in the ultrasound group of patients compared with the landmark group (p < .05). In the landmark group, artery puncture and hematoma occurred in 5.4% of patients, respectively, hemothorax in 4.4%, pneumothorax in 4.9%, brachial plexus injury in 2.9%, phrenic nerve injury in 1.5%, and cardiac tamponade in 0.5%, which were all increased compared with the ultrasound group (p < .05). Catheter misplacements did not differ between groups. In this study, the real-time ultrasound method was rated on a semiquantitative scale as technically difficult by the participating physicians. Conclusions:The present data suggested that ultrasound-guided cannulation of the subclavian vein in critical care patients is superior to the landmark method and should be the method of choice in these patients.

Clinical Significance of Ephrin (Eph)-A1, -A2, -A4, -A5 and -A7 Receptors in Pancreatic Ductal Adenocarcinoma

Ephrin (Eph) receptors have been reported to be frequently overexpressed in a wide variety of cancer types, being associated with tumor growth, invasion, metastasis and angiogenesis. The aim of the present study was to evaluate the clinical significance of Eph-A1, -A2, -A4, -A5 and -A7 expression in pancreatic ductal adenocarcinoma. Eph-A1, -A2, -A4, -A5 and -A7 expression and staining intensity were assessed immunohistochemically in tumoral samples of 67 pancreatic adenocarcinoma patients and were statistically analyzed in relation to clinicopathological characteristics, tumor proliferative capacity and patients’ survival. Eph receptors were abundantly expressed in pancreatic ductal adenocarcinoma cases examined. Eph-A1 staining intensity was significantly associated with tumor size (pT, p = 0.008) and tumor histopathological stage (pStage, p = 0.012). Eph-A2 expression was significantly associated with patients’ age (p = 0.007), while Eph-A4 and Eph-A5 with tumor proliferative capacity (p = 0.019 and p = 0.011, respectively). Pancreatic adenocarcinoma patients with moderate/intense Eph-A5 or Eph-A7 staining presented significantly shorter survival times compared to those with negative/mild one (log-rank test, p = 0.024 and p = 0.009, respectively). Multivariate analysis identified Eph-A5 and Eph-A7 staining intensity as independent prognostic factors (p = 0.048 and p = 0.004, respectively). In conclusion, the present study revealed that Eph receptors were associated with pancreatic cancer characteristics, supporting evidence for their potential clinical application in management and prognosis of pancreatic adenocarcinoma patients.

Expression and Clinical Significance of Focal Adhesion Kinase in the Two Distinct Histological Types, Intestinal and Diffuse, of Human Gastric Adenocarcinoma

Focal adhesion kinase (FAK), a non-receptor tyrosine kinase protein, acts as an early modulator of integrin signaling cascade, regulating basic cellular functions. In transformed cells, unopposed FAK signaling has been considered to promote tumor growth, progression and metastasis. The aim of this study was to assess the clinical significance of FAK expression in the two distinct histological types of human gastric neoplasia. FAK expression was assessed immunohistochemically in tumoral samples of 66 gastric adenocarcinoma cases, 30 intestinal and 36 diffuse type, and was statistically analyzed in relation to various clinicopathological characteristics, tumor proliferative capacity and patients’ survival. In intestinal type carcinomas, enhanced FAK expression was significantly associated with increased tumor proliferative capacity (P = 0.012). In diffuse type carcinomas, FAK staining intensity was significantly correlated with tumor size (P = 0.026) and disease stage (P = 0.024), presenting also a borderline association with nodal status (P = 0.053). In diffuse type carcinomas, enhanced FAK expression was significantly associated with longer overall survival times (log-rank test, P = 0.014), being also identified as an independent prognostic factor in multivariate analysis (Cox regression, P = 0.016). In contrast, patients with intestinal type tumors and enhanced FAK expression were characterized by shorter overall survival times, without though reaching statistical significance (log-rank test, P = 0.092). The current data support evidence that FAK protein may be considered as a diagnostic and prognostic marker in gastric neoplasia. Further studies conducted on larger clinical samples and highlighting on the distinct impact of the two histological types are warranted to delineate the clinical significance of FAK protein in gastric neoplasia.

Expression of PDGF-A, tgfb and VCAM-1 during the developmental stages of experimental atherosclerosis

Purpose: A considerable number of growth factors, cytokines, and adhesion molecules are implicated in the development of atherosclerotic lesions. These molecules interact in a complex network influencing the evolution of several processes, such as lipid metabolism, cellular proliferation and tissue repair. The aim of this study was to evaluate the expression of the growth factors PDGF-A, and TGFb, and the adhesion molecule VCAM-1 in the sequential steps of experimental atherogenesis. Methods: Forty-two New Zealand white male rabbits were divided into 4 groups. The group A rabbits (n = 8) received normal diet and served as control animals. The remaining groups were fed with a diet enriched with 1% cholesterol and 6% corn oil. The rabbits of group B (n = 9) were sacrificed 1 month after the beginning of the study, of group C (n = 15) after 2 months and of group D (n = 10) after 3 months. In tissue sections of the aortic arch the antibodies of the prementioned factors were detected immunohistochemically. Results: In group A only TGFb and PDGF-A were detectable. In lesions of the first month PDGF-A expression was high but declined towards the third month. VCAM-1 expression was getting more intense up to the second month and subsided thereafter. TGFb expression intensified towards the third month. Changes in the expression of these factors were statistically significant. Conclusion: PDGF-A, responsible for the uncontrollable growth of smooth muscle cells, and VCAM-1, regulating monocyte recruitment in the intima, acts mainly during the early stages of atherogenesis. TGFb, one of the main factors controlling the formation of connective tissue matrix, has a gradually increasing expression towards the third month contributing probably to the fibrous plaque formation.

Individual patient data systematic review and meta-analysis of optic nerve sheath diameter ultrasonography for detecting raised intracranial pressure: protocol of the ONSD research group

BackgroundThe purpose of the optic nerve sheath diameter (ONSD) research group project is to establish an individual patient-level database from high quality studies of ONSD ultrasonography for the detection of raised intracranial pressure (ICP), and to perform a systematic review and an individual patient data meta-analysis (IPDMA), which will provide a cutoff value to help physicians making decisions and encourage further research. Previous meta-analyses were able to assess the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP but failed to determine a precise cutoff value. Thus, the ONSD research group was founded to synthesize data from several recent studies on the subject and to provide evidence on the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP.MethodsThis IPDMA will be conducted in different phases. First, we will systematically search for eligible studies. To be eligible, studies must have compared ONSD ultrasonography to invasive intracranial devices, the current reference standard for diagnosing raised ICP. Subsequently, we will assess the quality of studies included based on the QUADAS-2 tool, and then collect and validate individual patient data. The objectives of the primary analyses will be to assess the diagnostic accuracy of ONSD ultrasonography and to determine a precise cutoff value for detecting raised ICP. Secondly, we will construct a logistic regression model to assess whether patient and study characteristics influence diagnostic accuracy.DiscussionWe believe that this IPD MA will provide the most reliable basis for the assessment of diagnostic accuracy of ONSD ultrasonography for detecting raised ICP and to provide a cutoff value. We also hope that the creation of the ONSD research group will encourage further study.Systematic review registrationPROSPERO registration number: CRD42012003072

Correlation of Peroxisome Proliferator-Activated Receptor-gamma (PPAR-gamma) and Retinoid X Receptor-alpha (RXR-alpha) expression with clinical risk factors in patients with advanced carotid atherosclerosis

Summary Background Peroxisome proliferator-activated Receptor-γ (PPAR-γ) and its nuclear partners, the Retinoid X Receptors (RXRs), have been recognized as crucial players in the pathogenesis of atherosclerosis. The present study aimed to assess the clinical significance of PPAR-γ and RXR-α expression in different cellular populations localized within advanced carotid atherosclerosis lesions. Material/Methods PPAR-γ and RXR-α expression was assessed by immunohistochemistry ïn 134 carotid atherosclerotic plaques obtained from an equal number of patients that underwent endarterectomy procedure for vascular repair, and was correlated with patients’ medical history, risk factors and medication intake. Results Increased incidence of low PPAR-γ expression in both macrophages and smooth muscle cells was noted in patients presenting coronary artery disease (p=0.032 and p=0.046, respectively). PPAR-γ expression in smooth muscle cells was borderline down-regulated in symptomatic compared to asymptomatic patients (p=0.061), reaching statistical significance when analyzing groups of patients with specific cerebrovascular events; amaurosis fugax (p=0.008), amaurosis fugax/stroke (p=0.020) or amaurosis fugax/transient ischemic attack patients (p=0.028) compared to asymptomatic patients. Low RXR-α expression in macrophages was more frequently observed in hypertensive (p=0.048) and hyperlipidemic patients (p=0.049). Increased incidence of low RXR-α expression in smooth muscle cells was also noted in patients presenting advanced carotid stenosis grade (p=0.015). Conclusions PPAR-γ and RXR-α expression down-regulation in macrophages and smooth muscle cells was associated with a more pronounced disease progression in patients with advanced carotid atherosclerotic lesions.

Histone deacetylase (HDAC)-1, -2, -4 and -6 expression in human pancreatic adenocarcinoma: associations with clinicopathological parameters, tumor proliferative capacity and patients' survival.

BackgroundHistone deacetylases (HDACs) have been associated with malignant tumor development and progression in humans. HDAC inhibitors (HDACIs) are currently being explored as anti-cancer agents in clinical trials. The present study aimed to evaluate the clinical significance of HDAC-1, −2, −4 and −6 protein expression in pancreatic adenocarcinoma.MethodsHDAC-1, −2, −4 and −6 protein expression was assessed immunohistochemically on 70 pancreatic adenocarcinoma tissue specimens and was statistically analyzed with clinicopathological characteristics and patients’ survival.ResultsEnhanced HDAC-1 expression was significantly associated with increased tumor proliferative capacity (p = 0.0238) and borderline with the absence of lymph node metastases (p = 0.0632). Elevated HDAC-4 expression was significantly associated with the absence of organ metastases (p = 0.0453) and borderline with the absence of lymph node metastases (p = 0.0571) and tumor proliferative capacity (p = 0.0576). Enhanced HDAC-6 expression was significantly associated with earlier histopathological stage (p = 0.0115) and borderline with smaller tumor size (p = 0.0864). Pancreatic adenocarcinoma patients with enhanced HDAC-1 and −6 expression showed significantly longer survival times compared to those with low expression (p = 0.0022 and p = 0.0113, respectively), while a borderline association concerning HDAC-2 expression was noted (p = 0.0634).ConclusionsThe present study suggested that HDACs may be implicated in pancreatic malignant disease progression, being considered of clinical utility with potential use as therapeutic targets.

Expression and promoter methylation status of hMLH1, MGMT, APC, and CDH1 genes in patients with colon adenocarcinoma

Colorectal cancer (CRC) is the third most common cancer in men and the second in women worldwide. CRC development is the result of genetic and epigenetic alterations accumulation in the epithelial cells of colon mucosa. In the present study, DNA methylation, an epigenetic event, was evaluated in tumoral and matching normal epithelium in a cohort of 61 CRC patients. The results confirmed and expanded knowledge for the tumor suppressor genes hMLH1, MGMT, APC, and CDH1. Promoter methylation was observed for all the examined genes in different percentage. A total of 71% and 10% of the examined cases were found to be methylated in two or more and in all genes, respectively. mRNA and protein levels were also evaluated. Promoter methylation of hMLH1, MGMT, APC, and CDH1 genes was present at the early stages of tumor’s formation and it could also be detected in the normal mucosa. Correlations of the methylated genes with patient’s age and tumor’s clinicopathological characteristics were also observed. Our findings suggest that DNA methylation is a useful marker for tumor progression monitoring and that promoter methylation in certain genes is associated with more advanced tumor stage, poor differentiation, and metastasis.

Serum tissue inhibitor of metalloproteinase 1 and 2 (TIMP-1 and TIMP-2) levels in colorectal cancer patients: associations with clinicopathological variables and patient survival.

Tissue inhibitors of metalloproteinases (TIMPs) appear to affect many aspects of cancer biology, playing a crucial role in cell signaling by regulating cell growth, apoptosis, invasion, metastasis, angiogenesis, and genomic instability. The aim of the present study was to elucidate the diagnostic and prognostic utility of TIMP-1 and TIMP-2 in patients with colon cancer. Serum TIMP-1 and TIMP-2 concentrations were quantified using an enzyme-linked immunosorbent assay in 97 colon cancer patients. Elevated serum TIMP-1 levels were found in patients with advanced disease stage (p=0.0512) and poorly differentiated histopathological tumor grade (p=0.0059). Patients with increased TIMP-1 levels had shorter overall survival times (log-rank test, p=0.0143). Multivariate analysis also identified TIMP-1 as an independent prognostic factor (Cox regression analysis, p=0.0149). Serum TIMP-2 levels were not significantly associated with disease stage, histopathological grade or survival. In the subgroup of patients with well and moderately differentiated tumors, TIMP-1 and TIMP-2 were identified as independent prognostic factors (Cox regression analysis, p=0.0379 and p=0.0451, respectively). In conclusion, assessment of serum TIMP-1 can be considered a useful biomarker in colon cancer, whereas TIMP-2 appears to be of limited value.