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Biomedical subjects

F Fischer

Publications and source records attributed to F Fischer.

At least 19 recordsLinked to original sources
PubMed2005

Laparoscopic TME: better vision, better results?

One of the most controversial discussions on laparoscopic surgery deals with the question of whether to apply this technique to malignant disease and specifically to rectal cancer. The four major issues are the adequacy of oncologic resection, recurrence rates and patterns, long-term survival and quality of life. There is evidence, from nonrandomized studies, suggesting that margins of excision and lymph node harvest achieved laparoscopically reached comparable results to those known from conventional open resection. Our own experience of laparoscopic surgery on rectal cancer is based on 52 patients treated with curative intent. Focusing on the postoperative long-term run, we gained the following results: The median age of patients was 66.7 years and ranged from 42-88. Anastomotic leakage was seen in 6.1% of cases. In a median follow-up of 48 months (36-136), we reached an overall 3-year survival rate of 93% and a 5-year survival rate of 62%. Local recurrence was 1.9%, distant metastasis occurred in 11.5% of cases. We saw no port-site metastasis. To evaluate functional results following laparoscopic surgery a matched pair analysis was carried out. Matching of patients after laparoscopic and conventional open surgery was performed according to sex, age, type of resection, time period of surgery, and stage of disease classified by UICC. Regarding bladder and sexual dysfunction, using the EORTC QLQ CR38 score we found no statistical significant difference between the examined groups. As far as can be seen, laparoscopic surgery in rectal carcinoma may achieve the same or, in selected patients, even better results than open surgery. However, at present no published study has shown much evidence. Many more studies are necessary to define the place of laparoscopic technique in rectal cancer surgery, regarding appropriate selection of patients and evaluating adjuvant or neoadjuvant treatment in combination with the laparoscopic approach.

Adult↗
PubMed2004

Laparoscopic colectomy for recurrent and complicated diverticulitis: a prospective study of 396 patients.

BACKGROUND: It was the aim of this prospective study to evaluate the outcome of laparoscopic surgery for diverticular disease. METHODS: All patients who underwent elective laparoscopic colectomy for diverticular disease within a 10-year period were prospectively entered into a PC database registry. Indications for laparoscopic surgery were acute complicated diverticulitis (Hinchey stages I and IIa), chronically recurrent diverticulitis, sigmoid stenosis or outlet obstruction caused by chronic diverticulitis. Surgical procedures (sigmoid and anterior resection, left colectomy and resection rectopexy) included intracorporeal dissection and colorectal anastomosis. Parameters studied included age, gender, stage of disease, procedure, duration of surgery, intraoperative technical variables, transfusion requirements, conversion rate, total complication rate including major (requiring re-operation), minor (conservative treatment) and late-onset (post-discharge) complication rates, stay on ICU, hospitalisation, mortality, and recurrence. For objective evaluation, only laparoscopically completed procedures were analysed. Comparative outcome analysis was performed with respect to stage of disease and experience. RESULTS: A total of 396 patients underwent laparoscopic colectomy. Conversion rate was 6.8% ( n=27), so that laparoscopic completion rate was 93.2% ( n=369). Most common reasons for conversion were directly related to the inflammatory process, abscess or fistulas. The most common procedure was sigmoid resection ( n=279), followed by anterior resection ( n=36) and left colectomy ( n=29). Total complication rate was 18.4% ( n=68). Major complication rate was 7.6% ( n=28), whereas the most common complication requiring re-operation was haemorrhage in 3.3% ( n=12). Anastomotic leakage occurred in 1.6% ( n=6). Minor complications were noted in 10.7% ( n=40), late-onset complications occurred in 2.7% ( n=10). Mortality was 0.5% ( n=2). Mean duration of surgery was 193 (range 75-400) min, return to normal diet was completed after 6.8 (range 3-19) days. Mean hospital stay was 11.8 (range 4-71) days. No recurrence of diverticulitis occurred. CONCLUSION: Laparoscopic surgery for diverticular disease is safe, feasible and effective. Therefore, laparoscopic colectomy has replaced open resection as standard surgery for recurrent and complicated diverticulitis at our institution.

Adult↗
PubMed2004

[Obstructed defecation].

Adequate therapy of obstructed defecation (pelvic outlet obstruction) is often challenging, as the etiology and clinical symptoms include a wide range of disorders. Standardized diagnostic assessment has to differentiate between obstructed defecation caused by either pelvic outlet obstruction or slow transit constipation. Additionally, morphologic changes of colon, rectum, or the pelvic floor have to be separated from functional disorders. Providing defecography or dynamic MR of the pelvic floor, common causes of outlet obstruction such as sigmoidoceles, in which surgery is indicated, and rectal prolapse can be diagnosed with high accuracy. However, the diagnosis and therapeutic options in symptomatic rectocele and intussusception are controversial. Patients with functional disorders such as rectoanal dyssynergia are candidates for conservative treatment (biofeedback). To identify patients who will benefit from surgery for obstructed defecation, careful patient selection remains the crucial issue in diagnostic assessment.

Adolescent↗
PubMed2004

[Repeated thromboembolism during pregnancy with constitutional antithrombin deficiency].

We report the case of a twenty-three-year old woman with constitutional antithrombin deficiency, who had oral anticoagulation since she was four years old. During her first pregnancy, after the introduction of unfractionated heparin prophylactic therapy, she presented a first venous thromboembolism at nine weeks, and a second one with low-molecular-weight heparin therapy at nineteen weeks. Because of a severe antithombin deficiency, regular infusions of antithrombin concentrates were necessary until delivery to ensure effective anticoagulation by heparin. Patients with antithrombin deficiency have a very high risk of venous thromboses during the pregnancy and post-partum. We discuss the significant points of management for this period.

Adult↗
PubMed2004

[Early results of laparoscopic surgical procedures in Crohn's disease].

INTRODUCTION: During the last years laparoscopic surgical procedures are used more frequently in benign bowel diseases like Crohn's disease. We are reporting early results of laparoscopic procedures in Crohn's disease at our hospital. PATIENTS AND METHOD: From 1994 to 2003 54 patients (20 male and 34 female) underwent laparoscopic colonic and small bowel surgery in Crohn's disease. The mean age was 32 years (range: 16 to 55 years). RESULTS: Complications occurred in 6 patients (11.1 %). 3 patients needed a laparotomy. One computed tomography puncture was performed due to a hematoma. The remaining patients are treated successfully non-operatively. No patient died during the perioperative period. The mean operating time was 152 minutes (range 35 to 360 minutes) and the mean postoperative stay in hospital was 10 days (range 6-35 days). 0.2 blood cell concentrates were needed per operation (range 0 to 6), on average. The patients needed no analgesics after the 5 (th) day (range 1 to 13 days), got liquid diet on the 2 (nd) (range 0 to 6 days) and solid diet on the 3 (rd) day after surgery (range 1 to 14 days). DISCUSSION: Laparoscopic surgery in Crohńs disease is safe when performed by an experienced surgeon. The laparoscopic procedure results in a better cosmetic result, while the longer operating time is the mean disadvantage. There are low complication rates during the early postoperative period.

Adolescent↗
PubMed2004

Successful use of recombinant factor VIIa for management of severe menorrhagia in an adolescent with an acquired inhibitor of human thrombin.

UNLABELLED: Antibodies directed against human thrombin are exceedingly rare, having only been reported in adult patients with underlying diseases. Consensus on the most appropriate management has not yet been reached. A 12-y-old girl presented with intractable menorrhagia several days after an acute infectious episode. Laboratory tests revealed disturbed clotting tests: prothrombin index 17%, activated partial thromboplastin time >150 s, thrombin time >120 s, and failure to achieve correction with a normal pooled plasma. Further studies demonstrated the presence of an antibody directed against human thrombin. Viral serology revealed a 1/128 titre for adenovirus. Massive haemorrhage was unresponsive to standard treatments, but intravenous administration of recombinant factor VIIa resulted in a successful outcome. CONCLUSION: This is the first report of an anti-human thrombin antibody associated with severe bleeding in a child. Recombinant factor VIIa could represent a novel therapeutic approach for such patients.

Child↗
PubMed2003

[Nosocomial transfer of HBV and HCV by public health workers].

Transmission of HBV and HCV from people who work in medical professions to their patients is still an unsolved hygienic and legal problem. In Germany, cases of nosocomial hepatitis virus infection in health care units have received great public interest. Medical examinations of the employees according to occupational safety regulations aim at the employees only. Legal regulations including regulations of the European Union limit the purpose of these examinations on safety and health of the employees. These examinations do not serve the safety of patients. Protection against infections is regulated by the relevant German public health law, however regulations--especially those that concern the protection of the public--are incomplete. In Germany it is mandatory to inform the public health departments only in cases of acute hepatitis. Doctors do not need to give information about chronic liver infections. This may lead to the situation that a health care worker is unaware of a chronic, potentially infectious condition and his immunological status may remain unknown for a long period. Examinations in occupational medicine cannot solve this problem. In order to improve the protection of the public, there is a need to extend the regulations concerning the notification of chronic hepatitis and to implement solutions for this difficult and sensible problem in Germany.

Communicable Disease Control↗
PubMed2002

[Long-term outcome of AV node modulation in 387 consecutive patients with AV nodal reentrant tachycardia].

UNLABELLED: Aim of this study was to assess the long-term results of AV-node modulation in patients with AV nodal reetrant tachycardia. METHODS: From December 1991 until September 1999, AV node modulation (ablation of the fast pathway or ablation/modification of the slow pathway) was performed in 387 consecutive patients with clinically apparent AV nodal reentrant tachycardia. Follow-up data was available in 95% of patients with a mean of 41 +/- 26 months after ablation. RESULTS: Acute success rate was 97%. During long-term follow-up recurrence rate was 7.4% without any difference between fast and slow pathway ablation. Recurrence occurred in 23% of patients with persistent dual AV node physiology after ablation (modification of the slow pathway) in contrast to 3% without dual AV node physiology (ablation of the slow pathway) (p = 0.002). The presence of a dual AV node physiology after slow pathway modulation was the only predictor of recurrence during long-term follow-up. The complication rate was 5.7%. The incidence of complete heart block was 1% without any difference between fast and slow pathway ablation. CONCLUSIONS: Catheter modulation of the AV node for the treatment of AV nodal reentrant tachycardia is effective and safe. During long-term follow-up, the recurrence rate was low. Modulation of the slow pathway is associated with a significantly higher recurrence rate than ablation of the slow pathway.

Adult↗
PubMed2002

[Supporting primary stent implantation by angiographic length measurement].

In this study a procedure for online measurement of a coronary segment length during primary stenting is presented. The spatial segmental axis is calculated from a biplane angiogram and the corresponding projection data by simple delineation of the proximal and distal segment sites in each image. In a clinical evaluation the length error, projectional foreshortening and time frame during measurement of 222 stents or carrier balloons were calculated. The overall percentage length error was 3.3(+)-2.4%. The device length imaged with a mean projectional foreshortening of 18(+)-20% was measured within 18(+)-4 s. The procedure yields the accurate length of coronary segments within a short computation time taking projectional foreshortening into account.

Angioplasty, Balloon, Coronary↗
PubMed2002

[Use of heparin in acute myocardial infarction in routine clinical practice in Germany. Results of the MITRA and MIR registries].

OBJECTIVE: Among other adjunctive medication, heparin is widely used in the therapy of acute myocardial infarction (AMI) today. Large randomized trials, however, have shown inconclusive data on the benefit of adjunctive heparin therapy for patients with AMI. The aim of this study was to describe the use of heparin and complication rates in routine clinical practice today. METHODS: MITRA and MIR were multicenter registries of AMI patients in Germany. During the years 1994 to 1998, 22,697 patients were registered with MITRA and MIR. Of these patients 49.9% received reperfusion therapy. RESULTS: 21,004 patients (92%) received heparin during acute therapy of AMI. The following factors were associated with withholding heparin: Bleeding at admission (OR 4.7; CI 3.2-6.8), cardiogenic shock (OR 1.8; CI 1.4-2.3) and fibrinolytic therapy with streptokinase (OR 2.1; CI 1.8-2.3). Complication rates of patients with heparin were only slightly higher than among those without heparin: 1.7% strokes and 1.9% bleedings were reported among the patients with fibrinolysis and heparin compared to 1.3% strokes and 1.4% bleedings among patients without heparin (p = ns). Mortality rates were 14.1% for patients with and 27.3% for patients without heparin (p < 0.001). CONCLUSIONS: Of the patients in MITRA and MIR 92% received heparin during AMI. Patients with active bleeding or in critical condition received heparin significantly less often. The selection of critically ill patients may have contributed to the high mortality of patients without heparin for AMI. Bleeding complication rates of patients with adjunctive heparin were only slightly higher than reported in randomized trials.

Adult↗
PubMed2001

Association of serum apolipoprotein A-I (but not high-density lipoprotein cholesterol) with healed myocardial infarction in men independent of serum insulin and C-peptide.

Low serum levels of high-density lipoprotein (HDL) cholesterol or apolipoprotein A-I and high serum levels of insulin increase the risk of coronary heart disease (CHD) and can indicate insulin resistance. We tested the strength, independence, and interactions of associations between HDL cholesterol (or apolipoprotein A-I), insulin (or C-peptide), glucose, and CHD in 95 male nondiabetic patients with CHD who were <60 years old, in 92 probands from the PROCAM study, and in 61 non-cardiologic patients; all subjects were matched by age, body mass index, and smoking habits. Systemic hypertension (odds radio [OR] 2.8, 95% confidence intervals [CI] 1.6 to 4.8), high serum levels of glucose (OR 2.3, 95% CI 1.6 to 4.8), insulin (OR 2.1, 95% CI 1.3 to 3.6), and C-peptide (OR 4.1, 95% CI 2.2 to 7.5) as well as low serum levels of HDL cholesterol (OR 2.0, 95% CI 1.1 to 3.5) or apolipoprotein A-I (OR 3.9, 95% CI 2.1 to 7.1) had significant associations with CHD. At multivariate analysis, systolic blood pressure, glucose, apolipoprotein A-I, and C-peptide, but not HDL cholesterol and insulin, had consistent independent associations with CHD. Thus, the combined measurement of apolipoprotein A-I and C-peptide may improve the identification of nondiabetic patients at increased risk for CHD.

Adult↗
PubMed2001

A splice variant of beta-secretase deficient in the amyloidogenic processing of the amyloid precursor protein.

beta-Secretase (BACE) initiates the amyloidogenic processing of the amyloid precursor protein leading to the generation of the beta-amyloid, the main component of Alzheimer's disease senile plaques. BACE is a type I transmembrane aspartyl protease of 501 amino acids. Here we describe a novel BACE mRNA lacking 132 base pairs that is expressed in the pancreas but not in the brain. Sequence alignment indicates that the deleted fragment matches the terminal two-thirds of exon 3. The new BACE variant is short of a 44-amino acid region located between the two catalytic aspartyl residues. Accordingly, a 50-kDa form of BACE (BACE457) is detected in the human pancreas. When expressed in cells, BACE457 colocalizes with the marker for the endoplasmic reticulum BiP. Moreover, BACE457 remains in a proenzymatic and endoglycosidase H-sensitive state, suggesting that its transport along the secretory pathway is blocked at the level of the endoplasmic reticulum. Notably, this novel form of BACE does not contribute to the processing of the amyloid precursor protein. Our findings suggest that tissue-specific splicing of the BACE mRNA may explain the observation that in the human pancreas robust transcription of the BACE gene does not translate into recovered enzymatic activity.

Amino Acid Sequence↗
PubMed2001

An affordable, portable fluorescence imaging device for skin lesion detection using a dual wavelength approach for image contrast enhancement and aminolaevulinic acid-induced protoporphyrin IX. Part I. Design, spectral and spatial characteristics.

Steady-state fluorescence imaging can be used in conjunction with selective exogenous or endogenous fluorescent compounds for the diagnosis of skin lesions, for example cancerous lesions. Depending on the excitation and emission properties of the fluorescent compound used, various excitation and/or emission wavelengths can be chosen in order to allow fluorescence imaging. Unwanted background signals like autofluorescence and scattering can decrease the image quality and hence the diagnosis potential of this imaging method. A method involving two excitation and/or emission wavelengths was used in order to suppress the unwanted background signal and allow contrast enhanced fluorescence imaging. A fluorescence imaging device prototype was assembled using both the two wavelength excitation method and the two wavelength emission method. Additionally, a white light source was included to allow the collection of images as seen with the naked eye. The prototype was designed to be affordable and portable and was laid out towards the diagnosis of skin lesions using aminolaevulinic acid-induced protoporphyrin IX (PpIX). This paper describes the excitation and detection characteristics of a fluorescence imaging device prototype. This includes spectral and spatial characteristics of the various light sources included in the device as well as specifications of the image detector used. Furthermore, the image analysis procedure used for the dual wavelength excitation/emission is described.

Aminolevulinic Acid↗
PubMed2001

An affordable, portable fluorescence imaging device for skin lesion detection using a dual wavelength approach for image contrast enhancement and aminolaevulinic acid-induced protoporphyrin IX. Part II. In vivo testing.

A fluorescence imaging prototype for skin lesion detection and diagnosis using aminolaevulinic acid (ALA) induced protoporphyrin IX (PpIX) was tested in vivo and in the clinic. The prototype was designed as an affordable, portable device to allow contrast enhanced imaging of skin lesions using either the dual excitation wavelength method or the dual emission wavelength method or both. In this study the prototype was tested first on an animal model. Topical application of ALA on defined spots on mouse skin gave PpIX fluorescence after about 3 hours of application. After successful in vivo testing the instrument was tested on basal cell carcinoma patients before ALA-PpIX photodynamic therapy. The patients were topically applied with ALA. After three hours the device was tested (immediately before treatment). The prototype showed good results in terms of contrast enhancement (elimination of unwanted background signals, e.g. autofluorescence) using either contrast enhancement method, both methods achieving similar results. The results achieved in this study, combined with the affordable design of the device, seem to allow cost-effective, contrast-enhanced imaging of skin lesions before or during photodynamic therapy using ALA induced PpIX.

Aminolevulinic Acid↗
PubMed2000

Beneficial effects of pravastatin (+/-colestyramine/niacin) initiated immediately after a coronary event (the randomized Lipid-Coronary Artery Disease [L-CAD] Study).

Secondary prevention of coronary heart disease by antilipidemic therapy beginning at > or =3 months after an acute coronary syndrome is well documented. The impact, however, of immediate initiation of antilipidemic therapy on coronary stenoses and clinical outcome in patients with acute coronary syndrome is unknown. In our study, patients were randomized, on average, 6 days after an acute myocardial infarction and/or percutaneous transluminal coronary angioplasty secondary to unstable angina, to pravastatin (combined, when necessary, with cholestyramine and/or nicotinic acid) to achieve low-density lipoprotein cholesterol levels of < or =130 mg/dl (group A, n = 70). In controls (group B, n = 56), antilipidemic therapy was determined by family physicians. Quantitative coronary angiography was performed at inclusion, and at 6- and 24-month follow-up. The combined clinical end points were total mortality, cardiovascular death, nonfatal myocardial infarction, need for coronary intervention, stroke, and new onset of peripheral vascular disease. Minimal lumen diameter in group A increased by 0.05 +/- 0.20 mm after 6 months and 0.13 +/- 0.29 mm after 24 months, whereas it decreased by 0.08 +/- 0.20 mm and 0.18 +/- 0.27 mm, respectively, in group B (p = 0.004 at 6 months and p <0.001 at 24 months). After 2 years, 29 patients of 56 patients in group B, but only 16 of 70 patients in group A, experienced a clinical end point (p = 0.005; odds ratio 0.28, confidence intervals 0.13 to 0.6). We conclude that pravastatin-based therapy initiated immediately after an acute coronary syndrome is well tolerated and safe, lessens coronary atherosclerosis, and has a pronounced clinical benefit.

Adult↗
PubMed2000

Reduced synaptic clustering of GABA and glycine receptors in the retina of the gephyrin null mutant mouse.

Clustering of neurotransmitter receptors in postsynaptic densities involves proteins that aggregate the receptors and link them to the cytoskeleton. In the case of glycine and GABA(A) receptors, gephyrin has been shown to serve this function. However, it is unknown whether gephyrin is involved in the clustering of all glycine and GABA(A) receptors or whether it interacts only with specific isoforms. This was studied in the retinae of mice, whose gephyrin gene was disrupted, with immunocytochemistry and antibodies that recognize specific subunits of glycine and GABA(A) receptors. Because homozygous (geph -/-) mutants die around birth, an organotypic culture system of the mouse retina was established to study the clustering of gephyrin and the receptors in vitro. We found that all gephyrin and all glycine receptor clusters (hot spots) were abolished in the geph (-/-) mouse retina. In the case of GABA(A) receptors, there was a significant reduction of clusters incorporating the gamma2, alpha2, and alpha3 subunits; however, a substantial number of hot spots was still present in geph (-/-) mutant retinae. This shows that gephyrin interacts with all glycine receptor isoforms but with only certain forms of GABA(A) receptors. In heterozygous geph (+/-) mutants, no reduction of hot spots was observed in the retina in vivo, but a significant reduction was found in the organotypic cultures. This suggests that mechanisms may exist in vivo that allow for the compensation of a partial gephyrin deficit.

Animals↗