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Biomedical subjects

C M Seiler

Publications and source records attributed to C M Seiler.

17 recordsLinked to original sources
PubMed2006

Protocol design and current status of CLIVIT: a randomized controlled multicenter relevance trial comparing clips versus ligatures in thyroid surgery.

BACKGROUND: Annually, more than 90000 surgical procedures of the thyroid gland are performed in Germany. Strategies aimed at reducing the duration of the surgical procedure are relevant to patients and the health care system especially in the context of reducing costs. However, new techniques for quick and safe hemostasis have to be tested in clinically relevance randomized controlled trials before a general recommendation can be given. The current standard for occlusion of blood vessels in thyroid surgery is ligatures. Vascular clips may be a safe alternative but have not been investigated in a large RCT. METHODS/DESIGN: CLIVIT (Clips versus Ligatures in Thyroid Surgery) is an investigator initiated, multicenter, patient-blinded, two-group parallel relevance randomized controlled trial designed by the Study Center of the German Surgical Society. Patients scheduled for elective resection of at least two third of the gland for benign thyroid disease are eligible for participation. After surgical exploration patients are randomized intraoperatively into either the conventional ligature group, or into the clip group. The primary objective is to test for a relevant reduction in operating time (at least 15 min) when using the clip technique. Since April 2004, 121 of the totally required 420 patients were randomized in five centers. DISCUSSION: As in all trials the different forms of bias have to be considered, and as in this case, a surgical trial, the role of surgical expertise plays a key role, and will be documented and analyzed separately. This is the first randomized controlled multicenter relevance trial to compare different vessel occlusion techniques in thyroid surgery with adequate power and other detailed information about the design as well as framework. If significant, the results might be generalized and may change the current surgical practice.

Journal Article↗
PubMed2006

Comparison of Venae Sectio vs. modified Seldinger Technique for totally implantable access ports; Portas-trial [ISRCTN:52368201].

BACKGROUND: The insertion of a Totally Implantable Access Port (TIAP) is a routinely employed technique in patients who need a safe and permanent venous access. The number of TIAP implantations is increasing constantly mainly due to advanced treatment options for malignant diseases. Therefore it is important to identify the implantation technique which has the optimal benefit/risk ratio for the patient. STUDY DESIGN: A single-centre, randomized, controlled superiority trial to compare two different TIAP implantation techniques. SAMPLE SIZE: 160 patients will be included and randomized intra-operatively. ELIGIBILITY CRITERIA: Age equal or older than 18 years, patients scheduled for primary elective implantation of a TIAP in local anaesthesia and a signed informed consent. Primary endpoint: Primary success rate of the randomized technique. INTERVENTION: Venae Sectio in combination with the Seldinger Technique (guide wire and a peel away sheath) will be used to place a TIAP. Reference treatment: Conventional Venae Sectio will be used with a direct insertion of the TIAP without guide wire or peel away sheath. Duration of study: Approximately 20 months. ORGANISATION/RESPONSIBILITY: The trial will be conducted in compliance with the protocol and in accordance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and Good Clinical Practice (GCP). The trial will also be carried out in keeping with local and regulatory requirements. The Klinisches Studienzentrum Chirurgie (KSC)--Centre of Clinical Trials in Surgery at the Department of Surgery, University Hospital Heidelberg is responsible for planning and conduction of the trial. Documentation of patient's data will be accomplished via electronical Case Report Files (eCRF) with MACRO-Software by the KSC. Randomization, data management, monitoring and biometry are provided by the independent Koordinierungszentrum für Klinische Studien (KKS)--Coordination Centre for Clinical Trails at the University of Heidelberg.

Journal Article↗
PubMed2006

Does a negative screening colonoscopy ever need to be repeated?

BACKGROUND AND AIMS: Screening colonoscopy is thought to be a powerful and cost-effective tool to reduce colorectal cancer incidence and mortality. Whether and when colonoscopy with negative findings has to be repeated is not well defined. The aim of this study was to assess the long term risk of clinically manifest colorectal cancer among subjects with negative findings at colonoscopy. PATIENTS: 380 cases and 485 controls participating in a population based case-control study in Germany. METHODS: Detailed history and results of previous colonoscopies were obtained by interview and from medical records. Adjusted relative risks of colorectal cancer among subjects with a previous negative colonoscopy compared with those without previous colonoscopy were estimated according to time since colonoscopy. RESULTS: Subjects with previous negative colonoscopy had a 74% lower risk of colorectal cancer than those without previous colonoscopy (adjusted odds ratio (aOR) = 0.26 (95% confidence interval, 0.16 to 0.40)). This low risk was seen even if the colonoscopy had been done up to 20 or more years previously. Particularly low risks were seen for sigma cancer (aOR = 0.13 (0.04 to 0.43)) and for rectal cancer (aOR = 0.19 (0.09 to 0.39)), and after a negative screening colonoscopy at ages 55 to 64 (aOR = 0.17 (0.08 to 0.39)) and older (aOR = 0.21 (0.10 to 0.41)). CONCLUSIONS: Subjects with negative findings at colonoscopy are at very low risk of colorectal cancer and might not need to undergo repeat colonoscopy for 20 years or more, if at all. The possibility of extending screening intervals to 20 years or more might reduce complications and increase the feasibility and cost-effectiveness of colonoscopy based screening programmes.

Adult↗
PubMed2006

[Operative standardization in randomized controlled surgical trials. Meeting of the INSECT trial].

BACKGROUND: INSECT is an internationally registered, three-armed, multicentre, intraoperatively randomised model trial of the Study Centre of the German Surgical Society. The interventions being compared are running suture technique with slowly absorbable monofilament suture material (PDS vs MonoPlus) and interrupted technique with a braided, rapidly absorbable suture material (Vicryl). The primary endpoint is the rate of incisional hernias 1 year postoperatively. MATERIAL AND METHODS: A total of 25 surgeons from 24 different institutions at all levels of care evaluated the theoretical and practical sessions of the surgical investigator meeting using 25 criteria, including course organisation, content, and speaker evaluation, and a categorical grading system from 1 (very good) to 6 (insufficient). RESULTS: Distribution of the 625 grades was: very good (1) n=367, good (2) n=207, satisfactory (3) n=39, adequate (4) n=2, and "No statement" n=10. The average score for the investigator meeting was 1.5. CONCLUSION: The participants felt they were successfully prepared theoretically and practically for trial interventions and conduct by attending the meeting. Clear explanation of the measures for treatment equivalence before and during trials is mandatory in randomised controlled surgical trials.

Abdominal Wall↗
PubMed2006

[Project selection and protocol design in the Study Centre of the German Surgical Society].

BACKGROUND: The Study Centre of the German Surgical Society (SDGC) designs, conducts, and analyses multicentre randomised controlled surgical trials. The aim of this paper is to present the decision-making process and responsibilities of the SDGC from submission of a study idea to full protocol development in order to achieve transparency in trial selection. METHODS: The process is divided into four steps. Study ideas can be submitted electronically by members of the German Surgical Society using a form via the homepage of the institution. Firstly, ideas are screened by staff members within 4 weeks for methodological and clinical relevance. Feasible and novel ideas are then converted to trial outlines in cooperation with the submitting surgeon. As a third step, the Steering Committee of the SDGC decides whether to accept the project using a list of defined criteria. Finally, the SDGC draws up a full protocol together with the submitting surgeon. All ideas and decisions are accessible via the SDGC homepage. CONCLUSIONS: The process described should help in the selection of relevant projects, acquisition of grants, and maintenance of transparency in trial selection and the protocol development process.

Decision Making↗
PubMed2006

[Aim, content, evaluation and perspectives of surgical training in randomized trials at the Study Centre of the German Surgical Society].

BACKGROUND: Clinical research, especially the management of randomized controlled multicentre trials, is a challenge for surgical investigators. To provide the theoretical background and practical knowledge needed for surgical trials, it is necessary to revise standard training programmes, which focus on pharmacological research. The main differences concern regulatory aspects and content, especially in achieving and maintaining comparability, equal treatment, and outcome assessment using special randomisation techniques and standardised surgical procedures. METHODS: In November 2005, in cooperation with the Coordinating Centre for Clinical Trials in Heidelberg, the Study Centre of the German Surgical Society Study Group (SDGC) hosted a clinical investigation course for surgeons. During 3 days, 24 participants were systematically instructed by 16 lecturers on clinical trials (planning, treatment by protocol, data management, biometrics, ethics, and law), followed by participants' evaluation of the course. RESULTS: On a scale of 1 to 6 (excellent to insufficient, respectively) the mean grades for the course were 1.6 for content, 1.55 for clarity, and 1.55 for learning effect. Partial repetition, lack of work in small groups, and not enough materials to take home were the major criticisms. CONCLUSIONS: The evaluation emphasised the necessity and value of the course. Further courses with continued evaluation are necessary and can be based on the same underlying concept. However, the mere qualification of surgeons as clinical investigators without substantial additional improvements in structural problems and increased financial project support will not fundamentally improve clinical research in Germany.

Attitude of Health Personnel↗
PubMed2006

[Randomized and nonrandomized controlled clinical trials in a German surgical journal].

BACKGROUND: Comprehensive identification of relevant literature is mandatory for valid assessment of the effectiveness of surgical interventions. Thus, electronic database searches are often complemented by handsearching of relevant surgical journals. The aim of this study was to assess the quantity and quality of randomized controlled (RCTs) and controlled clinical trials (CCTs) in the German surgical journal Der Chirurg. METHODS: Quantitative and qualitative assessment was made after handsearching of studies published from 1948 to 2005 in Der Chirurg. Systematic database search (MEDLINE) was used for comparison of RCTs published in Der Chirurg and international surgical journals. RESULTS: Overall, 112 controlled clinical trials (90 RCTs, 22 CCTs) were identified by handsearching. The implementation of sample size calculation was reported in 12 of 90 (13%) RCTs. Forty-six (51%) did not specify the randomization process, and five (6%) incorporated the "intention to treat" principle in their analyses. After 2000, RCTs were published in declining frequency in Der Chirurg, whereas international surgical journals printed stable quantities of these studies. CONCLUSION: Improving the prerequisites of patient-centered clinical research in surgery, rigorous implementation of principles of the CONSORT statement, and modified publication strategies may improve the quality and quantity of reports on clinical studies in Germany.

Controlled Clinical Trials as Topic↗
PubMed2005

Evidence-based medicine--from best research evidence to a better surgical practice and health care.

BACKGROUND: The use of the terms evidence-based medicine (EBM) and healthcare (EBHC) has become commonplace in the medical as well as in the surgical literature. Using the best available evidence, however, is not yet a working routine among surgeons because of the large amount and complexity of published research and the lack of user-friendly tools and necessary skills for the use of research results. DISCUSSION: This article encourages to formulate surgically relevant questions and to answer them on the basis of high-quality research, preferably by using systematic reviews which are based on the quality criteria of the Cochrane Collaboration. CONCLUSIONS: As currently only 77 Cochrane reviews address surgical procedures; much work remains to be done to enlarge the number of high-quality and relevant reviews. Similarly, the number and quality of randomized controlled trials need to be increased in all surgical specialties.

Clinical Trials as Topic↗
PubMed2005

Systematic review and meta-analysis of technique for closure of the pancreatic remnant after distal pancreatectomy.

BACKGROUND: Appropriate closure of the pancreatic remnant after distal pancreatectomy is still debated. A variety of procedures have been recommended to reduce the frequency of pancreatic fistula. This review quantitatively compares the available techniques. METHODS: Original articles and abstracts published up to the end of June 2004 were searched without language restriction in the Cochrane Controlled Trials Register, Medline and Embase. Three reviewers independently assessed each study's eligibility and quality, and extracted the data. A random effects model was performed using weighted odds ratios. RESULTS: Only ten of 262 articles could be included, two randomized clinical trials and eight observational studies. Reported postoperative morbidity varied from 13.3 to 64 per cent. The primary outcome measure, pancreatic fistula rate, occurred within the range 0-60.9 per cent. Meta-analysis of the six studies comparing stapler versus hand-sutured closure showed a non-significant combined odds ratio for occurrence of a pancreatic fistula of 0.66 (95 per cent confidence interval 0.35 to 1.26, P = 0.21) in favour of stapler closure. CONCLUSIONS: The quality and quantity of information extracted from the available trials are insufficient to enable any firm conclusion to be drawn on the optimal surgical technique of pancreatic stump closure; there is a trend in favour of the stapling technique.

Epidemiologic Methods↗
PubMed1998

[Graduate education for specialist in surgery in the USA--aspects for the young German and American physician].

Due to high standards in clinical practice and outstanding research opportunities in the USA, German residents wish to do a part of their surgical education in an American teaching hospital. Currently, German applicants must have an unrestricted license and a valid Standard ECFMG Certificate. For this certificate they must have passed Step I and II of the United States Medical Licensing Examination, which also includes an English test. The examination requirements are about to be changed. A 1-year participation in one of the 267 surgical residency programs is generally not possible. In Germany, American residents have the opportunity to apply for a supervised training year without passing the German medical exams. At present, there are no clinical exchange programs in surgery between Germany and the USA. Therefore, the German and American College of Surgeons should develop an exchange program for residents in surgery.

Curriculum↗
PubMed1997

Oral administration of unsaturated fatty acids: effects on human peripheral blood T lymphocyte proliferation.

Oils enriched in certain polyunsaturated fatty acids suppress joint pain and swelling in rheumatoid arthritis (RA) patients. Because T lymphocyte activation is important to propagation of joint tissue injury in patients with RA, we examined the effects of fatty acids administered by mouth in vivo on proliferation of human lymphocytes activated through the T cell receptor complex. T cell proliferation was reduced after oral administration of 2.4 g gammalinolenic acid in capsules of borage seed oil. Oral administration of oils enriched in linoleic acid, the parent n-6 fatty acid, and alpha linolenic acid, the parent n-3 fatty acid, did not influence growth of stimulated cells. Fatty acid analyses indicated that suppression of lymphocyte proliferation after gammalinolenic acid administration was associated with increased plasma and peripheral blood mononuclear cell concentrations of gammalinolenic acid and dihomogammalinolenic acid.

Administration, Oral↗
PubMed1997

Effects of unsaturated fatty acids on interleukin-1beta production by human monocytes.

Dihomogammalinolenic acid is derived from gammalinolenic acid, administration of which suppresses joint inflammation. It is reported here that interleukin 1beta (IL-1beta) production by human monocytes is enhanced markedly when cells are incubated 18-24 h with the polyunsaturated fatty acids dihomogammalinolenic acid (DGLA) and arachidonic acid (AA), then stimulated with lipopolysaccharide. Effects of eicosapentaenoic acid (EPA) on IL-1beta production are minimal, and palmitic acid (PA) does not influence IL-1beta production.

8,11,14-Eicosatrienoic Acid↗
PubMed1995

Differential regulation of human T lymphocyte protein kinase C activity by unsaturated fatty acids.

Administration of gamma-linolenic acid suppresses active synovitis in patients with rheumatoid arthritis. We therefore examined the effects of gamma-linolenic acid and its first metabolite, dihomo-gamma-linolenic acid, on protein kinase C, a key element in transduction of signals from cell surface to nucleus. We report here that gamma-linolenic acid and dihomo-gamma-linolenic acid suppress total protein kinase C activity, but facilitate translocation of protein kinase C activity from cytosol to membrane in human peripheral blood T lymphocytes stimulated with phorbol 12-myristate 13-acetate. Arachidonic acid and eicosapentaenoic acid do not influence total protein kinase C activity and have only modest effects on enzyme translocation. These findings in whole cells are in contrast to results of experiments performed with isolated protein kinase C, in which unsaturated fatty acids uniformly enhance protein kinase C activity. The differential effects of unsaturated fatty acids underscore the complexity of protein kinase C regulation and indicate that gamma-linolenic and dihomo-gamma-linolenic acids influence T lymphocyte protein kinase C metabolism in a manner that is unique among unsaturated fatty acid precursors of eicosanoids.

8,11,14-Eicosatrienoic Acid↗
PubMed1993

Gene expression and serum thyroxine-binding globulin are regulated by adrenal status and corticosterone in the rat.

Supraphysiological doses of glucocorticoids reduce serum T4-binding globulin (TBG) concentrations when administered to human subjects. Studies were performed in rats to determine if glucocorticoid administration alters serum TBG in another species, if circulating concentrations of glucocorticoids tonically affect serum TBG concentrations, and if changes in TBG production are likely to be a cause of the glucocorticoid-induced changes in serum TBG concentrations that are observed in humans. The serum TBG-binding capacity was 14.9 +/- 2.3 nmol/liter in adrenalectomized male rats compared to 6.6 +/- 1.0 nmol/liter in intact male rats and 4.8 +/- 0.9 nmol/liter in adrenalectomized male rats that received corticosterone in a dose equal to or less than the replacement dose, as assessed by thymus weight (P < 0.01 for serum TBG in adrenalectomized vs. intact or adrenalectomized corticosterone-treated groups). Hepatic TBG mRNA content, as assessed by polymerase chain reaction amplification and expressed as a ratio of beta-actin mRNA content, was 0.10 +/- 0.03 density units in intact male rats, 0.59 +/- 0.17 density units in adrenalectomized male rats, and 0.05 +/- 0.02 density units in adrenalectomized corticosterone-treated male rats (P < 0.03 for adrenalectomized vs. intact or adrenalectomized corticosterone-treated rats). Adrenalectomy increased the serum TBG-binding capacity in female rats (intact female rats, 13.9 +/- 1.0 nmol/liter; adrenalectomized female rats, 39.0 +/- 6.4 nmol/liter; P < 0.01). These studies indicate that serum TBG is tonically down-regulated by adrenal glucocorticoids, because corticosterone decreases the TBG production rate, probably at the level of transcription. This effect is similar to that described for corticosterone-binding globulin, but differs from that for many proteins of the serine protease inhibitor family that are related to TBG.

Actins↗
PubMedDate not supplied

Human peripheral blood T lymphocyte proliferation after activation of the T cell receptor: effects of unsaturated fatty acids.

Oils enriched in certain polyunsaturated fatty acids suppress joint pain and swelling in rheumatoid arthritis patients with active synovitis. Because T lymphocyte activation is important for propagation of joint tissue injury in patients with rheumatoid arthritis, we examined the effects of fatty acids added in vitro on proliferation of human T lymphocytes stimulated with monoclonal antibodies to CD3 and CD4. Unsaturated fatty acids reduced T cell proliferation in a dose dependent manner (dihomogammalinolenic acid > gammalinolenic acid > eicosapentaenoic acid > arachidonic acid). Removal of fatty acids from cultures before cell stimulation did not change the effects, but addition of fatty acids after cell stimulation failed to reduce T cell responses. The saturated palmitic acid did not influence T cell growth. These studies indicate that small changes in cellular fatty acids can have profound effects on early events in T cell signaling and on T cell function.

8,11,14-Eicosatrienoic Acid↗