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Biomedical subjects

M Arndt

Publications and source records attributed to M Arndt.

At least 19 recordsLinked to original sources

[Physician's errors--legal advise for physicians accused of malpractice].

At some time or other, every doctor may be confronted by a claim for damages, and he/she should be familiar with the most important rules on how to react. Of relevance with regard to liability are improper treatment and the provision of inadequate information to the patient. The essential basis for a defense against the charge of malpractice is proper patient documentation. Since this latter is accepted by the court as evidence, the physician should take great care to ensure complete and accurate records. Before court proceedings are initiated, it is recommended that arbitration or an expert opinion be sought, which in many cases may result in an out-of-court settlement. Criminal and civil proceedings are separate, and may lead to different outcomes. In the case of the latter, the patient may be awarded compensation and damages for pain and suffering.

Documentation↗

[Cognitive impairment after accidental high-dose corticosteroid therapy].

Synthetic glucocorticosteroids can induce various severe mental disorders. Persisting cognitive disorder represents a rare complication of corticoid therapy involving memory, concentration, attention, or occupational performance. We observed the effects of a 20-day self-induced high-dose corticosteroid treatment on the cognitive functions in a 54-year-old patient. Having excluded dementia due to other organic causes, we examined the patient neuropsychologically immediately at the end of the steroid therapy and at follow-up (1, 2, 4, and 6 months). The initial tests showed seriously impaired functioning of concentration, attention, learning, and memory as well as of common ability to solve problems. The follow-up tests up to 6 months revealed an improvement of concentration and attention, but there were still serious deficits of the declarative memory with a high confabulating tendency. Our results confirm those of human experimental studies that exogenous steroids can cause serious persisting specific cognitive disorders especially of the declarative, hippocampus-dependent memory.

Bipolar Disorder↗

[Remifentanil analgesia for aspiration of follicles for oocyte retrieval].

Remifentanil is an esterase-metabolized ultra-short acting mu-agonist opioid with a rapid clearance. The aim of this study was to determine the efficacy of remifentanil infusion for the short-lasting, but painful, transvaginal puncture for oocyte retrieval. Eighty consenting adult women (ASA I and II) aged 30.5 +/- 5 years and with a body weight of 69.1 +/- 9.1 kg were enrolled in this prospective study. After an oral premedication with 7.5 mg midazolam, all patients received 3 l/min oxygen. Subsequently, the remifentanil infusion was started with a rate of 0.3 microg/kg/min. Remifenanil doses were adjusted as needed for painless puncture and sufficient oxygen saturation in steps of 0.05 microg/kg/min. Dosage requirements, blood pressure, heart rate, oxygen saturation (pulse oxymetry, SaO2) and the level of analgesia were recorded every 3 minutes. Follicular aspiration lasted 11.8 +/- 4.1 min and the time of remifentanil infusion was 18.7 +/- 4.6 min. Dosage requirements of remifentanil were 0.3 microg/kg/min in 48.7% of all patients, but 27.8% needed only 0.25 microg/kg/min and 16.6% needed only 0.2 microg/kg/min. However, 4.2% of patients needed 0.35 microg/kg/min and 2.7% of all cases needed 0.4 microg/kg/min. Vital parameters remained nearly unchanged. Oxygen saturation decreased significantly from 99.2 +/- 0.7% to 98.2 +/- 2.4% after 3 min and to 94.9 +/- 7.2% after 10 min. Nine women showed motoric reactions to puncture. In many cases, the infusion of remifentanil after premedication with midazolam provided a suitable and satisfying anaesthesia for oocyte retrieval. Some patients, however, showed motoric reactions to vaginal puncture, while in other cases significant and clinical relevant decreases in Hb-oxygen saturation occurred. Therefore, we no longer carry out remifentanil infusion for transvaginal oocyte retrieval. We now prefer a remifentanil infusion of 0.2 microg/kg/min and propofol (1 mg/kg initially with intermittent doses of 0.5 mg/kg) combined with assisted ventilation by mask.

Adult↗

Obesity is a risk factor for recurrence after incisional hernia repair.

BACKGROUND: Any individualisation of incisional hernia repair requires a profound knowledge of risk factors for recurrence. METHODS: A series of 160 patients underwent incisional hernia repair and were prospectively followed up at 3, 6, 12, and 24 months after surgery. We analysed the importance of various variables to predict recurrence. RESULTS: An overall recurrence rate of 11% ( n=17) was observed. The risk for recurrence was not significantly affected by any of the clinical variables except for obesity ( P=0.03). Even when controlling for the influence of age, gender, hernia size, and surgical technique, obesity remained a significant predictor with a rate ratio of 1.10 per unit BMI (95%-CI: 1.02-1.18; P=0.01). CONCLUSION: This and other studies found hernia recurrence to be more likely in obese patients. Probably, such patients, therefore, should receive mesh rather than suture repair.

Adult↗

Optimization of the extracellular production of a bacterial phytase with Escherichia coli by using different fed-batch fermentation strategies.

The extracellular production of Escherichia coli phytase was studied in fed-batch fermentations. Two different feeding strategies were compared: control by keeping the glucose concentration constant, and control by keeping a low constant oxygen level in the medium. For the feeding control based on glucose concentration, a recently developed rapid glucose controlling system was tested for the first time in bacterial cultivations and used to establish the fermentative production of extracellular phytase with E. coli. High activity levels (120 U ml(-1)) at short cultivation times (14 h) were obtained. Even higher activity levels - albeit at longer cultivation times - were reached by applying a feeding control, the main characteristic of which was a constant low oxygen concentration. The optimum oxygen level for the production of phytase was in the range of 5-10% saturation.

6-Phytase↗

Patients' autonomy in surgical care: a comparison of nurses' perceptions in five European countries.

BACKGROUND: This report forms part of the results of an international comparative study funded by the European Commission (1998-2001). AIM: To describe and compare the maintenance of patients' autonomy on surgical wards, from the point of view of nursing staff, in five European countries (Finland, Spain, Greece, Germany and Scotland). Autonomy is defined in terms of information received and decision making by patients. METHOD: The data were collected using a questionnaire specifically designed for use in this study. Responses (response rate 66%) were obtained from 1280 nurses working on surgical wards. Data analysis was based on descriptive statistics, t-tests, analysis of variance (ANOVA) with posthoc Tukey's HSD test and logistic regression. RESULTS: There were clear between-country differences in nurses' perceptions, especially on a north-south axis (Finland and Scotland vs. Greece and Spain), regarding the extent to which the autonomy of surgical patients is supported by nursing staff. Training and ethics education, in particular, were associated with nurses' perceptions of the maintenance of patient autonomy in Finland and Greece. CONCLUSION: Further research is needed to establish whether the results obtained are caused by differences in cultures, nursing practices or roles of health-care personnel or patients in different European countries.

Adult↗

[Perioperative management of a patient with Sneddon syndrome--a case report].

Sneddon's syndrome is a rare combination of generalised livedo reticularis and cerebrovascular accidents. Its clinical presentation varies widely and its aetiology is still not known. 60 to 80% of patients are female. First symptoms of the syndrome are mostly repetitive cerebral strokes, but reduced perfusion of the skin, seen as blue or red-brown mottling, precedes the strokes. The vascular disease is generalised and often accompanied by arteriosclerosis, systemic arterial hypertension, valvular heart disease and the presence of antiphospholipid antibodies. The diagnostic procedures are complicated and have to exclude other autoimmunological diseases. Therapeutic options are anticoagulatory therapy with warfarin, ASS or heparin, reduction of endothelial proliferation with ACE-inhibitors, and improvement of microvascular perfusion with prostaglandine. The increased anaesthesiological risk with these patients is due to the acute risk of thromboembolism and ischaemic cerebral and cardiovascular insults. The anaesthetic management must provide stable perfusion pressures for cerebral and myocardial arteries and avoid increasing risk factors for thromboembolism such as increased blood viscosity or stasis due to improper positioning of the patient. The choice of anaesthetic drugs is dependent on good controllability for haemodynamic stability. The high risk of patients with Sneddon's syndrome justifies a more invasive haemodynamic monitoring and postoperative surveillance on an intensive care unit. This case report describes the anaesthesiological considerations for, and management of, a patient with Sneddon's syndrome who was admitted to hospital for vaginal hysterectomy.

Adult↗

Randomized clinical trial of suture repair, polypropylene mesh or autodermal hernioplasty for incisional hernia.

BACKGROUND: Since conventional suture repair for incisional hernia is associated with high recurrence rates, alloplastic and autoplastic prosthetic techniques have been suggested. METHODS: In a randomized trial, 160 patients with simple or complex hernias underwent either suture repair, autodermal skin graft or onlay polypropylene mesh repair. Suture repair was not done in complex hernias. This report concerns a planned interim analysis. RESULTS: At mean follow-up of 16 months, there were 17 hernia recurrences that were distributed similarly between the surgical techniques. There were fewer infectious complications after suture repair (three of 33 patients) than after skin graft or mesh repair (seven of 39 and five of 28 for simple hernias; seven of 31 and ten of 29 respectively for complex hernias) (P not significant). The severity of infections after polypropylene mesh implantation prompted the trial committee to discontinue the study. No differences were noted in duration of stay in hospital and quality of life. However, pain was significantly more frequent after polypropylene mesh repair (pooled risk ratio 2.9 and 1.8 at 6 weeks and 1 year respectively). CONCLUSION: Suture repair was safe for small incisional hernias. Both autoplastic and alloplastic hernia repair yielded comparably low recurrence rates, but led to a high rate of wound infection.

Female↗

Icodextrin as salvage therapy in peritoneal dialysis patients with refractory fluid overload.

BACKGROUND: Icodextrin is a high molecular weight, starch-derived glucose polymer, which is capable of inducing sustained ultrafiltration over prolonged (12-16 hour) peritoneal dialysis (PD) dwells. The aim of this study was to evaluate the ability of icodextrin to alleviate refractory, symptomatic fluid overload and prolong technique survival in PD patients. METHODS: A prospective, open-label, pre-test/post-test study was conducted in 17 PD patients (8 females/9 males, mean age 56.8 +/- 2.9 years) who were on the verge of being transferred to haemodialysis because of symptomatic fluid retention that was refractory to fluid restriction, loop diuretic therapy, hypertonic glucose exchanges and dwell time optimisation. One icodextrin exchange (2.5 L 7.5%, 12-hour dwell) was substituted for a long-dwell glucose exchange each day. RESULTS: Icodextrin significantly increased peritoneal ultrafiltration (885 +/- 210 ml to 1454 +/- 215 ml, p < 0.05) and reduced mean arterial pressure (106 +/- 4 to 96 +/- 4 mmHg, p < 0.05), but did not affect weight, plasma albumin concentration, haemoglobin levels or dialysate:plasma creatinine ratio. Diabetic patients (n = 12) also experienced improved glycaemic control (haemoglobin Alc decreased from 8.9 +/- 0.7% to 7.9 +/- 0.7%, p < 0.05). Overall PD technique survival was prolonged by a mean of 11.6 months (95% CI 6.0-17.3 months). On multivariate Cox proportional hazards analysis, extension of technique survival by icodextrin was only significantly predicted by baseline net daily peritoneal ultrafiltration (adjusted HR 2.52, 95% CI 1.13-5.62, p < 0.05). CONCLUSIONS: Icodextrin significantly improved peritoneal ultrafiltration and extended technique survival in PD patients with symptomatic fluid overload, especially those who had substantially impaired peritoneal ultrafiltration.

Dialysis Solutions↗

Activity and cellular origin of gelatinases in patients with colon and rectal carcinoma differential activity of matrix metalloproteinase-9.

BACKGROUND: Expression and enzymatic activity of gelatinases were examined in biopsy specimens from patients with colon and rectal neoplasms. The objective of this study was to determine whether the activity of these enzymes is altered between tumor areas compared with areas of noninvolved, normal mucosa and between colon and rectal carcinoma. METHODS: Matrix metalloproteinase (MMP) production was analyzed by Western immunoblot analysis and gelatin zymography. mRNA was determined by quantitative, real-time polymerase chain reaction analysis. RESULTS: Patients with colon carcinoma (n = 20 patients) showed a significant increase in levels of MMP-9 (92 kDa and 88 kDa) and MMP-2 (72 kDa and 62 kDa) in tumor areas compared with noninvolved regions. In contrast, patients with rectal carcinoma (n = 10 patients) had revealed the same high activity of MMP-9 in tumor regions and corresponding healthy tissue. Confirming activity measurements, in colon tumors, but not in rectal tumors, there was significant up-regulation of MMP-9 transcription compared with healthy tissue in the same patients. There were no significant changes in the tissue inhibitor of metalloproteinase-1 protein when colon and rectal tumor tissues were compared with the corresponding noninvolved regions. Cell culture experiments revealed fibroblasts as the cellular origin of MMPs. The findings showed that the secretion and activation of gelatinases depend on soluble factors secreted by tumor cells and are influenced by extracellular matrix components. CONCLUSIONS: This is the first report showing differences in MMP-9 activity between rectal carcinoma and colon carcinoma. Previous results indicating an active involvement of stromal cells in the generation of MMPs during tumor invasion are extended. Because the abundance of gelatinases increases in colorectal carcinoma, inhibitors of these proteases may be of therapeutic value.

Blotting, Western↗

Diffraction of complex molecules by structures made of light.

We demonstrate that structures made of light can be used to coherently control the motion of complex molecules. In particular, we show diffraction of the fullerenes C(60) and C(70) at a thin grating based on a standing light wave. We prove experimentally that the principles of this effect, well known from atom optics, can be successfully extended to massive and large molecules which are internally in a thermodynamic mixed state and which do not exhibit narrow optical resonances. Our results will be important for the observation of quantum interference with even larger and more complex objects.

Journal Article↗

Expression and activity of ectopeptidases in fibrillating human atria.

Recent studies have demonstrated that atrial fibrillation (AF) occurs in the presence of degenerative changes of atrial tissue. In contrast, bradykinin (BK) appears to have cardioprotective effects diminishing myocardial hypertrophy and fibrosis. It is unknown, however, whether AF has direct effects on BK metabolism. Therefore, the purpose of this study was to determine the atrial expression of the membrane-bound peptidases, also referred to as ectopeptidases, carboxypeptidase M (CPM), dipeptidyl peptidase IV (DPIV), and alanyl-aminopeptidase (APN) in patients with and without AF. Atrial tissue samples of 35 patients undergoing open heart surgery were examined. Seventeen patients had chronic persistent AF (> or = 6 months; CAF), the remaining 18 patients (controls) had no history of AF. Peptidase expression was analyzed at the mRNA (quantitative RT-PCR) level and apparent changes were confirmed at the protein level. In case of unaltered mRNA levels, enzyme activity was determined. Reduced amounts of CPM-mRNA were found in patients with CAF (41.3+/-9.7 U nu controls: 86.1+/-17.5 U P<0.05). CPM protein was decreased to 47.5% in patients with CAF compared with controls (P<0.01). DPIV and APN mRNA amounts were similar in both groups. DPIV activity, however, was increased during CAF (219.6+/-30 pkat/mg protein v controls: 195.8+/-21.8 pkat/mg P<0.05). APN activity was unchanged. In conclusion, atrial bradykinin metabolizing activities are significantly altered during AF in humans. The observed alterations in ectopeptidase expression/activity may play a role in the structural remodeling of fibrillating atria.

Atrial Fibrillation↗

Classification and surgical treatment of incisional hernia. Results of an experts' meeting.

BACKGROUND: The treatment of incisional hernia (IH) is a current problem in modern surgery. Many important aspects of incisional hernia surgery are yet to be answered, especially the choice of surgical technique and its adaptation to the individual patient. The aim of this experts' meeting was to resolve some current questions in incisional hernia surgery and to organise an international hernia register. METHODS: An international panel of ten experts met under the auspices of the European Hernia Society (GREPA) to investigate the classification and therapeutic alternatives for incisional hernia. Prior to the conference, all experts were asked to submit their arguments in the form of published results. All papers received were weighted according to their scientific quality and relevance. The information from this correspondence was used as a basis for panel discussion. The personal experiences of the participants and other aspects of individualised therapy were also considered. RESULTS: The expert panel suggested a new classification of incisional hernia based on localisation, size, recurrences and symptoms. All experts agreed that the fascia duplication and the fascia adaptation should only be used for small incisional hernias. Fascia duplication is of value only in the horizontal direction. The technical details and the pros and cons of each procedure were discussed for prosthetic implantation using onlay and sublay techniques and the technique of autodermal hernioplasty. CONCLUSIONS: The management of incisional hernia is currently not standardised. In order to answer relevant questions of incisional hernia surgery, an international hernia register should be established.

Hernia, Ventral↗

Privacy: a review of the literature.

The concept of privacy is used in many disciplines and is recognised as one of the important concepts also in nursing. In this review, a description about the perspectives and dimensions of the concept will be made and empirical studies in the area will be analysed. Perspectives include units experiencing privacy, desired-achieved state, and reactiveness. Dimensions are divided into physical, psychological, social and informational. In the empirical studies, the concept of the privacy has mainly been studied in hospital organisations using the physical dimension. The concept needs further clarification in future.

Confidentiality↗

The role of CNSs in promoting elderly patients' autonomy in long-term institutions: problems and implications for nursing practice and research.

Autonomy has become an important focus within healthcare. Elderly patients, however, are often denied the right to independent decision making on grounds of incompetence and incapacity. In long-term institutions there are several ways in which the clinical nurse specialist can promote the autonomy of elderly patients. This article provides an overview of the concept of autonomy and discusses some of the problems in its realization in long-term nursing institutions. It also outlines strategies for supporting autonomy in elderly patients and concludes with a discussion of the implications of autonomy to nursing practice and research.

Age Factors↗

Dipeptidyl peptidase IV (DP IV/CD26) mRNA expression in PWM-stimulated T-cells is suppressed by specific DP IV inhibition, an effect mediated by TGF-beta(1).

Stimulation of human T-cells by pokeweed mitogen (PWM) results in a significant increase of IL-2, IFN-gamma, and DP IV mRNA expression as analyzed by quantitative RT-PCR. Here we show for the first time that the changes observed in cytokine mRNA expression are dose-dependently suppressed by the specific dipeptidyl peptidase IV inhibitor Lys[Z(NO(2))]-thiazolidide. Most interestingly, the inhibition of DP IV activity leads to a decrease in mRNA expression of the enzyme itself. Furthermore, evidence is provided that this suppression is mediated by TGF-beta(1). The presented data fit into the hypothesis that inhibition of DP IV leads to the induction of TGF-beta(1), which in turn provokes an arrest of cell cycle in late G(1).

Antibodies↗

Inhibition of alanyl-aminopeptidase suppresses the activation-dependent induction of glycogen synthase kinase-3beta (GSK-3beta) in human T cells.

Inhibition of alanyl-aminopeptidase (APN, CD13) gene expression or enzymatic activity compromises T cell proliferation and function. Molecular mechanisms mediating these effects are not known as yet. Recently, we found the expression of the proto-oncogen Wnt-5a to be strongly affected by APN-inhibition. Wnt-5a and other members of the Wnt family of secreted factors are implicated in cell growth and differentiation. Here, we analyzed by quantitative RT-PCR and immunoblotting the expression in mitogen-activated T cells of a major constituent of the Wnt-5a pathway, glycogen synthase kinase-3beta (GSK-3beta). T cell activation by phytohaemagglutinin or pokeweed mitogen results in a strong increase of GSK-3beta mRNA amounts. At the protein level, we observed an up-regulation of both GSK-3beta and phosphorylated GSK-3beta. This induction-dependent increase of GSK-3beta is markedly reduced in response to inhibitors of alanyl-aminopeptidase, actinonin, leuhistin, and RB3014. These findings may provide a rational for the growth inhibition resulting from a diminished expression or activity of alanyl aminopeptidase.

Amino Acids↗