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A Koch

Publications and source records attributed to A Koch.

At least 73 records · Page 4Linked to original sources
PubMed2002

[Laparoscopic treatment of iatrogenic perforations of the colon].

Iatrogenic perforations of the colon are serious complications that have been observed in association with both diagnostic and therapeutic colonoscopies, and are not always avoidable, even in the hands of an experienced investigator. Patients suffering from a perforation during elective colonoscopy are starving, and have a clean bowel. If the perforation is quickly diagnosed with only local mild peritonitis, laparoscopic treatment is often possible. The therapeutic options available are: oversewing, wedge resection and, in the individual case, tubular resection, as well as laparoscopic-assisted reconstruction, if indicated including a protective stoma. The decision to perform a laparoscopic procedure should depend on the time of detection of the lesion, and on the skills of the existing surgical team; otherwise, a laparotomy is indicated. We describe four cases that reflect the relevance of the laparoscopic approach.

Aged↗
PubMed2002

[Appendicitis in the last decade of the 20th century--Analysis of two prospective multicenter clinical observational studies].

AIMS OF THE STUDY: The authors present an accurate and comprehensive snapshot of appendicitis in the last decade of the 20 (th) century. The present study also aims to determine the influence of introduction of laparoscopic techniques on the quality of appendicitis therapy. PATIENTS AND METHODS: All consecutive patients admitted for suspected appendicitis were recruited into this prospective multicenter study. Two different periods of time were considered: from 1. 7. 1988 to 31. 12. 1989, 6 266 patients from 18 hospitals were included, and from 1. 6. 1996 to 31. 5. 1997, 7 398 patients from 34 institutions. RESULTS: In the first period (1988/89), 1 869 patients were treated conservatively (29.8 %), 4 397 (70.2 %) were operated. Histopathological analysis of the appendix documented no acute inflammation in 28.8 %, the perforation rate was 8.3 % and the wound infection rate 9.6 %. In the second period (1996/97), 2 430 patients were treated conservatively (32.8 %), in 24.9 % of all operated cases, the histopathological examination shows no acute inflammation of the appendix, the perforation rate was 5.9 % and the rate of wound infections 2.5 %. During this second period, 33.2 % of all appendectomies were performed using the laparoscope, the conversion rate was 7.2 %. CONCLUSIONS: The introduction of laparoscopic techniques did not modify the operative indications for treatment of appendicitis. An increase in the number of normal appendices removed was not observed. The number of perforations and the incidence of wound infections was significantly reduced in the second period.

Adolescent↗
PubMed2002

[Prospective multi-center study colon/rectum carcinoma (primary tumors)--Results of the year 2000].

INTRODUCTION: Surgical quality control in the form of multicentre studies make it possible to analyse the treatment status of a given surgical illness under quality assurance aspects. MATERIAL/METHODS: On 1. 1. 2000, under the patronage of the Convent of Hospital Chief Surgeons a project (ongoing) - organised and conducted by the Institute for Quality Management in Operative Medicine at the Otto-von-Guericke University of Magdeburg - was initiated to document and collect the data of patients with colorectal cancer throughout the whole of Germany. This work is supported by the German Society of Surgery, and the Surgical Working Group, Quality Assurance within the German Society of Surgery. Currently, some 282 hospitals throughout the country are involved in establishing a prospective documentation of colorectal carcinoma. Participation in this study is on a voluntary basis. The anonymity of both patients and hospitals is guaranteed, and no hospitals wishing to participate are excluded. Both operatively and conservatively treated patients are being documented, and no randomization takes place. RESULTS: In the year 2000, the participating hospitals documented a total of 9 477 patients with a colorectal carcinoma, including 6 975 patients with a carcinoma of the colon, and 3 402 with a rectal carcinoma. The average age of the patients was 68.5 years, and there were 5 010 men and 4 467 women. The operation rate was 99.2 %, the resection rate 95.6 %. The abdominoperineal resection rate was 27.4 %. The indicators for diagnostic quality as set out by Hermanek were largely complied with, but some deviations were noted. DISCUSSION: On the basis of the data collected, structures were established for a uniform Germany-wide quality management for a clinical condition with a major health policy impact. This information make it possible for the hospitals to identify and eliminate deficits in the structural and process quality in the diagnosis and treatment of colorectal cancer, and in this way to improve outcome quality. This means that the results of medical care research have an immediate impact on the individual treatment received by a given patient.

Adult↗
PubMed2002

[Which factors are responsible for postoperative mortality in colorectal cancer patients?].

INTRODUCTION: The postoperative decease is the most severe complication in surgery. PATIENTS AND METHOD: Within the framework of a multicentre study between January 1 (st) and December 31, 1999, 3,756 patients, 1,463 of them suffering from rectal cancer and 2 293 from colon carcinoma, from 75 clinics were documented with the help of a standardized questionnaire. We compared data of 211 patients who died postoperatively with data of 3,484 patients who survived after surgical treatment of colorectal cancer. Logistical regressions, under inclusion and exclusion of intra- and postoperative complications, show independent influence factors on the postoperative decease and provide models for the prediction of the postoperative death. RESULTS: Compared to the patients who survived, the postoperative deceased patients were significantly older. They had a poorer risk profile and therefore a higher ASA-score (p < 0.001). 20.4 % of the patients underwent an emergency operation. General and specific postoperative complications occurred significantly more frequently. The model of a logistical regression allowed the prediction of postoperative decease with a sensitivity and specificity of 91 %. General postoperative complications such as pulmonary embolism (relative risk: 30.3), cardiac (relative risk: 24.1), renal (relative risk: 22.1), and pulmonary complications (relative risk: 12.0) are crucial for lethality. DISCUSSION: The postoperative decease is influenced by several factors. It is impossible to reduce the number of influence factors for the prediction of outcome. The general postoperative complications, however, represent a crucial problem. It is important to avoid these problems in order to reduce postoperative lethality.

Adolescent↗
PubMed2001

Deletions of AXIN1, a component of the WNT/wingless pathway, in sporadic medulloblastomas.

Medulloblastoma (MB) represents the most frequent malignant brain tumor in children. Most MBs appear sporadically; however, their incidence is highly elevated in two inherited tumor predisposition syndromes, Gorlin's and Turcot's syndrome. The genetic defects responsible for these diseases have been identified. Whereas Gorlin's syndrome patients carry germ-line mutations in the patched (PTCH) gene, Turcot's syndrome patients with MBs carry germ-line mutations of the adenomatous polyposis coli (APC) gene. The APC gene product is a component of a multiprotein complex controlling beta-catenin degradation. In this complex, Axin plays a major role as scaffold protein. Whereas APC mutations are rare in sporadic MBs, a hot-spot region of beta-catenin (CTNNB1) mutations was identified in a subset of MBs. To find out if Axin is also involved in the pathogenesis of sporadic MBs, we analyzed 86 MBs and 11 MB cell lines for mutations in the AXIN1 gene. Using single-strand conformation polymorphism analysis, screening for large deletions by reverse transcription-PCR, and sequencing analysis, a single somatic point mutation in exon 1 (Pro255Ser) and seven large deletions (12%) of AXIN1 were detected. This indicates that AXIN1 may function as a tumor suppressor gene in MBs.

Adolescent↗
PubMed2001

Somatic mutations of WNT/wingless signaling pathway components in primitive neuroectodermal tumors.

Primitive neuroectodermal tumors (PNETs) represent the most frequent malignant brain tumors in childhood. The majority of these neoplasms occur in the cerebellum and are classified as medulloblastomas (MB). Most PNETs develop sporadically; however, their incidence is highly elevated in patients carrying germline APC gene mutations. The APC gene encodes a central component of the WNT/wingless developmental signaling pathway. It regulates the levels of cytoplasmic beta-catenin protein that plays a central role in neural development and cell proliferation. We analyzed 87 sporadic PNETs and 10 PNET cell lines for mutations of the APC gene and beta-catenin (CTNNB1) gene using single strand conformational polymorphism (SSCP) and sequencing analysis. We examined the mutation cluster region of APC (codons 1255--1641) for germline variants and somatic mutations. The medulloblastoma cell line MHH-MED-2 carried a Glu1317Gln missense germline variant and a sporadic MB sample showed a somatic Pro1319Leu substitution. Mutational analysis of exon 3 of CTNNB1 uncovered 4 PNETs (4.8%) with somatic missense mutations. These mutations caused amino acid substitutions in 3 of 80 medulloblastomas (Ser33Phe, Ser33Cys and Ser37Cys) and 1 of 4 supratentorial PNETs (Gly34Val). All mutations affected GSK-3 beta phosphorylation sites of the degradation targeting box of beta-catenin and resulted in nuclear beta-catenin protein accumulation. Deletions of CTNNB1 were not detected by PCR amplification with primers spanning exons 1--5. Our data indicate that inappropriate activation of the WNT/wingless signaling pathway by mutations of its components may contribute to the pathogenesis of a subset of PNETs.

Adenomatous Polyposis Coli Protein↗
PubMed2001

Substituent influences on the stability of the ring and chain tautomers in 1,3-O,N-heterocyclic systems: characterization by 13C NMR chemical shifts, PM3 charge densities, and isodesmic reactions.

Substituent effects on the stabilities of the ring and chain forms in a tautomeric equilibrium of five series of 2-phenyloxazolidines or -perhydro-1,3-oxazines possessing nine different substitutions at the phenyl moiety have been studied with the aid of 13C NMR spectroscopy and PM3 charge density and energy calculations. Reaction energies of the isodesmic reactions, obtained from the calculated energies of formation, show that electron-donating substituents stabilize both the chain and ring tautomers but the effect is stronger on the stability of the chain form than on that of the ring form. The 13C chemical shift changes induced by the phenyl substituents (SCS) were analyzed by several different single and dual substituent parameter approaches. The best correlations were obtained by equation SCS = rhoFsigmaF + rhoRsigmaR. In all cases the rhoF values and in most cases also the rhoR values were negative at both the C=N and C-2 carbons, indicating a reverse behavior of the electron density. This concept could be verified by the charge density calculations. The 13C chemical shifts of the C=N and C-2 carbons show a normal dependence on the charge density (q(tot)), but the charge density shows a reverse dependence on substitution. Correlation analysis of the 13C chemical shifts, solvent effect (CDCl3 vs DMSO-d6) on the NMR behavior as well as the effect of substituents on the electron densities and on the stabilities of the ring and chain tautomers show that the substituent dependence of the relative stability of the ring and chain tautomers in equilibrium is governed by several different electronic effects. At least intramolecular hydrogen bonding between the imine nitrogen and the hydroxyl group as well as polarization of the C=N bond seem to contribute in the chain form. Stereoelectronic and electrostatic effects are possible to explain the increase in stability of the ring form by electron-donating substituents.

Journal Article↗
PubMed2001

Low molecular weight heparin and unfractionated heparin in thrombosis prophylaxis: meta-analysis based on original patient data.

A meta-analysis (MA) based on original patient data has been performed comparing low molecular weight heparins (LMWH) with unfractionated heparin (UFH) in thrombosis prophylaxis after major surgical interventions. The analyses have been done for the following prespecified groups of studies: all studies, studies in orthopaedic surgery (OS) and studies in general surgery (GS, with further separation into low-dose studies [GS-LD] and high-dose studies [GS-HD]). Deep vein thrombosis (DVT, all locations) and wound haematoma were used as primary endpoints for efficacy and safety, respectively. The analysis confirms the results of previous publication-based meta-analyses. In GS there is no relevant difference between LMWH and UFH regarding efficacy; the safety results strongly depend on the dosage: under low-dose LMWH the risk of wound haematoma is significantly lower, under high-dose LMWH it is significantly higher than under UFH. However, most of the studies in the last group used regimens of LMWH that are not considered appropriate any more. In OS there is a trend towards a better efficacy and safety of LMWH. In addition, LMWHs are superior to UFH, in OS, with respect to the secondary endpoints proximal DVT and pulmonary embolism. The rates of proximal DVT and pulmonary embolism, respectively, are consistently lower under LMWH than under UFH, whereas slightly smaller rates of distal DVT are observed under UFH.

Double-Blind Method↗
PubMed2001

Laparoscopy of a traumatic rupture of a dysontogenetic splenic cyst. A case report.

The role of laparoscopy in the stepped approach to the diagnosis and treatment of blunt abdominal trauma has not yet been fully elucidated. Despite the use of a variety of imaging modalities, it can still be difficult to make a proper evaluation in cases where there are questionable abdominal injuries. In particular, when there is a discrepancy between a bland clinical picture and the results of diagnostic imaging procedures, laparoscopy should be given preference over laparotomy, provided the patient's circulatory situation is stable. Herein we describe a case in which laparoscopy allowed the detection and treatment of a traumatic rupture of a dysontogenetic splenic cyst that had mimicked a rupture of the spleen on both the ultrasound (US) and computed tomography (CT) images.

Abdominal Injuries↗
PubMed2001

Acute respiratory tract infections and mannose-binding lectin insufficiency during early childhood.

CONTEXT: Hospital-based studies have found that increased susceptibility to certain infections is associated with low serum levels of mannose-binding lectin (MBL) due to MBL variant alleles. However, the contribution of MBL insufficiency to incidence of common childhood infections at a population level is unknown. OBJECTIVE: To investigate the effect of MBL insufficiency on risk for acute respiratory tract infection (ARI) in unselected children younger than 2 years. DESIGN AND SETTING: Population-based, prospective, cohort study conducted in Sisimiut, Greenland. PARTICIPANTS: Two hundred fifty-two children younger than 2 years who were followed up weekly between August 1996 and August 1998 for morbidity surveillance. MAIN OUTCOME MEASURE: Risk of ARI, based on medical history and clinical examination, compared by MBL genotype, determined from blood samples based on presence of structural and promoter alleles. RESULTS: A 2.08-fold (95% confidence interval [CI], 1.41-3.06) increased relative risk (RR) of ARI was found in MBL-insufficient children (n = 13) compared with MBL-sufficient children (n = 239; P<.001). The risk association was largely restricted to children aged 6 to 17 months (RR, 2.92; 95% CI, 1.78-4.79) while less effect (RR, 1.47; 95% CI, 0.45-4.82) and no effect (RR, 1.00; 95% CI, 0.42-2.37) was shown among children aged 0 to 5 months and 18 to 23 months, respectively. CONCLUSION: These data suggest that genetic factors such as MBL insufficiency play an important role in host defense, particularly during the vulnerable period of childhood from age 6 through 17 months, when the adaptive immune system is immature.

Acute Disease↗
PubMed2001

In situ NMR observation of mono- and binuclear rhodium dihydride complexes using parahydrogen-induced polarization.

Starting from the binuclear complex [RhCl(NBD)]2 (NBD = 2,5-norbornadiene) in the presence of the phosphines L = PMe3, PMe2Ph, PMePh2, PEt3, PEt2Ph, PEtPh2, or P(n-butyl)3, various mononuclear dihydrides of the type Rh(H)2CIL3, i.e., those of the homogeneous hydrogenation catalysts RhCIL3, have been obtained upon addition of parahydrogen, and their 1H NMR spectra have been investigated using parahydrogen-induced polarization (PHIP). Furthermore, the two binuclear complexes (H)(Cl)Rh(PMe3)2(mu-Cl)(mu-H)Rh(PMe3) and (H)(Cl)Rh(PMe2Ph)2(mu-Cl)(mu-H)Rh(PMe2Ph) have been detected and characterized by means of this in situ NMR method. Analogous complexes with trifluoroacetate instead of chloride, i.e., Rh(H)2(CF3COO)L3, have been generated in situ starting from Rh(NBD)(acac) in the presence of trifluoroacetic acid in combination with the phosphines L = PPh3, PEt2Ph, PEt3, and P(n-butyl)3, and their 1H NMR parameters have been determined.

Journal Article↗
PubMed2001

Strictureplasty for large bowel stenosis in Crohn's disease: quality of life after surgical therapy.

The aim of surgical therapy in Crohn's disease is to improve quality of life. Surgery does not provide cure with radical resection of inflamed bowel. Therefore strictureplasty has become a useful bowel-preserving surgical technique in the treatment of small-bowel stenosis. To preserve functional bowel we extended the indication of this surgical technique to strictures in large bowel. The aim of this retrospective study was to define the efficacy of strictureplasty and resection in patients with obstructive Crohn's disease of the colon. The results were evaluated in terms of postoperative complications, surgical recurrence, and quality of life. The charts of 58 patients with Crohn's colitis were analyzed retrospectively. Patients were either treated by strictureplasty or resection. Quality of life was evaluated in follow-up examinations using the Inflammatory Bowel Disease Questionnaire. The incidence of postoperative surgical recurrence was 36% in those treated by strictureplasty and 24% in those treated by resection (ns). Postoperative morbidity was 16.1% in the former and 22.3% in the latter. There was no significant difference between the groups in quality of life measures (177 versus 182 points). Strictureplasty in Crohn's colitis is a valuable surgical technique which results in low recurrence rates and in surgical outcome comparable to that in resection without sacrificing functional large bowel length. In our study quality of life after strictureplasty was comparable with quality of life after resection.

Adult↗
PubMed2001

Effect of caseload on the short-term outcome of colon surgery: results of a multicenter study.

This prospective multicenter study investigated the effect of hospital caseload on early postoperative outcome of surgery for carcinoma of the colon in 75 German hospitals and included 2293 patients. The hospitals were divided into those with a caseload of 1-30 (group A), 31-60 (group B), and more than 60 (group C) operations. Increasing caseload was associated only with fewer general postoperative complications. It was also associated with significantly greater use of antibiotic prophylaxis. No significant differences between the groups were found in resection rates, intraoperative complications, specific postoperative complications, overall postoperative morbidity, hospital mortality, or 30-day mortality. The significance of hospital caseload for the short-term postoperative outcome following surgery on the colon should not be overestimated. Basing conclusions about the results to be expected simply on the case volume is impermissible. On the basis of the available data it is not possible to establish a threshold value, that is, a minimum number of required operations.

Adenocarcinoma↗
PubMed2001

[Balloon dilatation of the pulmonary valve. Short-, middle- and long-term results].

BACKGROUND: Immediate and long-term results after balloon dilatation of pulmonary valve stenosis in our unit. METHODS AND PATIENTS: All 111 patients (1 day-18 years) who have had balloon dilatation of a pulmonary valvar stenosis between 12/1987 and 8/1997 were divided into 4 groups: Typical valvar pulmonary stenosis (group A; n = 78), stenosis with dysplastic pulmonary valve (group B; n = 10), critical pulmonary stenosis (group C; n = 16) and pulmonary atresia after transcatheter or operative opening of the valve (group D; n = 7). Patients with pulmonary stenosis and complex congenital heart disease were excluded. RESULTS: The average systolic transvalvular gradient was reduced from 68.5 to 27.2 mmHg (60%) immediately after balloon dilatation. After a follow up of 48.8 +/- 37 months 101 patients could be reevaluated. In group A (n = 69 at FU) and C (n = 16 at FU) 81% showed a systolic transvalvular gradient < 30 mmHg after one and 83% (A) respective 94% (C) after two balloon dilatations. In group B (n = 9 at FU) 44% exhibited a systolic gradient < 30 mmHg after one and 56% after two balloon dilatations. In group D (n = 7 at FU) 57% showed a systolic gradient < 30 mmHg with no further improvement by a second dilatation. Over all, 80% of our patients could be treated sufficiently by transcatheter means. The rate of major complications was 7.3% with no lasting residuals at follow up and no deaths. CONCLUSION: Balloon dilatation of the pulmonary valve is secure and effective. Best results are obtained in patients with typical pulmonary valve stenosis and in newborns and infants with critical pulmonary valve stenosis.

Adolescent↗
PubMed2001

[Advances in interventional occlusion of persistent ductus arteriosus: comparison of results using different occlusion devices].

This report describes our results with transcatheter closure of patent ductus arteriosus between March 1993 and May 2000 including our early experience with the Amplatzer duct occluder. One hundred and sixty-six consecutive procedures were performed in 160 patients. The mean age was 6.8 years (range 0.8 to 26.2), mean weight 24.3 kg (range 7.7 to 84.0). Single or multiple coils were implanted successfully in 114 cases, a Rashind double umbrella in 35 patients, and an Amplatzer duct occluder in 16 patients. After failure to implant coils in one patient, a second attempt with a Rashkind double umbrella was successful. Complete closure of the patent ductus arteriosus was achieved in a total of 148 patients (92.5%), mean fluoroscopy time was 13.7 min (range 3.1 to 126 min). In 144 patients (90.0%), occlusion without residual shunting was achieved by the first interventional approach. Angiography showed immediate closure in 44%, echocardiography within 48 h revealed complete closure in additional 28%. In a further 18%, a residual shunt disappeared spontaneously in the following months. In five patients a second procedure was performed to terminate residual shunting after placement of a Rashkind occluder system by coils. In three patients, the residual shunt resolved. In 12 patients (7.5%) echocardiography showed a residual shunt 2-1259 days after interventional approach. Occlusion rates of the different devices were 83% for the Rashkind occluder, 92% for detachable coils, and 100% for the Amplatzer duct occluder. Coil embolisation into the pulmonary artery occurred in two patients, interventional removal was successful in one of them. There were no further complications. According to our experience interventional occlusion of patent ductus arteriosus is highly effective and associated with a low complication rate. Transcatheter closure using the Amplatzer duct occluder seems to be safe and effective also in small children with a body weight of 8 kg and a large ductus diameter. Compared to the total group of patients, the occlusion rate of the Amplatzer duct occluder was significantly higher (p = 0.005), and of the Rashkind occluder system significantly lower (p = 0.026). Therefore, we recommend the use of detachable coils in patients with small ductus (diameter < or = 2 mm) and the Amplatzer duct occluder in those with a larger ductus. Transcatheter closure of the patent ductus arteriosus according to this regimen should achieve occlusion rates above 95%.

Adolescent↗
PubMed2001

[Aortic root abscess without involvement of the aortic valve: diagnosis and therapy in a 2.5-year-old child].

Although formation of an aortic root abscess is a frequent complication of aortic valve endocarditis in adults, this complication has been rarely observed in children. In the majority of cases it has been described in children without underlying congenital heart disease. Due to the rarity of this complication, diagnosis and treatment is frequently delayed in childhood. We report a 2 1/2 year old girl who developed pericardial effusion in the course of pneumonia. Echocardiographic examinations, which were performed because of the pericardial effusion, revealed after 6 days the development of a cystic structure posterior to the aortic root. There was a perforation of this aortic root abscess to the left ventricular outflow tract; the aortic and mitral valves however were normal without endocarditic vegetations. Surgery was performed on the 10th day following a rapid increase in the size of the abscess. During surgery the abscess was drained and the perforation to the left ventricle was closed with direct sutures. Intraoperative transesophageal echocardiography confirmed a good surgical result. Blood cultures remained negative; in the material from the abscess however we found staphylococcus aureus. The postoperative course was uneventful. Our case demonstrates the necessity of detailed and repeated echocardiographic examinations in children with possible symptoms of bacterial endocarditis (in our case pericardial effusion) as well as the requirement of cultures of the abscess for identification of the infective organism. Intraoperative transesophageal echocardiography allows exact description of an aortic root abscess, its relation to other cardiac structures and immediate evaluation of the surgical result.

Abscess↗
PubMed2001

Effects of ambient cold and depth on lung function in humans after a single scuba dive.

This study evaluated the subacute respiratory effects of diving, to try to separate the effects of ambient temperature from those of depth. In the first experiment 10 healthy men made a compressed-air dive to 50 m that exposed them to cold. They were compared with 10 matched control subjects who underwent the same dive profile but were exposed to a comfortable temperature. In the second experiment 16 healthy subjects made randomized cold dives to both 50 m and 10 m. Pulmonary function tests were made before, after 1 h, and 24 h after the dives. In the first experiment there was an increase in residual volume (P < 0.05) and a decrease in forced expiratory volume at 1 s (FEV1), in forced vital capacity (FVC) and in mid-expiratory flow at 75% of FVC (MEF75) 1 h after the cold dives (P < 0.05). In the second experiment significant increases in specific airways resistance (sR(AW)) (P < 0.05) and decreases in FEV1 (P<0.01), in MEF75 (P<0.05), and in mid-expiratory flow at 25% of FVC (P<0.05), were obtained after the 50 m-dives, whereas SR(AW) increased after the 10 m-dives (P<0.05). The respiratory pattern observed 1 h after cold dives to 50 m indicated airway narrowing. The changes after cold dives to 10 m, however, were of minor magnitude. Both cold and depth seemed to contribute to the adverse effects of a single compressed-air dive on pulmonary function.

Adult↗