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Biomedical subjects

S Schulze

Publications and source records attributed to S Schulze.

At least 73 records · Page 4Linked to original sources
PubMed1997

Effect of prednisolone on the systemic response and wound healing after colonic surgery.

OBJECTIVE: To study the effect of preoperative treatment with a single high-dose glucocorticoid on the systemic and immunologic responses, wound healing, and convalescence after colonic surgery. DESIGN: Double-blind, placebo-controlled, randomized trial. SETTING: Department of surgery in a university hospital. PATIENTS: Thirty patients scheduled for open colonic resection; 6 patients were excluded from the study (N = 24). INTERVENTIONS: Patients were randomized to either of 2 treatment regimens: methylprednisolone sodium succinate 90 minutes before induction of anesthesia and epidural analgesia (group 1, n = 12), or placebo 90 minutes before anesthesia and epidural analgesia (group 2, n = 12). MAIN OUTCOME MEASURES: Assessments of pain, pulmonary function, convalescence, and various injury and wound-healing factors were done several times until 10 days after surgery. RESULTS: Conventional reduction in pulmonary function and mobilization was improved in group 1. Interleukin-6 and C-reactive protein levels increased significantly less in group 1, as delayed-type hypersensitivity was abolished in group 1. Plasma cascade system activations were significantly less pronounced in group 1. Reduction of collagen turnover was observed in group 1, but without detrimental effects on collagen accumulation. CONCLUSION: Treatment with a single high-dose glucocorticoid before colonic surgery may improve postoperative pulmonary function and mobilization and reduce plasma cascade system activations, the inflammatory response, and immunofunction, but without detrimental effects on wound healing.

Adult↗
PubMed1997

Topography and dipole analysis of reafferent electrical brain activity following the Bereitschaftspotential.

The cerebral events related to limb movements can be studied noninvasively with the method of evoked potentials. In this study, a brain potential is analysed that follows the onset of a simple finger movement. Because this potential occurred after active as well as after passive movements, its previously alleged reafferent somatosensory nature is confirmed in this study. Detailed topographic analysis revealed that this potential has the same polarity and merges with the preceeding Bereitschaftspotential (BP; in the active movement) at central electrodes, whereas at parietal electrodes polarity is opposite to the BP. In individual subjects, the maximum of the BP and the peak of the reafferent potential are separated by a small gap, previously described as pre-motion positivity. A comparison with the N20 potential of the electrically evoked somatosensory potential showed similar potential topography, albeit opposite polarity. The dipole analysis supported the view that the reafferent and the electrically evoked potentials are likely to arise from the same cortical area, namely the primary somatosensory cortex.

Adult↗
PubMed1997

Evaluation of the Abbott Cell Dyn 4000 automated fluorescent reticulocyte measurements: comparison with manual, FACScan and Sysmex R1000 methods.

The Abbott Cell Dyn 4000 (CD4000) is the first haematology analyser in which fully-automated reticulocyte measurements can be routinely determined by fluorescence as part of the full blood count. This communication reports the first evaluation of this method which was undertaken by three independent reference laboratories in Belgium, Germany and Italy. A total of 695 different samples was entered into the study which was designed to compare CD4000 reticulocyte information (enumeration and qualitative maturational data) with results determined in parallel with the existing manual (supravital staining) reference procedure, and two semi-automated fluorescent assays (Becton Dickinson FACScan and Sysmex R1000 instruments). These studies revealed good agreement between the CD4000 and the manual procedure, with no inter-method bias. Comparison of CD4000 and FACScan reticulocyte measurements, however, indicated a distinct tendency for the FACScan to give higher reticulocyte estimates than the CD4000. Finally, the comparison of the CD4000 with the Sysmex R1000 showed excellent agreement in the range 0-6% reticulocytes, although there was some inter-method bias in the higher range (> 15%). Analysis of agreement levels between the methods using specific 'clinical decision points' confirmed the tendency for overestimation by the FACScan, in that 58% of the samples with a reticulocytopenia of < 0.5% as defined by the CD4000 gave FACScan results within the normal range (0.5-1.8%). In contrast, there was absolute agreement between the CD4000 and the Sysmex R1000 for all reticulocytopenias. Comparison (195 samples) of instrument fluorescent reticulocyte maturation profiles demonstrated an exponential relationship (r = 0.78) between CD4000 IRF and R1000 HFR (highly fluorescent reticulocyte fraction) values. The suggestion that the CD4000 IRF values includes some of the MFR as well the HFR reticulocyte fraction was confirmed as the correlation between the CD4000 IRF and the Sysmex R1000 MFR plus HFR percentages was linear (r = 0.82). This study confirms a high performance level for the CD4000 automated fluorescent reticulocyte method.

Autoanalysis↗
PubMed1997

Prospective randomized study of laparoscopic versus open colonic resection for adenocarcinoma.

BACKGROUND: Laparoscopic techniques have been evaluated for many operations, but retrospective and prospective studies have failed to show these techniques to be superior to open operations in all patients with colorectal disease. This study compares laparoscopic and open colonic resection in a randomized fashion with special reference to outcome, complications and immunomodulation. METHODS: The clinical course, assessment of convalescence parameters, immunofunction and pathological evaluation of the operative specimen were compared in 34 patients with colonic adenocarcinoma. The patients were randomized to either laparoscopic surgery (group 1, n = 18) or open surgery (group 2, n = 16). As five patients were excluded the number of patients was 15 in group 1 and 14 in group 2. RESULTS: Patients in group 1 were discharged earlier (P < 0.05) and suffered less pain (P < 0.01 at rest, P < 0.05 during coughing and mobilization). Surgery was equally radical in the two groups. Intraoperative bleeding, postoperative reduction in pulmonary function, and level of fatigue were identical in the two groups. The immunodepression was more pronounced in patients in group 1 (P < 0.01). CONCLUSION: Laparoscopic colonic resection is an acceptable and safe alternative to open procedures; the differences between the two techniques are not marked.

Adenocarcinoma↗
PubMed1997

Bile duct injury during laparoscopic cholecystectomy: a prospective nationwide series.

BACKGROUND: The risk of bile duct injury in laparoscopic cholecystectomy has been a concern since the procedure became part of the surgical armamentarium. Our study assesses the incidence, types, and treatment for laparoscopic bile duct injury. STUDY DESIGN: Prospective case registration in a national database with participation by all departments of surgery performing laparoscopic cholecystectomy in Denmark since the first operation in January 1991. The case notes for bile duct injury have been reviewed. RESULTS: From 1991 through 1994, 57 of 7,654 patients sustained bile duct injury (0.74 percent; 95 percent confidence interval, 0.55 percent to 0.94 percent), including nine injuries occurring after conversion. The annual incidence did not decrease. Thirty-nine percent of the laparoscopic bile duct injuries were incisions, 39 percent were transections, and 12 percent were clip injuries or strictures. One patient, who sustained transection during open reoperation for bleeding after a converted procedure, died. Bile leaks for reasons other than bile duct injury occurred in 2.1 percent; 71 percent of these were cystic duct leaks. Acute cholecystitis was the indication for laparoscopic cholecystectomy in 968 patients, with 1.3 percent sustaining laparoscopic bile duct injury (95 percent confidence interval, 0.62 percent to 2.08 percent), while the incidence in patients with other indications for laparoscopic cholecystectomy was 0.62 percent (95 percent confidence interval, 0.44 percent to 0.82 percent) (p > 0.05). Preoperative knowledge of bile duct anatomy was available by means of preoperative endoscopic retrograde cholangiopancreatography or intravenous cholangiography in 26 percent of patients undergoing laparoscopic cholecystectomy but this did not reduce the risk of bile duct injury. The frequency of bile duct injury in patients who had intraoperative cholangiography was not significantly different from those who did not. Intraoperative cholangiography was done in 14 cases of injury (diagnostic for injury in 8, misinterpreted in 2, and normal in 4 patients). The case notes described operative difficulties in 11 of 48 cases of laparoscopic bile duct injury, most often because of fibrosis or difficulty delineating the anatomy. CONCLUSIONS: The incidence of bile duct injury in laparoscopic cholecystectomy is higher than previously generally anticipated and did not decrease from 1991 through 1994. Risk factors and possible preventive measures should be evaluated in prospective studies.

Bile Ducts↗
PubMed1996

Double blind randomised controlled trial of effect of metoprolol on myocardial ischaemia during endoscopic cholangiopancreatography.

OBJECTIVE: To evaluate the effect of metoprolol, a beta adrenergic blocking drug, on the occurrence of myocardial ischaemia during endoscopic cholangiopancreatography. DESIGN: Double blind, randomised, controlled trial. SETTING: University Hospital. SUBJECTS: 38 (two groups of 19) patients scheduled for endoscopic cholangiopancreatography. INTERVENTIONS: Metoprolol 100 mg or placebo as premedication two hours before endoscopy. MAIN OUTCOME MEASURES: Heart rate, arterial oxygen saturation by continuous pulse oximetry, ST segment changes during endoscopic cholangiopancreatography (an ST segment deviation > 1 mV was defined as myocardial ischaemia), electrocardiogram monitored continuously with a Holter tape recorder. RESULTS: All patients had increased heart rate during endoscopy compared with rate before endoscopy, but heart rate during endoscopy was significantly lower in the metoprolol group compared with the placebo group (P = 0.0002). Twenty one patients (16 placebo, 5 metoprolol; P = 0.0008) developed tachycardia (heart rate > 100/min) during the procedure, and 11 patients (10 placebo, 1 metoprolol; P = 0.003) developed myocardial ischaemia. One patient in the placebo group had an acute inferolateral myocardial infarction. In the 10 other patients with signs of myocardial ischaemia during endoscopy the ST deviation disappeared when the endoscope was retracted. In all patients myocardial ischaemia was related to increases in heart rate, and 10 of the 11 patients had tachycardia coherent with myocardial ischaemia. CONCLUSIONS: Metoprolol prevented myocardial ischaemia during endoscopic cholangiopancreatography, probably through lowering the heart rate. Thus, tachycardia seems to be a key pathogenic factor in the development of myocardial ischaemia during endoscopy.

Adrenergic beta-Agonists↗
PubMed1996

Covered stents for prevention of restenosis. Experimental and clinical results with different stent designs.

RATIONALE AND OBJECTIVES: Metallic stents in small vessels go along with a significant risk of restenosis and reocclusion. Different models of stents and covering materials have been purported to prevent intraluminal neointimal proliferation by cover-based closure of the spaces in the wire mesh. METHODS: Tantalum stents covered with polyethylacrylate/polymethylmethacrylate (PEM) were implanted in the infrarenal aorta of six New Zealand white rabbits by aortotomy and compared with eight rabbits treated with uncovered tantalum stents. For deployment, covered and uncovered stents necessitated a 7-French (F) and 5-F sheath, respectively. In addition, nine human patients with arteriosclerotic lesions of the superficial femoral arteries (stenosis > 5 cm or total occlusion) were treated percutaneously with a Dacron-covered nitinol vascular stent via a 9-F sheath. Patients were followed for a mean of 13.5 months, and control angiography was performed after 6 months. RESULTS: Experimental placement of the tantalum Wiktor stent was feasible technically in all cases. Five of six stents covered with PEM were occluded 3 days after placement despite the intravenous use of heparin and aspirin. In the group with uncovered stents, no area of stenosis greater than 10% was observed. There was a neointimal layer of 89 +/- 68 microns around the stent wires. Stent placement was successful in all patients. In four patients, a hyperergic reaction occurred, resulting in noninfectious periarteriitis. This complication was treated successfully with nonsteroidal antiinflammatory drugs. The primary patency was 50%, and the secondary patency (after application of a second covered stent in two patients) was 63%. CONCLUSIONS: The uncovered stent induces little neointimal proliferation around the stent wires. The insertion of stents covered with PEM into the rabbit aorta was accompanied by a strong thrombotic reaction, despite sufficient anticoagulation. Dacron-covered nitinol stents showed a surprisingly high restenosis rate after 9 months of follow-up. Further research concerning the in vivo properties of new covering materials is mandatory before routine vascular clinical application.

Aged↗
PubMed1996

Cooperative binding to nucleic acids by barley yellow mosaic bymovirus coat protein and characterization of a nucleic acid-binding domain.

The capacity of several coat protein (CP) mutants of a German isolate of barley yellow mosaic bymovirus (BaYMV) to bind of nucleic acids was studied in vitro. Recombinant CP, produced by overexpression in Escherichia coli, was purified from inclusion bodies and subsequently renatured. Binding to single-stranded (ss) RNA and ssDNA oligonucleotides was found to be cooperative and sequence non-specific. By deletion mutagenesis, several truncated CP derivatives were created and their nucleic acid-binding capacity was investigated in order to define a protein domain responsible for RNA- and DNA-binding. The nucleic acid-binding domain consists of a core which was located to an internal 23 amino acid peptide (aa 125-147) and an adjacent domain (aa 148-184) which stimulates binding.

Amino Acid Sequence↗
PubMed1996

In vivo interference of heparin bolus injection with photometric continuous lipase determination.

The new photometric lipase determinations use diacylglycerols as substrates in a micellar solution, whereas the turbidimetric method is based on emulsified triacylglycerols degradation. Extrahepatic lipoprotein lipase, which is well known to be liberated by heparin from the capillar binding sites, may cleave triacylglycerols as well as diacylglycerols. When a heparin bolus injection is given to a patient, the released lipoprotein lipase renders high lipase activities in blood misleading for a pancreatic disorder.

Acute Disease↗
PubMed1996

Hepatobiliary elimination of certain peptide-mimicking drugs: linear hydrophobic and hydrophilic renin-inhibitors and hydrophobic cyclopeptides.

Kinetic investigations on the hepatocellular uptake of certain peptide-mimicking drugs revealed that in most cases carrier-mediated mechanisms are responsible for their rapid extraction from portal blood. The driving forces for uptake, however, are unknown. Uptake is not dependent on the presence of sodium ions. The membrane potential or other energy sources may drive their uphill transport. Efforts to isolate the transport proteins involved in hepatocellular uptake using the Xenopus laevis oocyte system failed due to high unspecific binding of the peptides. Intracellular cytosolic and membrane-associated binding proteins, however, were isolated and sequenced. Uptake of certain of the drugs investigated is related to the uptake of bile acids. The recently cloned bile acid transporters ntcp and oatp are not the related transport systems. The carrier protein for these peptide-mimicking drugs has yet to be cloned. At the canalicular pole of the cell, excretion of two linear renin-inhibitors EMD 51,921 and CGP 38,560 is due to ATP-dependent transport mechanisms. MDR gene products seem to be involved in the elimination of the renin-inhibitor CGP 38,560, whereas the endogenous ATP-dependent transport system for the renin-inhibitor EMD 51,921 has not been identified.

Animals↗
PubMed1995

[Laparoscopic cholecystectomy in Denmark. A prospective registration].

Laparoscopic cholecystectomy (LC) was introduced in Denmark in 1991, and a prospective case register was established. All departments performing LC agreed to participate. In 1991-1992, 2,415 patients underwent LC in 44 departments. The median number of procedures was 32 (interquartile range 18-58, range 1-370), performed by a median of four surgeons per department (3-5, 1-23). Two hundred and forty-two patients (10%) had acute cholecystitis. Eighteen point five percent had had an ERCP performed prior to LC. The rate of conversion to open operation was 10.5%, occurring significantly more often in acute cholecystitis (25.6%) than in patients with other indications (8.8%) (p < 0.001). Intraoperative cholangiography was used in 22.4%. The median duration of LC was 90 minutes (70-120, 25-415). The postoperative course was without complications in 90.4%. Laparotomy for complications was necessary in 43 patients (2.0%), mainly because of bile leaks. Twelve patients (0.6%) were treated endoscopically for complications. Bile duct injury occurred in 16 patients (0.66%, 95% CI 0.34-0.99%), including three transsections, one stricture, and 12 minor injuries. Six patients (0.25%, 95% CI 0-0.45%), three of whom had procedure-related complications, died postoperatively. All were > or = 72 years of age. Median time to discharge was two days, while median time to resumed work/normal activity was eight days. A comparison with the number of LC registered in the National Patient Register indicates that reporting is complete.

Adolescent↗
PubMed1995

Chromosome polymorphisms close to the cm-ADE1 locus of candida maltosa.

The imperfect yeast Candida maltosa has an ill-defined genetic constitution; it is nominally diploid, but probably highly aneuploid, in nature. We report on polymorphisms specifically affecting those chromosomes which bear the cm-ADE1 gene. This gene encodes phosphoribosylaminoimidazole-succino-carboxamide synthetase, an enzyme in the adenine biosynthetic pathway. By electrophoretic karyotype analysis, three differently sized chromosomes were demonstrated to carry cm-ADE1; the size (but not the number) of these chromosomes was also found to vary, both between strains and during the mitotic growth of a single strain. Four different alleles of cm-ADE1 have been cloned and sequenced from one prototrophic strain. DNA sequence divergence between these different alleles is as high as 8%, with the greatest divergence being found in the upstream region. Mitotic recombination events that led to changes in the karyotype were followed by using cm-ADE1 DNA as an hybridization probe. A recombination hot-spot in the neighbourhood of the gene appears to be responsible for the instability of the chromosomes on which it residues.

Alleles↗