PubMed Health⌕ Search

Biomedical subjects

I Celik

Publications and source records attributed to I Celik.

At least 37 records · Page 2Linked to original sources
PubMed2004

Analysis of mice tumor models using dynamic MRI data and a dedicated software platform*.

PURPOSE: To implement a software platform (DynaVision) dedicated to analyze data from functional imaging of tumors with different mathematical approaches, and to test the software platform in pancreatic carcinoma xenografts in mice with severe combined immunodeficiency disease (SCID). MATERIALS AND METHODS: A software program was developed for extraction and visualization of tissue perfusion parameters from dynamic contrast-enhanced images. This includes regional parameter calculation from enhancement curves, parametric images (e. g., blood flow), animation, 3D visualization, two-compartment modeling, a mode for comparing different datasets (e. g., therapy monitoring), and motion correction. We analyzed xenograft tumors from two pancreatic carcinoma cell lines (BxPC3 and ASPC1) implanted in 14 SCID mice after injection of Gd-DTPA into the tail vein. These data were correlated with histopathological findings. RESULTS: Image analysis was completed in approximately 15 minutes per data set. The possibility of drawing and editing ROIs within the whole data set makes it easy to obtain quantitative data from the intensity-time curves. In one animal, motion artifacts reduced the image quality to a greater extent but data analysis was still possible after motion correction. Dynamic MRI of mice tumor models revealed a highly heterogeneous distribution of the contrast-enhancement curves and derived parameters, which correlated with differences in histopathology. ASPC1 tumors showed a more hypervascular type of curves with faster and higher signal enhancement rate (wash-in) and a faster signal decrease (wash-out). BXPC3 tumors showed a more hypovascular type with slower wash-in and wash-out. This correlated with the biological properties of the tumors. CONCLUSION: With the described software, it was possible to analyze tissue perfusion parameters in small xenograft tumor models in mice. Our data correlated with histopathological data, and the qualitative and quantitative perfusion parameters could distinguish two tumor entities with different growth characteristics.

Animals↗
PubMed2004

[Cross-validation of simple questioning methods to determine patient satisfaction with anaesthesia care].

INTRODUCTION: Evaluation of patient satisfaction with the perioperative care is an integral part of modern quality management. For this purpose simple questioning techniques are often used in clinical practise or reports of clinical trials. However, little research has been performed to investigate whether these tools and methods are useful and provide valid information. METHODS: Two-hundred patients undergoing elective surgical procedures were interviewed. Five different simple techniques or questions that have been used in the international and in the German literature throughout the last years were applied in random sequence together with the validated German translation of the QoR-9 questionnaire to measure quality of recovery. All analyses were performed descriptively. RESULTS: All investigated techniques could be answered without help by another person in 95 % up to 100 %. All simple dichotomous questions regarding satisfaction were insufficient to discriminate satisfied from less satisfied patients. A rating using grades known from the German school system (1 - 6) and a visual analogue scale (VAS; 0 - 100 mm) obtained ratings lower than the maximum possible values in 10 % and 11 % of the patients respectively. Furthermore, the flexibility that was provided by these tools was not utilized by the patients. The results of the QoR-9 questionnaire as a marker of postoperative recovery showed only a moderate correlation with ratings of patient satisfaction. CONCLUSION: Until now, there is no method or questioning technique in the German language that can be recommended for a quality assurance program. Thus, further research is needed to develop tools that provide valid information with adequate resolution to allow discrimination of patient satisfaction with perioperative care.

Adult↗
PubMed2004

Tamoxifen-induced tissue factor pathway inhibitor reduction: a clue for an acquired thrombophilic state?

BACKGROUND: Current understanding of hemostatic systems enables us to better explore the enigmatic pathobiology of tamoxifen (TAM)-induced thrombotic diathesis. We have therefore aimed to assess the hemostatic changes in breast cancer patients receiving TAM on an adjuvant basis. PATIENTS AND METHODS: The study population consisted of 43 female patients with hormone receptor-positive breast cancer who received TAM 20 mg/day as part of their adjuvant treatment. Mean age was 52+/-12 years (range 25-74). Twenty-one patients (49%) were premenopausal. Plasma samples were collected prior to and following 6 months of TAM therapy and were assayed for total tissue factor pathway inhibitor (TFPI), free TFPI, lipid-bound TFPI, thrombomodulin, D dimer, activated protein C resistance (APC res), factors VIIa, II, V, VII and X, and global fibrinolytic capacity (GFC). RESULTS: Median total TFPI decreased significantly from 48.5 ng/ml to 36.2 ng/ml (P=0.001), free TFPI from 10 to 7.6 ng/ml (P=0.001) and lipid-bound TFPI from 39.1 to 28.7 ng/ml (P=0.001). There were significant decreases in the levels of factor II (P=0.03), factor V (P=0.001), factor VII (P=0.06), thrombomodulin (P=0.01) and D dimer (P=0.001). However, APC res times were significantly prolonged (P=0.04). The remaining parameters that we have studied were not significantly affected. CONCLUSION: Our findings suggest that TAM tends to activate the coagulation pathway by counteracting major molecules involved in coagulation inhibition, namely TFPI and TM. As reflected by unchanged GFC, the drug appears to impair the expected compensatory activation of the fibrinolytic system, which removes fibrin polymers resulting from coagulation activation.

Activated Protein C Resistance↗
PubMed2003

Prevalence of multiple endocrine neoplasia type 1 in young patients with apparently sporadic primary hyperparathyroidism or pancreaticoduodenal endocrine tumours.

BACKGROUND: The appropriate treatment for a sporadic endocrine tumour may be different from those that present as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome. As primary hyperparathyroidism (pHPT) and pancreaticoduodenal endocrine tumours (PETs) are the most common organ manifestations of MEN1, the prevalence of germline mutations in the MEN1 gene was determined in young patients with apparently sporadic pHPT or PETs. METHODS: Eighteen of 705 patients with pHPT and 11 of 93 patients with PETs operated on between 1987 and 2001 had no family history of MEN1, only one organ manifestation and were aged 40 years or less at the time of diagnosis. Fifteen patients with pHPT and eight with PETs agreed to MEN1 gene mutation analysis, which was performed by single-strand conformational variant analysis and direct DNA sequencing. RESULTS: Two of 15 patients (13.3 (95 per cent confidence interval (c.i.) 1.6 to 40.4) per cent) with apparently sporadic pHPT had a MEN1 germline mutation. Both mutations were found in patients with pHPT due to multiglandular disease, whereas the remaining 13 patients had a solitary adenoma. None of the eight patients with PETs carried a MEN1 germline mutation. CONCLUSION: Sporadic pHPT due to multiglandular disease in patients younger than 40 years may represent the first organ manifestation of MEN1 despite a negative family history.

Adolescent↗
PubMed2003

Early and late histamine release induced by albumin, hetastarch and polygeline: some unexpected findings.

OBJECTIVE: The perioperative use of colloidal plasma substitutes is still under discussion. We therefore conducted a prospective randomised study with three commonly used plasma substitutes to examine their histamine releasing effects in 21 volunteers. MATERIAL OR SUBJETS: 21 male volunteers were enrolled in this prospective, randomised, controlled clinical study. Endpoints were the incidence of early and late histamine release and the time course of the release kinetics. Normovolemic hemodilution technique was used with hydroxyethyl starch (n = 6), human albumin (n = 6) and polygeline (n = 9). Measurement and observation period was 240 min after the start of the plasma substitute infusion. Heart rate, blood pressure, SaO(2), clinical symptoms/signs and plasma histamine were measured during the observation period. RESULTS: The incidence of histamine release over the whole observation period in all three groups was 100%. Histamine release occurred frequently in all three groups until 30 min (50%-78%) and up to 240 min (late release reaction: 67%-83%) after the start of infusion. Surprisingly even hydroxyethyl starch, which is regarded as a generally safe and effective plasma substitute, caused high incidences of late histamine release (67%). Histamine release is a well known side effect of polygeline and - to a lesser extent - also of albumin, but was a novel finding for hydroxyethyl starch. CONCLUSIONS: We demonstrated for the first time histamine releasing effects of hydroxyethyl starch over a long period of time after administration. This perioperatively and for intensive care possibly relevant finding should make clinicians aware of late side effects not yet connected with the clinical use of these colloidal plasma substitutes.

Adult↗
PubMed2003

The efficacy of oral cyclophosphamide plus prednisolone in early diffuse systemic sclerosis.

Pharmacological treatment of diffuse systemic sclerosis (SSc) directed at the tissue fibrosis has generally been ineffective. Many immunosuppressive drugs have been tried as therapy for SSc, regardless of the disease subtype and/or stage. The aim of this study was to show the efficacy and the toxicity of oral cyclophosphamide and prednisolone therapy on the prevention of fibrosis-based tissue damage in the early stages of the diffuse SSc. Twenty-seven patients with early diffuse SSc were treated with oral cyclophosphamide (1-2 mg/kg/day) plus oral prednisolone (40 mg/every other day) between the years 1995 and 1998. The results regarding the efficacy and toxicity of cyclophosphamide were compared with those of 22 early SSc patients who had been treated with oral D-penicillamine between 1992 and 1995. All the patients were evaluated using clinical and laboratory parameters every 6 months for 2 years. There was a significant improvement on the skin score, maximal oral opening, flexion index, predicted forced vital capacity (FVC) and carbon monoxide diffusing capacity (DLCO) in the cyclophosphamide group. The decrease in skin score in the cyclophosphamide group started earlier than in the D-penicillamine group. No life-threatening or irreversible adverse reaction was observed. This open study supports the use of oral cyclophosphamide plus prednisolone therapy to prevent fibrosis and its complications in the early stages of diffuse SSc.

Administration, Oral↗
PubMed2003

Effects of aflatoxin B1 on the development of the bursa of Fabricius and blood lymphocyte acid phosphatase of the chicken.

1. In this study, embryotoxicity and effects of in ovo administration of aflatoxin B1 (AFB1) on the embryonic development of the bursa of Fabricius were determined in fertilised chicken eggs by histological methods and histochemical demonstration of acid phosphatase (ACP-ase) enzyme. Peripheral blood lymphocyte percentages were also estimated. 2. Embryonic stages were determined according to the Hamburger-Hamilton (H-H) scale. Mortality rates increased in AFB1-injected groups in a dose-dependent manner. Embryonic deaths were concentrated at H-H 31 in the 5 ng AFB1/egg group while the deaths were highest at H-H 25 in the 10 and 20 ng AFB1/egg groups. In the 40ng AFB1/egg group, embryonic deaths mostly occurred during the first 70 to 72 h of incubation (H-H 20). 3. Bursal development was quite similar at d 7 of incubation in control and all experimental groups although development had been substantially impaired and retarded at d 10 of incubation in 10, 20 and 40 ng AFB1/egg groups. A gradual decrease of ACP-ase positive lymphocyte numbers was observed with increasing AFB1 doses. The chicks in AFB1-treated groups hatched with poorly developed bursae compared with those of the controls. However, proportions of ACP-ase positive lymphocytes substantially increased at hatch and at 21 d of incubation all groups had similar numbers. 4. The results revealed that breeder diets should be investigated for aflatoxins and specifically AFB1, in cases of low hatchability and flock immunity, because low concentration of AFB1 transferred into the fertilised eggs might be the cause of serious problems.

Acid Phosphatase↗
PubMed2003

[Mesenteric traction syndrome during the operation of aneurysms of the abdominal aorta--histamine release and prophylaxis with antihistaminics].

Mesenteric traction syndrome occurs during abdominal surgery and is described as sudden tachycardia, hypotension and flush. Among other etiological factors, eventeration or mesenteric traction of the small intestine may cause histamine release from mesenteric mast cells. Therefore, our hypothesis was that mesenteric traction syndrome could be positively influenced by prophylactic administration of H1- and and H2-antihistamines. Seventeen male patients (ASA groups III-V, 48-78 years old) were investigated in a randomised double blind study during elective abdominal aortic aneurysm (AAA) repair; which, in our opinion, is one of the most standardised surgical procedures. Eight patients had pre-anaesthetic prophylaxis with 0.1 mg/kg BW dimetindene (H1-receptor antagonist) plus 5 mg/kg BW cimetidine (H2-receptor antagonist) diluted with 100 ml 0.9% NaCl, while 9 patients received a placebo (100 ml 0.9% NaCl). Anaesthesia and invasive haemodynamic monitoring were standardised in all patients. Haemodynamic parameters, plasma histamine concentrations and clinical symptoms were determined one min after skin incision (HS), and 5 and 20 min after mesenteric traction (5' EV and 20' EV). Statistical analyses were performed using the Student's t-test, the Mann-Whitney-U-test for continuous data and Chi2-test for incidences. The incidence of histamine release was 55.5% (5/9) in the placebo group vs. 37.5% (3/8) in the antihistamine group (p > 0.05, Chi2-test). Plasma histamine levels (mean +/- SD) were higher in the placebo group than in the antihistamine group at 5 and 20 min after mesenteric traction, but there was no statistical significance. Arrhythmias were significantly more frequent in the placebo group (6 times) than in the antihistamine group (none) (p = 0.005 Chi2-test). Systolic blood pressure was not statistically different between the groups (e.g. 5 min after mesenteric traction, mean +/- SD; placebo 111 +/- 20 mm Hg vs. antihistamines 119 +/- 35 mm Hg). In the placebo group, however, the haemodynamics only stabilised 5 min after mesenteric traction when anaesthetic gas concentration was repeatedly reduced and vasopressor/volume administration was increased (placebo group = 20 times vs. antihistamine group = 8 times (p = 0.001, Chi2-test). From these results we conclude that prophylactic administration of antihistamines reduces in particular the incidence of arrhythmias and the number of stabilising measures during mesenteric traction. Prophylaxis with H1- and H2-antihistamines may therefore be of perioperative benefit and should be considered in AAA surgery.

Aged↗
PubMed2002

Histamine release in mesenteric traction syndrome during abdominal aortic aneurysm surgery: prophylaxis with H1 and H2 antihistamines.

OBJECTIVE AND DESIGN: Mesenteric traction syndrome is described as sudden tachycardia, hypotension and flush. Among other etiological factors eventeration or mesenteric traction of the small intestine may cause histamine release from mesenteric mast cells. We hypothesized that mesenteric traction syndrome may be positively influenced by prophylactic antihistamine administration. METHODS: Male patients (n = 17, ASA groups III-IV, 48-78 years old) were investigated in a randomised double blind study during elective abdominal aortic aneurysm (AAA) repair. Eight patients had pre-anaesthetic prophylaxis with dimetindene (H1-receptor antagonist) plus cimetidine (H2-receptor antagonist), 9 patients received placebo. Anaesthesia and invasive haemodynamic monitoring were standardised in all patients. Haemodynamic parameters, plasma histamine concentrations and clinical symptoms were determined 1 min after skin incision, as well as 5 and 20 min after mesenteric traction. Statistical analyses were performed using the Student's t-test, Chi2-test for incidences and Mann-Whitney-U-test for continuous data. RESULTS: The incidence of histamine release was 55.5% (5/9) in the placebo group vs. 37.5% (3/8) in the antihistamine group (p > 0.05, Chi2-test). Plasma histamine levels (mean +/- SD) were higher in the placebo group than in the antihistamine group at 5 and 20 min after mesenteric traction but the difference did not reach statistical significance. Arrhythmias were significantly more frequent in the placebo group (6 times) than in the antihistamine group (none) (p = 0.005 Chi2-test). Systolic blood pressure was not statistically different between groups (e.g. 5 min after mesenteric traction, mean +/- SD; placebo 111 +/- 20 mm Hg vs. antihistamines 119 +/- 35 mm Hg). However, in the placebo group the haemodynamics only stabilised 5 min after mesenteric traction when anaesthetic gas concentration was repeatedly reduced and vasopressor/volume administration was increased (placebo-group = 20 times/antihistamine-group = 8 times, p = 0.001, t-test). CONCLUSION: Prophylactic administration of antihistamines reduced the incidence of histamine release as well as the incidence of arrhythmias and the amount of stabilising measures during mesenteric traction. Prophylaxis with H1 and H2 antihistamines may be of perioperative benefit and should therefore be considered in AAA-surgery.

Aortic Aneurysm, Abdominal↗
PubMed2002

[Computed tomography for the assessment of posterior pelvic injuries in patients with isolated fractures of the pubic rami in conventional radiography].

To investigate the incidence of occult posterior injuries of the pelvic ring in patients with isolated fractures of the pubic rami, additional computed tomography (CT) was performed. Data from 70 patients were collected within a prolective study. Solitary fractures of the anterior pelvic ring based on conventional radiographic diagnosis were included. Spiral CT, slice thickness 5 mm, was carried out in all patients. In only 47% of cases was the diagnosis of isolated fractures of the pubic rami confirmed. A further 35 fractures of the sacrum and two partial disruptions of the sacroiliac joint were diagnosed using CT. All sacral fractures were incomplete, most were found at the anterior part of the bone. Furthermore, CT revealed three acetabular fractures. Dorsal injuries were significantly more frequent after high energy accidents. Clinical examination did not assist in the prediction of posterior injuries of the pelvic ring. There was no correlation between the extent of the anterior injuries in conventional x-ray and incidence of the posterior injuries in CT. None of the patients with dorsal injuries underwent operative treatment. In conclusion, CT is not required for the routine diagnosis of supposed isolated fractures of the pubic rami.

Aged↗
PubMed2002

[Pathomorphology, diagnosis and treatment of "hangman's fractures"].

In a retrospective study diagnostic procedures and outcome of treatment were evaluated in 33 patients with traumatic spondylolisthesis of the axis (Hangman's fracture) who were treated in our department between 1986 and 1999. There were 18 men and 15 women with an average age of 41 (17-88) years. The cause of the injury was in 23 cases an accident as a driver of a car, in 2 cases an accident with a bike, 2 patients had an accident as a pedestrian. 5 patients fell on their head and 1 patient was hit by a beam. In 15 cases there were relevant accompanying injuries. To assess the stability of the injury, a subtle radiological examination was performed including functional X-rays. After introduction of the MRI and increasing experience with the method as a standard procedure in clinical practice it was used instead of functional X-rays to get a direct image of the involvement of the discoligamental structures.17 patients with stable lesions were treated conservatively, 15 with a Minerva-cast, 2 with a halo-jacket. One polytraumatized patient had temporary immobilization with a stiff-neck. 16 patients with discoligamental instability C2/3 were treated operatively by Robinson-spondylodesis with additional anterior plating. In one case an additional posterior fusion was necessary. After 6-8 weeks all of the conservative treated patients achieved solid bony consolidation. The patients operated on did so as well within 6 to 8 weeks. Two polytraumatized patients died. 18 of the 31 surviving patients were free of pain. 12 patients complained of pain or tension of the cervical muscles during physical stress. 1 patient suffered of paresthesia of the ulnar left hand. Average duration of hospital stay was 12,9 days (1-47). All working people returned to their job. Differences in the outcome of the conservative and the operative treatment group could not be seen. We derive from these results that Hangman's fractures, mostly caused by a hyperextension trauma, achieve solid bony fusion by conservative treatment in most of the cases. The Minerva-cast has proved its capability. In cases of instable luxation fractures including tearment of the anterior longitudinal ligament and affection of the intervertebral disc C2/3 we suggest operative stabilization. We prefer the modified Robinson-spondylodesis with additional anterior plating which proved its value as a method achieving solid bony fusion combined with low rate of complications.

Adolescent↗
PubMed2002

Bloodstream thrombopoietin in rheumatoid arthritis with thrombocytosis.

Thrombopoietin (TPO) is the major regulator of growth and differentiation of megakaryocytes. Recent studies have shown that TPO may also act as an acute-phase reactant, and it has been suggested as a component of inflammatory reactions. In this study our objective was to investigate serum TPO levels in patients with rheumatoid arthritis, a complex chronic inflammatory disorder not uncommonly associated with thrombocytosis. Bloodstream TPO concentrations were assessed in 13 RA patients with platelet counts between 450 and 650 x 10(9)/l, 10 RA patients with platelet counts >650 x 10(9)/l, 15 RA patients with normal platelet counts and 12 healthy controls. RA patients with normal platelet counts had TPO levels comparable with healthy controls. TPO concentrations in patients with mild thrombocytosis were significantly elevated, whereas patients with markedly increased thrombocyte counts had prominently decreased TPO levels. These results indicate that TPO seems to be associated with reactive thrombocytosis in RA patients with active disease. In patients with extremely increased thrombocytosis serum TPO levels might be regulated by increased platelet mass via receptor-mediated uptake and metabolism.

Adult↗
PubMed2002

Granulocyte colony-stimulating factor but not peritoneal lavage increases survival rate after experimental abdominal contamination and infection.

BACKGROUND: The value of peritoneal lavage for intra-abdominal contamination and infection has never been proven scientifically. In contrast, the stimulation of host defence mechanisms with cytokines such as granulocyte colony-stimulating factor (G-CSF) has appeared promising in recent clinical trials. METHODS: Clinic modelling randomized trials (CMRTs), which model the complexity of the clinical reality, were used in rats in which peritoneal contamination and infection (PCI) was produced with human stool bacteria. The following groups were compared: trial 1, intraoperative peritoneal lavage with saline versus taurolin (18 rats per group); trial 2, no lavage versus saline lavage versus saline lavage plus subcutaneous administration of G-CSF (18 rats per group); trial 3, lavage with saline versus no lavage (30 rats per group). The primary endpoint was mortality at 120 h. Secondary endpoints were the phagocytic activity of granulocytes, and systemic and peritoneal cytokine levels. RESULTS: In trial 1 lavage with taurolin was not superior to that with saline (five of 18 versus eight of 18 animals survived; P = 0.32). In trial 2, six of 18 animals having no lavage and three of 18 receiving saline lavage survived. The combination of lavage and G-CSF increased the number of animals surviving to 11 of 18 (P < 0.05). Lavage combined with G-CSF stimulated granulocyte phagocytic activity (P < 0.01) and reduced the levels of interleukin (IL) 6 (P < 0.01) and tumour necrosis factor alpha (P < 0.05) in peritoneal fluid, as well as plasma levels of IL-6 (P < 0.05) and IL-10 (P < 0.01). In trial 3, survival was not significantly different in animals having lavage (14 of 30) and no lavage (19 of 30) (P = 0.14). CONCLUSION: In these CMRTs of intra-abdominal contamination and infection, peritoneal lavage was not beneficial, but when lavage was combined with subcutaneous administration of G-CSF mortality was reduced and the local and systemic cytokine response was downgraded. Results from these CMRTs were used directly to define the trial conditions of a randomized clinical trial with G-CSF. Peritoneal lavage is not recommended.

Abdomen↗
PubMed2002

Effect of experimental therapeutic ultrasound on the distal antebrachial growth plates in one-month-old rabbits.

The effect of therapeutic ultrasound (US) on the growth plates of growing bone was determined through fluorescence labelling and histopathological evaluation in one-month-old rabbits. Mean growth rates and mean heights of the growth plates of the US exposed radius vs. control radius, and US exposed ulna vs. control ulna showed no statistically significant differences at all intensities and time intervals. Mean growth rates and heights of the growth plates of the US exposed radius for 0.2 W/cm(2) (SATA) US vs. 0.5 W/cm(2) US showed the same type of pattern compared to those of the control radius for 0.2 W/cm(2)vs. 0.5 W/cm(2) at days 10, 15 and 20. Similar results were also found for the ulna. Effects of 0.5 W/cm(2) US on the mean growth rates and mean heights of the growth plates were superior to those of 0.2 W/cm(2) US at day 10. The results at day 10 were reversed for the same comparisons at days 15 and 20. No cavitation effect of US was observed on growth plate cells. There was no evidence of partial or complete premature closure of the growth plates or of angular deformity of the carpal region.

Animals↗