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Biomedical subjects

I Celik

Publications and source records attributed to I Celik.

At least 55 records · Page 3Linked to original sources

Granulocyte-colony stimulating factor in the prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). Protocol of a controlled clinical trial developed by consensus of an international study group. Part one: rationale and hypothesis.

GENERAL DESIGN: Presentation of a novel study protocol to evalue the effectiveness of an immune modifier (rhG-CSF, filgrastim): prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). The rationale and hypothesis are presented in this part of the protocol of the randomised, placebo controlled, double-blinded, single-centre study performed at an university hospital (n = 40 patients for each group). OBJECTIVE: Part one of this protocol describes the concepts of three major sections of the study: Definition of optimum and sub-optimal recovery after operation. Recovery, as an outcome, is not a simple univariate endpoint, but a complex construction of mechanistic variables (i. e. death, complications and health status assessed by the surgeon), quality of life expressed by the patient, and finally a weighted outcome judgement by both the patient and the surgeon (true endpoint). Its conventional early assessment within 14-28 days is artificial: longer periods (such as 6 months) are needed for the patient to state: "I am now as well as I was before". Identification of suitable target patients: the use of biological response modifiers (immune modulators) in addition to traditional prophylaxes (i. e. antibiotics, heparin, volume substitutes) may improve postoperative outcome in appropriate selected patients with reduced host defence and increased immunological stress response, but these have to be defined. Patients classified as ASA 3 and 4 (American Society for Anaesthesiologists) and with colorectal cancer will be studied to prove this hypothesis. Choice of biological response modifier: Filgrastim has been chosen as an example of a biological response modifier because it was effective in a new study type, clinic-modelling randomised trials in rodents, and has shown promise in some clinical trials for indications other than preoperative prophylaxis. It has also enhanced host defence and has been anti-inflammatory in basic research. CONCLUSION: The following hypothesis will be tested in patients with operations for colorectal cancer and increased preoperative risk (ASA 3 and 4): is the outcome as evaluated by the hermeneutic endpoint (quality of life expressed by the patient) and mechanistic endpoints (mortality rate, complication rate, relative hospital stay, assessed by the doctor) improved in the group receiving filgrastim prophylaxis in comparison with the placebo group? Quality of life will be the first primary endpoint in the hierarchical, statistical testing of confirmatory analysis.

Bacterial Infections↗

Granulocyte-colony stimulating factor in the prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). Protocol for a controlled clinical trial developed by consensus of an international study group. Part two: design of the study.

GENERAL DESIGN: Presentation of a new type of a study protocol for evaluation of the effectiveness of an immune modifier (rhG-CSF, filgrastim): prevention of postoperative infectious complications and of sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). This part describes the design of the randomised, placebo controlled, double-blinded, single-centre study performed at an university hospital (n = 40 patients for each group). OBJECTIVE: The trial design includes the following elements for a prototype protocol: * The study population is restricted to patients with colorectal cancer, including a left sided resection and an increased perioperative risk (ASA 3 and 4). * Patients are allocated by random to the control or treatment group. * The double blinding strategy of the trial is assessed by psychometric indices. * An endpoint construct with quality of life (EORTC QLQ-C30) and a recovery index (modified Mc Peek index) are used as primary endpoints. Qualitative analysis of clinical relevance of the endpoints is performed by both patients and doctors. * Statistical analysis uses an area under the curve (AUC) model for improvement of quality of life on leaving hospital and two and six months after operation. A confirmatory statistical model with quality of life as the first primary endpoint in the hierarchic test procedure is used. Expectations of patients and surgeons and the negative affect are analysed by social psychological scales. CONCLUSION: This study design differs from other trials on preoperative prophylaxis and postoperative recovery, and has been developed to try a new concept and avoid previous failures.

Clinical Protocols↗

Granulocyte-colony stimulating factor in the prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). Protocol of a controlled clinical trial developed by consensus of an international study group. Part three: individual patient, complication algorithm and quality manage.

GENERAL DESIGN: Presentation of a new type of a study protocol for evaluation of the effectiveness of an immune modifier (rhG-CSF, filgrastim): prevention of postoperative infectious complications and of sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). A randomised, placebo controlled, double-blinded, single-centre study is performed at an University Hospital (n = 40 patients for each group). This part presents the course of the individual patient and a complication algorithm for the management of anastomotic leakage and quality management. OBJECTIVE: In part three of the protocol, the three major sections include: The course of the individual patient using a comprehensive graphic display, including the perioperative period, hospital stay and post discharge outcome. A center based clinical practice guideline for the management of the most important postoperative complication--anastomotic leakage--including evidence based support for each step of the algorithm. Data management, ethics and organisational structure. CONCLUSIONS: Future studies with immune modifiers will also fail if not better structured (reduction of variance) to achieve uniform patient management in a complex clinical scenario. This new type of a single-centre trial aims to reduce the gap between animal experiments and clinical trials or--if it fails--at least demonstrates new ways for explaining the failures.

Algorithms↗

[Outcome of minimally invasive surgery. Qualitative analysis and evaluation of the clinical relevance of study variables by the patient and physician].

INTRODUCTION: Mechanistic study endpoints, evaluated exclusively by the physician, are mostly used in clinical studies evaluating new treatment modalities (e.g. laparoscopic cholecystectomy). Those endpoints often lack clinical relevance. The patient's opinion concerning the importance of a study endpoint is particularly important in the evaluation of minimally invasive procedures, which place special emphasis on patient comfort. METHODS: In a first step it was evaluated by meta-analysis, which clinical endpoints have been used for comparison of laparoscopic and conventional cholecystectomy. Furthermore, using a qualitative analysis it was investigated how important the individual study endpoints are for patients and physicians. Ten patients and five surgeons were questioned in a structured interview. RESULTS: Of all outcome variables used world-wide, approximately one third were hermeneutic study endpoints, depending on the quality of the study, but often the method of evaluation was insufficient. Only three of 215 endpoints (< 2%) were quality of life scores, an integrated concept of outcome was missing completely. The qualitative analysis confirms the claimed difference between isolated and integrated evaluation of treatment goals. The importance of postoperative death is underestimated by patients and physicians; postoperative pain is overestimated. Patients ranked the outcome variable "restoration of full physical fitness" as the most important study endpoint after avoidance of complications and death. It is underestimated in isolated evaluation and has not been used in the world literature at all. CONCLUSION: The analysis of clinical relevance of study endpoints should be the first and not the last step of studies to evaluate surgical technology. It cannot be based purely on intuition; it must make use of scientifically accepted techniques (e.g. qualitative analysis).

Attitude of Health Personnel↗

Plasma fibronectin- and thrombospondin-adhesive molecules during acute attacks and attack-free periods of familial Mediterranean fever.

We assessed plasma concentrations of fibronectin (FN) and thrombospondin (TSP) during acute attacks and attack-free periods of patients with familial Mediterranean fever (FMF). Seven female and three male FMF patients (mean age 34+/-7 years) were enrolled in the study. Plasma samples were obtained during acute FMF attacks and after 3 months of freedom from attacks. Erythrocyte sedimentation rate, C-reactive protein, and white blood cell count were evaluated concurrently. Plasma levels of FN and TSP were assayed by enzyme-linked immunosorbent assay (ELISA). Both FN and TSP concentrations were found to increase during acute attacks. Levels of adhesive molecules decreased during attack-free periods (P < 0.05). Significant correlations were found between FN and TSP levels and the concentrations of acute-phase response indicators (P< 0.05). This study disclosed for the first time significantly higher increments in the plasma levels of FN and TSP during acute FMF attacks than in attack-free periods. Therefore, the two matrix glycoproteins may play precipitating and/or regulatory roles in the inflammatory processes of these attacks.

Adult↗

Sickness behaviour, an animal equivalent to human quality of life, is improved in septic rats by G-CSF and antibiotic prophylaxis.

BACKGROUND AND AIM: New biological response modifiers are usually tested in reductionistic, pharmacological animal models by the determination of mechanistic endpoints (mortality rate, cellular/physiological parameters). In the meantime, quality of life had become an important endpoint in clinical trials but adequate animal experiments are very rare. The aim of this study was to demonstrate alterations in the behavioural response of septic rats due to a prophylaxis with cytokine (G-CSF) plus antibiotics. METHODS: Sickness behaviour (locomotor activity, circadian rhythms of blood pressure, heart rate and temperature) was determined by the use of radio telemetry. Complex animal experiments in rats were performed including anaesthesia, antibiotic and G-CSF prophylaxis, volume substitution, laparotomy, contamination and infection with human faecal suspension and postoperative analgesia. RESULTS: Prior to infection, rats showed circadian rhythm in locomotor activity, blood pressure, heart rate and temperature. Sham operation did not alter these parameters significantly. Immediately after abdominal contamination and infection, locomotor activity was strongly reduced and circadian rhythm was lost in all parameters. Body temperature showed a continuous rise, peaking 38 h after infection. Untreated animals died in 63% (8/14) of cases. Antibiotic prophylaxis blunted the febrile response and markedly reduced mortality to 20% (2/10) or 0% (0/10) using G-CSF plus antibiotics. Blood pressure and heart rate were increased in parallel with the rise in temperature. These early physiological changes were not prevented by prophylaxis, but normal behaviour was restored faster with G-CSF plus antibiotic prophylaxis. CONCLUSIONS: In septic rats, sickness behaviour (locomotor activity) is significantly improved in parallel to the mortality rate by a prophylaxis with G-CSF plus antibiotics. Sickness behaviour can be considered as an equivalent to human quality of life.

Analysis of Variance↗

Prospective controlled trial of a standardized meal stimulation test in the detection of pancreaticoduodenal endocrine tumours in patients with multiple endocrine neoplasia type 1.

BACKGROUND: Use of a standardized meal stimulation test has been recommended for the early diagnosis of pancreaticoduodenal endocrine tumours (PETs) in patients with multiple endocrine neoplasia type 1 (MEN 1). The diagnostic value of this test was re-evaluated. METHODS: In a prospective, controlled trial 58 standardized meal stimulation tests (563 kcal) were performed in 12 patients with MEN 1 and histologically, biochemically and/or radiologically confirmed PETs (group 1), 11 carriers of an MEN 1 mutation with no evidence of PETs (group 2) and in 27 healthy controls (group 3). Serum pancreatic polypeptide (PP) and gastrin concentrations were measured before and during the test meal. RESULTS: Patients in group 1 had significantly higher mean basal serum PP and gastrin concentrations than patients in group 2 and controls (P < 0.05). In all three groups an increase in serum PP was observed after meal stimulation, but there was no significant difference between the groups. No increase in gastrin level was found in any of the groups after meal stimulation. CONCLUSION: The standardized meal stimulation test does not reliably indicate the presence of PETs in patients with MEN 1, whereas raised basal serum PP and gastrin levels do. The expensive and time-consuming meal test can be excluded from MEN 1 screening programmes.

Adult↗

[Arthroscopic diagnosis of concomitant scapholunate ligament injuries in fractures of the distal radius].

To investigate the occurrence of carpal ligamentous injuries in patients with fractures of the distal radius, the results of 122 wrist arthroscopies were analysed within a retrospective study. Indications for arthroscopy included suspected carpal instability according to radiographic findings and/or the necessity for internal fixation of the radius fracture. Arthroscopy revealed acute scapholunate ligament tears in 84 patients. Scapholunate separation was found to be of prognostic value for ligament tears. There was no association between ligamentous lesions and carpal angles or fracture dislocation. Scapholunate ligament tears were most frequent in sagittal articular fractures. In these cases, wrist arthroscopy should be performed during operative treatment of the radius fracture to allow direct visualization and subsequent repair of ligamentous tears.

Adolescent↗

Long-term neurological outcome of acute encephalitis.

To understand the viral etiology of acute childhood encephalitis in Elaziğ, Eastern Turkey, 36 children aged between 4 months and 14 years who were treated in a regional medical center between January 1995 and June 1999 were studied. Viral etiology was identified in 16 of 34 (47.1 per cent) cases and the most frequently detected pathogens was mumps (seven cases, 20.6 per cent). No specific etiology was found in 18 (52.9 per cent) cases. Among the survivors, mental and/or focal neurological deficits persisted in 18 (52.9 per cent). Two children died and 32 survived, of whom 16 were left with no neurological sequel, 10 had persistent neurological sequel, and eight recovered with some degree of handicap. Improvement in the general health and sanitation of the population, and the universal use and development of new vaccination will significantly reduce the incidence of viral encephalitis.

Acute Disease↗

Role of the classical pathway of complement activation in experimentally induced polymicrobial peritonitis.

The complement system and the natural antibody repertoire provide a critical first-line defense against infection. The binding of natural antibodies to microbial surfaces opsonizes invading microorganisms and activates complement via the classical pathway. Both defense systems cooperate within the innate immune response. We studied the role of the complement system in the host defense against experimental polymicrobial peritonitis using mice lacking either C1q or factor B and C2. The C1q-deficient mice lacked the classical pathway of complement activation. The factor B- and C2-deficient mice were known to lack the classical and alternative pathways, and we demonstrate here that these mice also lacked the lectin pathway of complement activation. Using inoculum doses adjusted to cause 42% mortality in the wild-type strain, none of the mice deficient in the three activation routes of complement (factor B and C2 deficient) survived (mortality of 100%). Mortality in mice deficient only in the classical pathway of complement activation (C1q deficient) was 83%. Application of further dilutions of the polymicrobial inoculum showed a dose-dependent decrease of mortality in wild-type controls, whereas no changes in mortality were observed in the two gene-targeted strains. These results demonstrate that the classical activation pathway is required for an effective antimicrobial immune defense in polymicrobial peritonitis and that, in the infection model used, the remaining antibody-independent complement activation routes (alternative and lectin pathways) provide a supporting line of defense to gain residual protection in classical pathway deficiency.

Animals↗

Management of nonfunctioning islet cell carcinomas.

Tumors arising from the pancreatic islet cells are rare and represent a heterogeneous group of benign or malignant lesions. Most tumors present with well characterized syndromes, whereas others appear to be nonfunctioning. The clinical features of 11 men and 7 women with nonfunctioning islet cell carcinomas operated on between 1983 and 1998 were reviewed. The median patient age was 53.5 years (range 26-74 years). The most frequent presenting symptoms were abdominal pain (13 patients), weight loss (7 patients), and obstructive jaundice (4 patients). Gut hormone profiles were normal in all patients. Abdominal sonography and computed tomography localized the tumor in 17 patients, and correct prediction of an endocrine tumor was achieved in 12 patients. Six of seven patients showed a hypervascular tumor upon angiography, and seven of eight patients preoperatively had positive somatostatin receptor scintigraphy. At operation, regional or distant metastases were present in 15 (83%) and 6 (33%) patients, respectively. Eleven patients underwent potentially curative resections, and the remaining seven patients were managed palliatively by resection (four patients) or bypass procedures (three patients). Three patients had up to three more resection for metastases. Eight patients received postoperative octreotide, interferon alpha therapy, or both. The overall cumulative 5- and 10-year survival rates were 65.4% and 49.1%, respectively. Of the 11 patients who underwent curative resection, 10 were alive after a median follow-up of 63 months (range 7-180 months), but only 5 are free from disease. Although surgical cure is rare in nonfunctioning islet cell carcinomas, significant long-term palliation can be achieved in a large proportion of patients with an aggressive surgical approach and, when indicated, additional medical therapy.

Adult↗

Pancreaticoduodenal endocrine tumors in multiple endocrine neoplasia type 1: surgery or surveillance?

BACKGROUND: The management of pancreaticoduodenal endocrine tumors (PETs) remains controversial in multiple endocrine neoplasia type 1 (MEN 1). METHODS: Twenty-one patients with MEN 1 and PETs were analyzed for outcome of surgery and surveillance with special regard to the genotype based on MEN1 gene mutation analysis. RESULTS: Nine patients had gastrinomas, 5 had nonfunctioning tumors, 4 had insulinomas, 2 had insulinomas and gastrinomas, and 1 had a VIPoma. Seven patients (33%) had malignant tumors. Sixteen patients (76%) were initially treated by pancreatic resections or tumor enucleations or both. Six patients underwent reoperations for recurrences or lymph node metastases or both. Fifteen of the 16 operated patients are alive, and 12 have no evidence of disease after a median follow-up of 78 months (range, 1-198 months). Five patients with gastrinomas or nonfunctioning tumors, but no symptoms, underwent surveillance; 1 of them developed lymph node metastases. Patients with truncating mutations in the N- or C-terminal region (exons 2, 9, or 10) of the MEN1 gene had a significantly higher rate of malignant tumors (55% vs 10%; P <.05) than patients with other mutations. CONCLUSIONS: An aggressive surgical approach is justified for PETs in patients with MEN 1. However, MEN1 gene mutations in exons 3 to 8 seem to be associated with mild behavior of PETs, possibly allowing surveillance in asymptomatic patients.

Adult↗

Efficacy of polyvinylpolypyrrolidone in reducing the immunotoxicity of aflatoxin in growing broilers.

1. Protective action of an enzyme-linked polyvinylpolypyrrolidone (PVPP, Mycofix Plus) against the immunosuppressive effect of afatoxins (AF) was evaluated by determination of peripheral blood T-lymphocyte proportions and splenic plasma cell counts. Histological changes in lymphoid organs were also investigated by light microscopy. One-d-old broiler chicks (Hybro) received 2.5 mg/kg diet AF (83.06% AFB1, 12.98% AFB2, 2.84% AFG1, 1.12% AFG2) with or without PVPP (3g/kg diet) until 21 d of age. When compared with controls, AF treatment significantly decreased peripheral T-lymphocyte counts. AF caused a slight decrease in splenic plasma cell counts. The addition of PVPP to an AF-containing diet significantly increased T-lymphocyte counts. Splenic plasma cell counts were numerically intermediate between control and AF groups. 3. The dietary addition of PVPP to AF-free diet did not significantly alter either T-lymphocyte or splenic plasma cell counts.

Aflatoxin B1↗

Embryotoxicity assay of aflatoxin produced by Aspergillus parasiticus NRRL 2999.

1. The embryotoxicity of mixed aflatoxins (AF) and aflatoxin B1 (AFB1) were evaluated by a modified chick embryotoxicity screening test (CHEST). Adverse effects on the early embryonic development of thymus and bursa of Fabricius were also investigated by light microscopy. AF consisted of 83.06% AFB1, 12.98% AFB2, 2.84% AFG1 and 1.12% AFG2. 2. A total of 448 fertilised laying hens' eggs were used. AF and AFB1 were injected into the eggs at doses of 10, 100 and 1000 ng/egg. Embryonic developmental stages were evaluated according to the Hamburger-Hamilton scale (HH-scale). 3. The results showed that AFB1 given at 10 ng/egg had a significantly (P<0.05) greater embryotoxic effect than AF given at a similar dose. The higher doses of both AF and AFB1 caused higher embryonic mortality and also an increase in early deaths. 4. In the groups receiving 100 ng/egg AF and AFB1 an abnormal development was seen, with a protruded central region, corresponding to the area pellucida of the blastoderm. No other developmental abnormality attributable to AF or AFB1 was found.

Aflatoxin B1↗